Heat exchanger

Abstract

A heat exchanger includes a first heat exchange portion (10) and a second heat exchange portion (20). The first heat exchange portion includes a first header tank (11) having an inflow portion (110) into which a heat medium flows. The second heat exchange portion includes a second header tank (21) having an outflow portion (210) from which the heat medium flows. The first header tank and the second header tank are connected to each other via a connecting portion (30). A slit (31) is formed through the connecting portion.

Description

[0001] Cross-reference of related applications

[0002] This application is based on and claims priority to Japanese Patent Application No. 2020-074064, filed on April 17, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a heat exchanger. Background Technology

[0004] Conventionally, there exists a heat exchanger as described in Patent Document 1. The heat exchanger described in Patent Document 1 performs heat exchange between a refrigerant flowing inside it and air flowing outside it. This heat exchanger includes a first heat exchange section and a second heat exchange section arranged in series with respect to the air flow direction. The first and second heat exchange sections each have a core portion formed by stacking multiple tubes for refrigerant flow and a manifold box connected to the ends of the multiple tubes. The manifold box of each heat exchange section has a tube joint portion that engages with the multiple tubes and a main body portion that, together with the tube joint portion, forms the internal space of the box. The tube joint portions of each heat exchange section are integrally formed. Therefore, in the heat exchanger described in Patent Document 1, the manifold boxes of each heat exchange section are interconnected.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-2609

[0008] When the heat exchanger described in Patent Document 1 is used as a condenser, for example, in a heat pump cycle, a high-temperature gaseous heat medium flows into the manifold of the first heat exchange section. As the gaseous heat medium flows into the manifold of the first heat exchange section and the core of the second heat exchange section, it exchanges heat with air. As a result, the heat of the heat medium is absorbed by the air, thereby heating the air. In a heat pump cycle, for example, heating of the vehicle interior can be achieved by blowing this heated air into the vehicle interior. The temperature of the gaseous heat medium gradually decreases through heat exchange with the air, transitioning to a liquid phase heat medium. The low-temperature liquid phase heat medium is collected in the manifold of the second heat exchange section and then discharged to the outside.

[0009] Thus, when the heat exchanger described in Patent Document 1 is used as a condenser, the manifold of the first heat exchange section, which supplies the high-temperature gaseous heat medium, deforms thermally in the extending direction, while the manifold of the second heat exchange section, which supplies the low-temperature liquid heat medium, deforms thermally in the contracting direction. As a result, there is a possibility that the entire first and second manifolds may deform into an arc shape. Thus, when each manifold deforms due to thermal strain, stress is generated in the pipes connected to the manifolds. Through simulation analysis by the inventors, it has been confirmed that such stress is particularly prone to concentrate at the ends of the pipes located inside the manifolds. Because of this stress concentration at the pipe ends, there is a concern that pipe deformation or deterioration may lead to pipe breakage. Summary of the Invention

[0010] The purpose of this invention is to provide a heat exchanger that can mitigate stress concentration caused by the deformation of a manifold based on thermal strain.

[0011] One aspect of the heat exchanger of the present invention is a heat exchanger that exchanges heat between a heat medium flowing inside and air flowing outside. The heat exchanger includes a first heat exchange section and a second heat exchange section, which are arranged opposite to each other in the direction of air flow and connected in a manner that allows the heat medium to flow between them. The first heat exchange section includes: a first core, which is constructed of a stacked structure of a plurality of tubes through which the heat medium flows; and a first manifold box, which is connected to the ends of the plurality of first cores and has an inlet for the heat medium to flow into. The second heat exchange section includes: a second core, which is constructed of a stacked structure of a plurality of tubes through which the heat medium flows; and a second manifold box, which is connected to the ends of the plurality of second cores and has an outlet for the heat medium to flow out. A gaseous heat medium flows in the first manifold box, and a liquid heat medium flows in the second manifold box, the liquid phase of which is at a lower temperature than the gaseous heat medium flowing in the first manifold box. The first manifold box and the second manifold box are connected to each other via a connecting part, and a slit is formed in the connecting part in such a way that it passes through the connecting part.

[0012] According to this structure, since the hot medium flowing into the first manifold box from the inlet section exchanges heat with air in the first and second core sections before flowing into the second manifold box, the temperature of the hot medium flowing in each manifold box is different. Therefore, the aforementioned thermal strain occurs in the first and second manifold boxes. In this structure, when each manifold box deforms due to thermal strain, the difference in deformation between the manifold boxes can be absorbed through the slits in the connecting section in the airflow direction. Furthermore, by providing slits in the connecting section, deformation of each manifold box in the length direction of the pipe is allowed, thus the pipe is less likely to be restricted by each manifold box in the length direction of the pipe. In this way, the difference in deformation between the manifold boxes is absorbed through the slits in the connecting section, and the pipe is less likely to be restricted by each manifold box, thereby minimizing stress in the pipe even when the manifold boxes deform due to thermal strain. Therefore, stress concentration in the pipe can be mitigated. Attached Figure Description

[0013] Figure 1 This is a diagram schematically showing the structure of the heat exchanger according to the first embodiment.

[0014] Figure 2 This is a front view showing the front structure of the heat exchanger in the first embodiment.

[0015] Figure 3 This is a rear view showing the back structure of the heat exchanger in the first embodiment.

[0016] Figure 4 This is a top view showing the upper surface structure of the heat exchanger in the first embodiment.

[0017] Figure 5 This is a cross-sectional view showing the cross-sectional structure of the downwind first box and the upwind first box of the heat exchanger in the first embodiment.

