Cooling heat exchanger

Abstract

To provide a cooling heat exchanger having a novel structure that can improve cooling performance by efficiently causing a flow of the heat medium to overcome protrusions while stably flowing the heat medium in a cooling flow path. [Solution] A cooling heat exchanger that has a cooling flow path (16) formed inside, through which a heat medium for cooling flows, and that cools a cooling object (17) placed on a cooling surface (18), wherein the cooling flow path (16) has protrusions (34) that disrupt the flow of the heat medium, protruding from the bottom surface of the cooling flow path (16), the protrusions (34) extending across the entire width of the cooling flow path (16), and both ends of the protrusions (34) each serve as connecting ends (54) that continue with the side wall portions of the cooling flow path (16), and the connecting ends (54) of the protrusions (34) are formed as flow adjustment sections (56) that are concave toward the bottom surface and extend in the flow direction of the cooling flow path (16).

Description

[Technical Field]

[0001] The present invention relates to a cooling heat exchanger used to cool an object to be cooled, such as a battery pack used in an electric vehicle. [Background technology]

[0002] For example, in electrically powered vehicles such as electric vehicles and hybrid vehicles, the amount of heat generated by battery packs and other components to be cooled is increasing due to miniaturization and improved performance, making the cooling performance of battery packs and other components increasingly important. Conventionally, cooling heat exchangers used to cool battery packs and other components have been proposed, including those with internal cooling channels through which a cooling heat medium flows, as disclosed in U.S. Patent No. 10,355,331 (Patent Document 1). The cooling surface of this cooling heat exchanger is superimposed on the object to be cooled, such as a battery pack, and the cooling surface is cooled by the heat medium flowing through the cooling channel, thereby cooling the object to be cooled. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 10,355,331 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, Fig. 10 of Patent Document 1 illustrates a structure in which protrusions are provided in a cooling flow path. In Patent Document 1, the protrusions are used to partially reduce the cross-sectional area of ​​the cooling flow path. The protrusions are formed by recessing at least one of the upper and lower wall portions of the cooling flow path in spots, and are provided partially in the flow path width and length directions of the cooling flow path.

[0005] However, forming such partial protrusions makes it easier for the heat transfer medium to detour around the protrusions in the cooling flow path width direction, suppressing the flow from overcoming the protrusions. Also, the heat transfer medium that detours around the protrusions and passes between the protrusions and the side wall of the cooling flow path becomes faster, which may cause the wall of the cooling flow path including the protrusions to be scraped by the heat transfer medium with a high flow rate, resulting in problems such as leakage.

[0006] Fig. 11 of Patent Document 1 also shows protrusions that are continuous over the entire length of the cooling flow channel in the width direction. However, the heat transfer medium flowing at both ends of the cooling flow channel in the width direction experiences greater flow resistance due to the influence of the side walls of the cooling flow channel than the heat transfer medium flowing in the middle of the flow channel in the width direction. Therefore, if protrusions of a constant height as in Patent Document 1 are formed over the entire length of the cooling flow channel in the width direction, a local decrease in the flow rate of the heat transfer medium will occur at both ends of the flow channel in the width direction, which could result in problems such as obstruction of the heat transfer medium flow or the generation of unintended vortices.

[0007] The problem to be solved by the present invention is to provide a cooling heat exchanger having a novel structure that can improve cooling performance by efficiently causing the heat medium to flow over protrusions while stably flowing in the cooling flow path. [Means for solving the problem]

[0008] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely examples and may be appropriately combined with one another. Multiple components described in each embodiment may be recognized and employed independently to the greatest extent possible, and may also be appropriately combined with any of the components described in other embodiments. Accordingly, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0009] The first aspect is a cooling heat exchanger that has a cooling flow path formed therein through which a heat medium for cooling flows and that cools a cooling object placed over a cooling surface, and that has protrusions that protrude from the bottom surface of the cooling flow path to disturb the flow of the heat medium, and that extend across the entire width of the cooling flow path, with both ends of the protrusions serving as connecting ends that are continuous with the side wall portions of the cooling flow path, and that have a shape that is recessed toward the bottom surface and serve as flow adjustment portions that extend in the flow direction of the cooling flow path.

[0010] In a cooling heat exchanger constructed according to this embodiment, since there are no gaps between the protrusions and the side wall of the cooling flow path, the flow of the heat medium through the gaps is restricted, making it easier for the heat medium to flow over the protrusions, and therefore the protrusions efficiently promote turbulence (stir the heat medium).

[0011] The connecting ends that form both ends of the protrusion are continuous with the side wall portion of the cooling flow path, and no gap without protrusions is formed between the protrusion and the side wall portion of the cooling flow path, thereby preventing the fast flow through the gap from causing wear on the flow path wall surface, and avoiding problems such as leakage.

[0012] Since the heat medium flowing in the end portions close to the side walls of the flow path tends to have greater flow resistance than the heat medium flowing in the middle portion away from the side walls, if protrusions of the same height as the middle portion are provided at the connecting ends with the side walls, the flow may be excessively restricted, and the flow of the heat medium may become poor at both end portions in the flow path width direction of the cooling flow path. Therefore, by making the connecting ends constituting both end portions of the protrusions continuous with the side walls of the cooling flow path flow adjusting portions shaped concave toward the bottom, the height of both end portions of the protrusions can be adjusted so that the heat medium flows appropriately, thereby improving and stabilizing cooling performance.

[0013] In a second aspect, in the cooling heat exchanger according to the first aspect, the bottom of the concave flow control portion is curved.

[0014] In a cooling heat exchanger constructed according to this aspect, it is easy to smoothly connect the bottom of the flow control portion to the inner surface of the side wall of the cooling flow path, and the heat transfer medium that passes over the flow control portion can easily flow smoothly.

[0015] In a third aspect, in the cooling heat exchanger described in the first or second aspect, the bottom of the flow adjustment section is directly continuous with the protruding tip of the side wall section protruding from the bottom surface of the cooling flow path.

