Cooler

Abstract

To provide a cooler that suppresses the deterioration of cooling performance. [Solution] The cooler 100 includes a case member provided with an inlet 101H through which refrigerant flows in and an outlet 102H through which refrigerant flows out. The case member includes a first member including a first surface that receives heat from the object to be cooled and a second surface opposite to the first surface, a second member 1 having a third surface 103 facing the second surface, a plurality of protrusions 3 projecting from the third surface 103 toward the second surface, and at least one wall portion 4 arranged corresponding to one or more of the plurality of protrusions and projecting from the third surface toward the second surface. The protrusion height of the at least one wall portion is lower than the protrusion height of each of the one or more protrusions, the at least one wall portion is spaced apart from the one or more protrusions and is located on the opposite side from the inlet of the one or more protrusions.

Description

Technical Field

[0001] The present disclosure relates to a cooler.

Background Art

[0002] Semiconductor devices such as power conversion devices that convert DC power into AC power are known. A cooler for dissipating the heat of a heating element is mounted on the semiconductor device.

[0003] The cooler described in Patent Document 1 includes a heat dissipation substrate joined to an insulating substrate on which a semiconductor element is mounted, a plurality of fins provided on the side opposite to the insulating substrate of the heat dissipation substrate, and a box-shaped cooling case that houses the plurality of fins. The cooling case is provided with an inlet and an outlet for a refrigerant, and the refrigerant flows into the cooling case. Further, the plurality of fins are arranged at a predetermined pitch with an interval therebetween. Since the heat dissipation area can be increased by such a plurality of fins, heat exchange is efficiently performed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a cooling device having a plurality of protrusions, in the direction in which the refrigerant flows, a region where the flow velocity of the refrigerant becomes slow occurs on the back surface of the protrusion. In this region, it is difficult for the refrigerant to flow, so heat dissipation is hindered. As a result, there is a possibility that the cooling performance may deteriorate.

Means for Solving the Problems

[0006] To solve the above problems, a cooler according to a preferred embodiment of the present disclosure comprises a case member provided with an inlet for refrigerant to flow into the interior and an outlet for refrigerant to flow out to the exterior, the heat dissipation member comprises a first member including a first surface that receives heat from the object to be cooled and a second surface opposite to the first surface, a second member having a third surface facing the second surface, a plurality of protrusions projecting from the third surface toward the second surface, and at least one wall portion arranged corresponding to one or more of the plurality of protrusions and projecting from the third surface toward the second surface, wherein the protrusion height of the at least one wall portion is lower than the protrusion height of each of the one or more protrusions, the at least one wall portion is spaced apart from the one or more protrusions and is arranged on the opposite side of the inlet of the one or more protrusions. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view of the cooler according to the first embodiment. [Figure 2] This is a perspective view of the second component of the cooler shown in Figure 1. [Figure 3] Figure 2 shows the top view, front view, side view, and cross-sectional view of the second member. [Figure 4] Figure 2 is a plan view of the multiple protrusions and multiple wall sections shown. [Figure 5] Figure 4 is a cross-sectional view of the multiple protrusions and multiple wall sections shown. [Figure 6] This diagram shows the flow of the refrigerant in the comparative example. [Figure 7] This diagram shows the flow of the refrigerant in this embodiment. [Figure 8] This figure shows the refrigerant flow rate in the comparative example. [Figure 9] This figure shows the flow velocity of the refrigerant in this embodiment. [Figure 10] This figure shows the thermal resistance in this embodiment and comparative example. [Figure 11] This figure shows the protrusion and wall portion of Figure 4. [Figure 12] This figure shows multiple wall sections and multiple protrusions of the first modified example. [Figure 13] It is a plan view showing the wall part of the second modification example. [Figure 14] It is a plan view showing the wall part of the third modification example. [Figure 15] It is a plan view showing the wall part of the fourth modification example. [Figure 16] It is a plan view showing the wall part of the fifth modification example. [Figure 17] It is a view showing a plurality of wall parts and a plurality of protrusions of the sixth modification example. [Figure 18] It is a cross-sectional view of the wall part of the seventh modification example. [Figure 19] It is a cross-sectional view of the wall part of the eighth modification example. [Figure 20] It is a cross-sectional view of the wall part of the ninth modification example. [Figure 21] It is a view showing a part of the second member of the tenth modification example. [Figure 22] It is a cross-sectional view taken along the α-α line of FIG. 21. [Figure 23] It is a cross-sectional view showing a part of the second member of the eleventh modification example. [Figure 24] It is a cross-sectional view showing a part of the second member of the twelfth modification example. [Figure 25] It is a cross-sectional view showing a part of the second member of the thirteenth modification example. [Figure 26] It is a view showing a part of the second member of the fourteenth modification example. [Figure 27] It is a cross-sectional view taken along the α-α line of FIG. 26. [Figure 28] It is a view showing a part of the second member of the fifteenth modification example. [Figure 29] It is a cross-sectional view taken along the α-α line of FIG. 28. [Figure 30] It is a view showing a part of the second member of the sixteenth modification example. [Figure 31] It is a cross-sectional view taken along the α-α line of FIG. 30. [Figure 32] It is a cross-sectional view showing a part of the second member of the seventeenth modification example. [Figure 33] It is a cross-sectional view showing a part of the second member of the eighteenth modification example. [Figure 34]This is a diagram showing a part of the second component of the 19th modified example. [Figure 35] This is a cross-sectional view along line segment A2 in Figure 26. [Figure 36] This is a cross-sectional view showing a part of the second member of the 20th modified example. [Figure 37] This is a cross-sectional view showing a part of the second member of the 21st modified example. [Figure 38] Figure 37 shows a cross-sectional view of a β-β ray. [Figure 39] This figure shows a part of the second member 1 of the 22nd modified example. [Figure 40] Figure 39 is a cross-sectional view of gamma-gamma rays. [Figure 41] This is a cross-sectional view along line segment A2 in Figure 39. [Modes for carrying out the invention]

[0008] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. Note that the dimensions and scale of each part in the drawings differ from the actual dimensions as appropriate, and some parts are shown schematically for ease of understanding. Furthermore, the scope of the present invention is not limited to these embodiments unless otherwise stated in the following description. In this specification, "equal" means not only substantially equal but also includes differences due to manufacturing tolerances, etc.