[0018] Figure 6 This is a top view schematically illustrating the deformation of the upper surface structure of the heat exchanger in the first embodiment caused by thermal strain.

[0019] Figure 7 This is a top view showing the upper surface structure of the heat exchanger in the second embodiment.

[0020] Figure 8 This is a top view showing the upper surface structure of the heat exchanger in the third embodiment.

[0021] Figure 9 This is a top view showing the upper surface structure of the heat exchanger according to the fourth embodiment.

[0022] Figure 10 This is a top view showing the upper surface structure of a heat exchanger in other embodiments.

[0023] Figure 11 This is a diagram schematically illustrating the structure of a heat exchanger in other embodiments.

[0024] Figure 12 This is a top view showing the upper surface structure of a heat exchanger in other embodiments.

[0025] Figure 13 This is a diagram schematically illustrating the structure of a heat exchanger in other embodiments.

[0026] Figure 14 This is a diagram schematically illustrating the structure of a heat exchanger in other embodiments.

[0027] Figure 15 (A) and (B) are cross-sectional views showing the cross-sectional structure of the heat exchanger in other embodiments. Detailed Implementation

[0028] Hereinafter, one embodiment of the heat exchanger will be described with reference to the accompanying drawings. For ease of understanding, the same symbols will be used as much as possible to represent the same structural elements in the drawings, and repeated descriptions will be omitted.

[0029] <First Implementation Method>

[0030] First, refer to Figure 1 The heat exchanger 1 of the first embodiment will be described.

[0031] Figure 1 The heat exchanger 1 shown can be used as an indoor condenser, for example, as a structural element of a heat pump cycle in an air conditioning system installed in a vehicle. The air conditioning system is a device that cools or heats the interior of a vehicle by cooling or heating air flowing within air conditioning ducts and blowing it into the vehicle interior. The heat pump cycle includes, in addition to the indoor condenser, an expansion valve, an indoor evaporator, an outdoor heat exchanger, and a compressor. The heat exchanger 1, acting as the indoor condenser, is disposed within the air conditioning ducts, and is used to heat the air conditioning air by exchanging heat between a heat medium flowing within it and the air conditioning air flowing within the ducts, thereby allowing the air conditioning air to absorb heat from the heat medium.

[0032] Next, the specific structure of heat exchanger 1 will be described.

[0033] like Figure 1As shown, the heat exchanger 1 includes a downwind heat exchange section 10 and an upwind heat exchange section 20. The heat exchanger 1 is formed of aluminum alloy or the like. The downwind heat exchange section 10 and the upwind heat exchange section 20 are arranged opposite each other in the airflow direction Y. The downwind heat exchange section 10 is located downstream of the upwind heat exchange section 20 in the airflow direction Y. In this embodiment, the downwind heat exchanger 10 corresponds to the first heat exchange section, and the upwind heat exchanger 20 corresponds to the second heat exchange section.

[0034] In addition, with Figure 1 The Z-axis direction, orthogonal to the airflow direction Y, is the vertical direction. Hereinafter, the upper part of the vertical direction Z will be referred to as "upper vertical direction Z1," and the lower part of the vertical direction Z will be referred to as "lower vertical direction Z2." Furthermore, the direction orthogonal to both the airflow direction Y and the vertical direction Z will be called the X-axis direction.

[0035] The downwind heat exchange section 10 includes a downwind first box 11, a downwind core 12, and a downwind second box 13. The downwind first box 11, the downwind core 12, and the downwind second box 13 are arranged in this order facing downward in the vertical direction Z2.

[0036] like Figure 2 As shown, the downwind core 12 has a stacked structure in which multiple tubes 120 and multiple fins 121 are arranged alternately. In this embodiment, the downwind core 12 corresponds to the first core.

[0037] The tube 120 is a flattened component with a cross-sectional shape orthogonal to the vertical direction Z. Multiple tubes 120 are stacked at predetermined intervals along the X-axis. Each tube 120 extends in the vertical direction Z. The internal space of each tube 120 forms a flow path for the heating medium. Air flows in the direction indicated by arrow Y through the gaps formed between adjacent tubes 120.

[0038] Fins 121 are disposed in the gap between adjacent tubes 120, 120. Fins 121 are so-called corrugated fins, formed by corrugatingly bending a thin metal plate. The tips of the bent portions of fins 121 are brazed to the outer surface of tubes 120. Fins 121 are provided to increase the heat transfer area for air flowing outside tubes 120.

[0039] A leeward first housing 11 is located at the upper end of the leeward core 12. The leeward first housing 11 is cylindrical with axis m1 as its center. Axis m1 is a direction parallel to the X-axis. The leeward first housing 11 extends in the X-axis direction. The upper ends of each pipe 120 of the leeward core 12 are connected to the leeward first housing 11. An inflow portion 110 is provided at one end of the leeward first housing 11 in the X-axis direction. The inflow portion 110 functions as a connector for connecting pipes, etc., and is a portion that allows the heat medium supplied through pipes, etc., to flow into the interior of the leeward first housing 11. In this embodiment, the leeward first housing 11 corresponds to a first manifold box.

[0040] The second box 13 on the leeward side is located at the lower end of the core 12 on the leeward side. The second box 13 on the leeward side is cylindrical in shape, just like the first box 11 on the leeward side. The lower ends of each tube 120 of the core 12 on the leeward side are connected to the second box 13 on the leeward side.

