Refrigeration cycle device

Abstract

A refrigeration cycle device is provided with a compressor, a heating unit, a high-stage-side pressure reduction unit, a gas-liquid separation unit, a refrigerant branching unit, a first pressure reduction unit, a first evaporator, a second pressure reduction unit, and a second evaporator. The compressor has an intermediate pressure port into which the intermediate pressure refrigerant within the circulation flows and merges with the refrigerant of the compression process. The gas-liquid separation unit performs gas-liquid separation on the intermediate-pressure refrigerant decompressed by the high-stage-side decompressing unit, and guides the separated gas-phase refrigerant to the intermediate-pressure port. The refrigerant branching section branches the flow of the liquid-phase refrigerant separated by the gas-liquid separation section. In a cooling mode in which the fluid to be heat exchanged is cooled, switching to a refrigerant circuit in which the low-pressure refrigerant flows from the refrigerant branch part to the first evaporator is performed, and in a heating mode in which the fluid to be heat exchanged is heated, switching to a refrigerant circuit in which the low-pressure refrigerant flows from the refrigerant branch part to the second evaporator is performed.

Description

[0001] This application is a divisional application of the following patent application:

[0002] Application No.: 201880049061.3

[0003] Filing Date: July 5, 2018

[0004] Title of the Invention: Refrigeration Cycle Device

[0005] Cross-reference to Related Applications

[0006] This application is based on Japanese Patent Application No. 2017-148189 filed on July 31, 2017, the contents of which are incorporated herein by reference. Technical Field

[0007] The present invention relates to a refrigeration cycle device. Background Art

[0008] Conventionally, as one of the refrigeration cycle devices, a refrigeration cycle device adopting a so-called gas injection cycle (energy-saving refrigeration cycle) has been known.

[0009] As the technology related to the above refrigeration cycle device, the invention described in Patent Document 1 is known. The refrigeration cycle described in Patent Document 1 switches the refrigerant circuit between a heating mode and a cooling mode, and causes the outdoor heat exchanger to function as a radiator in the heating mode and as an evaporator in the cooling mode.

[0010] Moreover, the refrigeration cycle described in Patent Document 1 is configured as a gas injection cycle. In the heating mode, the refrigerant flowing out from the high-stage expansion valve is gas-liquid separated by a gas-liquid separator, and the intermediate-pressure refrigerant in the gas phase state is introduced into the compressor.

[0011] Prior Art Documents

[0012] Patent Documents

[0013] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2012-181005

[0014] Here, in the gas injection cycle, it is necessary to introduce the gas-phase refrigerant gas-liquid separated by the gas-liquid separation unit into the compressor and supply the liquid-phase refrigerant to the evaporator. Therefore, the gas-liquid separation unit needs to be arranged between the high-stage expansion valve and the heat exchanger functioning as an evaporator.

[0015] However, in the invention disclosed in Patent Document 1, since it is configured to switch the high and low pressures of the outdoor heat exchanger according to the operating mode, it may be impossible to introduce the intermediate-pressure refrigerant in the gas phase state into the compressor in the cooling mode, and it may be impossible to configure a gas injection cycle.

[0016] Moreover, when a refrigerant pipe is added to the structure described in Patent Document 1 and the refrigerant circuit is switched so that a gas injection cycle can be formed in any operating mode, the complexity of the refrigerant circuit may increase. SUMMARY OF THE INVENTION

[0017] The present invention has been made in view of the above aspects, and an object thereof is to simplify the circuit structure in a refrigeration cycle device having a gas injection cycle configured to be able to switch operating modes.

[0018] A refrigeration cycle device according to one embodiment of the present invention includes: a compressor, a heating unit, a high-pressure side decompression unit, a gas-liquid separation unit, a refrigerant branch unit, a first decompression unit, a first evaporator, a second decompression unit, and a second evaporator. The compressor compresses the low-pressure refrigerant sucked from the suction port until it becomes a high-pressure refrigerant, discharges the refrigerant from the discharge port, and has an intermediate-pressure port that allows the intermediate-pressure refrigerant in the cycle to flow in and merge with the refrigerant in the compression process. The heating unit uses the high-pressure refrigerant discharged from the discharge port of the compressor as a heat source to heat the heat exchange target fluid. The high-pressure side decompression unit decompresses the high-pressure refrigerant flowing out from the heating unit until it becomes an intermediate-pressure refrigerant. The gas-liquid separation unit performs gas-liquid separation on the intermediate-pressure refrigerant decompressed by the high-pressure side decompression unit, and guides the separated gaseous refrigerant to the intermediate-pressure port. The refrigerant branch unit branches the flow of the liquid-phase refrigerant separated by the gas-liquid separation unit. The first decompression unit decompresses one of the liquid-phase refrigerants branched by the refrigerant branch unit until it becomes a low-pressure refrigerant. The first evaporator allows the low-pressure refrigerant decompressed by the first decompression unit to evaporate by absorbing the heat of the heat exchange target fluid and flow out to the suction port. The second decompression unit decompresses the other liquid-phase refrigerant branched by the refrigerant branch unit until it becomes a low-pressure refrigerant. The second evaporator allows the low-pressure refrigerant decompressed by the second decompression unit to evaporate by absorbing the heat of an external heat source and flow out to the suction port. In the cooling mode for cooling the heat exchange target fluid, the refrigerant circuit is switched so that the low-pressure refrigerant flows from the refrigerant branch unit to the first evaporator, and in the heating mode for heating the heat exchange target fluid, the refrigerant circuit is switched so that the low-pressure refrigerant flows from the refrigerant branch unit to the second evaporator.

[0019] In this refrigeration cycle device, the first decompression unit and the first evaporator are connected to one side of the refrigerant branch unit, and the second decompression unit and the second evaporator are connected to the other side of the refrigerant branch unit. Therefore, even in either the refrigeration mode or the heating mode, the heating unit dissipates the heat of the refrigerant, and the first evaporator and the second evaporator absorb heat from the refrigerant. That is, according to the refrigeration cycle device, the high and low pressures on the Mollier diagram related to the heating unit, the first evaporator, and the second evaporator do not change according to the operating mode switch, so that the circuit structure can be simplified.

[0020] Further, in this refrigeration cycle device, a gas-liquid separator is disposed between the high-stage decompression section and the refrigerant branch section, and guides the gas-phase refrigerant after gas-liquid separation to the intermediate-pressure port of the compressor, constituting a gas injection cycle.

[0021] Since the high and low pressures on the Mollier chart do not change according to the operating mode, this refrigeration cycle device can form a gas injection cycle in any one of the heating mode and the cooling mode, and can improve the compression efficiency of the compressor, etc., thereby improving the performance of the refrigeration cycle device.

[0022] That is, this refrigeration cycle device can simplify the circuit structure and realize a gas injection cycle corresponding to each switchable operating mode, thereby improving the cycle performance in each operating mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a refrigeration cycle device according to at least one embodiment of the present invention.

[0024] Figure 2 is a control block diagram of a refrigeration cycle device according to at least one embodiment of the present invention.

[0025] Figure 3 is a schematic structural diagram of a refrigeration cycle device according to at least one embodiment of the present invention.

[0026] Figure 4 is a structural diagram of the periphery of the refrigerant branch section of a refrigeration cycle device according to at least one embodiment of the present invention.

[0027] Figure 5 is a structural diagram of the heating section and the heat medium circuit of a refrigeration cycle device according to at least one embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Hereinafter, a plurality of modes for implementing the present invention will be described with reference to the drawings. In each mode, there are cases where the same reference numerals are given to the parts corresponding to those described in the previous mode, and redundant explanations are omitted. When only a part of the structure is described in each mode, the other previously described modes can be applied to the other parts of the structure. Not only can the parts that can be specifically combined in each embodiment be combined with each other, but also the embodiments can be partially combined with each other as long as the combination is not particularly hindered even if not explicitly stated.

[0029] Hereinafter, embodiments of the present invention will be described based on the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

[0030] (First Embodiment)

[0031] First, the refrigeration cycle device 10 of the first embodiment will be described. The refrigeration cycle device 10 is applied to the vehicle air conditioner 1 of an electric vehicle that obtains the driving force for vehicle travel from a driving electric motor. The refrigeration cycle device 10 functions in the vehicle air conditioner 1 to cool or heat the supply air blown into the air conditioning target space, that is, the vehicle interior.

[0032] That is, as Figure 1 shown, the refrigeration cycle device 10 of the first embodiment is configured to be able to switch between a plurality of operating modes, and the plurality of operating modes include a refrigeration mode for refrigerating the vehicle interior and a heating mode for heating the vehicle interior.

[0033] In the first embodiment, the supply air blown into the vehicle interior corresponds to the heat exchange target fluid of the present invention. And the refrigeration mode corresponds to the cooling mode of the present invention, and the heating mode corresponds to the heating mode of the present invention. In addition, in Figure 1 , the solid arrow indicates the flow of the refrigerant in the heating mode, and the dashed arrow indicates the flow of the refrigerant in the refrigeration mode.

[0034] Moreover, in the refrigeration cycle device 10, an HFC-based refrigerant (specifically, R134a) is used as the refrigerant, and a vapor compression subcritical refrigeration cycle is configured in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant. Of course, an HFO-based refrigerant (for example, R1234yf) can also be used. The refrigeration oil for lubricating the compressor 11 is mixed into the above refrigerant, and a part of the refrigeration oil circulates in the cycle together with the refrigerant.

[0035] The refrigeration cycle device 10 of the first embodiment has a gas injection cycle (economizer type refrigeration cycle), a heating unit 30, and a heat medium circuit 40. The compressor 11, the refrigerant radiator 12, the high-stage expansion valve 13, the gas-liquid separator 14, the low-stage fixed throttle portion 16, the first expansion valve 19, the first evaporator 20, the evaporation pressure regulating valve 21, the second expansion valve 23, the second evaporator 24, and the liquid storage portion 26 are connected to constitute the gas injection cycle of the refrigeration cycle device 10.

[0036] In the refrigeration cycle device 10, the compressor 11 sucks in the refrigerant, compresses it, and discharges it. The compressor 11 is disposed in the engine hood of the vehicle. The compressor 11 is configured such that two compression mechanisms, a low-stage compression mechanism and a high-stage compression mechanism, and an electric motor that drives the two compression mechanisms to rotate are accommodated inside the housing that constitutes its outer shell. That is, the compressor 11 is a two-stage boost type electric compressor.

[0037] The housing of the compressor 11 is provided with a suction port 11a, an intermediate pressure port 11b, and a discharge port 11c. The suction port 11a is a suction port for sucking low-pressure refrigerant from the outside of the housing into the low-stage compression mechanism. The discharge port 11c is a discharge port for discharging the high-pressure refrigerant discharged from the high-stage compression mechanism to the outside of the housing.

[0038] The intermediate pressure port 11b is an intermediate pressure suction port as follows: It is used to allow the intermediate pressure refrigerant to flow from the outside of the housing into the inside and merge with the refrigerant in the compression process from low pressure to high pressure. That is, the intermediate pressure port 11b is connected inside the housing to the discharge port side of the low-stage compression mechanism and the suction port side of the high-stage compression mechanism.

[0039] The operation (rotation speed) of the electric motor is controlled by a control signal output from a control device 60 described later. That is, the refrigerant discharge capacity of the compressor 11 is changed through the above-mentioned rotation speed control.

[0040] In addition, in the first embodiment, a compressor 11 that houses two compression mechanisms in one housing is adopted, but as long as it is a two-stage boosting compressor, various types can be adopted. That is, as long as the intermediate pressure refrigerant can flow in from the intermediate pressure port 11b and merge with the refrigerant in the compression process from low pressure to high pressure, it can also be an electric compressor configured to house a fixed-capacity compression mechanism and an electric motor that drives the compression mechanism to rotate inside the housing.

