JP2011257111A - Evaporator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporator which can enhance performance and equalize temperature distribution.SOLUTION: The evaporator 1 includes a leeward tube row 11 including first to third tube groups, and a windward tube row 12 including fourth and fifth tube groups. The first rube group is defined as a first path 15, the second tube group is defined as a second path 16, the third and fourth tube groups are defined as a third path 17, and the fifth tube group is defined as a fourth path 18. The total channel sectional area of refrigerant channels of heat exchanger tubes 9 constituting the second and third paths 16, 17 is controlled to be equal to or larger than the total channel sectional area of refrigerant channels of heat exchanger tubes 9 constituting the paths 15, 16, which are located immediately upstream of the respective paths. The total channel sectional area of the refrigerant channels of heat exchange tubes 9 constituting the fourth path 18 is controlled to be larger than the total channel sectional area of the refrigerant channels of heat exchange tubes 9 constituting the third path 17.

Description

  The present invention relates to a heat exchanger that is suitably used for an evaporator of a car air conditioner that is a refrigeration cycle mounted on an automobile, for example.

  In this specification and claims, the top and bottom of FIGS. 2 and 3 are referred to as top and bottom.

  As this type of evaporator, two rows of tubes, each of which is composed of a plurality of heat exchange tubes arranged in the vertical direction and at intervals in a direction perpendicular to the ventilation direction, are provided side by side in the ventilation direction. The first to third tube groups composed of a plurality of heat exchange tubes are provided in the side tube row side by side from one end side to the other end side of the leeward tube row, and a plurality of heat is supplied to the windward tube row. A fourth and fifth tube group consisting of exchange tubes are provided side by side from the other end side of the windward tube row toward the one end side, and the first tube group is arranged so that the refrigerant passes through the heat exchange tube from above. The first pass flows down, the second tube group becomes the second pass through which the refrigerant flows from the bottom through the heat exchange tube, and the third and fourth tube groups pass through the heat exchange tube from the top to the bottom. The third path flows, the fifth tube group is a fourth path in which the refrigerant flows from the bottom to the top in the heat exchange tube, and the total passage cross-sectional area of the refrigerant path of the heat exchange tube constituting the fourth path is , The total passage cross-sectional area of the refrigerant passage of the heat exchange tube constituting the third path, the total passage cross-sectional area of the refrigerant passage of the heat exchange tube of the third tube group on the leeward side constituting the third path, and a third The total passage sectional area of the refrigerant passages of the heat exchange tubes of the third and fourth tube groups is equal to the total passage sectional area of the refrigerant passages of the heat exchange tubes of the fourth tube group on the windward side constituting the path. Are equal to the total passage cross-sectional area of the refrigerant passage of the heat exchange tube constituting the second path, and the upper and lower end portions of the heat exchange tubes of the leeward side and the windward side tube row are respectively the leeward side and the windward side upper and lower header portions. A first section through which the heat exchange tube of the first tube group communicates, and a second section through which the heat exchange tubes of the second and third tube groups communicate, are provided in the upper header part on the leeward side, The lower header section on the leeward side is provided with a third section through which the heat exchange tubes of the first and second tube groups communicate and a fourth section through which the heat exchange tube of the third tube group communicates, and the upper header section on the leeward side Are provided with a fifth section through which the heat exchange tube of the fourth tube group communicates and a sixth section through which the heat exchange tube of the fifth tube group communicates, and heat exchange of the fourth tube group at the lower header portion on the windward side A seventh compartment through which the tube communicates and an eighth compartment through which the heat exchange tube of the fifth tube group communicates are provided, a refrigerant inlet is provided in the first compartment, and a refrigerant outlet is provided in the sixth compartment. And 5th section, 4th section And the seventh compartment, and the seventh compartment and the eighth compartment are communicated with each other, and the refrigerant flowing into the first compartment from the refrigerant inlet is the second compartment, the fifth compartment, the seventh compartment, and the eighth compartment. An evaporator is known that flows into the sixth section through the section and flows out from the refrigerant outlet (see Patent Document 1).

  In the evaporator described in Patent Document 1, it is possible to suppress an increase in passage resistance in the fourth pass having the superheat region.

  However, in the evaporator described in Patent Document 1, although the increase in the passage resistance of the fourth pass can be suppressed, the total passage cross-sectional area of the refrigerant passage of the heat exchange tubes constituting the first pass and the second pass is reversed. Therefore, there is a problem that the passage resistance is increased and offset.

JP 2009-156532 A

  An object of the present invention is to provide an evaporator capable of solving the above-described problems, improving the performance by suppressing an increase in the overall passage resistance, and making the temperature distribution uniform.

