JP2018192967A - Air-conditioning system for vehicle - Google Patents

Abstract

To make it possible for an air-conditioning system for a vehicle, which has a first circulation passage and a second circulation passage, to cool a heating element whichever the refrigerant is circulated in the first circulation passage or the second circulation passage.SOLUTION: An air-conditioning system for a vehicle comprises: a compressor that compresses a refrigerant; an expansion valve that expands the refrigerant; an indoor device that exchanges heat between the refrigerant and air in a vehicle cabin; an outdoor device that exchanges heat between the refrigerant and outdoor air; and a circulation passage switchable between a first a circulation passage that circulates the refrigerant in the compressor, the outdoor device, the expansion valve, the indoor device, a heating element provided in the vehicle, and the compressor in that order and a second circulation passage that circulates the refrigerant in the compressor, the indoor device, the expansion valve, the outdoor device, the heating element, and the compressor in that order.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle air conditioning system.

  Patent Document 1 discloses a vehicle cooling device that cools a heating element of a vehicle using a refrigeration cycle for air conditioning.

JP 2013-147152 A

  Here, a vehicle air conditioning system that performs cooling and heating using a refrigeration cycle normally has a first circulation path that circulates refrigerant during cooling operation and a second circulation that circulates refrigerant during heating operation and is different from the first circulation path. And a route. In the vehicle air conditioning system having the first circulation path and the second circulation path, when the vehicle heating element is cooled using the refrigerant, the refrigerant is used in any of the first circulation path and the second circulation path. Even if it is circulated, it is desirable that the heating element can be cooled by the refrigerant.

  In consideration of the above facts, in the vehicle air conditioning system having the first circulation path and the second circulation path, the present invention provides the refrigerant regardless of which of the first circulation path and the second circulation path is circulated. The purpose of this is to allow the heating element to be cooled.

  The invention according to claim 1 includes a compressor that compresses the refrigerant, an expansion valve that expands the refrigerant, an indoor unit that exchanges heat between the refrigerant and air in the vehicle interior, and between the refrigerant and outside air. An outdoor unit for heat exchange, the compressor, the outdoor unit, the expansion valve, the indoor unit, a heating element provided in a vehicle, and a first circulation path for circulating the refrigerant in the order of the compressor, A circulation path that can be switched to a second circulation path that circulates refrigerant in the order of the compressor, the indoor unit, the expansion valve, the outdoor unit, the heating element, and the compressor.

  According to the configuration of the first aspect, the circulation path can be switched between the first circulation path and the second circulation path. In the first circulation path, the refrigerant circulates in the order of the compressor, the outdoor unit, the expansion valve, the indoor unit, the heating element provided in the vehicle, and the compressor. Thus, the following effects can be produced by circulating the refrigerant in the first circulation path.

  That is, in the first circulation path, the refrigerant is compressed by the compressor to be in a high temperature and high pressure state and passes through the outdoor unit. The refrigerant passing through the outdoor unit exchanges heat with the outside air in the outdoor unit. Thereby, the refrigerant | coolant which passes an outdoor unit discharges | emits heat to outside air, and is condensed. The refrigerant condensed in the outdoor unit becomes a low-temperature and low-pressure state by being expanded by the expansion valve, and passes through the indoor unit and the heating element in this order. The refrigerant passing through the indoor unit exchanges heat with the air in the passenger compartment in the indoor unit. Thereby, the refrigerant passing through the indoor unit evaporates by taking heat from the air in the passenger compartment. As a result, the air in the passenger compartment is cooled. Further, the refrigerant passing through the heating element is exchanged with the heating element. Thereby, the refrigerant | coolant which passes a heat generating body takes heat from a heat generating body, and evaporates. As a result, the heating element is cooled.

  In the second circulation path, the refrigerant circulates in the order of the compressor, the indoor unit, the expansion valve, the outdoor unit, the heating element, and the compressor. Thus, the following effects can be produced by circulating the refrigerant in the second circulation path.

