WO2022030182A1

WO2022030182A1 - Refrigeration cycle device

Info

Publication number: WO2022030182A1
Application number: PCT/JP2021/025950
Authority: WO
Inventors: 祐一加見; 大輝加藤
Original assignee: 株式会社デンソー
Priority date: 2020-08-05
Filing date: 2021-07-09
Publication date: 2022-02-10
Also published as: JP7468237B2; DE112021004134T5; JP2022029629A

Abstract

This refrigeration cycle device is provided with: a refrigerant circuit switching unit (15a, 15b) that performs switching between a refrigerant circuit of a waste-heat heating mode for not absorbing heat from outside air at an outdoor heat exchanger (16) but absorbing heat from a heat-absorption-target object (80) at a heat absorption unit (19, 50) and a refrigerant circuit of an outside-air-waste-heat heating mode for absorbing heat from the outside at the outdoor heat exchanger (16) and absorbing heat from the heat-absorption-target object (80) at the heat absorption unit (19, 50); and a control unit (60) that controls the refrigerant circuit switching unit (15a, 15b) to switch to the waste-heat heating mode when an outside air/refrigerant temperature difference which is a temperature difference obtained by subtracting the temperature (Ts) of a refrigerant sucked into a compressor (11) from an outside air temperature (Tam) is equal to or lower than a lower limit temperature difference (α2) and the temperature (TWL 2) of the heat-absorption-target object (80) is equal to or higher than a heat absorbable temperature (TW 1) in the outside-air-waste-heat heating mode.

Description

Refrigeration cycle device

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2020-13310 filed on August 5, 2020, and the contents of the description are incorporated herein by reference.

The present disclosure relates to a refrigeration cycle device that absorbs heat from a plurality of heat sources to perform heating.

Conventionally, the vehicle air conditioner described in Patent Document 1 heats the vehicle interior by absorbing heat from an outdoor heat exchanger and a non-temperature control target. In this conventional technique, not only the heat absorption from the outside air but also the waste heat of the non-temperature control target is used for heating, thereby improving the efficiency and performance of the heating.

Japanese Unexamined Patent Publication No. 2020-26196

However, in the above-mentioned conventional technique, since the low pressure of the refrigeration cycle rises due to waste heat endothermic, when the amount of waste heat is large, the refrigerant temperature in the outdoor heat exchanger may be higher than the outside air temperature. When the refrigerant temperature in the outdoor heat exchanger becomes higher than the outside air temperature, the outdoor heat exchanger dissipates heat from the refrigerant to the outside air, which deteriorates the efficiency and performance of heating.

In view of the above points, the present disclosure aims to improve the efficiency of heating in a refrigeration cycle apparatus that absorbs heat from a plurality of heat sources to perform heating.

The refrigerating cycle apparatus according to one aspect of the present disclosure includes a compressor, a heating unit, an expansion valve for heating, an outdoor heat exchanger, an expansion valve for cooling, an indoor evaporator, an expansion valve for heat absorption, and an endothermic unit. , A refrigerant circuit switching unit, and a control unit.

The compressor compresses and discharges the refrigerant. The heating unit heats the air blown to the air-conditioned space using the discharged refrigerant discharged from the compressor as a heat source.

The expansion valve for heating decompresses the refrigerant flowing out from the heating part. The outdoor heat exchanger exchanges heat between the refrigerant flowing out from the heating expansion valve and the outside air.

The cooling expansion valve reduces the pressure of the refrigerant flowing out of the outdoor heat exchanger. The indoor evaporator evaporates the refrigerant flowing out from the cooling expansion valve to cool the air before being heated by the heating unit.

The endothermic expansion valve reduces the pressure of the refrigerant flowing out of the outdoor heat exchanger. The endothermic unit evaporates the refrigerant flowing out from the endothermic expansion valve and absorbs heat from the endothermic object.

The refrigerant circuit switching unit is a waste heat heating mode refrigerant circuit that does not absorb heat from the outside air with the outdoor heat exchanger but absorbs heat from the endothermic object with the heat absorbing part, and the outdoor heat exchanger absorbs heat from the outside air and the endothermic object with the heat absorbing part. Switch to the outside air waste heat heating mode endothermic circuit that absorbs heat from.

In the outside air waste heat heating mode, the control unit has the outside air refrigerant temperature difference, which is the temperature difference obtained by subtracting the temperature of the refrigerant sucked into the compressor from the outside air temperature Tam, not more than the lower limit temperature difference, and the temperature of the heat absorbing object. If is equal to or higher than the heat absorption temperature, the refrigerant circuit switching unit is controlled so as to switch to the waste heat heating mode.

According to this, even if the low pressure of the refrigeration cycle rises due to waste heat endothermic, by switching to the waste heat heating mode, it is possible to suppress heat dissipation from the refrigerant from the refrigerant by the outdoor heat exchanger, so the efficiency and performance of heating deteriorates. Can be suppressed.

The above objectives and other objectives, features and advantages of the present disclosure will be further clarified by the detailed description below with reference to the accompanying drawings.
It is an overall block diagram of the vehicle air conditioner of 1st Embodiment. It is a block diagram which shows the electric control part of the air-conditioning apparatus for a vehicle of 1st Embodiment. It is explanatory drawing which shows the switching condition of the operation mode in the control program of 1st Embodiment. It is a Moriel diagram which shows the change of the state of the refrigerant in the outside air waste heat heating mode of 1st Embodiment. It is a Moriel diagram which shows the change of the state of the refrigerant in the outside air waste heat heating mode of a comparative example. It is an overall block diagram of the air conditioner for vehicles of 2nd Embodiment.

Hereinafter, a plurality of forms for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be given to the parts corresponding to the matters described in the preceding embodiments, and duplicate explanations may be omitted. When only a part of the configuration is described in each embodiment, other embodiments described above can be applied to the other parts of the configuration. Not only the combinations of the parts that clearly indicate that they can be combined in each embodiment, but also the parts of the embodiments that are not explicitly combined can be partially combined if there is no particular problem in the combination. It is possible.

(First Embodiment)
The first embodiment will be described with reference to FIGS. 1 to 5. The refrigeration cycle device 10 of the present embodiment 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 air-conditions the interior of the vehicle, which is the space to be air-conditioned.

As shown in the overall configuration diagram of FIG. 1, the vehicle air conditioner 1 includes a refrigerating cycle device 10, an indoor air conditioner unit 30, a high temperature side heat medium circuit 40, a low temperature side heat medium circuit 50, and the like.

The refrigerating cycle device 10 cools the air blown into the vehicle interior and heats the high temperature side heat medium circulating in the high temperature side heat medium circuit 40 in order to air-condition the vehicle interior. The refrigeration cycle device 10 cools the low temperature side heat medium circulating in the low temperature side heat medium circuit 50 in order to absorb heat from the waste heat device 80.

The refrigerating cycle device 10 can switch the refrigerant circuit for various operation modes in order to perform air conditioning in the vehicle interior. For example, the refrigerant circuit in the cooling mode, the refrigerant circuit in the dehumidifying / heating mode, the refrigerant circuit in the heating mode, and the like can be switched.

The refrigeration cycle apparatus 10 employs an HFO-based refrigerant (specifically, R1234yf) as the refrigerant, and the pressure of the discharged refrigerant discharged from the compressor 11 does not exceed the critical pressure of the refrigerant, which is a steam compression type subcritical. It constitutes a refrigeration cycle. Refrigerant oil for lubricating the compressor 11 is mixed in the refrigerant. Some of the refrigerating machine oil circulates in the cycle together with the refrigerant.

Among the constituent devices of the refrigerating cycle device 10, the compressor 11 sucks the refrigerant in the refrigerating cycle device 10, compresses it, and discharges it. The compressor 11 is arranged in front of the vehicle interior and is arranged in the drive unit chamber in which the electric motor and the like are housed. The compressor 11 is an electric compressor that rotationally drives a fixed-capacity compression mechanism having a fixed discharge capacity by an electric motor. The number of revolutions (that is, the refrigerant discharge capacity) of the compressor 11 is controlled by the control signal output from the control device 60 shown in FIG.

As shown in FIG. 1, the inlet side of the refrigerant passage of the water refrigerant heat exchanger 12 is connected to the discharge port of the compressor 11. The water-refrigerant heat exchanger 12 has a refrigerant passage for circulating the high-pressure refrigerant discharged from the compressor 11 and a water passage for circulating the high-temperature side heat medium circulating in the high-temperature side heat medium circuit 40. The water refrigerant heat exchanger 12 is a heat exchanger for heating that heats the high temperature side heat medium by exchanging heat between the high pressure refrigerant flowing through the refrigerant passage and the high temperature side heat medium flowing through the water passage.

The inlet side of the first joint 13a having three inflow outlets communicating with each other is connected to the outlet of the refrigerant passage of the water refrigerant heat exchanger 12. As such a three-way joint, one formed by joining a plurality of pipes or one formed by providing a plurality of refrigerant passages in a metal block or a resin block can be adopted.

The refrigeration cycle device 10 includes second to fourth joints 13b to 13d. The third joint 13c is a three-way joint similar to the first joint 13a. The second joint 13b and the fourth joint 13d are four-sided joints having four inflow ports communicating with each other.

The inlet side of the heating expansion valve 14a is connected to one of the outlets of the first joint 13a. One inlet side of the second joint 13b is connected to the other outlet of the first joint 13a via a bypass passage 22a. A dehumidifying on-off valve 15a is arranged in the bypass passage 22a.

The dehumidifying on-off valve 15a is a solenoid valve that opens and closes the bypass passage 22a. The refrigeration cycle device 10 includes a heating on-off valve 15b. The basic configuration of the heating on-off valve 15b is the same as that of the dehumidifying on-off valve 15a.

The dehumidifying on-off valve 15a and the heating on-off valve 15b can switch the refrigerant circuit of each operation mode by opening and closing the refrigerant passage. The dehumidifying on-off valve 15a and the heating on-off valve 15b are refrigerant circuit switching units that switch the refrigerant circuit of the cycle. The dehumidifying on-off valve 15a and the heating on-off valve 15b are controlled by a control voltage output from the control device 60.

The heating expansion valve 14a reduces the pressure of the high-pressure refrigerant flowing out from the refrigerant passage of the water refrigerant heat exchanger 12 at least in the operation mode of heating the vehicle interior, and reduces the flow rate (mass flow rate) of the refrigerant flowing out to the downstream side. It is a decompression unit for heating to be adjusted. The heating expansion valve 14a is an electric type having a valve body configured to change the throttle opening degree and an electric actuator (in other words, an electric mechanism) for changing the opening degree of the valve body. Variable throttle mechanism (in other words, an electric expansion valve).

