Heat exchanger

Abstract

To maintain high heat conductivity even when components are joined to each other with adhesive.SOLUTION: A tube 10 and a fin 20 are joined by a resin material 6 having a melting point lower than a melting point of each of them, and the resin material 6 contains a plurality of fillers 5a, 5b, 5c. The heat conductivity of the fillers 5a, 5b, 5c is higher than that of the resin material 6, and the fillers 5a, 5b have a first contact surface in contact with the tube 10, and a second contact surface in contact with the fin.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a heat exchanger. [Background technology]

[0002] The following Patent Document 1 describes a heat exchanger in which components are bonded together with an adhesive. The components of the heat exchanger are required to maintain high thermal conductivity, but the adhesive has low thermal conductivity. Therefore, the following Patent Document 1 attempts to solve this problem by including a filler with high thermal conductivity in the adhesive. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6341098 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, heat is transferred through the contact area between the component and the filler, but if the filler is, for example, spherical, the contact area between the component and the filler is extremely narrow. If heat is transferred through this narrow contact area, the heat transfer is hindered by the contact resistance according to the smallness of the contact area. Therefore, it is conceivable to increase the surface area by making the filler larger, but since the total volume of the part bonded by the adhesive does not change, if the filler is made larger, the content tolerance will decrease, and as a result, the contact area cannot be increased.

[0005] An object of the present disclosure is to maintain high thermal conductivity even when components are joined together with an adhesive. [Means for solving the problem]

[0006] The present disclosure relates to a heat exchanger including a plurality of tubes (10) arranged at a predetermined interval, each of which has a first flow path (1b) through which a first medium passes, and fins (20) that contact each of the tubes arranged opposite to each other and form a second flow path (1a) through which a second medium passes and exchanges heat with the first medium. The tubes and the fins are joined by a resin material (6) having a melting point lower than the melting points of the tubes and the resin material contains a plurality of fillers (5a, 5b, 5c, 5, 5A, 5B). The thermal conductivity of the fillers is higher than that of the resin material, and the fillers include those having first contact surfaces (51a, 51b) in contact with the tubes and second contact surfaces (52a, 52b) in contact with the fins. Effect of the Invention

[0007] According to the present disclosure, high thermal conductivity can be maintained even when components are joined together with an adhesive. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a heat exchanger in this embodiment. [Diagram 2] FIG. 2 is a view taken along line II of FIG. [Diagram 3] FIG. 3 is an enlarged view for explaining the joint portion between the tube and the fin. [Figure 4] FIG. 4 is a diagram for explaining the process of joining the tubes and the fins. [Diagram 5] FIG. 5 is a diagram for explaining an example of the filler. [Figure 6] FIG. 6 is a diagram for explaining an example of the filler. [Figure 7] FIG. 7 is a diagram for explaining an example of the filler. [Figure 8] FIG. 8 is a diagram for explaining an example of the filler. [Figure 9] FIG. 9 is a diagram for explaining an example of the filler. [Figure 10] FIG. 10 is a diagram for explaining an example of the filler. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicated description will be omitted.

[0010] As shown in Fig. 1, the heat exchanger 1 includes a core section 2 and header tanks 3 and 4. The heat exchanger 1 exchanges heat between a first medium and a second medium. The core section 2 includes tubes 10 and fins 20. The tubes 10 are configured so that the first medium flows therethrough. A plurality of tubes 10 are provided, and the tubes 10 and the fins 20 are stacked alternately.

[0011] The refrigerant, which is the first medium, flows from the header tank 3 into the tubes 10, turns around at the header tank 3, re-flows into the tubes 10, and flows back into the header tank 3. The header tank 3 is provided with an inlet portion 31 that receives the refrigerant and an outlet portion 32 that allows the refrigerant to flow out.

[0012] In Fig. 1, x-axis, y-axis, and z-axis are set to be perpendicular to each other. The x-axis is set along the longitudinal direction of the tube 10 so as to be in the positive direction from the header tank 4 toward the header tank 3. The y-axis is set along the flow direction of the air flowing into the core part 2 so as to be in the positive direction from the upstream side of the air flow toward the downstream side (Fig. 1). The z-axis is set along the longitudinal direction of the header tanks 3 and 4 so as to be in the positive direction from the bottom to the top of Fig. 1.