[0041] In addition, a two-stage boosting compressor 11 can also be formed by connecting the low-stage compressor and the high-stage compressor in series. In this case, the suction port of the low-stage compressor arranged on the low side is used as the suction port 11a, and the discharge port of the high-stage compressor arranged on the high side is used as the discharge port 11c. And as long as an intermediate pressure port 11b is provided in the refrigerant passage connecting the discharge port of the low-stage compressor and the suction port of the high-stage compressor.

[0042] The refrigerant inlet side of the refrigerant radiator 12 is connected to the discharge port 11c of the compressor 11. The refrigerant radiator 12 constitutes a part of the heating unit 30 formed as a heat medium circuit, and is a heat exchanger that exchanges heat between the heat medium, that is, cooling water, circulating in the heating unit 30 and the high-pressure refrigerant discharged from the high-stage compression mechanism of the compressor 11.

[0043] That is, in the present invention, the above-mentioned refrigerant radiator 12 functions as a medium-refrigerant heat exchanger. The refrigerant radiator 12 dissipates the heat of the high-pressure refrigerant discharged from the discharge port 11c of the compressor 11 to the heat medium circulating in the heating unit 30. In addition, the structure of the heating unit 30 and the specific structure of the heat medium in the heating unit 30 will be described in detail later.

[0044] The inlet side of the high-pressure expansion valve 13 is connected to the refrigerant outlet side of the refrigerant radiator 12. The high-pressure expansion valve 13 includes a valve element and an electric actuator composed of a stepping motor to form an electric variable throttle mechanism. The valve element is configured to be able to change the throttle opening degree, and the stepping motor changes the throttle opening degree of the valve element.

[0045] Moreover, the high-pressure expansion valve 13 is configured to be able to be set to a throttle state that exerts a pressure-reducing function and a fully open state that does not exert a pressure-reducing function. Therefore, the high-pressure expansion valve 13 can reduce the pressure of the high-pressure refrigerant flowing out of the refrigerant radiator 12 until it becomes an intermediate-pressure refrigerant, and functions as a high-pressure pressure-reducing section in the present invention. In addition, the operation of the high-pressure expansion valve 13 is controlled by a control signal output from the control device 60.

[0046] The refrigerant inlet of the gas-liquid separator 14 is connected to the refrigerant outlet of the high-pressure expansion valve 13. The gas-liquid separator 14 is a gas-liquid separation section that separates the refrigerant in a gas-liquid two-phase state flowing out of the high-pressure expansion valve 13, and functions as a gas-liquid separation section in the present invention.

[0047] Specifically, as the gas-liquid separator 14, a structure of a centrifugal separation method (cyclone separator method) that separates the gas and liquid of the refrigerant by the action of the centrifugal force generated by swirling the refrigerant flowing into the internal space of the cylindrical main body is adopted.

[0048] In addition, the internal volume of the gas-liquid separator 14 in the first embodiment is a volume of such a degree that even if a load change occurs in the cycle and the refrigerant circulation flow rate circulating in the cycle changes, it is substantially impossible to store the surplus refrigerant.

[0049] And one end of the intermediate-pressure refrigerant passage 15 is connected to the gas-phase refrigerant outlet of the gas-liquid separator 14. The other end of the intermediate-pressure refrigerant passage 15 is connected to the intermediate-pressure port 11b of the compressor 11. Therefore, the intermediate-pressure refrigerant passage 15 can guide the gas-phase intermediate-pressure refrigerant separated by the gas-liquid separator 14 to the intermediate-pressure port 11b of the compressor 11.

[0050] A check valve (not shown) is arranged in the intermediate-pressure refrigerant passage 15 to prevent the refrigerant from flowing back from the compressor 11 side to the gas-liquid separator 14 side. In addition, the check valve only needs to be arranged between the flow paths from the gas-phase refrigerant outlet of the gas-liquid separator 14 to the intermediate-pressure port 11b of the compressor 11, and can be arranged at the intermediate-pressure port 11b of the compressor 11 or at the gas-phase refrigerant outlet of the gas-liquid separator 14.

[0051] On the other hand, the refrigerant inlet of the low-stage fixed throttling portion 16 is connected to the liquid-phase refrigerant outlet of the gas-liquid separator 14. The low-stage fixed throttling portion 16 is composed of a nozzle with a fixed throttling opening, a throttle hole, a capillary tube, etc., and reduces the pressure of the liquid-phase refrigerant separated by the gas-liquid separator 14.

[0052] In a fixed throttling portion such as a nozzle or a throttle hole, since the throttling passage area sharply decreases or sharply increases, the flow rate of the refrigerant passing through the low-stage fixed throttling portion 16 and the dryness of the refrigerant on the upstream side of the low-stage fixed throttling portion 16 can be self-regulated (balanced) along with the change in the pressure difference (pressure difference between the inlet and outlet) between the upstream side and the downstream side.

[0053] Moreover, the refrigerant branch portion 17 is arranged at the refrigerant outlet of the low-stage fixed throttling portion 16. The refrigerant branch portion 17 is configured to have one refrigerant inlet and a plurality of refrigerant outlets, and branches the flow of the refrigerant flowing out from the low-stage fixed throttling portion 16 into a plurality of flows.

[0054] The refrigerant branch portion 17 of the first embodiment has two refrigerant outlets. One of the refrigerant outlets in the refrigerant branch portion 17 is connected to the first parallel flow path 18, and the other is connected to the second parallel flow path 22. Therefore, the refrigerant branch portion 17 branches the refrigerant flow flowing out from the low-stage fixed throttling portion 16 into a refrigerant flow passing through the first parallel flow path 18 and a refrigerant flow passing through the second parallel flow path 22.

[0055] The first parallel flow path 18 is provided with a first expansion valve 19, a first evaporator 20, and an evaporation pressure regulating valve 21. The first expansion valve 19 is configured as an electric variable throttling mechanism having a valve core and an electric actuator. The valve core is configured to be able to change the throttling opening, and the electric actuator changes the opening of the valve core.

[0056] The first expansion valve 19 has the following functions: a throttling function, which realizes an arbitrary refrigerant pressure reduction effect by making the valve opening an intermediate opening; a fully open function, which hardly exerts a flow rate regulating effect and a refrigerant pressure reduction effect and only functions as a refrigerant passage by making the valve opening fully open; and a fully closed function, which closes the refrigerant passage by making the valve opening fully closed. The operation of the first expansion valve 19 is controlled by a control signal (control pulse) output from the control device 60.

[0057] Thus, the first expansion valve 19 can reduce the pressure of the refrigerant flowing into the first parallel flow path 18 until it becomes a low-pressure refrigerant and then flows out, functioning as the first pressure reduction portion of the present invention. And since the first expansion valve 19 can regulate the refrigerant flow rate flowing through the refrigerant branch portion 17 and into the first parallel flow path 18, it can relatively regulate the refrigerant flow rate flowing into the second parallel flow path 22.

[0058] The refrigerant outlet of the first expansion valve 19 is connected to the refrigerant inlet side of the first evaporator 20 via the first parallel flow path 18. As Figure 1 shown, the first evaporator 20 is a heat exchanger disposed within the air conditioning housing 51 of the indoor air conditioning unit 50 described later, and cools the supply air passing through the air conditioning housing 51 by evaporating the low-pressure refrigerant flowing through it to exert a heat absorption effect.

[0059] The refrigerant outlet side of the first evaporator 20 is connected to the inlet side of the evaporation pressure regulating valve 21 via the first parallel flow path 18. The evaporation pressure regulating valve 21 is composed of a mechanical mechanism and functions as follows: in order to suppress frosting of the first evaporator 20, the refrigerant evaporation pressure of the first evaporator 20 is regulated to a reference pressure or higher that can suppress frosting. In other words, the evaporation pressure regulating valve 21 functions to regulate the refrigerant evaporation temperature of the first evaporator 20 to a reference temperature or higher that can suppress frosting.

[0060] Connected to the other side of the refrigerant outlet of the refrigerant branch portion 17 is a second parallel flow path 22. Disposed in the second parallel flow path 22 are a second expansion valve 23 and a second evaporator 24. Similar to the first expansion valve 19, the second expansion valve 23 has a valve element and an electric actuator and is configured as an electrically variable throttling mechanism, wherein the valve element is configured to be able to change the throttling opening, and the electric actuator changes the opening of the valve element.

[0061] Similar to the first expansion valve 19, the second expansion valve 23 can exert a throttling function, a fully open function, and a fully closed function by appropriately adjusting the valve opening between the fully open state and the fully closed state. The operation of the second expansion valve 23 is controlled by a control signal (control pulse) output from the control device 60.

[0062] Thereby, the second expansion valve 23 can reduce the pressure of the refrigerant flowing into the second parallel flow path 22 until it becomes a low-pressure refrigerant and then flow out, functioning as the second pressure reduction portion of the present invention. And since the second expansion valve 23 can regulate the refrigerant flow rate flowing through the refrigerant branch portion 17 to the second parallel flow path 22, it can relatively regulate the refrigerant flow rate flowing to the first parallel flow path 18.

[0063] That is, the first expansion valve 19 and the second expansion valve 23 have the function of regulating the refrigerant flow rates through the first parallel flow path 18 and the second parallel flow path 22 by cooperating with each other. And the first expansion valve 19 and the second expansion valve 23 exert a flow path switching function by making either one of them exert a fully closed function.

[0064] And the refrigerant outlet of the second expansion valve 23 is connected to the refrigerant inlet side of the second evaporator 24 via the first parallel flow path 22. AsFigure 1 As shown, the second evaporator 24 is a heat exchanger that forms part of a heat medium circuit 40 described later, and functions as a heat absorber by evaporating the low-pressure refrigerant flowing through it, thereby absorbing the heat of the heat medium (i.e., cooling water) circulating in the heat medium circuit 40. In addition, the structure and the like of the heat medium circuit 40 will be described in detail later.

[0065] As Figure 1 shown, the refrigerant confluence section 25 is configured to have a plurality of refrigerant inlets and one refrigerant outlet, and merges the flows of the plurality of refrigerants branched by the refrigerant branch section 17 into one.

[0066] The refrigerant confluence section 25 of the first embodiment has two refrigerant inlets. One of the refrigerant inlets of the refrigerant confluence section 25 is connected to the refrigerant outlet side of the evaporation pressure regulating valve 21, and the other is connected to the refrigerant outlet side of the second evaporator 24. Therefore, the refrigerant confluence section 25 merges the refrigerant flow after passing through the first parallel flow path 18 and the refrigerant flow after passing through the second parallel flow path 22 into one refrigerant flow and discharges it.

[0067] A liquid storage section 26 is arranged at the refrigerant outlet of the refrigerant confluence section 25. The liquid storage section 26 is a low-pressure side gas-liquid separator that separates the gas and liquid of the refrigerant flowing in from the refrigerant confluence section 25 and stores the remaining liquid-phase refrigerant in the cycle. And, a suction port 11a of the compressor 11 is connected to the gas-phase refrigerant outlet of the liquid storage section 26. Therefore, the liquid storage section 26 supplies the gas-phase refrigerant to the suction port 11a of the compressor 11 and functions to suppress the supply of the liquid-phase refrigerant, thus preventing liquid compression of the refrigerant in the compressor 11.

[0068] Next, with reference to Figure 1 the structure of the heating section 30 of the first embodiment will be described. As Figure 1 shown, the heating section 30 is a high-temperature side heat medium circuit configured to have the following components: a refrigerant radiator 12 that forms part of a gas injection cycle; a heat medium circulation path 31 as a heat medium flow path; a pressure pump 32; a heater core 33; a radiator 34; and a three-way valve 35.

[0069] The heating section 30 is configured to connect the refrigerant radiator 12, the heater core 33, etc. through the heat medium circulation path 31, and is configured to circulate the cooling water as the heat medium in the heat medium circulation path 31 by the operation of the pressure pump 32. The cooling water in the heating section 30 is a high-temperature heat medium, and for example, a liquid or an antifreeze containing at least ethylene glycol, dimethylpolysiloxane or nanofluid is used.