The refrigeration cycle device 10 includes a cooling expansion valve 14b and an endothermic expansion valve 14c. The basic configuration of the cooling expansion valve 14b and the endothermic expansion valve 14c is the same as that of the heating expansion valve 14a.

The expansion valve 14a for heating, the expansion valve 14b for cooling, and the expansion valve 14c for endothermic function have a fully open function that functions as a mere refrigerant passage without exerting a flow rate adjusting action and a refrigerant depressurizing action by fully opening the valve opening. It also has a fully closed function that closes the refrigerant passage by fully closing the valve opening.

With this fully open function and fully closed function, the heating expansion valve 14a, the cooling expansion valve 14b, and the endothermic expansion valve 14c can switch the refrigerant circuit in each operation mode. The heating expansion valve 14a, the cooling expansion valve 14b, and the endothermic expansion valve 14c function as a refrigerant circuit switching unit. The heating expansion valve 14a, the cooling expansion valve 14b, and the endothermic expansion valve 14c are controlled by a control signal (control pulse) output from the control device 60.

The refrigerant inlet side of the outdoor heat exchanger 16 is connected to the outlet of the heating expansion valve 14a. The outdoor heat exchanger 16 is a heat exchanger that exchanges heat between the refrigerant flowing out from the heating expansion valve 14a and the outside air blown by a cooling fan (not shown). The outdoor heat exchanger 16 is arranged on the front side in the drive unit room. Therefore, when the vehicle is running, the running wind can be applied to the outdoor heat exchanger 16.

The inlet side of the third joint 13c is connected to the refrigerant outlet of the outdoor heat exchanger 16. The first inlet side of the fourth joint 13d is connected to one outlet of the third joint 13c via the heating passage 22b. A heating on-off valve 15b for opening and closing the refrigerant passage is arranged in the heating passage 22b. A first check valve 17a is arranged in the heating passage 22b. The first check valve 17a allows the refrigerant to flow from the third joint 13c side to the fourth joint 13d side, and prohibits the refrigerant from flowing from the fourth joint 13d side to the third joint 13c side.

The other inlet side of the second joint 13b is connected to the other outlet of the third joint 13c. A second check valve 17b is arranged in a refrigerant passage connecting the other outlet side of the third joint 13c and the other inlet side of the second joint 13b. The second check valve 17b allows the refrigerant to flow from the third joint 13c side to the second joint 13b side, and prohibits the refrigerant from flowing from the second joint 13b side to the third joint 13c side.

The inlet side of the cooling expansion valve 14b is connected to one of the outlets of the second joint 13b. The inlet side of the endothermic expansion valve 14c is connected to the other outlet of the second joint 13b.

The cooling expansion valve 14b is an air-conditioning decompression unit that depressurizes the refrigerant flowing out from the outdoor heat exchanger 16 and adjusts the flow rate of the refrigerant flowing out to the downstream side at least in the operation mode for cooling the vehicle interior.

The refrigerant inlet side of the indoor evaporator 18 is connected to the outlet of the cooling expansion valve 14b. The indoor evaporator 18 is arranged in the air conditioning case 31 of the indoor air conditioning unit 30. The indoor evaporator 18 exchanges heat between the low-pressure refrigerant decompressed by the cooling expansion valve 14b and the air blown from the blower 32 to evaporate the low-pressure refrigerant, and causes the low-pressure refrigerant to exert a heat absorbing action to absorb air. It is an air conditioning evaporative unit that cools. The indoor evaporator 18 is the first evaporation unit. The second inflow port side of the fourth joint 13d is connected to the refrigerant outlet of the indoor evaporator 18.

A third check valve 17c is arranged in the refrigerant passage connecting the refrigerant outlet side of the indoor evaporator 18 and the second inlet side of the fourth joint 13d. The third check valve 17c allows the refrigerant to flow from the indoor evaporator 18 side to the fourth joint 13d side, and prohibits the refrigerant from flowing from the fourth joint 13d side to the indoor evaporator 18 side.

The endothermic expansion valve 14c is an endothermic decompression unit that reduces the pressure of the refrigerant flowing out of the outdoor heat exchanger 16 and adjusts the flow rate of the refrigerant flowing out to the downstream side in the operation mode in which heat is absorbed from the waste heat device 80. ..

The inlet side of the refrigerant passage of the chiller 19 is connected to the outlet of the endothermic expansion valve 14c. The chiller 19 has a refrigerant passage for circulating a low-pressure refrigerant decompressed by the heat absorption expansion valve 14c, and a water passage for circulating a low-temperature side heat medium circulating in the low-temperature side heat medium circuit 50. The chiller 19 is an evaporation unit that exchanges heat between the low-pressure refrigerant flowing through the refrigerant passage and the low-temperature side heat medium flowing through the water passage to evaporate the low-pressure refrigerant and exert a heat absorbing action. The third inflow port side of the fourth joint 13d is connected to the outlet of the refrigerant passage of the chiller 19. The indoor evaporator 18 and the chiller 19 are connected in parallel to each other with respect to the refrigerant flow.

The inlet side of the accumulator 21 is connected to the outlet of the fourth joint 13d. The accumulator 21 is a gas-liquid separation unit that separates the gas-liquid of the refrigerant that has flowed into the inside and stores the excess liquid-phase refrigerant in the cycle. The suction port side of the compressor 11 is connected to the gas phase refrigerant outlet of the accumulator 21.

The accumulator 21 is formed with an oil return hole for returning the refrigerating machine oil mixed in the separated liquid phase refrigerant to the compressor 11. The refrigerating machine oil in the accumulator 21 is returned to the compressor 11 together with a small amount of liquid phase refrigerant.

The high temperature side heat medium circuit 40 is a heat medium circulation circuit that circulates the high temperature side heat medium. As the high temperature side heat medium, a solution containing ethylene glycol, dimethylpolysiloxane, a nanofluid, or the like, an antifreeze solution, or the like can be adopted. In the high temperature side heat medium circuit 40, a water passage of the water refrigerant heat exchanger 12, a high temperature side heat medium pump 41, a heater core 42, an electric heater 43, and the like are arranged.

The high temperature side heat medium pump 41 is a water pump that pumps the high temperature side heat medium to the inlet side of the water passage of the water refrigerant heat exchanger 12. The high temperature side heat medium pump 41 is an electric pump whose rotation speed (that is, pumping capacity) is controlled by a control voltage output from the control device 60.

The heat medium inlet side of the heater core 42 is connected to the outlet of the water passage of the water refrigerant heat exchanger 12. The heater core 42 is a heat exchanger that heats the air by exchanging heat between the high temperature side heat medium heated by the water refrigerant heat exchanger 12 and the air that has passed through the indoor evaporator 18. The heater core 42 is arranged in the air conditioning case 31 of the indoor air conditioning unit 30. The suction port side of the high temperature side heat medium pump 41 is connected to the heat medium outlet of the heater core 42.

Therefore, in the high temperature side heat medium circuit 40, the high temperature side heat medium pump 41 adjusts the flow rate of the high temperature side heat medium flowing into the heater core 42 to dissipate heat of the high temperature side heat medium in the heater core 42 to the air (that is, that is). , The amount of heat of air in the heater core 42) can be adjusted.

The water-refrigerant heat exchanger 12, the high-temperature side heat medium circuit 40, and the heater core 42 are heating units that heat air using the refrigerant discharged from the compressor 11 as a heat source.

The electric heater 43 is, for example, a PTC heater having a PTC element (that is, a positive characteristic thermistor). The electric heater 43 can arbitrarily adjust the amount of heat for heating the high temperature side heat medium by the control voltage output from the control device 60.

The low temperature side heat medium circuit 50 is a heat medium circulation circuit that circulates the low temperature side heat medium. As the low temperature side heat medium, the same fluid as the high temperature side heat medium can be adopted. In the low temperature side heat medium circuit 50, a water passage of a chiller 19, a low temperature side heat medium pump 51, a waste heat device 80, and the like are arranged.

The low temperature side heat medium pump 51 is a water pump that pumps the low temperature side heat medium to the inlet side of the water passage of the chiller 19. The basic configuration of the low temperature side heat medium pump 51 is the same as that of the high temperature side heat medium pump 41.

The inlet side of the waste heat device 80 is connected to the discharge port of the low temperature side heat medium pump 51. The waste heat device 80 is provided with a heat medium flow path through which the low temperature side heat medium flows. The waste heat device 80 is an in-vehicle device that generates waste heat as it operates. The waste heat device 80 is, for example, an inverter, a motor generator, a power control unit, or the like, which generates waste heat as the vehicle travels. The waste heat device 80 may be a secondary battery for storing electric power supplied to an in-vehicle device such as an electric motor. The inlet side of the water passage of the chiller 19 is connected to the heat medium outlet of the waste heat apparatus 80. The suction port side of the low temperature side heat medium pump 51 is connected to the outlet of the water passage of the chiller 19.

The low temperature side heat medium circuit 50 may be provided with a low temperature side radiator that dissipates heat from the low temperature side heat medium to the outside air.

In the low temperature side heat medium circuit 50, the low temperature side heat medium pump 51 adjusts the flow rate of the low temperature side heat medium flowing into the waste heat device 80 to adjust the amount of heat absorbed by the low temperature side heat medium from the waste heat device 80. can do.

The chiller 19 and the low temperature side heat medium circuit 50 are endothermic portions that evaporate the refrigerant flowing out from the endothermic expansion valve 14c and absorb heat from the waste heat apparatus 80. The waste heat device 80 and the low temperature side heat medium are endothermic objects that are endothermic by the refrigerant flowing through the chiller 19.

The indoor air conditioning unit 30 blows out air whose temperature has been adjusted by the refrigeration cycle device 10 into the vehicle interior. The indoor air conditioning unit 30 is arranged inside the instrument panel (instrument panel) at the front of the vehicle interior.

As shown in FIG. 1, the indoor air conditioning unit 30 houses a blower 32, an indoor evaporator 18, a heater core 42, and the like in an air passage formed in an air conditioning case 31 forming an outer shell thereof.

The air conditioning case 31 forms an air passage for air to be blown into the vehicle interior. The air-conditioning case 31 is made of a resin (for example, polypropylene) having a certain degree of elasticity and excellent strength.

An inside / outside air switching device 33 is arranged on the most upstream side of the air flow of the air conditioning case 31. The inside / outside air switching device 33 switches and introduces the inside air (that is, the vehicle interior air) and the outside air (that is, the vehicle interior outside air) into the air conditioning case 31.

The inside / outside air switching device 33 continuously adjusts the opening areas of the inside air introduction port for introducing the inside air into the air conditioning case 31 and the outside air introduction port for introducing the outside air by the inside / outside air switching door, and the introduction air volume of the inside air and the outside air. Change the introduction ratio with the introduction air volume. The inside / outside air switching door is driven by an electric actuator for the inside / outside air switching door. The electric actuator for the inside / outside air switching door is controlled by a control signal output from the control device 60.

