JP2013092301A - Indoor heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indoor heat exchanger which makes a discharge air temperature uniform when used for heat pump refrigeration cycles.SOLUTION: The indoor heat exchanger 7 used for heat pump refrigeration cycles includes a leeward side header part 21 and a windward side header part 22 which are disposed with a space therebetween and a refrigerant circulation path 23 which connects both the headers 21 and 22. A refrigerant inlet 24 is arranged at one end of the leeward side header 21, while a refrigerant outlet 25 is arranged at the same side end as for the refrigerant inlet 24 at the windward side header part 22. The refrigerant circulation path 23 is formed in a substantially inverted U shape when viewed from outside in the longitudinal directions of both header parts 21 and 22, and is composed of a pair of vertical parts 26 and 27 which are upward extensions from the header parts 21 and 22 and a connecting part 28 which mutually connects the upper ends of both the longitudinal parts 26 and 27.

Description

  The present invention relates to an indoor heat exchanger used in a heat pump refrigeration cycle.

  As a heat pump refrigeration cycle used in vehicle air conditioners for vehicles with relatively little waste heat, such as hybrid vehicles and electric vehicles, heat is generated from the compressor, the refrigerant placed outside the passenger compartment, and compressed by the compressor during cooling. An outdoor heat exchanger that heats and condenses and evaporates the refrigerant depressurized during heating, a first decompressor that depressurizes the refrigerant that has passed through the outdoor heat exchanger during cooling, and is disposed in the passenger compartment and during cooling An evaporator that receives and evaporates the refrigerant decompressed by the first decompressor, an indoor heat exchanger that is disposed in the vehicle interior and dissipates heat from the refrigerant compressed by the compressor during heating and condenses the refrigerant, and during heating A second decompressor for decompressing the refrigerant that has passed through the indoor heat exchanger, and the outdoor heat exchanger is configured to evaporate the refrigerant decompressed by the second decompressor during heating, Exchanger those has a heat source providing heat to the air is known at the time of heating (see Patent Document 1).

  All equipment in the heat pump refrigeration cycle compresses refrigerant during cooling, cooling piping that circulates refrigerant between the compressor, indoor heat exchanger, outdoor heat exchanger, first decompressor and evaporator, and heating. A heating pipe that circulates between the compressor, the indoor heat exchanger, the second pressure reducer, and the outdoor heat exchanger, and at the time of dehumidification, the refrigerant is circulated among the compressor, the indoor heat exchanger, the second pressure reducer, and the evaporator. It is connected by dehumidification piping.

  The three pipes described above have a common part, and a three-way valve for controlling the flow direction of the refrigerant is provided in a part downstream of the indoor heat exchanger in the cooling pipe, the heating pipe and the dehumidifying pipe, The outdoor heat exchanger in the heating pipe is provided with a first solenoid valve having a function of reducing the pressure of the refrigerant at a portion connecting the downstream side of the outdoor heat exchanger and the evaporator in the cooling pipe to the first pressure reducer. The second solenoid valve is provided at the portion connecting the downstream side of the compressor and the compressor, the receiver is provided downstream of the three-way valve in the heating pipe and the dehumidifying pipe, and more than the receiver in the heating pipe and the dehumidifying pipe. A second pressure reducer is provided on the downstream side. The refrigerant is switched so as to flow into any one of the cooling pipe, the heating pipe, and the dehumidifying pipe by the action of the three-way valve and the two electromagnetic valves. During cooling, the refrigerant is compressed by the compressor, passes through the indoor heat exchanger, then dissipates heat in the outdoor heat exchanger, condenses, and then is depressurized by the first decompressor and then is heated by the evaporator. It receives heat and evaporates and is then returned to the compressor. During heating, the refrigerant is compressed by the compressor, then dissipates heat from the indoor heat exchanger, condenses, and after being separated by gas and liquid at the receiver, it is decompressed by the second decompressor, and then heated by the outdoor heat exchanger. After being taken away and evaporated, it is returned to the compressor. At the time of dehumidification, the refrigerant is compressed by the compressor, dissipates heat by the indoor heat exchanger, condenses, and after being gas-liquid separated by the receiver, the refrigerant is decompressed by the second decompressor, and then the heat is taken away by the evaporator. It is evaporated and returned to the compressor. And the air which passed the indoor heat exchanger is sent into a vehicle interior as warm air.

