JP2008180478A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger capable of adjusting the dividing state of a refrigerant flow to heat exchange tubes of a final heat exchange tube group. <P>SOLUTION: Header portion arrays 6 composed of two header portions 3, 4 are disposed on an upper header tank 31 in front and rear two arrays. One of the header portions of the front-side header portion array is a refrigerant inlet header portion 1, and one of the header portions of the rear-side header portion array 6 is a refrigerant outlet header portion 3. Intermediate header portions 8 are respectively disposed at front and rear both sides of a lower header tank 32, and the rear-side intermediate header portion 8 is applied as a final refrigerant circulating header portion. The final heat exchange tube group 13 is constituted by a plurality of heat exchange tubes 33 communicated with downstream-side parts of the refrigerant outlet header portion 3 and the rear-side intermediate header portion 8. A flow control portion 14 for controlling the flow to a downstream side of the refrigerant is disposed on a part communicated with the heat exchange tubes 33 of the final heat exchange tube group 13, of the final refrigerant circulating header portion 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a heat exchanger, and more particularly to a heat exchanger suitably used for an evaporator of a supercritical refrigeration cycle in which a supercritical refrigerant such as CO ₂ (carbon dioxide) is used.

  In this specification and claims, the term “supercritical refrigeration cycle” means a refrigeration cycle in which the refrigerant is in a supercritical state exceeding the critical pressure on the high pressure side, and “supercritical refrigerant” It shall mean a refrigerant used in a supercritical refrigeration cycle. Further, in this specification and claims, the upper, lower, left, and right sides of FIGS. 1 and 2 are referred to as the upper and lower sides and the left and right sides, respectively, and the downstream side of the air flowing in the ventilation gap between adjacent heat exchange tubes (in FIG. The direction indicated by arrow X) is the front, and the opposite side is the rear.

  For example, as a heat exchanger used in an evaporator of a supercritical refrigeration cycle used as a car air conditioner, the present applicant has previously made a pair of header tanks extending in the left-right direction and spaced apart in the vertical direction, A plurality of heat exchange pipes arranged in parallel between both header tanks and having both upper and lower ends connected to both header tanks, and having a refrigerant inlet and a refrigerant outlet. In addition, two header sections composed of two header sections arranged in the left-right direction are provided at intervals in the front-rear direction, and the header section on the right side of the front header section sequence is a refrigerant inlet header section, and the upper header A refrigerant inlet leading to the refrigerant inlet header is formed at one end of the tank, and the right header in the rear header row is a refrigerant outlet header, and the upper header A refrigerant outlet communicating with the refrigerant outlet header portion is formed at the same end as the refrigerant inlet in the tank, the other header portion of both header portion rows of the upper header tank is an intermediate header portion, and the inside of both intermediate header portions is One intermediate header portion is provided on both the front and rear sides of the lower header tank so as to straddle the two header portions of the front and rear header portion rows of the upper header tank. It is composed of a plurality of heat exchange tubes arranged in the direction and two rows of heat exchange tubes are provided side by side in the front-rear direction, and both end portions of the heat exchange tubes are connected to the upper and lower header tanks so as to communicate with the header portion, The rear intermediate header portion of the lower header tank is a final refrigerant distribution header portion in which the refrigerant flows in the left-right direction, and the refrigerant is disposed between the refrigerant outlet header portion and the downstream portion of the final refrigerant distribution header portion. It proposed a heat exchanger final heat exchange tube group composed of a plurality of heat exchange tubes which flows from bottom to top are provided (see Patent Document 1).

  In general, in an evaporator used in a supercritical refrigeration cycle for a car air conditioner, it passes through a ventilation gap between adjacent heat exchange tubes for the purpose of improving the comfort of the passenger compartment of the vehicle equipped with the car air conditioner. Although it is desirable to make the blown air temperature uniform in each part of the evaporator, it is necessary to adjust the refrigerant distribution state of the refrigerant flowing in the evaporator.

For example, in an evaporator of a supercritical refrigeration cycle, since the superheat degree of the supercritical refrigerant coming out from the refrigerant outlet is usually about 1 ° C., it flows through the total heat exchange pipe of the final heat exchange pipe group in which the supercritical refrigerant evaporates. It is important to make the temperature distribution of the supercritical refrigerant uniform. However, in the case of the heat exchanger described in Patent Document 1, in the final refrigerant circulation header portion of the lower header tank, the refrigerant easily flows to the downstream end side due to inertial force, so heat exchange on the refrigerant outlet side in the final heat exchange tube group The amount of supercritical refrigerant flowing through the pipe is larger than the amount of supercritical refrigerant flowing through the other heat exchange pipes in the final heat exchange pipe group, and the temperature of the supercritical refrigerant flowing through the heat exchange pipe on the refrigerant outlet side is final. It becomes lower than the temperature of the supercritical refrigerant flowing through the other heat exchange pipes of the heat exchange pipe group. As a result, the expansion valve may be controlled so that the superheat degree becomes 1 ° C. based on the temperature of the low-temperature supercritical refrigerant. In this case, the flow rate of the supercritical refrigerant flowing to the evaporator is unnecessarily reduced. As a result, the performance of the evaporator may be reduced.
JP-A-2005-300135

  An object of the present invention is to provide a heat exchanger that solves the above-described problems and can adjust the refrigerant distribution state to the heat exchange tubes of the final heat exchange tube group.

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

1) A pair of header tanks extending in the left-right direction spaced apart in the vertical direction, and a plurality of heat exchanges arranged in parallel between both header tanks, with both upper and lower ends connected to both header tanks. And a refrigerant inlet and a refrigerant outlet, and the upper header tank is provided with a plurality of rows of header portions composed of a plurality of header portions arranged in the left-right direction at intervals in the front-rear direction. The header portion at one end of the header portion of the last row is a refrigerant outlet header portion, and a refrigerant outlet is formed in the upper header tank so as to communicate with the refrigerant outlet header portion. At a position corresponding to the header part row, one header part that is one less than the number of header parts constituting each header part row of the upper header tank is two adjacent header part rows of the upper header tank. It is provided so as to straddle the header part, and is composed of a plurality of heat exchange tubes arranged in the left-right direction between the upper and lower header tanks, and the same number of heat exchange tube rows as the header part row of the upper header tank are arranged in the front-rear direction. Provided, and both end portions of the heat exchange pipe are connected to the upper and lower header tanks so as to lead into the header portion, and the header portion extending over the refrigerant outlet header portion of the upper header tank and the header portion adjacent thereto in the lower header tank, The final refrigerant flow header portion in which the refrigerant flows in the left-right direction, and the final flow is composed of a plurality of heat exchange tubes in which the refrigerant flows from bottom to top between the refrigerant outlet header portion and the downstream portion of the final refrigerant flow header portion. In the heat exchanger provided with the heat exchange tube group,
The heat exchanger by which the flow suppression part which suppresses the flow to the downstream of a refrigerant | coolant is provided in the part which the heat exchange pipe | tube of the final heat exchange pipe group in the last refrigerant | coolant distribution | circulation header part leads.