[0016] In a cooling heat exchanger constructed according to this embodiment, for example, since the connection end of the protrusion is continuous with the protruding tip of the side wall portion, the height of the connection end tends to be higher on the side where it is continuous with the side wall portion; however, since the connection end of the protrusion is made into a concave flow adjustment portion, it is possible to prevent the flow of the heat medium from being excessively obstructed by the connection end of the protrusion.

[0017] In a fourth aspect, in the cooling heat exchanger described in any one of the first to third aspects, the protrusions extend in the width direction of the cooling flow path while being inclined in the length direction of the cooling flow path.

[0018] Since the heat medium flowing through the cooling flow path passes over the protrusions in a direction substantially perpendicular to the protrusions, in the cooling heat exchanger according to this aspect, in which the protrusions extend at an angle to the length of the cooling flow path, which is the flow direction of the heat medium, the flow direction of the heat medium when passing over the protrusions is likely to be in a direction oblique to the length of the flow path. As a result, the heat medium that has passed over the protrusions is likely to change its flow direction in the width direction of the flow path, which can more efficiently cause turbulence in the flow of the heat medium.

[0019] Furthermore, when the protrusions are inclined as in this embodiment, the heat transfer medium easily flows along the protrusions toward the end of the flow path in the width direction. In this case, if the protrusions are formed across the entire width of the cooling flow path, for example, and the height of the widthwise end (connection end) of the protrusions is high, the heat transfer medium guided along the protrusions in the flow path width direction may flow into a dead-end corner formed at the connection between the connection end of the protrusion and the side wall of the flow path. This may cause the heat transfer medium to stagnate or flow turbulently in the corner, hindering the flow of the heat transfer medium and resulting in a decrease in cooling performance. Therefore, by forming the connection end of the protrusions as a concave flow adjustment portion, it is possible to prevent unintended stagnation or turbulence of the heat transfer medium at the end of the flow path in the width direction, and the heat transfer medium can overcome the protrusions, thereby effectively improving cooling performance. On the other hand, if there are gaps between the ends of the protrusions and the side walls of the flow channel in the width direction of the flow channel, this, combined with the guiding action of the heat medium by the inclined protrusions, may result in linear, high-speed flow sections connecting such gaps in the length direction of the flow channel, which may reduce heat exchange performance or cause problems with erosion of the side walls that form the gaps. In this aspect, by providing flow adjustment sections between the ends of the protrusions and the side walls, it is possible to appropriately adjust the flow state of the heat medium in such gaps, thereby making it possible to reduce or eliminate such problems.

[0020] In a fifth aspect, in the cooling heat exchanger described in the fourth aspect, the protrusions extend obliquely toward either the upstream or downstream side of the cooling flow path toward both sides of the flow path width direction of the cooling flow path.

[0021] In the cooling heat exchanger constructed according to this aspect, the inclination directions of both sides of the protrusion are opposite to each other, so that the heat medium that has passed over both sides of the protrusion either joins together downstream of the protrusion or flows away from each other toward the side wall. In either case, the flow direction of the heat medium changes in the flow path width direction, reducing the temperature difference of the heat medium in the flow path width direction and improving cooling performance by uniforming the temperature of the heat medium.

[0022] In a sixth aspect, in the cooling heat exchanger described in the fifth aspect, the protrusions are V-shaped and extend obliquely toward the downstream side of the cooling flow path toward both sides in the flow path width direction of the cooling flow path.

[0023] In the cooling heat exchanger constructed according to this aspect, the protrusions are V-shaped and inclined downstream on both sides in the flow path width direction, so that the heat medium that has flowed over both sides of the protrusions joins together downstream of the protrusions, thereby turbulent flow of the heat medium downstream of the protrusions, forming vortices, and advantageously improving cooling performance by stirring the heat medium.

[0024] In a seventh aspect, in the cooling heat exchanger described in any one of the first to sixth aspects, the width dimension of the flow control portion in the flow path width direction of the cooling flow path is within the range of 1 to 30% of the width dimension of the protrusion in the flow path width direction of the cooling flow path.

[0025] In the cooling heat exchanger constructed according to this embodiment, the width of the flow control portion is set to 1% or more of the width of the protrusion, thereby enabling the efficient flow of the heat medium by providing the flow control portion. Also, the width of the flow control portion is set to 30% or less of the width of the protrusion, allowing the middle portion of the protrusion (the portion outside the flow control portion toward the inside in the flow path width direction) to be provided with a sufficiently wide width to more effectively agitate the heat medium. [Effects of the Invention]

[0026] According to the present invention, the heat medium can flow stably in the cooling flow path while efficiently causing the heat medium to flow over the protrusions, thereby improving the cooling performance of the cooling heat exchanger. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is an exploded perspective view of a cooling heat exchanger according to a first embodiment of the present invention; [Figure 2]2 is a cross-sectional view of the cooling heat exchanger shown in FIG. 1, which corresponds to the cross section II-II of FIG. 3. [Figure 3] III-III cross section of Figure 2 [Figure 4] 4 is an enlarged view of a portion of the IV-IV cross section of FIG. [Figure 5] FIG. 4 is an enlarged view of a portion of the VV cross section of FIG. 3. [Figure 6] FIG. 10 is a cross-sectional view showing a part of a cooling heat exchanger according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0029] 1 to 3 show a cooling heat exchanger 10 according to a first embodiment of the present invention. The cooling heat exchanger 10 has a structure in which an upper plate 12 and a lower plate 14 are overlapped and fixed to each other, and a cooling flow path 16 is formed therein through which a cooling heat medium flows. The cooling heat exchanger 10 cools the battery pack 17 as an object to be cooled by heat exchange between the heat medium flowing through the cooling flow path 16 and the battery pack 17 overlapped on the upper plate 12. In the following description, as a general rule, the up-down direction refers to the up-down direction in FIG. 3, the left-right direction refers to the left-right direction in FIG. 2 which is the flow path length direction of the cooling flow path 16, and the front-rear direction refers to the up-down direction in FIG. 2 which is the flow path width direction of the cooling flow path 16.

