WO2019220957A1 - Refrigeration cycle device - Google Patents
Refrigeration cycle device Download PDFInfo
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- WO2019220957A1 WO2019220957A1 PCT/JP2019/018318 JP2019018318W WO2019220957A1 WO 2019220957 A1 WO2019220957 A1 WO 2019220957A1 JP 2019018318 W JP2019018318 W JP 2019018318W WO 2019220957 A1 WO2019220957 A1 WO 2019220957A1
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- pressure
- refrigerant
- refrigeration cycle
- phase refrigerant
- cycle apparatus
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- 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
- F25B1/04—Compression machines, plants or systems with non-reversible cycle with compressor of rotary type
- F25B1/053—Compression machines, plants or systems with non-reversible cycle with compressor of rotary type of turbine type
Definitions
- the present disclosure relates to a refrigeration cycle apparatus.
- a refrigerant reverse flow phenomenon from the discharge port to the suction port of the turbo compressor is known. This phenomenon occurs when the pressure ratio in the refrigeration cycle apparatus exceeds an allowable value determined according to the rotational speed of the turbo compressor, and causes noise and shaft vibration.
- Patent Document 1 As a method for lowering the pressure ratio, it is known that a condenser and an evaporator are connected by a gas bypass pipe (Patent Document 1). The amount of refrigerant circulating through the cycle is increased by the gas bypass pipe, and the pressure ratio is lowered. Thereby, turning stall, that is, surging can be prevented.
- This disclosure provides a novel technique for lowering the pressure ratio in a refrigeration cycle apparatus.
- An evaporator that evaporates liquid phase refrigerant to produce gas phase refrigerant; At least one turbo compressor for compressing the gas-phase refrigerant produced in the evaporator; A condenser for condensing the gas-phase refrigerant compressed by the turbo compressor; When a plurality of turbo compressors are provided, the turbo compressor having the highest discharge pressure extends from the turbo compressor to the condenser, and when only one turbo compressor is provided, A high-pressure path extending from the turbo compressor to the condenser, and A refrigerant supply path for guiding the liquid refrigerant from the evaporator toward a high-pressure space including a vapor space inside the condenser and the high-pressure path; A refrigeration cycle apparatus is provided.
- the pressure ratio in the refrigeration cycle apparatus can be lowered.
- FIG. 1 is a configuration diagram of a refrigeration cycle apparatus according to an embodiment of the present disclosure.
- FIG. 2 is a graph showing the characteristics of the compressor.
- FIG. 3 is a flowchart of the surging prevention control.
- FIG. 4 is a configuration diagram of a refrigeration cycle apparatus according to a modification.
- FIG. 5 is a configuration diagram of a refrigeration cycle apparatus according to another modification.
- Patent Document 1 The technique described in Patent Document 1 is suitable for a refrigeration cycle apparatus using a Freon refrigerant having a relatively high density in a gas phase.
- a refrigerant with a low density in the gas phase has a small heat capacity in the gas phase, so that even if a gas bypass pipe is applied to a refrigeration cycle apparatus using such a refrigerant, the pressure ratio is sufficiently reduced. Is difficult. Regardless of the type of refrigerant, it is desired to reliably reduce the pressure ratio to prevent or eliminate surging.
- the refrigeration cycle apparatus includes: An evaporator that evaporates liquid phase refrigerant to produce gas phase refrigerant; At least one turbo compressor for compressing the gas-phase refrigerant produced in the evaporator; A condenser for condensing the gas-phase refrigerant compressed by the turbo compressor; When a plurality of turbo compressors are provided, the turbo compressor having the highest discharge pressure extends from the turbo compressor to the condenser, and when only one turbo compressor is provided, A high-pressure path extending from the turbo compressor to the condenser, and A refrigerant supply path for guiding the liquid refrigerant from the evaporator toward a high-pressure space including a vapor space inside the condenser and the high-pressure path; It has.
- the pressure ratio in the refrigeration cycle apparatus can be lowered. As a result, surging can be prevented or eliminated.
- the refrigeration cycle apparatus further includes a pump disposed in the refrigerant supply path.
- a pump disposed in the refrigerant supply path.
- the refrigerant supply path has a supply mechanism located at an end portion on the discharge side. According to the supply mechanism, the pressure ratio can be quickly reduced.
- the supply mechanism includes an atomization nozzle. If an atomization nozzle is used as the supply mechanism, the contact area between the liquid-phase refrigerant and the gas-phase refrigerant can be sufficiently increased.
- the supply mechanism applies a velocity component parallel to a flow direction of the gas-phase refrigerant to the liquid-phase refrigerant. It arrange
- the pressure of the gas-phase refrigerant discharged from the compressor can be increased by the momentum of the liquid-phase refrigerant. That is, the pressure increase width in the compressor can be reduced.
- the high-pressure path flows from the upstream side toward the downstream side in the flow direction of the gas-phase refrigerant. It has a reduced diameter part where the road cross-sectional area is gradually reduced. According to the sixth aspect, it can be expected that the momentum of the liquid-phase refrigerant is efficiently transported to the gas-phase refrigerant and the effect of increasing the pressure is enhanced.
- the rotational speed of the turbo compressor is increased to start the refrigeration cycle apparatus from a stopped state.
- the liquid phase enters the high-pressure space through the refrigerant supply path. Refrigerant is supplied. According to the seventh aspect, it is possible to reliably prevent surging from occurring when starting and stopping the refrigeration cycle apparatus.
- the operating state of the turbo compressor when the operating state of the turbo compressor is in a surging state or the operating state of the turbo compressor is When the transition to the surging state is predicted, the liquid-phase refrigerant is supplied to the high-pressure space through the refrigerant supply path.
- surging is immediately eliminated or the occurrence of surging can be reliably prevented.
- the ninth aspect of the present disclosure for example, in the refrigeration cycle apparatus according to any one of the first to sixth aspects, when the rotational speed of the turbo compressor is equal to or lower than a threshold rotational speed, The liquid phase refrigerant is supplied to the high pressure space. According to the ninth aspect, it is possible to reliably prevent surging from occurring when starting and stopping the refrigeration cycle apparatus.
- the refrigerant contains a substance whose saturation vapor pressure at room temperature is a negative pressure as a main component.
- FIG. 1 shows a configuration of a refrigeration cycle apparatus according to an embodiment of the present disclosure.
- the refrigeration cycle apparatus 100 includes an evaporator 2, a compressor 3 and a condenser 4.
- the compressor 3 is connected to the evaporator 2 by a low pressure path 6 and is connected to the condenser 4 by a high pressure path 8.
- the condenser 4 is connected to the evaporator 2 by a return path 9.
- the evaporator 2, the compressor 3, and the condenser 4 are annularly connected in this order to constitute the refrigerant circuit 10.
- the refrigerant evaporates, and a gas phase refrigerant (refrigerant vapor) is generated.
- the gas-phase refrigerant generated in the evaporator 2 is sucked into the compressor 3 through the low-pressure path 6 and compressed.
- the compressed gas-phase refrigerant is supplied to the condenser 4 through the high-pressure path 8.
- the gas phase refrigerant is cooled to generate a liquid phase refrigerant (refrigerant liquid).
- the liquid phase refrigerant is sent from the condenser 4 to the evaporator 2 through the return path 9.
- each path and each circuit can be configured by one or a plurality of pipes.
- the refrigeration cycle apparatus 100 contains, for example, a substance whose saturation vapor pressure at normal temperature (Japanese Industrial Standard: 20 ° C. ⁇ 15 ° C./JIS Z8703) is negative (absolute pressure lower than atmospheric pressure) as a main component.
- Refrigerant is filled. Examples of such a refrigerant include a refrigerant containing water as a main component.
- the “main component” means a component that is contained most in mass ratio.
- a refrigerant containing a substance whose saturation vapor pressure at room temperature is a negative pressure as a main component has a small density in a gas phase.
- the refrigeration cycle apparatus 100 further includes a heat absorption circuit 12 and a heat dissipation circuit 14.
- the heat absorption circuit 12 is a circuit for using the liquid phase refrigerant cooled by the evaporator 2 and has necessary devices such as a pump and an indoor heat exchanger. A part of the heat absorption circuit 12 is located inside the evaporator 2. In the evaporator 2, a part of the endothermic circuit 12 may be located above the liquid level of the liquid phase refrigerant or may be located below the liquid level of the liquid phase refrigerant.
- the heat absorption circuit 12 is filled with a heat medium such as water or brine.
- the liquid-phase refrigerant stored in the evaporator 2 comes into contact with members (piping) constituting the heat absorption circuit 12. Heat exchange is performed between the liquid refrigerant and the heat medium in the heat absorption circuit 12, and the liquid refrigerant evaporates.
- the heat medium in the endothermic circuit 12 is cooled by the latent heat of vaporization of the liquid refrigerant.
- the refrigeration cycle apparatus 100 is an air conditioner that cools a room
- the room air is cooled by the heat medium of the heat absorption circuit 12.
- the indoor heat exchanger is, for example, a fin tube heat exchanger.
- the cooling target of the liquid refrigerant in the evaporator 2 is not limited to indoor air.
- the cooling target of the evaporator 2 may be a gas other than air or a liquid.
- the heat dissipation circuit 14 is a circuit used to take heat from the refrigerant inside the condenser 4 and has necessary devices such as a pump and a cooling tower. A part of the heat dissipation circuit 14 is located inside the condenser 4. Specifically, a part of the heat dissipation circuit 14 is located above the liquid level of the liquid-phase refrigerant in the condenser 4. The heat dissipation circuit 14 is filled with a heat medium such as water or brine.
- the refrigeration cycle apparatus 100 is an air conditioner that cools a room, the condenser 4 is disposed outside the room, and the refrigerant in the condenser 4 is cooled by the heat medium of the heat dissipation circuit 14.
- the high-temperature gas-phase refrigerant discharged from the compressor 3 contacts a member (pipe) constituting the heat dissipation circuit 14 inside the condenser 4. Heat exchange is performed between the gas-phase refrigerant and the heat medium inside the heat dissipation circuit 14, and the gas-phase refrigerant is condensed.
- the heat medium inside the heat dissipation circuit 14 is heated by the condensation latent heat of the gas-phase refrigerant.
- the heat medium heated by the gas-phase refrigerant is cooled by outside air or cooling water in a cooling tower (not shown) of the heat dissipation circuit 14, for example.
- the evaporator 2 is constituted by a container having heat insulation and pressure resistance, for example.
- the evaporator 2 stores the liquid phase refrigerant and evaporates the liquid phase refrigerant inside.
- the liquid refrigerant inside the evaporator 2 absorbs heat generated from the outside of the evaporator 2 and evaporates. That is, the liquid-phase refrigerant heated by absorbing heat from the heat absorption circuit 12 evaporates in the evaporator 2.
- the liquid-phase refrigerant stored in the evaporator 2 indirectly contacts the heat medium circulating in the heat absorption circuit 12.
- a part of the liquid phase refrigerant stored in the evaporator 2 is heated by the heat medium of the heat absorption circuit 12 and used to heat the liquid phase refrigerant in the saturated state.
- the temperature of the liquid-phase refrigerant stored in the evaporator 2 and the temperature of the gas-phase refrigerant generated in the evaporator 2 are 5 ° C., for example.
- the evaporator 2 is an indirect contact heat exchanger (for example, a shell tube heat exchanger).
- the evaporator 2 may be a direct contact type heat exchanger such as a spray type or filler type heat exchanger. That is, the liquid phase refrigerant may be heated by circulating the liquid phase refrigerant in the heat absorption circuit 12. Further, the endothermic circuit 12 may be omitted.
- the compressor 3 sucks and compresses the gas-phase refrigerant generated by the evaporator 2.
- the compressor 3 is, for example, a speed type compressor (dynamic compressor).
- the speed type compressor is a compressor that increases the pressure of the gas-phase refrigerant by giving momentum to the gas-phase refrigerant and then decelerating it.
- Examples of the speed type compressor include a centrifugal compressor, a mixed flow compressor, and an axial flow compressor.
- the speed type compressor is also called a turbo compressor.
- the compressor 3 may include a variable speed mechanism for changing the rotation speed.
- An example of the variable speed mechanism is an inverter that drives the motor of the compressor 3.
- the temperature of the refrigerant at the discharge port of the compressor 3 is in the range of 100 to 150 ° C., for example.
- the condenser 4 is constituted by a container having heat insulation and pressure resistance, for example.
- the condenser 4 condenses the gas-phase refrigerant compressed by the compressor 3 and stores the liquid-phase refrigerant generated by condensing the gas-phase refrigerant.
- the gas-phase refrigerant indirectly condenses and condenses on the heat medium cooled by releasing heat to the external environment. That is, the gas phase refrigerant is cooled and condensed by the heat medium of the heat dissipation circuit 14.
- the temperature of the gas-phase refrigerant introduced into the condenser 4 is in the range of 100 to 150 ° C., for example.
- the temperature of the liquid phase refrigerant stored in the condenser 4 is, for example, 35 ° C.