  That is, in the second circulation path, the refrigerant is compressed by the compressor to be in a high temperature and high pressure state and passes through the indoor unit. The refrigerant passing through the indoor unit exchanges heat with the air in the passenger compartment in the indoor unit. Thereby, the refrigerant | coolant which passes an indoor unit discharge | releases heat to the air in a vehicle interior, and is condensed. As a result, the air in the passenger compartment is warmed. The refrigerant condensed in the indoor unit becomes a low-temperature and low-pressure state by being expanded by the expansion valve, and passes through the outdoor unit and the heating element in this order. The refrigerant passing through the outdoor unit exchanges heat with the outside air in the outdoor unit. Thereby, the refrigerant | coolant which passes an outdoor unit takes heat from outside air, and evaporates. The refrigerant passing through the heating element is heat exchanged with the heating element. Thereby, the refrigerant passing through the heating element evaporates by taking heat from the heating element. As a result, the heating element is cooled.

  As described above, according to the configuration of the first aspect, the heating element can be cooled by the refrigerant regardless of which of the first circulation path and the second circulation path is circulated.

  In the second aspect of the present invention, in the cooling operation, the gas-liquid two-phase refrigerant is sent to the heating element, and the gas-liquid two-phase refrigerant is evaporated by heat exchange with the heating element. The refrigerant is circulated through one circulation path, and in the heating operation, the gas-liquid two-phase refrigerant is sent to the heating element, and the gas-liquid two-phase refrigerant is evaporated by heat exchange with the heating element. However, the refrigerant is circulated in the second circulation path.

  According to the configuration of claim 2, in the cooling operation, the gas-liquid two-phase refrigerant is sent to the heating element, and the gas-liquid two-phase refrigerant evaporates by heat exchange with the heating element. The refrigerant circulates in the circulation path. In this way, the heat generator is cooled by evaporating the refrigerant by heat exchange between the gas-liquid two-phase refrigerant and the heat generator.

  In the heating operation, the gas-liquid two-phase refrigerant is sent to the heating element, and the refrigerant circulates in the second circulation path while the gas-liquid two-phase refrigerant evaporates by heat exchange with the heating element. . In this way, the heat generator is cooled by evaporating the refrigerant by heat exchange between the gas-liquid two-phase refrigerant and the heat generator.

  As described above, according to the configuration of the second aspect, the heating element can be cooled in both the cooling and heating operation states.

  According to a third aspect of the present invention, in the cooling operation and the heating operation, the gas-liquid two-phase refrigerant is subjected to forced convection boiling by exchanging heat with the heating element while circulating the gas-liquid two-phase refrigerant. Let

  According to the configuration of the third aspect, in the cooling operation and the heating operation, the gas-liquid two-phase refrigerant undergoes forced convection boiling by exchanging heat with the heating element while flowing through the heating element. Thereby, a heat generating body is cooled. Thus, since a heat generating body is cooled by forced convection boiling of a refrigerant | coolant, compared with the structure by which a heat generating body is cooled by pool boiling in the state where the refrigerant | coolant was stored, heat exchange efficiency improves.

  The invention according to claim 4 is an accumulator having a storage unit that separates the refrigerant into a gas-phase refrigerant and a liquid-phase refrigerant, sends the gas-phase refrigerant to the compressor, and stores the liquid-phase refrigerant. The circulation path circulates the refrigerant in the order of the compressor, the outdoor unit, the expansion valve, the indoor unit, the heating element, the accumulator, and the compressor in the first circulation path. In the second circulation path, the refrigerant is circulated in the order of the compressor, the indoor unit, the expansion valve, the outdoor unit, the heating element, the accumulator, and the compressor.

  According to the configuration of claim 4, even when the refrigerant circulating in the first circulation path is in the gas-liquid two-phase after passing through the heating element, the liquid-phase refrigerant is not sent to the compressor. An increase in the load is suppressed. Furthermore, even when the refrigerant circulating in the second circulation path becomes a gas-liquid two-phase after passing through the heating element, the liquid-phase refrigerant is not sent to the compressor, and an increase in the load on the compressor is suppressed. The Therefore, even if the refrigerant is circulated through any of the first circulation path and the second circulation path, the liquid-phase refrigerant is not sent to the compressor, and an increase in load on the compressor is suppressed.

  According to a fifth aspect of the present invention, the circulation path has a heating element bypass circuit in which the refrigerant bypasses the heating element.