[0030] The upper plate 12 is shaped like a generally rectangular plate with rounded corners, and is longer in the left-right direction than in the front-rear direction. The upper plate 12 is desirably formed of a material with high thermal conductivity, such as a metal such as iron or aluminum alloy, or a conductive synthetic resin mixed with a conductive filler such as metal particles. In this embodiment, the upper plate 12 is made of metal. The upper surface of the upper plate 12 serves as a cooling surface 18 on which the battery pack 17 is placed. The cooling surface 18 is flat and extends perpendicular to the up-down direction. In this embodiment, the upper plate 12 has a generally constant thickness throughout, and the upper surface (cooling surface 18) and lower surface of the upper plate 12 are generally parallel to each other.

[0031] The lower plate 14 has a generally rounded rectangular plate shape corresponding to the upper plate 12 when viewed in the up-down direction, and is longer in the left-right direction than in the front-rear direction. The lower plate 14 is formed from, for example, a metal such as iron or an aluminum alloy, or a synthetic resin. The lower plate 14 may be a molded product, but in this embodiment, it is a pressed metal piece.

[0032] The lower plate 14 has an outer peripheral end portion that projects upward to form an outer peripheral fixing portion 20. The cross section of the outer peripheral fixing portion 20 is roughly U-shaped with an upside-down configuration, and the upper end surface has a flat portion that extends roughly parallel to the up-down direction. The flat portion of the upper end surface of the outer peripheral fixing portion 20 is placed on the lower surface of the outer peripheral end portion of the upper plate 12 and fixed by means of adhesive, welding, brazing, or the like, thereby fixing the upper plate 12 and the lower plate 14 to each other at their outer peripheral ends.

[0033] The outer peripheral fixing portion 20 of the lower plate 14 and the upper plate 12 are fixed liquid-tight around the entire periphery. As a result, a liquid-sealed region 22 that is liquid-tightly separated from the external space is formed between the overlapping surfaces of the upper plate 12 and the lower plate 14 on the inner peripheral side of the outer peripheral fixing portion 20.

[0034] A plurality of partition wall portions 24 are provided in the middle portion of the lower plate 14 in the left-right direction. Like the outer periphery fixing portion 20, the partition wall portions 24 are provided to protrude upward. In this embodiment, the partition wall portions 24 have a cross-sectional shape that is approximately U-shaped and upside down. The partition wall portions 24 extend linearly in the left-right direction. Both ends of the partition wall portions 24 are separated from the outer periphery fixing portion 20 in the left-right direction. In this embodiment, four partition wall portions 24, 24, 24, 24 are arranged at approximately equal intervals in the front-rear direction in the liquid sealing region 22. The four partition wall portions 24, 24, 24, 24 divide the left-right middle portion of the liquid sealing region 22 into five portions in the front-rear direction, and cooling flow paths 16 are formed between the partition wall portions 24 and the front and rear sides of the outer periphery fixing portion 20 adjacent in the flow path width direction, and between the partition wall portions 24, 24 adjacent in the flow path width direction.

[0035] In this embodiment, the bottom wall of each cooling flow passage 16 is formed by the flat lower wall of the lower plate 14. Furthermore, the side wall portions on both sides of each cooling passage 16 in the width direction are formed by partition wall portions 24 and outer periphery fixing portions 20 that rise from the bottom wall of the lower plate 14. Furthermore, the top wall portion of each cooling passage 16 is formed by the flat upper plate 12. That is, the upper ends of each side wall portion are formed as protruding tip surfaces of the partition wall portions 24 and outer periphery fixing portions 20 that rise from the bottom wall of the lower plate 14 and are overlapped with the upper plate 12.

[0036] The cooling flow passage 16 has an upstream left end connected to the inlet-side flow passage section 26. The inlet-side flow passage section 26 is located to the left of the partition wall section 24 and constitutes the left end of the liquid seal region 22. The inlet-side flow passage section 26 is not divided by the partition wall section 24 in the flow passage width direction, and five cooling flow passages 16, 16, 16, 16, 16 branch off from the inlet-side flow passage section 26 and extend to the right. The inlet-side flow passage section 26 is provided with a supply port 28 that penetrates the lower wall section of the lower plate 14, and the supply port 28 is connected to an external pipe (not shown). When the cooling heat exchanger 10 is in use, a low-temperature heat medium is supplied from the external pipe through the supply port 28 to the inlet-side flow passage section 26.

[0037] The cooling flow passage 16 has a downstream right end connected to the outlet-side flow passage section 30. The outlet-side flow passage section 30 is located to the right of the partition wall 24 and constitutes the right end of the liquid seal region 22. Like the inlet-side flow passage section 26, the outlet-side flow passage section 30 is not divided in the flow passage width direction by the partition wall 24, and five cooling flow passages 16, 16, 16, 16, 16 join together at the outlet-side flow passage section 30. The outlet-side flow passage section 30 is provided with an exhaust port 32 that penetrates the lower wall portion of the lower plate 14, and the exhaust port 32 is connected to an external duct (not shown). When the cooling heat exchanger 10 is in use, the heat medium heated by heat exchange with a cooling object (described later) is discharged from the outlet-side flow passage section 30 to the external duct through the exhaust port 32. The supply port 28 and the exhaust port 32 are located at diagonal corners of the lower plate 14. The inlet-side flow passage section 26 and the outlet-side flow passage section 30 have substantially the same flow passage length and flow passage width.

[0038] A large number of protrusions 34 are formed in the cooling flow channel 16. The protrusions 34 are formed so as to protrude upward from a bottom surface 35 of the cooling flow channel 16. As shown in FIG. 2, the protrusions 34 are generally V-shaped in top view. That is, the protrusions 34 have a pair of inclined portions 36, 36 that extend in the flow channel width direction while inclining in the flow channel length direction of the cooling flow channel 16, and the inclination directions of the pair of inclined portions 36, 36 are different from each other. The pair of inclined portions 36, 36 extend from the center of the cooling flow channel 16 in the flow channel width direction toward both outside sides, inclining toward the right side, which is the downstream side. The protrusions 34 have a ridge line 38 connecting the vertices of the cross section that extends in a V-shape in top view.