  In the case of the heat pump refrigeration cycle described in Patent Document 1, the indoor heat exchanger has a function of radiating heat from the refrigerant compressed by the compressor during heating to condense the refrigerant.

  By the way, a vapor compression refrigeration cycle is used in a vehicle air conditioner for a vehicle that uses only an engine as a drive source. In the vapor compression refrigeration cycle, a heat exchanger having a condensing function is disposed outside the passenger compartment. In addition, it is a condenser that dissipates heat from the refrigerant compressed by the compressor during cooling. As is well known, a condenser used in a vapor compression refrigeration cycle is arranged in a horizontal manner with a pair of headers arranged in the vertical direction spaced apart from each other and in the vertical direction between the headers. A plurality of flat heat exchange tubes whose both ends are respectively connected to the headers, and fins disposed between adjacent heat exchange tubes, and a plurality of heat exchange tubes arranged continuously in the vertical direction. There are three or more heat exchange paths arranged vertically, and all the heat exchange tubes constituting each heat exchange path have the same refrigerant flow direction, and the heat exchange tubes of two adjacent heat exchange paths The refrigerant flow directions of the two headers are different, and a refrigerant inlet for allowing the refrigerant to flow into one of the headers is formed at one end of the header, and a refrigerant outlet for allowing the refrigerant to flow out of the other header at the other end of the other header Formed and the refrigerant entered The refrigerant flowing into one header from and all the heat exchange path sequentially flows entering the other header portion, and then flows out from the refrigerant outlet.

  However, when a condenser of a vapor compression refrigeration cycle is used as an indoor heat exchanger of a heat pump refrigeration cycle, the refrigerant gradually condenses while sequentially passing through the entire heat exchange path, so that each heat exchange path The temperature of the refrigerant that passes is different. Therefore, there is a problem that the air discharge temperature, which is the temperature of the air that has passed through the condenser, becomes uneven.

JP 2009-23564 A

  An object of the present invention is to provide an indoor heat exchanger that can solve the above-described problems and can make the air discharge temperature uniform when used in a heat pump refrigeration cycle.

  In order to achieve the above object, the present invention comprises the following aspects.

1) A compressor, an outdoor heat exchanger that is disposed outside the passenger compartment and radiates heat from the refrigerant during cooling and receives heat from the refrigerant during heating, and a first decompressor that decompresses the refrigerant that has passed through the outdoor heat exchanger during cooling An evaporator that evaporates the refrigerant decompressed by the first decompressor during cooling and evaporates the refrigerant that is decompressed by the compressor during cooling, and indoor heat that dissipates heat from the refrigerant compressed by the compressor during heating and condenses the refrigerant In the indoor heat exchanger used for the heat pump refrigeration cycle having the exchanger and the second decompressor that decompresses the refrigerant that has passed through the indoor heat exchanger during heating,
The leeward header section and the leeward header section that are spaced apart from each other, and a refrigerant flow path that passes through both header sections, a refrigerant inlet is provided at one end of the leeward header section, and the leeward header A refrigerant outlet is provided at the same end as the refrigerant inlet in the section, and the refrigerant flow path has a substantially inverted U shape when viewed from the outside in the length direction of both header sections, and is a pair of vertical lines extending upward from both header sections. The indoor heat exchanger which consists of a connection part which connects the direction part and the upper end part of both vertical direction parts mutually.

