WO2018016219A1 - Ejector-type refrigeration cycle - Google Patents

Ejector-type refrigeration cycle Download PDF

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Publication number
WO2018016219A1
WO2018016219A1 PCT/JP2017/021414 JP2017021414W WO2018016219A1 WO 2018016219 A1 WO2018016219 A1 WO 2018016219A1 JP 2017021414 W JP2017021414 W JP 2017021414W WO 2018016219 A1 WO2018016219 A1 WO 2018016219A1
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WO
WIPO (PCT)
Prior art keywords
refrigerant
pressure
passage
valve body
refrigerant passage
Prior art date
Application number
PCT/JP2017/021414
Other languages
French (fr)
Japanese (ja)
Inventor
龍 福島
照之 堀田
池上　真
Original Assignee
株式会社デンソー
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Publication of WO2018016219A1 publication Critical patent/WO2018016219A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60H—ARRANGEMENTS OF HEATING, COOLING, VENTILATING OR OTHER AIR-TREATING DEVICES SPECIALLY ADAPTED FOR PASSENGER OR GOODS SPACES OF VEHICLES
    • B60H1/00—Heating, cooling or ventilating [HVAC] devices
    • B60H1/22—Heating, cooling or ventilating [HVAC] devices the heat being derived otherwise than from the propulsion plant
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K31/00—Actuating devices; Operating means; Releasing devices
    • F16K31/12—Actuating devices; Operating means; Releasing devices actuated by fluid
    • F16K31/126—Actuating devices; Operating means; Releasing devices actuated by fluid the fluid acting on a diaphragm, bellows, or the like
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60H—ARRANGEMENTS OF HEATING, COOLING, VENTILATING OR OTHER AIR-TREATING DEVICES SPECIALLY ADAPTED FOR PASSENGER OR GOODS SPACES OF VEHICLES
    • B60H1/00—Heating, cooling or ventilating [HVAC] devices
    • B60H1/32—Cooling devices
    • B60H2001/3286—Constructional features
    • B60H2001/3298—Ejector-type refrigerant circuits