- the condenser 4 is an indirect contact heat exchanger (for example, a shell tube heat exchanger).
- the condenser 4 may be a direct contact type heat exchanger such as a spray type or filler type heat exchanger. That is, the liquid phase refrigerant may be cooled by circulating the liquid phase refrigerant in the heat dissipation circuit 14. Further, the heat dissipation circuit 14 may be omitted.
- the low pressure path 6 is a flow path for guiding the gas phase refrigerant from the evaporator 2 to the compressor 3.
- the outlet of the evaporator 2 is connected to the suction port of the compressor 3 through the low pressure path 6.
- the high-pressure path 8 is a flow path for guiding the gas-phase refrigerant compressed from the compressor 3 to the condenser 4.
- the discharge port of the compressor 3 is connected to the inlet of the condenser 4 through the high pressure path 8.
- the high pressure path 8 is a flow path extending from the compressor 3 to the condenser 4.
- the return path 9 is a flow path for guiding the liquid refrigerant from the condenser 4 to the evaporator 2.
- the evaporator 2 and the condenser 4 are connected by the return path 9.
- a valve 17 is arranged in the return path 9.
- the valve 17 may be an on-off valve or a flow rate adjustment valve.
- Other components such as a pump and a sensor may be arranged in the return path 9.
- the refrigeration cycle apparatus 100 further includes a sensor 20.
- the sensor 20 is attached to the evaporator 2.
- the sensor 20 may be a temperature sensor, a pressure sensor, or both of them.
- the sensor 20 detects the temperature of the liquid-phase refrigerant or the gas-phase refrigerant in the evaporator 2. That is, the sensor 20 can detect the evaporation temperature in the evaporator 2.
- the sensor 20 is a pressure sensor
- the sensor 20 detects the pressure inside the evaporator 2. That is, the sensor 20 can detect the saturated vapor pressure in the evaporator 2.
- the refrigeration cycle apparatus 100 further includes a sensor 21.
- the sensor 21 is attached to the condenser 4.
- the sensor 21 may be a temperature sensor, a pressure sensor, or both of them.
- the sensor 21 detects the temperature of the liquid-phase refrigerant or the gas-phase refrigerant in the condenser 4. That is, the sensor 21 can detect the condensation temperature in the condenser 4.
- the sensor 21 detects the pressure inside the condenser 4. That is, the sensor 21 can detect the saturated vapor pressure in the condenser 4.
- the sensor 20 may be disposed in the low pressure path 6.
- the sensor 21 may be disposed in the high pressure path 8.
- the temperature sensor includes a temperature sensor using a thermistor, a temperature sensor using a thermocouple, and the like.
- Examples of the pressure sensor include a capacitive pressure sensor, a resistance wire pressure sensor, and a piezoresistive pressure sensor.
- the refrigeration cycle apparatus 100 further includes a refrigerant supply path 11.
- the refrigerant supply path 11 is a flow path that guides the liquid phase refrigerant from the evaporator 2 toward the high-pressure space 15.
- the refrigerant supply path 11 connects the evaporator 2 and the high-pressure path 8.
- the refrigerant supply path 11 may connect the evaporator 2 and the vapor space inside the condenser 4.
- the refrigerant supply path 11 may be branched, and each of the branched refrigerant supply paths 11 may be connected to the high-pressure path 8 and the vapor space inside the condenser 4.
- the high-pressure space 15 is a space including the vapor space inside the condenser 4 and the high-pressure path 8.
- “Vapor space inside the condenser 4” means a space above the liquid level of the liquid-phase refrigerant stored in the condenser 4.
- the inlet of the refrigerant supply path 11 is located below the evaporator 2. According to such a configuration, the low-temperature liquid phase refrigerant can be stably supplied to the high-pressure space 15 through the refrigerant supply path 11.
- the “lower part of the evaporator 2” means a part below the liquid level of the liquid-phase refrigerant stored in the evaporator 2.
- the liquid-phase refrigerant stored in the evaporator 2 When the low-temperature liquid phase refrigerant stored in the evaporator 2 is supplied to the high-pressure space 15 through the refrigerant supply path 11, the liquid-phase refrigerant comes into contact with the high-temperature gas phase refrigerant discharged from the compressor 3. Allow the refrigerant to condense. Thereby, the condensation temperature, that is, the condensation pressure can be lowered. By reducing the condensation pressure, the pressure ratio can be lowered. According to the present disclosure, the effect of reducing the pressure ratio can be sufficiently obtained even when a refrigerant having a low density in the gas phase is used.
- the “pressure ratio” is the ratio of the pressure (discharge pressure) at the discharge port to the pressure (suction pressure) at the suction port of the compressor 3.
- the pressure ratio can be calculated from detection values obtained from one or more sensors. For example, when both the sensors 20 and 21 are pressure sensors, the pressure ratio can be calculated by dividing the detection value of the sensor 21 by the detection value of the sensor 20.
- the saturated vapor pressure can be calculated from the temperature of the liquid refrigerant, and the pressure ratio can be calculated from the saturated vapor pressure.
- the pressure ratio can also be estimated from the condensation temperature (detected value of the sensor 21) in the condenser 4. is there.
- the method for calculating the pressure ratio is not particularly limited.
- a pump 16 is disposed in the refrigerant supply path 11. By controlling the pump 16, the timing of supplying the liquid phase refrigerant to the high pressure space 15 can be freely controlled.
- the pump 16 is, for example, a positive displacement pump such as a piston pump, a plunger pump, a gear pump, or a vane pump.
- the pump 16 may be a pump that can change the supply flow rate. In this case, it is easy to supply the liquid refrigerant to the high-pressure space 15 at an appropriate flow rate according to the operating state of the refrigeration cycle apparatus 100.
- the refrigerant supply path 11 has a supply mechanism 11a located at the end on the discharge side.
- the supply mechanism 11 a has a role of increasing the surface area of the liquid-phase refrigerant and increasing the contact area between the liquid-phase refrigerant and the gas-phase refrigerant discharged from the compressor 3. According to the supply mechanism 11a, the pressure ratio can be quickly reduced.
- the structure of the supply mechanism 11a is not particularly limited.
- the supply mechanism 11a is, for example, an atomization nozzle that atomizes and supplies liquid phase refrigerant. If an atomizing nozzle is used as the supply mechanism 11a, the contact area between the liquid-phase refrigerant and the gas-phase refrigerant can be sufficiently increased.
- the atomizing nozzle include an ultrasonic atomizing nozzle, a swirl flow type atomizing nozzle, and a collision type atomizing nozzle.
- the ultrasonic atomizing nozzle is a spray nozzle that atomizes a liquid using ultrasonic waves.
- a swirl-type atomizing nozzle is a spray nozzle that atomizes a liquid using centrifugal force.
- the collision type atomizing nozzle is a spray nozzle that atomizes a liquid by colliding with an obstacle (target).
- the discharge direction (spraying direction) of the liquid refrigerant from the supply mechanism 11a may be parallel to or perpendicular to the flow direction of the gas-phase refrigerant.
- the discharge direction of the liquid phase refrigerant may intersect the flow direction of the gas phase refrigerant.
- the supply mechanism 11 a may be configured to flow the liquid phase refrigerant along the inner surface of the high-pressure path 8, or may be configured to flow the liquid phase refrigerant along the inner surface of the condenser 4. .
- valves and sensors may be arranged in the refrigerant supply path 11.
- the refrigeration cycle apparatus 100 further includes a controller 22.
- the controller 22 is, for example, a DSP (Digital Signal Processor) including an A / D conversion circuit, an input / output circuit, an arithmetic circuit, a storage device, and the like. Detection signals from measuring devices such as the sensor 20 and the sensor 21 are input to the controller 22.
- the controller 22 controls controlled objects such as the compressor 3, the pump 16, and the valve 17 based on the measurement results of various measuring devices.
- the controller 22 stores a program for appropriately operating the refrigeration cycle apparatus 100.
- the controller 22 may include an inverter that drives the compressor 3, and may include an inverter that drives the pump 16.
- the controller 22 may be constituted by a single microcomputer or a plurality of microcomputers. Furthermore, the refrigeration cycle apparatus 100 may have a plurality of controllers.
- Controller 22 acquires a sensor signal from sensor 20 and / or sensor 21, and specifies a pressure ratio (discharge pressure / intake pressure) in refrigeration cycle apparatus 100 from the acquired sensor signal.
- the controller 22 specifies the operating state of the compressor 3 based on the specified pressure ratio and the flow rate (mass flow rate) of the refrigerant in the compressor 3, and if necessary, enters the liquid phase into the high-pressure space 15 through the refrigerant supply path 11.
- An electrical process for supplying the refrigerant is executed.
- the flow rate of the refrigerant can be estimated from the rotational speed of the compressor 3. In general, when the turbo compressor is operated at a sufficiently high rotational speed, the flow rate is approximately proportional to the rotational speed. The “sufficiently large number of revolutions” depends on the design of the turbo compressor.
- Surging occurs when the pressure ratio exceeds the allowable value when the turbo compressor is operating at a specific speed.
- FIG. 2 shows the characteristics of the compressor 3.
- the graph of FIG. 2 is stored in the memory of the controller 22 in the form of a lookup table, for example.
- the region defined by the solid curve P is a region where the compressor 3 can be operated normally without causing surging and choking.
- the pressure ratio increases and the operating state of the compressor 3 deviates from the region defined by the curve P, that is, when the operating state of the compressor 3 is in the surging state
- the liquid is supplied to the high-pressure space 15 through the refrigerant supply path 11. Phase refrigerant can be supplied.
- the refrigerant supply path The liquid phase refrigerant may be supplied to the high-pressure space through 11. In this way, surging can be eliminated immediately or the occurrence of surging can be reliably prevented.
- the pressure ratio in the curve P1 can be set to a value lower than the allowable value.
- the pressure ratio in the curve P1 is about 1% to 10% smaller than the pressure ratio in the curve P.
- the operating state of the compressor 3 can be determined using the rotation speed of the compressor 3. Specifically, the flow rate of the refrigerant is determined according to the suction pressure and the rotation speed of the compressor 3. Based on the suction pressure, the discharge pressure, and the rotation speed of the compressor 3, the operating state of the compressor 3 can be specified.
- the “threshold rotation speed” is a design value of the compressor 3.
- the rotational speed of the compressor 3 is a value that is always stored in the memory of a controller (for example, the controller 22) for controlling the motor of the compressor 3.
- the start-up operation for increasing the rotation speed of the compressor 3 to start the refrigeration cycle apparatus 100 from the stop state and the stop operation for decreasing the rotation speed of the compressor 3 to stop the refrigeration cycle apparatus 100 are selected.
- the liquid-phase refrigerant may be supplied to the high-pressure space 15 through the refrigerant supply path 11. Thereby, it is possible to reliably prevent surging from occurring when the refrigeration cycle apparatus 100 is started and stopped.
- “Stopped state” means, for example, a state where the rotational speed of the compressor 3 is zero.
- the pressure ratio varies depending on the size of the load and the outside air temperature.
- the refrigeration cycle apparatus 100 When the refrigeration cycle apparatus 100 is stopped by reducing the rotation speed of the compressor 3 from the rated operation or the partial load operation, it is necessary to decrease the rotation speed of the compressor 3 from a state where the pressure ratio is high. There is a possibility that the rate of decrease in the pressure ratio cannot follow the rate of decrease in the rotational speed, and the operating state of the compressor 3 shifts to the surging region. Therefore, when an instruction to stop the operation is given to the refrigeration cycle apparatus 100 (for example, when the stop switch is turned on), the liquid phase refrigerant is supplied to the high-pressure space 15 through the refrigerant supply path 11 to sufficiently reduce the pressure ratio. After that, the rotational speed of the compressor 3 may be decreased. In this way, the refrigeration cycle apparatus 100 can be smoothly and safely stopped without causing surging.
- the rotation speed of the compressor 3 is not more than a threshold rotation speed (for example, 20,000 rotations / min), the refrigerant does not flow sufficiently. This phenomenon is remarkable when the internal pressure of the refrigeration cycle apparatus 100 is lower than atmospheric pressure. Therefore, when the rotation speed of the compressor 3 is equal to or lower than the threshold rotation speed, the liquid phase refrigerant can be supplied to the high-pressure space 15 through the refrigerant supply path 11. Thereby, it is possible to reliably prevent surging from occurring when the refrigeration cycle apparatus 100 is started and stopped.
- a threshold rotation speed for example, 20,000 rotations / min
- the controller 22 executes the surging prevention control shown in FIG. 3 as necessary.
- step S1 it is determined whether or not the current rotational speed of the compressor 3 is equal to or greater than a threshold rotational speed.
- the pump 16 is operated in step S4. Thereby, the liquid phase refrigerant is supplied to the high-pressure space 15, and the pressure ratio can be lowered. As a result, surging can be prevented.