[0009] 1. Embodiment 1-1. Overview of Cooler 100 Figure 1 is a perspective view of the cooler 100 of the first embodiment. Figure 2 is a perspective view of the cooling case of the cooler 100 shown in Figure 1. Figure 3 is a top view, front view, side view, and cross-sectional view of the second member 1 of Figure 2. Figure 3(a) is a top view, Figure 3(b) is a front view, Figure 3(c) is a left side view, Figure 3(d) is a right side view, and Figure 3(e) is a cross-sectional view.

[0010] The following explanation will use the intersecting X, Y, and Z axes as appropriate. One direction along the X axis is called the X1 direction, and the opposite direction is called the X2 direction. Opposite directions along the Y axis are called the Y1 and Y2 directions. Opposite directions along the Z axis are called the Z1 and Z2 directions. Viewing along the Z axis is called a "planar view." The Z1 direction is the upper side, and the Z2 direction is the lower side.

[0011] The cooler 100 shown in Figure 1 is used for cooling power electronics products such as inverters or rectifiers mounted in railway vehicles, automobiles, or household electrical appliances. Power electronics products include power semiconductor elements such as diodes or IGBTs (Insulated Gate Bipolar Transistors). These power semiconductor elements are examples of objects to be cooled 9 in the cooler 100. The object to be cooled 9 is a heat-generating element. Furthermore, the object to be cooled 9 is not limited to power semiconductor elements; it may be any other electrical or electronic component that generates heat through operation or energization, as long as cooling is required.

[0012] As shown in Figures 1 to 3, the cooler 100 has a case member 10, a plurality of protrusions 3, and a plurality of wall portions 4.

[0013] 1-1a. Case component 10 The case member 10 is a case having an internal space. This internal space is a flow path space through which the refrigerant RE flows. The case member 10 is provided with an inlet 101H through which the refrigerant RE flows into the interior and an outlet 102H through which the refrigerant RE flows out to the outside. The refrigerant RE flows into the flow path space from the inlet 101H and is discharged from the outlet 102H. Therefore, the refrigerant RE flows from the inlet 101H towards the outlet 102H.

[0014] The refrigerant RE is, for example, a medium that is liquid at room temperature and includes water such as pure water, or a mixture of water and alcohol. The alcohol is, for example, ethanol or methanol. The type of refrigerant RE may be other than those mentioned above. It is also preferable that a surfactant is added to the refrigerant RE. The surfactant may be a nonionic surfactant, or an ionic surfactant such as anionic or cationic surfactant. Specific examples of surfactants include fluorine-based surfactants, silicone-based surfactants, and hydrocarbon-based surfactants. When the refrigerant is water, it is preferable to use a hydrocarbon-based surfactant that has excellent solubility.

[0015] The case member 10 is made of a material with excellent thermal conductivity, specifically, a metal or alloy such as copper or aluminum. The case member 10 has a first member 2 and a second member 1. The second member 1 is a box having an opening in the Z1 direction. The first member 2 is a lid that closes the opening. The first member 2 and the second member 1 may be made of the same material or different materials.

[0016] As shown in Figure 3(e), the first member 2 is a flat plate-shaped member. The first member 2 has a first surface 201 and a second surface 202. As shown in Figure 1, a plurality of cooling objects 9 are provided on the first surface 201. The first surface 201 receives heat from the cooling objects 9. The first surface 201 and each cooling object 9 may be in direct contact, or other members may be interposed between the first surface 201 and each cooling object 9. The second surface 202 is the surface opposite to the first surface 201.

[0017] The second member 1 has a bottom portion 11, a side wall portion 15, and a base portion 13. The bottom portion 11, the side wall portion 15, and the base portion 13 are formed as a single unit, but they may also be formed individually and then bonded together. The bottom portion 11 is the bottom part of the second member 1 and is flat.

[0018] The side wall portion 15 extends from the bottom portion 11 in the Z1 direction. The side wall portion 15 has a first side wall 151, a second side wall 152, a third side wall 153, and a fourth side wall 154. The first side wall 151 and the second side wall 152 face each other, and the third side wall 153 and the fourth side wall 154 face each other. An inlet 101H is formed in the first side wall 151. An outlet 102H is formed in the second side wall 152. The inlet 101H is a hole that penetrates the first side wall 151, and the outlet 102H is a hole that penetrates the second side wall 152.

[0019] The base portion 13 is provided in the Z1 direction of the bottom portion 11. The thickness of the base portion 13 along the Z axis is greater than the thickness of the bottom portion 11. In the illustrated example, the cross-sectional shape of the base portion 13 is trapezoidal. The presence of the base portion 13 improves the cooling performance of the cooler 100 compared to when it is not provided. The upper surface of the base portion 13 is the third surface 103. The third surface 103 faces the second surface 202.

[0020] 1-1b. Multiple protrusions 3 and multiple wall portions 4 As shown in Figures 2 and 3, the multiple protrusions 3 are spaced apart from each other and arranged in the internal space of the case member 10. Each protrusion 3 is a columnar projection connected to the third surface 103 and projecting toward the second surface 202. Each protrusion 3 does not contact the first member 2, but may do so. In the illustrated example, each protrusion 3 is cylindrical. However, the protrusions 3 are not limited to a cylindrical shape. The protrusions 3 may be columnar shapes other than cylinders. For example, the protrusions 3 may be prisms such as triangular prisms, pyramidal shapes such as triangular pyramids, tapering shapes such as cones, hemispherical shapes, i.e., dome shapes, or combinations of these shapes.

[0021] The presence of multiple protrusions 3 increases the flow velocity of the refrigerant RE that contacts the second surface 202 of the first member 2. This improves the cooling performance of the cooler 100.

[0022] As shown in Figures 2 and 3, the multiple wall sections 4 are arranged in the internal space of the case member 10. Each wall section 4 is a columnar projection connected to the third surface 103 and projecting toward the second surface 202. The multiple wall sections 4 are provided corresponding to the multiple projections 3. In this implementation, the multiple wall sections 4 correspond one-to-one with the multiple projections 3. Each wall section 4 is wall-shaped. Each wall section 4 is provided spaced apart from the multiple projections 3.

[0023] Figure 4 is a plan view of the multiple protrusions 3 and multiple wall portions 4 shown in Figure 2. As shown in Figure 4, the multiple protrusions 3 are arranged in a staggered pattern in plan view. The multiple protrusions 3 are divided into multiple rows of protrusions L arranged at intervals from each other along the Y2 direction, which is the direction in which the refrigerant RE flows. In the illustrated example, there are seven rows of protrusions L. Each row of protrusions L is a collection of several protrusions 3 arranged linearly along the Y axis. In this embodiment, the multiple rows of protrusions L are arranged at equal intervals.

