JP2006118795A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce mounting cost and heat insulation cost of an evaporator and a decompression means, to improve the reliability against refrigerant leakage, and to improve the layout property, in a refrigerating cycle of an air conditioner for a vehicle employing carbon dioxide gas as a refrigerant. <P>SOLUTION: The refrigerating cycle comprises: a compressor 101 for compressing a refrigerant; a radiator 103 for cooling the refrigerant compressed by the compressor 101; a decompressing means 115 for decompressing the refrigerant cooled by the radiator 103; the evaporator 113 for evaporating the refrigerant decompressed by the decompressing means 115; and an internal heat exchanger 109 for exchanging heat between the refrigerant cooled by the radiator 103 and the refrigerant evaporated by the evaporator 113. A heat exchanger 111 is formed by integrally joining the decompressing means 115 to the evaporator 113, and is connected to the downstream side of the internal heat exchanger 109. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat exchanger used in a vehicle air conditioner using carbon dioxide as a refrigerant, and more particularly to a heat exchanger in which a decompression unit and an evaporator are integrated.

  FIG. 8 is an overall configuration diagram of a refrigeration cycle of a vehicle air conditioner using carbon dioxide gas as a refrigerant. The refrigeration cycle shown in FIG. 8 includes a compressor 101 that compresses refrigerant, a radiator 103 that cools the refrigerant compressed by the compressor 101 with outside air, and an expansion valve 105 that decompresses the refrigerant cooled by the radiator 103. And an evaporator 107 that evaporates the refrigerant decompressed by the expansion valve 105, and an internal heat exchanger 109 that exchanges heat between the refrigerant cooled by the radiator 103 and the refrigerant evaporated by the evaporator 107. The refrigerant that has passed through the internal heat exchanger 109 is returned to the compressor 101, and the refrigerant that has been given kinetic energy (pressure) by the compressor 101 is circulated. Hereinafter, each part will be briefly described.

  The radiator 103 is disposed outside the passenger compartment, and cools the temperature of the refrigerant to near the outside temperature (medium temperature) by dissipating the heat of the high-temperature and high-pressure refrigerant discharged from the compressor 101 to the outside air. For example, an electric fan or the like is driven to the radiator 103 to blow outside air. The high-temperature and high-pressure refrigerant is cooled by causing heat exchange between the high-temperature and high-pressure refrigerant passing through the radiator 103 and the outside air to be blown.

  The internal heat exchanger 109 exchanges heat between the high-pressure refrigerant cooled by the radiator 103 and the low-pressure refrigerant evaporated by the evaporator 107.

  The expansion valve 105 depressurizes (expands) the medium-temperature and high-pressure refrigerant output from the internal heat exchanger 109 to obtain a low-temperature and low-pressure refrigerant.

The evaporator 107 is disposed, for example, in an air conditioning duct, and absorbs heat of the conditioned air into the low-temperature and low-pressure refrigerant supplied from the internal heat exchanger 109 via the expansion valve 105. The refrigerant supplied to the evaporator 107 as a low-temperature and low-pressure refrigerant by the expansion valve 105 is vaporized (evaporated) by taking heat flowing in the air conditioning duct when passing through the evaporator 107. Then, the conditioned air absorbed by the refrigerant in the evaporator 107 is dehumidified to be cooled and supplied to the passenger compartment (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2004-198060

  In the conventional refrigeration cycle as described above, since the evaporator 107 and the expansion valve 105 are connected by piping, assembly costs are required, and there is a risk of refrigerant leakage at the connection portion, so that the reliability is low. It has become. Moreover, since the expansion valve 105 is installed in an engine room having a high temperature, an exterior with a heat insulating material is required, and the heat insulation cost is increased. Furthermore, since the expansion valve 105 is installed in the engine room together with the piping, the layout is restricted in a narrow engine room.

  An object of the present invention is to provide a heat exchanger that achieves reduction in assembly cost and heat insulation cost, improvement in reliability against refrigerant leakage, and improvement in layout.