- step S2 If the rotation speed of the compressor 3 is equal to or greater than the threshold rotation speed, it is determined in step S2 whether or not the current pressure ratio is equal to or less than the threshold pressure ratio. If the pressure ratio exceeds the threshold pressure ratio, the pump 16 is operated in step S4. Thereby, the liquid phase refrigerant is supplied to the high-pressure space 15, and the pressure ratio can be lowered. As a result, surging is prevented.
- the threshold pressure ratio corresponds to, for example, the curve P1 described with reference to FIG. 2, and is determined according to the rotation speed (flow rate) of the compressor 3.
- the pump 16 is stopped in step S3. Thereby, it can avoid that the performance and efficiency of the refrigerating-cycle apparatus 100 fall more than necessary.
- the pump 16 may be operated immediately without performing the control shown in FIG.
- FIG. 4 shows a configuration of a refrigeration cycle apparatus according to a modification.
- the supply mechanism 11a is disposed in the high-pressure space 15 so as to impart a velocity component parallel to the flow direction of the gas-phase refrigerant to the liquid-phase refrigerant.
- the discharge direction (spraying direction) of the liquid-phase refrigerant from the supply mechanism 11a substantially matches the flow direction of the gas-phase refrigerant.
- the pressure of the gas-phase refrigerant discharged from the compressor 3 can be increased by the momentum of the liquid-phase refrigerant. That is, the pressure increase width in the compressor 3 can be reduced.
- Such a configuration is particularly effective during high load operation. Examples of the high load operation include an operation under a high outside air temperature condition and an operation under a high pressure ratio condition.
- the high-pressure path 8 has a reduced diameter portion 8a in which the flow path cross-sectional area gradually decreases (continuously) from the upstream side to the downstream side in the flow direction of the gas-phase refrigerant.
- the supply mechanism 11a sprays the liquid phase refrigerant toward the high-pressure space 15 of the reduced diameter portion 8a.
- the flow path cross-sectional area of the vapor space of the condenser 4 is larger than the flow path cross-sectional area of the high-pressure path 8. For this reason, the cross-sectional area of the flow path rapidly increases at the connection portion between the reduced diameter portion 8 a and the condenser 4. It can be expected that the vapor space of the condenser 4 functions as a diffuser that restores static pressure.
- FIG. 5 shows a configuration of a refrigeration cycle apparatus according to another modification.
- the refrigeration cycle apparatus 300 is different from the refrigeration cycle apparatus 100 described with reference to FIG. 1 in that it includes a plurality of compressors.
- the refrigeration cycle apparatus 300 further includes a second compressor 13 in addition to the compressor 3 (hereinafter referred to as “first compressor 3”).
- the first compressor 3 and the second compressor 13 are connected in series.
- the first compressor 3 and the second compressor 13 are arranged so that the gas-phase refrigerant compressed by the first compressor 3 is further compressed by the second compressor 13.
- the intermediate pressure path 7 connects the discharge port of the first compressor 3 and the suction port of the second compressor 13.
- the high-pressure path 8 extends to the condenser 4 starting from the second compressor 13 which is a compressor having the highest discharge pressure.
- a path connecting the first compressor 3 and the second compressor 13 is an intermediate pressure path 7.
- the liquid phase refrigerant is supplied to the high-pressure path 8 at an appropriate timing. This reduces the pressure ratio and prevents surging.
- the refrigeration cycle apparatus disclosed in this specification is useful for an air conditioner, a chiller, a heat storage device, and the like.
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Abstract
This refrigeration cycle device (100) is provided with: an evaporator (2) that causes a liquid-phase refrigerant to evaporate and generates a gas-phase refrigerant; at least one turbo compressor (3) that compresses the gas-phase refrigerant generated by the evaporator (2); a condenser (4) that condenses the gas-phase refrigerant compressed by the turbo compressor (3); a high-pressure channel (8) configured so that, when a plurality of turbo compressors (3) are provided, the high-pressure channel (8) extends to the condenser (4) from the turbo compressor (3) having the highest discharge output, and when only one turbo compressor (3) is provided, the high-pressure channel (8) extends to the condenser (4) from the turbo compressor (3); and a refrigerant supply path (11) that guides the liquid-phase refrigerant from the evaporator (2) toward a high-pressure space (15) that includes the high-pressure channel (8) and a vapor space inside the condenser (4).
Description
本開示は、冷凍サイクル装置に関する。
The present disclosure relates to a refrigeration cycle apparatus.
ターボ圧縮機を搭載した冷凍サイクル装置の技術課題の1つとして、ターボ圧縮機の吐出口から吸入口への冷媒の逆流現象(旋回失速)が知られている。この現象は、冷凍サイクル装置における圧力比がターボ圧縮機の回転数に応じて決まる許容値を超過したときに起こり、騒音及び軸振動の原因となる。
As one of the technical problems of a refrigeration cycle apparatus equipped with a turbo compressor, a refrigerant reverse flow phenomenon (swing stall) from the discharge port to the suction port of the turbo compressor is known. This phenomenon occurs when the pressure ratio in the refrigeration cycle apparatus exceeds an allowable value determined according to the rotational speed of the turbo compressor, and causes noise and shaft vibration.
従来、圧力比を下げる方法として、凝縮器と蒸発器とをガスバイパス管によって接続することが知られている(特許文献1)。ガスバイパス管によってサイクルを循環する冷媒の量が増加し、圧力比が下がる。これにより、旋回失速、すなわち、サージングを防止できる。
Conventionally, as a method for lowering the pressure ratio, it is known that a condenser and an evaporator are connected by a gas bypass pipe (Patent Document 1). The amount of refrigerant circulating through the cycle is increased by the gas bypass pipe, and the pressure ratio is lowered. Thereby, turning stall, that is, surging can be prevented.
ただし、凝縮器と蒸発器とをガスバイパス管によって接続したとしても、圧力比を速やかに低減できるとは限らない。例えば、気相状態での密度が低い冷媒が使用されている場合、凝縮器と蒸発器とを接続するガスバイパス管による効果は限定的である。
However, even if the condenser and the evaporator are connected by a gas bypass pipe, the pressure ratio cannot always be reduced quickly. For example, when a refrigerant having a low density in the gas phase is used, the effect of the gas bypass pipe connecting the condenser and the evaporator is limited.
本開示は、冷凍サイクル装置における圧力比を下げるための新規な技術を提供する。
This disclosure provides a novel technique for lowering the pressure ratio in a refrigeration cycle apparatus.
本開示は、
液相冷媒を蒸発させて気相冷媒を生成する蒸発器と、
前記蒸発器において生成された前記気相冷媒を圧縮する少なくとも1つのターボ圧縮機と、
前記ターボ圧縮機によって圧縮された前記気相冷媒を凝縮させる凝縮器と、
前記ターボ圧縮機が複数設けられている場合には、最も高い吐出圧力を有する前記ターボ圧縮機を起点として前記凝縮器まで延び、前記ターボ圧縮機が1つのみ設けられている場合には、そのターボ圧縮機を起点として前記凝縮器まで延びている高圧経路と、
前記凝縮器の内部の蒸気空間と前記高圧経路とを含む高圧空間に向けて前記蒸発器から前記液相冷媒を導く冷媒供給路と、
を備えた、冷凍サイクル装置を提供する。 This disclosure
An evaporator that evaporates liquid phase refrigerant to produce gas phase refrigerant;
At least one turbo compressor for compressing the gas-phase refrigerant produced in the evaporator;
A condenser for condensing the gas-phase refrigerant compressed by the turbo compressor;
When a plurality of turbo compressors are provided, the turbo compressor having the highest discharge pressure extends from the turbo compressor to the condenser, and when only one turbo compressor is provided, A high-pressure path extending from the turbo compressor to the condenser, and
A refrigerant supply path for guiding the liquid refrigerant from the evaporator toward a high-pressure space including a vapor space inside the condenser and the high-pressure path;
A refrigeration cycle apparatus is provided.
液相冷媒を蒸発させて気相冷媒を生成する蒸発器と、
前記蒸発器において生成された前記気相冷媒を圧縮する少なくとも1つのターボ圧縮機と、
前記ターボ圧縮機によって圧縮された前記気相冷媒を凝縮させる凝縮器と、
前記ターボ圧縮機が複数設けられている場合には、最も高い吐出圧力を有する前記ターボ圧縮機を起点として前記凝縮器まで延び、前記ターボ圧縮機が1つのみ設けられている場合には、そのターボ圧縮機を起点として前記凝縮器まで延びている高圧経路と、
前記凝縮器の内部の蒸気空間と前記高圧経路とを含む高圧空間に向けて前記蒸発器から前記液相冷媒を導く冷媒供給路と、
を備えた、冷凍サイクル装置を提供する。 This disclosure
An evaporator that evaporates liquid phase refrigerant to produce gas phase refrigerant;
At least one turbo compressor for compressing the gas-phase refrigerant produced in the evaporator;
A condenser for condensing the gas-phase refrigerant compressed by the turbo compressor;
When a plurality of turbo compressors are provided, the turbo compressor having the highest discharge pressure extends from the turbo compressor to the condenser, and when only one turbo compressor is provided, A high-pressure path extending from the turbo compressor to the condenser, and
A refrigerant supply path for guiding the liquid refrigerant from the evaporator toward a high-pressure space including a vapor space inside the condenser and the high-pressure path;
A refrigeration cycle apparatus is provided.
本開示によれば、冷凍サイクル装置における圧力比を下げることができる。
According to the present disclosure, the pressure ratio in the refrigeration cycle apparatus can be lowered.
(本開示の基礎となった知見)
特許文献1に記載された技術は、気相状態での密度が比較的大きいフロン冷媒を用いた冷凍サイクル装置に適している。一方、気相状態での密度が小さい冷媒は、気相状態での熱容量も小さいので、このような冷媒を用いた冷凍サイクル装置にガスバイパス管を適用したとしても、圧力比を十分に下げることは難しい。冷媒の種類によらず、圧力比を確実に下げてサージングを防止又は解消することが望まれている。 (Knowledge that became the basis of this disclosure)
The technique described in Patent Document 1 is suitable for a refrigeration cycle apparatus using a Freon refrigerant having a relatively high density in a gas phase. On the other hand, a refrigerant with a low density in the gas phase has a small heat capacity in the gas phase, so that even if a gas bypass pipe is applied to a refrigeration cycle apparatus using such a refrigerant, the pressure ratio is sufficiently reduced. Is difficult. Regardless of the type of refrigerant, it is desired to reliably reduce the pressure ratio to prevent or eliminate surging.
特許文献1に記載された技術は、気相状態での密度が比較的大きいフロン冷媒を用いた冷凍サイクル装置に適している。一方、気相状態での密度が小さい冷媒は、気相状態での熱容量も小さいので、このような冷媒を用いた冷凍サイクル装置にガスバイパス管を適用したとしても、圧力比を十分に下げることは難しい。冷媒の種類によらず、圧力比を確実に下げてサージングを防止又は解消することが望まれている。 (Knowledge that became the basis of this disclosure)
The technique described in Patent Document 1 is suitable for a refrigeration cycle apparatus using a Freon refrigerant having a relatively high density in a gas phase. On the other hand, a refrigerant with a low density in the gas phase has a small heat capacity in the gas phase, so that even if a gas bypass pipe is applied to a refrigeration cycle apparatus using such a refrigerant, the pressure ratio is sufficiently reduced. Is difficult. Regardless of the type of refrigerant, it is desired to reliably reduce the pressure ratio to prevent or eliminate surging.
(本開示に係る一態様の概要)
本開示の第1態様に係る冷凍サイクル装置は、
液相冷媒を蒸発させて気相冷媒を生成する蒸発器と、
前記蒸発器において生成された前記気相冷媒を圧縮する少なくとも1つのターボ圧縮機と、
前記ターボ圧縮機によって圧縮された前記気相冷媒を凝縮させる凝縮器と、
前記ターボ圧縮機が複数設けられている場合には、最も高い吐出圧力を有する前記ターボ圧縮機を起点として前記凝縮器まで延び、前記ターボ圧縮機が1つのみ設けられている場合には、そのターボ圧縮機を起点として前記凝縮器まで延びている高圧経路と、
前記凝縮器の内部の蒸気空間と前記高圧経路とを含む高圧空間に向けて前記蒸発器から前記液相冷媒を導く冷媒供給路と、
を備えている。 (Outline of one aspect according to the present disclosure)
The refrigeration cycle apparatus according to the first aspect of the present disclosure includes:
An evaporator that evaporates liquid phase refrigerant to produce gas phase refrigerant;
At least one turbo compressor for compressing the gas-phase refrigerant produced in the evaporator;
A condenser for condensing the gas-phase refrigerant compressed by the turbo compressor;
When a plurality of turbo compressors are provided, the turbo compressor having the highest discharge pressure extends from the turbo compressor to the condenser, and when only one turbo compressor is provided, A high-pressure path extending from the turbo compressor to the condenser, and
A refrigerant supply path for guiding the liquid refrigerant from the evaporator toward a high-pressure space including a vapor space inside the condenser and the high-pressure path;
It has.