[0070] The pressure-feed pump 32 is a heat medium pump that sucks in and discharges cooling water as a heat medium, and is composed of an electric pump. The pressure-feed pump 32 circulates the cooling water in the heat medium circulation passage 31 of the heating unit 30 by pressure-feeding the cooling water in the heat medium circulation passage 31.

[0071] The operation of the pressure-feed pump 32 is controlled by a control signal output from the control device 60. That is, the pressure-feed pump 32 can adjust the flow rate of the cooling water circulating in the heating unit 30 through the control of the control device 60, and functions as a heat medium flow rate adjustment unit in the heating unit 30.

[0072] A refrigerant radiator 12 is connected to the discharge port side of the pressure-feed pump 32. Therefore, the refrigerant radiator 12 exchanges heat between the high-pressure refrigerant passing through its interior and the cooling water circulating in the heat medium circulation passage 31, so that the heat possessed by the high-pressure refrigerant can be dissipated to the cooling water.

[0073] Moreover, a three-way valve 35 is connected to the cooling water outlet side of the refrigerant radiator 12. The three-way valve 35 has two outlets, and can switch the flow of the cooling water flowing in from one inlet to either outlet side.

[0074] As Figure 1 shown, a heater core 33 is connected to one outlet of the three-way valve 35, and a radiator 34 is connected to the other outlet. Therefore, the three-way valve 35 can switch the flow of the cooling water after passing through the refrigerant radiator 12 to the heater core 33 side or the radiator 34 side. The three-way valve 35 functions as a heat medium flow path switching unit in the heating unit 30.

[0075] As Figure 1 shown, the heater core 33 is disposed downstream of the supply air flow with respect to the first evaporator 20 in the air-conditioning housing 51 of the in-vehicle air-conditioning unit 50. The heater core 33 is a high-temperature side heat medium heat exchanger that exchanges heat between the cooling water circulating in the heat medium circulation passage 31 of the heating unit 30 and the supply air blown into the vehicle interior to heat the supply air.

[0076] In the heater core 33, the cooling water dissipates heat to the supply air blown into the vehicle interior due to sensible heat change. Thus, since the supply air blown into the vehicle interior of the electric vehicle is heated, the refrigeration cycle device 10 can heat the vehicle interior. In addition, in the heater core 33, even if the cooling water dissipates heat to the supply air, the cooling water remains in a liquid phase state without phase change.

[0077] The radiator 34 is a heat - releasing heat exchanger that exchanges heat between the cooling water circulating in the heat medium circulation passage 31 of the heating unit 30 and the outside air outside the electric vehicle, and dissipates the heat possessed by the cooling water to the outside air. The radiator 34 is connected in parallel to the heater core 33 through the heat medium circulation passage 31 of the heating unit 30. And since the heat possessed by the cooling water is dissipated from the radiator 34 to the outside air, the refrigeration cycle device 10 can discharge heat to the outside of the vehicle compartment without heating the blown - air.

[0078] With the above - described structure, the heating unit 30 of the refrigeration cycle device 10 can switch the flow of the cooling water by means of the three - way valve 35, thereby changing the utilization mode of the heat possessed by the high - pressure refrigerant. That is, the heating unit 30 can utilize the heat possessed by the high - pressure refrigerant for heating the blown - air and heating the vehicle compartment by switching to the cooling water flow via the heater core 33. On the other hand, the heating unit 30 can discharge the heat possessed by the high - pressure refrigerant to the outside air by switching to the cooling water flow via the radiator 34.

[0079] Next, Figure 1 the structure of the heat medium circuit 40 of the first embodiment will be described. As Figure 1 shown, the heat medium circuit 40 is a low - temperature - side heat medium circuit configured to include the following components: a second evaporator 24 that forms part of the gas injection cycle; a heat medium circulation passage 41 as a heat medium flow path; a pressure - feed pump 42; a radiator 43; in - vehicle equipment 44; an opening - closing valve 45; and an opening - closing valve 46.

[0080] The heat medium circuit 40 is configured to connect the second evaporator 24, the radiator 43, etc. through the heat medium circulation passage 41, and is configured to circulate the cooling water as a heat medium in the heat medium circulation passage 41 by the operation of the pressure - feed pump 42. The cooling water in this heat medium circuit 40 is a low - temperature heat medium, and for example, a liquid or an antifreeze containing at least ethylene glycol, dimethylpolysiloxane, or nanofluid is used.

[0081] The pressure - feed pump 42 is a heat medium pump that sucks and discharges the cooling water as a heat medium, and is composed of an electric pump. The pressure - feed pump 42 circulates the cooling water in the heat medium circulation passage 41 of the heat medium circuit 40 by feeding the cooling water in the heat medium circulation passage 41.

[0082] The operation of the pressure - feed pump 42 is controlled by a control signal output from the control device 60. That is, the pressure - feed pump 42 can adjust the flow rate of the cooling water circulating in the heat medium circuit 40 under the control of the control device 60, and functions as a heat medium flow rate adjustment unit in the heat medium circuit 40.

[0083] The second evaporator 24 is connected to the discharge port side of the pressure feed pump 42. Therefore, the second evaporator 24 can cause the low-pressure refrigerant passing through its interior to exchange heat with the cooling water circulating in the heat medium circulation passage 41, so that the low-pressure refrigerant absorbs the heat possessed by the cooling water.

[0084] Moreover, a heat medium passage having a radiator 43 etc. and a heat medium passage having in-vehicle equipment 44 etc. are connected to the cooling water outlet side of the second evaporator 24. That is, in the heat medium circuit 40 of the first embodiment, the radiator 43 and the on-off valve 45 are connected in parallel with the in-vehicle equipment 44 and the on-off valve 46.

[0085] The radiator 43 is a heat exchanger that causes the cooling water circulating in the heat medium circulation passage 41 of the heat medium circuit 40 to exchange heat with the outside air outside the electric vehicle, so that the cooling water absorbs the heat possessed by the outside air. That is, when the cooling water is circulated through the radiator 43, the heat medium circuit 40 uses the outside air outside the electric vehicle as an external heat source.

[0086] Moreover, an on-off valve 45 is disposed on the upstream side of the cooling water flow of the cooling water inlet of the radiator 43. The on-off valve 45 is configured to be able to adjust the opening degree of the cooling water passage leading to the cooling water inlet of the radiator 43 between a fully closed state and a fully open state. The operation of the on-off valve 45 is controlled by a control signal output from the control device 60.

[0087] That is, by controlling the opening degree of the on-off valve 45 using the control device 60, the heat medium circuit 40 can switch the presence or absence of the cooling water flow with respect to the radiator 43. In other words, the refrigeration cycle device 10 can switch whether to use the outside air as an external heat source.

[0088] The in-vehicle equipment 44 is mounted on the above-mentioned electric vehicle and is composed of equipment that generates heat during operation, including, for example, a charger for charging the battery of the electric vehicle, an electric generator, an inverter, etc. The in-vehicle equipment 44 functions as a heat generating device in the present invention. Moreover, the heat medium circulation passage 41 in the heat medium circuit 40 is arranged to be in contact with the outer surface of the above-mentioned in-vehicle equipment 44, so that the heat possessed by the in-vehicle equipment 44 can exchange heat with the cooling water flowing in the heat medium passage.

[0089] Moreover, an on-off valve 46 is disposed on the upstream side of the cooling water flow of the cooling water inlet of the in-vehicle equipment 44. The on-off valve 46 is configured to be able to adjust the opening degree of the cooling water passage leading to the cooling water inlet of the in-vehicle equipment 44 between a fully closed state and a fully open state. The operation of the on-off valve 46 is controlled by a control signal output from the control device 60.

[0090] That is, by controlling the opening degree of the on-off valve 46 using the control device 60, the heat medium circuit 40 can switch the presence or absence of the cooling water flow relative to the vehicle-mounted device 44. In other words, the refrigeration cycle device 10 can switch whether to use the vehicle-mounted device 44 as an external heat source.

[0091] Next, Figure 1 The structure of the indoor air-conditioning unit 50 that constitutes the vehicle air-conditioning device 1 will be described. The indoor air-conditioning unit 50 forms a part of the vehicle air-conditioning device 1 and blows the air whose temperature has been adjusted by the refrigeration cycle device 10 into the vehicle interior.

[0092] The indoor air-conditioning unit 50 is arranged inside the dashboard (instrument panel) at the foremost part of the vehicle interior of the electric vehicle. The indoor air-conditioning unit 50 houses a blower 52, a second evaporator 24, a heater core 33, etc. in the air passage, and the above-mentioned air passage is formed in the air-conditioning housing 51 that forms the outer shell of the indoor air-conditioning unit 50.

[0093] Since the air-conditioning housing 51 forms the air passage for the air blown into the vehicle interior, it is formed of a resin (for example, polypropylene) having a certain degree of elasticity and excellent strength.

[0094] An inside / outside air switching device 53 is arranged on the most upstream side of the air flow of the air blown by the air-conditioning housing 51. The inside / outside air switching device 53 switches and introduces internal air (air inside the vehicle) and external air (air outside the vehicle) into the air-conditioning housing 51.

[0095] Specifically, the inside / outside air switching device 53 continuously adjusts the opening areas of the internal air inlet for introducing internal air into the air-conditioning housing 51 and the external air inlet for introducing external air through an inside / outside air switching door, thereby changing the introduction ratio of the internal air introduction air volume and the external air introduction air volume. The inside / outside air switching door is driven by an electric actuator for the inside / outside air switching door, and the operation of this electric actuator is controlled by a control signal output from the control device 60.

[0096] The blower 52 is arranged on the downstream side of the air flow of the inside / outside air switching device 53. The blower 52 is an electric blower that uses an electric motor to drive a centrifugal multi-blade fan, and blows the air inhaled through the inside / outside air switching device 53 into the vehicle interior. The rotation speed (i.e., the air supply capacity) of the blower 52 is controlled by a control voltage output from the control device 60.

[0097] On the downstream side of the air flow of the blower 52, a first evaporator 20 and a heater core 33 are arranged in sequence with respect to the air flow of the air blown. That is, the first evaporator 20 is arranged on the upstream side of the air flow of the heater core 33.

[0098] Further, a bypass passage 55 is provided within the air-conditioning case 51. The bypass passage 55 is configured such that the supply air that has passed through the first evaporator 20 flows around the heater core 33.

[0099] Further, an air mix door 54 is disposed on the downstream side of the supply air flow of the first evaporator 20 and on the upstream side of the supply air flow of the heater core 33 within the air-conditioning case 51. The air mix door 54 is an air volume ratio adjustment unit that adjusts the air volume ratio between the supply air that has passed through the heater core 33 and the supply air that has passed through the bypass passage 55 among the supply air that has passed through the first evaporator 20.

[0100] Further, the air mix door 54 is driven by an electric actuator for the air mix door. The operation of the electric actuator is controlled by a control signal output from the control device 60.

[0101] A confluence space 56 is formed on the downstream side of the supply air flow of the heater core 33 and the bypass passage 55. The confluence space 56 is configured such that the supply air heated by heat exchange with a heat medium (i.e., cooling water) through the heater core 33 and the supply air that has passed through the bypass passage 55 without being heated are made to confluence. Therefore, the air mix door 54 adjusts the air volume ratio, thereby adjusting the temperature of the supply air that confluences through the confluence space 56.

[0102] In addition, although not shown in the drawings, a plurality of types of opening holes are disposed at the most downstream portion of the supply air flow of the air-conditioning case 51. Specifically, a defrost opening hole, a face opening hole, and a foot opening hole are provided as the plurality of types of opening holes, and are configured to blow out the supply air whose temperature has been adjusted through the confluence space 56 into the vehicle interior from different positions within the vehicle compartment.

[0103] Further, a door for adjusting the area of each opening is disposed on the upstream side of the supply air flow of the plurality of types of opening holes. Specifically, a defrost door, a face door, and a foot door are disposed corresponding to the defrost opening hole, the face opening hole, and the foot opening hole, respectively. The operation of each door is controlled by a control signal from the control device 60, and constitutes a blow-out mode switching device that switches the blow-out mode by opening and closing each opening hole.

