Vehicle-mounted heat exchanger

Abstract

A vehicle-mounted heat exchanger (100) includes a heat exchanging unit (108) comprising a plurality of plate fins (101) which are plate-shaped and are disposed parallel to one another, and a plurality of tubes (102) which penetrate through the plurality of plate fins and through which a refrigerant flows. If a refrigerant flow passage through which the refrigerant flows in the heat exchanging unit is defined as a path (110 to 150), the plurality of tubes form at least one path. A most downstream tube (121, 141) positioned most downstream, in the refrigerant flow, within the at least one path is disposed on an airflow most downstream side of the heat exchanging unit in an airflow direction parallel to a surface direction of the plurality of plate fins.

Description

Automotive heat exchanger CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2022-88212 filed on May 31, 2022, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a heat exchanger for a vehicle.

[0003] Conventionally, a heat exchanger having a plurality of plate fins arranged in parallel and tubes that are inserted into insertion holes formed in the plate fins and allow a refrigerant to flow from an inlet to an outlet has been proposed, for example, in Patent Document 1.

[0004] Japanese Patent Application Laid-Open No. 2020-165548

[0005] Typically, heat exchangers are arranged so that the direction of refrigerant movement is countercurrent to the airflow, i.e., the tubes are arranged so that the cold refrigerant flows downstream of the airflow and the warm refrigerant flows upstream of the airflow.

[0006] Furthermore, when the air is cooled below the dew point by the plate fins, condensation occurs on the plate fins. For this reason, a drain pan is provided below the heat exchanger to catch and drain the condensed water.

[0007] However, some of the condensed water generated on the plate fins is carried by the air flow and moves downstream of the heat exchanger. The condensed water then freezes around the tubes through which the cold refrigerant flows, causing ice to grow, which causes the gaps on the air outlet side of the heat exchanger to become clogged with ice.

[0008] As a result, it becomes difficult for the air to pass through the inside of the heat exchanger, so it passes through the gap between the drain pan and the heat exchanger. Because the gap between the drain pan and the heat exchanger is narrower than the gap inside the heat exchanger, the speed of the air passing through the gap between the heat exchanger and the drain pan increases, and the condensed water is pushed by the air and splashes out of the drain pan. Also, because the air passes through the gap between the drain pan and the heat exchanger, heat exchange with the air is not performed. This reduces the refrigeration efficiency of the heat exchanger.

[0009] In particular, when the doors of the loading compartment are opened and closed, humid air enters the loading compartment of the vehicle heat exchanger, which means that the vehicle heat exchanger is likely to be placed in an environment where condensation is likely to occur, and ice is likely to form on the air outlet side of the vehicle heat exchanger.

[0010] In view of the above, the present disclosure aims to provide an in-vehicle heat exchanger that can suppress the scattering of condensed water from the air blowing side while suppressing a decrease in refrigeration efficiency.

[0011] According to one aspect of the present disclosure, an automotive heat exchanger includes a heat exchange section having a plurality of plate-shaped plate fins arranged in parallel, and a plurality of tubes that penetrate the plurality of plate fins and through which a refrigerant flows.

[0012] If a refrigerant flow path that allows the refrigerant to flow through the heat exchanger is defined as a path, then the plurality of tubes constitute at least one path.

[0013] The most downstream tube located most downstream in the refrigerant flow of at least one path is arranged at the most downstream side of the heat exchange section in the air flow direction parallel to the surface direction of the plurality of plate fins.

[0014] This makes it difficult for the air passing through the most downstream side of the heat exchanger to be cooled by the high-temperature refrigerant flowing through the most downstream tube, which makes it difficult for condensed water to freeze around the most downstream tube, making it difficult for the air outlet side of the heat exchanger to become clogged with ice.

[0015] This makes it difficult for condensed water to pass through the gap between the drain pan and the heat exchanger, and therefore prevents condensed water that falls from the heat exchanger into the drain pan from being pushed by the air and scattering from the air outlet side of the heat exchanger.