Definitions

  • the present disclosure relates to an ejector refrigeration cycle including an ejector.
  • an ejector-type refrigeration cycle which is a vapor compression refrigeration cycle apparatus including an ejector
  • This type of ejector sucks the refrigerant flowing out of the evaporator from the refrigerant suction port and sucks the injected refrigerant and the sucked refrigerant in the ejector refrigeration cycle by the suction action of the high-speed jet refrigerant jetted from the nozzle section.
  • a suction pressurizing action (so-called pump action) in which the pressure is increased by mixing in the section is exhibited.
  • the refrigerant whose pressure has been increased by the pump action of the ejector is caused to flow out to the suction port side of the compressor.
  • the pressure of the suction refrigerant can be increased as compared with a normal refrigeration cycle apparatus in which the refrigerant evaporation pressure in the evaporator and the pressure of the suction refrigerant sucked into the compressor are substantially equal. Therefore, in the ejector refrigeration cycle, the power consumption of the compressor can be reduced as compared with a normal refrigeration cycle apparatus, and the coefficient of performance (COP) of the cycle can be improved.
  • the pumping action of the ejector described above is caused by the suction action and speed energy of the injected refrigerant injected from the nozzle part, so that the flow rate of the injected refrigerant decreases during low load operation where the flow rate of refrigerant circulating in the cycle decreases.
  • the pumping action is also reduced. If the pumping action is reduced, the refrigerant cannot flow into the evaporator, and the ejector refrigeration cycle may not be able to exhibit the refrigeration capacity.
  • Patent Document 1 discloses an ejector refrigeration cycle configured to be able to switch between a refrigerant circuit during normal operation and a refrigerant circuit during low-load operation.
  • the ejector-type refrigeration cycle of Patent Document 1 includes a bypass passage that allows the high-pressure refrigerant flowing out of the radiator to flow around the nozzle portion of the ejector.
  • the refrigerant circuit is switched to a refrigerant circuit that causes high pressure refrigerant to flow into the nozzle portion of the ejector and cause the ejector to exert a pumping action.
  • the high-pressure refrigerant is caused to flow into the bypass passage and switched to a similar refrigerant circuit of a normal refrigerant cycle device.
  • Patent Document 1 the ejector refrigeration cycle of Patent Document 1 employs a three-way valve as a refrigerant circuit switching device for switching the refrigerant circuit.
  • Patent Document 1 does not describe a specific configuration of the three-way valve.
  • a detection device for determining the operation condition of the electric three-way valve and a control device for controlling the operation of the electric three-way valve are provided. Necessary. For this reason, it becomes easy to invite the enlargement as the whole ejector type refrigerating cycle, and the complexity of a control mode. Therefore, it is desirable that a refrigerant circuit switching device that automatically operates according to a load change by a mechanical mechanism is employed.
  • a refrigerant circuit switching device of a mechanical mechanism for example, when a differential pressure valve that opens and closes a bypass passage according to a pressure difference between a high-pressure side refrigerant and a low-pressure side refrigerant in a cycle, the differential pressure valve is bypassed during low load operation. Even if the passage is opened, the inlet side of the nozzle part of the ejector cannot be closed. As a result, the high-pressure refrigerant flows into both the bypass passage and the nozzle portion of the ejector, and the refrigerant circuit cannot be switched reliably.
  • an object of the present disclosure is to provide an ejector-type refrigeration cycle in which a refrigerant circuit can be switched mechanically and reliably according to a load change.
  • an ejector refrigeration cycle includes a compressor that compresses and discharges a refrigerant, a radiator that dissipates heat from the refrigerant discharged from the compressor, and an outflow from the radiator.
  • An ejector having a boosting unit that sucks the refrigerant from the refrigerant suction port by the suction action of the jetted refrigerant jetted from the nozzle unit that depressurizes the refrigerant, and mixes the injected refrigerant and the suction refrigerant sucked from the refrigerant suction port to boost the pressure;
  • An evaporator that evaporates the refrigerant and flows out to the refrigerant suction port side, a bypass path that bypasses the nozzle section and guides the refrigerant radiated by the radiator to the upstream side from the refrigerant outlet of the evaporator, and a bypass path
  • a decompression section for decompressing the refrigerant flowing into the evaporator, and opening and closing the first refrigerant passage for guiding the refrigerant radiated by the radiator to the nozzle section side, and bypassing the refrigerant radiated by the radiator
  • the circuit switching valve is configured by a mechanical mechanism that closes the other when either one of the first refrigerant passage and the second refrigerant passage is opened. Further, when the differential pressure before and after subtracting the refrigerant pressure on the suction port side from the refrigerant pressure on the discharge port side of the compressor is lower than a predetermined reference front and rear differential pressure, the circuit switching valve Open the passage.
  • the circuit switching valve a mechanical mechanism that closes one of the first refrigerant passage and the second refrigerant passage when the other one is opened is adopted, and the front-rear differential pressure is the reference front-rear differential pressure. When it is lower than that, the one that opens the second refrigerant passage is adopted.
  • the circuit switching valve sets the reference front-rear differential pressure so as to open the first refrigerant passage side, so that the refrigerant radiated by the radiator flows into the ejector nozzle section.
  • the refrigerant circuit can be switched to.
  • annular cycle a normal refrigeration cycle in which the second refrigerant passage side opens and the refrigerant radiated by the radiator flows into the evaporator through the bypass passage. Therefore, it is easy to return the refrigeration oil remaining in the evaporator to the compressor at the start of the cycle.
  • the pressure difference obtained by subtracting the low-pressure side pressure of the refrigerant on the downstream side of the decompression section from the high-pressure side pressure of the refrigerant on the upstream side of the circuit switching valve as the circuit switching valve is a predetermined reference pressure.
  • the difference is greater than or equal to the difference, the first refrigerant passage is opened and the second refrigerant passage is closed. Further, when the pressure difference is lower than the reference pressure difference, the first refrigerant passage is closed and the first refrigerant passage is closed. You may employ
  • the first refrigerant passage is opened when the high pressure side pressure of the refrigerant upstream of the circuit switching valve is equal to or higher than a predetermined reference high pressure side pressure as the circuit switching valve.
  • the second refrigerant passage may be closed, and when the high-pressure side pressure is lower than the reference high-pressure side pressure, the first refrigerant passage may be closed and the second refrigerant passage may be opened.
  • the front-rear differential pressure when the high-pressure side pressure is the reference high-pressure side pressure may be set to the reference front-rear differential pressure.
  • refrigerant dissipated by a radiator means a refrigerant dissipated by at least a part of the radiator.
  • leading to the upstream side of the refrigerant outlet of the evaporator includes guiding to the upstream side of the refrigerant inlet of the evaporator. Furthermore, if it is upstream from the refrigerant outlet of the evaporator, it also includes guiding to the downstream side of the refrigerant outlet of the evaporator (for example, in the refrigerant passage of the evaporator).
  • the first embodiment will be described with reference to FIGS.
  • the ejector refrigeration cycle 10 of this embodiment shown in the overall configuration diagram of FIG. 1 is applied to a vehicle air conditioner, and has a function of cooling blown air that is blown into a vehicle interior (indoor space) that is an air-conditioning target space. Fulfill. Therefore, the fluid to be cooled in the ejector refrigeration cycle 10 is blown air.
  • the refrigerant circuit can be switched according to the air conditioning heat load. More specifically, during normal operation, the circuit is switched to a refrigerant circuit through which refrigerant flows as shown by the black arrows in FIG. 1, and during low load operation where the thermal load of the ejector refrigeration cycle 10 is lower than during normal operation. 1 can be switched to a refrigerant circuit through which the refrigerant flows, as indicated by the white arrows in FIG.
  • the ejector refrigeration cycle 10 employs an HFC refrigerant (specifically, R134a) as a refrigerant, and constitutes a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the refrigerant critical pressure.
  • This refrigerant is mixed with refrigerating machine oil for lubricating the compressor 11, and a part of the refrigerating machine oil circulates in the cycle together with the refrigerant.
  • the compressor 11 sucks the refrigerant and discharges it until it becomes a high-pressure refrigerant.
  • the compressor 11 is disposed in an engine room together with an engine (internal combustion engine) that outputs a driving force for vehicle travel.
  • the compressor 11 is an engine-driven compressor that is driven by a rotational driving force output from the engine via a pulley, a belt, and the like.
  • the compressor 11 is a swash plate type variable displacement compressor configured such that the refrigerant discharge capacity can be adjusted by changing the discharge capacity.
  • the compressor 11 has a discharge capacity control valve (not shown) for changing the discharge capacity. The operation of the discharge capacity control valve is controlled by a control current output from a control device described later.
  • the refrigerant inlet side of the condenser 12 a of the radiator 12 is connected to the discharge port of the compressor 11.
  • the radiator 12 is a heat exchanger for heat radiation that radiates and cools the high-pressure refrigerant by exchanging heat between the high-pressure refrigerant discharged from the compressor 11 and the outside air (outside air) blown from the cooling fan 12d. .
  • the radiator 12 is arranged on the vehicle front side in the engine room.
  • the condensing unit 12a is a heat exchange unit for condensation that exchanges heat between the high-pressure gas-phase refrigerant discharged from the compressor 11 and the outside air blown from the cooling fan 12d, and dissipates the high-pressure gas-phase refrigerant to condense.
  • the receiver unit 12b is a refrigerant container that separates the gas-liquid refrigerant flowing out from the condensing unit 12a and stores excess liquid-phase refrigerant.
  • the supercooling unit 12c is a heat exchange unit for supercooling that heat-exchanges the liquid refrigerant flowing out from the receiver unit 12b and the outside air blown from the cooling fan 12d to supercool the liquid refrigerant.
  • the cooling fan 12d is an electric blower whose rotation speed (amount of blown air) is controlled by a control voltage output from the control device.
  • FIG. 2 is a schematic cross-sectional view showing a state in which the circuit switching valve 13 is switched to a refrigerant circuit that causes the refrigerant flowing out of the radiator 12 to flow into the nozzle portion 15a side of the ejector 15.
  • FIG. 3 is a schematic cross-sectional view showing a state where the circuit switching valve 13 is switched to a refrigerant circuit that allows the refrigerant flowing out of the radiator 12 to flow into the bypass passage 20 side.
  • FIG. 4 is a schematic view showing a state where the circuit switching valve 13 instantaneously opens both the refrigerant passage on the nozzle portion 15a side and the refrigerant passage on the bypass passage 20 side when the circuit switching valve 13 switches the refrigerant circuit.
  • FIG. 4 is a schematic view showing a state where the circuit switching valve 13 instantaneously opens both the refrigerant passage on the nozzle portion 15a side and the refrigerant passage on the bypass passage 20 side when the circuit switching valve 13 switches the refrigerant circuit.
  • the circuit switching valve 13 includes a valve body 31, a valve body 32, a coil spring 33, and the like. As shown in FIGS. 2 to 4, the valve body 31 is formed in a prismatic shape or a cylindrical shape by combining a plurality of structural members made of metal or resin. The valve body 31 forms an outer shell of the circuit switching valve 13 and houses a valve body 32, a coil spring 33, and the like therein.
  • the valve body 31 has a high-pressure refrigerant inlet 31a, a first refrigerant outlet 31b, and a second refrigerant outlet 31c.
  • a plurality of refrigerant passages such as an inflow passage 30a, a first refrigerant passage 30b, and a second refrigerant passage 30c are formed inside the valve body 31.
  • the high-pressure refrigerant inlet 31a is a refrigerant inlet through which the refrigerant that has flowed out of the radiator 12 flows into the inflow passage 30a.
  • the first refrigerant outlet 31b is a refrigerant outlet through which refrigerant flowing through the first refrigerant passage 30b flows out to the nozzle portion 15a side of the ejector 15 (more specifically, to the refrigerant inlet side of the expansion valve 14 described later).
  • the second refrigerant outlet 31c is a refrigerant outlet through which the refrigerant flowing through the second refrigerant passage 30c flows out to the bypass passage 20 side.
  • the first refrigerant passage 30b is a refrigerant passage that communicates with the inflow passage 30a and guides the refrigerant flowing out of the radiator 12 to the nozzle portion 15a side of the ejector 15.
  • the second refrigerant passage 30c is a refrigerant passage that communicates with the inflow passage 30a and guides the refrigerant flowing out of the radiator 12 to the bypass passage 20 side.
  • the valve body 32 includes a spherical ball valve 32a that opens and closes the inlet of the first refrigerant passage 30b, and a disk-like plate valve 32b that opens and closes the inlet of the second refrigerant passage 30c.
  • a rubber seal member 32c is disposed in a portion of the plate-like valve 32b that contacts the inlet of the second refrigerant passage 30c.
  • the ball valve 32a and the plate valve 32b are connected by a connecting rod extending in the displacement direction of the valve body 32.
  • the plate valve 32b is displaced toward the side that opens the second refrigerant passage 30c.
  • the plate-like valve 32b is displaced toward the side closing the second refrigerant passage 30c.
  • valve body 32 is connected to a pressure receiving portion 34 disposed in a columnar space of the second refrigerant passage 30c on the downstream side of the refrigerant flow with respect to the plate-like valve 32b.
  • the pressure receiving part 34 is formed of a metal columnar member.
  • the inner diameter of the second refrigerant passage 30c and the outer diameter of the pressure receiving portion 34 are in a dimensional relationship with a clearance fit. For this reason, the pressure receiving part 34 is disposed in the second refrigerant passage 30c so as to be slidable in the central axis direction.
  • an O-ring as a seal member is disposed in the gap between the inner peripheral surface of the second refrigerant passage 30c and the outer peripheral surface of the pressure receiving portion 34, and the refrigerant does not leak from these gaps.
  • the pressure receiving portion 34 is formed with an orifice hole 34a extending in the central axis direction and communicating the inlet side of the second refrigerant passage 30c and the outlet side of the second refrigerant passage 30c.
  • the orifice hole 34a is formed with a sufficiently thin diameter with respect to the second refrigerant passage 30c.
  • the refrigerant flowing through the second refrigerant passage 30c and flowing out from the second refrigerant outlet 31c is decompressed when passing through the orifice hole 34a. Further, a differential pressure between the inlet side pressure Pri of the inlet side refrigerant in the orifice hole 34a and the outlet side pressure Pro of the outlet side refrigerant in the orifice hole 34a acts on the pressure receiving portion 34.
  • the orifice hole 34a is a pressure reducing unit that depressurizes the refrigerant flowing into the evaporator 19 to be described later via the bypass passage 20.
  • the pressure reducing part is formed in the circuit switching valve 13
  • the pressure reducing part and the circuit switching valve are integrally formed.
  • the coil spring 33 is an elastic member that applies a load to the valve body portion 32 while the ball valve 32a closes the first refrigerant passage 30b and the plate-like valve 32b opens the second refrigerant passage 30c.
  • the load of the coil spring 33 of this embodiment is set as follows. First, in the following description, a value obtained by subtracting the low pressure side pressure PL of the refrigerant downstream of the orifice hole 34a from the high pressure side pressure PH of the refrigerant upstream of the circuit switching valve 13 is defined as a pressure difference ⁇ P.
  • the load of the coil spring 33 of the present embodiment opens the first refrigerant passage 30b and closes the second refrigerant passage 30c. Is set to On the other hand, when the pressure difference ⁇ P is lower than the reference pressure difference K ⁇ P, the first refrigerant passage 30b is closed and the second refrigerant passage 30c is opened.
  • the low-pressure side pressure PL is the pressure of the refrigerant on the downstream side of the orifice hole 34a, the pressure of the refrigerant on the inlet side of the evaporator 19, the pressure of the refrigerant on the outlet side of the evaporator 19 described later, or the compressor 11
  • the pressure of the suction refrigerant can be adopted.
  • the pressure of the evaporator 19 outlet side refrigerant is adopted as the low pressure side pressure PL.
  • the outlet side pressure Pro of the outlet side refrigerant of the orifice hole 34a may be adopted as the low pressure side pressure PL.
  • the front-rear differential pressure ⁇ Pc obtained by subtracting the refrigerant pressure on the suction side from the refrigerant pressure on the discharge port side of the compressor 11 when the pressure difference ⁇ P is the reference pressure difference K ⁇ P is obtained.
  • the pressure is defined as K ⁇ Pc. Therefore, when the front-rear differential pressure ⁇ Pc is lower than the reference front-rear differential pressure K ⁇ Pc, the load of the coil spring 33 according to the present embodiment closes the first refrigerant passage 30b and the second refrigerant. It is set to open the passage 30c.
  • the circuit switching valve 13 of the present embodiment is a mechanical mechanism that selectively opens one of the first refrigerant passage 30b and the second refrigerant passage 30c (that is, closes the other when one of them is opened). It consists of
  • the set load and various specifications of the coil spring 33 are determined so as to satisfy the following formulas F1 to F3.
  • A1 is the difference between the high pressure side pressure PH and the inlet side pressure Pri of the valve body portion 32 when the valve body portion 32 closes the second refrigerant passage 30c. This is the first pressure receiving area A1 where pressure acts.
  • a ⁇ b> 2 is a second pressure receiving area A ⁇ b> 2 in which a differential pressure between the inlet side pressure Pri and the outlet side pressure Pro of the pressure receiving unit 34 acts.
  • Fsp1 is a first set load Fsp1 that the coil spring 33 acts on the valve body portion 32 when the pressure difference ⁇ P becomes the reference pressure difference K ⁇ P.
  • FIG. 2 to FIG. 4 a portion corresponding to the diameter of the first pressure receiving area A1 having a circular shape is denoted by A1. The same applies to the second pressure receiving area A2 and the third pressure receiving area.
  • the relationship of the above formula F1 is realized by the difference between the inner diameter and the outer diameter of the cylindrical seat portion 31d with which the seal member 32c of the plate valve 32b abuts.
  • the set load and various specifications of the coil spring 33 are determined so as to satisfy the relationships of the following formulas F4 to F6.
  • A3 indicates that when the valve body 32 closes the first refrigerant passage 30b, the high pressure side pressure PH and the first refrigerant passage 30b side ( That is, it is the third pressure receiving area A3 on which the differential pressure with the nozzle side pressure Pnoz on the inlet side of the nozzle portion 15a acts.
  • Fsp2 is a second set load Fsp2 that the coil spring 33 acts on the valve body portion 32 when the valve body portion 32 closes the first refrigerant passage 30b.
  • valve body 31 is provided with a receiving member 33a for supporting the coil spring 33.
  • the receiving member 33a is fixed to the valve body 31 with screws. Therefore, the load of the coil spring 33 can be adjusted by displacing the receiving member 33a.
  • the refrigerant inlet side of the expansion valve 14 is connected to the first refrigerant outlet 31b of the circuit switching valve 13.
  • the expansion valve 14 is a so-called external pressure equalizing box type temperature expansion valve.
  • the expansion valve 14 is a flow rate adjusting device that depressurizes the high-pressure liquid-phase refrigerant that has flowed out of the supercooling portion 12c of the radiator 12 until it becomes an intermediate-pressure refrigerant and adjusts the circulating refrigerant flow rate that circulates in the cycle. Further, the expansion valve 14 of the present embodiment adjusts the circulating refrigerant flow rate so that the superheat degree SH of the evaporator 19 outlet side refrigerant approaches a predetermined reference superheat degree KSH.
  • Such an expansion valve 14 includes a temperature sensing part having a displacement member (diaphragm) that is displaced according to the temperature and pressure of the refrigerant that has flowed out of the evaporator 19, and the outlet of the evaporator 19 according to the displacement of the displacement member. It is possible to employ one in which the valve opening degree (refrigerant flow rate) is adjusted by a mechanical mechanism so that the superheat degree of the side refrigerant approaches the reference superheat degree.
  • the inlet side of the nozzle portion 15 a of the ejector 15 is connected to the refrigerant outlet of the expansion valve 14.
  • the ejector 15 functions as a decompression device that decompresses the refrigerant flowing out of the expansion valve 14 (that is, the refrigerant flowing out of the radiator 12) during normal operation.
  • the ejector 15 injects the refrigerant that has flowed out of the expansion valve 14 by reducing the pressure at the nozzle portion 15a, and the refrigerant that has flowed out of the evaporator 19 by the suction action of the injected refrigerant that is injected at a high speed (that is, the evaporator 19). It functions as a refrigerant transport device that sucks and transports (exit-side refrigerant).
  • the ejector 15 has a nozzle portion 15a and a body portion 15b.
  • the nozzle portion 15a is formed of a substantially cylindrical member made of metal (stainless steel in the present embodiment) that gradually tapers in the direction of refrigerant flow.
  • the nozzle portion 15a decompresses the refrigerant in an isentropic manner in the refrigerant passage formed inside.
  • a throat portion (minimum passage area portion) having the smallest passage cross-sectional area is formed, and further, from the throat portion toward the refrigerant injection port for injecting the refrigerant.
  • a divergent portion in which the refrigerant passage area is enlarged is formed. That is, the nozzle portion 15a is configured as a Laval nozzle.
  • the nozzle unit 15a is set such that the flow rate of the injected refrigerant injected from the refrigerant injection port is equal to or higher than the sonic speed during normal operation of the ejector refrigeration cycle 10.
  • the body portion 15b is formed of a cylindrical member made of metal (in this embodiment, made of an aluminum alloy), and functions as a fixing member that supports and fixes the nozzle portion 15a therein, and forms an outer shell of the ejector 15. To do.
  • the nozzle portion 15a is fixed by press-fitting so as to be accommodated inside the longitudinal end of the body portion 15b. For this reason, a refrigerant
  • a refrigerant suction port 15c provided so as to penetrate the inside and outside of the outer peripheral surface of the body portion 15b and communicate with the refrigerant injection port of the nozzle portion 15a is provided in a portion corresponding to the outer peripheral side of the nozzle portion 15a. Is formed.
  • the refrigerant suction port 15c is a through hole that sucks the refrigerant that has flowed out of the evaporator 19 into the ejector 15 by the suction action of the injection refrigerant that is injected from the nozzle portion 15a.
  • a suction passage that guides the suction refrigerant sucked from the refrigerant suction port 15c to the refrigerant injection port side of the nozzle portion 15a, and a suction refrigerant that flows into the ejector 15 through the suction passage.
  • a diffuser portion 15d which is a pressure increasing portion that increases the pressure by mixing the injected refrigerant, is formed.
  • the diffuser portion 15d is disposed so as to be continuous with the outlet of the suction passage, and is formed so that the refrigerant passage area gradually increases.
  • the inlet side of the accumulator 16 is connected to the refrigerant outlet of the diffuser part 15d.
  • the accumulator 16 is a gas-liquid separation unit that separates the gas-liquid refrigerant flowing out of the diffuser unit 15d.
  • the accumulator 16 is provided with a gas phase refrigerant outlet through which the separated gas phase refrigerant flows out and a liquid phase refrigerant outlet through which the separated liquid phase refrigerant flows out.
  • One refrigerant inlet of the three-way joint 18 is connected to the liquid phase refrigerant outlet of the accumulator 16 via a check valve 17.
  • the check valve 17 only allows the refrigerant flowing out from the liquid-phase refrigerant outlet of the accumulator 16 to flow to the three-way joint 18 side.
  • the three-way joint 18 is a pipe joint having three refrigerant outlets.
  • two of the three refrigerant inlets / outlets are used as refrigerant inlets, and the remaining one is used as a refrigerant outlet.
  • the refrigerant inlet of the evaporator 19 is connected to the refrigerant outlet of the three-way joint 18. Therefore, the check valve 17 is a suppression mechanism that suppresses the refrigerant from flowing from the inlet side of the evaporator 19 to the liquid phase refrigerant outlet side of the accumulator 16.
  • the evaporator 19 performs heat exchange between the low-pressure refrigerant decompressed by the ejector 15 and the blown air blown into the vehicle compartment from the blower fan 19a, thereby evaporating the low-pressure refrigerant and exerting an endothermic effect. It is a vessel.
  • the blower fan 19a is an electric blower in which the rotation speed (the amount of blown air) is controlled by a control voltage output from the control device.
  • the refrigerant suction port 15 c side of the ejector 15 is connected to the outlet side of the evaporator 19. Further, the suction port side of the compressor 11 is connected to the gas-phase refrigerant outlet of the accumulator 16.
  • bypass passage 20 guides the refrigerant radiated by the radiator 12 to the side of the three-way joint 18 disposed on the upstream side of the refrigerant flow from the refrigerant outlet of the evaporator 19 by bypassing the nozzle portion 15a of the ejector 15. It is a refrigerant passage.
  • a control device (not shown) includes a known microcomputer including a CPU, a ROM, a RAM, and the like and its peripheral circuits. This control device performs various calculations and processes based on a control program stored in the ROM. The control device controls the operation of the various electric compressors 11 and the cooling fan 12d described above.
  • the control device is connected to a plurality of air conditioning control sensor groups such as an inside air temperature sensor, an outside air temperature sensor, a solar radiation sensor, an evaporator temperature sensor, an outlet side temperature sensor, and an outlet side pressure sensor.
  • the detected value is input.
  • the inside air temperature sensor is an inside air temperature detecting device that detects the vehicle interior temperature.
  • the outside air temperature sensor is an outside air temperature detecting device that detects outside air temperature.
  • a solar radiation sensor is a solar radiation amount detection apparatus which detects the solar radiation amount in a vehicle interior.
  • the evaporator temperature sensor is an evaporator temperature detection device that detects the blown air temperature (evaporator temperature) of the evaporator 19.
  • the outlet side temperature sensor is an outlet side temperature detecting device that detects the temperature of the radiator 12 outlet side refrigerant.
  • the outlet-side pressure sensor is an outlet-side pressure detection device that detects the pressure of the radiator 12 outlet-side refrigerant.
  • an operation panel (not shown) disposed near the instrument panel in the front part of the vehicle interior is connected to the input side of the control device, and operation signals from various operation switches provided on the operation panel are input to the control device.
  • various operation switches provided on the operation panel there are provided an air conditioning operation switch for requesting air conditioning in the vehicle interior, a vehicle interior temperature setting switch for setting the vehicle interior temperature, and the like.
  • control device of the present embodiment is configured such that a control unit that controls the operation of various control target devices connected to the output side is integrally configured.
  • the configuration (hardware and software) for controlling the operation of the system constitutes a control unit of each control target device.
  • the configuration for controlling the refrigerant discharge capacity of the compressor 11 by controlling the operation of the discharge capacity control valve of the compressor 11 constitutes the discharge capacity control unit.
  • the discharge capacity control unit may be configured as a separate control device with respect to the control device.
  • the operation of the ejector refrigeration cycle 10 of the present embodiment having the above configuration will be described.
  • the refrigerant circuit during normal operation and the refrigerant circuit during low-load operation can be switched.
  • the refrigerant circuit is switched to the refrigerant circuit during normal operation, and the pressure difference ⁇ P Is switched to the refrigerant circuit at the time of low load operation when the pressure difference is equal to or less than the reference pressure difference K ⁇ P.
  • the control device executes an air conditioning control program stored in advance, and the electric motor and cooling fan of the compressor 11 12d and the operation of the blower fan 19a are controlled.
  • the refrigerant in the ejector refrigeration cycle 10 is often pressure-equalized, except when the vehicle is restarted in a short time after stopping.
  • the front-rear differential pressure ⁇ Pc is lower than the reference front-rear differential pressure K ⁇ Pc. Therefore, in the circuit switching valve 13, as shown in FIG. 3, the first refrigerant passage 30b is closed and the second refrigerant passage 30c is opened.
  • the refrigerant pressure in the cycle has a relationship shown in the following formulas F7 to F10.
  • PH Pri (F7) Pri> Pro (F8) Pro ⁇ PL (F9) Pro ⁇ Pnoz (F10)
  • the load on the side that opens the first refrigerant passage 30b due to the pressure difference ⁇ P that is, (A2-A3) ⁇ ⁇ P
  • the state where the second refrigerant passage 30c is opened is maintained until it becomes larger than the set load Fsp2.
  • the pressure of the refrigerant on the outlet side of the radiator 12 (that is, the refrigerant pressure at the high pressure refrigerant inlet 31a of the circuit switching valve 13) is adopted as the high pressure side pressure PH. Further, the pressure of the refrigerant on the inlet side of the expansion valve 14 (that is, the refrigerant pressure at the first refrigerant outlet 31b of the circuit switching valve 13) is employed as the nozzle side pressure Pnoz.
  • valve body portion When the pressure difference ⁇ P between the high-pressure side pressure PH and the low-pressure side pressure PL is expanded by the suction compression action of the compressor 11 during normal operation and reaches the reference pressure difference K ⁇ P, the valve body portion is shown in FIG.
  • the 32 ball valves 32a open the first refrigerant passage 30b, and the plate-like valve 32b is displaced to close the second refrigerant passage 30c. That is, both the first refrigerant passage 30b and the second refrigerant passage 30c are opened.
  • the pressure in the cycle changes to a relationship represented by mathematical formulas F11 and F12 below.
  • PH ⁇ Pri (F12) the first refrigerant passage 30b is caused by the pressure difference ⁇ P. Is larger than the second set load Fsp2 on the side where the first refrigerant passage 30b is closed instantaneously.
  • the high-temperature and high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12 a of the radiator 12.
  • the refrigerant flowing into the condensing part 12a exchanges heat with the outside air blown from the cooling fan 12d, and dissipates heat to condense.
  • the refrigerant condensed in the condensing unit 12a is gas-liquid separated in the receiver unit 12b.
  • the liquid phase refrigerant separated from the gas and liquid by the receiver unit 12b exchanges heat with the outside air blown from the cooling fan 12d by the supercooling unit 12c, and further dissipates heat to become a supercooled liquid phase refrigerant (a in FIG. 5). Point ⁇ b).
  • the valve body 32 opens the first refrigerant passage 30b and closes the second refrigerant passage 30c, so that the refrigerant flowing into the inflow passage 30a flows from the first refrigerant outlet 31b. It flows out and flows into the expansion valve 14.
  • the refrigerant that has flowed into the expansion valve 14 is decompressed in an enthalpy manner until it becomes an intermediate pressure refrigerant (point b ⁇ point b1 in FIG. 5).
  • the opening degree of the expansion valve 14 is adjusted such that the superheat degree SH of the evaporator 19 outlet side refrigerant (point h in FIG. 5) approaches the reference superheat degree KSH.
  • the intermediate pressure refrigerant that has flowed out of the expansion valve 14 flows into the nozzle portion 15 a of the ejector 15.
  • the refrigerant flowing into the nozzle portion 15a is isentropically depressurized and injected (point b1 ⁇ c in FIG. 5).
  • the refrigerant on the outlet side of the evaporator 19 is sucked from the refrigerant suction port 15 c of the ejector 15 by the suction action of the jet refrigerant.
  • the refrigerant injected from the nozzle portion 15a and the suction refrigerant sucked from the refrigerant suction port 15c flow into the diffuser portion 15d (point c ⁇ d, point h1 ⁇ d in FIG. 5).
  • the suction passage of the present embodiment is formed in a shape in which the passage cross-sectional area decreases in the refrigerant flow direction. For this reason, the suction refrigerant passing through the suction passage increases the flow velocity while decreasing the pressure (point h ⁇ point h1 in FIG. 5). Thereby, the speed difference between the suction refrigerant and the injection refrigerant is reduced, and the energy loss (mixing loss) when the suction refrigerant and the injection refrigerant are mixed in the diffuser portion 15d is reduced.
  • the velocity energy of the refrigerant is converted into pressure energy by expanding the refrigerant passage area.
  • the pressure of the mixed refrigerant of the injected refrigerant and the suction refrigerant increases (point d ⁇ point e in FIG. 5).
  • the refrigerant that has flowed out of the diffuser portion 15d flows into the accumulator 16 and is separated into gas and liquid.
  • a pressure loss occurs (point g ⁇ point g1 in FIG. 5).
  • the ejector refrigeration cycle 10 during normal operation operates as described above, and can cool the blown air blown into the passenger compartment.
  • the power consumption of the compressor 11 can be reduced compared with the normal refrigeration cycle apparatus in which the refrigerant evaporation pressure in the evaporator and the pressure of the refrigerant sucked by the compressor are substantially equal.
  • Coefficient of performance (COP) can be improved.
  • the suction pressure increase action (so-called pump action) of the ejector 15 during normal operation is caused by the suction action and speed energy of the high-speed jet refrigerant injected from the nozzle portion 15a.
  • the nozzle portion 15a of the ejector 15 is bypassed and switched to a refrigerant circuit that allows the refrigerant to flow, so that the refrigeration capacity can be reliably exhibited.
  • valve body portion 32 of the valve body 32 is shown in FIG.
  • the ball valve 32a is displaced toward the side of closing the first refrigerant passage 30b, and the plate valve 32b opens the second refrigerant passage 30c. That is, both the first refrigerant passage 30b and the second refrigerant passage 30c are opened.
  • the first pressure receiving area A1 is larger than the second pressure receiving area A2 as shown in Formula F1, and therefore, as shown in Formula F3, the first refrigerant passage 30b is caused by the pressure difference ⁇ P. Is smaller than the second set load Fsp1 on the side that closes the first refrigerant passage 30b instantaneously (ie, A2 ⁇ K ⁇ P).
  • the high-temperature and high-pressure refrigerant (point a in FIG. 6) discharged from the compressor 11 is supercooled by the radiator 12 in the same manner as during normal operation. It becomes a phase refrigerant (point a ⁇ b in FIG. 6).
  • the supercooled liquid phase refrigerant that has flowed out of the supercooling portion 12 c of the radiator 12 flows into the inflow passage 30 a of the circuit switching valve 13.
  • valve body 32 closes the first refrigerant passage 30b and opens the second refrigerant passage 30c, so that the refrigerant that has flowed into the inflow passage 30a goes to the second refrigerant passage 30c. Inflow.
  • the refrigerant flowing into the second refrigerant passage 30c is decompressed in an enthalpy manner at an orifice hole 34a provided in the pressure receiving portion 34 of the valve body 32 (point b ⁇ point g in FIG. 6), and the second refrigerant outlet 31c. And flows into the bypass path 20.
  • the refrigerant flowing into the bypass passage 20 flows into the evaporator 19 via the three-way joint 18.
  • the refrigerant flowing into the evaporator 19 absorbs heat from the blown air blown by the blower fan 19a and evaporates (g point ⁇ h point in FIG. 6). Thereby, blowing air is cooled.
  • the refrigerant that has flowed out of the evaporator 19 flows into the refrigerant suction port 15 c of the ejector 15.
  • the flow rate characteristic of the orifice hole 34a of the present embodiment is that the refrigerant that flows out of the evaporator 19 (that is, the refrigerant on the outlet side of the evaporator 19) is a saturated gas phase refrigerant or gas-liquid when the low load operation is performed. It is set to be a two-phase refrigerant. For this reason, the expansion valve 14 closes the throttle passage during low-load operation.
  • coolant is a saturated gaseous-phase refrigerant
  • the gas-phase refrigerant separated by the accumulator 16 is sucked into the compressor 11 and compressed again (point h ⁇ point a in FIG. 6).
  • the ejector refrigeration cycle 10 during low-load operation operates as described above, and can cool the blown air blown into the passenger compartment.
  • the discharge capacity control unit of the control device increases the refrigerant discharge capacity of the compressor 11.
  • the pressure difference ⁇ P becomes larger than the reference pressure difference K ⁇ P
  • the valve body portion 32 of the circuit switching valve 13 opens the first refrigerant passage 30b and closes the second refrigerant passage 30c.
  • a mechanical mechanism is employed as the circuit switching valve 13 that closes one of the first refrigerant passage 30b and the second refrigerant passage 30c when the other is opened. Further, as the circuit switching valve 13, a valve that opens the second refrigerant passage when the front-rear differential pressure ⁇ Pc is lower than the reference front-rear differential pressure K ⁇ Pc is employed.
  • the circuit switching valve 13 opens the first refrigerant passage 30b, so that the refrigerant dissipated by the radiator 12 can flow into the nozzle portion 15a of the ejector 15. Further, at the time of low load operation, the circuit switching valve 13 opens the second refrigerant passage 30c side so that the refrigerant radiated by the radiator 12 flows into the bypass passage 20 and is led to the refrigerant inlet side of the evaporator 19. Can do.
  • the refrigerant circuit can be switched mechanically and reliably in accordance with the load fluctuation.
  • the front-rear differential pressure ⁇ Pc becomes lower than the reference front-rear differential pressure K ⁇ Pc.
  • the second refrigerant passage 30c is opened, and the refrigerant radiated by the radiator 12 is caused to flow into the evaporator 19 via the bypass passage 20.
  • a normal refrigeration cycle (so-called annular cycle) can be formed. Therefore, the refrigerating machine oil staying in the evaporator 19 is easily returned to the compressor 11 at the start of the cycle.
  • the circuit switching valve 13 when the pressure difference ⁇ P is greater than or equal to the reference pressure difference K ⁇ P, the first refrigerant passage 30b is opened, and the pressure difference ⁇ P is lower than the reference pressure difference K ⁇ P.
  • the one that opens the second refrigerant passage 30c is employed.
  • the pressure difference ⁇ P is greater than or equal to the reference pressure difference K ⁇ P. In this case, it is possible to instantaneously switch from the refrigerant circuit during normal operation to the refrigerant circuit during low-load operation.
  • the second pressure receiving area A2, the third pressure receiving area A3, and the set load Fsp2 of the coil spring 33 are set so as to satisfy the above formulas F4 to F6, the pressure difference ⁇ P becomes lower than the reference pressure difference K ⁇ P. In this case, it is possible to instantaneously switch from the refrigerant circuit during low load operation to the refrigerant circuit during normal operation.
  • the pressure reducing portion is configured by the orifice hole 34a of the pressure receiving portion 34, the pressure reducing portion can be easily formed.
  • a refrigerant passage that connects the upstream and downstream sides of the refrigerant flow of the pressure receiving portion 34 may be formed in the valve body 31, and an orifice, a capillary tube, or the like as a decompression portion may be disposed in the refrigerant passage.
  • FIG. 7 is a schematic cross-sectional view showing a state in which the circuit switching valve 24 switches to a refrigerant circuit that allows the refrigerant flowing out of the radiator 12 to flow into the nozzle portion 15a side of the ejector 15.
  • FIG. 8 is a schematic cross-sectional view showing a state in which the circuit switching valve 24 is switched to a refrigerant circuit that allows the refrigerant flowing out of the radiator 12 to flow into the bypass path 20 side.
  • the circuit switching valve 24 includes a valve body 41, a first valve body portion 42, a first coil spring 43, a first drive mechanism 44, a second valve body portion 45, a second coil spring 46, a second drive mechanism 47, and the like. Yes.
  • the valve body 41 is formed in a prismatic shape or a cylindrical shape by combining a plurality of structural members made of metal or resin.
  • the valve body 41 forms an outer shell of the circuit switching valve 24 and houses the first valve body portion 42, the first coil spring 43, the second valve body portion 45, the second coil spring 46, and the like.
  • the valve body 41 is formed with a high-pressure refrigerant inlet 41a, a first refrigerant outlet 41b, and a second refrigerant outlet 41c similar to the circuit switching valve 13 described in the first embodiment.
  • a plurality of refrigerant passages such as an inflow passage 40a, a first refrigerant passage 40b, and a second refrigerant passage 40c similar to the circuit switching valve 13 are formed inside the valve body 41.
  • the first valve body portion 42 is a cylindrical valve body that opens and closes the first refrigerant passage 40b.
  • the first coil spring 43 is a first elastic member that applies a load on the side that opens the first refrigerant passage 40 b to the first valve body portion 42.
  • the first drive mechanism 44 is for displacing the first valve body 42 according to the high-pressure side pressure PH of the refrigerant upstream of the circuit switching valve 24 (in this embodiment, the pressure of the refrigerant on the outlet side of the radiator 12). Outputs driving force.
  • the first drive mechanism 44 is attached to the outside of the valve body 41 as shown in FIGS.
  • the first drive mechanism 44 has a first case 44a and a first diaphragm 44b.
  • the first case 44a is a first space forming member formed by joining the opening side of metal cup-shaped members (that is, cup-shaped members). For this reason, a space is formed inside the first case 44a.
  • the 1st diaphragm 44b which is a 1st pressure response member is arrange
  • the first diaphragm 44b is formed of a metal circular thin plate.
  • the outer peripheral edge of the first diaphragm 44b is fixed to the first case 44a over the entire circumference. For this reason, the internal space of the first case 44a is partitioned into two spaces, a first enclosure space 44c and a first introduction space 44d, by the first diaphragm 44b.
  • an inert gas in this embodiment, helium gas
  • the first introduction space 44d communicates with the inflow passage 40a.
  • the refrigerant pressure in the first introduction space 44d becomes the high-pressure side pressure PH of the radiator 12 outlet-side refrigerant. Therefore, the first diaphragm 44b is displaced according to the pressure difference between the pressure of the inert gas in the enclosed space 44c and the high-pressure side pressure PH.
  • the inert gas in the first enclosed space 44c does not change greatly even if the temperature changes slightly. For this reason, the pressure in the 1st enclosure space 44c of this embodiment becomes substantially constant under the general use environment of the ejector-type refrigeration cycle 10. Accordingly, the first diaphragm 44b of the present embodiment is displaced substantially according to the high pressure side pressure PH of the radiator 12 outlet side refrigerant.
  • the displacement of the first diaphragm 44b is transmitted to the first valve body portion 42 via the columnar first operating rod 42a extending in the displacement direction of the first valve body portion 42.
  • the high-pressure side pressure PH is equal to or higher than a predetermined reference high-pressure side pressure KPH, the first enclosed space 44c so that the first valve body portion 42 opens the first refrigerant passage 40b.
  • the reference sealing pressure of the inert gas is set.
  • the second valve body portion 45 is a spherical valve body that opens and closes the second refrigerant passage 40c.
  • the second coil spring 46 is a second elastic member that applies a load on the side that closes the second refrigerant passage 40 c to the second valve body portion 45.
  • the second drive mechanism 47 outputs a driving force for displacing the second valve body portion 45 according to the high-pressure side pressure PH of the refrigerant upstream of the circuit switching valve 24.
  • the second drive mechanism 47 is attached to the outside of the valve body 41 as shown in FIGS.
  • the basic configuration of the second drive mechanism 47 is the same as that of the first drive mechanism 44. Accordingly, the second drive mechanism 47 includes a second case 47a that is a second space forming member and a second diaphragm 47b that is a second pressure responsive member.
  • the internal space of the second case 47a is divided into two spaces, a second enclosure space 47c and a second introduction space 47d, by a second diaphragm 47b. Similar to the first diaphragm 44b of the first drive mechanism 44, the second diaphragm 47b is displaced substantially according to the high-pressure side pressure PH of the radiator 12 outlet side refrigerant.
  • the displacement of the second diaphragm 47 b is transmitted to the second valve body 45 via a cylindrical second operating rod 45 a extending in the displacement direction of the second valve body 45.
  • the circuit switching valve 24 of the present embodiment when the high pressure side pressure PH is equal to or higher than the reference high pressure side pressure KPH, the first refrigerant passage 40b is opened and the second refrigerant passage 40c is closed.
  • the high pressure side pressure PH is lower than the reference high pressure side pressure KPH, the first refrigerant passage 40b is closed and the second refrigerant passage 40c is opened.
  • the front-rear differential pressure ⁇ Pc of the compressor 11 when the high-pressure side pressure PH is the reference high-pressure side pressure KPH is defined as a reference front-rear differential pressure K ⁇ Pc.
  • the front-rear differential pressure ⁇ Pc is lower than the reference front-rear differential pressure K ⁇ Pc, such as when starting a general cycle, the first refrigerant passage 40b is opened. While closing, the second refrigerant passage 40c is opened.
  • a fixed throttle is disposed as a decompression unit that decompresses the refrigerant flowing into the evaporator 19 in the bypass passage 20.
  • this fixed throttle an orifice, a capillary tube or the like can be employed.
  • the circuit switching valve 24 having the first and second drive mechanisms 44 and 47 is employed.
  • the drive mechanism that displaces the pressure responsive member (diaphragm) by the pressure difference between the gas pressure in the enclosed space and the refrigerant pressure in the introduction space the pressure in the introduction space (in this embodiment, the high pressure side pressure PH). )
  • the enclosed space functions as a damper. For this reason, sudden displacement of the pressure responsive member (diaphragm) is suppressed.
  • the refrigerant circuit can be switched mechanically and reliably according to the load fluctuation.
  • the first valve body portion 42 of the present embodiment is formed with a first pilot hole 42b that allows the inflow passage 40a and the first refrigerant passage 40b to communicate with each other.
  • the first operating rod 42a is arranged to open and close the first pilot hole 42b according to the displacement of the first diaphragm 44b.
  • the valve body 41 is formed with a communication passage 41d for communicating the inflow passage 40a and the first refrigerant passage 40b.
  • Other configurations of the circuit switching valve 24 are the same as those of the second embodiment.
  • the operation of the circuit switching valve 24 of this embodiment will be described.
  • the high-pressure side pressure PH increases, the first diaphragm 44b is displaced to the side that reduces the first enclosed space 44c.
  • the high pressure side pressure PH becomes equal to or higher than the reference high pressure side pressure KPH, the first operating rod 42a connected to the first diaphragm 44b opens the first pilot hole 42b.
  • the refrigerant flowing out of the radiator 12 flows into the downstream side of the first valve body portion 42 through the communication passage 41d and the first pilot hole 42b.
  • the pressure difference between the refrigerant pressure upstream of the refrigerant flow of the first valve body portion 42 and the refrigerant pressure of the downstream side is reduced, and the first valve body portion 42 opens the first refrigerant passage 40b by the load of the first coil spring 43. .
  • the first diaphragm 44b is displaced to the side that expands the first enclosed space 44c, and the first operating rod 42a closes the first pilot hole 42b of the first valve body portion 42.
  • the high pressure side pressure PH becomes equal to or higher than the reference high pressure side pressure KPH, the first valve body 42 is displaced together with the first operating rod 42a to close the first refrigerant passage 40b.
  • circuit switching valve 24 other operations of the circuit switching valve 24 are the same as in the second embodiment. Also in the circuit switching valve 24 of this embodiment, when the high pressure side pressure PH is equal to or higher than the reference high pressure side pressure KPH, the first refrigerant passage 40b is opened and the second refrigerant passage 40c is closed. On the other hand, when the high pressure side pressure PH is lower than the reference high pressure side pressure KPH, the first refrigerant passage 40b is closed and the second refrigerant passage 40c is opened.
  • the first valve body 42 can be opened by opening and closing the pilot hole 42b. Accordingly, the first valve body portion 42 can be opened with a relatively small driving force, and an increase in the size of the first drive mechanism 44 can be suppressed.
  • the second valve body portion 45 communicates the inflow passage 40a and the second refrigerant passage 40c.
  • the second pilot hole 45b may be provided, and the second diaphragm 47b of the second drive mechanism 47 may be connected to a second operating rod 45a that opens and closes the second pilot hole 45b.
  • the circuit switching valve 25 includes a valve body 51, a first valve body 52, a first coil spring 53, a second valve body 55, a second coil spring 56, a common drive mechanism 57, a common operation rod 58, and the like.
  • the valve body 51 is formed in a prismatic shape or a cylindrical shape by combining a plurality of structural members made of metal or resin.
  • the valve body 51 forms an outer shell of the circuit switching valve 24 and accommodates a first valve body 52, a first coil spring 53, a second valve body 55, a second coil spring 56, a common operating rod 58, and the like. To do.
  • the valve body 51 is formed with a high-pressure refrigerant inlet 51a, a first refrigerant outlet 51b, and a second refrigerant outlet 51c similar to the circuit switching valve 13 described in the first embodiment.
  • a plurality of refrigerant passages such as an inflow passage 50a, a first refrigerant passage 50b, and a second refrigerant passage 50c similar to the circuit switching valve 13 are formed inside the valve body 51.
  • the first valve body 52 is a cylindrical valve body that opens and closes the inlet of the first refrigerant passage 50b.
  • the first coil spring 53 is a first elastic member that applies a load that closes the first refrigerant passage 50 b to the first valve body 52.
  • a through hole penetrating in the axial direction is formed at the center of the first valve body 52.
  • a common operating rod 58 is disposed inside the through hole.
  • the second valve body portion 55 is a spherical valve body that opens and closes the inlet portion of the second refrigerant passage 50c.
  • the second coil spring 56 is a second elastic member that applies a load on the side that closes the second refrigerant passage 50 c to the second valve body portion 55.
  • the common drive mechanism 57 has a common case 57a that is a common space forming member and a common diaphragm 57b that is a common pressure response member.
  • the internal space of the shared case 57a is divided into two spaces, a shared enclosed space 57c and a shared introduction space 57d, by a shared diaphragm 57b.
  • the common diaphragm 57b is displaced substantially according to the high pressure side pressure PH of the radiator 12 outlet side refrigerant.
  • the displacement of the common diaphragm 57b is caused by the first valve body 52 and the second valve body through the cylindrical common operating rod 58 extending in the displacement direction of the first valve body 52 and the second valve body 55. 55 is transmitted to both.
  • the common operation rod 58 is also displaced to the same side as the common diaphragm 57b.
  • the 1st valve body part 52 is displaced to the side which closes the 1st refrigerant path 50b with the load of the 1st coil spring 53.
  • the 2nd valve body part 55 is displaced to the side which opens the 2nd refrigerant path 50c with the common action
  • the first refrigerant passage 50b is opened and the second refrigerant passage 50c is closed, so that the high-pressure side pressure PH is
  • the reference sealing pressure of the inert gas in the shared sealing space 57c is set so that the first refrigerant passage 50b is closed and the second refrigerant passage 50c is opened.
  • the cycle configuration of the ejector refrigeration cycle is not limited to the configuration disclosed in the above-described embodiment.
  • an auxiliary evaporator that evaporates the refrigerant may be disposed between the refrigerant outlet of the diffuser portion 15 d of the ejector 15 and the inlet of the accumulator 16.
  • the refrigerant evaporating pressure (refrigerant evaporating temperature) in the auxiliary evaporator can be made higher than the refrigerant evaporating pressure (refrigerant evaporating temperature) in the evaporator 19 by the boosting action of the ejector 15. Therefore, in both evaporators, the refrigerant can be evaporated at different temperature zones. Furthermore, even during low-load operation, the evaporator 19 and the auxiliary evaporator can be connected in series, and the refrigeration capacity can be exhibited in both evaporators.
  • an internal heat exchanger for exchanging heat between the high-pressure refrigerant flowing out from the radiator 12 and the low-pressure refrigerant flowing out from the evaporator 19 or the suction refrigerant sucked into the compressor 11 may be added to the ejector refrigeration cycle 10. Good.
  • Each component device constituting the ejector refrigeration cycle 10 is not limited to that disclosed in the above-described embodiment.
  • a normal radiator including only the condensing unit 12a may be employed.
  • a receiver-integrated condenser that integrates a receiver (receiver) that separates the gas-liquid of the refrigerant radiated by this radiator and stores excess liquid phase refrigerant is adopted. Also good.
  • the expansion valve 14 is adopted.
  • the expansion valve 14 is not an essential component in the ejector refrigeration cycle.
  • the expansion valve 14, the ejector 15, the accumulator 16, and the like may be integrally configured.
  • a needle-shaped or conical valve body portion is disposed inside the nozzle portion 15a of the ejector 15, and the valve body portion is displaced so that the superheat degree SH of the evaporator 19 outlet side refrigerant approaches the reference superheat degree KSH.
  • the expansion valve 14 and the ejector 15 may be integrated.
  • the refrigerant is not limited to this.
  • HFO refrigerants R1234yf, HFO-1234ze, HFO-1234zd
  • a supercritical refrigeration cycle in which carbon dioxide is employed as the refrigerant and the high-pressure side refrigerant pressure is equal to or higher than the critical pressure of the refrigerant may be configured.
  • the ejector refrigeration cycle 10 is applied to a vehicle air conditioner.
  • the application of the ejector refrigeration cycle 10 is not limited thereto.
  • the present invention may be applied to a stationary air conditioner, a cold / hot storage, a cooling / heating device for a vending machine, and the like.
  • the radiator 12 of the ejector-type refrigeration cycle 10 including the ejector 15 is an outdoor heat exchanger that exchanges heat between the refrigerant and the outside air
  • the evaporator 19 is used side heat exchange that cools the blown air. It is a vessel.
  • the evaporator 19 may be used as an outdoor heat exchanger that absorbs heat from a heat source such as outside air
  • the radiator 12 may be used as a use side heat exchanger that heats a heated fluid such as air or water.

