Heat pump cycle equipment

Abstract

A heat pump cycle device according to the present invention includes a compressor (11), a branch portion (12a), a heating unit (13, 30), a heating-unit-side depressurizing unit (14c, 14e), a bypass channel (21a), a bypass-side flow rate adjusting unit (14d), a mixing unit (12f), a target temperature deciding unit (S3) that decides a target temperature (TAO) that is a target value for an object temperature (TAV) of an object to be heated, and a target low pressure deciding unit (S11) that decides a target low pressure (PSO) that is a target value of an intake refrigerant pressure (Ps) of a refrigerant. When the object temperature (TAV) is lower than the target temperature (TAO) while executing a hot gas mode in which the object to be heated is being heated, high-pressure boosting control, in which discharge refrigerant pressure (Pd) of the refrigerant flowing into the heating unit (13, 30) is boosted, is executed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2021-173703 filed on October 25, 2021, the contents of which are incorporated herein by reference. [Technical field]

[0002] The present disclosure relates to a heat pump cycle device that heats an object to be heated by using heat generated by work of a compressor. [Background technology]

[0003] 2. Description of the Related Art Patent Document 1 discloses a heat pump cycle device that is applied to a vehicle air conditioner.

[0004] In the heat pump cycle device of Patent Document 1, when frost forms on the outdoor heat exchanger, the device operates in a non-frost mode. In the non-frost mode of Patent Document 1, the refrigerant discharged from the compressor is switched to a refrigerant circuit that circulates the refrigerant through the high-pressure refrigerant passage of the internal heat exchanger on the discharge side, the radiator, the expansion valve, the low-pressure refrigerant passage of the internal heat exchanger on the discharge side, the accumulator, and the suction port of the compressor, in that order.

[0005] As a result, in the non-frost mode of the heat pump cycle device of Patent Document 1, when frost forms on the outdoor heat exchanger, the low-pressure refrigerant is prevented from evaporating in the indoor heat exchanger, thereby suppressing the progression of frost on the outdoor heat exchanger. Furthermore, the radiator exchanges heat between the refrigerant flowing out from the high-pressure refrigerant passage of the discharge-side internal heat exchanger and the blown air blown into the vehicle cabin, thereby continuing to heat the vehicle cabin.

[0006] That is, in the non-frost mode of the heat pump cycle device of Patent Document 1, the heat generated by the work of the compressor is used to heat the blown air, which is the object to be heated, without using heat absorbed from the outside air or the like.

[0007] However, in the non-frost mode of the heat pump cycle device of Patent Document 1, the discharge refrigerant discharged from the compressor is heat-exchanged with the suction refrigerant drawn into the compressor in the internal heat exchanger on the discharge side, which reduces the enthalpy of the refrigerant flowing into the radiator, and the heat generated by the work of the compressor cannot be effectively used to heat the blown air.

[0008] In contrast, Patent Document 2 discloses a heat pump cycle device that can heat an object to be heated by using heat generated by the work of a compressor, without using heat absorbed from the outside air, etc., and that can effectively utilize the heat generated by the work of the compressor to heat the object to be heated.

[0009] In the heat pump cycle device of Patent Document 2, the flow of refrigerant discharged from the compressor is branched, and one of the branched refrigerant flows into the heating section. In the heating section, the refrigerant exchanges heat with an object to be heated, thereby heating the object to be heated. Furthermore, the refrigerant flowing out of the heating section is depressurized in a heating section side depressurization section. In addition, the other branched refrigerant is depressurized by a bypass side flow rate adjustment valve disposed in a bypass passage. Then, the refrigerant depressurized in the heating section side depressurization section and the refrigerant depressurized in the bypass side flow rate adjustment valve are mixed and sucked into the compressor.

[0010] In the heat pump cycle device of Patent Document 2, the refrigerant with high enthalpy discharged from the compressor can be made to flow into the heating section, so that the heat generated by the work of the compressor can be effectively utilized to heat the object to be heated. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] JP 2014-226979 A [Patent Document 2] Patent Publication No. 2021-156567 Summary of the Invention

[0012] However, in the heat pump cycle device of Patent Document 2, in order to stabilize the operation of the cycle, both the discharge refrigerant pressure and the suction refrigerant pressure must be adjusted so that the amount of work done by the compressor is an appropriate amount of heat for heating the object to be heated. Therefore, in the heat pump cycle device of Patent Document 2, if the discharge refrigerant pressure cannot be increased sufficiently, the temperature of the object to be heated cannot be increased to a desired temperature, and the temperature adjustment range of the object to be heated may become narrow.

[0013] In view of the above, an object of the present disclosure is to provide a heat pump cycle device capable of expanding the temperature adjustment range of an object to be heated.

[0014] First Aspect of the Disclosure , and the second aspect The heat pump cycle device includes a compressor, a branching section, a heating section, a heating section-side pressure reducing section, a bypass passage, a bypass-side flow rate adjusting section, a mixing section, a target temperature determining section, and a target low pressure determining section.

[0015] The compressor compresses and discharges the refrigerant. The branching section branches the flow of the refrigerant discharged from the compressor. The heating section heats an object to be heated using one of the refrigerants branched at the branching section as a heat source. The heating section side decompression section decompresses the refrigerant flowing out from the heating section. The bypass passage leads the other refrigerant branched at the branching section to the suction port side of the compressor. The bypass side flow rate adjustment section adjusts the flow rate of the refrigerant flowing through the bypass passage. The mixing section mixes the refrigerant flowing out from the bypass side flow rate adjustment section and the refrigerant flowing out from the heating section side decompression section, and causes the mixture to flow out to the suction port side of the compressor. The target temperature determination section determines a target temperature that is a target value of the object temperature of the object to be heated heated by the heating section. The target low pressure determination section determines a target low pressure that is a target value of the suction refrigerant pressure of the refrigerant to be sucked into the compressor.

[0016] The hot gas mode is an operation mode for heating an object to be heated, and the operation of at least one of the compressor, the heating unit side pressure reducing unit, and the bypass side flow rate adjusting unit is controlled so that the object temperature approaches a target temperature and the suction refrigerant pressure approaches a target low pressure.

[0017] Furthermore, when the hot gas mode is being executed and the object temperature is lower than the target temperature, high pressure increase control is executed to increase the discharge refrigerant pressure of the refrigerant flowing into the heating section.

[0018] According to this, when the object temperature is equal to or lower than the target temperature during execution of the hot gas mode, the high pressure increase control is performed, so that the discharge refrigerant pressure can be increased. Therefore, the discharge refrigerant temperature of the refrigerant that serves as the heat source for heating the object to be heated in the heating unit can be increased. As a result, the first aspect of the present disclosure , and the second aspect According to the heat pump cycle device, the temperature adjustment range of the object to be heated can be expanded. In addition, the first aspect of the present disclosure The heat pump cycle device of the present invention of In the hot gas mode, the operation of at least the compressor is controlled so that the object temperature approaches the target temperature and the suction refrigerant pressure approaches the target low pressure. Furthermore, when the hot gas mode is being executed, the object temperature is lower than the target temperature, and the refrigerant discharge capacity of the compressor is equal to or higher than a predetermined reference capacity, high pressure increase control is executed to increase the discharge refrigerant pressure of the refrigerant flowing into the heating unit. 。 Also, The present disclosure 2 The heat pump cycle device of the present invention of In the hot gas mode, the operation of at least the bypass side flow rate regulator is controlled so that the object temperature approaches the target temperature and the suction refrigerant pressure approaches the target low pressure. Furthermore, when the hot gas mode is being executed, the object temperature is lower than the target temperature, and the throttle opening of the bypass side flow rate adjustment unit is equal to or smaller than a predetermined reference opening, high pressure increase control is executed to increase the discharge refrigerant pressure of the refrigerant flowing into the heating unit. 。 [Brief description of the drawings]

[0019] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. [Figure 1] 1 is a schematic overall configuration diagram of a vehicle air conditioner according to a first embodiment. [Diagram 2] 2 is a block diagram showing an electric control unit of the vehicle air conditioner of the first embodiment. FIG. [Diagram 3] 4 is a flowchart of a main routine of a control program according to the first embodiment. [Figure 4] 5 is a flowchart of a subroutine of a control program according to the first embodiment. [Diagram 5] FIG. 2 is a schematic overall configuration diagram showing a flow of a refrigerant in a hot gas heating mode of the heat pump cycle of the first embodiment. [Figure 6] FIG. 4 is a Mollier diagram showing changes in the state of a refrigerant in a hot gas heating mode of the heat pump cycle of the first embodiment. [Figure 7] FIG. 2 is a schematic overall configuration diagram showing a flow of a refrigerant in a hot gas dehumidification heating mode of the heat pump cycle of the first embodiment. [Figure 8] FIG. 4 is a Mollier diagram showing a change in state of a refrigerant in a hot gas dehumidification heating mode of the heat pump cycle of the first embodiment. [Figure 9] FIG. 11 is a Mollier diagram showing changes in the state of a refrigerant in a hot gas heating mode of a heat pump cycle of a second embodiment. [Figure 10] FIG. 11 is a schematic overall configuration diagram of a vehicle air conditioner according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, a number of embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, other embodiments described previously may be applied to other parts of the configuration. In addition to combinations of parts that are specifically indicated as being possible in each embodiment, it is also possible to partially combine embodiments even if not specified, as long as there is no particular problem with the combination.

[0021] (First embodiment) A first embodiment of a heat pump cycle device according to the present disclosure will be described with reference to Figs. 1 to 8. In this embodiment, the heat pump cycle device according to the present disclosure is applied to a vehicle air conditioner 1 mounted on an electric vehicle. An electric vehicle is a vehicle that obtains driving force for traveling from an electric motor. The vehicle air conditioner 1 performs air conditioning of the vehicle cabin, which is the space to be air-conditioned, and also adjusts the temperature of on-board equipment. Therefore, the vehicle air conditioner 1 can be called an air conditioner with an on-board equipment temperature adjustment function, or an on-board equipment temperature adjustment device with an air conditioning function.

[0022] Specifically, the vehicle air conditioner 1 adjusts the temperature of a battery 70 as an in-vehicle device. The battery 70 is a secondary battery that stores power to be supplied to a plurality of in-vehicle devices that operate electrically. The battery 70 is an assembled battery formed by electrically connecting a plurality of stacked battery cells in series or parallel. The battery cells in this embodiment are lithium ion batteries.

[0023] The battery 70 generates heat during operation (i.e., during charging and discharging). The output of the battery 70 is likely to decrease at low temperatures, and deterioration is likely to progress at high temperatures. For this reason, the temperature of the battery 70 needs to be maintained within an appropriate temperature range (in this embodiment, 15° C. or higher and 55° C. or lower). Therefore, in the electric vehicle of this embodiment, the temperature of the battery 70 is adjusted using the vehicle air conditioner 1. Of course, the on-board equipment that is the subject of temperature adjustment by the vehicle air conditioner 1 is not limited to the battery 70.

[0024] The vehicle air conditioner 1 includes a heat pump cycle 10, a high-temperature side heat medium circuit 30, a low-temperature side heat medium circuit 40, an interior air conditioning unit 50, a control device 60, and the like.

[0025] First, the heat pump cycle 10 will be described. The heat pump cycle 10 is a vapor compression refrigeration cycle that adjusts the temperatures of the blown air blown into the vehicle cabin, the high-temperature side heat medium circulating in the high-temperature side heat medium circuit 30, and the low-temperature side heat medium circulating in the low-temperature side heat medium circuit 40. The heat pump cycle 10 is configured to be able to switch the refrigerant circuit according to various operation modes described later for air conditioning in the vehicle cabin and cooling of on-board devices.

[0026] The heat pump cycle 10 employs an HFO refrigerant (specifically, R1234yf) as a refrigerant. The heat pump cycle 10 constitutes a subcritical refrigeration cycle in which the pressure of the high-pressure side refrigerant does not exceed the critical pressure of the refrigerant. The refrigerant is mixed with refrigerant oil for lubricating the compressor 11. The refrigerant oil is PAG oil (i.e., polyalkylene glycol oil) that is compatible with liquid-phase refrigerant. A portion of the refrigerant oil circulates through the heat pump cycle 10 together with the refrigerant.

[0027] The compressor 11 draws in, compresses, and discharges the refrigerant in the heat pump cycle 10. The compressor 11 is an electric compressor that uses an electric motor to rotate a fixed-capacity compression mechanism having a fixed discharge capacity. The rotation speed (i.e., refrigerant discharge capacity) of the compressor 11 is controlled by a control signal output from a control device 60, which will be described later.

[0028] The compressor 11 is disposed in a drive unit room formed in the front side of the vehicle interior. The drive unit room forms a space in which at least some of the devices used for generating and adjusting the driving force for running the vehicle (for example, an electric motor for running) are disposed.

[0029] The inlet side of a first three-way joint 12a is connected to the discharge port of the compressor 11. The first three-way joint 12a has three inlets and outlets that communicate with each other. As the first three-way joint 12a, a joint part formed by joining multiple pipes or a joint part formed by providing multiple refrigerant passages in a metal block or a resin block can be used.

[0030] Furthermore, the heat pump cycle 10 includes a second three-way joint 12b to a sixth three-way joint 12f, as described below. The second three-way joint 12b to the sixth three-way joint 12f have the same basic configuration as the first three-way joint 12a. Furthermore, the basic configuration of each three-way joint described in the embodiment described below is also the same as the first three-way joint 12a.

[0031] These three-way joints branch the flow of the refrigerant when one of the three inlet / outlets is used as an inlet and the remaining two are used as outlets. When two of the three inlet / outlets are used as inlet / outlets and the remaining one is used as an outlet, the refrigerant flows are joined together. The first three-way joint 12a is a branching section that branches the flow of the refrigerant discharged from the compressor 11.

[0032] One of the outlets of the first three-way joint 12a is connected to an inlet side of the refrigerant passage of the water-refrigerant heat exchanger 13. One of the inlet sides of the sixth three-way joint 12f is connected to the other of the outlets of the first three-way joint 12a. The refrigerant passage extending from the other of the outlets of the first three-way joint 12a to one of the inlet sides of the sixth three-way joint 12f is a bypass passage 21a. A bypass-side flow control valve 14d is disposed in the bypass passage 21a.

[0033] The bypass-side flow rate control valve 14d is a pressure reducing part on the bypass passage side that reduces the pressure of the discharged refrigerant flowing out from the other outlet of the first three-way joint 12a (i.e., the other discharged refrigerant branched at the first three-way joint 12a) during a hot gas heating mode, etc., which will be described later. The bypass-side flow rate control valve 14d is a bypass-side flow rate control part that adjusts the flow rate (mass flow rate) of the refrigerant flowing through the bypass passage 21a.

[0034] The bypass-side flow rate control valve 14d is an electric variable throttle mechanism having a valve body that changes the throttle opening and an electric actuator (specifically, a stepping motor) that displaces the valve body. The operation of the bypass-side flow rate control valve 14d is controlled by a control pulse output from the control device 60.

[0035] The bypass-side flow rate control valve 14d has a full-open function that functions simply as a refrigerant passage without exerting any refrigerant pressure reduction or flow rate adjustment action by fully opening the valve, and a full-close function that closes the refrigerant passage by fully closing the valve.

[0036] Furthermore, the heat pump cycle 10 includes a heating expansion valve 14a, a cooling expansion valve 14b, and a cooling expansion valve 14c, as described below. The heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 14c have the same basic configuration as the bypass-side flow control valve 14d. Furthermore, the basic configurations of each expansion valve and each flow control valve described in the embodiments described below are also the same as the bypass-side flow control valve 14d.

[0037] The heating expansion valve 14a, the cooling expansion valve 14b, the cooling expansion valve 14c, and the bypass side flow rate control valve 14d can switch the refrigerant circuit by exerting the above-mentioned fully closed function. Therefore, the heating expansion valve 14a, the cooling expansion valve 14b, the cooling expansion valve 14c, and the bypass side flow rate control valve 14d also function as a refrigerant circuit switching unit.

[0038] Of course, the heating expansion valve 14a, the cooling expansion valve 14b, the cooling expansion valve 14c, and the bypass side flow rate control valve 14d may be formed by combining a variable throttle mechanism that does not have a full closing function with an on-off valve that opens and closes the throttle passage. In this case, each on-off valve serves as a refrigerant circuit switching unit.

[0039] The water-refrigerant heat exchanger 13 is a heat exchange unit that exchanges heat between the discharge refrigerant flowing out from one outlet of the first three-way joint 12a (i.e., one of the discharge refrigerant branched at the first three-way joint 12a) and the high-temperature side heat medium circulating through the high-temperature side heat medium circuit 30. The water-refrigerant heat exchanger 13 dissipates heat contained in the discharge refrigerant to the high-temperature side heat medium, heating the high-temperature side heat medium.

[0040] The inlet side of the second three-way joint 12b is connected to the outlet of the refrigerant passage of the water-refrigerant heat exchanger 13. The inlet side of the heating expansion valve 14a is connected to one of the outlets of the second three-way joint 12b. The inlet side of one of the four-way joints 12x is connected to the other outlet of the second three-way joint 12b. The refrigerant passage extending from the other outlet of the second three-way joint 12b to one of the inlets of the four-way joint 12x is the dehumidification passage 21b.

[0041] A dehumidification on-off valve 22a is disposed in the dehumidification passage 21b. The dehumidification on-off valve 22a is an on-off valve that opens and closes the dehumidification passage 21b. The dehumidification on-off valve 22a is an electromagnetic valve whose opening and closing operation is controlled by a control voltage output from the control device 60. The dehumidification on-off valve 22a can switch the refrigerant circuit by opening and closing the dehumidification passage 21b. Therefore, the dehumidification on-off valve 22a is a refrigerant circuit switching unit.

[0042] The four-way joint 12x is a joint part having four inlet and outlet ports that communicate with each other. A joint part formed in the same manner as the above-mentioned three-way joint can be used as the four-way joint 12x. A joint part formed by combining two three-way joints may also be used as the four-way joint 12x.

[0043] The heating expansion valve 14a is a pressure reducing section on the outdoor heat exchanger side that reduces the pressure of the refrigerant flowing into the outdoor heat exchanger 15 during a heating mode, which will be described later, etc. Furthermore, the heating expansion valve 14a is a flow rate adjusting section on the outdoor heat exchanger side that adjusts the flow rate (mass flow rate) of the refrigerant flowing into the outdoor heat exchanger 15.

[0044] The outlet of the heating expansion valve 14a is connected to the refrigerant inlet side of the exterior heat exchanger 15. The exterior heat exchanger 15 is an exterior heat exchanger that exchanges heat between the refrigerant flowing out of the heating expansion valve 14a and the outside air blown by an outside air fan (not shown). The exterior heat exchanger 15 is disposed on the front side of the drive unit compartment. Therefore, when the vehicle is traveling, the traveling wind that flows into the drive unit compartment through the grill can be applied to the exterior heat exchanger 15.

