CN110998198B

CN110998198B - Refrigeration cycle device

Info

Publication number: CN110998198B
Application number: CN201880050700.8A
Authority: CN
Inventors: 铃木聪; 加藤吉毅
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2017-08-10
Filing date: 2018-07-09
Publication date: 2021-09-14
Anticipated expiration: 2038-07-09
Also published as: CN110998198A; DE112018004104T5; JP2019035520A; JP6733625B2; WO2019031131A1

Abstract

A refrigeration cycle device (10) is provided with: a first heat exchange unit (20) that heats a fluid to be heat-exchanged using, as a heat source, a high-pressure refrigerant discharged from the compressor (11); a pressure reducing valve (13) that reduces the pressure of the refrigerant; a heat medium evaporator (15) that evaporates the refrigerant after having been depressurized by exchanging heat with the low-stage side heat medium; a heat generating device (34) that is disposed in the low-stage-side heat medium circulation circuit (30) and heats the low-stage-side heat medium; a second heat exchanger (39) that heats the fluid to be heat-exchanged using the low-stage-side heat medium heated by the heat-generating device (34) as a heat source; a flow rate control valve (35) that controls the flow rate of the low-stage-side heat medium flowing into the heat medium evaporator (15) and the flow rate of the low-stage-side heat medium flowing into the second heat exchanger (39); and a flow rate control unit (50c) that controls the operation of the flow rate adjustment valve (35).

Description

Refrigeration cycle device

Cross reference to related applications

This application is based on japanese patent application No. 2017-155679, filed on 8/10/2017, the disclosure of which is incorporated herein by reference.

Technical Field

The present invention relates to a refrigeration cycle apparatus.

Background

Patent document 1 discloses a refrigeration cycle device that adjusts the temperature of a battery, which is a heat generating portion that generates heat during operation, and that adjusts the temperature of air that is a fluid to be heat-exchanged. In this refrigeration cycle apparatus, heat of the heat generating portion is absorbed by the refrigerant on the low-pressure side of the refrigeration cycle apparatus, and the absorbed heat is radiated from the refrigerant on the high-pressure side to the air to be blown, thereby heating the space to be air-conditioned.

Documents of the prior art

Patent document

Patent document 1: japanese patent application No. 2014-37959

However, in the refrigeration cycle apparatus of patent document 1, if the amount of heat absorbed by the refrigerant on the low-pressure side is increased, the pressure of the refrigerant on the high-pressure side of the refrigeration cycle apparatus is unnecessarily increased. If the pressure of the refrigerant on the high-pressure side is unnecessarily increased in this way, the durability life of the components of the refrigeration cycle apparatus is adversely affected.

In contrast, a method of reducing the refrigerant discharge capacity of the compressor to prevent the pressure of the refrigerant on the high-pressure side from unnecessarily increasing is considered. However, if the refrigerant discharge capacity of the compressor is reduced, the heat absorbed by the low-pressure-side refrigerant from the heat generating portion cannot be properly dissipated from the high-pressure-side refrigerant to the feed air. That is, the air to be blown cannot be heated effectively by the heat generated in the heat generating portion.

Therefore, in order to prevent the refrigerant pressure on the high-pressure side of the refrigeration cycle apparatus from unnecessarily increasing, there is a problem as follows: the refrigerant on the low-pressure side cannot sufficiently absorb the heat generated in the heat generating portion, and the heat generated in the heat generating portion cannot be effectively utilized.

Disclosure of Invention

In view of the above-described problems, an object of the present invention is to provide a refrigeration cycle apparatus capable of effectively utilizing heat generated in a heat generating portion when heating a fluid to be heat-exchanged.

A refrigeration cycle apparatus according to a first characteristic example of the present invention includes:

a compressor compressing and discharging a refrigerant; a first heat exchange unit that heats a fluid to be heat-exchanged using a high-pressure refrigerant discharged from the compressor as a heat source; a decompressor configured to decompress the refrigerant flowing out of the first heat exchanger; a heat medium evaporator that evaporates the refrigerant decompressed by the decompressor by heat exchange with the low-stage-side refrigerant; a heating unit disposed in a low-stage-side heat medium circulation circuit for circulating a low-stage-side heat medium to heat the low-stage-side heat medium; a second heat exchange unit that heats the fluid to be heat exchanged using, as a heat source, the low-stage-side heat medium heated by the heat generation unit; a flow rate adjustment unit that adjusts a flow rate of the low-stage-side heat medium flowing into the heat medium evaporator and a flow rate of the low-stage-side heat medium flowing into the second heat exchange unit; and a flow rate control unit for controlling the operation of the flow rate adjustment unit. In a first heating mode in which the fluid to be heat-exchanged is heated by the first heat exchanging portion, the flow rate control portion controls the operation of the flow rate adjusting portion so that the low-stage-side heat medium heated by the heat generating portion flows into the heat medium evaporator; in a second heating mode in which the fluid to be heat-exchanged is heated by the second heat exchange unit, the flow rate control unit controls the operation of the flow rate adjustment unit so that the low-stage-side heat medium heated by the heat generation unit flows into the second heat exchange unit.

In the first heating mode, therefore, the heat of the low-stage side heat medium heated by the heat generating portion is absorbed by the refrigerant in the heat medium evaporator, and the heat absorbed by the refrigerant is used as a heat source to heat the fluid to be heat exchanged in the first heat exchange portion. In the second heating mode, the heat of the low-stage side heat medium heated by the heat generating portion can be used as a heat source to heat the fluid to be heat exchanged in the second heat exchange portion.

Therefore, under an operation condition in which the heat generation of the heat generating portion increases and the pressure of the refrigerant discharged from the compressor may unnecessarily increase, the first heating mode is switched to the second heating mode, whereby the heat generated in the heat generating portion can be effectively used to heat the fluid to be heat exchanged.

A refrigeration cycle apparatus according to a second characteristic example of the present invention includes: a compressor compressing and discharging a refrigerant; a condenser that heats a heat medium by exchanging heat between a high-pressure refrigerant discharged from the compressor and the heat medium; a decompressor configured to decompress the refrigerant flowing out of the condenser; a heat medium evaporator that evaporates the refrigerant decompressed by the decompressor by exchanging heat with a heat medium; a heating portion that heats the heat medium; a heater core that heats the fluid to be heat-exchanged using at least one of the heat medium heated by the condenser and the heat medium heated by the heat generating portion as a heat source; a flow rate adjusting unit that adjusts a flow rate of the heat medium heated by the heat generating unit flowing into the heat medium evaporator and a flow rate of the heat medium heated by the heat generating unit flowing into the heater core; and a flow rate control unit for controlling the operation of the flow rate adjustment unit. In a refrigeration cycle heating mode in which the fluid to be heat exchanged is heated using the heat medium heated by the condenser as a heat source, the flow rate control unit controls the operation of the flow rate adjustment unit so that the heat medium heated by the heat generation unit flows into the heat medium evaporator.

In the refrigeration cycle heating mode, therefore, the heat of the heat medium heated by the heat generating portion is absorbed by the refrigerant in the heat medium evaporator, and the heat absorbed by the refrigerant is used as a heat source to heat the fluid to be heat exchanged by the first heat exchanging portion. In the heat source heating mode, the heat of the heat medium heated by the heat generating portion can be used as the heat source to heat the fluid to be heat exchanged by the heater core.

Therefore, under an operation condition in which the heat generation of the heat generating portion increases and the pressure of the refrigerant discharged from the compressor unnecessarily increases, the refrigeration cycle heating mode is switched to the heat source heating mode, whereby the heat generated in the heat generating portion can be effectively used to heat the fluid to be heat exchanged.

Drawings

Fig. 1 is an overall configuration diagram of an air conditioner according to a first embodiment.

Fig. 2 is a block diagram showing an electric control unit of the air conditioner.

Fig. 3 is an overall configuration diagram of an air conditioner according to a second embodiment.

Fig. 4 is an overall configuration diagram of an air conditioner according to a third embodiment.

Fig. 5 is an overall configuration diagram of an air conditioner according to a fourth embodiment.

Fig. 6 is an overall configuration diagram of an air conditioner according to a fifth embodiment.

Detailed Description

(first embodiment)

An air conditioning apparatus 1 having a refrigeration cycle apparatus 10 according to a first embodiment mounted thereon will be described with reference to fig. 1 and 2. The air conditioner 1 shown in fig. 1 is suitable for use in a vehicle air conditioner that adjusts the interior space of a vehicle to an appropriate temperature. The air conditioning apparatus 1 of the present embodiment is mounted on a hybrid vehicle that obtains a driving force for traveling of the vehicle from an engine (in other words, an internal combustion engine) and a motor for traveling.

The hybrid vehicle of the present embodiment is configured as a plug-in hybrid vehicle that can charge a battery mounted on the vehicle (in other words, an in-vehicle battery) with electric power supplied from an external power supply (in other words, a commercial power supply) when the vehicle is stopped. As the battery, for example, a lithium ion battery can be used.

The driving force output from the engine is used not only for running of the vehicle but also for operating the generator. The electric power generated by the generator and the electric power supplied from the external power supply can be stored in the battery, and the electric power stored in the battery can be supplied not only to the traveling motor but also to various in-vehicle devices including electric components constituting the refrigeration cycle apparatus 10.

The air conditioner 1 heats the vehicle interior, which is a space to be air-conditioned (that is, heats the air to be blown as a fluid to be heat-exchanged). The air conditioning apparatus 1 includes a refrigeration cycle apparatus 10, a first heat exchange unit 20, a low-stage-side heat medium circulation circuit 30, and an indoor air conditioning unit 40.