[0041] like Figure 1 As shown, the upwind heat exchange section 20 includes an upwind first chamber 21, an upwind core 22, and an upwind second chamber 23. The upwind first chamber 21, the upwind core 22, and the upwind second chamber 23 are arranged in this order, facing downwards in the vertical direction Z2. Figure 3 As shown, the upwind core 22 is composed of a tube 220 and fins 221. In this embodiment, the upwind core 22 corresponds to the second core.

[0042] Since the structures of the components constituting the upwind heat exchange section 20 are basically the same as those of the corresponding components of the downwind second housing 13, detailed descriptions of these structures are omitted. However, an outflow section 210 is provided at one end of the upwind first housing 21 in the X-axis direction, instead of the inflow section 110. The outflow section 210 functions as a connector for connecting pipes, etc., and is a portion that allows the heat medium collected inside the upwind first housing 21 to flow out to the outside through pipes, etc. In this embodiment, the upwind first housing 21 corresponds to the second manifold box. Furthermore, Figure 3 The symbol m2 shown represents the central axis of the first box 21 on the upwind side.

[0043] The internal space of the downwind second box 13 and the internal space of the upwind second box 23 are directly connected or indirectly connected via piping, other boxes, etc. Therefore, the heat medium flowing in the internal space of the downwind second box 13 can flow into the internal space of the upwind second box 23. Thus, in the heat exchanger 1 of this embodiment, the downwind heat exchange section 10 and the upwind heat exchange section 20 are connected in a manner that allows the heat medium to flow between them.

[0044] like Figure 4As shown, the central axis m1 of the first box 11 on the leeward side and the central axis m2 of the first box 21 on the upwind side are parallel to each other. Hereinafter, the X-axis direction, which is parallel to each central axis m1 and m2, will be referred to as the "box length direction X".

[0045] like Figure 4 As shown, the leeward first box 11 and the upwind first box 21 are connected to each other via a connecting part 30. Specifically, as... Figure 5 As shown, the downwind first box 11 and the upwind first box 21 are composed of a first plate component 41 and a second plate component 42.

[0046] The first plate component 41 is formed of a flat aluminum alloy. A first insertion hole 411 and a second insertion hole 412 are formed separately in the first plate component 41 in the Y-axis direction. The first insertion hole 411 and the second insertion hole 412 are formed to penetrate the first plate component 41 in the thickness direction. Multiple first insertion holes 411 are arranged at predetermined intervals in the box length direction X. The upper end of the tube 120 of the downwind core 12 is inserted into and engaged with the first insertion hole 411. Similarly, multiple second insertion holes 412 are arranged at predetermined intervals in the box length direction X. The upper end of the tube 220 of the upwind core 22 is inserted into and engaged with the second insertion hole 412.

[0047] The second plate component 42 is formed by bending a flat aluminum alloy plate to create two hills 420 and 421. The two hills 420 and 421 are formed to protrude vertically upward Z1 and extend parallel to each other in the length direction X of the box.

[0048] The first plate component 41 is joined to the bottom surface of the second plate component 42 by brazing or the like. Multiple claw portions 410 of the first plate component 41 are riveted to both ends of the second plate component 42 in the airflow direction Y. Furthermore, in Figure 4 The illustration of the claw part 410 is omitted in the text.

[0049] In the heat exchanger 1 of this embodiment, the downwind first box 11 is composed of Figure 5 The first plate member 41 and the second plate member 42 shown are formed by the mountain portion 420. Furthermore, the upwind side first box 21 is formed by the mountain portion 421 of the first plate member 41 and the second plate member 42. The downwind side first box 11 and the upwind side first box 21 are connected to each other via the joint portion 30 of the first plate member 41 and the second plate member 42 disposed between them. In this embodiment, since the joint portion 30 corresponds to the connecting portion connecting the downwind side first box 11 and the upwind side first box 21, the joint portion 30 will be referred to as "connecting portion 30" below. The downwind side first box 11, the upwind side first box 21, and the connecting portion 30 are disposed vertically upward Z1 relative to the downwind side core portion 12 and the upwind side core portion 22.

[0050] like Figure 4 As shown, a plurality of slits 31 are formed in the connecting portion 30. Each slit 31 is formed to penetrate the connecting portion 30 in the vertical direction Z. Each slit 31 is constituted by a through hole having a rectangular shape in the length direction X of the box. The plurality of slits 31 are arranged at a predetermined slit interval W1 in the length direction X of the box. Each slit 31 is positioned to overlap with the pipe 120 of the downwind core 12 and the pipe 220 of the upwind core 22 in the airflow direction Y. The length W2 of each slit 31 in the length direction X of the box is longer than the slit interval W1.

[0051] Furthermore, when the end face opposite to the portion of the first leeward box 11 connected to the connecting portion 30 in the airflow direction Y is designated as the box end face 111, the tube 120 of the leeward core 12 is positioned closer to the connecting portion 30 in the airflow direction Y than the box end face 111. Consequently, the shortest distance H12 from the box end face 111 of the leeward first box 11 to the outer edge of the tube 120 in the airflow direction Y is longer than the shortest distance H11 from the slit 31 to the outer edge of the tube 120 in the airflow direction Y. Similarly, the shortest distance H22 from the box end face 211 of the upwind first box 21 to the outer edge of the tube 220 in the airflow direction Y is longer than the shortest distance H21 from the slit 31 to the outer edge of the tube 220 in the airflow direction Y.

[0052] Next, an example of the operation of the heat exchanger 1 in this embodiment will be described.