[0045] An inlet side of a third three-way joint 12c is connected to a refrigerant outlet of the outdoor heat exchanger 15. Another inlet side of a four-way joint 12x is connected to one outlet side of the third three-way joint 12c via a first check valve 16a. One inlet side of a fourth three-way joint 12d is connected to the other outlet side of the third three-way joint 12c. The refrigerant passage that runs from the other outlet side of the third three-way joint 12c to one inlet side of the fourth three-way joint 12d is a heating passage 21c.

[0046] A heating on-off valve 22b is disposed in the heating passage 21c. The heating on-off valve 22b is an on-off valve that opens and closes the heating passage 21c. The heating on-off valve 22b has a basic configuration similar to that of the dehumidification on-off valve 22a. Therefore, the heating on-off valve 22b is a refrigerant circuit switching unit. Furthermore, the basic configurations of the on-off valves described in the embodiments described below are also similar to that of the dehumidification on-off valve 22a.

[0047] The first check valve 16a allows the refrigerant to flow from the third three-way joint 12c side to the four-way joint 12x side and prohibits the refrigerant from flowing from the four-way joint 12x side to the third three-way joint 12c side.

[0048] One outlet of the four-way joint 12x is connected to the refrigerant inlet side of the indoor evaporator 18 via a cooling expansion valve 14b. The cooling expansion valve 14b is a pressure reducing section on the indoor evaporator side that reduces the pressure of the refrigerant flowing out from one outlet of the four-way joint 12x during a cooling mode, which will be described later. Furthermore, the cooling expansion valve 14b is a flow rate adjusting section on the indoor evaporator side that adjusts the flow rate (mass flow rate) of the refrigerant flowing into the indoor evaporator 18.

[0049] The interior evaporator 18 is disposed in an air conditioning case 51 of the interior air conditioning unit 50, which will be described later. The interior evaporator 18 is a cooling evaporation section that exchanges heat between a low-pressure refrigerant decompressed by the cooling expansion valve 14b and the blown air blown from the interior blower 52 toward the vehicle interior. The interior evaporator 18 cools the blown air by evaporating the low-pressure refrigerant and exerting a heat absorption effect.

[0050] A refrigerant outlet of the indoor evaporator 18 is connected to one inlet side of a fifth three-way joint 12e via an evaporation pressure regulating valve 19 and a second check valve 16b.

[0051] The evaporation pressure regulating valve 19 is a variable throttle mechanism that maintains the refrigerant evaporation temperature in the indoor evaporator 18 at a temperature (1°C in this embodiment) or higher that can suppress frost formation on the indoor evaporator 18. The evaporation pressure regulating valve 19 is configured with a mechanical mechanism that increases the valve opening degree as the refrigerant pressure on the refrigerant outlet side of the indoor evaporator 18 increases.

[0052] The second check valve 16b allows the refrigerant to flow from the outlet side of the evaporation pressure regulating valve 19 to the fifth three-way joint 12e side and prohibits the refrigerant from flowing from the fifth three-way joint 12e side to the evaporation pressure regulating valve 19 side.

[0053] The other inlet side of a sixth three-way joint 12f is connected to another outlet of the four-way joint 12x via a cooling expansion valve 14c. The outlet of the sixth three-way joint 12f is connected to the inlet side of the refrigerant passage of the chiller 20.

[0054] The cooling expansion valve 14c is a chiller-side pressure reducing unit that reduces the pressure of the refrigerant flowing into the chiller 20 in a cooling / air-cooling mode or a hot gas heating mode, which will be described later. Furthermore, the cooling expansion valve 14c is a chiller-side flow rate adjusting unit that adjusts the flow rate (mass flow rate) of the refrigerant flowing into the chiller 20.

[0055] The chiller 20 is a cooling evaporation section that evaporates the low-pressure refrigerant by exchanging heat between the low-pressure refrigerant decompressed by the cooling expansion valve 14c and the low-temperature side heat medium circulating in the low-temperature side heat medium circuit 40. The chiller 20 evaporates the low-pressure refrigerant to exert a heat absorption effect, thereby cooling the low-temperature side heat medium.

[0056] The other inlet side of fourth three-way joint 12d is connected to the outlet of the refrigerant passage of chiller 20. The other inlet side of fifth three-way joint 12e is connected to the outlet of fourth three-way joint 12d.

[0057] The outlet of the fifth three-way joint 12e is connected to the inlet side of the accumulator 23. The accumulator 23 is a low-pressure side gas-liquid separator that separates the refrigerant that flows into the inside into gas and liquid and stores the excess liquid-phase refrigerant in the cycle. The gas-phase refrigerant outlet of the accumulator 23 is connected to the suction port side of the compressor 11.

[0058] Next, the high-temperature side heat medium circuit 30 will be described. The high-temperature side heat medium circuit 30 is a heat medium circulation circuit that circulates the high-temperature side heat medium. In this embodiment, an ethylene glycol aqueous solution is used as the high-temperature side heat medium. The high-temperature side heat medium circuit 30 includes a heat medium passage of the water-refrigerant heat exchanger 13, a high-temperature side pump 31, a heater core 32, and the like.

[0059] The high-temperature side pump 31 is a high-temperature side heat medium pumping section that pumps the high-temperature side heat medium flowing out from the heat medium passage of the water-refrigerant heat exchanger 13 to the heat medium inlet side of the heater core 32. The high-temperature side pump 31 is an electric pump whose rotation speed (i.e., pumping capacity) is controlled by a control voltage output from the control device 60.

[0060] The heater core 32 is a heating heat exchanger that heats the blown air by exchanging heat between the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 and the blown air that has passed through the indoor evaporator 18. The heater core 32 is disposed in an air conditioning case 51 of the indoor air conditioning unit 50. The inlet side of the heat medium passage of the water-refrigerant heat exchanger 13 is connected to the heat medium outlet of the heater core 32.

[0061] Therefore, in this embodiment, the water-refrigerant heat exchanger 13 and each component of the high-temperature side heat medium circuit 30 are a heating section that heats the blown air, which is the object to be heated, using one of the discharged refrigerants branched off at the first three-way joint 12a as a heat source.

[0062] Next, the low-temperature side heat medium circuit 40 will be described. The low-temperature side heat medium circuit 40 is a heat medium circuit that circulates the low-temperature side heat medium. In this embodiment, the same type of fluid as the high-temperature side heat medium is used as the low-temperature side heat medium. The low-temperature side heat medium circuit 40 is connected to a low-temperature side pump 41, a cooling water passage 70a of the battery 70, a heat medium passage of the chiller 20, etc.

[0063] The low-temperature side pump 41 is a low-temperature side heat medium pump that pumps the low-temperature side heat medium flowing out from the cooling water passage 70a of the battery 70 to the inlet side of the heat medium passage of the chiller 20. The basic configuration of the low-temperature side pump 41 is similar to that of the high-temperature side pump 31. The inlet side of the cooling water passage 70a of the battery 70 is connected to the outlet side of the heat medium passage of the chiller 20.

[0064] The cooling water passage 70a of the battery 70 is a cooling water passage formed to cool the battery 70 by circulating the low-temperature side heat medium cooled by the chiller 20. The cooling water passage 70a is formed inside a dedicated battery case that houses a plurality of stacked battery cells.

[0065] The cooling water passage 70a is configured with multiple passages connected in parallel inside the battery case. This allows the cooling water passage 70a to cool all battery cells evenly. The outlet of the cooling water passage 70a is connected to the suction port side of the low-temperature side pump 41.

[0066] Next, the interior air conditioning unit 50 will be described. The interior air conditioning unit 50 is a unit that integrates a number of components to blow air adjusted to an appropriate temperature for air conditioning the vehicle interior to an appropriate location within the vehicle interior. The interior air conditioning unit 50 is disposed inside the instrument panel at the front end of the vehicle interior.

[0067] The indoor air conditioning unit 50 is formed by accommodating an indoor blower 52, an indoor evaporator 18, a heater core 32, etc. in an air conditioning case 51 that forms an air passage for the blown air. The air conditioning case 51 is molded from a resin (e.g., polypropylene) that has a certain degree of elasticity and excellent strength.

[0068] An inside / outside air switching device 53 is disposed on the most upstream side of the blown air flow of the air conditioning case 51. The inside / outside air switching device 53 switches between introducing inside air (i.e., air inside the vehicle cabin) and outside air (i.e., air outside the vehicle cabin) into the air conditioning case 51. The operation of the inside / outside air switching device 53 is controlled by a control signal output from the control device 60.

[0069] An interior blower 52 is disposed downstream of the inside / outside air switching device 53 in the flow of blown air. The interior blower 52 is a blower that blows air drawn in through the inside / outside air switching device 53 toward the vehicle interior. The rotation speed (i.e., blowing capacity) of the interior blower 52 is controlled by a control voltage output from the control device 60.

[0070] The indoor evaporator 18 and the heater core 32 are disposed downstream of the indoor blower 52 in the flow of air blown. The indoor evaporator 18 is disposed upstream of the heater core 32 in the flow of air blown. A cold air bypass passage 55 is formed in the air conditioning case 51, which allows the air blown after passing through the indoor evaporator 18 to bypass the heater core 32.

[0071] An air mix door 54 is disposed downstream of the indoor evaporator 18 in the air conditioning case 51 in terms of the blown air flow and upstream of the heater core 32 and the cool air bypass passage 55 in terms of the blown air flow.

[0072] The air mix door 54 adjusts the ratio of the amount of air passing through the heater core 32 side to the amount of air passing through the cold air bypass passage 55, among the amount of air passing through the indoor evaporator 18. The operation of the actuator for driving the air mix door 54 is controlled by a control signal output from the control device 60.

[0073] A mixing space 56 is disposed downstream of the heater core 32 and the cold air bypass passage 55 in the flow of blown air. The mixing space 56 is a space in which the blown air heated by the heater core 32 and the blown air that has passed through the cold air bypass passage 55 and has not been heated are mixed.

[0074] Therefore, in the interior air conditioning unit 50, the temperature of the blown air (i.e., the conditioned air) mixed in the mixing space 56 and blown into the vehicle cabin can be adjusted by adjusting the opening degree of the air mix door 54. The air mix door 54 in this embodiment is a flow rate adjusting unit that adjusts the flow rate of the blown air that is heat exchanged in the heater core 32.

[0075] At the most downstream part of the blown air flow of the air conditioning case 51, a plurality of openings (not shown) are formed for blowing out the conditioned air toward various parts in the vehicle cabin. A blow mode door (not shown) for opening and closing each of the openings is disposed in each of the openings. The operation of the actuator for driving the blow mode door is controlled by a control signal output from the control device 60.

[0076] Therefore, in the interior air conditioning unit 50, by switching the opening hole that the blowing mode door opens and closes, conditioned air that has been adjusted to an appropriate temperature can be blown out to an appropriate location in the vehicle cabin.

[0077] Next, the electric control unit of this embodiment will be described. The control device 60 has a well-known microcomputer including a CPU, ROM, RAM, etc., and its peripheral circuits. The control device 60 performs various calculations and processing based on a control program stored in the ROM. Then, the control device 60 controls the operation of various control target devices 11, 14a to 14d, 22a, 22b, 31, 41, 52, 53, etc. connected to the output side based on the calculation and processing results.

[0078] As shown in the block diagram of FIG. 2, a group of control sensors are connected to the input side of the control device 60, such as an inside air temperature sensor 61a, an outside air temperature sensor 61b, a solar radiation sensor 61c, a discharge refrigerant temperature and pressure sensor 62a, a high-pressure side refrigerant temperature and pressure sensor 62b, an outdoor unit side refrigerant temperature and pressure sensor 62c, an evaporator side refrigerant temperature and pressure sensor 62d, a chiller side refrigerant temperature and pressure sensor 62e, an intake refrigerant temperature and pressure sensor 62f, a high-temperature side heat medium temperature sensor 63a, a low-temperature side heat medium temperature sensor 63b, a battery temperature sensor 64 and an air-conditioning air temperature sensor 65.

[0079] The inside air temperature sensor 61a is an inside air temperature detector that detects the temperature inside the vehicle cabin (inside air temperature) Tr. The outside air temperature sensor 61b is an outside air temperature detector that detects the temperature outside the vehicle cabin (outside air temperature) Tam. The solar radiation sensor 61c is an solar radiation amount detector that detects the amount of solar radiation As irradiated into the vehicle cabin.

[0080] The discharge refrigerant temperature and pressure sensor 62a is a discharge refrigerant temperature and pressure detection unit that detects the discharge refrigerant temperature Td and the discharge refrigerant pressure Pd of the refrigerant discharged from the compressor 11.

[0081] The high-pressure side refrigerant temperature and pressure sensor 62b is a high-pressure side refrigerant temperature and pressure detection unit that detects the high-pressure side refrigerant temperature T1 and the high-pressure side refrigerant pressure P1 of the refrigerant flowing out from the water-refrigerant heat exchanger 13.

[0082] The outdoor unit side refrigerant temperature and pressure sensor 62c is an outdoor unit side refrigerant temperature and pressure detection unit that detects the outdoor unit side refrigerant temperature T2 of the refrigerant flowing out from the outdoor heat exchanger 15 and the outdoor unit side refrigerant pressure P2.

[0083] The evaporator side refrigerant temperature and pressure sensor 62d is an evaporator side refrigerant temperature and pressure detection unit that detects the evaporator side refrigerant temperature Te and the evaporator side refrigerant pressure Pe of the refrigerant flowing out from the indoor evaporator .

[0084] The chiller side refrigerant temperature and pressure sensor 62e is a chiller side refrigerant temperature and pressure detection unit that detects the chiller side refrigerant temperature Tc and chiller side refrigerant pressure Pc of the refrigerant flowing out from the refrigerant passage of the chiller 20.

[0085] The suction refrigerant temperature and pressure sensor 62f is a suction refrigerant temperature and pressure detection unit that detects the suction refrigerant temperature Ts and the suction refrigerant pressure Ps of the suction refrigerant suctioned into the compressor 11.

[0086] In addition, in this embodiment, a detection unit in which the pressure detection unit and the temperature detection unit are integrated is used as the refrigerant temperature pressure sensor, but of course, a pressure detection unit and a temperature detection unit that are each configured as separate units may also be used. The high-temperature side heat medium temperature sensor 63 a is a high-temperature side heat medium temperature detection unit that detects a high-temperature side heat medium temperature TWH, which is the temperature of the high-temperature side heat medium flowing into the heater core 32.

[0087] The low-temperature side heat medium temperature sensor 63b is a low-temperature side heat medium temperature detection unit that detects the low-temperature side heat medium temperature TWL, which is the temperature of the low-temperature side heat medium flowing into the coolant passage a of the battery .

[0088] The battery temperature sensor 64 is a battery temperature detection unit that detects the battery temperature TB, which is the temperature of the battery 70. The battery temperature sensor 64 has multiple temperature sensors and detects the temperatures at multiple locations of the battery 70. Therefore, the control device 60 can detect the temperature difference and temperature distribution of each battery cell that forms the battery 70. Furthermore, the average value of the detection values ​​of the multiple temperature sensors is used as the battery temperature TB.

[0089] The conditioned air temperature sensor 65 is an air conditioner temperature detection unit that detects the temperature TAV of the air blown from the mixing space 56 into the vehicle interior. The blown air temperature TAV is the object temperature of the blown air, which is the object to be heated.

[0090] 2, an operation panel 69 disposed near the instrument panel at the front of the vehicle interior is connected to the input side of the control device 60. Operation signals are input to the control device 60 from various operation switches provided on the operation panel 69.

[0091] The various operation switches provided on the operation panel 69 specifically include an auto switch, an air conditioner switch, an air volume setting switch, a temperature setting switch, and the like.

[0092] The auto switch is an automatic control setting unit that sets or cancels automatic control operation of the vehicle air conditioner 1. The air conditioner switch is a cooling request unit that requests cooling of the blown air by the interior evaporator 18. The air volume setting switch is an air volume setting unit that manually sets the blown air volume of the interior blower 52. The temperature setting switch is a temperature setting unit that sets the set temperature Tset in the vehicle cabin.

[0093] The control device 60 of this embodiment is a device that is integrated with a control unit that controls various control target devices connected to its output side. Therefore, the configuration (hardware and software) that controls the operation of each control target device constitutes a control unit that controls the operation of each control target device.

[0094] For example, in the control device 60, a configuration for controlling the rotation speed of the compressor 11 constitutes a discharge capacity control section 60a. A configuration for controlling the operation of the heating section side pressure reducing section (in this embodiment, the cooling expansion valve 14c) constitutes a heating section side control section 60b. A configuration for controlling the operation of the bypass side flow rate adjustment valve 14d constitutes a bypass side control section 60c.

[0095] Next, the operation of the vehicle air conditioner 1 of this embodiment configured as described above will be described. In the vehicle air conditioner 1 of this embodiment, various operation modes are switched in order to condition the air in the vehicle cabin and adjust the temperature of the battery 70. The operation modes are switched by executing a control program stored in advance in the control device 60.

[0096] The control program is executed not only when the so-called IG switch is turned on (ON) and the vehicle system is running, but also when the battery 70 is being charged from an external power source. A main routine of the control program will be described with reference to the flowchart of Fig. 3. Each control step shown in the flowchart of Fig. 3 is a part for implementing various functions of the control device 60.

[0097] First, in step S1 in Fig. 3, initialization of flags, timers, etc., and initial position alignment of electric actuators, etc. are performed. Next, in step S2, detection signals of the control sensors and operation signals of the operation panel 69 are read. Next, in step S3, a target blown temperature TAO is determined. The target blown temperature TAO is the target temperature of the blown air to be blown into the vehicle cabin. Therefore, step S3 is a target temperature determination section.

[0098] Specifically, in step S3, the target blown air temperature TAO is determined using the following formula F1. TAO=Kset×Tset-Kr×Tr-Kam×Tam-Ks×As+C…(F1) Tset is the vehicle interior target temperature set by the temperature setting switch. Tr is the inside air temperature detected by the inside air temperature sensor 61a. Tam is the outside air temperature detected by the outside air temperature sensor 61b. As is the amount of solar radiation detected by the solar radiation sensor 61c. Kset, Kr, Kam, and Ks are control gains, and C is a correction constant.

[0099] Next, in step S4, an operation mode is selected using the detection signal and operation signal read in step S2 and the target blow-out temperature TAO determined in step S3. Next, in step S5, the operation of various controlled devices is controlled so that the operation mode selected in step S4 is executed.

[0100] Next, in step S6, it is determined whether or not a predetermined termination condition for the vehicle air conditioner 1 is satisfied. If it is determined in step S6 that the termination condition is not satisfied, Ta If so, the process returns to step S2. If it is determined in step S6 that the termination condition is met, the program is terminated.

[0101] Here, the termination condition of this embodiment is met when the IG switch is turned off (OFF) while the battery 70 is not being charged from the external power source. The termination condition of this embodiment is also met when charging of the battery 70 from the external power source is completed while the IG switch is turned off (OFF). Hereinafter, detailed operations of each operation mode selected in step S4 will be described.

[0102] (a) Cooling mode The cooling mode is an operation mode in which cooled air is blown into the vehicle cabin to cool the vehicle cabin. In the control program of this embodiment, the cooling mode is selected when the outside air temperature Tam is relatively high (25° C. or higher in this embodiment), such as in summer.