The refrigeration cycle apparatus 10 includes a compressor 11, a condenser 12, a pressure reducing valve 13 (pressure reducer), a refrigerant flow control valve 14, a heat medium evaporator 15, and an accumulator 16 (liquid storage unit). The refrigeration cycle apparatus 10 further includes an external evaporator 18 and a blower 19 for an outdoor heat exchanger. In the refrigeration cycle apparatus 10 of the present embodiment, a freon refrigerant is used as the refrigerant, and a subcritical refrigeration cycle in which the high-pressure refrigerant pressure does not exceed the critical pressure of the refrigerant is configured.

The compressor 11 is an electric compressor driven by electric power supplied from a battery, and sucks and compresses a refrigerant of the refrigeration cycle device 10 and discharges the refrigerant. The operation of the compressor 11 is controlled based on a control signal output from the discharge capacity control unit 50a (shown in fig. 2).

A refrigerant inlet side of the condenser 12 is connected to a discharge port of the compressor 11. The condenser 12 is a heating radiator that exchanges heat between a high-temperature and high-pressure refrigerant discharged from the compressor 11 (hereinafter, simply referred to as a high-pressure refrigerant) and cooling water, which is a high-stage side heat medium, and radiates heat of the high-pressure refrigerant to the cooling water to heat the cooling water. When heat of the high-pressure refrigerant is radiated to the cooling water, the high-pressure refrigerant is condensed.

The first heat exchange unit 20 includes a high-stage-side heat medium circulation circuit 21, a high-stage-side pump 22, and a heater core 23. The first heat exchange unit 20 heats the feed air using the high-pressure refrigerant discharged from the compressor 11 as a heat source.

As the cooling water flowing through the high-stage-side heat medium circulation circuit 21 and the cooling water flowing through the low-stage-side heat medium circulation circuit 30 described later, a liquid containing at least ethylene glycol, dimethylpolysiloxane, or a nanofluid, or an antifreeze liquid is used.

The high-stage-side heat medium circulation circuit 21 is an annular flow path that circulates cooling water between the condenser 12 and the heater core 23. The condenser 12, the heater core 23, and the high-stage-side pump 22 are disposed in the high-stage-side heat medium circulation circuit 21.

The high-stage-side pump 22 sucks in the cooling water and discharges the cooling water to the condenser 12 side, thereby circulating the cooling water in the high-stage-side heat medium circulation circuit 21. The high-stage-side pump 22 is an electric pump, and is a high-stage-side flow rate adjustment unit that adjusts the flow rate of the cooling water circulating in the high-stage-side heat medium circulation circuit 21.

The heater core 23 is disposed in a housing 41 described later. The heater core 23 heats the air to be heat-exchanged by exchanging heat between the cooling water heated by the condenser 12 and the air to be heat-exchanged. In this manner, the condenser 12 heats the supply air via the heater core 23.

A refrigerant inlet side of a pressure reducing valve 13 is connected to a refrigerant outlet side of the condenser 12. The pressure reducing valve 13 is a pressure reducer that reduces and expands the pressure of the liquid-phase refrigerant flowing out of the condenser 12. That is, the pressure reducing valve 13 reduces the pressure of the refrigerant on the downstream side of the condenser 12.

The pressure reducing valve 13 is an electric variable throttle mechanism whose operation is controlled in accordance with a control signal output from the control device 50, and includes a valve body and an electric actuator. The valve body is configured to be able to change a passage opening degree (in other words, a throttle opening degree) of the refrigerant passage. The electric actuator includes a stepping motor that changes the throttle opening of the valve body.

The refrigerant flow path regulating valve 14 branches the flow of the refrigerant flowing out of the pressure reducing valve 13 to the external evaporator 18 and the heat medium evaporator 15. Therefore, the exterior evaporator 18 and the heat medium evaporator 15 are arranged in parallel with respect to the refrigerant flow. The refrigerant flow path regulating valve 14 is an inflow amount regulating portion that regulates the flow rate of the refrigerant flowing out of the pressure reducing valve 13 into the external evaporator 18 and the flow rate of the refrigerant flowing out of the pressure reducing valve 13 into the heat medium evaporator 15. The refrigerant flow path regulating valve 14 is a three-way flow rate regulating valve that operates by being supplied with electric power, and the operation of the refrigerant flow path regulating valve 14 is controlled in accordance with a control signal output from the control device 50.

A refrigerant outlet side of the pressure reducing valve 13 is connected to a refrigerant inlet side of the external evaporator 18 via a refrigerant flow path adjusting valve 14. The exterior evaporator 18 is an outdoor air evaporation unit that evaporates the low-pressure refrigerant by exchanging heat of the low-pressure refrigerant decompressed by the decompression valve 13 with the outdoor air blown by the outdoor heat exchanger blower 19. In the external evaporator 18, the low-pressure refrigerant absorbs heat from the outside air and evaporates.

The outdoor heat exchanger blower 19 is an electric blower in which a fan is driven by an electric motor, and the operation of the outdoor heat exchanger blower 19 is controlled based on a control signal output from the control device 50. The exterior evaporator 18 is disposed on the front side in the vehicle hood. Therefore, when the vehicle is traveling, the traveling wind can be brought into contact with the exterior evaporator 18.

A refrigerant outlet side of the pressure reducing valve 13 is connected to a refrigerant inlet side of the heat medium evaporator 15 via a refrigerant flow path adjusting valve 14. The heat medium evaporator 15 evaporates the low-pressure refrigerant by exchanging heat of the low-pressure refrigerant decompressed by the decompression valve 13 with the cooling water as the low-stage side heat medium flowing through the low-stage side heat medium circuit 30. In the heat medium evaporator 15, the low-pressure refrigerant absorbs heat from the cooling water and evaporates, whereby the cooling water is cooled.

The low-stage-side heat medium circulation circuit 30 is an annular flow path through which cooling water serving as a low-stage-side heat medium circulates. The low-stage-side heat medium circulation circuit 30 is provided with a heat medium evaporator 15, a low-stage-side flow rate adjustment valve 31, a low-stage-side radiator 32, a low-stage-side pump 33, a heat generating device 34, and a flow rate adjustment valve 35 (flow rate adjustment unit).

A radiator bypass passage 37 is connected to the low-stage side heat medium circuit 30, and the radiator bypass passage 37 allows the coolant, which is the low-stage side heat medium, discharged from the low-stage side pump 33 to flow while bypassing the low-stage side radiator 32. Both ends of the radiator bypass passage 37 are connected to the low-stage-side heat medium circulation circuit 30 on the inflow side and the outflow side of the low-stage-side radiator 32.

The low-stage-side flow rate adjustment valve 31 branches the flow of the cooling water flowing out of the heat medium evaporator 15 to the low-stage-side radiator 32 and the radiator bypass flow path 37. The low-stage-side flow rate adjustment valve 31 is a low-stage-side inflow rate adjustment portion that adjusts the flow rate at which the cooling water flowing out of the heat medium evaporator 15 flows into the low-stage-side radiator 32 and the flow rate at which the cooling water flowing out of the heat medium evaporator 15 flows into the radiator bypass flow path 37. The low-stage-side flow rate adjustment valve 31 is a three-way valve, is an electromagnetic valve that operates by being supplied with electric power, and controls the operation of the low-stage-side flow rate adjustment valve 31 in accordance with a control signal output from the control device 50.

The low-stage-side radiator 32 exchanges heat between the cooling water cooled by the heat medium evaporator 15 and the outside air blown by the low-stage-side radiator air-sending device 36, thereby absorbing heat from the cooling water.

The low-stage-side radiator fan 36 is an electric fan in which a fan is driven by an electric motor, and the operation of the low-stage-side radiator fan 36 is controlled based on a control signal output from the control device 50. The low-stage-side radiator 32 is disposed on the front side in the vehicle hood. Therefore, the traveling wind can be brought into contact with the low-stage-side radiator 32 during traveling of the vehicle.

The low-stage-side pump 33 is a low-stage-side heat medium pump that sucks and discharges cooling water. The low-stage-side pump 33 is an electric pump, and is a low-stage-side flow rate adjustment unit that adjusts the flow rate of the cooling water circulating in the low-stage-side heat medium circulation circuit 30.

The heat generating device 34 is a heat generating unit that generates heat by operation and heats the cooling water discharged from the low-stage pump 33. As the heat generating device 34, a PTC heater (electric heater) or the like can be used. The operation of the heat generating device 34 is controlled in accordance with a control signal output from the control device 50.

The second heat exchange unit flow path 38 is connected to the low-stage-side heat medium circulation circuit 30, and the cooling water discharged by the low-stage-side pump 33 and heated by the heat generating device 34 flows through the second heat exchange unit flow path 38. Both ends of the second heat exchange portion channel 38 are connected to the low-stage side heat medium circulation circuit 30 on the intake side of the low-stage side pump 33 and the flow rate adjustment valve 35.

A second heat exchanger 39 is disposed in the second heat exchange portion passage 38. The second heat exchanger 39 is disposed in a casing 41 described later. The second heat exchanger 39 heats the feed air by exchanging heat between the coolant discharged from the low-stage pump 33 and heated by the heat generating device 34 and the feed air as a fluid to be heat-exchanged. That is, the second heat exchanger 39 heats the air using the cooling water heated by the heat generating device 34 as a heat source.

The flow rate adjustment valve 35 is a flow rate adjustment unit that adjusts the flow rate of the cooling water discharged by the low-stage pump 33 and heated by the heat generating device 34, which flows into the heat medium evaporator 15, and the flow rate of the cooling water which flows into the second heat exchanger 39. The flow rate control valve 35 is a three-way type flow rate control valve that operates by being supplied with electric power, and the operation of the flow rate control valve 35 is controlled based on a control signal output from the control device 50.

