JP2019027729A - Complex type heat exchanger - Google Patents

Abstract

To provide a complex type heat exchanger which can reduce pressure loss occurring in a fluid circulating inside.SOLUTION: A complex heat exchanger includes: a branch part 13 for branching a refrigerant discharged from a compressor 11 of a refrigeration cycle device 10; a water-refrigerant heat exchange part 14 for exchanging heat between one refrigerant branched at the branch part 13 and a heating medium circulating in a water circulation circuit 40; an air-water heat exchange part 15 for exchanging heat between the heating medium and the outside air; and an air-refrigerant heat exchange part 16 for exchanging heat between the other refrigerant branched at the branch part 13 and the outside air. It also includes a confluence port 16c for allowing the refrigerant flowed out from the water-refrigerant heat exchange part 14 to join in the middle of a refrigerant passage of the air-refrigerant heat exchange part 16. Thereby, pressure loss at the time of the refrigerant circulating in the water-refrigerant heat exchange part 14 can be reduced.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a composite heat exchanger having a plurality of heat exchange units.

  Conventionally, in Patent Document 1, as a combined heat exchanger for a vehicle, a first fluid (specifically, a refrigerant of a refrigeration cycle device) and a second fluid (specifically, cooling water of an engine cooling water circuit) , And a third heat exchanger (specifically, outside air), a composite heat exchanger configured to be able to exchange heat between three types of fluid is disclosed.

  The composite heat exchanger of Patent Document 1 has three heat exchange units, a first to a third heat exchange unit. The first heat exchanging unit is a water-refrigerant heat exchanging unit that cools the refrigerant by exchanging heat between the high-pressure refrigerant discharged from the compressor of the refrigeration cycle apparatus and the cooling water. The second heat exchange unit is a radiator unit that cools the cooling water supplied to the first heat exchange unit by exchanging heat between the cooling water and the outside air. The third heat exchange unit is a condenser unit that causes heat exchange between the refrigerant flowing out of the first heat exchange unit and the outside air to cool and condense the refrigerant.

  Further, in Patent Document 1, a so-called stacked heat exchanger structure is adopted as the water-refrigerant heat exchange section, and a so-called tank-and-tube heat exchanger structure is adopted as the radiator section and the condenser section. Is adopted. And the water-refrigerant heat exchange part formed comparatively small is superposed on the radiator part and the tank part of the condenser part when viewed from the flow direction of the outside air.

  Thereby, in the composite heat exchanger of patent document 1, it is going to suppress that a water-refrigerant heat exchange part obstructs a ventilation air flow and reduces the effective heat exchange area of a radiator part and a capacitor | condenser part. . And it is going to suppress the fall of the cooling capacity of the cooling water and a refrigerant | coolant in a radiator part and a capacitor | condenser part.

  Patent Document 2 discloses a refrigeration cycle apparatus applied to a vehicle air conditioner and configured to be able to switch a refrigerant circuit according to an operation mode. The refrigeration cycle apparatus of Patent Document 2 includes two heats of an indoor heat exchanger that exchanges heat between the refrigerant and the blown air that is blown into the air-conditioning target space, and an outdoor heat exchanger that exchanges heat between the refrigerant and the outside air. Has an exchanger. Then, the flow direction of the refrigerant in the two heat exchangers is reversed according to the operation mode, and the heat exchanger that functions as a condenser and the heat exchanger that functions as an evaporator of the two heat exchangers are switched.

  Thereby, in the refrigerating cycle device of patent documents 2, the refrigerant circuit of cooling mode and the refrigerant circuit of heating mode are switched.

JP 2014-129907 A Japanese Utility Model Publication No. 6-61526

  However, in the composite heat exchanger of Patent Document 1, the amount of heat released from the high-pressure refrigerant may be insufficient. The reason for this is that, in the configuration in which the high-pressure gas-phase refrigerant discharged from the compressor flows into a small water-refrigerant heat exchange unit, as in the composite heat exchanger of Patent Document 1, the high-pressure gas-phase refrigerant is water-refrigerant. This is because the pressure loss that occurs when circulating through the heat exchange section tends to increase.

  When the high-pressure refrigerant whose temperature has dropped due to the pressure loss is caused to flow into the condenser part, the temperature difference between the temperature of the high-pressure refrigerant and the outside air temperature in the condenser part is reduced, and the heat release amount of the refrigerant is reduced.

  Further, when the composite heat exchanger of Patent Document 1 is adopted as the heat exchanger of the refrigeration cycle apparatus of Patent Document 2 and the refrigerant flow direction is reversed to function as an evaporator, the low-pressure refrigerant evaporates and the volume is increased. Since it expands, the pressure loss at the time of circulating through each heat exchange part will increase.

  And when such a pressure loss arises, the distribution property of the refrigerant | coolant in each heat exchange part will deteriorate, and it will become impossible to distribute a liquid phase refrigerant | coolant uniformly in the whole region of each heat exchange part. As a result, the amount of heat absorbed by the refrigerant in the composite heat exchanger decreases.

  An object of this invention is to provide the composite heat exchanger which can reduce the pressure loss which arises in the fluid which distribute | circulates an inside in view of the said point.

  Furthermore, an object of the present invention is to provide a composite heat exchanger that can suppress a decrease in the amount of heat exchange caused by pressure loss that occurs in a fluid flowing through the inside.

In order to achieve the above object, the invention according to claim 1 is directed to a branch section (13) for branching the flow of the first fluid and a first heat exchange section (14) for exchanging heat between the first fluid and the second fluid. ), A second heat exchange part (15) for exchanging heat between the second fluid and the third fluid, and a third heat exchange part (16) for exchanging heat between the first fluid and the third fluid,
The first heat exchange section (14) is for exchanging heat between the first fluid branched at the branch section (13) and the second fluid flowing out from the second heat exchange section (15).
The first fluid inlet (16a) for allowing the other first fluid branched at the branching portion (13) to flow into the third heat exchanging portion (16), and the first fluid from the third heat exchanging portion (16). A first fluid outlet (16b) to be flown out, and a first fluid joining port for joining the first fluid flowing out from the first heat exchange part (14) to the first fluid flowing from the first fluid inlet toward the first fluid outlet This is a composite heat exchanger provided with (16c).

  According to this, since one of the first fluids branched at the branching portion (13) is caused to flow into the first heat exchanging portion (14), the first fluid having a full flow rate is supplied to the first heat exchanging portion (14). The pressure loss when the first fluid flows through the first heat exchanging portion (14) can be reduced as compared with the case where the fluid is introduced.

  Accordingly, it is possible to suppress a reduction in the temperature difference between the temperature of the first fluid flowing into the third heat exchange section (16) and the temperature of the third fluid. As a result, it is possible to suppress the amount of heat released from the first fluid in the third heat exchange section (16) from becoming insufficient.

  That is, according to the invention described in claim 1, it is possible to provide a composite heat exchanger capable of reducing the pressure loss generated in the first fluid. Furthermore, according to the first aspect of the present invention, there is provided a composite heat exchanger capable of suppressing a decrease in the heat exchange amount (that is, the heat radiation amount) of the first fluid due to the pressure loss generated in the first fluid. be able to.

  Here, the composite heat exchanger according to the first aspect of the present invention is used under the condition that the temperature of the first fluid flowing into the third heat exchange section (16) is higher than the temperature of the third fluid. It is valid. Therefore, the composite heat exchanger according to the first aspect of the present invention is a vapor compression refrigeration cycle in which the refrigerant as the first fluid dissipates heat to the outside air as the third fluid in the first heat exchange section (14). It is suitable for application to an apparatus.