A blower 32 is arranged on the downstream side of the air flow of the inside / outside air switching device 33. The blower 32 blows the air sucked through the inside / outside air switching device 33 toward the vehicle interior. The blower 32 is an electric blower that drives a centrifugal multi-blade fan with an electric motor. The rotation speed (that is, the blowing capacity) of the blower 32 is controlled by the control voltage output from the control device 60.

On the downstream side of the air flow of the blower 32, the indoor evaporator 18 and the heater core 42 are arranged in this order with respect to the air flow. The indoor evaporator 18 is arranged on the upstream side of the air flow with respect to the heater core 42.

The air conditioning case 31 is provided with a cold air bypass passage 35 that allows air after passing through the indoor evaporator 18 to bypass the heater core 42. An air mix door 34 is arranged on the downstream side of the air flow of the indoor evaporator 18 in the air conditioning case 31 and on the upstream side of the air flow of the heater core 42.

The air mix door 34 is an air volume ratio adjusting unit that adjusts the air volume ratio between the air volume of the air passing through the heater core 42 side and the air volume of the air passing through the cold air bypass passage 35 among the air after passing through the indoor evaporator 18. .. The air mix door 34 is driven by an electric actuator for the air mix door. This electric actuator is controlled by a control signal output from the control device 60.

A mixing space is arranged on the downstream side of the air flow of the heater core 42 and the cold air bypass passage 35 in the air conditioning case 31. The mixing space is a space in which the air heated by the heater core 42 and the unheated air passing through the cold air bypass passage 35 are mixed.

In the downstream portion of the air flow of the air conditioning case 31, an opening hole for blowing out the air mixed in the mixing space (that is, the air conditioning air) into the vehicle interior, which is the air conditioning target space, is arranged.

As this opening hole, a face opening hole, a foot opening hole, and a defroster opening hole (none of which are shown) are provided. The face opening hole is an opening hole for blowing air-conditioned air toward the upper body of the occupant in the vehicle interior. The foot opening hole is an opening hole for blowing air-conditioned air toward the feet of the occupant. The defroster opening hole is an opening hole for blowing air conditioning air toward the inner side surface of the front window glass of the vehicle.

These face opening holes, foot opening holes, and defroster opening holes are the face outlets, foot outlets, and defroster outlets (none of which are shown) provided in the vehicle interior via ducts forming air passages, respectively. )It is connected to the.

The temperature of the conditioned air mixed in the mixing space is adjusted by adjusting the air volume ratio between the air volume passing through the heater core 42 and the air volume passing through the cold air bypass passage 35 by the air mix door 34. As a result, the temperature of the air (air-conditioned air) blown from each outlet into the vehicle interior is adjusted.

Face doors, foot doors, and defroster doors (none of which are shown) are arranged on the upstream side of the air flow of the face opening hole, the foot opening hole, and the defroster opening hole, respectively. The face door adjusts the opening area of the face opening hole. The foot door adjusts the opening area of the foot opening hole. The defroster door adjusts the opening area of the defroster opening hole.

These face doors, foot doors, and defroster doors constitute an outlet mode switching device that switches the outlet mode. These doors are connected to an electric actuator for driving the outlet mode door via a link mechanism or the like, and are rotated in conjunction with each other. The operation of this electric actuator is also controlled by a control signal output from the control device 60.

Specific examples of the outlet mode that can be switched by the outlet mode switching device include face mode, bi-level mode, and foot mode.

The face mode is an outlet mode in which the face outlet is fully opened and air is blown out from the face outlet toward the upper body of the passenger in the passenger compartment. The bi-level mode is an outlet mode in which both the face outlet and the foot outlet are opened to blow air toward the upper body and feet of the passengers in the passenger compartment. The foot mode is an outlet mode in which the foot outlet is fully opened and the defroster outlet is opened by a small opening, and air is mainly blown out from the foot outlet.

The occupant can also switch to the defroster mode by manually operating the blowout mode changeover switch provided on the operation panel 70 shown in FIG. The defroster mode is an outlet mode in which the defroster outlet is fully opened and air is blown from the defroster outlet to the inner surface of the front window glass.

Next, the outline of the electric control unit of this embodiment will be described. The control device 60 includes a well-known microcomputer including a CPU, ROM, RAM, and the like, and peripheral circuits thereof. Then, various operations and processes are performed based on the control program stored in the ROM, and various controlled

devices

11, 14a to 14c, 15a to 15b, 32, 41, 51 and the like connected to the output side are operated. To control.

On the input side of the control device 60, as shown in the block diagram of FIG. 2, the inside temperature sensor 61, the outside temperature sensor 62, the solar radiation sensor 63, the first to fifth refrigerant temperature sensors 64a to 64e, and the evaporator temperature sensor 64f , A first refrigerant pressure sensor 65a, a second refrigerant pressure sensor 65b, a high temperature side heat medium temperature sensor 66a, a first low temperature side heat medium temperature sensor 67a, a second low temperature side heat medium temperature sensor 67b, and the like are connected. Then, the detection signals of these sensor groups are input to the control device 60.

The internal air temperature sensor 61 is an internal air temperature detection unit that detects the internal air temperature Tr (that is, the vehicle interior temperature). The outside air temperature sensor 62 is an outside air temperature detection unit that detects the outside air temperature Tam (that is, the outside air temperature of the vehicle interior). The solar radiation sensor 63 is a solar radiation amount detection unit that detects the solar radiation amount As irradiated to the vehicle interior.

The first refrigerant temperature sensor 64a is a discharge refrigerant temperature detection unit that detects the temperature T1 of the refrigerant discharged from the compressor 11. The second refrigerant temperature sensor 64b is a second refrigerant temperature detecting unit that detects the temperature T2 of the refrigerant flowing out from the refrigerant passage of the water refrigerant heat exchanger 12. The third refrigerant temperature sensor 64c is a third refrigerant temperature detection unit that detects the temperature T3 of the refrigerant flowing out of the outdoor heat exchanger 16.

The fourth refrigerant temperature sensor 64d is a fourth refrigerant temperature detection unit that detects the temperature T4 of the refrigerant flowing out from the indoor evaporator 18. The fifth refrigerant temperature sensor 64e is a fifth refrigerant temperature detection unit that detects the temperature T5 of the refrigerant flowing out from the refrigerant passage of the chiller 19.

The evaporator temperature sensor 64f is an evaporator temperature detection unit that detects the evaporator temperature Tefien, which is the refrigerant evaporation temperature in the indoor evaporator 18. The evaporator temperature sensor 64f of the present embodiment detects the heat exchange fin temperature of the indoor evaporator 18.

The first refrigerant pressure sensor 65a is a first refrigerant pressure detecting unit that detects the pressure P1 of the refrigerant flowing out from the refrigerant passage of the water refrigerant heat exchanger 12. The second refrigerant pressure sensor 65b is a second refrigerant pressure detecting unit that detects the pressure P2 of the refrigerant flowing out from the refrigerant passage of the chiller 19.

The high temperature side heat medium temperature sensor 66a is a high temperature side heat medium temperature detection unit that detects the high temperature side heat medium temperature TWH, which is the temperature of the high temperature side heat medium flowing out from the water passage of the water refrigerant heat exchanger 12.

The first low temperature side heat medium temperature sensor 67a is a first low temperature side heat medium temperature detection unit that detects the first low temperature side heat medium temperature TWL1, which is the temperature of the low temperature side heat medium flowing out from the water passage of the chiller 19. The second low temperature side heat medium temperature sensor 67b is a second low temperature side heat medium temperature detection unit that detects the second low temperature side heat medium temperature TWL2 which is the temperature of the low temperature side heat medium flowing out from the waste heat apparatus 80.

As shown in FIG. 2, an operation panel 70 arranged near the instrument panel in the front part of the vehicle interior is connected to the input side of the control device 60, and operation signals from various operation switches provided on the operation panel 70 are connected. Is entered.

Specific examples of the various operation switches provided on the operation panel 70 include an auto switch that sets or cancels the automatic control operation of the vehicle air conditioner, an air conditioner switch that requires the indoor evaporator 18 to cool the air, and the like. There are an air volume setting switch for manually setting the air volume of the blower 32, a temperature setting switch for setting the target temperature Tset in the vehicle interior, a blow mode changeover switch for manually setting the blow mode, and the like.

The control device 60 of the present embodiment is integrally configured with a control unit that controls various controlled devices connected to the output side of the control device 60. The configuration (hardware and software) that controls the operation of each of the control target devices in the control device 60 is a control unit that controls the operation of each control target device.

For example, in the control device 60, the configuration for controlling the refrigerant discharge capacity of the compressor 11 (specifically, the rotation speed of the compressor 11) is the compressor control unit 60a. Further, the configuration for controlling the operation of the heating expansion valve 14a, the cooling expansion valve 14b, and the endothermic expansion valve 14c is the expansion valve control unit 60b. The configuration that controls the operation of the dehumidifying on-off valve 15a and the heating on-off valve 15b is the refrigerant circuit switching control unit 60c.

The configuration for controlling the pumping capacity of the high temperature side heat medium of the high temperature side heat medium pump 41 is the high temperature side heat medium pump control unit 60d. The configuration for controlling the pumping capacity of the low temperature side heat medium of the low temperature side heat medium pump 51 is the low temperature side heat medium pump control unit 60e.

Next, the operation of the present embodiment in the above configuration will be described. In the refrigerating cycle device 10 of the present embodiment, the refrigerant circuit can be switched to perform air conditioning operation in the following five operation modes.

(1) Cooling mode: The cooling mode is an operation mode in which the interior of the vehicle is cooled by cooling the air and blowing it into the interior of the vehicle.

(2) Outside air heating mode: The outside air heating mode is an operation mode in which the inside of the vehicle is heated by heating the air using the heat absorbed from the outside air and blowing it into the vehicle interior.

(3) Outside air waste heat heating mode: In the outside air waste heat heating mode, the air is heated by using the heat absorbed from the outside air and the waste heat absorbed from the waste heat device 80 and blown into the vehicle interior. This is an operation mode for heating.

(4) Waste heat heating mode: The waste heat heating mode is an operation mode in which the inside of the vehicle is heated by heating the air using the waste heat absorbed from the waste heat device 80 and blowing it into the vehicle interior.

(5) Waste heat heating mode during frost formation: In the waste heat heating mode during frost formation, the air is heated by using the waste heat absorbed from the waste heat device 80 when the outdoor heat exchanger 16 is frosted and cannot be used. This is an operation mode in which the interior of the vehicle is heated by blowing it into the interior of the vehicle.

Switching between these operation modes is performed by executing the control program. The control program is executed when the ignition switch of the vehicle is turned on (ON).

