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

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.

Technical Field

[0002] The present disclosure relates to an in-vehicle heat exchanger.

Background Art

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

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] Normally, a heat exchanger is arranged such that the direction of movement of the refrigerant is countercurrent to the air flow. That is, the tube is arranged such that cold refrigerant flows on the downstream side of the air flow while warm refrigerant flows on the upstream side of the air flow.

[0006] Also, when air is cooled below the dew point by the plate fins, condensed water is generated on the plate fins. Therefore, a drain pan for receiving and draining the condensed water is arranged at the lower part of the heat exchanger.

[0007] However, a part of the condensed water generated on the plate fins rides on the air flow and moves to the downstream side of the heat exchanger. Then, the condensed water freezes around the tube through which cold refrigerant flows and the ice grows. For this reason, the gap on the air outlet side of the heat exchanger is blocked by ice.

[0008] As a result, air has difficulty passing through the inside of the heat exchanger and is forced to pass through the gap between the drain pan and the heat exchanger. Since the gap between the drain pan and the heat exchanger is narrower than the gap inside the heat exchanger, the speed of air passing through the gap between the heat exchanger and the drain pan increases, and the condensed water is pushed by the air and scattered from the drain pan. Also, since air passes through the gap between the drain pan and the heat exchanger, the air does not undergo heat exchange. Therefore, the refrigeration efficiency of the heat exchanger decreases.

[0009] In particular, in-vehicle heat exchangers used in vehicle-mounted refrigeration units, humid air enters the cargo area when the cargo door is opened and closed. As a result, in-vehicle heat exchangers are often placed in an environment where condensation is likely to occur, and ice is more likely to form on the air outlet side of the heat exchanger.

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

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

[0012] If we define the refrigerant flow path through the heat exchange section as a path, then multiple tubes... is Pa Constitutes Furthermore, the airflow path is continuously connected from the upstream to the downstream side of the airflow within the heat exchange section, in an airflow direction parallel to the plane direction of the multiple plate fins.

[0013] The pass is, The downstream tube, located at the lowest point of the refrigerant flow within the heat exchange section, is positioned at the lowest point of the airflow within the heat exchange section in the airflow direction, and a parallel flow path is provided where the refrigerant movement direction, which indicates the direction of refrigerant movement in the airflow direction, and the airflow direction are parallel flows. The upstream tube, located at the uppermost point of the refrigerant flow within the heat exchange section, is positioned at the lowermost point of the airflow within the heat exchange section in the airflow direction, and the refrigerant movement direction and the airflow direction are in opposite directions in the counter-flow path. Includes. Parallel flow paths and counter-flow paths are arranged alternately so as to be adjacent to each other along a vertical direction perpendicular to the refrigerant flow direction and the airflow direction through which the refrigerant flows in the multiple tubes. Furthermore, it includes a distributor that independently distributes and supplies refrigerant to parallel flow paths and counterflow paths, respectively.

[0014] According to this, the air passing through the air flow most downstream side of the heat exchange section becomes difficult to be cooled by the high-temperature refrigerant flowing into the most downstream tube. Therefore, the condensed water becomes difficult to freeze around the most downstream tube, and the air blowing side of the heat exchange section becomes difficult to be blocked by ice.

[0015] Therefore, it is possible to make the condensed water difficult to pass through the gap between the drain pan and the heat exchange section. Along with this, it is possible to suppress the condensed water falling from the heat exchange section to the drain pan from being pushed by the air and scattered from the air blowing side of the heat exchange section.

[0016] Also, since the air becomes difficult to pass through the gap between the drain pan and the heat exchange section, the air becomes easier to pass through the heat exchange section. Therefore, it is possible to suppress a decrease in the refrigeration efficiency of the heat exchange section.

Brief Description of the Drawings

[0017] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. In the accompanying drawings, [Figure 1] FIG. 1 is a plan view of an in-vehicle heat exchanger according to an embodiment. [Figure 2] FIG. 2 is a side view of the side plate in FIG. 1, [Figure 3] FIG. 3 is a diagram showing a case where a plurality of paths are arranged on one plane, [Figure 4] FIG. 4 is a diagram comparing the refrigerant flow images, operations immediately after the start of operation, and operations during the operation of the current product and the improved product, [Figure 5] FIG. 5 is a diagram showing a performance comparison between the current product and the improved product, [Figure 6] FIG. 6 is a diagram showing a path according to another embodiment.