The flow rate control valve 35 can continuously adjust the flow rate ratio of the cooling water fed under pressure from the low-stage pump 33 and heated by the heat generating device 34 to the heat medium evaporator 15 and the cooling water fed under pressure from the low-stage pump 33 and heated by the heat generating device 34 to the second heat exchanger 39, to the heat exchanger side flow rate. Further, the entire amount of the cooling water fed under pressure from the low-stage pump 33 and heated by the heat generating device 34 can be made to flow into the heat medium evaporator 15, and the entire amount of the cooling water can be made to flow into the second heat exchanger 39. The flow rate control valve 35 is configured such that the entire amount of the cooling water flows into the second heat exchanger 39 when no current is supplied thereto.

A refrigerant inlet side of an accumulator 16 is connected to a refrigerant outlet side of the heat medium evaporator 15. That is, the accumulator 16 is provided between the heat medium evaporator 15 and the compressor 11, that is, on the upstream side of the compressor 11. The accumulator 16 is a gas-liquid separation portion that separates gas and liquid of the refrigerant flowing into the inside, and is a liquid storage portion that stores the remaining refrigerant in the cycle.

A gas-phase refrigerant outlet of the accumulator 16 is connected to a suction port side of the compressor 11. Thus, the reservoir 16 functions as follows: the liquid-phase refrigerant is suppressed from being sucked into the compressor 11, preventing the liquid in the compressor 11 from being compressed.

Next, the indoor air conditioning unit 40 will be explained. The indoor air conditioning unit 40 is used to blow out the supply air temperature-conditioned by the refrigeration cycle apparatus 10 into the vehicle interior, which is the air-conditioning target space. The indoor air conditioning unit 40 is disposed inside an instrument panel (instrument panel) at the forefront of the vehicle interior. The indoor air conditioning unit 40 is configured by housing the second heat exchanger 39, the heater core 23, and the like in a case 41 forming an outer shell thereof.

The casing 41 is an air passage forming portion that forms an air passage of the blast air to be blown into the vehicle compartment as the air conditioning target space. The case 41 is molded from a resin (e.g., polypropylene) having a certain degree of elasticity and excellent strength. An inside/outside air switching device 43 serving as an inside/outside air switching unit is disposed on the most upstream side of the flow of the blast air in the casing 41, and the inside/outside air switching device 43 switches and introduces inside air (air in the space to be air-conditioned) and outside air (air outside the space to be air-conditioned) into the casing 41. The inside/outside air switching device 43 can continuously change the air volume ratio of the inside air volume to the outside air volume.

An air conditioning blower 42 is disposed on the downstream side of the flow of the air blown by the inside/outside air switching device 43, and the air conditioning blower 42 blows the air sucked through the inside/outside air switching device 43 into the air conditioning target space. The air conditioning fan 42 is an electric fan in which a centrifugal sirocco fan (sirocco fan) is driven by an electric motor, and the rotation speed (air blowing amount) is controlled based on a control voltage output from the control device 50.

A second heat exchanger 39 is disposed on the downstream side of the flow of the air for the air-conditioning blower 42 in the air passage formed in the case 41. The heater core 23 is disposed on the downstream side of the second heat exchanger 39 in the flow of the blowing air in the air passage formed in the casing 41.

A plurality of opening holes for blowing out the air (air-conditioned air) having passed through the heater core 23 into the vehicle interior as the air-conditioned space are disposed in the most downstream portion of the flow of the air in the casing 41.

Next, an outline of an electric control unit of the air conditioner 1 of the present embodiment will be described. The control device 50 shown in fig. 2 is constituted by a known microcomputer including a CPU, a ROM, a RAM, and the like, and peripheral circuits thereof. The control device 50 performs various calculations and processes based on control programs stored in the ROM. Various controlled devices are connected to the output side of the control device 50. The control device 50 is a control unit that controls operations of various devices to be controlled.

The control target devices controlled by the control device 50 are the compressor 11, the pressure reducing valve 13, the refrigerant flow path regulating valve 14, the outdoor heat exchanger blower 19, the high-stage pump 22, the low-stage flow rate regulating valve 31, the low-stage pump 33, the heat generating device 34, the flow rate regulating valve 35, the low-stage radiator blower 36, the air conditioner blower 42, and the like.

The control device 50 is integrally provided with a control unit that controls various devices to be controlled connected to the output side thereof. The configuration (hardware and software) of the control device 50 that controls the operation of each control target device constitutes a control unit that controls the operation of each control target device. For example, the control device 50 is configured to control the discharge capacity of the refrigerant of the compressor 11 by a discharge capacity control unit 50 a. The controller 50 is configured to control the amount of heat generated by the heat generating device 34, and is a heat generation amount control unit 50 b. The controller 50 is configured to control the operation of the flow rate adjustment valve 35 by a flow rate control unit 50 c.

Various control sensor groups such as an inside air temperature sensor 51, an outside air temperature sensor 52, an insolation amount sensor 53, and an outdoor heat exchanger temperature sensor 54 are connected to an input side of the control device 50. The inside air temperature sensor 51 detects the vehicle interior temperature Tr. The outside air temperature sensor 52 detects the outside air temperature Tam. The insolation amount sensor 53 detects an amount of insolation Ts in the vehicle compartment. The outdoor heat exchanger temperature sensor 54 detects the temperature of the refrigerant flowing through the exterior evaporator 18.

The control device 50 includes a frost formation determination unit 50d, and the frost formation determination unit 50d determines whether or not frost is formed on the external evaporator 18 or whether or not an operating condition capable of forming frost on the external evaporator 18 is satisfied (hereinafter, simply referred to as "frost formation on the external evaporator 18"). The frost formation determination unit 50d determines that frost formation has occurred in the external evaporator 18 when the refrigerant evaporation temperature in the external evaporator 18 becomes equal to or lower than a predetermined reference temperature, for example, based on the temperature of the refrigerant flowing through the external evaporator 18 detected by the outdoor heat exchanger temperature sensor 54.

An operation unit 60 is connected to an input side of the control device 50. The operation unit 60 is operated by the occupant. The operation unit 60 is disposed near the instrument panel in the front of the vehicle interior. An operation signal from the operation unit 60 is input to the control device 50. The operation unit 60 is provided with an air conditioning switch, a temperature setting switch, and the like. The air conditioning switch sets whether or not the supply air is cooled by the indoor air conditioning unit. The temperature setting switch sets a set temperature in the vehicle interior.

Next, the operation of the above-described configuration will be described. The control device 50 calculates a target outlet temperature TAO of the blowing air to be blown into the vehicle interior based on the detection signal detected by the control sensor group and the operation signal from the operation unit 60, and determines the operation mode of the air conditioner 1 to be any one of the first heating mode, the third heating mode, and the defrosting operation mode. Hereinafter, each operation mode will be described.

(first heating mode)

The first heating mode is an operation mode in which the supply air is heated by the heater core 23. In the first heating mode, the control device 50 determines the operation states of various control target devices (control signals to be output to various control devices) based on the detection signals, the target outlet air temperature TAO, and the like. Specifically, the controller 50 operates the compressor 11, the high-stage pump 22, the outdoor heat exchanger blower 19, the low-stage pump 33, the heat generating device 34, and the low-stage radiator blower 36. The control device 50 determines a control signal output to the pressure reducing valve 13 so that the pressure reducing valve 13 reaches a predetermined throttle opening degree of the first heating mode.

The flow rate control unit 50c controls the operation of the flow rate adjustment valve 35 so that the entire amount of the cooling water discharged from the low-stage pump 33 and heated by the heat generating device 34 flows into the heat medium evaporator 15.

The heat generation amount control unit 50b operates the heat generation device 34 when the temperature of the blowing air blown into the vehicle interior does not reach the target blowout temperature TAO, when the rotation speed of the compressor 11 reaches a predetermined rotation speed set in advance in accordance with the durability of the compressor 11, or when the power consumption in the compressor 11 exceeds a predetermined value. The heat generation amount control unit 50b controls the amount of heat generated by the heat generation device 34 so that the blown air blown into the vehicle interior reaches the target blowing temperature TAO.

Therefore, in the refrigeration cycle device 10 in the first heating mode, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12. The high-pressure refrigerant flowing into the condenser 12 exchanges heat with the cooling water and is condensed. At this time, the heat of the high-pressure refrigerant is radiated to the cooling water, and the cooling water is heated. Then, the cooling water heated by the condenser 12 in the heater core 23 exchanges heat with the supply air, thereby heating the supply air.

The high-pressure refrigerant flowing out of the condenser 12 is decompressed by the decompression valve 13 to become a low-pressure refrigerant.

The low-pressure refrigerant decompressed by the decompression valve 13 flows into the heat medium evaporator 15 and the external evaporator 18. The low-pressure refrigerant flowing into the heat medium evaporator 15 absorbs heat from the cooling water circulating in the low-stage side heat medium circuit 30 and evaporates. Thereby, the cooling water circulating in the low-stage side heat medium circulation circuit 30 is cooled. The low-pressure refrigerant flowing into the external evaporator 18 absorbs heat from the outside air and evaporates.

In the first heating mode, the low-stage-side flow rate adjustment valve 31 causes cooling water to flow into the low-stage-side radiator 32. Therefore, the cooling water cooled by the heat medium evaporator 15 exchanges heat with the outside air in the low-stage radiator 32 to absorb heat, and is heated.

The cooling water flowing out of the low-stage radiator 32 is taken into the low-stage pump 33. The cooling water pumped from the low-stage pump 33 is heated by the heat generating device 34, and then flows into the heat medium evaporator 15 via the flow rate control valve 35. In the heat medium evaporator 15, the cooling water heated by the heat generating device 34 exchanges heat with the refrigerant, and the refrigerant evaporates. Thereby, the refrigerant absorbs heat generated by the heat generating device 34 via the cooling water.