  In order to achieve the above object, the invention of claim 1 is at least a compressor for compressing a refrigerant, a radiator for cooling the refrigerant compressed by the compressor, and decompressing the refrigerant cooled by the radiator. A pressure reducing means, an evaporator for evaporating the refrigerant decompressed by the pressure reducing means, and an internal heat exchanger for exchanging heat between the refrigerant cooled by the radiator and the refrigerant evaporated by the evaporator, A heat exchanger used in a refrigeration cycle in which the refrigerant that has passed through the internal heat exchanger is circulated back to the compressor, wherein the decompression means is integrally joined to the evaporator. .

  According to a second aspect of the present invention, in the first aspect of the invention, the evaporator includes a core portion formed by alternately arranging tubes through which refrigerant flows and fins for cooling, and a first header communicating with one end of each tube. A pipe, a second header pipe communicating with the other end of each tube, an inlet joint pipe for supplying a refrigerant to the first header pipe, and an outlet side for discharging the refrigerant from the first header pipe or the lower header pipe The pressure reducing means is brazed integrally with the inlet side joint pipe.

  The invention of claim 3 is characterized in that, in claim 2, the pressure reducing means is an orifice.

  A fourth aspect of the present invention is characterized in that, in the first aspect, the pressure reducing means is one of refrigerant flow paths formed inside a header pipe communicating with one end of each tube.

  The invention of claim 5 is characterized in that, in claim 4, the pressure reducing means is an orifice.

  A sixth aspect of the invention is characterized in that, in the first aspect, the pressure reducing means is configured as a part of the tube.

  According to a seventh aspect of the present invention, the tube is configured as a multi-hole structure tube having a plurality of tube holes formed therein, and the pressure reducing means is one of the tube holes formed in the multi-hole structure tube. It is characterized by that.

  According to the first aspect of the present invention, since it is not necessary to connect the evaporator and the pressure reducing means with a pipe, the assembling cost can be reduced, and since there is no connection point that causes the refrigerant leakage, the reliability against the refrigerant leakage is reduced. Can be improved. Further, since the decompression means is integrally joined to the evaporator, it is not necessary to externally attach the decompression means with a heat insulating material, and the heat insulation cost can be reduced. Furthermore, since the space between the evaporator and the pressure reducing means can be omitted, the space can be saved, so that the layout in the engine room is less restricted and the layout can be improved.

  According to the invention of claim 2, since the pressure reducing means is integrally brazed with the inlet side joint pipe of the evaporator, the heat exchanger can be made compact.

  According to the invention of claim 3, since the orifice is used as the pressure reducing means, the pressure reducing means can be easily integrated with the inlet side joint pipe.

  According to the invention of claim 4, since the decompression means is configured as one of the refrigerant flow paths formed in the header pipe, the heat exchanger can be made compact and manufactured at low cost. it can.

  According to the invention of claim 5, since the orifice is used as the pressure reducing means, the pressure reducing means can be easily integrated with the header pipe.

  According to the invention of claim 6, since the pressure reducing means is configured as a part of the tube, the inlet side joint pipe communicating with the tube can be positioned immediately above the tube, so that the width of the heat exchanger can be reduced. Can be narrowed.

  According to the invention of claim 7, since one tube hole of the multi-hole structure tube is used as the pressure reducing means, the pressure reducing means can be easily integrated with the core portion, and other tube holes are usually used. Therefore, the space can be saved.

  Hereinafter, the best mode for carrying out the heat exchanger according to the present invention will be described with reference to the drawings.

  Initially, the structure of the refrigerating cycle in a present Example is demonstrated. FIG. 1 is a circuit diagram of a refrigeration cycle in the present embodiment, and the same parts as those in FIG. 8 are denoted by the same reference numerals.

  In the refrigeration cycle of this embodiment, a heat exchanger 111 having functions of an evaporator 113 and a decompression means (expansion valve) 115 is connected to the high-pressure refrigerant outlet side and the low-pressure refrigerant inlet side of the internal heat exchanger 109. . This heat exchanger 111 is obtained by integrally joining an evaporator 113 and a decompression means 115 as will be described later.