[0053] In the heat exchanger 1 of this embodiment, the heat medium is as follows: Figure 1 The flow is as indicated by the arrow. That is, in the heat exchanger 1, when the heat medium flows from the inlet 110 into the interior space of the downwind first box 11, the heat medium is distributed from the downwind first box 11 to each pipe 120 of the downwind core 12. The heat medium flowing through each pipe 120 of the downwind core 12 is collected in the interior space of the downwind second box 13 and then flows into the interior space of the upwind second box 23. The heat medium flowing into the interior space of the upwind second box 23 is distributed to each pipe 220 of the upwind core 22 and then collected in the upwind first box 21. The heat medium collected in the upwind first box 21 flows outward from the outlet 210.

[0054] In this heat exchanger 1, a high-temperature gaseous heat medium, or a high-temperature two-phase heat medium consisting of a gaseous and liquid mixture, flows into the downwind first chamber 11 via the inlet 110. The high-temperature heat medium flowing into the inlet 110 exchanges heat with the air as it flows through the pipes 120 of the downwind core 12 and the pipes 220 of the upwind core 22, thereby releasing its heat to the air. Thus, the air is heated. In contrast, the high-temperature gaseous heat medium is cooled and transitions to a liquid phase. Therefore, the proportion of liquid heat medium is greater than the proportion of gaseous heat medium as it flows from the downwind first chamber 11 towards the upwind first chamber 21. Furthermore, most of the heat medium flowing within the upwind first chamber 21 becomes a low-temperature liquid phase.

[0055] Thus, in heat exchanger 1, heat media with large temperature differences flow in the downwind first box 11 and the upwind first box 21, which are connected to each other. With this configuration, the thermal strain generated in boxes 11 and 21 results in concerns about deformation of the pipes 120 and 220.

[0056] Specifically, the downwind first box 11, which supplies the high-temperature heat medium, undergoes thermal deformation by extending in the box length direction X, while the upwind first box 21, which supplies the low-temperature heat medium, undergoes thermal deformation by contracting in the box length direction X. Thus, as... Figure 6 As shown, the first box 11 on the leeward side and the first box 21 on the upwind side are deformed into an arc shape. Thus, through simulation analysis by the inventors, it has been confirmed that stress is particularly prone to concentrate when deforming through boxes 11 and 21. Figure 4 Regions A1 and A2 on the inner sides of each of the tubes 120 and 220 are shown. Due to stress concentration in these regions, there is a concern about deformation of each of the tubes 120 and 220.

[0057] In this respect, such as Figure 4 and Figure 5 As shown, in the heat exchanger 1 of this embodiment, since multiple slits 31 are formed in the connecting portion 30, when the housings 11 and 21 deform into an arc shape due to thermal strain, the difference in the amount of deformation of the housings 11 and 21 can be absorbed through the slits 31 of the connecting portion 30 in the airflow direction Y. Furthermore, by providing slits 31 in the connecting portion 30, deformation of the housings 11 and 21 in the vertical direction Z is allowed; in other words, deformation of the housings 11 and 21 in the length direction of each tube 120 and 220 is allowed. Therefore, the tubes 120 and 220 are less likely to be restricted by the housings 11 and 21 in their length direction. Thus, the difference in the amount of deformation of the housings 11 and 21 is absorbed by the slits 31 of the connecting portion 30, and the tubes 120 and 220 are less likely to be restricted by the housings 11 and 21. Therefore, even when the housings 11 and 21 deform due to thermal strain, stress is less likely to be generated in the tubes 120 and 220. Therefore, stress concentration in the tubes 120 and 220 can be alleviated.

[0058] The heat exchanger 1 of this embodiment described above can achieve the following functions and effects (1) to (5).

[0059] (1) A slit 31 is formed in the connecting portion 30 through the connecting portion 30, which connects the downwind first box 11 and the upwind first box 21 to each other. According to this structure, since the difference in the amount of deformation of boxes 11 and 21 caused by thermal strain can be absorbed through the slit 31, the stress concentration of pipes 120 and 220 can be mitigated.

[0060] (2) Figure 4 As shown, the length W2 of the slit 31 in the box length direction X is longer than the length W1 of the slit interval in the box length direction X. According to this structure, compared with the case where the length W2 of the slit 31 is shorter than the slit interval W1, since the slit 31 can more easily absorb the difference in the amount of deformation of the boxes 11 and 21 caused by thermal strain, the stress concentration of the tubes 120 and 220 can be more accurately mitigated.

[0061] (3) Figure 6 As shown, when boxes 11 and 21 deform into an arc shape due to thermal strain, the deformation of the portion near the end face 111 of the first box 11 on the leeward side is greater than the deformation of the portion near the connecting portion 30. Similarly, on the first box 21 on the leeward side, the deformation of the portion near the end face 211 is greater than the deformation of the portion near the connecting portion 30. In this respect, in the heat exchanger 1 of this embodiment, as... Figure 4 As shown, the shortest distance H12 from the end face 111 of the leeward first box 11 to the outer edge of the pipe 120 in the airflow direction Y is longer than the shortest distance H11 from the slit 31 to the outer edge of the pipe 120 in the airflow direction Y. Similarly, the shortest distance H22 from the end face 211 of the upwind first box 21 to the outer edge of the pipe 220 in the airflow direction Y is longer than the shortest distance H21 from the slit 31 to the outer edge of the pipe 220 in the airflow direction Y. According to this structure, since it is possible to avoid placing the pipes 120 and 220 in the parts where the deformation is likely to increase when the boxes 11 and 21 deform into an arc shape due to thermal strain, the stress concentration of the pipes 120 and 220 can be further mitigated more accurately.

[0062] (4) The slit 31 is positioned in the airflow direction Y, overlapping with the tube 120 of the downwind core 12 and the tube 220 of the upwind core 22. According to this structure, since the slit 31 is arranged near each tube 120 and 220, the stress concentration of each tube 120 and 220 can be further mitigated by the slit 31.