本開示の第1態様に係る冷凍サイクル装置は、
液相冷媒を蒸発させて気相冷媒を生成する蒸発器と、
前記蒸発器において生成された前記気相冷媒を圧縮する少なくとも1つのターボ圧縮機と、
前記ターボ圧縮機によって圧縮された前記気相冷媒を凝縮させる凝縮器と、
前記ターボ圧縮機が複数設けられている場合には、最も高い吐出圧力を有する前記ターボ圧縮機を起点として前記凝縮器まで延び、前記ターボ圧縮機が1つのみ設けられている場合には、そのターボ圧縮機を起点として前記凝縮器まで延びている高圧経路と、
前記凝縮器の内部の蒸気空間と前記高圧経路とを含む高圧空間に向けて前記蒸発器から前記液相冷媒を導く冷媒供給路と、
を備えている。 (Outline of one aspect according to the present disclosure)
The refrigeration cycle apparatus according to the first aspect of the present disclosure includes:
An evaporator that evaporates liquid phase refrigerant to produce gas phase refrigerant;
At least one turbo compressor for compressing the gas-phase refrigerant produced in the evaporator;
A condenser for condensing the gas-phase refrigerant compressed by the turbo compressor;
When a plurality of turbo compressors are provided, the turbo compressor having the highest discharge pressure extends from the turbo compressor to the condenser, and when only one turbo compressor is provided, A high-pressure path extending from the turbo compressor to the condenser, and
A refrigerant supply path for guiding the liquid refrigerant from the evaporator toward a high-pressure space including a vapor space inside the condenser and the high-pressure path;
It has.
第1態様によれば、冷凍サイクル装置における圧力比を下げることができる。その結果、サージングを防止又は解消することができる。
According to the first aspect, the pressure ratio in the refrigeration cycle apparatus can be lowered. As a result, surging can be prevented or eliminated.
本開示の第2態様において、例えば、第1態様に係る冷凍サイクル装置は、前記冷媒供給路に配置されたポンプをさらに備えている。ポンプを制御することによって、高圧空間への液相冷媒の供給のタイミングを自由に制御できる。
In the second aspect of the present disclosure, for example, the refrigeration cycle apparatus according to the first aspect further includes a pump disposed in the refrigerant supply path. By controlling the pump, the timing of supplying the liquid phase refrigerant to the high-pressure space can be freely controlled.
本開示の第3態様において、例えば、第1又は第2態様に係る冷凍サイクル装置では、前記冷媒供給路は、吐出側の端部に位置している供給機構を有する。供給機構によれば、圧力比を速やかに下げることができる。
In the third aspect of the present disclosure, for example, in the refrigeration cycle apparatus according to the first or second aspect, the refrigerant supply path has a supply mechanism located at an end portion on the discharge side. According to the supply mechanism, the pressure ratio can be quickly reduced.
本開示の第4態様において、例えば、第3態様に係る冷凍サイクル装置では、前記供給機構は、霧化ノズルを含む。供給機構として霧化ノズルを使用すれば、液相冷媒と気相冷媒との接触面積を十分に増やすことができる。
In the fourth aspect of the present disclosure, for example, in the refrigeration cycle apparatus according to the third aspect, the supply mechanism includes an atomization nozzle. If an atomization nozzle is used as the supply mechanism, the contact area between the liquid-phase refrigerant and the gas-phase refrigerant can be sufficiently increased.
本開示の第5態様において、例えば、第3又は第4態様に係る冷凍サイクル装置では、前記供給機構は、前記気相冷媒の流れ方向に平行な速度成分を前記液相冷媒に付与するように前記高圧空間に配置されている。第5態様によれば、圧力比を下げることに加え、液相冷媒の運動量により、圧縮機から吐出された気相冷媒の圧力を上昇させうる。つまり、圧縮機での圧力上昇幅を減らすことができる。
In the fifth aspect of the present disclosure, for example, in the refrigeration cycle apparatus according to the third or fourth aspect, the supply mechanism applies a velocity component parallel to a flow direction of the gas-phase refrigerant to the liquid-phase refrigerant. It arrange | positions in the said high voltage | pressure space. According to the fifth aspect, in addition to lowering the pressure ratio, the pressure of the gas-phase refrigerant discharged from the compressor can be increased by the momentum of the liquid-phase refrigerant. That is, the pressure increase width in the compressor can be reduced.
本開示の第6態様において、例えば、第1~第5態様のいずれか1つに係る冷凍サイクル装置では、前記高圧経路は、前記気相冷媒の流れ方向における上流側から下流側に向かって流路断面積が徐々に縮小している縮径部を有する。第6態様によれば、液相冷媒の運動量が気相冷媒に効率的に輸送され、圧力上昇の効果が高まることを期待できる。
In the sixth aspect of the present disclosure, for example, in the refrigeration cycle apparatus according to any one of the first to fifth aspects, the high-pressure path flows from the upstream side toward the downstream side in the flow direction of the gas-phase refrigerant. It has a reduced diameter part where the road cross-sectional area is gradually reduced. According to the sixth aspect, it can be expected that the momentum of the liquid-phase refrigerant is efficiently transported to the gas-phase refrigerant and the effect of increasing the pressure is enhanced.
本開示の第7態様において、例えば、第1~第6態様のいずれか1つに係る冷凍サイクル装置では、前記冷凍サイクル装置を停止状態から起動するために前記ターボ圧縮機の回転数を増加させる起動運転、及び、前記冷凍サイクル装置を停止させるために前記ターボ圧縮機の回転数を減少させる停止運転から選ばれる少なくとも1つの運転が行われるとき、前記冷媒供給路を通じて前記高圧空間に前記液相冷媒が供給される。第7態様によれば、冷凍サイクル装置を起動するとき、及び、停止させるときにサージングが発生することを確実に防止できる。
In the seventh aspect of the present disclosure, for example, in the refrigeration cycle apparatus according to any one of the first to sixth aspects, the rotational speed of the turbo compressor is increased to start the refrigeration cycle apparatus from a stopped state. When at least one operation selected from a start-up operation and a stop operation that reduces the number of revolutions of the turbo compressor to stop the refrigeration cycle apparatus is performed, the liquid phase enters the high-pressure space through the refrigerant supply path. Refrigerant is supplied. According to the seventh aspect, it is possible to reliably prevent surging from occurring when starting and stopping the refrigeration cycle apparatus.
本開示の第8態様において、例えば、第1~第6態様のいずれか1つに係る冷凍サイクル装置では、前記ターボ圧縮機の運転状態がサージング状態にあるとき又は前記ターボ圧縮機の運転状態がサージング状態に移行すると予測されるとき、前記冷媒供給路を通じて前記高圧空間に前記液相冷媒が供給される。第8態様によれば、サージングが直ちに解消されるか、サージングの発生を確実に防止できる。
In the eighth aspect of the present disclosure, for example, in the refrigeration cycle apparatus according to any one of the first to sixth aspects, when the operating state of the turbo compressor is in a surging state or the operating state of the turbo compressor is When the transition to the surging state is predicted, the liquid-phase refrigerant is supplied to the high-pressure space through the refrigerant supply path. According to the eighth aspect, surging is immediately eliminated or the occurrence of surging can be reliably prevented.
本開示の第9態様において、例えば、第1~第6態様のいずれか1つに係る冷凍サイクル装置では、前記ターボ圧縮機の回転数が閾値回転数以下であるとき、前記冷媒供給路を通じて前記高圧空間に前記液相冷媒が供給される。第9態様によれば、冷凍サイクル装置を起動するとき、及び、停止させるときにサージングが起こることを確実に防止できる。
In the ninth aspect of the present disclosure, for example, in the refrigeration cycle apparatus according to any one of the first to sixth aspects, when the rotational speed of the turbo compressor is equal to or lower than a threshold rotational speed, The liquid phase refrigerant is supplied to the high pressure space. According to the ninth aspect, it is possible to reliably prevent surging from occurring when starting and stopping the refrigeration cycle apparatus.
本開示の第10態様において、例えば、第1~第9態様のいずれか1つに係る冷凍サイクル装置では、前記冷媒は、常温での飽和蒸気圧が負圧の物質を主成分として含む。このような冷媒を用いた冷凍サイクル装置に本開示の技術を適用することによって、圧力比を十分に低減でき、サージングを確実に防止することができる。
In the tenth aspect of the present disclosure, for example, in the refrigeration cycle apparatus according to any one of the first to ninth aspects, the refrigerant contains a substance whose saturation vapor pressure at room temperature is a negative pressure as a main component. By applying the technique of the present disclosure to a refrigeration cycle apparatus using such a refrigerant, the pressure ratio can be sufficiently reduced, and surging can be reliably prevented.
以下、本開示の実施形態について、図面を参照しながら説明する。本開示は、以下の実施形態に限定されない。
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments.
(実施形態)
図1は、本開示の一実施形態に係る冷凍サイクル装置の構成を示している。冷凍サイクル装置100は、蒸発器2、圧縮機3及び凝縮器4を備えている。圧縮機3は、低圧経路6によって蒸発器2に接続され、高圧経路8によって凝縮器4に接続されている。凝縮器4は、戻し経路9によって蒸発器2に接続されている。蒸発器2、圧縮機3及び凝縮器4は、この順番で環状に接続されて冷媒回路10を構成している。 (Embodiment)
FIG. 1 shows a configuration of a refrigeration cycle apparatus according to an embodiment of the present disclosure. Therefrigeration cycle apparatus 100 includes an evaporator 2, a compressor 3 and a condenser 4. The compressor 3 is connected to the evaporator 2 by a low pressure path 6 and is connected to the condenser 4 by a high pressure path 8. The condenser 4 is connected to the evaporator 2 by a return path 9. The evaporator 2, the compressor 3, and the condenser 4 are annularly connected in this order to constitute the refrigerant circuit 10.
図1は、本開示の一実施形態に係る冷凍サイクル装置の構成を示している。冷凍サイクル装置100は、蒸発器2、圧縮機3及び凝縮器4を備えている。圧縮機3は、低圧経路6によって蒸発器2に接続され、高圧経路8によって凝縮器4に接続されている。凝縮器4は、戻し経路9によって蒸発器2に接続されている。蒸発器2、圧縮機3及び凝縮器4は、この順番で環状に接続されて冷媒回路10を構成している。 (Embodiment)
FIG. 1 shows a configuration of a refrigeration cycle apparatus according to an embodiment of the present disclosure. The
蒸発器2において冷媒が蒸発し、気相冷媒(冷媒蒸気)が生成される。蒸発器2で生成された気相冷媒は、低圧経路6を通じて、圧縮機3に吸入されて圧縮される。圧縮された気相冷媒は、高圧経路8を通じて、凝縮器4に供給される。凝縮器4において気相冷媒が冷却されて液相冷媒(冷媒液)が生成される。液相冷媒は、戻し経路9を通じて、凝縮器4から蒸発器2に送られる。
In the evaporator 2, the refrigerant evaporates, and a gas phase refrigerant (refrigerant vapor) is generated. The gas-phase refrigerant generated in the evaporator 2 is sucked into the compressor 3 through the low-pressure path 6 and compressed. The compressed gas-phase refrigerant is supplied to the condenser 4 through the high-pressure path 8. In the condenser 4, the gas phase refrigerant is cooled to generate a liquid phase refrigerant (refrigerant liquid). The liquid phase refrigerant is sent from the condenser 4 to the evaporator 2 through the return path 9.
冷凍サイクル装置100において、各経路及び各回路は、それぞれ、1又は複数の配管によって構成されうる。
In the refrigeration cycle apparatus 100, each path and each circuit can be configured by one or a plurality of pipes.
冷凍サイクル装置100には、例えば、常温(日本工業規格:20℃±15℃/JIS Z8703)での飽和蒸気圧が負圧(絶対圧で大気圧よりも低い圧力)の物質を主成分として含む冷媒が充填されている。このような冷媒としては、水を主成分として含む冷媒が挙げられる。「主成分」とは、質量比で最も多く含まれた成分を意味する。
The refrigeration cycle apparatus 100 contains, for example, a substance whose saturation vapor pressure at normal temperature (Japanese Industrial Standard: 20 ° C. ± 15 ° C./JIS Z8703) is negative (absolute pressure lower than atmospheric pressure) as a main component. Refrigerant is filled. Examples of such a refrigerant include a refrigerant containing water as a main component. The “main component” means a component that is contained most in mass ratio.
常温での飽和蒸気圧が負圧の物質を主成分として含む冷媒は、気相状態で小さい密度を有する。このような冷媒を用いた冷凍サイクル装置に本開示の技術を適用することによって、圧力比を十分に低減でき、サージングを確実に防止又は解消することができる。
A refrigerant containing a substance whose saturation vapor pressure at room temperature is a negative pressure as a main component has a small density in a gas phase. By applying the technology of the present disclosure to a refrigeration cycle apparatus using such a refrigerant, the pressure ratio can be sufficiently reduced, and surging can be reliably prevented or eliminated.