[0024] Of the multiple rows of protrusions L, the row of protrusions L closest to the inlet 101H is designated as the first row of protrusions L1. The row of protrusions L next closest to the inlet 101H is designated as the second row of protrusions L2. Of the multiple rows of protrusions L, the row of protrusions L closest to the outlet 102H is designated as the third row of protrusions L3. The row of protrusions L next closest to the outlet 102H is designated as the fourth row of protrusions L4. The distance D1 between the first row of protrusions L1 and the second row of protrusions L2 is equal to the distance D3 between the third row of protrusions L3 and the fourth row of protrusions L4.

[0025] Furthermore, the centers of several protrusions 3 belonging to a certain row of protrusions L, when viewed from a plan view, and the centers of several protrusions 3 in a row of protrusions L adjacent to that row of protrusions L, when viewed from a plan view, do not overlap in the Y2 direction, which is the direction in which the refrigerant RE flows. By arranging multiple protrusions 3 in this manner, the refrigerant RE can be made to flow more easily throughout the entire internal space.

[0026] As described above, the multiple wall sections 4 are arranged in a one-to-one correspondence with the multiple protrusions 3. Each wall section 4 is positioned on the outlet 102H side with respect to the corresponding protrusion 3. In this embodiment, each wall section 4 is arc-shaped in plan view. In addition, in this embodiment, several wall sections 4 corresponding to several protrusions 3 belonging to each row of protrusions L are connected to one another.

[0027] Figure 5 is a cross-sectional view of the multiple protrusions 3 and multiple wall portions 4 shown in Figure 4. As shown in Figure 5, the projection height T3 of each protrusion 3 in the Z1 direction is higher than the projection height T4 of each wall portion 4 in the Z1 direction. Also, the width W3 of each protrusion 3 in the direction along the Y axis, which is the direction in which the refrigerant RE flows, is greater than the width W41 of each wall portion 4 in the direction along the Y axis, which is the direction in which the refrigerant RE flows. Note that the width W3 is greater than the width W40 in the direction along the Y axis at the connection portion of two adjacent wall portions 4.

[0028] Each projection 3 also has a top surface 31 and a side surface 32. The top surface 31 is the part of the projection 3 closest to the second surface 202. In this embodiment, the top surface 31 is a surface parallel to the third surface 103 and perpendicular to the Z-axis. The top surface 31 is circular in plan view. The side surface 32 is cylindrical. The side surface 32 connects the top surface 31 and the third surface 103. In this embodiment, the side surface 32 is parallel to the Z-axis.

[0029] Each wall portion 4 also has a top surface 41 and a side surface 42. The top surface 41 is the portion of the wall portion 4 closest to the second surface 202. In this embodiment, the top surface 41 is a surface parallel to the third surface 103 and perpendicular to the Z-axis. The top surface 41 is circular in plan view. The side surface 42 is cylindrical. The side surface 42 connects the top surface 41 and the third surface 103. In this embodiment, the side surface 42 is parallel to the Z-axis.

[0030] As described above, the protruding height T3 of each projection 3 is higher than the protruding height T4 of each wall portion 4 in the Z1 direction. Furthermore, as described above, the wall portion 4 is spaced apart from the corresponding projection 3 and is located on the opposite side from the inlet 101H of the corresponding projection 3. Having such wall portions 4 suppresses the slowing of the refrigerant RE flow on the outlet 102H side of the projection 3. Therefore, the thermal resistance on the third surface 103 is reduced over the entire area. As a result, the cooling performance of the cooler 100 can be improved.

[0031] Figure 6 shows the flow of refrigerant RE in a comparative example. Figure 7 shows the flow of refrigerant RE in this embodiment. In the comparative example shown in Figure 6, the wall portion 4 is not provided. In contrast, in this embodiment shown in Figure 7, the wall portion 4 is provided. In Figures 6 and 7, the streamlines of the refrigerant RE are drawn.

[0032] In the comparative example in Figure 6, the refrigerant RE has difficulty flowing in the region Sx on the outlet 102H side of the projection 3. In contrast, in this embodiment shown in Figure 7, the refrigerant RE flows efficiently in the region S on the outlet 102H side of the projection 3, just as it does on the inlet 101H side. This is because the refrigerant RE hits the inlet 101H side of the wall 4, and the direction of flow of the refrigerant RE changes in the region S between the projection 3 and the wall 4. As a result, the flow rate of refrigerant RE passing through region S in this embodiment is increased compared to the region Sx on the outlet 102H side of the projection 3.

[0033] As shown in Figures 6 and 7, the presence of the wall portion 4 makes it possible to suppress the decrease in flow rate in the region S on the outlet 102 side of the projection 3.

[0034] Figure 8 shows the flow velocity of refrigerant RE in a comparative example. Figure 9 shows the flow velocity of refrigerant RE in this embodiment. In the comparative example in Figure 8, the brightness in region Sx on the outlet 102H side of projection 3 is lower than the brightness in region Sy on the inlet 101H side of projection 3. This indicates that the flow velocity of refrigerant RE in region Sx is slower than the flow velocity of refrigerant RE in region Sy.

[0035] In this embodiment shown in Figure 9, the brightness in region S on the outlet 102H side of projection 3 is approximately the same as the brightness in region S0 on the inlet 101H side of projection 3. This indicates that the flow velocity of the refrigerant RE in region S is not inferior to that of the refrigerant RE in region S0, and is approximately the same.

[0036] As shown in Figures 8 and 9, the presence of the wall portion 4 makes it possible to suppress the decrease in flow velocity in the region S on the outlet 102H side of the projection 3.

[0037] Furthermore, the protruding height T4 of the wall portion 4 is lower than the protruding height T3 of the projection 3. If the protruding height T4 is greater than or equal to the protruding height T3, there is a risk of a decrease in the flow rate and velocity of the refrigerant RE on the outlet 102H side of the wall portion 4. In contrast, because the protruding height T4 is lower than the protruding height T3, the problem of such a decrease in flow rate and velocity is less likely to occur.