[0016] Furthermore, since it is difficult for air to pass through the gap between the drain pan and the heat exchanger, it is easier for air to pass through the heat exchanger, thereby preventing a decrease in the refrigeration efficiency of the heat exchanger.

[0017] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a plan view of an on-vehicle heat exchanger according to one embodiment. Fig. 2 is a side view of a side plate in Fig. 1, Fig. 3 is a diagram showing a case in which multiple paths are arranged on a single plane, Fig. 4 is a diagram comparing refrigerant flow images and operation immediately after start-up and over time for a current model and an improved model, Fig. 5 is a diagram comparing performance between the current model and the improved model, and Fig. 6 is a diagram showing paths according to another embodiment.

[0018] An embodiment of the present invention will be described below with reference to the drawings. The in-vehicle heat exchanger according to this embodiment is applied to, for example, a plate-fin tube type heat exchanger that exchanges heat between a refrigerant and air in a refrigeration cycle. The in-vehicle heat exchanger is mounted on the cargo bed of a refrigerated vehicle and is used to cool the inside of a freezer to a medium temperature range of, for example, 0°C to 20°C.

[0019] As shown in FIGS. 1 and 2 , the vehicle-mounted heat exchanger 100 includes a plurality of plate fins 101 , a plurality of tubes 102 , two side plates 103 and 104 , a plurality of connecting pipes 105 , a distributor 106 , and a collector 107 .

[0020] Each tube 102, each plate fin 101, each side plate 103, 104, and each connecting pipe 105 are made of, for example, aluminum or copper. "Made of aluminum" means that they are made of aluminum or an aluminum alloy. "Made of copper" means that they are made of copper or a copper alloy.

[0021] The plate fins 101 are heat transfer promoting members that promote heat exchange between the air and the refrigerant by increasing the heat transfer area between the air and the tubes 102. The plate fins 101 are formed in a plate shape and arranged in parallel. The refrigerant that can be used is, for example, R404A or R452A.

[0022] The direction parallel to the surface of each plate fin 101 is the air flow direction. The air flow direction is determined by the air being supplied to the vehicle-mounted heat exchanger 100 by a fan (not shown). The air flow direction is unidirectional. Note that a turbo fan, which can supply a stable air volume without decreasing in volume, can be used as the fan.

[0023] The side plates 103 and 104 are plate components provided on the uppermost and lowermost layers of the plurality of plate fins 101 .

[0024] The tubes 102 are straight pipes through which the refrigerant flows. The longitudinal portions of the multiple tubes 102 are arranged in parallel. The multiple tubes 102 pass through through holes provided in each plate fin 101 and each side plate 103, 104, and are fixed to each plate fin 101 and each side plate 103, 104. Therefore, the refrigerant flow direction in each tube 102 is perpendicular to the air flow direction.

[0025] The connecting pipes 105 are U-shaped pipes that connect the ends of the tubes 102. Each connecting pipe 105 is disposed on the side of the side plates 103, 104 opposite to the tubes 102, i.e., on the outside of the side plates 103, 104. Each connecting pipe 105 is joined to each tube 102 by brazing.

[0026] The plate fins 101, the tubes 102, the side plates 103 and 104, and the connecting pipes 105 constitute a heat exchange section 108 that exchanges heat between the air and the refrigerant.

[0027] Here, if the refrigerant flow paths that flow the refrigerant through the heat exchange unit 108 are defined as paths 110 to 150, then each tube 102 and each connecting pipe 105 constitutes a plurality of paths. In the on-vehicle heat exchanger 100 shown in Figures 1 and 2, five paths 110 to 150 are provided.

[0028] 1 shows the path 150 located in the uppermost layer. The temperature of the refrigerant increases as it progresses through each of the paths 110 to 150. The refrigerant temperature also changes depending on various operating conditions.

[0029] The distributor 106 is a container-like device for distributing the refrigerant to each of the paths 110 to 150. The collector 107 is a container-like device for collecting the refrigerant from each of the paths 110 to 150. The distributor 106 and the collector 107 are connected to a path through which the refrigerant circulates.