[0063] (5) The downwind first box 11 and the upwind first box 21 are each composed of a first plate component 41 for connecting the tubes 120 and 220 of the cores 12 and 22, and a second plate component 42 assembled on the first plate component 41. The second plate component 42 and the first plate component 41 together form the internal space of the downwind first box 11 and the internal space of the upwind first box 21. The connecting part 30 is composed of the portion of the first plate component 41 and the second plate component 42 located between the internal space of the downwind first box 11 and the internal space of the upwind first box 21. According to this structure, the downwind first box 11 and the upwind first box 21 can be easily connected via the connecting part 30.

[0064] <Second Implementation Method>

[0065] Next, the heat exchanger 1 of the second embodiment will be described. Hereinafter, the description will focus on the differences from the heat exchanger 1 of the first embodiment.

[0066] like Figure 7 As shown, in the heat exchanger 1 of this embodiment, the lengths of the end slit 31a and the central slit 31b are different. Specifically, the end slit 31a is one of the plurality of slits 31 that is located at the end of the connecting portion 30 in the box length direction X. The central slit 31b is one of the plurality of slits 31 that is located near the center of the connecting portion 30 compared to the end slit 31a. The length of the end slit 31a in the box length direction X is longer than the length of the central slit 31b in the box length direction X.

[0067] The heat exchanger 1 of this embodiment described above can further achieve the following functions and effects (6).

[0068] (6) When boxes 11 and 21 deform into an arc shape due to thermal strain, the deformation at the ends of boxes 11 and 21 is greater than that at the center. In this respect, if, as in the heat exchanger 1 of this embodiment, the length of the end slit 31a in the box length direction X is longer than the length of the central slit 31b in the box length direction X, since the portion where the deformation is likely to be greater when boxes 11 and 21 deform into an arc shape due to thermal strain is provided with a longer end slit 31a, the difference in the deformation of boxes 11 and 21 can be absorbed more accurately through the end slit 31a. Therefore, the stress concentration of tubes 120 and 220 can be further mitigated.

[0069] <Third Implementation Method>

[0070] Next, the heat exchanger 1 of the third embodiment will be described. Hereinafter, the description will focus on the differences from the heat exchanger 1 of the second embodiment.

[0071] like Figure 8As shown, in the heat exchanger 1 of this embodiment, the widths of the two ends 310a and 310b of the end slit 31a in the box length direction X are different. Specifically, one end 310a is the portion of the two ends of the end slit 31a in the box length direction X that is more disposed near the end of the connecting portion 30. The other end 310b is the portion of the two ends of the end slit 31a in the box length direction X that is more disposed near the center of the connecting portion 30. The width of the end 310a in the airflow direction Y is longer than the width of the other end 310b in the airflow direction Y.

[0072] The heat exchanger 1 of this embodiment described above can further achieve the following functions and effects (7).

[0073] (7) When boxes 11 and 21 deform into an arc shape due to thermal strain, the deformation at the ends of boxes 11 and 21 is greater than that at the center. In this respect, if, as in the heat exchanger 1 of this embodiment, the width of one end 310a of the end slit 31a is longer than the width of the other end 310b, since a wider slit is provided in the part where the deformation of boxes 11 and 21 is likely to be greater when they deform into an arc shape due to thermal strain, the difference in the deformation of boxes 11 and 21 can be absorbed more accurately through the end slit 31a. Therefore, the stress concentration of tubes 120 and 220 can be further mitigated.

[0074] <Fourth Implementation Method>

[0075] Next, the heat exchanger 1 of the fourth embodiment will be described. Hereinafter, the description will focus on the differences from the heat exchanger 1 of the first embodiment.

[0076] like Figure 9 As shown, in the heat exchanger 1 of this embodiment, the slit 31 is formed in an elliptical shape, and in the box length direction X, the slit 31 is disposed between two adjacent tubes 120a and 120b of the downwind side core 12. Tube 120a is the tube among the two adjacent tubes that is disposed further in the box length direction X near the end 11a of the downwind side first box 11. Tube 120b is the tube among the two adjacent tubes that is disposed further in the box length direction X near the center of the downwind side first box 11. The shortest distance B11 from tube 120a to slit 31 is longer than the shortest distance B12 from tube 120b to slit 31.

[0077] Furthermore, the slit 31 is positioned in the box length direction X between two adjacent pipes 220a and 220b of the windward core 22. Pipe 220a is the one of the two adjacent pipes positioned further in the box length direction X near the end 21a of the windward first box 21. Pipe 220b is the one of the two adjacent pipes positioned further in the box length direction X near the center of the windward first box 21. The shortest distance B21 from pipe 220a to slit 31 is longer than the shortest distance B22 from pipe 220b to slit 31.

[0078] Furthermore, in this embodiment, pipes 120a and 220a correspond to the first pipe, and pipes 120b and 220b correspond to the second pipe.

[0079] The heat exchanger 1 of this embodiment described above can further achieve the following functions and effects (8).

[0080] (8) When boxes 11 and 21 deform into an arc shape due to thermal strain, the portion inside the tube 120 located near the connecting part 30, Figure 9 The deformation of part P11 is greater than that of part P12. Part P11 is the portion of the inner side of pipe 120 located near the end 11a of the first box 11 on the leeward side. Part P12 is the portion of the inner side of pipe 120 located near the center of the first box 11 on the leeward side. If, as in the heat exchanger 1 of this embodiment, the shortest distance B11 from pipe 120a to slit 31 is longer than the shortest distance B12 from pipe 120b to slit 31, then slit 31 is arranged near part P11 of pipe 120 where the deformation is greater. Therefore, stress concentration in pipe 120 can be further mitigated. The same effect can be obtained for pipe 220.

