WO2018092464A1 - Refrigeration cycle device - Google Patents

Abstract

This refrigeration cycle device is provided with switching units (38, 39) which switch between: a state in which a heat medium in a first heat medium refrigerant heat exchanger and a heat medium in a second heat medium refrigerant heat exchanger circulate independently of each other; and a state in which the heat media circulate between the first heat medium refrigerant heat exchanger and the second heat medium refrigerant heat exchanger. In this refrigeration cycle device, a control device (40) switches between: a first mode in which a first pressure reduction unit and a second pressure reduction unit operate so that a refrigerant absorbs heat in an outside air refrigerant heat exchanger and in which the switching unit operates so that the heat medium in the first heat medium refrigerant heat exchanger and the heat medium in the second heat medium refrigerant heat exchanger circulate independently of each other; and a second mode in which the first pressure reduction unit and the second pressure reduction unit operate so that the refrigerant radiates heat in the outside air refrigerant heat exchanger and in which the switching unit operates so that the heat medium circulates between the first heat medium refrigerant heat exchanger and the second heat medium refrigerant heat exchanger.

Description

Refrigeration cycle equipment Cross-reference of related applications

This application is based on Japanese Patent Application No. 2016-222348 filed on November 15, 2016, the disclosure of which is incorporated herein by reference.

The present disclosure relates to a refrigeration cycle apparatus that performs defrosting of a heat exchanger when frost forms on the heat exchanger.

Conventionally, Patent Document 1 describes a refrigeration cycle apparatus capable of switching between a heating mode and a defrosting mode.

In the heating mode, a refrigeration cycle is constructed in which the refrigerant circulates in the order of compressor → condenser → first throttle valve → outdoor heat exchanger → accumulator → compressor. The condenser functions as a radiator and the outdoor heat exchanger is It functions as an evaporator. Thus, the refrigerant absorbs heat from the outside air in the outdoor heat exchanger, and the refrigerant dissipates heat to the air blown into the vehicle interior by the condenser, so that the vehicle interior can be heated.

In the defrosting mode, the refrigerant circulates in the same order as the compressor, the condenser, the first throttle valve, the outdoor heat exchanger, the accumulator, the compressor and the heating mode, but the condenser does not exchange heat, or the gas refrigerant. Constitutes a hot gas cycle that absorbs heat. The low-pressure and high-temperature refrigerant compressed by the compressor flows into the outdoor heat exchanger and radiates heat. Thereby, an outdoor heat exchanger is heated and defrosting of an outdoor heat exchanger is implement | achieved.

JP 2015-33953 A

According to the above prior art, in the heating mode, there are a region where the refrigerant becomes a gas phase and a region where it becomes a liquid phase in the cycle. In other words, in the heating mode, the refrigerant changes phase in the cycle.

On the other hand, in the defrosting mode, unlike the heating mode, the refrigerant enters the gas phase in the entire region of the cycle. Therefore, when switching from the heating mode to the defrosting mode, it takes time until the refrigerant becomes a gas phase in the entire region of the cycle.

In the conventional hot gas cycle, it is difficult to increase the pressure of the refrigerant flowing into the outdoor heat exchanger. Therefore, the temperature and density of the refrigerant flowing into the outdoor heat exchanger are increased to increase the defrosting capacity. Is difficult.

Therefore, with the above conventional technology, defrosting cannot be terminated early.

This indication aims at providing the refrigerating cycle device which can finish defrosting early in view of the above-mentioned point.

A refrigeration cycle apparatus according to an example of the present disclosure includes:
A compressor for sucking and discharging refrigerant;
A first heat medium refrigerant heat exchanger for radiating heat from the refrigerant discharged from the compressor to the heat medium;
A first decompression unit that decompresses the refrigerant flowing out of the first heat medium refrigerant heat exchanger;
An outside air refrigerant heat exchanger for exchanging heat between the refrigerant flowing out of the first decompression unit and the outside air;
A second decompression unit for decompressing the refrigerant that has flowed out of the outside-air refrigerant heat exchanger;
A second heat medium refrigerant heat exchanger that causes the refrigerant flowing out from the second decompression section to absorb heat from the heat medium;
A state in which the heat medium circulates independently of each other with respect to the first heat medium refrigerant heat exchanger and the second heat medium refrigerant heat exchanger, a first heat medium refrigerant heat exchanger, a second heat medium refrigerant heat exchanger, and A switching unit that switches between a state in which the heat medium circulates between,
The first decompression unit and the second decompression unit operate so that the refrigerant absorbs heat in the outside air refrigerant heat exchanger, and the heat medium is mutually exchanged with respect to the first heat medium refrigerant heat exchanger and the second heat medium refrigerant heat exchanger. The first mode in which the switching unit operates so as to circulate independently, and the first decompression unit and the second decompression unit operate so that the refrigerant radiates heat in the outside-air refrigerant heat exchanger, and the first heat medium refrigerant heat exchange And a control device that switches between a second mode in which the switching unit operates so that the heat medium circulates between the heat exchanger and the second heat medium refrigerant heat exchanger.

According to this, in the second mode, since the high-temperature refrigerant flows into the outside air refrigerant heat exchanger, the outside air refrigerant heat exchanger can be defrosted. In addition, since the refrigerant changes phase not only in the first mode but also in the second mode, defrosting of the outside-air refrigerant heat exchanger can be started early in the second mode.

Furthermore, since the heat is radiated from the refrigerant to the heat medium by the first heat medium refrigerant heat exchanger, and the heat of the heat medium is absorbed by the refrigerant by the second heat medium refrigerant heat exchanger, compared with the conventional hot gas cycle, The pressure of the refrigerant flowing into the outdoor air refrigerant heat exchanger can be increased. Therefore, the temperature and density of the refrigerant flowing into the outside air refrigerant heat exchanger can be increased, and the defrosting of the outside air refrigerant heat exchanger can be terminated early.

It is a whole block diagram which shows the refrigerating-cycle apparatus in 1st Embodiment, and has shown the operation state of the air_conditioning | cooling mode. It is a block diagram which shows the electric control apparatus of the refrigerating-cycle apparatus in 1st Embodiment. It is a whole block diagram which shows the refrigerating-cycle apparatus in 1st Embodiment, and has shown the operating state of heating mode. It is a whole block diagram which shows the refrigerating-cycle apparatus in 1st Embodiment, and has shown the operating state of the defrost mode. It is a flowchart which shows the control processing which the control apparatus of the refrigerating-cycle apparatus in 1st Embodiment performs.

Hereinafter, embodiments will be described with reference to the drawings. A refrigeration cycle apparatus 10 shown in FIG. 1 is applied to a vehicle air conditioner. The vehicle air conditioner is an air conditioner that adjusts the vehicle interior space to an appropriate temperature. In the present embodiment, the refrigeration cycle apparatus 10 is mounted on a hybrid vehicle that obtains driving force for vehicle travel from an engine (in other words, an internal combustion engine) and a travel electric motor.

The hybrid vehicle of the present embodiment is configured as a plug-in hybrid vehicle capable of charging power supplied from an external power source (in other words, commercial power source) when the vehicle is stopped to a battery (in other words, an in-vehicle battery) mounted on the vehicle. Has been. As the battery, for example, a lithium ion battery can be used.