[0104] Next, refer to Figure 2 The control system of the vehicle air-conditioning apparatus 1 according to the first embodiment will be described. The control device 60 is constituted by a known microcomputer including a CPU, a ROM, a RAM, and the like and its peripheral circuits. Further, the control device 60 performs various operations and processes based on an air-conditioning control program stored in the ROM, and controls the operations of various air-conditioning control devices connected to the output side.

[0105] A plurality of types of air-conditioning control devices and electric actuators are connected to the output side of the control device 60. AsFigure 2 As shown, various types of air-conditioning control devices, etc. include: a compressor 11, a high-pressure side expansion valve 13, a first expansion valve 19, a second expansion valve 23, a blower 52, an inside / outside air switching device 53, an air mixing door 54, a pressure pump 32, a three-way valve 35, a pressure pump 42, an on-off valve 45, and an on-off valve 46.

[0106] Moreover, an operation panel 61 for various input operations is connected to the input side of the control device 60. The operation panel 61 is arranged near the instrument panel at the front of the vehicle interior and has various operation switches. Therefore, operation signals from the various operation switches provided on the operation panel 61 are input to the control device 60.

[0107] The various operation switches of the operation panel 61 include an auto switch, a running mode switching switch, an air volume setting switch, a temperature setting switch, a blowing mode switching switch, etc. Therefore, the refrigeration cycle device 10 can appropriately switch the running mode of the refrigeration cycle device 10 by receiving the input from the operation panel 61.

[0108] Moreover, a sensor group 62 for air-conditioning control is connected to the input side of the control device 60. The sensor group 62 for air-conditioning control includes an internal air temperature sensor, an outside air temperature sensor, a solar radiation sensor, etc. The internal air temperature sensor is an internal air temperature detection unit that detects the temperature inside the vehicle interior (internal air temperature). The outside air temperature sensor is an outside air temperature detection unit that detects the temperature outside the vehicle (outside air temperature). The solar radiation sensor is a solar radiation amount detection unit that detects the amount of solar radiation irradiating the vehicle interior.

[0109] Therefore, the detection signals of the above-mentioned sensor group 62 for air-conditioning control are input to the control device 60. Thus, the refrigeration cycle device 10 can adjust the temperature of the supply air blown into the vehicle interior according to the physical quantities detected by the sensor group 62 for air-conditioning control, thereby enabling a comfortable air-conditioning.

[0110] Moreover, in this control device 60, a control unit for controlling the operations of various control devices connected to its output side is integrally formed, but the structures (such as software and hardware) for respectively controlling the operations of the control devices form control units for controlling the operations of their respective control devices.

[0111] For example, a structure that controls at least one of the high - side expansion valve 13, the first expansion valve 19, and the second expansion valve 23 constitutes a flow rate ratio control unit 60a, and the flow rate ratio control unit 60a performs control for adjusting the refrigerant flow rate ratio in each operation mode. In the first embodiment, the refrigerant flow rate ratio is defined by the ratio of the suction refrigerant flow rate sucked from the suction port 11a of the compressor 11 to the discharge refrigerant flow rate discharged from the discharge port 11c of the compressor 11.

[0112] Next, the operation of the vehicle air - conditioning device 1 configured as described above will be described. The vehicle air - conditioning device of the first embodiment can execute a refrigeration mode, a heating mode, and a device cooling mode as operation modes.

[0113] The refrigeration mode is an operation mode in which the supply air, which is the fluid to be heat - exchanged, is cooled to cool the vehicle interior, and is an example of the cooling mode in the present invention. And, the heating mode is an operation mode in which heat is absorbed from the outside air as an external heat source, and the supply air, which is the fluid to be heat - exchanged, is heated to heat the vehicle interior, and is an example of the heating mode in the present invention. And, the device cooling mode is an operation mode in which cooling is performed by absorbing heat from a heat - generating device (i.e., in - vehicle device 44) as an external heat source.

[0114] First, the operation method in the refrigeration mode of the vehicle air - conditioning device 1 of the first embodiment will be described with reference to the drawings. In the refrigeration mode, the throttling openings of the high - side expansion valve 13 and the first expansion valve 19 are determined to be the specified openings for the refrigeration mode set in advance. For the throttling opening of the second expansion valve 23, it is determined to be in a fully - closed state. Thus, the refrigerant circuit indicated by the dotted arrow in Figure 1 is switched to.

[0115] Also, for the control signal output to the servo - motor of the air - mix door 54, it is determined that the air - mix door 54 closes the upstream side of the supply - air flow of the heater core 33, and all the flow rate of the supply air after passing through the first evaporator 20 passes through the bypass passage 55. In addition, for the control signals to the compressor 11, the blower 52, and the inside - outside air switching device 53, they are appropriately determined using the input operations of the operation panel 61 and the detection signals of the sensor group 62.

[0116] Therefore, in the refrigeration mode of the refrigeration cycle device 10, the high - pressure refrigerant discharged from the discharge port 11c of the compressor 11 flows to the refrigerant radiator 12. The refrigerant flowing to the refrigerant radiator 12 dissipates heat with respect to the cooling water flowing in the heat - medium circulation passage 31 of the heating unit 30. Therefore, the cooling water in the heating unit 30 is heated by the heat of the high - pressure refrigerant, and the refrigerant radiator 12 functions as a radiator.

[0117] The refrigerant flowing out of the refrigerant radiator 12 is isenthalpically depressurized and expanded through the high-pressure side expansion valve 13 in a throttling state until it becomes an intermediate-pressure refrigerant. Then, the intermediate-pressure refrigerant depressurized by the high-pressure side expansion valve 13 is separated into gas and liquid by the gas-liquid separator 14.

[0118] The gaseous refrigerant separated by the gas-liquid separator 14 flows through the intermediate-pressure refrigerant passage 15 to the intermediate-pressure port 11b of the compressor 11, merges with the discharged refrigerant of the low-pressure side compression mechanism in the compressor 11, and is inhaled by the high-pressure side compression mechanism.

[0119] On the other hand, the liquid refrigerant separated by the gas-liquid separator 14 is depressurized by the low-pressure side fixed throttle portion 16 and sent to the refrigerant branch portion 17. Here, in the refrigeration mode, the first expansion valve 19 is in a throttling state and the second expansion valve 23 is in a fully closed state. Therefore, the refrigerant flowing out of the refrigerant branch portion 17 flows into the first parallel flow path 18 and is isenthalpically depressurized by the first expansion valve 19 until it becomes a low-pressure refrigerant.

[0120] The low-pressure refrigerant flowing out of the first expansion valve 19 flows into the first evaporator 20 disposed in the air-conditioning housing 51 and absorbs heat by exchanging heat with the supply air blown by the blower 52. Thereby, the supply air generated by the blower 52 is cooled and blown into the vehicle interior via the bypass passage 55.

[0121] The refrigerant flowing out of the first evaporator 20 flows into the liquid storage portion 26 via the evaporation pressure regulating valve 21 and the refrigerant merging portion 25 and is separated into gas and liquid. Then, the gaseous refrigerant separated by the liquid storage portion 26 is inhaled from the suction port 11a of the compressor 11 and compressed again. On the other hand, the liquid refrigerant separated by the liquid storage portion 26 is stored in the liquid storage portion 26 as surplus refrigerant that is not required to exert the refrigeration capacity required for the cycle.

[0122] Here, the operation of the heating unit 30 in the refrigeration mode will be described. The control signal of the three-way valve 35 in the refrigeration mode is determined such that all the cooling water flowing out of the refrigerant radiator 12 flows into the radiator 34.

[0123] As described above, the heat of the high-pressure refrigerant is dissipated to the cooling water of the heating unit 30 through the refrigerant radiator 12. Therefore, the cooling water flowing out of the refrigerant radiator 12 remains in a high-temperature state, passes through the three-way valve 35, and flows into the radiator 34.

[0124] The cooling water flowing into the radiator 34 dissipates heat to the outside air outside the electric vehicle via the radiator 34. That is, according to this refrigeration cycle device 10, the heat of the high-pressure refrigerant is dissipated to the outside air via the cooling water of the heating unit 30.

[0125] Next, the cooling water cooled by the radiator 34 circulates with the operation of the feed pump 32, is sucked into the feed pump 32 again, and is fed to the refrigerant radiator 12.

[0126] In addition, in the refrigeration mode, the low-pressure refrigerant in the refrigeration cycle device 10 does not pass through the second evaporator 24. Therefore, the operation state of the heat medium circuit 40 thermally connected to the second evaporator 24 can be arbitrarily determined.

[0127] In this way, in the refrigeration mode, the heat of the high-pressure refrigerant can be dissipated to the outside air via the cooling water of the heating unit 30, and the low-pressure refrigerant can absorb heat from the supply air blown into the vehicle interior by the first evaporator 20 for cooling. Thus, refrigeration in the vehicle interior can be achieved.

[0128] Furthermore, in the refrigeration mode, the low-pressure refrigerant flowing out of the first evaporator 20 can be sucked into the suction port 11a of the compressor 11, and the intermediate-pressure refrigerant in the gas phase state after passing through the high-stage expansion valve 13 and the gas-liquid separator 14 can flow into the intermediate-pressure port 11b and merge with the refrigerant in the boosting process. That is, the refrigeration cycle device 10 can form a gas injection cycle (economizer-type refrigeration cycle) in the refrigeration mode.

[0129] Therefore, the compression efficiency of the high-stage compression mechanism can be improved by making the high-stage compression mechanism suck the lower-temperature mixed refrigerant, and the pressure difference between the suction refrigerant pressure and the discharge refrigerant pressure of both the low-stage compression mechanism and the high-stage compression mechanism can be reduced, thereby improving the compression efficiency of both compression mechanisms. As a result, the COP of the entire refrigeration cycle device 10 can be improved.

[0130] Next, the operation mode of the vehicle air conditioner 1 in the heating mode according to the first embodiment will be described with reference to the drawings. In the heating mode, the throttling openings of the high-stage expansion valve 13 and the second expansion valve 23 are determined to be the specified openings for the preset heating mode. For the throttling opening of the first expansion valve 19, it is determined to be in the fully closed state. Thus, the refrigerant circuit indicated by the solid arrows in Figure 1 is switched.

[0131] Moreover, for the control signal output to the servo motor of the air mix door 54, it is determined that the air mix door 54 closes the bypass passage 55, and all the flow rate of the supply air after passing through the first evaporator 20 passes through the heater core 33. In addition, for the control signals to the compressor 11, the blower 52, and the inside / outside air switching device 53, they are appropriately determined using the input operations of the operation panel 61 and the detection signals of the sensor group 62.

[0132] Therefore, in the heating mode of the refrigeration cycle device 10, the high-pressure refrigerant discharged from the discharge port 11c of the compressor 11 flows toward the refrigerant radiator 12. The refrigerant flowing toward the refrigerant radiator 12 dissipates heat with respect to the cooling water flowing in the heat medium circulation path 31 of the heating unit 30. Therefore, the cooling water in the heating unit 30 is heated by the heat possessed by the high-pressure refrigerant, and the refrigerant radiator 12 functions as a radiator.

[0133] In the heating mode, the refrigerant flowing out of the refrigerant radiator 12 is also isenthalpically depressurized and expanded through the high-stage expansion valve 13 in a throttling state until it becomes an intermediate-pressure refrigerant. Then, the intermediate-pressure refrigerant depressurized by the high-stage expansion valve 13 is gas-liquid separated by the gas-liquid separator 14.

[0134] The gaseous refrigerant separated by the gas-liquid separator 14 flows through the intermediate-pressure refrigerant passage 15 toward the intermediate-pressure port 11b of the compressor 11, merges with the discharged refrigerant of the low-stage compression mechanism of the compressor 11, and is sucked into the high-stage compression mechanism.