  According to the structure of Claim 5, when cooling of a heat generating body is unnecessary, cooling of a heat generating body can be stopped by detouring all the refrigerant | coolants sent to a heat generating body by a heat generating body detour. When it is desired to keep the degree of cooling of the heating element small, the degree of cooling of the heating element can be reduced by diverting a part of the refrigerant sent to the heating element by the heating element bypass.

  According to a sixth aspect of the present invention, the circulation path includes a compressor bypass circuit in which the refrigerant bypasses the compressor, and the compressor bypass circuit is provided with a pump for pumping the refrigerant.

  According to the structure of Claim 6, in the state which the drive of the compressor has stopped, a pump can be driven and a refrigerant | coolant can be pumped. Therefore, the heating element can be cooled even when the compressor is stopped.

  Since the present invention is configured as described above, in the vehicle air conditioning system having the first circulation path and the second circulation path, the refrigerant can be circulated through any of the first circulation path and the second circulation path. Can cool the heating element.

It is a schematic block diagram in the air_conditioning | cooling driving | running state of the vehicle air conditioning system which concerns on this embodiment. It is a schematic block diagram in the heating operation state of the vehicle air conditioning system which concerns on this embodiment. It is a schematic block diagram in the heating operation state of the vehicle air conditioning system which concerns on a 1st modification. It is a schematic block diagram in the heating operation state of the vehicle air conditioning system which concerns on a 2nd modification.

  Below, an example of an embodiment concerning the present invention is described based on a drawing.

(Vehicle air conditioning system 10)
First, the configuration of the vehicle air conditioning system 10 will be described. The schematic block diagram of the vehicle air conditioning system 10 is shown by FIG.1 and FIG.2.

  The vehicle air-conditioning system 10 is a system that adjusts (adjusts) the temperature of air in the passenger compartment of the vehicle, and has a function of heating and cooling the passenger compartment of the vehicle. Furthermore, the vehicle air conditioning system 10 has a function of cooling a heating element 80 provided in the vehicle. Examples of the heating element 80 that generates heat include a secondary battery when an electric vehicle and a hybrid electric vehicle are used as a vehicle, and a fuel cell when a fuel cell vehicle is used as a vehicle. Note that, when the temperature of the secondary battery and the fuel cell rise and the temperature exceeds a predetermined temperature, the battery performance is deteriorated and easily deteriorated.

  Specifically, as shown in FIGS. 1 and 2, the vehicle air conditioning system 10 is a heat pump type air conditioning system, and includes a compressor 12, an indoor unit 30, an outdoor unit 50, an expansion valve 16, and the like. The accumulator 18 and the circulation path 20 are provided.

  The compressor 12 has a function of compressing a refrigerant (heat medium). The compressor 12 has an inlet 12A for sucking refrigerant and an outlet 12B for sending refrigerant. The compressor 12 is provided with a drive unit 13 that drives the compressor 12. The compressor 12 is driven by the drive unit 13 to send out the refrigerant that has become a high-temperature and high-pressure state by compressing the refrigerant from the outlet 12B.

  The expansion valve 16 has a function of expanding the refrigerant. The refrigerant is depressurized by expansion by the expansion valve 16, thereby becoming a low temperature and low pressure state, and is sent out from the expansion valve 16.

  The indoor unit 30 was heat-exchanged between the air in the vehicle compartment (hereinafter referred to as vehicle interior air) taken in from the vehicle compartment and the refrigerant, and the heat exchanger 33 exchanged heat with the refrigerant. And a blower 37 for releasing the air in the vehicle into the vehicle interior. In the indoor unit 30, the vehicle interior air taken from the vehicle interior is heat-exchanged with the refrigerant by the heat exchanger 33, and the vehicle interior air is discharged into the vehicle interior by the blower 37.

  Specifically, in the indoor unit 30, in the cooling operation of the vehicle air conditioning system 10, the refrigerant takes heat from the air in the vehicle by heat exchange in the heat exchanger 33, cools the air in the vehicle, and cools the cold air by the blower 37. Release into the passenger compartment. At this time, the refrigerant evaporates and changes from the liquid phase to the gas-liquid two phase. Further, in the indoor unit 30, in the heating operation of the vehicle air conditioning system 10, the refrigerant releases heat to the vehicle interior air by heat exchange in the heat exchanger 33 to heat the vehicle interior air, and the hot air is blown by the blower 37 to the vehicle interior. To release. At this time, at least a part of the refrigerant condenses and changes from the gas phase to the liquid phase.