[0013] As shown in Fig. 2, the fins 20 are configured to allow passing air, which is a second medium, to flow therethrough. A second flow path 1a through which the passing air flows is provided within the fins 20. A first flow path 1b through which a refrigerant, which is a first medium, flows is provided within the tubes 10. The fins 20 and the tubes 10 are in contact with each other and configured to be capable of heat exchange. Therefore, the configuration is such that heat exchange is possible between the passing air flowing through the fins 20 and the refrigerant flowing through the tubes 10.

[0014] The joint portion between the tube 10 and the fin 20 will be described with reference to Fig. 3. As shown in Fig. 3, the tube 10 and the fin 20 are joined by a resin material 6. The resin material 6 functions as an adhesive, and a material having a melting point lower than the melting points of the tube 10 and the fin 20 is selected. As the resin material 6, for example, a liquid material having thermoplasticity and thermosetting properties and containing epoxy resin as a main component is selected.

[0015] The resin material 6 is made of a material that functions as an adhesive, and therefore has low thermal conductivity, e.g., λ=0.3 [W / mK]. On the other hand, the tubes 10 and the fins 20 are made of aluminum, and therefore have high thermal conductivity, e.g., 250 [W / mK].

[0016] If the tube 10 and the fin 20 are bonded only with the resin material 6, the thermal conductivity decreases, and the performance as a heat exchanger decreases, so fillers 5a, 5b, and 5c are mixed into the resin material 6. For example, materials such as aluminum and boron nitride are used for the fillers 5a, 5b, and 5c. When boron nitride is selected as the material, the thermal conductivity is higher than that of the resin material 6, for example, 200 [W / mK].

[0017] As shown in FIG. 4, resin material 6 mixed with fillers 5a, 5b, and 5c is applied between tube 10 and fin 20. In the initial state, fillers 5a, 5b, and 5c are all spherical. Before resin material 6 hardens, it is pressurized along the z-axis to the state shown in FIG. 3. In the state shown in FIG. 4, the distance between tube 10 and fin 20 is the thickness tb of resin material 6. In the state shown in FIG. 3 after pressurization, the distance between tube 10 and fin 20 is the thickness ta of resin material 6. Before and after pressurization, the relationship is: thickness after pressurization ta < thickness before pressurization tb.

[0018] 3, filler 5a is compressed to a thickness approximately equal to thickness ta. Filler 5b is located slightly outside filler 5a, so it is compressed to a thickness greater than tb, but not to thickness ta. Filler 5c is not compressed to a thickness greater than tb, so it remains spherical.

[0019] The filler 5a will be described with reference to Fig. 5. Fig. 5(A) is a plan view of the filler 5a in the crushed state as described with reference to Fig. 3. Fig. 5(B) is a side view of the filler 5a in the crushed state as described with reference to Fig. 3. The filler 5a is crushed to a thickness 5at. The thickness 5at is equal to the thickness ta of the resin material described with reference to Fig. 3.

[0020] As shown in Fig. 5(B), the filler 5a has a first contact surface 51a that contacts the tube 10 and a second contact surface 52a that contacts the fin 20. As shown in Fig. 5(A), the longest part of the line segment included in the second contact surface 52a is defined as a maximum contact length 52al. Although not shown in the figure, a similar maximum contact length is also defined for the first contact surface 51a.

[0021] The first contact surface 51a is a surface that comes into contact with the tube 10, and therefore has a shape that conforms to the surface of the tube 10. In the present embodiment, the surface of the tube 10 is flat in the region where the fin 20 and the tube 10 are joined, and therefore the first contact surface 51a is also flat.

[0022] The second contact surface 52a is a surface that comes into contact with the fin 20, and therefore has a shape that follows the surface of the fin 20. In the present embodiment, the surface of the fin 20 is curved in the region where the filler 5a comes into contact with the fin 20, and therefore the second contact surface 52a also has a shape that follows the curved surface.

