CN102829568A

CN102829568A - Refrigeration cycle apparatus and hydronic heater having the refrigeration cycle apparatus

Info

Publication number: CN102829568A
Application number: CN2012102003518A
Authority: CN
Inventors: 森胁俊二; 青山繁男; 日下道美
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2011-06-17
Filing date: 2012-06-14
Publication date: 2012-12-19
Anticipated expiration: 2032-06-14
Also published as: CN102829568B; DK2535674T3; JP5816789B2; EP2535674B1; EP2535674A3; EP2535674A2; JP2013002744A

Abstract

The invention provides a refrigeration cycle apparatus. The refrigeration cycle apparatus of the present invention includes a first temperature sensor (61), a pressure sensor (51), a second temperature sensor (62), and a control device (4). The control device (4) controls operation of a bypass expansion valve (31) such that a temperature at an outlet of the bypass passage (3) becomes equal to a saturation temperature in a section until a number of rotation of the compressor (21) reaches a predetermined compressor target number of rotations after the compressor (21) is actuated. When the temperature at the outlet of the bypass passage (3) reaches the saturation temperature, the control device (4) increases the number of rotation of the compressor (21) to a number of rotations of a next stage, and the control device (4) controls the refrigeration cycle into an appropriate refrigeration cycle state, thereby ensuring efficient and sufficient heating efficiency even at low atmospheric temperature.

Description

Refrigerating circulatory device and the hot-water central heating device that possesses this device

Technical field

The present invention relates to a kind of refrigerating circulatory device, the part of the cold-producing medium that will flow out from radiator is carried out by-pass shunt, between main flow cold-producing medium and bypass flow cryogen, carries out heat exchange, thus the main flow cold-producing medium is carried out supercooling.

Background technology

Always; This refrigerating circulatory device and the hot-water central heating device that possesses this device; Downstream at the radiator of refrigerant loop is provided with the supercooling heat exchanger; Cold-producing medium through making expansion flows into this supercooling heat exchanger, and the cold-producing medium that flows out from radiator is carried out supercooling (for example, with reference to patent documentation 1).

Fig. 6 is the figure of the existing refrigerating circulatory device of record in the expression patent documentation 1.

As shown in Figure 6, refrigerating circulatory device 100 comprises the refrigerant loop 110 and bypass 120 that makes the cold-producing medium circulation.Refrigerant loop 110 is that compressor 111, radiator 112, supercooling heat exchanger 113, main expansion valve 114 and evaporimeter 115 are connected to ring-type through pipe arrangement respectively and constitute.

The bypass 120 that refrigerating circulatory device 100 is possessed from refrigerant loop 110 branches, is connected with refrigerant loop 110 between evaporimeter 115 and compressor 111 via supercooling heat exchanger 113 between supercooling heat exchanger 113 and main expansion valve 114.In addition, in bypass 120, more be provided with bypass expansion valve 121 by upstream side than supercooling heat exchanger 113.

In addition, in refrigerating circulatory device 100, possess: detection is from the temperature sensor 141 of temperature (the compressor discharge pipe temperature) Td of the cold-producing medium of compressor 111 discharges; The temperature sensor 142 of temperature (evaporator inlet temperature) Te of the cold-producing medium of detection inflow evaporator 115; In bypass 120, detect the temperature sensor 143 of temperature (the bypass side entrance temperature) Tbi of the cold-producing medium that flows into supercooling heat exchanger 113; With the temperature sensor 144 of detection in bypass 120 from temperature (the bypass side outlet temperature) Tbo of the cold-producing medium of supercooling heat exchanger 113 outflows.

The target temperature Td (target) of the discharge pipe of compressor sets according to the evaporator inlet temperature T e that is detected by temperature sensor 142.And main expansion valve control part control main expansion valve 114 makes the discharge pipe temperature T d that is detected by temperature sensor 141 become above-mentioned target temperature Td (target).In addition, bypass expansion valve control part control bypass expansion valve 121 makes bypass side outlet temperature T bo and bypass side entrance temperature T bi in supercooling heat exchanger 113 poor (Tbo-Tbi) become the desired value of regulation.