The refrigerant flowing out of the heat medium evaporator 15 flows into the accumulator 16 and is subjected to gas-liquid separation. The gas-phase refrigerant separated in the accumulator 16 is sucked into the compressor 11 and compressed again.

As described above, in the first heating mode, the feed air heated by the heater core 23 can be blown into the vehicle interior. This enables heating of the vehicle interior.

In addition, in the first heating mode, the refrigerant condensing temperature in the condenser 12 can be increased compared to the temperature of the cooling water circulating in the low-stage side heat medium circulation circuit 30 by using the compression work of the compressor 11 in addition to the heat absorbed by the refrigerant from the cooling water heated by the heat generating device 34. Therefore, the feed air can be heated in a higher temperature range than in the second heating mode described below.

(second heating mode)

The second heating mode is an operation mode in which the second heat exchanger 39 heats the supply air. In the second heating mode, the control device 50 determines the operation states of various control target devices (control signals to be output to various control devices) based on the detection signals, the target outlet air temperature TAO, and the like. Specifically, the controller 50 operates the low-stage pump 33 and the heat generating device 34. In the second heating mode, the control device 50 stops the compressor 11, the high-stage pump 22, the outdoor heat exchanger blower 19, and the low-stage radiator blower 36.

The flow rate control unit 50c controls the flow rate control valve 35 so that the entire amount of the cooling water discharged by the low-stage pump 33 and heated by the heat generating device 34 flows into the second heat exchanger 39.

The heat generation amount control unit 50b controls the amount of heat generated by the heat generation device 34 so that the blown air blown into the vehicle interior reaches the target blowing temperature TAO.

Therefore, in the air conditioning apparatus 1 in the second heating mode, the entire amount of the cooling water discharged by the low-stage-side pump 33 and heated by the heat generating device 34 flows into the second heat exchanger 39. As a result, the cooling water heated by the heat generating device 34 in the second heat exchanger 39 exchanges heat with the air, thereby heating the air.

As described above, in the second heating mode, the feed air heated by the second heat exchanger 39 can be blown into the vehicle interior. This enables heating of the vehicle interior.

(third heating mode)

The third heating mode is an operation mode in which the supply air heated by the second heat exchanger 39 is heated by the heater core 23. In other words, the operation mode is an operation mode in which the second heat exchanger 39 and the heater core 23 are used to heat the feed air in stages.

In the third heating mode, the control device 50 determines the operation states of various control target devices (control signals to be output to various control devices) based on the detection signals, the target outlet air temperature TAO, and the like. Specifically, the control device 50 operates the compressor 11, the outdoor heat exchanger blower 19, the high-stage pump 22, the low-stage pump 33, the heat generating device 34, and the low-stage radiator blower 36. The control device 50 determines a control signal output to the pressure reducing valve 13 so that the pressure reducing valve 13 reaches a predetermined throttle opening degree of the third heating mode.

The flow rate control unit 50c controls the flow rate control valve 35 so that the cooling water heated by the heat generating device 34 flows into both the heat medium evaporator 15 and the second heat exchanger 39. The flow rate control unit 50c controls the flow rate of the cooling water heated by the heat generating device 34 flowing into the heat medium evaporator 15 and the flow rate of the cooling water heated by the heat generating device 34 flowing into the second heat exchanger 39 by controlling the flow rate adjusting valve 35 based on the operating state of the refrigeration cycle apparatus 10 and the target outlet temperature TAO.

Therefore, in the refrigeration cycle device 10 in the third heating mode, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12. The high-pressure refrigerant flowing into the condenser 12 exchanges heat with the cooling water and is condensed. At this time, the heat of the high-pressure refrigerant is radiated to the cooling water, and the cooling water is heated. Then, the cooling water heated by the condenser 12 in the heater core 23 exchanges heat with the supply air, thereby heating the supply air.

In the third heating mode, the low-stage-side flow rate adjustment valve 31 causes cooling water to flow into the low-stage-side radiator 32. Therefore, the cooling water cooled by the heat medium evaporator 15 exchanges heat with the outside air in the low-stage radiator 32 to absorb heat, and is heated.

The cooling water flowing out of the low-stage-side radiator 32 is heated by the heat generating device 34, and then flows into the heat medium evaporator 15 and the second heat exchanger 39. In the heat medium evaporator 15, the cooling water heated by the heat generating device 34 exchanges heat with the refrigerant, and the refrigerant absorbs heat from the cooling water and evaporates. On the other hand, in the second heat exchanger 39, the cooling water heated by the heat generating device 34 exchanges heat with the air, and the air is heated.

As described above, in the third heating mode, the feed air heated by the second heat exchanger 39 and the heater core 23 can be blown into the vehicle interior. This enables heating of the vehicle interior.

In addition, in the third heating mode, the compression work of the compressor 11 is used in addition to the heat absorbed by the refrigerant from the cooling water heated by the heat generating device 34, so that the refrigerant condensation temperature in the condenser 12 can be increased compared to the temperature of the cooling water circulating in the low-stage side heat medium circulation circuit 30. Therefore, the air can be heated in stages in the order of the second heat exchanger 39 → the heater core 23.

(defrosting operation mode)

When the frost formation determination portion 50d of the control device 50 determines that frost formation has occurred in the exterior evaporator 18 while the first heating mode or the third heating mode is being executed, a defrosting operation mode shown below is executed.

The heat generation amount control unit 50b increases the amount of heat generated by the heat generation device 34 to increase the amount of heat of the cooling water flowing into the heat medium evaporator 15. As a result, in the heat medium evaporator 15, the amount of heat absorbed by the refrigerant from the cooling water increases, the refrigerant temperature rises, and frost is melted in the external evaporator 18, and frost formation is suppressed.

The flow rate control unit 50c decreases the rotation speed of the compressor 11 to decrease the discharge capacity of the compressor 11. This reduces the amount of heat absorbed by the refrigerant in the external evaporator 18 from the outside air, thereby suppressing frost formation in the external evaporator 18. As described above, in the heat medium evaporator 15, since the amount of heat absorbed by the refrigerant from the cooling water increases and the refrigerant temperature increases, a decrease in the pressure of the high-pressure refrigerant caused by a decrease in the discharge capacity of the compressor 11 can be suppressed, and a decrease in the heating capacity of the air conditioner 1 in the defrosting operation mode can be suppressed.

As described above, in the first heating mode, the flow rate control portion 50c controls the operation of the flow rate adjustment valve 35 so that the cooling water heated by the heat generating device 34 flows into the heat medium evaporator 15. In the second heating mode, the flow rate control portion 50c controls the operation of the flow rate adjustment valve 35 so that the cooling water heated by the heat generating device 34 flows into the second heat exchanger 39.

Thus, in the first heating mode, the heat of the cooling water heated by the heat generating device 34 is absorbed by the refrigerant in the heat medium evaporator 15, and the cooling water flowing into the heater core 23 can be heated using the heat absorbed by the refrigerant as a heat source. Further, the heater core 23 can heat the blowing air. In the second heating mode, the second heat exchanger 39 can heat the air using the heat of the cooling water heated by the heat generating device 34 as a heat source.

Here, in the first heating mode, the refrigerant on the low-pressure side absorbs heat of the cooling water circulating in the low-stage side heat medium circulation circuit 30, and therefore, if the amount of heat absorption of the refrigerant on the low-pressure side increases, the pressure of the refrigerant on the high-pressure side may unnecessarily increase. If the pressure of the refrigerant on the high-pressure side is unnecessarily increased in this way, the durability life of the components of the refrigeration cycle apparatus 10 is adversely affected.

In contrast, according to the refrigeration cycle apparatus 10 of the present embodiment, in the state of operation in the first heating mode, the amount of heat generation of the heat generating device 34 increases, and there is a possibility that the pressure of the refrigerant discharged from the compressor 11 may unnecessarily increase, and under such operating conditions, switching from the first heating mode to the second heating mode is possible.

Then, by switching from the first heating mode to the second heating mode, unnecessary increase in the pressure of the refrigerant on the high-pressure side of the refrigeration cycle device 10 can be reliably suppressed, and the supply air can be heated by effectively using the heat generated by the heat generating device 34.

Even in a state where the refrigerant cannot be circulated through the refrigeration cycle apparatus 10, such as when the compressor 11 is operating in a defective state, the second heating mode is switched to, so that the second heat exchanger 39 can heat the feed air using the heat of the cooling water heated by the heat generating device 34 as a heat source.

In the third heating mode, the flow rate control unit 50c of the present embodiment controls the operation of the flow rate adjustment valve 35 so that the cooling water heated by the heat generating device 34 flows into both the heat medium evaporator 15 and the second heat exchanger 39.

In the third heating mode, the second heat exchanger 39 can be used to heat the supply air in the same manner as in the second heating mode, and the heater core 23 can be used to heat the supply air in the same manner as in the first heating mode. More specifically, in the third heating mode, the air heated by the second heat exchanger 39 can be further heated by the heater core 23 using, as a heat source, heat generated by the refrigeration cycle device 10 having high energy conversion efficiency. Therefore, in the third heating mode, the maintenance of the energy conversion efficiency and the suppression of the reduction of the heating performance can be simultaneously achieved.

According to the refrigeration cycle apparatus 10 of the present embodiment, in the state of operation in the first heating mode, the amount of heat generation of the heat generating device 34 increases, and there is a possibility that the pressure of the refrigerant discharged from the compressor 11 may unnecessarily increase, and under such operation conditions, switching from the first heating mode to the third heating mode is possible.

Then, by switching from the first heating mode to the third heating mode, it is possible to suppress a rise in pressure of the refrigerant on the high-pressure side of the refrigeration cycle device 10 and also suppress a decrease in the temperature band of the heated feed air.