  According to the indoor heat exchanger of the above 1), the leeward header section and the leeward header section that are spaced apart from each other, and the refrigerant flow path that passes through both header sections, A refrigerant inlet is provided at one end, a refrigerant outlet is provided at the same end as the refrigerant inlet in the windward header portion, and the refrigerant flow path has a substantially inverted U shape when viewed from the outside in the length direction of both header portions. And a pair of vertically extending portions extending upward from both header portions, and a connecting portion that interconnects the upper end portions of both vertically extending portions, so that the refrigerant flows into the leeward header portion from the refrigerant inlet, After flowing into the flow path, flowing through the refrigerant flow path and into the windward header portion, it flows out from the refrigerant outlet. When the refrigerant flows into the leeward header portion from the refrigerant inlet, the refrigerant tends to flow to the opposite side of the refrigerant inlet due to inertial force, and in the initial stage of heat exchange, in the leeward vertical portion of the refrigerant flow path , A large amount of refrigerant flows in a portion opposite to the refrigerant inlet. Accordingly, a large amount of refrigerant flows through the refrigerant inlet, that is, the portion on the opposite side to the refrigerant outlet, also in the vertical direction of the refrigerant flow path. However, when the refrigerant flowing through the refrigerant flow path of the indoor heat exchanger and the air passing through the indoor heat exchanger start heat exchange and the heat of the refrigerant is radiated to the air, the refrigerant is discharged from the refrigerant outlet of the windward header section. At the lower part of the windward vertical portion of the refrigerant flow path, a supercooling portion that gradually expands toward the refrigerant outlet side and that is filled with the liquid-phase main refrigerant is generated. As a result, a large amount of refrigerant flows, and the amount of refrigerant flowing in the refrigerant outlet side portion and the portion on the opposite side of the refrigerant outlet in the vertical portion on the windward side is made uniform. Therefore, the amount of the refrigerant flowing through the refrigerant inlet side portion and the portion opposite to the refrigerant inlet is also made uniform in the leeward vertical portion of the refrigerant flow path. As a result, during heating, the temperature of air passing through the indoor heat exchanger is also made uniform in the length direction of both header portions.

It is the schematic which shows the heat pump type refrigeration cycle of the vehicle air conditioner using the indoor heat exchanger by this invention. 1 is a perspective view schematically showing an indoor heat exchanger according to the present invention. It is a figure explaining the effect | action of the indoor heat exchanger by this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a heat pump refrigeration cycle of a vehicle air conditioner according to the present invention, and FIG. 2 shows an indoor heat exchanger according to the present invention.

  In FIG. 1, a heat pump refrigeration cycle (1) of a vehicle air conditioner dissipates heat from a compressor (3), which is disposed outside the passenger compartment and compressed by the compressor (3) during cooling, and condenses. And an outdoor heat exchanger (4) for receiving and evaporating the refrigerant depressurized during heating, and a first depressurizer (5) for depressurizing the refrigerant disposed in the passenger compartment and passing through the outdoor heat exchanger (4) during cooling. ), An evaporator (6) for evaporating the refrigerant depressurized by the first pressure reducer (5) during cooling, and dissipating heat from the refrigerant disposed in the passenger compartment and compressed by the compressor (3) during heating It has an indoor heat exchanger (7) that condenses, and an expansion valve (9) as a second pressure reducer that depressurizes the refrigerant that has passed through the indoor heat exchanger (7) during heating. (11), a heating pipe (12), and a dehumidifying pipe (13). The outdoor heat exchanger (4) evaporates the refrigerant decompressed by the expansion valve (9) during heating.

  The cooling pipe (11) circulates refrigerant between the compressor (3), the indoor heat exchanger (7), the outdoor heat exchanger (4), the first pressure reducer (5) and the evaporator (6) during cooling. It is something to be made. The heating pipe (12) circulates the refrigerant between the compressor (3), the indoor heat exchanger (7), the expansion valve (9), and the outdoor heat exchanger (4) during heating. The dehumidifying pipe (13) circulates the refrigerant between the compressor (3), the indoor heat exchanger (7), the expansion valve (9), and the evaporator (6) during dehumidification. These pipes (11), (12), and (13) have a shared part, and the refrigerant flows to the downstream side of the indoor heat exchanger (7) in all the pipes (11), (12), and (13). A three-way valve (15) for controlling the direction is provided, and a first pressure reducer (5) is provided in a pipe portion (11a) connecting the outdoor heat exchanger (4) and the evaporator (6) in the cooling pipe (11). A receiver (16) and an expansion valve (9) as a gas-liquid separator are provided in a pipe part (12a) that is provided and connects the three-way valve (15) and the outdoor heat exchanger (4) in the heating pipe (12). The former is provided on the three-way valve (15) side. In addition, a solenoid valve (17) is provided in a pipe portion (12b) connecting the outdoor heat exchanger (4) and the compressor (3) in the heating pipe (12). The first pressure reducer (5) is composed of an electromagnetic valve having a function of reducing the pressure of the refrigerant, and the refrigerant is cooled by the operation of the first pressure reducer (5), the three-way valve (15) and the electromagnetic valve (17). (11), switching to flow to any one of the heating pipe (12) and the dehumidifying pipe (13).