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Abstract

An ejector-type refrigeration cycle is provided with: a compressor; a radiator; an ejector; an evaporator; a diversion passage for diverting refrigerant that has released heat in the radiator away from the nozzle part of the ejector and guiding the refrigerant to the upstream side of the refrigerant outlet of the evaporator; a decompression unit (34a) for decompressing the refrigerant flowing into the evaporator via the diversion passage; and a circuit-switching valve (13) for opening and closing a first refrigerant passage (30b) for guiding the refrigerant to the nozzle part, and opening and closing a second refrigerant passage (30c) for guiding the refrigerant to the diversion passage. The circuit-switching valve is constituted from a mechanical mechanism for closing the first refrigerant passage (30b) or the second refrigerant passage (30c) when the other refrigerant passage is opened. The circuit-switching valve opens the second refrigerant passage (30c) when the before-after pressure difference (ΔPc) obtained by subtracting the refrigerant pressure on the intake side of the compressor from the refrigerant pressure on the discharge side is lower than a preset reference before-after pressure difference (KΔPc).

Description

エジェクタ式冷凍サイクルEjector refrigeration cycle 関連出願の相互参照Cross-reference of related applications
　本出願は、２０１６年７月１８日に出願された日本特許出願２０１６－１４０９６０号に基づくもので、ここにその記載内容を援用する。 This application is based on Japanese Patent Application No. 2016-140960 filed on July 18, 2016, the contents of which are incorporated herein by reference.
　本開示は、エジェクタを備えるエジェクタ式冷凍サイクルに関する。 The present disclosure relates to an ejector refrigeration cycle including an ejector.
　従来、エジェクタを備える蒸気圧縮式の冷凍サイクル装置であるエジェクタ式冷凍サイクルが知られている。この種のエジェクタは、エジェクタ式冷凍サイクルにおいて、ノズル部から噴射された高速度の噴射冷媒の吸引作用によって、蒸発器から流出した冷媒を冷媒吸引口から吸引し、噴射冷媒と吸引冷媒とをディフューザ部にて混合させて昇圧させる吸引昇圧作用（いわゆる、ポンプ作用）を発揮する。 Conventionally, an ejector-type refrigeration cycle, which is a vapor compression refrigeration cycle apparatus including an ejector, is known. This type of ejector sucks the refrigerant flowing out of the evaporator from the refrigerant suction port and sucks the injected refrigerant and the sucked refrigerant in the ejector refrigeration cycle by the suction action of the high-speed jet refrigerant jetted from the nozzle section. A suction pressurizing action (so-called pump action) in which the pressure is increased by mixing in the section is exhibited.
　さらに、エジェクタ式冷凍サイクルでは、エジェクタのポンプ作用によって昇圧された冷媒を圧縮機の吸入口側へ流出させる。これにより、エジェクタ式冷凍サイクルでは、蒸発器における冷媒蒸発圧力と圧縮機へ吸入される吸入冷媒の圧力が略同等となる通常の冷凍サイクル装置よりも、吸入冷媒の圧力を上昇させることができる。従って、エジェクタ式冷凍サイクルでは、通常の冷凍サイクル装置よりも圧縮機の消費動力を低減させて、サイクルの成績係数（ＣＯＰ）の向上を狙うことができる。 Furthermore, in the ejector type refrigeration cycle, the refrigerant whose pressure has been increased by the pump action of the ejector is caused to flow out to the suction port side of the compressor. Thereby, in the ejector type refrigeration cycle, the pressure of the suction refrigerant can be increased as compared with a normal refrigeration cycle apparatus in which the refrigerant evaporation pressure in the evaporator and the pressure of the suction refrigerant sucked into the compressor are substantially equal. Therefore, in the ejector refrigeration cycle, the power consumption of the compressor can be reduced as compared with a normal refrigeration cycle apparatus, and the coefficient of performance (COP) of the cycle can be improved.
　ところが、上述したエジェクタのポンプ作用は、ノズル部から噴射される噴射冷媒の吸引作用および速度エネルギによって生じるので、サイクルを循環する冷媒流量が低下する低負荷運転時には、噴射冷媒の流速が低下してポンプ作用も小さくなってしまう。そして、ポンプ作用が小さくなってしまうと、蒸発器へ冷媒を流入させることができなくなり、エジェクタ式冷凍サイクルが冷凍能力を発揮できなくなってしまうおそれがある。 However, the pumping action of the ejector described above is caused by the suction action and speed energy of the injected refrigerant injected from the nozzle part, so that the flow rate of the injected refrigerant decreases during low load operation where the flow rate of refrigerant circulating in the cycle decreases. The pumping action is also reduced. If the pumping action is reduced, the refrigerant cannot flow into the evaporator, and the ejector refrigeration cycle may not be able to exhibit the refrigeration capacity.
　これに対して、特許文献１には、通常運転時における冷媒回路と低負荷運転時における冷媒回路とを切替可能に構成されたエジェクタ式冷凍サイクルが開示されている。 On the other hand, Patent Document 1 discloses an ejector refrigeration cycle configured to be able to switch between a refrigerant circuit during normal operation and a refrigerant circuit during low-load operation.
　具体的には、特許文献１のエジェクタ式冷凍サイクルでは、放熱器から流出した高圧冷媒をエジェクタのノズル部を迂回させて流す迂回通路を備えている。そして、通常運転時には、高圧冷媒をエジェクタのノズル部へ流入させてエジェクタにポンプ作用を発揮させる冷媒回路に切り替える。一方、低負荷運転時には、高圧冷媒を迂回通路へ流入させて通常の冷媒サイクル装置の同様の冷媒回路に切り替える。 Specifically, the ejector-type refrigeration cycle of Patent Document 1 includes a bypass passage that allows the high-pressure refrigerant flowing out of the radiator to flow around the nozzle portion of the ejector. During normal operation, the refrigerant circuit is switched to a refrigerant circuit that causes high pressure refrigerant to flow into the nozzle portion of the ejector and cause the ejector to exert a pumping action. On the other hand, at the time of low load operation, the high-pressure refrigerant is caused to flow into the bypass passage and switched to a similar refrigerant circuit of a normal refrigerant cycle device.
　これにより、特許文献１のエジェクタ式冷凍サイクルでは、負荷変動によらず冷凍能力を発揮できるようにしている。 Thus, in the ejector refrigeration cycle of Patent Document 1, the refrigeration capacity can be exhibited regardless of load fluctuations.
特許第４０７８９０１号公報Japanese Patent No. 4078901
　ところで、特許文献１のエジェクタ式冷凍サイクルでは、冷媒回路を切り替える冷媒回路切替装置として、三方弁を採用している。しかし、特許文献１には、この三方弁の具体的構成について記載されていない。 Incidentally, the ejector refrigeration cycle of Patent Document 1 employs a three-way valve as a refrigerant circuit switching device for switching the refrigerant circuit. However, Patent Document 1 does not describe a specific configuration of the three-way valve.
　例えば、三方弁として、電気的に作動する電気式三方弁が採用されていると、電気式三方弁の作動条件を判定するための検出装置や、電気式三方弁の作動を制御する制御装置が必要となる。このため、エジェクタ式冷凍サイクル全体としての大型化や、制御態様の複雑化を招きやすい。従って、冷媒回路切替装置としては、機械的な機構によって負荷変動に応じて自動的に作動するものが採用されていることが望ましい。 For example, when an electrically operated three-way valve is employed as the three-way valve, a detection device for determining the operation condition of the electric three-way valve and a control device for controlling the operation of the electric three-way valve are provided. Necessary. For this reason, it becomes easy to invite the enlargement as the whole ejector type refrigerating cycle, and the complexity of a control mode. Therefore, it is desirable that a refrigerant circuit switching device that automatically operates according to a load change by a mechanical mechanism is employed.
　しかしながら、機械的な機構の冷媒回路切替装置として、例えば、サイクルの高圧側冷媒と低圧側冷媒との圧力差に応じて迂回通路を開閉する差圧弁を採用すると、低負荷運転時に差圧弁が迂回通路を開いても、エジェクタのノズル部の入口側を閉じることができない。その結果、高圧冷媒が迂回通路側とエジェクタのノズル部側の双方へ流入してしまい、冷媒回路を確実に切り替えることができなくなってしまう。 However, as a refrigerant circuit switching device of a mechanical mechanism, for example, when a differential pressure valve that opens and closes a bypass passage according to a pressure difference between a high-pressure side refrigerant and a low-pressure side refrigerant in a cycle, the differential pressure valve is bypassed during low load operation. Even if the passage is opened, the inlet side of the nozzle part of the ejector cannot be closed. As a result, the high-pressure refrigerant flows into both the bypass passage and the nozzle portion of the ejector, and the refrigerant circuit cannot be switched reliably.
　本開示は、上記点に鑑み、負荷変動に応じて冷媒回路を、機械的に、かつ、確実に切替可能に構成されたエジェクタ式冷凍サイクルを提供することを目的とする。 In view of the above points, an object of the present disclosure is to provide an ejector-type refrigeration cycle in which a refrigerant circuit can be switched mechanically and reliably according to a load change.
　上記目的を達成するため、本開示の一態様において、エジェクタ式冷凍サイクルは、冷媒を圧縮して吐出する圧縮機と、圧縮機から吐出された冷媒を放熱させる放熱器と、放熱器から流出した冷媒を減圧させるノズル部から噴射された噴射冷媒の吸引作用によって冷媒吸引口から冷媒を吸引し、噴射冷媒と冷媒吸引口から吸引された吸引冷媒とを混合させて昇圧させる昇圧部を有するエジェクタと、冷媒を蒸発させて冷媒吸引口側へ流出させる蒸発器と、放熱器にて放熱した冷媒を、ノズル部を迂回させて蒸発器の冷媒出口よりも上流側へ導く迂回通路と、迂回通路を介して蒸発器へ流入する冷媒を減圧させる減圧部と、放熱器にて放熱した冷媒をノズル部側へ導く第１冷媒通路を開閉するとともに、放熱器にて放熱した冷媒を迂回通路側へ導く第２冷媒通路を開閉する回路切替弁と、を備える。 In order to achieve the above object, in one aspect of the present disclosure, an ejector refrigeration cycle includes a compressor that compresses and discharges a refrigerant, a radiator that dissipates heat from the refrigerant discharged from the compressor, and an outflow from the radiator. An ejector having a boosting unit that sucks the refrigerant from the refrigerant suction port by the suction action of the jetted refrigerant jetted from the nozzle unit that depressurizes the refrigerant, and mixes the injected refrigerant and the suction refrigerant sucked from the refrigerant suction port to boost the pressure; An evaporator that evaporates the refrigerant and flows out to the refrigerant suction port side, a bypass path that bypasses the nozzle section and guides the refrigerant radiated by the radiator to the upstream side from the refrigerant outlet of the evaporator, and a bypass path A decompression section for decompressing the refrigerant flowing into the evaporator, and opening and closing the first refrigerant passage for guiding the refrigerant radiated by the radiator to the nozzle section side, and bypassing the refrigerant radiated by the radiator Comprising a circuit switching valve for opening and closing the second refrigerant passage for introducing, a.
　回路切替弁は、第１冷媒通路および第２冷媒通路のいずれか一方を開いた際に他方を閉じる機械的機構で構成されている。さらに、回路切替弁は、圧縮機の吐出口側の冷媒圧力から吸入口側の冷媒圧力を減算した前後差圧が予め定めた基準前後差圧よりも低くなっている際には、第２冷媒通路を開く。 The circuit switching valve is configured by a mechanical mechanism that closes the other when either one of the first refrigerant passage and the second refrigerant passage is opened. Further, when the differential pressure before and after subtracting the refrigerant pressure on the suction port side from the refrigerant pressure on the discharge port side of the compressor is lower than a predetermined reference front and rear differential pressure, the circuit switching valve Open the passage.
　これによれば、回路切替弁として、第１冷媒通路および第２冷媒通路のいずれか一方を開いた際に他方を閉じる機械的機構が採用されており、さらに、前後差圧が基準前後差圧よりも低くなっている際に、第２冷媒通路を開くものを採用している。 According to this, as the circuit switching valve, a mechanical mechanism that closes one of the first refrigerant passage and the second refrigerant passage when the other one is opened is adopted, and the front-rear differential pressure is the reference front-rear differential pressure. When it is lower than that, the one that opens the second refrigerant passage is adopted.
　従って、前後差圧が大きくなる通常運転時に、回路切替弁が、第１冷媒通路側を開くように基準前後差圧を設定することで、放熱器にて放熱した冷媒をエジェクタのノズル部へ流入させる冷媒回路に切り替えることができる。 Therefore, during normal operation when the front-rear differential pressure increases, the circuit switching valve sets the reference front-rear differential pressure so as to open the first refrigerant passage side, so that the refrigerant radiated by the radiator flows into the ejector nozzle section. The refrigerant circuit can be switched to.
　さらに、前後差圧が小さくなる低負荷運転時に、回路切替弁が、第２冷媒通路側を開くように基準前後差圧を設定することで、放熱器にて放熱した冷媒を迂回通路へ流入させて蒸発器の冷媒入口側へ導くことができる。 Furthermore, during low load operation where the front-rear differential pressure is reduced, the circuit switching valve sets the reference front-rear differential pressure so that the second refrigerant passage side is opened, so that the refrigerant radiated by the radiator flows into the bypass passage. Can be led to the refrigerant inlet side of the evaporator.
　すなわち、負荷変動に応じて冷媒回路を、機械的に、かつ、確実に切替可能に構成されたエジェクタ式冷凍サイクルを提供することができる。 That is, it is possible to provide an ejector-type refrigeration cycle configured such that the refrigerant circuit can be switched mechanically and reliably in accordance with load fluctuations.
　ここで、サイクルの起動時等にサイクル内の均圧化が進行していると、前後差圧が基準前後差圧よりも低くなる。 Here, if pressure equalization in the cycle is in progress at the start of the cycle, the differential pressure across the front and rear becomes lower than the differential pressure across the reference.
　従って、サイクルの起動時には、第２冷媒通路側が開き、放熱器にて放熱した冷媒を、迂回通路を介して蒸発器へ流入させる、通常の冷凍サイクル（いわゆる、環状サイクル）を形成することができる。従って、サイクルの起動時に、蒸発器内に滞留している冷凍機油を圧縮機へ戻しやすい。 Therefore, at the start of the cycle, a normal refrigeration cycle (so-called annular cycle) can be formed in which the second refrigerant passage side opens and the refrigerant radiated by the radiator flows into the evaporator through the bypass passage. . Therefore, it is easy to return the refrigeration oil remaining in the evaporator to the compressor at the start of the cycle.
　また、上記のエジェクタ式冷凍サイクルにおいて、回路切替弁として、回路切替弁の上流側の冷媒の高圧側圧力から減圧部の下流側の冷媒の低圧側圧力を減算した圧力差が予め定めた基準圧力差以上となっている際には、第１冷媒通路を開くとともに第２冷媒通路を閉じ、さらに、圧力差が基準圧力差よりも低くなっている際には、第１冷媒通路を閉じるとともに第２冷媒通路を開くものを採用してもよい。 In the ejector refrigeration cycle, the pressure difference obtained by subtracting the low-pressure side pressure of the refrigerant on the downstream side of the decompression section from the high-pressure side pressure of the refrigerant on the upstream side of the circuit switching valve as the circuit switching valve is a predetermined reference pressure. When the difference is greater than or equal to the difference, the first refrigerant passage is opened and the second refrigerant passage is closed. Further, when the pressure difference is lower than the reference pressure difference, the first refrigerant passage is closed and the first refrigerant passage is closed. You may employ | adopt what opens 2 refrigerant paths.
　この場合は、圧力差が基準圧力差になっている際の前後差圧を、基準前後差圧に設定すればよい。 In this case, the front-rear differential pressure when the pressure difference is the reference pressure difference may be set to the reference front-rear differential pressure.
　また、上記のエジェクタ式冷凍サイクルにおいて、回路切替弁として、回路切替弁の上流側の冷媒の高圧側圧力が予め定めた基準高圧側圧力以上となっている際には、第１冷媒通路を開くとともに第２冷媒通路を閉じ、さらに、高圧側圧力が基準高圧側圧力より低くなっている際には、第１冷媒通路を閉じるとともに第２冷媒通路を開くものを採用してもよい。 In the ejector refrigeration cycle, the first refrigerant passage is opened when the high pressure side pressure of the refrigerant upstream of the circuit switching valve is equal to or higher than a predetermined reference high pressure side pressure as the circuit switching valve. In addition, the second refrigerant passage may be closed, and when the high-pressure side pressure is lower than the reference high-pressure side pressure, the first refrigerant passage may be closed and the second refrigerant passage may be opened.
　この場合は、高圧側圧力が基準高圧側圧力になっている際の前後差圧を、基準前後差圧に設定すればよい。 In this case, the front-rear differential pressure when the high-pressure side pressure is the reference high-pressure side pressure may be set to the reference front-rear differential pressure.
　ここで、「放熱器にて放熱した冷媒」とは、放熱器の少なくとも一部で放熱した冷媒を意味している。また、「蒸発器の冷媒出口よりも上流側へ導く」とは、蒸発器の冷媒入口よりも上流側へ導くことも含まれる。さらに、蒸発器の冷媒出口よりも上流側であれば、蒸発器の冷媒出口よりも下流側（例えば、蒸発器の冷媒通路内）へ導くことも含まれる。 Here, “refrigerant dissipated by a radiator” means a refrigerant dissipated by at least a part of the radiator. Further, “leading to the upstream side of the refrigerant outlet of the evaporator” includes guiding to the upstream side of the refrigerant inlet of the evaporator. Furthermore, if it is upstream from the refrigerant outlet of the evaporator, it also includes guiding to the downstream side of the refrigerant outlet of the evaporator (for example, in the refrigerant passage of the evaporator).
　なお、特許請求の範囲で記載した各手段の括弧内の符号は、後述する実施形態に記載の具体的手段との対応関係を示す。 In addition, the code | symbol in the bracket | parenthesis of each means described in the claim shows the correspondence with the specific means as described in the embodiment described later.
第１実施形態のエジェクタ式冷凍サイクルの模式的な全体構成図である。It is a typical whole block diagram of the ejector-type refrigerating cycle of 1st Embodiment. 第１実施形態の回路切替弁が第１冷媒通路を開いた際の軸方向断面図である。It is an axial sectional view when the circuit switching valve of the first embodiment opens the first refrigerant passage. 第１実施形態の回路切替弁が第２冷媒通路を開いた際の軸方向断面図である。It is an axial direction sectional view at the time of the circuit change-over valve of a 1st embodiment opening the 2nd refrigerant passage. 第１実施形態の回路切替弁が瞬間的に第１冷媒通路および第２冷媒通路の双方を開いている状態の軸方向断面図である。FIG. 3 is an axial cross-sectional view of a state in which the circuit switching valve of the first embodiment instantaneously opens both the first refrigerant passage and the second refrigerant passage. 第１実施形態のエジェクタ式冷凍サイクルの通常運転時における冷媒の状態の変化を示すモリエル線図である。It is a Mollier diagram which shows the change of the state of the refrigerant | coolant at the time of normal driving | operating of the ejector-type refrigerating cycle of 1st Embodiment. 第１実施形態のエジェクタ式冷凍サイクルの低負荷運転時における冷媒の状態の変化を示すモリエル線図である。It is a Mollier diagram which shows the change of the state of the refrigerant | coolant at the time of the low load driving | running of the ejector type refrigeration cycle of 1st Embodiment. 第２実施形態の回路切替弁が第１冷媒通路を開いた際の軸方向断面図である。It is an axial direction sectional view at the time of the circuit change-over valve of a 2nd embodiment opening the 1st refrigerant passage. 第２実施形態の回路切替弁が第２冷媒通路を開いた際の軸方向断面図である。It is an axial direction sectional view at the time of the circuit change-over valve of a 2nd embodiment opening the 2nd refrigerant passage. 第３実施形態の回路切替弁が第１冷媒通路を開いた際の軸方向断面図である。It is an axial direction sectional view at the time of the circuit change-over valve of a 3rd embodiment opening the 1st refrigerant passage. 第４実施形態の回路切替弁が第１冷媒通路を開いた際の軸方向断面図である。It is an axial direction sectional view at the time of the circuit change-over valve of a 4th embodiment opening the 1st refrigerant passage. 第５実施形態の回路切替弁が第１冷媒通路を開いた際の軸方向断面図である。It is an axial sectional view at the time of the circuit change-over valve of a 5th embodiment opening the 1st refrigerant passage. 第５実施形態の回路切替弁が第２冷媒通路を開いた際の軸方向断面図である。It is an axial sectional view at the time of the circuit change-over valve of a 5th embodiment opening the 2nd refrigerant passage.
　（第１実施形態）
　図１～図６を用いて、第１実施形態を説明する。図１の全体構成図に示す本実施形態のエジェクタ式冷凍サイクル１０は、車両用空調装置に適用されており、空調対象空間である車室内（室内空間）へ送風される送風空気を冷却する機能を果たす。従って、エジェクタ式冷凍サイクル１０の冷却対象流体は、送風空気である。 (First embodiment)
The first embodiment will be described with reference to FIGS. The ejector refrigeration cycle 10 of this embodiment shown in the overall configuration diagram of FIG. 1 is applied to a vehicle air conditioner, and has a function of cooling blown air that is blown into a vehicle interior (indoor space) that is an air-conditioning target space. Fulfill. Therefore, the fluid to be cooled in the ejector refrigeration cycle 10 is blown air.
　このエジェクタ式冷凍サイクル１０では、空調熱負荷に応じて、冷媒回路を切り替えることができる。より具体的には、通常運転時は、図１の黒塗矢印に示すように冷媒が流れる冷媒回路に切り替え、通常運転時よりもエジェクタ式冷凍サイクル１０の熱負荷が低くなる低負荷運転時は、図１の白抜矢印に示すように冷媒が流れる冷媒回路に切り替えることができる。 In the ejector refrigeration cycle 10, the refrigerant circuit can be switched according to the air conditioning heat load. More specifically, during normal operation, the circuit is switched to a refrigerant circuit through which refrigerant flows as shown by the black arrows in FIG. 1, and during low load operation where the thermal load of the ejector refrigeration cycle 10 is lower than during normal operation. 1 can be switched to a refrigerant circuit through which the refrigerant flows, as indicated by the white arrows in FIG.
　さらに、エジェクタ式冷凍サイクル１０では、冷媒としてＨＦＣ系冷媒（具体的には、Ｒ１３４ａ）を採用しており、高圧側冷媒圧力が冷媒の臨界圧力を超えない亜臨界冷凍サイクルを構成している。この冷媒には圧縮機１１を潤滑するための冷凍機油が混入されており、冷凍機油の一部は冷媒とともにサイクルを循環している。 Furthermore, the ejector refrigeration cycle 10 employs an HFC refrigerant (specifically, R134a) as a refrigerant, and constitutes a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the refrigerant critical pressure. This refrigerant is mixed with refrigerating machine oil for lubricating the compressor 11, and a part of the refrigerating machine oil circulates in the cycle together with the refrigerant.
　エジェクタ式冷凍サイクル１０の構成機器のうち、圧縮機１１は、冷媒を吸入して高圧冷媒となるまで昇圧して吐出する。圧縮機１１は、車両走行用の駆動力を出力するエンジン（内燃機関）とともにエンジンルーム内に配置されている。圧縮機１１は、プーリ、ベルト等を介してエンジンから出力される回転駆動力によって駆動されるエンジン駆動式の圧縮機である。 Among the components of the ejector refrigeration cycle 10, the compressor 11 sucks the refrigerant and discharges it until it becomes a high-pressure refrigerant. The compressor 11 is disposed in an engine room together with an engine (internal combustion engine) that outputs a driving force for vehicle travel. The compressor 11 is an engine-driven compressor that is driven by a rotational driving force output from the engine via a pulley, a belt, and the like.
　より具体的には、この圧縮機１１は、吐出容量を変化させることによって冷媒吐出能力を調整可能に構成された斜板式の可変容量型圧縮機である。圧縮機１１では、吐出容量を変化させるための図示しない吐出容量制御弁を有している。吐出容量制御弁は、後述する制御装置から出力される制御電流によって、その作動が制御される。 More specifically, the compressor 11 is a swash plate type variable displacement compressor configured such that the refrigerant discharge capacity can be adjusted by changing the discharge capacity. The compressor 11 has a discharge capacity control valve (not shown) for changing the discharge capacity. The operation of the discharge capacity control valve is controlled by a control current output from a control device described later.
　圧縮機１１の吐出口には、放熱器１２の凝縮部１２ａの冷媒入口側が接続されている。放熱器１２は、圧縮機１１から吐出された高圧冷媒と冷却ファン１２ｄから送風された車室外空気（外気）を熱交換させることによって、高圧冷媒を放熱させて冷却する放熱用熱交換器である。放熱器１２は、エンジンルーム内の車両前方側に配置されている。 The refrigerant inlet side of the condenser 12 a of the radiator 12 is connected to the discharge port of the compressor 11. The radiator 12 is a heat exchanger for heat radiation that radiates and cools the high-pressure refrigerant by exchanging heat between the high-pressure refrigerant discharged from the compressor 11 and the outside air (outside air) blown from the cooling fan 12d. . The radiator 12 is arranged on the vehicle front side in the engine room.
　より具体的には、この放熱器１２は、凝縮部１２ａ、レシーバ部１２ｂ、および過冷却部１２ｃを有する、いわゆるサブクール型の凝縮器として構成されている。 More specifically, the radiator 12 is configured as a so-called subcool type condenser having a condensing unit 12a, a receiver unit 12b, and a supercooling unit 12c.
　凝縮部１２ａは、圧縮機１１から吐出された高圧気相冷媒と冷却ファン１２ｄから送風された外気とを熱交換させ、高圧気相冷媒を放熱させて凝縮させる凝縮用の熱交換部である。レシーバ部１２ｂは、凝縮部１２ａから流出した冷媒の気液を分離して余剰液相冷媒を蓄える冷媒容器である。過冷却部１２ｃは、レシーバ部１２ｂから流出した液相冷媒と冷却ファン１２ｄから送風される外気とを熱交換させ、液相冷媒を過冷却する過冷却用の熱交換部である。 The condensing unit 12a is a heat exchange unit for condensation that exchanges heat between the high-pressure gas-phase refrigerant discharged from the compressor 11 and the outside air blown from the cooling fan 12d, and dissipates the high-pressure gas-phase refrigerant to condense. The receiver unit 12b is a refrigerant container that separates the gas-liquid refrigerant flowing out from the condensing unit 12a and stores excess liquid-phase refrigerant. The supercooling unit 12c is a heat exchange unit for supercooling that heat-exchanges the liquid refrigerant flowing out from the receiver unit 12b and the outside air blown from the cooling fan 12d to supercool the liquid refrigerant.