When the air conditioner switch provided on the operation panel 70 is turned on (ON) and the target blowing temperature TAO is equal to or lower than the cooling reference temperature Tcl, the cooling mode is selected. The target blowout temperature TAO is calculated using the following formula F1.
TAO = Kset x Tset-Kr x Tr-Kam x Tam-Ks x As + C ... (F1)
In addition, Tset is the vehicle interior set temperature set by the temperature setting switch. Tr is the vehicle interior temperature detected by the internal air temperature sensor 61. Tam is the outside temperature of the vehicle interior detected by the outside air temperature sensor 62. As is the amount of solar radiation detected by the solar radiation sensor 63. Kset, Kr, Kam, and Ks are control gains, and C is a correction constant.

When the outside air temperature Tam is less than the heating reference temperature Tht, or when the air conditioner switch is not turned on (OFF), one of the outside air heating mode, the outside air waste heat heating mode, and the waste heat heating mode is selected. To.

When any one of the outside air heating mode, the outside air waste heat heating mode, and the waste heat heating mode is selected, as shown in FIG. 3, the intake refrigerant temperature Ts, the outside temperature Tam, and the second low temperature side heat medium temperature are selected. Based on TWL2, the outside air heating mode, the outside air waste heat heating mode, and the waste heat heating mode are switched. As shown in FIG. 3, when frost is formed on the outdoor heat exchanger 16 in the outside air heating mode, the outside air waste heat heating mode, and the waste heat heating mode, the mode is switched to the waste heat heating mode at the time of frost formation.

The suction refrigerant temperature Ts is the temperature of the refrigerant sucked into the compressor 11. In the present embodiment, as the suction refrigerant temperature Ts, the refrigerant saturation temperature calculated from the refrigerant pressure P2 (that is, the pressure of the refrigerant flowing out from the refrigerant passage of the chiller 19) detected by the second refrigerant pressure sensor 65b is used. .. As the intake refrigerant temperature Ts, the temperature T3 of the refrigerant detected by the third refrigerant temperature sensor 64c (that is, the temperature of the refrigerant flowing out from the outdoor heat exchanger 16) and the temperature T5 of the refrigerant detected by the fifth refrigerant temperature sensor 64e (that is, the temperature of the refrigerant flowing out from the outdoor heat exchanger 16). That is, the lower temperature of the temperature of the refrigerant flowing out from the refrigerant passage of the chiller 19) may be used. The second low temperature side heat medium temperature TWL2 is the temperature of the low temperature side heat medium flowing out from the waste heat apparatus 80.

Hereinafter, the switching conditions of the outside air heating mode, the outside air waste heat heating mode, the waste heat heating mode, and the waste heat heating mode at the time of frost formation will be described with reference to FIG.

In the outside air heating mode, the state in which the temperature difference (outside air refrigerant temperature difference) obtained by subtracting the intake refrigerant temperature Ts from the outside air temperature Tam is equal to or more than the heat-absorbable temperature difference α1 continues for the first duration t1 or more, and is the first. 2 When the low temperature side heat medium temperature TWL2 is equal to or higher than the value obtained by adding the first predetermined temperature difference β1 to the heat absorption possible temperature TW1, the mode shifts to the outside air waste heat heating mode.

The endothermic temperature difference α1 is about 0 to 10 ° C (for example, 5 ° C). The first duration t1 is about 0 to 60 seconds (for example, 30 seconds). The values of the endothermic temperature difference α1 and the first duration t1 are the values experimentally obtained as the endothermic temperature difference and time that can be reliably absorbed from the outside air by the outdoor heat exchanger 16.

The first predetermined temperature difference β1 is about 0 to 5 ° C. The value of the first predetermined temperature difference β1 is a value experimentally obtained as a temperature difference capable of reliably absorbing heat from the low temperature side heat medium in the chiller 19.

The endothermic temperature TW1 is the larger of the value obtained by adding the second predetermined temperature difference β2 to the outside air temperature Tam and the value obtained by adding the third predetermined temperature difference β3 to the endothermic lower limit temperature TWmin. That is, the endothermic temperature TW1 is determined using the following mathematical formula F2.
TW1 = MAX [Tam + β2, TWmin + β3] ... (F2)
The second predetermined temperature difference β2 is about 0 to 10 ° C (for example, 5 ° C). The third predetermined temperature difference β3 is about 0 to 10 ° C (for example, 5 ° C). The values of the second predetermined temperature difference β2 and the third predetermined temperature difference β3 are the values experimentally obtained as the temperature difference in which the low temperature side heat medium can be used as the heat source for heating.

The endothermic lower limit temperature TWmin is a temperature set from the viewpoint of preventing dew condensation on the waste heat device 80 and from the device characteristics, and is basically set to a temperature equal to or higher than the outside air temperature.

In the outside air waste heat heating mode, the state in which the temperature difference obtained by subtracting the intake refrigerant temperature Ts from the outside air temperature Tam is the lower limit temperature difference α2 or less continues for the second duration t2 or more, and the second low temperature side heat medium. When the temperature TWL2 is equal to or higher than the heat absorbing temperature TW1, the mode shifts to the waste heat heating mode.

The lower limit temperature difference α2 is about 0 to 4 ° C (for example, 2 ° C). The second duration t2 is about 0 to 60 seconds (for example, 30 seconds). The lower limit temperature difference α2 and the second duration t2 are values experimentally obtained as the temperature difference and time at which it becomes difficult for the outdoor heat exchanger 16 to absorb heat from the outside air.

The lower limit temperature difference α2 is set to a value smaller than the endothermic temperature difference α1. As a result, the transition from the outside air waste heat heating mode to the waste heat heating mode can be suppressed as much as possible, and the efficiency and performance of heating can be improved as much as possible.

In the waste heat heating mode, when the temperature difference obtained by subtracting the intake refrigerant temperature Ts from the outside air temperature Tam is the endothermic temperature difference α1 or more for the first duration t1 or more, the outside air waste heat heating mode is set. Transition.

In the waste heat heating mode, when the second low temperature side heat medium temperature TWL2 is equal to or less than the endothermic lower limit temperature TWmin, the mode shifts to the outside air heating mode.

In the outside air waste heat heating mode, the state in which the temperature difference obtained by subtracting the intake refrigerant temperature Ts from the outside air temperature Tam is the lower limit temperature difference α2 or less continues for the second duration t2 or more, and the second low temperature side heat medium. When the temperature TWL2 is lower than the heat absorbing temperature TW1, the mode shifts to the outside air heating mode. In the outside air waste heat heating mode, even when the second low temperature side heat medium temperature TWL2 is equal to or less than the endothermic lower limit temperature TWmin, the mode shifts to the outside air heating mode.

If frost occurs on the outdoor heat exchanger 16 in any of the outside air heating mode, the outside air waste heat heating mode, and the waste heat heating mode, the mode shifts to the waste heat heating mode at the time of frost formation. For example, when the intake refrigerant temperature Ts is lower than the outside air temperature Tam by a predetermined value or more for a predetermined time or longer, it is determined that frost has formed on the outdoor heat exchanger 16.

In the waste heat heating mode at the time of frost formation, if the outdoor heat exchanger 16 is not frosted, the mode shifts to one of the outside air heating mode, the outside air waste heat heating mode, and the waste heat heating mode. For example, it shifts to the operation mode that was executed immediately before shifting to the waste heat heating mode at the time of frost formation. For example, when the suction refrigerant temperature Ts continues to be at or above the frosting temperature (for example, 0 ° C.) for a predetermined time or longer, it is determined that frosting has not occurred in the outdoor heat exchanger 16.

The operation of the vehicle air conditioner 1 in each operation mode will be described below. In each operation mode, the control device 60 executes the control flow of each operation mode.

(1) Cooling mode In the control flow of the cooling mode, the rotation speed of the compressor 11 is based on the deviation between the target evaporator temperature TEO and the evaporator temperature Tefin detected by the evaporator temperature sensor 64f, by a feedback control method. , The evaporator temperature Tefin is determined to approach the target evaporator temperature TEO.

The target evaporator temperature TEO is determined based on the target blowout temperature TAO with reference to the control map stored in the control device 60. In the control map of the present embodiment, it is determined that the target evaporator temperature TEO increases as the target blowout temperature TAO increases.

In the control flow of the cooling mode, the throttle opening of the cooling expansion valve 14b is based on the deviation between the target supercooling degree SCO1 and the supercooling degree SC1 of the outlet side refrigerant of the outdoor heat exchanger 16 by the feedback control method. The supercooling degree SC1 of the outlet side refrigerant of the outdoor heat exchanger 16 is determined to approach the target supercooling degree SCO1.

The target supercooling degree SCO1 is determined with reference to the control map, for example, based on the outside air temperature Tam. In the control map of the present embodiment, the target supercooling degree SCO1 is determined so that the coefficient of performance (COP) of the cycle approaches the maximum value.

The degree of supercooling SC1 of the outlet side refrigerant of the outdoor heat exchanger 16 is calculated based on the temperature T3 detected by the third refrigerant temperature sensor 64c and the pressure P1 detected by the first refrigerant pressure sensor 65a.

In the control flow of the cooling mode, the opening SW of the air mix door 34 is calculated using the following mathematical formula F3.
SW = {TAO- (Tefin + C2)} / {TWH- (Tefin + C2)} ... (F3)
The TWH is the high temperature side heat medium temperature detected by the high temperature side heat medium temperature sensor 66a. C2 is a constant for control.

In the control flow of the cooling mode, in order to switch the refrigerating cycle device 10 to the refrigerant circuit of the cooling mode, the expansion valve 14a for heating is set to the fully open state, the expansion valve 14b for cooling is set to the throttle state to exert the refrigerant depressurizing action, and endothermic. The expansion valve 14c is fully closed, the dehumidifying on-off valve 15a is closed, and the heating on-off valve 15b is closed.

Therefore, in the refrigerating cycle device 10 in the cooling mode, the compressor 11, the water refrigerant heat exchanger 12, the heating expansion valve 14a, the outdoor heat exchanger 16, the second check valve 17b, the cooling expansion valve 14b, and the indoor evaporator A steam compression type refrigeration cycle in which the refrigerant circulates in the order of 18, the evaporation pressure regulating valve 20, the accumulator 21, and the compressor 11 is configured.

That is, in the refrigerating cycle device 10 in the cooling mode, the water refrigerant heat exchanger 12 and the outdoor heat exchanger 16 function as a radiator (in other words, a radiator) for dissipating the refrigerant discharged from the compressor 11 for cooling. A steam compression type refrigeration cycle is configured in which the expansion valve 14b functions as a pressure reducing unit for reducing the pressure of the refrigerant, and the indoor evaporator 18 functions as an evaporator.