  The outdoor unit 50 includes a heat exchanger 53 that exchanges heat between outside air taken from outside the vehicle and the refrigerant, and a blower 57 that discharges outside air heat-exchanged between the refrigerant and the refrigerant by the heat exchanger 53 to the outside of the vehicle. Have. In the outdoor unit 50, the outside air taken from the outside of the vehicle is heat-exchanged with the refrigerant by the heat exchanger 53, and the outside air is discharged outside the vehicle by the blower 57.

  Specifically, in the outdoor unit 50, during the heating operation of the vehicle air conditioning system 10, the refrigerant removes heat from the outside air by heat exchange in the heat exchanger 53 to cool the outside air, and the cold air is blown out of the vehicle by the blower 57. discharge. At this time, the refrigerant evaporates and changes from the liquid phase to the gas-liquid two phase. In the outdoor unit 50, in the cooling operation of the vehicle air conditioning system 10, the refrigerant releases heat to the outside air by heat exchange in the heat exchanger 53 to heat the outside air, and the hot air is released to the outside by the blower 57. . At this time, at least a part of the refrigerant condenses and changes from the gas phase to the liquid phase.

  The accumulator 18 has a function of separating the gas-phase refrigerant and the liquid-phase refrigerant and sending the gas-phase refrigerant to the compressor 12. The accumulator 18 has a reservoir 18A that stores a liquid-phase refrigerant separated from a gas-phase refrigerant.

  The circulation path 20 is a flow path for circulating the refrigerant, and has a four-way valve 40 as switching means for switching the refrigerant circulation path. The four-way valve 40 has a first port 41, a second port 42, a third port 43, and a fourth port 44. In the four-way valve 40, the first port 41 and the second port 42 communicate with each other, and the third port 43 and the fourth port 44 communicate with each other. And the fourth port 44 can communicate with each other and the second port 42 and the third port 43 can communicate with each other in the second communication state (the state shown in FIG. 2). The four-way valve 40 is provided with a drive unit 49 that switches the four-way valve 40 between the first communication state and the second communication state.

  Furthermore, the circulation path 20 includes a first flow path 21, a second flow path 22, a third flow path 23, a fourth flow path 24, a fifth flow path 25, and a sixth flow path 26. doing. The first flow path 21 communicates the outlet 12 </ b> B of the compressor 12 and the first port 41 of the four-way valve 40. The second flow path 22 communicates the second port 42 of the four-way valve 40 and the outdoor unit 50. The third flow path 23 communicates the outdoor unit 50 and the expansion valve 16. The fourth flow path 24 communicates the expansion valve 16 and the indoor unit 30. The fifth flow path 25 communicates the indoor unit 30 with the fourth port 44 of the four-way valve 40. The sixth flow path 26 communicates the third port 43 of the four-way valve 40 and the suction port 12A of the compressor 12. In FIGS. 1 and 2, the flow direction of the refrigerant circulating in the circulation path 20 is indicated by arrows. Hereinafter, the refrigerant distribution direction is referred to as “refrigerant distribution direction”.

  In the sixth flow path 26, the heating element 80 and the accumulator 18 described above are arranged in this order. Therefore, the heating element 80 is disposed downstream of the third port 43 of the four-way valve 40 in the refrigerant flow direction and upstream of the accumulator 18 in the refrigerant flow direction. The accumulator 18 is disposed downstream of the heat generator 80 in the refrigerant flow direction and upstream of the compressor 12 in the refrigerant flow direction. The sixth channel 26 is in thermal contact with the heating element 80, and heat exchange is performed between the refrigerant flowing through the sixth channel 26 and the heating element 80.

  The cooling operation in the vehicle air conditioning system 10 is started in a state in which the four-way valve 40 is maintained in the first continuous state when the four-way valve 40 is in the first continuous state (the state shown in FIG. 1). In addition, when the four-way valve 40 is in the second communication state, the cooling operation is started after being switched to the first continuous state by the drive unit 49.