　冷却ファン１２ｄは、制御装置から出力される制御電圧によって回転数（送風空気量）が制御される電動式送風機である。 The cooling fan 12d is an electric blower whose rotation speed (amount of blown air) is controlled by a control voltage output from the control device.
　放熱器１２の過冷却部１２ｃの冷媒出口には、回路切替弁１３の高圧冷媒入口３１ａが接続されている。回路切替弁１３は、放熱器１２の過冷却部１２ｃから流出した冷媒を後述するエジェクタ１５のノズル部１５ａへ流入させる通常運転時の冷媒回路と、放熱器１２の過冷却部１２ｃから流出した冷媒を後述する迂回通路２０へ流入させる低負荷運転時の冷媒回路とを切り替える冷媒回路切替装置である。 The high-pressure refrigerant inlet 31 a of the circuit switching valve 13 is connected to the refrigerant outlet of the supercooling section 12 c of the radiator 12. The circuit switching valve 13 includes a refrigerant circuit during normal operation in which the refrigerant flowing out from the supercooling section 12c of the radiator 12 flows into a nozzle section 15a of an ejector 15 described later, and the refrigerant flowing out from the subcooling section 12c of the radiator 12. Is a refrigerant circuit switching device for switching between a refrigerant circuit and a refrigerant circuit during low load operation that flows into a bypass passage 20 described later.
　回路切替弁１３の詳細構成については、図２～図４を用いて説明する。図２は、回路切替弁１３が、放熱器１２から流出した冷媒をエジェクタ１５のノズル部１５ａ側へ流入させる冷媒回路に切り替えている状態を示す模式的な断面図である。図３は、回路切替弁１３が、放熱器１２から流出した冷媒を迂回通路２０側へ流入させる冷媒回路に切り替えている状態を示す模式的な断面図である。 The detailed configuration of the circuit switching valve 13 will be described with reference to FIGS. FIG. 2 is a schematic cross-sectional view showing a state in which the circuit switching valve 13 is switched to a refrigerant circuit that causes the refrigerant flowing out of the radiator 12 to flow into the nozzle portion 15a side of the ejector 15. FIG. 3 is a schematic cross-sectional view showing a state where the circuit switching valve 13 is switched to a refrigerant circuit that allows the refrigerant flowing out of the radiator 12 to flow into the bypass passage 20 side.
　さらに、図４は、回路切替弁１３が、冷媒回路を切り替える際に、瞬間的に、冷媒をノズル部１５ａ側の冷媒通路および迂回通路２０側の冷媒通路の双方を開いた状態を示す模式的な断面図である。 Further, FIG. 4 is a schematic view showing a state where the circuit switching valve 13 instantaneously opens both the refrigerant passage on the nozzle portion 15a side and the refrigerant passage on the bypass passage 20 side when the circuit switching valve 13 switches the refrigerant circuit. FIG.
　回路切替弁１３は、バルブボデー３１、弁体部３２、コイルバネ３３等を有している。バルブボデー３１は、図２～図４に示すように、金属製あるいは樹脂製の複数の構成部材を組み合わせることによって、角柱状あるいは円柱状に形成されている。バルブボデー３１は、回路切替弁１３の外殻を形成するとともに、内部に弁体部３２、コイルバネ３３等を収容する。 The circuit switching valve 13 includes a valve body 31, a valve body 32, a coil spring 33, and the like. As shown in FIGS. 2 to 4, the valve body 31 is formed in a prismatic shape or a cylindrical shape by combining a plurality of structural members made of metal or resin. The valve body 31 forms an outer shell of the circuit switching valve 13 and houses a valve body 32, a coil spring 33, and the like therein.
　バルブボデー３１には、高圧冷媒入口３１ａ、第１冷媒出口３１ｂ、第２冷媒出口３１ｃが形成されている。また、バルブボデー３１の内部には、流入通路３０ａ、第１冷媒通路３０ｂ、第２冷媒通路３０ｃといった複数の冷媒通路が形成されている。 The valve body 31 has a high-pressure refrigerant inlet 31a, a first refrigerant outlet 31b, and a second refrigerant outlet 31c. A plurality of refrigerant passages such as an inflow passage 30a, a first refrigerant passage 30b, and a second refrigerant passage 30c are formed inside the valve body 31.
　高圧冷媒入口３１ａは、放熱器１２から流出した冷媒を流入通路３０ａ内に流入させる冷媒入口である。第１冷媒出口３１ｂは、第１冷媒通路３０ｂを流通する冷媒をエジェクタ１５のノズル部１５ａ側（より具体的には、後述する膨張弁１４の冷媒入口側）へ流出させる冷媒出口である。第２冷媒出口３１ｃは、第２冷媒通路３０ｃを流通する冷媒を迂回通路２０側へ流出させる冷媒出口である。 The high-pressure refrigerant inlet 31a is a refrigerant inlet through which the refrigerant that has flowed out of the radiator 12 flows into the inflow passage 30a. The first refrigerant outlet 31b is a refrigerant outlet through which refrigerant flowing through the first refrigerant passage 30b flows out to the nozzle portion 15a side of the ejector 15 (more specifically, to the refrigerant inlet side of the expansion valve 14 described later). The second refrigerant outlet 31c is a refrigerant outlet through which the refrigerant flowing through the second refrigerant passage 30c flows out to the bypass passage 20 side.
　第１冷媒通路３０ｂは、流入通路３０ａに連通して、放熱器１２から流出した冷媒をエジェクタ１５のノズル部１５ａ側へ導く冷媒通路である。第２冷媒通路３０ｃは、流入通路３０ａに連通して、放熱器１２から流出した冷媒を迂回通路２０側へ導く冷媒通路である。 The first refrigerant passage 30b is a refrigerant passage that communicates with the inflow passage 30a and guides the refrigerant flowing out of the radiator 12 to the nozzle portion 15a side of the ejector 15. The second refrigerant passage 30c is a refrigerant passage that communicates with the inflow passage 30a and guides the refrigerant flowing out of the radiator 12 to the bypass passage 20 side.
　弁体部３２は、第１冷媒通路３０ｂの入口部を開閉する球体状のボールバルブ３２ａ、および第２冷媒通路３０ｃの入口部を開閉する円板状の板状バルブ３２ｂを有している。板状バルブ３２ｂのうち、第２冷媒通路３０ｃの入口部に当接する部位には、ゴム製のシール部材３２ｃが配置されている。 The valve body 32 includes a spherical ball valve 32a that opens and closes the inlet of the first refrigerant passage 30b, and a disk-like plate valve 32b that opens and closes the inlet of the second refrigerant passage 30c. A rubber seal member 32c is disposed in a portion of the plate-like valve 32b that contacts the inlet of the second refrigerant passage 30c.
　ボールバルブ３２ａと板状バルブ３２ｂは、弁体部３２の変位方向へ延びる連結棒によって連結されている。そして、ボールバルブ３２ａが第１冷媒通路３０ｂを閉じる側に変位すると、板状バルブ３２ｂが第２冷媒通路３０ｃを開く側に変位する。また、ボールバルブ３２ａが第１冷媒通路３０ｂを開く側に変位すると、板状バルブ３２ｂが第２冷媒通路３０ｃを閉じる側に変位する。 The ball valve 32a and the plate valve 32b are connected by a connecting rod extending in the displacement direction of the valve body 32. When the ball valve 32a is displaced toward the side that closes the first refrigerant passage 30b, the plate valve 32b is displaced toward the side that opens the second refrigerant passage 30c. Further, when the ball valve 32a is displaced toward the side opening the first refrigerant passage 30b, the plate-like valve 32b is displaced toward the side closing the second refrigerant passage 30c.
　さらに、弁体部３２には、板状バルブ３２ｂよりも冷媒流れ下流側の第２冷媒通路３０ｃの円柱状の空間内に配置された受圧部３４が連結されている。受圧部３４は金属製の円柱状部材で形成されている。第２冷媒通路３０ｃの内径と受圧部３４の外径は、隙間バメの寸法関係になっている。このため、受圧部３４は、第２冷媒通路３０ｃ内に中心軸方向へ摺動可能に配置されている。 Furthermore, the valve body 32 is connected to a pressure receiving portion 34 disposed in a columnar space of the second refrigerant passage 30c on the downstream side of the refrigerant flow with respect to the plate-like valve 32b. The pressure receiving part 34 is formed of a metal columnar member. The inner diameter of the second refrigerant passage 30c and the outer diameter of the pressure receiving portion 34 are in a dimensional relationship with a clearance fit. For this reason, the pressure receiving part 34 is disposed in the second refrigerant passage 30c so as to be slidable in the central axis direction.
　なお、第２冷媒通路３０ｃの内周面と受圧部３４の外周面との隙間には、シール部材としてのＯリングが配置されており、これらの隙間から冷媒が漏れることはない。 It should be noted that an O-ring as a seal member is disposed in the gap between the inner peripheral surface of the second refrigerant passage 30c and the outer peripheral surface of the pressure receiving portion 34, and the refrigerant does not leak from these gaps.
　また、受圧部３４には、中心軸方向に延びて、第２冷媒通路３０ｃの入口側と第２冷媒通路３０ｃの出口側とを連通させるオリフィス孔３４ａが形成されている。オリフィス孔３４ａは、第２冷媒通路３０ｃに対して、充分に細い径で形成されている。 Further, the pressure receiving portion 34 is formed with an orifice hole 34a extending in the central axis direction and communicating the inlet side of the second refrigerant passage 30c and the outlet side of the second refrigerant passage 30c. The orifice hole 34a is formed with a sufficiently thin diameter with respect to the second refrigerant passage 30c.
　従って、第２冷媒通路３０ｃを流通して第２冷媒出口３１ｃから流出する冷媒は、オリフィス孔３４ａを通過する際に減圧される。さらに、受圧部３４には、オリフィス孔３４ａの入口側冷媒の入口側圧力Ｐｒｉとオリフィス孔３４ａの出口側冷媒の出口側圧力Ｐｒｏとの差圧が作用する。 Therefore, the refrigerant flowing through the second refrigerant passage 30c and flowing out from the second refrigerant outlet 31c is decompressed when passing through the orifice hole 34a. Further, a differential pressure between the inlet side pressure Pri of the inlet side refrigerant in the orifice hole 34a and the outlet side pressure Pro of the outlet side refrigerant in the orifice hole 34a acts on the pressure receiving portion 34.
　つまり、オリフィス孔３４ａは、迂回通路２０を介して後述する蒸発器１９へ流入する冷媒を減圧させる減圧部である。本実施形態では、減圧部が回路切替弁１３内に形成されていることによって、減圧部と回路切替弁が一体的に形成されている。 That is, the orifice hole 34a is a pressure reducing unit that depressurizes the refrigerant flowing into the evaporator 19 to be described later via the bypass passage 20. In the present embodiment, since the pressure reducing part is formed in the circuit switching valve 13, the pressure reducing part and the circuit switching valve are integrally formed.
　コイルバネ３３は、弁体部３２に対して、ボールバルブ３２ａが第１冷媒通路３０ｂを閉じるとともに、板状バルブ３２ｂが第２冷媒通路３０ｃを開く側に荷重をかける弾性部材である。 The coil spring 33 is an elastic member that applies a load to the valve body portion 32 while the ball valve 32a closes the first refrigerant passage 30b and the plate-like valve 32b opens the second refrigerant passage 30c.
　本実施形態のコイルバネ３３の荷重は、次に示すように設定されている。まず、以下の説明では、回路切替弁１３の上流側の冷媒の高圧側圧力ＰＨからオリフィス孔３４ａよりも下流側の冷媒の低圧側圧力ＰＬを減算した値を圧力差ΔＰと定義する。 The load of the coil spring 33 of this embodiment is set as follows. First, in the following description, a value obtained by subtracting the low pressure side pressure PL of the refrigerant downstream of the orifice hole 34a from the high pressure side pressure PH of the refrigerant upstream of the circuit switching valve 13 is defined as a pressure difference ΔP.
　この際、本実施形態のコイルバネ３３の荷重は、圧力差ΔＰが予め定めた基準圧力差ＫΔＰ以上となっている際には、第１冷媒通路３０ｂを開くとともに、第２冷媒通路３０ｃを閉じるように設定されている。一方、圧力差ΔＰが基準圧力差ＫΔＰよりも低くなっている際には、第１冷媒通路３０ｂを閉じるとともに、第２冷媒通路３０ｃを開くように設定されている。 At this time, when the pressure difference ΔP is equal to or larger than a predetermined reference pressure difference KΔP, the load of the coil spring 33 of the present embodiment opens the first refrigerant passage 30b and closes the second refrigerant passage 30c. Is set to On the other hand, when the pressure difference ΔP is lower than the reference pressure difference KΔP, the first refrigerant passage 30b is closed and the second refrigerant passage 30c is opened.
　ここで、低圧側圧力ＰＬは、オリフィス孔３４ａよりも下流側の冷媒の圧力であるから、後述する蒸発器１９の入口側冷媒の圧力、蒸発器１９の出口側冷媒の圧力、あるいは、圧縮機１１吸入冷媒の圧力を採用することができる。本実施形態では、低圧側圧力ＰＬとして、蒸発器１９出口側冷媒の圧力を採用している。もちろん、低圧側圧力ＰＬとして、オリフィス孔３４ａの出口側冷媒の出口側圧力Ｐｒｏを採用してもよい。 Here, since the low-pressure side pressure PL is the pressure of the refrigerant on the downstream side of the orifice hole 34a, the pressure of the refrigerant on the inlet side of the evaporator 19, the pressure of the refrigerant on the outlet side of the evaporator 19 described later, or the compressor 11 The pressure of the suction refrigerant can be adopted. In this embodiment, the pressure of the evaporator 19 outlet side refrigerant is adopted as the low pressure side pressure PL. Of course, the outlet side pressure Pro of the outlet side refrigerant of the orifice hole 34a may be adopted as the low pressure side pressure PL.
　さらに、本実施形態では、圧力差ΔＰが基準圧力差ＫΔＰになっている際の圧縮機１１の吐出口側の冷媒圧力から吸入口側の冷媒圧力を減算した前後差圧ΔＰｃを、基準前後差圧ＫΔＰｃと定義する。このため、本実施形態のコイルバネ３３の荷重は、前後差圧ΔＰｃが基準前後差圧ＫΔＰｃよりも低くなっている際には、回路切替弁１３が第１冷媒通路３０ｂを閉じるとともに、第２冷媒通路３０ｃを開くように設定されている。 Further, in this embodiment, the front-rear differential pressure ΔPc obtained by subtracting the refrigerant pressure on the suction side from the refrigerant pressure on the discharge port side of the compressor 11 when the pressure difference ΔP is the reference pressure difference KΔP is obtained. The pressure is defined as KΔPc. Therefore, when the front-rear differential pressure ΔPc is lower than the reference front-rear differential pressure KΔPc, the load of the coil spring 33 according to the present embodiment closes the first refrigerant passage 30b and the second refrigerant. It is set to open the passage 30c.
　つまり、本実施形態の回路切替弁１３は、第１冷媒通路３０ｂおよび第２冷媒通路３０ｃのいずれか一方を選択的に開く（すなわち、いずれか一方を開いた際に他方を閉じる）機械的機構で構成されている。 That is, the circuit switching valve 13 of the present embodiment is a mechanical mechanism that selectively opens one of the first refrigerant passage 30b and the second refrigerant passage 30c (that is, closes the other when one of them is opened). It consists of
　また、本実施形態の回路切替弁１３では、以下数式Ｆ１～Ｆ３の関係を満たすようにコイルバネ３３の設定荷重および各種諸元が決定されている。
Ａ１＞Ａ２　…（Ｆ１）
Ａ１×ＫΔＰ＞Ｆｓｐ１　…（Ｆ２）
Ｆｓｐ１＞Ａ２×ＫΔＰ　…（Ｆ３）
　ここで、Ａ１は、図２～図４に示すように、弁体部３２が第２冷媒通路３０ｃを閉じた際に、弁体部３２のうち高圧側圧力ＰＨと入口側圧力Ｐｒｉとの差圧が作用する第１受圧面積Ａ１である。Ａ２は、受圧部３４うち入口側圧力Ｐｒｉと出口側圧力Ｐｒｏとの差圧が作用する第２受圧面積Ａ２である。Ｆｓｐ１は、圧力差ΔＰが基準圧力差ＫΔＰとなった際にコイルバネ３３が弁体部３２に作用させる第１セット荷重Ｆｓｐ１である。 Further, in the circuit switching valve 13 of the present embodiment, the set load and various specifications of the coil spring 33 are determined so as to satisfy the following formulas F1 to F3.
A1> A2 (F1)
A1 × KΔP> Fsp1 (F2)
Fsp1> A2 × KΔP (F3)
Here, as shown in FIGS. 2 to 4, A1 is the difference between the high pressure side pressure PH and the inlet side pressure Pri of the valve body portion 32 when the valve body portion 32 closes the second refrigerant passage 30c. This is the first pressure receiving area A1 where pressure acts. A <b> 2 is a second pressure receiving area A <b> 2 in which a differential pressure between the inlet side pressure Pri and the outlet side pressure Pro of the pressure receiving unit 34 acts. Fsp1 is a first set load Fsp1 that the coil spring 33 acts on the valve body portion 32 when the pressure difference ΔP becomes the reference pressure difference KΔP.
　なお、図２～図４では、円形状となる第１受圧面積Ａ１の直径に相当する箇所にＡ１の符号を付している。このことは、第２受圧面積Ａ２、および第３受圧面積においても同様である。 In FIG. 2 to FIG. 4, a portion corresponding to the diameter of the first pressure receiving area A1 having a circular shape is denoted by A1. The same applies to the second pressure receiving area A2 and the third pressure receiving area.
　また、本実施形態では、板状バルブ３２ｂのシール部材３２ｃが当接する円筒状のシート部３１ｄの内径と外径の差によって、上記数式Ｆ１の関係を実現している。 Further, in the present embodiment, the relationship of the above formula F1 is realized by the difference between the inner diameter and the outer diameter of the cylindrical seat portion 31d with which the seal member 32c of the plate valve 32b abuts.
　これに加えて、本実施形態の回路切替弁１３では、以下数式Ｆ４～Ｆ６の関係を満たすようにコイルバネ３３の設定荷重および各種諸元が決定されている。
Ａ２＞Ａ３　…（Ｆ４）
Ｆｓｐ２＞（Ａ２－Ａ３）×ＫΔＰ　…（Ｆ５）
Ａ２×ＫΔＰ＞Ｆｓｐ２　…（Ｆ６）
　ここで、Ａ３は、図２～図４に示すように、弁体部３２が第１冷媒通路３０ｂを閉じた際に、弁体部３２のうち高圧側圧力ＰＨと第１冷媒通路３０ｂ側（すなわち、ノズル部１５ａの入口側）のノズル側圧力Ｐｎｏｚとの差圧が作用する第３受圧面積Ａ３である。Ｆｓｐ２は、弁体部３２が第１冷媒通路３０ｂを閉じている際にコイルバネ３３が弁体部３２に作用させる第２セット荷重Ｆｓｐ２である。 In addition to this, in the circuit switching valve 13 of the present embodiment, the set load and various specifications of the coil spring 33 are determined so as to satisfy the relationships of the following formulas F4 to F6.
A2> A3 (F4)
Fsp2> (A2-A3) × KΔP (F5)
A2 × KΔP> Fsp2 (F6)
Here, as shown in FIGS. 2 to 4, A3 indicates that when the valve body 32 closes the first refrigerant passage 30b, the high pressure side pressure PH and the first refrigerant passage 30b side ( That is, it is the third pressure receiving area A3 on which the differential pressure with the nozzle side pressure Pnoz on the inlet side of the nozzle portion 15a acts. Fsp2 is a second set load Fsp2 that the coil spring 33 acts on the valve body portion 32 when the valve body portion 32 closes the first refrigerant passage 30b.
　さらに、バルブボデー３１には、コイルバネ３３を支持する受け部材３３ａが配置されている。この受け部材３３ａは、バルブボデー３１にネジ止めにて固定されている。従って、コイルバネ３３の荷重は、受け部材３３ａを変位させることによって調整することができる。 Further, the valve body 31 is provided with a receiving member 33a for supporting the coil spring 33. The receiving member 33a is fixed to the valve body 31 with screws. Therefore, the load of the coil spring 33 can be adjusted by displacing the receiving member 33a.
　回路切替弁１３の第１冷媒出口３１ｂには、膨張弁１４の冷媒入口側が接続されている。この膨張弁１４は、いわゆる外部均圧式のボックス型の温度式膨張弁である。 The refrigerant inlet side of the expansion valve 14 is connected to the first refrigerant outlet 31b of the circuit switching valve 13. The expansion valve 14 is a so-called external pressure equalizing box type temperature expansion valve.
　膨張弁１４は、放熱器１２の過冷却部１２ｃから流出した高圧液相冷媒を中間圧冷媒となるまで減圧させるとともに、サイクルを循環する循環冷媒流量を調整する流量調整装置である。さらに、本実施形態の膨張弁１４は、蒸発器１９出口側冷媒の過熱度ＳＨが、予め定めた基準過熱度ＫＳＨに近づくように循環冷媒流量を調整する。 The expansion valve 14 is a flow rate adjusting device that depressurizes the high-pressure liquid-phase refrigerant that has flowed out of the supercooling portion 12c of the radiator 12 until it becomes an intermediate-pressure refrigerant and adjusts the circulating refrigerant flow rate that circulates in the cycle. Further, the expansion valve 14 of the present embodiment adjusts the circulating refrigerant flow rate so that the superheat degree SH of the evaporator 19 outlet side refrigerant approaches a predetermined reference superheat degree KSH.
　このような膨張弁１４としては、蒸発器１９から流出した冷媒の温度および圧力に応じて変位する変位部材（ダイヤフラム）を有する感温部を備え、この変位部材の変位に応じて蒸発器１９出口側冷媒の過熱度が基準過熱度に近づくように機械的機構によって弁開度（冷媒流量）が調整されるものを採用することができる。 Such an expansion valve 14 includes a temperature sensing part having a displacement member (diaphragm) that is displaced according to the temperature and pressure of the refrigerant that has flowed out of the evaporator 19, and the outlet of the evaporator 19 according to the displacement of the displacement member. It is possible to employ one in which the valve opening degree (refrigerant flow rate) is adjusted by a mechanical mechanism so that the superheat degree of the side refrigerant approaches the reference superheat degree.
　膨張弁１４の冷媒出口には、エジェクタ１５のノズル部１５ａの入口側が接続されている。エジェクタ１５は、通常運転時に、膨張弁１４から流出した冷媒（すなわち、放熱器１２から流出した冷媒）を減圧させる減圧装置としての機能を果たす。 The inlet side of the nozzle portion 15 a of the ejector 15 is connected to the refrigerant outlet of the expansion valve 14. The ejector 15 functions as a decompression device that decompresses the refrigerant flowing out of the expansion valve 14 (that is, the refrigerant flowing out of the radiator 12) during normal operation.
　さらに、エジェクタ１５は、膨張弁１４から流出した冷媒をノズル部１５ａで減圧させて噴射し、高速度で噴射される噴射冷媒の吸引作用によって蒸発器１９から流出した冷媒を（すなわち、蒸発器１９出口側冷媒）を吸引して輸送する冷媒輸送装置としての機能を果たす。 Further, the ejector 15 injects the refrigerant that has flowed out of the expansion valve 14 by reducing the pressure at the nozzle portion 15a, and the refrigerant that has flowed out of the evaporator 19 by the suction action of the injected refrigerant that is injected at a high speed (that is, the evaporator 19). It functions as a refrigerant transport device that sucks and transports (exit-side refrigerant).
　より具体的には、エジェクタ１５は、ノズル部１５ａおよびボデー部１５ｂを有している。ノズル部１５ａは、冷媒の流れ方向に向かって徐々に先細る形状の金属製（本実施形態では、ステンレス製）の略円筒状部材で形成されている。ノズル部１５ａは、内部に形成された冷媒通路にて冷媒を等エントロピ的に減圧させる。 More specifically, the ejector 15 has a nozzle portion 15a and a body portion 15b. The nozzle portion 15a is formed of a substantially cylindrical member made of metal (stainless steel in the present embodiment) that gradually tapers in the direction of refrigerant flow. The nozzle portion 15a decompresses the refrigerant in an isentropic manner in the refrigerant passage formed inside.
　ノズル部１５ａの内部に形成された冷媒通路には、通路断面積が最も縮小した喉部（最小通路面積部）が形成され、さらに、この喉部から冷媒を噴射する冷媒噴射口へ向かうに伴って冷媒通路面積が拡大する末広部が形成されている。つまり、ノズル部１５ａは、ラバールノズルとして構成されている。 In the refrigerant passage formed in the nozzle portion 15a, a throat portion (minimum passage area portion) having the smallest passage cross-sectional area is formed, and further, from the throat portion toward the refrigerant injection port for injecting the refrigerant. As a result, a divergent portion in which the refrigerant passage area is enlarged is formed. That is, the nozzle portion 15a is configured as a Laval nozzle.
　さらに、本実施形態では、ノズル部１５ａとして、エジェクタ式冷凍サイクル１０の通常作動時に、冷媒噴射口から噴射される噴射冷媒の流速が音速以上となるように設定されたものが採用されている。もちろん、ノズル部１５ａを先細ノズルで構成してもよい。 Furthermore, in the present embodiment, the nozzle unit 15a is set such that the flow rate of the injected refrigerant injected from the refrigerant injection port is equal to or higher than the sonic speed during normal operation of the ejector refrigeration cycle 10. Of course, you may comprise the nozzle part 15a with a tapered nozzle.
　ボデー部１５ｂは、金属製（本実施形態では、アルミニウム合金製）の円筒状部材で形成されており、内部にノズル部１５ａを支持固定する固定部材として機能するとともに、エジェクタ１５の外殻を形成する。ノズル部１５ａは、ボデー部１５ｂの長手方向一端側の内部に収容されるように圧入にて固定されている。このため、ノズル部１５ａとボデー部１５ｂとの固定部（圧入部）から冷媒が漏れることはない。 The body portion 15b is formed of a cylindrical member made of metal (in this embodiment, made of an aluminum alloy), and functions as a fixing member that supports and fixes the nozzle portion 15a therein, and forms an outer shell of the ejector 15. To do. The nozzle portion 15a is fixed by press-fitting so as to be accommodated inside the longitudinal end of the body portion 15b. For this reason, a refrigerant | coolant does not leak from the fixing | fixed part (press-fit part) of the nozzle part 15a and the body part 15b.
　また、ボデー部１５ｂの外周面のうち、ノズル部１５ａの外周側に対応する部位には、その内外を貫通してノズル部１５ａの冷媒噴射口と連通するように設けられた冷媒吸引口１５ｃが形成されている。この冷媒吸引口１５ｃは、ノズル部１５ａから噴射される噴射冷媒の吸引作用によって、蒸発器１９から流出した冷媒をエジェクタ１５の内部へ吸引する貫通穴である。 In addition, a refrigerant suction port 15c provided so as to penetrate the inside and outside of the outer peripheral surface of the body portion 15b and communicate with the refrigerant injection port of the nozzle portion 15a is provided in a portion corresponding to the outer peripheral side of the nozzle portion 15a. Is formed. The refrigerant suction port 15c is a through hole that sucks the refrigerant that has flowed out of the evaporator 19 into the ejector 15 by the suction action of the injection refrigerant that is injected from the nozzle portion 15a.
　さらに、ボデー部１５ｂの内部には、冷媒吸引口１５ｃから吸引された吸引冷媒をノズル部１５ａの冷媒噴射口側へ導く吸引通路、および吸引通路を介してエジェクタ１５の内部へ流入した吸引冷媒と噴射冷媒とを混合させて昇圧させる昇圧部であるディフューザ部１５ｄが形成されている。 Further, inside the body portion 15b, a suction passage that guides the suction refrigerant sucked from the refrigerant suction port 15c to the refrigerant injection port side of the nozzle portion 15a, and a suction refrigerant that flows into the ejector 15 through the suction passage. A diffuser portion 15d, which is a pressure increasing portion that increases the pressure by mixing the injected refrigerant, is formed.
　ディフューザ部１５ｄは、吸引通路の出口に連続するように配置されて、冷媒通路面積が徐々に拡大するように形成されている。これにより、噴射冷媒と吸引冷媒とを混合させながら、その流速を減速させて噴射冷媒と吸引冷媒との混合冷媒の圧力を上昇させる機能を果たす。従って、エジェクタ１５は、冷媒を吸引して、混合冷媒を昇圧させる吸引昇圧作用（いわゆる、ポンプ作用）を発揮することができる。 The diffuser portion 15d is disposed so as to be continuous with the outlet of the suction passage, and is formed so that the refrigerant passage area gradually increases. Thereby, while mixing the injection refrigerant and the suction refrigerant, a function of reducing the flow velocity and increasing the pressure of the mixed refrigerant of the injection refrigerant and the suction refrigerant is achieved. Therefore, the ejector 15 can exhibit a suction pressure increasing action (so-called pump action) for sucking the refrigerant and boosting the mixed refrigerant.
