Cooling heat exchanger

Abstract

Provided is a cooling heat exchanger which has a new structure and with which further improvement of cooling performance can be expected.　A cooling heat exchanger 10 has formed therein cooling flow passages 18 through which a cooling heat medium flows, and cools a cooling target which is overlaid on a cooling surface 12 provided on the surface of the cooling heat exchanger. In a wall part of each of the cooling flow passages 18, first projections 36a, which include first inclined portions 38, 38 extending to be inclined from the upstream to the downstream toward both sides in the width direction, and second projections 36b, which include second inclined portions 40, 40 extending to be inclined from the downstream to the upstream toward both sides in the width direction, are arranged side by side in the flow passage longitudinal direction.

Description

Cooling heat exchanger

[0001] The present invention relates to a cooling heat exchanger used for cooling a cooling target such as a battery used in an electrified vehicle.

[0002] Conventionally, cooling heat exchangers used for cooling batteries, inverters, etc. are known. As disclosed in, for example, Japanese Patent Application Laid-Open No. 2011-165939 (Patent Document 1), the cooling heat exchanger has a structure in which a refrigerant passage through which a cooling medium flows is formed in an internal region between the opposing surfaces of a pair of outer shell plates that are overlapped with each other. Then, the surface of the outer shell plate is cooled by heat exchange with the cooling medium flowing through the refrigerant passage, and the cooling target overlapped on the surface is cooled.

[0003] Japanese Patent Application Laid-Open No. 2011-165939

[0004] By the way, in the cooling heat exchanger of Patent Document 1, the cooling medium flowing near the cooling target in the refrigerant passage is easily warmed by heat exchange with the cooling target, while the cooling medium flowing away from the cooling target hardly undergoes heat exchange with the cooling target and hardly contributes to the cooling performance. Therefore, in Patent Document 1, protrusions (constriction parts) protruding into the refrigerant passage are formed, and the cooling medium is agitated by climbing over the protrusions.

[0005] However, as a result of the inventors' studies, it has been found that even if protrusions such as those in Patent Document 1 are provided, the cooling performance may still be insufficient.

[0006] The problem to be solved by the present invention is to provide a cooling heat exchanger with a novel structure that can be expected to further improve the cooling performance.

[0007] Hereinafter, preferred embodiments for understanding the present invention will be described. However, each of the embodiments described below is described exemplarily, and not only can be appropriately combined and adopted with each other, but also for the plurality of components described in each embodiment, they can be recognized and adopted independently as much as possible, and can also be appropriately combined with any of the components described in other embodiments and adopted. Thereby, in the present invention, various other embodiments can be realized without being limited to the embodiments described below.

[0008] The first embodiment is a cooling heat exchanger in which a cooling medium flows through a cooling channel formed inside, and a cooling object superimposed on a cooling surface provided on the surface is cooled, wherein the wall portion of the cooling channel is provided with a first projection having a first inclined portion that extends inclined from the upstream side to the downstream side as it goes toward both sides in the width direction, and a second projection having a second inclined portion that extends inclined from the downstream side to the upstream side as it goes toward both sides in the width direction, arranged in the direction of the length of the channel.

[0009] In a cooling heat exchanger with a structure according to this embodiment, the heat transfer medium that overcomes the first inclined portion of the first projection flows inward in the direction of the flow width of the cooling channel, and the heat transfer medium that overcomes the second inclined portion of the second projection flows outward in the direction of the flow width of the cooling channel. Therefore, as the heat transfer medium flows over the first and second projections which are arranged side by side in the direction of the flow length of the cooling channel, the stirring action of the heat transfer medium is exerted not only in the direction of the flow depth of the cooling channel but also in the direction of the flow width. As a result, local temperature rise of the heat transfer medium within the cooling channel is effectively prevented, and the heat capacity of the heat transfer medium can be efficiently utilized for cooling the object to be cooled, thus improving cooling performance.

[0010] The second embodiment is a cooling heat exchanger described in the first embodiment, wherein the first projection and the second projection are arranged alternately in the direction of the length of the cooling channel.

[0011] According to the cooling heat exchanger structured in this embodiment, the heat transfer medium flows over the first and second protrusions, which are alternately arranged in the longitudinal direction of the cooling channel, in sequence. This guides the heat transfer medium alternately inward and outward in the width direction of the channel, resulting in more efficient agitation of the heat transfer medium in the width direction of the cooling channel. Therefore, the temperature difference of the heat transfer medium within the cooling channel is further reduced, improving the cooling performance.