  When the four-way valve 40 is switched to the first continuous state, as shown in FIG. 1, the circulation path 20 includes a first flow path 21, a second flow path 22, a third flow path 23, a fourth flow path 24, The fifth flow path 25, the sixth flow path 26, and the first flow path 21 are communicated in this order. Thereby, in the cooling operation in the vehicle air conditioning system 10, the refrigerant is circulated in the order of the compressor 12, the outdoor unit 50, the expansion valve 16, the indoor unit 30, the heating element 80, the accumulator 18, and the compressor 12. A circulation path (path shown in FIG. 1) is formed.

  On the other hand, the heating operation in the vehicle air conditioning system 10 is started in a state where the second communication state is maintained when the four-way valve 40 is in the second communication state (the state shown in FIG. 2). The heating operation is started after the four-way valve 40 is switched to the second communication state by the drive unit 49 when the four-way valve 40 is in the first communication state.

  By switching the four-way valve 40 to the second communication state, as shown in FIG. 2, the circulation path 20 includes the first flow path 21, the fifth flow path 25, the fourth flow path 24, the third flow path 23, The two flow paths 22, the sixth flow path 26, and the first flow path 21 are communicated in this order. Thereby, in the heating operation in the vehicle air conditioning system 10, the refrigerant is circulated in the order of the compressor 12, the indoor unit 30, the expansion valve 16, the outdoor unit 50, the heating element 80, the accumulator 18, and the compressor 12. A circulation path (path shown in FIG. 2) is formed. In the second circulation path and the first circulation path, the refrigerant flow directions in the second flow path 22, the third flow path 23, the fourth flow path 24, and the fifth flow path 25 are reversed, and the first flow path The refrigerant flow directions in 21 and the sixth flow path 26 are the same.

  As described above, the four-way valve 40 is switched between the first communication state (the state shown in FIG. 1) and the second communication state (the state shown in FIG. 2), so that the circulation path 20 is connected to the first circulation path and the first communication path. It is designed to switch to a two-circulation path.

  Further, in the vehicle air conditioning system 10, in the cooling operation, by adjusting the refrigerant flow rate in the indoor unit 30 and the output of the blower 37 in the indoor unit 30, the gas-liquid two-phase refrigerant is transferred from the indoor unit 30 to the heating element. To 80. The refrigerant flow rate in the indoor unit 30 is adjusted by drive control in the compressor 12, the opening degree of the expansion valve 16, and the like.

  Furthermore, in the vehicle air conditioning system 10, in the heating operation, the refrigerant flow rate in the outdoor unit 50 and the output of the blower 57 in the outdoor unit 50 are adjusted so that the gas-liquid two-phase refrigerant is heated from the outdoor unit 50 to the heating element. To 80. The refrigerant flow rate in the outdoor unit 50 is adjusted by drive control in the compressor 12, the opening degree of the expansion valve 16, and the like.

  In the vehicle air conditioning system 10, the gas-liquid two-phase refrigerant circulates through the sixth flow path 26 and exchanges heat with the heating element 80, whereby the refrigerant undergoes forced convection boiling, and the heating element. 80 is configured to be cooled.

(Operational effect of the vehicle air conditioning system 10)
Next, the effect of the vehicle air conditioning system 10 will be described.

  In the vehicle air conditioning system 10, the circulation path 20 can be switched between a first circulation path (path shown in FIG. 1) and a second circulation path (path shown in FIG. 2) by switching the four-way valve 40. Yes. In the vehicle air conditioning system 10, in the cooling operation, as shown in FIG. 1, the refrigerant is circulated through the first circulation path. In the first circulation path, the refrigerant circulates in the order of the compressor 12, the outdoor unit 50, the expansion valve 16, the indoor unit 30, the heating element 80, the accumulator 18, and the compressor 12.

  The refrigerant circulating in the first circulation path is compressed by the compressor 12 to be in a high temperature and high pressure state and passes through the outdoor unit 50. The refrigerant passing through the outdoor unit 50 exchanges heat with the outside air in the outdoor unit 50. As a result, the refrigerant passing through the outdoor unit 50 is condensed by releasing heat to the outside air. The refrigerant condensed in the outdoor unit 50 is expanded by the expansion valve 16 to be in a low temperature and low pressure state, and passes through the indoor unit 30 and the heating element 80 in this order. The refrigerant passing through the indoor unit 30 exchanges heat with the air in the passenger compartment in the indoor unit 30. Thereby, the refrigerant | coolant which passes the indoor unit 30 takes heat from the air of a vehicle interior, and evaporates. As a result, the air in the passenger compartment is cooled, and the cool air is discharged by the blower 37 into the passenger compartment. The refrigerant passing through the heating element 80 passes through the heating element 80 in a gas-liquid two-phase and is heat-exchanged with the heating element 80. Thereby, the refrigerant passing through the heating element 80 takes heat from the heating element 80 and evaporates. As a result, the heating element 80 is cooled. In this embodiment, the gas-liquid two-phase refrigerant is forced to convection boil by exchanging heat with the heating element 80 while flowing through the heating element 80, thereby cooling the heating element 80.