[0135] On the other hand, the liquid refrigerant separated by the gas-liquid separator 14 is depressurized by the low-stage fixed throttle portion 16 and sent to the refrigerant branch portion 17. Here, in the heating mode, the second expansion valve 23 is in a throttling state and the first expansion valve 19 is in a fully closed state. Therefore, the refrigerant flowing out of the refrigerant branch portion 17 flows into the second parallel flow path 22 and is isenthalpically depressurized by the second expansion valve 23 until it becomes a low-pressure refrigerant.

[0136] The low-pressure refrigerant flowing out of the second expansion valve 23 flows into the second evaporator 24 and exchanges heat with the cooling water circulating in the heat medium circuit 40. That is, in the second evaporator 24, the low-pressure refrigerant absorbs the heat possessed by the cooling water in the heat medium circuit 40 and is heated, and the cooling water in the heat medium circuit 40 is cooled by exchanging heat with the low-pressure refrigerant.

[0137] The refrigerant flowing out of the second evaporator 24 flows into the liquid storage portion 26 via the refrigerant merging portion 25 and is gas-liquid separated. Then, the gaseous refrigerant separated by the liquid storage portion 26 is sucked from the suction port 11a of the compressor 11 and compressed again. On the other hand, the liquid refrigerant separated by the liquid storage portion 26 is stored as the remaining refrigerant in the circulation in the liquid storage portion 26.

[0138] Here, the operation of the heating unit 30 in the heating mode will be described. The control signal of the three-way valve 35 in the heating mode is determined so that all the cooling water flowing out of the refrigerant radiator 12 flows into the heater core 33.

[0139] As described above, the heat of the high-pressure refrigerant is dissipated to the cooling water of the heating unit 30 through the refrigerant radiator 12. Therefore, the cooling water flowing out of the refrigerant radiator 12 remains in a high-temperature state, passes through the three-way valve 35, and flows into the heater core 33.

[0140] The cooling water flowing into the heater core 33 exchanges heat with the supply air blown by the blower 52 through the heater core 33. In the heating mode, since the first expansion valve 19 is fully closed, the supply air is not cooled by the first evaporator 20 and is sent to the heater core 33.

[0141] That is, according to the refrigeration cycle device 10, the heat of the high-pressure refrigerant is dissipated to the supply air blown into the vehicle interior via the cooling water of the heating unit 30. Thereby, the supply air heated by the heat of the high-pressure refrigerant can be supplied into the vehicle interior, thereby heating the vehicle interior.

[0142] The cooling water dissipated by the heater core 33 circulates with the operation of the pressure pump 32, is sucked into the pressure pump 32 again, and is pumped to the refrigerant radiator 12.

[0143] Next, the operation of the heat medium circuit 40 in the heating mode will be described. The control signals of the on-off valve 45 and the on-off valve 46 in the heating mode are determined such that, for example, the on-off valve 45 is fully opened and the on-off valve 46 is fully closed. In this case, since all the cooling water in the heat medium circuit 40 passes through the radiator 43, this cooling water absorbs heat from the outside air through the radiator 43. That is, the refrigeration cycle device 10 uses the outside air as an external heat source at this time.

[0144] The cooling water flowing out of the radiator 43 flows into the second evaporator 24 via the pressure pump 42 with the operation of the pressure pump 42. As described above, in the second evaporator 24, heat exchange occurs between the low-pressure refrigerant and the cooling water of the heat medium circuit 40. Therefore, the heat of the cooling water in the heat medium circuit 40 is absorbed by the low-pressure refrigerant. Thereby, the refrigeration cycle device 10 can use the outside air as an external heat source in the heating mode.

[0145] In addition, in the above example, since the on-off valve 45 is fully opened and the on-off valve 46 is fully closed, the cooling water passes through the radiator 43. That is, the method of using the outside air as an external heat source in the heating mode. However, various methods can also be adopted as the method of using an external heat source through the opening and closing control of the on-off valve 45 and the on-off valve 46.

[0146] For example, when the on-off valve 45 is fully closed and the on-off valve 46 is fully opened, since the cooling water passes through the in-vehicle device 44, the heat of the in-vehicle device 44 is absorbed. In this case, the refrigeration cycle device 10 can use the in-vehicle device 44 as an external heat source in the heating mode.

[0147] Moreover, when the on-off valves 45 and 46 are fully opened, since the cooling water merges after passing through the radiator 43 and the in-vehicle device 44, it can absorb the heat of the outside air and the in-vehicle device 44. In this case, the refrigeration cycle device 10 can use the outside air and the in-vehicle device 44 together as an external heat source in the heating mode.

[0148] In this way, in the heating mode, the low-pressure refrigerant absorbs the heat of the external heat source (i.e., the outside air, the in-vehicle device 44) via the cooling water in the heat medium circuit 40, and the heat of the high-pressure refrigerant is dissipated to the supply air blown into the vehicle interior via the cooling water in the heating unit 30 for heating. Thus, heating in the vehicle interior can be achieved.

[0149] In addition, in the heating mode, since the high and low pressures on the Mollier diagram of the refrigerant radiator 12 etc. do not switch from the refrigeration mode, the low-pressure refrigerant flowing out from the second evaporator 24 can be sucked from the suction port 11a of the compressor 11, and the vapor-phase intermediate-pressure refrigerant after passing through the high-stage expansion valve 13 and the gas-liquid separator 14 flows into the intermediate-pressure port 11b and merges with the refrigerant in the boosting process. That is, not only in the refrigeration mode, but also in the heating mode, the refrigeration cycle device 10 can form a gas injection cycle (economizer-type refrigeration cycle).

[0150] Therefore, the compression efficiency of the high-stage compression mechanism can be improved by making the high-stage compression mechanism suck the lower-temperature mixed refrigerant, and the pressure difference between the suction refrigerant pressure and the discharge refrigerant pressure of both the low-stage compression mechanism and the high-stage compression mechanism can be reduced, thereby improving the compression efficiency of both compression mechanisms. As a result, the COP of the entire refrigeration cycle device 10 can be improved.

[0151] And, in the above heating mode, by controlling the throttling opening degree of at least one of the high-stage expansion valve 13, the first expansion valve 19, and the second expansion valve 23, the control device 60 controls the refrigerant flow rate ratio in the heating mode to be smaller than the refrigerant flow rate ratio in the refrigeration mode.

[0152] Here, the refrigerant flow rate ratio is defined by the ratio of the suction refrigerant flow rate sucked from the suction port 11a of the compressor 11 to the discharge refrigerant flow rate discharged from the discharge port 11c of the compressor 11. Since the discharge refrigerant flow rate is equivalent to the total amount of the intermediate-pressure refrigerant flow rate introduced from the intermediate-pressure port 11b and the discharge refrigerant flow rate, it can also be grasped as the ratio of the intermediate-pressure refrigerant flow rate to the discharge refrigerant flow rate.

[0153] In the heating mode, the density of the refrigerant sucked in from the suction port 11a is lower than that in the cooling mode. Therefore, by making the refrigerant flow rate ratio in the heating mode lower than that in the cooling mode, the heat exchange performance of the refrigerant radiator 12 can be improved, thereby enhancing the cycle performance. The control device 60 functions as the flow rate ratio control unit of the present invention at this time.

[0154] Next, the operation mode of the vehicle air conditioner 1 according to the first embodiment in the equipment cooling mode will be described with reference to the drawings. In the equipment cooling mode, the throttling openings of the high-stage expansion valve 13 and the second expansion valve 23 are determined to be the specified openings for the preset equipment cooling mode. For the throttling opening of the first expansion valve 19, it is determined to be in the fully closed state. Therefore, in the equipment cooling mode, similar to the heating mode, the refrigerant circuit indicated by the solid arrows in Figure 1 is switched to.

[0155] In addition, for the control signals to the compressor 11, the blower 52, the inside / outside air switching device 53, and the air mixing door 54, they are appropriately determined using the input operations of the operation panel 61 and the detection signals of the sensor group 62.

[0156] Therefore, in the equipment cooling mode of the refrigeration cycle device 10, the high-pressure refrigerant discharged from the discharge port 11c of the compressor 11 flows to the refrigerant radiator 12. The refrigerant flowing to the refrigerant radiator 12 dissipates heat to the cooling water flowing in the heating unit 30. Therefore, the cooling water in the heating unit 30 is heated by the heat possessed by the high-pressure refrigerant, and the refrigerant radiator 12 functions as a radiator.

[0157] In the equipment cooling mode, the refrigerant flowing out of the refrigerant radiator 12 is also isenthalpically decompressed and expanded by the high-stage expansion valve 13 in the throttling state until it becomes an intermediate-pressure refrigerant. The intermediate-pressure refrigerant decompressed by the high-stage expansion valve 13 is gas-liquid separated by the gas-liquid separator 14.

[0158] The gaseous refrigerant separated by the gas-liquid separator 14 flows through the intermediate-pressure refrigerant passage 15 to the intermediate-pressure port 11b of the compressor 11, merges with the discharged refrigerant of the low-stage compression mechanism of the compressor 11, and is sucked into the high-stage compression mechanism.

[0159] On the other hand, the liquid refrigerant separated by the gas-liquid separator 14 is decompressed by the low-stage fixed throttling portion 16 and reaches the refrigerant branch portion 17. Here, in the equipment cooling mode, similar to the heating mode, the second expansion valve 23 is in the throttling state and the first expansion valve 19 is in the fully closed state. Therefore, the refrigerant flowing out of the refrigerant branch portion 17 flows into the second parallel flow path 22 and is isenthalpically decompressed by the second expansion valve 23 until it becomes a low-pressure refrigerant.

[0160] The low-pressure refrigerant flowing out of the second expansion valve 23 flows into the second evaporator 24 and exchanges heat with the cooling water circulating in the heat medium circuit 40. That is, in the second evaporator 24, the low-pressure refrigerant absorbs the heat possessed by the cooling water in the heat medium circuit 40 and is heated, and the cooling water in the heat medium circuit 40 is cooled by exchanging heat with the low-pressure refrigerant.

[0161] The refrigerant flowing out of the second evaporator 24 flows into the liquid storage section 26 via the refrigerant confluence section 25 and is separated into gas and liquid. Then, the gaseous refrigerant separated by the liquid storage section 26 is sucked in from the suction port 11a of the compressor 11 and compressed again. On the other hand, the liquid refrigerant separated by the liquid storage section 26 is stored as the remaining refrigerant in the cycle inside the liquid storage section 26.

[0162] Here, the operation of the heating section 30 in the equipment cooling mode will be described. The control signal of the three-way valve 35 in the equipment cooling mode is determined such that all the cooling water flowing out of the refrigerant radiator 12 flows into the radiator 34.

[0163] As described above, the heat possessed by the high-pressure refrigerant is dissipated to the cooling water of the heating section 30 through the refrigerant radiator 12. Therefore, the cooling water flowing out of the refrigerant radiator 12 remains in a high-temperature state, passes through the three-way valve 35, and flows into the radiator 34. The cooling water flowing into the radiator 34 dissipates heat to the outside air of the electric vehicle through the radiator 34. That is, according to this refrigeration cycle device 10, the heat possessed by the high-pressure refrigerant is dissipated to the outside air via the cooling water of the heating section 30.

[0164] Next, the cooling water after being dissipated by the radiator 34 circulates with the operation of the pressure pump 32, is sucked into the pressure pump 32 again, and is pumped towards the refrigerant radiator 12.

[0165] Next, the operation of the heat medium circuit 40 in the equipment cooling mode will be described. The control signals of the on-off valve 45 and the on-off valve 46 in the equipment cooling mode are determined such that, for example, the on-off valve 45 is fully closed and the on-off valve 46 is fully open. In this case, since all the cooling water in the heat medium circuit 40 passes through the vehicle-mounted equipment 44, this cooling water absorbs heat from the vehicle-mounted equipment 44.

[0166] The cooling water after passing through the on-off valve 46 and the vehicle-mounted equipment 44 flows into the second evaporator 24 via the pressure pump 42. As described above, in the second evaporator 24, heat exchange occurs between the low-pressure refrigerant and the cooling water in the heat medium circuit 40. Therefore, the heat of the cooling water in the heat medium circuit 40 is absorbed by the low-pressure refrigerant.