[0030] Next, each of the paths 110 to 150 will be described in detail. As shown in Fig. 2, in this embodiment, the paths 110 to 150 are arranged in five stages in the vertical direction. The vertical direction is a direction perpendicular to the refrigerant flow direction and the air flow direction. In Fig. 2, the refrigerant flow direction is a direction perpendicular to the plane of the paper.

[0031] 3, each of the passes 110 to 150 includes parallel flow passes 120 and 140 and counter flow passes 110, 130 and 150. Although the passes 110 to 150 are shown as being separated into a single plane in FIG. 3, in reality, the passes 110 to 150 are stacked.

[0032] The parallel flow paths 120, 140 are paths in which the most downstream tubes 121, 141 located most downstream in the refrigerant flow of the parallel flow paths 120, 140 are arranged most downstream in the air flow direction of the heat exchange unit 108. That is, the most downstream tubes 121, 141 are arranged most downstream in the air flow direction of the heat exchange unit 108. The parallel flow paths 120, 140 are paths in which the refrigerant movement direction, which indicates the direction of refrigerant movement in the air flow direction, and the air flow direction are parallel to each other.

[0033] The refrigerant movement direction indicates the direction in which the refrigerant moves along the air flow direction. The direction in which the refrigerant flows through the tube 102 and the connecting pipe 105 is the refrigerant flow direction, not the refrigerant movement direction.

[0034] The counterflow paths 110, 130, 150 are paths in which the most upstream tubes 112, 132, 152 located most upstream in the refrigerant flow among the counterflow paths 110, 130, 150 are arranged most downstream in the air flow direction among the heat exchanger 108. The counterflow paths 110, 130, 150 are paths in which the refrigerant movement direction and the air flow direction are counterflows.

[0035] The number of counterflow paths 110, 130, 150 is greater than the number of parallel flow paths 120, 140. In this embodiment, the number of counterflow paths 110, 130, 150 is three, and the number of parallel flow paths 120, 140 is two. Note that when the number of paths is configured to six stages, for example, the number of counterflow paths is four and the number of parallel flow paths is two.

[0036] 2 , the upstream-most tubes 112, 132, 152 of the counterflow paths 110, 130, 150 and the downstream-most tubes 121, 141 of the parallel flow paths 120, 140 are staggered in the vertical direction at the most downstream air flow position in the heat exchange unit 108. The downstream-most tubes 121, 141 of the parallel flow paths 120, 140 are located closer to the air outlet 108B of the heat exchange unit 108 than the upstream-most tubes 112, 132, 152 of the counterflow paths 110, 130, 150 in the refrigerant movement direction.

[0037] Furthermore, the downstream-most tubes 111, 131, 151 located at the most downstream side of the refrigerant flow in the counterflow paths 110, 130, 150 and the upstream-most tubes 122, 142 located at the most upstream side of the refrigerant flow in the parallel flow paths 120, 140 are arranged in a staggered pattern in the vertical direction at the most upstream side of the air flow in the heat exchange unit 108. The downstream-most tubes 111, 131, 151 of the counterflow paths 110, 130, 150 are located closer to the air inlet 108A of the heat exchange unit 108 than the upstream-most tubes 122, 142 of the parallel flow paths 120, 140 in the refrigerant flow direction. This completes the overall configuration of the on-vehicle heat exchanger 100.

[0038] Next, a comparison will be made between a case where all of the passes 110 to 150 are arranged in counterflow and a case where some of the passes 110 to 150 are arranged in parallel flow passes 120 and 140. Hereinafter, the case where all of the passes 110 to 150 are arranged in counterflow passes 110, 130, and 150 and parallel flow passes 120 and 140 will be referred to as the current product, and the case where the passes 110 to 150 are arranged in counterflow passes 110, 130, and 150 and parallel flow passes 120 and 140 will be referred to as the improved product.