The prior art document

Patent documentation

Patent documentation 1: japanese kokai publication hei 10-68553 communique

Summary of the invention

The problem that invention will solve

But; In the formation of said existing apparatus; Be located at the bypass expansion valve 121 of bypass 120, move with the temperature difference of entrance side and the outlet side of control bypass 120, be the degree of superheat of bypass 120 outlets, so can not the refrigerant condition that bypass 120 exports be controlled at moisture state.

Therefore; During heating operation when atmospheric temperature is the utmost point low temperature of-20 ℃ of that kind; Under the situation of having opened bypass expansion valve 121, during the refrigerant flow of bypass side was increased to appropriate amount, the cold-producing medium that flows through bypass 120 was heated in supercooling heat exchanger 113 terrifically.Therefore, the suction refrigerant condition of compressor 111 becomes excessive superheat state, and compressor 111 discharge temperatures might abnormal ascending.

Therefore, when the atmospheric temperature of this utmost point low temperature, can not use bypass 120, the effect that the operational efficiency that can not obtain to use bypass 120 to play improves.Therefore, in this one type of prior art syringe, have efficient poor, can not guarantee this problem of enough heating efficiencies.

The present invention accomplishes for the problem that solves existing apparatus; It is a kind of through this refrigerating circulatory device being controlled to be suitable kind of refrigeration cycle state that its purpose is to provide, even under low atmospheric temperature, also can guarantee efficiently, the hot-water central heating device that this device was drunk and possessed to the refrigerating circulatory device of heating efficiency fully.

Be used to solve the method for problem

In order to solve the problem of existing apparatus, refrigerating circulatory device of the present invention possesses: refrigerant loop, and it is connected to ring-type with compressor, radiator, supercooling heat exchanger, main expansion mechanism and evaporimeter; Bypass, it from said refrigerant loop branch, is connected with said compressor or is connected with said refrigerant loop between said evaporimeter and the said compressor via said supercooling heat exchanger between said radiator and said main expansion mechanism; The bypass expansion mechanism, it is located at and more leans in the said bypass of upstream side than said supercooling heat exchanger; First temperature sensor, it detects from the temperature of the cold-producing medium of said supercooling heat exchanger outflow; Saturation temperature testing agency, its detection is inhaled into the saturation temperature of the cold-producing medium of said compressor; And control device; Being characterized as of said refrigerating circulatory device, said controlling organization begins till the compressor rotating speed of target that reaches regulation from the starting of said compressor; Control the action of said bypass expansion mechanism; Making becomes the saturation temperature that is detected by said saturation temperature testing agency by the detected temperature of said first temperature sensor, and when reaching said saturation temperature by the detected temperature of said first temperature sensor, the rotating speed of said compressor is risen.

Formation according to this refrigerating circulatory device; Under the little low speed state of the compression ratio of compressor; After controlling the cooling agent state that makes bypass outlet and becoming saturation state from superheat state; Because while making gas-liquid two-phase cooling agent by-pass shunt that the rotating speed of compressor is risen, so can suppress the abnormal ascending of compressor discharge temperature.

The invention effect

According to the present invention, can provide a kind of through refrigerating circulatory device being controlled to be suitable kind of refrigeration cycle state, even under low atmospheric temperature, also can guarantee efficiently, fully heating efficiency refrigerating circulatory device and possess the hot-water central heating device of this device.

Description of drawings

Fig. 1 is the summary pie graph of the refrigerating circulatory device of embodiment one of the present invention.

Fig. 2 is the mollier diagram of different compression machine rotating speed of the refrigerating circulatory device of embodiment one of the present invention.

The figure of kind of refrigeration cycle timeliness when Fig. 3 is the bypass of the same refrigerating circulatory device of expression.

Fig. 4 realizes that with function mechanism representes that the control of same refrigerating circulatory device carries the calcspar of putting.

Fig. 5 is the flow chart of the operation control of same refrigerating circulatory device.

Fig. 6 is the summary pie graph of existing refrigerating circulatory device.

The figure of timeliness of the kind of refrigeration cycle when Fig. 7 is the by-pass shunt of the existing refrigerating circulatory device of expression.

Fig. 8 is the mollier diagram of existing refrigerating circulatory device.