Mode for Carrying Out the Invention

[0018] Hereinafter, an embodiment will be described 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 performs heat exchange between the refrigerant of a refrigeration cycle and air. The in-vehicle heat exchanger is mounted on the cargo bed of a refrigerated vehicle and is used to cool the inside of the refrigerator to a medium temperature range of, for example, 0°C to 20°C.

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

[0020] Each tube 102, each plate fin 101, each side plate 103, 104, and each connecting tube 105 is made of, for example, aluminum or copper. Made of aluminum means being composed of aluminum or an aluminum alloy. Made of copper means being composed of copper or a copper alloy.

[0021] The plate fin 101 is a heat transfer promoting member that increases the heat transfer area between the air and the tube 102 to promote heat exchange between the air and the refrigerant. The plate fin 101 is formed in a plate shape and a plurality of them are arranged in parallel. As the refrigerant, for example, R404A or R452A can be used.

[0022] The direction parallel to the plane direction of each plate fin 101 is the air flow direction. When air is supplied to the in-vehicle heat exchanger 100 by a fan (not shown), the air flow direction is determined. The air flow direction is unidirectional. As the fan, a turbo fan that can supply a stable air volume with little air volume drop can be used.

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

[0024] Tube 102 is a straight pipe through which the refrigerant flows. Multiple tubes 102 are arranged in parallel along their longitudinal sections. Multiple tubes 102 pass through through holes provided in each plate fin 101 and each side plate 103, 104, and are also fixed to each plate fin 101 and each side plate 103, 104. Therefore, the direction of refrigerant flow through each tube 102 is perpendicular to the direction of airflow.

[0025] The connecting pipe 105 is a U-shaped pipe that connects the ends of each tube 102. Each connecting pipe 105 is positioned on the side plates 103 and 104 on the opposite side from each tube 102, i.e., on the outside of the side plates 103 and 104. Each connecting pipe 105 is joined to each tube 102 by brazing.

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

[0027] Here, if we define the refrigerant flow paths through the heat exchange section 108 as paths 110 to 150, then each tube 102 and each connecting pipe 105 constitutes multiple paths. In the vehicle-mounted heat exchanger 100 shown in Figures 1 and 2, five paths 110 to 150 are provided.

[0028] Note that Figure 1 shows path 150, located at the top layer. The temperature of the refrigerant increases as it moves through each path 110 to 150. Also, the refrigerant temperature changes under various operating conditions.

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

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

[0031] As shown in Figure 3, each path 110-150 includes parallel flow paths 120 and 140 and counterflow paths 110, 130, and 150. Although Figure 3 shows multiple paths 110-150 separated into a single plane, in reality, each path 110-150 is stacked on top of the others.

[0032] The parallel flow paths 120 and 140 are paths in which the downstream tubes 121 and 141, located at the furthest downstream point of the refrigerant flow within the parallel flow paths 120 and 140, are positioned at the furthest downstream point of the airflow within the heat exchange section 108 in the airflow direction. In other words, the downstream tubes 121 and 141 are positioned on the furthest downstream side of the airflow within the heat exchange section 108 in the airflow direction. Furthermore, the parallel flow paths 120 and 140 are paths in which the refrigerant movement direction, which indicates the direction of refrigerant movement in the airflow direction, and the airflow direction are parallel.

[0033] Note that the refrigerant movement direction indicates the direction in which the refrigerant moves along the airflow direction. The direction of the refrigerant flowing through tube 102 and connecting pipe 105 is the refrigerant flow direction, not the refrigerant movement direction.

[0034] The counterflow paths 110, 130, and 150 are paths in which the uppermost tubes 112, 132, and 152, located at the uppermost part of the refrigerant flow among the counterflow paths 110, 130, and 150, are positioned at the lowermost part of the airflow in the heat exchange section 108 in the airflow direction. Furthermore, the counterflow paths 110, 130, and 150 are paths in which the refrigerant movement direction and the airflow direction are in opposition to each other.

[0035] Furthermore, the number of counterflow paths 110, 130, and 150 is greater than the number of parallel flow paths 120 and 140. In this embodiment, there are 3 counterflow paths 110, 130, and 150, and 2 parallel flow paths 120 and 140. Note that if the number of paths is configured in 6 stages, for example, there are 4 counterflow paths and 2 parallel flow paths.