[0103] The cooling modes include a single cooling mode in which the vehicle cabin is cooled without cooling the battery 70, and a cooling and cooling mode in which the vehicle cabin is cooled while cooling the battery 70. In the control program of this embodiment, when the battery temperature TB becomes equal to or higher than a predetermined reference upper limit temperature KTBH, an operation mode for cooling the battery 70 is executed.

[0104] (a-1) Single cooling mode In the heat pump cycle 10 in the cooling only mode, the control device 60 fully opens the heating expansion valve 14a, fully closes the cooling expansion valve 14b, fully closes the bypass-side flow control valve 14d, and fully closes the dehumidification opening / closing valve 22a and the heating opening / closing valve 22b.

[0105] For this reason, in the heat pump cycle 10 in the cooling only mode, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the following order: the water-refrigerant heat exchanger 13, the heating expansion valve 14a which is in a fully open state, the outdoor heat exchanger 15, the cooling expansion valve 14b which is in a throttled state, the indoor evaporator 18, the evaporation pressure control valve 19, the accumulator 23, and the suction port of the compressor 11.

[0106] In the high-temperature side heat medium circuit 30 in the sole cooling mode, the control device 60 operates the high-temperature side pump 31 to exert a predetermined reference pumping capacity. Therefore, in the high-temperature side heat medium circuit 30, the high-temperature side heat medium pumped by the high-temperature side pump 31 circulates through the heater core 32, the heat medium passage of the water-refrigerant heat exchanger 13, and the suction port of the high-temperature side pump 31 in that order.

[0107] In addition, in the indoor air conditioning unit 50 in the single cooling mode, the control device 60 adjusts the opening degree of the air mix door 54 so that the blown air temperature TAV detected by the conditioned air temperature sensor 65 approaches the target blown air temperature TAO.

[0108] Furthermore, the control device 60 determines the control voltage to be output to the indoor blower 52 based on the target blowing temperature TAO by referring to a control map previously stored in the control device 60. In the control map, the airflow rate of the indoor blower 52 is maximized in the extremely low temperature range (maximum cooling range) and extremely high temperature range (maximum heating range) of the target blowing temperature TAO, and the airflow rate is reduced as the temperature approaches the intermediate temperature range.

[0109] Furthermore, the control device 60 controls the operation of the inside / outside air switching device 53 and the blowing mode door based on the target blowing temperature TAO. The control device 60 also appropriately controls the operation of other devices to be controlled.

[0110] Therefore, in the heat pump cycle 10 in the cooling only mode, the water-refrigerant heat exchanger 13 and the outdoor heat exchanger 15 function as condensers that condense the refrigerant by dissipating heat, and the indoor evaporator 18 functions as an evaporator that evaporates the refrigerant, forming a vapor compression refrigeration cycle.

[0111] In the high-temperature side heat medium circuit 30 in the single cooling mode, the high-temperature side heat medium pumped from the high-temperature side pump 31 flows into the heater core 32 and exchanges heat with the blown air. The high-temperature side heat medium flowing out of the heater core 32 flows into the heat medium passage of the water-refrigerant heat exchanger 13 and exchanges heat with the discharged refrigerant. This heats the high-temperature side heat medium. The high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 is sucked into the high-temperature side pump 31 and pumped back to the heater core 32.

[0112] In the indoor air conditioning unit 50 in the single cooling mode, the blown air blown from the indoor blower 52 is cooled by the indoor evaporator 18. The blown air cooled by the indoor evaporator 18 is reheated by heat exchange with the high-temperature side heat medium in the heater core 32 so as to approach the target blown air temperature TAO according to the opening degree of the air mix door 54. Then, the temperature-adjusted blown air is blown into the vehicle cabin, thereby cooling the vehicle cabin.

[0113] (a-2) Cooling mode In the heat pump cycle 10 in the cooling / air-cooling mode, the control device 60 controls the cooling expansion valve 14c to be in a throttling state, unlike the single cooling mode.

[0114] Therefore, in the heat pump cycle 10 in the cooling / cooling mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single cooling mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the order of the water-refrigerant heat exchanger 13, the heating expansion valve 14a in the fully open state, the outdoor heat exchanger 15, the cooling expansion valve 14c in the throttled state, the chiller 20, the accumulator 23, and the suction port of the compressor 11. In other words, the indoor evaporator 18 and the chiller 20 are switched to a refrigerant circuit connected in parallel with respect to the flow of the refrigerant.

[0115] In the high-temperature side heat medium circuit 30 in the cooling / air-cooling mode, the control device 60 controls the operation of the high-temperature side pump 31 in the same manner as in the single cooling mode.

[0116] In the low-temperature side heat medium circuit 40 in the cooling / air-cooling mode, the controller 60 operates the low-temperature side pump 41 to exert a predetermined reference pumping capacity. Therefore, in the low-temperature side heat medium circuit 40, the low-temperature side heat medium pumped by the low-temperature side pump 41 circulates through the heat medium passage of the chiller 20, the cooling water passage 70a of the battery 70, and the suction port of the low-temperature side pump 41 in that order.

[0117] In the indoor air conditioning unit 50 in the cooling / cooling mode, the control device 60 controls the blowing capacity of the indoor blower 52, the opening degree of the air mix door 54, the inside / outside air switching device 53, and the operation of the blowing mode door, in the same way as in the single cooling mode. The control device 60 also controls the operation of other control target devices as appropriate.

[0118] Therefore, in the heat pump cycle 10 in the cooling / air-conditioning mode, the water-refrigerant heat exchanger 13 and the outdoor heat exchanger 15 function as condensers, and the indoor evaporator 18 and the chiller 20 function as evaporators, forming a vapor compression refrigeration cycle.

[0119] In the high-temperature side heat medium circuit 30 in the cooling / air-cooling mode, the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0120] In the low-temperature side heat medium circuit 40 in the cooling / air-cooling mode, the low-temperature side heat medium pumped from the low-temperature side pump 41 flows into the chiller 20 and exchanges heat with the low-pressure refrigerant. This cools the low-pressure refrigerant. The low-temperature side heat medium cooled in the chiller 20 flows through the cooling water passage 70a of the battery 70. This cools the battery 70. The low-temperature side heat medium flowing out of the cooling water passage 70a of the battery 70 is sucked into the low-temperature side pump 41 and pumped back to the chiller 20.

[0121] In the interior air conditioning unit 50 in the cooling / air-conditioning mode, temperature-adjusted air is blown into the vehicle compartment, thereby cooling the vehicle compartment, similarly to the single cooling mode.

[0122] (b) Series dehumidification and heating mode The serial dehumidifying and heating mode is an operation mode in which the cooled and dehumidified blown air is reheated and blown into the vehicle cabin to dehumidify and heat the vehicle cabin. In the control program of this embodiment, the serial dehumidifying and heating mode is selected when the outside air temperature Tam is in a predetermined medium-high temperature range (in this embodiment, 10° C. or higher and lower than 25° C.).

[0123] The series dehumidifying and heating modes include a single series dehumidifying and heating mode in which the vehicle interior is dehumidified and heated without cooling the battery 70, and a cooling series dehumidifying and heating mode in which the battery 70 is cooled and the vehicle interior is dehumidified and heated.

[0124] (b-1) Single series dehumidification and heating mode In the heat pump cycle 10 in the single series dehumidification heating mode, the control device 60 controls the heating expansion valve 14a to be throttled, the cooling expansion valve 14b to be throttled, the cooling expansion valve 14c to be fully closed, and the bypass side flow rate control valve 14d to be fully closed. The control device 60 also closes the dehumidification opening / closing valve 22a and the heating opening / closing valve 22b.

[0125] For this reason, in the heat pump cycle 10 in the single-serial dehumidification heating mode, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the following order: the water-refrigerant heat exchanger 13, the heating expansion valve 14a which is in a throttled state, the outdoor heat exchanger 15, the cooling expansion valve 14b which is in a throttled state, the indoor evaporator 18, the evaporation pressure control valve 19, the accumulator 23, and the suction port of the compressor 11.

[0126] In the high-temperature side heat medium circuit 30 in the single series dehumidifying and heating mode, the control device 60 controls the operation of the high-temperature side pump 31 in the same manner as in the single cooling mode.

[0127] In the indoor air conditioning unit 50 in the independent series dehumidifying and heating mode, the control device 60 controls the blowing capacity of the indoor blower 52, the opening degree of the air mix door 54, the inside / outside air switching device 53, and the operation of the blowing mode door, in the same manner as in the independent cooling mode. The control device 60 also controls the operation of other control target devices as appropriate.

[0128] Therefore, in the heat pump cycle 10 in the single series dehumidifying and heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser and the indoor evaporator 18 functions as an evaporator.

[0129] Furthermore, in the single serial dehumidification and heating mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 15 is higher than the outdoor air temperature Tam, the outdoor heat exchanger 15 is made to function as a condenser. When the saturation temperature of the refrigerant in the outdoor heat exchanger 15 is lower than the outdoor air temperature Tam, the outdoor heat exchanger 15 is made to function as an evaporator.

[0130] In the high-temperature side heat medium circuit 30 in the single series dehumidification and heating mode, the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0131] In the interior air conditioning unit 50 in the single serial dehumidifying and heating mode, the blown air blown from the interior blower 52 is cooled and dehumidified in the interior evaporator 18. The blown air cooled and dehumidified in the interior evaporator 18 is reheated in the heater core 32 so as to approach the target blown temperature TAO according to the opening degree of the air mix door 54. Then, the temperature-adjusted blown air is blown into the vehicle cabin, thereby realizing dehumidifying and heating the vehicle cabin.

[0132] (b-2) Cooling series dehumidification heating mode In the heat pump cycle 10 in the cooling series dehumidification heating mode, the controller 60 controls the cooling expansion valve 14c to the throttling state, unlike in the single series dehumidification heating mode.

[0133] Therefore, in the heat pump cycle 10 in the cooling series dehumidification heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single series dehumidification heating mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the order of the water-refrigerant heat exchanger 13, the heating expansion valve 14a in the throttling state, the outdoor heat exchanger 15, the cooling expansion valve 14c in the throttling state, the chiller 20, the accumulator 23, and the suction port of the compressor 11. In other words, the indoor evaporator 18 and the chiller 20 are switched to a refrigerant circuit connected in parallel with respect to the flow of the refrigerant.

[0134] In the high-temperature side heat medium circuit 30 in the cooling serial dehumidification and heating mode, the control device 60 controls the operation of the high-temperature side pump 31 in the same manner as in the single cooling mode.

[0135] In the low-temperature side heat medium circuit 40 in the cooling serial dehumidification heating mode, the controller 60 controls the operation of the low-temperature side pump 41 in the same manner as in the cooling / cooling mode.

[0136] In the indoor air conditioning unit 50 in the cooling serial dehumidification heating mode, the control device 60 controls the blowing capacity of the indoor blower 52, the opening degree of the air mix door 54, the inside / outside air switching device 53, and the operation of the blowing mode door, in the same way as in the single cooling mode. The control device 60 also controls the operation of other control target devices as appropriate.

[0137] Therefore, in the heat pump cycle 10 in the cooling-series dehumidification-heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser, and the indoor evaporator 18 and the chiller 20 function as evaporators.

[0138] Furthermore, in the cooling serial dehumidification heating mode, similarly to the single serial dehumidification heating mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 15 is higher than the outdoor air temperature Tam, the outdoor heat exchanger 15 is made to function as a condenser. Also, when the saturation temperature of the refrigerant in the outdoor heat exchanger 15 is lower than the outdoor air temperature Tam, the outdoor heat exchanger 15 is made to function as an evaporator.

[0139] In the high-temperature side heat medium circuit 30 in the cooling serial dehumidification and heating mode, the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0140] In the low-temperature side heat medium circuit 40 in the cooling serial dehumidification heating mode, the low-temperature side heat medium cooled in the chiller 20 flows through the coolant passage 70a of the battery 70, as in the cooling air-conditioning mode, to cool the battery 70.

[0141] In the interior air conditioning unit 50 in the cooling series dehumidification heating mode, similarly to the single series dehumidification heating mode, temperature-adjusted ventilation air is blown into the vehicle compartment, thereby realizing dehumidification and heating of the vehicle compartment.

[0142] (c) Parallel dehumidification and heating mode The parallel dehumidifying and heating mode is an operation mode in which the cooled and dehumidified blown air is reheated with a heating capacity higher than that of the serial dehumidifying and heating mode and blown into the vehicle cabin to dehumidify and heat the vehicle cabin. In the control program of this embodiment, the parallel dehumidifying and heating mode is selected when the outside air temperature Tam is in a predetermined low-medium temperature range (in this embodiment, 0°C or higher and lower than 10°C).

[0143] The parallel dehumidifying and heating modes include a single parallel dehumidifying and heating mode in which the vehicle interior is dehumidified and heated without cooling the battery 70, and a cooling / parallel dehumidifying and heating mode in which the battery 70 is cooled and the vehicle interior is dehumidified and heated.

[0144] (c-1) Single parallel dehumidification and heating mode In the heat pump cycle 10 in the single-parallel dehumidification heating mode, the control device 60 throttles the heating expansion valve 14a, throttles the cooling expansion valve 14b, fully closes the cooling expansion valve 14c, and fully closes the bypass-side flow control valve 14d. The control device 60 also opens the dehumidification on-off valve 22a and the heating on-off valve 22b.

[0145] Therefore, in the heat pump cycle 10 in the single-parallel dehumidification heating mode, the refrigerant discharged from the compressor 11 circulates in the order of the water-refrigerant heat exchanger 13, the heating expansion valve 14a in the throttled state, the outdoor heat exchanger 15, the heating passage 21c, the accumulator 23, and the suction port of the compressor 11. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which the refrigerant circulates in the order of the water-refrigerant heat exchanger 13, the dehumidification passage 21b, the cooling expansion valve 14b in the throttled state, the indoor evaporator 18, the evaporation pressure control valve 19, the accumulator 23, and the suction port of the compressor 11. In other words, the outdoor heat exchanger 15 and the indoor evaporator 18 are switched to a refrigerant circuit in which the refrigerant flows in parallel.

[0146] In the high-temperature side heat medium circuit 30 in the single-parallel dehumidifying and heating mode, the control device 60 controls the operation of the high-temperature side pump 31 in the same manner as in the single-cooling mode.

[0147] In the indoor air conditioning unit 50 in the single parallel dehumidifying and heating mode, the control device 60 controls the blowing capacity of the indoor blower 52, the opening degree of the air mix door 54, the inside / outside air switching device 53, and the operation of the blowing mode door, in the same way as in the single cooling mode. The control device 60 also controls the operation of other control target devices as appropriate.

[0148] Therefore, in the heat pump cycle 10 in the single-parallel dehumidifying and heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser, and the outdoor heat exchanger 15 and the indoor evaporator 18 function as evaporators.

[0149] In the high-temperature side heat medium circuit 30 in the single parallel dehumidification and heating mode, the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0150] In the interior air conditioning unit 50 in the single parallel dehumidifying and heating mode, the blown air blown from the interior blower 52 is cooled and dehumidified by the interior evaporator 18. The blown air cooled and dehumidified by the interior evaporator 18 is reheated by the heater core 32 so as to approach the target blown temperature TAO according to the opening degree of the air mix door 54. Then, the temperature-adjusted blown air is blown into the vehicle cabin, thereby realizing dehumidifying and heating the vehicle cabin.

[0151] Furthermore, in the heat pump cycle 10 in the single-parallel dehumidifying and heating mode, the throttle opening of the heating expansion valve 14a can be made smaller than the throttle opening of the cooling expansion valve 14b. This makes it possible to lower the refrigerant evaporation temperature in the outdoor heat exchanger 15 to a temperature lower than the refrigerant evaporation temperature in the indoor evaporator 18.

[0152] Therefore, in the single parallel dehumidifying and heating mode, the amount of heat absorbed by the refrigerant from the outside air in the outdoor heat exchanger 15 can be increased more than in the single series dehumidifying and heating mode, and the amount of heat released from the refrigerant to the high temperature side heat medium in the water-refrigerant heat exchanger 13 can be increased. As a result, in the single parallel dehumidifying and heating mode, the heating capacity of the heater core 32 for the blown air can be improved more than in the single series dehumidifying and heating mode.

[0153] (c-2) Parallel cooling, dehumidification and heating mode In the heat pump cycle 10 in the cooling-parallel dehumidification-heating mode, the controller 60 controls the cooling expansion valve 14c to the throttling state, unlike in the single-parallel dehumidification-heating mode.

[0154] Therefore, in the heat pump cycle 10 in the cooling-parallel dehumidification-heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single-parallel dehumidification-heating mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates through the water-refrigerant heat exchanger 13, the dehumidification passage 21b, the cooling expansion valve 14c in the throttled state, the chiller 20, the accumulator 23, and the suction port of the compressor 11 in that order. In other words, the outdoor heat exchanger 15, the indoor evaporator 18, and the chiller 20 are switched to a refrigerant circuit in which they are connected in parallel with respect to the flow of the refrigerant.

[0155] In the high-temperature side heat medium circuit 30 in the cooling parallel dehumidification heating mode, the control device 60 controls the operation of the high-temperature side pump 31 in the same manner as in the single cooling mode.

[0156] In the low-temperature side heat medium circuit 40 in the cooling parallel dehumidification heating mode, the controller 60 controls the operation of the low-temperature side pump 41 in the same manner as in the cooling / cooling mode.

[0157] In the indoor air-conditioning unit 50 in the cooling parallel dehumidification heating mode, the control device 60 controls the blowing capacity of the indoor blower 52, the opening degree of the air mix door 54, the inside / outside air switching device 53, and the operation of the blowing mode door, in the same way as in the single cooling mode. The control device 60 also controls the operation of other control target devices as appropriate.

[0158] Therefore, in the heat pump cycle 10 in the cooling parallel dehumidification heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser, and the outdoor heat exchanger 15, the indoor evaporator 18 and the chiller 20 function as evaporators.

[0159] In the high-temperature side heat medium circuit 30 in the cooling parallel dehumidification heating mode, the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0160] In the low-temperature side heat medium circuit 40 in the cooling parallel dehumidification heating mode, the low-temperature side heat medium cooled in the chiller 20 flows through the coolant passage 70a of the battery 70, thereby cooling the battery 70, as in the cooling and air-conditioning mode.

[0161] In the interior air conditioning unit 50 in the cooling-parallel dehumidifying-heating mode, temperature-adjusted ventilation air is blown into the vehicle compartment, as in the single-parallel dehumidifying-heating mode, thereby realizing dehumidifying and heating the vehicle compartment.

[0162] (d) Parallel hot gas dehumidification heating mode The parallel hot gas dehumidifying and heating mode is an operation mode that is executed to suppress a decrease in the heating capacity of the blown air when it is determined that frost has formed on the outdoor heat exchanger 15 during the parallel dehumidifying and heating mode. In the control program of this embodiment, it is determined that frost has formed on the outdoor heat exchanger 15 when a predetermined frosting condition is met.