The driving force output from the engine is used not only for driving the vehicle but also for operating the generator. And the electric power generated by the generator and the electric power supplied from the external power source can be stored in the battery, and the electric power stored in the battery constitutes the refrigeration cycle apparatus 10 as well as the electric motor for traveling. It is supplied to various in-vehicle devices such as electric components.

The refrigeration cycle apparatus 10 is a vapor compression refrigerator that includes a compressor 11, a condenser 12, a first expansion valve 13, an outdoor heat exchanger 14, a second expansion valve 15, and an evaporator 16. In the refrigeration cycle apparatus 10 of the present embodiment, a chlorofluorocarbon refrigerant is used as the refrigerant, and a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the refrigerant critical pressure is configured.

The compressor 11, the condenser 12, the first expansion valve 13, the outdoor heat exchanger 14, the second expansion valve 15 and the evaporator 16 are arranged in series with each other in the refrigerant flow.

The compressor 11 is an electric compressor that is driven by electric power supplied from a battery, and sucks, compresses, and discharges the refrigerant of the refrigeration cycle apparatus 10. The compressor 11 may be a variable capacity compressor driven by a belt.

The condenser 12 is a first heat medium refrigerant heat exchanger that condenses the high-pressure side refrigerant by exchanging heat between the high-pressure side refrigerant discharged from the compressor 11 and the cooling water of the high-temperature cooling water circuit 20.

The cooling water of the high-temperature cooling water circuit 20 is a fluid as a heat medium. The cooling water of the high temperature cooling water circuit 20 is a high temperature heat medium. In this embodiment, a liquid containing at least ethylene glycol, dimethylpolysiloxane or nanofluid, or an antifreeze liquid is used as the cooling water of the high-temperature cooling water circuit 20.

The first expansion valve 13 is a first decompression unit that decompresses and expands the liquid refrigerant flowing out of the condenser 12. The first expansion valve 13 is an electric variable throttle mechanism, and includes a valve body and an electric actuator. The valve body is configured to be able to change the passage opening (in other words, the throttle opening) of the refrigerant passage. The electric actuator has a stepping motor that changes the throttle opening of the valve body.

The first expansion valve 13 is composed of a variable throttle mechanism with a fully open function that fully opens the refrigerant passage when the throttle opening is fully opened. That is, the first expansion valve 13 can prevent the refrigerant from depressurizing by fully opening the refrigerant passage. The operation of the first expansion valve 13 is controlled by a control signal output from the control device 40 shown in FIG.

The outdoor heat exchanger 14 is an outside air refrigerant heat exchanger that exchanges heat between the refrigerant flowing out of the first expansion valve 13 and the outside air. Outside air is blown to the outdoor heat exchanger 14 by an outdoor blower 17.

The outdoor blower 17 is an outside air blower that blows outside air toward the outdoor heat exchanger 14. The outdoor blower 17 is an electric blower that drives a fan with an electric motor. The outdoor heat exchanger 14 and the outdoor blower 17 are disposed in the foremost part of the vehicle. Accordingly, the traveling wind can be applied to the outdoor heat exchanger 14 when the vehicle is traveling.

When the temperature of the refrigerant flowing through the outdoor heat exchanger 14 is lower than the temperature of the outside air, the outdoor heat exchanger 14 functions as a heat absorber that causes the refrigerant to absorb the heat of the outside air. When the temperature of the refrigerant flowing through the outdoor heat exchanger 14 is higher than the temperature of the outside air, the outdoor heat exchanger 14 functions as a radiator that radiates the heat of the refrigerant to the outside air.

The second expansion valve 15 is a second decompression unit that decompresses and expands the liquid-phase refrigerant that has flowed out of the outdoor heat exchanger 14. The second expansion valve 15 is an electric variable throttle mechanism, and includes a valve body and an electric actuator. The valve body is configured to be able to change the passage opening (in other words, the throttle opening) of the refrigerant passage. The electric actuator has a stepping motor that changes the throttle opening of the valve body.

The second expansion valve 15 is composed of a variable throttle mechanism with a fully open function that fully opens the refrigerant passage when the throttle opening is fully opened. That is, the second expansion valve 15 can prevent the refrigerant from depressurizing by fully opening the refrigerant passage. The operation of the second expansion valve 15 is controlled by a control signal output from the control device 40.

1) By changing the throttle opening degree of the first expansion valve 13 and the second expansion valve 15, the cooling mode shown in FIG. 1, the heating mode shown in FIG. 3, and the defrosting mode shown in FIG. 4 are switched. The first expansion valve 13 and the second expansion valve 15 are operation mode switching units that switch between a cooling mode, a heating mode, and a defrosting mode.

The cooling mode and the defrosting mode are heat radiation modes in which the outdoor heat exchanger 14 radiates heat from the refrigerant to the outside air. The heating mode is an endothermic mode in which the outdoor heat exchanger 14 absorbs heat from the outside air to the refrigerant. The heating mode is the first mode, and the defrosting mode is the second mode.

The evaporator 16 is a second heat medium refrigerant heat exchanger that evaporates the low-pressure refrigerant by exchanging heat between the low-pressure refrigerant flowing out of the second expansion valve 15 and the cooling water of the low-temperature cooling water circuit 30. The gas-phase refrigerant evaporated in the evaporator 16 is sucked into the compressor 11 and compressed.

The cooling water in the low-temperature cooling water circuit 30 is a fluid as a heat medium. The cooling water of the low-temperature cooling water circuit 30 is a low-temperature heat medium. In this embodiment, as the cooling water of the low-temperature cooling water circuit 30, a liquid containing at least ethylene glycol, dimethylpolysiloxane or nanofluid, or an antifreeze liquid is used.

The outdoor heat exchanger 14 includes a heat exchange unit 141, a liquid storage unit 142, and a supercooling unit 143. The heat exchanging unit 141 of the outdoor heat exchanger 14 exchanges heat between the refrigerant flowing out of the first expansion valve 13 and the outside air. The liquid storage part 142 of the outdoor heat exchanger 14 is a refrigerant storage part that separates the gas-liquid refrigerant flowing out from the heat exchange part 141 of the outdoor heat exchanger 14 and stores excess refrigerant. The supercooling unit 143 of the outdoor heat exchanger 14 supercools the liquid phase refrigerant by exchanging heat between the liquid refrigerant flowing out of the liquid storage unit 142 of the outdoor heat exchanger 14 and the outside air.

In the high temperature cooling water circuit 20, a condenser 12, a high temperature side pump 21, a heater core 22, and a high voltage heater 23 are arranged. In the low-temperature cooling water circuit 30, an evaporator 16, a low-temperature side pump 31, a cooler core 32 and a waste heat device 33 are arranged.

The high temperature side pump 21 and the low temperature side pump 31 are heat medium pumps that draw in and discharge cooling water. The high temperature side pump 21 and the low temperature side pump 31 are electric pumps. The high temperature side pump 21 is a high temperature side flow rate adjusting unit that adjusts the flow rate of the cooling water circulating in the high temperature cooling water circuit 20. The low temperature side pump 31 is a low temperature side flow rate adjusting unit that adjusts the flow rate of the cooling water circulating in the low temperature cooling water circuit 30.