  The refrigerant flow path shown in FIG. 1 is the same as that shown in FIG. 8, and the refrigerant (compressor) 101 → the radiator 103 → the internal heat exchanger 109 → the pressure reducing means 115 → the evaporator 113 → the compressor 101 is circulated in this order. Yes. Hereinafter, the structure of the heat exchanger 111 will be described as Example 1 to Example 3.

  In this embodiment, the decompression means is integrally brazed with the inlet side joint pipe of the evaporator (an embodiment corresponding to claims 1 to 3).

  FIG. 2 is a perspective view of the heat exchanger 111 according to the first embodiment, and FIG. 3 is a cross-sectional view in a range A of FIG.

  As shown in FIG. 2, the evaporator 113 includes an upper header pipe (first header pipe) 117, a lower header pipe (second header pipe) 119, and a core portion 121 serving as a heat exchange region. Yes.

  The core part 121 has a structure in which a plurality of tubes 123 through which a refrigerant flows and cooling fins 125 are alternately arranged. The upper end portion of the core portion 121 is connected to the upper header pipe 117 and communicates with one end portion of each tube 123. Furthermore, an inlet side joint pipe 127 for taking in the refrigerant from the outside is provided at one end of the upper header pipe 117, and an outlet side joint pipe 129 for discharging the refrigerant that has passed through the core portion 121 is provided at the other end. It has been. On the other hand, the lower end portion of the core portion 121 is connected to the lower header pipe 119 and communicates with the other end portion of each tube 123.

  As shown in FIG. 3, a plurality of refrigerant channels 117a extending in the longitudinal direction are formed in the upper header pipe 117. Further, a partition plate 128 for turning the refrigerant to the opposite header tank is inserted at a predetermined location. The lower header pipe 119 (not shown) is also provided with one or a plurality of refrigerant flow paths, and a partition plate is inserted at a predetermined location.

  Further, as shown in FIG. 3, the pressure reducing means 115 is integrally brazed and joined to the inlet joint pipe 127 at the inlet portion of the refrigerant. In the present embodiment, an orifice is used as the pressure reducing means 115 and is brazed integrally with the inlet side joint pipe 127. A pipe connection portion 127a for connecting to an inlet pipe (not shown) is formed on the refrigerant inlet side of the inlet side joint pipe 127, and an internal flow path 127b for distributing the refrigerant is provided on the downstream side of the decompression means 115. Is formed. The refrigerant that has passed through the decompression means 115 is distributed from the internal flow path 127b to the respective refrigerant flow paths 117a and flows into the upper header pipe 117.

  In the heat exchanger 111 configured as described above, the high-pressure refrigerant discharged from the internal heat exchanger 109 is taken in from the inlet-side joint pipe 127 (arrow IN in the figure) and depressurized by the decompression means 115 (orifice). It becomes a low-temperature and low-pressure refrigerant. The refrigerant is distributed from the internal flow path 127b to each refrigerant flow path 117a and flows into the upper header pipe 117, and then passes through the core portion 121 while turning between the upper header pipe 117 and the lower header pipe 119. It is discharged from the outlet side joint pipe 129 of the upper header pipe 117 (arrow OUT in the figure).

  During this time, in the evaporator 113, heat exchange is performed between the low-temperature and low-pressure refrigerant that has passed through the core 121 and the conditioned air, and the heat of the conditioned air is absorbed by the refrigerant. That is, the refrigerant that has passed through the decompression means 115 and has become a low temperature and a low pressure is vaporized (evaporated) while taking the heat of the conditioned air when passing through the core portion 121 of the evaporator 113. Then, the conditioned air absorbed by the refrigerant passing through the core portion 121 of the evaporator 113 is dehumidified to become a cooling air and is supplied to the passenger compartment.