In the invention according to claim 4, the first heat exchange section (14) for exchanging heat between the first fluid and the second fluid, and the second heat exchange section for exchanging heat between the second fluid and the third fluid. (15), a third heat exchange section (16) for exchanging heat between the first fluid and the third fluid, a flow of the first fluid flowing out from the first heat exchange section (14), and a third heat exchange section ( 16), a merging portion (13a) for merging the flow of the first fluid flowing out from 16),
The third heat exchanging unit (16) includes a gas-liquid separating unit (164) for separating the gas-liquid of the first fluid, and the first fluid flowing out from the liquid-phase fluid outlet of the gas-liquid separating unit (164). And an evaporation section (165a) for evaporating by heat exchange with
The first heat exchanging part (14) exchanges heat between the first fluid flowing out from the gas phase fluid outlet of the gas-liquid separating part (164) and the second fluid flowing out from the second heat exchanging part,
The merge part (13a) is a composite heat exchanger that merges the flow of the first fluid flowing out from the first heat exchange part (14) and the flow of the first fluid flowing out from the evaporation part (165a).

  According to this, the first heat exchange part (165a) is allowed to flow into the evaporation part (165a) of the third heat exchange part (16) without causing the first fluid in the gas phase separated by the gas-liquid separation part (164) to flow into the evaporation part (165a). 14), and the separated first fluid in the liquid phase is allowed to flow into the evaporation section (165a) of the third heat exchange section (16).

  Therefore, in contrast to the case where the first fluid in a gas-liquid mixed state is caused to flow into the evaporation section (165a), pressure loss caused when the first fluid flows through the evaporation section (165a) can be reduced, and evaporation can be performed. It is easy to distribute evenly throughout the part (165a). As a result, it is possible to suppress the endothermic amount of the first fluid in the evaporation section (165a) from becoming insufficient.

  That is, according to the invention described in claim 4, it is possible to provide a composite heat exchanger capable of reducing the pressure loss generated in the first fluid. Furthermore, according to the fourth aspect of the present invention, there is provided a composite heat exchanger capable of suppressing a decrease in the heat exchange amount (that is, the heat absorption amount) of the first fluid due to the pressure loss generated in the first fluid. be able to.

  Here, the composite heat exchanger according to the fourth aspect of the invention is effective when used under the condition that the temperature of the first fluid flowing into the evaporation section (165a) is lower than the temperature of the third fluid. . Therefore, the composite heat exchanger according to the invention described in claim 4 is a steam that evaporates the refrigerant that is the first fluid in the evaporating section (165a) of the third heat exchanging section (16) to exert an endothermic effect. It is suitable for application to a compression refrigeration cycle apparatus.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim is an example which shows a corresponding relationship with the specific means described in embodiment mentioned later.

It is a whole lineblock diagram of the refrigerating cycle device of a 1st embodiment. It is a typical front view of the composite heat exchanger of 1st Embodiment. It is a whole block diagram of the refrigerating-cycle apparatus of 2nd Embodiment. It is a typical front view which shows the refrigerant | coolant flow in the air_conditioning | cooling mode in the composite heat exchanger of 2nd Embodiment. It is a typical front view which shows the refrigerant | coolant flow of the heating mode in the composite heat exchanger of 2nd Embodiment.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, the composite heat exchanger 20 according to the present invention is applied to the refrigeration cycle apparatus 10 shown in the overall configuration diagram of FIG. Furthermore, the refrigeration cycle apparatus 10 is applied to a vehicle air conditioner, and fulfills a function of cooling blown air that is blown into a vehicle interior that is a space to be air-conditioned. Therefore, the temperature adjustment target fluid of the refrigeration cycle apparatus 10 of the present embodiment is blown air.

  The refrigeration cycle apparatus 10 employs an HFC-based refrigerant (specifically, R134a) as the refrigerant, and constitutes a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant. This refrigerant is mixed with refrigerating machine oil for lubricating the compressor 11, and a part of the refrigerating machine oil circulates in the cycle together with the refrigerant. As the refrigerating machine oil, PAG oil (polyalkylene glycol oil) having compatibility with the liquid phase refrigerant can be used.

  First, each component apparatus which comprises the refrigerating-cycle apparatus 10 is demonstrated using the whole block diagram of FIG.

  In the refrigeration cycle apparatus 10, the compressor 11 sucks in refrigerant, compresses it, and discharges it. The compressor 11 is arrange | positioned in the vehicle bonnet. In the present embodiment, as the compressor 11, an electric compressor is employed in which a fixed capacity type compression mechanism with a fixed discharge capacity is rotationally driven by an electric motor. The compressor 11 has its rotation speed (that is, refrigerant discharge capacity) controlled by a control signal output from a control device described later.

  The refrigerant inlet 20 a side of the composite heat exchanger 20 is connected to the discharge port of the compressor 11. The composite heat exchanger 20 is obtained by integrating the cycle constituent devices surrounded by a broken line in FIG. More specifically, the composite heat exchanger 20 is obtained by integrating the branching unit 13, the water-refrigerant heat exchanging unit 14, the air-water heat exchanging unit 15, the air-refrigerant heat exchanging unit 16, and the like. . The composite heat exchanger 20 is disposed on the vehicle front side in the bonnet.

  The branch part 13 is a part that branches the flow of the refrigerant discharged from the compressor 11. Therefore, the refrigerant inlet of the branch portion 13 communicates with the refrigerant inlet 20a as the composite heat exchanger 20 as a whole. Further, in the branching section 13, one branched refrigerant flows out to the inlet side of the refrigerant passage of the water-refrigerant heat exchanging section 14, and the other branched refrigerant is input to the refrigerant passage of the air-refrigerant heat exchanging section 16. It flows out to the 16a side.

  The water-refrigerant heat exchanging unit 14 is a first heat exchanging unit that exchanges heat between one refrigerant branched by the branching unit 13 and the heat medium circulating in the water circulation circuit 40. The outlet of the refrigerant passage of the water-refrigerant heat exchange unit 14 communicates with a junction 16 c formed in the middle of the refrigerant passage of the air-refrigerant heat exchange unit 16. In addition, the outlet of the heat medium passage of the water-refrigerant heat exchanger 14 communicates with the heat medium outlet 20d as the composite heat exchanger 20 as a whole.

  The air-water heat exchanger 15 is a second heat exchanger that exchanges heat between the heat medium circulating in the water circulation circuit 40 and the outside air blown from an outside air fan (not shown). The inlet of the heat medium passage of the air-water heat exchanger 15 communicates with the heat medium inlet 20c of the composite heat exchanger 20 as a whole. The outlet of the heat medium passage of the air-water heat exchange unit 15 communicates with the inlet of the heat medium passage of the water-refrigerant heat exchange unit 14.

  The air-refrigerant heat exchange unit 16 is a third heat exchange unit that exchanges heat between the refrigerant on the downstream side of the branch unit 13 and the outside air blown from the outside air fan. The outlet 16 b of the refrigerant passage of the air-refrigerant heat exchanger 16 communicates with the refrigerant outlet 20 b as the composite heat exchanger 20 as a whole.

  As is clear from the above description, the refrigerant corresponds to the first fluid described in the claims, the heat medium corresponds to the second fluid described in the claims, and the outside air corresponds to the patent. This corresponds to the third fluid described in the claims. The inlet 16a of the refrigerant passage of the air-refrigerant heat exchanger 16 corresponds to the first fluid inlet described in the claims, and the outlet 16b of the refrigerant passage of the air-refrigerant heat exchanger 16 is claimed. The junction 16c corresponds to the first fluid junction described in the claims.

  In addition, the water-refrigerant heat exchange unit 14 of the present embodiment functions as a water-cooled condenser unit that dissipates heat of the refrigerant to the heat medium and condenses the refrigerant. The air-water heat exchanger 15 functions as a radiator that radiates the heat of the heat medium to the outside air. The air-refrigerant heat exchange unit 16 functions as a condenser unit that radiates heat of the refrigerant to the outside air to condense the refrigerant.