　ディフューザ部１５ｄの冷媒出口には、アキュムレータ１６の入口側が接続されている。アキュムレータ１６は、ディフューザ部１５ｄから流出した冷媒の気液を分離する気液分離部である。アキュムレータ１６には、分離された気相冷媒を流出させる気相冷媒出口と、分離された液相冷媒を流出させるための液相冷媒出口が設けられている。 The inlet side of the accumulator 16 is connected to the refrigerant outlet of the diffuser part 15d. The accumulator 16 is a gas-liquid separation unit that separates the gas-liquid refrigerant flowing out of the diffuser unit 15d. The accumulator 16 is provided with a gas phase refrigerant outlet through which the separated gas phase refrigerant flows out and a liquid phase refrigerant outlet through which the separated liquid phase refrigerant flows out.
　アキュムレータ１６の液相冷媒出口には、逆止弁１７を介して、三方継手１８の一方の冷媒入口が接続されている。逆止弁１７は、アキュムレータ１６の液相冷媒出口から流出した冷媒が三方継手１８側へ流れることのみを許容する。 One refrigerant inlet of the three-way joint 18 is connected to the liquid phase refrigerant outlet of the accumulator 16 via a check valve 17. The check valve 17 only allows the refrigerant flowing out from the liquid-phase refrigerant outlet of the accumulator 16 to flow to the three-way joint 18 side.
　三方継手１８は３つの冷媒出入口を有する配管継手である。本実施形態では、３の冷媒出入口のうち２つを冷媒入口として利用し、残りの１つを冷媒出口として利用している。三方継手１８の冷媒出口には、蒸発器１９の冷媒入口が接続されている。従って、逆止弁１７は、冷媒が蒸発器１９の入口側からアキュムレータ１６の液相冷媒出口側へ流れることを抑制する抑制機構である。 The three-way joint 18 is a pipe joint having three refrigerant outlets. In the present embodiment, two of the three refrigerant inlets / outlets are used as refrigerant inlets, and the remaining one is used as a refrigerant outlet. The refrigerant inlet of the evaporator 19 is connected to the refrigerant outlet of the three-way joint 18. Therefore, the check valve 17 is a suppression mechanism that suppresses the refrigerant from flowing from the inlet side of the evaporator 19 to the liquid phase refrigerant outlet side of the accumulator 16.
　蒸発器１９は、エジェクタ１５にて減圧された低圧冷媒と送風ファン１９ａから車室内へ送風される送風空気とを熱交換させることによって、低圧冷媒を蒸発させて吸熱作用を発揮させる吸熱用熱交換器である。 The evaporator 19 performs heat exchange between the low-pressure refrigerant decompressed by the ejector 15 and the blown air blown into the vehicle compartment from the blower fan 19a, thereby evaporating the low-pressure refrigerant and exerting an endothermic effect. It is a vessel.
　送風ファン１９ａは、制御装置から出力される制御電圧によって回転数（送風空気量）が制御される電動式送風機である。蒸発器１９の出口側には、エジェクタ１５の冷媒吸引口１５ｃ側が接続されている。さらに、アキュムレータ１６の気相冷媒出口には、圧縮機１１の吸入口側が接続されている。 The blower fan 19a is an electric blower in which the rotation speed (the amount of blown air) is controlled by a control voltage output from the control device. The refrigerant suction port 15 c side of the ejector 15 is connected to the outlet side of the evaporator 19. Further, the suction port side of the compressor 11 is connected to the gas-phase refrigerant outlet of the accumulator 16.
　また、回路切替弁１３の第２冷媒出口３１ｃには、迂回通路２０の入口側が接続されている。迂回通路２０の出口側には、三方継手１８の他方の冷媒入口が接続されている。従って、迂回通路２０は、放熱器１２にて放熱した冷媒を、エジェクタ１５のノズル部１５ａを迂回させて、蒸発器１９の冷媒出口よりも冷媒流れ上流側に配置された三方継手１８側へ導く冷媒通路である。 Further, the inlet side of the bypass passage 20 is connected to the second refrigerant outlet 31c of the circuit switching valve 13. The other refrigerant inlet of the three-way joint 18 is connected to the outlet side of the bypass passage 20. Therefore, the bypass passage 20 guides the refrigerant radiated by the radiator 12 to the side of the three-way joint 18 disposed on the upstream side of the refrigerant flow from the refrigerant outlet of the evaporator 19 by bypassing the nozzle portion 15a of the ejector 15. It is a refrigerant passage.
　次に、図示しない制御装置は、ＣＰＵ、ＲＯＭおよびＲＡＭ等を含む周知のマイクロコンピュータとその周辺回路から構成される。この制御装置は、そのＲＯＭ内に記憶された制御プログラムに基づいて各種演算、処理を行う。制御装置は、上述の各種電気式の圧縮機１１、冷却ファン１２ｄ等の作動を制御する。 Next, a control device (not shown) includes a known microcomputer including a CPU, a ROM, a RAM, and the like and its peripheral circuits. This control device performs various calculations and processes based on a control program stored in the ROM. The control device controls the operation of the various electric compressors 11 and the cooling fan 12d described above.
　また、制御装置には、内気温センサ、外気温センサ、日射センサ、蒸発器温度センサ、出口側温度センサ、出口側圧力センサ等の複数の空調制御用のセンサ群が接続され、これらのセンサ群の検出値が入力される。 The control device is connected to a plurality of air conditioning control sensor groups such as an inside air temperature sensor, an outside air temperature sensor, a solar radiation sensor, an evaporator temperature sensor, an outlet side temperature sensor, and an outlet side pressure sensor. The detected value is input.
　より具体的には、内気温センサは、車室内温度を検出する内気温検出装置である。外気温センサは、外気温を検出する外気温検出装置である。日射センサは、車室内の日射量を検出する日射量検出装置である。蒸発器温度センサは、蒸発器１９の吹出空気温度（蒸発器温度）を検出する蒸発器温度検出装置である。出口側温度センサは、放熱器１２出口側冷媒の温度を検出する出口側温度検出装置である。出口側圧力センサは、放熱器１２出口側冷媒の圧力を検出する出口側圧力検出装置である。 More specifically, the inside air temperature sensor is an inside air temperature detecting device that detects the vehicle interior temperature. The outside air temperature sensor is an outside air temperature detecting device that detects outside air temperature. A solar radiation sensor is a solar radiation amount detection apparatus which detects the solar radiation amount in a vehicle interior. The evaporator temperature sensor is an evaporator temperature detection device that detects the blown air temperature (evaporator temperature) of the evaporator 19. The outlet side temperature sensor is an outlet side temperature detecting device that detects the temperature of the radiator 12 outlet side refrigerant. The outlet-side pressure sensor is an outlet-side pressure detection device that detects the pressure of the radiator 12 outlet-side refrigerant.
　さらに、制御装置の入力側には、車室内前部の計器盤付近に配置された図示しない操作パネルが接続され、この操作パネルに設けられた各種操作スイッチからの操作信号が制御装置へ入力される。操作パネルに設けられた各種操作スイッチとしては、車室内空調を行うことを要求する空調作動スイッチ、車室内温度を設定する車室内温度設定スイッチ等が設けられている。 Furthermore, an operation panel (not shown) disposed near the instrument panel in the front part of the vehicle interior is connected to the input side of the control device, and operation signals from various operation switches provided on the operation panel are input to the control device. The As various operation switches provided on the operation panel, there are provided an air conditioning operation switch for requesting air conditioning in the vehicle interior, a vehicle interior temperature setting switch for setting the vehicle interior temperature, and the like.
　なお、本実施形態の制御装置は、その出力側に接続された各種の制御対象機器の作動を制御する制御部が一体的に構成されたものであるが、制御装置のうち、各制御対象機器の作動を制御する構成（ハードウェアおよびソフトウェア）が各制御対象機器の制御部を構成している。 Note that the control device of the present embodiment is configured such that a control unit that controls the operation of various control target devices connected to the output side is integrally configured. The configuration (hardware and software) for controlling the operation of the system constitutes a control unit of each control target device.
　例えば、本実施形態では、圧縮機１１の吐出容量制御弁の作動を制御することによって、圧縮機１１の冷媒吐出能力を制御する構成が吐出能力制御部を構成している。もちろん、吐出能力制御部を制御装置に対して、別体の制御装置で構成してもよい。 For example, in the present embodiment, the configuration for controlling the refrigerant discharge capacity of the compressor 11 by controlling the operation of the discharge capacity control valve of the compressor 11 constitutes the discharge capacity control unit. Of course, the discharge capacity control unit may be configured as a separate control device with respect to the control device.
　次に、上記構成における本実施形態のエジェクタ式冷凍サイクル１０の作動について説明する。前述の如く、本実施形態のエジェクタ式冷凍サイクル１０では、通常運転時の冷媒回路と低負荷運転時の冷媒回路とを切り替えることができる。 Next, the operation of the ejector refrigeration cycle 10 of the present embodiment having the above configuration will be described. As described above, in the ejector refrigeration cycle 10 of the present embodiment, the refrigerant circuit during normal operation and the refrigerant circuit during low-load operation can be switched.
　より具体的には、本実施形態のエジェクタ式冷凍サイクル１０では、回路切替弁１３における圧力差ΔＰが基準圧力差ＫΔＰより大きくなっている際に通常運転時の冷媒回路に切り替えられ、圧力差ΔＰが基準圧力差ＫΔＰ以下となっている際に低負荷運転時の冷媒回路に切り替えられる。 More specifically, in the ejector refrigeration cycle 10 of the present embodiment, when the pressure difference ΔP in the circuit switching valve 13 is larger than the reference pressure difference KΔP, the refrigerant circuit is switched to the refrigerant circuit during normal operation, and the pressure difference ΔP Is switched to the refrigerant circuit at the time of low load operation when the pressure difference is equal to or less than the reference pressure difference KΔP.
　まず、通常運転時の作動について説明する。本実施形態のエジェクタ式冷凍サイクル１０では、操作パネルの作動スイッチが投入（ＯＮ）されると、制御装置が、予め記憶された空調制御プログラムを実行して、圧縮機１１の電動モータ、冷却ファン１２ｄ、送風ファン１９ａ等の作動を制御する。 First, the operation during normal operation will be described. In the ejector refrigeration cycle 10 of this embodiment, when the operation switch of the operation panel is turned on (ON), the control device executes an air conditioning control program stored in advance, and the electric motor and cooling fan of the compressor 11 12d and the operation of the blower fan 19a are controlled.
　ここで、車両の停止後、短時間で再起動する場合等を除き、一般的に、サイクルの起動時には、エジェクタ式冷凍サイクル１０内の冷媒の均圧化がなされていることが多い。そして、冷媒の均圧化がなされている場合には、前後差圧ΔＰｃが基準前後差圧ＫΔＰｃよりも低くなる。従って、回路切替弁１３では、図３に示すように、第１冷媒通路３０ｂが閉じ、第２冷媒通路３０ｃが開いた状態となる。 Here, generally, when the cycle is started, the refrigerant in the ejector refrigeration cycle 10 is often pressure-equalized, except when the vehicle is restarted in a short time after stopping. When the refrigerant is equalized, the front-rear differential pressure ΔPc is lower than the reference front-rear differential pressure KΔPc. Therefore, in the circuit switching valve 13, as shown in FIG. 3, the first refrigerant passage 30b is closed and the second refrigerant passage 30c is opened.
　その結果、サイクルの起動直後のエジェクタ式冷凍サイクル１０では、図１の白抜矢印に示すように冷媒が流れる。この際、サイクル内の冷媒圧力は、以下、数式Ｆ７～Ｆ１０に示す関係になっている。
ＰＨ＝Ｐｒｉ　…（Ｆ７）
Ｐｒｉ＞Ｐｒｏ　…（Ｆ８）
Ｐｒｏ≒ＰＬ　…（Ｆ９）
Ｐｒｏ≒Ｐｎｏｚ　…（Ｆ１０）
　このため、前述した数式Ｆ５に示すように、圧力差ΔＰによって第１冷媒通路３０ｂを開く側の荷重（すなわち、（Ａ２－Ａ３）×ΔＰ）が、第１冷媒通路３０ｂを閉じる側の第２セット荷重Ｆｓｐ２より大きくなるまで、第２冷媒通路３０ｃを開いた状態が維持される。 As a result, in the ejector refrigeration cycle 10 immediately after the start of the cycle, the refrigerant flows as shown by the white arrow in FIG. At this time, the refrigerant pressure in the cycle has a relationship shown in the following formulas F7 to F10.
PH = Pri (F7)
Pri> Pro (F8)
Pro ≒ PL (F9)
Pro≈Pnoz (F10)
For this reason, as shown in Formula F5, the load on the side that opens the first refrigerant passage 30b due to the pressure difference ΔP (that is, (A2-A3) × ΔP) is the second on the side that closes the first refrigerant passage 30b. The state where the second refrigerant passage 30c is opened is maintained until it becomes larger than the set load Fsp2.
　なお、本実施形態では、高圧側圧力ＰＨとして放熱器１２出口側冷媒の圧力（すなわち、回路切替弁１３の高圧冷媒入口３１ａにおける冷媒圧力）を採用している。また、ノズル側圧力Ｐｎｏｚとして、膨張弁１４入口側冷媒の圧力（すなわち、回路切替弁１３の第１冷媒出口３１ｂにおける冷媒圧力）を採用している。 In the present embodiment, the pressure of the refrigerant on the outlet side of the radiator 12 (that is, the refrigerant pressure at the high pressure refrigerant inlet 31a of the circuit switching valve 13) is adopted as the high pressure side pressure PH. Further, the pressure of the refrigerant on the inlet side of the expansion valve 14 (that is, the refrigerant pressure at the first refrigerant outlet 31b of the circuit switching valve 13) is employed as the nozzle side pressure Pnoz.
　そして、通常運転時の圧縮機１１の吸入圧縮作用によって、高圧側圧力ＰＨと低圧側圧力ＰＬとの圧力差ΔＰが拡大し、基準圧力差ＫΔＰに到達すると、図４に示すように弁体部３２のボールバルブ３２ａが第１冷媒通路３０ｂを開くとともに、板状バルブ３２ｂが第２冷媒通路３０ｃを閉じる側に変位する。すなわち、第１冷媒通路３０ｂおよび第２冷媒通路３０ｃの双方が開いた状態になる。 When the pressure difference ΔP between the high-pressure side pressure PH and the low-pressure side pressure PL is expanded by the suction compression action of the compressor 11 during normal operation and reaches the reference pressure difference KΔP, the valve body portion is shown in FIG. The 32 ball valves 32a open the first refrigerant passage 30b, and the plate-like valve 32b is displaced to close the second refrigerant passage 30c. That is, both the first refrigerant passage 30b and the second refrigerant passage 30c are opened.
　この際、サイクル内の圧力は、以下、数式Ｆ１１、Ｆ１２に示す関係に変化する。
ＰＨ≒Ｐｎｏｚ　…（Ｆ１１）
ＰＨ≒Ｐｒｉ　…（Ｆ１２）
　ここで、本実施形態では、数式Ｆ４に示すように、第２受圧面積Ａ２が第３受圧面積Ａ３よりも大きくなっているので、数式Ｆ６に示すように、圧力差ΔＰによって第１冷媒通路３０ｂを開く側の荷重（すなわち、Ａ２×ΔＰ）が、瞬時に第１冷媒通路３０ｂを閉じる側の第２セット荷重Ｆｓｐ２よりも大きくなる。 At this time, the pressure in the cycle changes to a relationship represented by mathematical formulas F11 and F12 below.
PH≈Pnoz (F11)
PH≈Pri (F12)
Here, in the present embodiment, since the second pressure receiving area A2 is larger than the third pressure receiving area A3 as shown in Formula F4, as shown in Formula F6, the first refrigerant passage 30b is caused by the pressure difference ΔP. Is larger than the second set load Fsp2 on the side where the first refrigerant passage 30b is closed instantaneously.
　その結果、第１冷媒通路３０ｂおよび第２冷媒通路３０ｃの双方が開いた状態から、瞬時に、図２に示すように、第１冷媒通路３０ｂが開き、第２冷媒通路３０ｃが閉じた状態となる。このため、通常運転時のエジェクタ式冷凍サイクル１０では、図１の黒塗矢印に示すように冷媒が流れる。 As a result, from the state where both the first refrigerant passage 30b and the second refrigerant passage 30c are opened, as shown in FIG. 2, the first refrigerant passage 30b is opened and the second refrigerant passage 30c is closed as shown in FIG. Become. For this reason, in the ejector refrigeration cycle 10 during normal operation, the refrigerant flows as shown by the black arrows in FIG.
　より具体的には、図５のモリエル線図に示すように、圧縮機１１から吐出された高温高圧冷媒（図５のａ点）は、放熱器１２の凝縮部１２ａへ流入する。凝縮部１２ａへ流入した冷媒は、冷却ファン１２ｄから送風された外気と熱交換し、放熱して凝縮する。凝縮部１２ａにて凝縮した冷媒は、レシーバ部１２ｂにて気液分離される。レシーバ部１２ｂにて気液分離された液相冷媒は、過冷却部１２ｃにて冷却ファン１２ｄから送風された外気と熱交換し、さらに放熱して過冷却液相冷媒となる（図５のａ点→ｂ点）。 More specifically, as shown in the Mollier diagram of FIG. 5, the high-temperature and high-pressure refrigerant discharged from the compressor 11 (point a in FIG. 5) flows into the condenser 12 a of the radiator 12. The refrigerant flowing into the condensing part 12a exchanges heat with the outside air blown from the cooling fan 12d, and dissipates heat to condense. The refrigerant condensed in the condensing unit 12a is gas-liquid separated in the receiver unit 12b. The liquid phase refrigerant separated from the gas and liquid by the receiver unit 12b exchanges heat with the outside air blown from the cooling fan 12d by the supercooling unit 12c, and further dissipates heat to become a supercooled liquid phase refrigerant (a in FIG. 5). Point → b).
　放熱器１２の過冷却部１２ｃから流出した過冷却液相冷媒は、回路切替弁１３の高圧冷媒入口３１ａから流入通路３０ａへ流入する。通常運転時の回路切替弁１３では、弁体部３２が第１冷媒通路３０ｂを開くとともに、第２冷媒通路３０ｃを閉じているので、流入通路３０ａへ流入した冷媒は、第１冷媒出口３１ｂから流出して、膨張弁１４へ流入する。 The supercooled liquid phase refrigerant that has flowed out of the supercooling portion 12c of the radiator 12 flows from the high-pressure refrigerant inlet 31a of the circuit switching valve 13 into the inflow passage 30a. In the circuit switching valve 13 during normal operation, the valve body 32 opens the first refrigerant passage 30b and closes the second refrigerant passage 30c, so that the refrigerant flowing into the inflow passage 30a flows from the first refrigerant outlet 31b. It flows out and flows into the expansion valve 14.
　膨張弁１４へ流入した冷媒は、中間圧冷媒となるまで等エンタルピ的に減圧される（図５のｂ点→ｂ１点）。この際、膨張弁１４の絞り開度は、蒸発器１９出口側冷媒（図５のｈ点）の過熱度ＳＨが基準過熱度ＫＳＨに近づくように調整される。膨張弁１４から流出した中間圧冷媒はエジェクタ１５のノズル部１５ａへ流入する。 The refrigerant that has flowed into the expansion valve 14 is decompressed in an enthalpy manner until it becomes an intermediate pressure refrigerant (point b → point b1 in FIG. 5). At this time, the opening degree of the expansion valve 14 is adjusted such that the superheat degree SH of the evaporator 19 outlet side refrigerant (point h in FIG. 5) approaches the reference superheat degree KSH. The intermediate pressure refrigerant that has flowed out of the expansion valve 14 flows into the nozzle portion 15 a of the ejector 15.
　ノズル部１５ａへ流入した冷媒は、等エントロピ的に減圧されて噴射される（図５のｂ１→ｃ点）。そして、この噴射冷媒の吸引作用によって、蒸発器１９出口側冷媒が、エジェクタ１５の冷媒吸引口１５ｃから吸引される。ノズル部１５ａから噴射された噴射冷媒および冷媒吸引口１５ｃから吸引された吸引冷媒は、ディフューザ部１５ｄへ流入する（図５のｃ→ｄ点、ｈ１点→ｄ点）。 The refrigerant flowing into the nozzle portion 15a is isentropically depressurized and injected (point b1 → c in FIG. 5). The refrigerant on the outlet side of the evaporator 19 is sucked from the refrigerant suction port 15 c of the ejector 15 by the suction action of the jet refrigerant. The refrigerant injected from the nozzle portion 15a and the suction refrigerant sucked from the refrigerant suction port 15c flow into the diffuser portion 15d (point c → d, point h1 → d in FIG. 5).
　ここで、本実施形態の吸引通路は、冷媒流れ方向に向かって通路断面積が縮小する形状に形成されている。このため、吸引通路を通過する吸引冷媒は、その圧力を低下させながら（図５のｈ点→ｈ１点）、流速を増加させる。これにより、吸引冷媒と噴射冷媒との速度差を縮小し、ディフューザ部１５ｄにて吸引冷媒と噴射冷媒が混合する際のエネルギ損失（混合損失）を減少させている。 Here, the suction passage of the present embodiment is formed in a shape in which the passage cross-sectional area decreases in the refrigerant flow direction. For this reason, the suction refrigerant passing through the suction passage increases the flow velocity while decreasing the pressure (point h → point h1 in FIG. 5). Thereby, the speed difference between the suction refrigerant and the injection refrigerant is reduced, and the energy loss (mixing loss) when the suction refrigerant and the injection refrigerant are mixed in the diffuser portion 15d is reduced.
　ディフューザ部１５ｄでは、冷媒通路面積の拡大により、冷媒の速度エネルギが圧力エネルギに変換される。これにより、噴射冷媒と吸引冷媒との混合冷媒の圧力が上昇する（図５のｄ点→ｅ点）。ディフューザ部１５ｄから流出した冷媒はアキュムレータ１６へ流入して気液分離される。 In the diffuser portion 15d, the velocity energy of the refrigerant is converted into pressure energy by expanding the refrigerant passage area. Thereby, the pressure of the mixed refrigerant of the injected refrigerant and the suction refrigerant increases (point d → point e in FIG. 5). The refrigerant that has flowed out of the diffuser portion 15d flows into the accumulator 16 and is separated into gas and liquid.
　アキュムレータ１６にて分離された液相冷媒（図５のｇ点）は、逆止弁１７および三方継手１８を介して、蒸発器１９へ流入する。液相冷媒が逆止弁１７を通過する際には、圧力損失が生じる（図５のｇ点→ｇ１点）。蒸発器１９へ流入した冷媒は、送風ファン１９ａによって送風された送風空気から吸熱して蒸発する（図５のｇ１点→ｈ点）。これにより、送風空気が冷却される。 The liquid refrigerant (g point in FIG. 5) separated by the accumulator 16 flows into the evaporator 19 via the check valve 17 and the three-way joint 18. When the liquid-phase refrigerant passes through the check valve 17, a pressure loss occurs (point g → point g1 in FIG. 5). The refrigerant flowing into the evaporator 19 absorbs heat from the blown air blown by the blower fan 19a and evaporates (g1 point → h point in FIG. 5). Thereby, blowing air is cooled.
　一方、アキュムレータ１６にて分離された気相冷媒（図５のｆ点）は、圧縮機１１へ吸入されて再び圧縮される（図５のｆ点→ａ点）。 On the other hand, the gas-phase refrigerant separated by the accumulator 16 (point f in FIG. 5) is sucked into the compressor 11 and compressed again (point f → point a in FIG. 5).
　通常運転時のエジェクタ式冷凍サイクル１０は、以上の如く作動して、車室内へ送風される送風空気を冷却することができる。 The ejector refrigeration cycle 10 during normal operation operates as described above, and can cool the blown air blown into the passenger compartment.
　また、通常運転時のエジェクタ式冷凍サイクル１０では、ディフューザ部１５ｄにて昇圧された冷媒を圧縮機１１へ吸入させることができる。従って、エジェクタ式冷凍サイクル１０によれば、蒸発器における冷媒蒸発圧力と圧縮機吸入冷媒の圧力が略同等となる通常の冷凍サイクル装置よりも、圧縮機１１の消費動力を低減させて、サイクルの成績係数（ＣＯＰ）を向上させることができる。 Further, in the ejector refrigeration cycle 10 during normal operation, the refrigerant whose pressure has been increased by the diffuser portion 15d can be sucked into the compressor 11. Therefore, according to the ejector-type refrigeration cycle 10, the power consumption of the compressor 11 can be reduced compared with the normal refrigeration cycle apparatus in which the refrigerant evaporation pressure in the evaporator and the pressure of the refrigerant sucked by the compressor are substantially equal. Coefficient of performance (COP) can be improved.
　ここで、通常運転時におけるエジェクタ１５の吸引昇圧作用（いわゆる、ポンプ作用）は、ノズル部１５ａから噴射される高速度の噴射冷媒の吸引作用および速度エネルギによって生じる。 Here, the suction pressure increase action (so-called pump action) of the ejector 15 during normal operation is caused by the suction action and speed energy of the high-speed jet refrigerant injected from the nozzle portion 15a.
　このため、サイクルを循環する冷媒流量が低下する低負荷運転時には、噴射冷媒の流速が低下してポンプ作用も小さくなってしまう。さらに、ポンプ作用が小さくなってしまうと、蒸発器１９へ冷媒を流入させることができなくなってしまい、エジェクタ式冷凍サイクル１０が冷凍能力を発揮できなくなってしまうおそれがある。 For this reason, at the time of low load operation in which the flow rate of the refrigerant circulating in the cycle is lowered, the flow rate of the injected refrigerant is lowered and the pump action is also reduced. Furthermore, if the pumping action is reduced, the refrigerant cannot be allowed to flow into the evaporator 19, and the ejector refrigeration cycle 10 may not be able to exhibit the refrigeration capacity.
　そこで、本実施形態のエジェクタ式冷凍サイクル１０では、低負荷運転時には、エジェクタ１５のノズル部１５ａを迂回させて冷媒を流す冷媒回路に切り替えて冷凍能力を確実に発揮できるようにしている。 Therefore, in the ejector-type refrigeration cycle 10 of the present embodiment, during low-load operation, the nozzle portion 15a of the ejector 15 is bypassed and switched to a refrigerant circuit that allows the refrigerant to flow, so that the refrigeration capacity can be reliably exhibited.
　より詳細には、通常運転時には、弁体部３２が第１冷媒通路３０ｂを開き、第２冷媒通路３０ｃを閉じているので、サイクルの冷媒圧力は、以下、数式Ｆ１３、Ｆ１４に示す関係になっている。
ＰＨ＝Ｐｎｏｚ　…（Ｆ１３）
ＰＨ＝Ｐｒｉ　…（Ｆ１４）
　このため、前述した数式Ｆ２に示すように、圧力差ΔＰによって第１冷媒通路３０ｂを開く側の荷重（すなわち、Ａ１×ＫΔＰ）が、第１冷媒通路３０ｂを閉じる側の第１セット荷重Ｆｓｐ１よりも小さくなるまで、第１冷媒通路３０ｂを開いた状態を維持することができる。 More specifically, during normal operation, the valve body 32 opens the first refrigerant passage 30b and closes the second refrigerant passage 30c, so that the refrigerant pressure in the cycle has a relationship expressed by the following formulas F13 and F14. ing.
PH = Pnoz (F13)
PH = Pri (F14)
Therefore, as shown in Formula F2 described above, the load on the side that opens the first refrigerant passage 30b due to the pressure difference ΔP (ie, A1 × KΔP) is greater than the first set load Fsp1 on the side that closes the first refrigerant passage 30b. The first refrigerant passage 30b can be kept open until the value becomes smaller.
　そして、サイクルに要求される負荷が低下して、高圧側圧力ＰＨと低圧側圧力ＰＬとの圧力差ΔＰが縮小し、基準圧力差ＫΔＰに到達すると、図４に示すように弁体部３２のボールバルブ３２ａが第１冷媒通路３０ｂを閉じる側に変位するとともに、板状バルブ３２ｂが第２冷媒通路３０ｃを開く。すなわち、第１冷媒通路３０ｂおよび第２冷媒通路３０ｃの双方が開いた状態になる。 Then, when the load required for the cycle decreases and the pressure difference ΔP between the high pressure side pressure PH and the low pressure side pressure PL decreases and reaches the reference pressure difference KΔP, the valve body portion 32 of the valve body 32 is shown in FIG. The ball valve 32a is displaced toward the side of closing the first refrigerant passage 30b, and the plate valve 32b opens the second refrigerant passage 30c. That is, both the first refrigerant passage 30b and the second refrigerant passage 30c are opened.
　この際、本実施形態では、数式Ｆ１に示すように、第１受圧面積Ａ１が第２受圧面積Ａ２よりも大きくなっているので、数式Ｆ３に示すように、圧力差ΔＰによって第１冷媒通路３０ｂを開く側の荷重（すなわち、Ａ２×ＫΔＰ）が、瞬時に第１冷媒通路３０ｂを閉じる側の第２セット荷重Ｆｓｐ１よりも小さくなる。 At this time, in the present embodiment, the first pressure receiving area A1 is larger than the second pressure receiving area A2 as shown in Formula F1, and therefore, as shown in Formula F3, the first refrigerant passage 30b is caused by the pressure difference ΔP. Is smaller than the second set load Fsp1 on the side that closes the first refrigerant passage 30b instantaneously (ie, A2 × KΔP).