[0038] Figure 10 shows the thermal resistance in this embodiment and comparative example. The vertical axis in Figure 10 shows the thermal resistance of the cooled object 9, and the horizontal axis shows the position of the cooled object 9. Specifically, for example, six cooled objects 9 are provided on the first surface 201. Of the six cooled objects 9, the one provided closest to the inlet 101H is designated as "1," and they are designated as "2," "3," "4," "5," and "6" in order from "1" toward the outlet 102H. These six cooled objects 9 are arranged in a straight line at approximately equal intervals from the inlet 101H toward the outlet 102H.

[0039] As shown in Figure 10, with the cooler 100 of this embodiment, the thermal resistance of all cooled objects 9 is lower than in the comparative example, regardless of their location on the first surface 201. As can also be seen from Figure 10, with the cooler 100 of this embodiment, the cooling performance can be improved by providing the wall portion 4.

[0040] Figure 11 shows the projection 3 and wall portion 4 in Figure 4. As shown in Figure 11, consider the case where a virtual line A1 is placed along the X1 direction, which is perpendicular to the direction in which the refrigerant RE flows, passing through the center O1 of the projection 3 in a plan view. In this case, in this embodiment, the wall portion 4 is provided on the outlet 102H side of the virtual line A1 of the corresponding projection 3.

[0041] The provision of the wall portion 4 in this manner makes it particularly effective to suppress the decrease in the flow velocity and flow rate of the refrigerant RE on the outlet 102H side. Note that the wall portion 4 may include a portion located on the inlet 101H side of the imaginary line A1. However, if the wall portion 4 includes such a portion, the flow rate and flow velocity of the refrigerant RE in region S may decrease compared to when it does not include such a portion.

[0042] Furthermore, as described above, several wall portions 4 corresponding to several protrusions 3 belonging to the same row of protrusions L are connected to one another. That is, each of the multiple protrusions 3 has two or more protrusions 3 spaced apart from each other in the X1 direction, which is perpendicular to the direction in which the refrigerant RE flows, and two or more wall portions 4 corresponding to these two or more protrusions 3 are provided, and these two or more wall portions 4 are connected to one another.

[0043] By connecting several wall portions 4 in the same row of protrusions L to each other, the decrease in the flow velocity and flow rate of the refrigerant RE in region S can be suppressed compared to when they are not connected.

[0044] Furthermore, as mentioned above, each projection 3 is circular in plan view. And each wall portion 4 is arc-shaped corresponding to the projection 3 in plan view. Because the wall portions 4 are arc-shaped corresponding to the projection 3, the flow rate and velocity of the refrigerant RE in region S can be increased without bias, compared to, for example, a straight line.

[0045] Furthermore, each wall portion 4 is provided concentrically with respect to the projection 3. Therefore, the distance between the wall portion 4 and the projection 3 is equal throughout the entire area of ​​the wall portion 4. A line segment A2 passing through the center O1 of the projection 3 and along the direction of refrigerant flow passes through the center O2 of the wall portion 4. Centers O1 and O2 are the geometric centers in a plan view, respectively.

[0046] By being positioned concentrically with respect to the projection 3, the flow rate and velocity of the refrigerant RE in region S can be increased without any particular bias.

[0047] Furthermore, in this embodiment, a wall portion 4 is provided corresponding to all of the multiple protrusions 3. That is, the multiple wall portions 4 are provided in a one-to-one ratio for the multiple protrusions 3. Therefore, a decrease in the flow velocity and flow rate of the refrigerant RE can be suppressed on the outlet 102H side of all the protrusions 3. Thus, the cooling performance of the cooler 100 can be improved particularly effectively.

[0048] 2. Variations The present invention is not limited to the embodiments described above, and various modifications described below are possible. Furthermore, each modification can be combined as appropriate, as long as it does not contradict the original.

[0049] 2-1. First variation Figure 12 is a plan view showing multiple wall portions 4 and multiple protrusions 3 of the first modified example. As shown in Figure 12, it is not necessary to provide wall portions 4 corresponding to all of the multiple protrusions 3. In the example in Figure 12, wall portions 4 are not provided for the protrusions 3 belonging to the first row of protrusions L1, the third row of protrusions L3, and the third row of protrusions L closest to the inlet 101H. Wall portions 4 are provided for the protrusions 3 belonging to the other rows of protrusions L.

[0050] As shown in this modified example, the multiple wall portions 4 do not necessarily have to be provided in a one-to-one ratio with respect to the multiple protrusions 3. In other words, the multiple wall portions 4 only need to be arranged to correspond to one or more of the multiple protrusions 3.

[0051] Furthermore, the third surface 103 only needs to have at least one wall portion 4. Therefore, the wall portion 4 only needs to be provided corresponding to one or more of the multiple protrusions 3. However, providing multiple wall portions 4 can improve the cooling performance of the cooler 100.

[0052] 2-2. Second variation Figure 13 is a plan view showing the wall portion 4 of the second modified example. As shown in Figure 13, in the second modified example, several wall portions 4 corresponding to several protrusions 3 belonging to the same row of protrusions L are not connected to each other and are spaced apart. That is, the multiple protrusions 3 have two or more protrusions 3 that are spaced apart from each other in the X1 direction which is perpendicular to the direction in which the refrigerant RE flows, and two or more wall portions 4 corresponding to these two or more protrusions 3 are provided, and these two or more wall portions 4 are spaced apart from each other.

[0053] By having several wall portions 4 in the same row of protrusions L spaced apart from each other, it is possible to suppress the decrease in the flow velocity and flow rate of the refrigerant RE in region S, compared to when they are not connected, while mitigating the increase in pressure loss due to the provision of wall portions 4 and thereby suppressing the decrease in the overall flow rate.

[0054] 2-3. Third Variation Figure 14 is a plan view showing the wall portion 4 of the third modified example. In the third modified example shown in Figure 14, each wall portion 4 is not provided concentrically with respect to the projection 3. Therefore, the distance between the wall portion 4 and the projection 3 is not equal throughout the entire area of ​​the wall portion 4. The line segment A2 passing through the center O1 of the projection 3 and along the direction of flow of the refrigerant RE does not pass through the center O2 of the wall portion 4.

[0055] Thus, the wall portion 4B may be positioned off-center relative to the projection 3. For example, depending on the distance from the aforementioned side wall portion 15, the wall portion 4 may be positioned off-center relative to the projection 3. Depending on the bias in the flow rate and velocity of the refrigerant RE, the wall portion 4B may be positioned off-center relative to the projection 3.