The first heat exchange unit 20 of the refrigeration cycle device 10 of the present embodiment includes a high-stage side heat medium circuit 21 that circulates cooling water, a condenser 12 that exchanges heat between high-pressure refrigerant and cooling water, and a heater core 23 that exchanges heat between cooling water and ventilation air. Thus, in the heater core 23, the cooling water circulating in the high-stage side heat medium circuit 21 exchanges heat with the feed air, and the feed air can be heated.

The flow rate control valve 35 is configured such that the entire amount of the cooling water flows into the second heat exchanger 39 when no current is supplied thereto. Accordingly, even if the flow rate adjustment valve 35 is stuck due to freezing or the like, for example, by switching the operation mode to the second heating mode, the air can be heated by the second heat exchanger 39, and the vehicle interior can be heated.

When the frost formation determination unit 50d determines that frost is formed in the external evaporator 18, the heat generation amount control unit 50b increases the amount of heat generation in the heat generation device 34. As a result, in the heat medium evaporator 15, the amount of heat absorbed by the refrigerant from the cooling water increases, the refrigerant temperature rises, frost can be melted in the external evaporator 18, and frost formation in the external evaporator 18 can be suppressed.

When the frost formation determination unit 50d determines that frost is formed on the external evaporator 18, the controller 50 decreases the rotation speed of the compressor 11. This reduces the amount of heat absorbed by the refrigerant in the external evaporator 18 from the outside air, and thereby can suppress frost formation in the external evaporator 18.

(second embodiment)

Hereinafter, a difference between the air conditioner 2 of the second embodiment and the air conditioner 1 of the first embodiment will be described with reference to fig. 3. The air conditioning apparatus 2 of the second embodiment is different from the air conditioning apparatus 1 of the first embodiment in that an indoor condenser 25 is added, and the condenser 12, the high-stage-side heat medium circulation circuit 21, the high-stage-side pump 22, and the heater core 23 are eliminated.

The indoor condenser 25 is the first heat exchange unit 20 that heats the feed air using the high-pressure refrigerant discharged from the compressor 11 as a heat source. The indoor condenser 25 is disposed in the casing 41 on the downstream side of the second heat exchanger 39. The indoor condenser 25 exchanges heat between the high-pressure refrigerant discharged from the compressor 11 and the feed air, and radiates heat of the high-pressure refrigerant to the feed air, thereby heating the feed air.

In this way, in the air conditioning apparatus 2 according to the second embodiment, the indoor condenser 25 directly heats the feed air by using the heat of the high-pressure refrigerant. As a result, the feed air can be heated more efficiently than in a configuration in which the feed air is heated by the heat of the high-pressure refrigerant via the cooling water.

(third embodiment)

Hereinafter, a difference between the air conditioner 3 of the third embodiment and the air conditioner 1 of the first embodiment will be described with reference to fig. 4. The air conditioning apparatus 3 of the third embodiment is different from the air conditioning apparatus 1 of the first embodiment in that a first pressure reducing valve 55, a second pressure reducing valve 56, a first connecting passage 65, and a second connecting passage 66 are added, and the pressure reducing valve 13 and the second heat exchanger 39 are eliminated.

The first pressure reducing valve 55 and the second pressure reducing valve 56 are pressure reducers for reducing and expanding the liquid-phase refrigerant flowing out of the condenser 12. That is, the first pressure reducing valve 55 and the second pressure reducing valve 56 reduce the pressure of the refrigerant on the downstream side of the condenser 12. The low-pressure refrigerant decompressed by the first decompression valve 55 flows into the heat medium evaporator 15. The low-pressure refrigerant decompressed by the second decompression valve 56 flows into the exterior evaporator 18.

The first pressure reducing valve 55 and the second pressure reducing valve 56 are electric variable throttle mechanisms whose operation is controlled in accordance with a control signal output from the control device 50, and include a valve body and an electric actuator. The valve body is configured to be able to change a passage opening degree (in other words, a throttle opening degree) of the refrigerant passage. The electric actuator includes a stepping motor that changes the throttle opening of the valve body.

The first connection flow path 65 connects the flow rate adjustment valve 35 to the high-stage side heat medium circulation circuit 21 on the upstream side of the heater core 23. The first connection channel 65 is a channel that guides the cooling water in the low-stage side heat medium circulation circuit 30 to the high-stage side heat medium circulation circuit 21.

The second connection flow path 66 connects the high-stage side heat medium circulation circuit 21 on the downstream side of the heater core 23 and the high-stage side pump 22 to the low-stage side heat medium circulation circuit 30 on the upstream side of the low-stage side pump 33.

In the air conditioning apparatus 3 of the third embodiment, the flow rate adjustment valve 35 is a flow rate adjustment unit that adjusts the flow rate of the cooling water heated by the heat generating device 34 flowing into the heat medium evaporator 15 and the flow rate of the cooling water heated by the heat generating device 34 flowing into the heater core 23 via the first connection flow path 65.

The flow rate control valve 35 can cause the entire amount of the cooling water heated by the heat generating device 34 to flow into the heat medium evaporator 15 and can cause the entire amount of the cooling water to flow into the heater core 23. The flow rate control valve 35 is configured such that the entire amount of the cooling water flows into the heater core 23 when no current is supplied thereto.

The control device 50 calculates a target outlet air temperature TAO of the blowing air to be blown into the vehicle interior based on the detection signal detected by the control sensor group and the operation signal from the operation unit 60, and determines the operation mode of the air conditioner 3 as any one of the refrigeration cycle heating mode, the heat source heating mode, the refrigeration cycle heat source heating mode, and the defrosting operation mode. Hereinafter, each operation mode will be described.

(refrigeration cycle heating mode)

The refrigeration cycle heating mode is an operation mode in which the cooling water heated by the condenser 12 is used as a heat source to heat the air. In the refrigeration cycle heating mode, the control device 50 determines the operation states of various control target devices (control signals to be output to various control devices) based on the detection signals, the target outlet air temperature TAO, and the like. Specifically, the controller 50 operates the compressor 11, the high-stage pump 22, the low-stage pump 33, the heat generating device 34, and the low-stage radiator blower 36. The control device 50 determines control signals to be output to the first pressure reducing valve 55 and the second pressure reducing valve 56 so that they reach the throttle opening of the predetermined refrigeration cycle heating mode.

Similarly to the first heating mode described in the first embodiment, the heat generation amount control unit 50b operates the heat generation device 34 when the temperature of the feed air blown into the vehicle interior does not reach the target blowout temperature TAO, when the rotation speed of the compressor 11 reaches a predetermined rotation speed set in advance in accordance with the durability of the compressor 11, or when the power consumption in the compressor 11 exceeds a predetermined value. The heat generation amount control unit 50b controls the amount of heat generated by the heat generation device 34 so that the blown air blown into the vehicle interior reaches the target blowing temperature TAO.

Therefore, in the refrigeration cycle apparatus 10 in the refrigeration cycle heating mode, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12. The high-pressure refrigerant flowing into the condenser 12 exchanges heat with the cooling water and is condensed. At this time, the heat of the high-pressure refrigerant is radiated to the cooling water, and the cooling water is heated. Then, the cooling water heated by the condenser 12 in the heater core 23 exchanges heat with the supply air, thereby heating the supply air.

The high-pressure refrigerant flowing out of the condenser 12 is decompressed by the first and

second decompression valves

55 and 56 to become a low-pressure refrigerant.

The low-pressure refrigerant decompressed by the first decompression valve 55 flows into the heat medium evaporator 15. The low-pressure refrigerant flowing into the heat medium evaporator 15 absorbs heat from the cooling water circulating in the low-stage side heat medium circuit 30 and evaporates. Thereby, the cooling water circulating in the low-stage side heat medium circulation circuit 30 is cooled.

The low-pressure refrigerant decompressed by the second decompression valve 56 flows into the external evaporator 18. The low-pressure refrigerant flowing into the exterior evaporator 18 absorbs heat from the outside air and evaporates.

In the refrigeration cycle heating mode, the low-stage-side flow rate adjustment valve 31 causes cooling water to flow into the low-stage-side radiator 32. Therefore, the cooling water cooled by the heat medium evaporator 15 exchanges heat with the outside air in the low-stage radiator 32 to absorb heat, and is heated.

As described above, the refrigeration cycle heating mode can blow out the supply air heated by the heater core 23 into the vehicle interior. This enables heating of the vehicle interior.

In the refrigeration cycle heating mode, the refrigerant condensing temperature in the condenser 12 can be made higher than the temperature of the cooling water circulating in the low-stage side heat medium circulation circuit 30 by using the compression work of the compressor 11 in addition to the heat absorbed by the refrigerant from the cooling water heated by the heat generating device 34. Therefore, the air can be heated at a higher temperature than in the heat source heating mode described below.

(Heat source heating mode)

The heat source heating mode is an operation mode in which the cooling water heated by the heat generating device 34 is used as a heat source to heat the air. In the heat source heating mode, the control device 50 determines the operation states of various control target devices (control signals to be output to various control devices) based on the detection signals, the target outlet air temperature TAO, and the like. Specifically, the controller 50 operates the low-stage pump 33 and the heat generating device 34. In the heat source heating mode, the controller 50 stops the compressor 11, the high-stage pump 22, the outdoor heat exchanger blower 19, and the low-stage radiator blower 36.

The flow rate control unit 50c controls the flow rate control valve 35 so that the entire amount of the cooling water discharged by the low-stage pump 33 and heated by the heat generating device 34 flows into the heater core 23 via the first connection flow path 65.