According to this, the air can be cooled by the indoor evaporator 18, and the high temperature side heat medium can be heated by the water refrigerant heat exchanger 12.

Therefore, in the vehicle air conditioner 1 in the cooling mode, a part of the air cooled by the indoor evaporator 18 is reheated by the heater core 42 by adjusting the opening degree of the air mix door 34, and approaches the target blowout temperature TAO. By blowing out the air whose temperature has been adjusted so as to be blown into the vehicle interior, the vehicle interior can be cooled.

(2) Outside air heating mode In the control flow of the outside air heating mode, the rotation speed of the compressor 11 is on the high temperature side by the feedback control method based on the deviation between the target high temperature side heat medium temperature TWHO and the high temperature side heat medium temperature TWH. The heat medium temperature TWH is determined to approach the target high temperature side heat medium temperature TWHO.

The target high temperature side heat medium temperature TWHO is determined with reference to the control map based on the target blowout temperature TAO and the efficiency of the heater core 42. In the control map of the present embodiment, it is determined that the target high temperature side heat medium temperature TWHO increases as the target blowout temperature TAO increases.

In the control flow of the outside air heating mode, the throttle opening of the heating expansion valve 14a is a feedback control method based on the deviation between the target supercooling degree SCO2 and the supercooling degree SC2 of the outlet side refrigerant of the water refrigerant heat exchanger 12. Therefore, the supercooling degree SC2 is determined to approach the target supercooling degree SCO2.

The target supercooling degree SCO2 is determined with reference to the control map, for example, based on the outside air temperature Tam. In the control map of the present embodiment, the target supercooling degree SCO1 is determined so that the coefficient of performance (COP) of the cycle approaches the maximum value. The degree of supercooling SC2 of the outlet side refrigerant of the water refrigerant heat exchanger 12 is calculated based on the temperature T2 detected by the second refrigerant temperature sensor 64b and the pressure P1 detected by the first refrigerant pressure sensor 65a.

In the control flow of the outside air heating mode, the endothermic expansion valve 14c is fully closed, and the opening SW of the air mix door 34 is calculated in the same manner as in the cooling mode. In the outside air heating mode, the target outlet temperature TAO becomes high, so that the opening SW of the air mix door 34 approaches 100%. Therefore, in the outside air heating mode, the opening degree of the air mix door 34 is determined so that almost the entire flow rate of the air after passing through the indoor evaporator 18 passes through the heater core 42.

In the control flow of the outside air heating mode, in order to switch the refrigerating cycle device 10 to the refrigerant circuit of the outside air heating mode, the heating expansion valve 14a is set to the throttled state, the cooling expansion valve 14b is set to the fully closed state, and the endothermic expansion valve 14c is set. Is fully closed, the dehumidifying on-off valve 15a is closed, and the heating on-off valve 15b is opened.

Therefore, in the refrigeration cycle device 10 in the outside air heating mode, the compressor 11, the water refrigerant heat exchanger 12, the heating expansion valve 14a, the outdoor heat exchanger 16, the heating passage 22b, the accumulator 21, and the compressor 11 are used in this order. A circulating steam compression refrigeration cycle is constructed.

That is, in the refrigeration cycle device 10 in the outside air heating mode, the water refrigerant heat exchanger 12 functions as a radiator (in other words, a radiator) that dissipates heat from the refrigerant discharged from the compressor 11, and the heating expansion valve 14a decompresses. A refrigeration cycle is configured in which the outdoor heat exchanger 16 functions as an evaporator, which functions as a unit.

According to this, heat can be absorbed from the outside air by the outdoor heat exchanger 16 and the high temperature side heat medium can be heated by the water refrigerant heat exchanger 12. Therefore, in the vehicle air conditioner 1 in the outside air heating mode, the interior of the vehicle can be heated by blowing out the air heated by the heater core 42 into the interior of the vehicle.

(3) Outside air waste heat heating mode In the control flow of the outside air waste heat heating mode, the rotation speed of the compressor 11, the throttle opening of the heating expansion valve 14a, and the opening SW of the air mix door 34 are the same as in the outside air heating mode. Is decided.

In the control flow of the outside air waste heat heating mode, the throttle opening of the endothermic expansion valve 14c is based on the deviation between the target superheat degree SHCO and the superheat degree SHC of the outlet side refrigerant of the chiller 19, and the degree of superheat is determined by the feedback control method. The SHC is determined to approach the target superheat degree SHCO. As the target superheat degree SHCO, a predetermined constant (5 ° C. in this embodiment) can be adopted.

The degree of superheat SHC of the outlet side refrigerant of the chiller 19 is calculated based on the temperature T5 detected by the fifth refrigerant temperature sensor 64e and the pressure P2 detected by the second refrigerant pressure sensor 65b.

Further, in the outside air waste heat heating mode, the throttle opening of the heat absorption expansion valve 14c is the second by the feedback control method based on the deviation between the target low temperature side heat medium temperature TWLO and the second low temperature side heat medium temperature TWL2. The low temperature side heat medium temperature TWL2 is determined so as not to fall below the target low temperature side heat medium temperature TWLO. Specifically, when the second low temperature side heat medium temperature TWL2 is about to fall below the target low temperature side heat medium temperature TWLO, the throttle opening of the heat absorption expansion valve 14c is reduced to reduce the flow rate of the refrigerant in the chiller 19. Thereby, the amount of heat absorbed from the low temperature side heat medium in the chiller 19 is reduced to suppress the decrease in the second low temperature side heat medium temperature TWL2.

Further, in the control flow of the outside air waste heat heating mode, the suction refrigerant temperature Ts is set to the outside air temperature by the feedback control method based on the deviation between the outside air temperature Tam and the intake refrigerant temperature Ts in the throttle opening of the endothermic expansion valve 14c. It is decided not to exceed Tam. Specifically, when the suction refrigerant temperature Ts is about to exceed the outside temperature Tam, the throttle opening of the heat absorption expansion valve 14c is reduced to reduce the refrigerant flow rate in the chiller 19, thereby reducing the low temperature side in the chiller 19. The amount of heat absorbed from the heat medium is reduced to suppress an increase in the intake refrigerant temperature Ts.

In the control flow of the outside air waste heat heating mode, in order to switch the refrigeration cycle device 10 to the refrigerant circuit of the outside air waste heat heating mode, the heating expansion valve 14a is set to the throttled state, the cooling expansion valve 14b is set to the fully closed state, and heat absorption is performed. The expansion valve 14c is set to the throttled state, the dehumidifying on-off valve 15a is opened, and the heating on-off valve 15b is opened.

Therefore, in the refrigeration cycle device 10 in the outside air waste heat heating mode, the compressor 11, the water refrigerant heat exchanger 12, the heating expansion valve 14a, the outdoor heat exchanger 16, the heating passage 22b, the accumulator 21, and the compressor 11 are in this order. A steam compression type refrigeration cycle in which the refrigerant circulates in the order of the compressor 11, the water refrigerant heat exchanger 12, the bypass passage 22a, the heat absorption expansion valve 14c, the chiller 19, the accumulator 21, and the compressor 11 is configured. Will be done.

That is, in the refrigeration cycle device 10 in the outside air waste heat heating mode, the water-refrigerant heat exchanger 12 functions as a radiator (in other words, a radiator) that dissipates the refrigerant discharged from the compressor 11, and the heating expansion valve 14a A refrigeration cycle is configured in which the heat absorption expansion valve 14c functions as a pressure reducing unit, and the outdoor heat exchanger 16 and the chiller 19 function as an evaporator.

According to this, the outdoor heat exchanger 16 absorbs heat from the outside air, the chiller 19 absorbs heat from the waste heat device 80 via the low temperature side heat medium, and the water refrigerant heat exchanger 12 heats the high temperature side heat medium. can do. Therefore, in the vehicle air conditioner 1 in the outside air waste heat heating mode, the interior of the vehicle can be heated by blowing out the air heated by the heater core 42 into the interior of the vehicle.

(4) Waste heat heating mode In the control flow of the waste heat heating mode, the rotation speed of the compressor 11 and the opening SW of the air mix door 34 are determined as in the outside air heating mode. In the control flow of the waste heat heating mode, the heating expansion valve 14a is fully closed.

In the control flow of the waste heat heating mode, the throttle opening of the heat absorption expansion valve 14c is feedback controlled based on the deviation between the target supercooling degree SCO2 and the supercooling degree SC2 of the outlet side refrigerant of the water refrigerant heat exchanger 12. The method determines that the supercooling degree SC2 approaches the target supercooling degree SCO2.

In the control flow of the waste heat heating mode, in order to switch the refrigeration cycle device 10 to the refrigerant circuit of the waste heat heating mode, the heating expansion valve 14a and the cooling expansion valve 14b are fully closed, and the endothermic expansion valve 14c is throttled. In this state, the dehumidifying on-off valve 15a is opened, and the heating on-off valve 15b is closed.

Therefore, in the refrigeration cycle device 10 in the waste heat heating mode, the steam in which the refrigerant circulates in the order of the compressor 11, the water refrigerant heat exchanger 12, the bypass passage 22a, the heat absorption expansion valve 14c, the chiller 19, the accumulator 21, and the compressor 11. A compression refrigeration cycle is constructed.

That is, in the refrigeration cycle device 10 in the waste heat heating mode, the water-refrigerant heat exchanger 12 functions as a radiator (in other words, a heat dissipation unit) that dissipates heat from the refrigerant discharged from the compressor 11, and the endothermic expansion valve 14c is used. A refrigeration cycle is configured in which the chiller 19 functions as a decompressor and an evaporator.

According to this, the chiller 19 can absorb heat from the waste heat device 80 via the low temperature side heat medium, and the water refrigerant heat exchanger 12 can heat the high temperature side heat medium. Therefore, in the vehicle air conditioner 1 in the waste heat heating mode, the interior of the vehicle can be heated by blowing out the air heated by the heater core 42 into the interior of the vehicle.

(5) Waste heat heating mode during frost formation In the control flow of the waste heat heating mode during frost formation, the throttle opening of the endothermic expansion valve 14c and the opening SW of the air mix door 34 are determined as in the waste heat heating mode. Will be done. In the control flow of the waste heat heating mode at the time of frost formation, the heating expansion valve 14a is fully closed as in the waste heat heating mode.

In the control flow of the waste heat heating mode at the time of frost formation, the rotation speed of the compressor 11 is basically determined in the same manner as in the waste heat heating mode. However, in the control flow of the waste heat heating mode at the time of frost formation, the rotation speed of the compressor 11 is determined so that the second low temperature side heat medium temperature TWL2 does not fall below the endothermic lower limit temperature TWmin. Specifically, when the second low temperature side heat medium temperature TWL2 is likely to fall below the endothermic lower limit temperature TWmin, the rotation speed of the compressor 11 is lowered. This is because if the second low temperature side heat medium temperature TWL2 falls below the endothermic lower limit temperature TWmin, the chiller 19 cannot absorb heat, the compressor 11 stops, and heating cannot be performed.