[0039] FIG. 4 shows an enlarged cross section of one protrusion 34 in the flow channel length direction. In the cross section shown in FIG. 4, the protrusion 34 has a tapered cross section that narrows toward the protrusion tip. More specifically, in the cross section shown in FIG. 4, the protrusion 34 has a cross-sectional outer shape that continuously includes an arc-shaped protrusion apex 40, an upstream inclined portion 44 that extends from the upstream end of the protrusion apex 40 at an incline upstream toward the protrusion base 42 (the lower end of the protrusion 34), and a downstream inclined portion 46 that extends from the downstream end of the protrusion apex 40 at an incline downstream toward the protrusion base 42. Note that the cross section of the protrusion 34 perpendicular to the ridge line 38 has a substantially constant shape, and is substantially the same as the cross section in the flow channel length direction at the center between the front and rear shown in FIG. 4.

[0040] In the cross section shown in Fig. 4, the radius of curvature R of the protrusion apex 40, including the ridge line 38, is within a range of 0.05 to 1.5 times, and more preferably within a range of 0.2 to 1.45 times, the length dimension L of the protrusion base 42 in the flow channel length direction. By setting the radius of curvature R of the protrusion apex 40 to 0.05 times or more the length dimension L of the protrusion base 42, the protrusion apex 40 has a smooth, arc-shaped cross section without any substantial corners. Furthermore, by setting the radius of curvature R of the protrusion apex 40 to 1.5 times or less the length dimension L of the protrusion base 42, it is possible to prevent the length dimension of the protrusion 34 in the flow channel length direction from becoming excessively long, and it is possible to set the inclination angles α and β of the upstream inclined portion 44 and the downstream inclined portion 46, which are smoothly continuous with the protrusion apex 40, to be sufficiently large.

[0041] The upstream inclined portion 44 may be curved, but in this embodiment, it is linear. The upper end of the upstream inclined portion 44 extends from the upstream end of the protrusion apex 40 in the tangential direction of the protrusion apex 40 and smoothly connects to the protrusion apex 40 without any corners. The lower end of the upstream inclined portion 44 is curved in an arc and smoothly connects to the bottom surface 35 of the cooling channel 16 without any corners.

[0042] The inclination angle α of the upstream inclined portion 44 relative to the bottom surface 35 of the cooling flow channel 16 (the bottom surface of the turbulent flow portion 48) is set to be in the range of 20 to 70°, and more preferably in the range of 30 to 60°. When the upstream inclined portion 44 has a curved shape, the inclination angle α of the upstream inclined portion 44 can be understood as, for example, the average value of the inclination angles of the upstream inclined portion 44.

[0043] By setting the inclination angle α of the upstream inclined portion 44 to 20° or more, the flow of the heat medium from the upstream side toward the protrusions 34 is effectively disturbed by the upstream inclined portion 44, which forms a sufficiently large angle with the flow direction of the heat medium, thereby improving cooling performance through a stirring effect. In addition, by setting the inclination angle α of the upstream inclined portion 44 to 70° or less, the flow of the heat medium can be prevented from being excessively restricted by the protrusions 34.

[0044] The downstream inclined portion 46 may be curved, but in this embodiment, it is linear. The upper end of the downstream inclined portion 46 extends from the downstream end of the protrusion apex 40 in the tangential direction of the protrusion apex 40 and smoothly continues to the protrusion apex 40 without any corners. The lower end of the downstream inclined portion 46 is curved in an arc and smoothly continues to the bottom surface 35 of the cooling channel 16 without any corners.

[0045] The inclination angle β of the downstream inclined portion 46 relative to the bottom surface 35 of the cooling flow channel 16 is set to be within a range of 20 to 70°, and more preferably within a range of 30 to 60°. When the downstream inclined portion 46 has a curved shape, the inclination angle β of the downstream inclined portion 46 can be understood as, for example, the average value of the inclination angles of the downstream inclined portion 46.

[0046] By setting the inclination angle β of the downstream inclined portion 46 to 20° or more, it is expected that the flow of the heat medium that passes over the protrusions 34 will easily separate from the downstream inclined portion 46, which will make it easier for a turbulent flow such as a vortex to occur downstream of the protrusions 34. Furthermore, by setting the inclination angle β of the downstream inclined portion 46 to 70° or less, the flow of the heat medium along the downstream inclined portion 46 is also ensured, and efficient stirring of the heat medium due to merging with the flow that has separated from the downstream inclined portion 46 can be expected.

[0047] A plurality of protrusions 34 having approximately the same shape and size are provided. In this embodiment, the plurality of protrusions 34 are arranged side by side at predetermined intervals in the length direction of one cooling flow passage 16. In this embodiment, the plurality of protrusions 34 provided in one cooling flow passage 16 are arranged at approximately constant intervals, but the intervals may vary; for example, the intervals may become narrower toward the downstream side, or may become narrower toward a middle part in the length direction of the flow passage.

[0048] In this embodiment, the protrusions 34 are provided in the downstream portion (right portion) of the cooling flow channel 16, but not in the upstream portion (left portion). Therefore, the downstream portion of the cooling flow channel 16 is a turbulent flow section 48 in which the protrusions 34 are provided, and the upstream portion of the cooling flow channel 16 is a laminar flow section 50 in which the protrusions 34 are not provided. In the cooling flow channel 16 of this embodiment, as shown in FIG. 2 , the flow channel length of the turbulent flow section 48 is greater than the flow channel length of the laminar flow section 50. The flow channel length of the turbulent flow section 48 is preferably within a range of 1.5 to 5 times, and more preferably within a range of 2 to 3 times, the flow channel length of the laminar flow section 50. The position of the turbulent flow section 48 is not necessarily limited to the downstream portion of the cooling flow channel 16, and may be set, for example, in the center portion of the cooling flow channel 16 in the flow channel length direction.