冷凍サイクル装置100は、さらに、吸熱回路12及び放熱回路14を備えている。
The refrigeration cycle apparatus 100 further includes a heat absorption circuit 12 and a heat dissipation circuit 14.
吸熱回路12は、蒸発器2で冷却された液相冷媒を使用するための回路であり、ポンプ、室内熱交換器などの必要な機器を有している。吸熱回路12の一部は蒸発器2の内部に位置している。蒸発器2の内部において、吸熱回路12の一部は、液相冷媒の液面よりも上に位置していてもよいし、液相冷媒の液面よりも下に位置していてもよい。吸熱回路12には、水、ブラインなどの熱媒体が充填されている。
The heat absorption circuit 12 is a circuit for using the liquid phase refrigerant cooled by the evaporator 2 and has necessary devices such as a pump and an indoor heat exchanger. A part of the heat absorption circuit 12 is located inside the evaporator 2. In the evaporator 2, a part of the endothermic circuit 12 may be located above the liquid level of the liquid phase refrigerant or may be located below the liquid level of the liquid phase refrigerant. The heat absorption circuit 12 is filled with a heat medium such as water or brine.
蒸発器2に貯留された液相冷媒は、吸熱回路12を構成する部材(配管)に接触する。液相冷媒と吸熱回路12の内部の熱媒体との間で熱交換が行われ、液相冷媒が蒸発する。吸熱回路12の内部の熱媒体は、液相冷媒の蒸発潜熱によって冷却される。例えば、冷凍サイクル装置100が室内の冷房を行う空気調和装置である場合、吸熱回路12の熱媒体によって室内の空気が冷却される。室内熱交換器は、例えば、フィンチューブ熱交換器である。
The liquid-phase refrigerant stored in the evaporator 2 comes into contact with members (piping) constituting the heat absorption circuit 12. Heat exchange is performed between the liquid refrigerant and the heat medium in the heat absorption circuit 12, and the liquid refrigerant evaporates. The heat medium in the endothermic circuit 12 is cooled by the latent heat of vaporization of the liquid refrigerant. For example, when the refrigeration cycle apparatus 100 is an air conditioner that cools a room, the room air is cooled by the heat medium of the heat absorption circuit 12. The indoor heat exchanger is, for example, a fin tube heat exchanger.
蒸発器2の液相冷媒の冷却対象は室内の空気に限定されない。蒸発器2の冷却対象は、空気以外の気体であってもよく、液体であってもよい。
The cooling target of the liquid refrigerant in the evaporator 2 is not limited to indoor air. The cooling target of the evaporator 2 may be a gas other than air or a liquid.
放熱回路14は、凝縮器4の内部の冷媒から熱を奪うために使用される回路であり、ポンプ、冷却塔などの必要な機器を有している。放熱回路14の一部は凝縮器4の内部に位置している。詳細には、凝縮器4の内部において、放熱回路14の一部は、液相冷媒の液面よりも上に位置している。放熱回路14には、水、ブラインなどの熱媒体が充填されている。冷凍サイクル装置100が室内の冷房を行う空気調和装置である場合、凝縮器4は室外に配置され、放熱回路14の熱媒体によって凝縮器4の冷媒が冷却される。
The heat dissipation circuit 14 is a circuit used to take heat from the refrigerant inside the condenser 4 and has necessary devices such as a pump and a cooling tower. A part of the heat dissipation circuit 14 is located inside the condenser 4. Specifically, a part of the heat dissipation circuit 14 is located above the liquid level of the liquid-phase refrigerant in the condenser 4. The heat dissipation circuit 14 is filled with a heat medium such as water or brine. When the refrigeration cycle apparatus 100 is an air conditioner that cools a room, the condenser 4 is disposed outside the room, and the refrigerant in the condenser 4 is cooled by the heat medium of the heat dissipation circuit 14.
圧縮機3から吐出された高温の気相冷媒は、凝縮器4の内部において、放熱回路14を構成する部材(配管)に接触する。気相冷媒と放熱回路14の内部の熱媒体との間で熱交換が行われ、気相冷媒が凝縮する。放熱回路14の内部の熱媒体は、気相冷媒の凝縮潜熱によって加熱される。気相冷媒によって加熱された熱媒体は、例えば、放熱回路14の冷却塔(図示せず)において外気又は冷却水によって冷却される。
The high-temperature gas-phase refrigerant discharged from the compressor 3 contacts a member (pipe) constituting the heat dissipation circuit 14 inside the condenser 4. Heat exchange is performed between the gas-phase refrigerant and the heat medium inside the heat dissipation circuit 14, and the gas-phase refrigerant is condensed. The heat medium inside the heat dissipation circuit 14 is heated by the condensation latent heat of the gas-phase refrigerant. The heat medium heated by the gas-phase refrigerant is cooled by outside air or cooling water in a cooling tower (not shown) of the heat dissipation circuit 14, for example.
蒸発器2は、例えば、断熱性及び耐圧性を有する容器によって構成されている。蒸発器2は、液相冷媒を貯留するとともに、液相冷媒を内部で蒸発させる。蒸発器2の内部の液相冷媒は、蒸発器2の外部からもたらされた熱を吸収し、蒸発する。すなわち、吸熱回路12から熱を吸収することによって加熱された液相冷媒が蒸発器2の中で蒸発する。本実施形態において、蒸発器2に貯留された液相冷媒は、吸熱回路12を循環する熱媒体と間接的に接触する。つまり、蒸発器2に貯留された液相冷媒の一部は、吸熱回路12の熱媒体によって加熱され、飽和状態の液相冷媒を加熱するために使用される。蒸発器2に貯留された液相冷媒の温度、及び、蒸発器2で生成された気相冷媒の温度は、例えば5℃である。
The evaporator 2 is constituted by a container having heat insulation and pressure resistance, for example. The evaporator 2 stores the liquid phase refrigerant and evaporates the liquid phase refrigerant inside. The liquid refrigerant inside the evaporator 2 absorbs heat generated from the outside of the evaporator 2 and evaporates. That is, the liquid-phase refrigerant heated by absorbing heat from the heat absorption circuit 12 evaporates in the evaporator 2. In the present embodiment, the liquid-phase refrigerant stored in the evaporator 2 indirectly contacts the heat medium circulating in the heat absorption circuit 12. That is, a part of the liquid phase refrigerant stored in the evaporator 2 is heated by the heat medium of the heat absorption circuit 12 and used to heat the liquid phase refrigerant in the saturated state. The temperature of the liquid-phase refrigerant stored in the evaporator 2 and the temperature of the gas-phase refrigerant generated in the evaporator 2 are 5 ° C., for example.
本実施形態において、蒸発器2は、間接接触型の熱交換器(例えば、シェルチューブ熱交換器)である。ただし、蒸発器2は、噴霧式又は充填材式の熱交換器のような直接接触型の熱交換器であってもよい。つまり、吸熱回路12に液相冷媒を循環させることによって、液相冷媒を加熱してもよい。さらに、吸熱回路12が省略されていてもよい。
In the present embodiment, the evaporator 2 is an indirect contact heat exchanger (for example, a shell tube heat exchanger). However, the evaporator 2 may be a direct contact type heat exchanger such as a spray type or filler type heat exchanger. That is, the liquid phase refrigerant may be heated by circulating the liquid phase refrigerant in the heat absorption circuit 12. Further, the endothermic circuit 12 may be omitted.
圧縮機3は、蒸発器2で生成された気相冷媒を吸入して圧縮する。圧縮機3は、例えば、速度型圧縮機(dynamic compressor)である。速度型圧縮機は、気相冷媒に運動量を与え、その後、減速させることによって気相冷媒の圧力を上昇させる圧縮機である。速度型圧縮機として、遠心圧縮機、斜流圧縮機、軸流圧縮機などが挙げられる。速度型圧縮機は、ターボ圧縮機とも呼ばれる。圧縮機3は、回転数を変化させるための可変速機構を備えていてもよい。可変速機構の例は、圧縮機3のモータを駆動するインバータである。圧縮機3の吐出口における冷媒の温度は、例えば100~150℃の範囲にある。
The compressor 3 sucks and compresses the gas-phase refrigerant generated by the evaporator 2. The compressor 3 is, for example, a speed type compressor (dynamic compressor). The speed type compressor is a compressor that increases the pressure of the gas-phase refrigerant by giving momentum to the gas-phase refrigerant and then decelerating it. Examples of the speed type compressor include a centrifugal compressor, a mixed flow compressor, and an axial flow compressor. The speed type compressor is also called a turbo compressor. The compressor 3 may include a variable speed mechanism for changing the rotation speed. An example of the variable speed mechanism is an inverter that drives the motor of the compressor 3. The temperature of the refrigerant at the discharge port of the compressor 3 is in the range of 100 to 150 ° C., for example.
凝縮器4は、例えば、断熱性及び耐圧性を有する容器によって構成されている。凝縮器4は、圧縮機3で圧縮された気相冷媒を凝縮させるとともに、気相冷媒を凝縮させることによって生じた液相冷媒を貯留する。本実施形態では、外部環境に熱を放出することによって冷却された熱媒体に気相冷媒が間接的に接触して凝縮する。つまり、気相冷媒は、放熱回路14の熱媒体によって冷却され、凝縮する。凝縮器4に導入される気相冷媒の温度は、例えば、100~150℃の範囲にある。凝縮器4に貯留された液相冷媒の温度は、例えば35℃である。
The condenser 4 is constituted by a container having heat insulation and pressure resistance, for example. The condenser 4 condenses the gas-phase refrigerant compressed by the compressor 3 and stores the liquid-phase refrigerant generated by condensing the gas-phase refrigerant. In the present embodiment, the gas-phase refrigerant indirectly condenses and condenses on the heat medium cooled by releasing heat to the external environment. That is, the gas phase refrigerant is cooled and condensed by the heat medium of the heat dissipation circuit 14. The temperature of the gas-phase refrigerant introduced into the condenser 4 is in the range of 100 to 150 ° C., for example. The temperature of the liquid phase refrigerant stored in the condenser 4 is, for example, 35 ° C.
本実施形態において、凝縮器4は、間接接触型の熱交換器(例えば、シェルチューブ熱交換器)である。ただし、凝縮器4は、噴霧式又は充填材式の熱交換器のような直接接触型の熱交換器であってもよい。つまり、放熱回路14に液相冷媒を循環させることによって、液相冷媒を冷却してもよい。さらに、放熱回路14が省略されていてもよい。
In the present embodiment, the condenser 4 is an indirect contact heat exchanger (for example, a shell tube heat exchanger). However, the condenser 4 may be a direct contact type heat exchanger such as a spray type or filler type heat exchanger. That is, the liquid phase refrigerant may be cooled by circulating the liquid phase refrigerant in the heat dissipation circuit 14. Further, the heat dissipation circuit 14 may be omitted.
低圧経路6は、蒸発器2から圧縮機3に気相冷媒を導くための流路である。低圧経路6を介して、蒸発器2の出口が圧縮機3の吸入口に接続されている。
The low pressure path 6 is a flow path for guiding the gas phase refrigerant from the evaporator 2 to the compressor 3. The outlet of the evaporator 2 is connected to the suction port of the compressor 3 through the low pressure path 6.
高圧経路8は、圧縮機3から凝縮器4に圧縮された気相冷媒を導くための流路である。高圧経路8を介して、圧縮機3の吐出口が凝縮器4の入口に接続されている。
The high-pressure path 8 is a flow path for guiding the gas-phase refrigerant compressed from the compressor 3 to the condenser 4. The discharge port of the compressor 3 is connected to the inlet of the condenser 4 through the high pressure path 8.
本実施形態では、圧縮機3が1つのみ設けられている。高圧経路8は、その圧縮機3を起点として凝縮器4まで延びている流路である。
In this embodiment, only one compressor 3 is provided. The high pressure path 8 is a flow path extending from the compressor 3 to the condenser 4.
戻し経路9は、凝縮器4から蒸発器2に液相冷媒を導くための流路である。戻し経路9によって、蒸発器2と凝縮器4とが接続されている。戻し経路9には、弁17が配置されている。弁17は、開閉弁であってもよく、流量調整弁であってもよい。戻し経路9にポンプ、センサなどの他のコンポーネントが配置されていてもよい。
The return path 9 is a flow path for guiding the liquid refrigerant from the condenser 4 to the evaporator 2. The evaporator 2 and the condenser 4 are connected by the return path 9. A valve 17 is arranged in the return path 9. The valve 17 may be an on-off valve or a flow rate adjustment valve. Other components such as a pump and a sensor may be arranged in the return path 9.