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

1) There are two rows of tubes that consist of a plurality of heat exchange tubes that extend in the vertical direction and are spaced apart in a direction perpendicular to the ventilation direction. The first to third tube groups including a plurality of heat exchange tubes are provided side by side from one end side to the other end side of the leeward side tube row, and the plurality of heat exchange tubes are provided on the leeward side tube row. The fourth and fifth tube groups are provided side by side from the other end side of the windward tube row toward the one end side, and the first tube group is configured such that the refrigerant passes through the heat exchange tube from above or below. The second tube group becomes a second path in which the refrigerant flows in the direction opposite to the first path in the heat exchange tube, and the third and fourth tube groups serve as the heat exchange tube. Inside the first pass Becomes third path flowing in the same direction, the fifth tube group, the evaporator refrigerant from the first pass through the heat exchange tubes has a fourth path flows in the opposite direction,
The total passage cross-sectional area of the refrigerant passage of the heat exchange tube constituting the second and third paths is equal to or greater than the total passage cross-sectional area of the refrigerant passage of the heat exchange tube constituting the previous path, and the fourth path An evaporator in which the total passage cross-sectional area of the refrigerant passage of the heat exchange tube constituting the heat exchanger tube is larger than the total passage cross-sectional area of the refrigerant passage of the heat exchange tube constituting the third path.

  2) The total passage sectional area of the refrigerant passage of the heat exchange tube constituting the fourth path is 60% or more of the total passage sectional area of the refrigerant passage of the heat exchange tube of the fourth tube group constituting a part of the third path. The evaporator according to 1) above.

  3) The total cross-sectional area of the refrigerant passage of the heat exchange tube of the third tube group on the leeward side constituting the third path and the refrigerant passage of the heat exchange tube of the fourth tube group on the windward side constituting the third path The total passage cross-sectional area is equal, and the total passage sectional area of the refrigerant passages of the heat exchange tubes of the third and fourth tube groups is the total passage sectional area of the refrigerant passages of the heat exchange tubes constituting the second path, respectively. The evaporator according to 1) or 2), which is smaller than the above.

  4) The total passage sectional area of the refrigerant passages of the heat exchange tubes constituting the second and third paths is larger than the total passage sectional area of the refrigerant passages of the heat exchange tubes constituting the previous path, respectively. The evaporator according to any one of 1) to 3) above.

  5) The total heat exchange tubes have the same configuration, and the number of refrigerant passages in each heat exchange tube and the total of the cross-sectional areas of the plurality of refrigerant passages in each heat exchange tube are the same, constituting each path By adjusting the number of heat exchange tubes to be performed, the total passage sectional area of the refrigerant passages of the total heat exchange tubes constituting the first to fourth paths is determined, and the third tube group and the fourth group constituting the third path are determined. The evaporator according to any one of 1) to 4), wherein the number of heat exchange tubes in the heat exchange tube group is the same.

6) The upper and lower ends of the heat exchange tubes in the leeward and upper winder tube rows are respectively connected to the leeward and upper winder upper and lower header parts,
The first section where the heat exchange tube of the first tube group communicates with the header portion on the upstream side in the flow direction of the refrigerant of the first pass among the upper and lower header portions on the leeward side, and the heat exchange tubes of the second and third tube groups. A second compartment leading to it,
The third section where the heat exchange tubes of the first and second tube groups communicate with the header portion on the downstream side in the flow direction of the refrigerant in the first pass among the upper and lower header portions on the leeward side, and the heat exchange tubes of the third tube group. And a fourth section that leads to
The fifth section where the heat exchange tube of the fourth tube group communicates with the header section on the upstream side in the flow direction of the refrigerant in the first pass among the upper and lower header sections, and the sixth section where the heat exchange tube of the fifth tube group communicates. Compartments,
The seventh section where the heat exchange tube of the fourth tube group communicates with the header section on the downstream side in the flow direction of the refrigerant in the first path among the upper and lower header sections, and the eighth section where the heat exchange tube of the fifth tube group communicates. Compartments,
A refrigerant inlet is provided in the first compartment, a refrigerant outlet is provided in the sixth compartment, and the second compartment and the fifth compartment, the fourth compartment and the seventh compartment, and the seventh compartment and the eighth compartment are communicated with each other. And
The refrigerant that has flowed into the first compartment from the refrigerant inlet flows into the second compartment through the third compartment, and then flows into the seventh compartment from the second compartment through the fourth compartment, and from the second compartment to the fifth compartment. In any one of the above-mentioned 1) to 5), which flows into the seventh section through the seventh section, flows into the sixth section from the seventh section through the eighth section, and flows out from the refrigerant outlet. Evaporator.