[0163] The frost condition in this embodiment is met when the time during which the outdoor unit side refrigerant temperature T2 detected by the outdoor unit side refrigerant temperature pressure sensor 62c is below the reference frost temperature KTDF (-5°C in this embodiment) becomes equal to or longer than the reference frost time KTmDF (5 minutes in this embodiment).

[0164] The parallel hot gas dehumidifying and heating modes include a single parallel hot gas dehumidifying and heating mode and a cooling parallel hot gas dehumidifying and heating mode. The single parallel hot gas dehumidifying and heating mode is executed when a frosting condition is met during execution of the single parallel dehumidifying and heating mode. The cooling parallel hot gas dehumidifying and heating mode is executed when a frosting condition is met during execution of the cooling parallel dehumidifying and heating mode.

[0165] (d-1) Single parallel hot gas dehumidification heating mode In the heat pump cycle 10 in the single parallel hot gas dehumidification heating mode, the controller 60 controls the bypass side flow rate control valve 14d to be in a throttled state and the cooling expansion valve 14c to be in a throttled state in the single parallel dehumidification heating mode.

[0166] Therefore, in the heat pump cycle 10 in the single-parallel hot gas dehumidification and heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the cooling-parallel dehumidification and heating mode. At the same time, a portion of the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit that circulates through the bypass-side flow control valve 14d in a throttled state, the chiller 20, the accumulator 23, and the suction port of the compressor 11 in that order.

[0167] Furthermore, the control device 60 appropriately controls the operation of other controlled devices. For example, the refrigerant discharge capacity of the compressor 11 is increased by a predetermined amount compared to the single parallel dehumidification and heating mode. The control device 60 also controls the bypass side flow control valve 14d to a predetermined opening for the single parallel hot gas dehumidification and heating mode. The control device 60 also stops the low-temperature side pump. The other controlled devices are controlled in the same way as in the cooling-parallel dehumidification and heating mode.

[0168] Therefore, in the heat pump cycle 10 in the single parallel hot gas dehumidifying and heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser, and the outdoor heat exchanger 15 and the indoor evaporator 18 function as evaporators. However, in the single parallel hot gas dehumidifying and heating mode, frost forms on the outdoor heat exchanger 15, so the refrigerant that flows into the outdoor heat exchanger 15 cannot absorb much heat from the outside air.

[0169] In the high-temperature side heat medium circuit 30 in the single parallel hot gas dehumidification heating mode, the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0170] In the interior air conditioning unit 50 in the single parallel hot gas dehumidifying and heating mode, the blown air cooled and dehumidified in the interior evaporator 18 is reheated in the heater core 32 and blown into the vehicle cabin. This realizes dehumidifying and heating the vehicle cabin.

[0171] In the heat pump cycle 10 in the single parallel hot gas dehumidification and heating mode, frost forms on the outdoor heat exchanger 15, so the amount of heat absorbed by the refrigerant from the outdoor air in the outdoor heat exchanger 15 is less than in the single parallel dehumidification and heating mode.

[0172] Furthermore, as the amount of heat absorbed by the refrigerant from the outside air in the exterior heat exchanger 15 decreases, the amount of heat released from the refrigerant to the high-temperature side heat medium in the water-refrigerant heat exchanger 13 may decrease. As a result, the heating capacity of the heater core 32 for heating the blown air is likely to decrease.

[0173] In contrast, in the single parallel hot gas dehumidification heating mode of the present embodiment, the bypass side flow control valve 14d and the cooling expansion valve 14c are in a throttled state, so that the refrigerant with a relatively low enthalpy flowing out of the water-refrigerant heat exchanger 13 can be joined with the refrigerant with a relatively high enthalpy flowing out of the bypass side flow control valve 14d.

[0174] Therefore, in the heat pump cycle 10 in the single-parallel hot gas dehumidification heating mode, the refrigerant discharge capacity of the compressor 11 is increased more than in the parallel dehumidification heating mode, thereby suppressing the reduction in the amount of heat dissipated from the refrigerant to the high-temperature side heat medium in the water-refrigerant heat exchanger 13.

[0175] As a result, in the single-parallel hot gas dehumidification and heating mode, even if frost forms on outdoor heat exchanger 15 while the single-parallel dehumidification and heating mode is being executed, a decrease in the heating capacity of the blown air can be suppressed.

[0176] (d-2) Cooling parallel hot gas dehumidification heating mode In the heat pump cycle 10 in the cooling / parallel hot gas dehumidification / heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single parallel hot gas dehumidification / heating mode.

[0177] Furthermore, the control device 60 appropriately controls the operation of other control target devices in the same manner as in the single parallel hot gas dehumidification heating mode.

[0178] Therefore, in the heat pump cycle 10 in the cooling parallel hot gas dehumidification heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser, and the outdoor heat exchanger 15, the indoor evaporator 18 and the chiller 20 function as evaporators.

[0179] In the high-temperature side heat medium circuit 30 in the cooling parallel hot gas dehumidification heating mode, the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped to the heater core 32, as in the single cooling mode.

[0180] In the low-temperature side heat medium circuit 40 in the cooling parallel hot gas dehumidification heating mode, the low-temperature side heat medium cooled in the chiller 20 flows through the coolant passage 70a of the battery 70, thereby cooling the battery 70, as in the cooling and air conditioning mode.

[0181] In the interior air conditioning unit 50 in the cooling parallel hot gas dehumidification and heating mode, the blown air cooled and dehumidified by the interior evaporator 18 is reheated by the heater core 32 and blown into the vehicle cabin. This realizes dehumidification and heating of the vehicle cabin.

[0182] In the cooling parallel hot gas dehumidifying and heating mode, frost forms on the outdoor heat exchanger 15, so the refrigerant that flows into the outdoor heat exchanger 15 is unable to absorb much heat from the outside air. In contrast, in the cooling parallel hot gas dehumidifying and heating mode, the bypass side flow control valve 14d is in a throttled state, so a decrease in the heating capacity of the blown air can be suppressed, just like in the single parallel hot gas dehumidifying and heating mode.

[0183] (e) Outdoor air heat absorption heating mode The outside air heat absorption heating mode is an operation mode in which heated air is blown into the vehicle cabin to heat the vehicle cabin. In the control program of this embodiment, the outside air heat absorption heating mode is selected when the outside air temperature Tam is relatively low (in this embodiment, −10° C. or higher and lower than 0° C.), such as in winter.

[0184] The outside air heat absorption heating mode includes a sole outside air heat absorption heating mode in which the interior of the vehicle is heated without cooling the battery 70, and a cooled outside air heat absorption heating mode in which the battery 70 is cooled and the interior of the vehicle is heated.

[0185] (e-1) Single outdoor air heat absorption heating mode In the heat pump cycle 10 in the single outdoor air heat absorption heating mode, the controller 60 throttles the heating expansion valve 14a, fully closes the cooling expansion valve 14b, fully closes the cooling expansion valve 14c, and fully closes the bypass-side flow control valve 14d. The controller 60 also closes the dehumidification opening / closing valve 22a and opens the heating opening / closing valve 22b.

[0186] For this reason, in the heat pump cycle 10 in the single outdoor air heat absorption heating mode, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which the refrigerant circulates in the following order: the water-refrigerant heat exchanger 13, the heating expansion valve 14a which is in a throttled state, the outdoor heat exchanger 15, the heating passage 21c, the accumulator 23, and the suction port of the compressor 11.

[0187] In the high temperature side heat medium circuit 30 in the single outdoor air heat absorption heating mode, the control device 60 controls the operation of the high temperature side pump 31 in the same manner as in the single cooling mode.

[0188] In the indoor air conditioning unit 50 in the single outdoor air heat absorption heating mode, the control device 60 controls the blowing capacity of the indoor blower 52, the opening degree of the air mix door 54, the inside / outside air switching device 53, and the operation of the blowing mode door, in the same way as in the single cooling mode. The control device 60 also controls the operation of other control target devices as appropriate.

[0189] Therefore, in the heat pump cycle 10 in the single outdoor air heat absorption heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser and the outdoor heat exchanger 15 functions as an evaporator.

[0190] In the high temperature side heat medium circuit 30 in the single outdoor air heat absorption heating mode, the high temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0191] In the interior air conditioning unit 50 in the single outside air heat absorption heating mode, the blown air sent from the interior blower 52 passes through the interior evaporator 18. The blown air that has passed through the interior evaporator 18 is heated by the heater core 32 so as to approach the target blown air temperature TAO according to the opening degree of the air mix door 54. Then, the temperature-adjusted blown air is blown into the vehicle cabin, thereby heating the vehicle cabin.

[0192] (e-2) Cooling outdoor air heat absorption heating mode In the heat pump cycle 10 in the cooling outdoor air heat absorption heating mode, the controller 60 throttles the cooling expansion valve 14c in comparison with the single outdoor air heat absorption heating mode. Also, the controller 60 opens the dehumidification opening / closing valve 22a.

[0193] Therefore, in the heat pump cycle 10 in the cooling outdoor air heat absorption heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single outdoor air heat absorption heating mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates through the water-refrigerant heat exchanger 13, the dehumidification passage 21b, the cooling expansion valve 14c in the throttled state, the chiller 20, the accumulator 23, and the suction port of the compressor 11 in that order. In other words, the outdoor heat exchanger 15 and the chiller 20 are switched to a refrigerant circuit connected in parallel with respect to the refrigerant flow.

[0194] In the high temperature side heat medium circuit 30 in the cooled outdoor air heat absorption heating mode, the control device 60 controls the operation of the high temperature side pump 31 in the same manner as in the single cooling mode.

[0195] In the low-temperature side heat medium circuit 40 in the cooled outdoor air heat absorption heating mode, the controller 60 controls the operation of the low-temperature side pump 41 in the same manner as in the cooling / cooling mode.

[0196] In the indoor air conditioning unit 50 in the cooling outdoor air heat absorption heating mode, the control device 60 controls the blowing capacity of the indoor blower 52, the opening degree of the air mix door 54, the inside / outside air switching device 53, and the operation of the blowing mode door, in the same way as in the single cooling mode. The control device 60 also controls the operation of other control target devices as appropriate.

[0197] Therefore, in the heat pump cycle 10 in the cooled outdoor air heat absorption heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser, and the outdoor heat exchanger 15 and the chiller 20 function as evaporators.

[0198] In the high temperature side heat medium circuit 30 in the cooled outside air heat absorption heating mode, the high temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0199] In the low-temperature side heat medium circuit 40 in the cooling outside air heat absorption heating mode, the low-temperature side heat medium cooled in the chiller 20 flows through the coolant passage 70a of the battery 70, thereby cooling the battery 70, as in the cooling / cooling mode.

[0200] In the interior air-conditioning unit 50 in the cooled outside air heat absorption heating mode, the temperature-adjusted blown air is blown into the vehicle compartment, as in the single outside air heat absorption heating mode, thereby heating the vehicle compartment.

[0201] (f) Outdoor air heat absorption hot gas heating mode The outdoor air heat absorption hot gas heating mode is an operation mode that is executed to suppress a decrease in the heating capacity of the blown air when it is determined that frost has formed on the outdoor heat exchanger 15 during the outdoor air heat absorption heating mode. In the control program of this embodiment, it is determined that frost has formed on the outdoor heat exchanger 15 when the same frosting conditions as those in the parallel hot gas dehumidifying heating mode are met.

[0202] The outdoor air heat absorption hot gas heating mode includes a single outdoor air heat absorption hot gas heating mode and a cooled outdoor air heat absorption hot gas heating mode. The single outdoor air heat absorption hot gas heating mode is executed when a frosting condition is met during the execution of the single outdoor air heat absorption heating mode. The cooled outdoor air heat absorption hot gas heating mode is executed when a frosting condition is met during the execution of the cooled outdoor air heat absorption heating mode.

[0203] (f-1) Single outdoor air heat absorption hot gas heating mode In the heat pump cycle 10 in the single outdoor air heat absorption hot gas heating mode, the controller 60 throttles the bypass side flow rate control valve 14d and throttles the cooling expansion valve 14c for the single outdoor air heat absorption heating mode.

[0204] Therefore, in the heat pump cycle 10 in the single outdoor air heat absorption hot gas heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the cooling outdoor air heat absorption heating mode. At the same time, a part of the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit that circulates through the bypass side flow control valve 14d in the throttled state, the chiller 20, the accumulator 23, and the suction port of the compressor 11 in that order.

[0205] Furthermore, the control device 60 appropriately controls the operation of other controlled devices. For example, the refrigerant discharge capacity of the compressor 11 is increased by a predetermined amount compared to the single outdoor air heat absorption heating mode. The control device 60 also controls the bypass side flow rate control valve 14d to a predetermined opening degree for the single outdoor air heat absorption hot gas heating mode. The control device 60 also stops the low temperature side pump. The other controlled devices are controlled in the same way as in the cooled outdoor air heat absorption heating mode.

[0206] Therefore, in the heat pump cycle 10 in the single outdoor air heat absorption hot gas heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser and the exterior heat exchanger 15 functions as an evaporator, similar to the cooling outdoor air heat absorption heating mode. However, in the single outdoor air heat absorption hot gas heating mode, frost forms on the exterior heat exchanger 15, so the refrigerant that flows into the exterior heat exchanger 15 can hardly absorb heat from the exterior air.

[0207] In the high temperature side heat medium circuit 30 in the single outdoor air heat absorption hot gas heating mode, the high temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0208] In the interior air conditioning unit 50 in the single outside air heat absorption hot gas heating mode, the blown air that has passed through the interior evaporator 18 is heated by the heater core 32 and blown into the vehicle interior. This realizes heating of the vehicle interior.

[0209] In the heat pump cycle 10 in the single outdoor air heat absorption hot gas heating mode, frost forms on the outdoor heat exchanger 15, so the amount of heat absorbed by the refrigerant from the outdoor air in the outdoor heat exchanger 15 is less than in the single outdoor air heat absorption heating mode.

[0210] Furthermore, the amount of heat dissipated from the refrigerant to the high-temperature side heat medium in the water-refrigerant heat exchanger 13 may decrease with the decrease in the amount of heat absorbed by the refrigerant from the outdoor air in the outdoor heat exchanger 15. As a result, the heating capacity of the heater core 32 for heating the blown air is likely to decrease.

[0211] In contrast, in the single outdoor air heat absorption hot gas heating mode of the present embodiment, the bypass side flow control valve 14d and the cooling expansion valve 14c are in a throttled state. As a result, as in the parallel hot gas dehumidification heating mode, the refrigerant with a relatively high enthalpy flowing out from the bypass side flow control valve 14d can be merged with the refrigerant with a relatively low enthalpy flowing out from the water-refrigerant heat exchanger 13.

[0212] Therefore, in the heat pump cycle 10 in the single outdoor air heat absorption hot gas heating mode, as in the parallel hot gas dehumidification heating mode, the refrigerant discharge capacity of the compressor 11 can be increased to suppress the reduction in the amount of heat dissipated from the refrigerant to the high-temperature side heat medium in the water-refrigerant heat exchanger 13.

[0213] As a result, in the single outdoor air heat absorption hot gas heating mode, even if frost forms on outdoor heat exchanger 15 while the single outdoor air heat absorption heating mode is being executed, a decrease in the heating capacity of the blown air can be suppressed.

[0214] (f-2) Cooling outdoor air heat absorption hot gas heating mode In the heat pump cycle 10 in the cooled outdoor air heat absorption hot gas heating mode, the refrigerant circulates in the same manner as in the cooled outdoor air heat absorption heating mode. Furthermore, the control device 60 appropriately controls the operation of other control target devices.

[0215] Therefore, in the heat pump cycle 10 in the cooled outdoor air heat absorption hot gas heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser, and the outdoor heat exchanger 15 and the chiller 20 function as evaporators.

[0216] In the high temperature side heat medium circuit 30 in the cooled outside air heat absorption hot gas heating mode, the high temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0217] In the low-temperature side heat medium circuit 40 in the cooled outside air heat absorption hot gas heating mode, the low-temperature side heat medium cooled in the chiller 20 flows through the coolant passage 70a of the battery 70, as in the cooling and air-conditioning mode, to cool the battery 70.

[0218] In the interior air conditioning unit 50 in the cooled outside air heat absorption hot gas heating mode, the blown air that has passed through the interior evaporator 18 is heated by the heater core 32 and blown into the vehicle interior. This realizes heating of the vehicle interior.

[0219] In the cooling outdoor air heat absorption hot gas dehumidification heating mode, frost forms on the outdoor heat exchanger 15, so the refrigerant that flows into the outdoor heat exchanger 15 can hardly absorb heat from the outdoor air. In contrast, in the cooling outdoor air heat absorption hot gas heating mode, the bypass side flow control valve 14d is in a throttled state, so a decrease in the heating capacity of the blown air can be suppressed, as in the single outdoor air heat absorption hot gas heating mode.

[0220] (g) Hot gas heating mode The hot gas heating mode is an operation mode for heating the vehicle interior when the outside air temperature Tam is extremely low (in this embodiment, less than -10°C). In the control program of this embodiment, the hot gas heating mode is selected when the outside air temperature Tam is extremely low and the air conditioner switch is not turned on (OFF).

[0221] The hot gas heating mode includes a hot gas mode in which the operation of the controlled equipment is controlled so that the blowing air temperature TAV approaches the target blowing temperature TAO, and the operation of the controlled equipment is controlled so that the intake refrigerant pressure Ps detected by the intake refrigerant temperature and pressure sensor 62f approaches the target low pressure PSO.

[0222] Therefore, in the hot gas heating mode, the hot gas mode control process shown in the flowchart of Fig. 4 is executed. More specifically, the flowchart shown in Fig. 4 is a control process executed as a subroutine in step S5 when an operation mode in which the hot gas mode control process is executed is selected in step S4 of the main routine.

[0223] First, in step S11 of Fig. 4, a target low pressure PSO, which is a target value of the suction refrigerant pressure Ps, is determined according to the selected operation mode. Therefore, step S11 is a target low pressure determination section. In step S11 of the hot gas heating mode, the target low pressure PSO is determined to be a predetermined target value for the hot gas heating mode.

[0224] Here, controlling the suction refrigerant pressure Ps to approach a constant value is effective for stabilizing the discharge flow rate Gr (mass flow rate) of the compressor 11. More specifically, by making the suction refrigerant pressure Ps a saturated gas-phase refrigerant with a constant pressure, the density of the suction refrigerant becomes constant. Therefore, controlling the suction refrigerant pressure Ps to approach a constant pressure makes it easier to stabilize the discharge flow rate Gr of the compressor 11 at the same rotation speed.

[0225] Next, in step S12, a target high pressure PDO, which is a target value of the discharge refrigerant pressure Pd detected by the discharge refrigerant temperature / pressure sensor 62a, is determined. Therefore, step S11 is a target high pressure determination section. In step S12, the target high pressure PDO is determined based on the target blown-out temperature TAO by referring to a control map stored in advance in the control device 60.

[0226] Next, in step S13, a target high-low pressure difference ΔP0 is determined, which is a target value of the high-low pressure difference ΔP. The target high-low pressure difference ΔP0 is a value obtained by subtracting the suction refrigerant pressure Ps from the discharge refrigerant pressure Pd. Thus, step S13 is a target high-low pressure difference determining section.