  The water circulation circuit 40 is a heat medium circulation circuit that circulates the heat medium. As this heat medium, a solution containing ethylene glycol, an antifreeze solution, or the like can be employed. In the water circulation circuit 40, a water pump 40a that pumps the heat medium, a cooling water passage of the electric motor DM that outputs driving force for traveling the vehicle, and the like are arranged. The electric motor DM is a vehicle-mounted device that generates heat during operation. The cooling water passage of the electric motor DM is a heat medium passage formed in the electric motor DM so that the heat medium can absorb waste heat of the electric motor DM.

  More specifically, the suction port side of the water pump 40a is connected to the heat medium outlet 20d communicating with the outlet side of the heat medium passage of the water-refrigerant heat exchanging unit 14. The discharge port of the water pump 40a is connected to the inlet side of the cooling water passage of the electric motor DM. The outlet of the cooling water passage of the electric motor DM is connected to the heat medium inlet 20c side that communicates with the inlet side of the heat medium passage of the air-water heat exchanger 15.

  The water pump 40a is an electric pump in which the rotation speed (that is, water pumping ability) is controlled by a control voltage output from the control device. Therefore, when the control device operates the water pump 40a, the water circulation circuit 40 causes the water pump 40a → the cooling water passage of the electric motor DM → the combined heat exchanger 20 (the heat medium passage of the air-water heat exchanger 15 → water). -Heat medium passage of refrigerant heat exchanging unit 14) The heat medium circulates in the order of water pump 40a.

  The inlet side of the temperature type expansion valve 17 is connected to the refrigerant outlet 20b of the composite heat exchanger 20 (specifically, the outlet side of the refrigerant passage of the air-refrigerant heat exchanger 16). The temperature type expansion valve 17 is a variable throttle mechanism that changes the throttle opening (that is, the refrigerant passage area) so that the degree of superheat of the outlet side refrigerant of the evaporator 18 approaches a predetermined reference superheat degree.

  Such a temperature type expansion valve 17 includes a temperature sensing part having a deforming member (specifically, a diaphragm) that deforms according to the temperature and pressure of the refrigerant on the outlet side of the evaporator 18, so that the deforming member can be deformed. Accordingly, it is possible to employ a mechanical mechanism that adjusts the throttle opening.

  An outlet side of the refrigerant passage of the evaporator 18 is connected to the outlet of the temperature type expansion valve 17. The evaporator 18 performs heat exchange between the low-pressure refrigerant decompressed by the temperature type expansion valve 17 and the blown air blown from the blower 18a toward the vehicle interior, and evaporates the low-pressure refrigerant to exert an endothermic effect. It is a heat exchanger. The evaporator 18 is disposed inside an indoor air conditioning unit (not shown).

  The indoor air conditioning unit forms an air passage that is arranged in the passenger compartment and blows out the blown air whose temperature is adjusted by the refrigeration cycle apparatus 10 to an appropriate location in the passenger compartment. The suction side of the compressor 11 is connected to the outlet of the refrigerant passage of the evaporator 18.

  Next, the detailed configuration of the composite heat exchanger 20 will be described with reference to FIG. In addition, the up and down arrows in FIG. 2 indicate the up and down directions when the composite heat exchanger 20 is mounted on the vehicle. All of the cycle components constituting the composite heat exchanger 20 are formed of a metal (aluminum in this embodiment) having excellent heat conductivity, and are integrated by brazing.

  First, the water-refrigerant heat exchanging section 14 is a so-called double pipe heat exchanger configured by disposing an outer pipe 14b forming a refrigerant passage on the outer peripheral side of an inner pipe 14a forming a heat medium passage. Of structure. The longitudinal direction of the outer tube 14b extends in the vertical direction. The outlet side of the heat medium passage of the air-water heat exchanger 15 is connected to the upper end of the inner tube 14a. A connector for forming the heat medium outlet 20d is provided at the lower end of the inner tube 14a.

  A connector forming the refrigerant inlet 20a is connected to the outer peripheral portion on the upper side of the outer tube 14b. A connection portion for allowing the refrigerant flowing from the refrigerant inlet 20a to flow into the inlet 16a of the refrigerant passage of the air-refrigerant heat exchanging portion 16 is provided at a portion of the outer pipe 14b that is as high as the refrigerant inlet 20a. Yes.

  For this reason, the flow of the refrigerant flowing into the outer tube 14b from the refrigerant inlet 20a immediately after flowing into the outer tube 14b is the water-refrigerant heat exchanger 14 formed between the inner tube 14a and the outer tube 14b. Is branched into a flow flowing into the refrigerant passage and a flow flowing into the refrigerant passage of the air-refrigerant heat exchanger 16. That is, the branch part 13 of this embodiment is provided inside the outer tube 14 b of the water-refrigerant heat exchange part 14 and is formed integrally with the water-refrigerant heat exchange part 14.

  A connection portion that guides the refrigerant in the outer tube 14b to the junction 16c of the refrigerant passage of the air-refrigerant heat exchange unit 16 is provided on the outer peripheral portion on the lower side of the outer tube 14b.

  The air-water heat exchange unit 15 has a so-called tank-and-tube heat exchanger structure that includes a plurality of heat medium tubes 151 and a pair of heat medium tanks 152. The plurality of heat medium tubes 151 are tubular members through which the heat medium flows. The heat medium tube 151 is a flat tube having a flat cross-sectional shape.

  The heat medium tubes 151 and the flat surfaces (flat surfaces) of the outer surfaces are stacked and arranged with a certain interval so as to be parallel to each other. As a result, an air passage through which the outside air flows is formed between the adjacent heat medium tubes 151. That is, in the air-water heat exchanging unit 15, a plurality of heat medium tubes 151 are stacked and arranged to form a heat exchanging unit (heat exchanging core unit) that exchanges the outside air and the heat medium.

  Corrugated fins 153 that promote heat exchange between the outside air and the heat medium are disposed in the air passage formed between the adjacent heat medium tubes 151. In FIG. 2, only a part of the heat medium tube 151 and the like is illustrated for clarity of illustration, but the heat medium tube 151 and the like are arranged over the entire area of the heat exchange unit. .

  The pair of heat medium tanks 152 is connected to both ends and collects or distributes the heat medium flowing through the heat medium tube 151. The heat medium tank 152 is formed of a bottomed cylindrical member having a shape extending in the stacking direction of the plurality of heat medium tubes 151. Of the pair of heat medium tanks 152, a connector that forms the heat medium inlet 20c is connected to the heat medium tank 152 on the side where the inner pipe 14a of the water-refrigerant heat exchanger 14 is not connected.

  The air-refrigerant heat exchanger 16 has a tank-and-tube heat exchanger structure similar to the air-water heat exchanger 15. Therefore, the air-refrigerant heat exchange unit 16 includes a plurality of refrigerant tubes 161 similar to the air-water heat exchange unit 15, a pair of refrigerant tanks 162, and the like.

  The air-refrigerant heat exchange unit 16 is disposed on the lower side of the air-water heat exchange unit 15. And the heat exchange part of the air-water heat exchange part 15 and the heat exchange part of the air-refrigerant heat exchange part 16 are arrange | positioned on the same plane. Therefore, the heat exchange part of the air-water heat exchange part 15 and the heat exchange part of the air-refrigerant heat exchange part 16 are arranged in parallel to the flow of outside air.

  A plurality of separators that divide the internal space of the refrigerant tank 162 are arranged inside the refrigerant tank 162. Thus, the plurality of refrigerant tubes 161 are divided into a plurality of paths. Here, the path in the tank-and-tube heat exchanger refers to the same direction of the refrigerant in the same distribution space formed in one tank toward the same collective space formed in the other tank. It can be defined as a refrigerant flow path formed by a group of tubes that flow to.