　その結果、第１冷媒通路３０ｂおよび第２冷媒通路３０ｃの双方が開いた状態から、瞬時に図３に示すように、第１冷媒通路３０ｂが閉じ、第２冷媒通路３０ｃが開いた状態となる。このため、低負荷運転時のエジェクタ式冷凍サイクル１０では、図１の白抜矢印に示すように冷媒が流れる。 As a result, from the state where both the first refrigerant passage 30b and the second refrigerant passage 30c are opened, the first refrigerant passage 30b is instantaneously closed and the second refrigerant passage 30c is opened as shown in FIG. . For this reason, in the ejector refrigeration cycle 10 during low-load operation, the refrigerant flows as indicated by the white arrows in FIG.
　より具体的には、図６のモリエル線図に示すように、圧縮機１１から吐出された高温高圧冷媒（図６のａ点）は、通常運転時と同様に放熱器１２にて過冷却液相冷媒となる（図６のａ点→ｂ点）。放熱器１２の過冷却部１２ｃから流出した過冷却液相冷媒は、回路切替弁１３の流入通路３０ａへ流入する。 More specifically, as shown in the Mollier diagram of FIG. 6, the high-temperature and high-pressure refrigerant (point a in FIG. 6) discharged from the compressor 11 is supercooled by the radiator 12 in the same manner as during normal operation. It becomes a phase refrigerant (point a → b in FIG. 6). The supercooled liquid phase refrigerant that has flowed out of the supercooling portion 12 c of the radiator 12 flows into the inflow passage 30 a of the circuit switching valve 13.
　低負荷運転時の回路切替弁１３では、弁体部３２が第１冷媒通路３０ｂを閉じるとともに、第２冷媒通路３０ｃを開いているので、流入通路３０ａへ流入した冷媒は第２冷媒通路３０ｃへ流入する。 In the circuit switching valve 13 during low load operation, the valve body 32 closes the first refrigerant passage 30b and opens the second refrigerant passage 30c, so that the refrigerant that has flowed into the inflow passage 30a goes to the second refrigerant passage 30c. Inflow.
　第２冷媒通路３０ｃへ流入した冷媒は、弁体部３２の受圧部３４に設けられたオリフィス孔３４ａにて等エンタルピ的に減圧され（図６のｂ点→ｇ点）、第２冷媒出口３１ｃから流出して、迂回通路２０へ流入する。迂回通路２０へ流入した冷媒は、三方継手１８を介して、蒸発器１９へ流入する。 The refrigerant flowing into the second refrigerant passage 30c is decompressed in an enthalpy manner at an orifice hole 34a provided in the pressure receiving portion 34 of the valve body 32 (point b → point g in FIG. 6), and the second refrigerant outlet 31c. And flows into the bypass path 20. The refrigerant flowing into the bypass passage 20 flows into the evaporator 19 via the three-way joint 18.
　蒸発器１９へ流入した冷媒は、送風ファン１９ａによって送風された送風空気から吸熱して蒸発する（図６のｇ点→ｈ点）。これにより、送風空気が冷却される。蒸発器１９から流出した冷媒は、エジェクタ１５の冷媒吸引口１５ｃへ流入する。 The refrigerant flowing into the evaporator 19 absorbs heat from the blown air blown by the blower fan 19a and evaporates (g point → h point in FIG. 6). Thereby, blowing air is cooled. The refrigerant that has flowed out of the evaporator 19 flows into the refrigerant suction port 15 c of the ejector 15.
　ここで、本実施形態のオリフィス孔３４ａの流量特性は、低負荷運転時となった際に、蒸発器１９から流出した冷媒（すなわち、蒸発器１９出口側冷媒）が飽和気相冷媒あるいは気液二相冷媒となるように設定されている。このため、膨張弁１４は、低負荷運転時になると、絞り通路を閉塞させる。なお、図６では、蒸発器１９出口側冷媒が飽和気相冷媒となっている際のモリエル線図を示している。 Here, the flow rate characteristic of the orifice hole 34a of the present embodiment is that the refrigerant that flows out of the evaporator 19 (that is, the refrigerant on the outlet side of the evaporator 19) is a saturated gas phase refrigerant or gas-liquid when the low load operation is performed. It is set to be a two-phase refrigerant. For this reason, the expansion valve 14 closes the throttle passage during low-load operation. In addition, in FIG. 6, the Mollier diagram in case the evaporator 19 exit side refrigerant | coolant is a saturated gaseous-phase refrigerant | coolant is shown.
　エジェクタ１５の冷媒吸引口１５ｃへ流入した冷媒は、吸引通路およびディフューザ部１５ｄを流通して、アキュムレータ１６へ流入する。アキュムレータ１６にて分離された気相冷媒は、圧縮機１１へ吸入され再び圧縮される（図６のｈ点→ａ点）。 The refrigerant that has flowed into the refrigerant suction port 15c of the ejector 15 flows into the accumulator 16 through the suction passage and the diffuser portion 15d. The gas-phase refrigerant separated by the accumulator 16 is sucked into the compressor 11 and compressed again (point h → point a in FIG. 6).
　低負荷運転時のエジェクタ式冷凍サイクル１０は、以上の如く作動して、車室内へ送風される送風空気を冷却することができる。 The ejector refrigeration cycle 10 during low-load operation operates as described above, and can cool the blown air blown into the passenger compartment.
　さらに、低負荷運転時の冷媒回路に切り替わっている際に、エジェクタ式冷凍サイクル１０の熱負荷が増加すると、制御装置の吐出能力制御部が圧縮機１１の冷媒吐出能力を上昇させる。これにより、圧力差ΔＰが基準圧力差ＫΔＰより大きくなり、回路切替弁１３の弁体部３２が第１冷媒通路３０ｂを開くとともに、第２冷媒通路３０ｃを閉じる。その後の作動は、上述した通常運転時の作動で説明した通りである。 Furthermore, when the heat load of the ejector refrigeration cycle 10 increases while switching to the refrigerant circuit during low-load operation, the discharge capacity control unit of the control device increases the refrigerant discharge capacity of the compressor 11. Thereby, the pressure difference ΔP becomes larger than the reference pressure difference KΔP, and the valve body portion 32 of the circuit switching valve 13 opens the first refrigerant passage 30b and closes the second refrigerant passage 30c. The subsequent operation is as described in the above-described operation during normal operation.
　本実施形態のエジェクタ式冷凍サイクル１０では、回路切替弁１３として、第１冷媒通路３０ｂおよび第２冷媒通路３０ｃのいずれか一方を開いた際に他方を閉じる機械的機構が採用されている。さらに、回路切替弁１３として、前後差圧ΔＰｃが基準前後差圧ＫΔＰｃよりも低くなっている際に第２冷媒通路を開くものが採用されている。 In the ejector refrigeration cycle 10 of the present embodiment, a mechanical mechanism is employed as the circuit switching valve 13 that closes one of the first refrigerant passage 30b and the second refrigerant passage 30c when the other is opened. Further, as the circuit switching valve 13, a valve that opens the second refrigerant passage when the front-rear differential pressure ΔPc is lower than the reference front-rear differential pressure KΔPc is employed.
　従って、通常運転時には、回路切替弁１３が、第１冷媒通路３０ｂ側を開くことによって、放熱器１２にて放熱した冷媒をエジェクタ１５のノズル部１５ａへ流入させることができる。さらに、低負荷運転時には、回路切替弁１３が、第２冷媒通路３０ｃ側を開くことによって、放熱器１２にて放熱した冷媒を迂回通路２０へ流入させて蒸発器１９の冷媒入口側へ導くことができる。 Therefore, during normal operation, the circuit switching valve 13 opens the first refrigerant passage 30b, so that the refrigerant dissipated by the radiator 12 can flow into the nozzle portion 15a of the ejector 15. Further, at the time of low load operation, the circuit switching valve 13 opens the second refrigerant passage 30c side so that the refrigerant radiated by the radiator 12 flows into the bypass passage 20 and is led to the refrigerant inlet side of the evaporator 19. Can do.
　すなわち、本実施形態のエジェクタ式冷凍サイクル１０では、負荷変動に応じて冷媒回路を、機械的に、かつ、確実に切り替えることができる。 That is, in the ejector type refrigeration cycle 10 of the present embodiment, the refrigerant circuit can be switched mechanically and reliably in accordance with the load fluctuation.
　ここで、サイクルの起動時にサイクル内の圧力の均圧化が進行している際には、前後差圧ΔＰｃが基準前後差圧ＫΔＰｃよりも低くなる。 Here, when the pressure equalization of the pressure in the cycle is in progress at the start of the cycle, the front-rear differential pressure ΔPc becomes lower than the reference front-rear differential pressure KΔPc.
　従って、本実施形態のエジェクタ式冷凍サイクル１０によれば、サイクルの起動時には、第２冷媒通路３０ｃが開き、放熱器１２にて放熱した冷媒を、迂回通路２０を介して蒸発器１９へ流入させる、通常の冷凍サイクル（いわゆる、環状サイクル）を形成することができる。従って、サイクルの起動時に、蒸発器１９内に滞留している冷凍機油を圧縮機１１へ戻しやすい。 Therefore, according to the ejector refrigeration cycle 10 of the present embodiment, at the start of the cycle, the second refrigerant passage 30c is opened, and the refrigerant radiated by the radiator 12 is caused to flow into the evaporator 19 via the bypass passage 20. A normal refrigeration cycle (so-called annular cycle) can be formed. Therefore, the refrigerating machine oil staying in the evaporator 19 is easily returned to the compressor 11 at the start of the cycle.
　また、本実施形態では、回路切替弁１３として、圧力差ΔＰが基準圧力差ＫΔＰ以上となっている際に、第１冷媒通路３０ｂを開き、さらに、圧力差ΔＰが基準圧力差ＫΔＰよりも低くなっている際に、第２冷媒通路３０ｃを開くものを採用している。 In the present embodiment, as the circuit switching valve 13, when the pressure difference ΔP is greater than or equal to the reference pressure difference KΔP, the first refrigerant passage 30b is opened, and the pressure difference ΔP is lower than the reference pressure difference KΔP. In this case, the one that opens the second refrigerant passage 30c is employed.
　そして、上記数式Ｆ１～Ｆ３を満足するように、第１受圧面積Ａ１、第２受圧面積Ａ２、およびコイルバネ３３の設定荷重Ｆｓｐ１を設定しているので、圧力差ΔＰが基準圧力差ＫΔＰ以上となった際に、通常運転時の冷媒回路から低負荷運転時の冷媒回路へ、瞬時に切り替えることができる。 Since the first pressure receiving area A1, the second pressure receiving area A2, and the set load Fsp1 of the coil spring 33 are set so as to satisfy the above formulas F1 to F3, the pressure difference ΔP is greater than or equal to the reference pressure difference KΔP. In this case, it is possible to instantaneously switch from the refrigerant circuit during normal operation to the refrigerant circuit during low-load operation.
　さらに、上記数式Ｆ４～Ｆ６を満足するように、第２受圧面積Ａ２、第３受圧面積Ａ３、およびコイルバネ３３の設定荷重Ｆｓｐ２を設定しているので、圧力差ΔＰが基準圧力差ＫΔＰより低くなった際に、低負荷運転時の冷媒回路から通常運転時の冷媒回路へ、瞬時に切り替えることができる。 Further, since the second pressure receiving area A2, the third pressure receiving area A3, and the set load Fsp2 of the coil spring 33 are set so as to satisfy the above formulas F4 to F6, the pressure difference ΔP becomes lower than the reference pressure difference KΔP. In this case, it is possible to instantaneously switch from the refrigerant circuit during low load operation to the refrigerant circuit during normal operation.
　また、本実施形態の回路切替弁１３では、受圧部３４のオリフィス孔３４ａによって、減圧部を構成しているので、容易に減圧部を形成することができる。もちろん、バルブボデー３１に受圧部３４の冷媒流れ上流側と下流側との接続する冷媒通路を形成し、この冷媒通路に減圧部としてのオリフィス、キャピラリチューブ等を配置してもよい。 Further, in the circuit switching valve 13 of the present embodiment, since the pressure reducing portion is configured by the orifice hole 34a of the pressure receiving portion 34, the pressure reducing portion can be easily formed. Of course, a refrigerant passage that connects the upstream and downstream sides of the refrigerant flow of the pressure receiving portion 34 may be formed in the valve body 31, and an orifice, a capillary tube, or the like as a decompression portion may be disposed in the refrigerant passage.
　（第２実施形態）
　本実施形態では、第１実施形態に対して、回路切替弁の構成を変更した例を説明する。具体的には、本実施形態のエジェクタ式冷凍サイクル１０では、図７、図８に示す回路切替弁２４を採用している。 (Second Embodiment)
This embodiment demonstrates the example which changed the structure of the circuit switching valve with respect to 1st Embodiment. Specifically, in the ejector refrigeration cycle 10 of the present embodiment, the circuit switching valve 24 shown in FIGS. 7 and 8 is employed.
　図７は、回路切替弁２４が、放熱器１２から流出した冷媒をエジェクタ１５のノズル部１５ａ側へ流入させる冷媒回路に切り替えている状態を示す模式的な断面図である。図８は、回路切替弁２４が、放熱器１２から流出した冷媒を迂回通路２０側へ流入させる冷媒回路に切り替えている状態を示す模式的な断面図である。 FIG. 7 is a schematic cross-sectional view showing a state in which the circuit switching valve 24 switches to a refrigerant circuit that allows the refrigerant flowing out of the radiator 12 to flow into the nozzle portion 15a side of the ejector 15. FIG. 8 is a schematic cross-sectional view showing a state in which the circuit switching valve 24 is switched to a refrigerant circuit that allows the refrigerant flowing out of the radiator 12 to flow into the bypass path 20 side.
　回路切替弁２４は、バルブボデー４１、第１弁体部４２、第１コイルバネ４３、第１駆動機構４４、第２弁体部４５、第２コイルバネ４６、第２駆動機構４７等を有している。 The circuit switching valve 24 includes a valve body 41, a first valve body portion 42, a first coil spring 43, a first drive mechanism 44, a second valve body portion 45, a second coil spring 46, a second drive mechanism 47, and the like. Yes.
　バルブボデー４１は、図７、図８に示すように、金属製あるいは樹脂製の複数の構成部材を組み合わせることによって、角柱状あるいは円柱状に形成されている。バルブボデー４１は、回路切替弁２４の外殻を形成するとともに、内部に第１弁体部４２、第１コイルバネ４３、第２弁体部４５、第２コイルバネ４６等を収容する。 As shown in FIGS. 7 and 8, the valve body 41 is formed in a prismatic shape or a cylindrical shape by combining a plurality of structural members made of metal or resin. The valve body 41 forms an outer shell of the circuit switching valve 24 and houses the first valve body portion 42, the first coil spring 43, the second valve body portion 45, the second coil spring 46, and the like.
　バルブボデー４１には、第１実施形態で説明した回路切替弁１３と同様の高圧冷媒入口４１ａ、第１冷媒出口４１ｂ、第２冷媒出口４１ｃが形成されている。また、バルブボデー４１の内部には、回路切替弁１３と同様の流入通路４０ａ、第１冷媒通路４０ｂ、第２冷媒通路４０ｃといった複数の冷媒通路が形成されている。 The valve body 41 is formed with a high-pressure refrigerant inlet 41a, a first refrigerant outlet 41b, and a second refrigerant outlet 41c similar to the circuit switching valve 13 described in the first embodiment. In addition, a plurality of refrigerant passages such as an inflow passage 40a, a first refrigerant passage 40b, and a second refrigerant passage 40c similar to the circuit switching valve 13 are formed inside the valve body 41.
　第１弁体部４２は、第１冷媒通路４０ｂを開閉する円柱状の弁体である。第１コイルバネ４３は、第１弁体部４２に対して、第１冷媒通路４０ｂを開く側の荷重をかける第１弾性部材である。第１駆動機構４４は、回路切替弁２４の上流側の冷媒の高圧側圧力ＰＨ（本実施形態では、放熱器１２出口側冷媒の圧力）に応じて第１弁体部４２を変位させるための駆動力を出力する。 The first valve body portion 42 is a cylindrical valve body that opens and closes the first refrigerant passage 40b. The first coil spring 43 is a first elastic member that applies a load on the side that opens the first refrigerant passage 40 b to the first valve body portion 42. The first drive mechanism 44 is for displacing the first valve body 42 according to the high-pressure side pressure PH of the refrigerant upstream of the circuit switching valve 24 (in this embodiment, the pressure of the refrigerant on the outlet side of the radiator 12). Outputs driving force.
　より具体的には、第１駆動機構４４は、図７、図８に示すように、バルブボデー４１の外部に取り付けられている。第１駆動機構４４は、第１ケース４４ａおよび第１ダイヤフラム４４ｂを有している。第１ケース４４ａは、金属製の杯状部材（すなわち、カップ状部材）の開口部側同士を結合させることによって形成された第１空間形成部材である。このため、第１ケース４４ａの内部に空間が形成されている。 More specifically, the first drive mechanism 44 is attached to the outside of the valve body 41 as shown in FIGS. The first drive mechanism 44 has a first case 44a and a first diaphragm 44b. The first case 44a is a first space forming member formed by joining the opening side of metal cup-shaped members (that is, cup-shaped members). For this reason, a space is formed inside the first case 44a.
　第１ケース４４ａの内部には、第１圧力応動部材である第１ダイヤフラム４４ｂが配置されている。第１ダイヤフラム４４ｂは、金属製の円形薄板で形成されている。第１ダイヤフラム４４ｂの外周縁部は全周に亘って、第１ケース４４ａに固定されている。このため、第１ケース４４ａの内部空間は、第１ダイヤフラム４４ｂによって、第１封入空間４４ｃおよび第１導入空間４４ｄの２つの空間に仕切られている。 The 1st diaphragm 44b which is a 1st pressure response member is arrange | positioned inside the 1st case 44a. The first diaphragm 44b is formed of a metal circular thin plate. The outer peripheral edge of the first diaphragm 44b is fixed to the first case 44a over the entire circumference. For this reason, the internal space of the first case 44a is partitioned into two spaces, a first enclosure space 44c and a first introduction space 44d, by the first diaphragm 44b.
　第１封入空間４４ｃには、不活性ガス（本実施形態では、ヘリウムガス）が予め定めた基準封入圧力となるように封入されている。一方、第１導入空間４４ｄは、流入通路４０ａに連通している。このため、第１導入空間４４ｄ内の冷媒圧力は、放熱器１２出口側冷媒の高圧側圧力ＰＨとなる。従って、第１ダイヤフラム４４ｂは、封入空間４４ｃ内の不活性ガスの圧力と高圧側圧力ＰＨとの圧力差に応じて変位する。 In the first enclosure space 44c, an inert gas (in this embodiment, helium gas) is enclosed so as to have a predetermined reference enclosure pressure. On the other hand, the first introduction space 44d communicates with the inflow passage 40a. For this reason, the refrigerant pressure in the first introduction space 44d becomes the high-pressure side pressure PH of the radiator 12 outlet-side refrigerant. Therefore, the first diaphragm 44b is displaced according to the pressure difference between the pressure of the inert gas in the enclosed space 44c and the high-pressure side pressure PH.
　ここで、ボイル・シャルルの法則からも明らかなように、第１封入空間４４ｃ内の不活性ガスは、僅かに温度変化が生じても大きく圧力変化しない。このため、本実施形態の第１封入空間４４ｃ内の圧力は、エジェクタ式冷凍サイクル１０の一般的な使用環境下では、略一定となる。従って、本実施形態の第１ダイヤフラム４４ｂは、実質的に放熱器１２出口側冷媒の高圧側圧力ＰＨに応じて変位する。 Here, as is clear from Boyle-Charles' law, the inert gas in the first enclosed space 44c does not change greatly even if the temperature changes slightly. For this reason, the pressure in the 1st enclosure space 44c of this embodiment becomes substantially constant under the general use environment of the ejector-type refrigeration cycle 10. Accordingly, the first diaphragm 44b of the present embodiment is displaced substantially according to the high pressure side pressure PH of the radiator 12 outlet side refrigerant.
　さらに、第１ダイヤフラム４４ｂの変位は、第１弁体部４２の変位方向に延びる円柱状の第１作動棒４２ａを介して、第１弁体部４２に伝達される。 Furthermore, the displacement of the first diaphragm 44b is transmitted to the first valve body portion 42 via the columnar first operating rod 42a extending in the displacement direction of the first valve body portion 42.
　従って、高圧側圧力ＰＨが上昇して、第１ダイヤフラム４４ｂが第１封入空間４４ｃを縮小させる側へ変位すると、図７に示すように、第１弁体部４２は、第１冷媒通路４０ｂを開く側へ変位する。一方、高圧側圧力ＰＨが低下して、第１ダイヤフラム４４ｂが第１封入空間４４ｃを拡大させる側へ変位すると、図８に示すように、第１弁体部４２は、第１冷媒通路４０ｂを閉じる側へ変位する。 Accordingly, when the high-pressure side pressure PH rises and the first diaphragm 44b is displaced to the side that reduces the first enclosed space 44c, as shown in FIG. 7, the first valve body portion 42 moves through the first refrigerant passage 40b. Displace to open side. On the other hand, when the high pressure side pressure PH decreases and the first diaphragm 44b is displaced to the side that expands the first enclosed space 44c, as shown in FIG. 8, the first valve body portion 42 moves through the first refrigerant passage 40b. Displace to close side.
　そこで、本実施形態では、高圧側圧力ＰＨが予め定めた基準高圧側圧力ＫＰＨ以上となっている際に、第１弁体部４２が第１冷媒通路４０ｂを開くように、第１封入空間４４ｃ内の不活性ガスの基準封入圧力を設定している。 Therefore, in the present embodiment, when the high-pressure side pressure PH is equal to or higher than a predetermined reference high-pressure side pressure KPH, the first enclosed space 44c so that the first valve body portion 42 opens the first refrigerant passage 40b. The reference sealing pressure of the inert gas is set.
　次に、第２弁体部４５は、第２冷媒通路４０ｃを開閉する球状の弁体である。第２コイルバネ４６は、第２弁体部４５に対して、第２冷媒通路４０ｃを閉じる側の荷重をかける第２弾性部材である。第２駆動機構４７は、回路切替弁２４の上流側の冷媒の高圧側圧力ＰＨに応じて第２弁体部４５を変位させるための駆動力を出力する。 Next, the second valve body portion 45 is a spherical valve body that opens and closes the second refrigerant passage 40c. The second coil spring 46 is a second elastic member that applies a load on the side that closes the second refrigerant passage 40 c to the second valve body portion 45. The second drive mechanism 47 outputs a driving force for displacing the second valve body portion 45 according to the high-pressure side pressure PH of the refrigerant upstream of the circuit switching valve 24.
　第２駆動機構４７は、図７、図８に示すように、バルブボデー４１の外部に取り付けられている。第２駆動機構４７の基本的構成は、第１駆動機構４４と同様である。従って、第２駆動機構４７は、第２空間形成部材である第２ケース４７ａ、第２圧力応動部材である第２ダイヤフラム４７ｂを有している。 The second drive mechanism 47 is attached to the outside of the valve body 41 as shown in FIGS. The basic configuration of the second drive mechanism 47 is the same as that of the first drive mechanism 44. Accordingly, the second drive mechanism 47 includes a second case 47a that is a second space forming member and a second diaphragm 47b that is a second pressure responsive member.
　第２ケース４７ａの内部空間は、第２ダイヤフラム４７ｂによって、第２封入空間４７ｃおよび第２導入空間４７ｄの２つの空間に仕切られている。第２ダイヤフラム４７ｂは、第１駆動機構４４の第１ダイヤフラム４４ｂと同様に、実質的に放熱器１２出口側冷媒の高圧側圧力ＰＨに応じて変位する。 The internal space of the second case 47a is divided into two spaces, a second enclosure space 47c and a second introduction space 47d, by a second diaphragm 47b. Similar to the first diaphragm 44b of the first drive mechanism 44, the second diaphragm 47b is displaced substantially according to the high-pressure side pressure PH of the radiator 12 outlet side refrigerant.
　さらに、第２ダイヤフラム４７ｂの変位は、第２弁体部４５の変位方向に延びる円柱状の第２作動棒４５ａを介して、第２弁体部４５に伝達される。 Furthermore, the displacement of the second diaphragm 47 b is transmitted to the second valve body 45 via a cylindrical second operating rod 45 a extending in the displacement direction of the second valve body 45.
　従って、高圧側圧力ＰＨが上昇して、第２ダイヤフラム４７ｂが第２封入空間４７ｃを縮小させる側へ変位すると、図７に示すように、第２弁体部４５は、第２冷媒通路４０ｃを閉じる側へ変位する。一方、高圧側圧力ＰＨが低下して、第２ダイヤフラム４７ｂが第２封入空間４７ｃを拡大させる側へ変位すると、図８に示すように、第２弁体部４５は、第２冷媒通路４０ｃを開く側へ変位する。 Therefore, when the high-pressure side pressure PH rises and the second diaphragm 47b is displaced to the side that reduces the second enclosed space 47c, the second valve body portion 45 moves through the second refrigerant passage 40c as shown in FIG. Displace to close side. On the other hand, when the high pressure side pressure PH decreases and the second diaphragm 47b is displaced to the side that expands the second enclosed space 47c, the second valve body portion 45 moves through the second refrigerant passage 40c as shown in FIG. Displace to open side.
　そこで、本実施形態では、高圧側圧力ＰＨが基準高圧側圧力ＫＰＨ以上となっている際に、第２弁体部４５が第２冷媒通路４０ｃを閉じるように、第２封入空間４７ｃ内の不活性ガスの基準封入圧力を設定している。従って、第１封入空間４４ｃ内の不活性ガスの基準封入圧力と第２封入空間４７ｃ内の不活性ガスの基準封入圧力は同じである。 Therefore, in the present embodiment, when the high-pressure side pressure PH is equal to or higher than the reference high-pressure side pressure KPH, the second valve body portion 45 is closed in the second enclosed space 47c so as to close the second refrigerant passage 40c. The reference sealing pressure of active gas is set. Therefore, the reference sealing pressure of the inert gas in the first sealing space 44c is the same as the reference sealing pressure of the inert gas in the second sealing space 47c.
　これにより、本実施形態の回路切替弁２４では、高圧側圧力ＰＨが基準高圧側圧力ＫＰＨ以上となっている際には、第１冷媒通路４０ｂを開くとともに第２冷媒通路４０ｃを閉じる。一方、高圧側圧力ＰＨが基準高圧側圧力ＫＰＨより低くなっている際には、第１冷媒通路４０ｂを閉じるとともに第２冷媒通路４０ｃを開く。 Thereby, in the circuit switching valve 24 of the present embodiment, when the high pressure side pressure PH is equal to or higher than the reference high pressure side pressure KPH, the first refrigerant passage 40b is opened and the second refrigerant passage 40c is closed. On the other hand, when the high pressure side pressure PH is lower than the reference high pressure side pressure KPH, the first refrigerant passage 40b is closed and the second refrigerant passage 40c is opened.
　さらに、本実施形態では、高圧側圧力ＰＨが基準高圧側圧力ＫＰＨになっている際の圧縮機１１の前後差圧ΔＰｃを、基準前後差圧ＫΔＰｃと定義する。このため、本実施形態の回路切替弁２４では、一般的なサイクルの起動時のように、前後差圧ΔＰｃが基準前後差圧ＫΔＰｃよりも低くなっている際には、第１冷媒通路４０ｂを閉じるとともに、第２冷媒通路４０ｃを開く。 Furthermore, in this embodiment, the front-rear differential pressure ΔPc of the compressor 11 when the high-pressure side pressure PH is the reference high-pressure side pressure KPH is defined as a reference front-rear differential pressure KΔPc. For this reason, in the circuit switching valve 24 of the present embodiment, when the front-rear differential pressure ΔPc is lower than the reference front-rear differential pressure KΔPc, such as when starting a general cycle, the first refrigerant passage 40b is opened. While closing, the second refrigerant passage 40c is opened.
　また、本実施形態のエジェクタ式冷凍サイクル１０では、迂回通路２０に蒸発器１９へ流入する冷媒を減圧させる減圧部としての固定絞りが配置されている。この固定絞りとしては、オリフィス、キャピラリチューブ等を採用することができる。 Further, in the ejector refrigeration cycle 10 of the present embodiment, a fixed throttle is disposed as a decompression unit that decompresses the refrigerant flowing into the evaporator 19 in the bypass passage 20. As this fixed throttle, an orifice, a capillary tube or the like can be employed.