The heater core 22 is a high temperature side heat medium heat exchanger that heats the air blown into the vehicle interior by exchanging heat between the cooling water of the high-temperature coolant circuit 20 and the air blown into the vehicle interior. In the heater core 22, the cooling water radiates heat to the air blown into the vehicle interior.

The high voltage heater 23 is a heater that generates heat when high voltage power is supplied and heats the cooling water of the high temperature cooling water circuit 20.

The condenser 12, the high temperature side pump 21, the heater core 22, and the high voltage heater 23 are arranged in series with each other in the cooling water flow of the high temperature cooling water circuit 20.

The high-temperature cooling water circuit 20 has a condenser bypass passage 24 and a bypass three-way valve 25. The heater core bypass passage 24 is a cooling water passage through which the cooling water of the high-temperature cooling water circuit 20 flows by bypassing the condenser 12. The bypass three-way valve 25 is an electromagnetic valve that switches between opening and closing the cooling water passage on the condenser 12 side and the condenser bypass passage 24. The operation of the bypass three-way valve 25 is controlled by the control device 40.

The cooler core 32 is a low-temperature heat medium heat exchanger that cools the air blown into the vehicle interior by exchanging heat between the cooling water of the low-temperature coolant circuit 30 and the air blown into the vehicle interior. In the cooler core 32, the cooling water absorbs heat from the air blown into the vehicle interior.

The waste heat device 33 is an in-vehicle device that dissipates waste heat generated in operation to the cooling water of the low-temperature cooling water circuit 30. The waste heat device 33 is a heat supply unit that supplies heat to the cooling water of the low-temperature cooling water circuit 30. For example, the waste heat device 33 is a battery, an inverter, an electric motor for traveling, or the like. The inverter is a power converter that converts DC power supplied from the battery into AC power and outputs the AC power to the traveling electric motor.

The evaporator 16 and the low temperature side pump 31 are arranged in series with each other in the cooling water flow of the low temperature cooling water circuit 30. The cooler core 32 and the waste heat device 33 are arranged in parallel with each other in the cooling water flow of the low-temperature cooling water circuit 30.

The low-temperature cooling water circuit 30 has a cooler core side opening / closing valve 34 and a waste heat equipment side opening / closing valve 35. The cooler core side opening / closing valve 34 is an electromagnetic valve that opens and closes the cooling water passage on the cooler core 32 side. The waste heat equipment side opening / closing valve 35 is an electromagnetic valve that opens and closes the cooling water flow path on the waste heat equipment 33 side. The operation of the cooler core side opening / closing valve 34 and the waste heat equipment side opening / closing valve 35 is controlled by the control device 40.

The cooler core side on / off valve 34 and the waste heat equipment side on / off valve 35 are a cooler core switching unit that switches between a state in which the cooling water of the low-temperature cooling water circuit 30 flows through the cooler core 32 and a state in which the coolant flows by bypassing the cooler core 32. The cooler core side opening / closing valve 34 and the waste heat equipment side opening / closing valve 35 are switches for waste heat equipment that switch between a state in which the cooling water of the low-temperature cooling water circuit 30 flows through the waste heat equipment 33 and a state in which the cooling water flows by bypassing the waste heat equipment 33. Part.

A first connection flow path 36 and a second connection flow path 37 are connected to the high temperature cooling water circuit 20 and the low temperature cooling water circuit 30. The first connection flow path 36 communicates a portion on the cooling water outlet side of the condenser 12 in the high temperature cooling water circuit 20 and a portion on the cooling water suction side of the low temperature side pump 31 in the low temperature cooling water circuit 30. Yes. The second connection flow path 37 includes a portion on the cooling water outlet side of the cooler core 32 and the waste heat device 33 in the low temperature cooling water circuit 30 and a portion on the cooling water inlet side of the condenser 12 in the high temperature cooling water circuit 20. Communicate.

A first connection three-way valve 38 is disposed at a connection portion between the first connection flow path 36 and the low-temperature cooling water circuit 30. The first connection three-way valve 38 is an electromagnetic valve that switches between the cooling water flow path on the cooling water outlet side of the cooler core 32 and the waste heat device 33 and the first connection flow path 36. The operation of the first connection three-way valve 38 is controlled by the control device 40.

A second connection three-way valve 39 is disposed at a connection portion between the second connection flow path 37 and the high temperature cooling water circuit 20. The second connection three-way valve 39 is an electromagnetic valve that switches between the cooling water flow path on the cooling water discharge side of the high temperature side pump 21 and the second connection flow path 37. The operation of the second connection three-way valve 39 is controlled by the control device 40.

The cooler core 32 and the heater core 22 are accommodated in a casing (hereinafter referred to as an air conditioning casing) of an indoor air conditioning unit (not shown). The indoor air conditioning unit is disposed inside an instrument panel (not shown) at the front of the vehicle interior. The air conditioning casing is an air passage forming member that forms an air passage.

The heater core 22 is disposed on the air flow downstream side of the cooler core 32 in the air passage in the air conditioning casing. In the air conditioning casing, an inside / outside air switching box (not shown) and an indoor fan (not shown) are arranged. The inside / outside air switching box is an inside / outside air switching unit that switches between introduction of inside air and outside air into an air passage in the air conditioning casing. The indoor blower sucks and blows the inside air and the outside air introduced into the air passage in the air conditioning casing through the inside / outside air switching box.

An air mix door (not shown) is arranged between the cooler core 32 and the heater core 22 in the air passage in the air conditioning casing. The air mix door adjusts the air volume ratio between the cool air that has passed through the cooler core 32 and the cool air that flows into the heater core 22 and the cool air that bypasses the heater core 22 and flows.

The air mix door is a rotary door having a rotary shaft that is rotatably supported with respect to the air conditioning casing, and a door base plate portion coupled to the rotary shaft. By adjusting the opening position of the air mix door, the temperature of the conditioned air blown from the air conditioning casing into the vehicle compartment can be adjusted to a desired temperature.

¡The rotary shaft of the air mix door is driven by a servo motor. The operation of the servo motor is controlled by the control device 40.

The air mix door may be a slide door that slides in a direction substantially orthogonal to the air flow. The sliding door may be a plate-like door formed of a rigid body. It may be a film door formed of a flexible film material.

The control device 40 shown in FIG. 2 includes a known microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof. The control device 40 performs various calculations and processes based on a control program stored in the ROM. Various devices to be controlled are connected to the output side of the control device 40. The control device 40 is a control unit that controls operations of various devices to be controlled.

The control target devices controlled by the control device 40 include the compressor 11, the first expansion valve 13, the second expansion valve 15, the outdoor blower 17, the high temperature side pump 21, the high voltage heater 23, the bypass three-way valve 25, and the low temperature side pump. 31, a cooler core side opening / closing valve 34, a waste heat equipment side opening / closing valve 35, a first connection three-way valve 38, a second connection three-way valve 39, and the like.