  More specifically, the refrigerant tube 161 of the air-refrigerant heat exchange unit 16 of the present embodiment is divided into four paths. And the condensing part 165 which heat-exchanges a refrigerant | coolant and external air and condenses is formed with three path | passes of a refrigerant | coolant flow upstream. Moreover, the subcooling part 166 which supercools a liquid phase refrigerant | coolant is formed with the path | pass of a refrigerant | coolant flow most downstream.

  Further, the air-refrigerant heat exchange unit 16 has a modulator unit 164. The modulator unit 164 is a gas-liquid separation unit that separates the gas-liquid refrigerant flowing out of the condensing unit 165. The modulator unit 164 is formed of a bottomed cylindrical member having a shape extending in the same direction as the heat medium tank 152 and the refrigerant tank 162.

  For this reason, the inlet side of the modulator unit 164 is connected to the refrigerant outlet of the condensing unit 165. Further, the refrigerant inlet side of the supercooling unit 166 is connected to the outlet of the modulator unit 164. Further, the number of the refrigerant tubes 161 constituting each path decreases as the refrigerant flows toward the downstream side. Therefore, in the air-refrigerant heat exchanger 16, the refrigerant passage cross-sectional area decreases from the refrigerant passage inlet 16a toward the refrigerant passage outlet 16b.

  As is clear from FIG. 2, the water-refrigerant heat exchange unit 14 having a double-pipe heat exchanger structure includes an air-water heat exchange unit 15 having a tank-and-tube heat exchanger structure, and an air -It becomes a relatively small physique than the refrigerant | coolant heat exchange part 16.

  Next, an outline of the electric control unit of the present embodiment will be described. The control device is composed of a well-known microcomputer including a CPU, a ROM, a RAM and the like and its peripheral circuits. Then, various calculations and processes are performed based on the air conditioning control program stored in the ROM, and the operations of the various control target devices 11, 18a, 30a connected to the output side and other various electric actuators are controlled.

  A sensor group for air conditioning control such as an inside air temperature sensor, an outside air temperature sensor, a solar radiation sensor, a water temperature sensor, and an evaporator temperature sensor is connected to the input side of the control device. And the detection signal of the sensor group for an air-conditioning control is input into a control apparatus.

  The inside air temperature sensor is an inside air temperature detecting unit that detects a vehicle interior temperature (inside air temperature). The outside air temperature sensor is an outside air temperature detecting unit that detects the outside temperature (outside air temperature) of the passenger compartment. A solar radiation sensor is a solar radiation amount detection part which detects the solar radiation amount irradiated to a vehicle interior. The water temperature sensor is a heat medium temperature detection unit that detects a heat medium temperature that is the temperature of the heat medium flowing into the composite heat exchanger 20 (specifically, the air-water heat exchange unit 15). The evaporator temperature sensor is an evaporator temperature detector that detects a refrigerant evaporation temperature (evaporator temperature) in the evaporator 18.

  Furthermore, an operation panel disposed near the instrument panel in the front part of the vehicle interior is connected to the input side of the control device, and operation signals from various operation switches provided on the operation panel are input. Specific examples of the various operation switches provided on the operation panel include an auto switch for setting or canceling the automatic control operation of the vehicle air conditioner, a temperature setting switch for setting a target temperature in the vehicle compartment, and the like.

  Next, the operation of the refrigeration cycle apparatus 10 of the present embodiment having the above configuration will be described. First, when the auto switch of the operation panel is turned on (ON), the control device executes the air conditioning control program stored in the ROM. In the air conditioning control program, the target blowing temperature TAO of the blown air blown into the vehicle interior is determined based on the detection signal of the air conditioning control sensor group and the operation signal from the operation panel. The target blowing temperature TAO is a value having a correlation with the heat load of the refrigeration cycle apparatus 10.

  Further, the control device controls the operation of the compressor 11, the blower 18a, the water pump 40a, and the like according to the target blowing temperature TAO (that is, the heat load). Thereby, the compressor 11 sucks the refrigerant, compresses it, and discharges it. Further, the water pump 40a sucks and discharges the heat medium.

  The high-temperature and high-pressure gas-phase refrigerant discharged from the compressor 11 flows into the refrigerant inlet 20 a of the composite heat exchanger 20. The flow of the high-pressure refrigerant that has flowed into the refrigerant inlet 20 a of the composite heat exchanger 20 is branched at the branch portion 13.

  At this time, the distribution amount of the refrigerant in the branch portion 13 is self-controlled by the pressure loss ratio between the pressure loss in the refrigerant passage of the water-refrigerant heat exchange portion 14 and the pressure loss of the refrigerant passage in the air-refrigerant heat exchange portion 16. . In other words, it is self-controlled by the performance ratio between the refrigerant heat radiation performance in the water-refrigerant heat exchange section 14 and the refrigerant heat radiation performance in the air-refrigerant heat exchange section 16.

  One of the high-pressure refrigerants branched at the branching part 13 flows through the refrigerant passage of the water-refrigerant heat exchanging part 14 and is cooled by exchanging heat with the heat medium flowing through the heat medium passage of the water-refrigerant heat exchanging part 14 Is done. The refrigerant that has flowed out of the refrigerant passage of the water-refrigerant heat exchange unit 14 flows into the junction 16 c of the refrigerant passage of the air-refrigerant heat exchange unit 16.

  At this time, in the water circulation circuit 40, the water pump 40a is operating. Accordingly, the heat medium pumped from the water pump 40a flows into the cooling water passage of the electric motor DM. When the heat medium flowing into the cooling water passage of the electric motor DM passes through the cooling water passage, the heat medium absorbs waste heat of the electric motor DM and cools the electric motor DM.

  The heat medium flowing out from the cooling water passage of the electric motor DM flows into the heat medium inlet 20 c of the composite heat exchanger 20. The heat medium that has flowed into the heat medium inlet 20c flows into the heat medium passage of the air-water heat exchanger 15 and is cooled by exchanging heat with the outside air blown from the outside air fan. The heat medium cooled by the air-water heat exchanger 15 flows into the heat medium passage of the water-refrigerant heat exchanger 14.

  Thereby, in the water-refrigerant heat exchanging unit 14, the high-pressure refrigerant can be cooled by exchanging heat between the cooled heat medium and the high-pressure refrigerant. The heat medium that has cooled the high-pressure refrigerant in the water-refrigerant heat exchanger 14 flows out from the heat medium outlet 20d of the composite heat exchanger 20, is sucked into the water pump 40a, and again enters the cooling water passage of the electric motor DM. Pumped.

  Further, the other high-pressure refrigerant branched at the branching section 13 flows into the refrigerant passage inlet 16 a of the air-refrigerant heat exchange section 16. When the refrigerant flowing into the inlet 16a of the refrigerant passage of the air-refrigerant heat exchange unit 16 flows through the condensing unit 165 of the air-refrigerant heat exchange unit 16, it is cooled by exchanging heat with the outside air blown from the outside air fan. Condensed. And the refrigerant | coolant which flowed in from the junction port 16c merges with the refrigerant | coolant of a cooling process in the condensation part 165. FIG.

  The refrigerant flowing through the condensing unit 165 that has merged with the refrigerant flowing in from the junction port 16c flows into the modulator unit 164 and is separated into gas and liquid. The liquid-phase refrigerant separated by the modulator unit 164 flows into the supercooling unit 166 of the air-refrigerant heat exchange unit 16. The liquid-phase refrigerant that has flowed into the supercooling unit 166 is supercooled by exchanging heat with the outside air blown from the outside air fan when flowing through the supercooling unit 166.