  During cooling, the refrigerant is compressed by the compressor (3), then passes through the indoor heat exchanger (7), then dissipates heat in the outdoor heat exchanger (4) and condenses, and then the first decompressor (5 ), And after evaporating by removing heat from the evaporator (6), it is returned to the compressor (3). During heating, the refrigerant is compressed by the compressor (3), dissipates heat in the indoor heat exchanger (7), condenses, and then gas-liquid is separated by the receiver (16), and then is expanded by the expansion valve (9). The pressure is reduced, and then the heat is removed by the outdoor heat exchanger (4) to evaporate and then returned to the compressor (3). During dehumidification, the refrigerant is compressed by the compressor (3), dissipates heat in the indoor heat exchanger (7), condenses, and then gas-liquid is separated by the receiver (16), and then is expanded by the expansion valve (9). The pressure is reduced, and then the evaporator (6) is deprived of heat and evaporated, and then returned to the compressor (3).

  As shown in FIG. 2, air flows through the indoor heat exchanger (7) in the direction indicated by the arrow X. The indoor heat exchanger (7) includes a leeward header section (21) and an upwind header section (22) that are spaced apart from each other, and a refrigerant flow path (23) through the header sections (21) (22). ). A refrigerant inlet (24) is provided at one end of the header portion of the leeward header portion (21), and a refrigerant outlet (25) is provided at the same end as the refrigerant inlet (24) in the leeward header portion (22). . The refrigerant flow path (23) has a substantially inverted U shape when viewed from the outside in the length direction of both header portions (21) and (22), and extends straight down from the leeward header portion (21). An arcuate shape that connects the facing part (26), the windward vertical part (27) that extends straight up from the windward header part (22), and the upper ends of both vertical parts (26, 27). The connecting portion (28). Although not shown, the refrigerant flow path (23) has a lower end connected to the leeward header portion (21) and extends upward, and one end is connected to the leeward header portion (22). A plurality of substantially inverted U-shaped refrigerant flow pipes, each of which has a connecting portion that connects the second vertical portion and the upper ends of both vertical portions, are spaced apart in the length direction of both header portions (21, 22). A ventilation gap is provided between adjacent refrigerant circulation pipes in the refrigerant circulation path (23), and fins are arranged in the ventilation gap.

  During cooling such as in summer, the refrigerant is compressed by the compressor (3), then passes through the indoor heat exchanger (7), and is radiated and condensed in the outdoor heat exchanger (4). Next, the refrigerant is decompressed by the decompressor (5), is then received by the evaporator (6) and evaporated, and then returned to the compressor (3). Air deprived of heat in the evaporator (6) is blown out into the passenger compartment.

  At the time of heating in winter, the refrigerant is compressed by the compressor (3), and then is radiated and condensed in the indoor heat exchanger (7) by the air flowing in the direction indicated by the arrow X in FIG. Is heated, and the heated air is blown into the passenger compartment. The refrigerant condensed by releasing heat in the indoor heat exchanger (7) is gas-liquid separated by the receiver (16) and then decompressed by the expansion valve (9), and then heated by the outdoor heat exchanger (4). It is returned to the compressor (3) after evaporating.