[0036] As shown in Figure 2, the uppermost tubes 112, 132, and 152 of the counterflow paths 110, 130, and 150, and the lowermost tubes 121 and 141 of the parallel flow paths 120 and 140 are arranged in a staggered vertical configuration at the lowest point of the airflow within the heat exchange section 108. The lowermost tubes 121 and 141 of the parallel flow paths 120 and 140 are located closer to the air outlet 108B of the heat exchange section 108 than the uppermost tubes 112, 132, and 152 of the counterflow paths 110, 130, and 150, in the direction of refrigerant movement.

[0037] Furthermore, the downstream tubes 111, 131, and 151, located at the lowest point of the refrigerant flow in the counterflow paths 110, 130, and 150, and the upstream tubes 122 and 142, located at the highest point of the refrigerant flow in the parallel flow paths 120 and 140, are arranged in a staggered vertical configuration at the uppermost point of the airflow in the heat exchange section 108. The downstream tubes 111, 131, and 151 of the counterflow paths 110, 130, and 150 are located closer to the air inlet 108A of the heat exchange section 108 than the upstream tubes 122 and 142 of the parallel flow paths 120 and 140, in the direction of refrigerant movement. The above describes the overall configuration of the vehicle-mounted heat exchanger 100. Furthermore, the downstream tubes 111, 131, and 151 correspond to the opposing downstream tubes, while the upstream tubes 122 and 142 correspond to the parallel upstream tubes.

[0038] Next, we will compare the case where all paths 110-150 are arranged in counterflow, and the case where some of paths 110-150 are arranged in parallel flow paths 120 and 140. Hereafter, the case where all paths 110-150 are arranged in counterflow will be called the current product, and the case where paths 110-150 are arranged in counterflow paths 110, 130, and 150, and parallel flow paths 120 and 140 will be called the improved product.

[0039] As shown in Figure 4, in the current product, all of the upstream tubes 112, 122, 132, 142, and 152, which are located at the uppermost part of the refrigerant flow, are positioned on the side of the air outlet 108B of the heat exchange section 108. Therefore, in terms of refrigerant flow, the lower temperature refrigerant concentrates and flows downstream of the heat exchange section 108 in the direction of airflow, causing the downstream side of the heat exchange section 108 to be cooled intensively.

[0040] Furthermore, all of the downstream tubes 111, 121, 131, 141, and 151, located at the very downstream end of the refrigerant flow, are positioned on the side of the air inlet 108A of the vehicle-mounted heat exchanger 100. Therefore, in terms of refrigerant flow, the high-temperature refrigerant concentrates and flows on the upstream side of the heat exchange section 108 in the direction of airflow.

[0041] Then, in the initial stage of refrigeration, immediately after the start of operation of the vehicle-mounted heat exchanger 100, when air is sent to the heat exchange section 108, the air is cooled below the dew point by the plate fins 101, causing condensation water 200 to form on the plate fins 101. The condensation water 200 that falls from the heat exchange section 108 is collected by a drain pan 300 located below the vehicle-mounted heat exchanger 100 and is also drained away.

[0042] Furthermore, some of the condensate 200 is carried by the wind to the downstream side of the heat exchanger 108, where it is cooled intensively. As a result, the condensate 200 freezes around the uppermost tubes 112, 122, 132, 142, and 152, and frost 400 grows. In the initial stages of freezing, the drainage of the condensate 200 is normal.

[0043] Here, the operating conditions for the vehicle-mounted heat exchanger 100 were set to an outside temperature of 20°C, a humidity of 90%, an internal temperature of 1°C, an open freezer door, and an operating time of 2 hours. These are among the conditions most likely to cause water evaporation.

[0044] After some operation, the air outlet 108B became blocked due to the growth of frost 400. As a result, air had difficulty passing through the inside of the heat exchange section 108 and instead passed through the gap between the drain pan 300 and the heat exchange section 108. In other words, the gap between the drain pan 300 and the heat exchange section 108 became the air passage.

[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 exchange unit 108 and scattered into the chamber. For example, when using a turbo fan, it is difficult to reduce the airflow, making it difficult to suppress the amount of water scattered. Furthermore, after a period of operation, the amount of condensed water 200 drained decreased.