[0012] A third embodiment is a cooling heat exchanger described in the first or second embodiment, wherein the first projection and the second projection each include a low projection and a high projection.

[0013] In a cooling heat exchanger with a structure according to this embodiment, by providing a low protrusion and a high protrusion on the first and second protrusions, respectively, the heat transfer medium flows more easily through the low protrusion than through the high protrusion, thus the flow of the heat transfer medium can be controlled by the arrangement of the low protrusion. Furthermore, since the stirring action of the heat transfer medium is advantageously exerted in the high protrusion, the cooling performance can also be improved by stirring the heat transfer medium.

[0014] The fourth embodiment is a cooling heat exchanger described in the third embodiment, wherein the first projection has a central portion in the flow path width direction that is either the high projection or the low projection, and both ends that are either the low projection or the high projection, and the second projection has a central portion in the flow path width direction that is either the low projection or the high projection, and both ends that are either the high projection or the low projection.

[0015] According to the cooling heat exchanger structured in this embodiment, when the heat transfer medium overcomes either the first or second projection, which has low protrusions at both ends in the width direction of the cooling channel, it is easily guided to the outer sides in the width direction of the cooling channel, and when it overcomes the other of the first or second projection, which has a low protrusion at the center in the width direction of the cooling channel, it is easily guided towards the center in the width direction of the cooling channel. Therefore, the heat transfer medium overcoming the first and second projections is easily agitated in the width direction of the cooling channel, and further improvement in cooling performance can be expected.

[0016] The fifth embodiment is a cooling heat exchanger described in the third or fourth embodiment, wherein the height of the first projection and the second projection gradually changes from the low projection to the high projection.

[0017] According to the cooling heat exchanger with a structure conforming to this embodiment, unintended flow disturbances caused by abrupt changes in height at the first and second protrusions can be prevented, thereby achieving smooth flow of the heat transfer medium.

[0018] The sixth embodiment is a cooling heat exchanger described in any one of the first to fifth embodiments, which includes a parallel flow path section in which a plurality of the cooling flow paths are arranged in parallel.

[0019] According to the cooling heat exchanger structured in this embodiment, a wide cooling surface can be set in the direction of the flow path width by the parallel flow path section. Furthermore, since the parallel flow path section is composed of multiple cooling flow paths arranged in parallel, and the flow path width of each cooling flow path can be set with a large degree of freedom, instability of the heat transfer medium flow, which may occur when the flow path width of the cooling flow path is made excessively large in order to secure a wide cooling surface, can be avoided.

[0020] The seventh embodiment is a cooling heat exchanger described in any one of the first to sixth embodiments, wherein the width dimension of the first projection and the second projection is 50% or more of the flow path width of the cooling channel.

[0021] In a cooling heat exchanger with a structure according to this embodiment, both the first and second protrusions are formed with a width dimension that is sufficiently large relative to the flow width of the cooling channel, thereby effectively generating a flow of the heat transfer medium over these first and second protrusions, and improving the cooling performance through the stirring action of the heat transfer medium.

[0022] The eighth embodiment is a cooling heat exchanger described in any one of the first to seventh embodiments, wherein the first projection and the second projection are provided continuously over the entire width of the cooling channel and are continuously connected to the side wall of the cooling channel.

[0023] In a cooling heat exchanger with a structure according to this embodiment, since both the first and second protrusions are formed continuously over the entire width of the cooling channel, the flow of the heat transfer medium bypassing these first and second protrusions is more effectively prevented, and an improvement in cooling performance is achieved by allowing the heat transfer medium to flow over the first and second protrusions.

[0024] The ninth embodiment is a cooling heat exchanger described in any one of the first to eighth embodiments, wherein the widthwise center of the first projection overlaps with the second projection in the projection in the direction of the flow path length of the cooling channel, and the widthwise center of the second projection overlaps with the first projection in the projection in the direction of the flow path length of the cooling channel.

[0025] In a cooling heat exchanger with a structure according to this embodiment, the first projection and the second projection are arranged so as not to deviate significantly from each other in the flow width direction of the cooling channel, which makes it easier for the heat transfer medium to flow over the first projection and the second projection, respectively, and effectively exerts a stirring action of the heat transfer medium in the flow width direction.

[0026] According to the present invention, further improvements in cooling performance can be expected in a cooling heat exchanger.