[0167] That is, according to the refrigeration cycle device 10, the heat of the in-vehicle device 44 generated by the operation can be dissipated to the outside of the electric vehicle via the cooling water of the heat medium circuit 40, the refrigerant of the refrigeration cycle device 10, and the cooling water of the heating unit 30. That is, the refrigeration cycle device 10 can cool the in-vehicle device 44 that generates heat during operation and adjust it to an appropriate temperature range, thereby suppressing thermal runaway and failures of the in-vehicle device 44.

[0168] In addition, in the equipment cooling mode, since the high and low pressures on the Mollier diagram of the refrigerant radiator 12 and the like do not switch from the states of the refrigeration mode and the heating mode, the low-pressure refrigerant flowing out of the second evaporator 24 can also be sucked from the suction port 11a of the compressor 11, and the intermediate-pressure refrigerant in the gas phase state after passing through the high-stage expansion valve 13 and the gas-liquid separator 14 flows into the intermediate-pressure port 11b and merges with the refrigerant in the boosting process.

[0169] That is, not only in the refrigeration mode and the heating mode, but also in the equipment cooling mode, the refrigeration cycle device 10 can form a gas injection cycle (economizer refrigeration cycle).

[0170] Therefore, the compression efficiency of the high-stage compression mechanism can be improved by making the high-stage compression mechanism suck the lower-temperature mixed refrigerant, and the pressure difference between the suction refrigerant pressure and the discharge refrigerant pressure of both the low-stage compression mechanism and the high-stage compression mechanism can be reduced, thereby improving the compression efficiency of both compression mechanisms. As a result, the COP of the entire refrigeration cycle device 10 can be improved.

[0171] In addition, as the above operation modes, although the refrigeration mode, the heating mode, and the equipment cooling mode are listed, the refrigeration cycle device 10 can implement other operation modes. As a specific example, a dehumidifying heating mode can be listed.

[0172] In this case, the opening degrees of the high-stage expansion valve 13 and the first expansion valve 19 are set to the specified throttling opening degrees, and the second expansion valve 23 is fully closed, so as to absorb heat from the supply air in the first evaporator 20. At the same time, the three-way valve 35 of the heating unit 30 is controlled so that all the cooling water flowing out of the refrigerant radiator 12 flows to the heater core 33, and the bypass passage 55 is closed by the air mixing door 54.

[0173] Thereby, the supply air blown out from the blower 52 is dehumidified through heat exchange in the first evaporator 20, and then heated by the heater core 33 and supplied to the vehicle interior. That is, dehumidifying heating in the vehicle interior can be realized. And in this case, similarly to the above operation modes, a gas injection cycle can also be formed.

[0174] As described above, in the refrigeration cycle device 10 of the first embodiment, the first expansion valve 19 and the first evaporator 20 are connected to one side of the refrigerant branch portion 17, and the second expansion valve 23 and the second evaporator 24 are connected to the other side of the refrigerant branch portion 17.

[0175] Therefore, even in any of the refrigeration mode, the heating mode, and the equipment cooling mode, the heating unit 30 dissipates the heat possessed by the high-pressure refrigerant, and the first evaporator 20 and the second evaporator 24 absorb heat through the low-pressure refrigerant. That is, according to this refrigeration cycle device 10, the high and low pressures on the Mollier diagram related to the refrigerant radiator 12 of the heating unit 30, the first evaporator 20, and the second evaporator 24 do not change according to the operation mode, thereby simplifying the circuit structure.

[0176] Moreover, in this refrigeration cycle device 10, the gas-liquid separator 14 is disposed between the high-stage expansion valve 13 and the refrigerant branch portion 17, and guides the gas-phase refrigerant after gas-liquid separation to the intermediate-pressure port 11b of the compressor 11, constituting a gas injection cycle.

[0177] Since the high and low pressures on the Mollier diagram do not change according to the operation mode, this refrigeration cycle device 10 can form a gas injection cycle in any of the refrigeration mode, the heating mode, and the equipment cooling mode, and can improve the compression efficiency of the compressor 11, etc., thereby improving the performance of the refrigeration cycle device 10.

[0178] That is, this refrigeration cycle device 10 can simplify the circuit structure and achieve a gas injection cycle corresponding to each switchable operation mode, improving the cycle performance in each operation mode.

[0179] As Figure 1 shown, the second evaporator 24 is configured to utilize the heat medium circuit 40, so that external air can be used as an external heat source. That is, the refrigeration cycle device 10 can improve the cycle performance in the heating mode by using external air as an external heat source.

[0180] In addition, the second evaporator 24 is configured to utilize the heat medium circuit 40, so that in-vehicle equipment 44 can be used as an external heat source. That is, the refrigeration cycle device 10 can improve the cycle performance in the heating mode by using the in-vehicle equipment 44 as an external heat source.

[0181] Moreover, when the in-vehicle equipment 44 is used as an external heat source, since the heat possessed by the in-vehicle equipment 44 is absorbed, the refrigeration cycle device 10 can cool the in-vehicle equipment 44. That is, this refrigeration cycle device 10 can prevent malfunctions and defects of the in-vehicle equipment 44 by maintaining the in-vehicle equipment 44 in an appropriate temperature range.

[0182] As Figure 1As shown, the second evaporator 24 forms part of the heat medium circuit 40 and is configured to be able to perform heat exchange with cooling water as the heat medium and an external heat source (i.e., external air, in-vehicle device 44).

[0183] Moreover, in the heating mode and the device cooling mode, the cooling water in the heat medium circuit 40 absorbs the heat possessed by the external heat source. And the heat possessed by the cooling water in the heat medium circuit 40 is absorbed by the low-pressure refrigerant through the second evaporator 24. By adopting the above structure, the refrigeration cycle device 10 can further appropriately perform heat management on the low-temperature side.

[0184] Moreover, in the heating mode, the heating unit 30 dissipates the heat possessed by the high-pressure refrigerant discharged from the discharge port 11c, thereby supplying heat for heating the supply air as the fluid to be heat-exchanged. That is, the refrigeration cycle device 10 can achieve comfortable heating by dissipating the heat of the high-pressure refrigerant in the gas injection cycle.

[0185] In addition, at this time, as long as there is heat for finally heating the supply air as the fluid to be heat-exchanged, it can be configured as a structure of cooling water passing through the heating unit 30 (i.e., the structure of the heating unit 30 in the first embodiment, etc.), or it can be configured as a structure in which the high-pressure refrigerant directly performs heat exchange with the supply air (so-called in-room condenser).

[0186] Here, in the refrigeration cycle device 10, the heating unit 30 is configured to have a heat medium circulation path 31, a refrigerant radiator 12, and a heater core 33. In the case of the heating mode, the heat discharged from the high-pressure refrigerant to the cooling water through the refrigerant radiator 12 is dissipated to the supply air as the fluid to be heat-exchanged through the heater core 33.

[0187] In this way, the heating unit 30 is configured as a cooling water circuit in which cooling water as the heat medium circulates, so that the structure of a vehicle air conditioner device having a heater core for heat-exchanging with engine cooling water can be utilized. That is, the refrigeration cycle device 10 can achieve the sharing of structural devices in the refrigeration cycle device and can reduce the manufacturing cost.

[0188] Moreover, in the refrigeration cycle device 10, the heating unit 30 is configured to have a heat medium circulation path 31, a refrigerant radiator 12, and a radiator 34. In the case of the cooling mode, the heat discharged from the high-pressure refrigerant to the cooling water through the refrigerant radiator 12 is dissipated to the external air.

[0189] According to the refrigeration cycle device 10, the surplus heat in the refrigeration mode can be dissipated to the external air through the radiator 34, so that the vehicle interior can be reliably cooled.

[0190] In the heating mode, the control device 60 controls the refrigerant flow rate ratio in the heating mode to be smaller than that in the cooling mode by controlling the throttling opening degree of at least one of the high-pressure side expansion valve 13, the first expansion valve 19, and the second expansion valve 23.

[0191] Here, the refrigerant flow rate ratio represents the proportion of the suction refrigerant flow rate sucked in from the suction port 11a of the compressor 11 relative to the discharge refrigerant flow rate discharged from the discharge port 11c of the compressor 11.

[0192] In the heating mode, the density of the suction refrigerant sucked in from the suction port 11a is smaller than that in the cooling mode. Therefore, by making the refrigerant flow rate ratio in the heating mode smaller than that in the cooling mode, the heat exchange performance of the refrigerant radiator 12 can be improved, thereby improving the cycle performance.

[0193] (Second Embodiment)

[0194] Next, a second embodiment different from the above-described first embodiment will be described with reference to Figure 3 Similar to the first embodiment, the refrigeration cycle device 10 of the second embodiment and the indoor air-conditioning unit 50 together constitute the vehicle air-conditioning device 1 of the electric vehicle. In addition, in Figure 3 the illustration of the specific structure of the indoor air-conditioning unit 50 is omitted.

[0195] And, as Figure 3 shown, the refrigeration cycle device 10 of the second embodiment is configured to be able to switch between a plurality of operating modes, and the plurality of operating modes include a cooling mode for cooling the vehicle interior and a heating mode for heating the vehicle interior.

[0196] In addition, in Figure 3 the solid-line arrow represents the flow of the refrigerant in the heating mode, and the dashed-line arrow represents the flow of the refrigerant in the cooling mode. And the single-dot dash arrow represents the flow of the refrigerant in the equipment cooling mode.

[0197] The refrigeration cycle device 10 of the second embodiment has a gas injection cycle (economizer refrigeration cycle), a heating unit 30, an external air heat absorption circuit 40a, and an equipment heat absorption circuit 40b. In addition, the heating unit 30 of the second embodiment has the same structure as that of the above-described first embodiment. Therefore, the detailed description of the heating unit 30 is omitted.

[0198] As Figure 3As shown, the compressor 11, refrigerant radiator 12, high-pressure side expansion valve 13, gas-liquid separator 14, low-pressure side fixed throttle portion 16, first expansion valve 19, first evaporator 20, evaporation pressure regulating valve 21, second expansion valve 23, second evaporator 24, third expansion valve 23a, third evaporator 24a, and liquid storage portion 26 are connected to form the gas injection cycle of the refrigeration cycle device 10.

[0199] In the refrigeration cycle device 10 of the second embodiment, the structure from the discharge port 11c of the compressor 11 to the refrigerant branch portion 17, the structure from the refrigerant confluence portion 25 to the suction port 11a of the compressor 11, and the structure from the gas-liquid separator 14 to the intermediate pressure port 11b of the compressor 11 are the same as those of the first embodiment described above. Therefore, the repeated description of the above structures is omitted.

[0200] Moreover, in the refrigeration cycle device 10 of the second embodiment, the structure between the refrigerant branch portion 17 and the refrigerant confluence portion 25 is different from that of the first embodiment. Therefore, the differences are described with reference to the drawings.

[0201] The refrigerant branch portion 17 of the second embodiment is configured to have one refrigerant inlet and three refrigerant outlets, and branches the flow of the refrigerant flowing out of the low-pressure side fixed throttle portion 16 into three flows. One of the refrigerant outlets in the refrigerant branch portion 17 is connected to the first parallel flow path 18, and the other refrigerant outlets are connected to the second parallel flow path 22. Moreover, the refrigerant outlet different from the above in the refrigerant branch portion 17 is connected to the third parallel flow path 22a.

[0202] In the first parallel flow path 18 of the second embodiment, the first expansion valve 19, the first evaporator 20, and the evaporation pressure regulating valve 21 are arranged, and in the second parallel flow path 22, the first expansion valve 23 and the first evaporator 24 are arranged. Regarding the above points, since they are the same as those of the first embodiment, the detailed description is omitted.

[0203] As Figure 3 shown, the third expansion valve 23a and the third evaporator 24a are arranged in the third parallel flow path 22a. Similar to the first expansion valve 19 and the second expansion valve 23, the third expansion valve 23a is configured as an electric variable throttle mechanism having a valve element and an electric actuator, wherein the valve element is configured to be able to change the throttle opening degree, and the electric actuator changes the opening degree of the valve element.