  7) The 8th section is provided with a flow dividing member that divides the inside of the 8th section into a first space on the heat exchange tube side and a second space on the opposite side of the heat exchange tube, and a refrigerant passage hole is formed in the flow distribution member. The evaporator according to 6) above.

  8) The evaporator according to 7) above, wherein a flow promoting member for promoting the flow of the refrigerant from the seventh compartment to the second space of the eighth compartment is provided in the header portion provided with the seventh compartment and the eighth compartment. .

  9) The header portion on the upstream side in the flow direction of the first path and the header portion on the downstream side in the flow direction are provided in any one of the above 1) to 8) so that the former is positioned above The evaporator.

  According to the evaporators 1) to 9) described above, the total passage cross-sectional area of the refrigerant passages of the heat exchange tubes constituting the second and third paths is the same as that of the refrigerant passages of the heat exchange tubes constituting the previous path. The total passage sectional area of the refrigerant passage of the heat exchange tube constituting the fourth path is larger than the total passage sectional area of the refrigerant passage of the heat exchange tube constituting the third path. Therefore, even if the gas-liquid mixed phase refrigerant that has flowed into the evaporator sequentially flows through the first to fourth paths and the liquid phase component of the refrigerant evaporates and the specific volume increases, the passage resistance in the second to fourth paths Can be suppressed. In addition, when the gas-liquid mixed phase refrigerant that has flowed into the evaporator sequentially flows through the first to fourth paths, an increase in the passage resistance of the fourth path in which there is a superheat region and a large amount of gas-phase refrigerant flows can be suppressed. The performance of the evaporator can be improved.

  According to the evaporator of the above 3), the total cross-sectional area of the refrigerant passage of the heat exchange tube of the third tube group on the leeward side constituting the third path, and the fourth tube group on the windward side constituting the third path The total passage cross-sectional area of the refrigerant passage of the heat exchange tube is equal, and the total passage cross-sectional area of the refrigerant passage of the heat exchange tube of the third and fourth tube groups is the heat exchange tube of the second path, respectively. Since the total passage cross-sectional area of the refrigerant passage is smaller than the total passage cross-sectional area of the refrigerant passage of the heat exchange tube constituting the second pass, the flow distribution to the three-pass heat exchange tube is made uniform Can be achieved.

  According to the evaporator of 4) above, the total passage cross-sectional area of the refrigerant passages of the heat exchange tubes constituting the second and third passes is the total passage breakage of the refrigerant passages of the heat exchange tubes constituting the previous pass, respectively. Since the gas-liquid mixed phase refrigerant that has flowed into the evaporator sequentially flows through the first to fourth paths and the evaporation of the liquid phase component of the refrigerant proceeds and the specific volume is increased. An increase in passage resistance in four passes can be effectively suppressed.

  According to the evaporator of the above 5), the total passage cross-sectional area of the refrigerant passages of the heat exchange tubes constituting the second and third paths can be relatively easily compared with the refrigerant of the heat exchange tubes constituting the previous path. The total passage sectional area of the refrigerant passage of the heat exchange tube constituting the fourth path is larger than the total passage sectional area of the refrigerant passage of the heat exchange tube constituting the third path. can do. Moreover, the total passage cross-sectional area of the refrigerant passage of the heat exchange tube of the fifth tube group that constitutes the entire fourth path is relatively easily calculated from the heat exchange tube of the fourth tube group that constitutes a part of the third path. It can be 60% or more of the total passage sectional area of the refrigerant passage. In addition, the types of parts can be reduced.

  According to the evaporator of the above 7), it is possible to make uniform the flow of the refrigerant to the refrigerant passage of the heat exchange tube of the fifth tube group constituting the entire fourth path.

  According to the evaporator of 8), since the flow of the refrigerant from the seventh section to the second space of the eighth section is promoted by the flow promoting member, the refrigerant that has entered the second space is the refrigerant of the flow dividing member. It will enter the first space through the passage hole and then flow into the heat exchange tube. Therefore, the uniform distribution of the refrigerant to the refrigerant passage of the heat exchange tube of the fifth tube group constituting the entire fourth path can be more effectively performed.