[0027] Figure 1 shows an exploded perspective view of a cooling heat exchanger as the first embodiment of the present invention, a plan view of the cooling heat exchanger shown in Figure 1, which shows the cooling surface components through the glass, a partially enlarged cross-sectional view of the cooling heat exchanger shown in Figure 1, which corresponds to the III-III cross-section in Figure 2, a partially enlarged cross-sectional view of the cooling heat exchanger shown in Figure 1, which corresponds to the IV-IV cross-section in Figure 3, a figure showing the simulation results of the velocity distribution in the cooling channel of the cooling heat exchanger according to the embodiment, a figure showing the simulation results of the velocity distribution in the cooling channel of the cooling heat exchanger according to the comparative example, a plan view of a cooling heat exchanger as the second embodiment of the present invention, which shows the upper plate through the glass, a partially enlarged cross-sectional view of the cooling heat exchanger shown in Figure 6 A cross-sectional view, corresponding to the VII-VII section of Figure 6. A partially enlarged cross-sectional view of the cooling heat exchanger shown in Figure 6, corresponding to the VIII-VIII section of Figure 6. A partially enlarged cross-sectional view of the cooling heat exchanger shown in Figure 6, corresponding to the IX-IX section of Figure 6. A cross-sectional view showing a part of a cooling heat exchanger as another embodiment of the present invention. An exploded perspective view of a cooling heat exchanger as a third embodiment of the present invention. A plan view of the inner fins constituting the cooling heat exchanger shown in Figure 11. A partially enlarged cross-sectional view of the inner fins shown in Figure 12, corresponding to the XIII-XIII section of Figure 12. A partially enlarged cross-sectional view of the cooling heat exchanger shown in Figure 12, corresponding to the XIV-XIV section of Figure 12.

[0028] Embodiments of the present invention will be described below with reference to the drawings.

[0029] Figures 1 to 4 show a cooling heat exchanger 10 as a first embodiment of the present invention. The cooling heat exchanger 10 has a structure in which a flat upper plate 14 with a cooling surface 12 is superimposed on a concave lower plate 16, and a cooling channel 18 through which a cooling heat transfer medium flows is formed between the upper plate 14 and the lower plate 16. A cooling object, such as a battery (not shown), which is superimposed on the cooling surface 12, is cooled by heat exchange with the heat transfer medium via the upper plate 14. In the following description, the vertical direction refers to the vertical direction in Figure 3, the front-rear direction refers to the vertical direction in Figure 2, and the left-right direction refers to the left-right direction in Figure 2.

[0030] The upper plate 14 is made of, for example, a metal such as iron or an aluminum alloy, or a heat-conducting synthetic resin mixed with a heat-conducting filler, and preferably has a higher thermal conductivity than the lower plate 16. The upper plate 14 is a thin, roughly rectangular flat plate that extends to a roughly constant thickness, and its upper surface is a flat cooling surface 12. The upper plate 14 is longer in the left-right direction, which is the length direction of the cooling channel 18, than in the front-back direction, which is the width direction of the cooling channel 18.

[0031] The lower plate 16 is made of a metal such as iron or aluminum alloy, or a synthetic resin, and has a generally rectangular plate shape. The lower plate 16 has an outer shape that corresponds to the upper plate 14 when viewed in the vertical direction. A rectangular frame-shaped outer peripheral wall portion 20 is provided at the outer peripheral end of the lower plate 16, projecting upward. The inner circumference of the outer peripheral wall portion 20 of the lower plate 16 is a rectangular recess that opens upward, and a supply hole 22 and a discharge hole 24 are formed at one diagonal portion of the recess, penetrating in the vertical direction. The supply hole 22 and the discharge hole 24 are each provided with cylindrical connecting portions that project from the lower surface of the lower plate 16.

[0032] Multiple partition walls 26 are provided on the inner circumference side of the outer peripheral wall 20 of the lower plate 16. The partition walls 26 protrude upward from the lower wall of the lower plate 16 and extend linearly in the left-right direction with a substantially constant cross-section. The left and right ends of the partition walls 26 do not reach the outer peripheral wall 20, but are located away from the left and right center. The number of partition walls 26 is not particularly limited, but in this embodiment there are four, and they are arranged at substantially equal intervals in the front-rear direction.