  During heating, the refrigerant flows into the leeward header (21) from the refrigerant inlet (24) of the indoor heat exchanger (7). The refrigerant that has flowed into the leeward header section (21) is divided into all the refrigerant distribution pipes of the refrigerant distribution path (23) and flows into the leeward header section (22) through the refrigerant distribution pipe, It flows out from the refrigerant outlet (25). When the refrigerant flows into the leeward header portion (21) from the refrigerant inlet (24), the refrigerant easily flows to the side opposite to the refrigerant inlet (24) due to inertial force, and in the initial stage of heat exchange, In the leeward vertical portion (26) of the refrigerant flow path (23), a large amount of refrigerant flows through the first vertical portion of the refrigerant flow pipe opposite to the refrigerant inlet (24) (see FIG. 3 (a)). ). Accordingly, a large amount of refrigerant flows through the refrigerant inlet (24), that is, the portion on the opposite side of the refrigerant outlet (25), also in the windward vertical portion (27) of the refrigerant flow path (23). However, when the refrigerant flowing through the refrigerant flow path (23) of the indoor heat exchanger (7) and the air passing through the indoor heat exchanger (7) start heat exchange and the heat of the refrigerant is radiated to the air, the refrigerant Is sucked to the refrigerant outlet (25) side of the windward header section (22), so that the lower part of the windward vertical portion (27) of the refrigerant flow path (23) is directed to the refrigerant outlet (25) side. The subcooling section (S) that gradually spreads and is filled with the liquid phase main refrigerant is generated, so that a large amount of refrigerant flows through the refrigerant outlet (25) side, and the refrigerant in the windward vertical section (27) The amount of refrigerant flowing through the outlet (25) side portion and the portion on the opposite side of the refrigerant outlet (25) is made uniform (see FIG. 3 (b)). Therefore, also in the leeward vertical portion (26) of the refrigerant flow path (23), the amount of refrigerant flowing through the refrigerant inlet (24) side portion and the portion opposite to the refrigerant inlet (24) is made uniform. As a result, the air discharge temperature, which is the temperature of the air passing through the indoor heat exchanger (7), is also made uniform in the length direction of both header portions (21) and (22). In addition, the width of the arrow in FIG.

  During dehumidification, the refrigerant is compressed by the compressor (3) and then dissipated in the indoor heat exchanger (7) to be condensed. The refrigerant condensed in the indoor heat exchanger (7) is gas-liquid separated by the receiver (16), then depressurized by the expansion valve (9), then received by the evaporator (6) to evaporate, and then the compressor Returned to (3). The air deprived of heat by the evaporator (6) is heated by the heat radiated from the indoor heat exchanger (7) and then blown into the vehicle interior.

  In the above embodiment, the outdoor heat exchanger (4) is configured to dissipate heat from the refrigerant during cooling and condense it, and to deprive heat from the refrigerant during heating to evaporate, but is not limited thereto. Instead, a first outdoor heat exchanger that dissipates heat from the refrigerant during cooling and a second outdoor heat exchanger that evaporates by removing heat from the refrigerant during heating may be provided separately. .

  The vehicle air conditioner equipped with the heat pump refrigeration cycle using the indoor heat exchanger according to the present invention is suitably used for hybrid vehicles and electric vehicles with relatively little waste heat.

(1): Heat pump refrigeration cycle
(3): Compressor
(4): Outdoor heat exchanger
(5): First decompressor
(6): Evaporator
(7): Indoor heat exchanger
(9): Expansion valve (second pressure reducer)
(21): leeward header
(22): Upwind header
(23): Refrigerant distribution channel
(24): Refrigerant inlet
(25): Refrigerant outlet
(26): Downward vertical part
(27): Upward vertical part
(28): Linked part

Claims (1)

A compressor, an outdoor heat exchanger that is disposed outside the passenger compartment and dissipates heat from the refrigerant during cooling and receives heat from the refrigerant during heating; a first decompressor that decompresses the refrigerant that has passed through the outdoor heat exchanger during cooling; An evaporator that evaporates the refrigerant decompressed by the first decompressor during cooling and an indoor heat exchanger that dissipates heat from the refrigerant that is disposed in the passenger compartment and compressed by the compressor during heating to condense the refrigerant And an indoor heat exchanger used in a heat pump refrigeration cycle having a second decompressor that decompresses the refrigerant that has passed through the indoor heat exchanger during heating.
The leeward header section and the leeward header section that are spaced apart from each other, and a refrigerant flow path that passes through both header sections, a refrigerant inlet is provided at one end of the leeward header section, and the leeward header A refrigerant outlet is provided at the same end as the refrigerant inlet in the section, and the refrigerant flow path has a substantially inverted U shape when viewed from the outside in the length direction of both header sections, and is a pair of vertical lines extending upward from both header sections. The indoor heat exchanger which consists of a connection part which connects the direction part and the upper end part of both vertical direction parts mutually.

Images