Software and hardware for controlling the electric motor of the compressor 11 in the control device 40 is a refrigerant discharge capacity control unit. Software and hardware for controlling the first expansion valve 13 in the control device 40 is a first throttle control unit. Software and hardware for controlling the second expansion valve 15 in the control device 40 is a second throttle control unit.

Software and hardware for controlling the outdoor blower 17 in the control device 40 are an outside air blowing capacity control unit. Software and hardware for controlling the high temperature side pump 21 in the control device 40 is a high temperature heat medium flow control unit. Software and hardware for controlling the low temperature side pump 31 in the control device 40 is a low temperature heat medium flow control unit.

Software and hardware for controlling the high voltage heater 23 in the control device 40 is a heater control unit. Software and hardware for controlling the bypass three-way valve 25 in the control device 40 is a bypass three-way valve control unit.

Software and hardware for controlling the cooler core side on / off valve 34 in the control device 40 is a cooler core side on / off valve controller. Software and hardware for controlling the waste heat equipment side on / off valve 35 in the control device 40 is a waste heat equipment side on / off valve controller.

Software and hardware for controlling the first connection three-way valve 38 and the second connection three-way valve 39 in the control device 40 are a connection three-way valve control unit.

On the input side of the control device 40, an inside air temperature sensor 41, an outside air temperature sensor 42, a solar radiation amount sensor 43, an outdoor heat exchanger temperature sensor 44, an evaporator temperature sensor 45, a heater core temperature sensor 46, a refrigerant pressure sensor 47, high temperature cooling. Various control sensor groups such as a water temperature sensor 48 and a low-temperature cooling water temperature sensor 49 are connected.

The inside air temperature sensor 41 detects the passenger compartment temperature Tr. The outside air temperature sensor 42 detects the outside air temperature Tam. The solar radiation amount sensor 43 detects the solar radiation amount Ts in the passenger compartment.

The outdoor heat exchanger temperature sensor 44 is a temperature detection unit that detects the temperature of the outdoor heat exchanger 14. The outdoor heat exchanger temperature sensor 44 includes, for example, a fin thermistor that detects the temperature of heat exchange fins of the outdoor heat exchanger 14, a water temperature sensor that detects the temperature of cooling water flowing through the outdoor heat exchanger 14, and an outdoor heat exchanger. 14 is an air temperature sensor that detects the temperature of the outside air that has flowed out of the air.

The evaporator temperature sensor 45 is a temperature detection unit that detects the temperature of the evaporator 16. The evaporator temperature sensor 45 is, for example, a fin thermistor that detects the temperature of the heat exchange fins of the evaporator 16, a refrigerant temperature sensor that detects the temperature of the refrigerant flowing through the evaporator 16, and the like.

The heater core temperature sensor 46 is a temperature detection unit that detects the temperature of the heater core 22. The heater core temperature sensor 46 is, for example, a fin thermistor that detects the temperature of heat exchange fins of the heater core 22, a refrigerant temperature sensor that detects the temperature of cooling water that flows through the heater core 22, or air that detects the temperature of the air that has flowed out of the heater core 22. Temperature sensor or the like.

The refrigerant pressure sensor 47 is a refrigerant pressure detector that detects the pressure of the refrigerant discharged from the compressor 11. Instead of the refrigerant pressure sensor 47, a refrigerant temperature sensor may be connected to the input side of the control device 40. The refrigerant temperature sensor is a refrigerant pressure detection unit that detects the temperature of the refrigerant discharged from the compressor 11. The control device 40 may estimate the refrigerant pressure based on the refrigerant temperature.

The high temperature cooling water temperature sensor 48 is a temperature detection unit that detects the temperature of the cooling water in the high temperature cooling water circuit 20. For example, the high-temperature cooling water temperature sensor 48 detects the temperature of the cooling water in the condenser 12.

The low-temperature cooling water temperature sensor 49 is a temperature detection unit that detects the temperature of the cooling water in the low-temperature cooling water circuit 30. For example, the low-temperature cooling water temperature sensor 49 detects the temperature of the cooling water in the evaporator 16.

Various control switches (not shown) are connected to the input side of the control device 40. Various operation switches are provided on the operation panel 50 and are operated by a passenger. The operation panel 50 is disposed near the instrument panel in the front part of the vehicle interior. Operation signals from various operation switches are input to the control device 40.

The various operation switches are air conditioner switches, temperature setting switches, and the like. The air conditioner switch sets whether to cool the air in the indoor air conditioning unit. The temperature setting switch sets a set temperature in the passenger compartment.

Next, the operation in the above configuration will be described. The control device 40 switches the operation mode to either the cooling mode shown in FIG. 1 or the heating mode shown in FIG. 3 based on the target outlet temperature TAO or the like.

The target air temperature TAO is the target temperature of the air that is blown out into the passenger compartment. The control device 40 calculates the target blowing temperature TAO based on the following mathematical formula.

TAO = Kset × Tset−Kr × Tr−Kam × Tam−Ks × Ts + C
In this equation, Tset is the vehicle interior set temperature set by the temperature setting switch of the operation panel 50, Tr is the inside air temperature detected by the inside air temperature sensor 41, Tam is the outside air temperature detected by the outside air temperature sensor 42, and Ts is This is the amount of solar radiation detected by the solar radiation amount sensor 43. Kset, Kr, Kam, Ks are control gains, and C is a correction constant.

When the control device 40 determines that the outdoor heat exchanger 14 may be frosted in the heating mode, the control device 40 switches to the defrosting mode shown in FIG. For example, in the heating mode, the control device 40 determines that the outdoor heat exchanger 14 may be frosted based on a temperature difference obtained by subtracting the temperature of the cooling water in the low-temperature cooling water circuit 30 from the outside air temperature.

Next, the operation in the cooling mode, heating mode and defrosting mode will be described.

(Cooling mode)
In the cooling mode shown in FIG. 1, the control device 40 sets the first expansion valve 13 to a fully open state and the second expansion valve 15 to a throttle state.

The control device 40 determines the operating states (control signals output to the various control devices) of the various control devices connected to the control device 40 based on the target blowing temperature TAO, the detection signal of the sensor group, and the like.

With respect to the control signal output to the second expansion valve 15, the superheat degree of the refrigerant flowing into the compressor 11 approaches the target superheat degree that is set in advance so that the coefficient of performance (so-called COP) of the cycle approaches the maximum value. To be determined.

Regarding the control signal output to the servo motor of the air mix door (not shown), the air mix door closes the air passage of the heater core 22, and the total flow rate of the blown air passing through the cooler core 32 bypasses the air passage of the heater core 22. Decided to flow.

In the cooling mode, the compressor 11 and the low temperature side pump 31 are operated, and the high temperature side pump 21 is stopped.

In the cooling mode, the cooler core side opening / closing valve 34 opens the cooling water flow path on the cooler core 32 side. Thereby, the cooling water of the low-temperature cooling water circuit 30 circulates in the cooler core 32 and the air is cooled by the cooler core 32.

In the cooling mode, the waste heat equipment side opening / closing valve 35 opens the cooling water flow path on the waste heat equipment 33 side when the waste heat equipment 33 needs to be cooled. Thereby, the cooling water of the low-temperature cooling water circuit 30 circulates in the waste heat equipment 33 and the waste heat equipment 33 is cooled.