[0039] 4, in the current product, all of the most upstream tubes 112, 122, 132, 142, and 152 located at the most upstream side of the refrigerant flow are arranged on the side of the air outlet 108B of the heat exchange unit 108. Therefore, in terms of refrigerant flow, low-temperature refrigerant flows intensively on the downstream side of the heat exchange unit 108 in the air flow direction, causing the downstream side of the heat exchange unit 108 to be cooled intensively.

[0040] Furthermore, all of the most downstream tubes 111, 121, 131, 141, and 151 located at the most downstream side of the refrigerant flow are arranged on the side of the air inlet 108A of the in-vehicle heat exchanger 100. Therefore, in terms of refrigerant flow, high-temperature refrigerant flows intensively on the upstream side of the heat exchange unit 108 in the air flow direction.

[0041] In the initial stage of freezing, immediately after the start of operation of the vehicle-mounted heat exchanger 100, when air is sent to the heat exchange unit 108, the air is cooled to a temperature below the dew point by the plate fins 101, causing condensed water 200 to form on the plate fins 101. The condensed water 200 that falls from the heat exchange unit 108 is received and drained by the drain pan 300 disposed below the vehicle-mounted heat exchanger 100.

[0042] Furthermore, some of the condensed water 200 is carried by the wind and moves downstream of the heat exchange unit 108, where it is cooled intensively. As a result, the condensed water 200 freezes around the most upstream tubes 112, 122, 132, 142, and 152, and frost 400 grows. Note that in the early stages of freezing, the condensed water 200 is normally discharged.

[0043] Here, the operating conditions of the in-vehicle heat exchanger 100 were an outside air temperature of 20°C, humidity of 90%, a set temperature inside the freezer of 1°C, the freezer door open, and an operating time of 2 hours, which is one of the conditions most likely to cause water splashing.

[0044] After operation has continued, the air outlet 108B has become clogged as the frost 400 has grown, making it difficult for air to pass through the inside of the heat exchanger 108, and instead the air passes through the gap between the drain pan 300 and the heat exchanger 108. In other words, the gap between the drain pan 300 and the heat exchanger 108 becomes the air path.

[0045] The condensed water 200 that accumulated in the drain pan 300 was carried by the air passing through the gap between the drain pan 300 and the heat exchanger 108 and scattered around the refrigerator. For example, when a turbofan is used, it is difficult to reduce the airflow, making it difficult to suppress the amount of water splashing. After the operation had progressed, the amount of condensed water 200 that was discharged decreased.

[0046] Furthermore, the air passes through the gap between the drain pan 300 and the heat exchanger 108 without undergoing heat exchange in the heat exchanger 108, reducing the refrigeration efficiency of the in-vehicle heat exchanger 100. Specifically, the heat exchange area is reduced by approximately 20% due to the freezing of the condensed water. In other words, if the refrigeration performance of the current product immediately after starting operation is taken as 100, the refrigeration performance after the condensed water freezes is reduced by approximately 20% to approximately 80.

[0047] In contrast, in the improved product, the most downstream tubes 121, 141 located at the most downstream side of the refrigerant flow in the parallel flow paths 120, 140 are arranged at the most downstream side of the air flow in the heat exchange section 108. In other words, a high-temperature refrigerant flows on the downstream side of the heat exchange section 108 in the air flow direction.

[0048] As a result, the situation in which the downstream side of the heat exchange unit 108 in the air flow direction is cooled intensively is alleviated. In other words, the low-temperature region is dispersed in the air flow direction. As a result, the air passing through the most downstream part of the heat exchange unit 108 in the air flow direction is less likely to be cooled by the high-temperature refrigerant flowing in the most downstream tubes 121, 141.

[0049] Furthermore, the most upstream tubes 122, 142, which are located most upstream in the refrigerant flow of the parallel flow paths 120, 140, are arranged most upstream in the air flow direction of the heat exchange unit 108. Therefore, in terms of the refrigerant flow, a situation in which the upstream side of the heat exchange unit 108 in the air flow direction becomes hot in a concentrated manner is alleviated.