[0033] The upper plate 14 is then superimposed on the upper surface of the lower plate 16, and the upper plate 14 and the lower plate 16 are fixed to each other. The upper plate 14 is superimposed on the upper surfaces of the outer peripheral wall portion 20 and the plurality of partition wall portions 26 of the lower plate 16, and the overlapping surfaces of the upper plate 14 and the lower plate 16 are fixed together by means of brazing, bonding, welding, etc., and are sealed in a liquid-tight manner.

[0034] Between the upper plate 14 and the lower plate 16, a sealed region 28 is formed on the inner circumference side of the outer peripheral wall portion 20, in which a heat transfer medium is sealed. The sealed region 28 can be connected to an external pipeline (not shown) by a supply hole 22 and a discharge hole 24, so that the heat transfer medium is supplied through the supply hole 22 and discharged through the discharge hole 24.

[0035] Multiple cooling channels 18 are formed in the sealed region 28. The cooling channels 18 are formed between adjacent outer peripheral wall portions 20 and partition wall portions 26 in the front-rear direction, and between adjacent partition wall portions 26, 26 in the front-rear direction. In the cooling channel 18, the left side (left side in Figure 2), which is on the supply hole 22 side, is the upstream side, and the right side (right side in Figure 2), which is on the discharge hole 24 side, is the downstream side. In this embodiment, five cooling channels 18a to 18e are arranged in the front-rear direction, and these five cooling channels 18a to 18e arranged in parallel constitute a parallel channel section 32.

[0036] Single-channel sections 34a and 34b are formed on both the left and right sides of the enclosed region 28, away from the parallel channel section 32 in the left-right direction. Each of the single-channel sections 34 is connected to one of the five cooling channels 18a to 18e. A supply hole 22 is formed in the upstream single-channel section 34a, and a discharge hole 24 is formed in the downstream single-channel section 34b. The heat transfer medium supplied from an external supply pipeline (not shown) through the supply hole 22 to the upstream single-channel section 34a is distributed and flows through the five cooling channels 18a to 18e, then merges in the downstream single-channel section 34b, and is discharged through the discharge hole 24 to an external discharge pipeline (not shown). This causes the heat transfer medium to circulate within the enclosed region 28, including the cooling channels 18. Devices that cool the heat transfer medium, such as radiators or refrigerators, are connected to the external supply pipeline. The heat transfer medium is supplied in a low-temperature state from an external supply pipeline to the cooling channel 18, where it is heated through heat exchange with the battery pack or other object to be cooled. After heating, it is discharged to an external discharge pipeline and cooled again by a heat sink or the like. In this way, it is desirable for the heat transfer medium to flow circulatingly through a closed circuit.

[0037] Multiple protrusions 36 are formed on the bottom wall portion of the cooling channel 18, which is composed of a lower plate 16. The protrusions 36 are integrally formed with the lower plate 16 and protrude upward from the lower plate 16. As shown in Figure 3, the protrusions 36 in this embodiment have a substantially triangular cross-section that tapers toward the tip of the protrusion in the cross-section in the length direction of the cooling channel 18 and extend in the width direction of the cooling channel 18. The maximum width dimension of the protrusions 36 is preferably 50% or more of the width dimension of the cooling channel 18, and more preferably 70% or more. The protrusions 36 in this embodiment are provided continuously over the entire width direction of the cooling channel 18, and the ends in the width direction of the flow path are directly and continuously connected to the outer peripheral wall portion 20 or the partition wall portion 26. In this embodiment, multiple protrusions 36 are provided distributed throughout the parallel channel portion 32, which is composed of five cooling channels 18a to 18e.

[0038] The projection 36 includes a first projection 36a and a second projection 36b. The first projection 36a and the second projection 36b are V-shaped when viewed from above, with the front-to-back width dimension of the first projection 36a decreasing towards the upstream side, and the front-to-back dimension of the second projection 36b decreasing towards the downstream side.

[0039] The first projection 36a is provided with a pair of first inclined portions 38, 38 that are inclined toward both outer sides in the width direction of the cooling channel 18, from the front (upstream side) to the rear (downstream side) of the cooling channel 18, and the front-to-back width dimension gradually decreases toward the front. The first inclined portions 38 in this embodiment are inclined at a substantially constant angle with respect to the length direction of the channel and extend linearly.