In the cooling mode, the first connection three-way valve 38 closes the first connection flow path 36, and the second connection three-way valve 39 closes the second connection flow path 37. Thereby, the cooling water of the low-temperature cooling water circuit 30 does not circulate to the condenser 12.

In the refrigeration cycle apparatus 10 in the cooling mode, the state of the refrigerant circulating in the cycle changes as follows.

That is, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12. At this time, since the cooling water does not circulate in the condenser 12, the refrigerant flowing into the condenser 12 hardly exchanges heat with the cooling water.

The refrigerant that has flowed out of the condenser 12 flows into the first expansion valve 13. At this time, since the first expansion valve 13 fully opens the refrigerant passage, the refrigerant flowing out of the condenser 12 flows into the outdoor heat exchanger 14 without being depressurized by the first expansion valve 13.

The refrigerant flowing into the outdoor heat exchanger 14 radiates heat to the outside air. Thereby, the refrigerant is cooled and condensed in the outdoor heat exchanger 14.

The refrigerant that has flowed out of the outdoor heat exchanger 14 flows into the second expansion valve 15 and is decompressed and expanded at the second expansion valve 15 until it becomes a low-pressure refrigerant. The low-pressure refrigerant decompressed by the second expansion valve 15 flows into the evaporator 16 and absorbs heat from the cooling water in the low-temperature cooling water circuit 30 to evaporate. Thereby, the cooling water of the low-temperature cooling water circuit 30 is cooled.

The refrigerant flowing out of the evaporator 16 flows to the suction side of the compressor 11 and is compressed again by the compressor 11.

As described above, in the cooling mode, the evaporator 16 absorbs heat from the cooling water of the low-temperature cooling water circuit 30 to the low-pressure refrigerant, and the cooler core 32 absorbs heat from the air to the cooling water of the low-temperature cooling water circuit 30 to be cooled. Air can be blown into the passenger compartment. Thereby, cooling of a vehicle interior is realizable.

(Heating mode)
In the heating mode shown in FIG. 3, the control device 40 places the first expansion valve 13 in the throttle state and makes the second expansion valve 15 fully open.

The control device 40 determines the operating states (control signals output to the various control devices) of the various control devices connected to the control device 40 based on the target blowing temperature TAO, the detection signal of the sensor group, and the like.

The control signal output to the first expansion valve 13 is determined so that the superheat degree of the refrigerant flowing into the first expansion valve 13 approaches a predetermined target superheat degree. The target superheat degree is determined so that the coefficient of performance (so-called COP) of the cycle approaches the maximum value.

As for a control signal output to a servo motor of an air mix door (not shown), the air mix door fully opens the air passage of the heater core 22 so that the total flow rate of the blown air that has passed through the cooler core 32 passes through the air passage of the heater core 22. To be determined.

In the heating mode, the compressor 11, the outdoor blower 17, the high temperature side pump 21, and the low temperature side pump 31 are operated.

In the heating mode, the bypass three-way valve 25 closes the condenser bypass passage 24. Thereby, the cooling water of the high-temperature cooling water circuit 20 circulates in the condenser 12.

In the heating mode, the cooler core side opening / closing valve 34 closes the cooling water flow path on the cooler core 32 side. Thereby, the cooling water of the low-temperature cooling water circuit 30 does not circulate in the cooler core 32. In the heating mode, the waste heat equipment side opening / closing valve 35 opens the cooling water flow path on the waste heat equipment 33 side. Thereby, the cooling water of the low-temperature cooling water circuit 30 circulates in the waste heat equipment 33.

In the heating mode, the first connection three-way valve 38 closes the first connection flow path 36, and the second connection three-way valve 39 closes the second connection flow path 37. Thereby, in the high temperature cooling water circuit 20 and the low temperature cooling water circuit 30, the cooling water circulates independently of each other.

In the heating mode, the state of the refrigerant circulating in the cycle changes as follows. That is, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12 and radiates heat by exchanging heat with the cooling water in the high-temperature cooling water circuit 20. Thereby, the cooling water of the high temperature cooling water circuit 20 is heated.

The refrigerant that has flowed out of the condenser 12 flows into the first expansion valve 13 and is decompressed until it becomes a low-pressure refrigerant. The low-pressure refrigerant decompressed by the first expansion valve 13 flows into the outdoor heat exchanger 14, absorbs heat from the outside air blown from the outdoor blower 17, and evaporates.

The refrigerant that has flowed out of the outdoor heat exchanger 14 flows into the second expansion valve 15. At this time, since the second expansion valve 15 is fully opened, the refrigerant flowing out of the outdoor heat exchanger 14 flows into the evaporator 16 without being depressurized by the second expansion valve 15.

The low-pressure refrigerant flowing into the evaporator 16 exchanges heat with the cooling water in the low-temperature cooling water circuit 30 and absorbs heat. Thereby, the cooling water of the low-temperature cooling water circuit 30 is cooled. The refrigerant flowing out of the evaporator 16 flows to the suction side of the compressor 11 and is compressed again by the compressor 11.

As described above, in the heating mode, the heat of the high-pressure refrigerant discharged from the compressor 11 is radiated to the cooling water of the high-temperature cooling water circuit 20 by the condenser 12, and the heat of the cooling water of the high-temperature cooling water circuit 20 is released. Heat can be radiated to the air by the heater core 22, and the air heated by the heater core 22 can be blown out into the vehicle interior. Thereby, heating of a vehicle interior is realizable.

Since the cooling water of the low-temperature cooling water circuit 30 circulates through the waste heat equipment 33, the waste heat of the waste heat equipment 33 is absorbed into the cooling water of the low-temperature cooling water circuit 30 and the evaporator 16 cools the low-temperature cooling water circuit 30. Heat can be absorbed from the water into the low-pressure refrigerant. Therefore, the waste heat of the waste heat device 33 can be used for heating the passenger compartment.

(Defrost mode)
In the defrosting mode shown in FIG. 4, the control device 40 sets the first expansion valve 13 to a fully open state and the second expansion valve 15 to a throttle state.

The control device 40 determines the operating states (control signals output to the various control devices) of the various control devices connected to the control device 40 based on the target blowing temperature TAO, the detection signal of the sensor group, and the like.

As for a control signal output to a servo motor of an air mix door (not shown), the air mix door fully opens the air passage of the heater core 22 so that the total flow rate of the blown air that has passed through the cooler core 32 passes through the air passage of the heater core 22. To be determined.

In the defrosting mode, the compressor 11, the high temperature side pump 21, and the low temperature side pump 31 are operated, and the outdoor blower 17 is stopped.

In the defrosting mode, the bypass three-way valve 25 closes the cooling water passage on the condenser 12 side and opens the condenser bypass passage 24. Thereby, the cooling water of the high-temperature cooling water circuit 20 does not circulate in the condenser 12.

In the defrosting mode, the cooler core side opening / closing valve 34 closes the cooling water flow path on the cooler core 32 side. Thereby, the cooling water of the low-temperature cooling water circuit 30 does not circulate in the cooler core 32.