冷凍サイクル装置100は、センサ20をさらに備えている。本実施形態では、センサ20は、蒸発器2に取り付けられている。センサ20は、温度センサであってもよく、圧力センサであってもよく、その両方を含んでいてもよい。センサ20が温度センサであるとき、センサ20は、蒸発器2の中の液相冷媒又は気相冷媒の温度を検出する。つまり、センサ20は、蒸発器2における蒸発温度を検出しうる。センサ20が圧力センサであるとき、センサ20は、蒸発器2の内部の圧力を検出する。つまり、センサ20は、蒸発器2における飽和蒸気圧を検出しうる。
The refrigeration cycle apparatus 100 further includes a sensor 20. In the present embodiment, the sensor 20 is attached to the evaporator 2. The sensor 20 may be a temperature sensor, a pressure sensor, or both of them. When the sensor 20 is a temperature sensor, the sensor 20 detects the temperature of the liquid-phase refrigerant or the gas-phase refrigerant in the evaporator 2. That is, the sensor 20 can detect the evaporation temperature in the evaporator 2. When the sensor 20 is a pressure sensor, the sensor 20 detects the pressure inside the evaporator 2. That is, the sensor 20 can detect the saturated vapor pressure in the evaporator 2.
冷凍サイクル装置100は、センサ21をさらに備えている。本実施形態では、センサ21は、凝縮器4に取り付けられている。センサ21は、温度センサであってもよく、圧力センサであってもよく、その両方を含んでいてもよい。センサ21が温度センサであるとき、センサ21は、凝縮器4の中の液相冷媒又は気相冷媒の温度を検出する。つまり、センサ21は、凝縮器4における凝縮温度を検出しうる。センサ21が圧力センサであるとき、センサ21は、凝縮器4の内部の圧力を検出する。つまり、センサ21は、凝縮器4における飽和蒸気圧を検出しうる。
The refrigeration cycle apparatus 100 further includes a sensor 21. In the present embodiment, the sensor 21 is attached to the condenser 4. The sensor 21 may be a temperature sensor, a pressure sensor, or both of them. When the sensor 21 is a temperature sensor, the sensor 21 detects the temperature of the liquid-phase refrigerant or the gas-phase refrigerant in the condenser 4. That is, the sensor 21 can detect the condensation temperature in the condenser 4. When the sensor 21 is a pressure sensor, the sensor 21 detects the pressure inside the condenser 4. That is, the sensor 21 can detect the saturated vapor pressure in the condenser 4.
センサ20は、低圧経路6に配置されていてもよい。センサ21は、高圧経路8に配置されていてもよい。
The sensor 20 may be disposed in the low pressure path 6. The sensor 21 may be disposed in the high pressure path 8.
温度センサとしては、サーミスタを用いた温度センサ、熱電対を用いた温度センサなどが挙げられる。圧力センサとしては、静電容量式圧力センサ、抵抗線式圧力センサ、ピエゾ抵抗式圧力センサなどが挙げられる。
The temperature sensor includes a temperature sensor using a thermistor, a temperature sensor using a thermocouple, and the like. Examples of the pressure sensor include a capacitive pressure sensor, a resistance wire pressure sensor, and a piezoresistive pressure sensor.
冷凍サイクル装置100は、冷媒供給路11をさらに備えている。冷媒供給路11は、高圧空間15に向けて蒸発器2から液相冷媒を導く流路である。図1に示す例では、冷媒供給路11は、蒸発器2と高圧経路8とを接続している。あるいは、冷媒供給路11は、蒸発器2と凝縮器4の内部の蒸気空間とを接続していてもよい。さらに、冷媒供給路11は、分岐していてもよく、分岐した冷媒供給路11のそれぞれが高圧経路8と凝縮器4の内部の蒸気空間とに接続されていてもよい。高圧空間15は、凝縮器4の内部の蒸気空間と高圧経路8とを含む空間である。「凝縮器4の内部の蒸気空間」は、凝縮器4に貯留された液相冷媒の液面の上方の空間を意味する。冷媒供給路11の入口は、蒸発器2の下部に位置している。このような構成によれば、冷媒供給路11を通じて高圧空間15に低温の液相冷媒を安定して供給できる。「蒸発器2の下部」は、蒸発器2に貯留された液相冷媒の液面よりも下の部分を意味する。
The refrigeration cycle apparatus 100 further includes a refrigerant supply path 11. The refrigerant supply path 11 is a flow path that guides the liquid phase refrigerant from the evaporator 2 toward the high-pressure space 15. In the example shown in FIG. 1, the refrigerant supply path 11 connects the evaporator 2 and the high-pressure path 8. Alternatively, the refrigerant supply path 11 may connect the evaporator 2 and the vapor space inside the condenser 4. Further, the refrigerant supply path 11 may be branched, and each of the branched refrigerant supply paths 11 may be connected to the high-pressure path 8 and the vapor space inside the condenser 4. The high-pressure space 15 is a space including the vapor space inside the condenser 4 and the high-pressure path 8. “Vapor space inside the condenser 4” means a space above the liquid level of the liquid-phase refrigerant stored in the condenser 4. The inlet of the refrigerant supply path 11 is located below the evaporator 2. According to such a configuration, the low-temperature liquid phase refrigerant can be stably supplied to the high-pressure space 15 through the refrigerant supply path 11. The “lower part of the evaporator 2” means a part below the liquid level of the liquid-phase refrigerant stored in the evaporator 2.
蒸発器2に貯留された低温の液相冷媒が冷媒供給路11を通じて高圧空間15に供給されると、液相冷媒は、圧縮機3から吐出された高温の気相冷媒に接触し、気相冷媒を凝縮させる。これにより、凝縮温度、すなわち、凝縮圧力を下げることができる。凝縮圧力を下げることによって、圧力比を下げることができる。本開示によれば、気相状態での密度が小さい冷媒が使用されている場合にも、圧力比を低減する効果は十分に得られる。
When the low-temperature liquid phase refrigerant stored in the evaporator 2 is supplied to the high-pressure space 15 through the refrigerant supply path 11, the liquid-phase refrigerant comes into contact with the high-temperature gas phase refrigerant discharged from the compressor 3. Allow the refrigerant to condense. Thereby, the condensation temperature, that is, the condensation pressure can be lowered. By reducing the condensation pressure, the pressure ratio can be lowered. According to the present disclosure, the effect of reducing the pressure ratio can be sufficiently obtained even when a refrigerant having a low density in the gas phase is used.
「圧力比」は、圧縮機3の吸入口における圧力(吸入圧力)に対する吐出口における圧力(吐出圧力)の比率である。圧力比は、1又は複数のセンサから得られた検出値から算出することができる。例えば、センサ20及び21がともに圧力センサである場合、センサ21の検出値をセンサ20の検出値で除することによって、圧力比を算出できる。センサ20及び21が温度センサである場合、液相冷媒の温度から飽和蒸気圧を算出し、飽和蒸気圧から圧力比を算出できる。蒸発器2に貯留された液相冷媒の温度が一定になるように制御が行われることが多いので、凝縮器4における凝縮温度(センサ21の検出値)から圧力比を推定することも可能である。圧力比の算出方法は特に限定されない。
The “pressure ratio” is the ratio of the pressure (discharge pressure) at the discharge port to the pressure (suction pressure) at the suction port of the compressor 3. The pressure ratio can be calculated from detection values obtained from one or more sensors. For example, when both the sensors 20 and 21 are pressure sensors, the pressure ratio can be calculated by dividing the detection value of the sensor 21 by the detection value of the sensor 20. When the sensors 20 and 21 are temperature sensors, the saturated vapor pressure can be calculated from the temperature of the liquid refrigerant, and the pressure ratio can be calculated from the saturated vapor pressure. Since control is often performed so that the temperature of the liquid-phase refrigerant stored in the evaporator 2 is constant, the pressure ratio can also be estimated from the condensation temperature (detected value of the sensor 21) in the condenser 4. is there. The method for calculating the pressure ratio is not particularly limited.
冷媒供給路11には、ポンプ16が配置されている。ポンプ16を制御することによって、高圧空間15への液相冷媒の供給のタイミングを自由に制御できる。ポンプ16は、例えば、ピストンポンプ、プランジャポンプ、ギヤポンプ、ベーンポンプなどの容積式ポンプである。ポンプ16は、供給流量を変更可能なポンプであってもよい。この場合、冷凍サイクル装置100の運転状態に応じて適切な流量にて液相冷媒を高圧空間15に供給しやすい。
A pump 16 is disposed in the refrigerant supply path 11. By controlling the pump 16, the timing of supplying the liquid phase refrigerant to the high pressure space 15 can be freely controlled. The pump 16 is, for example, a positive displacement pump such as a piston pump, a plunger pump, a gear pump, or a vane pump. The pump 16 may be a pump that can change the supply flow rate. In this case, it is easy to supply the liquid refrigerant to the high-pressure space 15 at an appropriate flow rate according to the operating state of the refrigeration cycle apparatus 100.
冷媒供給路11は、吐出側の端部に位置している供給機構11aを有する。供給機構11aは、液相冷媒の表面積を拡大させ、液相冷媒と圧縮機3から吐出された気相冷媒との接触面積を増大させる役割を担っている。供給機構11aによれば、圧力比を速やかに下げることができる。
The refrigerant supply path 11 has a supply mechanism 11a located at the end on the discharge side. The supply mechanism 11 a has a role of increasing the surface area of the liquid-phase refrigerant and increasing the contact area between the liquid-phase refrigerant and the gas-phase refrigerant discharged from the compressor 3. According to the supply mechanism 11a, the pressure ratio can be quickly reduced.
供給機構11aの構造は特に限定されない。供給機構11aは、例えば、液相冷媒を微粒化して供給する霧化ノズルである。供給機構11aとして霧化ノズルを使用すれば、液相冷媒と気相冷媒との接触面積を十分に増やすことができる。霧化ノズルとして、超音波霧化ノズル、旋回流式の霧化ノズル、衝突式の霧化ノズルなどが挙げられる。超音波霧化ノズルは、超音波を利用して液体を微粒化する噴霧ノズルである。旋回式の霧化ノズルは、遠心力を利用して液体を微粒化する噴霧ノズルである。衝突式の霧化ノズルは、液体を障害物(ターゲット)に衝突させることによって微粒化する噴霧ノズルである。
The structure of the supply mechanism 11a is not particularly limited. The supply mechanism 11a is, for example, an atomization nozzle that atomizes and supplies liquid phase refrigerant. If an atomizing nozzle is used as the supply mechanism 11a, the contact area between the liquid-phase refrigerant and the gas-phase refrigerant can be sufficiently increased. Examples of the atomizing nozzle include an ultrasonic atomizing nozzle, a swirl flow type atomizing nozzle, and a collision type atomizing nozzle. The ultrasonic atomizing nozzle is a spray nozzle that atomizes a liquid using ultrasonic waves. A swirl-type atomizing nozzle is a spray nozzle that atomizes a liquid using centrifugal force. The collision type atomizing nozzle is a spray nozzle that atomizes a liquid by colliding with an obstacle (target).
供給機構11aからの液相冷媒の吐出方向(噴霧方向)は、気相冷媒の流れ方向に平行であってもよく、垂直であってもよい。液相冷媒の吐出方向が気相冷媒の流れ方向に交差していてもよい。
The discharge direction (spraying direction) of the liquid refrigerant from the supply mechanism 11a may be parallel to or perpendicular to the flow direction of the gas-phase refrigerant. The discharge direction of the liquid phase refrigerant may intersect the flow direction of the gas phase refrigerant.
さらに、供給機構11aは、高圧経路8の内面に沿って液相冷媒を流すように構成されていてもよく、凝縮器4の内面に沿って液相冷媒を流すように構成されていてもよい。
Further, the supply mechanism 11 a may be configured to flow the liquid phase refrigerant along the inner surface of the high-pressure path 8, or may be configured to flow the liquid phase refrigerant along the inner surface of the condenser 4. .
冷媒供給路11には、弁、センサなどの他のコンポーネントが配置されていてもよい。
Other components such as valves and sensors may be arranged in the refrigerant supply path 11.
冷凍サイクル装置100は、制御器22をさらに備えている。制御器22は、例えば、A/D変換回路、入出力回路、演算回路、記憶装置などを含むDSP(Digital Signal Processor)である。センサ20、センサ21などの計測機器の検出信号が制御器22に入力される。制御器22は、各種計測機器の計測結果に基づき、圧縮機3、ポンプ16、弁17などの制御対象を制御する。制御器22には、冷凍サイクル装置100を適切に運転するためのプログラムが格納されている。
The refrigeration cycle apparatus 100 further includes a controller 22. The controller 22 is, for example, a DSP (Digital Signal Processor) including an A / D conversion circuit, an input / output circuit, an arithmetic circuit, a storage device, and the like. Detection signals from measuring devices such as the sensor 20 and the sensor 21 are input to the controller 22. The controller 22 controls controlled objects such as the compressor 3, the pump 16, and the valve 17 based on the measurement results of various measuring devices. The controller 22 stores a program for appropriately operating the refrigeration cycle apparatus 100.
制御器22は、圧縮機3を駆動するインバータを含んでいてもよく、ポンプ16を駆動するインバータを含んでいてもよい。制御器22は、単一のマイクロコンピュータによって構成されていてもよく、複数のマイクロコンピュータによって構成されていてもよい。さらに、冷凍サイクル装置100が複数の制御器を有していてもよい。
The controller 22 may include an inverter that drives the compressor 3, and may include an inverter that drives the pump 16. The controller 22 may be constituted by a single microcomputer or a plurality of microcomputers. Furthermore, the refrigeration cycle apparatus 100 may have a plurality of controllers.