[0046] Furthermore, because the air passes through the gap between the drain pan 300 and the heat exchange unit 108 without undergoing heat exchange in the heat exchange unit 108, the refrigeration efficiency of the vehicle-mounted heat exchanger 100 decreased. Specifically, the heat exchange area decreased by approximately 20% due to condensate freezing. In other words, if the refrigeration performance immediately after starting operation of the current product is set to 100, the refrigeration performance when condensate freezes decreases by approximately 20% to approximately 80.

[0047] In contrast, in the improved version, the downstream tubes 121 and 141, located at the furthest downstream point of the refrigerant flow among the parallel flow paths 120 and 140, are positioned at the furthest downstream point of the airflow in the heat exchange section 108 in the airflow direction. That is, high-temperature refrigerant flows on the downstream side of the heat exchange section 108 in the airflow direction.

[0048] Therefore, in terms of refrigerant flow, the situation in which the downstream side of the heat exchange section 108 is concentrated and cooled in the direction of airflow is mitigated. In other words, the low-temperature region is dispersed in the direction of airflow. Consequently, the air passing through the downstream end of the airflow in the heat exchange section 108 is less likely to be cooled by the high-temperature refrigerant flowing through the downstream tubes 121 and 141.

[0049] Furthermore, the uppermost tubes 122 and 142, located at the uppermost reaches of the refrigerant flow in the parallel flow paths 120 and 140, are positioned at the uppermost reaches of the airflow in the heat exchange section 108 in the airflow direction. Therefore, the situation in which the upstream side of the heat exchange section 108 becomes intensely hot in the airflow direction is mitigated in terms of the refrigerant flow image.

[0050] Therefore, the area where the refrigerant temperature is concentrated is dispersed in the direction of airflow, resulting in a uniform temperature distribution in the direction of airflow. As a result, immediately after the start of operation of the vehicle-mounted heat exchanger 100, the condensate 200 is less likely to freeze around the downstream tubes 121 and 141, thus suppressing the freezing and growth of the condensate 200. In other words, the side of the heat exchange section 108 near the air outlet 108B is less likely to be blocked by frost 400.

[0051] In particular, in this embodiment, the uppermost tubes 112, 132, and 152 of the counterflow paths 110, 130, and 150, and the lowermost tubes 121 and 141 of the parallel flow paths 120 and 140 are arranged in a staggered vertical configuration at the lowest point of the airflow in the heat exchange section 108. This arrangement allows the high-temperature refrigerant and the low-temperature refrigerant to be dispersed in the airflow direction within the heat exchange section 108. As a result, the concentration of tubes 112, 122, 132, 142, and 152 carrying the low-temperature refrigerant is eliminated at the lowest point of the airflow in the heat exchange section 108. Therefore, the amount of freezing of the condensate 200 can be reduced.

[0052] After the vehicle-mounted heat exchanger 100 has been in operation for a while, the air outlet 108B is not blocked by frost 400, so that condensed water 200 is less likely to pass through the gap between the drain pan 300 and the heat exchange section 108. Consequently, it is possible to suppress the scattering of condensed water 200 from the heat exchange section 108 into the interior of the chamber due to being pushed by the air. Under the above conditions, the amount of water scattering was zero.

[0053] In other words, in this embodiment, since the vehicle-mounted heat exchanger 100 includes parallel flow paths 120 and 140, the amount of freezing on the downstream side of the airflow in the heat exchange section 108 is reduced. Therefore, the amount of ice scattered by the cold air can be reduced.

[0054] Furthermore, since it becomes more difficult for air to pass through the gap between the drain pan 300 and the heat exchange section 108, it becomes easier for air to pass through the heat exchange section 108. Therefore, since the air undergoes heat exchange in the heat exchange section 108, a decrease in the cooling efficiency of the heat exchange section 108 can be suppressed.

[0055] Specifically, if the cooling performance of the current product immediately after starting operation is set to 100, the improved product, which includes parallel flow paths 120 and 140, will have a cooling performance of 92 immediately after starting operation. In addition, because the heat exchange area of ​​the improved product decreases by approximately 5% due to condensate freezing, the decrease in cooling performance due to condensate freezing immediately after starting operation is 5%.

[0056] As mentioned above, the freezing performance of the current product decreased from 100 to 80 when freezing condensate, but the improved product's freezing performance only decreased by 5% from 92, resulting in a freezing performance of 88. In other words, the improved product's freezing performance when freezing condensate is 10% better than the current product.

[0057] In this embodiment, since the number of counterflow paths 110, 130, and 150 is greater than the number of parallel flow paths 120 and 140, it was possible to reduce the decrease in refrigeration performance during the initial stages of refrigeration immediately after starting operation.