Symbol description

1A, refrigerating circulatory device

2, refrigerant loop

3, bypass

4, control device

21, compressor

22, radiator

23, supercooling heat exchanger

24, main expansion valve (main expansion mechanism)

25, evaporimeter

31, bypass expansion valve (bypass expansion mechanism)

51, pressure sensor (saturation temperature testing agency)

61, first temperature sensor

62, second temperature sensor

The specific embodiment

The first aspect of invention provides a kind of refrigerating circulatory device, possesses: refrigerant loop, and it is connected to ring-type with compressor, radiator, supercooling heat exchanger, main expansion mechanism and evaporimeter; Bypass, it from said refrigerant loop branch, is connected with said compressor or is connected with said refrigerant loop between said evaporimeter and the said compressor via said supercooling heat exchanger between said radiator and said main expansion mechanism; The bypass expansion mechanism, it is located at than said supercooling heat exchanger and leans in the bypass of upstream side; First temperature sensor, it detects from the temperature of the cold-producing medium of said supercooling heat exchanger outflow; Saturation temperature testing agency, its detection is inhaled into the saturation temperature of the cold-producing medium of said compressor; And control device; Being characterized as of said refrigerating circulatory device in controlling organization, begins till the compressor rotating speed of target that reaches regulation from the starting of said compressor; Control the action of said bypass expansion mechanism; Making becomes the saturation temperature that is detected by said saturation temperature testing agency by the detected temperature of said first temperature sensor, and when reaching said saturation temperature by the detected temperature of said first temperature sensor, the rotating speed of said compressor is risen.

Formation according to the refrigerating circulatory device of inventing first aspect; Under the little low speed state of the compression ratio of compressor; Control and make the cooling agent state of bypass outlet after superheat state becomes saturation state; Make gas-liquid two-phase cooling agent by-pass shunt on one side, on one side the rotating speed of compressor is risen, so can suppress the abnormal ascending of compressor discharge temperature.

Therefore; Even when atmospheric temperature is the utmost point low temperature of-20 ℃ of that kind, the pressure loss of the low-pressure side coolant path that the bypass that the bypass of also can applying in a flexible way causes utilizes enthalpy difference in the evaporimeter that heat exchange produced of main flow cold-producing medium and bypass refrigerant in the supercooling heat exchanger to increase effect and cold-producing medium is played reduces effect.Thus, in this refrigerating circulatory device, can obtain higher operational efficiency and sufficient heating efficiency.

The refrigerating circulatory device of invention second aspect; It is characterized by; On the basis of first aspect, possess second temperature sensor of detection, in controlling organization from the temperature of the cold-producing medium of said compressor discharge; Become set point of temperature by the detected temperature of said second temperature sensor when above, the aperture that makes said main expansion mechanism is to closing the direction action.

According to the formation of the refrigerating circulatory device of inventing second aspect, when in bypass, flowing through cold-producing medium, be judged as discharge temperature and rise, main expansion mechanism closed rule amount.Therefore, the refrigerant flow that flows to the bypass side promptly increases, and can the excessive superheat state that bypass exports cold-producing medium be controlled at saturation state with the shorter time.

Therefore, the discharge temperature that can alleviate the compressor that is connected with refrigerant loop exceeds the situation of (overshoot) target, except that the effect of foregoing invention first aspect, further improves the reliability of controlled, the compressor of kind of refrigeration cycle.

The invention third aspect provides a kind of hot-water central heating device; Through being set at the refrigerating circulatory device of first or the second aspect that possess invention; Not being only applicable to radiator is under the situation of cold-producing medium to air heat exchanger, but also is applicable to it is the situation of cold-producing medium to water heat exchanger.And then can obtain and invent first or the same effect of second aspect.

Below, to embodiment of the present invention, describe with reference to accompanying drawing.And the present invention is not limited by this embodiment.

(embodiment)

Fig. 1 is the summary pie graph of hot-water central heating device that expression possesses the refrigerating circulatory device of embodiment of the present invention.

In Fig. 1, refrigerating circulatory device 1A comprises refrigerant loop 2, bypass 3 that is connected with this refrigerant loop 2 that makes the cold-producing medium circulation and the control device 4 of controlling this refrigerant loop 2 and bypass 3.