  2) The upper header tank is provided with two front and rear header sections each including two header sections arranged in the left-right direction, and one header section of the front header section is a refrigerant inlet header section. A refrigerant inlet leading to the refrigerant inlet header portion is formed in the header tank, and one header portion on the same side as the refrigerant inlet header portion in the rear header portion row is a refrigerant outlet header portion, and a refrigerant outlet is provided in the upper header tank. A refrigerant outlet leading to the header part is formed, the other header part of both header part rows of the upper header tank is an intermediate header part, and the inside of both intermediate header parts is communicated with each other so that the front and rear of the lower header tank One intermediate header section is provided on both sides so as to straddle the two header sections of the front and rear header section rows of the upper header tank, and the rear intermediate header section of the lower header tank The above-mentioned heat exchanger 1), characterized in that a final refrigerant flow header.

  3) Each header tank is constituted by a tank forming member and a pipe connecting plate that covers a surface of the tank forming member facing the heat exchange pipe side, and the tank forming member includes the first plate, the first plate, and the pipe. The second plate interposed between the connection plate and the first plate of the tank forming member is formed with a plurality of outwardly bulging portions extending in the left-right direction and closed by the second plate. A plurality of tube insertion holes are formed in the portion corresponding to the outward bulging portion of the tube connection plate so as to penetrate in the left-right direction, and each tube of the tube connection plate is inserted into the second plate. A hole for communicating the hole into the outwardly bulging portion of the first plate is formed in a penetrating shape, and both ends of the heat exchange pipe are inserted into the pipe insertion holes of the pipe connection plates of both header tanks, and the pipe connection plate Brazed And a header portion is formed at a portion corresponding to each outward bulge portion of the first plate in the tank forming member and the pipe connection plate, and the outward bulge portion of the first plate constituting the final refrigerant circulation header portion The heat exchanger according to 1) or 2) above, further comprising a flow suppressing unit that suppresses the flow of the refrigerant to the downstream side.

  4) The cross-sectional area of the downstream part of the internal space of the part where the heat exchange pipe of the final heat exchange pipe group communicates in the outward bulging part of the first plate constituting the final refrigerant distribution header part is the crossing of the upstream part. The heat exchanger according to 3) above, which is smaller than the area.

  5) G1 represents the cross-sectional area of the downstream portion of the inner space of the portion where the heat exchange pipe of the final heat exchange tube group communicates with the outwardly expanded portion of the first plate constituting the final refrigerant distribution header portion, and When the cross-sectional area is G, the heat exchanger according to the above 4) that satisfies the relationship of G1 = 0.2G to 0.6G.

  6) The length of the portion of the final heat exchange tube group that communicates with the heat exchange tube in the outward bulge portion of the first plate constituting the final refrigerant distribution header portion is L, and the final heat exchange tube group in the outward bulge portion 4) or 5) above, where L1 is the length of the upstream portion where the cross-sectional area of the internal space of the portion through which the heat exchange pipe communicates is not small, and L1 = 0.4L to 0.7L. Heat exchanger.

  7) The internal height of the downstream part where the cross-sectional area of the internal space of the part where the heat exchange pipe of the final heat exchange pipe group communicates in the outward bulging part of the outer plate constituting the final refrigerant distribution header part is small. The heat exchanger according to any one of 4) to 6), which is lower than the internal height of the upstream portion.

  8) The internal front-rear width of the downstream portion in which the cross-sectional area of the internal space of the portion where the heat exchange pipe of the final heat exchange pipe group communicates in the outward bulging portion of the outer plate constituting the final refrigerant distribution header portion is small. The heat exchanger according to any one of the above 4) to 6), which is narrower than the inner front-rear width of the upstream portion.

  9) A supercritical refrigeration cycle equipped with a compressor, gas cooler, evaporator, decompressor, and intermediate heat exchanger that exchanges heat between the refrigerant coming out of the gas cooler and the refrigerant coming out of the evaporator, and using a supercritical refrigerant. A supercritical refrigeration cycle in which the evaporator comprises the heat exchanger according to any one of 1) to 8) above.

  According to the heat exchanger of the above 1), the flow suppressing part for suppressing the flow of the refrigerant to the downstream side is provided in the part where the heat exchange pipe of the final heat exchange pipe group in the final refrigerant circulation header part communicates. Therefore, even in the final refrigerant circulation header part, even if the refrigerant is likely to flow to the downstream end side due to inertial force, the flow rate of the refrigerant on the downstream end side of the final refrigerant circulation header part is biased by the action of the flow suppressing part. The increase can be prevented, and the amount of refrigerant flowing through all the heat exchange tubes of the final heat exchange tube group is made uniform. As a result, when used as an evaporator, the temperature of the refrigerant flowing through all the heat exchange tubes of the final heat exchange tube group is also made uniform, and the temperature of the refrigerant flowing out from the refrigerant outlet is also made uniform. Even when the expansion valve is controlled so as to achieve a predetermined degree of superheat based on the temperature of the refrigerant, it is possible to prevent the amount of refrigerant flowing through the evaporator from being reduced more than necessary, thereby preventing deterioration of the evaporator performance. Can do.

  According to the heat exchangers of 3) and 4) above, it is possible to form the flow suppressing portion in the final refrigerant circulation header portion relatively easily.

  According to the heat exchangers 5) and 6), it is possible to effectively prevent an uneven increase in the refrigerant flow rate on the downstream end side of the final refrigerant circulation header portion.

  According to the heat exchangers of the above 7) and 8), it is possible to form the flow suppressing portion in the final refrigerant circulation header portion relatively easily.

  Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the heat exchanger according to the present invention is applied to an evaporator of a supercritical refrigeration cycle.

  In the following description, the term “aluminum” includes aluminum alloys in addition to pure aluminum.