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

[0059] The current model has a freezing performance of 100, while the improved model has a freezing performance of 92. Therefore, in the initial stages of operation, the current model will reach the lower limit of the temperature control range first. For example, the current model will reach the lower limit of the temperature control range in 120 minutes. The improved model will reach the lower limit of the temperature control range later, by a time corresponding to -8% of the freezing performance of the current model. The time to reach the lower limit will be about 9 minutes later than that of the current model.

[0060] After the internal temperature reaches the lower limit of the temperature control range, control is implemented to prevent the internal temperature from exceeding the temperature control range. In other words, the refrigeration unit stops. If the internal temperature reaches the upper limit of the temperature control range during the refrigeration unit stop period, the refrigeration unit starts again. In this way, the internal temperature is controlled within the temperature control range by the refrigeration unit repeatedly starting and stopping.

[0061] Furthermore, when condensate is frozen, the current product takes, for example, 10 minutes to reach the lower limit of the temperature control range. The current product has a freezing performance of 80, while the improved product has a freezing performance of 88, so the improved product will reach the lower limit of the temperature control range faster than the current product. The improved product's freezing performance is 10% higher than the current product, so it will reach the lower limit of the temperature control range about 1 minute faster than the current product. In this way, when condensate is frozen, the improved product's freezing performance can shorten the time it takes to cool the inside of the refrigerator.

[0062] This disclosure is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit of this disclosure, as follows.

[0063] For example, the number of paths 110-150 is not limited to 5.

[0064] The heat exchange section 108 only needs to have at least one path 110-150. As shown in Figure 6, in the case of one path 110, the downstream tube 111, which is located at the downstream end of the refrigerant flow, should be positioned on the downstream side of the airflow within the heat exchange section 108 in the airflow direction.

[0065] If the number of paths 110-150 is large, such as 10, then the distributor 106 and the manifold 107 may be provided in multiple stages rather than just one.

[0066] The uppermost tubes 112, 132, and 152 of the counterflow paths 110, 130, and 150, and the lowermost tubes 121 and 141 of the parallel flow paths 120 and 140, do not necessarily have to be arranged in a staggered vertical configuration at the lowest point of the airflow within the heat exchange section 108. For example, the uppermost tubes 112, 132, and 152 of the counterflow paths 110, 130, and the lowermost tubes 121 and 141 of the parallel flow paths 120 and 140 may be positioned at the same location in the direction of airflow. The same applies to the lowermost tubes 111, 131, and 151 of the counterflow paths 110, 130, and the uppermost tubes 122 and 142 of the parallel flow paths 120 and 140.

[0067] The number of counterflow paths 110, 130, and 150 and the number of parallel flow paths 120 and 140 can be set as appropriate. It is preferable that the number of counterflow paths 110, 130, and 150 is greater than the number of parallel flow paths 120 and 140, i.e., that the number of paths is odd, but it is also acceptable for the number of counterflow paths 110, 130, and 150 and the number of parallel flow paths 120 and 140 to be the same.

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

[0069] Each path 110-150 may be connected vertically across layers, as long as the refrigerants are either in opposing or parallel flows. For example, tube 102 of the opposing flow path 110 is connected to tube 102 of the opposing flow path 130.

[0070] This disclosure is described in accordance with the embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the equivalence. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure.