[0056] 2-4. Fourth Variation Figure 15 shows the wall portion 4A of the fourth modified example. The wall portion 4A of the fourth modified example shown in Figure 15 is not arc-shaped in plan view, but includes a straight portion. Specifically, the wall portion 4A includes a first wall portion 451 and a second wall portion 452. In each of the first wall portion 451 and the second wall portion 452, the portion through which line segment A2 passes, which is part of the wall portion 4A that extends linearly from the center O2 in directions intersecting the X and Y axes, is closest to the outlet 102H. Also, several wall portions 4A corresponding to several protrusions 3 belonging to the same row of protrusions L are connected to each other, but may be spaced apart.

[0057] Even with such a wall section 4A, the decrease in flow rate and flow velocity in region S can be suppressed.

[0058] 2-5. Fifth Variation Figure 16 shows the wall portion 4B of the fifth modified example. The wall portion 4B of the fifth modified example shown in Figure 16 includes a linear portion in plan view, rather than being arc-shaped. Specifically, the wall portion 4B includes a third wall portion 453, a fourth wall portion 454, and a fifth wall portion 455. The third wall portion 453 extends linearly in the X1 direction, which is perpendicular to the direction in which the refrigerant RE flows through the line segment A2. The fourth wall portion 454 extends linearly from one end of the third wall portion 453 in directions intersecting the X and Y axes. The fifth wall portion 455 extends linearly from the other end of the third wall portion 453 in directions intersecting the X and Y axes. In addition, several wall portions 4B corresponding to several projections 3 belonging to the same row of projections L may be spaced apart from each other but connected.

[0059] This wall section 4B can also suppress the decrease in flow rate and flow velocity in region S.

[0060] 2-6. Sixth Variation Figure 17 shows a diagram of multiple wall sections 4 and multiple protrusions 3 in the sixth modified example. In the sixth modified example shown in Figure 17, the spacing between two adjacent rows of protrusions L is not constant. Specifically, the spacing D1 between the first row of protrusions L1 and the second row of protrusions L2 is greater than the spacing D3 between the third row of protrusions L3 and the fourth row of protrusions L4. Furthermore, in this modified example, the row of protrusions L between the second row of protrusions L2 and the third row of protrusions L3 is designated as the fifth row of protrusions L5. In this case, the spacing D1, the spacing D2 between the second row of protrusions L2 and the fifth row of protrusions L5, the spacing D4 between the fifth row of protrusions L5 and the third row of protrusions L3, and the spacing D3 decrease in this order from D1. That is, the spacings D1, D2, D4, and D3 satisfy the relationship D1>D2>D4>D3. Therefore, the spacing between two adjacent rows of protrusions L gradually decreases from the inlet 101H towards the outlet 102H.

[0061] Furthermore, as the distance between two adjacent rows of protrusions L decreases from the inlet 101H towards the outlet 102H, the flow velocity of the refrigerant RE can be gradually increased from the inlet 101H towards the outlet 102H. This makes it particularly effective to reduce the non-uniformity of the cooling performance on the first surface 201 of the second member 1. Note that the distance between the rows of protrusions L does not necessarily have to decrease gradually. There may be portions where the distance between adjacent rows of protrusions is equal.

[0062] 2-7. Seventh Variation Figure 18 shows the wall portion 4C of the seventh modified example. In the seventh modified example shown in Figure 18, the side surface 42C of the wall portion 4C is not parallel to the Z-axis. The wall portion 4C is trapezoidal in cross-sectional view. The width of the wall portion 4C narrows as it moves away from the third surface 103.

[0063] 2-8. Variation 8 Figure 19 shows the wall 4D of the eighth modified example. The eighth modified example shown in Figure 19 has a vertex 43D and a side surface 42D. The side surface 42D is not parallel to the Z-axis. The wall 4D is triangular in cross-sectional view. The width of the wall 4D narrows as it moves away from the third surface 103. At vertex 43D, its width is zero.

[0064] 2-9. Variation 9 Figure 20 shows the wall portion 4E of the ninth modified example. In the ninth modified example shown in Figure 20, there is a vertex 43E and an outer surface 44E. The outer surface 44E is hemispherical. The wall portion 4E is semicircular in cross-sectional view.

[0065] 2-10. Tenth variation Figure 21 shows a part of the second member 1 of the 10th modified example. Figure 22 is a cross-sectional view along the line α-α in Figure 21.

[0066] As shown in Figures 21 and 22, multiple grooves 5 are provided on the third surface 103 of the second member 1. In Figure 21, dots are added to the grooves 5 for easier understanding. The grooves 5 are provided between the projection 3 and the wall portion 4. The grooves 5 are recesses provided on the third surface 103. Also, the grooves 5 are located on the opposite side of the inlet 101H of the projection 3. The grooves 5 are provided on the outlet 102H side of the dashed line A1.

[0067] Because the groove 5 is provided, compared to when it is not provided, the flow of refrigerant RE passing alongside the projection 3 flows into the groove 5 and flows along the groove 5, thus increasing the flow rate of refrigerant RE in the region S between the projection 3 and the wall 4. As a result, the cooling performance of the cooler 100 can be improved.

[0068] In this modified example, the cross-sectional shape of groove 5 is rectangular. Groove 5 has a bottom and a side. The bottom is the surface furthest from the third surface 103. In this modified example, the bottom is parallel to the XY plane, just like the third surface 103. The side is the surface connecting the third surface 103 and the bottom. In this modified example, the side is parallel to the Z axis. The bottom and side are composed of flat surfaces.

[0069] The depth T5 of the groove 5 is not particularly limited, but is equal to the protrusion height T4 and smaller than the protrusion height T3. This depth T5 is particularly effective in suppressing the slowing of the refrigerant RE flow in region S.

[0070] Furthermore, the depth T5 may be less than or greater than the protrusion height T4. Also, the depth T5 may be less than or equal to the protrusion height T3.

[0071] Furthermore, the groove 5 is provided throughout the entire region S. Therefore, compared to the case where the groove 5 is provided only in a part of region S, the slowing of the refrigerant RE flow in region S is particularly effectively suppressed.

[0072] 2-11. 11th Variation Figure 23 is a cross-sectional view showing a part of the second member 1 of the 11th modified example. The following explanation will focus on the differences from the 10th modified example.

[0073] As shown in Figure 23, the cross-sectional shape of groove 5A in the 11th modified example is triangular. The depth T5 of groove 5A is not constant but varies. The depth T5 is deepest at the center line of groove 5A, which is equidistant from the projection 3 and the wall portion 4 in a plan view. The sides are gradually inclined with respect to the Z axis such that the depth T5 increases toward the center line.