  1 to 4 show the overall configuration of an evaporator to which the present invention is applied, FIGS. 5 to 10 show the configuration of the main part of the evaporator, and FIG. 11 shows the flow of refrigerant in the evaporator of FIG.

1 to 4, an evaporator (30) of a supercritical refrigeration cycle using a supercritical refrigerant, for example, CO ₂ , is provided with two header tanks (31) (31) ( 32) and a plurality of flat heat exchange tubes (33) extending in the vertical direction and arranged in parallel with a space in the left-right direction between both header tanks (31) (32), and adjacent heat exchange tubes (33) Ventilation gap between the corrugated fins (34) disposed outside the heat exchange pipes (33) on both the left and right ends and brazed to the heat exchange pipes (33); And an aluminum bear side plate (35) brazed to the corrugated fin (34).

  As shown in FIGS. 2 to 7, the upper header tank (31) is formed from an aluminum tank forming member (36) and a brazing sheet having a brazing filler metal layer on both sides, here an aluminum brazing sheet, and tank formation. And a pipe connecting plate (37) brazed to the tank forming member (36) so as to cover the lower surface of the member (36). The tank forming member (36) is formed of a brazing sheet having a brazing filler metal layer on both sides, here an aluminum brazing sheet, and disposed on the upper side (outside), and a metal bear material, here A second plate (36B) made of aluminum bare material and interposed between the first plate (36A) and the pipe connection plate (37) and brazed to both plates (36A) (37). It is configured. In the upper header tank (31), a header section row composed of two header sections (1), (2) and (3) (4) which are formed in the left-right direction and are arranged side by side with an interval in the left-right direction. 5) (6) is provided in two rows at intervals in the front-rear direction (see FIG. 1).

  Two outward bulges (39A) (39B) (39C) extending in the left-right direction on the front and rear portions of the first plate (36A) of the tank forming member (36) of the upper header tank (31) (39D) are formed at intervals in the left-right direction. Hereinafter, in this embodiment, the outer bulging portion (39A) of the front right portion is the first outer bulging portion, the outer bulging portion (39B) of the front left portion is the second outer bulging portion, and the rear The outward bulging portion (39C) in the right side portion is referred to as a third outward bulging portion, and the outward bulging portion (39D) in the rear left portion is referred to as a fourth outward bulging portion. The length, bulge height, and width in the left-right direction of each outward bulge portion (39A) to (39D) are equal. The opening of the first plate (36A) facing the lower side of the internal space (39a) (39b) (39c) (39d) of the first to fourth outward bulges (39A) to (39D) is the second plate. It is blocked by (36B). The first plate (36A) is formed by pressing an aluminum brazing sheet having a brazing filler metal layer on both sides.

  A plurality of through-tube insertion holes (41) that are long in the front-rear direction are formed in the front-rear side portions of the pipe connection plate (37), with a space in the left-right direction. The plurality of tube insertion holes (41) on the right side of the front row are formed in the left-right direction range of the first outer bulge portion (39A) of the first plate (36A), and the plurality of tube insertion holes on the left side of the front row (41) is formed within the range in the left-right direction of the second outer bulge portion (39B), and the plurality of tube insertion holes (41) on the right side of the rear row are formed on the third outer bulge portion (39C). The plurality of tube insertion holes (41) on the left side of the rear row are formed in the left-right range, and are formed in the left-right range of the fourth outward bulge portion (39D). In addition, the length of each tube insertion hole (41) is slightly longer than the width in the front-rear direction of each outward bulge portion (39A) to (39D), and both front and rear end portions of the tube insertion hole (41) are It protrudes outward from the front and rear side edges of the side bulges (39A) to (39D) (see FIG. 3). Also, the pipe connecting plate (37) protrudes upward and downward on both side edges, and the tip reaches the outer surface of the first plate (36A), and the first plate (36A) and the second plate (36B) A covering wall (42) covering the entire boundary is formed integrally, and is brazed to both the front and rear side surfaces of the first plate (36A) and the second plate (36B). A plurality of engaging portions (43) that engage with the outer surface of the first plate (36A) are integrally formed at the protruding end of each covering wall (42) at intervals in the left-right direction. ) Is brazed. The pipe connecting plate (37) is formed by pressing an aluminum brazing sheet having a brazing filler metal layer on both sides.

  In the second plate (36B) of the tank forming member (36) of the upper header tank (31), the pipe insertion hole (41) of the pipe connecting plate (37) is connected to the outwardly bulging portion of the first plate (36A) ( The same number of penetrating communication holes (44) that lead to the internal spaces (39a) to (39d) of 39A) to (39D) are formed as the tube insertion holes (41). The communication hole (44) is slightly larger than the tube insertion hole (41). The plurality of tube insertion holes (41) on the right side of the front row of the pipe connection plate (37) are connected to the first outward expansion via the plurality of communication holes (44) on the right side of the front row of the second plate (36B). The plurality of tube insertion holes (41) on the left side of the front row are connected to the inner space (39a) of the outlet (39A), and the plurality of communication holes (44) on the right side of the front row of the second plate (36B) Through the inner space (39b) of the second outer bulge portion (39B), and the plurality of tube insertion holes (41) on the right side of the rear row are also provided on the right side of the rear row of the second plate (36B). The plurality of tube insertion holes (41) on the left side of the rear row are connected to the second plate (36B) through the communication hole (44) of the third outer bulge portion (39C). ) Through the inner space (39d) of the fourth outwardly bulging portion (39D) through a plurality of communication holes (44) in the left half of the rear side.

  All the communication holes (44) leading to the internal space (39a) of the first outward bulging portion (39A) of the first plate (36A) in the second plate (36B) of the tank forming member (36), and the third All the communication holes (44) leading to the internal space (39c) of the outward bulge part (39C) are centered in the front-rear direction between the communication holes (44) adjacent to each other in the left-right direction in the second plate (36B). The communication part (46) formed by excision makes it communicate. And the communication part (46) which makes all the communication holes (44) communicated with the internal space (39a) (39c) of the 1st and 3rd outward bulge part (39A) (39C) of a 1st plate (36A) communicate. ), And the center part in the front-rear direction of the communication hole (44) (the part corresponding to the communication part (46) in the communication hole (44)), the first plate 36A is connected to the first plate 36A by the first plate 36A. Refrigerant circulation portions (40A) and (40B) are formed which communicate with the internal spaces (39a) and (39c) of the third outwardly bulging portions (39A) and (39C) and through which the refrigerant flows in the left-right direction.