1 is a partially cutaway perspective view showing an overall configuration of an evaporator according to the present invention. It is the sectional view on the AA line of FIG. 1 which abbreviate | omitted one part. It is the BB sectional drawing of FIG. 1 which abbreviate | omitted one part. It is CC sectional view taken on the line of FIG. It is the DD sectional view taken on the line of FIG. It is a figure which shows the flow of the refrigerant | coolant in the evaporator of FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In the embodiment described below, the heat exchanger according to the present invention is applied to an evaporator of a car air conditioner using a chlorofluorocarbon refrigerant.

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

  In the following description, the downstream side of the air flowing in the ventilation gap between adjacent heat exchange tubes (the direction indicated by the arrow X in FIGS. 1, 4 and 5) is referred to as the front, and the opposite side is referred to as the rear. Assume that the left and right sides of FIGS.

  This embodiment is shown in FIG. 1 and FIG. 1 and 2 show the overall configuration of the evaporator.

  In FIG. 1, the evaporator (1) includes an aluminum first header tank (2) and an aluminum second header tank (3) which are spaced apart in the vertical direction, and both header tanks (2) (3). And a heat exchange core part (4) provided between the two.

  The first header tank (2) has a leeward header part (5) located on the leeward side (front side) and an upwind side located on the leeward side (rear side) and integrated with the leeward header part (5). And a header section (6). The second header tank (3) has a leeward header part (7) located on the leeward side (front side) and an upwind side located on the leeward side (rear side) and integrated with the leeward header part (7). And a header portion (8).

  The heat exchange core section (4) is a tube row (11) composed of a plurality of aluminum flat heat exchange tubes (9) that are oriented in the width direction in the ventilation direction and spaced in the left-right direction and extend in the up-down direction. ) (12) is provided in two rows in the front-rear direction, and the ventilation gap between adjacent heat exchange tubes (9) in each tube row (11) (12) and the heat exchange tubes (9) on both left and right ends Aluminum corrugated fins (13) are placed outside the front and rear tube rows (11) and (12) across the heat exchange tubes (9) and brazed to the heat exchange tubes (9). An aluminum side plate (14) is disposed on the outside of each corrugated fin (13) and brazed to the corrugated fin (13). The heat exchange tube (9) is made of an aluminum extruded profile and has a plurality of refrigerant passages arranged in the width direction. The upper and lower ends of the leeward side tube row (11) are connected in communication with the leeward side header portions (5) and (7) of the first and second header tanks (2) and (3). ) Are connected to the windward header sections (6) and (8) of the first and second header tanks (2) and (3) in a continuous manner.

  As shown in FIGS. 2 to 5, the leeward side tube row (11) has first to third tube groups (11 </ b> A), (11 </ b> A), (11 </ b> C) composed of a plurality of heat exchange tubes (9) at the right end. Toward the left end (from one end side to the other end side of the leeward side tube row (11)), and the windward side tube row (12) includes fourth and fourth heat exchange tubes. Five tube groups (12A) and (12B) are provided side by side from the left end toward the right end (from the other end side of the windward tube row (12) toward the one end side). The first tube group (11A) serves as a first path (15) in which the refrigerant flows through the heat exchange tube (9) from top to bottom, and the second tube group (11B) serves as a refrigerant in the heat exchange tube (9). Becomes the second path (16) that flows from the bottom to the top (in the opposite direction to the first path (15)), and the third and fourth tube groups (11C) and (12A) are connected to the heat exchange tube (9). From the top to the bottom (same direction as the first path (15)) is the third path (17), and the fifth tube group (12B) moves the refrigerant through the heat exchange tube (9) from the bottom (first The fourth path (18) flows in the direction opposite to the path (15).

  The total passage cross-sectional area of the refrigerant passage of the heat exchange tube (9) of the fifth tube group (12B) constituting the entire fourth path (18) constitutes the upwind portion (part) of the third path (17). It is 60% or more of the total passage sectional area of the refrigerant passage of the heat exchange tube (9) of the fourth tube group (12A). Further, the total passage cross-sectional area of the refrigerant passage of the heat exchange tube (9) constituting the second and third passes (16), (17) is the heat exchange constituting the previous pass (15), (16), respectively. The total passage cross-sectional area of the refrigerant passage of the tube (9) is equal to or greater than that, and the total passage cross-sectional area of the refrigerant passage of the heat exchange tube (9) constituting the fourth path (18) constitutes the third path (17). The total cross-sectional area of the refrigerant passage of the heat exchange tube (9) is larger. The total passage cross-sectional area of the refrigerant passages of the heat exchange tubes (9) constituting the second and third passes (16), (17) is the heat exchange constituting the previous passes (15), (16), respectively. The total passage cross-sectional area of the refrigerant passage of the tube (9) is preferably larger.