As the cold-producing medium that uses among the present invention, for example, can use near azeotropic mixed refrigerants such as mixed non-azeotropic refrigerant, R410A such as R407C or unitary system cryogen etc.

The refrigerant loop 2 that refrigerating circulatory device 1A possesses constitutes compressor 21, radiator 22, supercooling heat exchanger 23, main expansion valve (main expansion mechanism) 24 and evaporimeter 25 is connected into ring-type through pipe arrangement.

In this embodiment, utilizing pipe arrangement to be connected between the evaporimeter 25 and compressor 21 of ring-type, be provided with the auxiliary energy-storage device (Accumlator) 26 and main accumulator 27 that carry out gas-liquid separation.

In addition, in refrigerant loop 2, be provided with and be used to switch the common operation of refrigerating circulatory device and the cross valve 28 of Defrost operation.

In this embodiment; Refrigerating circulatory device 1A constitutes the heating arrangements of the hot-water central heating device that will be used to heat by the warm water that heating arrangements generates; The radiator 22 that refrigerant loop 2 possesses becomes and between cold-producing medium and water, carries out heat exchange and with the heat exchanger of water heating.

Particularly, be connected with supply pipe 71 and recovery tube 72, supply water to radiator 22, be recovered through recovery tube 72 at radiator 22 heated water (warm water) through supply pipe 71 at radiator 22.

Warm water by the recovery tube 72 that is connected with radiator 22 is reclaimed for example directly or via fluid reservoir is delivered to radiator heating machines such as (radiator), heats thus.

In this embodiment; The bypass 3 that is connected with refrigerant loop 2; Supercooling heat exchanger 23 and main expansion valve (main expansion mechanism) between 24 from refrigerant loop 2 branches, link to each other via refrigerant loop 2 between supercooling heat exchanger 23 and evaporimeter 25 and the compressor 21, between auxiliary energy-storage device 26 and the main accumulator 27.

And, bypass 3 also can supercooling heat exchanger 23 and main expansion valve (main expansion mechanism) between 24 from refrigerant loop 2 branches, be connected with the discharge chambe suction inlet of compressor 21 via supercooling heat exchanger 23.

In addition, in bypass 3,, be provided with bypass expansion valve (bypass expansion mechanism) 31 leaning on upstream side than supercooling heat exchanger 23.

In the common operation (warm-water heating operation) of refrigerating circulatory device, the cold-producing medium of discharging from compressor 21 is sent to radiator 22 via cubic valve 28, and in Defrost operation, the cold-producing medium of discharging from compressor 21 is sent to evaporimeter 25 via cross valve 28.In Fig. 1, the flow of coolant direction when representing to move usually with arrow.

Below, the state variation of the cold-producing medium in the common operation (warm-water heating operation) of refrigerating circulatory device is described.

The high-pressure refrigerant inflow radiator 22 of discharging from the compressor 21 that constitutes refrigerant loop 2 is to the water-cooled through radiator 22.The high-pressure refrigerant that flows out from radiator 22 flows into supercooling heat exchanger 23, carries out supercooling by the low pressure refrigerant 1 after in bypass expansion valve 31, being depressurized.High-pressure refrigerant from supercooling heat exchanger 23 flows out is assigned to main expansion valve 24 sides and bypass expansion valve 31 sides.

Be assigned to the high-pressure refrigerant of main expansion valve (main expansion mechanism) 24 sides, by main expansion valve 24 decompression after expanding, inflow evaporator 25.Flowed into the low pressure refrigerant of evaporimeter 25, from air, absorbed heat at this.

On the other hand, be assigned to the high-pressure refrigerant of bypass expansion valve (bypass expansion mechanism) 31 sides, after expanding, flow into supercooling heat exchanger 23 by 31 decompressions of bypass expansion valve.Flowed into the low pressure refrigerant of supercooling heat exchanger 23, by the high-pressure refrigerant heating of flowing out from radiator 22.Afterwards, the low pressure refrigerant from supercooling heat exchanger 23 flows out converges with the low pressure refrigerant that flows out from evaporimeter 25, is inhaled into compressor 21 again.