  Each communication hole (44) communicating with the internal space (39b) of the second outward bulge portion (39B) of the first plate (36A) in the second plate (36B) and the front side of the communication hole (44) In addition, each communication hole (44) communicating with the internal space (39d) of the fourth outward bulge portion (39D) is a portion between the communication holes (44) adjacent in the front-rear direction in the second plate (36B). The refrigerant turn communication portion (45) formed by cutting is communicated, whereby the internal space (39b) of the second and fourth outward bulge portions (39B) (39D) of the first plate (36A) ) (39d) The two communicate with each other. The second plate (36B) is formed by pressing an aluminum bare material.

  Two right protrusions (36a) (36b) (37a) are formed at the right ends of the three plates (36A), (36B), and (37) at intervals in the front-rear direction. The second plate (36B) is formed with a notch (47) that leads from the front ends of the two front and rear outward projections (36b) to the communication hole (44) at the right end. ) At the right end of the second plate (36B), the refrigerant inlet (40A) on the right side of the front row, and the refrigerant inlet leading to the internal space (39a) of the first outer bulge (39A) of the first plate (36A) (48) and a refrigerant outlet (40B) on the right side of the rear row of the second plate (36B) and a refrigerant outlet communicating with the internal space (39c) of the third outer bulging portion (39C) of the first plate (36A) ( 49) and are formed. The refrigerant inflow passage (52) and the refrigerant outlet (52) leading to the refrigerant inlet (48) span the two right protrusions (36a) (36b) (37a) of the three plates (36A) (36B) (37). 49) A refrigerant inlet / outlet member (51) having a refrigerant outlet passage (53) leading to 49) is brazed to the upper header tank (31) by a brazing sheet having a brazing filler metal layer on both sides, here an aluminum brazing sheet (57). Yes. The refrigerant inlet / outlet member (51) is made of a metal bare material, here an aluminum bear material.

  And the part corresponding to the 1st outward bulge part (39A) in the two plates (36A) (36B) and the pipe connection plate (37) constituting the tank forming member (36) of the upper header tank (31) As a result, the refrigerant inlet header (1) is formed, and the second outside of the two plates (36A) (36B) and the pipe connection plate (37) constituting the tank forming member (36) of the upper header tank (31). The front intermediate header portion (2) is formed by the portion corresponding to the side bulge portion (39B), and the front header row (5) is formed by the inlet header portion (1) and the front intermediate header portion (2). Has been. Further, the portions corresponding to the third outwardly bulging portion (39C) in the two plates (36A) (36B) and the pipe connecting plate (37) constituting the tank forming member (36) of the upper header tank (31) The outlet header portion (3) is formed by the fourth outer side of the two plates (36A) (36B) and the pipe connection plate (37) that also constitute the tank forming member (36) of the upper header tank (31). The rear intermediate header portion (4) is formed by the portion corresponding to the bulging portion (39D), and the rear header portion row (6) is formed by the outlet header portion (3) and the rear intermediate header portion (4). Is configured. The internal space (39a) (39c) of the first and third outward bulges (39A) (39C) of the first plate (36A) of the tank forming member (36) and the refrigerant circulation part of the second plate (36B) (40A) (40B) and the hollow portion (1A) (3A) of the inlet header portion (1) and the outlet header portion (3) that are opened downward and closed by the pipe connection plate (37). ) Is formed. Further, the internal space (39b) (39d) of the second and fourth outwardly bulging portions (39B) (39D) of the first plate (36A) of the tank forming member (36) and the second plate (36B) The intermediate hole portions (2) and (4) of the intermediate header portions (2) and (4) that are opened downward by the communication hole (44) and a part of the refrigerant turn communication portion (45) and that the opening is blocked by the pipe connection plate (37). Hollow portions (2A) (4A) are formed. The hollow portions (2A) and (4A) of both intermediate header portions (2) and (4) are communicated with each other.

  As shown in FIGS. 1 to 4 and 8, the lower header tank (32) has substantially the same configuration as the upper header tank (31), and the same components and the same parts are denoted by the same reference numerals. Both header tanks (31) and (32) are arranged so that the pipe connecting plates (37) face each other. The differences between the lower header tank (32) and the upper header tank (31) are as described below.

Two outward bulging portions (54A) (54B) extending in the left-right direction are formed in the first plate (36A) of the lower header tank (32) at intervals in the front-rear direction. Both outwardly bulging portions (54A) and (54B) are respectively a first outwardly bulging portion (39A) and a second outwardly bulging portion (39B) of the first plate (36A) of the upper header tank (31). , And the third outer bulging portion (39C) and the fourth outer bulging portion (39D), respectively, are formed from the right end portion to the left end portion of the first plate (36A). The bulging height and width of the inner space (54a) of the front outer bulging portion (54A) are determined by the outer bulging portions (39A) to (39D) of the first plate (36A) of the upper header tank (31). It is equal to the bulging height and width of the internal spaces (39a) to (39d). The width of the internal space (54b) of the rear outer bulge portion (54B) is equal to the width of the internal space (54a) of the front outer bulge portion (54A). The internal space of the front and rear outward bulging portion (54A) (54B) (54a ) (54b) is adapted to flow the CO ₂ in the lateral direction, respectively, CO ₂ is the front outward bulging portion (54A ) Flows from right to left, and flows from left to right in the inner space (54b) of the rear outward bulge portion (54B). Note that the both outwardly bulged portions (54A) and (54B) are not communicated with each other.

  A plurality of through-tube insertion holes (41) that are long in the front-rear direction are formed in the front-rear side portions of the pipe connection plate (37), with a space in the left-right direction. All the tube insertion holes (41) on the front side are formed within the lateral direction of the front outward bulge portion (54A) of the first plate (36A), and all the tube insertion holes (41) on the rear side are The rear outer bulge portion (54B) is formed within the range in the left-right direction.

  The tank forming member (36) is formed at a position corresponding to the pipe insertion hole (41) of the pipe connection plate (37) in the second plate (36B), and the pipe insertion hole (41) is formed in each outwardly bulging portion. All of the communication holes (44) communicating with the internal spaces (54a) and (54b) of (54A) and (54B) cut out portions between the communication holes (44) adjacent in the left-right direction in the second plate (36B). The communication part (46) formed by this is connected. And a communicating portion (46) for communicating all the communicating holes (44) leading to the internal spaces (54a) (54b) of the front and rear outwardly bulging portions (54A) (54B) of the first plate (36A), and The front and rear center of the communication hole (44) (the part corresponding to the communication part (46) in the communication hole (44)) causes the second plate (36B) to bulge both the front and rear sides of the first plate (36A). Refrigerant circulation portions (55A) and (55B) are formed which communicate with the internal spaces (54a) and (54b) of the portions (54A) and (54B) and through which the refrigerant flows in the left-right direction.