  The liquid phase refrigerant supercooled by the supercooling unit 166 flows out from the refrigerant outlet 20b of the composite heat exchanger 20 via the outlet 16b of the refrigerant passage of the air-refrigerant heat exchange unit 16. The refrigerant flowing out from the refrigerant outlet 20b flows into the temperature type expansion valve 17 and is depressurized. At this time, the throttle opening degree of the temperature type expansion valve 17 is adjusted so that the superheat degree of the outlet side refrigerant of the evaporator 18 approaches the reference superheat degree.

  The low-pressure refrigerant decompressed by the temperature type expansion valve 17 flows into the evaporator 18. The low-pressure refrigerant flowing into the evaporator 18 absorbs heat from the blown air from the blower 18a and evaporates. Thereby, blowing air is cooled. The refrigerant flowing out of the evaporator 18 is sucked into the compressor 11 and compressed again.

  As described above, in the refrigeration cycle apparatus 10 of the present embodiment, cooling of the vehicle interior can be realized by blowing the blown air cooled by the evaporator 18 into the vehicle interior.

  Furthermore, in this embodiment, since the refrigeration cycle apparatus 10 employs the composite heat exchanger 20, the high-pressure refrigerant discharged from the compressor 11 is exchanged with the water-refrigerant heat exchange unit 14 and the air-refrigerant heat exchange. Both parts 16 can be sufficiently cooled until the refrigerant has a supercooling degree.

  Therefore, the cooling capacity exhibited by the evaporator 18 can be increased and the coefficient of performance (COP) of the refrigeration cycle apparatus 10 can be improved. The cooling capacity exhibited by the evaporator 18 can be defined by using an enthalpy difference obtained by subtracting the enthalpy of the inlet side refrigerant from the enthalpy of the outlet side refrigerant of the evaporator 18.

  Here, in the configuration in which the high-temperature and high-pressure gas-phase refrigerant discharged from the compressor flows into the relatively small water-refrigerant heat exchanger 14 as in the composite heat exchanger 20 of the present embodiment, the high-temperature and high-pressure Pressure loss that occurs when the gas-phase refrigerant flows through the water-refrigerant heat exchange section tends to increase.

  For this reason, even if the high-pressure refrigerant whose temperature has decreased due to this pressure loss flows into the air-refrigerant heat exchange unit 16, the temperature difference between the temperature of the high-pressure refrigerant in the air-refrigerant heat exchange unit 16 and the outside air temperature is reduced. As a result, the amount of heat released from the refrigerant decreases. As a result, there is a risk that the amount of heat released from the high-pressure refrigerant will be insufficient.

  On the other hand, according to the composite heat exchanger 20 of the present embodiment, since one of the refrigerants branched at the branching part 13 flows into the water-refrigerant heat exchange part 14, the water-refrigerant heat exchange part 14 The pressure loss when the refrigerant flows through the water-refrigerant heat exchanger 14 can be reduced as compared with the case where the refrigerant of the entire flow rate discharged from the compressor 11 is allowed to flow.

  Therefore, reduction of the temperature difference between the temperature of the refrigerant flowing into the air-refrigerant heat exchange unit 16 and the temperature of the outside air can be suppressed. As a result, it is possible to suppress the amount of heat released from the refrigerant in the air-refrigerant heat exchange unit 16 from becoming insufficient.

  That is, according to the composite heat exchanger 20 of the present embodiment, the pressure loss generated in the refrigerant can be reduced. Furthermore, it is possible to suppress a decrease in the heat exchange amount (that is, the heat release amount) of the refrigerant due to the pressure loss generated in the refrigerant.

  Furthermore, according to the composite heat exchanger 20 of the present embodiment, it is possible to suppress stagnation of refrigerating machine oil in the water-refrigerant heat exchanger 14 by reducing the pressure loss generated in the refrigerant. In addition, the refrigerant at the entire flow rate discharged from the compressor 11 is heated by the water-refrigerant heat exchange unit 14 even under operating conditions in which the heat medium cannot be sufficiently cooled by the air-water heat exchange unit 15. Can be prevented.

  Further, in the composite heat exchanger 20 of the present embodiment, since the branch portion 13 is formed integrally with the water-refrigerant heat exchanger portion 14, the branch portion 13 is formed by another member having a structure such as a three-way joint. In contrast to this, the composite heat exchanger 20 as a whole can be downsized.

(Second Embodiment)
In the present embodiment, the composite heat exchanger 20 according to the present invention is applied to the refrigeration cycle apparatus 10a shown in the overall configuration diagram of FIG. In FIG. 3, the same or equivalent parts as those in the first embodiment are denoted by the same reference numerals. The same applies to the following drawings.

  The refrigeration cycle apparatus 10a is applied to the vehicle air conditioner 1, and fulfills a function of cooling or heating the blown air blown into the vehicle interior that is the air conditioning target space. Therefore, in the vehicle air conditioner 1 of the present embodiment, the operation in the cooling mode and the operation in the heating mode can be switched.

  Furthermore, the refrigeration cycle apparatus 10a is configured to be capable of switching between a cooling mode refrigerant circuit and a heating mode refrigerant circuit in accordance with the operation mode of the vehicle air conditioner 1. In FIG. 3, the refrigerant flow in the cooling mode refrigerant circuit is indicated by a white arrow, and the refrigerant flow in the cooling mode refrigerant circuit is indicated by a black arrow.

  As is clear from the directions of the white arrow and the black arrow in FIG. 3, in the composite heat exchanger 20 of the present embodiment, the refrigerant flow direction in the cooling mode is different from the refrigerant flow direction in the heating mode. ing. Therefore, in the present embodiment, the refrigerant inlet 20a described in the first embodiment is referred to as a first refrigerant inlet / outlet 20a, and the refrigerant outlet 20b described in the first embodiment is referred to as a second refrigerant outlet / inlet 20b.

  The refrigerant inlet side of the indoor condenser 12 is connected to the discharge port of the compressor 11 of the refrigeration cycle apparatus 10a of the present embodiment. The refrigerant inlet side of the indoor condenser 12 is connected. The indoor condenser 12 is a heat exchanger for heating that heat-exchanges the high-pressure refrigerant discharged from the compressor 11 and the blown air after passing through the evaporator 18 to heat the blown air using the high-pressure refrigerant as a heat source. The indoor condenser 12 is disposed in the casing 31 of the indoor air conditioning unit 30.

  The refrigerant outlet of the indoor condenser 12 is connected to the inlet side of the first three-way joint 21a having three inlets and outlets communicating with each other. As such a three-way joint, one formed by joining a plurality of pipes or one formed by providing a plurality of refrigerant passages in a metal block or a resin block can be adopted.

  Furthermore, the refrigeration cycle apparatus 10a includes second to fourth three-way joints 21b to 21d as described later. The basic configuration of the second to fourth three-way joints 21b to 21d is the same as that of the first three-way joint 21a.

  One inflow port of the first three-way joint 21a is connected to the inflow port side of the second three-way joint 21b through the first on-off valve 22a. One inflow port of the first three-way joint 21a is connected to the inflow port side of the third three-way joint 21c through the heating expansion valve 17a.

  The 1st on-off valve 22a is an electromagnetic valve which opens and closes the refrigerant path connected with one outflow port of the 1st three-way joint 21a, and the inflow port of the 2nd three-way joint 21b. The operation of the first on-off valve 22a is controlled by a control voltage output from the control device. Further, the refrigeration cycle apparatus 10a includes a second on-off valve 22b as will be described later. The basic configuration of the second on-off valve 22b is the same as that of the first on-off valve 22a.

  The heating expansion valve 17a is a heating decompression unit that decompresses the refrigerant that has flowed out of the indoor condenser 12 at least in the heating mode, and is a heating flow rate adjustment unit that adjusts the flow rate of the refrigerant that flows out of the indoor condenser 12. is there.