  Further, the total cross-sectional area of the refrigerant passage of the heat exchange tube (9) of the third tube group (11C) on the leeward side constituting the third path (17) and the upwind side constituting the third path (17) The total passage sectional area of the refrigerant passage of the heat exchange tube (9) of the fourth tube group (12A) is equal, and the heat exchange tube (9) of the third and fourth tube groups (11C) (12A) The total passage sectional area of the refrigerant passage is smaller than the total passage sectional area of the refrigerant passage of the heat exchange tube (9) that constitutes the second path (16).

  Here, all the heat exchange tubes (9) have the same configuration, and the total number of refrigerant passages of each heat exchange tube (9) and the passage cross-sectional areas of the plurality of refrigerant passages of each heat exchange tube (9) Are the same. And by adjusting the number of the heat exchange tubes (9) constituting the first to fourth paths (15), (16), (17), (18), the first to fourth paths (15), (16) ( 17) The total passage sectional area of the refrigerant passage of the total heat exchange tube (9) constituting (18) is determined. That is, the number of heat exchange tubes (9) constituting the fourth path (18) is the number of heat exchange tubes (9) of the fourth tube group (12A) constituting the windward portion of the third path (17). And the number of heat exchange tubes (9) constituting the second and third passes (16) (17) is respectively the heat exchange tube constituting the previous pass (15) (16). The number of heat exchange tubes (9) constituting the fourth path (18) is greater than the number of heat exchange tubes (9) constituting the third path (17). ing. Further, the third tube group (11C) and the fourth tube group (12A) constituting the third path (17) have the same number of heat exchange tubes (9), and the third and fourth tube groups. The number of heat exchange tubes (9) in (11C) and (12A) is smaller than the number of heat exchange tubes (9) constituting the second path (16).

  The leeward header portion (5) of the leeward header portion (5) of the first header tank (2) (the header portion of the leeward upper and lower header portions on the upstream side in the refrigerant flow direction of the first path (15)) By dividing the interior by a partition wall (19), the first section (21) through which the heat exchange tube (9) of the first tube group (11A) communicates, and the second and third tube groups (11B) (11C) And a second section (22) through which the heat exchange tube (9) communicates. The leeward header section (7) of the leeward header section (7) of the second header tank (3) (the header section of the leeward upper and lower header sections on the downstream side in the refrigerant flow direction of the first path (15)) By dividing the interior by a partition wall (23), a third section (24) through which the heat exchange tubes (9) of the first and second tube groups (11A) and (11B) communicate, and a third tube group (11C) And a fourth compartment (25) through which the heat exchange tube (9) communicates.

  The windward header portion (6) of the windward header portion (6) of the first header tank (2) (the upstream portion of the windward upper and lower header portions on the upstream side in the refrigerant flow direction of the first path (15)) By dividing the interior by the partition wall (26), the fifth compartment (27) through which the heat exchange tube (9) of the fourth tube group (12A) communicates and the heat exchange tube (9 of the fifth tube group (12B)) ) To the sixth section (28). The windward header portion (8) of the second header tank (3) is connected to the windward header portion (8) (the header portion on the downstream side in the refrigerant flow direction of the first path (15) of the upper and lower header portions). By dividing the interior by a partition wall (29), the seventh section (31) through which the heat exchange tube (9) of the fourth tube group (12A) communicates and the heat exchange tube (9 of the fifth tube group (12B)) ) To the eighth section (32).

  A refrigerant inlet (33) is provided at the right end of the first compartment (21) of the first header tank (2), and a refrigerant is provided at the right end of the sixth compartment (28) (the same end as the refrigerant inlet (33)). An outlet (30) is provided. Further, the second section (22) and the fifth section (27) of the first header tank (2) are communicated with each other via a communication portion (34) provided in the first header tank (2), The communication in which the fourth section (25) and the seventh section (31) of the two header tanks (3) and the seventh section (31) and the eighth section (32) are provided in the second header tank (3), respectively. It is connected via the parts (35) and (36). Then, the refrigerant flowing into the first compartment (21) from the refrigerant inlet (33) becomes the third compartment (24), the second compartment (22), the fifth compartment (27), the seventh compartment (31), and the first compartment. The refrigerant flows into the sixth section (28) through the eight sections (32) and flows out from the refrigerant outlet (30).