制御器22は、センサ20及び/又はセンサ21からセンサ信号を取得し、取得したセンサ信号から冷凍サイクル装置100における圧力比(吐出圧力/吸入圧力)を特定する。制御器22は、特定した圧力比及び圧縮機3における冷媒の流量(質量流量)に基づき、圧縮機3の運転状態を特定し、必要に応じて、冷媒供給路11を通じて高圧空間15に液相冷媒を供給するための電気的処理を実行する。冷媒の流量は、圧縮機3の回転数から推定することができる。一般に、ターボ圧縮機が十分に大きい回転数で運転されているとき、流量は回転数に概ね比例する。「十分に大きい回転数」は、ターボ圧縮機の設計に応じて決まる。
Controller 22 acquires a sensor signal from sensor 20 and / or sensor 21, and specifies a pressure ratio (discharge pressure / intake pressure) in refrigeration cycle apparatus 100 from the acquired sensor signal. The controller 22 specifies the operating state of the compressor 3 based on the specified pressure ratio and the flow rate (mass flow rate) of the refrigerant in the compressor 3, and if necessary, enters the liquid phase into the high-pressure space 15 through the refrigerant supply path 11. An electrical process for supplying the refrigerant is executed. The flow rate of the refrigerant can be estimated from the rotational speed of the compressor 3. In general, when the turbo compressor is operated at a sufficiently high rotational speed, the flow rate is approximately proportional to the rotational speed. The “sufficiently large number of revolutions” depends on the design of the turbo compressor.
ターボ圧縮機が特定の回転数で運転されているときに圧力比が許容値を超えると、サージングが発生する。ターボ圧縮機の回転数と圧力比との間には一定の制約が存在し、その制約の範囲外でターボ圧縮機を運転するとサージングが発生する。
Surging occurs when the pressure ratio exceeds the allowable value when the turbo compressor is operating at a specific speed. There is a certain restriction between the rotational speed of the turbo compressor and the pressure ratio, and surging occurs when the turbo compressor is operated outside the restriction.
図2は、圧縮機3の特性を示している。図2のグラフは、例えば、ルックアップテーブルの形式で制御器22のメモリに記憶されている。実線の曲線Pによって規定された領域は、サージング及びチョーキングを起こすことなく、圧縮機3を正常に運転できる領域である。圧力比が上昇して圧縮機3の運転状態が曲線Pによって規定された領域から逸脱したとき、つまり、圧縮機3の運転状態がサージング状態にあるとき、冷媒供給路11を通じて高圧空間15に液相冷媒が供給されうる。安全性を考慮して、圧縮機3の運転状態が破線の曲線P1によって規定された領域から逸脱したとき、すなわち、圧縮機3の運転状態がサージング状態に移行すると予測されるとき、冷媒供給路11を通じて高圧空間に液相冷媒が供給されてもよい。このようにすれば、サージングが直ちに解消されるか、サージングの発生を確実に防止できる。
FIG. 2 shows the characteristics of the compressor 3. The graph of FIG. 2 is stored in the memory of the controller 22 in the form of a lookup table, for example. The region defined by the solid curve P is a region where the compressor 3 can be operated normally without causing surging and choking. When the pressure ratio increases and the operating state of the compressor 3 deviates from the region defined by the curve P, that is, when the operating state of the compressor 3 is in the surging state, the liquid is supplied to the high-pressure space 15 through the refrigerant supply path 11. Phase refrigerant can be supplied. In consideration of safety, when the operating state of the compressor 3 deviates from the region defined by the dashed curve P1, that is, when the operating state of the compressor 3 is predicted to shift to the surging state, the refrigerant supply path The liquid phase refrigerant may be supplied to the high-pressure space through 11. In this way, surging can be eliminated immediately or the occurrence of surging can be reliably prevented.
曲線Pにおける流量と圧力比との組が圧縮機3の許容値であるとき、サージングに関して言えば、曲線P1における圧力比は、許容値よりも低い値に設定されうる。例えば、同一の流量で比較したとき、曲線P1における圧力比は、曲線Pにおける圧力比よりも1%~10%程度小さい。
When the combination of the flow rate and the pressure ratio in the curve P is an allowable value of the compressor 3, regarding surging, the pressure ratio in the curve P1 can be set to a value lower than the allowable value. For example, when compared at the same flow rate, the pressure ratio in the curve P1 is about 1% to 10% smaller than the pressure ratio in the curve P.
圧縮機3の回転数が所定の閾値回転数(例えば、2万回転/min)よりも大きいとき、冷媒の流量は、圧縮機3の回転数に応じて決まる。したがって、圧縮機3の回転数を用いて、圧縮機3の運転状態を判断することができる。詳細には、吸入圧力及び圧縮機3の回転数に応じて、冷媒の流量が決まる。吸入圧力、吐出圧力及び圧縮機3の回転数に基づいて、圧縮機3の運転状態を特定することができる。「閾値回転数」は、圧縮機3の設計値である。圧縮機3の回転数は、圧縮機3のモータを制御するための制御器(例えば、制御器22)のメモリに常に格納されている値である。
When the rotation speed of the compressor 3 is larger than a predetermined threshold rotation speed (for example, 20,000 rotations / min), the flow rate of the refrigerant is determined according to the rotation speed of the compressor 3. Therefore, the operating state of the compressor 3 can be determined using the rotation speed of the compressor 3. Specifically, the flow rate of the refrigerant is determined according to the suction pressure and the rotation speed of the compressor 3. Based on the suction pressure, the discharge pressure, and the rotation speed of the compressor 3, the operating state of the compressor 3 can be specified. The “threshold rotation speed” is a design value of the compressor 3. The rotational speed of the compressor 3 is a value that is always stored in the memory of a controller (for example, the controller 22) for controlling the motor of the compressor 3.
冷凍サイクル装置100を停止状態から起動させるとき、及び、冷凍サイクル装置100を停止させるとき、圧縮機3の回転数は、閾値回転数を下回る。したがって、冷凍サイクル装置100を停止状態から起動するために圧縮機3の回転数を増加させる起動運転、及び、冷凍サイクル装置100を停止させるために圧縮機3の回転数を減少させる停止運転から選ばれる少なくとも1つの運転が行われるとき、冷媒供給路11を通じて高圧空間15に液相冷媒を供給してもよい。これにより、冷凍サイクル装置100を起動するとき、及び、停止させるときにサージングが発生することを確実に防止できる。「停止状態」は、例えば、圧縮機3の回転数がゼロである状態を意味する。
When the refrigeration cycle apparatus 100 is started from a stopped state and when the refrigeration cycle apparatus 100 is stopped, the rotational speed of the compressor 3 is lower than the threshold rotational speed. Therefore, the start-up operation for increasing the rotation speed of the compressor 3 to start the refrigeration cycle apparatus 100 from the stop state and the stop operation for decreasing the rotation speed of the compressor 3 to stop the refrigeration cycle apparatus 100 are selected. When at least one operation is performed, the liquid-phase refrigerant may be supplied to the high-pressure space 15 through the refrigerant supply path 11. Thereby, it is possible to reliably prevent surging from occurring when the refrigeration cycle apparatus 100 is started and stopped. “Stopped state” means, for example, a state where the rotational speed of the compressor 3 is zero.
圧力比は、負荷の大きさ、外気温度などに応じて変動する。定格運転又は部分負荷運転から圧縮機3の回転数を下げて冷凍サイクル装置100を停止させるとき、圧力比が高い状態から圧縮機3の回転数を下げる必要がある。圧力比の低下速度が回転数の低下速度に追従できず、圧縮機3の運転状態がサージング領域に移行する可能性がある。したがって、運転停止の命令が冷凍サイクル装置100に与えられた場合(例えば、停止スイッチがオンされた場合)、冷媒供給路11を通じて高圧空間15に液相冷媒を供給し、圧力比を十分に下げたのち、圧縮機3の回転数を低下させてもよい。このようにすれば、サージングを発生させることなく、冷凍サイクル装置100をスムーズかつ安全に停止させることができる。
The pressure ratio varies depending on the size of the load and the outside air temperature. When the refrigeration cycle apparatus 100 is stopped by reducing the rotation speed of the compressor 3 from the rated operation or the partial load operation, it is necessary to decrease the rotation speed of the compressor 3 from a state where the pressure ratio is high. There is a possibility that the rate of decrease in the pressure ratio cannot follow the rate of decrease in the rotational speed, and the operating state of the compressor 3 shifts to the surging region. Therefore, when an instruction to stop the operation is given to the refrigeration cycle apparatus 100 (for example, when the stop switch is turned on), the liquid phase refrigerant is supplied to the high-pressure space 15 through the refrigerant supply path 11 to sufficiently reduce the pressure ratio. After that, the rotational speed of the compressor 3 may be decreased. In this way, the refrigeration cycle apparatus 100 can be smoothly and safely stopped without causing surging.
圧縮機3の回転数が閾値回転数(例えば、2万回転/min)以下のとき、冷媒が十分に流れない。この現象は、冷凍サイクル装置100の内部の圧力が大気圧よりも低い場合に顕著である。したがって、圧縮機3の回転数が閾値回転数以下であるとき、冷媒供給路11を通じて高圧空間15に液相冷媒が供給されうる。これにより、冷凍サイクル装置100を起動するとき、及び、停止させるときにサージングが起こることを確実に防止できる。
When the rotation speed of the compressor 3 is not more than a threshold rotation speed (for example, 20,000 rotations / min), the refrigerant does not flow sufficiently. This phenomenon is remarkable when the internal pressure of the refrigeration cycle apparatus 100 is lower than atmospheric pressure. Therefore, when the rotation speed of the compressor 3 is equal to or lower than the threshold rotation speed, the liquid phase refrigerant can be supplied to the high-pressure space 15 through the refrigerant supply path 11. Thereby, it is possible to reliably prevent surging from occurring when the refrigeration cycle apparatus 100 is started and stopped.
次に、サージングを防止するための制御について説明する。
Next, control for preventing surging will be described.
冷凍サイクル装置100の起動スイッチがオンされたのち、制御器22は、図3に示すサージング防止制御を必要に応じて実行する。
After the start-up switch of the refrigeration cycle apparatus 100 is turned on, the controller 22 executes the surging prevention control shown in FIG. 3 as necessary.
ステップS1において、圧縮機3の現在の回転数が閾値回転数以上であるかどうかを判断する。圧縮機3の回転数が閾値回転数未満である場合、ステップS4において、ポンプ16を作動させる。これにより、高圧空間15に液相冷媒が供給され、圧力比を下げることができる。その結果、サージングが防止されうる。
In step S1, it is determined whether or not the current rotational speed of the compressor 3 is equal to or greater than a threshold rotational speed. When the rotation speed of the compressor 3 is less than the threshold rotation speed, the pump 16 is operated in step S4. Thereby, the liquid phase refrigerant is supplied to the high-pressure space 15, and the pressure ratio can be lowered. As a result, surging can be prevented.
圧縮機3の回転数が閾値回転数以上である場合、ステップS2において、現在の圧力比が閾値圧力比以下であるかどうかを判断する。圧力比が閾値圧力比を超えている場合、ステップS4において、ポンプ16を作動させる。これにより、高圧空間15に液相冷媒が供給され、圧力比を下げることができる。その結果、サージングが防止される。閾値圧力比は、例えば、図2を参照して説明した曲線P1に対応しており、圧縮機3の回転数(流量)に応じて定められる。
If the rotation speed of the compressor 3 is equal to or greater than the threshold rotation speed, it is determined in step S2 whether or not the current pressure ratio is equal to or less than the threshold pressure ratio. If the pressure ratio exceeds the threshold pressure ratio, the pump 16 is operated in step S4. Thereby, the liquid phase refrigerant is supplied to the high-pressure space 15, and the pressure ratio can be lowered. As a result, surging is prevented. The threshold pressure ratio corresponds to, for example, the curve P1 described with reference to FIG. 2, and is determined according to the rotation speed (flow rate) of the compressor 3.
圧縮機3の回転数が閾値回転数以上であり、かつ、圧力比が閾値圧力比以下である場合、ステップS3においてポンプ16を停止させる。これにより、冷凍サイクル装置100の性能及び効率が必要以上に下がることを回避できる。
When the rotation speed of the compressor 3 is equal to or higher than the threshold rotation speed and the pressure ratio is equal to or lower than the threshold pressure ratio, the pump 16 is stopped in step S3. Thereby, it can avoid that the performance and efficiency of the refrigerating-cycle apparatus 100 fall more than necessary.
先に説明したように、冷凍サイクル装置100の停止スイッチがオンされた場合、図3に示す制御を行わず、直ちにポンプ16を作動させてもよい。
As described above, when the stop switch of the refrigeration cycle apparatus 100 is turned on, the pump 16 may be operated immediately without performing the control shown in FIG.