[0227] Here, in the control map for the hot gas heating mode, the target high pressure PDO is determined to increase with an increase in the target blowing temperature TAO. Furthermore, in the control map for the hot gas heating mode, the target high pressure PDO is determined so that the target high-low pressure difference ΔPO is equal to or greater than a predetermined reference high-low pressure difference ΔPmin. The reference high-low pressure difference ΔPmin is determined so that the workload of the compressor 11 is equal to or greater than a predetermined reference workload.

[0228] Next, in step S14, the operation of each controlled device is controlled in accordance with the selected operation mode, i.e., normal control in the hot gas mode is executed in accordance with the selected operation mode.

[0229] Next, in step S15, it is determined whether the heating capacity exhibited by the vehicle air conditioner 1 has reached a target heating capacity capable of raising the blown air temperature TAV to the target outlet temperature TAO.

[0230] If it is determined in step S15 that the heating capacity has reached the target heating capacity, the process returns to the main routine. If it is determined in step S15 that the heating capacity has not reached the target heating capacity, the process proceeds to step S16. In step S16, high pressure increase control is executed, and the process returns to the main routine.

[0231] In step S15 of this embodiment, when the blowing air temperature TAV is lower than the target blowing temperature TAO and the rotation speed of the compressor 11 (i.e., the refrigerant discharge capacity) is equal to or higher than a predetermined reference rotation speed (i.e., the reference capacity), it is determined that the heating capacity does not reach the target heating capacity. In this embodiment, the maximum rotation speed determined from the durability performance of the compressor 11 is used as the reference rotation speed.

[0232] Furthermore, in step S15 of this embodiment, when the blown air temperature TAV is lower than the target blowing temperature TAO and the throttle opening of the bypass side flow rate control valve 14d is equal to or smaller than a predetermined reference opening, it is determined that the heating capacity has not reached the target heating capacity. In this embodiment, the reference opening is set to the minimum opening that is controllably achievable by the control signal output from the control device 60.

[0233] Next, the normal control executed in step S14 in the hot gas heating mode will be described.

[0234] In the heat pump cycle 10 in the hot gas heating mode, the controller 60 fully closes the heating expansion valve 14a, fully closes the cooling expansion valve 14b, throttles the cooling expansion valve 14c, and throttles the bypass-side flow control valve 14d. The controller 60 also opens the dehumidification on-off valve 22a and closes the heating on-off valve 22b.

[0235] Therefore, in the heat pump cycle 10 in the hot gas heating mode, as shown by the solid arrow in Fig. 5, the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the water-refrigerant heat exchanger 13, the dehumidification passage 21b, the four-way joint 12x, the cooling expansion valve 14c in the throttled state, the sixth three-way joint 12f, the chiller 20, the accumulator 23, and the suction port of the compressor 11. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the order of the first three-way joint 12a, the bypass side flow control valve 14d in the throttled state arranged in the bypass passage 21a, the sixth three-way joint 12f, the chiller 20, the accumulator 23, and the suction port of the compressor 11.

[0236] Therefore, in the hot gas heating mode, the cooling expansion valve 14c serves as a heating section side pressure reducing section, and the sixth three-way joint 12f serves as a mixing section.

[0237] Furthermore, the control device 60 appropriately controls the operation of other controlled devices. Specifically, for the compressor 11, the control device 60 controls the refrigerant discharge capacity (i.e., the rotation speed) of the compressor 11 so that the suction refrigerant pressure Ps approaches the target low pressure PSO.

[0238] The control device 60 also adjusts the throttle opening of the cooling expansion valve 14c so that the degree of subcooling SC1 of the refrigerant flowing out of the water-refrigerant heat exchanger 13 approaches a first target degree of subcooling SCO1. The degree of subcooling SC1 can be obtained from the high-pressure side refrigerant temperature T1 and the high-pressure side refrigerant pressure P1 detected by the high-pressure side refrigerant temperature and pressure sensor 62b. The first target degree of subcooling SCO1 is determined by referring to a control map stored in advance in the control device 60.

[0239] Furthermore, the control device 60 adjusts the throttle opening of the bypass-side flow rate adjustment valve 14d so that the high-low pressure difference ΔP approaches the target high-low pressure difference ΔP. More specifically, in this embodiment, the throttle opening of the bypass-side flow rate adjustment valve 14d is adjusted so that the high-low pressure difference ΔP becomes equal to or larger than the target high-low pressure difference ΔP.

[0240] As described above, the target high-low pressure difference ΔPO is determined using the target high pressure PDO that correlates with the target outlet temperature TAO. Therefore, adjusting the throttle opening of the bypass-side flow control valve 14d so that the high-low pressure difference ΔP approaches the target high-low pressure difference ΔPO means adjusting the throttle opening of the bypass-side flow control valve 14d so that the blown air temperature TAV approaches the target outlet temperature TAO.

[0241] In the high-temperature side heat medium circuit 30 in the hot gas heating mode, the control device 60 controls the operation of the high-temperature side pump 31 in the same manner as in the single cooling mode.

[0242] Furthermore, in the low-temperature side heat medium circuit 40 in the hot gas heating mode, the control device 60 stops the low-temperature side pump 41.

[0243] In the indoor air conditioning unit 50 in the hot gas heating mode, the control device 60 controls the opening degree of the air mix door 54 in the same manner as in the single cooling mode. In the hot gas heating mode, the control device 60 often controls the opening degree of the air mix door 54 so that almost the entire amount of the air blown from the indoor blower 52 passes through the heater core 32.

[0244] The control device 60 also controls the operation of the inside / outside air switching device 53 so as to introduce inside air into the air conditioning case 51. Similarly to the single cooling mode, the control device 60 also controls the blowing capacity of the indoor blower 52, the opening degree of the air mix door 54, and the operation of the blowing mode door.

[0245] Therefore, in the heat pump cycle 10 in the hot gas heating mode, the state of the refrigerant changes as shown by the thick solid line in the Mollier diagram of FIG.

[0246] That is, the flow of the discharged refrigerant (point ah in FIG. 6) discharged from the compressor 11 is branched at the first three-way joint 12a. One of the refrigerants branched at the first three-way joint 12a flows into the water-refrigerant heat exchanger 13 and dissipates heat to the high-temperature side heat medium (from point ah to point bh in FIG. 6). This heats the high-temperature side heat medium.

[0247] The refrigerant flowing out of the water-refrigerant heat exchanger 13 flows into the dehumidification passage 21b. Since the cooling expansion valve 14b is in a fully closed state, the refrigerant that has flowed into the dehumidification passage 21b flows into the cooling expansion valve 14c and is reduced in pressure (from point bh to point ch in FIG. 6). The refrigerant with a relatively low enthalpy that has flowed out of the cooling expansion valve 14c flows into the other inlet of the sixth three-way joint 12f.

[0248] The other refrigerant branched at the first three-way joint 12a flows into the bypass passage 21a. The refrigerant flowing into the bypass passage 21a is flow-regulated and depressurized by the bypass-side flow control valve 14d (from point ah to point dh in FIG. 6). The refrigerant with a relatively high enthalpy depressurized by the bypass-side flow control valve 14d flows into one inlet of the sixth three-way joint 12f.

[0249] The refrigerant flowing out from the bypass-side flow control valve 14d and the refrigerant flowing out from the cooling expansion valve 14c are mixed in the sixth three-way joint 12f. The refrigerant flowing out from the sixth three-way joint 12f flows into the chiller 20. In the hot gas heating mode, the low-temperature side pump 41 is stopped, so the refrigerant flowing into the chiller 20 is mixed homogeneously in the chiller 20 without exchanging heat with the low-temperature side heat medium when flowing through the refrigerant passage of the chiller 20 (point eh in FIG. 6).

[0250] The refrigerant flowing out from the refrigerant passage of the chiller 20 flows into the accumulator 23. The gas-phase refrigerant separated in the accumulator 23 is sucked into the compressor 11 and compressed again.

[0251] In the high-temperature side heat medium circuit 30 in the hot gas heating mode, the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0252] In the interior air conditioning unit 50 in the hot gas heating mode, the blown air that has passed through the interior evaporator 18 is heated by the heater core 32 and blown out into the vehicle compartment, thereby achieving heating of the vehicle compartment.

[0253] Here, the hot gas heating mode is an operation mode that is executed when the outdoor air temperature Tam is extremely low. Therefore, when the refrigerant that flows out of the water-refrigerant heat exchanger 13 flows into the outdoor heat exchanger 15, the refrigerant may dissipate heat to the outdoor air in the outdoor heat exchanger 15. If the refrigerant dissipates heat to the outdoor air, the amount of heat that the refrigerant dissipates to the blown air in the water-refrigerant heat exchanger 13 decreases, and the heating capacity of the blown air decreases.

[0254] In contrast, in the hot gas heating mode of this embodiment, a refrigerant circuit is provided that does not allow the refrigerant flowing out of the water-refrigerant heat exchanger 13 to flow into the outdoor heat exchanger 15, thereby preventing the refrigerant from releasing heat to the outside air in the outdoor heat exchanger 15. Therefore, in the hot gas heating mode, the heat generated by the work of the compressor 11 can be effectively used to heat the blown air.

[0255] Next, the high pressure increase control executed in step S16 in the hot gas heating mode will be described.

[0256] In the high pressure increase control of this embodiment, control is performed to increase the degree of subcooling of the refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 13. More specifically, in step S16, the throttle opening of the cooling expansion valve 14c, which is the heating section side pressure reducing section, is reduced from the throttle opening determined in step S14. The operating states determined in step S14 are maintained for the other controlled devices.

[0257] Therefore, in the heat pump cycle 10 under high pressure rise control, the state of the refrigerant changes as shown by the thick dashed line in the Mollier diagram in Fig. 6. That is, since the throttle opening of the cooling expansion valve 14c is reduced, the pressure of the refrigerant discharged from the compressor 11 (point ah6 in Fig. 6) increases more than that during normal control.

[0258] Therefore, one of the refrigerants branched at the first three-way joint 12a flows into the water-refrigerant heat exchanger 13 and dissipates heat to the high-temperature side heat medium at a pressure higher than that in normal control (from point ah6 to point bh6 in FIG. 6). As a result, the high-temperature side heat medium is heated to a temperature higher than that in normal control. The refrigerant flowing out of the water-refrigerant heat exchanger 13 flows into the cooling expansion valve 14c and is reduced in pressure (from point bh6 to point ch in FIG. 6).

[0259] The other refrigerant branched at the first three-way joint 12a is flow-regulated and decompressed at the bypass-side flow control valve 14d of the bypass passage 21a (from point ah6 to point dh6 in FIG. 6). The refrigerant flowing out from the bypass-side flow control valve 14d and the refrigerant flowing out from the cooling expansion valve 14c are mixed at the sixth three-way joint 12f.

[0260] Other operations are the same as those of the normal control. Therefore, in the high pressure rise control, the temperature of the high temperature side heat medium can be increased more than in the normal control. This increases the temperature of the blown air heated by the heater core 32, and makes it possible to bring the blown air temperature TAV closer to the target blown air temperature TAO.

[0261] (h) Temperature-controlled hot gas heating mode The temperature regulated hot gas heating mode is an operation mode that regulates the temperature of the battery 70 while the hot gas heating mode is being executed. The temperature regulated hot gas heating mode includes a cooling hot gas heating mode that cools the battery 70, and a warming hot gas heating mode that warms the battery 70.

[0262] In the control program of this embodiment, when the hot gas heating mode is being executed, the cooling hot gas heating mode is selected when the battery temperature TB is equal to or higher than the reference upper limit temperature KTBH and the intake refrigerant temperature Ts is lower than the low-temperature side heat medium temperature TWL detected by the low-temperature side heat medium temperature sensor 63b.

[0263] In addition, in the control program of this embodiment, when the hot gas heating mode is being executed, the warm-up hot gas heating mode is selected when the battery temperature TB is below the reference lower limit temperature KTBL and the intake refrigerant temperature Ts is higher than the low-temperature side heat medium temperature TWL.

[0264] The temperature regulated hot gas heating mode is included in the hot gas mode, and therefore, in the temperature regulated hot gas heating mode, the control process of the hot gas mode is executed.

[0265] (h-1) Cooling hot gas heating mode In the normal control executed in step S14 in the cooling hot gas heating mode, the controller 60 operates the low-temperature side pump 41 so as to exert a predetermined reference pumping capacity for the hot gas heating mode. The other operations are the same as those in the hot gas heating mode.

[0266] Therefore, in the cooled hot gas heating mode, the heat generated by the work of the compressor 11 can be effectively used to heat the blown air. Also, when the heating capacity has not reached the target heating capacity, the blown air temperature TAV can be brought closer to the target blown air temperature TAO by executing the high pressure increase control, as in the hot gas heating mode.

[0267] Furthermore, in the heat pump cycle 10 in the cooling hot gas heating mode, the refrigerant flowing into the chiller 20 absorbs heat from the low-temperature side heat medium. This cools the low-temperature side heat medium. In the low-temperature side heat medium circuit 40 in the cooling hot gas heating mode, the low-temperature side heat medium cooled by the chiller 20 flows through the coolant passage 70a of the battery 70. This allows the battery 70 to be cooled.

[0268] (h-2) Warm-up hot gas heating mode In the normal control executed in step S14 in the warm-up hot gas heating mode, the controller 60 operates the low-temperature side pump 41 so as to exert a predetermined reference pumping capacity for the hot gas heating mode. The other operations are the same as those in the hot gas heating mode.

[0269] Therefore, in the warm-up hot gas heating mode, the heat generated by the work of the compressor 11 can be effectively used to heat the blown air. Also, when the heating capacity has not reached the target heating capacity, the blown air temperature TAV can be made to approach the target blown air temperature TAO by executing the high pressure increase control, as in the hot gas heating mode.

[0270] Furthermore, in the heat pump cycle 10 in the warm-up hot gas heating mode, the refrigerant that has flowed into the chiller 20 releases heat to the low-temperature side heat medium. This heats the low-temperature side heat medium. In the low-temperature side heat medium circuit 40 in the warm-up hot gas heating mode, the low-temperature side heat medium heated by the chiller 20 flows through the coolant passage 70a of the battery 70. This allows the battery 70 to be warmed up.

[0271] (i) Hot gas dehumidification heating mode The hot gas dehumidifying and heating mode is an operating mode that performs dehumidifying and heating inside the vehicle cabin when the outside air temperature Tam is low. In the control program of this embodiment, the hot gas dehumidifying and heating mode is selected when the outside air temperature Tam is in the low to medium temperature range (in this embodiment, 0°C or higher and lower than 10°C) and the air conditioner switch is turned on (ON).

[0272] The hot gas dehumidifying and heating mode is included in the hot gas mode. Therefore, in the hot gas dehumidifying and heating mode, the control process of the hot gas mode is executed. The hot gas dehumidifying and heating mode includes a single hot gas dehumidifying and heating mode in which the vehicle interior is dehumidified and heated without cooling the battery 70, and a cooled hot gas dehumidifying and heating mode in which the battery 70 is cooled and the vehicle interior is dehumidified and heated.

[0273] (i-1) Single hot gas dehumidification heating mode First, normal control executed in step S14 in the single hot gas dehumidification heating mode will be described. In the heat pump cycle 10 in the single hot gas dehumidification heating mode, the control device 60 fully closes the heating expansion valve 14a, throttles the cooling expansion valve 14b, throttles the cooling expansion valve 14c, and throttles the bypass side flow control valve 14d. The control device 60 also opens the dehumidification opening / closing valve 22a and closes the heating opening / closing valve 22b.

[0274] Therefore, in the heat pump cycle 10 in the single hot gas dehumidification heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the hot gas heating mode, as shown by the solid arrows in Fig. 7. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which the refrigerant circulates in the order of the first three-way joint 12a, the water-refrigerant heat exchanger 13, the dehumidification passage 21b, the four-way joint 12x, the cooling expansion valve 14b in the throttled state, the indoor evaporator 18, the evaporation pressure control valve 19, the accumulator 23, and the suction port of the compressor 11.

[0275] Therefore, in the single hot gas dehumidifying and heating mode, the cooling expansion valve 14c serves as a heating section side pressure reducing section, and the sixth three-way joint 12f serves as a mixing section.

[0276] Furthermore, the control device 60 appropriately controls the operation of other controlled devices. Specifically, for the compressor 11, the control device 60 controls the refrigerant discharge capacity (i.e., the rotation speed) of the compressor 11 so that the suction refrigerant pressure Ps approaches the target low pressure PSO. In step S11 of the single hot gas dehumidifying heating mode, the control device 60 refers to a control map stored in advance in the control device 60 to determine the target low pressure PSO.

[0277] In addition, the control device 60 adjusts the throttle opening of the cooling expansion valve 14c so that the degree of subcooling SC1 of the refrigerant flowing out from the water-refrigerant heat exchanger 13 approaches a second target degree of subcooling SCO2. The second target degree of subcooling SCO2 is determined by referring to a control map stored in advance in the control device 60.

[0278] Furthermore, the control device 60 adjusts the throttle opening of the bypass-side flow rate adjustment valve 14d so that the high-low pressure difference ΔP approaches the target high-low pressure difference ΔP. More specifically, in this embodiment, the throttle opening of the bypass-side flow rate adjustment valve 14d is adjusted so that the high-low pressure difference ΔP becomes equal to or larger than the target high-low pressure difference ΔP.

[0279] In the high-temperature side heat medium circuit 30 in the single hot gas dehumidifying heating mode, the control device 60 controls the operation of the high-temperature side pump 31 in the same manner as in the single cooling mode.

[0280] In addition, in the low-temperature side heat medium circuit 40 in the single hot gas dehumidification heating mode, the control device 60 stops the low-temperature side pump 41.

[0281] In the indoor air conditioning unit 50 in the single hot gas dehumidifying heating mode, the control device 60 controls the opening degree of the air mix door 54 in the same manner as in the single cooling mode. The control device 60 also controls the operation of the inside / outside air switching device 53 so as to introduce inside air into the air conditioning case 51. The control device 60 also controls the blowing capacity of the indoor blower 52, the opening degree of the air mix door 54, and the operation of the blowing mode door in the same manner as in the single cooling mode.

[0282] Therefore, in the heat pump cycle 10 in the single hot gas dehumidification heating mode, the state of the refrigerant changes as shown in the Mollier diagram of FIG.

[0283] That is, the flow of the discharged refrigerant (point ah8 in FIG. 8) discharged from the compressor 11 is branched at the first three-way joint 12a. One of the refrigerants branched at the first three-way joint 12a flows into the water-refrigerant heat exchanger 13 and dissipates heat to the high temperature side heat medium (from point ah8 to point bh8 in FIG. 8).

[0284] The refrigerant flowing out of the water-refrigerant heat exchanger 13 passes through the dehumidification passage 21b and flows into one inlet of the four-way joint 12x.

[0285] The refrigerant flowing out from one outlet of the four-way joint 12x flows into the cooling expansion valve 14b and is reduced in pressure (from point bh8 to point fh8 in FIG. 8). The refrigerant reduced in pressure by the cooling expansion valve 14b flows into the indoor evaporator 18.