[0074] The presence of such groove 5A suppresses the slowing of the refrigerant RE flow in region S, similar to the 10th modified example, compared to when the groove 5A is not provided.

[0075] 2-12. Twelfth Variation Figure 24 is a cross-sectional view showing a part of the second member 1 of the 12th modified example. The following explanation will focus on the differences from the 11th modified example.

[0076] As shown in Figure 24, the groove 5B of the 12th modified example is composed of a curved surface. Thus, the groove 5B does not have to be a flat surface; it may be curved, or it may have steps or irregularities.

[0077] The presence of the groove 5B suppresses the slowing of the refrigerant RE flow in region S compared to when the groove is not provided.

[0078] 2-13. 13th Variation Figure 25 is a cross-sectional view showing a part of the second member 1 of the 13th modified example. The following explanation will focus on the differences from the 10th modified example.

[0079] As shown in Figure 25, the depth T5 of the groove 5C is not constant throughout but varies. In this modified example, for example, the depth T5 gradually increases from the inlet 101H to the outlet 102H. In Figure 25, the left side is the inlet 101H and the right side is the outlet 102H.

[0080] As the depth T5 increases from the inlet 101H to the outlet 102H, the flow flows smoothly along the shape, increasing the flow rate of refrigerant RE flowing into region S without causing pressure loss due to flow separation.

[0081] 2-14. 14th Variation Figure 26 shows a part of the second member 1 of the 14th modified example. Figure 27 is a cross-sectional view along the line α-α in Figure 26. The following explanation will focus on the differences from the 10th modified example.

[0082] As shown in Figures 26 and 27, in this modified example, the groove 5D is not provided throughout the entire region S, but rather in a part of region S. Specifically, in this modified example, the groove 5D is provided on the projection 3 side in region S. A part of the side of the groove 5D is flush with a part of the side surface 32 of the projection 3.

[0083] The presence of the groove 5D suppresses the slowing of the refrigerant RE flow in region S compared to when the groove 5D is not provided.

[0084] 2-15. Variation 15 Figure 28 shows a part of the second member 1 of the 15th modified example. Figure 29 is a cross-sectional view along the line α-α in Figure 28. The following explanation will focus on the differences from the 14th modified example.

[0085] As shown in Figures 28 and 29, in this modified example, a groove 5E is provided on the wall portion 4 side in region S. A portion of the side of the groove 5E is flush with a portion of the side surface 42 of the wall portion 4.

[0086] The presence of the groove 5E suppresses the slowing of the refrigerant RE flow in region S compared to when the groove 5E is not provided.

[0087] 2-16. Variation 16 Figure 30 shows a part of the second member 1 of the 16th modified example. Figure 31 is a cross-sectional view along the line α-α in Figure 30. The following explanation will focus on the differences from the 14th modified example.

[0088] As shown in Figures 30 and 31, in this modified example, the groove 5F is spaced approximately equidistant from the wall portion 4 and the projection 3 in a plan view. The groove 5F is provided along the centerline of region S in a plan view.

[0089] The presence of the groove 5F suppresses the slowing of the refrigerant RE flow in region S compared to when the groove 5F is not provided.

[0090] 2-17. Variation 17 Figure 32 is a cross-sectional view showing a part of the second member 1 of the 17th modified example. The following explanation will focus on the differences from the 10th modified example.

[0091] As shown in Figure 32, in this modified example, the depth T5 of the groove 5G is not constant throughout the entire region S, but changes from the protrusion 3 towards the wall 4. Specifically, in this modified example, the depth T5 gradually decreases from the protrusion 3 towards the wall 4. Such groove 5G also suppresses the slowing of the refrigerant RE flow in region S.

[0092] The cross-sectional shape of the groove 5G is triangular. Furthermore, the depth T5 does not change gradually from the projection 3 towards the wall portion 4; for example, it may change in steps. Also, in the illustrated example, the groove 5G is provided throughout the entire region S, but it may not be provided only in a part of the region S. For example, the groove 5G may be provided only in a part, as in the 14th, 15th, and 16th modified examples.

[0093] 2-18. Variation 18 Figure 33 shows a part of the second member 1 of the 18th modified example. The following explanation will focus on the differences from the 17th modified example.

[0094] As shown in Figure 33, in this modified example, the depth T5 of the groove 5H gradually decreases from the wall portion 4 toward the projection 3. This groove 5H also suppresses the slowing of the refrigerant RE flow in region S.

[0095] The cross-sectional shape of the groove 5H is triangular. Furthermore, the depth T5 does not change gradually from the wall 4 towards the projection 3; for example, it may change in steps. Also, in the illustrated example, the groove 5H is provided throughout the entire region S, but it does not have to be provided throughout the entire region. For example, the groove 5H may be provided only in a part of the region, as in the 14th, 15th, and 16th modified examples.

[0096] 2-19. Variation No. 19 Figure 34 shows a part of the second member 1 of the 19th modified example. Figure 35 is a cross-sectional view along line segment A2 in Figure 34. The following explanation will focus on the differences from the 10th modified example.

[0097] As shown in Figures 34 and 35, in this modified example, the groove 5J is provided not only on the outlet 102H side but also on the inlet 101H side relative to the projection 3. Therefore, in this modified example, the groove 5J surrounds the projection 3 in a plan view.

[0098] Groove 5J has an outlet side groove 54 and an inlet side groove 55. The inlet side groove 55 is provided on the inlet 101H side of projection 3 and is located on the inlet 101H side of the imaginary line A1. The outlet side groove 54 is provided on the outlet 102H side of projection 3 and is located on the outlet 102H side of the imaginary line A1.

[0099] In this modified example, the depth T5 of the outlet channel 54 and the depth T5 of the inlet channel 55 are the same, but they may be different. Also, the cross-sectional shape of the outlet channel 54 and the cross-sectional shape of the inlet channel 55 are the same rectangle, but they may be different.

[0100] The groove 5J also helps to suppress the slowing of the refrigerant RE flow in region S. Furthermore, because the groove 5J is provided so as to surround the projection 3, the stagnation of refrigerant RE in region S can be reduced compared to the case where it is not provided.

[0101] 2-20. 20th Variation Figure 36 shows a part of the second member 1 of the 20th modified example. The following explanation will focus on the differences from the 19th modified example.