The formation of the refrigerating circulatory device 1A of this embodiment, the pressure that when hanging down atmospheric temperature, is inhaled into the cold-producing medium of compressor 21 reduces, and circulating mass of refrigerant reduces, and is used to thus prevent that the heating efficiency of radiator 22 from reducing.

For the reduction of the heat-sinking capability that realizes radiator 22 prevents, the enthalpy difference in evaporimeter 25 is increased through supercooling.In addition, simultaneously through utilizing bypass 3 to make cold-producing medium, suppress to flow through the amount of the little vapor phase refrigerant of the endothermic effect of low-pressure side part of refrigerant loop 2 to bypass 3 circulation.Thus, it is very important making the pressure loss reduction in the low-pressure side part of refrigerant loop 2.

If the pressure loss in the low-pressure side part of the refrigerant loop 2 that refrigerating circulatory device 1A possesses reduces, the so that part of pressure rising specific volume (specific volume) that is inhaled into the cold-producing medium of compressor 21 reduces, so circulating mass of refrigerant increases.

In addition,, in bypass 3, circulate, descend, also can guarantee the caloric receptivity in the evaporimeter 25 even pass through the mass flow of the cold-producing medium of evaporimeter 25 through making cold-producing medium as long as the enthalpy difference in the evaporimeter 25 that constitutes refrigerant loop 2 is increased.

That is,, can obtain achievement (refrigeration) the coefficient raising effect that the heating efficiency of radiator 22 to greatest extent improves effect and refrigerating circulatory device 1A if the mass flow of the cold-producing medium of the supercooling degree of cold-producing medium and bypass 3 is made as maximum.

But; In atmospheric temperature during for the utmost point low temperature of-20 ℃ of that kind and/or utilize under the little situation of side load; Apply in a flexible way and make the situation of cold-producing medium mobile effect in bypass 3; Also exist flow up to the cold-producing medium that flows through bypass 3 become suitable during, the such problem of discharge temperature abnormal ascending of compressor.

The cause of this problem be because, after heating operation begins, open the bypass expansion valve and when beginning by-pass shunt, cold-producing medium flowed sharp to bypass 3, to shown in a ' point, refrigerant mass fluxes increases gradually like a point of Fig. 7.

Therefore; When with bypass 3 that refrigerant loop 2 is connected in the refrigerant mass fluxes that flows after a little while; Through the heat exchange in supercooling heat exchanger 23; The cooling agent state of bypass 3 outlets becomes the excessive superheat state shown in a point of Fig. 8, and discharge temperature is such abnormal ascending shown in the b point of Fig. 8.

In order to improve effect in bypass 3, and improve the efficient of above-mentioned these equipment, importantly suppress the abnormal ascending of this discharge temperature in the performance that cold-producing medium is circulated brought of applying in a flexible way under the wide in range condition.

In this embodiment; Details as after state; But the control device 4 of control refrigerant loop 2 and bypass 3; Begin in the interval till the compressor rotating speed of target that reaches regulation in starting, make 31 actions of bypass expansion valve, make the outlet cold-producing medium of bypass 3 become saturation state from compressor 21.In addition, control the feasible compressor rotary speed that when the outlet cold-producing medium of bypass 3 becomes saturation state, rises to next stage simultaneously.

In addition, become in the discharge temperature of compressor 21 under the situation more than the temperature of regulation, control device 4 is controlled and is made main expansion valve 24 to aperture closing direction action prescribed.

Thus, the compressor rotary speed step-down of cold-producing medium when bypass 3 has begun circulation.Therefore, for example, shown in the c point of Fig. 2, in 40Hz when operation, compared when move with 80Hz, and compression ratio diminishes, the discharge temperature step-down, so can reduce the discharge temperature rising.

In addition; As shown in Figure 3; When cold-producing medium had begun circulation in bypass 3 after, the common control of the opening ratio of main expansion valve 24 was closed quickly, therefore; Refrigerant mass fluxes to bypass 3 sides increases fast, and the refrigerant condition of bypass 3 outlet is like a among Fig. 6 " be controlled as saturation state at short notice the point.Therefore, the abnormal ascending of the discharge temperature of compressor 21 is able to suppress.