[0204] Similar to the first expansion valve 19 and the second expansion valve 23, the third expansion valve 23 can perform a throttling function, a fully open function, and a fully closed function by appropriately adjusting the valve opening degree between the fully open state and the fully closed state. Thus, the third expansion valve 23a can reduce the pressure of the refrigerant flowing into the third parallel flow path 22a until it becomes a low-pressure refrigerant and then let it flow out.

[0205] Moreover, the first expansion valve 19, the second expansion valve 23, and the third expansion valve 23a cooperate with each other to regulate the flow rate of the refrigerant flowing through the first parallel flow path 18, the second parallel flow path 22, and the third parallel flow path 22a. Further, the first expansion valve 19, the second expansion valve 23, and the third expansion valve 23a function as a flow path switching means in combination with an expansion valve that functions as a fully closed valve.

[0206] Moreover, the refrigerant outlet of the third expansion valve 23a is connected to the refrigerant inlet side of the third evaporator 24a via the third parallel flow path 22a. As Figure 3 shown, the third evaporator 24a is a heat exchanger that forms part of the equipment heat absorption circuit 40b described later, and functions as a heat absorber by evaporating the low-pressure refrigerant flowing through it, thereby absorbing the heat of the heat medium (i.e., cooling water) circulating in the equipment heat absorption circuit 40b.

[0207] The refrigerant merging portion 25 of the third embodiment is configured to have a plurality of refrigerant inlets and one refrigerant outlet, and merges the refrigerant flows after passing through the first parallel flow path 18, the second parallel flow path 22, and the third parallel flow path 22a into one. Further, similar to the first embodiment, a liquid storage portion 26 is disposed at the refrigerant outlet of the refrigerant merging portion 25 of the second embodiment.

[0208] Next, the structure of the outside air heat absorption circuit 40a of the second embodiment will be described with reference to Figure 3 The outside air heat absorption circuit 40a is one of the low-temperature side heat medium circuits configured to include the following components: a second evaporator 24 forming part of the gas injection cycle, a heat medium circulation path 41a as a heat medium flow path, a feed pump 42a, and a radiator 43.

[0209] As Figure 3 shown, the outside air heat absorption circuit 40a is formed by connecting the second evaporator 24 and the radiator 43 with the heat medium circulation path 41a, and the cooling water as the heat medium is circulated by being pumped by the feed pump 42a.

[0210] The cooling water in the outside air heat absorption circuit 40a is a low-temperature heat medium, and for example, a liquid or an antifreeze containing at least ethylene glycol, dimethylpolysiloxane, or nanofluid is used.

[0211] Similar to the feed pump 42 of the first embodiment, the feed pump 42a is a heat medium pump that sucks and discharges the cooling water as the heat medium, and is constituted by an electric pump.

[0212] The second evaporator 24 is connected to the discharge port side of the pressure-feed pump 42a. Therefore, the second evaporator 24 can cause the low-pressure refrigerant passing through its interior to exchange heat with the cooling water circulating in the heat medium circulation passage 41a, so that the low-pressure refrigerant absorbs the heat possessed by the cooling water.

[0213] Moreover, a radiator 43 is connected to the cooling water outlet side of the second evaporator 24. Similar to the first embodiment, the radiator 43 is a heat exchanger that causes the cooling water circulating in the heat medium circulation passage 41a of the external air heat absorption circuit 40a to exchange heat with the external air, so that the cooling water absorbs the heat possessed by the external air. That is, the external air heat absorption circuit 40a is configured to circulate the cooling water through the radiator 43, so that the external air of the electric vehicle can be used as an external heat source.

[0214] Next, refer to Figure 3 The structure of the equipment heat absorption circuit 40b of the second embodiment will be described. The equipment heat absorption circuit 40b is one of the low-temperature side heat medium circuits configured to include the following components: a third evaporator 24a that forms part of the gas injection cycle, a heat medium circulation passage 41b as a heat medium flow path, a pressure-feed pump 42b, and in-vehicle equipment 44.

[0215] As Figure 3 shown, the equipment heat absorption circuit 40b is formed by connecting the third evaporator 24a and the in-vehicle equipment 44 with the heat medium circulation passage 41b, and the pressure-feed pump 42b is used to pressure-feed the cooling water as a heat medium to circulate it.

[0216] The cooling water in the equipment heat absorption circuit 40b is a low-temperature heat medium, and for example, a liquid or antifreeze containing at least ethylene glycol, dimethylpolysiloxane, or nanofluid is used.

[0217] Similar to the pressure-feed pump 42 of the first embodiment, the pressure-feed pump 42b is a heat medium pump that sucks and discharges the cooling water as a heat medium, and is composed of an electric pump.

[0218] The third evaporator 24a is connected to the discharge port side of the pressure-feed pump 42b. Therefore, the third evaporator 24a can cause the low-pressure refrigerant passing through its interior to exchange heat with the cooling water circulating in the heat medium circulation passage 41b, so that the low-pressure refrigerant absorbs the heat possessed by the cooling water.

[0219] Also, a vehicle-mounted device 44 is connected to the cooling water outlet side of the third evaporator 24a. Similar to the first embodiment, the vehicle-mounted device 44 is mounted on an electric vehicle and is composed of devices that generate heat during operation. The heat medium circulation path 41b in the device heat absorption circuit 40b is arranged to contact the outer surface of the above-mentioned vehicle-mounted device 44, so that the heat possessed by the vehicle-mounted device 44 can exchange heat with the cooling water flowing in the heat medium path.

[0220] Therefore, the device heat absorption circuit 40a is configured to circulate the cooling water through the vehicle-mounted device 44, so that the vehicle-mounted device 44 of the electric vehicle can be used as an external heat source. At this time, since the cooling water can absorb the heat possessed by the vehicle-mounted device 44 in the device heat absorption circuit 40b, the vehicle-mounted device 44 can also be cooled.

[0221] Similar to the first embodiment, the refrigeration cycle device 10 of the second embodiment configured as above can operate in the refrigeration mode, heating mode, and device cooling mode using the gas injection cycle. In addition, since the control method of the heating mode of the second embodiment is the same as that of the first embodiment, its description is omitted.

[0222] In the heating mode of the second embodiment, the control device 60 sets the high-side expansion valve 13 to the throttling state and the first expansion valve 19 to the fully closed state. And at least one of the second expansion valve 23 and the third expansion valve 23a is set to the throttling state. It is also possible to set both the second expansion valve 23 and the third expansion valve 23a to the throttling state.

[0223] At this time, for the heat medium circuit corresponding to the expansion valve in the throttling state among the second expansion valve 23 and the third expansion valve 23a (that is, the external air heat absorption circuit 40a and the device heat absorption circuit 40b), heat absorption from the external heat source to the cooling water is performed.

[0224] In the heating unit 30 in the above case, the three-way valve 35 is controlled so that the cooling water flowing out of the refrigerant radiator 12 flows into the heater core 33. The air mixing door 54 of the indoor air conditioning unit 50 is controlled to close the bypass passage 55.

[0225] By performing the above control, the refrigeration cycle device 10 of the second embodiment can achieve the same method as the heating mode of the first embodiment, and can use the external air and the vehicle-mounted device 44 as external heat sources to achieve heating in the vehicle interior.

[0226] Next, the case of the device cooling mode of the second embodiment will be described. In this case, the control device 60 sets the high-side expansion valve 13 and the third expansion valve 23a to the throttling state, and sets the first expansion valve 19 and the second expansion valve 23 to the fully closed state.

[0227] At this time, for the equipment heat absorption circuit 40b corresponding to the third expansion valve 23a in the throttling state, the pressure pump 42b is operated to absorb heat from the in-vehicle equipment 44 to the cooling water. Thereby, the in-vehicle equipment 44 is cooled by the heat exchange between the in-vehicle equipment 44 and the cooling water. And in the heating unit 30, the three-way valve 35 is controlled to make the cooling water flowing out from the refrigerant radiator 12 flow into the radiator 34.

[0228] By performing the control as described above, the refrigeration cycle device 10 of the second embodiment can achieve the same manner as the equipment cooling mode of the first embodiment, and can cool the in-vehicle equipment 44 to utilize the in-vehicle equipment 44 in an appropriate temperature range.

[0229] As described above, in the refrigeration cycle device 10 of the second embodiment, the first expansion valve 19 and the first evaporator 20, the second expansion valve 23 and the second evaporator 24, and the third expansion valve 23a and the third evaporator 24a are respectively connected to the three refrigerant outlets of the refrigerant branch portion 17, and the above components are arranged in parallel with each other.

[0230] Therefore, even in any one of the refrigeration mode, the heating mode, and the equipment cooling mode, the heating unit 30 dissipates the heat of the high-pressure refrigerant, and the first evaporator 20, the second evaporator 24, and the third evaporator 24a absorb heat through the low-pressure refrigerant.

[0231] That is, according to this refrigeration cycle device 10, the high and low pressures on the Mollier diagram related to the refrigerant radiator 12, the first evaporator 20, the second evaporator 24, and the third evaporator 24a of the heating unit 30 do not switch according to the operation mode, so that the circuit structure can be simplified.

[0232] And in this refrigeration cycle device 10, the gas-liquid separator 14 is arranged between the high-stage expansion valve 13 and the refrigerant branch portion 17, and guides the gas-phase refrigerant after gas-phase separation to the intermediate pressure port 11b of the compressor 11, constituting a gas injection cycle.

[0233] Since the high and low pressures on the Mollier diagram do not switch according to the operation mode, this refrigeration cycle device 10 can constitute a gas injection cycle in any one of the refrigeration mode, the heating mode, and the equipment cooling mode, and can improve the compression efficiency of the compressor 11, etc., thereby improving the performance of the refrigeration cycle device 10.

[0234] That is, this refrigeration cycle device 10 can achieve the simplification of the circuit structure and the gas injection cycle corresponding to the refrigeration mode, the heating mode, and the equipment cooling mode respectively, and improve the cycle performance in each operation mode.

[0235] (Third Embodiment)

[0236] Next, refer toFigure 4 A third embodiment different from the above-described embodiments will be described. Similar to the first embodiment, the refrigeration cycle device 10 of the third embodiment and the indoor air-conditioning unit 50 together constitute the vehicle air-conditioning device 1 of the electric vehicle.

[0237] The refrigeration cycle device 10 of the third embodiment is configured to be able to switch between a plurality of operating modes, and the plurality of operating modes include a refrigeration mode, a heating mode, and an equipment cooling mode. And, as Figure 4 shown, the refrigeration cycle device 10 of the third embodiment is provided with an integrated evaporator 70 instead of the second evaporator 24 of the first embodiment, and is otherwise configured in the same manner as the first embodiment.

[0238] Therefore, in the following description, the differences, that is, the structure of the integrated evaporator 70 will be described, and the description of other structures of the refrigeration cycle device 10 of the third embodiment will be omitted.

[0239] As Figure 4 shown, the integrated evaporator 70 of the third embodiment is disposed in the second parallel flow path 22 branched from the refrigerant branch portion 17 of the refrigeration cycle device 10, and the refrigerant inlet side of the integrated evaporator 70 is connected to the refrigerant outlet of the second expansion valve 23. The integrated evaporator 70 is an evaporator formed by integrating an external air side heat exchanger 71 and an equipment side heat exchanger 72.

[0240] The external air side heat exchanger 71 is a heat exchange portion for absorbing heat from the external air as an external heat source, and functions the same as the second evaporator 24 of the second embodiment. The equipment side heat exchanger 72 is a heat exchange portion for absorbing heat from the in-vehicle equipment 44 as an external heat source, and functions the same as the third evaporator 24a of the second embodiment.

[0241] In addition, the integrated evaporator 70 may also be a structure in which a plurality of evaporators corresponding to the external air side heat exchanger 71 and the equipment side heat exchanger 72 are assembled and integrated, or the flow path structure of the heat exchange portion in one evaporator may be changed, and functionally divided into the external air side heat exchanger 71 and the equipment side heat exchanger 72.