  In the eighth section (32) of the windward header section (7) of the second header tank (3), the first space (32A) on the upper side (the heat exchange tube (9) side) inside the eighth section (32). A plate-shaped flow dividing member (37) is provided to divide into the second space (32B) on the lower side (opposite to the heat exchange tube (9)), and the flow dividing member (37) is spaced horizontally. A plurality of refrigerant passage holes (38) are formed. In addition, the windward header section (7) provided with the seventh section (31) and the eighth section (32) of the second header tank (3) closes the left end opening of the first space (32A), and A plate-like flow promoting member (39) for promoting the flow of the refrigerant from the seventh section (31) to the second space (32B) of the eighth section (32) is provided. If the flow of the refrigerant from the seventh section (31) to the second space (32B) of the eighth section (32) is not hindered, a refrigerant passage hole is formed in the flow promotion member (39). It may be. The flow promoting member (39) is composed of an upper portion of a partition wall (29) that divides the inside of the windward header section (8) to provide a seventh section (31) and an eighth section (32). In addition, the communication part (36) that allows the seventh section (31) and the eighth section (32) to pass through is formed in the lower part of the partition wall (29), and the seventh section (31) and the eighth section ( 32) is communicated with the second space (32B) through the communication part (36).

  The evaporator (1) described above constitutes a refrigeration cycle that uses a chlorofluorocarbon refrigerant together with a compressor, a condenser as a refrigerant cooler, and an expansion valve as a decompressor, and is mounted on a vehicle, for example, an automobile, as a car air conditioner. The gas-liquid mixed-phase two-phase refrigerant that has passed through the compressor, the condenser, and the expansion valve passes through the refrigerant inlet (33), and the first section (21) of the leeward header section (5) of the first header tank (2). ) The refrigerant that has entered the first section (21) is divided and flows into the heat exchange tube (9) of the first tube group (11A) constituting the first path (15) in the leeward tube row (11). Then, it flows downward in the heat exchange tube (9) and enters the third section (24) of the leeward header portion (7) of the second header tank (3). The refrigerant that has entered the third section (24) flows to the left and is divided, and the heat exchange tubes (9B) of the second tube group (11B) constituting the second path (16) in the leeward tube row (11) (9). ) Flows in. The refrigerant flowing into the heat exchange tube (9) flows upward in the heat exchange tube (9) and enters the second section (22) of the leeward header portion (5) of the first header tank (2).

  The refrigerant that has entered the second section (22) flows to the left and is divided into heat exchange tubes (11C) of the third tube group (11C) constituting the third path (17) in the leeward tube row (11). 9) Inflow into. At the same time, the refrigerant flowing into the second section (22) and flowing to the left flows backward through the communication section (34) to the windward header section (6) of the first header tank (2). It enters into the fifth section (27), and flows into the heat exchange tube (9) of the fourth tube group (12A) constituting the third path (17) in the windward tube row (12). The refrigerant flowing into the heat exchange tube (9) of the third tube group (11C) constituting the third path (17) flows downward in the heat exchange tube (9) and flows into the second header tank (3). The seventh section (8) of the windward header section (8) of the second header tank (3) enters the fourth section (25) of the leeward header section (5), flows backward, passes through the communication section (35). Enter 31). At the same time, the refrigerant flowing into the heat exchange tube (9) of the fourth tube group (12A) constituting the third path (17) flows downward in the heat exchange tube (9) to the second header tank. Enter the seventh section (31) of the windward header section (8) of (3).

  The refrigerant that has entered the seventh section (31) enters the second space (32B) of the eighth section (32) through the communication portion (36). The refrigerant that has entered the second space (32B) enters the first space (32A) through the refrigerant passage hole (38) of the flow dividing member (37), and passes through the fourth path (12) in the windward tube row (12). It flows into the heat exchange tube (9) of the fifth tube group (12B) constituting 18). The refrigerant that has flowed into the heat exchange tube (9) of the fifth tube group (12B) flows upward in the heat exchange tube (9) and reaches the first side of the upwind header section (6) of the first header tank (2). The air enters the sixth section (28), flows rightward in the sixth section (28), and flows out through the refrigerant outlet (30).

  While the refrigerant flows in the heat exchange tube (9) of the leeward tube row (11) and in the heat exchange tube (9) of the windward tube row (12), the ventilation of the heat exchange core section (4) Heat exchange is performed with air passing through the gap (see arrow X in FIG. 1), the air is cooled, and the refrigerant flows out as a gas phase.

  Here, the total passage sectional area of the refrigerant passage of the heat exchange tube (9) of the fifth tube group (12B) constituting the entire fourth path (18) constitutes a part of the third path (17). Since the total cross-sectional area of the refrigerant passage of the heat exchange tube (9) of the four-tube group (12A) is 60% or more, the gas-liquid mixed phase refrigerant flowing into the evaporator (1) is passed through the first to fourth passes (15). (16) (17) (18), when flowing sequentially, it is possible to suppress the increase in passage resistance of the fourth path (18) where there is a superheat region and a large amount of gas-phase refrigerant flows. Performance can be improved.