  The heating expansion valve 17a includes an electric valve body configured to be able to change the throttle opening degree and an electric actuator (specifically, a stepping motor) that changes the opening degree of the valve body. This is a variable aperture mechanism of the type. The operation of the heating expansion valve 17a is controlled by a control signal (control pulse) output from the control device. The heating expansion valve 17a has a fully closed function of closing the refrigerant passage by fully closing the valve opening.

  Further, the first refrigerant inlet / outlet 20a side of the composite heat exchanger 20 is connected to the inlet / outlet of the second three-way joint 21b, and the outlet of the second three-way joint 21b is connected via the second on-off valve 22b. The one inlet side of the fourth three-way joint 21d is connected.

  The inflow / outlet side of the third three-way joint 21c is connected to the second refrigerant entrance / exit 20b of the composite heat exchanger 20. The refrigerant inlet side of the evaporator 18 is connected to the outlet of the third three-way joint 21c via the check valve 23 and the cooling expansion valve 17b.

  The check valve 23 allows the refrigerant to flow from the third three-way joint 21c side to the refrigerant inlet side of the evaporator 18 (specifically, the inlet side of the cooling expansion valve 17b), and the refrigerant inlet of the evaporator 18 The refrigerant is prohibited from flowing from the side to the third three-way joint 21c side.

  The cooling expansion valve 17b is a cooling pressure reducing unit that depressurizes the refrigerant flowing out of the indoor condenser 12 at least in the heating mode, and adjusts the flow rate of cooling flowing out of the composite heat exchanger 20 Part. Therefore, the cooling expansion valve 17b has a configuration corresponding to the temperature type expansion valve 17 described in the first embodiment. The basic configuration of the cooling expansion valve 17b is the same as that of the heating expansion valve 17a.

  The refrigerant outlet of the evaporator 18 is connected to the other inlet side of the fourth three-way joint 21d. The inlet side of the accumulator 24 is connected to the outlet of the fourth three-way joint 21d. The accumulator 24 is a gas-liquid separator that separates the gas-liquid of the refrigerant that has flowed into the accumulator 24 and stores excess liquid-phase refrigerant in the cycle. The suction port side of the compressor 11 is connected to the gas phase refrigerant outlet of the accumulator 24.

  Next, the detailed structure of the composite heat exchanger 20 of this embodiment is demonstrated using FIG. 4, FIG. In addition, the thick solid line arrow in the air-refrigerant heat exchange part 16 of FIG. 4 has shown the flow direction of the refrigerant | coolant at the time of air_conditioning | cooling mode. The thick solid line arrow in the air-refrigerant heat exchanger 16 in FIG. 5 indicates the flow direction of the refrigerant in the heating mode.

  The basic configuration of the composite heat exchanger 20 of the present embodiment is the same as that of the first embodiment. In the composite heat exchanger 20 of the present embodiment, the longitudinal direction of the outer tube 14b of the double-pipe water-refrigerant heat exchanger 14 extends in the horizontal direction. That is, the outer tube 14 b of the water-refrigerant heat exchange unit 14 extends in parallel with the heat medium tube 151 of the air-water heat exchange unit 15 and the refrigerant tube 161 of the air-refrigerant heat exchange unit 16.

  Furthermore, the water-refrigerant heat exchanger 14 is disposed between the air-water heat exchanger 15 and the air-refrigerant heat exchanger 16 that are disposed in the vertical direction. Further, the junction 16c of the present embodiment is formed in the modulator section 164.

  Next, the indoor air conditioning unit 30 will be described. The indoor air conditioning unit 30 is disposed inside the instrument panel (that is, the instrument panel) at the foremost part of the vehicle interior. The indoor air conditioning unit 30 forms an air passage for blowing out the blown air whose temperature has been adjusted by the refrigeration cycle apparatus 10a to an appropriate location in the passenger compartment.

  As shown in FIG. 3, the indoor air conditioning unit 30 includes a blower 18 a, an evaporator 18, an indoor condenser 12, and the like in an air passage formed inside a casing 31 that forms an outer shell thereof.

  The casing 31 forms an air passage for blown air that is blown into the vehicle interior, and is formed of a resin (specifically, polypropylene) having a certain degree of elasticity and excellent in strength. An inside / outside air switching device 33 for switching and introducing inside air (vehicle compartment air) and outside air (vehicle compartment outside air) into the casing 31 is disposed on the most upstream side of the blast air flow in the casing 31.

  The inside / outside air switching device 33 continuously adjusts the opening area of the inside air introduction port for introducing the inside air into the casing 31 and the outside air introduction port for introducing the outside air, by the inside / outside air switching door, The introduction ratio with the introduction air volume can be changed. The inside / outside air switching door is driven by an electric actuator for the inside / outside air switching door. The operation of the electric actuator is controlled by a control signal output from the air conditioning controller 40.

  A blower 18 a is arranged on the downstream side of the blown air flow of the inside / outside air switching device 33. On the downstream side of the blower air flow of the blower 18a, the evaporator 18 and the indoor condenser 12 are arranged in this order with respect to the flow of the blown air. That is, the evaporator 18 is disposed upstream of the blower air flow with respect to the indoor condenser 12.

  Further, in the casing 31, a cold air bypass passage 35 is formed in which the blown air that has passed through the evaporator 18 bypasses the indoor condenser 12 and flows downstream.

  On the downstream side of the blower air flow of the evaporator 18 and on the upstream side of the blower air flow of the indoor condenser 12, of the blown air that has passed through the evaporator 18, the amount of air passing through the indoor condenser 12 and the cold air An air mix door 34 that adjusts the air volume ratio with the air volume that passes through the bypass passage 35 is disposed.

  On the downstream side of the blower air flow of the indoor condenser 12, mixing that mixes blown air heated by the indoor condenser 12 and blown air that has passed through the cold air bypass passage 35 and is not heated by the indoor condenser 12. A space is provided. Furthermore, the opening hole which blows off the blowing air (air-conditioning wind) mixed in the mixing space in the vehicle interior at the most downstream part of the blowing air flow of the casing 31 is arranged.

  As this opening hole, a face opening hole, a foot opening hole, and a defroster opening hole (all not shown) are provided. The face opening hole is an opening hole for blowing conditioned air toward the upper body of the passenger in the vehicle interior. The foot opening hole is an opening hole for blowing conditioned air toward the feet of the passenger. The defroster opening hole is an opening hole for blowing out conditioned air toward the inner side surface of the vehicle front window glass.

  These face opening hole, foot opening hole, and defroster opening hole are respectively connected to a face air outlet, a foot air outlet, and a defroster air outlet (not shown) through a duct that forms an air passage. )It is connected to the.

  Therefore, the air mix door 34 adjusts the air volume ratio between the air volume that passes through the indoor condenser 12 and the air volume that passes through the cold air bypass passage 35, thereby adjusting the temperature of the conditioned air mixed in the mixing space. . Thereby, the temperature of the blast air (air conditioned air) blown out from each outlet into the vehicle compartment is also adjusted.

  The air mix door 34 is driven by an electric actuator for driving the air mix door, and the operation of the electric actuator is controlled by a control signal output from the air conditioning control device 40.

  Further, on the upstream side of the air flow of the face opening hole, foot opening hole, and defroster opening hole, a face door for adjusting the opening area of the face opening hole, a foot door for adjusting the opening area of the foot opening hole, and a defroster opening, respectively. A defroster door (both not shown) for adjusting the opening area of the hole is disposed.

  These face doors, foot doors, and defroster doors constitute an air outlet mode switching device that switches an air outlet from which air-conditioned air is blown out. The face door, the foot door, and the defroster door are connected to an electric actuator for driving the air outlet mode door via a link mechanism and the like, and are rotated in conjunction with each other. The operation of the electric actuator is controlled by a control signal output from the air conditioning controller 40.