[0040] The width dimension of the first projection 36a is preferably 50% or more of the flow path width dimension of the cooling channel 18, and more preferably 70% or more. In this embodiment, the first projection 36a is continuously provided over the entire flow path width direction of the cooling channel 18, and both ends in the width direction are integrally connected to the outer peripheral wall portion 20 or partition wall portion 26 that constitute the side wall of the cooling channel 18. The width dimensions of the first projection 36a and the second projection 36b in the flow path width direction of the cooling channel 18 change in the flow path length direction of the cooling channel 18, but the width dimension referred to here is the distance between the ends in the width direction in the flow path width direction of the cooling channel 18, and is the maximum width dimension.

[0041] The second projection 36b has a pair of second inclined portions 40, 40 that incline from the rear (downstream side) to the front (upstream side) of the cooling channel 18 toward both outer sides in the width direction of the cooling channel 18, and the front-to-back width dimension gradually decreases toward the rear. The second inclined portions 40 in this embodiment are inclined at a substantially constant angle with respect to the length direction of the flow path and extend linearly. The second projection 36b in this embodiment has a plane-symmetric shape with respect to the first projection 36a with respect to a plane orthogonal to the length direction of the flow path, in other words, a rotationally symmetric shape of 180 degrees with respect to the central axis extending in the vertical direction.

[0042] The width dimension (maximum width dimension) of the second protrusion 36b is desirably 50% or more, more preferably 70% or more, relative to the channel width dimension of the cooling channel 18. The second protrusion 36b of the present embodiment is continuously provided over the entire width direction of the cooling channel 18, and both ends in the width direction are integrally connected to the outer peripheral wall portion 20 or the partition portion 26 that constitutes the side wall of the cooling channel 18.

[0043] The first protrusion 36a and the second protrusion 36b are arranged side by side in the channel length direction of the cooling channel 18, and in the present embodiment, they are provided alternately in the channel length direction. As shown in FIG. 3, in the channel length direction, the first protrusion 36a and the second protrusion 36b adjacent to each other have both end portions in the channel width direction of the cooling channel 18 approaching each other compared to the central portion, and form a pair arranged in a substantially rhombic shape in a top view. A plurality of pairs of the first protrusion 36a and the second protrusion 36b are provided spaced apart from each other in the channel length direction. In the present embodiment, 10 pairs are arranged at substantially equal intervals in the channel length direction. In the present embodiment, the pairs of the first protrusion 36a and the second protrusion 36b are distributed over the entire parallel channel portion 32. Note that both end portions in the channel width direction of the first protrusion 36a and the second protrusion 36b forming a pair approach each other but are separated without contacting each other.

[0044] The center in the width direction of the first protrusion 36a overlaps with the second protrusion 36b in the projection in the channel length direction of the cooling channel 18, and the center in the width direction of the second protrusion 36b overlaps with the first protrusion 36a in the projection in the channel length direction of the cooling channel 18. In the present embodiment, the center in the width direction of the first protrusion 36a and the center in the width direction of the second protrusion 36b overlap with each other in the projection in the channel length direction of the cooling channel 18. Note that in the present embodiment, the center in the width direction of the first protrusion 36a is the portion located most upstream, and the center in the width direction of the second protrusion 36b is the portion located most downstream.

[0045] A cooling heat exchanger 10 is formed when an upper plate 14 is superimposed on a lower plate 16 with this structure. In the cooling heat exchanger 10, an external conduit (not shown) is connected to a supply hole 22 and a discharge hole 24 provided in the lower plate 16, and a heat transfer medium flows through a cooling channel 18 formed between the upper plate 14 and the lower plate 16.

[0046] Furthermore, a battery pack (not shown), which is the object to be cooled, is placed on top of the cooling surface 12, which is the upper surface of the upper plate 14. Then, heat exchange occurs between the battery pack, which generates heat when operating, and the low-temperature heat transfer medium flowing through the cooling channel 18, via the upper plate 14, thereby cooling the battery pack. The arrangement of the battery pack on the cooling surface 12 is not particularly limited, but for example, multiple battery packs may be arranged in line along the length of the cooling channel 18, and all of these battery packs will be cooled by the heat transfer medium flowing through the cooling channel 18. In addition, the battery pack may be placed directly on top of the cooling surface 12, but it may also be placed indirectly via, for example, a flexible heat conductive gel or a heat conductive sheet, so that the gap with the cooling surface 12 is filled with a material with high thermal conductivity, and an improvement in heat exchange efficiency can be expected.