  Further, the total passage cross-sectional area of the refrigerant passage of the heat exchange tube (9) constituting the second and third passes (16), (17) is the heat exchange constituting the previous pass (15), (16), respectively. The total passage cross-sectional area of the refrigerant passage of the tube (9) is equal to or greater than that, and the total passage cross-sectional area of the refrigerant passage of the heat exchange tube (9) constituting the fourth path (18) constitutes the third path (17). Since the total cross-sectional area of the refrigerant passage of the heat exchange tube (9) is larger, the gas-liquid mixed phase refrigerant that has flowed into the evaporator (1) sequentially flows through the first to fourth paths (18). Even if the evaporation of the liquid phase component proceeds and the specific volume increases, an increase in passage resistance in the second to fourth passes (16), (17) and (18) can be suppressed.

  Further, the total cross-sectional area of the refrigerant passage of the heat exchange tube (9) of the third tube group (11C) on the leeward side constituting the third path (17) and the upwind side constituting the third path (17) The total passage sectional area of the refrigerant passage of the heat exchange tube (9) of the fourth tube group (12A) is equal, and the heat exchange tube (9) of the third and fourth tube groups (11C) (12A) Since the total passage sectional area of the refrigerant passage is smaller than the total passage sectional area of the refrigerant passage of the heat exchange tube (9) constituting the second path (16), the heat exchange tube constituting the second path. It is possible to achieve a uniform flow distribution to the three-pass heat exchange tube while ensuring the total passage cross-sectional area of the refrigerant passage.

  In the above-described embodiment, the header portion on the upstream side in the flow direction of the first path and the header portion on the downstream side in the flow direction are provided so that the former is positioned above, but the present invention is not limited to this. On the contrary, the header portion on the upstream side in the flow direction of the first path and the downstream header portion on the downstream side in the flow direction may be provided so that the former is positioned below. That is, it may be provided upside down from the above embodiment.

  In the evaporator according to the present invention, a plurality of flat hollow bodies formed by brazing the peripheral portions with a pair of plate-shaped plates facing each other are arranged in parallel, and are lined up in the ventilation direction in each flat hollow body. Two heat exchange tubes that extend in the vertical direction, and header forming parts that lead to the upper and lower ends of both heat exchange tubes are provided, and flat hollow so that the two upper and lower header forming parts of all flat hollow bodies can communicate with each other When the bodies are brazed to each other, two rows of tube rows each including a plurality of heat exchange tubes extending in the vertical direction and spaced apart in a direction perpendicular to the ventilation direction are provided side by side in the ventilation direction. In addition, both the leeward and leeward upper and lower headers where the upper and lower ends of the leeward and upper winder tube rows communicate with each other by the flat hollow body header forming portion. Is also applicable to form a so-called laminated evaporator provided.

  The evaporator according to the present invention is suitably used for a refrigeration cycle constituting a car air conditioner.

(1): Evaporator
(5): First header tank leeward header (leeward upper header)
(6): Windward header section of the first header tank (windward upper header section)
(7): The leeward header of the second header tank (leeward lower header)
(8): Windward header part of the second header tank (windward lower header part)
(9): Heat exchange tube
(11): Downward tube row
(11A) (11B) (11C): First to third tube groups
(12): Windward tube row
(12A) (12B): Fourth and fifth tube groups
(15): First pass
(16): Second pass
(17): Third pass
(18): Fourth pass
(21): Section 1
(22): Second section
(24): Third section
(25): Section 4
(27): Fifth section
(28): Section 6
(30): Refrigerant outlet
(31): Section 7
(32): Section 8
(33): Refrigerant inlet
(37): Shunt member
(38): Refrigerant passage hole
(39): Flow promoting member

Claims (9)