  Note that the refrigerant inlet (48) and the refrigerant outlet (49) are not formed in the lower header tank (32).

  The two plates (36A) (36B) and the pipe connecting plate (37) constituting the tank forming member (36) of the lower header tank (31) and the front and rear outer bulge portions (54A) (54B) Two corresponding intermediate header portions (7) and (8) are formed by the corresponding portions. The internal space (54a) (54b) of the front and rear outwardly bulging portions (54A) (54B) of the first plate (36A) of the tank forming member (36) and the refrigerant circulation portion (55A) of the second plate (36B) (55B) and the hollow portions (7A) (8A) of both intermediate header portions (7) (8) are formed which open upward and are closed by the pipe connection plate (37). . Here, the rear intermediate header portion (8) of the lower header tank (32) is a final refrigerant distribution header portion in which the refrigerant flows from the left to the right.

  The heat exchange pipe (33) is made of a bare metal material, here an aluminum extruded shape, and has a flat shape that is wide in the front-rear direction, and a plurality of refrigerant passages (33a) that extend in the length direction are arranged in parallel in the heat exchange pipe (33). The cross-sectional areas of the heat exchange tubes are equal. Both ends of the heat exchange pipe (33) are inserted into the pipe insertion holes (41) of the header tanks (31) and (32), respectively, using the brazing material layer of the pipe connection plate (37). It is brazed to the pipe connection plate (37). Both ends of the heat exchange pipe (33) enter the communication hole (44) up to the middle part in the thickness direction of the second plate (36B).

  The total number of heat exchange pipes (33) is the same as the number of header sections (5) and (6) of the upper header tank (31) consisting of a plurality of heat exchange pipes (33) arranged in parallel in the left-right direction. That is, it is divided into two heat exchange tube rows (10) and (11). The upper and lower ends of the plurality of heat exchange tubes (33) located in the right half of the front heat exchange tube row (10) are in the hollow portion (1A) of the inlet header portion (1) of the upper header tank (31) and Connected to both header tanks (31) and (32) so as to communicate with the right side in the hollow portion (7A) of the front intermediate header portion (7) of the lower header tank (32) The upper and lower ends of the heat exchange pipe (33) are inside the hollow part (2A) of the front intermediate header part (2) of the front header part row (5) of the upper header tank (31) and the front side of the lower header tank (32). It is connected to both header tanks (31) and (32) so as to communicate with the left side portion in the hollow portion (7A) of the intermediate header portion (7). The upper and lower ends of the plurality of heat exchange tubes (33) located in the right half of the rear heat exchange tube row (11) are hollow portions (3A) of the outlet header portion (3) of the upper header tank (31). ) It is connected to both header tanks (31) and (32) so that it leads to the right side in the hollow part (8A) of the rear middle header part (8) in the inner and lower header tanks (32). The upper and lower ends of the plurality of heat exchange pipes (33) positioned in the hollow part (4A) of the left intermediate header part (4) of the rear header part row (6) of the upper header tank (31) and the lower header tank (32) The rear intermediate header portion (8) is connected to both header tanks (31) and (32) so as to communicate with the left side portion in the hollow portion (8A).

  And the heat exchange pipe (33) leading to the hollow part (1A) of the inlet header part (1) of the upper header tank (31) and the hollow part (7A) of the front intermediate header part (7) of the lower header tank (32) And the hollow portion (4A) of the intermediate header portion (4) of the rear header portion row (6) of the upper header tank (31) and the hollow portion of the rear intermediate header portion (8) of the lower header tank (32) ( A first heat exchange tube group (12) in which the refrigerant flows from top to bottom is formed by the heat exchange tube (33) leading to 8A). Further, the heat exchange pipe (33A) communicating with the hollow portion (3A) of the outlet header portion (3) of the upper header tank (31) and the hollow portion (8A) of the rear intermediate header portion (8) of the lower header tank (32). ), And the hollow portion (2A) of the intermediate header portion (2) of the front header portion row (5) of the upper header tank (31) and the hollow portion (7A of the front intermediate header portion (7) of the lower header tank (32) ) To form a second heat exchange tube group (13) through which the refrigerant flows from the bottom to the top. Accordingly, the first heat exchange tube group (12) and the second heat exchange tube group (13) are provided side by side in the left-right direction in each of the heat exchange tube rows (10), (11), and the refrigerant outlet header portion. A plurality of heat exchange pipes (33) communicating with (3) and the right side portion of the rear intermediate header section (8), that is, the second heat exchange pipe group (13) of the rear heat exchange pipe row (11) is a refrigerant. Is the final heat exchange tube group that flows from bottom to top.

  The heat exchange pipe (33) was formed by rolling an aluminum brazing sheet having a brazing filler metal layer on both sides, instead of one made of an aluminum extruded profile, and continued through a connecting portion. Two flat wall forming portions, a side wall forming portion integrally formed in a raised shape from the side edge on the opposite side of the connecting portion in each flat wall forming portion, and a predetermined interval in the width direction of the flat wall forming portion. A plate having a plurality of partition wall forming portions integrally formed in a protruding shape from the flat wall forming portion is bent into a hairpin shape at the connecting portion, and the side wall forming portions are butted against each other to form a partition wall. You may use what formed the partition wall by the part.

  Here, in the internal space (54b) of the outward bulging portion (54B) of the first plate (36A) constituting the rear intermediate header portion (8) (final refrigerant circulation header portion) of the lower header tank (32). The internal height (H1) of the downstream part (541b) of the final part (540b) through which the second heat exchange pipe group (13) (final heat exchange pipe group) communicates is the interior of the upstream part (542b). It is lower than the height (H2) (see FIGS. 3 and 4). Therefore, since the width in the front-rear direction of the rear outer bulge portion (54B) is the same over the entire length, the downstream portion in the final portion (540b) of the internal space (54b) of the rear outer bulge portion (54B) The cross-sectional area of (541b) is smaller than the cross-sectional area of the upstream portion (542b), the cross-sectional area of the downstream portion (541b) is G1, and the cross-sectional area of the upstream portion (542b) is G It is preferable that the relationship of G1 = 0.2G to 0.6G is satisfied. When the length of the final part (540b) of the internal space (54b) of the rear outward bulge part (54B) is L and the length of the upstream part (542b) is L1, L1 = 0.4L It is preferable to satisfy the relationship of -0.7L (refer FIG. 2). The internal height (H2) of the upstream portion (542b) of the final portion (540b) in the internal space (54b) of the outward bulge portion (54B) is the internal space of the outward bulge portion (54B) ( It is equal to the internal height of the left side portion through which the first heat exchange tube group (12) in 54b) communicates.