[0047] In conventional cooling heat exchangers, the heat transfer medium flowing through the cooling channel 18 gradually becomes hotter as it moves downstream due to heat transfer from the battery pack. Therefore, the temperature difference between the heat transfer medium and the battery pack becomes smaller downstream of the cooling channel 18 compared to the upstream side, reducing the cooling efficiency of the battery pack, or in other words, the cooling performance of the cooling heat exchanger. In particular, the heat transfer medium flowing in the upper part of the cooling channel 18, which is close to the cooling surface 12, is prone to temperature increases due to heat exchange with the battery pack. As a result, in conventional cooling heat exchangers, the temperature of the upper heat transfer medium rises, reducing the cooling performance even if the lower heat transfer medium remains at a low temperature.

[0048] Therefore, in the heat exchanger 10 for cooling of the present embodiment, a protrusion 36 is provided on the bottom surface (lower wall surface) of the cooling flow path 18. When the heat medium passes over the protrusion 36 and flows through the cooling flow path 18, the heat medium flowing through the upper part of the cooling flow path 18 and the heat medium flowing through the lower part are mixed when passing over the protrusion 36. Thereby, it is possible to prevent only the upper heat medium from becoming high temperature by heat exchange with the battery pack, and to efficiently utilize the heat capacity of the heat medium flowing in the cooling flow path 18, thereby realizing excellent cooling performance. In particular, since it is also possible to suppress the temperature rise of the heat medium up to the downstream side of the cooling flow path 18, the battery pack arranged on the downstream side of the cooling flow path 18 can also be effectively cooled.

[0049] Further, on the downstream side of the first protrusion 36a, the heat medium that has passed over the pair of first inclined portions 38, 38 flows inward in the flow path width direction of the cooling flow path 18 and merges, so that the formation of a swirling flow can also be expected. Thus, in the heat exchanger 10 for cooling, since the heat medium is also agitated by the formation of the eddy current, the cooling performance is improved by averaging the temperature of the heat medium.

[0050] Note that, for example, when a plurality of battery packs are arranged side by side in the flow path length direction of the cooling flow path 18, it may be important to effectively cool all of those battery packs. That is, if the performance of even one of those plurality of battery packs deteriorates, the performance of the entire battery may significantly deteriorate. In this case, for example, in a conventional heat exchanger for cooling in which the battery pack arranged on the downstream side of the cooling flow path 18 is likely to deteriorate due to insufficient cooling, there is a possibility that the intended battery performance cannot be obtained. On the other hand, the heat exchanger 10 for cooling of the present embodiment is easier to maintain the cooling performance up to the downstream side of the cooling flow path 18 than the conventional heat exchanger for cooling. Therefore, it is possible to prevent the battery pack on the downstream side from deteriorating due to heat and to realize stabilization of the battery performance.

[0051] The projection 36 includes a V-shaped first projection 36a that widens outward in the flow path width direction toward the downstream side, and an inverted V-shaped second projection 36b that narrows inward in the flow path width direction toward the downstream side. When the heat transfer fluid overcomes the first projection 36a, it tends to flow in a direction perpendicular to the pair of first inclined sections 38, 38 where the flow resistance is reduced, forming a flow toward the center in the flow path width direction. Also, when the heat transfer fluid overcomes the second projection 36b, it tends to flow in a direction perpendicular to the pair of second inclined sections 40, 40 where the flow resistance is reduced, forming a flow toward both outer sides in the flow path width direction. Therefore, the heat transfer fluid flowing through the cooling channel 18 is mixed not only in the depth direction of the cooling channel 18 but also in the flow path width direction of the cooling channel 18 by overcoming the projection 36 including the first projection 36a and the second projection 36b, thereby further improving the cooling performance by averaging the temperature of the heat transfer fluid.

[0052] In this embodiment, the first projection 36a and the second projection 36b are arranged alternately in the direction of the length of the flow path, so that the heat transfer medium is efficiently stirred in the direction of the width of the flow path. Furthermore, the first projection 36a and the second projection 36b adjacent to it downstream are arranged in close proximity to each other to form a pair, and the stirring action of the heat transfer medium in the direction of the width of the flow path can be advantageously exerted by these closely positioned first and second projections 36a and 36b.