  On the other hand, in the heating operation, as shown in FIG. 2, the refrigerant is circulated through the second circulation path. In the second circulation path, the refrigerant circulates in the order of the compressor 12, the indoor unit 30, the expansion valve 16, the outdoor unit 50, the heating element 80, the accumulator 18, and the compressor 12.

  The refrigerant circulating in the second circulation path is compressed by the compressor 12 to be in a high temperature and high pressure state, and passes through the indoor unit 30. The refrigerant passing through the indoor unit 30 exchanges heat with the air in the passenger compartment in the indoor unit 30. Thereby, the refrigerant | coolant which passes the indoor unit 30 discharge | releases heat to vehicle interior air, and is condensed. As a result, the air in the passenger compartment is warmed and the hot air is released by the blower 37 into the passenger compartment. The refrigerant condensed in the indoor unit 30 is expanded at the expansion valve 16 to be in a low temperature and low pressure state, and passes through the outdoor unit 50 and the heating element 80 in this order. The refrigerant passing through the outdoor unit 50 exchanges heat with the outside air in the outdoor unit 50. Thereby, the refrigerant | coolant which passes the outdoor unit 50 takes heat from outside air, and evaporates. The refrigerant passing through the heating element 80 passes through the heating element 80 in a gas-liquid two-phase and is heat-exchanged with the heating element 80. Thereby, the refrigerant passing through the heating element 80 takes heat from the heating element 80 and evaporates. As a result, the heating element 80 is cooled. In this embodiment, the gas-liquid two-phase refrigerant is forced to convection boil by exchanging heat with the heating element 80 while flowing through the heating element 80, thereby cooling the heating element 80.

  As described above, according to the vehicle air conditioning system 10, the heating element 80 can be cooled by the refrigerant regardless of which of the first circulation path and the second circulation path is circulated. In other words, the vehicle air conditioning system 10 can cool the heating element 80 in both the cooling and heating operation states.

  Furthermore, according to the configuration of the vehicle air-conditioning system 10, forced convection boiling is performed by heat exchange between the gas-liquid two-phase refrigerant and the heating element 80 while circulating in the heating element 80 in the cooling operation and the heating operation. Then, the heating element 80 is cooled. For this reason, compared with the structure (comparative example) which cools the heat generating body 80 by pool boiling in the state where the refrigerant | coolant was stored, heat exchange efficiency improves.

  In the vehicle air-conditioning system 10, the heating element 80 is disposed in the sixth flow path 26 through which the refrigerant can be circulated in a gas-liquid two-phase in the first circulation path (cooling operation) and the second circulation path (heating operation). ing. In the sixth flow path 26, the refrigerant is adjusted by adjusting the refrigerant flow rate, the cooling load in the cooling operation, and the heating load in the heating operation without adding elements (for example, an expansion valve, an indoor unit, and a flow path). It can be distributed in two phases. For this reason, the heat generating body 80 can be cooled using a refrigerant with a simple configuration. Since the vehicle air conditioning system 10 can have a simple configuration, the size of the vehicle air conditioning system 10 can be reduced.

  In the vehicle air conditioning system 10, the refrigerant circulating in the first circulation path passes through the heating element 80, and then the gas-phase refrigerant and the liquid-phase refrigerant are separated by the accumulator 18. It is sent to the compressor 12. For this reason, even when the refrigerant circulating in the first circulation path becomes a gas-liquid two-phase after passing through the heating element 80, the liquid-phase refrigerant is not sent to the compressor 12, and the load on the compressor 12 is increased. Increase is suppressed.