  Then, the cross-sectional area of the downstream portion (541b) in the final portion (540b) of the internal space (54b) of the rear outer bulge portion (54B) is smaller than the cross-sectional area of the upstream portion (542b). Therefore, the cross-sectional area of the portion corresponding to the downstream portion (541b) in the hollow portion (8A) of the rear intermediate header portion (8) is larger than the cross-sectional area of the portion corresponding to the upstream portion (542b). As a result, the refrigerant flow suppressing portion (14) is formed.

  The corrugated fin (34) is formed in a wave shape using an aluminum brazing sheet having a brazing filler metal layer on both sides, and a plurality of the corrugated fins (34) are connected in parallel in the front-rear direction to the connecting portion connecting the wave head and the wave bottom. A louver is formed. The corrugated fin (34) is shared by both the front and rear heat exchange tube rows (10) and (11), and the width in the front and rear direction is the front edge and the rear edge of the heat exchange tube (33) of the front heat exchange tube row (10). The distance between the side heat exchange tube row (11) and the rear edge of the heat exchange tube (33) is substantially equal. In addition, instead of sharing one corrugated fin (34) with both the front and rear heat exchange tube rows (10) and (11), the adjacent heat exchange tubes (33) between the heat exchange tube rows (10) and (11) are connected to each other. Corrugated fins may be arranged between the two.

  Both header tanks (31) and (32) are manufactured as shown in FIGS.

  First, an aluminum brazing sheet having a brazing filler metal layer on both sides is pressed to form a first plate (36A) having outward bulges (39A) (39B) (39C) (39D) (54A) (54B). ). The internal height of the inner space (54b) of the rear outward bulge (54B) of the first plate (36A) of the lower header tank (32) is the same in the downstream portion (541b) of the final portion (540b). It should be lower than the upstream portion (542b). Further, by pressing the aluminum bear material, the second plate (36B) having the communication hole (44), the communication part (45) (46), and the refrigerant circulation part (40A) (40B) (55A) (55B). ). Furthermore, by pressing the aluminum brazing sheet having the brazing filler metal layer on both sides, the engaging portion forming protrusion piece straightly connected to the tube insertion hole (41), the covering wall (42) and the covering wall (42). A pipe connecting plate (37) having (43A) is formed. The first plate (36A), the second plate (36B) and the pipe connection plate (37) of the upper header tank (31) are respectively provided with rightward protruding portions (36a) (36b) (37a), and A notch (47) is formed in the second plate (36B).

  Next, after the three plates (36A), (36B), and (37) are combined in a laminated form, the protruding piece (43A) is bent to form the engaging portion (43), and the engaging portion (43) is the first plate. Engage with (36A) to make a temporary fix. Thereafter, the three plates (36A) (36B) (37) are brazed to each other using the brazing material layer of the first plate (36A) and the brazing material layer of the pipe connecting plate (37), and the covering wall (42) is brazed to the front and rear side surfaces of the second plate (36B) and the first plate (36A), and the engaging portion (43) is brazed to the first plate (36A). Thus, both header tanks (31) and (32) are manufactured.

  The evaporator (30) is prepared by preparing the above-mentioned two temporary fixing bodies when manufacturing the header tanks (31) and (32), a plurality of heat exchange pipes (33) and corrugated fins (34), Temporary fixing bodies are arranged at intervals so that the pipe connection plates (37) face each other, multiple heat exchange pipes (33) and corrugated fins (34) are arranged alternately, heat exchange Insert both ends of the pipe (33) into the pipe insertion holes (41) of the pipe connection plates (37) of both temporary fixing bodies, and attach the side plates (35) to the outside of the corrugated fins (34) at both ends. Arranging the refrigerant inlet / outlet member (51) through the brazing sheet (57) so as to straddle the three plates (36A) (36B) (37), and the three plates (36A ) (36B) (37) are brazed together to form the header tank (31) (32), and at the same time, the heat exchange pipe (33) is attached to the header tank (31) (32). The fins (34) heat exchange tubes (33) and the side plates (35) fin (34), are prepared by respectively brazed to the upper header tank (31) to and out member (51).

  The evaporator (30) constitutes a supercritical refrigeration cycle together with an intermediate heat exchanger for exchanging heat between the refrigerant coming out of the compressor, the gas cooler, the decompressor and the gas cooler and the refrigerant coming out of the evaporator. For example, it is installed in a car.

In the above-described evaporator (30), as shown in FIG. 11, the liquid-phase CO ₂ decompressed through the expansion valve as the decompressor passes through the refrigerant inflow passage (52) of the inlet / outlet member (51). The refrigerant enters the hollow part (1A) of the inlet header part (1) of the upper header tank (31) from the refrigerant inlet (48), and flows into the left side to divide the inside of the front header heat exchange pipe line (10). It flows into the refrigerant passage (33a) of the heat exchange pipe (33) of the first heat exchange pipe group (12).

The CO ₂ flowing into the refrigerant passage (33a) of the heat exchange pipe (33) of the first heat exchange pipe group (12) of the front heat exchange pipe row (10) flows downward in the refrigerant passage (33a). The right part in the hollow part (7A) of the front intermediate header part (7) of the lower header tank (32) flows in, flows to the left inside, and divides the second heat of the front heat exchange pipe row (10). It flows into the refrigerant passage (33a) of the heat exchange pipe (33) of the exchange pipe group (13).