[0050] Therefore, the area where the refrigerant temperature is concentrated is dispersed in the air flow direction, and the temperature distribution in the air flow direction is made uniform. Therefore, immediately after the start of operation of the vehicle-mounted heat exchanger 100, the condensed water 200 is less likely to freeze around the most downstream tubes 121, 141, and the freezing and growth of the condensed water 200 can be suppressed. In other words, the side of the heat exchange section 108 near the air outlet 108B is less likely to be clogged with frost 400.

[0051] In particular, in this embodiment, the most upstream tubes 112, 132, 152 of the counterflow paths 110, 130, 150 and the most downstream tubes 121, 141 of the parallel flow paths 120, 140 are vertically staggered at the most downstream airflow position in the heat exchange unit 108. This allows high-temperature refrigerant and low-temperature refrigerant to be dispersed in the airflow direction in the heat exchange unit 108. This eliminates the concentrated arrangement of the tubes 112, 122, 132, 142, 152 through which the low-temperature refrigerant flows at the most downstream airflow position in the heat exchange unit 108. This reduces the amount of frozen condensed water 200.

[0052] After the vehicle-mounted heat exchanger 100 has been in operation, the air outlet 108B is not clogged with frost 400, making it difficult for the condensed water 200 to pass through the gap between the drain pan 300 and the heat exchange unit 108. As a result, the condensed water 200 that falls from the heat exchange unit 108 into the drain pan 300 is prevented from being pushed by the air and splashing from the heat exchange unit 108 into the interior of the refrigerator. Under the above conditions, the amount of splashing water was zero.

[0053] That is, in this embodiment, the in-vehicle heat exchanger 100 includes the parallel flow paths 120 and 140, so the amount of freezing at the most downstream side of the air flow in the heat exchange section 108 is reduced, thereby reducing the amount of ice that is entrained in the cold air and scattered.

[0054] Furthermore, since it becomes difficult for air to pass through the gap between the drain pan 300 and the heat exchanger 108, the air can easily pass through the heat exchanger 108. Therefore, the air exchanges heat in the heat exchanger 108, and a decrease in the refrigeration efficiency of the heat exchanger 108 can be suppressed.

[0055] Specifically, if the refrigeration performance of the current model immediately after the start of operation is taken as 100, the refrigeration performance of the improved model immediately after the start of operation is 92 because it includes parallel flow paths 120 and 140. Furthermore, the heat exchange area of ​​the improved model was reduced by approximately 5% due to the freezing of condensed water, so the reduction in refrigeration performance when the condensed water froze immediately after the start of operation was 5%.

[0056] As mentioned above, the refrigeration performance of the current product dropped from 100 to 80 when the condensed water froze, but the improved product's refrigeration performance of 92 only dropped by 5%, resulting in a refrigeration performance of 88. In other words, the improved product's refrigeration performance when the condensed water froze was 10% better than the current product.

[0057] In this embodiment, the number of counterflow paths 110, 130, 150 is greater than the number of parallel flow paths 120, 140, so that it is possible to reduce the deterioration of refrigeration performance in the initial stage of refrigeration immediately after starting operation.

[0058] As shown in Figure 5, for example, the internal temperature is set to 0°C. In this case, the temperature control range is, for example, +2°C to -2°C. The refrigerant temperature in the refrigerant outlet heating temperature region of the heat exchanger 108 is set to be 10°C or higher above the refrigerant evaporation temperature.

[0059] Since the refrigeration performance of the current model is 100 and that of the improved model is 92, in the initial stage of operation, the current model will reach the lower limit of the temperature control range first. The current model will reach the lower limit of the temperature control range in, for example, 120 minutes. The improved model will reach the lower limit of the temperature control range with a delay of approximately 9 minutes compared to the current model, corresponding to a refrigeration performance of -8%.

[0060] After the internal temperature reaches the lower limit of the temperature control range, control is performed so that the internal temperature does not exceed the temperature control range. In other words, the refrigerator is stopped. If the internal temperature reaches the upper limit of the temperature control range during the refrigerator stop period, the refrigerator is started again. In this way, the refrigerator is repeatedly started and stopped, so that the internal temperature is controlled within the temperature control range.