[0023] The maximum outer length 5al of the filler 5a is defined as the longest part of the line segment included in the projected area when viewed on the xy plane as shown in Fig. 5(A). The maximum outer length 5al of the filler 5a is longer than the thickness 5at of the resin material 6 along the thickness direction.

[0024] The filler 5b will be described with reference to Fig. 6. Fig. 6(A) is a plan view of the filler 5b in the crushed state as described with reference to Fig. 3. Fig. 6(B) is a side view of the filler 5b in the crushed state as described with reference to Fig. 3. The filler 5b is crushed to a thickness 5bt. Since the filler 5b is crushed at a portion shifted outward from the filler 5a, the thickness 5bt is thicker than the thickness ta of the resin material described with reference to Fig. 3.

[0025] As shown in Fig. 6(B), the filler 5b has a first contact surface 51b that contacts the tube 10 and a second contact surface 52b that contacts the fin 20. As shown in Fig. 6(A), the longest part of the line segment included in the second contact surface 52b is defined as a maximum contact length 52bl. Although not shown in the figure, a similar maximum contact length is also defined for the first contact surface 51b.

[0026] The first contact surface 51b is a surface that comes into contact with the tube 10, and therefore has a shape that conforms to the surface of the tube 10. In the present embodiment, the surface of the tube 10 is flat in the region where the fin 20 and the tube 10 are joined, and therefore the first contact surface 51b is also flat.

[0027] The second contact surface 52b is a surface that comes into contact with the fin 20, and therefore has a shape that follows the surface of the fin 20. In the present embodiment, the surface of the fin 20 is curved in the region where the filler 5b comes into contact with the fin 20, and therefore the second contact surface 52b also has a shape that follows the curved surface.

[0028] The maximum outer length 5bl of the filler 5b is defined as the longest part of the line segment included in the projected area when viewed on the xy plane as shown in Fig. 6(A). The maximum outer length 5bl of the filler 5b is longer than the thickness 5bt of the resin material 6 along the thickness direction.

[0029] The filler 5c will be described with reference to Fig. 7. Although the filler 5c is between the tube 10 and the fin 20, it is not crushed by being sandwiched between the tube 10 and the fin 20. Fig. 7(A) is a plan view of the filler 5c. Fig. 7(B) is a side view of the filler 5c.

[0030] Although the filler 5c is in contact with the tube 10, it is not crushed as described above, and therefore the contact with the tube 10 is point contact, not surface contact. The filler 5c is not in contact with the fins 20. Therefore, the filler 5c does not have a first contact surface that contacts the tube 10, and also does not have a second contact surface that contacts the fins 20.

[0031] The filler 5 shown in FIG. 8 is a filler having the same shape as the fillers 5a, 5b, and 5c, and is spherical. The shape of the filler is not limited to this, and a needle-like or fibrous filler 5A as shown in FIG. 9 can also be used. The filler 5A is easily deformed and broken when a compressive load is applied, so that the contact area with the tube 10 and the fin 20 can be made larger. In addition, as shown in FIG. 10, a scale-like filler 5B can also be used. The filler 5B can have a large surface area and is easily deformed, so that the contact area can be made larger. The fillers 5, 5A, and 5B can also be made into a porous structure. By making it a porous structure, it becomes easier to deform and the contact area can be made larger.

[0032] [Note] Notes 1 to 15 below can be combined in any way as long as there is no technical contradiction.

[0033] [Appendix 1] A plurality of tubes 10 are formed therein with a first flow path 1b through which a first medium passes, the tubes 10 being arranged at predetermined intervals; fins 20 that contact the tubes 10 arranged opposite to each other and form a second flow path 1a through which a second medium that exchanges heat with the first medium passes; A heat exchanger 1, in which the tubes 10 and the fins 20 are joined by a resin material 6 having a melting point lower than the melting point of each of the tubes 10 and the fins 20, the resin material 6 containing a plurality of fillers 5a, 5b, 5c, 5, 5A, 5B, the thermal conductivity of the fillers 5a, 5b, 5c, 5, 5A, 5B being higher than the thermal conductivity of the resin material 6, and the fillers 5a, 5b having first contact surfaces 51a, 51b in contact with the tubes 10 and second contact surfaces 52a, 52b in contact with the fins 20.