[0102] As shown in Figure 36, in this modified example, the cross-sectional shape and depth are not constant but vary. In the example in Figure 36, the outlet channel 54 and the inlet channel 55 have different cross-sectional shapes and depths T5 from each other. Both the outlet channel 54 and the inlet channel 55 have curved surfaces. The maximum depth of the outlet channel 54 is greater than the maximum depth of the inlet channel 55. Also, both the outlet channel 54 and the inlet channel 55 are deeper on the projection 3 side than on the wall 4 side.

[0103] Note that the cross-sectional shapes of the outlet channel 54 and the inlet channel 55 are not limited to the example shown in Figure 36.

[0104] Furthermore, because both the outlet channel 54 and the inlet channel 55 are curved surfaces, the stagnation of refrigerant RE in region S can be reduced compared to the case where they are flat surfaces.

[0105] 2-21. Variation 21 Figure 37 shows a part of the second member 1 of the 21st modified example. Figure 38 is a cross-sectional view taken along the β-β line in Figure 35. The following explanation will focus on the differences from the 10th modified example.

[0106] As shown in Figures 37 and 38, the grooves 5I have groove sections of different shapes and depths. Specifically, the depth T5 of the grooves 5I differs between the inlet 101H side and the outlet 102H side, and the cross-sectional shape of the grooves 5I differs between the inlet 101H side and the outlet 102H side.

[0107] More specifically, in this modified example, the groove 5I has two first grooves 51 and one second groove 52. In plan view, the second groove 52 is located between the two first grooves 51. The two first grooves 51 and the second groove 52 are connected to each other. The second groove 52 is located on the outlet 102H side relative to one of the first grooves 51.

[0108] The cross-sectional shape of the first groove 51 is triangular. The cross-sectional shape of the second groove 52 is quadrilateral. The bottom of the second groove 52 is parallel to the XY plane, and the sides are parallel to the Z axis. Also, the depth T5 of the first groove 51 is smaller than the depth T5 of the second groove 52. Furthermore, the depth T5 of the first groove 51 increases as it approaches the second groove 52. Note that the depth T5 of the first groove 51 may be the same as the depth T5 of the second groove 52.

[0109] The groove 5I also helps to suppress the slowing of the refrigerant RE flow in region S. Furthermore, the increasing depth T5 from the inlet 101H to the outlet 102H reduces the stagnation of refrigerant RE in region S compared to the case without this groove.

[0110] 2-22. Variation 22 Figure 39 shows a part of the second member 1 of the 22nd modified example. Figure 40 is a cross-sectional view taken along the gamma-gamma line in Figure 39. Figure 41 is a cross-sectional view taken along line segment A2 in Figure 39. The following explanation will focus on the differences from the 21st modified example.

[0111] As shown in Figures 39, 40, and 41, groove 5J is mainly provided in a part of region S, specifically on the wall 4 side of region S. Also, the width W51 of groove 5J is not constant. Specifically, the width W51 gradually increases from the inlet 101H to the outlet 102H. The width W51 is the length of groove 5J along the radial direction with center O1. In this modified example, the depth T5 is constant, but it does not have to be constant.

[0112] The groove 5J also helps to suppress the slowing of the refrigerant RE flow in region S. Furthermore, the width W51 increases from the inlet 101H to the outlet 102H, which reduces the stagnation of refrigerant RE in region S compared to the case where this is not the case.

[0113] 2-23. Other variations The shape of the wall portion 4 is not limited to the shapes of the first embodiment, the seventh, eighth, and ninth modifications. For example, the inclination angle of the side surface 42 with respect to the Z axis may differ between the inlet 101H side and the outlet 102H side of the wall portion 4. Also, the top surface 41 does not have to be parallel to the third surface 103. Furthermore, not all of the multiple wall portions 4 have the same shape or the same projection height.

[0114] Furthermore, the shape of the projection 3 is not limited to the shape of the first embodiment. For example, the projection 3 may have a shape like the wall portion 4 of the seventh, eighth, and ninth modified examples. Also, for example, the inclination angle of the side surface 32 of the projection 3 with respect to the Z axis may differ on the inlet 101H side and the outlet 102H side. Also, the top surface 31 does not have to be parallel to the third surface 103. In addition, not all of the multiple projections 3 have to be the same shape and have the same projection height.

[0115] Although the present invention has been described above based on the illustrated embodiments, the present invention is not limited thereto. Furthermore, the configuration of each part of the present invention can be replaced with any configuration that performs a similar function to the embodiments described above, and any configuration can also be added.

[0116] 3. Addendum From the above embodiments or modifications, for example, the following embodiments can be understood.

[0117] A first embodiment of the cooler, a preferred example of the present disclosure, comprises a case member having an inlet for a refrigerant to flow into the interior and an outlet for the refrigerant to flow out to the exterior, wherein the case member comprises a first member including a first surface that receives heat from an object to be cooled and a second surface opposite to the first surface, a second member having a third surface opposite to the second surface, a plurality of protrusions projecting from the third surface toward the second surface, and at least one wall portion arranged corresponding to one or more of the plurality of protrusions, connected to the third surface, and projecting toward the second surface, wherein the protruding height of the at least one wall portion is lower than the protruding height of each of the one or more protrusions, the at least one wall portion is spaced apart from the one or more protrusions and is arranged on the opposite side of the one or more protrusions from the inlet.

[0118] According to this first embodiment, the presence of a wall prevents the refrigerant flow from slowing down on the outlet side of the protrusion. As a result, the thermal resistance on the third surface is reduced across the entire surface. This improves the cooling performance of the cooler.

[0119] In the second embodiment, which is a preferred example of the first embodiment, when a virtual line is set in a plan view that passes through the center of the one or more protrusions and is perpendicular to the direction in which the refrigerant flows, the at least one wall portion is positioned on the outlet side of the virtual line.

[0120] Such a cooler can particularly effectively suppress the decrease in refrigerant flow velocity and flow rate at the outlet side.

[0121] In a third embodiment, which is a preferred example of the second embodiment, the plurality of protrusions have two or more protrusions that are spaced apart from each other in a direction perpendicular to the direction of flow of the refrigerant, and the at least one wall portion has two or more wall portions corresponding to the two or more protrusions, and the two or more wall portions are connected to each other.

[0122] The connection of the wall sections helps to suppress the decrease in refrigerant flow velocity and flow rate on the outlet side of the protrusions, compared to when they are not connected.