[0286] The refrigerant that has flowed into the indoor evaporator 18 evaporates through heat exchange with the air (indoor air in this embodiment) blown from the indoor blower 52 (from point fh8 to point eh8 in FIG. 8). As a result, the air blown from the indoor blower 52 is cooled and dehumidified. The refrigerant that has flowed out of the indoor evaporator 18 flows into the fifth three-way joint 12e via the second check valve 16b.

[0287] The refrigerant flowing out from another outlet of the four-way joint 12x flows into the cooling expansion valve 14c and is depressurized (from point bh8 to point ch8 in FIG. 8), similar to the hot gas heating mode. The refrigerant depressurized by the cooling expansion valve 14c flows into the other inlet of the sixth three-way joint 12f, similar to the hot gas heating mode.

[0288] Here, in Fig. 8, for clarity of illustration, the pressure of the refrigerant decompressed by the cooling expansion valve 14c (point ch8 in Fig. 8) is set to a value higher than the pressure of the refrigerant decompressed by the cooling expansion valve 14b (point fh8 in Fig. 8), but is not limited to this. The pressure of the refrigerant decompressed by the cooling expansion valve 14c may be lower than or equal to the pressure of the refrigerant decompressed by the cooling expansion valve 14b.

[0289] The other refrigerant branched off at the first three-way joint 12a is flow-regulated and decompressed by the bypass-side flow control valve 14d arranged in the bypass passage 21a (from point ah8 to point dh8 in FIG. 8). The refrigerant decompressed by the bypass-side flow control valve 14d flows into one inlet of the sixth three-way joint 12f, as in the hot gas heating mode.

[0290] The refrigerant flowing out from the bypass-side flow control valve 14d and the refrigerant flowing out from the cooling expansion valve 14c are mixed in the sixth three-way joint 12f, as in the hot gas heating mode. Furthermore, the refrigerant flowing into the chiller 20 from the sixth three-way joint 12f is mixed homogeneously in the chiller 20 (point eh8 in FIG. 8). The refrigerant flowing out from the chiller 20 flows into the fifth three-way joint 12e.

[0291] At the fifth three-way joint 12e, the flow of the refrigerant flowing out from the indoor evaporator 18 and the flow of the refrigerant flowing out from the chiller 20 join together. The refrigerant flowing out from the fifth three-way joint 12e flows into the accumulator 23. The gas-phase refrigerant separated in the accumulator 23 is sucked into the compressor 11 and compressed again.

[0292] In the high-temperature side heat medium circuit 30 in the single hot gas dehumidification heating mode, the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0293] In the interior air conditioning unit 50 in the single hot gas dehumidifying and heating mode, the blown air cooled and dehumidified by the interior evaporator 18 is reheated by the heater core 32 and blown into the vehicle cabin. This realizes dehumidifying and heating the vehicle cabin.

[0294] In the single hot gas dehumidifying and heating mode, like the hot gas heating mode, the heat generated by the work of the compressor 11 can be effectively used to heat the blown air. Furthermore, in the single hot gas dehumidifying and heating mode, the heat absorbed by the refrigerant from the blown air in the indoor evaporator 18 can be used to reheat the blown air.

[0295] Furthermore, when the heating capacity has not reached the target heating capacity, the high pressure increase control is executed in the same manner as in the hot gas heating mode, so that the blown air temperature TAV can be made to approach the target blown air temperature TAO.

[0296] (i-2) Cooling hot gas dehumidification heating mode In the heat pump cycle 10 in the cooling hot gas dehumidification heating mode, the refrigerant circulates in the same manner as in the single hot gas dehumidification heating mode.

[0297] In the high-temperature side heat medium circuit 30 in the cooled hot gas dehumidification heating mode, the control device 60 controls the operation of the high-temperature side pump 31 in the same manner as in the single cooling mode.

[0298] In the low-temperature side heat medium circuit 40 in the cooling hot gas dehumidification heating mode, the control device 60 controls the low-temperature side pump 41 Operation To make.

[0299] In the indoor air conditioning unit 50 in the cooling hot gas dehumidification heating mode, the control device 60 controls the blowing capacity of the indoor blower 52, the opening of the air mix door 54, the inside / outside air switching device 53, and the operation of the blowing mode door, in the same way as in the single hot gas dehumidification heating mode. In addition, the control device 60 appropriately controls the operation of other control target devices, in the same way as in the single hot gas dehumidification heating mode.

[0300] Therefore, in the heat pump cycle 10 in the cooling hot gas dehumidification heating mode, the water-refrigerant heat exchanger 13 functions as a condenser, the indoor evaporator 18 functions as well as the single hot gas dehumidification heating mode. Furthermore, the chiller 20 functions as an evaporator.

[0301] In the high-temperature side heat medium circuit 30 in the cooling hot gas dehumidification heating mode, the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 is pumped and sent to the heater core 32, similarly to the single cooling mode.

[0302] In the low-temperature side heat medium circuit 40 in the cooling hot gas dehumidification heating mode, the low-temperature side heat medium cooled in the chiller 20 flows through the coolant passage 70a of the battery 70, thereby cooling the battery 70, as in the cooling and air-conditioning mode.

[0303] In the cooling hot gas dehumidifying heating mode, as in the single hot gas dehumidifying heating mode, the heat generated by the work of the compressor 11 can be effectively used to heat the blown air. Furthermore, in the cooling hot gas dehumidifying heating mode, the heat absorbed by the refrigerant from the blown air in the indoor evaporator 18 can be used to reheat the blown air.

[0304] Furthermore, when the heating capacity has not reached the target heating capacity, the high pressure increase control is executed in the same manner as in the hot gas heating mode, so that the blown air temperature TAV can be made to approach the target blown air temperature TAO.

[0305] As described above, in the vehicle air conditioner 1 of this embodiment, by switching the operation mode, it is possible to perform comfortable air conditioning for the vehicle interior and appropriate temperature adjustment of the battery 70, which is an on-board device.

[0306] In the hot gas heating mode, temperature controlled hot gas heating mode, and hot gas dehumidification heating mode of the vehicle air conditioner 1 of this embodiment, the blown air, which is the object to be heated, is heated mainly using heat generated by the work of the compressor 11. For this reason, in the hot gas heating mode and the like, in order to stabilize the operation of the cycle, it is necessary to appropriately control the operation of the controlled devices so that the amount of work of the compressor 11 is an appropriate amount of heat for heating the blown air.

[0307] The reason for this is that, for example, if the workload of the compressor 11 is greater than the amount of heat required to heat the blown air, the discharge refrigerant pressure Pd will continue to rise, and it may become impossible to operate the cycle stably.

[0308] Therefore, in the hot gas heating mode and the like of this embodiment, a control process for the hot gas mode is executed. In the control process for the hot gas mode, the rotation speed of the compressor 11 is controlled so that the suction refrigerant pressure Ps approaches the target low pressure PSO. Furthermore, the throttle opening of the bypass side flow rate control valve 14d is adjusted so that the high-low pressure difference ΔP approaches the target high-low pressure difference ΔPO.

[0309] According to this, the discharge refrigerant pressure Pd and the suction refrigerant pressure Ps can be adjusted so that the workload of the compressor 11 is an appropriate amount of heat for heating the blown air. This is because the workload of the compressor 11 is determined by the high-low pressure difference ΔP. Therefore, by executing the control process in the hot gas mode, the operation of the cycle of It can be stabilized.

[0310] On the other hand, even if the operation of the cycle is stabilized, if the actual discharge refrigerant pressure Pd cannot be increased sufficiently when the outside air temperature Tam is extremely low, the discharge refrigerant temperature Td cannot be increased to a desired temperature, and as a result, it may not be possible to increase the blown air temperature TAV to the target blown air temperature TAO.

[0311] In contrast, in the hot gas heating mode and the like of this embodiment, when it is determined that the heating capacity of the air blown by the vehicle air conditioner 1 does not reach the target heating capacity, the high pressure increase control is executed. This makes it possible to increase the discharge refrigerant pressure Pd and the discharge refrigerant temperature Td. Therefore, it is possible to expand the temperature adjustment range of the blown air.

[0312] In addition, in the high pressure increase control of the vehicle air conditioner 1 of this embodiment, the degree of subcooling of the refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 13 is increased more than in the normal control of the hot gas mode. This reduces the heat exchange efficiency in the water-refrigerant heat exchanger 13, and reliably increases the discharge refrigerant pressure Pd.

[0313] Furthermore, in this embodiment, the degree of subcooling of the refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 13 is increased by reducing the throttle opening of the cooling expansion valve 14c. Therefore, the high pressure rise control can be realized without requiring a new configuration or complex control for executing the high pressure rise control.

[0314] In addition, in the vehicle air conditioner 1 of this embodiment, when the blowing air temperature TAV is lower than the target blowing temperature TAO and the rotation speed of the compressor 11 is equal to or higher than the maximum rotation speed, it is determined that the heating capacity does not reach the target heating capacity. This makes it possible to effectively execute the high pressure increase control to increase the blowing air temperature TAV when it becomes impossible to increase the rotation speed of the compressor 11.

[0315] In the vehicle air conditioner 1 of this embodiment, when the blown air temperature TAV is lower than the target blown air temperature TAO and the throttle opening of the bypass side flow rate control valve 14d is equal to or smaller than the minimum opening, it is determined that the heating capacity does not reach the target heating capacity. This makes it possible to effectively execute the high pressure increase control to increase the blown air temperature TAV when it becomes impossible to reduce the throttle opening of the bypass side flow rate control valve 14d.

[0316] The control process of the hot gas mode may be applied to the parallel hot gas dehumidification heating mode and the outdoor air heat absorption hot gas heating mode. In the parallel hot gas dehumidification heating mode and the outdoor air heat absorption hot gas heating mode, frost forms on the outdoor heat exchanger 15, so the refrigerant cannot absorb heat from the outdoor air in the outdoor heat exchanger 15. In other words, the outdoor heat exchanger 15 is equivalent to a refrigerant passage.

[0317] Therefore, when the hot gas mode control process is applied in the parallel dehumidification hot gas heating mode and the outdoor air heat absorption hot gas heating mode, the heating expansion valve 14a becomes the heating section side pressure reducing section, and the fifth three-way joint 12e becomes the mixing section. Therefore, in the high pressure rise control, the throttle opening of the heating expansion valve 14a may be reduced from the throttle opening determined in step S14.

[0318] Second embodiment In this embodiment, an example will be described in which the control process for the high pressure rise control described in step S16 of FIG. 4 in the first embodiment is modified.

[0319] In the high pressure rise control of this embodiment, the flow rate of the object to be heated flowing into the heating section is reduced compared to the normal control in the hot gas mode. More specifically, in step S16 of this embodiment, the opening degree of the air mix door 54 is changed to the side that reduces the amount of air passing through the heater core 32 compared to the opening degree determined in step S14. The operation of the other controlled devices is the same as in the first embodiment.

[0320] Therefore, in the heat pump cycle 10 in the hot gas heating mode of this embodiment, the state of the refrigerant changes as shown by the thick solid line in the Mollier diagram of Fig. 9. That is, in normal control in the hot gas mode, the state of the refrigerant changes in exactly the same way as in the first embodiment.

[0321] In addition, in the high pressure rise control of this embodiment, the temperature of the high temperature side heat medium flowing out of the heater core 32 and flowing into the water-refrigerant heat exchanger 13 becomes higher than that in the normal control. Therefore, the load on the water-refrigerant heat exchanger 13 decreases, and the pressure of the refrigerant flowing through the refrigerant passage of the water-refrigerant heat exchanger 13 becomes balanced at a higher pressure than that in the normal control (from point ah9 to point bh9 in FIG. 9), as shown by the thick dashed line in the Mollier diagram of FIG.

[0322] The refrigerant flowing out of the water-refrigerant heat exchanger 13 flows into the cooling expansion valve 14c and is reduced in pressure (see FIG. 9). b At this time, the throttle opening of the cooling expansion valve 14c is controlled in the same manner as in normal control, based on the refrigerant flowing out of the water-refrigerant heat exchanger 13 ( b The degree of supercooling at point h9) is adjusted to approach the first target degree of supercooling SCO1.

[0323] The other refrigerant branched at the first three-way joint 12a is flow-regulated and decompressed at the bypass-side flow control valve 14d of the bypass passage 21a (from point ah9 to point dh9 in FIG. 9). The refrigerant flowing out from the bypass-side flow control valve 14d and the refrigerant flowing out from the cooling expansion valve 14c are mixed at the sixth three-way joint 12f.

[0324] Other operations are the same as those of the first embodiment. In the high pressure rise control, the temperature of the high temperature side heat medium can be increased more than in the normal control. This increases the temperature of the blown air heated by the heater core 32, and makes it possible to bring the blown air temperature TAV closer to the target blown air temperature TAO. Therefore, even if the control process of the high pressure rise control is changed as in this embodiment, the same effects as those of the first embodiment can be obtained.

[0325] The control for reducing the flow rate of the object to be heated flowing into the heating section compared to the normal control in the hot gas mode, such as the high pressure rise control of the present embodiment, is not limited to adjusting the opening degree of the air mix door 54. For example, the rotation speed (i.e., the blowing capacity) of the indoor blower 52 may be reduced. In addition, in a configuration in which the high-temperature side heat medium is circulated in the high-temperature side heat medium circuit 30 as in the heating section of this embodiment, control for reducing the flow rate of the high-temperature side heat medium compared to normal control in the hot gas mode may be adopted as the high-pressure increase control. Specifically, the flow rate of the high-temperature side heat medium may be reduced by lowering the rotation speed (i.e., pumping capacity) of the high-pressure side pump compared to normal control in the hot gas mode.

[0326] Furthermore, the high pressure rise control to be executed may be changed in response to a user request. For example, when the user sets the air volume of the indoor blower 52 using the air volume setting switch, the high pressure rise control may be executed to change the opening degree of the air mix door 54. On the other hand, when the user does not set the air volume of the indoor blower 52 using the air volume setting switch, the high pressure rise control may be executed to reduce the rotation speed of the indoor blower 52.

[0327] Third embodiment In this embodiment, the heat pump cycle device according to the present disclosure is applied to a vehicle air conditioner 1a. The vehicle air conditioner 1a includes a heat pump cycle 10a. In the heat pump cycle 10a, the accumulator 23 and the like are eliminated from the heat pump cycle 10 described in the first embodiment, and a receiver 24 and the like are adopted.

[0328] In the heat pump cycle 10a, the inlet side of the receiver 24 is connected to the other outlet of the second three-way joint 12b. The refrigerant passage from the other outlet of the second three-way joint 12b to the inlet of the receiver 24 is the inlet-side passage 21d. The first inlet-side opening / closing valve 22c, the seventh three-way joint 12g, and the subcooling expansion valve 14e are arranged in the inlet-side passage 21d.

[0329] The receiver 24 is a high-pressure side gas-liquid separator that separates the refrigerant that has flowed into it into gas and liquid and stores the separated liquid-phase refrigerant as surplus refrigerant for the cycle. The receiver 24 allows a portion of the separated liquid-phase refrigerant to flow downstream from a liquid-phase refrigerant outlet.

[0330] The first inlet side on-off valve 22c is an on-off valve that opens and closes the inlet side passage 21d. More specifically, the first inlet side on-off valve 22c opens and closes the refrigerant passage in the inlet side passage 21d that extends from the other outlet of the second three-way joint 12b to one inlet of the seventh three-way joint 12g. The first inlet side on-off valve 22c is a refrigerant circuit switching unit.

[0331] The subcooling expansion valve 14e is a receiver-side pressure reducing unit that reduces the pressure of the refrigerant flowing into the receiver 24 during high pressure increase control in the hot gas heating mode, etc. Furthermore, the subcooling expansion valve 14e is a receiver-side flow rate adjusting unit that adjusts the flow rate (mass flow rate) of the refrigerant flowing into the receiver 24.

[0332] Further, one of the outlets of the second three-way joint 12b is connected to one of the inlet sides of the eighth three-way joint 12h. A second inlet side opening / closing valve 22d is disposed in the refrigerant passage extending from one of the outlets of the second three-way joint 12b to one of the inlet sides of the eighth three-way joint 12h. The second inlet side opening / closing valve 22d opens and closes the refrigerant passage extending from one of the outlets of the second three-way joint 12b to one of the inlet sides of the eighth three-way joint 12h. The second inlet side opening / closing valve 22d is a refrigerant circuit switching unit.

[0333] The inlet side of the heating expansion valve 14a is connected to the outlet of the eighth three-way joint 12h. The other inlet side of the seventh three-way joint 12g arranged in the inlet-side passage 21d is connected to one outlet of the third three-way joint 12c connected to the outlet side of the outdoor heat exchanger 15 via the first check valve 16a.

[0334] The other inlet side of the eighth three-way joint 12h is connected to the liquid phase refrigerant outlet of the receiver 24. The refrigerant passage leading from the outlet of the receiver 24 to the other inlet of the eighth three-way joint 12h is the outlet-side passage 21e. The ninth three-way joint 12i and the third check valve 16c are arranged in the outlet-side passage 21e.

[0335] The third check valve 16c allows the refrigerant to flow from the ninth three-way joint 12i side to the eighth three-way joint 12h side and prohibits the refrigerant from flowing from the eighth three-way joint 12h side to the ninth three-way joint 12i side.

[0336] The other outlet of the ninth three-way joint 12i is connected to the inlet side of a tenth three-way joint 12j. The refrigerant inlet side of an indoor evaporator 18 is connected to one outlet of the tenth three-way joint 12j via a cooling expansion valve 14b. The other outlet of the tenth three-way joint 12j is connected to the inlet side of a refrigerant passage of a chiller 20 via a cooling expansion valve 14c.

[0337] Furthermore, in the heat pump cycle 10a, the outlet of the fifth three-way joint 12e is connected to the suction port side of the compressor 11. The rest of the configuration of the vehicle air conditioner 1a is similar to that of the vehicle air conditioner 1 described in the first embodiment.

[0338] Next, the operation of the vehicle air conditioner 1a of this embodiment with the above configuration will be described. In the vehicle air conditioner 1a of this embodiment, various operation modes are switched in the same manner as in the first embodiment in order to condition the air in the vehicle cabin and adjust the temperature of the battery 70. The detailed operation of each operation mode will be described below.

[0339] (a-1) Single cooling mode In the heat pump cycle 10a in the cooling only mode, the control device 60 fully opens the heating expansion valve 14a, throttles the cooling expansion valve 14b, fully closes the cooling expansion valve 14c, fully closes the bypass flow control valve 14d, and fully opens the supercooling expansion valve 14e. The control device 60 also closes the heating on-off valve 22b, closes the first inlet on-off valve 22c, and opens the second inlet on-off valve 22d.

[0340] Therefore, in the heat pump cycle 10a in the cooling only mode, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the following order: the water-refrigerant heat exchanger 13, the heating expansion valve 14a which is in a fully open state, the outdoor heat exchanger 15, the subcooling expansion valve 14e which is in a fully open state, the receiver 24, the cooling expansion valve 14b which is in a throttled state, the indoor evaporator 18, and the suction port of the compressor 11.