[0034] According to Supplementary Note 1, the fillers 5a and 5b have first contact surfaces 51a and 51b that contact the tubes 10, so that the cross-sectional area of ​​the heat transfer path between the tubes 10 and the fillers 5a and 5b can be increased, and the thermal resistance is reduced compared to the case of point contact. Also, the fillers 5a and 5b have second contact surfaces 52a and 52b that contact the fins 20, so that the cross-sectional area of ​​the heat transfer path between the fins 20 and the fillers 5a and 5b can be increased, and the thermal resistance is reduced compared to the case of point contact. Therefore, while the tubes 10 and the fins 20 are bonded with the resin material 6, the thermal conductivity between the tubes 10 and the fins 20 is improved, and the performance of the heat exchanger 1 can be improved.

[0035] [Appendix 2] The heat exchanger 1 according to appendix 1, wherein the fillers 5a, 5b, 5c, 5, 5A, and 5B include fillers whose first contact surfaces have different shapes or whose second contact surfaces have different shapes. For example, the shape of the first contact surface 51a of the filler 5a is different from the shape of the first contact surface 51b of the filler 5b. For example, the shape of the second contact surface 52a of the filler 5a is different from the shape of the second contact surface 52b of the filler 5b.

[0036] 3 and 4, the fillers 5a, 5b, and 5c are dispersed in the resin material 6 that bonds the tube 10 and the fins 20, so that the shape of the tube 10 is a fixed flat surface, but the shape of the fins 20 is a curved surface. Therefore, by including fillers 5a, 5b, 5c, 5, 5A, and 5B whose first contact surfaces have different shapes or whose second contact surfaces have different shapes, the contact surfaces with the tube 10 and the fins 20 can be shaped according to the location, and the contact area can be expanded.

[0037] [Appendix 3] The heat exchanger 1 according to appendix 1 or 2, wherein the fillers 5a, 5b, 5c, 5, 5A, and 5B include fillers in which the areas of the first contact surfaces are different from each other or the areas of the second contact surfaces are different from each other. For example, the area of ​​the first contact surface 51a of the filler 5a is different from the area of ​​the first contact surface 51b of the filler 5b. For example, the area of ​​the second contact surface 52a of the filler 5a is different from the area of ​​the second contact surface 52b of the filler 5b.

[0038] 3 and 4, the fillers 5a, 5b, and 5c are dispersed in the resin material 6 that bonds the tube 10 and the fins 20, so that the shape of the tube 10 is a fixed flat surface, but the shape of the fins 20 is a curved surface. Therefore, by including fillers 5a, 5b, 5c, 5, 5A, and 5B whose first contact surfaces have different shapes or whose second contact surfaces have different shapes, the contact surfaces with the tube 10 and the fins 20 can be shaped according to the location, and the contact area can be expanded.

[0039] [Appendix 4] The heat exchanger 1 according to any one of appendices 1 to 3, wherein the fillers 5a, 5b, 5c, 5, 5A, and 5B do not have the first contact surface or the second contact surface. For example, the filler 5c does not have the first contact surface or the second contact surface.

[0040] When fillers 5a, 5b, 5c, 5, 5A, and 5B of the same shape are used and the filling rate of the fillers 5a, 5b, 5c, 5, 5A, and 5B in the resin material 6 is increased, filler 5c that is not crushed and retains its original shape is included, as described with reference to Figures 3 and 4. In this way, by including filler 5c that does not have a first contact surface or a second contact surface, the filling rate of the filler can be increased while keeping the shape of the filler the same, the thermal conductivity between the tubes 10 and the fins 20 is improved, and the performance of the heat exchanger 1 can be improved.

[0041] [Appendix 5] The heat exchanger 1 according to any one of appendices 1 to 3, wherein the fillers 5a, 5b, 5c, 5, 5A, and 5B include fillers whose maximum contact length at the first contact surface and the second contact surface is greater than the thickness of the resin material 6 along the thickness direction. For example, the filler 5a has a maximum contact length 52al at the first contact surface 51a and the second contact surface 52a greater than the thickness 5at of the resin material 6 along the thickness direction.