Therefore, in the air conditioner 3 in the heat source heating mode, the entire amount of the cooling water discharged by the low-stage pump 33 and heated by the heat generating device 34 flows into the heater core 23. In the heater core 23, the cooling water heated by the heat generating device 34 exchanges heat with the air, thereby heating the air.

As described above, in the heat source heating mode, the air heated by the heater core 23 can be blown into the vehicle interior. This enables heating of the vehicle interior.

(Heat source heating mode of refrigeration cycle)

The refrigeration cycle heat source heating mode is an operation mode in which the cooling water heated by the condenser 12 and the cooling water heated by the heat generating device 34 are used as heat sources to heat the air. In the refrigeration cycle heat source heating mode, the control device 50 determines the operation states of various control target devices (control signals to be output to various control devices) based on the detection signals, the target outlet air temperature TAO, and the like. Specifically, the controller 50 operates the compressor 11, the high-stage pump 22, the low-stage pump 33, the heat generating device 34, and the low-stage radiator blower 36. The control device 50 determines control signals to be output to the first pressure reducing valve 55 and the second pressure reducing valve 56 so that they reach a predetermined throttle opening degree of the heat source heating mode of the refrigeration cycle.

The flow rate control unit 50c controls the flow rate control valve 35 so that the cooling water heated by the heat generating device 34 flows into both the heat medium evaporator 15 and the heater core 23. The flow rate control unit 50c controls the flow rate of the cooling water heated by the heat generating device 34 flowing into the heat medium evaporator 15 and the flow rate of the cooling water heated by the heat generating device 34 flowing into the heater core 23 by controlling the flow rate adjusting valve 35 based on the operating state of the refrigeration cycle apparatus 10 and the target outlet air temperature TAO.

Therefore, in the refrigeration cycle device 10 in the refrigeration cycle heat source heating mode, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12. The high-pressure refrigerant flowing into the condenser 12 exchanges heat with the cooling water and is condensed. At this time, the heat of the high-pressure refrigerant is radiated to the cooling water, and the cooling water is heated. Then, the cooling water heated by the condenser 12 in the heater core 23 exchanges heat with the supply air, thereby heating the supply air.

second decompression valves

55 and 56 to become a low-pressure refrigerant.

In the refrigeration cycle heat source heating mode, the low-stage-side flow rate adjustment valve 31 causes cooling water to flow into the low-stage-side radiator 32. Therefore, the cooling water cooled by the heat medium evaporator 15 exchanges heat with the outside air in the low-stage radiator 32, absorbs heat, and is heated.

The cooling water flowing out of the low-stage-side radiator 32 is heated by the heat generating device 34, and then flows into the heat medium evaporator 15 and the heater core 23. When the cooling water flows into the heat medium evaporator 15, the cooling water heated by the heat generating device 34 exchanges heat with the refrigerant in the heat medium evaporator 15, and the refrigerant is heated. In this manner, the heat generating device 34 heats the refrigerant.

On the other hand, the cooling water heated by the heat generating device 34 flows into the heater core 23, and the cooling water heated by the heat generating device 34 in the heater core 23 exchanges heat with the air to heat the air.

As described above, in the refrigeration cycle heat source heating mode, the air heated by the heater core 23 can be blown into the vehicle interior. This enables heating of the vehicle interior.

(defrosting operation mode)

When the frost formation determination unit 50d of the control device 50 determines that frost formation has occurred in the external evaporator 18 while the refrigeration cycle heating mode or the refrigeration cycle heat source heating mode is being executed, the following defrosting operation mode is executed.

The discharge capacity control unit 50a reduces the rotation speed of the compressor 11 to reduce the discharge capacity of the compressor 11. This reduces the amount of heat absorbed by the refrigerant in the external evaporator 18 from the outside air, thereby suppressing frost formation in the external evaporator 18.

The flow rate control unit 50c controls the flow rate control valve 35 so that the inflow amount of the cooling water heated by the heat generating device 34 into the heater core 23 increases. The heat generation amount control unit 50b increases the amount of heat generated by the heat generation device 34. This increases the amount of heat of the cooling water flowing into the heater core 23. Therefore, even if the amount of heat radiation from the condenser 12 to the cooling water is reduced as the discharge capacity of the compressor 11 is reduced, the temperature of the cooling water flowing into the heater core 23 is suppressed from being reduced, and the heating capacity of the air conditioner 3 is maintained.

As described above, in the cooling cycle heating mode, the flow rate control portion 50c controls the operation of the flow rate adjustment valve 35 so that the cooling water heated by the heat generating device 34 flows into the heat medium evaporator 15, and in the heat source heating mode, the flow rate control portion 50c controls the operation of the flow rate adjustment valve 35 so that the cooling water heated by the heat generating device 34 flows into the heater core 23.

Thus, in the refrigeration cycle heating mode, the heat of the cooling water heated by the heat generating device 34 is absorbed by the refrigerant in the heat medium evaporator 15, and the cooling water flowing into the heater core 23 can be heated using the heat absorbed by the refrigerant as a heat source. Further, the heater core 23 can heat the blowing air. In the heat source heating mode, the air can be heated by the heater core 23 using the heat of the cooling water heated by the heat generating device 34 as a heat source.

Therefore, under operating conditions in which the heat generation of the heat generating device 34 increases and the pressure of the refrigerant discharged from the compressor 11 may unnecessarily increase, it is possible to switch from the refrigeration cycle heating mode to the heat source heating mode.

Then, by switching from the refrigeration cycle heating mode to the heat source heating mode, unnecessary increase in the pressure of the refrigerant on the high-pressure side of the refrigeration cycle device 10 can be reliably suppressed, and the air can be heated by effectively using the heat generated by the heat generating device 34.

Even in a state where the refrigerant cannot be circulated through the refrigeration cycle apparatus 10, such as when the compressor 11 is operating in a defective state, the air can be heated by the heater core 23 using the heat of the cooling water heated by the heat generating device 34 as a heat source by switching to the heat source heating mode.

When the frost formation determination unit 50d determines that frost formation has occurred in the external evaporator 18, the flow rate control unit 50c controls the flow rate adjustment valve 35 so as to increase the inflow amount of the cooling water heated by the heat generation device 34 into the heater core 23.

Thus, even if the discharge capacity of the compressor 11 is reduced to defrost the external evaporator 18, and therefore the amount of heat released to the cooling water in the condenser 12 is reduced, the temperature of the cooling water flowing into the heater core 23 can be suppressed from being reduced, and the heating capacity of the air conditioner 3 can be maintained.

The flow rate control valve 35 is configured such that the entire amount of the cooling water flows into the heater core 23 when no current is supplied thereto. Accordingly, even if the flow rate control valve 35 is stuck due to freezing or the like, for example, by executing the operation in the heat source heating mode, the air can be heated by the heater core 23, and the vehicle interior can be reliably heated.

(fourth embodiment)

Hereinafter, a difference between the air conditioner 4 of the fourth embodiment and the air conditioner 1 of the first embodiment will be described with reference to fig. 5. The air conditioner 4 of the fourth embodiment is different from the air conditioner 1 of the first embodiment in that an outdoor heat exchanger 61, a first pressure reducing valve 62, a second pressure reducing valve 63, and an outdoor heat exchanger blower 64 are added, and the refrigerant flow path adjustment valve 14, the external evaporator 18, and the outdoor heat exchanger blower 19 are eliminated.

The refrigeration cycle device 10 of the air conditioning apparatus 4 according to the fourth embodiment includes a compressor 11, a condenser 12, a first pressure reducing valve 62 (first pressure reducer), an outdoor heat exchanger 61, a second pressure reducing valve 63, a heat medium evaporator 15, and an accumulator 16 (liquid receiver).

A refrigerant inlet side of the first pressure reducing valve 62 is connected to a refrigerant outlet side of the condenser 12. The first pressure reducing valve 62 is a first pressure reducer that reduces and expands the liquid-phase refrigerant flowing out of the condenser 12. That is, the first pressure reducing valve 62 reduces the pressure of the refrigerant on the downstream side of the condenser 12. The first pressure reducing valve 62 is configured as a variable throttle mechanism with a fully open function that functions only as a refrigerant passage by fully opening the throttle opening degree and hardly performs a refrigerant pressure reducing function.

The first pressure reducing valve 62 is an electric variable throttle mechanism whose operation is controlled in accordance with a control signal output from the control device 50, and includes a valve body and an electric actuator. The valve body is configured to be able to change a passage opening degree (in other words, a throttle opening degree) of the refrigerant passage.

A refrigerant outlet side of the first pressure reducing valve 62 is connected to a refrigerant inlet side of the outdoor heat exchanger 61. When the throttle opening degree of the first pressure reducing valve 62 is fully opened, the outdoor heat exchanger 61 can condense the high-pressure refrigerant by exchanging heat between the high-pressure refrigerant and the outdoor air blown by the outdoor heat exchanger air blower 64. On the other hand, when the flow path through which the refrigerant flows is throttled by the first pressure reducing valve 62, the outdoor heat exchanger 61 can exchange heat between the low-pressure medium decompressed by the first pressure reducing valve 62 and the outside air blown by the outdoor heat exchanger blower 64 to absorb heat in the low-pressure medium and evaporate the low-pressure medium.

The outdoor heat exchanger air-sending device 64 is an electric air-sending device in which a fan is driven by an electric motor, and the operation of the outdoor heat exchanger air-sending device 64 is controlled based on a control signal output from the control device 50. The outdoor heat exchanger 61 and the outdoor heat exchanger blower 64 are disposed on the front side in the vehicle hood. Therefore, when the vehicle is traveling, the traveling wind can be brought into contact with the outdoor heat exchanger blower 64.