Below, the action that the operation of refrigerating circulatory device of the present invention is controlled describes.

In the refrigerant loop 2 that constitutes refrigerating circulatory device, be provided with the pressure sensor 51 and second temperature sensor 62 of detection of pressure (suction pressure) Ps that detects the cold-producing medium that is inhaled into compressor 21 from temperature (discharge temperature) Td of the cold-producing medium of compressor 21 discharges.

On the other hand, with bypass 3 that refrigerant loop 2 is connected in, be provided with first temperature sensor 61 of temperature (bypass outlet temperature) Tbo of the cold-producing medium that detection flows out from supercooling heat exchanger 23.

Control device 4 makes the rotating speed of compressor 21, the switching of cross valve 28 and the aperture action of main expansion valve 24 and bypass expansion valve 31 based on the detected value that is detected by

various sensors

51,61,62 etc.

In this embodiment, control device 4 makes 31 actions of bypass expansion valve when the common operation of refrigerating circulatory device, make bypass outlet temperature Tbo become the suction saturation temperature Ts that is calculated based on suction pressure Ps.

In addition; When control device 4 begins in the operation of refrigerating circulatory device; Make compressor 21 with the starting speed Hzi operation lower than the compressor rotating speed of target Hzt of predefined regulation; Become when sucking saturation temperature Ts at bypass outlet temperature Tbo, make the rotating speed rising ormal weight of compressor 21 and move.Repeat this action, up to becoming compressor rotating speed of target Hzt.

In addition, control device 4, the temperature of the cold-producing medium of discharging from compressor 21 be discharge temperature Td than the high situation of the define objective discharge temperature of predesignating under, make main expansion valve 24 close direction and move prescribed to aperture.

Fig. 4 representes to realize with function the calcspar of the control device that mechanism representes.

In order to operate main expansion valve 24, control device 4 has discharge temperature relatively mechanism 40 and main valve operation determination means 41.

In addition, in order to operate bypass expansion valve 31, control device 4 has the saturation temperature of suction calculation mechanism 42, saturation temperature relatively mechanism 43, bypass valve operation determination means 44.

In addition, control device 4 has: the compressor rotary speed change mechanism 45 of the rotating speed of change compressor 21; Judge that rotating ratio that whether rotating speed of compressor 21 equate with the compressor rotating speed of target Hzt of regulation is than mechanism 46; Under the rotating speed of compressor 21 and situation that the compressor rotating speed of target Hzt of regulation equates, control finishes decision mechanism during starting that the control when being judged as starting finishes.

In sucking saturation temperature calculation mechanism 42, according to the suction saturation temperature Ts under the pressure that calculates the cold-producing medium that is inhaled into compressor 21 by pressure sensor 51 detected suction pressure Ps.

Compare in the mechanism 43 in saturation temperature, relatively by the suction saturation temperature Ts that sucks 42 calculating of saturation temperature calculation mechanism with by first temperature sensor, 61 detected bypass outlet temperature Tbo.

In bypass valve operation determination means 44; Be judged as bypass outlet temperature Tbo and suck under the unequal situation of saturation temperature Ts with saturation temperature comparison mechanism 43; Determine the aperture of bypass expansion valve 31 with bypass outlet temperature Tbo with sucking mode that saturation temperature Ts equates, bypass expansion valve 31 is exported the operational ton that is determined.

Under bypass outlet temperature Tbo and suction saturation temperature Ts situation about equally, in compressor rotary speed change mechanism 45, make the rotating speed rising regulation rotating speed of compressor 21.

Rotating ratio than mechanism 46 in, judge that whether the present rotating speed of compressor 21 equates with the compressor rotating speed of target Hzt of regulation.

Finish in the decision mechanism 47 in when starting control, under the rotating speed of present compressor 21 and situation that compressor rotating speed of target Hzt equates, be judged as the control end when starting, shift to suitable control.

Rotating ratio than mechanism 46 in; Under the unequal situation of compressor rotating speed of target Hzt of the present rotating speed of compressor 21 and regulation, in discharge temperature comparison mechanism 40, the temperature T dt by second temperature sensor, 62 detected discharge temperature Td and the regulation that sets is in advance compared.Store target discharge temperature Tdt in advance.