[0123] In the fourth embodiment, which is a preferred example of the second embodiment, the plurality of protrusions have two or more protrusions that are spaced apart from each other in a direction perpendicular to the direction in which the refrigerant flows, and the at least one wall portion has two or more wall portions corresponding to the two or more protrusions, and the two or more wall portions are spaced apart from each other.

[0124] Because the walls are spaced apart from each other, compared to when they are not connected, the decrease in refrigerant flow velocity and flow rate on the outlet side of the protrusion can be suppressed, while the increase in pressure loss due to the presence of the walls can be mitigated, thereby suppressing a decrease in the overall flow rate.

[0125] In the fifth embodiment, which is a preferred example of the first to fourth embodiments, the one or more projections are circular in plan view, and the at least one wall portion is arc-shaped in plan view, corresponding to the one or more projections.

[0126] Because the wall section is arc-shaped corresponding to the protrusion, the flow rate and velocity of the refrigerant on the outlet side of the protrusion can be increased more evenly compared to, for example, a straight line.

[0127] In the sixth embodiment, which is a preferred example of the first embodiment, the at least one wall portion is provided concentrically with respect to the one or more protrusions.

[0128] By being positioned concentrically with respect to the protrusion, the flow rate and velocity of the refrigerant on the outlet side of the protrusion can be increased without any particular bias.

[0129] In the seventh embodiment, which is a preferred example of the first to sixth embodiments, the at least one wall portion is a plurality of wall portions provided in a one-to-one ratio with respect to the plurality of protrusions.

[0130] At the outlet side of all protrusions, the decrease in refrigerant flow velocity and flow rate can be suppressed. Therefore, the cooling performance of the cooler can be improved particularly effectively.

[0131] In the eighth embodiment, which is a preferred example of the first to seventh embodiments, the plurality of protrusions are divided into a plurality of rows of protrusions arranged side by side at intervals along the direction of flow of the refrigerant, and the distance between the first row of protrusions closest to the inlet and the second row of protrusions closest to the inlet after the first row of protrusions is greater than the distance between the third row of protrusions closest to the outlet and the fourth row of protrusions closest to the outlet after the third row of protrusions.

[0132] The flow velocity of the refrigerant near the outlet can be increased. Therefore, the temperature rise of the refrigerant near the outlet can be reduced. Consequently, the non-uniformity of the cooling performance on the first surface of the second component can be reduced.

[0133] In the eighth embodiment, which is a preferred example of the first to eighth embodiments, the third surface has a groove provided in the region between the at least one wall portion and the one or more protrusions.

[0134] The presence of grooves more effectively suppresses the slowing of refrigerant flow in the region between the wall and the protrusions. [Explanation of symbols]

[0135] 1…Second part, 2…First part, 3…Protrusion, 4…Wall, 4A…Wall, 4B…Wall, 4C…Wall, 4D…Wall, 4E…Wall, 9…Cooled body, 10…Case part, 11…Bottom, 13…Base, 15…Side wall, 31…Top surface, 32…Side surface, 41…Top surface, 42…Side surface, 42C…Side surface, 42D…Side surface, 43D…Vertex, 43E…Vertex, 44E…Outer surface, 100…Cooler, 101H…Inlet, 102H…Outlet, 103…Third surface, 151…First side wall, 152…Second side wall, 153…Third side wall, 154…Fourth side wall, 20 1…First side, 202…Second side, 451…First wall, 452…Second wall, 453…Third wall, 454…Fourth wall, 455…Fifth wall, A1…Imaginary line, A2…Line division, D1…Interval, D2…Interval, D3…Interval, D4…Interval, L…Protrusion column, L1…First protrusion column, L2…Second protrusion column, L3…Third protrusion column, L4…Fourth protrusion column, L5…Fifth protrusion column, O1…Center, O2…Center, RE…Refrigerator, S…Field, S0…Field, Sx…Field, Sy…Field, T1…Protrusion height, T2…Protrusion height, W3…Diameter, W40…Width, W41…Width.

Claims

1. The device comprises a case member having an inlet for refrigerant to flow into the interior and an outlet for the refrigerant to flow out to the outside. The case member is A first member including a first surface that receives heat from the object to be cooled, and a second surface opposite to the first surface, A second member having a third surface opposite to the second surface, Multiple protrusions projecting from the third surface toward the second surface, It comprises at least one wall portion that is arranged in correspondence with one or more of the plurality of protrusions and protrudes from the third surface toward the second surface, The protruding height of the at least one wall portion is lower than the protruding height of each of the one or more protrusions. The at least one wall portion is spaced apart from the one or more protrusions and is positioned on the side of the one or more protrusions opposite to the inlet. A cooler characterized by the following features.

2. When a virtual line is set in a plan view, passing through the center of the one or more protrusions and in a direction perpendicular to the direction of flow of the refrigerant, The at least one wall portion is positioned on the outlet side of the imaginary line. The cooler according to feature 1.

3. The plurality of protrusions have two or more protrusions that are spaced apart from each other in a direction perpendicular to the direction in which the refrigerant flows, The at least one wall portion has two or more wall portions corresponding to the two or more protrusions, The two or more wall sections are connected to each other. The cooler according to feature 2.

4. The plurality of protrusions have two or more protrusions that are spaced apart from each other in a direction perpendicular to the direction in which the refrigerant flows, The at least one wall portion has two or more wall portions corresponding to the two or more protrusions, The two or more wall portions are spaced apart from each other. The cooler according to feature 2.

5. The one or more of the aforementioned protrusions are circular in plan view, The at least one wall portion is arc-shaped in a plan view, corresponding to the one or more protrusions. The cooler according to claim 1.

6. The at least one wall portion is provided concentrically with respect to the one or more protrusions. The cooler according to claim 5.

7. The at least one wall portion is a plurality of wall portions provided in a one-to-one ratio with respect to the plurality of protrusions. The cooler according to claim 1.

8. The aforementioned plurality of protrusions are divided into a plurality of rows of protrusions arranged side by side at intervals along the direction of flow of the refrigerant, Of the plurality of rows of protrusions, the distance between the first row of protrusions closest to the inlet and the second row of protrusions closest to the inlet after the first row of protrusions is greater than the distance between the third row of protrusions closest to the outlet and the fourth row of protrusions closest to the outlet after the third row of protrusions. The cooler according to claim 1.

9. The third surface has a groove provided in the region between the at least one wall portion and the one or more protrusions. The cooler according to claim 1.

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