　その他のエジェクタ式冷凍サイクル１０の構成および作動は、第１実施形態と同様である。従って、本実施形態のエジェクタ式冷凍サイクル１０においても、第１実施形態と同様の効果を得ることができる。 Other configurations and operations of the ejector refrigeration cycle 10 are the same as those in the first embodiment. Therefore, also in the ejector type refrigeration cycle 10 of the present embodiment, the same effect as that of the first embodiment can be obtained.
　すなわち、本実施形態では、回路切替弁２４として、第１、第２駆動機構４４、４７を備えるものを採用している。このように封入空間内の気体圧力と導入空間内の冷媒圧力との圧力差によって、圧力応動部材（ダイヤフラム）を変位させる駆動機構では、導入空間内の圧力（本実施形態では、高圧側圧力ＰＨ）が急変動しても、封入空間がダンパーとして機能する。このため、圧力応動部材（ダイヤフラム）の急変位が抑制される。 That is, in the present embodiment, the circuit switching valve 24 having the first and second drive mechanisms 44 and 47 is employed. Thus, in the drive mechanism that displaces the pressure responsive member (diaphragm) by the pressure difference between the gas pressure in the enclosed space and the refrigerant pressure in the introduction space, the pressure in the introduction space (in this embodiment, the high pressure side pressure PH). ) Suddenly fluctuates, the enclosed space functions as a damper. For this reason, sudden displacement of the pressure responsive member (diaphragm) is suppressed.
　従って、通常運転時の冷媒回路と低負荷運転時の冷媒回路とを切り替える際の第１、第２弁体部４２、４５の振動やハンチング現象を抑制することができる。その結果、本実施形態のエジェクタ式冷凍サイクル１０においても、負荷変動に応じて冷媒回路を、機械的に、かつ、確実に切り替えることができる。 Therefore, vibration and hunting phenomenon of the first and second valve body portions 42 and 45 when switching between the refrigerant circuit during normal operation and the refrigerant circuit during low-load operation can be suppressed. As a result, also in the ejector refrigeration cycle 10 of the present embodiment, the refrigerant circuit can be switched mechanically and reliably according to the load fluctuation.
　（第３実施形態）
　本実施形態では、第２実施形態に対して、図９に示すように、回路切替弁２４の構成を変更した例を説明する。 (Third embodiment)
This embodiment demonstrates the example which changed the structure of the circuit switching valve 24 with respect to 2nd Embodiment, as shown in FIG.
　より具体的には、本実施形態の第１弁体部４２には、流入通路４０ａと第１冷媒通路４０ｂとを連通させる第１パイロット孔４２ｂが形成されている。また、第１作動棒４２ａは、第１ダイヤフラム４４ｂの変位に応じて、第１パイロット孔４２ｂを開閉するように配置されている。さらに、バルブボデー４１には、流入通路４０ａと第１冷媒通路４０ｂとを連通させるための連通路４１ｄが形成されている。その他の回路切替弁２４の構成は、第２実施形態と同様である。 More specifically, the first valve body portion 42 of the present embodiment is formed with a first pilot hole 42b that allows the inflow passage 40a and the first refrigerant passage 40b to communicate with each other. The first operating rod 42a is arranged to open and close the first pilot hole 42b according to the displacement of the first diaphragm 44b. Further, the valve body 41 is formed with a communication passage 41d for communicating the inflow passage 40a and the first refrigerant passage 40b. Other configurations of the circuit switching valve 24 are the same as those of the second embodiment.
　次に、本実施形態の回路切替弁２４の作動について説明する。まず、高圧側圧力ＰＨが上昇すると第１ダイヤフラム４４ｂが第１封入空間４４ｃを縮小させる側に変位する。そして、高圧側圧力ＰＨが基準高圧側圧力ＫＰＨ以上になると、第１ダイヤフラム４４ｂに連結された第１作動棒４２ａが第１パイロット孔４２ｂを開く。 Next, the operation of the circuit switching valve 24 of this embodiment will be described. First, when the high-pressure side pressure PH increases, the first diaphragm 44b is displaced to the side that reduces the first enclosed space 44c. When the high pressure side pressure PH becomes equal to or higher than the reference high pressure side pressure KPH, the first operating rod 42a connected to the first diaphragm 44b opens the first pilot hole 42b.
　これにより、連通路４１ｄおよび第１パイロット孔４２ｂを介して、第１弁体部４２の下流側に放熱器１２から流出した冷媒が流れ込む。第１弁体部４２の冷媒流れ上流側の冷媒圧力と下流側の冷媒圧力との圧力差が縮小し、第１コイルバネ４３の荷重によって、第１弁体部４２が第１冷媒通路４０ｂを開く。 Thereby, the refrigerant flowing out of the radiator 12 flows into the downstream side of the first valve body portion 42 through the communication passage 41d and the first pilot hole 42b. The pressure difference between the refrigerant pressure upstream of the refrigerant flow of the first valve body portion 42 and the refrigerant pressure of the downstream side is reduced, and the first valve body portion 42 opens the first refrigerant passage 40b by the load of the first coil spring 43. .
　一方、高圧側圧力ＰＨが上昇すると第１ダイヤフラム４４ｂが第１封入空間４４ｃを拡大させる側に変位して、第１作動棒４２ａが第１弁体部４２の第１パイロット孔４２ｂを閉じる。そして、高圧側圧力ＰＨが基準高圧側圧力ＫＰＨ以上になると、第１作動棒４２ａとともに第１弁体部４２が変位して第１冷媒通路４０ｂを閉じる。 On the other hand, when the high-pressure side pressure PH rises, the first diaphragm 44b is displaced to the side that expands the first enclosed space 44c, and the first operating rod 42a closes the first pilot hole 42b of the first valve body portion 42. When the high pressure side pressure PH becomes equal to or higher than the reference high pressure side pressure KPH, the first valve body 42 is displaced together with the first operating rod 42a to close the first refrigerant passage 40b.
　その他の回路切替弁２４の作動は、第２実施形態と同様である。本実施形態の回路切替弁２４においても、高圧側圧力ＰＨが基準高圧側圧力ＫＰＨ以上となっている際には、第１冷媒通路４０ｂを開くとともに第２冷媒通路４０ｃを閉じる。一方、高圧側圧力ＰＨが基準高圧側圧力ＫＰＨより低くなっている際には、第１冷媒通路４０ｂを閉じるとともに第２冷媒通路４０ｃを開く。 Other operations of the circuit switching valve 24 are the same as in the second embodiment. Also in the circuit switching valve 24 of this embodiment, when the high pressure side pressure PH is equal to or higher than the reference high pressure side pressure KPH, the first refrigerant passage 40b is opened and the second refrigerant passage 40c is closed. On the other hand, when the high pressure side pressure PH is lower than the reference high pressure side pressure KPH, the first refrigerant passage 40b is closed and the second refrigerant passage 40c is opened.
　従って、本実施形態のエジェクタ式冷凍サイクル１０においても、第２実施形態と同様の効果を得ることができる。 Therefore, also in the ejector type refrigeration cycle 10 of this embodiment, the same effect as that of the second embodiment can be obtained.
　さらに、本実施形態の回路切替弁２４では、低負荷運転時に、第１弁体部４２の冷媒流れ上流側の冷媒圧力と下流側の冷媒圧力との圧力差が大きくなっていても、第１パイロット孔４２ｂを開閉することで、第１弁体部４２を開くことができる。従って、比較的小さな駆動力で第１弁体部４２を開くことができ、第１駆動機構４４の大型化を抑制することができる。 Furthermore, in the circuit switching valve 24 of the present embodiment, even when the pressure difference between the refrigerant pressure upstream of the refrigerant flow in the first valve body 42 and the refrigerant pressure downstream is large during low load operation, The first valve body 42 can be opened by opening and closing the pilot hole 42b. Accordingly, the first valve body portion 42 can be opened with a relatively small driving force, and an increase in the size of the first drive mechanism 44 can be suppressed.
　なお、本実施形態では、第１弁体部４２に第１パイロット孔４２ｂを形成した例を説明したが、もちろん、第２弁体部４５が、流入通路４０ａと第２冷媒通路４０ｃとを連通させる第２パイロット孔４５ｂを有し、第２駆動機構４７の第２ダイヤフラム４７ｂが第２パイロット孔４５ｂを開閉する第２作動棒４５ａに連結されていてもよい。 In the present embodiment, an example in which the first pilot hole 42b is formed in the first valve body portion 42 has been described. Of course, the second valve body portion 45 communicates the inflow passage 40a and the second refrigerant passage 40c. The second pilot hole 45b may be provided, and the second diaphragm 47b of the second drive mechanism 47 may be connected to a second operating rod 45a that opens and closes the second pilot hole 45b.
　（第４実施形態）
　本実施形態では、第２実施形態に対して、図１０に示すように、回路切替弁２４の構成を変更した例を説明する。より具体的には、本実施形態の回路切替弁２４は、第１封入空間４４ｃと第２封入空間４７ｃとを連通させる封入空間連通路４１ｅを有している。その他の回路切替弁２４およびエジェクタ式冷凍サイクル１０の構成および作動は、第２実施形態と同様である。 (Fourth embodiment)
This embodiment demonstrates the example which changed the structure of the circuit switching valve 24 with respect to 2nd Embodiment, as shown in FIG. More specifically, the circuit switching valve 24 of the present embodiment has a sealed space communication path 41e that allows the first sealed space 44c and the second sealed space 47c to communicate with each other. Other configurations and operations of the circuit switching valve 24 and the ejector refrigeration cycle 10 are the same as those in the second embodiment.
　これによれば、第１封入空間４４ｃ内の不活性ガスの圧力と第２封入空間４７ｃ内の不活性ガスの圧力を一致させることができるので、第１弁体部４２および第２弁体部４５を確実に連動させることができる。従って、本実施形態のエジェクタ式冷凍サイクル１０よれば、より一層、確実に負荷変動に応じて冷媒回路を切り替えることができる。 According to this, the pressure of the inert gas in the first sealed space 44c and the pressure of the inert gas in the second sealed space 47c can be matched, so the first valve body portion 42 and the second valve body portion. 45 can be reliably interlocked. Therefore, according to the ejector refrigeration cycle 10 of the present embodiment, the refrigerant circuit can be switched more reliably in accordance with the load fluctuation.
　（第５実施形態）
　本実施形態では、第２実施形態に対して、回路切替弁の構成を変更した例を説明する。具体的には、本実施形態のエジェクタ式冷凍サイクル１０では、図１１、図１２に示す回路切替弁２５を採用している。 (Fifth embodiment)
This embodiment demonstrates the example which changed the structure of the circuit switching valve with respect to 2nd Embodiment. Specifically, in the ejector type refrigeration cycle 10 of the present embodiment, the circuit switching valve 25 shown in FIGS. 11 and 12 is employed.
　図１１は、回路切替弁２５が、放熱器１２から流出した冷媒をエジェクタ１５のノズル部１５ａ側へ流入させる冷媒回路に切り替えている状態を示す模式的な断面図である。図１２は、回路切替弁２５が、放熱器１２から流出した冷媒を迂回通路２０側へ流入させる冷媒回路に切り替えている状態を示す模式的な断面図である。 FIG. 11 is a schematic cross-sectional view showing a state in which the circuit switching valve 25 switches to a refrigerant circuit that allows the refrigerant flowing out of the radiator 12 to flow into the nozzle portion 15a side of the ejector 15. FIG. 12 is a schematic cross-sectional view showing a state where the circuit switching valve 25 is switched to a refrigerant circuit that allows the refrigerant flowing out of the radiator 12 to flow into the bypass passage 20 side.
　回路切替弁２５は、バルブボデー５１、第１弁体部５２、第１コイルバネ５３、第２弁体部５５、第２コイルバネ５６、共用駆動機構５７、共用作動棒５８等を有している。 The circuit switching valve 25 includes a valve body 51, a first valve body 52, a first coil spring 53, a second valve body 55, a second coil spring 56, a common drive mechanism 57, a common operation rod 58, and the like.
　バルブボデー５１は、図１１、図１２に示すように、金属製あるいは樹脂製の複数の構成部材を組み合わせることによって、角柱状あるいは円柱状に形成されている。バルブボデー５１は、回路切替弁２４の外殻を形成するとともに、内部に第１弁体部５２、第１コイルバネ５３、第２弁体部５５、第２コイルバネ５６、共用作動棒５８等を収容する。 As shown in FIGS. 11 and 12, the valve body 51 is formed in a prismatic shape or a cylindrical shape by combining a plurality of structural members made of metal or resin. The valve body 51 forms an outer shell of the circuit switching valve 24 and accommodates a first valve body 52, a first coil spring 53, a second valve body 55, a second coil spring 56, a common operating rod 58, and the like. To do.
　バルブボデー５１には、第１実施形態で説明した回路切替弁１３と同様の高圧冷媒入口５１ａ、第１冷媒出口５１ｂ、第２冷媒出口５１ｃが形成されている。また、バルブボデー５１の内部には、回路切替弁１３と同様の流入通路５０ａ、第１冷媒通路５０ｂ、第２冷媒通路５０ｃといった複数の冷媒通路が形成されている。 The valve body 51 is formed with a high-pressure refrigerant inlet 51a, a first refrigerant outlet 51b, and a second refrigerant outlet 51c similar to the circuit switching valve 13 described in the first embodiment. In addition, a plurality of refrigerant passages such as an inflow passage 50a, a first refrigerant passage 50b, and a second refrigerant passage 50c similar to the circuit switching valve 13 are formed inside the valve body 51.
　第１弁体部５２は、第１冷媒通路５０ｂの入口部を開閉する円柱状の弁体である。第１コイルバネ５３は、第１弁体部５２に対して、第１冷媒通路５０ｂを閉じる側の荷重をかける第１弾性部材である。第１弁体部５２の中心部には、軸方向に貫通する貫通穴が形成されている。この貫通穴の内部には、共用作動棒５８が配置されている。 The first valve body 52 is a cylindrical valve body that opens and closes the inlet of the first refrigerant passage 50b. The first coil spring 53 is a first elastic member that applies a load that closes the first refrigerant passage 50 b to the first valve body 52. A through hole penetrating in the axial direction is formed at the center of the first valve body 52. A common operating rod 58 is disposed inside the through hole.
　第２弁体部５５は、第２冷媒通路５０ｃの入口部を開閉する球状の弁体である。第２コイルバネ５６は、第２弁体部５５に対して、第２冷媒通路５０ｃを閉じる側の荷重をかける第２弾性部材である。 The second valve body portion 55 is a spherical valve body that opens and closes the inlet portion of the second refrigerant passage 50c. The second coil spring 56 is a second elastic member that applies a load on the side that closes the second refrigerant passage 50 c to the second valve body portion 55.
　共用駆動機構５７は、第１弁体部５２および第２弁体部５５の双方を変位させるための駆動力を出力するものである。共用駆動機構５７は、図１１、図１２に示すように、バルブボデー５１の外部に取り付けられている。共用駆動機構５７の基本的構成は、第２実施形態で説明した第１、第２駆動機構４４、４７と同様である。 The common drive mechanism 57 outputs a driving force for displacing both the first valve body portion 52 and the second valve body portion 55. The common drive mechanism 57 is attached to the outside of the valve body 51 as shown in FIGS. The basic configuration of the shared drive mechanism 57 is the same as that of the first and second drive mechanisms 44 and 47 described in the second embodiment.
　従って、共用駆動機構５７は、共用空間形成部材である共用ケース５７ａ、共用圧力応動部材である共用ダイヤフラム５７ｂを有している。共用ケース５７ａの内部空間は、共用ダイヤフラム５７ｂによって、共用封入空間５７ｃおよび共用導入空間５７ｄの２つの空間に仕切られている。共用ダイヤフラム５７ｂは、実質的に放熱器１２出口側冷媒の高圧側圧力ＰＨに応じて変位する。 Therefore, the common drive mechanism 57 has a common case 57a that is a common space forming member and a common diaphragm 57b that is a common pressure response member. The internal space of the shared case 57a is divided into two spaces, a shared enclosed space 57c and a shared introduction space 57d, by a shared diaphragm 57b. The common diaphragm 57b is displaced substantially according to the high pressure side pressure PH of the radiator 12 outlet side refrigerant.
　さらに、共用ダイヤフラム５７ｂの変位は、第１弁体部５２および第２弁体部５５の変位方向に延びる円柱状の共用作動棒５８を介して、第１弁体部５２および第２弁体部５５の双方へ伝達される。 Further, the displacement of the common diaphragm 57b is caused by the first valve body 52 and the second valve body through the cylindrical common operating rod 58 extending in the displacement direction of the first valve body 52 and the second valve body 55. 55 is transmitted to both.
　具体的には、高圧側圧力ＰＨが上昇して、共用ダイヤフラム５７ｂが共用封入空間５７ｃを縮小させる側へ変位すると、共用作動棒５８も共用ダイヤフラム５７ｂと同じ側へ変位する。これにより、図１１に示すように、第１弁体部５２は、共用作動棒５８の外表面に形成された突起部５８ａと係合して第１冷媒通路５０ｂを開く側へ変位する。一方、第２弁体部５５は、第２コイルバネ５６の荷重によって、第２冷媒通路５０ｃを閉じる側へ変位する。 Specifically, when the high-pressure side pressure PH rises and the common diaphragm 57b is displaced to the side that reduces the common enclosed space 57c, the common operation rod 58 is also displaced to the same side as the common diaphragm 57b. As a result, as shown in FIG. 11, the first valve body 52 is engaged with the protrusion 58a formed on the outer surface of the common operation rod 58 and displaced to the side where the first refrigerant passage 50b is opened. On the other hand, the second valve body portion 55 is displaced toward the side of closing the second refrigerant passage 50 c by the load of the second coil spring 56.
　また、高圧側圧力ＰＨが低下して、共用ダイヤフラム５７ｂが共用封入空間５７ｃを拡大させる側へ変位すると、共用作動棒５８も共用ダイヤフラム５７ｂと同じ側へ変位する。これにより、図１２に示すように、第１弁体部５２は、第１コイルバネ５３の荷重によって、第１冷媒通路５０ｂを閉じる側へ変位する。一方、第２弁体部５５は、共用作動棒５８とともに、第２冷媒通路５０ｃを開く側へ変位する。 Further, when the high pressure side pressure PH is reduced and the common diaphragm 57b is displaced to the side that expands the common enclosed space 57c, the common operation rod 58 is also displaced to the same side as the common diaphragm 57b. Thereby, as shown in FIG. 12, the 1st valve body part 52 is displaced to the side which closes the 1st refrigerant path 50b with the load of the 1st coil spring 53. As shown in FIG. On the other hand, the 2nd valve body part 55 is displaced to the side which opens the 2nd refrigerant path 50c with the common action | operation stick | rod 58. FIG.
　そこで、本実施形態では、高圧側圧力ＰＨが予め定めた基準高圧側圧力ＫＰＨ以上となっている際には、第１冷媒通路５０ｂを開くとともに第２冷媒通路５０ｃを閉じ、高圧側圧力ＰＨが基準高圧側圧力ＫＰＨより低くなっている際には、第１冷媒通路５０ｂを閉じるとともに第２冷媒通路５０ｃを開くように、共用封入空間５７ｃ内の不活性ガスの基準封入圧力を設定している。 Therefore, in the present embodiment, when the high-pressure side pressure PH is equal to or higher than a predetermined reference high-pressure side pressure KPH, the first refrigerant passage 50b is opened and the second refrigerant passage 50c is closed, so that the high-pressure side pressure PH is When the pressure is lower than the reference high pressure side pressure KPH, the reference sealing pressure of the inert gas in the shared sealing space 57c is set so that the first refrigerant passage 50b is closed and the second refrigerant passage 50c is opened. .
　その他のエジェクタ式冷凍サイクル１０の構成および作動は、第２実施形態と同様である。従って、本実施形態のエジェクタ式冷凍サイクル１０においても、第２実施形態と同様の効果を得ることができる。さらに、本実施形態の回路切替弁２５によれば、第１弁体部５２および第２弁体部５５を変位させる駆動機構および作動棒を共通のものとすることができるので、回路切替弁２５の小型化や低コスト化を図ることができる。 Other configurations and operations of the ejector refrigeration cycle 10 are the same as those in the second embodiment. Therefore, also in the ejector type refrigeration cycle 10 of the present embodiment, the same effect as that of the second embodiment can be obtained. Furthermore, according to the circuit switching valve 25 of the present embodiment, since the drive mechanism and the operating rod for displacing the first valve body portion 52 and the second valve body portion 55 can be made common, the circuit switching valve 25 Can be reduced in size and cost.
　（他の実施形態）
　本開示は上述の実施形態に限定されることなく、趣旨を逸脱しない範囲内で、以下のように種々変形可能である。 (Other embodiments)
The present disclosure is not limited to the above-described embodiment, and can be variously modified as follows without departing from the spirit of the present disclosure.
　（１）エジェクタ式冷凍サイクルのサイクル構成は、上述の実施形態に開示された構成に限定されない。例えば、エジェクタ１５のディフューザ部１５ｄの冷媒出口とアキュムレータ１６の入口との間に、冷媒を蒸発させる補助蒸発器を配置してもよい。 (1) The cycle configuration of the ejector refrigeration cycle is not limited to the configuration disclosed in the above-described embodiment. For example, an auxiliary evaporator that evaporates the refrigerant may be disposed between the refrigerant outlet of the diffuser portion 15 d of the ejector 15 and the inlet of the accumulator 16.
　これによれば、通常運転時には、エジェクタ１５の昇圧作用によって、補助蒸発器における冷媒蒸発圧力（冷媒蒸発温度）を蒸発器１９における冷媒蒸発圧力（冷媒蒸発温度）よりも上昇させることができる。従って、双方の蒸発器において、異なる温度帯で冷媒を蒸発させることができる。さらに、低負荷運転時にも、蒸発器１９および補助蒸発器を直列的に接続して、双方の蒸発器にて、冷凍能力を発揮することができる。 According to this, during normal operation, the refrigerant evaporating pressure (refrigerant evaporating temperature) in the auxiliary evaporator can be made higher than the refrigerant evaporating pressure (refrigerant evaporating temperature) in the evaporator 19 by the boosting action of the ejector 15. Therefore, in both evaporators, the refrigerant can be evaporated at different temperature zones. Furthermore, even during low-load operation, the evaporator 19 and the auxiliary evaporator can be connected in series, and the refrigeration capacity can be exhibited in both evaporators.
　また、エジェクタ式冷凍サイクル１０に、放熱器１２から流出した高圧冷媒と、蒸発器１９から流出した低圧冷媒あるいは圧縮機１１へ吸入させる吸入冷媒とを熱交換させる内部熱交換器を追加してもよい。 Further, an internal heat exchanger for exchanging heat between the high-pressure refrigerant flowing out from the radiator 12 and the low-pressure refrigerant flowing out from the evaporator 19 or the suction refrigerant sucked into the compressor 11 may be added to the ejector refrigeration cycle 10. Good.
　（２）エジェクタ式冷凍サイクル１０を構成する各構成機器は、上述の実施形態に開示されたものに限定されない。 (2) Each component device constituting the ejector refrigeration cycle 10 is not limited to that disclosed in the above-described embodiment.
　例えば、上述の実施形態では、圧縮機１１として、エンジン駆動式の可変容量型圧縮機を採用した例を説明したが、圧縮機１１として、電磁クラッチの断続により圧縮機の稼働率を変化させて冷媒吐出能力を調整する固定容量型圧縮機を採用してもよい。さらに、固定容量型圧縮機構と電動モータとを備え、電力を供給されることによって作動する電動圧縮機を採用してもよい。電動圧縮機では、電動モータの回転数を調整することによって、冷媒吐出能力を制御することができる。 For example, in the above-described embodiment, an example in which an engine-driven variable displacement compressor is employed as the compressor 11 has been described. However, as the compressor 11, the operating rate of the compressor is changed by the on / off of an electromagnetic clutch. You may employ | adopt the fixed capacity type compressor which adjusts a refrigerant | coolant discharge capability. Furthermore, you may employ | adopt an electric compressor provided with a fixed displacement type compression mechanism and an electric motor, and act | operating by supplying electric power. In the electric compressor, the refrigerant discharge capacity can be controlled by adjusting the rotation speed of the electric motor.
　また、上述の実施形態では、放熱器１２として、サブクール型の熱交換器を採用した例を説明したが、凝縮部１２ａのみからなる通常の放熱器を採用してもよい。さらに、通常の放熱器とともに、この放熱器にて放熱した冷媒の気液を分離して余剰液相冷媒を蓄える受液器（レシーバ）を一体化させたレシーバ一体型の凝縮器を採用してもよい。 In the above-described embodiment, an example in which a subcool type heat exchanger is employed as the radiator 12 has been described, but a normal radiator including only the condensing unit 12a may be employed. In addition to a normal radiator, a receiver-integrated condenser that integrates a receiver (receiver) that separates the gas-liquid of the refrigerant radiated by this radiator and stores excess liquid phase refrigerant is adopted. Also good.
　また、上述の実施形態では、膨張弁１４を採用したが、膨張弁１４はエジェクタ式冷凍サイクルにおいて、必須の構成ではない。さらに、膨張弁１４を採用する場合には、膨張弁１４、エジェクタ１５、アキュムレータ１６等を一体的に構成してもよい。例えば、エジェクタ１５のノズル部１５ａの内部にニードル状あるいは円錐状の弁体部を配置し、この弁体部を蒸発器１９出口側冷媒の過熱度ＳＨが基準過熱度ＫＳＨに近づくように変位させることで、膨張弁１４とエジェクタ１５とを一体化させてもよい。 In the above-described embodiment, the expansion valve 14 is adopted. However, the expansion valve 14 is not an essential component in the ejector refrigeration cycle. Further, when the expansion valve 14 is employed, the expansion valve 14, the ejector 15, the accumulator 16, and the like may be integrally configured. For example, a needle-shaped or conical valve body portion is disposed inside the nozzle portion 15a of the ejector 15, and the valve body portion is displaced so that the superheat degree SH of the evaporator 19 outlet side refrigerant approaches the reference superheat degree KSH. Thus, the expansion valve 14 and the ejector 15 may be integrated.
　また、上述の実施形態では、冷媒としてＲ１３４ａを採用した例を説明したが、冷媒はこれに限定されない。例えば、ＨＦＯ系冷媒（Ｒ１２３４ｙｆ、ＨＦＯ－１２３４ｚｅ、ＨＦＯ－１２３４ｚｄ）、Ｒ６００ａ、Ｒ４１０Ａ、Ｒ４０４Ａ、Ｒ３２、Ｒ４０７Ｃ、等を採用することができる。または、これらの冷媒のうち複数種を混合させた混合冷媒等を採用してもよい。さらに、冷媒として二酸化炭素を採用して、高圧側冷媒圧力が冷媒の臨界圧力以上となる超臨界冷凍サイクルを構成してもよい。 In the above-described embodiment, the example in which R134a is adopted as the refrigerant has been described, but the refrigerant is not limited to this. For example, HFO refrigerants (R1234yf, HFO-1234ze, HFO-1234zd), R600a, R410A, R404A, R32, R407C, etc. can be employed. Or you may employ | adopt the mixed refrigerant | coolant etc. which mixed multiple types among these refrigerant | coolants. Furthermore, a supercritical refrigeration cycle in which carbon dioxide is employed as the refrigerant and the high-pressure side refrigerant pressure is equal to or higher than the critical pressure of the refrigerant may be configured.
　（３）上述の実施形態では、エジェクタ式冷凍サイクル１０を、車両用空調装置に適用した例を説明したが、エジェクタ式冷凍サイクル１０の適用はこれに限定されない。例えば、据置型空調装置、冷温保存庫、自動販売機用冷却加熱装置等に適用してもよい。 (3) In the above-described embodiment, the example in which the ejector refrigeration cycle 10 is applied to a vehicle air conditioner has been described. However, the application of the ejector refrigeration cycle 10 is not limited thereto. For example, the present invention may be applied to a stationary air conditioner, a cold / hot storage, a cooling / heating device for a vending machine, and the like.
　また、上述の実施形態では、エジェクタ１５を備えるエジェクタ式冷凍サイクル１０の放熱器１２を冷媒と外気とを熱交換させる室外側熱交換器とし、蒸発器１９を送風空気を冷却する利用側熱交換器としている。これに対して、蒸発器１９を外気等の熱源から吸熱する室外側熱交換器として用い、放熱器１２を空気あるいは水等の被加熱流体を加熱する利用側熱交換器として用いてもよい。