[0049] In the laminar flow section 50, the inner wall surface of the lower wall portion formed by the lower plate 14 is formed as an inclined surface 52 that slopes upward from the upstream side to the downstream side. As a result, the cross-sectional area of ​​the cooling flow channel 16 decreases toward the downstream side in the laminar flow section 50. On the other hand, the cross-sectional area of ​​the turbulent flow section 48, apart from the protrusions 34, is substantially constant along the flow channel length. Because the bottom surface of the laminar flow section 50 is formed as an inclined surface 52, the depth of the inlet-side flow channel section 26 located upstream of the laminar flow section 50 is greater than the depth of the outlet-side flow channel section 30 located downstream of the turbulent flow section 48. As a result, the volume of the inlet-side flow channel section 26 is greater than the volume of the outlet-side flow channel section 30. Note that the protruding height of the outer circumferential fixing portion 20 and the partition wall portion 24 that constitute the side wall portion of the laminar flow section 50 of the cooling flow channel 16 from the bottom surface 35 of the cooling flow channel 16 gradually decreases toward the downstream side. In addition, the portion of the outer peripheral fixing portion 20 that forms the wall of the inlet side flow path portion 26 has a larger protruding height dimension from the bottom surface 35 of the cooling flow path 16 than the portion that forms the wall of the outlet side flow path portion 30.

[0050] The protrusions 34 are provided in each of the five cooling flow paths 16, 16, 16, 16, 16. In this embodiment, the same number of protrusions 34 are provided at approximately the same intervals in the five cooling flow paths 16, 16, 16, 16, 16. Furthermore, in this embodiment, the positions and ranges in the flow path length direction at which the protrusions 34 are provided are also approximately the same in the five cooling flow paths 16, 16, 16, 16, 16. Note that the positions at which the protrusions 34 are formed (the positions of the turbulent flow sections 48) in the five cooling flow paths 16, 16, 16, 16, 16 may differ from one another depending on, for example, the heat-generating parts of the cooling target. Furthermore, the number, shape, size, spacing, etc. of the protrusions 34 formed in the five cooling flow paths 16, 16, 16, 16, 16 may differ from one another.

[0051] 5 , the protrusions 34 are provided continuously over the entire cooling flow passage 16 in the flow passage width direction, and both end portions are continuous with the outer peripheral fixing portion 20 or the side wall portion of the cooling flow passage 16 formed by the partition wall portion 24. In other words, both end portions of the protrusions 34 in the flow passage width direction are connection end portions 54 that are continuous with the outer peripheral fixing portion 20 or the partition wall portion 24. As can be seen from the fact that the protrusions 34 are provided from the bottom surface 35 of the cooling flow passage 16 to partway in the depth direction, it is sufficient that the protrusions 34 are provided continuously over the entire cooling flow passage 16 in the flow passage width direction on the bottom surface 35 side of the cooling flow passage 16 in the depth direction, and have connection end portions 54.

[0052] As shown in FIG. 5 , the connection end 54 forms a flow control portion 56 that extends in the length direction of the cooling flow channel 16 and is recessed downward toward the bottom surface 35 of the cooling flow channel 16. The flow control portion 56 has a bottom (upper surface) that is a concave curved surface and is smoothly and continuously connected to the inner sidewall surface of the cooling flow channel 16 without any corners. At least a portion of the flow control portion 56 in the flow channel width direction is located closer to the bottom surface 35 of the cooling flow channel 16 (lower) than the ridge line 38 of the protrusion 34. The minimum height dimension h of the flow control portion 56 relative to the bottom surface 35 of the cooling flow channel 16 is 0.05 to 0.8 times, and more preferably 0.1 to 0.5 times, the height dimension H of the protrusion 34 at the ridge line 38. Furthermore, the width dimension w1 of the flow control portion 56 is smaller than the width dimension w2 of an intermediate portion of the protrusion 34 that is not within the flow control portion 56. The width w1 of the flow adjusting portion 56 is set within a range of 1 to 30% of the width W of the projection 34, and more preferably within a range of 3 to 20%.

[0053] The flow control section 56 of this embodiment has an inner portion in the flow path width direction that slopes linearly downward toward the outside in the flow path width direction, and an outer portion in the flow path width direction that is recessed toward the bottom surface 35 of the cooling flow path 16. The flow control section 56 of this embodiment has an outer end portion in the flow path width direction that is continuous with the side wall portion of the cooling flow path 16, positioned higher than the end portion on the center side in the flow path width direction. The flow control section 56 has a substantially constant cross-sectional shape and extends linearly in the flow path length direction.

[0054] The inner end of the flow control section 56 in the flow path width direction is located inside, in the flow path width direction, the R of the corner connecting the side wall surface and the bottom surface 35 of the cooling flow path 16. In other words, the flow control section 56 is provided so as to extend onto the bottom surface 35 of the cooling flow path 16 in the flow path width direction.

[0055] 3, the cooling heat exchanger 10 having such a structure is used in a state in which a battery pack 17, which is the object to be cooled, is placed on the cooling surface 18 of the upper plate 12. For example, a plurality of battery packs 17 are arranged side by side in the left-right direction, which is the length direction of the cooling flow path 16.

[0056] With the battery pack 17 placed on the cooling surface 18, a low-temperature heat medium supplied to the inlet-side flow path section 26 from an external flow path (not shown) flows through the cooling flow path 16, thereby cooling the battery pack 17 through heat exchange between the heat medium and the battery pack 17 via the upper plate 12. The heat medium warmed by the heat exchange with the battery pack 17 is discharged from the outlet-side flow path section 30 to the external flow path (not shown).