[0341] Furthermore, the control device 60 appropriately controls the operation of other control target devices in the same manner as in the single cooling mode of the first embodiment.

[0342] Therefore, in the heat pump cycle 10a in the sole cooling mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 and the outdoor heat exchanger 15 function as a condenser, and the indoor evaporator 18 functions as an evaporator. Also, the high temperature side heat medium circuit 30 and the indoor air conditioning unit 50 operate in the same manner as in the sole cooling mode of the first embodiment.

[0343] As a result, in the single cooling mode, cooling of the vehicle interior is achieved in the same manner as in the single cooling mode of the first embodiment.

[0344] (a-2) Cooling mode In the heat pump cycle 10a in the cooling / air-cooling mode, the controller 60 controls the cooling expansion valve 14c to be in the throttling state in contrast to the single cooling mode.

[0345] Therefore, in the heat pump cycle 10a in the cooling / cooling mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single cooling mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the order of the water-refrigerant heat exchanger 13, the heating expansion valve 14a in the fully open state, the outdoor heat exchanger 15, the supercooling expansion valve 14e in the fully open state, the receiver 24, the cooling expansion valve 14c in the throttled state, the chiller 20, and the suction port of the compressor 11. In other words, the indoor evaporator 18 and the chiller 20 are switched to a refrigerant circuit in which they are connected in parallel with respect to the flow of the refrigerant.

[0346] Furthermore, the control device 60 appropriately controls the operation of other control target devices in the same manner as in the cooling / air-cooling mode of the first embodiment.

[0347] Therefore, in the heat pump cycle 10a in the cooling / air-conditioning mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 and the outdoor heat exchanger 15 function as condensers, and the indoor evaporator 18 and the chiller 20 function as evaporators. The high-temperature side heat medium circuit 30, the low-temperature side heat medium circuit 40, and the indoor air-conditioning unit 50 operate in the same manner as in the single cooling mode of the first embodiment.

[0348] As a result, in the cooling / air-cooling mode, cooling of the battery 70 and cooling of the vehicle compartment are achieved, similarly to the cooling / air-cooling mode of the first embodiment.

[0349] (b-1) Single series dehumidification and heating mode In the heat pump cycle 10a in the single serial dehumidification and heating mode, the controller 60 throttles the heating expansion valve 14a, throttles the cooling expansion valve 14b, fully closes the cooling expansion valve 14c, fully closes the bypass flow control valve 14d, and fully opens the subcooling expansion valve 14e. The controller 60 also closes the heating on-off valve 22b, closes the first inlet on-off valve 22c, and opens the second inlet on-off valve 22d.

[0350] For this reason, in the heat pump cycle 10a in the single-serial dehumidification and heating mode, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the following order: the water-refrigerant heat exchanger 13, the heating expansion valve 14a which is in a throttled state, the outdoor heat exchanger 15, the subcooling expansion valve 14e which is in a fully open state, the receiver 24, the cooling expansion valve 14b which is in a throttled state, the indoor evaporator 18, and the suction port of the compressor 11.

[0351] Furthermore, the control device 60 appropriately controls the operation of other devices to be controlled, similarly to the single series dehumidification and heating mode of the first embodiment.

[0352] Therefore, in the heat pump cycle 10a in the single series dehumidifying and heating mode, the water-refrigerant heat exchanger 13 and the outdoor heat exchanger 15 function as condensers, and the indoor evaporator 18 functions as an evaporator, forming a vapor compression refrigeration cycle. The high temperature side heat medium circuit 30 and the indoor air conditioning unit 50 operate in the same manner as in the single cooling mode of the first embodiment.

[0353] As a result, in the single series dehumidification and heating mode, dehumidification and heating of the vehicle interior is achieved, similarly to the single series dehumidification and heating mode of the first embodiment.

[0354] Here, since the heat pump cycle 10a has a receiver 24, the single series dehumidification heating mode and the cooling series dehumidification heating mode are performed in a temperature range where the saturation temperature of the refrigerant in the outdoor heat exchanger 15 is higher than the outdoor air temperature Tam.

[0355] (b-2) Cooling series dehumidification heating mode In the heat pump cycle 10a in the cooling series dehumidification heating mode, the controller 60 controls the cooling expansion valve 14c to the throttling state, unlike the single series dehumidification heating mode.

[0356] Therefore, in the heat pump cycle 10a in the cooling serial dehumidification heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single serial dehumidification heating mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the order of the water-refrigerant heat exchanger 13, the heating expansion valve 14a in the fully open state, the outdoor heat exchanger 15, the supercooling expansion valve 14e in the fully open state, the receiver 24, the cooling expansion valve 14c in the throttled state, the chiller 20, and the suction port of the compressor 11. In other words, the indoor evaporator 18 and the chiller 20 are switched to a refrigerant circuit in which they are connected in parallel with respect to the flow of the refrigerant.

[0357] Furthermore, the control device 60 appropriately controls the operation of other devices to be controlled, similarly to the cooling serial dehumidification heating mode of the first embodiment.

[0358] Therefore, in the heat pump cycle 10a in the cooling serial dehumidification heating mode, the water-refrigerant heat exchanger 13 and the outdoor heat exchanger 15 function as condensers, and the indoor evaporator 18 and the chiller 20 function as evaporators, forming a vapor compression refrigeration cycle. The high-temperature side heat medium circuit 30, the low-temperature side heat medium circuit 40, and the indoor air conditioning unit 50 operate in the same manner as in the cooling serial dehumidification heating mode of the first embodiment.

[0359] As a result, in the cooling series dehumidification heating mode, cooling of the battery 70 and dehumidification and heating of the vehicle interior are achieved, similarly to the cooling series dehumidification heating mode of the first embodiment.

[0360] (c-1) Single parallel dehumidification and heating mode In the heat pump cycle 10a in the single-parallel dehumidification heating mode, the control device 60 throttles the heating expansion valve 14a, throttles the cooling expansion valve 14b, fully closes the cooling expansion valve 14c, fully closes the bypass-side flow control valve 14d, and fully opens the subcooling expansion valve 14e. The control device 60 also opens the heating on-off valve 22b, opens the first inlet side on-off valve 22c, and closes the second inlet side on-off valve 22d.

[0361] Therefore, in the heat pump cycle 10a in the single parallel dehumidification heating mode, the refrigerant discharged from the compressor 11 circulates in the order of the water-refrigerant heat exchanger 13, the supercooling expansion valve 14e in the fully open state, the receiver 24, the heating expansion valve 14a in the throttled state, the outdoor heat exchanger 15, the heating passage 21c, and the suction port of the compressor 11. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which the refrigerant discharged from the compressor 11 circulates in the order of the water-refrigerant heat exchanger 13, the supercooling expansion valve 14e in the fully open state, the receiver 24, the cooling expansion valve 14b in the throttled state, the indoor evaporator 18, and the suction port of the compressor 11. In other words, the outdoor heat exchanger 15 and the indoor evaporator 18 are switched to a refrigerant circuit connected in parallel with respect to the flow of the refrigerant.

[0362] Furthermore, the control device 60 appropriately controls the operation of other devices to be controlled, similarly to the single-parallel dehumidifying and heating mode of the first embodiment.

[0363] Therefore, in the heat pump cycle 10a in the single-parallel dehumidifying and heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser, and the indoor evaporator 18 and the outdoor heat exchanger 15 function as evaporators. The high-temperature side heat medium circuit 30 and the indoor air conditioning unit 50 operate in the same manner as in the single-parallel dehumidifying and heating mode of the first embodiment.

[0364] As a result, in the single-parallel dehumidifying and heating mode, dehumidifying and heating the vehicle interior is achieved, similarly to the single-parallel dehumidifying and heating mode of the first embodiment.

[0365] (c-2) Parallel cooling, dehumidification and heating mode In the heat pump cycle 10a in the cooling-parallel dehumidification-heating mode, the controller 60 controls the cooling expansion valve 14c to be in the throttling state, unlike in the single-parallel dehumidification-heating mode.

[0366] Therefore, in the heat pump cycle 10a in the cooling-parallel dehumidification-heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single-parallel dehumidification-heating mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the order of the water-refrigerant heat exchanger 13, the supercooling expansion valve 14e in the fully open state, the receiver 24, the cooling expansion valve 14c in the throttled state, the chiller 20, and the suction port of the compressor 11. In other words, the outdoor heat exchanger 15, the indoor evaporator 18, and the chiller 20 are switched to a refrigerant circuit in which the refrigerant flow is connected in parallel.

[0367] Furthermore, the control device 60 appropriately controls the operation of other devices to be controlled, similarly to the cooling parallel dehumidification heating mode of the first embodiment.

[0368] Therefore, in the heat pump cycle 10a in the cooling parallel dehumidification heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser, and the outdoor heat exchanger 15, the indoor evaporator 18, and the chiller 20 function as evaporators. The high-temperature side heat medium circuit 30, the low-temperature side heat medium circuit 40, and the indoor air conditioning unit 50 operate in the same manner as in the cooling parallel dehumidification heating mode of the first embodiment.

[0369] As a result, in the cooling / parallel dehumidification / heating mode, cooling of the battery 70 and dehumidification / heating of the vehicle cabin are achieved, similarly to the cooling / parallel dehumidification / heating mode of the first embodiment.

[0370] (d-1) Single parallel hot gas dehumidification heating mode In the heat pump cycle 10a in the single parallel hot gas dehumidification heating mode, the controller 60 controls the bypass side flow rate control valve 14d to be in the throttled state and the cooling expansion valve 14c to be in the throttled state, in contrast to the single parallel dehumidification heating mode.

[0371] Therefore, in the heat pump cycle 10a in the single parallel hot gas dehumidification and heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the cooling-parallel dehumidification and heating mode. At the same time, a portion of the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit that circulates through the bypass-side flow control valve 14d in a throttled state, the chiller 20, and the suction port of the compressor 11 in that order.

[0372] Furthermore, the control device 60 appropriately controls the operation of other control target devices in the same manner as in the single parallel hot gas dehumidification heating mode of the first embodiment.

[0373] Therefore, in the parallel hot gas dehumidification heating mode, as in the first embodiment, even if frost forms on the outdoor heat exchanger 15 while the single parallel dehumidification heating mode is being executed, a decrease in the heating capacity of the blown air can be suppressed.

[0374] (d-2) Cooling parallel hot gas dehumidification heating mode In the heat pump cycle 10a in the cooling-parallel hot gas dehumidification and heating mode, the refrigerant circulates in the same manner as in the single-parallel hot gas dehumidification and heating mode.

[0375] Furthermore, the control device 60 appropriately controls the operation of other control target devices in the same manner as in the cooling parallel hot gas dehumidification heating mode of the first embodiment.

[0376] Therefore, in the cooling parallel hot gas dehumidification heating mode, as in the first embodiment, even if frost forms on the outdoor heat exchanger 15 while the cooling parallel dehumidification heating mode is being executed, a decrease in the heating capacity of the blown air can be suppressed.

[0377] (e-1) Single outdoor air heat absorption heating mode In the heat pump cycle 10a in the single outdoor air heat absorption heating mode, the controller 60 throttles the heating expansion valve 14a, fully closes the cooling expansion valve 14b, fully closes the cooling expansion valve 14c, fully closes the bypass flow control valve 14d, and fully opens the supercooling expansion valve 14e. The controller 60 also opens the heating on-off valve 22b, opens the first inlet side on-off valve 22c, and closes the second inlet side on-off valve 22d.

[0378] Therefore, in the heat pump cycle 10a in the single outdoor air heat absorption heating mode, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the following order: the water-refrigerant heat exchanger 13, the supercooling expansion valve 14e which is in a fully open state, the receiver 24, the heating expansion valve 14a which is in a throttled state, the outdoor heat exchanger 15, the heating passage 21c, and the suction port of the compressor 11.

[0379] Furthermore, the control device 60 appropriately controls the operation of other control target devices in the same manner as in the single outdoor air heat absorption heating mode of the first embodiment.

[0380] Therefore, in the heat pump cycle 10a in the single outdoor air heat absorption heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser and the outdoor heat exchanger 15 functions as an evaporator. The high temperature side heat medium circuit 30 and the indoor air conditioning unit 50 operate in the same manner as in the single outdoor air heat absorption heating mode of the first embodiment.

[0381] As a result, in the single outside air heat absorption heating mode, heating of the vehicle interior is achieved in the same manner as in the single outside air heat absorption heating mode of the first embodiment.

[0382] (e-2) Cooling outdoor air heat absorption heating mode In the heat pump cycle 10a in the cooling outdoor air heat absorption heating mode, the controller 60 controls the cooling expansion valve 14c to the throttling state, unlike the single outdoor air heat absorption heating mode.

[0383] Therefore, in the heat pump cycle 10a in the cooling outdoor air heat absorption heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single outdoor air heat absorption heating mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the order of the water-refrigerant heat exchanger 13, the supercooling expansion valve 14e in the fully open state, the receiver 24, the cooling expansion valve 14c in the throttled state, the chiller 20, and the suction port of the compressor 11. In other words, the outdoor heat exchanger 15 and the chiller 20 are switched to a refrigerant circuit in which they are connected in parallel with respect to the refrigerant flow.

[0384] Furthermore, the control device 60 appropriately controls the operation of other devices to be controlled, similarly to the cooled outdoor air heat absorption heating mode of the first embodiment.

[0385] Therefore, in the heat pump cycle 10a in the cooled outdoor air heat absorption heating mode, a vapor compression refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser, and the outdoor heat exchanger 15 and the chiller 20 function as evaporators. The high-temperature side heat medium circuit 30, the low-temperature side heat medium circuit 40, and the indoor air conditioning unit 50 operate in the same manner as in the cooled outdoor air heat absorption heating mode of the first embodiment.

[0386] As a result, in the cooled outside air heat absorption heating mode, cooling of the battery 70 and heating of the vehicle compartment are achieved, similarly to the cooled outside air heat absorption heating mode of the first embodiment.

[0387] (f-1) Single outdoor air heat absorption hot gas heating mode In the heat pump cycle 10a in the single outdoor air heat absorption hot gas heating mode, the controller 60 throttles the bypass side flow rate control valve 14d and throttles the cooling expansion valve 14c for the single outdoor air heat absorption heating mode.

[0388] Therefore, in the heat pump cycle 10a in the single outdoor air heat absorption hot gas heating mode, the refrigerant circulates in the same manner as in the cooling outdoor air heat absorption heating mode. At the same time, a part of the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit that circulates through the bypass side flow control valve 14d in the throttled state, the chiller 20, and the suction port of the compressor 11 in that order.

[0389] Furthermore, the control device 60 appropriately controls the operation of other control target devices in the same manner as in the single outdoor air heat absorption hot gas heating mode of the first embodiment.

[0390] Therefore, in the single outdoor air heat absorption hot gas heating mode, as in the first embodiment, even if frost forms on the outdoor heat exchanger 15 while the single outdoor air heat absorption heating mode is being executed, a decrease in the heating capacity of the blown air can be suppressed.

[0391] (f-2) Cooling outdoor air heat absorption hot gas heating mode In the heat pump cycle 10a in the cooled outdoor air heat absorption hot gas heating mode, the refrigerant circulates in the same manner as in the single outdoor air heat absorption hot gas heating mode.

[0392] Furthermore, the control device 60 appropriately controls the operation of other devices to be controlled, similarly to the cooled outdoor air heat absorption hot gas heating mode of the first embodiment.

[0393] Therefore, in the cooled outdoor air heat absorption hot gas heating mode, as in the first embodiment, even if frost forms on the outdoor heat exchanger 15 while the cooled outdoor air heat absorption heating mode is being executed, a decrease in the heating capacity of the blown air can be suppressed.

[0394] (g) Hot gas heating mode The hot gas heating mode is included in the hot gas heating mode, and therefore, in the hot gas heating mode, the control process of the hot gas mode described with reference to the flowchart of Fig. 4 in the first embodiment is executed.

[0395] In normal control of the hot gas heating mode, the control device 60 fully closes the heating expansion valve 14a, fully closes the cooling expansion valve 14b, throttles the cooling expansion valve 14c, throttles the bypass side flow control valve 14d, and fully opens the supercooling expansion valve 14e. The control device 60 also closes the heating opening / closing valve 22b, opens the first inlet side opening / closing valve 22c, and closes the second inlet side opening / closing valve 22d.

[0396] Therefore, in the heat pump cycle 10a in the hot gas heating mode, the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the water-refrigerant heat exchanger 13, the supercooling expansion valve 14e in the fully open state, the receiver 24, the cooling expansion valve 14c in the throttled state, the sixth three-way joint 12f, the chiller 20, and the suction port of the compressor 11. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the order of the first three-way joint 12a, the bypass-side flow control valve 14d in the throttled state arranged in the bypass passage 21a, the sixth three-way joint 12f, the chiller 20, and the suction port of the compressor 11.

[0397] Therefore, in the hot gas heating mode of this embodiment, the subcooling expansion valve 14e and the cooling expansion valve 14c serve as a heating section side pressure reducing section, and the sixth three-way joint 12f serves as a mixing section.

[0398] Furthermore, the control device 60 appropriately controls the operation of other control target devices in the same manner as in the hot gas heating mode of the first embodiment.

[0399] Therefore, in normal control of the hot gas heating mode, as in the hot gas heating mode of the first embodiment, the heat generated by the work of the compressor 11 can be effectively utilized to heat the blown air, thereby heating the vehicle cabin.

[0400] In the high pressure increase control in the hot gas heating mode, the throttle opening of the subcooling expansion valve 14e is reduced to increase the degree of subcooling of the refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 13. Other operations are the same as those in the normal control.

[0401] Therefore, in the high pressure rise control, the temperature of the high temperature side heat medium can be increased more than in the normal control, as in the first embodiment. This increases the temperature of the blown air heated by the heater core 32, and makes it possible to bring the blown air temperature TAV closer to the target blown air temperature TAO.

[0402] (h-1) Cooling hot gas heating mode The cooling hot gas heating mode is included in the hot gas mode, and therefore, in the cooling hot gas heating mode, the control process of the hot gas mode is executed.

[0403] In normal control of the cooling hot gas heating mode, the control device 60 operates the low-temperature side pump 41 so as to exert a predetermined reference pumping capacity for the hot gas heating mode. Other operations are the same as those of the hot gas heating mode.

[0404] Therefore, in the cooling hot gas heating mode, the heat generated by the work of the compressor 11 can be effectively used to heat the blown air. When the heating capacity has not reached the target heating capacity, the high pressure increase control is executed to bring the blown air temperature TAV closer to the target blown air temperature TAO. Furthermore, the battery 70 can be cooled in the same way as in the cooling hot gas heating mode of the first embodiment.

[0405] (h-2) Warm-up hot gas heating mode The warm-up hot gas heating mode is included in the hot gas heating mode, and therefore, in the warm-up hot gas heating mode, the control process of the hot gas mode is executed.

[0406] In normal control of the warm-up hot gas heating mode, the controller 60 operates the low-temperature side pump 41 so as to exert a predetermined reference pumping capacity for the hot gas heating mode. Other operations are the same as those for the hot gas heating mode.