  Further, in the above-described embodiment, the radiator 12 of the ejector-type refrigeration cycle 10 including the ejector 15 is an outdoor heat exchanger that exchanges heat between the refrigerant and the outside air, and the evaporator 19 is used side heat exchange that cools the blown air. It is a vessel. On the other hand, the evaporator 19 may be used as an outdoor heat exchanger that absorbs heat from a heat source such as outside air, and the radiator 12 may be used as a use side heat exchanger that heats a heated fluid such as air or water.

Claims (12)

  1. 　冷媒を圧縮して吐出する圧縮機（１１）と、
    　前記圧縮機から吐出された冷媒を放熱させる放熱器（１２）と、
    　前記放熱器から流出した冷媒を減圧させるノズル部（１５ａ）から噴射された噴射冷媒の吸引作用によって冷媒吸引口（１５ｃ）から冷媒を吸引し、前記噴射冷媒と前記冷媒吸引口から吸引された吸引冷媒とを混合させて昇圧させる昇圧部（１５ｄ）を有するエジェクタ（１５）と、
    　冷媒を蒸発させて前記冷媒吸引口側へ流出させる蒸発器（１９）と、
    　前記放熱器にて放熱した冷媒を、前記ノズル部を迂回させて前記蒸発器の冷媒出口よりも上流側へ導く迂回通路（２０）と、
    　前記迂回通路を介して前記蒸発器へ流入する冷媒を減圧させる減圧部（３４ａ）と、
    　前記放熱器にて放熱した冷媒を前記ノズル部側へ導く第１冷媒通路（３０ｂ、４０ｂ、５０ｂ）を開閉するとともに、前記放熱器にて放熱した冷媒を前記迂回通路側へ導く第２冷媒通路（３０ｃ、４０ｃ、５０ｃ）を開閉する回路切替弁（１３、２４、２５）と、を備え、
    　前記回路切替弁は、前記第１冷媒通路および前記第２冷媒通路のいずれか一方を開いた際に他方を閉じる機械的機構で構成されており、
    　前記回路切替弁は、前記圧縮機の吐出口側の冷媒圧力から吸入口側の冷媒圧力を減算した前後差圧（ΔＰｃ）が予め定めた基準前後差圧（ＫΔＰｃ）よりも低くなっている際には、前記第２冷媒通路を開くエジェクタ式冷凍サイクル。     A compressor (11) for compressing and discharging the refrigerant;
    A radiator (12) for dissipating heat from the refrigerant discharged from the compressor;
    The refrigerant sucked from the refrigerant suction port (15c) by the suction action of the jetted refrigerant jetted from the nozzle part (15a) for depressurizing the refrigerant flowing out of the radiator, and sucked from the jetted refrigerant and the refrigerant suction port An ejector (15) having a boosting section (15d) for mixing and increasing the pressure of the refrigerant;
    An evaporator (19) for evaporating the refrigerant to flow out to the refrigerant suction port side;
    A bypass passage (20) for guiding the refrigerant radiated by the radiator to the upstream side of the refrigerant outlet of the evaporator by bypassing the nozzle portion;
    A decompression section (34a) for decompressing the refrigerant flowing into the evaporator via the bypass passage;
    The second refrigerant passage that opens and closes the first refrigerant passages (30b, 40b, 50b) for guiding the refrigerant radiated by the radiator to the nozzle portion side and guides the refrigerant radiated by the radiator to the bypass passage side. Circuit switching valves (13, 24, 25) for opening and closing (30c, 40c, 50c),
    The circuit switching valve is configured by a mechanical mechanism that closes one of the first refrigerant passage and the second refrigerant passage when the other opens.
    In the circuit switching valve, when the front-rear differential pressure (ΔPc) obtained by subtracting the refrigerant pressure on the suction port side from the refrigerant pressure on the discharge port side of the compressor is lower than a predetermined reference front-rear differential pressure (KΔPc). The ejector-type refrigeration cycle that opens the second refrigerant passage.
  2. 　前記回路切替弁（１３）は、前記回路切替弁の上流側の冷媒の高圧側圧力（ＰＨ）から前記減圧部の下流側の冷媒の低圧側圧力（ＰＬ）を減算した圧力差（ΔＰ）が予め定めた基準圧力差（ＫΔＰ）以上となっている際には、前記第１冷媒通路を開くとともに前記第２冷媒通路を閉じ、
    　前記回路切替弁（１３）は、前記圧力差（ΔＰ）が前記基準圧力差（ＫΔＰ）よりも低くなっている際には、前記第１冷媒通路を閉じるとともに前記第２冷媒通路を開く請求項１に記載のエジェクタ式冷凍サイクル。     The circuit switching valve (13) has a pressure difference (ΔP) obtained by subtracting the low pressure side pressure (PL) of the refrigerant on the downstream side of the decompression section from the high pressure side pressure (PH) of the refrigerant on the upstream side of the circuit switching valve. When the pressure difference is equal to or greater than a predetermined reference pressure difference (KΔP), the first refrigerant passage is opened and the second refrigerant passage is closed,
    The circuit switching valve (13) closes the first refrigerant passage and opens the second refrigerant passage when the pressure difference (ΔP) is lower than the reference pressure difference (KΔP). 2. The ejector refrigeration cycle according to 1.
  3. 　前記回路切替弁（１３）は、前記第１冷媒通路（３０ｂ）および前記第２冷媒通路（３０ｃ）が形成されたボデー（３１）、前記第１冷媒通路および前記第２冷媒通路を開閉する弁体部（３２）、前記弁体部に連結されて前記弁体部よりも冷媒流れ下流側に配置される受圧部（３４）、および前記弁体部に対して荷重をかける弾性部材（３３）を有し、
    　前記受圧部には、前記減圧部の入口側冷媒の入口側圧力（Ｐｒｉ）と前記減圧部の出口側冷媒の出口側圧力（Ｐｒｏ）との差圧が作用しており、
    　前記弾性部材は、前記弁体部に対して前記弁体部が前記第１冷媒通路を閉じるとともに前記第２冷媒通路を開く側に荷重をかけるものであり、
    　前記弁体部が前記第２冷媒通路を閉じた際に、前記弁体部のうち前記高圧側圧力（ＰＨ）と前記減圧部の入口側冷媒の入口側圧力（Ｐｒｉ）との差圧が作用する面積である第１受圧面積をＡ１と定義し、
    　前記受圧部のうち前記入口側圧力（Ｐｒｉ）と前記減圧部の出口側冷媒の出口側圧力（Ｐｒｏ）との差圧が作用する面積である第２受圧面積をＡ２と定義し、
    　前記基準圧力差をＫΔＰと定義し、
    　前記圧力差（ΔＰ）が前記基準圧力差（ＫΔＰ）となった際の前記弾性部材が前記弁体部に作用させる荷重を第１セット荷重Ｆｓｐ１と定義したときに、
    　Ａ１＞Ａ２
    　となっており、
    　Ａ１×ＫΔＰ＞Ｆｓｐ１、かつ、Ｆｓｐ１＞Ａ２×ＫΔＰ
    　となっている請求項２に記載のエジェクタ式冷凍サイクル。     The circuit switching valve (13) includes a body (31) in which the first refrigerant passage (30b) and the second refrigerant passage (30c) are formed, and a valve that opens and closes the first refrigerant passage and the second refrigerant passage. A body part (32), a pressure receiving part (34) connected to the valve body part and arranged downstream of the valve body part, and an elastic member (33) for applying a load to the valve body part Have
    A differential pressure between the inlet side pressure (Pri) of the inlet side refrigerant of the pressure reducing part and the outlet side pressure (Pro) of the outlet side refrigerant of the pressure reducing part acts on the pressure receiving part,
    The elastic member applies a load to the valve body portion on the side where the valve body portion closes the first refrigerant passage and opens the second refrigerant passage,
    When the valve body portion closes the second refrigerant passage, a differential pressure between the high pressure side pressure (PH) of the valve body portion and the inlet side pressure (Pri) of the inlet side refrigerant of the pressure reducing portion acts. The first pressure receiving area that is the area to be defined is defined as A1,
    A second pressure receiving area, which is an area on which the differential pressure between the inlet side pressure (Pri) and the outlet side refrigerant outlet pressure (Pro) of the pressure reducing unit acts, is defined as A2.
    The reference pressure difference is defined as KΔP,
    When the load that the elastic member acts on the valve body when the pressure difference (ΔP) becomes the reference pressure difference (KΔP) is defined as a first set load Fsp1,
    A1> A2
    And
    A1 × KΔP> Fsp1 and Fsp1> A2 × KΔP
    The ejector type refrigeration cycle according to claim 2.
  4. 　前記減圧部は、前記受圧部に形成されている請求項３に記載のエジェクタ式冷凍サイクル。 The ejector refrigeration cycle according to claim 3, wherein the pressure reducing part is formed in the pressure receiving part.
  5. 　前記回路切替弁（１３）は、前記第１冷媒通路（３０ｂ）および前記第２冷媒通路（３０ｃ）が形成されたボデー（３１）、前記第１冷媒通路および前記第２冷媒通路を開閉する弁体部（３２）、前記弁体部に連結されて前記弁体部よりも冷媒流れ下流側に配置される受圧部（３４）、および前記弁体部に対して荷重をかける弾性部材（３３）を有し、
    　前記受圧部のうち入口側圧力（Ｐｒｉ）と前記減圧部の出口側冷媒の出口側圧力（Ｐｒｏ）との差圧が作用する面積である第２受圧面積をＡ２と定義し、
    　前記弁体部が前記第１冷媒通路を閉じた際に、前記弁体部のうち前記高圧側圧力（ＰＨ）と前記ノズル部の入口側のノズル側圧力（Ｐｎｏｚ）との差圧が作用する面積である第３受圧面積をＡ３と定義し、
    　前記基準圧力差をＫΔＰと定義し、
    　前記弁体部が前記第１冷媒通路を閉じている際に前記弾性部材が前記弁体部に作用させる荷重を第２セット荷重Ｆｓｐ２と定義したときに、
    　Ａ２＞Ａ３
    　となっており、
    　Ｆｓｐ２＞（Ａ２－Ａ３）×ＫΔＰ、かつ、Ａ２×ＫΔＰ＞Ｆｓｐ２
    　となっている請求項２ないし４のいずれか１つに記載のエジェクタ式冷凍サイクル。     The circuit switching valve (13) includes a body (31) in which the first refrigerant passage (30b) and the second refrigerant passage (30c) are formed, and a valve that opens and closes the first refrigerant passage and the second refrigerant passage. A body part (32), a pressure receiving part (34) connected to the valve body part and arranged downstream of the valve body part in the refrigerant flow, and an elastic member (33) for applying a load to the valve body part Have
    The second pressure receiving area, which is an area where the differential pressure between the inlet side pressure (Pri) and the outlet side refrigerant outlet pressure (Pro) of the pressure reducing unit acts, is defined as A2.
    When the valve body portion closes the first refrigerant passage, a differential pressure between the high pressure side pressure (PH) and the nozzle side pressure (Pnoz) on the inlet side of the nozzle portion acts on the valve body portion. The third pressure receiving area, which is the area, is defined as A3,
    The reference pressure difference is defined as KΔP,
    When the load that the elastic member acts on the valve body portion when the valve body portion closes the first refrigerant passage is defined as a second set load Fsp2,
    A2> A3
    And
    Fsp2> (A2-A3) × KΔP and A2 × KΔP> Fsp2
    The ejector-type refrigeration cycle according to any one of claims 2 to 4.
  6. 　前記回路切替弁（２４、２５）は、前記回路切替弁の上流側の冷媒の高圧側圧力（ＰＨ）が予め定めた基準高圧側圧力（ＫＰＨ）以上となっている際には、前記第１冷媒通路を開くとともに前記第２冷媒通路を閉じ、
    　前記回路切替弁（２４、２５）は、前記高圧側圧力（ＰＨ）が前記基準高圧側圧力（ＫＰＨ）より低くなっている際には、前記第１冷媒通路を閉じるとともに前記第２冷媒通路を開く請求項１に記載のエジェクタ式冷凍サイクル。     When the high-pressure side pressure (PH) of the refrigerant upstream of the circuit switching valve is equal to or higher than a predetermined reference high-pressure side pressure (KPH), the circuit switching valve (24, 25) Opening the refrigerant passage and closing the second refrigerant passage;
    When the high pressure side pressure (PH) is lower than the reference high pressure side pressure (KPH), the circuit switching valve (24, 25) closes the first refrigerant passage and opens the second refrigerant passage. The ejector-type refrigeration cycle according to claim 1, which is opened.
  7. 　前記回路切替弁（２４）は、前記放熱器にて放熱した冷媒を流入させる流入通路（４０ａ）が形成されたボデー（４１）、前記第１冷媒通路を開閉する第１弁体部（４２）、前記第１弁体部を変位させる第１駆動機構（４４）、前記第２冷媒通路を開閉する第２弁体部（４５）、および前記第２弁体部を変位させる第２駆動機構（４７）とを有し、
    　前記第１冷媒通路（４０ｂ）および前記第２冷媒通路（４０ｃ）は、前記ボデーに形成されており、
    　前記第１駆動機構は、予め定めた基準封入圧力となるように気体が封入される第１封入空間（４４ｃ）を形成する第１空間形成部材（４４）、および前記第１封入空間内の気体圧力と前記流入通路内の冷媒圧力との圧力差に応じて変位する第１圧力応動部材（４４ｂ）を有し、
    　前記第２駆動機構は、前記基準圧力となるように気体が封入される第２封入空間（４７ｃ）を形成する第２空間形成部材（４７）、および前記第２封入空間内の気体圧力と前記流入通路内の冷媒圧力との圧力差に応じて変位する第２圧力応動部材（４７ｂ）を有している請求項６に記載のエジェクタ式冷凍サイクル。     The circuit switching valve (24) includes a body (41) formed with an inflow passage (40a) for allowing the refrigerant radiated by the radiator to flow in, and a first valve body portion (42) for opening and closing the first refrigerant passage. A first drive mechanism (44) for displacing the first valve body, a second valve body (45) for opening and closing the second refrigerant passage, and a second drive mechanism (45) for displacing the second valve body. 47)
    The first refrigerant passage (40b) and the second refrigerant passage (40c) are formed in the body,
    The first drive mechanism includes a first space forming member (44) that forms a first sealed space (44c) in which a gas is sealed so as to have a predetermined reference sealed pressure, and a gas in the first sealed space. A first pressure responsive member (44b) that is displaced according to a pressure difference between the pressure and the refrigerant pressure in the inflow passage,
    The second drive mechanism includes a second space forming member (47) that forms a second sealed space (47c) in which gas is sealed so as to be the reference pressure, and the gas pressure in the second sealed space and the The ejector-type refrigeration cycle according to claim 6, further comprising a second pressure responsive member (47b) that is displaced according to a pressure difference from the refrigerant pressure in the inflow passage.
  8. 　前記第１弁体部は、前記流入通路と前記第１冷媒通路とを連通させる第１パイロット孔（４２ｂ）を有し、
    　前記第１圧力応動部材は、前記第１パイロット孔を開閉する第１作動棒（４２ａ）に連結されている請求項７に記載のエジェクタ式冷凍サイクル。     The first valve body portion has a first pilot hole (42b) for communicating the inflow passage and the first refrigerant passage,
    The ejector-type refrigeration cycle according to claim 7, wherein the first pressure responsive member is connected to a first operating rod (42a) that opens and closes the first pilot hole.
  9. 　前記第１封入空間と前記第２封入空間とを連通させる封入空間連通路（４１ｅ）を有している請求項７または８に記載のエジェクタ式冷凍サイクル。 The ejector-type refrigeration cycle according to claim 7 or 8, further comprising an enclosed space communication path (41e) for communicating the first enclosed space and the second enclosed space.
  10. 　前記回路切替弁（２５）は、前記放熱器にて放熱した冷媒を流入させる流入通路（５０ａ）が形成されたボデー（５１）、前記第１冷媒通路（５０ｂ）を開閉する第１弁体部（５２）、前記第２冷媒通路（５０ｃ）を開閉する第２弁体部（５５）、並びに、前記第１弁体部および前記第２弁体部の双方を変位させる共用駆動機構（５７）とを有し、
    　前記第１冷媒通路および前記第２冷媒通路は、前記ボデーに形成されており、
    　前記共用駆動機構は、予め定めた基準圧力となるように気体が封入される共用封入空間（５７ｃ）を形成する共用空間形成部材（５７ａ）、前記共用空間形成部材内の気体圧力と前記流入通路内の冷媒圧力との差圧に応じて変位する共用圧力応動部材（５７ｂ）、前記共用圧力応動部材の変位を前記第１弁体部および前記第２弁体部の双方へ伝達する共用作動棒（５８）を有している請求項６に記載のエジェクタ式冷凍サイクル。     The circuit switching valve (25) includes a body (51) formed with an inflow passage (50a) for allowing the refrigerant radiated by the radiator to flow in, and a first valve body portion for opening and closing the first refrigerant passage (50b). (52), a second valve body portion (55) for opening and closing the second refrigerant passage (50c), and a common drive mechanism (57) for displacing both the first valve body portion and the second valve body portion. And
    The first refrigerant passage and the second refrigerant passage are formed in the body,
    The common drive mechanism includes a common space forming member (57a) that forms a common enclosed space (57c) in which gas is enclosed so as to have a predetermined reference pressure, a gas pressure in the common space forming member, and the inflow passage. A common pressure responsive member (57b) that displaces in accordance with a differential pressure with respect to the refrigerant pressure inside, and a common operating rod that transmits the displacement of the common pressure responsive member to both the first valve body and the second valve body. The ejector-type refrigeration cycle according to claim 6, having (58).
  11. 　前記気体は、不活性ガスである請求項７ないし１０のいずれか１つに記載のエジェクタ式冷凍サイクル。 The ejector refrigeration cycle according to any one of claims 7 to 10, wherein the gas is an inert gas.
  12. 　さらに、前記昇圧部から流出した冷媒の気液を分離する気液分離部（１６）と、
    　冷媒が前記蒸発器の冷媒入口側から前記気液分離部の液相冷媒出口側へ流れること抑制する抑制機構（１７）と、を備え、
    　前記気液分離部の気相冷媒出口は、前記圧縮機の吸入口側に接続されており、
    　前記液相冷媒出口は、前記蒸発器の冷媒入口側に接続されている請求項１ないし１１のいずれか１つに記載のエジェクタ式冷凍サイクル。

          Furthermore, a gas-liquid separator (16) that separates the gas-liquid of the refrigerant that has flowed out of the pressurizer,
    A suppression mechanism (17) for suppressing the refrigerant from flowing from the refrigerant inlet side of the evaporator to the liquid phase refrigerant outlet side of the gas-liquid separation unit,
    A gas-phase refrigerant outlet of the gas-liquid separator is connected to an inlet side of the compressor;
    The ejector refrigeration cycle according to claim 1, wherein the liquid-phase refrigerant outlet is connected to a refrigerant inlet side of the evaporator.

PCT/JP2017/021414 2016-07-18 2017-06-09 Ejector-type refrigeration cycle WO2018016219A1 (en)

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JP2017089964A (en) * 2015-11-09 2017-05-25 株式会社デンソー Ejector type refrigeration cycle
WO2022038950A1 (en) * 2020-08-17 2022-02-24 株式会社デンソー Refrigeration cycle device

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JP4078901B2 (en) * 2002-07-08 2008-04-23 株式会社デンソー Ejector cycle

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JP2004053028A (en) * 2002-07-16 2004-02-19 Denso Corp Refrigeration cycle device
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JP2017089964A (en) * 2015-11-09 2017-05-25 株式会社デンソー Ejector type refrigeration cycle
WO2022038950A1 (en) * 2020-08-17 2022-02-24 株式会社デンソー Refrigeration cycle device
JP7472714B2 (en) 2020-08-17 2024-04-23 株式会社デンソー Refrigeration Cycle Equipment

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