In the control flow of the waste heat heating mode at the time of frost, the refrigeration cycle device 10 is switched to the same refrigerant circuit as the waste heat heating mode.

According to this, when the outdoor heat exchanger 16 is frosted and cannot absorb heat from the outside air, the interior of the vehicle can be heated while maintaining the state where the chiller 19 can absorb heat from the low temperature side heat medium as much as possible.

In each of the heating modes (2) to (5), dehumidifying and heating can be performed by setting the cooling expansion valve 14b to the throttled state.

As described above, in the refrigerating cycle device 10 of the present embodiment, various operation modes can be switched. As a result, the vehicle air conditioner 1 can realize comfortable air conditioning in the vehicle interior.

FIG. 4 is a Moriel diagram showing a change in the state of the refrigerant in the outside air waste heat heating mode of the present embodiment. As shown in FIG. 4, in the outside air waste heat heating mode, the refrigerant temperature in the outdoor heat exchanger 16 is lower than the outside air temperature, and the refrigerant temperature in the chiller 19 is higher than the waste heat temperature (that is, the temperature of the low temperature side heat medium). If it is low, the heat can be absorbed from the outside air and the waste heat of the waste heat apparatus 80 can be absorbed for heating, so that the efficiency and performance of heating can be improved.

FIG. 5 is a Moriel diagram showing a change in the state of the refrigerant in the outside air waste heat heating mode of the comparative example. In this comparative example, the low pressure of the refrigeration cycle rises by absorbing the waste heat of the waste heat device 80 in the outside air waste heat heating mode, and the refrigerant temperature in the outdoor heat exchanger 16 becomes higher than the outside air temperature. Shows. As described above, when the refrigerant temperature in the outdoor heat exchanger 16 becomes higher than the outside air temperature, the outdoor heat exchanger 16 dissipates heat from the refrigerant to the outside air, resulting in deterioration of heating efficiency and performance.

In view of this point, in the present embodiment, in the outside air waste heat heating mode, the temperature difference obtained by subtracting the intake refrigerant temperature Ts from the outside air temperature Tam is the lower limit temperature difference α2 or less, and the temperature TWL2 of the low temperature side heat medium absorbs heat. If the possible temperature is TW1 or higher, the mode is switched to the waste heat heating mode.

According to this, even if the low pressure of the refrigeration cycle rises due to waste heat endothermic, it is possible to suppress heat dissipation from the refrigerant by the outdoor heat exchanger 16 by switching to the waste heat heating mode, so that the efficiency and performance of heating can be improved. Deterioration can be suppressed.

In the present embodiment, in the outside air heating mode, the temperature difference obtained by subtracting the intake refrigerant temperature Ts from the outside air temperature Tam is equal to or more than the heat absorbing temperature difference α1, and the temperature TWL2 of the low temperature side heat medium is first predetermined to the heat absorbing temperature TW1. If the temperature difference is equal to or greater than the value obtained by adding β1, the mode is switched to the outside air waste heat heating mode.

As a result, when heat can be absorbed from the waste heat device 80 in the outside air heating mode, the heating efficiency and performance can be improved by switching to the outside air waste heat heating mode.

In the present embodiment, in the waste heat heating mode, when the temperature difference obtained by subtracting the intake refrigerant temperature Ts from the outside air temperature Tam is equal to or more than the heat absorbing possible temperature difference α1, the mode is switched to the outside air waste heat heating mode. As a result, when heat can be absorbed from the outside air in the waste heat heating mode, the heating efficiency and performance can be improved by switching to the outside air waste heat heating mode.

In the present embodiment, in the waste heat heating mode, when the temperature TWL2 of the low temperature side heat medium is equal to or less than the endothermic lower limit temperature TWmin, the mode is switched to the outside air heating mode. As a result, the heating operation can be continued while suppressing the supercooling of the waste heat device 80.

In the present embodiment, in the outside air waste heat heating mode, the temperature difference obtained by subtracting the intake refrigerant temperature Ts from the outside temperature Tam is the lower limit temperature difference α2 or less, and the temperature TWL2 of the low temperature side heat medium is less than the heat absorbing temperature difference α1. In this case, or when the temperature TWL2 of the low temperature side heat medium is equal to or less than the heat absorption lower limit temperature TWmin, the mode is switched to the outside air heating mode.

According to this, if heat cannot be absorbed from the outside air in the outside air waste heat heating mode and heat cannot be absorbed from the waste heat device 80, the heat can be absorbed from the outside air as soon as possible by switching to the outside air heating mode. When the outside air waste heat heating mode cannot absorb heat from the outside air or the waste heat device 80 cannot absorb heat, the waste heat device 80 can switch to the outside air heating mode and continue the heating operation while suppressing supercooling.

In the present embodiment, the refrigerant discharge capacity of the compressor 11 is controlled so as to prevent the temperature TWL2 of the low temperature side heat medium from falling below the heat absorption lower limit temperature TWmin in the waste heat heating mode at the time of frost formation.

As a result, it is possible to prevent the compressor 11 from stopping due to the inability to absorb waste heat in the waste heat heating mode at the time of frost formation, so that it is possible to suppress a large fluctuation in the temperature of the air blown into the vehicle interior.

In the present embodiment, in the outside air heating mode, the opening degree of the heating expansion valve 14a is controlled based on the supercooling degree SC2 of the refrigerant flowing out from the water refrigerant heat exchanger 12. In the waste heat heating mode, the opening degree of the endothermic expansion valve 14c is controlled based on the supercooling degree SC2 of the refrigerant flowing out from the water refrigerant heat exchanger 12. In the outside air waste heat heating mode, the opening degree of the heating expansion valve 14a is controlled based on the supercooling degree SC2 of the refrigerant flowing out from the water refrigerant heat exchanger 12, and based on the superheating degree SHC of the refrigerant flowing out from the chiller 19. The opening degree of the heat absorption expansion valve 14c is controlled.

Thereby, in the outside air heating mode, the waste heat heating mode, and the outside air waste heat heating mode, the opening degree of the heating expansion valve 14a and the opening degree of the heat absorption expansion valve 14c are appropriately controlled, and the outdoor heat exchanger 16 and the chiller are used. The refrigerant pressure at 19 (in other words, the refrigerant temperature) can be appropriately controlled.

In the outside air waste heat heating mode, the opening degree of the heat absorption expansion valve 14c is controlled based on the supercooling degree SC2 of the refrigerant flowing out from the water refrigerant heat exchanger 12, and the evaporated refrigerant flowing out from the outdoor heat exchanger 16 is controlled. The opening degree of the heating expansion valve 14a may be controlled based on the degree of superheat SHC.

In the present embodiment, in the outside air waste heat heating mode, the opening degree of the endothermic expansion valve 14c is controlled so that the temperature Ts of the refrigerant sucked into the compressor 11 does not exceed the outside air temperature Tam. As a result, the frequency of switching between the outside air waste heat heating mode and the waste heat heating mode can be reduced, so that the fluctuation of the blowing temperature due to the mode switching can be reduced.

In the present embodiment, in the outside air waste heat heating mode, the opening degree of the endothermic expansion valve 14c is controlled so as to prevent the temperature TWL2 of the low temperature side heat medium from becoming the endothermic lower limit temperature TWmin or less. As a result, the frequency of switching between the outside air waste heat heating mode and the outside air heating mode can be reduced, so that the fluctuation of the blowing temperature due to the mode switching can be reduced.

(Second Embodiment)
The refrigerating cycle device 10 of the first embodiment is an accumulator cycle including an accumulator 21, but the refrigerating cycle device 10 of the present embodiment is a receiver cycle including a receiver 25 instead of the accumulator 21 as shown in FIG. Is.

The inlet side of the three-way valve 15e is arranged at the discharge port of the compressor 11. The three-way valve 15e is an electric three-way flow rate adjusting valve having one inlet and two outlets and capable of continuously adjusting the passage area ratio of the two outlets. The three-way valve 15e is controlled by a control signal output from the control device 60.

The inlet side of the refrigerant passage of the water refrigerant heat exchanger 12 is connected to one of the outlets of the three-way valve 15e. The first connection port side of the seventh joint 13g is connected to the other outlet of the three-way valve 15e via the first cooling passage 22c.

One connection port side of the outdoor heat exchanger 16 is connected to the second connection port of the 7th joint 13g. The first inflow port side of the fourth joint 13d is connected to the third connection port of the seventh joint 13g via the heating passage 22b. A heating on-off valve 15b is arranged at a portion of the heating passage 22b between the 7th joint 13g and the 4th joint 13d.

One inflow port side of the eighth joint 13h is connected to the outlet of the refrigerant passage of the water refrigerant heat exchanger 12. A fourth check valve 17d is arranged in the refrigerant passage connecting the outlet side of the refrigerant passage of the water refrigerant heat exchanger 12 and the one inlet side of the eighth joint 13h. The fourth check valve 17d allows the refrigerant to flow from the water-refrigerant heat exchanger 12 side to the eighth joint 13h side, and prohibits the refrigerant from flowing from the eighth joint 13h side to the water-refrigerant heat exchanger 12 side. do.

The refrigerant inlet side of the receiver 25 is connected to the outlet of the 8th joint 13h. The receiver 25 is a liquid storage unit having a gas-liquid separation function. That is, the receiver 25 separates the gas and liquid of the refrigerant flowing out from the heat exchange unit that functions as a condenser that condenses the refrigerant in the refrigeration cycle device 10. Then, the receiver 25 causes a part of the separated liquid phase refrigerant to flow out to the downstream side, and stores the remaining liquid phase refrigerant as the surplus refrigerant in the cycle.

The inlet side of the first joint 13a is connected to the refrigerant outlet of the receiver 25. The inlet side of the heating expansion valve 14a is connected to one of the outlets of the first joint 13a. The first connection port side of the ninth joint 13i is connected to the outlet of the heating expansion valve 14a. The refrigerant inlet side of the outdoor heat exchanger 16 is connected to the second connection port of the ninth joint 13i. The other inlet side of the eighth joint 13h is connected to the third connection port of the ninth joint 13i via the second cooling passage 22d.

A fifth check valve 17e is arranged in the second cooling passage 22d. The fifth check valve 17e allows the refrigerant to flow from the ninth joint 13i side to the eighth joint 13h side, and prohibits the refrigerant from flowing from the eighth joint 13h side to the ninth joint 13i side.

The inlet side of the fifth joint 13e is connected to the other outlet of the first joint 13a via the bypass passage 22a. The fifth joint 13e is a three-way joint similar to the first joint 13a. The inlet side of the cooling expansion valve 14b is connected to one of the outlets of the fifth joint 13e. The inlet side of the endothermic expansion valve 14c is connected to the other outlet of the fifth joint 13e.