In main valve operation determination means 41, be based on the relatively comparative result in the mechanism 40 of discharge temperature, the mode that equates with the temperature T dt of regulation with discharge temperature Td determines the aperture of main expansion valve 24, and main expansion valve 24 is exported the operational ton that is determined.

The control of the control device 4 when then, the common operation of refrigerating circulatory device at length being described with reference to flow chart shown in Figure 5.

At first, control device 4 makes the starting speed Hzi operation (step S1) of compressor 21 with regulation.Then, bypass expansion valve 31 is set at the initial opening (step S2) of regulation.

Then, control device 4 detects suction pressure Ps by pressure sensor 51, and detects bypass outlet temperature Tbo (step S3) by first temperature sensor 61.

In addition, according to by pressure sensor 51 detected suction pressure Ps, calculate the suction saturation temperature Ts (step S4) under the pressure of the cold-producing medium that is inhaled into compressor 21.The calculating of this suction saturation temperature Ts is adopted cold-producing medium rerum natura formula and is carried out.

Afterwards, 4 pairs of bypass outlet temperatures of control device Tbo and suction saturation temperature Ts compare, and judge whether Tbo and Ts equate (step S5).

Under bypass outlet temperature Tbo and the unequal situation of suction saturation temperature Ts (being to deny (NO) among the step S5), being judged as bypass outlet cold-producing medium is superheat state.Thus, become and suck the aperture (step S6) that mode that saturation temperature Ts equates is regulated bypass expansion valve 31, advance to step S9 with bypass outlet temperature Tbo.

On the other hand, bypass outlet temperature Tbo with suck under the saturation temperature Ts situation about equally (among the step S5 for being (YES)), being judged as bypass, to export cold-producing medium be saturation state.Thus, make the rotating speed rising regulation rotating speed of compressor and move (step S7), judge whether present rotating speed equates (step S8) with the compressor rotating speed of target Hzt of regulation.

Under present compressor rotary speed and situation that compressor rotating speed of target Hzt equates (among the step S8 for being (YES)), the control when being judged as starting is through with, and shifts to suitable control.

On the other hand, present compressor rotary speed and the unequal situation of rotating speed of target Hzt (being to deny (NO) among the step S8) detect discharge temperature Td (step S9) by second temperature sensor 62.Thus, judge that discharge temperature Td is whether than the temperature T dt high (step S10) of predefined regulation.

Discharge temperature Td is the situation (being to deny (NO) among the step S10) below the set point of temperature Tdt, is judged as the refrigerant flow of having guaranteed bypass 3, directly returns step S3.

On the other hand, discharge temperature Td is judged as the refrigerant flow that needs to increase bypass 3 sides than the high situation of temperature T dt of regulation (among the step S10 for being (YES)), and makes main expansion valve 24 close direction to prescribed to move.

As stated; In this embodiment; In refrigerant loop 21, possess: detect the pressure of the cold-producing medium that the machine that is compressed 21 sucks first pressure sensor 51, detect the temperature of the cold-producing medium of discharging from compressor 21 second temperature sensor 62, bypass 3, detect first temperature sensor 61 and the control device 4 of the temperature of the cold-producing medium that flows out from supercooling heat exchanger 23.Control device 4 begins the interval till the compressor rotating speed of target that reaches regulation in the starting from compressor 21, makes 31 actions of bypass expansion valve, makes the outlet cold-producing medium of bypass 3 become saturation state.In addition, when the outlet cold-producing medium of bypass 3 becomes saturation state, control the feasible compressor rotary speed that rises to next stage simultaneously.

Formation according to the embodiment of refrigerating circulatory device; Under the little low speed state of the compression ratio of compressor; Control make that the refrigerant condition of bypass outlet becomes saturation state from superheat state after; Make the shunting of gas-liquid two-phase refrigerant bypassing on one side, on one side the rotating speed of compressor is risen.The abnormal ascending that can suppress thus, the compressor discharge temperature.