In the defrosting mode, the waste heat equipment side opening / closing valve 35 opens the cooling water flow path on the waste heat equipment 33 side. Thereby, the cooling water of the low-temperature cooling water circuit 30 circulates in the waste heat equipment 33.

In the defrosting mode, the first connection three-way valve 38 closes the cooling water flow path on the waste heat equipment 33 side and opens the first connection flow path 36, and the second connection three-way valve 39 operates on the cooling water flow on the high temperature side pump 21 side. The path is closed and the second connection flow path 37 is opened. Thereby, the cooling water of the low-temperature cooling water circuit 30 circulates in the condenser 12.

In the refrigeration cycle apparatus 10 in the defrosting mode, the state of the refrigerant circulating in the cycle changes as follows.

That is, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12. At this time, since the cooling water of the low-temperature cooling water circuit 30 circulates in the condenser 12, the refrigerant flowing into the condenser 12 exchanges heat with the cooling water of the low-temperature cooling water circuit 30 and dissipates heat. Thereby, the cooling water of the low-temperature cooling water circuit 30 is heated.

The refrigerant that has flowed out of the condenser 12 flows into the first expansion valve 13. At this time, since the first expansion valve 13 fully opens the refrigerant passage, the refrigerant flowing out of the condenser 12 flows into the outdoor heat exchanger 14 without being depressurized by the first expansion valve 13.

At this time, since the outdoor blower 17 is stopped, the refrigerant flowing into the outdoor heat exchanger 14 melts frost adhering to the surface of the outdoor heat exchanger 14 without radiating heat to the outside air.

The refrigerant that has flowed out of the outdoor heat exchanger 14 flows into the second expansion valve 15 and is decompressed and expanded at the second expansion valve 15 until it becomes a low-pressure refrigerant. The low-pressure refrigerant decompressed by the second expansion valve 15 flows into the evaporator 16 and absorbs heat from the cooling water in the low-temperature cooling water circuit 30 to evaporate. Thereby, the cooling water of the low-temperature cooling water circuit 30 is cooled.

The refrigerant flowing out of the evaporator 16 flows to the suction side of the compressor 11 and is compressed again by the compressor 11.

As described above, in the defrosting mode, frost adhering to the surface of the outdoor heat exchanger 14 can be melted.

In the defrosting mode, the cooling water of the low-temperature cooling water circuit 30 circulates through the waste heat device 33, so that the waste heat of the waste heat device 33 is transferred to the low-pressure refrigerant of the evaporator 16 via the cooling water of the low-temperature cooling water circuit 30. Can absorb heat.

Since the cooling water in the low-temperature cooling water circuit 30 circulates in the condenser 12, the heat of the high-pressure refrigerant in the condenser 12 can be absorbed by the low-pressure refrigerant in the evaporator 16 through the cooling water in the low-temperature cooling water circuit 30. it can.

Since the cooling water of the high-temperature cooling water circuit 20 circulates through the heater core 22 and the high-voltage heater 23, the heat of the high-voltage heater 23 is dissipated to the cooling water of the high-temperature cooling water circuit 20, and the heater core 22 The heat of the cooling water can be dissipated to the air, and the heated air can be blown out into the passenger compartment. Thereby, heating of a vehicle interior is realizable.

Thus, in the vehicle air conditioner 1 of the present embodiment, appropriate cooling, heating, and defrosting of the vehicle interior are executed by changing the throttle opening of the first expansion valve 13 and the second expansion valve 15. As a result, comfortable air conditioning in the passenger compartment can be realized.

In the heating mode, the cooler core side opening / closing valve 34 opens the cooling water flow path on the cooler core 32 side, whereby the cooling water in the low-temperature cooling water circuit 30 circulates in the cooler core 32 and cools the air in the cooler core 32. It can be performed.

The control device 40 executes the control process shown in the flowchart of FIG. 5 in the defrosting mode. First, in step S100, it is determined whether or not the pressure of the refrigerant discharged from the compressor 11 has reached the target pressure Pt, or whether or not the temperature of the cooling water flowing through the condenser 12 has reached the target cooling water temperature Tt. judge. The target refrigerant pressure Pt is a pressure range having a certain width. The target cooling water temperature Tt is a temperature range having a certain width.

Based on the temperature of the refrigerant discharged from the compressor 11, it may be determined whether or not the refrigerant discharged from the compressor 11 has reached the target pressure Pt.

If it is determined in step S100 that the target refrigerant pressure Pt or the target cooling water temperature Tt has been reached, the process proceeds to step S110, and it is determined whether or not the elapsed time since switching to the defrosting mode has exceeded the lower limit time.

If it is determined in step S110 that the elapsed time since switching to the defrost mode has exceeded the lower limit time, the process proceeds to step S120, and the mode is changed to the heating mode.

On the other hand, if it is determined in step S110 that the elapsed time since switching to the defrost mode does not exceed the lower limit time, the process returns to step S100.

On the other hand, if it is determined in step S100 that the target refrigerant pressure Pt or the target cooling water temperature Tt has not been reached, the process proceeds to step S130, where it is determined whether the elapsed time since switching to the defrost mode has exceeded the upper limit time. judge.

If it is determined in step S130 that the elapsed time since switching to the defrost mode has exceeded the upper limit time, the process proceeds to step S120, and the mode is changed to the heating mode.

On the other hand, if it is determined in step S130 that the elapsed time since switching to the defrost mode does not exceed the upper limit time, the process returns to step S100.

Thereby, in the transient state, it is possible to avoid the defrosting mode being ended when the pressure of the refrigerant discharged from the compressor 11 temporarily fluctuates and reaches the target pressure Pt.

Also, since the time for executing the defrost mode is limited to the maximum time at the longest, a fail-safe function can be provided, for example, when the refrigerant pressure cannot be detected due to a malfunction.

In the present embodiment, the control device 40 switches between the heating mode and the defrosting mode. In the heating mode, the first expansion valve 13 and the second expansion valve 15 operate so that the refrigerant absorbs heat in the outdoor heat exchanger 14, and cooling water circulates independently from each other with respect to the condenser 12 and the evaporator 16. Thus, the first connection three-way valve 38 and the second connection three-way valve 39 operate. In the defrost mode, the first expansion valve 13 and the second expansion valve 15 are operated so that the refrigerant radiates heat in the outdoor heat exchanger 14, and the cooling water is circulated between the condenser 12 and the evaporator 16. The first connection three-way valve 38 and the second connection three-way valve 39 are activated.

According to this, since the high-temperature refrigerant flows into the outdoor heat exchanger 14 in the defrost mode, the outdoor heat exchanger 14 can be defrosted. Further, since the refrigerant changes in phase not only in the heating mode but also in the defrosting mode, the defrosting of the outdoor heat exchanger 14 can be started early in the defrosting mode.

Further, since the condenser 12 radiates heat from the refrigerant to the cooling water, and the heat of the cooling water is absorbed by the refrigerant in the evaporator 16, the refrigerant flowing into the outdoor heat exchanger 14 is compared with the conventional hot gas cycle. The pressure can be increased. Therefore, the temperature and density of the refrigerant flowing into the outdoor heat exchanger 14 can be increased, and the defrosting of the outdoor heat exchanger 14 can be terminated early.