[0057] Due to heat exchange with the battery pack 17, the temperature of the heat medium increases as it moves downstream. Here, the heat medium preferentially reaches a high temperature in the portion flowing through the upper part of the cooling flow path 16 that is closer to the battery pack 17. However, this reduces the temperature difference between the battery pack 17 and the heat medium flowing through the upper part of the cooling flow path 16, resulting in a decrease in cooling performance. Therefore, in the cooling heat exchanger 10, protrusions 34 are provided on the cooling flow path 16. When the heat medium flows over the protrusions 34, the flow of the heat medium is disturbed, and the heat medium flowing through the upper part of the cooling flow path 16 mixes with the heat medium flowing through the lower part. This reduces the temperature of the heat medium flowing through the upper part of the cooling flow path 16, increasing the temperature difference between the heat medium flowing through the upper part and the battery pack 17. This allows for efficient heat exchange between the heat medium and the battery pack 17, thereby more effectively cooling the battery pack 17. In short, the battery pack 17 can be efficiently cooled by utilizing not only the heat capacity of the heat medium flowing through the upper part of the cooling flow path 16 but also the heat capacity of the entire heat medium flowing through the cooling flow path 16.

[0058] The temperature of the heat medium flowing through the upper part of the cooling flow path 16 increases as the heat medium moves downstream of the cooling flow path 16 due to heat exchange with the battery pack 17, and therefore the temperature difference between the upper and lower parts of the heat medium on the downstream side of the cooling flow path 16 is likely to increase. Therefore, in the cooling heat exchanger 10 of this embodiment, the downstream part of the cooling flow path 16 is formed as a turbulent flow section 48 with protrusions 34. As a result, in the downstream part of the cooling flow path 16 where a rise in temperature in the upper part of the heat medium affects cooling performance, the protrusions 34 exert a stirring effect on the heat medium, thereby reducing or eliminating the temperature difference in the vertical direction within the cooling flow path 16 and suppressing a rise in temperature in the upper part of the heat medium.

[0059] In the cooling heat exchanger 10 of this embodiment, the upstream portion of the cooling flow path 16 is a laminar flow section 50 without protrusions 34. This reduces the turbulence of the heat medium flow due to the protrusions 34 in the upstream portion of the cooling flow path 16, where high temperatures at the top of the heat medium are less likely to be a problem, facilitating smooth flow of the heat medium. The bottom surface of the laminar flow section 50 of this embodiment is an inclined surface 52 that is inclined relative to the bottom surface of the turbulent flow section 48, and the cross-sectional area of ​​the cooling flow path 16 gradually decreases downstream in the laminar flow section 50. This makes it difficult for the heat medium flowing through the laminar flow section 50 to decelerate downstream, effectively achieving smooth flow of the heat medium. As a result, it is possible to circulate the heat medium using a less expensive pump with lower performance.

[0060] As shown in Figure 2, the protrusions 34 are V-shaped when viewed from above, narrowing toward the upstream side. The heat transfer medium that has passed over each inclined portion 36 of the protrusions 34 in a direction approximately perpendicular to the ridge line 38 merges with other flows downstream of the protrusions 34, causing strong disturbance to the flow and sometimes forming a vortex-like flow (eddy current), thereby more efficiently stirring the heat transfer medium.

[0061] 5, the protrusions 34 are provided continuously across the entire cooling flow path 16 in the flow path width direction, and connection ends 54, 54 constituting both ends are connected to the side wall portions of the cooling flow path 16. This makes it possible to prevent the formation of a flow of the heat medium that detours around the protrusions 34 in the flow path width direction, and the stirring action of the heat medium by climbing over the protrusions 34 is efficiently exhibited.

[0062] However, the heat medium flowing at both ends of the cooling flow passage 16 in the flow passage width direction experiences high flow resistance due to its proximity to the sidewalls of the cooling flow passage 16, which can easily cause flow disturbances or stagnation. Therefore, in the cooling heat exchanger 10, the connection ends 54 constituting both ends of the protrusions 34 are formed as flow adjustment portions 56 that are recessed downward. As a result, the flow resistance exerted on the heat medium by the formation of the protrusions 34 is smaller at both ends of the protrusions 34 than at the middle portion of the protrusions 34. Therefore, even if the sidewalls of the cooling flow passage 16 apply resistance to the heat medium flowing at both ends of the cooling flow passage 16 in the flow passage width direction, the flow of the heat medium is not excessively hindered by the protrusions 34, and a stable flow of the heat medium in the cooling flow passage 16 is achieved.

[0063] In the flow control section 56 of this embodiment, the height dimension from the bottom surface 35 is smaller on both outer sides in the flow path width direction, which are the sides connected to the side wall portions of the cooling flow path 16, than on the center side in the flow path width direction. Therefore, in the portions closer to the side wall portions of the cooling flow path 16, the flow resistance caused by the protrusions 34 is further reduced, realizing a smooth flow of the heat transfer medium.

[0064] The minimum height h of the flow adjustment portion 56 relative to the bottom surface 35 of the cooling flow channel 16 is within a range of 0.05 to 0.8 times, and more preferably within a range of 0.1 to 0.5 times, the height H of the protrusions 34 at the ridge lines 38. By setting the minimum height h of the flow adjustment portion 56 to 0.05 times or more the height H of the protrusions 34 at the ridge lines 38, the heat medium can be effectively stirred even when the heat medium flows over the flow adjustment portion 56. Furthermore, by setting the minimum height h of the flow adjustment portion 56 to 0.8 times or less the height H of the protrusions 34 at the ridge lines 38, the heat medium can smoothly flow over the flow adjustment portion 56, effectively suppressing turbulence and stagnation of the heat medium flow due to excessive flow resistance.

[0065] The flow adjustment portions 56 have a width dimension w1, which is the dimension in the width direction of the cooling flow passage 16, that is smaller than a width dimension w2 of the intermediate portions of the protrusions 34 that are not adjacent to the flow adjustment portions 56. The width dimension w1 of the flow adjustment portions 56 is preferably within a range of 1 to 30% of the width dimension W of the protrusions 34, and more preferably within a range of 3 to 20%. As a result, the flow adjustment portions 56 that are partially provided in positions close to the side walls of the cooling flow passage 16 ensure a smooth flow of the heat transfer medium at the ends of the cooling flow passage 16 in the flow passage width direction, while the width dimension w2 of the intermediate portions of the protrusions 34, which have a large protruding height from the bottom surface 35, is sufficiently ensured, thereby allowing the protrusions 34 to efficiently stir the heat transfer medium.