Therefore; Even when atmospheric temperature is the utmost point low temperature of-20 ℃ of that kind, the pressure loss of the low-pressure side coolant path that the bypass that the bypass of also can applying in a flexible way causes utilizes enthalpy difference in the evaporimeter that heat exchange produced of main flow cold-producing medium and bypass refrigerant in the supercooling heat exchanger to increase effect and cold-producing medium causes reduces effect.Thus, in the refrigerating circulatory device of this embodiment, can obtain higher operational efficiency and sufficient heating efficiency.

In addition, control device 4 is judged the situation that discharge temperature rises when bypass begins, and with main expansion valve 24 closed rule amounts, therefore the refrigerant flow to bypass 3 sides promptly increases.Therefore, can the excessive superheat state of bypass 3 outlet cold-producing mediums be controlled to be saturation state at shorter time.

Therefore, the discharge temperature that can alleviate the compressor 21 that is connected with refrigerant loop 2 exceeds the situation of target, further improves the reliability of controlled, the compressor of kind of refrigeration cycle.

In addition; In Fig. 1; Detect first pressure sensor 51 of the suction refrigerant pressure of compressor 21; Be located between the position that is connected with bypass 3 and main accumulator 27 in the refrigerant loop 2, but first pressure sensor 51 can be located at the optional position of refrigerant loop 2 as long as between evaporimeter 25 and compressor 21.

Perhaps, pressure sensor 51 ratio that also can be located at bypass 3 is crossed the side that cool-heat-exchanger 23 leans on downstream.

In addition, in this embodiment, calculate the suction saturation temperature, substitute but suck the temperature of part that saturation temperature also can detect the two phase refrigerant circulation of the low pressure in refrigerant loop 2 and the bypass 3 according to first pressure sensor 51.

In addition, bypass 3 not necessarily must be between supercooling heat exchanger 23 and main expansion valve 24 from refrigerant loop 2 branches, also can and cross between the cool-heat-exchanger 23 at radiator 22 from refrigerant loop 2 branches.

In addition, the connecting portion of bypass 3 not necessarily must be the suction line of compressor 21, under the situation of certain compressor of injection equipment, for example is connected with spray-hole (port) and gets final product.

In addition, it must be expansion valve that main expansion mechanism of the present invention and bypass expansion mechanism do not need, and also can be the decompressor from the refrigerant-recovery power that expands.Under this situation, for example utilize the generator that links with decompressor that load is changed, the rotating speed of controlling decompressor thus gets final product.

Utilizability in the industry

The present invention is useful to the hot-water central heating device that generates warm water through refrigerating circulatory device and this warm water is used to heat especially.

Claims

1. refrigerating circulatory device is characterized in that possessing:

Refrigerant loop, it is connected to ring-type with compressor, radiator, supercooling heat exchanger, main expansion mechanism and evaporimeter;

Bypass, it from said refrigerant loop branch, is connected with said compressor or is connected with said refrigerant loop between said evaporimeter and the said compressor via said supercooling heat exchanger between said radiator and said main expansion mechanism;

The bypass expansion mechanism, it is located at than said supercooling heat exchanger and leans in the said bypass of upstream side;

First temperature sensor, it detects from the temperature of the cold-producing medium of said supercooling heat exchanger outflow;

Saturation temperature testing agency, its detection is inhaled into the saturation temperature of the cold-producing medium of said compressor; With

Controlling organization,

In said controlling organization; Begin till the compressor rotating speed of target that reaches regulation from the starting of said compressor; Control the action of said bypass expansion mechanism; Making becomes the saturation temperature that is detected by said saturation temperature testing agency by the detected temperature of said first temperature sensor, and when reaching said saturation temperature by the detected temperature of said first temperature sensor, the rotating speed of said compressor is risen.

2. refrigerating circulatory device as claimed in claim 1 is characterized in that:

Possess second temperature sensor of detection from the temperature of the cold-producing medium of said compressor discharge,

In said controlling organization, becoming set point of temperature by the detected temperature of said second temperature sensor when above, the aperture that makes said main expansion mechanism is to closing the direction action.

3. hot-water central heating device is characterized in that:

Possess claim 1 or 2 described refrigerating circulatory devices.