A refrigerant inlet side of the second pressure reducing valve 63 is connected to a refrigerant outlet side of the outdoor heat exchanger 61. The second pressure reducing valve 63 is a second pressure reducer that reduces and expands the pressure of the liquid-phase refrigerant flowing out of the outdoor heat exchanger 61. That is, the second pressure reducing valve 63 reduces the pressure of the refrigerant on the downstream side of the outdoor heat exchanger 61. The second pressure reducing valve 63 is configured as a variable throttle mechanism with a fully opening function that functions only as a refrigerant passage by fully opening the throttle opening degree and that hardly performs a refrigerant pressure reducing function.

The second pressure reducing valve 63 is an electric variable throttle mechanism whose operation is controlled in accordance with a control signal output from the control device 50, and includes a valve body and an electric actuator. The valve body is configured to be able to change a passage opening degree (in other words, a throttle opening degree) of the refrigerant passage.

The control device 50 calculates a target outlet temperature TAO of the blowing air to be blown into the vehicle interior based on the detection signal detected by the control sensor group and the operation signal from the operation unit 60, and determines the operation mode of the air conditioner 4 as any one of the first to third heating modes, the defrosting operation mode, and the cooling mode.

In the first to third heating modes and the defrosting operation mode, the controller 50 reduces the opening degree of at least one of the first and second

pressure reducing valves

62 and 63, and causes the low-pressure refrigerant to exchange heat with the outside air or the cooling water and absorb heat and evaporate in at least one of the outdoor heat exchanger 61 and the heat medium evaporator 15. The other operations are the same as the first to third heating modes and the defrosting operation mode of the air conditioning apparatus 1 according to the first embodiment.

(refrigeration mode)

The cooling mode is an operation mode in which the second heat exchanger 39 cools the feed air. In the cooling mode, the control device 50 determines the operation states of various control target devices (control signals to be output to the various control devices) based on the detection signals, the target outlet air temperature TAO, and the like. Specifically, the controller 50 operates the compressor 11, the low-stage pump 33, and the outdoor heat exchanger blower 64. On the other hand, the control device 50 stops the high-stage pump 22 and the low-stage radiator blower 36, and stops the heat generation in the heat generating device 34. The control device 50 fully opens the throttle opening degree of the first pressure reducing valve 62, and determines a control signal to be output to the second pressure reducing valve 63 so as to reach the throttle opening degree of a predetermined cooling mode.

The flow rate control unit 50c controls the flow rate adjustment valve 35 so that the cooling water discharged by the low-stage pump 33 flows into the heat medium evaporator 15 and the second heat exchanger 39.

The control device 50 controls the operation of the low-stage-side flow rate adjustment valve 31 so that the entire amount of the cooling water flowing out of the heat medium evaporator 15 flows into the radiator bypass flow path 37.

Therefore, in the refrigeration cycle device 10 in the cooling mode, the high-pressure refrigerant discharged from the compressor 11 flows into the condenser 12. Since the high-stage-side pump 22 is stopped, the high-pressure refrigerant flowing into the condenser 12 hardly exchanges heat with the cooling water. Therefore, the high-pressure refrigerant flowing into the condenser 12 flows out without being condensed.

The high-pressure refrigerant flowing out of the condenser 12 flows into the outdoor heat exchanger 61 without being decompressed by the first decompression valve 62. The high-pressure refrigerant flowing into the outdoor heat exchanger 61 is condensed by heat exchange with the outdoor air blown by the outdoor heat exchanger air-sending device 64. The high-pressure refrigerant flowing out of the outdoor heat exchanger 61 is decompressed by the second decompression valve 63 to become a low-pressure refrigerant.

The low-pressure refrigerant decompressed by the second decompression valve 63 flows into the heat medium evaporator 15. The low-pressure refrigerant flowing into the heat medium evaporator 15 absorbs heat from the cooling water circulating in the low-stage side heat medium circuit 30 and evaporates. Thereby, the cooling water circulating in the low-stage side heat medium circulation circuit 30 is cooled.

In the cooling mode, the low-stage-side flow rate adjustment valve 31 causes the cooling water to flow into the radiator bypass flow path 37. This prevents the cooling water cooled by the heat medium evaporator 15 from exchanging heat with the outside air in the low-stage-side radiator 32.

The cooling water flowing through the radiator bypass passage 37 and discharged from the low-stage pump 33 flows into the heat medium evaporator 15 and the second heat exchanger 39. The cooling water cooled by the heat medium evaporator 15 exchanges heat with the supply air in the second heat exchanger 39. Thereby, the supply air is cooled.

As described above, in the cooling mode, the air cooled by the second heat exchanger 39 can be blown into the vehicle interior, and thus cooling of the vehicle interior can be achieved.

(fifth embodiment)

Hereinafter, a difference between the air conditioner 5 of the fifth embodiment and the air conditioner 1 of the first embodiment will be described with reference to fig. 6. The air conditioner 5 of the fifth embodiment is the air conditioner 1 of the first embodiment, to which a first connection flow path 71, a second connection flow path 72, and an introduction amount adjustment valve 73 are added.

The first connection flow path 71 connects the second heat exchange portion flow path 38 on the downstream side of the flow rate adjustment valve 35 to the high-stage side heat medium circulation circuit 21 on the upstream side of the heater core 23. The second connection channel 72 is a channel for guiding the cooling water in the low-stage side heat medium circulation circuit 30 to the high-stage side heat medium circulation circuit 21.

The second connection flow path 72 connects the high-stage side heat medium circulation circuit 21 on the downstream side of the heater core 23 and the high-stage side pump 22 to the low-stage side heat medium circulation circuit 30 on the upstream side of the low-stage side pump 33.

The introduction amount adjusting valve 73 is an introduction amount adjusting portion that adjusts the introduction amount of the cooling water introduced from the second heat exchange portion flow path 38 into the high-stage side heat medium circulation circuit 21 through the first connection flow path 71.

Software and hardware for controlling the operation of the introduction amount adjusting valve 73 in the control device 50 of the air conditioner 5 according to the fifth embodiment are the introduction amount control unit 50 e.

The control device 50 calculates a target outlet temperature TAO of the blowing air to be blown into the vehicle interior based on the detection signals detected by the control sensor group and the operation signal from the operation unit 60, and determines the operation mode of the air conditioner 5 to be any one of the first heating mode, the third heating mode, and the defrosting operation mode.

The first to third heating modes of the air conditioner 5 of the fifth embodiment are the same as the first to third heating modes of the air conditioner 1 of the first embodiment.

(defrosting operation mode)

The discharge capacity control unit 50a reduces the rotation speed of the compressor 11 to reduce the discharge capacity of the compressor 11.

The introduction amount control unit 50e controls the introduction amount adjusting valve 73 so as to increase the introduction amount of the cooling water heated by the heat generating device 34 into the heater core 23. The heat generation amount control unit 50b increases the amount of heat generated by the heat generation device 34. Thus, even if the amount of heat released from the condenser 12 to the cooling water decreases as the discharge capacity of the compressor 11 decreases, the temperature of the cooling water flowing into the heater core 23 is suppressed from decreasing, and the heating capacity of the air conditioner 5 is maintained.

As described above, when the frost formation determination unit 50d determines that frost formation has occurred in the external evaporator 18, the discharge capacity control unit 50a decreases the rotation speed of the compressor 11 to decrease the discharge capacity of the compressor 11. This reduces the amount of heat absorbed by the refrigerant in the external evaporator 18 from the outside air, thereby suppressing frost formation in the external evaporator 18.

When the frost formation determination unit 50d determines that frost formation has occurred in the external evaporator 18, the introduction amount control unit 50e controls the introduction amount adjustment valve 73 so as to increase the inflow amount of the cooling water heated by the heat generation device 34 into the heater core 23.

Thus, even if the discharge capacity of the compressor 11 is reduced to defrost the external evaporator 18, and thus the amount of heat released to the cooling water in the condenser 12 is reduced, the temperature of the cooling water flowing into the heater core 23 can be suppressed from being reduced, and the heating capacity of the air conditioner 5 can be maintained.

(other embodiments)

The present invention is not limited to the above-described embodiments, and various modifications can be made as follows without departing from the scope of the present invention. The above embodiments may be combined as appropriate within the range where the embodiments can be implemented.

(1) In the above-described embodiment, the example in which the refrigeration cycle device 10 according to the present invention is applied to the air conditioner for a vehicle has been described, but the application of the refrigeration cycle device 10 according to the present invention is not limited to a vehicle, and may be applied to a stationary air conditioner. The application of the refrigeration cycle apparatus 10 according to the present invention is not limited to an air conditioner, and may be applied to a water heater in which the fluid to be heat-exchanged is drinking water or domestic water.

(2) In the above-described embodiment, the example in which the accumulator 16, which is a liquid storage portion for storing the refrigerant, is disposed on the upstream side of the compressor 11 has been described, but the liquid storage portion is not limited thereto. For example, as the liquid storage portion, a receiver (liquid receiver) that separates gas and liquid of the refrigerant flowing out of the condenser 12 and stores surplus liquid-phase refrigerant may be disposed downstream of the condenser 12. Of course, both the reservoir 16 and the receiver may be configured.

(3) The respective constituent devices constituting the refrigeration cycle apparatus 10 are not limited to those disclosed in the above-described embodiments. For example, in the above-described embodiment, the example in which the electric compressor is used as the compressor 11 has been described, but when the compressor is applied to a vehicle-running engine, an engine-driven compressor that is driven by a rotational driving force transmitted from the vehicle-running engine via a pulley, a belt, or the like may be used as the compressor 11.

(4) In the above embodiment, the heat generating device 34 is an electric heater such as a PTC heater. The heat generating device 34 may be an in-vehicle device that generates heat during operation. As the in-vehicle equipment, a battery, an inverter as a frequency conversion unit, and a traveling motor that outputs a driving force for traveling can be used. These in-vehicle devices are cooled by radiating heat to the cooling water of the low-stage side heat medium circulation circuit 30.