[0071] The technical features of the automotive heat exchanger disclosed herein are as follows: (Item 1) The heat exchange section (108) includes a plurality of plate fins (101) that are plate-shaped and arranged in parallel, and a plurality of tubes (102) that penetrate the plurality of plate fins and through which the refrigerant flows. If we define the refrigerant flow path through the heat exchange section as a path (110-150), then the plurality of tubes constitute at least one path. An in-vehicle heat exchanger in which the downstreammost tube (121, 141) located at the downstream end of the refrigerant flow in at least one of the aforementioned paths is positioned on the downstream side of the airflow in the heat exchange section in an airflow direction parallel to the plane direction of the plurality of plate fins. (Item 2) The aforementioned multiple tubes constitute multiple paths, The vehicle-mounted heat exchanger according to item 1, wherein at least one of the plurality of paths constitutes a parallel flow path (120, 140) in which the downstreammost tube is positioned at the downstreammost point of the airflow in the heat exchange section in the airflow direction, and the refrigerant movement direction, which indicates the direction of movement of the refrigerant in the airflow direction, and the airflow direction are parallel flows. (Item 3) The vehicle-mounted heat exchanger according to item 2, wherein the plurality of paths include an upstream tube (112, 132, 152) located at the uppermost upstream of the refrigerant flow in the heat exchange section, which is positioned at the lowermost downstream of the airflow in the heat exchange section in the airflow direction, and a counterflow path (110, 130, 150) in which the refrigerant movement direction and the airflow direction are in opposite directions. (Item 4) The vehicle-mounted heat exchanger according to item 3, wherein the uppermost tube of the counterflow path and the lowermost tube of the parallel flow path are arranged in a staggered vertical direction perpendicular to the refrigerant flow direction and the airflow direction in which the refrigerant flows through the plurality of tubes at the lowest point of the airflow in the heat exchange section. (Item 5) The plurality of paths include a counterflow path (110, 130, 150) in which the upstream tube (112, 132, 152) located at the uppermost upstream of the refrigerant flow in the heat exchange section is positioned at the lowermost downstream of the airflow in the heat exchange section in the airflow direction, and the refrigerant movement direction and the airflow direction are opposing flows. The vehicle-mounted heat exchanger according to item 3 or 4, wherein the number of counterflow paths is greater than the number of parallel flow paths. (Item 6) The plurality of paths include a counterflow path (110, 130, 150) in which the upstream tube (112, 132, 152) located at the uppermost upstream of the refrigerant flow in the heat exchange section is positioned at the lowermost downstream of the airflow in the heat exchange section in the airflow direction, and the refrigerant movement direction and the airflow direction are opposing flows. The vehicle-mounted heat exchanger according to any one of items 3 to 5, wherein the downstreammost tubes (111, 131, 151) located at the downstream end of the refrigerant flow in the counterflow path and the upstreammost tubes (122, 142) located at the upstream end of the refrigerant flow in the parallel flow path are arranged in a staggered manner in a vertical direction perpendicular to the refrigerant flow direction and the airflow direction at the upstream end of the airflow in the heat exchange section.

Claims

1. The heat exchange section (108) includes a plurality of plate fins (101) that are plate-shaped and arranged in parallel, and a plurality of tubes (102) that penetrate the plurality of plate fins and through which the refrigerant flows. If the refrigerant flow path through which the refrigerant flows in the heat exchange section is defined as a path (110-150), then the plurality of tubes constitute the path, and the path is continuously connected from the upstream side of the airflow in the heat exchange section to the downstream side of the airflow in the air exchange section in an airflow direction parallel to the plane direction of the plurality of plate fins. The aforementioned path is, The downstreammost tube (121, 141) located at the downstream end of the refrigerant flow in the heat exchange section is positioned at the downstream end of the airflow in the airflow direction of the heat exchange section, and the parallel flow path (120, 140) is such that the refrigerant movement direction, which indicates the direction of movement of the refrigerant in the airflow direction, and the airflow direction are parallel flows. The uppermost tube (112, 132, 152) located at the uppermost part of the refrigerant flow in the heat exchange section is positioned at the lowermost part of the airflow in the heat exchange section in the airflow direction, and the refrigerant movement direction and the airflow direction are in opposition to each other in the counterflow path (110, 130, 150), Includes, The parallel flow path and the opposing flow path are arranged alternately along a vertical direction perpendicular to the refrigerant flow direction and the airflow direction through which the refrigerant flows in the plurality of tubes, so as to be adjacent to each other. Furthermore, the vehicle-mounted heat exchanger includes a distributor (106) that independently distributes and supplies the refrigerant to the parallel flow path and the counterflow path, respectively.

2. The vehicle-mounted heat exchanger according to claim 1, wherein the upstream tube of the counterflow path and the downstream tube of the parallel flow path are arranged in a staggered manner in the vertical direction at the downstream end of the airflow in the heat exchange section.

3. The vehicle-mounted heat exchanger according to claim 1 or 2, wherein the number of counterflow paths is greater than the number of parallel flow paths.

4. The on-board heat exchanger according to claim 1 or 2, wherein the opposing downstream tubes (111, 131, 151) located at the downstream end of the refrigerant flow in the opposing flow path and the parallel upstream tubes (122, 142) located at the upstream end of the refrigerant flow in the parallel flow path are arranged in a staggered manner in the vertical direction at the upstream end of the air flow in the heat exchange section.

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