In the present embodiment, the dehumidifying on-off valve 15a of the first embodiment is not arranged in the bypass passage 22a.

The refrigerating cycle device 10 is provided with first, third to fifth

refrigerant temperature sensors

64a, 64c to 64e, and second to fifth refrigerant pressure sensors 65e. The detection signal of these sensor groups is input to the control device 60.

The third refrigerant pressure sensor 65c is a third refrigerant pressure detecting unit that detects the pressure P3 of the refrigerant discharged from the compressor 11. The fourth refrigerant pressure sensor 65d is a fourth refrigerant pressure detecting unit that detects the pressure P4 of the refrigerant flowing out from the outdoor heat exchanger 16. The fifth refrigerant pressure sensor 65e is a fifth refrigerant pressure detecting unit that detects the pressure P5 of the refrigerant flowing out of the indoor evaporator 18.

Next, the operation of the vehicle air conditioner of the present embodiment having the above configuration will be described. In the refrigeration cycle device 10 of the present embodiment, as in the first embodiment, there are five operation modes: cooling mode, outside air heating mode, outside air waste heat heating mode, waste heat heating mode, and waste heat heating mode at the time of frost formation. It is possible to perform air-conditioning operation in. The conditions for switching these operation modes are the same as those in the first embodiment.

(1) Cooling mode In the control flow of the cooling mode, the rotation speed of the compressor 11 and the opening degree SW of the air mix door 34 are determined as in the cooling mode of the first embodiment. In the control flow of the cooling mode, the endothermic expansion valve 14c is fully closed.

In the control flow of the cooling mode, the throttle opening of the expansion valve 14b for cooling is based on the deviation between the target superheat degree SHEO and the superheat degree SHE of the outlet side refrigerant of the indoor evaporator 18, and the indoor evaporator is operated by a feedback control method. The superheat degree SH of the outlet side refrigerant of 18 is determined to approach the target superheat degree SHEO.

As the target superheat degree SHEO, a predetermined constant (5 ° C. in this embodiment) can be adopted. The degree of superheat SHE of the outlet-side refrigerant of the indoor evaporator 18 is calculated based on the temperature T4 detected by the fourth refrigerant temperature sensor 64d and the pressure P5 detected by the fifth refrigerant pressure sensor 65e.

In the cooling mode control flow, in order to switch the refrigerating cycle device 10 to the cooling mode refrigerant circuit, the control device 60 closes the heating on-off valve 15b, and the three-way valve 15e closes the outlet on the water refrigerant heat exchanger 12 side. Close and open the outlet on the 22c side of the first cooling passage. Further, the control device 60 puts the heating expansion valve 14a in a fully closed state, the cooling expansion valve 14b in a throttle state that exerts a refrigerant depressurizing action, and the endothermic expansion valve 14c in a fully closed state.

As a result, in the refrigerating cycle device 10 in the cooling mode, the compressor 11, the first cooling passage 22c, the outdoor heat exchanger 16, the second cooling passage 22d, the receiver 25, the bypass passage 22a, the cooling expansion valve 14b, and the indoor. A steam compression type refrigeration cycle in which the refrigerant circulates in the order of the evaporator 18 and the compressor 11 is configured.

Therefore, the refrigerating cycle device 10 in the cooling mode can cool the vehicle interior in the same manner as in the cooling mode of the first embodiment.

(2) Outside air heating mode In the control flow of the outside air heating mode, the rotation speed of the compressor 11 and the opening degree SW of the air mix door 34 are determined as in the outside air heating mode of the first embodiment.

In the control flow of the outside air heating mode, the throttle opening of the heating expansion valve 14a is overheated by the feedback control method based on the deviation between the target superheat degree SHO1 and the superheat degree SH1 of the outlet side refrigerant of the outdoor heat exchanger 16. Degree SH1 is determined to approach the target superheat degree SHO1.

As the target superheat degree SHO1, a predetermined constant (5 ° C. in this embodiment) can be adopted. The degree of superheat SH1 of the outlet side refrigerant of the outdoor heat exchanger 16 is calculated based on the temperature T3 detected by the third refrigerant temperature sensor 64c and the pressure P4 detected by the fourth refrigerant pressure sensor 65d.

In the control flow of the outside air heating mode, in order to switch the refrigerating cycle device 10 to the refrigerant circuit of the outside air heating mode, the control device 60 opens the heating on-off valve 15b, and the three-way valve 15e is the flow on the water refrigerant heat exchanger 12 side. The outlet is opened and the outlet on the side of the first cooling passage 22c is closed. Further, the control device 60 puts the heating expansion valve 14a in a throttled state that exerts a refrigerant depressurizing action, and puts the cooling expansion valve 14b and the endothermic expansion valve 14c in a fully closed state.

As a result, in the refrigeration cycle device 10 in the outside air heating mode, steam compression in which the refrigerant circulates in the order of the compressor 11, the water refrigerant heat exchanger 12, the receiver 25, the heating expansion valve 14a, the outdoor heat exchanger 16, and the compressor 11. The formula refrigeration cycle is constructed.

Therefore, in the refrigerating cycle device 10 in the outside air heating mode, heat is absorbed from the outside air by the outdoor heat exchanger 16 and the high temperature side heat medium is used by the water refrigerant heat exchanger 12 as in the outside air heating mode of the first embodiment. It can be heated to heat the interior of the vehicle.

(3) Outside air waste heat heating mode In the control flow of the outside air waste heat heating mode, the rotation speed of the compressor 11, the throttle opening of the heating expansion valve 14a, and the air mix door 34 are the same as in the outside air heating mode of the present embodiment. The opening degree SW is determined.

In the control flow of the outside air waste heat heating mode, the throttle opening of the endothermic expansion valve 14c is determined as in the outside air waste heat heating mode of the first embodiment.

In the control flow of the outside air waste heat heating mode, in order to switch the refrigeration cycle device 10 to the refrigerant circuit of the outside air waste heat heating mode, the control device 60 opens the heating on-off valve 15b, and the three-way valve 15e is the water refrigerant heat exchanger. The outlet on the 12 side is opened and the outlet on the first cooling passage 22c side is closed. Further, the control device 60 puts the heating expansion valve 14a in a throttle state that exerts a refrigerant decompression effect, the cooling expansion valve 14b in a fully closed state, and the endothermic expansion valve 14c in a throttle state that exerts a refrigerant decompression action. ..

As a result, in the refrigeration cycle device 10 in the outside air waste heat heating mode, the compressor 11, the water refrigerant heat exchanger 12, the receiver 25, the expansion valve 14a for heating, the outdoor heat exchanger 16, and the suction port of the compressor 11 are circulated in this order. At the same time, a steam compression type refrigeration cycle in which the refrigerant circulates in the order of the receiver 25, the heat absorption expansion valve 14c, the chiller 19, and the suction port of the compressor 11 is configured.

Therefore, in the refrigerating cycle device 10 in the outside air waste heat heating mode, heat is absorbed from the outside air by the outdoor heat exchanger 16 and the low temperature side heat medium is used by the chiller 19 as in the outside air waste heat heating mode of the first embodiment. It is possible to heat the interior of the vehicle by absorbing heat from the waste heat device 80 and heating the heat medium on the high temperature side with the water refrigerant heat exchanger 12.

(4) Waste heat heating mode In the control flow of the waste heat heating mode, the rotation speed of the compressor 11 and the opening SW of the air mix door 34 are determined as in the waste heat heating mode of the first embodiment. ..

In the control flow of the waste heat heating mode, the throttle opening of the endothermic expansion valve 14c is based on the deviation between the target superheat degree SHCO and the superheat degree SHC of the outlet side refrigerant of the chiller 19, and the superheat degree SHC is used by the feedback control method. Is determined to approach the target superheat degree SHCO. As the target superheat degree SHCO, a predetermined constant (5 ° C. in this embodiment) can be adopted.

In the control flow of the waste heat heating mode, in order to switch the refrigeration cycle device 10 to the refrigerant circuit of the waste heat heating mode, the control device 60 closes the heating on-off valve 15b, and the three-way valve 15e is on the water refrigerant heat exchanger 12 side. The outlet on the 22c side of the first cooling passage 22c is closed by opening the outlet. Further, the control device 60 puts the heating expansion valve 14a and the cooling expansion valve 14b in a fully closed state, and puts the endothermic expansion valve 14c in a throttle state that exerts a refrigerant depressurizing action.

As a result, in the refrigeration cycle device 10 in the waste heat heating mode, the refrigerant is supplied in the order of the compressor 11, the water refrigerant heat exchanger 12, the receiver 25, the bypass passage 22a, the heat absorption expansion valve 14c, the chiller 19, and the suction port of the compressor 11. A circulating steam compression refrigeration cycle is constructed.

Therefore, in the refrigerating cycle device 10 in the waste heat heating mode, heat is absorbed from the waste heat device 80 via the low temperature side heat medium by the chiller 19 and heat exchange is performed in the water refrigerant, as in the waste heat heating mode of the first embodiment. The air inside the vehicle can be heated by heating the air with the vessel 12.

(5) Waste heat heating mode during frost In the control flow of the waste heat heating mode during frost formation, the throttle opening of the endothermic expansion valve 14c and the opening of the air mix door 34 are the same as in the waste heat heating mode of the present embodiment. The SW is determined, and the heating expansion valve 14a is fully closed.

In the control flow of the frosted waste heat heating mode, the rotation speed of the compressor 11 is determined as in the frosted waste heat heating mode of the first embodiment.

In the control flow of the waste heat heating mode at the time of frost formation, the refrigerating cycle device 10 is switched to the same refrigerant circuit as the waste heat heating mode of the present embodiment.

According to this, similar to the waste heat heating mode at the time of frost formation of the first embodiment, when the outdoor heat exchanger 16 is frosted and cannot absorb heat from the outside air, the chiller 19 absorbs heat from the low temperature side heat medium. It is possible to heat the interior of the vehicle while maintaining the state in which it can be done as much as possible.

Even for a heat pump cycle using a receiver as in the present embodiment, it is possible to switch to an appropriate heating mode as in the first embodiment.

In the present embodiment, in the outside air heating mode, the opening degree of the heating expansion valve 14a is controlled based on the superheat degree SH1 of the refrigerant flowing out from the outdoor heat exchanger 16. In the waste heat heating mode, the opening degree of the endothermic expansion valve 14c is controlled based on the superheat degree SHC of the refrigerant flowing out from the chiller 19. In the outside air waste heat heating mode, the opening degree of the heating expansion valve 14a is controlled based on the superheat degree SH1 of the refrigerant flowing out from the outdoor heat exchanger 16, and for heat absorption based on the superheat degree SH1 of the refrigerant flowing out from the chiller 19. The opening degree of the expansion valve 14c is controlled.