  Similarly, even when the refrigerant circulating in the second circulation path is in a gas-liquid two-phase after passing through the heating element 80, the liquid-phase refrigerant is not sent to the compressor 12, and the load on the compressor 12 is increased. Increase is suppressed. Therefore, even if the refrigerant is circulated through any of the first circulation path and the second circulation path, the liquid-phase refrigerant is not sent to the compressor 12, and an increase in load on the compressor 12 is suppressed.

(First modification of circulation path 20)
As shown in FIG. 3, the circulation path 20 may have a heating element bypass circuit 122 in which the refrigerant bypasses the heating element 80. In the configuration shown in FIG. 3, the upstream end of the heating element bypass 122 is connected (communication) to the upstream side in the refrigerant flow direction with respect to the heating element 80 in the sixth flow path 26. The downstream end of the heating element bypass 122 is connected (communication) between the heating element 80 and the accumulator 18 in the sixth flow path 26. The heating element bypass circuit 122 is provided with an on-off valve 124 that opens and closes the heating element bypass circuit 122. An open / close valve 129 that opens and closes the sixth flow path 26 is provided between the upstream end of the heat generating element bypass circuit 122 in the sixth flow path 26 and the heat generation element 80.

  In the configuration shown in FIG. 3, when cooling the heating element 80 in the cooling operation and the heating operation, the on-off valve 124 is closed and the on-off valve 129 is opened. Thus, the refrigerant is sent to the heating element 80 without flowing through the heating element bypass 122.

  On the other hand, in the cooling operation and the heating operation, when the heating element 80 does not need to be cooled, the on-off valve 124 is opened and the on-off valve 129 is closed. As a result, the refrigerant is not sent to the heating element 80 and flows through the heating element detour 122. In this manner, whether the refrigerant passes through the heating element 80 is switched by controlling the opening / closing of the on-off valves 124 and 129. That is, the on-off valves 124 and 129 function as switching means for switching whether or not the refrigerant passes through the heating element 80.

  As described above, in the configuration shown in FIG. 3, when cooling of the heating element 80 is not necessary, all of the refrigerant sent to the heating element 80 is bypassed by the heating element bypass circuit 122, thereby cooling the heating element 80. You can stop. In the configuration illustrated in FIG. 3, the on-off valves are provided in each of the sixth flow path 26 and the heating element bypass 122, but the configuration is not limited thereto. For example, a switching valve (three-way valve) that switches between a state in which the third port 43 of the four-way valve 40 and the heating element 80 communicate with each other and a state in which the third port 43 of the four-way valve 40 and the heating element bypass circuit 122 communicate with each other. Or the like may be provided at a branch portion (connection portion) between the sixth flow path 26 and the heating element bypass route 122.

  In the configuration shown in FIG. 3, all of the refrigerant sent to the heating element 80 is bypassed by the heating element bypass 122, but is not limited thereto. For example, a configuration in which a part of the refrigerant sent to the heating element 80 is bypassed by the heating element bypass 122 may be used. Specifically, for example, in the configuration shown in FIG. 3, the on-off valve 124 is eliminated, and an on-off valve 129 is provided instead of an on-off valve 129 and an adjustment valve capable of adjusting the flow rate of the refrigerant flowing through the sixth flow path 26 is provided. can do. Further, for example, in the configuration shown in FIG. 3, the on-off valve 129 may be eliminated, and an on-off valve 124 may be provided instead of an on-off valve 124 that can provide an adjustment valve that can adjust the flow rate of the refrigerant flowing through the heating element bypass circuit 122. According to this configuration, when it is desired to reduce the degree of cooling of the heating element 80 to a small level, the refrigerant flow rate in the sixth flow path 26 or the heating element bypass 122 is adjusted to reduce the amount of refrigerant sent to the heating element 80. The degree of cooling of the heating element 80 can be reduced by bypassing the part by the heating element bypass circuit 122.

(Second modification of circulation path 20)
As shown in FIG. 4, the circulation path 20 may have a compressor bypass circuit 233 in which the refrigerant bypasses the compressor 12. In the configuration shown in FIG. 4, the upstream end of the compressor bypass 233 is connected (communication) to the storage portion 18 </ b> A of the accumulator 18. The downstream end of the compressor bypass 233 is connected (communication) to the first flow path 21. In the compressor bypass 233, an on-off valve 235 for opening and closing the compressor bypass 233 and a pump 237 for pumping the refrigerant are arranged in this order along the refrigerant flow direction.