In the present embodiment, the waste heat device 33 supplies heat to the cooling water that circulates between the condenser 12 and the evaporator 16 in the defrosting mode.

According to this, since the heat supplied from the waste heat device 33 can be used as the heat for evaporating the refrigerant in the evaporator 16 in the defrosting mode, the heat for evaporating the refrigerant in the evaporator 16 is insufficient. Can be suppressed.

In this embodiment, the control device 40 operates the first connection three-way valve 38 and the second connection three-way valve 39 so that cooling water circulates between the heater core 22, the heater 23, and the condenser 12 in the heating mode. The control device 40 operates the first connection three-way valve 38 and the second connection three-way valve 39 so that the cooling water circulates between the heater core 22 and the heater 23 independently of the condenser 12 in the defrost mode. .

Thereby, in the defrost mode, the vehicle interior can be heated while defrosting the outdoor heat exchanger 14.

In the present embodiment, the control device 40 stops air blowing from the outdoor fan 17 to the outdoor heat exchanger 14 in the defrosting mode. Thereby, since it can suppress that the heat | fever of the refrigerant | coolant of the outdoor heat exchanger 14 is thermally radiated by outside air, the outdoor heat exchanger 14 can be defrosted efficiently.

In the present embodiment, the control device 40 switches to the defrosting mode when the temperature difference obtained by subtracting the temperature of the cooling water of the evaporator 16 from the temperature of the outside air in the heating mode becomes larger than the threshold value. Thereby, the necessity for defrosting of the outdoor heat exchanger 14 can be judged appropriately, and it can switch to defrosting mode.

In the present embodiment, the control device 40 controls the cooler core side on / off valve 34 and the waste heat equipment side on / off valve so that the cooling water cooled by the evaporator 16 flows bypassing the cooler core 32 during the heating mode and the defrost mode. 35 is activated.

According to this, in the heating mode and the defrosting mode, it is possible to suppress the heat of the cooling water from being radiated to the air via the cooler core 32. Therefore, in the heating mode, it can suppress that the air cooled with the cooler core 32 flows into the heater core 22, and heating efficiency falls, In the defrost mode, the outdoor heat exchanger 14 can be defrosted efficiently.

For example, in the defrost mode, the control device 40 increases the temperature of the coolant discharged from the compressor 11 to the target pressure or the temperature of the cooling water circulating between the condenser 12 and the evaporator 16 is the target temperature. The compressor 11 is actuated so as to rise.

This makes it possible to prioritize the defrosting efficiency of the outdoor heat exchanger 14 over the performance and efficiency of the refrigeration cycle in the defrosting mode, so that the defrosting of the outdoor heat exchanger 14 can be defrosted earlier.

In the present embodiment, as described in steps S100 to S120 of FIG. 5, the control device 40 increases the pressure of the refrigerant discharged from the compressor 11 to the target pressure in the defrosting mode, When the temperature of the cooling water circulating between the evaporator 16 rises to the target temperature and the time elapsed since switching to the defrosting mode exceeds the lower limit time, the heating mode is switched.

Thereby, in defrost mode, it can judge appropriately that defrost of outdoor heat exchanger 14 was completed, and it can switch to heating mode, and control hunting occurs in switching between heating mode and defrost mode. Can be suppressed.

In the present embodiment, as described in step S130 of FIG. 5, the control device 40 switches to the heating mode when the elapsed time after switching to the defrost mode reaches the upper limit time in the defrost mode.

This makes it possible to have a fail-safe function against excessive rises in refrigerant pressure and cooling water temperature.

In the defrost mode, the control device 40 operates the first connection three-way valve 38 and the second connection three-way valve 39 so that the cooling water circulates independently from each other with respect to the condenser 12 and the evaporator 16. It is preferable to operate the first connection three-way valve 38 and the second connection three-way valve 39 so as to switch to the heating mode.

For example, when the temperature of the cooling water circulating between the condenser 12 and the evaporator 16 rises to a predetermined temperature in the defrosting mode, the control device 40 makes the cooling water independent of the condenser 12 and the evaporator 16. Then, the first connection three-way valve 38 and the second connection three-way valve 39 are operated so as to circulate.

According to this, it is possible to avoid unnecessary energy being transmitted to the evaporator 16 when switching from the defrosting mode to the heating mode. This is because the heat accumulated in the evaporator 16 can be used for defrosting the outdoor heat exchanger 14 in the final stage of the defrost mode. Since unnecessary energy can be prevented from being transmitted to the evaporator 16, the power consumption of the compressor 11 can be reduced.

It is preferable that the control device 40 starts the outdoor blower 17 after operating the first connection three-way valve 38 and the second connection three-way valve 39 so as to switch from the defrosting mode to the heating mode.

For example, after switching from the defrost mode to the heating mode, the control device 40 activates the outdoor heat exchanger 14 after the temperature of the outdoor heat exchanger 14 falls below the outside air temperature.

According to this, heat loss to the outside air immediately after switching from the defrosting mode to the heating mode can be avoided. This is because immediately after switching from the defrosting mode to the heating mode, the temperature of the outdoor heat exchanger 14 is higher than the temperature of the outside air.

The control device 40 activates the heater 23 when the heating mode is switched to the defrosting mode, switches to the heating mode from the defrosting mode, and when the temperature of the cooling water circulating through the heater core 22 is equal to or higher than the predetermined temperature, the heater 23. Is preferably stopped.

According to this, it is possible to suppress the heater 23 from consuming electric power in the heating mode. For example, the control device 40 may gradually decrease the output of the heater 23 before switching from the defrost mode to the heating mode.

(Other embodiments)
The above embodiment can be variously modified as follows, for example.

(1) In the above embodiment, the heating mode and the defrosting mode are switched by changing the throttle opening of the first expansion valve 13 and the second expansion valve 15, but the first expansion valve 13 and the second expansion valve 13 are switched. The heating mode and the defrosting mode may be switched by switching the refrigerant flow path with respect to the expansion valve 15.

For example, a refrigerant flow path in which the refrigerant flows by bypassing the first expansion valve 13, a refrigerant flow path in which the refrigerant flows by bypassing the second expansion valve 15, and an on-off valve that opens and closes both refrigerant flow paths are provided. In the mode, the refrigerant flows through the first expansion valve 13 and bypasses the second expansion valve 15, and in the defrost mode, the refrigerant flows through the first expansion valve 13 and flows through the second expansion valve 15. Also good.

(2) In the above embodiment, cooling water is used as the heat medium, but various media such as oil may be used as the heat medium.

Nanofluid may be used as the heat medium. A nanofluid is a fluid in which nanoparticles having a particle size of the order of nanometers are mixed. By mixing the nanoparticles with the heat medium, the following effects can be obtained in addition to the effect of lowering the freezing point and making the antifreeze liquid like cooling water using ethylene glycol.

That is, the effect of improving the thermal conductivity in a specific temperature range, the effect of increasing the heat capacity of the heat medium, the effect of preventing the corrosion of metal pipes and the deterioration of rubber pipes, and the heat medium at an extremely low temperature The effect which improves the fluidity | liquidity of can be acquired.