[0066] 6 shows a portion of a cooling heat exchanger 70 according to a second embodiment of the present invention. The cooling heat exchanger 70 has a structure in which protrusions 72 are formed in the cooling flow passages 16. In the following description, components and parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals in the drawings, and description thereof will be omitted. Furthermore, the cooling heat exchanger 70 of this embodiment differs from the cooling heat exchanger 10 of the first embodiment in the structure of the protrusions 72, which will be described below, and therefore the first embodiment can be referenced for the structure of other parts.

[0067] Like the protrusions 34 of the first embodiment, the protrusions 72 of this embodiment are V-shaped in top view and narrow in the front-to-rear direction toward the upstream side. As shown in Fig. 6 , the protrusions 72 are provided continuously across the entire cooling flow passage 16 in the flow passage width direction, and both end portions serve as connecting end portions 74 that are continuous with the side wall portions of the cooling flow passage 16.

[0068] The connecting end 74 of the protrusion 72 is a flow adjustment portion 76 that is recessed toward the bottom surface 35 of the cooling flow channel 16. The flow adjustment portion 76 of this embodiment has an outer end in the flow channel width direction that is continuous with the upper end, which is the protruding tip of the side wall portion (the outer peripheral fixing portion 20 and the partition wall portion 24 in FIG. 6 ) that protrudes from the bottom surface 35 of the cooling flow channel 16. Therefore, the outer end of the flow adjustment portion 76 in the flow channel width direction is located above the ridge line 38 of the protrusion 72. The flow adjustment portion 76 is located below the ridge line 38 in the middle portion in the flow channel width direction, and the minimum height dimension h' from the bottom surface 35 of the cooling flow channel 16 is smaller than the height dimension H of the protrusion 72 at the ridge line 38. Furthermore, the minimum height dimension h' of the flow adjustment portion 76 of the protrusion 72 of this embodiment is larger than the minimum height dimension h of the flow adjustment portion 56 of the protrusion 34 of the first embodiment, and the difference between the minimum height dimension h of the flow adjustment portion 76 and the height dimension H of the protrusion 72 at the ridge line 38 is smaller than in the first embodiment.

[0069] The cooling heat exchanger 70 constructed according to this embodiment is used to cool a cooling target such as a battery pack, similar to the cooling heat exchanger 10 of the first embodiment. As in the first embodiment, effective cooling performance can be obtained up to the more downstream side of the cooling flow path 16 due to the agitation action of the heat medium by the protrusions 72, etc.

[0070] In this embodiment, the outer end of the flow control portion 76 in the flow path width direction is continuous with the upper end of the side wall of the cooling flow path 16. As a result, for example, when the side wall of the cooling flow path 16 has an inclined shape due to curvature as shown in Fig. 6, the protrusions 72 are provided over a wider range in the flow path width direction, and the stirring action of the heat transfer medium by the protrusions 72 can be more effectively obtained.

[0071] Furthermore, if both ends (connecting ends 74, 74) of the protrusions 72 in the flow path width direction are continuous with the upper ends of the side walls of the cooling flow path 16, the height of the connecting ends 74, 74 of the protrusions 72 is likely to be higher than the middle part of the protrusions 72. Therefore, by making the connecting ends 74, 74 of the protrusions 72 into concave flow adjustment portions 76, it is possible to prevent the connecting ends 74, 74 from becoming excessively high, even if the connecting ends 74, 74 of the protrusions 72 are continuous with the upper ends of the side walls of the cooling flow path 16.

[0072] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific description. For example, the lower plate is preferably a pressed metal piece, but may also be a die-molded product. The die-molded lower plate is not limited to being made of metal, but may be made of, for example, a synthetic resin containing a thermally conductive filler. The upper plate is preferably made of metal with high thermal conductivity, but may also be made of, for example, a synthetic resin with high thermal conductivity containing a thermally conductive filler.

[0073] The shapes and sizes of the upper plate and the lower plate in a top view are not particularly limited, and may be changed as appropriate depending on, for example, the space available in the vehicle for arranging the cooling heat exchanger.

[0074] In the first embodiment, a structure in which the liquid seal area 22 (cooling flow path 16) is formed between the overlapping surfaces of the upper plate 12 and the lower plate 14, which are separate from each other, has been exemplified, but the members that form the wall of such a liquid seal area are not limited to the separate upper plate and lower plate. Specifically, for example, the liquid seal area (cooling flow path) can also be formed inside by closing the openings on both axial sides of the cylindrical member with cover members.

[0075] The number, size (length, width, and depth) and arrangement of the cooling channels may be changed as appropriate. The shape of the cooling channels is not limited to a linear shape as in the first embodiment, and may be, for example, a shape that curves or bends in the width direction of the channel.

[0076] The protrusions are not necessarily limited to a V-shape, and may be in various shapes, such as an inverted V-shape that widens toward the upstream side, a W-shape or inverted W-shape formed by arranging two V-shapes or inverted V-shapes in the width direction of the flow channel, a zigzag shape formed by arranging three or more V-shapes or inverted V-shapes in the width direction of the flow channel, an inclined linear shape that inclines in one direction toward the upstream or downstream side in the width direction of the flow channel, a non-inclined linear shape that extends in the width direction of the flow channel without inclining in the length direction of the flow channel, a curved shape such as a semicircular arc, or a wavy shape that extends in a meandering manner in the width direction of the flow channel.