The present disclosure is not limited to the above-described embodiment, and can be variously modified as follows without departing from the spirit of the present disclosure.

In the above-described embodiment, the refrigeration cycle device 10 capable of switching to a plurality of operation modes has been described, but the switching of the operation mode of the refrigeration cycle device 10 is not limited to this. At least, it suffices if the operation mode targeted for oil return control can be executed.

The components of the refrigeration cycle device are not limited to those disclosed in the above-described embodiment. A plurality of cycle components may be integrated so that the above-mentioned effects can be exhibited. As the cooling expansion valve 14b and the endothermic expansion valve 14c, those in which an electric expansion valve having no fully closed function and an on-off valve are directly connected may be adopted.

In the above-described embodiment, an example in which R1234yf is adopted as the refrigerant has been described, but the refrigerant is not limited to this. For example, R134a, R600a, R410A, R404A, R32, R407C, etc. may be adopted. A mixed refrigerant or the like in which a plurality of types of these refrigerants are mixed may be adopted. Carbon dioxide may be adopted as the refrigerant to form a supercritical refrigeration cycle in which the pressure of the refrigerant on the high pressure side is equal to or higher than the critical pressure of the refrigerant.

The configuration of the heating unit is not limited to that disclosed in the above-described embodiment. For example, a radiator may be added to the high temperature side heat medium circuit 40 and the low temperature side heat medium circuit 50 described in the first embodiment to dissipate excess heat to the outside air. In a vehicle equipped with an internal combustion engine (engine) such as a hybrid vehicle, engine cooling water may be circulated in the high temperature side heat medium circuit 40.

The configuration of the endothermic unit is not limited to that disclosed in the above-described embodiment. For example, as the endothermic unit, a thermosiphon may be adopted in which the chiller 19 of the low temperature side heat medium circuit 50 described in the first embodiment is used as a condensing unit and the waste heat device 80 functions as an evaporation unit. According to this, the low temperature side heat medium pump 51 can be abolished.

The thermosiphon has an evaporating part for evaporating the refrigerant and a condensing part for condensing the refrigerant, and is configured by connecting the evaporating part and the condensing part in a closed loop shape (that is, in a ring shape). Then, the temperature difference between the temperature of the refrigerant in the evaporating part and the temperature of the refrigerant in the condensing part causes a difference in specific gravity in the refrigerant in the circuit, and the action of gravity naturally circulates the refrigerant to transport heat together with the refrigerant. It is a circuit.

In the above-described embodiment, heat is absorbed from the waste heat device 80 to the refrigerant via the low temperature side heat medium, but heat may be absorbed from the waste heat device 80 to the refrigerant via air, or waste heat may be absorbed. Heat may be absorbed directly from the device 80 to the refrigerant.

In each of the above-described embodiments, the refrigeration cycle device 10 according to the present disclosure is applied to the vehicle air conditioner 1, but the application of the refrigeration cycle device 10 is not limited to this. For example, it may be applied to an air conditioner or the like that performs indoor air conditioning.

Although the present disclosure has been described in accordance with the examples, it is understood that the present disclosure is not limited to the examples and structures. The present disclosure also includes various variations and variations within a uniform range. In addition, various combinations and forms, as well as other combinations and forms that include only one element, more, or less, are within the scope and scope of the present disclosure.

Claims

A compressor (11) that compresses and discharges the refrigerant,
A heating unit (12, 40, 42) that heats the air blown to the air-conditioned space using the discharged refrigerant discharged from the compressor as a heat source.
A heating expansion valve (14a) for reducing the pressure of the refrigerant flowing out of the heating unit, and
An outdoor heat exchanger (16) that exchanges heat between the refrigerant flowing out of the heating expansion valve and the outside air.
A cooling expansion valve (14b) for reducing the pressure of the refrigerant flowing out of the outdoor heat exchanger, and
An indoor evaporator (18) that evaporates the refrigerant flowing out of the cooling expansion valve to cool the air before being heated by the heating unit.
An endothermic expansion valve (14c) that reduces the pressure of the refrigerant flowing out of the outdoor heat exchanger.
An endothermic portion (19, 50) that evaporates the refrigerant flowing out of the endothermic expansion valve and absorbs heat from the endothermic object (80).
A waste heat heating mode refrigerant circuit that does not absorb heat from the outside air with the outdoor heat exchanger but absorbs heat from the endothermic object at the endothermic section, and the endothermic object while absorbing heat from the outside air with the outdoor heat exchanger. The refrigerant circuit switching unit (15a, 15b) that switches to the outside air waste heat heating mode endothermic circuit that absorbs heat from
In the outside air waste heat heating mode, the outside air refrigerant temperature difference, which is the temperature difference obtained by subtracting the temperature (Ts) of the refrigerant sucked into the compressor from the outside air temperature (Tam), is the lower limit temperature difference (α2) or less. Further, when the temperature (TWL2) of the heat-absorbing object is equal to or higher than the heat-absorbable temperature (TW1), the refrigerating cycle device includes a control unit (60) that controls the refrigerant circuit switching unit so as to switch to the waste heat heating mode. ..
The refrigerant circuit switching unit absorbs heat from the outside air by the waste heat heating mode refrigerant circuit, the outside air waste heat heating mode refrigerant circuit, and the outdoor heat exchanger, and does not absorb heat from the heat absorption object by the heat absorption unit. Switch to the refrigerant circuit in outside air heating mode,
In the outside air heating mode, when the outside air refrigerant temperature difference is equal to or greater than the endothermic temperature difference (α1) and the temperature of the endothermic object is equal to or greater than the endothermic temperature, the outside air waste heat heating is performed. The refrigerating cycle device according to claim 1, wherein the refrigerant circuit switching unit is controlled so as to switch to the mode.
The control unit controls the refrigerant circuit switching unit so as to switch to the outside air waste heat heating mode when the temperature difference of the outside air refrigerant is equal to or greater than the endothermic temperature difference (α1) in the waste heat heating mode. The refrigeration cycle apparatus according to 1 or 2.
The refrigerant circuit switching unit absorbs heat from the outside air by the waste heat heating mode refrigerant circuit, the outside air waste heat heating mode refrigerant circuit, and the outdoor heat exchanger, and does not absorb heat from the heat absorption object by the heat absorption unit. Switch to the refrigerant circuit in outside air heating mode,
The control unit controls the refrigerant circuit switching unit so as to switch to the outside air heating mode when the temperature of the endothermic object is equal to or lower than the endothermic lower limit temperature (TWmin) in the waste heat heating mode. The refrigeration cycle apparatus according to any one of 3.
The refrigerant circuit switching unit absorbs heat from the outside air by the waste heat heating mode refrigerant circuit, the outside air waste heat heating mode refrigerant circuit, and the outdoor heat exchanger, and does not absorb heat from the heat absorption object by the heat absorption unit. Switch to the refrigerant circuit in outside air heating mode,
In the outside air waste heat heating mode, the control unit has a case where the outside air refrigerant temperature difference is equal to or less than the lower limit temperature difference and the temperature of the endothermic object is lower than the heat absorbing temperature, or the temperature of the endothermic object is heat absorbing. The refrigerating cycle apparatus according to any one of claims 1 to 4, wherein when the temperature is not less than the lower limit temperature (TWmin), the refrigerant circuit switching unit is controlled so as to switch to the outside air heating mode.
The control unit controls the refrigerant circuit switching unit so as to switch to the refrigerant circuit in the waste heat heating mode when frost is formed on the outdoor heat exchanger, and the temperature of the endothermic object is the endothermic lower limit temperature. The refrigerating cycle apparatus according to any one of claims 1 to 5, wherein the refrigerant discharge capacity of the compressor is controlled so as to prevent the compressor from falling below (TWmin).
A gas-liquid separation unit (21) for separating the gas-liquid of the refrigerant sucked into the compressor and storing the liquid-phase refrigerant is provided.
The refrigerant circuit switching unit absorbs heat from the outside air by the waste heat heating mode refrigerant circuit, the outside air waste heat heating mode refrigerant circuit, and the outdoor heat exchanger, and does not absorb heat from the heat absorption object by the heat absorption unit. Switch to the refrigerant circuit in outside air heating mode,
The control unit
In the outside air heating mode, the opening degree of the heating expansion valve is controlled based on the degree of supercooling (SC2) of the refrigerant flowing out from the heating unit.
In the waste heat heating mode, the opening degree of the endothermic expansion valve is controlled based on the degree of supercooling (SC2) of the refrigerant flowing out from the heating unit.
In the outside air waste heat heating mode, the opening degree of one of the heating expansion valve and the endothermic expansion valve is controlled based on the degree of supercooling (SC2) of the refrigerant flowing out from the heating unit. Claims 1 to 6 for controlling the opening degree of the other expansion valve based on the degree of superheat (SHC) after evaporation of the refrigerant decompressed by the other expansion valve of the heating expansion valve and the endothermic expansion valve. The refrigeration cycle apparatus according to any one.
A gas-liquid separation unit (25) that separates the gas-liquid of the refrigerant flowing out from the heating unit and stores the refrigerant of the liquid phase is provided.
The refrigerant circuit switching unit absorbs heat from the outside air by the waste heat heating mode refrigerant circuit, the outside air waste heat heating mode refrigerant circuit, and the outdoor heat exchanger, and does not absorb heat from the heat absorption object by the heat absorption unit. Switch to the refrigerant circuit in outside air heating mode,
The control unit
In the outside air heating mode, the opening degree of the heating expansion valve is controlled based on the degree of superheat (SH1) of the refrigerant flowing out from the outdoor heat exchanger.
In the waste heat heating mode, the opening degree of the endothermic expansion valve is controlled based on the degree of superheat (SHC) of the refrigerant flowing out from the endothermic unit.
In the outside air waste heat heating mode, the opening degree of the heating expansion valve is controlled based on the superheat degree (SH1) of the refrigerant flowing out from the outdoor heat exchanger, and the superheat degree (SHC) of the refrigerant flowing out from the endothermic unit is controlled. The refrigeration cycle apparatus according to any one of claims 1 to 6, wherein the opening degree of the endothermic expansion valve is controlled based on the above.
The control unit controls the opening degree of the endothermic expansion valve so that the temperature of the refrigerant sucked into the compressor does not exceed the outside air temperature in the outside air waste heat heating mode. The refrigeration cycle device according to one.
The control unit controls the opening degree of the endothermic expansion valve so as to prevent the temperature of the endothermic object from becoming equal to or lower than the endothermic lower limit temperature (TWmin) in the outside air waste heat heating mode. 9. The refrigeration cycle apparatus according to any one of 9.