  Next, the operation of the refrigeration cycle apparatus 10a of the present embodiment having the above configuration will be described. As described above, in the vehicle air conditioner 1 of the present embodiment, it is possible to switch between the cooling mode operation and the heating mode operation. Furthermore, in the refrigeration cycle apparatus 10a, the refrigerant circuit can be switched according to the operation mode of the vehicle air conditioner 1. The switching of the refrigerant circuit is performed by executing an air conditioning control program.

  Specifically, in the air-conditioning control program of this embodiment, if the target blowing temperature TAO is equal to or lower than a predetermined reference temperature KT, switching to the cooling mode refrigerant circuit is performed, and the target blowing temperature TAO becomes higher than the reference temperature KT. If so, switch to the refrigerant circuit in the heating mode. Below, each operation mode is demonstrated.

  First, the cooling mode will be described. In the cooling mode, the control device sets the heating expansion valve 17a to a fully closed state, sets the cooling expansion valve 17b to a throttle state that exerts a refrigerant decompression action, opens the first on-off valve 22a, and closes the second on-off valve 22b. . Further, the control device controls the operation of the air mix door 34 so that the cold air bypass passage 35 is fully opened and the ventilation path on the indoor condenser 12 side is closed.

  Therefore, in the cooling mode, as indicated by the white arrow in FIG. 3, the refrigerant discharged from the compressor 11 flows into the indoor condenser 12 → the combined heat exchanger 20 → the check valve 23 → the cooling expansion valve 17 b → A vapor compression refrigeration cycle that circulates in the order of the evaporator 18 → accumulator 24 → compressor is configured.

  In this cycle configuration, the control device controls operations of the compressor 11, the blower 18a, the water pump 40a, and the like according to the target blowing temperature TAO. Thereby, the compressor 11 sucks the refrigerant, compresses it, and discharges it. Further, the water pump 40a sucks and discharges the heat medium.

  The high-temperature and high-pressure gas-phase refrigerant discharged from the compressor 11 flows into the indoor condenser 12. In the cooling mode, since the air mix door 34 is displaced so as to close the ventilation path on the indoor condenser 12 side, the gas-phase refrigerant flowing into the indoor condenser 12 hardly dissipates heat and the indoor condenser 12 is discharged. Spill from.

  The gas-phase refrigerant that has flowed out of the indoor condenser 12 flows into the first refrigerant inlet / outlet port 20a of the composite heat exchanger 20 because the first on-off valve 22a is opened and the second on-off valve 22b is closed. The composite heat exchanger 20 is cooled until it becomes a supercooled liquid phase refrigerant as in the first embodiment. The supercooled liquid phase refrigerant flowing out from the second refrigerant inlet / outlet 20b of the composite heat exchanger 20 flows into the cooling expansion valve 17b through the check valve 23.

  The refrigerant flowing into the cooling expansion valve 17b is depressurized until it becomes a low-pressure refrigerant and flows into the evaporator 18. At this time, the throttle opening degree of the cooling expansion valve 17b is set such that the degree of supercooling of the refrigerant flowing into the cooling expansion valve 17b is determined so that the coefficient of performance (COP) of the cycle becomes a maximum value. It is decided to approach.

  The low-pressure refrigerant flowing into the evaporator 18 absorbs heat from the blown air from the blower 18a and evaporates. Thereby, blowing air is cooled. The refrigerant that has flowed out of the evaporator 18 flows into the accumulator 24 and is separated into gas and liquid. The gas-phase refrigerant separated by the accumulator 24 is sucked into the compressor 11 and compressed again.

  As described above, in the refrigeration cycle apparatus 10a in the cooling mode, the composite heat exchanger 20 (specifically, the water-refrigerant heat exchange unit 14 and the air-refrigerant heat exchange unit 16) functions as a radiator, and an evaporator A vapor compression refrigeration cycle is configured to allow 18 to function as an evaporator. And the ventilation of a vehicle interior is realizable by blowing the ventilation air cooled with the evaporator 18 into a vehicle interior.

  Next, the heating mode will be described. In the heating mode, the control device sets the heating expansion valve 17a to the throttle state, sets the cooling expansion valve 17b to the fully closed state, closes the first on-off valve 22a, and opens the second on-off valve 22b. Further, the control device controls the operation of the air mix door 34 so that the cool air bypass passage 35 is closed by fully opening the air passage on the indoor condenser 12 side.

  Therefore, in the heating mode, as shown by the black arrows in FIG. 3, the refrigerant discharged from the compressor 11 is changed to the indoor condenser 12 → the heating expansion valve 17a → the combined heat exchanger 20 → the accumulator 24 → the compressor. A vapor compression refrigeration cycle that circulates in this order is configured.

  In this cycle configuration, the control device controls operations of the compressor 11, the blower 18a, the water pump 40a, and the like according to the target blowing temperature TAO. Thereby, the compressor 11 sucks the refrigerant, compresses it, and discharges it. Further, the water pump 40a sucks and discharges the heat medium.

  The high-temperature and high-pressure gas-phase refrigerant discharged from the compressor 11 flows into the indoor condenser 12. In the heating mode, since the air mix door 34 is displaced so as to open the ventilation path on the indoor condenser 12 side, the gas-phase refrigerant flowing into the indoor condenser 12 exchanges heat with the blown air and dissipates heat. Thereby, blowing air is heated. The gas-phase refrigerant flowing out of the indoor condenser 12 flows into the heating expansion valve 17a because the first on-off valve 22a is closed and the second on-off valve 22b is open.

  The refrigerant flowing into the heating expansion valve 17a is depressurized until it becomes a low-pressure refrigerant and flows into the second refrigerant inlet / outlet 20b of the composite heat exchanger 20. At this time, the throttle opening degree of the cooling expansion valve 17b is set such that the degree of supercooling of the refrigerant flowing into the cooling expansion valve 17b is determined so that the coefficient of performance (COP) of the cycle becomes a maximum value. It is decided to approach.

  The low-pressure refrigerant that has flowed into the second refrigerant inlet / outlet 20b flows into the heat exchange section 166a on the lower side of the air-refrigerant heat exchange section 16 (that is, the heat exchange section corresponding to the supercooling section 166 in the cooling mode). The refrigerant flowing into the heat exchanging unit 166a evaporates by absorbing heat from the outside air blown from the outside air fan when flowing through the heat exchanging unit 166a. The refrigerant that has flowed out of the heat exchange unit 166a flows into the modulator unit 164 and is gas-liquid separated.

  The gas-phase refrigerant separated by the modulator unit 164 passes through water-refrigerant heat from the gas-phase refrigerant outlet of the modulator unit 164 (that is, the gas-phase fluid outlet) through the junction 16c of the air-refrigerant heat exchange unit 16. It flows into the refrigerant passage of the exchange unit 14. The gas-phase refrigerant that has flowed into the refrigerant passage of the water-refrigerant heat exchanger 14 exchanges heat with the heat medium pumped from the water pump 40a that circulates through the inner pipe 14a, thereby raising the enthalpy.

  The liquid-phase refrigerant separated by the modulator unit 164 passes from the liquid-phase refrigerant outlet (that is, the liquid-phase fluid outlet) of the modulator unit 164 to the evaporation unit 165a above the air-refrigerant heat exchange unit 16 (that is, the cooling mode). Sometimes it flows into the heat exchanging part corresponding to the condensing part 165. The refrigerant flowing into the evaporation unit 165a evaporates by absorbing heat from the outside air blown from the outside air fan when flowing through the evaporation unit 165a.

  The refrigerant that has flowed out of the evaporator 165a flows into the water-refrigerant heat exchanger 14 through the inlet 16a of the air-refrigerant heat exchanger 16. The flow of the refrigerant flowing into the water-refrigerant heat exchange unit 14 from the evaporation unit 165a merges with the flow of the gas-phase refrigerant separated by the modulator unit 164.