[0053] In the projection of the cooling channel 18 in the direction of the channel length, the widthwise center of the first projection 36a overlaps with the second projection 36b, and the widthwise center of the second projection 36b overlaps with the first projection 36a. Therefore, the heat transfer medium can easily flow over both the first projection 36a and the second projection 36b, and the cooling performance is efficiently improved by stirring the heat transfer medium through the flow directed inward in the widthwise direction due to overcoming the first projection 36a and the flow directed outward in the widthwise direction due to overcoming the second projection 36b. In particular, in this embodiment, since both the first projection 36a and the second projection 36b are continuously provided over the entire widthwise direction of the cooling channel 18, it is not possible for a flow to bypass the first and second projections 36a and 36b without overcoming them, and the stirring action due to overcoming the first and second projections 36a and 36b is effectively exerted.

[0054] Figure 5A shows the velocity distribution when a heat transfer medium is flowed through a part of the cooling heat exchanger 10 according to this embodiment, which is equipped with a first projection 36a and a second projection 36b. Figure 5B shows the velocity distribution when a heat transfer medium is flowed through a part of a cooling heat exchanger as a comparative example, which is equipped with only the first projection 36a. Although it is not entirely clear from Figures 5A and 5B, which have been converted to grayscale due to constraints in the patent application procedure, in the original figures output as simulation results, parts with slow flow velocity are shown in blue and parts with fast flow velocity are shown in red. Therefore, the difference in hue due to the difference in flow velocity will be explained below.

[0055] In Figure 5B, which shows the flow velocity distribution of the comparative example, as the heat transfer medium flows over the first inclined portions 38, 38 of the first projection 36a, it flows toward the center in the flow path width direction. Therefore, downstream of each first projection 36a, there is a red portion α indicating a fast flow in the central part of the cooling flow path 18 in the flow path width direction, and at both ends of the cooling flow path 18 in the flow path width direction, particularly downstream of the first projection 36a, there is a blue portion β indicating flow stagnation. Thus, in the comparative example shown in Figure 5B, the heat transfer medium flows at a continuously fast velocity in the central part of the cooling flow path 18 in the flow path width direction, and the ends of the cooling flow path 18 in the flow path width direction tend to become stagnant regions with low flow velocity, making it difficult to obtain sufficient stirring action of the heat transfer medium.

[0056] On the other hand, in Figure 5A, which shows the flow velocity distribution of the cooling channel 18 in the cooling heat exchanger 10 according to this embodiment, there is a difference in the flow velocity distribution between the downstream side of the first projection 36a and the downstream side of the second projection 36b. Specifically, downstream of the first projection 36a, the flow velocity is faster in the central part in the width direction of the channel than at both ends, and downstream of the second projection 36b, the flow velocity is faster at both ends in the width direction of the channel than at the central part. As a result, the difference in flow velocity of the heat transfer medium in the width direction of the cooling channel 18 is relatively small, and the blue region with slow flow is narrower than in the comparative example. Therefore, in the embodiment according to Figure 5A (cooling heat exchanger 10), the heat transfer medium flows over both the first projection 36a and the second projection 36b, stirring the entire channel in the width direction, eliminating both the continuous fast flow in the central part in the width direction of the channel and the prominent stagnation at both ends in the width direction of the channel, as observed in the comparative example described above, and excellent cooling performance is achieved.

[0057] As described above, the stirring action of the heat transfer medium in the flow path width direction can be exhibited more advantageously in the cooling heat exchanger 10 according to this embodiment, as confirmed by the simulation results of the flow velocity distribution of the heat transfer medium in the cooling flow path 18 shown in Figures 5A and 5B.

[0058] Figures 6 to 9 show a cooling heat exchanger 50 as a second embodiment of the present invention. As shown in Figures 7 to 9, the cooling heat exchanger 50 is formed by overlapping an upper plate 14 and a lower plate 52. In the following description, components and parts that are substantially the same as those in the first embodiment may be denoted by the same reference numerals in the figures and their descriptions may be omitted.

[0059] As shown in Figure 6, the lower plate 52 is shaped like a rounded rectangular plate overall. The lower plate in this embodiment is integrally formed using press fittings. Five cooling channels 18a to 18e are formed in the lower plate 52, and a plurality of protrusions 54 are formed in each cooling channel 18. As shown in Figure 7, the protrusions 54 in this embodiment have an arc-shaped cross-section and are composed of smoothly continuous curved surfaces.