[0042] By forming the filler 5a so that the maximum contact length 52al is greater than the thickness 5at along the thickness direction of the resin material 6, it is possible to increase the contact area with the tubes 10 and the fins 20 and reduce the thickness of the resin material 6. Therefore, the thermal conductivity between the tubes 10 and the fins 20 is improved, and the performance of the heat exchanger 1 can be improved.

[0043] [Appendix 6] The heat exchanger 1 according to any one of appendices 1 to 3, wherein the fillers 5a, 5b, 5c, 5, 5A, and 5B include fillers whose maximum outer length is greater than the thickness along the thickness direction of the resin material 6. For example, the fillers 5a and 5b have maximum outer lengths 5al and 5bl that are greater than the thicknesses 5at and 5bt along the thickness direction of the resin material 6.

[0044] By forming the fillers 5a, 5b so that the maximum outer lengths 5al, 5bl are greater than the thicknesses 5at, 5bt along the thickness direction of the resin material 6, it is possible to increase the contact area with the tubes 10 and the fins 20 and reduce the thickness of the resin material 6. Therefore, the thermal conductivity between the tubes 10 and the fins 20 is improved, and the performance of the heat exchanger 1 can be improved.

[0045] [Appendix 7] 7. The heat exchanger according to claim 1, wherein the fillers (5a, 5b, 5c, 5, 5A, 5B) have a lower rigidity than the tubes (10) and the fins (20).

[0046] By making the rigidity of the fillers 5a, 5b, 5c, 5, 5A, and 5B lower than the rigidity of the tubes 10 and the fins 20, it is possible to reliably crush the fillers present between the tubes 10 and the fins 20. Therefore, the thermal conductivity between the tubes 10 and the fins 20 is improved, and the performance of the heat exchanger 1 can be improved.

[0047] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Any design modifications made by a person skilled in the art to these specific examples are also included within the scope of the present disclosure as long as they have the features of the present disclosure. The elements of each of the above-mentioned specific examples and their arrangements, conditions, shapes, etc. are not limited to those exemplified and can be changed as appropriate. The combination of each of the elements of each of the above-mentioned specific examples can be changed as appropriate as long as no technical contradiction occurs. [Explanation of symbols]

[0048] 10: Tube 20: Finn 5a, 5b, 5c, 5, 5A, 5B: Filler

Claims

1. A first flow path (1b) through which a first medium passes is formed inside a plurality of tubes (10) arranged at predetermined intervals; fins (20) in contact with the tubes arranged opposite to each other and forming a second flow path (1 a) through which a second medium passes that exchanges heat with the first medium; The tubes and the fins are joined by a resin material (6) having a melting point lower than the melting points of the tubes and the fins, and the resin material includes a plurality of fillers (5a, 5b, 5c, 5, 5A, 5B); the filler has a thermal conductivity higher than that of the resin material, The filler includes a filler having a first contact surface (51a, 51b) in contact with the tubes and a second contact surface (52a, 52b) in contact with the fins.

2. The heat exchanger according to claim 1 , wherein the fillers include fillers in which the first contact surfaces have different shapes or the second contact surfaces have different shapes.

3. The heat exchanger according to claim 1 , wherein the fillers include fillers in which the first contact surfaces have different areas or the second contact surfaces have different areas.

4. The heat exchanger according to claim 1 , wherein the filler does not have the first contact surface or the second contact surface.

5. The heat exchanger according to claim 1 , wherein the filler includes a filler having a maximum contact length (52 al) at the first contact surface and the second contact surface that is greater than a thickness (5 at) of the resin material along a thickness direction.

6. The heat exchanger according to claim 1 , wherein the filler includes a filler having a maximum outer length (5al, 5bl) greater than a thickness (5at, 5bt) along the thickness direction of the resin material.

7. The heat exchanger according to claim 1 , wherein the filler has a stiffness lower than a stiffness of the tubes and the fins.

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