[0081] <Other Implementation Methods>

[0082] In addition, each implementation method can also be implemented in the following ways.

[0083] like Figure 10 As shown, the inflow portion 110 of the downwind first box 11 and the outflow portion 210 of the upwind first box 21 can also be formed as one unit. In the heat exchanger 1, the temperature difference is greatest between the inflow portion 110, where a high-temperature heat medium flows in, and the outflow portion 210, where a low-temperature heat medium flows out. Therefore, when the inflow portion 110 and the outflow portion 210 are arranged adjacent to each other, there is a possibility that the thermal strain they generate is the greatest. In this respect, if as Figure 10As shown, the inflow portion 110 and the outflow portion 210 are formed as a single unit. Since their rigidity can be increased, deformation of the inflow portion 110 and the outflow portion 120 caused by thermal strain can be suppressed. As a result, since deformation of each box 11, 21 caused by thermal strain can be suppressed, stress concentration in the pipe 120 can be further mitigated.

[0084] In the heat exchanger 1 of each embodiment, the flow pattern of the heat medium can also be appropriately modified. For example, Figure 11 As shown in the heat exchanger 1, it can also be configured such that partition walls 14 and 24 are provided inside the downwind first chamber 11 and the upwind first chamber 21 respectively, and the heat medium flows in a U-shape in the downwind heat exchange section 10 and the upwind heat exchange section 20. In this heat exchanger 1, the high-temperature heat medium flows from the inlet 110 into the internal space S11 of one of the two internal spaces S11 and S12 separated by the partition wall 14 in the downwind first chamber 11. Meanwhile, the low-temperature heat medium flows out from the internal space S21 of one of the two internal spaces S21 and S22 separated by the partition wall 24 in the upwind first chamber 21 through the outlet 210. In this configuration, thermal strain is particularly prone to occur between the portion of the downwind first chamber 11 containing the internal space S11 and the portion of the upwind first chamber 21 containing the internal space S21. Therefore, as Figure 12 As shown, a slit 31 may also be provided only in the portion of the connecting part 30 between the internal space S11 of the downwind first box 11 and the internal space S21 of the upwind first box 21.

[0085] The construction of boxes 11 and 21 in each embodiment is not limited to Figure 5 The structure shown can be modified as appropriate. For example, the downwind first box 11 and the upwind first box 21 can be formed from different components, and the connecting portion 30, which is composed of other components, can be brazed to the boxes 11 and 21 respectively. Alternatively, the downwind first box 11 and the upwind first box 21 can be directly brazed together, and the connecting portion 30 is formed by the brazed joint. In either configuration, a heat exchanger can be realized in which the boxes 11 and 21 are connected to each other via the connecting portion 30.

[0086] Alternatively, at least one of the tube 120 of the downwind core 12 and the tube 220 of the upwind core 22 may include a tube disposed at a position that does not overlap with the slit 31 in the airflow direction Y.

[0087] The structures of the downwind heat exchange section 10 and the upwind heat exchange section 20 in each embodiment can be appropriately modified. For example, Figure 13 and Figure 14As shown, the downwind heat exchange section 10 may also have a structure in which boxes 11 and 13 are respectively located at both ends of the downwind core section 12 in the X-axis direction. In addition, the upwind heat exchange section 20 may also have a structure in which boxes 21 and 23 are respectively located at both ends of the upwind core section 22 in the X-axis direction.

[0088] like Figure 15 As shown in (A) and (B), the tube 220 of the upwind core 22 and the tube 120 of the downwind core 12 can also be connected to each other via fins 40. Additionally, as... Figure 15 As shown in (A), slits 400 can also be formed in the fins 40. According to this structure, since the expansion and contraction of the tubes 120 and 220 can be restricted, the thermal strain of the boxes 11 and 21 can be suppressed.

[0089] This invention is not limited to the specific examples described above. Structures modified by those skilled in the art to suitably design the specific examples, as long as they possess the features of this invention, are included within the scope of this invention. The elements, their configurations, conditions, shapes, etc., of each of the specific examples described above are not limited to the illustrated content and can be appropriately modified. The elements of each of the specific examples described above can be appropriately combined and modified as long as they do not create technical contradictions.

Claims

1. A heat exchanger that performs heat exchange between a heat medium flowing in the inside and air flowing in the outside, characterized by comprising: a first heat exchange portion and a second heat exchange portion that are arranged opposite to each other in the flow direction of the air and are connected in a manner that allows the heat medium to flow therethrough, the first heat exchange portion including: a first core portion that is configured by a stacked structure of a plurality of tubes through which the heat medium flows; and a first header tank that is connected to end portions of the plurality of first core portions and has an inflow portion through which the heat medium flows, the second heat exchange portion including: a second core portion that is configured by a stacked structure of a plurality of tubes through which the heat medium flows; and a second header tank that is connected to end portions of the plurality of second core portions and has an outflow portion through which the heat medium flows, the heat medium in a gas phase flows in the first header tank, the heat medium in a liquid phase flows in the second header tank, the heat medium in the liquid phase is lower in temperature than the heat medium in the gas phase flowing in the first header tank, the first header tank and the second header tank are connected to each other via a connecting portion, a slit is formed in the connecting portion in a manner that penetrates the connecting portion, when a direction parallel to central axes of the first header tank and the second header tank is set as a tank length direction, a plurality of the slits are arranged in the connecting portion at a prescribed slit interval in the tank length direction, and a length of the slit in the tank length direction is longer than a length of the slit interval in the tank length direction.