  According to the heat exchanger 111 of the present embodiment, since it is not necessary to connect the evaporator 113 and the pressure reducing means 115 with a pipe, the assembling cost can be reduced, and there is no connection point that causes refrigerant leakage. The reliability against refrigerant leakage can be improved. Further, since the decompression means 115 is integrally joined to the evaporator 113, it is not necessary to externally attach the decompression means 115 with a heat insulating material, and the heat insulation cost can be reduced. Furthermore, since the piping between the evaporator 113 and the decompression means 115 can be omitted to save space, the layout in the engine room is less restricted and the layout can be improved. (Effect of claim 1)

  In particular, in this embodiment, since the pressure reducing means 115 is integrally brazed and joined to the inlet side joint pipe 127 of the evaporator 113, the heat exchanger 111 can be made compact (effect of claim 2).

  In the present embodiment, since the orifice is used as the pressure reducing means 115, the pressure reducing means 115 can be easily integrated with the inlet side joint pipe 127 (the effect of claim 3).

  In the present embodiment, the decompression means is configured as one of the refrigerant channels formed in the upper header pipe (embodiments corresponding to claims 4 and 5).

  FIG. 4 is a perspective view of the heat exchanger 211 according to the second embodiment, and FIG. 5 is a cross-sectional view in a range B of FIG. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description of the overlapping parts is appropriately omitted.

  In the upper header pipe 217 of the present embodiment, a first joint pipe 227 that serves as an inlet and an outlet for the refrigerant, and a second joint that distributes the refrigerant that has passed through the decompression means 215 described later to each refrigerant flow path of the upper header pipe 217. A pipe 229 is connected.

  As shown in FIG. 5, a plurality of refrigerant channels 217a extending in the longitudinal direction are formed inside the upper header pipe 217, and a partition plate 128 is inserted at a predetermined location. Further, a decompression means 215 is provided as a part of the upper header pipe 217.

  The decompression means 215 provided in the upper header pipe 217 is the outermost refrigerant flow path 217b of the upper header pipe 217, and has a smaller diameter than the other refrigerant flow paths 217a so that the refrigerant flow path 217b becomes an orifice. It is molded so as to be a hole.

  The first joint pipe 227 is open at both ends in the longitudinal direction, and a partition plate 228 for guiding the refrigerant from the internal heat exchanger 109 to the decompression means 215 side is provided on the refrigerant inlet side. A pipe connecting portion 227a for connecting to an inlet pipe (not shown) is formed on the refrigerant inlet side as viewed from the partition plate 228, and an internal flow path 227b for joining the refrigerant is formed on the outlet side.

  The second joint pipe 229 has a structure in which both ends are sealed, and the refrigerant discharged from the decompression means 215 is distributed from the internal flow path 229a to each refrigerant flow path 217a of the upper header pipe 217.

  In the heat exchanger 211 configured as described above, the high-pressure refrigerant discharged from the internal heat exchanger 109 is taken in from the first joint pipe 227 (arrow IN in the figure) and becomes the decompression means 215 (orifice). The refrigerant is reduced in pressure in the refrigerant flow path 217b to become a low-temperature and low-pressure refrigerant. The refrigerant is distributed from the internal flow path 229a of the second joint pipe 229 to each refrigerant flow path 217a and flows into the upper header pipe 217, and then turns between the upper header pipe 217 and the lower header pipe 119 while turning the core portion. After passing through 121 and joining in the internal flow path 227b of the first joint pipe 227, it is discharged to the outside (arrow OUT in the figure).

  Meanwhile, in the evaporator 213, heat exchange is performed between the low-temperature and low-pressure refrigerant that has passed through the core 121 and the conditioned air, and the heat of the conditioned air is absorbed by the refrigerant. Then, the conditioned air absorbed by the refrigerant passing through the core part 121 of the evaporator 213 is dehumidified to become a cooling air and is supplied to the passenger compartment.

  In the heat exchanger 211 of the present embodiment, it is not necessary to connect the evaporator 213 and the decompression means 215 with piping, so that the assembly cost can be reduced, and there is no connection point that causes refrigerant leakage. The reliability against leakage can be improved. Further, since the decompression unit 215 is integrally joined with the evaporator 213, it is not necessary to externally attach the decompression unit 115 with a heat insulating material, and the heat insulation cost can be reduced. Furthermore, since the piping between the evaporator 213 and the pressure reducing means 215 can be omitted to save space, the layout in the engine room is less restricted and the layout can be improved. (Effect of claim 1)

  In particular, in this embodiment, since the decompression means 215 is configured as one of the refrigerant flow paths formed in the upper header pipe 217, the heat exchanger 211 can be made compact and manufactured at low cost. (Effect of claim 4).