[0242] Therefore, according to the refrigeration cycle device 10 of the third embodiment, since the integrated evaporator 70 having the external air side heat exchanger 71 and the equipment side heat exchanger 72 is connected to the refrigerant outlet side of the second expansion valve 23, the integrated evaporator 70 can be used for heat absorption from the external air, heat absorption from the in-vehicle equipment 44, and cooling.

[0243] Moreover, since the integrated evaporator 70 is configured to integrate the external air side heat exchanger 71 and the equipment side heat exchanger 72, compared with the case where the evaporator for external air heat absorption and the evaporator for equipment heat absorption are assembled independently, the assembly process of the integrated evaporator 70 can be reduced, etc., and the manufacturing cost of the vehicle air conditioner 1 and the refrigeration cycle device 10 can be lowered.

[0244] Moreover, when using this integrated evaporator 70, since a part of the structural components of the evaporator for external air heat absorption and the evaporator for equipment heat absorption can be shared, compared with the case where the evaporator for external air heat absorption and the evaporator for equipment heat absorption are assembled independently, reduction of structural components can be achieved, thereby reducing the weight of the refrigeration cycle device 10, etc.

[0245] (Fourth Embodiment)

[0246] Next, with reference to Figure 5 a fourth embodiment different from the above embodiments will be described. Similar to the first embodiment, the refrigeration cycle device 10 of the fourth embodiment and the indoor air conditioning unit 50 together constitute the vehicle air conditioner 1 of the electric vehicle.

[0247] The refrigeration cycle device 10 of the fourth embodiment is configured to be able to switch between a plurality of operating modes, and the plurality of operating modes include a refrigeration mode, a heating mode, and an equipment cooling mode. Moreover, in the refrigeration cycle device 10 of the fourth embodiment, except for the structure of the heating part 30 as the high-temperature side heat medium circuit and the heat medium circuit 40 as the low-temperature side heat medium circuit in the first embodiment, it is configured in the same way as the first embodiment.

[0248] Therefore, in the following description, the differences between the heating part 30 and the heat medium circuit 40 will be described, and the description of other structures of the refrigeration cycle device 10 of the fourth embodiment will be omitted.

[0249] In the fourth embodiment, the heating part 30 is configured to include the following components: a refrigerant radiator 12 that forms part of the gas injection cycle, a heat medium circulation path 31, a pressure pump 32, a heater core 33, a radiator 34, and a three-way valve 35. Each structural device of the heating part 30 of the fourth embodiment is configured in the same way as the first embodiment except for the radiator 34.

[0250] On the other hand, the heat medium circuit 40 of the fourth embodiment is configured to include the following components: a second evaporator 24 that forms part of the gas injection cycle, a heat medium circulation path 41, a pressure pump 42, a radiator 43, in-vehicle equipment 44, an on-off valve 45, and an on-off valve 46. Each structural device of the heat medium circuit 40 of the fourth embodiment is configured in the same way as the first embodiment except for the radiator 43.

[0251] In the fourth embodiment, with respect to the flow of outside air generated by a blower fan (not shown), the radiator 34 of the heating unit 30 is disposed upstream or downstream of the radiator 43 of the heat medium circuit 40. Further, the radiator 34 is joined to the radiator 43 via fins, and is configured to effect heat transfer between the cooling water flowing through the radiator 34 and the cooling water flowing through the radiator 43.

[0252] Therefore, in the refrigeration cycle device 10 according to the fourth embodiment, since the radiator 34 of the heating unit 30 and the radiator 43 of the heat medium circuit are joined via fins, heat transfer can be achieved between the cooling water flowing through the high-temperature heat medium circuit, i.e., the heating unit 30, and the cooling water flowing through the low-temperature heat medium circuit, i.e., the heat medium circuit 40. Thereby, the refrigeration cycle device 10 can effectively utilize the heat generated in the heating unit 30 and the heat medium circuit 40 of the refrigeration cycle device 10.

[0253] In addition, in the fourth embodiment, although the radiator 34 and the radiator 43 are joined using fins, it may be configured such that the functions of the radiator 34 and the radiator 43 are achieved using a single radiator. In this case, it is only necessary to connect the heat medium circulation passage 31 and the heat medium circulation passage 41 so that the heat medium can flow in and out, and to provide an on-off valve for controlling the inflow and outflow of the heat medium.

[0254] As described above, the present invention has been described based on the embodiments, but the present invention is not limited to the above embodiments. That is, various improvements and modifications can be made without departing from the gist of the present invention. For example, the above-described embodiments can be appropriately combined, or various modifications can be made to the above-described embodiments.

[0255] In the above embodiments, outside air and in-vehicle equipment 44 are cited as external heat sources that absorb heat using the second evaporator 24 and the third evaporator 24a, but the present invention is not limited to the above. For example, with respect to the in-vehicle equipment 44, the present invention is not limited to the above equipment, and various heat sources such as a battery for vehicle travel and a vehicle engine can be used.

[0256] Further, in the above embodiments, the heating unit 30 is configured as a high-temperature side heat medium circuit, and the heat of the high-pressure refrigerant is dissipated to the outside air and the blown air as a heat exchange target fluid via cooling water as the heat medium, but the present invention is not limited thereto. For example, an indoor condenser may be used instead of the refrigerant radiator 12 in the above-described embodiment, and this indoor condenser may be used as the heating unit of the present invention.

[0257] Also, in the above-described embodiment, a liquid reservoir 26 is disposed between the refrigerant confluence section 25 and the intake port 11a of the compressor 11. However, it is not limited to the above manner. For example, the liquid reservoir 26 may also be disposed downstream of the gas-liquid separator 14 and the low-stage fixed throttle section 16 and upstream of the refrigerant branch section 17.

[0258] Also, in the above-described embodiment, in the first parallel flow path 18, an evaporation pressure regulating valve 21 is disposed on the downstream side of the refrigerant flow of the first evaporator 20. However, it is not limited to the above manner. The refrigeration cycle device 10 may also be configured without disposing the evaporation pressure regulating valve 21 by combining the adopted operating modes.

[0259] Also, in the above-described embodiment, the low-stage fixed throttle section 16 is disposed at the liquid-phase refrigerant outlet of the gas-liquid separator 14. However, it is not limited to the above manner. As long as it can be controlled by controlling the opening degrees of the first expansion valve 19 and the second expansion valve 23 so as to decompress to a desired low-pressure refrigerant, the refrigeration cycle device 10 may be configured without disposing the low-stage fixed throttle section 16.

[0260] Although the present invention has been described according to the embodiments, it is understood that the present invention is not limited to the embodiments and structures. The present invention also includes various modifications and modifications within the equivalent scope. In addition, although the present invention shows various combinations and manners, other combinations and manners including only one element or more or less than one element also fall within the scope and spirit of the present invention.

Claims

1. A refrigeration cycle device, characterized in that, comprising: a compressor that compresses low-pressure refrigerant sucked in from a suction port until it becomes high-pressure refrigerant, discharges the refrigerant from a discharge port, and has an intermediate-pressure port through which intermediate-pressure refrigerant in the cycle flows in and merges with the refrigerant in the compression process; a heating unit that uses the high-pressure refrigerant discharged from the discharge port of the compressor as a heat source to heat a heat exchange target fluid; a high-side decompression unit that decompresses the high-pressure refrigerant flowing out from the heating unit until it becomes intermediate-pressure refrigerant; a gas-liquid separation unit that performs gas-liquid separation on the intermediate-pressure refrigerant decompressed by the high-side decompression unit and guides the separated gaseous refrigerant to the intermediate-pressure port; a refrigerant branch that branches the flow of the liquid-phase refrigerant separated by the gas-liquid separation unit; a first decompression unit that decompresses one of the liquid-phase refrigerants branched by the refrigerant branch until it becomes the low-pressure refrigerant; a first evaporator that allows the low-pressure refrigerant decompressed by the first decompression unit to evaporate by absorbing the heat of the heat exchange target fluid and flow out to the suction port; a second decompression unit that decompresses the other liquid-phase refrigerant branched by the refrigerant branch until it becomes the low-pressure refrigerant; a second evaporator that allows the low-pressure refrigerant decompressed by the second decompression unit to evaporate by absorbing the heat of external air or a heat-generating device that generates heat during operation and flow out to the suction port; and a heat medium circuit that circulates a heat medium and has a heat exchanger that performs heat exchange between the heat medium and the external air or the heat-generating device, in a cooling mode for cooling the heat exchange target fluid, it switches to a refrigerant circuit that allows low-pressure refrigerant to flow from the refrigerant branch to the first evaporator. In the cooling mode, the high-pressure refrigerant flowing out from the heating unit is decompressed by the high-side decompression unit until it becomes intermediate-pressure refrigerant, and the gaseous intermediate-pressure refrigerant is guided to the intermediate-pressure port through the gas-liquid separation unit, thereby forming a gas injection cycle, in a heating mode for heating the heat exchange target fluid, it switches to a refrigerant circuit that allows low-pressure refrigerant to flow from the refrigerant branch to the second evaporator, in a device cooling mode for cooling the heat-generating device, it switches to a refrigerant circuit that allows low-pressure refrigerant to flow from the refrigerant branch to the second evaporator.

2. The refrigeration cycle device according to claim 1, wherein in the cooling mode and the device cooling mode, the heating unit dissipates the heat of the high-pressure refrigerant.

3. The refrigeration cycle device according to claim 1, wherein In the cooling mode of the device, the high-pressure refrigerant flowing out of the heating unit is decompressed by the high-pressure side decompression unit until it becomes an intermediate-pressure refrigerant, and the intermediate-pressure refrigerant in the gas phase state is guided to the intermediate-pressure port through the gas-liquid separation unit, thereby constituting a gas injection cycle.

4. The refrigeration cycle device according to claim 1, characterized in that it has a third evaporator, which is connected in parallel with the second evaporator with respect to the refrigerant branch portion, and by causing the other liquid-phase refrigerant branched out from the refrigerant branch portion to absorb the heat of the heat-generating device that generates heat during operation, the other liquid-phase refrigerant is evaporated and flows out to the suction port. In the heating mode, the refrigerant circuit is switched to allow the low-pressure refrigerant to flow into at least one of the second evaporator and the third evaporator from the refrigerant branch portion.

5. The refrigeration cycle device according to any one of claims 1 to 3, characterized in that the second evaporator constitutes a part of the heat medium circuit. In the heating mode, the heat exchanger causes the heat medium to absorb the heat of the external heat source. The second evaporator causes the refrigerant flowing through the second evaporator to absorb the heat of the heat medium.

6. The refrigeration cycle device according to any one of claims 1 to 3, characterized in that In the heating mode, the heating unit dissipates the heat of the high-pressure refrigerant discharged from the discharge port and supplies the heat for heating the heat exchange target fluid.

7. The refrigeration cycle device according to claim 6, characterized in that the heating unit has: a heat medium flow path for circulating the heat medium; a medium-refrigerant heat exchanger that exchanges heat between the high-pressure refrigerant discharged from the discharge port and the heat medium passing through the heat medium flow path; and a heater core that exchanges heat between the heat medium and the heat exchange target fluid in the heating mode.

8. The refrigeration cycle device according to claim 6, characterized in that the heating unit has: a heat medium flow path for circulating the heat medium; a medium-refrigerant heat exchanger that exchanges heat between the high-pressure refrigerant discharged from the discharge port and the heat medium passing through the heat medium flow path; and a radiator that dissipates the remaining heat of the heat medium to the external air in the cooling mode.

9. The refrigeration cycle device according to claims 1 to 3, characterized in that it has a flow rate ratio control unit. When the ratio of the suction refrigerant flow rate sucked into the suction port of the compressor to the discharge refrigerant flow rate discharged from the discharge port of the compressor is defined as the refrigerant flow rate ratio, the flow rate ratio control unit controls the refrigerant flow rate so that the refrigerant flow rate ratio in the heating mode is less than the refrigerant flow rate ratio in the cooling mode.

Images