  That is, in the heating mode, a joining portion 13a that joins the flow of the refrigerant that has flowed out of the water-refrigerant heat exchanger 14 and the flow of the refrigerant that has flowed out of the evaporation portion 165a is formed in a portion that functions as the branch portion 13 in the cooling mode. Is done. That is, the junction 13 a of the present embodiment is provided inside the outer tube 14 b of the water-refrigerant heat exchange unit 14 and is formed integrally with the water-refrigerant heat exchange unit 14.

  The refrigerant joined at the junction 13a flows out from the first refrigerant inlet / outlet 20a of the composite heat exchanger 20. The refrigerant flowing out of the first refrigerant inlet / outlet 20a flows into the accumulator 24 and is separated into gas and liquid because the first on-off valve 22a is closed and the second on-off valve 22b is open. The gas-phase refrigerant separated by the accumulator 24 is sucked into the compressor 11 and compressed again.

  As described above, in the refrigeration cycle apparatus 10a in the heating mode, the indoor condenser 12 functions as a radiator, and the composite heat exchanger 20 (specifically, the air-refrigerant heat exchanger 16) functions as an evaporator. A vapor compression refrigeration cycle is configured. And the heating of a vehicle interior is realizable by blowing the ventilation air cooled with the indoor condenser 12 into the vehicle interior.

  Further, in the composite heat exchanger 20 of the present embodiment, the same function as that of the first embodiment is achieved as a radiator of the refrigeration cycle apparatus 10a in the cooling mode. Therefore, it is possible to suppress a decrease in the heat exchange amount (that is, the heat release amount) of the refrigerant due to the pressure loss generated in the refrigerant during the cooling mode.

  Furthermore, in the composite heat exchanger 20 of the present embodiment, since the junction 16c is formed in the modulator unit 164, the refrigerant can be reliably liquefied by the water-refrigerant heat exchange unit 14 in the cooling mode. . Thereby, stagnation of the refrigerating machine oil in the water-refrigerant heat exchange unit 14 can be further suppressed.

  Further, according to the composite heat exchanger 20 of the present embodiment, the gas-phase refrigerant separated by the modulator unit 164 is caused to flow into the refrigerant passage of the water-refrigerant heat exchange unit 14 without flowing into the evaporation unit 165a. Further, the liquid phase refrigerant separated by the modulator unit 164 is caused to flow into the evaporation unit 165a.

  Therefore, in contrast to the case where the refrigerant in the gas-liquid mixed state is caused to flow into the evaporation unit 165a, the pressure loss generated when the refrigerant flows through the evaporation unit 165a can be reduced, and the refrigerant can be evenly distributed throughout the evaporation unit 165a. It's easy to do. As a result, it is possible to suppress the heat absorption amount of the refrigerant in the evaporation unit 165a from becoming insufficient.

  That is, according to the composite heat exchanger 20 of the present embodiment, it is possible to reduce pressure loss generated in the refrigerant during the heating mode. Furthermore, it is possible to suppress a decrease in the heat exchange amount (that is, the heat absorption amount) of the refrigerant due to the pressure loss generated in the refrigerant.

  Moreover, in the composite heat exchanger 20 of this embodiment, since the junction part 13a is integrally formed with the water-refrigerant heat exchange part 14, the junction part 13a is formed by another member having a structure like a three-way joint. In contrast to this, the composite heat exchanger 20 as a whole can be downsized.

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

  In each of the embodiments described above, the composite heat exchanger 20 according to the present invention is configured to exchange heat between the three types of fluids of the refrigerant of the refrigeration cycle apparatuses 10 and 10a, the heat medium circulating in the water circulation circuit 40, and the outside air. However, the first to third heat media to be heat-exchanged by the composite heat exchanger 20 are not limited to this. For example, the third fluid may be blown air that is blown into the air-conditioning target space. That is, the composite heat exchanger 20 may be used as an indoor heat exchanger.

  In the above-described second embodiment, the example in which the composite heat exchanger 20 is applied to the refrigeration cycle apparatus 10a capable of switching between the operation mode in which the composite heat exchanger 20 functions as a radiator of the refrigeration cycle and the operation mode in which the composite heat exchanger 20 functions as an evaporator has been described. The application of the composite heat exchanger 20 is not limited to this. For example, you may apply to the refrigerating-cycle apparatus used only as an evaporator of a refrigerating cycle.

DESCRIPTION OF SYMBOLS 10, 10a Refrigeration cycle apparatus 13 Branch part 13a Merging part 14 Water-refrigerant heat exchanging part 15 Air-water heat exchanging part 16 Air-refrigerant heat exchanging part 16a, 16b, 16c Inlet, outlet, confluence 164 Modulator part (gas-liquid Separation part)
165 Condensing part 165a Evaporating part

Claims (6)

A branching section (13) for branching the flow of the first fluid;
A first heat exchange section (14) for exchanging heat between the first fluid and the second fluid;
A second heat exchange section (15) for exchanging heat between the second fluid and the third fluid;
A third heat exchange section (16) for exchanging heat between the first fluid and the third fluid,
The first heat exchange section (14) exchanges heat between the first fluid branched at the branch section (13) and the second fluid flowing out from the second heat exchange section (15). Is,
From the first fluid inlet (16a) through which the other first fluid branched at the branch portion (13) flows into the third heat exchange portion (16), from the third heat exchange portion (16) The first fluid outlet (16b) for allowing the first fluid to flow out, and the first fluid flowing from the first fluid inlet toward the first fluid outlet into the first fluid flowing out from the first heat exchanging portion (14). A composite heat exchanger provided with a first fluid junction (16c) for joining one fluid. The third heat exchange part (16) cools and condenses the first fluid that has flowed from the first fluid inlet (16a), and the third heat exchange part (16) flows from the condensing part (165). A gas-liquid separator (164) that separates the gas-liquid of one fluid;
The combined heat according to claim 1, wherein the first fluid junction (16c) is configured to allow the first fluid flowing out from the first heat exchange part to flow into the gas-liquid separation part (164). Exchanger.   The composite heat exchanger according to claim 1 or 2, wherein the branch portion (13) is formed integrally with the first heat exchange portion (14). A first heat exchange section (14) for exchanging heat between the first fluid and the second fluid;
A second heat exchange section (15) for exchanging heat between the second fluid and the third fluid;
A third heat exchange section (16) for exchanging heat between the first fluid and the third fluid;
A joining portion (13a) for joining the flow of the first fluid flowing out from the first heat exchanging portion (14) and the flow of the first fluid flowing out from the third heat exchanging portion (16); ,
The third heat exchange unit (16) includes a gas-liquid separation unit (164) that separates the gas-liquid of the first fluid, and the first fluid that has flowed out from a liquid-phase fluid outlet of the gas-liquid separation unit (164). An evaporation section (165a) for exchanging heat with the third fluid to evaporate,
The first heat exchange unit (14) exchanges heat between the first fluid flowing out from the gas-phase fluid outlet of the gas-liquid separation unit (164) and the second fluid flowing out from the second heat exchange unit. Is,
The said junction part (13a) joins the flow of the said 1st fluid which flowed out from the said 1st heat exchange part (14), and the flow of the said 1st fluid which flowed out from the said evaporation part (165a). Mold heat exchanger.   The combined heat exchanger according to claim 4, wherein the joining portion (13 a) is formed integrally with the first heat exchange portion (14). A combined heat exchanger mounted on a vehicle having a heat medium circulation circuit (30) for circulating a heat medium for cooling an in-vehicle device, and a vapor compression refrigeration cycle apparatus (10, 10a),
The first fluid is a refrigerant of the refrigeration cycle apparatus (10, 10a),
The second fluid is the heat medium;
The composite heat exchanger according to claim 1, wherein the third fluid is outside air.

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