  In this embodiment, since the orifice is used as the pressure reducing means 215, the pressure reducing means 215 can be easily integrated with the upper header pipe 217 (the effect of claim 5).

  In the present embodiment, the decompression means is configured as a part of the tube (examples corresponding to claims 6 and 7).

  6A is a perspective view of a heat exchanger 311 according to the third embodiment, FIG. 6B is a perspective view showing a cross-sectional shape of the tube, and FIG. 7 is a cross-sectional view in a range C of FIG. 6A. . Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description of the overlapping parts is appropriately omitted.

  In the upper header pipe 317 of this embodiment, as shown in FIG. 6A, an inlet-side joint pipe 327 for taking in the refrigerant from the outside and an outlet-side joint for discharging the refrigerant that has passed through the core portion 121. A pipe 329 is connected.

  Among the tubes (multi-hole structure tubes) 123 constituting the core portion 121, the tube 123A located on the outermost side is one of the tube holes 124 (124a), as shown in FIG. It is said. The outermost tube 123 </ b> A has one end connected to the inlet side joint pipe 327 and the other end connected to the lower header pipe 119 in the same manner as the other tubes 123.

  As shown in FIG. 7, the inlet side joint pipe 327 is provided with partition plates 328a and 328b so as to surround one tube hole 124a of the connected tube 123A. A pipe connection portion 327a for connecting to an inlet pipe (not shown) is formed on the refrigerant inlet side when viewed from the partition plates 328a and 328b, and an internal flow path 327b for distributing the refrigerant is formed on the opposite side of the partition plate 328a. Has been.

  Further, a plurality of refrigerant flow paths 317a extending in the longitudinal direction are formed inside the upper header pipe 317, one end of which communicates with the internal flow path 327b of the inlet side joint pipe 327 and the other end of the outlet header joint 317. It communicates with the pipe 329. In addition, a partition plate 128 for turning the refrigerant is inserted in a predetermined portion inside.

  An internal flow path (not shown) is formed inside the outlet side joint pipe 329, and the refrigerant flowing from the refrigerant flow path 317a of the upper header pipe 317 is joined and discharged to the outside.

  In the heat exchanger 311 configured as described above, the high-pressure refrigerant discharged from the internal heat exchanger 109 is taken in from the inlet-side joint pipe 327 (arrow IN in the figure) and becomes the pressure reducing means 315 (orifice). It passes through the tube hole 124a and is reduced in pressure to become a low-temperature and low-pressure refrigerant and flows into the lower header pipe 119. The refrigerant further flows through the tube hole 124 of the tube 123A and flows into the internal flow path 327b of the inlet side joint pipe 327. Then, after being distributed from the internal flow path 327b to each refrigerant flow path 317a and flowing into the upper header pipe 317, it passes through the core portion 121 while turning between the upper header pipe 317 and the lower header pipe 119, and exits. After merging in an internal flow path (not shown) of the side joint pipe 329, it is discharged to the outside (arrow OUT in the figure).

  Meanwhile, in the evaporator 313, heat exchange is performed between the low-temperature and low-pressure refrigerant that has passed through the core 121 and the conditioned air, and the heat of the conditioned air is absorbed by the refrigerant. The conditioned air absorbed by the refrigerant passing through the core portion 121 of the evaporator 313 is dehumidified to become a cooling air and is supplied to the vehicle interior.

  In the heat exchanger 311 of this embodiment, it is not necessary to connect the evaporator 313 and the pressure reducing means 315 with a pipe, so that the assembling cost can be reduced and there is no connection point that causes refrigerant leakage. The reliability against leakage can be improved. Further, since the decompression means 315 is integrally joined with the evaporator 313, it is not necessary to externally attach the decompression means 315 with a heat insulating material, and the heat insulation cost can be reduced. Furthermore, since the piping between the evaporator 313 and the decompression means 315 can be omitted to save space, the layout in the engine room is less restricted and the layout can be improved. (Effect of claim 1)

  In this embodiment, since the decompression means 315 is configured as a part of the tube 123A, the heat exchanger 311 can be made compact. In particular, in this embodiment, since the inlet side joint pipe 327 is located immediately above the tube 123A, the lateral width of the heat exchanger can be reduced (effect of claim 6).