[0061] When condensed water freezes, it takes, for example, 10 minutes for the current product to reach the lower limit of the temperature control range. Because the refrigeration performance of the current product is 80 and the refrigeration performance of the improved product is 88, the improved product reaches the lower limit of the temperature control range more quickly than the current product. Because the refrigeration performance of the improved product is 10% higher than that of the current product, it reaches the lower limit of the temperature control range about one minute faster than the current product. In this way, when condensed water freezes, the improved refrigeration performance of the improved product can shorten the time it takes to cool the interior of the refrigerator.

[0062] The present disclosure is not limited to the above-described embodiments, and various modifications can be made as follows within the scope of the present disclosure.

[0063] For example, the number of paths 110 to 150 is not limited to five.

[0064] The heat exchange unit 108 may include at least one path 110 to 150. As shown in Fig. 6, in the case of one path 110, the most downstream tube 111 located at the most downstream position in the refrigerant flow may be disposed at the most downstream side of the heat exchange unit 108 in the air flow direction.

[0065] When the number of paths 110 to 150 is as large as ten, the distributor 106 and the concentrator 107 may be provided in multiple stages instead of one stage.

[0066] The most upstream tubes 112, 132, 152 of the counterflow paths 110, 130, 150 and the most downstream tubes 121, 141 of the parallel flow paths 120, 140 do not have to be staggered in the vertical direction at the most downstream airflow position in the heat exchange section 108. For example, the most upstream tubes 112, 132, 152 of the counterflow paths 110, 130, 150 and the most downstream tubes 121, 141 of the parallel flow paths 120, 140 may be arranged at the same position in the airflow direction. The same applies to the most downstream tubes 111, 131, 151 of the counterflow paths 110, 130, 150 and the most upstream tubes 122, 142 of the parallel flow paths 120, 140.

[0067] The numbers of counterflow paths 110, 130, 150 and the numbers of parallel flow paths 120, 140 can be set as appropriate. It is preferable that the number of counterflow paths 110, 130, 150 is greater than the number of parallel flow paths 120, 140, i.e., the number of paths is an odd number; however, the number of counterflow paths 110, 130, 150 and the number of parallel flow paths 120, 140 may be the same.

[0068] Each of the paths 110 to 150 may be branched into multiple paths between the distributor 106 and the heat exchanger 108. This allows the number of paths in the heat exchanger 108 to be increased without increasing the number of distributors 106.

[0069] The paths 110 to 150 may be connected vertically across layers as long as the refrigerants flow in countercurrent or parallel directions. For example, the tube 102 of the countercurrent path 110 is connected to the tube 102 of the countercurrent path 130.