[0077] The cross-sectional shape of the protrusion perpendicular to the ridgeline is not limited to the mountain shape having the small-diameter arc-shaped protrusion apex 40 and the upstream and downstream inclined portions 44 and 46 shown in the first embodiment. Specifically, for example, the protrusion apex may be arc-shaped with a larger radius of curvature, and the upstream and downstream ends of the protrusion apex may be smoothly connected to the bottom surface of the cooling flow channel by curved surfaces. Also, for example, the protrusion may not have an arc-shaped protrusion apex, and the protruding tip of the protrusion may have a sharpened shape in a cross section perpendicular to the ridgeline.

[0078] The inclined portion of the protrusion may have a varying height at an inner portion in the width direction of the flow channel apart from the connecting end (flow adjusting portion). Specifically, for example, one end of the inclined portion in the width direction of the flow channel is a low-protruding portion having a small height from the bottom surface of the cooling channel, and the other end of the inclined portion in the width direction of the flow channel is a high-protruding portion having a large height from the bottom surface of the cooling channel. Furthermore, for example, central low protrusions having a low height from the bottom surface of the cooling channel at the center in the width direction of the flow channel and central high protrusions having a high height from the bottom surface of the cooling channel at the center in the width direction of the flow channel may be alternately arranged in the length direction of the flow channel, which is expected to efficiently stir the heat transfer medium.

[0079] The height of the multiple protrusions arranged in the cooling flow path length direction may vary. Specifically, for example, the height of the multiple protrusions arranged in the cooling flow path length direction may gradually increase toward the downstream side of the cooling flow path. This allows the protrusions to agitate the heat transfer medium more strongly toward the downstream side in the turbulent flow section where the protrusions are formed. Furthermore, for example, the height of the multiple protrusions arranged in the cooling flow path length direction may gradually increase toward the center of the cooling flow path. This allows for efficient cooling of a cooling target whose temperature is high toward the center of the cooling flow path length direction. Furthermore, when multiple cooling flow paths are arranged in parallel, the cooling flow path located in the center of the flow path width direction may be provided with more protrusions than the cooling flow paths located at both ends of the flow path width direction. This also reduces the difference in cooling performance between the cooling flow path located in the center of the flow path width direction, where cooling by outside air is unlikely, and the cooling flow paths located at both ends of the flow path width direction, where cooling by outside air can be expected.

[0080] The plurality of protrusions arranged in the cooling flow path length direction may have a varying distance between adjacent protrusions in the flow path length direction. If the distance between adjacent protrusions in the cooling flow path length direction is set narrow, the flow of the heat medium is more likely to be turbulent, improving the cooling performance by stirring the heat medium. Furthermore, if the distance between adjacent protrusions in the cooling flow path length direction is set wide, the heat medium can flow smoothly.

[0081] The flow control portion of the protrusion needs only to be recessed toward the bottom surface of the cooling flow path, and the upper surface (bottom) does not necessarily need to be curved. That is, the upper surface of the flow control portion can also be linear. For example, the upper surface of the flow control portion may be V-shaped when viewed in the flow path length direction, or may be flat and extend approximately perpendicular to the up-down direction.

[0082] For example, the present invention can be applied to a cooling heat exchanger having a double-sided cooling structure in which both the upper surface of the upper plate and the lower surface of the lower plate are cooling surfaces, and inner fins are arranged between the opposing surfaces of the upper plate and the lower plate to divide the liquid sealing area into upper and lower halves. In a cooling heat exchanger having a double-sided cooling structure, when the inner fins form the bottom wall and side wall of the cooling flow path, the protrusions having the flow adjusting portions are formed on the inner fins. [Explanation of symbols]

[0083] 10 Cooling heat exchanger (first embodiment) 12 Upper plate 14 Lower plate 16 Cooling Channel 17 Battery pack (cooling target) 18 Cooling surface 20 Periphery fixing part 22 Liquid seal area 24 Bulkhead 26 Inlet side channel section 28 Supply Port 30 Outlet side flow path section 32 exhaust port 34 Protrusion 35 bottom 36 Slope 38 Ridgeline 40 Top of protrusion 42 Protrusion base 44 Upstream slope 46 Downstream slope 48 Turbulence section 50 Laminar flow section 52 Slope 54 Connection end 56 Flow adjustment section 70 Cooling heat exchanger (second embodiment) 72 Protrusion 74 Connection end 76 Flow adjustment section R Radius of curvature of the top of the projection L Length of the protrusion base α Inclination angle of the upstream slope β Inclination angle of downstream slope h, h´ Minimum height of flow control section H Height dimension of the protrusion at the ridge line w1 Width of flow control section w2 Width of the middle part of the protrusion outside the flow control part W: width of protrusion

Claims

1. A cooling heat exchanger having a cooling flow path formed therein through which a heat medium for cooling flows, for cooling an object to be cooled that is placed on a cooling surface, The cooling flow path is provided with a protrusion protruding from a bottom surface of the cooling flow path to disturb the flow of the heat medium, the projection extends across the entire width of the cooling flow path, and both ends of the projection are connected to sidewall portions of the cooling flow path, the connecting end of the protrusion is a flow adjusting portion that is recessed toward the bottom surface and extends in the flow path length direction of the cooling flow path, a bottom of the flow control portion directly connected to a protruding tip of the side wall portion protruding from the bottom surface of the cooling flow path;

2. 2. The cooling heat exchanger according to claim 1, wherein the bottom of said concave flow control portion is curved.

3. 3. The cooling heat exchanger according to claim 1, wherein the projections extend in a width direction of the cooling flow passage while being inclined in a length direction of the cooling flow passage.

4. 4. The cooling heat exchanger according to claim 3, wherein the projections extend obliquely toward either the upstream side or the downstream side of the cooling flow path on both sides in the flow path width direction of the cooling flow path.

5. 5. The cooling heat exchanger according to claim 4, wherein the projections are V-shaped and extend obliquely downstream of the cooling flow path toward both sides in the flow path width direction of the cooling flow path.

6. 3. A cooling heat exchanger as described in claim 1 or 2, wherein the width dimension of the flow control portion in the flow path width direction of the cooling flow path is within the range of 1 to 30% of the width dimension of the protrusion in the flow path width direction of the cooling flow path.

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