The CO ₂ flowing into the refrigerant passage (33a) of the heat exchange pipe (33) of the second heat exchange pipe group (13) of the front heat exchange pipe row (10) changes its flow direction and enters the refrigerant passage (33a). And flows into the hollow portion (2A) of the intermediate header portion (2) of the front header portion row (5) of the upper header tank (31), and the refrigerant turn communicating portion (45) of the second plate (36B) ) And enters the hollow portion (4A) of the intermediate header portion (4) of the rear header portion row (6). The CO ₂ flowing into the hollow portion (4A) of the intermediate header portion (4) of the rear header portion row (6) is the heat of the first heat exchange tube group (12) of the rear heat exchange tube row (11). The hollow portion of the rear intermediate header portion (8) of the lower header tank (32) flows into the refrigerant passage (33a) of the exchange pipe (33) and flows downward in the refrigerant passage (33a) by changing the flow direction. (8A) flows into the left part of the inside, flows to the right inside, and divides the refrigerant in the heat exchange pipe (33) of the second heat exchange pipe group (13) of the rear heat exchange pipe row (11). It flows into the passage (33a).

The CO ₂ flowing into the refrigerant passage (33a) of the heat exchange pipe (33) of the final second heat exchange pipe group (13) of the rear heat exchange pipe row (11) changes its flow direction to change the refrigerant path ( 33a) flows upward in the hollow portion (3A) of the outlet header portion (3) of the upper header tank (31), flows to the right in the inside thereof, and enters the refrigerant outlet (49) and the inlet / outlet member (51). It flows out through the refrigerant outflow passage (53). While CO ₂ flows in the refrigerant passage (33a) of the heat exchange pipe (33), heat exchange is performed between the air flowing in the direction indicated by the arrow X in FIGS. 1 and 11 to form a gas phase. Leaked.

At this time, in the hollow portion (8A) of the rear intermediate header portion (8) of the lower header tank (32), CO ₂ tends to flow rightward (downstream end side in the refrigerant flow direction) due to inertial force. Therefore, it is easy to flow into the refrigerant passage (33a) of the heat exchange pipe (33) on the right end side. However, due to the action of the flow restricting section (14), it is possible to prevent an uneven increase in the refrigerant flow rate on the downstream end side of the rear intermediate header section (8), and the final second heat exchange pipe group (13). The amount of refrigerant flowing through the total heat exchange pipe (33) is made uniform. As a result, the temperature of the refrigerant flowing through the total heat exchange pipe (33) of the final second heat exchange pipe group (13) of the evaporator (30) is also made uniform, and the temperature of the refrigerant flowing out from the refrigerant outlet (49) is also reduced. Even when the expansion valve is controlled so as to achieve a predetermined degree of superheat based on the temperature of the refrigerant that has flowed out, the amount of refrigerant flowing to the evaporator (30) is reduced more than necessary. This can suppress the deterioration of the performance of the evaporator (30).

  In the above embodiment, the inner space (54B) of the outer bulging portion (54B) of the first plate (36A) constituting the rear intermediate header portion (8) (final refrigerant circulation header portion) of the lower header tank (32) ( 54b), the internal height (H1) of the downstream part (541b) of the final part (540b) through which the second heat exchange pipe group (13) (final heat exchange pipe group) communicates is defined as the upstream part (542b ) Lower than the internal height (H2) of the rear side outward bulge portion (54B), the cross-sectional area of the downstream portion (541b) in the final portion (540b) of the internal space (54b) of the rear outward bulge portion (54B) Although it is smaller than the cross-sectional area of the side portion (542b), instead of this, as shown in FIG. 12, the rear intermediate header portion (8) (final refrigerant distribution header portion) of the lower header tank (32) The final portion (540b) through which the second heat exchange tube group (13) (final heat exchange tube group) communicates in the internal space (54b) of the outward bulge portion (54B) of the first plate (36A) constituting Front / rear width (W1) of downstream part (541b) The downstream portion (541b) in the final portion (540b) of the internal space (54b) of the rear outward bulge portion (54B) is made narrower than the front-rear width (not shown) of the upstream portion (542b). ) May be smaller than the cross-sectional area of the upstream portion (542b). In the inner space (54b) of the outward bulge portion (54B) of the first plate (36A), the second heat exchange pipe group (13) (final heat exchange pipe group) communicates with the final portion (540b). The front-rear width of the upstream portion (542b) is the front-rear width of the portion communicating with the first heat exchange tube group (12) in the inner space (54b) of the rear outer bulge portion (54B), and the front outer portion It is equal to the front-rear width of the internal space (54a) of the bulging portion (54A). Further, the second heat exchange tube group (13 in the inner space (54b) of the outward bulge portion (54B) of the first plate (36A) constituting the rear intermediate header portion (8) (final refrigerant circulation header portion). ) (Final heat exchange tube group), the internal height (H1) of the downstream portion (541b) of the final portion (540b) is equal to the internal height (H2) of the upstream portion (542b).

  In the above embodiment, the number of the second plates (36B) of the tank forming member (36) is 1, but the number is not limited to this, and the first plate (36A), the pipe connecting plate (37), A plurality of second plates (36B) may be interposed between the two plates. In this case, a communication hole (44), a communication part (45) (46), etc. are formed in each 2nd plate (36B).

  Moreover, in the said embodiment, although the heat exchanger by this invention is applied to the evaporator of a supercritical refrigeration cycle, it is not restricted to this, The heat exchanger by this invention is provided for another use. Sometimes.

Furthermore, in the above embodiment, CO ₂ is used as the supercritical refrigerant in the supercritical refrigeration cycle, but is not limited to this, and ethylene, ethane, nitric oxide, or the like is used.

It is a perspective view which shows the whole structure of the evaporator to which the heat exchanger by this invention is applied. FIG. 2 is a partially omitted vertical sectional view of the rear portion of the evaporator of FIG. It is an AA line expanded sectional view of FIG. FIG. 3 is an enlarged sectional view taken along line B-B in FIG. 2. FIG. 3 is an enlarged sectional view taken along the line CC in FIG. 2. It is the DD sectional view taken on the line of FIG. It is a disassembled perspective view which shows the right end part of the upper header tank in the evaporator of FIG. It is the EE sectional view taken on the line of FIG. It is a disassembled perspective view which shows the part of the upper header tank of the evaporator of FIG. It is a disassembled perspective view which shows the part of the lower header tank of the evaporator of FIG. It is a figure which shows the flow of the refrigerant | coolant in the evaporator of FIG. It is sectional drawing equivalent to the lower part of FIG. 3 which shows the last refrigerant | coolant distribution | circulation header part of an evaporator.