[0070] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0071] The technical features of the on-vehicle heat exchanger disclosed in this specification are as follows: (Item 1) An on-vehicle heat exchanger including a heat exchange section (108) having a plurality of plate-shaped plate fins (101) arranged in parallel and a plurality of tubes (102) penetrating the plurality of plate fins and through which a refrigerant flows, wherein, when a refrigerant flow path through which the refrigerant flows in the heat exchange section is defined as a path (110-150), the plurality of tubes constitute at least one path, and a most downstream tube (121, 141) located most downstream in the refrigerant flow of the at least one path is arranged on the most downstream side of the heat exchange section in the air flow direction parallel to the surface direction of the plurality of plate fins. 10. The heat exchanger for a vehicle according to claim 1, wherein the plurality of tubes form a plurality of paths, and at least one of the plurality of paths forms a parallel flow path (120, 140) in which the most downstream tube is arranged at the most downstream position in the heat exchange unit in the air flow direction and a refrigerant movement direction indicating a movement of the refrigerant in the air flow direction and the air flow direction are parallel to each other. 11. The heat exchanger for a vehicle according to claim 1, wherein the plurality of paths includes a counterflow path (110, 130, 150) in which the most upstream tube (112, 132, 152) located at the most upstream position in the refrigerant flow of the heat exchange unit is arranged at the most downstream position in the air flow direction of the heat exchange unit and the refrigerant movement direction and the air flow direction are counterflows to each other. (Item 4) The vehicle-mounted heat exchanger according to item 3, wherein the upstream-most tube of the counterflow path and the downstream-most tube of the parallel flow path are staggered in a direction perpendicular to the air flow direction and in a refrigerant flow direction in which the refrigerant flows through the plurality of tubes, at a most downstream side of the heat exchange unit in the air flow direction. (Item 5) The vehicle-mounted heat exchanger according to item 3 or 4, wherein the plurality of paths include a counterflow path (110, 130, 150) in which the upstream-most tube (112, 132, 152) located most upstream in the refrigerant flow of the heat exchange unit is arranged most downstream in the air flow direction of the heat exchange unit, and the refrigerant movement direction and the air flow direction are counterflows, and the number of the counterflow paths is greater than the number of the parallel flow paths.(Item 6) The vehicle-mounted heat exchanger according to any one of Items 3 to 5, wherein the plurality of paths include a counterflow path (110, 130, 150) in which an upstream-most tube (112, 132, 152) located most upstream in a refrigerant flow of the heat exchange unit is arranged most downstream in the air flow direction of the heat exchange unit, and the refrigerant movement direction and the air flow direction are counterflows, and the downstream-most tube (111, 131, 151) located most downstream in a refrigerant flow of the counterflow path and the upstream-most tube (122, 142) located most upstream in a refrigerant flow of the parallel flow path are staggered in a vertical direction perpendicular to the refrigerant flow direction and the air flow direction at the most upstream of the air flow of the heat exchange unit.

Claims

1. The heat exchange unit (108) includes a plurality of plate fins (101) each having a plate shape and arranged in parallel, and a plurality of tubes (102) penetrating the plurality of plate fins and through which a refrigerant flows, When a refrigerant flow path through which the refrigerant flows in the heat exchange section is defined as a path (110 to 150), the plurality of tubes constitute the path, and the path is continuously connected from the most upstream side of the air flow in the heat exchange section to the most downstream side of the air flow in an air flow direction parallel to the surface direction of the plurality of plate fins, The path is: a parallel flow path (120, 140) in which a most downstream tube (121, 141) located at the most downstream of the refrigerant flow in the heat exchange unit is arranged at the most downstream of the air flow in the heat exchange unit in the air flow direction, and a refrigerant movement direction indicating the movement direction of the refrigerant in the air flow direction and the air flow direction are parallel flows; a counterflow path (110, 130, 150) in which a most upstream tube (112, 132, 152) located at the most upstream of the refrigerant flow in the heat exchange unit is arranged at the most downstream of the air flow in the air flow direction in the heat exchange unit, and in which the refrigerant movement direction and the air flow direction are counterflows; Including, the parallel flow paths and the counter flow paths are alternately arranged so as to be adjacent to each other along a vertical direction perpendicular to a refrigerant flow direction in which the refrigerant flows through the plurality of tubes and to an air flow direction, The vehicle-mounted heat exchanger further includes a distributor (106) that distributes and supplies the refrigerant independently to the parallel flow paths and the counter flow paths.

2. 2 . The heat exchanger for mounting on a vehicle according to claim 1 , wherein the most upstream tube of the counterflow path and the most downstream tube of the parallel flow path are staggered in the vertical direction at a most downstream air flow area of ​​the heat exchange section.

3. An automotive heat exchanger as described in claim 1 or 2, wherein the number of counterflow paths is greater than the number of parallel flow paths.

4. An automotive heat exchanger as described in claim 1 or 2, wherein the opposing downstream tube (111, 131, 151) located at the most downstream of the refrigerant flow in the opposing flow path and the parallel upstream tube (122, 142) located at the most upstream of the refrigerant flow in the parallel flow path are staggered in the vertical direction at the most upstream of the air flow in the heat exchange section.