  Further, in this embodiment, since one tube hole of a multi-hole structure tube is used as the decompression means 315, the decompression means 315 can be easily integrated with the core portion 121, and other tube holes can be provided. Since it can be a normal refrigerant flow path, space saving can be achieved (effect of claim 7).

The circuit diagram of the refrigerating cycle in an Example. 1 is a perspective view of a heat exchanger according to Embodiment 1. FIG. Sectional drawing in the range A of FIG. The perspective view of the heat exchanger concerning Example 2. FIG. Sectional drawing in the range B of FIG. (A) is a perspective view of the heat exchanger concerning Example 3. FIG. (B) is a perspective view which shows the cross-sectional shape of a tube. Sectional drawing in the range C of Fig.6 (a). The whole refrigeration cycle block diagram of the vehicle air conditioner which uses a carbon dioxide gas as a refrigerant | coolant.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Compressor 103 ... Radiator 105 ... Expansion valve 107 ... Evaporator 109 ... Internal heat exchanger 111, 211, 311 ... Heat exchanger 113, 213, 313 ... Evaporator 115, 215, 315 ... Decompression means 117, 217 ... Upper header pipe 117a ... Refrigerant flow path 119 ... Lower header pipe 121 ... Core part 123 (123A) ... Tube 124 (124a) ... Tube hole 125 ... Fin 128, 228, 328a, 328b ... Partition plate 127, 327 ... Inlet joint Pipe 127a, 327a ... Pipe connection portion 127b, 227b, 229a, 327a ... Internal flow path 129, 329 ... Outlet side joint pipe 217a, 217b, 317a ... Refrigerant flow path 227 ... First joint pipe 229 ... Second joint pipe

Claims (7)

At least a compressor (101) that compresses the refrigerant, a radiator (103) that cools the refrigerant compressed by the compressor (101), and a decompression unit that depressurizes the refrigerant cooled by the radiator (103) (115), an evaporator (113) for evaporating the refrigerant decompressed by the decompression means (115), a refrigerant cooled by the radiator (103), and a refrigerant evaporated by the evaporator (113) And an internal heat exchanger (109) for exchanging heat between them, and a heat exchanger (111) used in a refrigeration cycle for circulating the refrigerant that has passed through the internal heat exchanger (109) back to the compressor (101) ) And
The heat exchanger (111) is characterized in that the decompression means (115) is integrally joined with the evaporator (113). The evaporator (113) communicates with a core portion (121) formed by alternately arranging tubes (123) through which refrigerant flows and fins (125) for cooling, and one end of each tube (123). A first header pipe (117), a second header pipe (119) communicating with the other end of each tube (123), and an inlet side joint pipe (127) for supplying a refrigerant to the first header pipe (117) And an outlet side joint pipe (129) for discharging the refrigerant from the first header pipe (117) or the lower header pipe (119),
The heat exchanger according to claim 1, wherein the decompression means (115) is brazed and joined integrally with the inlet-side joint pipe (127).   The heat exchanger according to claim 2, wherein the pressure reducing means (115) is an orifice.   The said pressure reduction means (215) is one of the refrigerant flow paths (217b) formed in the header pipe (217) communicating with the end of each said tube (123), The Claim 1 characterized by the above-mentioned. The described heat exchanger.   The heat exchanger according to claim 4, wherein the pressure reducing means (215) is an orifice.   The heat exchanger according to claim 1, wherein the decompression means (315) is configured as a part of the tube. The tube (123) is configured as a multi-hole structure tube having a plurality of tube holes (124) formed therein,
The heat exchanger according to claim 6, wherein the pressure reducing means (315) is one of tube holes (124a) formed inside the multi-hole structure tube.

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