Such an effect varies depending on the particle configuration, particle shape, blending ratio, and additional substance of the nanoparticles.

According to this, since the thermal conductivity can be improved, it is possible to obtain the same cooling efficiency even with a small amount of heat medium as compared with the cooling water using ethylene glycol.

Also, since the heat capacity of the heat medium can be increased, the amount of cold storage heat due to the sensible heat of the heat medium itself can be increased.

Even if the compressor 11 is not operated by increasing the amount of cold storage heat, it is possible to control the temperature and cooling of the equipment using the cold storage heat for a certain amount of time. Can be realized.

The aspect ratio of the nanoparticles is preferably 50 or more. This is because sufficient thermal conductivity can be obtained. The aspect ratio is a shape index that represents the ratio of the vertical and horizontal dimensions of the nanoparticles.

Nanoparticles containing any of Au, Ag, Cu and C can be used. Specifically, Au nanoparticle, Ag nanowire, CNT, graphene, graphite core-shell nanoparticle, Au nanoparticle-containing CNT, and the like can be used as the constituent atoms of the nanoparticle.

CNT is a carbon nanotube. The graphite core-shell nanoparticle is a particle body having a structure such as a carbon nanotube surrounding the atom.

(3) In the refrigeration cycle apparatus 10 of the above embodiment, a chlorofluorocarbon refrigerant is used as the refrigerant. However, the type of the refrigerant is not limited to this, and natural refrigerants such as carbon dioxide, hydrocarbon refrigerants, and the like are used. It may be used.

Further, the refrigeration cycle apparatus 10 of the above embodiment constitutes a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant, but the supercritical refrigeration cycle in which the high-pressure side refrigerant pressure exceeds the critical pressure of the refrigerant. May be configured.

Claims (12)

A compressor (11) for sucking and discharging refrigerant;
A first heat medium refrigerant heat exchanger (12) for radiating heat from the refrigerant discharged from the compressor to a heat medium;
A first decompression section (13) for decompressing the refrigerant that has flowed out of the first heat medium refrigerant heat exchanger;
An outside air refrigerant heat exchanger (14) for exchanging heat between the refrigerant flowing out of the first decompression section and outside air;
A second decompression section (15) for decompressing the refrigerant that has flowed out of the outside-air refrigerant heat exchanger;
A second heat medium refrigerant heat exchanger (16) for causing the refrigerant that has flowed out of the second decompression section to absorb heat from the heat medium;
A state in which the heat medium circulates independently from each other with respect to the first heat medium refrigerant heat exchanger and the second heat medium refrigerant heat exchanger; the first heat medium refrigerant heat exchanger; and the second heat medium. A switching unit (38, 39) for switching between a state in which the heat medium circulates with the refrigerant heat exchanger;
The first pressure reducing unit and the second pressure reducing unit operate so that the refrigerant absorbs heat in the outside air refrigerant heat exchanger, and the first heat medium refrigerant heat exchanger and the second heat medium refrigerant heat exchanger On the other hand, the first mode in which the switching unit operates so that the heat medium circulates independently of each other, and the first decompression unit and the second decompression unit so that the refrigerant radiates heat in the outside-air refrigerant heat exchanger. And a control device that switches between a first mode in which the switching unit operates so that the heat medium circulates between the first heat medium refrigerant heat exchanger and the second heat medium refrigerant heat exchanger. (40) A refrigeration cycle apparatus comprising: The heat supply section (33) for supplying heat to the heat medium that circulates between the first heat medium refrigerant heat exchanger and the second heat medium refrigerant heat exchanger in the second mode. The refrigeration cycle apparatus described. A heater core (22) for heating the air by exchanging heat between the air blown into the passenger compartment and the heat medium;
An electric heater (23) that generates heat by supplying electric power and heats the heat medium;
The switching unit includes the state in which the heat medium circulates between the heater core, the electric heater, and the first heat medium refrigerant heat exchanger, and independently of the first heat medium refrigerant heat exchanger. The state in which the heat medium circulates between the heater core and the electric heater is switched,
The control device includes:
Operating the switching unit so that the heat medium circulates between the heater core, the electric heater, and the first heat medium refrigerant heat exchanger in the first mode;
3. The switch according to claim 1, wherein the switching unit is operated so that the heat medium circulates between the heater core and the electric heater independently of the first heat medium refrigerant heat exchanger in the second mode. The refrigeration cycle apparatus described. An outside air blowing section (17) for blowing the outside air to the outside air refrigerant heat exchanger,
The said control apparatus is a refrigerating-cycle apparatus as described in any one of Claim 1 thru | or 3 which stops ventilation to the said external air refrigerant | coolant heat exchanger from the said external air ventilation part at the time of the said 2nd mode. In the first mode, when the temperature difference obtained by subtracting the temperature of the heat medium of the second heat medium refrigerant heat exchanger (16) from the temperature of the outside air is greater than a threshold value during the first mode, The refrigeration cycle apparatus according to any one of claims 1 to 4, wherein the refrigeration cycle apparatus is switched to the second mode. A cooler core (32) for causing the heat medium cooled by the second heat medium refrigerant heat exchanger to absorb heat from the air;
A state in which the heat medium cooled by the second heat medium refrigerant heat exchanger flows through the cooler core, and a state in which the heat medium cooled by the second heat medium refrigerant heat exchanger flows by bypassing the cooler core; A cooler core switching unit (34, 35) for switching between
The control device operates the cooler core switching unit so that the heat medium cooled by the second heat medium refrigerant heat exchanger flows through the cooler core during the first mode and the second mode. The refrigeration cycle apparatus according to any one of claims 1 to 5. In the second mode, the control device increases the pressure of the refrigerant discharged from the compressor to a target pressure, or the first heat medium refrigerant heat exchanger and the second heat medium refrigerant heat exchanger The refrigeration cycle apparatus according to any one of claims 1 to 6, wherein the compressor is operated so that the temperature of the heat medium circulating between the two increases to a target temperature. In the second mode, the control device increases the pressure of the refrigerant discharged from the compressor to the target pressure, or the first heat medium refrigerant heat exchanger and the second heat medium refrigerant heat exchanger. The temperature of the heat medium circulated between and increases to the target temperature, and when the time elapsed since switching to the second mode exceeds a lower limit time, switching to the first mode. Refrigeration cycle equipment. The refrigeration cycle apparatus according to claim 7 or 8, wherein the control device switches to the first mode when the elapsed time after switching to the second mode reaches an upper limit time in the second mode. In the second mode, the control device operates the switching unit so that the heat medium circulates independently from each other with respect to the first heat medium refrigerant heat exchanger and the second heat medium refrigerant heat exchanger. The refrigeration cycle apparatus according to claim 8 or 9, wherein the switching unit is operated so as to be switched to the first mode after being operated. The refrigeration cycle apparatus according to claim 4, wherein the control device activates the outside air blowing unit after operating the switching unit to switch from the second mode to the first mode. When the controller switches from the first mode to the second mode, the controller operates the heater, switches from the second mode to the first mode, and the temperature of the heat medium circulating in the heater core is a predetermined temperature. The refrigeration cycle apparatus according to claim 3, wherein the heater is stopped when it is above.

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