2. The heat exchanger according to claim 1, characterized in that, of portions of the first header tank and the second header tank, portions at positions at which an inner space of the first header tank through which the heat medium in the gas phase flows and an inner space of the second header tank through which the heat medium in the liquid phase flows overlap in the flow direction of the air are connected to each other by the connecting portion at two or more positions.

3. The heat exchanger according to claim 1, characterized by further comprising fins that connect the first core portion and the second core portion.

4. The heat exchanger according to claim 1, characterized in that the slit is arranged at a position at which a tube of the first core portion and a tube of the second core portion overlap in the flow direction of the air.

5. The heat exchanger according to claim 4, characterized in that at least one of the tube of the first core portion and the tube of the second core portion includes a tube arranged at a position at which the tube does not overlap the slit in the flow direction of the air.

6. A heat exchanger that performs heat exchange between a heat medium flowing in the inside and air flowing in the outside, characterized by comprising: a first heat exchange portion and a second heat exchange portion that are arranged opposite to each other in the flow direction of the air and are connected in a manner that allows the heat medium to flow therethrough, the first heat exchange portion including: a first core portion that is configured by a stacked structure of a plurality of tubes through which the heat medium flows; and a first header tank that is connected to end portions of the plurality of first core portions and has an inflow portion through which the heat medium flows, the second heat exchange portion including: a second core portion that is configured by a stacked structure of a plurality of tubes through which the heat medium flows; and a second header tank that is connected to end portions of the plurality of second core portions and has an outflow portion through which the heat medium flows, the heat medium in a gas phase flows in the first header tank, the heat medium in a liquid phase flows in the second header tank, the heat medium in the liquid phase is lower in temperature than the heat medium in the gas phase flowing in the first header tank, the first header tank and the second header tank are connected to each other via a connecting portion, a slit is formed in the connecting portion in a manner that penetrates the connecting portion, when a direction parallel to central axes of the first header tank and the second header tank is set as a tank length direction, a plurality of the slits are arranged in the connecting portion at a prescribed slit interval in the tank length direction, and a length of the slit in the tank length direction is longer than a length of the slit interval in the tank length direction. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ a first header tank connected to end portions of a plurality of the first core portions and having an inflow portion into which the heat medium flows, the second heat exchange portion includes: a second core portion configured by a stacked structure of a plurality of tubes through which the heat medium flows; and a second header tank connected to end portions of a plurality of the second core portions and having an outflow portion from which the heat medium flows, the gaseous-phase heat medium flows in the first header tank, the liquid-phase heat medium flows in the second header tank, the liquid-phase heat medium being lower in temperature than the gaseous-phase heat medium flowing in the first header tank, the first header tank and the second header tank are connected to each other via a connection portion, a slit is formed through the connection portion, when an end surface of the first header tank on an opposite side to a portion connected to the connection portion in a flow direction of air is set as a tank end surface, a shortest distance in the flow direction of air from the tank end surface of the first header tank to an outer edge of the tube of the first core portion is longer than a shortest distance in the flow direction of air from the slit to the outer edge of the tube of the first core portion.

7. A heat exchanger that performs heat exchange between a heat medium flowing in an inside and air flowing in an outside, the heat exchanger being characterized by, including a first heat exchange portion and a second heat exchange portion that are arranged opposite to each other in a flow direction of air and are connected in a manner that the heat medium is able to flow through each other, the first heat exchange portion includes: a first core portion configured by a stacked structure of a plurality of tubes through which the heat medium flows; and a first header tank connected to end portions of a plurality of the first core portions and having an inflow portion into which the heat medium flows, the second heat exchange portion includes: a second core portion configured by a stacked structure of a plurality of tubes through which the heat medium flows; and a second header tank connected to end portions of a plurality of the second core portions and having an outflow portion from which the heat medium flows, the gaseous-phase heat medium flows in the first header tank, the liquid-phase heat medium flows in the second header tank, the liquid-phase heat medium being lower in temperature than the gaseous-phase heat medium flowing in the first header tank, the first header tank and the second header tank are connected to each other via a connection portion, a slit is formed through the connection portion, when an end surface of the second header tank on an opposite side to a portion connected to the connection portion in a flow direction of air is set as a tank end surface, a shortest distance in the flow direction of air from the tank end surface of the second header tank to an outer edge of the tube of the second core portion is longer than a shortest distance in the flow direction of air from the slit to the outer edge of the tube of the second core portion.

8. A heat exchanger that performs heat exchange between a heat medium flowing in an inside and air flowing in an outside, the heat exchanger being characterized by, including a first heat exchange portion and a second heat exchange portion that are arranged opposite to each other in a flow direction of air and are connected in a manner that the heat medium is able to flow through each other, The first heat exchange section includes: a first core section composed of a stacked structure of a plurality of tubes through which the heat medium flows; and a first header connected to end portions of the plurality of first core sections and having an inflow portion through which the heat medium flows, The second heat exchange section includes: a second core section composed of a stacked structure of a plurality of tubes through which the heat medium flows; and a second header connected to end portions of the plurality of second core sections and having an outflow portion through which the heat medium flows, The heat medium in a gas phase flows in the first header, The heat medium in a liquid phase flows in the second header, the heat medium in the liquid phase being lower in temperature than the heat medium in the gas phase flowing in the first header, The first header and the second header are connected to each other via a connection portion, A slit is formed in the connection portion in a manner that penetrates the connection portion, When a direction parallel to a central axis of the first header and a central axis of the second header is set as a header length direction, and an end portion of the two end portions of the slit in the header length direction that is disposed closer to an end portion of the connection portion is set as one end portion and an end portion that is disposed closer to a central portion of the connection portion is set as the other end portion, the width of the one end portion in the flow direction of the air is longer than the width of the other end portion in the flow direction of the air.