Two rows of tubes, each of which is formed of a plurality of heat exchange tubes arranged in the direction perpendicular to the ventilation direction and extending in the vertical direction, are provided side by side in the ventilation direction. The first to third tube groups made of the heat exchange tubes are provided side by side from one end side to the other end side of the leeward side tube row, and the fourth side made of a plurality of heat exchange tubes in the windward side tube row. And a fifth tube group are provided side by side from the other end side of the windward tube row toward the one end side, and the first tube group is configured such that the refrigerant passes through the heat exchange tube from above or from below. The second tube group becomes a second path through which the refrigerant flows in the heat exchange tube in the direction opposite to the first path, and the third and fourth tube groups form the refrigerant in the heat exchange tube. With the first pass Becomes third path flowing in the direction, the fifth tube group, the evaporator refrigerant from the first pass through the heat exchange tubes has a fourth path flows in the opposite direction,
The total passage cross-sectional area of the refrigerant passage of the heat exchange tube constituting the second and third paths is equal to or greater than the total passage cross-sectional area of the refrigerant passage of the heat exchange tube constituting the previous path, and the fourth path An evaporator in which the total passage cross-sectional area of the refrigerant passage of the heat exchange tube constituting the heat exchanger tube is larger than the total passage cross-sectional area of the refrigerant passage of the heat exchange tube constituting the third path. The total passage sectional area of the refrigerant passage of the heat exchange tube constituting the fourth path is 60% or more of the total passage sectional area of the refrigerant passage of the heat exchange tube of the fourth tube group constituting a part of the third path. The evaporator according to claim 1. The total passage cross-sectional area of the refrigerant passage of the heat exchange tube of the third tube group on the leeward side constituting the third path, and the total passage of the refrigerant passage of the heat exchange tube of the fourth tube group on the windward side constituting the third path The total cross-sectional area of the refrigerant passages of the heat exchange tubes of the third and fourth tube groups is equal to the cross-sectional area of the refrigerant passages of the heat exchange tubes constituting the second path, respectively. The evaporator according to claim 1 or 2, wherein the evaporator is small. The total passage sectional area of the refrigerant passages of the heat exchange tubes constituting the second and third paths is larger than the total passage sectional area of the refrigerant passages of the heat exchange tubes constituting the previous path, respectively. The evaporator in any one of 1-3. The total heat exchange tubes have the same configuration, the number of refrigerant passages of each heat exchange tube, and the total of the cross-sectional areas of the plurality of refrigerant passages of each heat exchange tube are the same, and the heat constituting each path By adjusting the number of the exchange tubes, the total passage sectional area of the refrigerant passages of the total heat exchange tubes constituting the first to fourth paths is determined, and the third tube group and the fourth heat exchange constituting the third path are determined. The evaporator according to any one of claims 1 to 4, wherein the number of heat exchange tubes in the tube group is the same. The upper and lower end portions of the heat exchange tubes of the leeward side and the windward side tube row are respectively connected to the leeward side and the windward upper and lower header portions,
The first section where the heat exchange tube of the first tube group communicates with the header portion on the upstream side in the flow direction of the refrigerant of the first pass among the upper and lower header portions on the leeward side, and the heat exchange tubes of the second and third tube groups. A second compartment leading to it,
The third section where the heat exchange tubes of the first and second tube groups communicate with the header portion on the downstream side in the flow direction of the refrigerant in the first pass among the upper and lower header portions on the leeward side, and the heat exchange tubes of the third tube group. And a fourth section that leads to
The fifth section where the heat exchange tube of the fourth tube group communicates with the header section on the upstream side in the flow direction of the refrigerant in the first pass among the upper and lower header sections, and the sixth section where the heat exchange tube of the fifth tube group communicates. Compartments,
The seventh section where the heat exchange tube of the fourth tube group communicates with the header section on the downstream side in the flow direction of the refrigerant in the first path among the upper and lower header sections, and the eighth section where the heat exchange tube of the fifth tube group communicates. Compartments,
A refrigerant inlet is provided in the first compartment, a refrigerant outlet is provided in the sixth compartment, and the second compartment and the fifth compartment, the fourth compartment and the seventh compartment, and the seventh compartment and the eighth compartment are communicated with each other. And
The refrigerant that has flowed into the first compartment from the refrigerant inlet flows into the second compartment through the third compartment, and then flows into the seventh compartment from the second compartment through the fourth compartment, and from the second compartment to the fifth compartment. The evaporator according to any one of claims 1 to 5, wherein the evaporator flows into the seventh section through the second section, further flows into the sixth section from the seventh section through the eighth section, and flows out from the refrigerant outlet. . In the eighth section, a flow dividing member is provided to divide the inside of the eighth section into a first space on the heat exchange tube side and a second space on the opposite side of the heat exchange tube, and a refrigerant passage hole is formed in the flow dividing member. The evaporator according to claim 6. The evaporator according to claim 7, wherein a flow promoting member that promotes the flow of the refrigerant from the seventh compartment to the second space of the eighth compartment is provided in the header portion provided with the seventh compartment and the eighth compartment. The evaporator according to any one of claims 1 to 8, wherein the header portion on the upstream side in the flow direction of the first path and the header portion on the downstream side in the flow direction are provided such that the former is positioned above.

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