  In the configuration shown in FIG. 4, the on-off valve 235 is closed while the compressor 12 is driven. And in the state which has stopped the air_conditionaing | cooling operation and heating operation of the vehicle air conditioning system 10, ie, the state which stopped the drive of the compressor 12, the on-off valve 235 can be opened and the pump 237 can be driven, and a refrigerant | coolant can be pumped. . Thereby, the heat generating body 80 can be cooled by circulating the refrigerant in the first circulation path or the second circulation path.

(Other variations)
In the present embodiment, the single heating element 80 is disposed in the sixth flow path 26, but the present invention is not limited to this. For example, a configuration in which a plurality of heating elements are arranged in the sixth flow path 26 may be used. In this case, heat exchange is performed between the refrigerant flowing through the sixth flow path 26 and each of the plurality of heating elements. Furthermore, in this case, in the cooling operation, the refrigerant flow rate in the indoor unit 30 and the blower 37 in the indoor unit 30 so that the refrigerant is in a gas-liquid two-phase in the heating element arranged on the most downstream side in the refrigerant flow direction. In the heating operation, the refrigerant flow rate in the outdoor unit 50, the output of the blower 57 in the outdoor unit 50, and the like are adjusted.

  In the present embodiment, the accumulator 18 is provided in the sixth flow path 26, but the present invention is not limited to this. For example, when most of the refrigerant is in a gas phase as a result of the refrigerant evaporating (boiling) in the heating element 80, the accumulator 18 may not be provided.

  The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made without departing from the spirit of the present invention. For example, the modification examples described above may be appropriately combined.

DESCRIPTION OF SYMBOLS 10 Vehicle air conditioning system 12 Compressor 16 Expansion valve 18 Accumulator 20 Circulation path 30 Indoor unit 50 Outdoor unit 80 Heating element 122 Heating element detour 233 Compressor detour 237 Pump

Claims (6)

A compressor for compressing the refrigerant;
An expansion valve for expanding the refrigerant;
An indoor unit that exchanges heat between the refrigerant and the air in the passenger compartment;
An outdoor unit that exchanges heat between the refrigerant and the outside air;
A first circulation path for circulating the refrigerant in the order of the compressor, the outdoor unit, the expansion valve, the indoor unit, a heating element provided in a vehicle, and the compressor, the compressor, the indoor unit, A circulation path that can be switched to a second circulation path for circulating the refrigerant in the order of the expansion valve, the outdoor unit, the heating element, and the compressor;
A vehicle air conditioning system comprising: In the cooling operation, the refrigerant in the first circulation path is sent while the gas-liquid two-phase refrigerant is sent to the heating element and the gas-liquid two-phase refrigerant is evaporated by heat exchange with the heating element. Circulate
In the heating operation, the refrigerant in the second circulation path is sent while the gas-liquid two-phase refrigerant is sent to the heating element and the gas-liquid two-phase refrigerant is evaporated by heat exchange with the heating element. The vehicle air conditioning system according to claim 1. 3. The forced convection boiling of the gas-liquid two-phase refrigerant by exchanging heat with the heating element while circulating the gas-liquid two-phase refrigerant in the cooling operation and the heating operation. Air conditioning system for vehicles. An accumulator having a storage section for separating the refrigerant into a gas phase refrigerant and a liquid phase refrigerant, sending the gas phase refrigerant to the compressor, and storing the liquid phase refrigerant;
The circuit is
In the first circulation path, the refrigerant is circulated in the order of the compressor, the outdoor unit, the expansion valve, the indoor unit, the heating element, the accumulator, and the compressor.
The refrigerant is circulated in the order of the compressor, the indoor unit, the expansion valve, the outdoor unit, the heating element, the accumulator, and the compressor in the second circulation path. The vehicle air conditioning system described in 1. The vehicle air conditioning system according to any one of claims 1 to 4, wherein the circulation path includes a heating element bypass circuit in which the refrigerant bypasses the heating element. The circulation path has a compressor bypass circuit in which the refrigerant bypasses the compressor,
The vehicular air conditioning system according to any one of claims 1 to 5, wherein the compressor bypass circuit is provided with a pump that pumps the refrigerant.