(変形例)
図4は、変形例に係る冷凍サイクル装置の構成を示している。冷凍サイクル装置200において、供給機構11aは、気相冷媒の流れ方向に平行な速度成分を液相冷媒に付与するように高圧空間15に配置されている。具体的には、供給機構11aからの液相冷媒の吐出方向(噴霧方向)が気相冷媒の流れ方向に概ね一致している。このような構成によれば、圧力比を下げることに加え、液相冷媒の運動量により、圧縮機3から吐出された気相冷媒の圧力を上昇させうる。つまり、圧縮機3での圧力上昇幅を減らすことができる。このような構成は、高負荷運転時において特に有効である。高負荷運転としては、高い外気温条件での運転、高い圧力比条件での運転などが挙げられる。 (Modification)
FIG. 4 shows a configuration of a refrigeration cycle apparatus according to a modification. In therefrigeration cycle apparatus 200, the supply mechanism 11a is disposed in the high-pressure space 15 so as to impart a velocity component parallel to the flow direction of the gas-phase refrigerant to the liquid-phase refrigerant. Specifically, the discharge direction (spraying direction) of the liquid-phase refrigerant from the supply mechanism 11a substantially matches the flow direction of the gas-phase refrigerant. According to such a configuration, in addition to lowering the pressure ratio, the pressure of the gas-phase refrigerant discharged from the compressor 3 can be increased by the momentum of the liquid-phase refrigerant. That is, the pressure increase width in the compressor 3 can be reduced. Such a configuration is particularly effective during high load operation. Examples of the high load operation include an operation under a high outside air temperature condition and an operation under a high pressure ratio condition.
図4は、変形例に係る冷凍サイクル装置の構成を示している。冷凍サイクル装置200において、供給機構11aは、気相冷媒の流れ方向に平行な速度成分を液相冷媒に付与するように高圧空間15に配置されている。具体的には、供給機構11aからの液相冷媒の吐出方向(噴霧方向)が気相冷媒の流れ方向に概ね一致している。このような構成によれば、圧力比を下げることに加え、液相冷媒の運動量により、圧縮機3から吐出された気相冷媒の圧力を上昇させうる。つまり、圧縮機3での圧力上昇幅を減らすことができる。このような構成は、高負荷運転時において特に有効である。高負荷運転としては、高い外気温条件での運転、高い圧力比条件での運転などが挙げられる。 (Modification)
FIG. 4 shows a configuration of a refrigeration cycle apparatus according to a modification. In the
本変形例において、高圧経路8は、気相冷媒の流れ方向における上流側から下流側に向かって流路断面積が徐々に(連続的に)縮小している縮径部8aを有する。供給機構11aは、縮径部8aの高圧空間15に向かって液相冷媒を噴霧する。このような構成によれば、液相冷媒の運動量が気相冷媒に効率的に輸送され、圧力上昇の効果が高まることを期待できる。
In this modification, the high-pressure path 8 has a reduced diameter portion 8a in which the flow path cross-sectional area gradually decreases (continuously) from the upstream side to the downstream side in the flow direction of the gas-phase refrigerant. The supply mechanism 11a sprays the liquid phase refrigerant toward the high-pressure space 15 of the reduced diameter portion 8a. According to such a configuration, it can be expected that the momentum of the liquid-phase refrigerant is efficiently transported to the gas-phase refrigerant and the effect of increasing the pressure is enhanced.
凝縮器4の蒸気空間の流路断面積は、高圧経路8の流路断面積よりも大きい。そのため、縮径部8aと凝縮器4との接続部分で流路断面積が急激に拡大している。凝縮器4の蒸気空間が静圧を回復させるディフューザとして機能することを期待できる。
The flow path cross-sectional area of the vapor space of the condenser 4 is larger than the flow path cross-sectional area of the high-pressure path 8. For this reason, the cross-sectional area of the flow path rapidly increases at the connection portion between the reduced diameter portion 8 a and the condenser 4. It can be expected that the vapor space of the condenser 4 functions as a diffuser that restores static pressure.
図5は、別の変形例に係る冷凍サイクル装置の構成を示している。冷凍サイクル装置300は、複数の圧縮機を備えている点で図1を参照して説明した冷凍サイクル装置100と相違する。
FIG. 5 shows a configuration of a refrigeration cycle apparatus according to another modification. The refrigeration cycle apparatus 300 is different from the refrigeration cycle apparatus 100 described with reference to FIG. 1 in that it includes a plurality of compressors.
冷凍サイクル装置300は、圧縮機3(以下、「第1圧縮機3」と称する)に加え、第2圧縮機13をさらに備えている。第1圧縮機3と第2圧縮機13とが直列に接続されている。言い換えれば、第1圧縮機3で圧縮された気相冷媒が第2圧縮機13でさらに圧縮されるように、第1圧縮機3と第2圧縮機13とが配列されている。中間圧経路7は、第1圧縮機3の吐出口と第2圧縮機13の吸入口とを接続している。
The refrigeration cycle apparatus 300 further includes a second compressor 13 in addition to the compressor 3 (hereinafter referred to as “first compressor 3”). The first compressor 3 and the second compressor 13 are connected in series. In other words, the first compressor 3 and the second compressor 13 are arranged so that the gas-phase refrigerant compressed by the first compressor 3 is further compressed by the second compressor 13. The intermediate pressure path 7 connects the discharge port of the first compressor 3 and the suction port of the second compressor 13.
本変形例において、高圧経路8は、最も高い吐出圧力を有する圧縮機である第2圧縮機13を起点として凝縮器4まで延びている。第1圧縮機3と第2圧縮機13とを接続している経路は、中間圧経路7である。本変形例においても、適切なタイミングで高圧経路8に液相冷媒が供給される。これにより、圧力比が低減され、サージングが防止される。
In this modification, the high-pressure path 8 extends to the condenser 4 starting from the second compressor 13 which is a compressor having the highest discharge pressure. A path connecting the first compressor 3 and the second compressor 13 is an intermediate pressure path 7. Also in this modification, the liquid phase refrigerant is supplied to the high-pressure path 8 at an appropriate timing. This reduces the pressure ratio and prevents surging.
本明細書に開示された冷凍サイクル装置は、空気調和装置、チラー、蓄熱装置などに有用である。
The refrigeration cycle apparatus disclosed in this specification is useful for an air conditioner, a chiller, a heat storage device, and the like.
2 蒸発器
3 圧縮機(第1圧縮機)
4 凝縮器
6 低圧経路
7 中間圧経路
8 高圧経路
8a 縮径部
9 戻し経路
10 冷媒回路
11 冷媒供給路
11a 供給機構
12 吸熱回路
13 第2圧縮機
14 放熱回路
15 高圧空間
16 ポンプ
17 弁
20,21 センサ
22 制御器
100,200,300 冷凍サイクル装置 2Evaporator 3 Compressor (first compressor)
4condenser 6 low pressure path 7 intermediate pressure path 8 high pressure path 8a reduced diameter portion 9 return path 10 refrigerant circuit 11 refrigerant supply path 11a supply mechanism 12 heat absorption circuit 13 second compressor 14 heat dissipation circuit 15 high pressure space 16 pump 17 valve 20, 21 Sensor 22 Controller 100, 200, 300 Refrigeration cycle apparatus
3 圧縮機(第1圧縮機)
4 凝縮器
6 低圧経路
7 中間圧経路
8 高圧経路
8a 縮径部
9 戻し経路
10 冷媒回路
11 冷媒供給路
11a 供給機構
12 吸熱回路
13 第2圧縮機
14 放熱回路
15 高圧空間
16 ポンプ
17 弁
20,21 センサ
22 制御器
100,200,300 冷凍サイクル装置 2
4
Claims (10)
- 液相冷媒を蒸発させて気相冷媒を生成する蒸発器と、
前記蒸発器において生成された前記気相冷媒を圧縮する少なくとも1つのターボ圧縮機と、
前記ターボ圧縮機によって圧縮された前記気相冷媒を凝縮させる凝縮器と、
前記ターボ圧縮機が複数設けられている場合には、最も高い吐出圧力を有する前記ターボ圧縮機を起点として前記凝縮器まで延び、前記ターボ圧縮機が1つのみ設けられている場合には、そのターボ圧縮機を起点として前記凝縮器まで延びている高圧経路と、
前記凝縮器の内部の蒸気空間と前記高圧経路とを含む高圧空間に向けて前記蒸発器から前記液相冷媒を導く冷媒供給路と、
を備えた、冷凍サイクル装置。 An evaporator that evaporates liquid phase refrigerant to produce gas phase refrigerant;
At least one turbo compressor for compressing the gas-phase refrigerant produced in the evaporator;
A condenser for condensing the gas-phase refrigerant compressed by the turbo compressor;
When a plurality of turbo compressors are provided, the turbo compressor having the highest discharge pressure extends from the turbo compressor to the condenser, and when only one turbo compressor is provided, A high-pressure path extending from the turbo compressor to the condenser, and
A refrigerant supply path for guiding the liquid refrigerant from the evaporator toward a high-pressure space including a vapor space inside the condenser and the high-pressure path;
A refrigeration cycle apparatus comprising: - 前記冷媒供給路に配置されたポンプをさらに備えた、請求項1に記載の冷凍サイクル装置。 The refrigeration cycle apparatus according to claim 1, further comprising a pump arranged in the refrigerant supply path.
- 前記冷媒供給路は、吐出側の端部に位置している供給機構を有する、請求項1又は2に記載の冷凍サイクル装置。 The refrigeration cycle apparatus according to claim 1 or 2, wherein the refrigerant supply path has a supply mechanism located at an end portion on a discharge side.
- 前記供給機構は、霧化ノズルを含む、請求項3に記載の冷凍サイクル装置。 The refrigeration cycle apparatus according to claim 3, wherein the supply mechanism includes an atomizing nozzle.
- 前記供給機構は、前記気相冷媒の流れ方向に平行な速度成分を前記液相冷媒に付与するように前記高圧空間に配置されている、請求項3又は4に記載の冷凍サイクル装置。 The refrigeration cycle apparatus according to claim 3 or 4, wherein the supply mechanism is disposed in the high-pressure space so as to impart a velocity component parallel to a flow direction of the gas-phase refrigerant to the liquid-phase refrigerant.
- 前記高圧経路は、前記気相冷媒の流れ方向における上流側から下流側に向かって流路断面積が徐々に縮小している縮径部を有する、請求項1~5のいずれか1項に記載の冷凍サイクル装置。 6. The reduced pressure portion according to claim 1, wherein the high-pressure path has a reduced diameter portion in which a flow path cross-sectional area gradually decreases from the upstream side to the downstream side in the flow direction of the gas-phase refrigerant. Refrigeration cycle equipment.
- 前記冷凍サイクル装置を停止状態から起動するために前記ターボ圧縮機の回転数を増加させる起動運転、及び、前記冷凍サイクル装置を停止させるために前記ターボ圧縮機の回転数を減少させる停止運転から選ばれる少なくとも1つの運転が行われるとき、前記冷媒供給路を通じて前記高圧空間に前記液相冷媒が供給される、請求項1~6のいずれか1項に記載の冷凍サイクル装置。 Selected from start operation for increasing the rotation speed of the turbo compressor to start the refrigeration cycle apparatus from a stopped state, and stop operation for decreasing the rotation speed of the turbo compressor to stop the refrigeration cycle apparatus The refrigeration cycle apparatus according to any one of claims 1 to 6, wherein when the at least one operation is performed, the liquid-phase refrigerant is supplied to the high-pressure space through the refrigerant supply path.
- 前記ターボ圧縮機の運転状態がサージング状態にあるとき又は前記ターボ圧縮機の運転状態がサージング状態に移行すると予測されるとき、前記冷媒供給路を通じて前記高圧空間に前記液相冷媒が供給される、請求項1~6のいずれか1項に記載の冷凍サイクル装置。 When the operating state of the turbo compressor is in a surging state or when the operating state of the turbo compressor is predicted to shift to a surging state, the liquid phase refrigerant is supplied to the high pressure space through the refrigerant supply path. The refrigeration cycle apparatus according to any one of claims 1 to 6.
- 前記ターボ圧縮機の回転数が閾値回転数以下であるとき、前記冷媒供給路を通じて前記高圧空間に前記液相冷媒が供給される、請求項1~6のいずれか1項に記載の冷凍サイクル装置。 The refrigeration cycle apparatus according to any one of claims 1 to 6, wherein when the rotation speed of the turbo compressor is equal to or less than a threshold rotation speed, the liquid-phase refrigerant is supplied to the high-pressure space through the refrigerant supply path. .
- 前記冷媒は、常温での飽和蒸気圧が負圧の物質を主成分として含む、請求項1~9のいずれか1項に記載の冷凍サイクル装置。 10. The refrigeration cycle apparatus according to any one of claims 1 to 9, wherein the refrigerant contains a substance whose saturation vapor pressure at room temperature is a negative pressure as a main component.
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