9. A heat exchanger that performs heat exchange between a heat medium flowing inside and air flowing outside, the heat exchanger being characterized by, including a first heat exchange section and a second heat exchange section that are disposed opposite each other in the flow direction of the air and are connected in a manner that allows the heat medium to flow therethrough, The first heat exchange section includes: a first core section composed of a stacked structure of a plurality of tubes through which the heat medium flows; and a first header connected to end portions of the plurality of first core sections and having an inflow portion through which the heat medium flows, The second heat exchange section includes: a second core section composed of a stacked structure of a plurality of tubes through which the heat medium flows; and a second header connected to end portions of the plurality of second core sections and having an outflow portion through which the heat medium flows, The heat medium in a gas phase flows in the first header, The heat medium in a liquid phase flows in the second header, the heat medium in the liquid phase being lower in temperature than the heat medium in the gas phase flowing in the first header, The first header and the second header are connected to each other via a connection portion, A slit is formed in the connection portion in a manner that penetrates the connection portion, When a direction parallel to a central axis of the first header and a central axis of the second header is set as a header length direction, a plurality of the slits are arranged in the connection portion in the header length direction, when a slit disposed at an end portion of the connection portion in the header length direction is set as an end slit and a slit disposed near a central portion of the connection portion in comparison with the end slit is set as a central slit, The length of the end slit in the tank length direction is longer than the length of the central slit in the tank length direction.

10. A heat exchanger that performs heat exchange between a heat medium flowing inside and air flowing outside, the heat exchanger being characterized by, having a first heat exchange portion and a second heat exchange portion that are arranged opposite each other in the flow direction of the air and are connected in a manner that allows the heat medium to flow therethrough, the first heat exchange portion having a first core portion that is configured by a stacked structure of a plurality of tubes through which the heat medium flows; and a first header tank that is connected to end portions of the plurality of first core portions and has an inflow portion through which the heat medium flows, the second heat exchange portion having a second core portion that is configured by a stacked structure of a plurality of tubes through which the heat medium flows; and a second header tank that is connected to end portions of the plurality of second core portions and has an outflow portion through which the heat medium flows, the heat medium in a gas phase flows in the first header tank, the heat medium in a liquid phase flows in the second header tank, the heat medium in the liquid phase being lower in temperature than the heat medium in the gas phase flowing in the first header tank, the first header tank and the second header tank are connected to each other via a connecting portion, a slit is formed in the connecting portion in a manner that penetrates the connecting portion, when a direction parallel to the central axis of the first header tank and the central axis of the second header tank is taken as a tank length direction, the slit is arranged between two adjacent tubes of the first core portion in the tank length direction, when a tube of the two tubes that is arranged closer to the end portion of the first header tank in the tank length direction is taken as a first tube, and a tube that is arranged closer to the central portion of the first header tank is taken as a second tube, the shortest distance from the first tube to the slit is longer than the shortest distance from the second tube to the slit.

11. A heat exchanger that performs heat exchange between a heat medium flowing inside and air flowing outside, the heat exchanger being characterized by, having a first heat exchange portion and a second heat exchange portion that are arranged opposite each other in the flow direction of the air and are connected in a manner that allows the heat medium to flow therethrough, the first heat exchange portion having a first core portion that is configured by a stacked structure of a plurality of tubes through which the heat medium flows; and a first header tank that is connected to end portions of the plurality of first core portions and has an inflow portion through which the heat medium flows, the second heat exchange portion having a second core portion that is configured by a stacked structure of a plurality of tubes through which the heat medium flows; and a second header tank that is connected to end portions of the plurality of second core portions and has an outflow portion through which the heat medium flows, the heat medium in a gas phase flows in the first header tank, the heat medium in a liquid phase flows in the second header tank, the heat medium in the liquid phase being lower in temperature than the heat medium in the gas phase flowing in the first header tank, the first header tank and the second header tank are connected to each other via a connecting portion, a slit is formed through the connection portion, when a direction parallel to the central axis of the first header tank and the central axis of the second header tank is set as a tank length direction, the slit is disposed between two adjacent tubes of the second core portion in the tank length direction, when a tube of the two tubes that is disposed closer to an end portion of the second header tank in the tank length direction is set as a first tube, and a tube that is disposed closer to a central portion of the second header tank is set as a second tube, a shortest distance from the first tube to the slit is longer than a shortest distance from the second tube to the slit.

12. The heat exchanger according to any one of claims 1 to 11, wherein the first header tank, the second header tank, and the connection portion are disposed above the first core portion and the second core portion in a vertical direction.

13. The heat exchanger according to any one of claims 1 to 11, wherein the first header tank and the second header tank are composed of a first plate member and a second plate member, the first plate member is connected to the tubes of the first core portion and the tubes of the second core portion, the second plate member is assembled to the first plate member, and the second plate member forms an internal space of the first header tank and an internal space of the second header tank together with the first plate member, the connection portion is composed of a portion of the first plate member and the second plate member that is disposed between the internal space of the first header tank and the internal space of the second header tank.

14. The heat exchanger according to any one of claims 1 to 11, wherein the inflow portion and the outflow portion are formed as one body.

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