Explanation of symbols

(1): Refrigerant inlet header
(1A): Hollow part
(2): Intermediate header
(2A): Hollow part
(3): Refrigerant outlet header
(3A): Hollow part
(4): Intermediate header
(4A): Hollow part
(5): Front header row
(6): Rear header column
(7) (8): Intermediate header
(7A) (8A): Hollow part
(10): Front heat exchange tube row
(11): Rear heat exchange tube row
(12): First heat exchange tube group
(13): Second heat exchange tube group
(14): Flow control part
(30): Evaporator (heat exchanger)
(31) (32): Header tank
(33): Heat exchange pipe
(36): Tank forming member
(36A): 1st plate
(36B): Second plate
(37): Pipe connection plate
(39A) to (39D): outward bulge
(39a) to (39d): Internal space
(41): Tube insertion hole
(44): Communication hole
(48): Refrigerant inlet
(49): Refrigerant outlet
(54A) (54B): Outward bulge
(54a) (54b): Interior space
(540b): Final part
(541b): Downstream part
(542b): Upstream part

Claims (9)

A pair of header tanks extending in the left-right direction spaced apart in the vertical direction, and a plurality of heat exchange tubes arranged in parallel between the header tanks and having upper and lower ends connected to the header tanks, respectively The upper header tank is provided with a plurality of header portions arranged in the left-right direction at intervals in the front-rear direction. The header portion at one end of the row header portion row is used as a refrigerant outlet header portion, and a refrigerant outlet is formed in the upper header tank so as to communicate with the refrigerant outlet header portion, and each header portion of the upper header tank in the lower header tank At a position corresponding to the row, a header portion that is one less than the number of header portions constituting each header portion row of the upper header tank is connected to two adjacent header portions of each header portion row of the upper header tank. Between the upper and lower header tanks, consisting of a plurality of heat exchange tubes arranged in the left-right direction, and the same number of heat-exchange tube rows as the header portion rows of the upper header tank are arranged in the front-rear direction And both end portions of the heat exchange pipe are connected to the upper and lower header tanks so as to communicate with the header portion, and the header portion extending over the refrigerant outlet header portion of the upper header tank in the lower header tank and the header portion adjacent thereto is a refrigerant. Is the final refrigerant flow header portion that flows in the left-right direction, and the final heat is composed of a plurality of heat exchange tubes in which the refrigerant flows from the bottom to the top between the refrigerant outlet header portion and the downstream portion of the final refrigerant flow header portion. In the heat exchanger provided with the exchange tube group,
The heat exchanger by which the flow suppression part which suppresses the flow to the downstream of a refrigerant | coolant is provided in the part which the heat exchange pipe | tube of the final heat exchange pipe group in the last refrigerant | coolant distribution | circulation header part leads. The upper header tank is provided with two front and rear header sections each including two header sections arranged in the left-right direction, and one header section of the front header section is a refrigerant inlet header section. A refrigerant inlet leading to the refrigerant inlet header portion is formed, and one header portion on the same side as the refrigerant inlet header portion in the rear header portion row is a refrigerant outlet header portion, and the refrigerant outlet header portion is formed in the upper header tank. The other header part of both header part rows of the upper header tank is an intermediate header part, and the inside of both intermediate header parts is communicated with each other on both the front and rear sides of the lower header tank. , One intermediate header portion is provided so as to straddle the two header portions of the front and rear header portion rows of the upper header tank, and the rear intermediate header portion of the lower header tank is The heat exchanger of claim 1 wherein a final refrigerant flow header. Each header tank is constituted by a tank forming member and a pipe connecting plate that covers a surface of the tank forming member facing the heat exchange pipe, and the tank forming member is used for connecting the first plate and the first plate to the pipe. A second plate interposed between the plate and the first plate of the tank forming member is formed with a plurality of outward bulges extending in the left-right direction and closed by the second plate, A plurality of tube insertion holes are formed in the portion corresponding to the outward bulging portion of the tube connection plate in a penetrating manner with a space in the left-right direction, and each tube insertion hole of the tube connection plate is formed in the second plate. A communication hole communicating with the outer bulging portion of the first plate is formed in a penetrating manner, and both end portions of the heat exchange pipe are inserted into the pipe insertion holes of the pipe connection plates of both header tanks to be connected to the pipe connection plate. Attached And a header portion is formed at a portion of the tank forming member and the pipe connection plate corresponding to each of the outward bulge portions of the first plate, and the outer bulge portion of the first plate constituting the final refrigerant circulation header portion. The heat exchanger according to claim 1, further comprising a flow suppressing unit that suppresses a flow of the refrigerant to the downstream side. The cross-sectional area of the downstream part of the internal space of the part where the heat exchange pipe of the final heat exchange pipe group communicates in the outward bulging part of the first plate constituting the final refrigerant distribution header part is greater than the cross-sectional area of the upstream part. The heat exchanger according to claim 3, which is also smaller. G1 is the cross-sectional area of the downstream portion of the internal space of the portion where the heat exchange pipe of the final heat exchange pipe group communicates in the outward bulging portion of the first plate constituting the final refrigerant distribution header, and the cross-sectional area of the upstream portion The heat exchanger according to claim 4, wherein G1 satisfies a relationship of G1 = 0.2G to 0.6G. The length of the portion of the final heat exchange tube group communicating with the heat exchange pipe in the outward bulge portion of the first plate constituting the final refrigerant distribution header portion is L, and the heat of the final heat exchange tube group in the outward bulge portion The heat exchange according to claim 4 or 5, wherein when the length of the upstream portion where the cross-sectional area of the internal space of the portion where the exchange pipe communicates is not small is L1, the relationship of L1 = 0.4L to 0.7L is satisfied. vessel. The internal height of the downstream part where the cross-sectional area of the internal space of the part where the heat exchange pipe of the final heat exchange pipe group communicates in the outward bulging part of the first plate constituting the final refrigerant distribution header part is small, The heat exchanger according to any one of claims 4 to 6, wherein the heat exchanger is lower than the internal height of the upstream portion. The internal front-rear width of the downstream portion where the cross-sectional area of the internal space of the portion where the heat exchange pipe of the final heat exchange pipe group communicates in the outward bulging portion of the first plate constituting the final refrigerant circulation header portion is reduced, The heat exchanger according to any one of claims 4 to 6, wherein the heat exchanger is narrower than an inner front-rear width of the upstream portion. A supercritical refrigeration cycle comprising a compressor, a gas cooler, an evaporator, a decompressor and an intermediate heat exchanger for exchanging heat between the refrigerant coming out of the gas cooler and the refrigerant coming out of the evaporator, and using a supercritical refrigerant A supercritical refrigeration cycle in which the evaporator comprises the heat exchanger according to any one of claims 1 to 8.

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