(5) The frost formation determination unit 50d may be an embodiment described below, for example, configured to determine that frost is formed in the external evaporator 18 as follows: the outside air temperature Tam detected by the outside air temperature sensor 52 is 0 ℃ or lower, and a value obtained by subtracting the temperature of the external evaporator 18 detected by the outdoor heat exchanger temperature sensor 54 from the outside air temperature Tam becomes equal to or higher than a predetermined reference temperature difference.

(6) The following embodiments are also possible: the air conditioner 1 according to the first embodiment, the air conditioner 2 according to the second embodiment, the air conditioner 3 according to the third embodiment, and the air conditioner 5 according to the fifth embodiment described above do not include the refrigerant flow path adjustment valve 14, the external evaporator 18, and the air blower 19 for the outdoor heat exchanger. The air conditioner 4 according to the fourth embodiment may be added with the first connection flow path 71, the second connection flow path 72, and the introduction amount adjustment valve 73 described in the air conditioner 5 according to the fifth embodiment.

(7) In the air conditioning apparatus 2 according to the second embodiment, an outdoor condenser that condenses the high-pressure refrigerant flowing out of the indoor condenser 25 by exchanging heat with the outside air may be provided downstream of the indoor condenser 25. In the first to third heating modes of this embodiment, the high-pressure refrigerant flowing out of the indoor condenser 25 is condensed by heat exchange with the outside air in the outdoor condenser, and excess heat of the high-pressure refrigerant is discharged to the outside air.

(8) In the air conditioner 4 of the fourth embodiment, the refrigerant flow path adjustment valve 14 and the exterior evaporator 18 may be added to execute the defrosting operation mode described in the air conditioner 1 of the first embodiment.

Claims

1. A refrigeration cycle apparatus includes:

a compressor (11) that compresses and discharges a refrigerant;

a first heat exchange unit (20) that heats a fluid to be heat-exchanged using a high-pressure refrigerant discharged from the compressor as a heat source;

a decompressor (13, 62, 63) that decompresses the refrigerant flowing out of the first heat exchanger;

a heat medium evaporator (15) that evaporates the refrigerant decompressed by the decompressor by exchanging heat with a low-stage side heat medium;

a heat generating unit (34) that is disposed in a low-stage-side heat medium circulation circuit (30) that circulates the low-stage-side heat medium and that heats the low-stage-side heat medium;

a second heat exchange unit (39) that heats the fluid to be heat exchanged using the low-stage-side heat medium heated by the heat generating unit as a heat source;

a flow rate adjustment unit (35) that adjusts the flow rate of the low-stage-side heat medium flowing into the heat medium evaporator and the flow rate of the low-stage-side heat medium flowing into the second heat exchange unit;

a flow rate control unit (50c) for controlling the operation of the flow rate adjustment unit,

a heat generation amount control unit (50b) that controls the amount of heat generated by the heat generation unit; and

an outdoor heat exchanger (61) for exchanging heat between the refrigerant flowing out of the first heat exchange unit and outside air,

in a cooling mode in which the second heat exchanging portion cools the fluid to be heat exchanged, the heat generation amount control portion controls the operation of the heat generating portion so that heat generation in the heat generating portion is stopped,

in a first heating mode in which the fluid to be heat-exchanged is heated by the first heat exchanging portion, the flow rate control portion controls the operation of the flow rate adjusting portion so that the low-stage side heat medium heated by the heat generating portion flows into the heat medium evaporator,

in a second heating mode in which the fluid to be heat-exchanged is heated by the second heat exchanging portion, the flow rate control portion controls the operation of the flow rate adjusting portion such that the low-stage-side thermal medium heated by the heat generating portion flows into the second heat exchanging portion,

in the cooling mode, the flow rate control portion controls the operation of the flow rate adjustment portion so that the low-stage side heat medium cooled by the heat medium evaporator flows into the second heat exchange portion.

2. The refrigeration cycle apparatus according to claim 1,

in a third heating mode in which the fluid to be heat-exchanged heated by the second heat exchange unit is heated by the first heat exchange unit, the flow rate control unit controls the operation of the flow rate adjustment unit so that the low-stage-side heat medium heated by the heat generation unit flows into both the heat medium evaporator and the second heat exchange unit.

3. The refrigeration cycle apparatus according to claim 1,

the first heat exchange unit has an indoor condenser (25) that exchanges heat between the high-pressure refrigerant and the fluid to be heat-exchanged.

4. The refrigeration cycle apparatus according to claim 1,

the first heat exchange portion includes:

a high-stage-side heat medium circulation circuit (21) that circulates a high-stage-side heat medium;

a condenser (12) that exchanges heat between the high-pressure refrigerant and the high-stage side heat medium; and

and a heater core (23) that exchanges heat between the high-stage side heat medium and the fluid to be heat-exchanged.

5. The refrigeration cycle apparatus according to any one of claims 1 to 4,

comprising:

an outdoor-air evaporation unit (18) that evaporates the refrigerant decompressed by the decompressor by exchanging heat with outdoor air; and

a frost formation determination unit (50d) for determining whether or not frost is formed in the outside air evaporation unit,

when the frost formation determination unit determines that frost formation has occurred in the outside air evaporation unit, the heat generation amount control unit increases the amount of heat generated in the heat generation unit.

6. A refrigeration cycle apparatus includes:

a compressor (11) that compresses and discharges a refrigerant;

an outdoor-air evaporation unit (18) that evaporates the refrigerant decompressed by the decompressor by exchanging heat with outdoor air;

7. A refrigeration cycle apparatus includes:

a compressor (11) that compresses and discharges a refrigerant;

a flow rate adjustment unit (35) that adjusts the flow rate of the low-stage-side heat medium flowing into the heat medium evaporator and the flow rate of the low-stage-side heat medium flowing into the second heat exchange unit; and

the first heat exchange portion includes: a high-stage-side heat medium circulation circuit (21) that circulates a high-stage-side heat medium; a condenser (12) that exchanges heat between the high-pressure refrigerant and the high-stage side heat medium; and a heater core (23) that exchanges heat between the high-stage side heat medium and the fluid to be heat-exchanged,

the refrigeration cycle device further includes:

a connection flow path (71) that guides the low-stage-side heat medium to the high-stage-side heat medium circulation circuit;

an introduction amount adjustment unit (73) that adjusts the amount of introduction of the low-stage-side heat medium that is introduced into the high-stage-side heat medium circulation circuit via the connection channel;

an introduction amount control unit (50e) that controls the operation of the introduction amount adjustment unit; and

the introduction amount adjustment unit increases the introduction amount when the frost formation determination unit determines that frost formation has occurred in the outside air evaporation unit.

8. The refrigeration cycle apparatus according to claim 7,

a discharge capacity control unit (50a) for controlling the discharge capacity of the refrigerant of the compressor,

the discharge performance control unit reduces the discharge performance of the refrigerant when the frost formation determination unit determines that frost formation has occurred in the outside air evaporation unit.

9. The refrigeration cycle apparatus according to claim 7 or 8,

the flow rate adjusting portion is an electromagnetic valve that operates by being supplied with electric power,

the flow rate adjustment unit is configured such that the entire amount of the low-stage side heat medium flows into the second heat exchange unit when no current is supplied.

10. A refrigeration cycle apparatus includes:

a compressor (11) that compresses and discharges a refrigerant;

the flow rate adjustment unit is configured such that the entire amount of the low-stage side heat medium flows into the second heat exchange unit when the current is not supplied,

in a second heating mode in which the fluid to be heat-exchanged is heated by the second heat exchanging portion, the flow rate control portion controls the operation of the flow rate adjusting portion so that the low-stage-side thermal medium heated by the heat generating portion flows into the second heat exchanging portion.

11. The refrigeration cycle apparatus according to claim 10,

12. The refrigeration cycle apparatus according to claim 10 or 11,

13. The refrigeration cycle apparatus according to claim 10 or 11,

the first heat exchange portion includes:

14. A refrigeration cycle apparatus includes:

a compressor (11) that compresses and discharges a refrigerant;

a condenser (12) that heats a heat medium by exchanging heat between a high-pressure refrigerant discharged from the compressor and the heat medium;

a decompressor (55) for decompressing the refrigerant flowing out of the condenser;

a heat medium evaporator (15) that evaporates the refrigerant decompressed by the decompressor by exchanging heat with the heat medium;

a heat generating unit (34) that heats the heat medium;

a heater core (23) that heats the fluid to be heat-exchanged using at least one of the heat medium heated by the condenser and the heat medium heated by the heat generating portion as a heat source;

a flow rate adjusting unit (35) that adjusts the flow rate of the heat medium heated by the heat generating unit flowing into the heat medium evaporator and the flow rate of the heat medium heated by the heat generating unit flowing into the heater core;

a flow rate control unit (50c) that controls the operation of the flow rate adjustment unit;

in a refrigeration cycle heating mode in which the heat medium heated by the condenser is used as a heat source to heat the fluid to be heat exchanged, the flow rate control unit controls the operation of the flow rate adjustment unit so that the heat medium heated by the heat generation unit flows into the heat medium evaporator,

in a heat source heating mode in which the heat medium heated by the heat generating portion is used as a heat source to heat the fluid to be heat exchanged, the flow rate control portion controls the operation of the flow rate adjusting portion so that the heat medium heated by the heat generating portion flows into the heater core,

when it is determined by the frost formation determination unit that frost is formed in the outside air evaporation unit, the flow rate control unit controls the operation of the flow rate adjustment unit so that the inflow amount of the heat medium heated by the heat generation unit into the heater core increases.