[0407] Therefore, in the warm-up hot gas heating mode, the heat generated by the work of the compressor 11 can be effectively used to heat the blown air. When the heating capacity has not reached the target heating capacity, the high pressure increase control is executed to bring the blown air temperature TAV closer to the target outlet temperature TAO. Furthermore, the battery 70 can be warmed up, as in the warm-up hot gas heating mode of the first embodiment.

[0408] (i-1) Single hot gas dehumidification heating mode The single hot gas dehumidification and heating mode is included in the hot gas mode, and therefore, in the single hot gas dehumidification and heating mode, the control process of the hot gas mode is executed.

[0409] In normal control of the single hot gas dehumidifying heating mode, the control device 60 fully closes the heating expansion valve 14a, throttles the cooling expansion valve 14b, throttles the cooling expansion valve 14c, throttles the bypass side flow control valve 14d, and fully opens the supercooling expansion valve 14e. The control device 60 also closes the heating on-off valve 22b, opens the first inlet side on-off valve 22c, and closes the second inlet side on-off valve 22d.

[0410] Therefore, in the heat pump cycle 10a in the single hot gas dehumidification heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the hot gas heating mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it circulates in the order of the first three-way joint 12a, the water-refrigerant heat exchanger 13, the supercooling expansion valve 14e in the fully open state, the receiver 24, the cooling expansion valve 14b in the throttling state, the indoor evaporator 18, and the suction port of the compressor 11.

[0411] Therefore, in the single hot gas dehumidifying and heating mode, the subcooling expansion valve 14e and the cooling expansion valve 14c function as a heating section side pressure reducing section, and the sixth three-way joint 12f functions as a mixing section.

[0412] Furthermore, the control device 60 appropriately controls the operation of other control target devices in the same manner as in the single hot gas dehumidification heating mode of the first embodiment.

[0413] Therefore, in the normal control of the single hot gas dehumidifying and heating mode, the heat generated by the work of the compressor 11 can be effectively used to heat the blown air, and the inside of the vehicle can be dehumidified and heated, similarly to the hot gas dehumidifying and heating mode of the first embodiment. Furthermore, in the single hot gas dehumidifying and heating mode, the heat absorbed by the refrigerant from the blown air in the interior evaporator 18 can be used to reheat the blown air.

[0414] In the high pressure increase control of the single hot gas dehumidifying heating mode, the throttle opening of the subcooling expansion valve 14e, which is the heating section side pressure reducing section, is reduced to increase the degree of subcooling of the refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 13. Other operations are the same as those of the normal control.

[0415] Therefore, in the high pressure rise control, like the hot gas heating mode, the temperature of the high temperature side heat medium can be increased more than in the normal control. This increases the temperature of the blown air heated by the heater core 32, and makes it possible to bring the blown air temperature TAV closer to the target blown air temperature TAO.

[0416] (i-2) Cooling hot gas dehumidification heating mode In the heat pump cycle 10a in the cooling hot gas dehumidification heating mode, the refrigerant circulates in the same manner as in the single hot gas dehumidification heating mode.

[0417] Furthermore, the control device 60 appropriately controls the operation of other control target devices in the same manner as in the cooling parallel hot gas dehumidification heating mode of the first embodiment.

[0418] Therefore, in the cooling hot gas dehumidifying heating mode, as in the single hot gas dehumidifying heating mode, the heat generated by the work of the compressor 11 can be effectively used to heat the blown air. Furthermore, in the cooling hot gas dehumidifying heating mode, the heat absorbed by the refrigerant from the blown air in the indoor evaporator 18 can be used to reheat the blown air.

[0419] Furthermore, when the heating capacity has not reached the target heating capacity, the high pressure increase control is executed in the same manner as in the single hot gas heating mode, so that the blown air temperature TAV can be brought closer to the target blown air temperature TAO.

[0420] As described above, in the vehicle air conditioner 1a of this embodiment, by switching the operation mode, it is possible to perform comfortable air conditioning for the vehicle interior and appropriate temperature adjustment for the battery 70, which is an on-board device.

[0421] Furthermore, since the heat pump cycle 10a of the present embodiment includes the receiver 24, the high-pressure side liquid phase refrigerant can be stored in the receiver 24 as surplus refrigerant of the cycle.

[0422] According to this, in the cooling mode, the serial dehumidification heating mode, the parallel dehumidification heating mode, the outdoor air heat absorption heating mode, etc., the refrigerant on the outlet side of the heat exchanger functioning as an evaporator can be made to have a degree of superheat. Therefore, the enthalpy difference obtained by subtracting the enthalpy of the inlet side refrigerant from the enthalpy of the outlet side refrigerant of the heat exchanger functioning as an evaporator can be increased. As a result, in the heat pump cycle 10a, the amount of heat absorption of the refrigerant in the heat exchanger functioning as an evaporator can be increased, thereby improving the COP.

[0423] In addition, in the hot gas heating mode, the temperature controlled hot gas heating mode, the hot gas dehumidification heating mode, and the like, the refrigerant drawn into the compressor 11 can be made to approach a saturated gas phase refrigerant. Therefore, a refrigerant having a higher density than a refrigerant having a degree of superheat can be drawn into the compressor 11. As a result, the discharge flow rate Gr of the compressor 11 at the same rotation speed can be stabilized and increased.

[0424] On the other hand, in a typical heat pump cycle including a receiver, the refrigerant flowing out of the heat exchange unit functioning as a condenser becomes a saturated liquid phase refrigerant, so that it is difficult for the refrigerant flowing out of the heat exchange unit functioning as a condenser to have a degree of subcooling. In other words, in a heat pump cycle including a receiver, it is difficult for the refrigerant flowing out of the heating unit to have a degree of subcooling.

[0425] In contrast, the heat pump cycle 10a of the present embodiment has, as a heating section-side decompression section, a supercooling expansion valve 14e arranged on the upstream side of the refrigerant flow of the receiver 24, and a cooling-side expansion valve 14c arranged on the downstream side of the refrigerant flow of the receiver 24. In the high pressure increase control, the throttle opening of the supercooling expansion valve 14e is reduced.

[0426] According to this, even if the heat pump cycle 10a includes the receiver 24, the refrigerant flowing out from the heating unit can have a degree of subcooling by executing the high pressure increase control. Therefore, in the vehicle air conditioner 1a of this embodiment, as in the first embodiment, the discharge refrigerant pressure Pd can be increased to expand the temperature adjustment range of the blown air.

[0427] In the vehicle air conditioner 1a of this embodiment, the control process of the hot gas mode may be applied to the parallel hot gas dehumidification heating mode and the outdoor air heat absorption hot gas heating mode. In this embodiment, too, in the parallel hot gas dehumidification heating mode and the outdoor air heat absorption hot gas heating mode, frost forms on the exterior heat exchanger 15, so the refrigerant cannot absorb heat from the outdoor air in the exterior heat exchanger 15. In other words, the exterior heat exchanger 15 is equivalent to a refrigerant passage.

[0428] Therefore, when the hot gas mode control process is applied in the parallel dehumidification hot gas heating mode and the outdoor air heat absorption hot gas heating mode, the subcooling expansion valve 14e and the heating expansion valve 14a become the heating section side pressure reducing section, and the fifth three-way joint 12e becomes the mixing section. Therefore, in the high pressure rise control, the throttle opening of the subcooling expansion valve 14e is reduced.

[0429] Moreover, the high pressure rise control described in the second embodiment may be applied to the vehicle air conditioner 1a of this embodiment. Furthermore, when the high pressure rise control described in the second embodiment is applied as the high pressure rise control, the subcooling expansion valve 14e may be eliminated.

[0430] The present disclosure is not limited to the above-described embodiment, and various modifications can be made as follows without departing from the spirit and scope of the present disclosure.

[0431] In the above embodiment, an example in which the heat pump cycle device according to the present disclosure is applied to an air conditioner has been described, but the application of the heat pump cycle device is not limited to air conditioners. For example, the heat pump cycle device may be applied to a hot water supply device that heats water for daily use or the like as an object to be heated.

[0432] The object to be heated is not limited to a fluid. For example, the object may be a heat generating device having a heat medium passage through which a high-temperature heat medium flows for warming up or the like. In this case, the high-pressure increase control may be a control that reduces the flow rate of the high-temperature heat medium compared to normal control.

[0433] The configuration of the heat pump cycle device according to the present disclosure is not limited to the configuration disclosed in the above embodiment.

[0434] In the above-described first embodiment, an example in which the heating section is formed by the components of the water-refrigerant heat exchanger 13 and the high-temperature side heat medium circuit 30 has been described, but the present invention is not limited to this. For example, an indoor condenser may be used as the heating section. The indoor condenser is a heating heat exchange section that heats the blown air by exchanging heat between one of the discharged refrigerants branched at the first three-way joint 12a and the blown air that has passed through the indoor evaporator 18. The indoor condenser may be disposed in the air passage of the indoor air-conditioning unit 50 in the same manner as the heater core 32.

[0435] In the above embodiment, an example has been described in which the sixth three-way joint 12f, which is the mixing part, is arranged on the upstream side of the refrigerant flow of the chiller 20, but it may be arranged on the downstream side of the refrigerant flow of the chiller 20. In this case, the refrigerant flowing out from the bypass-side flow control valve 14d and the refrigerant flowing out from the refrigerant passage of the chiller 20 are homogeneously mixed when flowing through the accumulator 23 and the refrigerant piping from the sixth three-way joint 12f to the suction side of the compressor 11.

[0436] In the above embodiment, the refrigerant flowing through the bypass passage 21a and the refrigerant decompressed by the cooling expansion valve 14c are mixed together, but the present invention is not limited to this. For example, in the (d-1) single parallel hot gas dehumidifying heating mode, the refrigerant flowing through the bypass passage 21a and the refrigerant decompressed by the cooling expansion valve 14b may be mixed together, and the cooling expansion valve may be fully closed.

[0437] In the above embodiment, an example in which the evaporation pressure regulating valve 19 configured as a mechanical mechanism is used has been described, but of course an evaporation pressure regulating valve configured as an electrical mechanism may also be used. As an evaporation pressure regulating valve with an electrical mechanism, a variable throttle mechanism having a similar configuration to the heating expansion valve 14a, etc. may be used. Also, a configuration in which the evaporation pressure regulating valve 19 is not used may also be used.

[0438] In the above embodiment, the refrigerant of the heat pump cycle 10, 10a is R1234yf, but the present invention is not limited thereto. For example, R134a, R600a, R410A, R404A, R32, R407C, etc. may be used. Alternatively, a mixed refrigerant of a mixture of a plurality of these refrigerants may be used. Furthermore, a supercritical refrigeration cycle may be configured in which carbon dioxide is used as the refrigerant and the high-pressure side refrigerant pressure is equal to or higher than the critical pressure of the refrigerant.

[0439] In addition, although an example in which an ethylene glycol aqueous solution is used as the low-temperature side heat medium and the high-temperature side heat medium in the above-mentioned embodiment has been described, the present invention is not limited to this. For example, dimethylpolysiloxane, a solution containing nanofluid, antifreeze, a water-based liquid refrigerant containing alcohol, a liquid medium containing oil, etc. may be used as the high-temperature side heat medium and the low-temperature side heat medium.

[0440] The control aspects of the heat pump cycle apparatus according to the present disclosure are not limited to the control aspects disclosed in the above-described embodiments.

[0441] In the above embodiment, the vehicle air conditioner 1, 1a capable of executing various operation modes has been described, but it is not necessary that all of the above operation modes can be executed. If at least one of the operation modes in which the control process of the hot gas mode is executed, such as (g) hot gas heating mode, (h) temperature control hot gas heating mode, (i) hot gas dehumidification heating mode, etc., can be executed, the effect of expanding the temperature adjustment range of the heated object can be obtained.

[0442] In the above embodiment, an example has been described in which the mode is switched to the (d) parallel hot gas dehumidification heating mode when it is determined that frost has formed on the outdoor heat exchanger 15 while the (c) parallel dehumidification heating mode is being executed, but this is not limiting. The mode may be switched to the (i) hot gas dehumidification heating mode when it is determined that frost has formed on the outdoor heat exchanger 15 while the (c) parallel dehumidification heating mode is being executed. Furthermore, even if the mode is switched to the (d) parallel hot gas dehumidification heating mode, the mode may be switched to the (i) hot gas dehumidification heating mode when frost has progressed on the outdoor heat exchanger 15.

[0443] In the above embodiment, an example has been described in which the outdoor air heat absorption hot gas heating mode (f) is executed when it is determined that frost has formed on the outdoor heat exchanger 15 while the outdoor air heat absorption heating mode (e) is being executed, but this is not limiting. The mode may be switched to the hot gas heating mode (g) when it is determined that frost has formed on the outdoor heat exchanger 15 while the outdoor air heat absorption heating mode (e) is being executed. The mode may be switched to the hot gas heating mode (g) when frost has progressed on the outdoor heat exchanger 15, even if the mode is switched to the outdoor air heat absorption hot gas heating mode (f).

[0444] In addition, in the control process of the hot gas mode in the above embodiment, an example has been described in which the operation of the compressor 11 and the bypass side flow control valve 14d is controlled to bring the blowing air temperature TAV closer to the target blowing temperature TAO and bring the suction refrigerant pressure P closer to the target low pressure PSO, but this is not limiting.

[0445] For example, the control device 60 may control the refrigerant discharge capacity of the compressor 11 so that the high-low pressure difference ΔP approaches the target high-low pressure difference ΔPO. In this case, the control device 60 may control the operation of the bypass-side flow rate control valve 14d so that the suction refrigerant pressure Ps approaches the target low pressure PSO. Furthermore, the control device 60 may control the operation of the cooling expansion valve 14c so that the subcooling degree SC1 approaches the first target subcooling degree SCO1.

[0446] For example, the control device 60 may control the operation of the cooling expansion valve 14c so that the high-low pressure difference ΔP approaches the target high-low pressure difference ΔPO. In this case, the control device 60 may control the refrigerant discharge capacity of the compressor 11 so that the suction refrigerant pressure Ps approaches the target low pressure PSO. Furthermore, the control device 60 may control the operation of the bypass side flow rate adjustment valve 14d so that the subcooling degree SC1 approaches the first target subcooling degree SCO1.

[0447] Although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, and other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and concept of the present disclosure.

Claims

1. A compressor (11) that compresses and discharges a refrigerant; a branching portion (12a) for branching the flow of the refrigerant discharged from the compressor; a heating section (13, 30) that heats an object to be heated using one of the refrigerants branched at the branch section as a heat source; a heating unit side decompression unit (14c, 14e) for decompressing the refrigerant flowing out from the heating unit; a bypass passage (21 a) for guiding the other of the refrigerant branched at the branch portion to a suction port side of the compressor; a bypass-side flow rate adjusting unit (14d) for adjusting a flow rate of the refrigerant flowing through the bypass passage; a mixing section (12f) for mixing the refrigerant flowing out from the bypass-side flow rate adjustment section and the refrigerant flowing out from the heating section-side pressure reduction section and flowing the refrigerant toward a suction port side of the compressor; A target temperature determination unit (S3) that determines a target temperature (TAO) that is a target value of an object temperature (TAV) of the object heated by the heating unit; A target low pressure determination unit (S11) that determines a target low pressure (PSO) that is a target value of a suction refrigerant pressure (Ps) of the refrigerant suctioned into the compressor, As an operation mode for heating the object to be heated, a hot gas mode is provided in which the operation of at least one of the compressor, the heating unit side pressure reducing unit, and the bypass side flow rate adjusting unit is controlled so that the object temperature (TAV) approaches the target temperature (TAO) and the suction refrigerant pressure (Ps) approaches the target low pressure (PSO); In the hot gas mode, the operation of at least the compressor is controlled so that the object temperature (TAV) approaches the target temperature (TAO) and the suction refrigerant pressure (Ps) approaches the target low pressure (PSO); When the hot gas mode is being executed, the object temperature (TAV) is lower than the target temperature (TAO) and the refrigerant discharge capacity of the compressor is equal to or higher than a predetermined reference capacity, the heat pump cycle device executes high-pressure increase control to increase the discharge refrigerant pressure (Pd) of the refrigerant flowing into the heating section.

2. A compressor (11) that compresses and discharges a refrigerant; a branching portion (12a) for branching the flow of the refrigerant discharged from the compressor; a heating section (13, 30) that heats an object to be heated using one of the refrigerants branched at the branch section as a heat source; a heating unit side decompression unit (14c, 14e) for decompressing the refrigerant flowing out from the heating unit; a bypass passage (21 a) for guiding the other of the refrigerant branched at the branch portion to a suction port side of the compressor; a bypass-side flow rate adjusting unit (14d) for adjusting a flow rate of the refrigerant flowing through the bypass passage; a mixing section (12f) for mixing the refrigerant flowing out from the bypass-side flow rate adjustment section and the refrigerant flowing out from the heating section-side pressure reduction section and flowing the refrigerant toward a suction port side of the compressor; A target temperature determination unit (S3) that determines a target temperature (TAO) that is a target value of an object temperature (TAV) of the object heated by the heating unit; A target low pressure determination unit (S11) that determines a target low pressure (PSO) that is a target value of a suction refrigerant pressure (Ps) of the refrigerant suctioned into the compressor, As an operation mode for heating the object to be heated, a hot gas mode is provided in which the operation of at least one of the compressor, the heating unit side pressure reducing unit, and the bypass side flow rate adjusting unit is controlled so that the object temperature (TAV) approaches the target temperature (TAO) and the suction refrigerant pressure (Ps) approaches the target low pressure (PSO); In the hot gas mode, the operation of at least the bypass side flow rate adjustment unit is controlled so that the object temperature (TAV) approaches the target temperature (TAO) and the suction refrigerant pressure (Ps) approaches the target low pressure (PSO); When the hot gas mode is being executed, and the object temperature (TAV) is lower than the target temperature (TAO) and the throttle opening of the bypass side flow rate adjustment unit is equal to or lower than a predetermined reference opening, the heat pump cycle device executes high pressure increase control to increase the discharge refrigerant pressure (Pd) of the refrigerant flowing into the heating unit.

3. 3. The heat pump cycle apparatus according to claim 1, wherein in the high pressure increase control, a degree of subcooling of the refrigerant flowing out from the heating section is increased more than in normal control in the hot gas mode.

4. The object to be heated is a fluid, 3. The heat pump cycle apparatus according to claim 1, wherein the high pressure rise control reduces a flow rate of the object to be heated flowing into the heating section compared to a normal control in the hot gas mode.

5. the heating section includes a high-temperature side heat medium circuit (30) for circulating a high-temperature side heat medium, a water-refrigerant heat exchanger (13) for exchanging heat between the high-temperature side heat medium and one of the refrigerants branched at the branch section, and a heating heat exchanger (32) for exchanging heat between the high-temperature side heat medium and the object to be heated, 3. The heat pump cycle apparatus according to claim 1, wherein, in the high pressure increase control, a flow rate of the high temperature side heat medium circulating through the high temperature side heat medium circuit (30) is reduced compared to that in normal control in the hot gas mode.

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