[0060] The projection 54 includes a first projection 54a having a pair of first inclined portions 38, 38 that inclin toward the downstream side toward both outer sides in the flow width direction of the cooling channel 18, and a second projection 54b having a pair of second inclined portions 40, 40 that inclin toward the downstream side toward the center in the flow width direction of the cooling channel 18. The first projection 54a and the second projection 54b located adjacent to it downstream form a pair, similar to the first and second projections 36a, 36b in the first embodiment.

[0061] As shown in Figures 7 and 9, the first projection 54a has a high projection 56 in the central part in the flow path width direction, and low projections 58, 58 at both ends in the flow path width direction. In this embodiment, the height of the first projection 54a gradually decreases from the high projection 56 to the low projections 58, 58.

[0062] As shown in Figures 8 and 9, the second projection 54b has a low projection 58 in the central part in the flow path width direction, and high projections 56, 56 at both ends in the flow path width direction. In this embodiment, the height of the second projection 54b gradually increases from the low projection 58 to the high projections 56, 56.

[0063] Furthermore, as shown in Figure 6, the first projection 54a and the second projection 54b have different shapes when viewed from above due to the difference in height. Specifically, the first projection 54a, which gradually slopes downward from the center in the width direction toward both outer sides, has a longer length in the flow path direction at the center in the width direction and a shorter length in the flow path direction at both ends in the width direction compared to the second projection 54b, which gradually slopes upward from the center in the width direction toward both outer sides.

[0064] The cooling heat exchanger 50 according to this second embodiment provides the same effects as the cooling heat exchanger 10 according to the first embodiment. Furthermore, since the lower plate 52 is made of pressed metal, it is easy to manufacture.

[0065] Furthermore, a high protrusion 56 is set in the widthwise center of the first projection 54a, and low protrusions 58 are set at both widthwise ends of the first projection 54a, and high protrusions 56 are set at both widthwise ends of the second projection 54b, and low protrusions 58 are set in the widthwise center of the second projection 54b. As a result, the heat transfer medium flows more easily toward the low protrusions 58 which have low flow resistance, and the heat transfer medium flows more easily in the flow path width direction. Thus, the cooling performance due to stirring of the heat transfer medium in the flow path width direction is also achieved by the formation of high protrusions 56 and low protrusions 58 on the projections 54.

[0066] As shown in Figure 10, a high protrusion 56 and a low protrusion 58 can also be set for the projection 36 with a substantially triangular cross-section shown in the first embodiment.

[0067] Figure 11 shows a cooling heat exchanger 60 as a third embodiment of the present invention. The cooling heat exchanger 60 has a structure in which inner fins 64 are arranged between an upper plate 14 and a lower plate 62.

[0068] The lower plate 62 is a substantially rectangular plate shape in which the length direction of the cooling channel 18, described later, is longer than the width direction of the channel. An outer peripheral wall portion 20 is integrally provided at the outer peripheral end of the lower plate 62, projecting upward and extending continuously around the entire circumference. In this embodiment, the lower plate 62 is preferably made of a material with high thermal conductivity, similar to the upper plate 14, and its lower surface (not shown) serves as a cooling surface, similar to the upper surface of the upper plate 14.

[0069] The inner fin 64 is made of metal, synthetic resin, or the like, and is in the shape of a thin plate. In this embodiment, the inner fin 64 is a pressed metal fitting. The inner fin 64 has a cross-section that is folded in a zigzag or wave-like manner. In this embodiment, a plurality of flat, inclined plate portions 66 that spread out inclined in the vertical and front-to-back directions are provided to be integrally continuous in the front-to-back direction at the tops 68 of the folds, resulting in a zigzag cross-section. The inner fin 64 extends linearly in the left-to-right direction with a substantially constant cross-sectional shape. The number of folds (number of tops 68) of the zigzag or wave-shaped inner fin 64 is not particularly limited and can be set appropriately, for example, by considering the cross-sectional area of ​​the cooling channel 18 (described later) partitioned by the inner fin 64.

[0070] The inner fin 64 is positioned between the upper plate 14 and the lower plate 16. The inner fin 64 has a smaller length in the left-right direction compared to the upper plate 14 and the lower plate 16, and is positioned in the central part in the left-right direction, away from the supply holes 22 and discharge holes 24 provided at both ends of the lower plate 62. As a result, the single-flow channels 34a and 34b of this embodiment are provided on both sides away from the inner fin 64 to the left and right.

[0071] The inner fin 64 is positioned relative to the upper plate 14 and the lower plate 16, for example, by brazing its top portion 68 to the upper plate 14 and the lower plate 16. As a result, multiple cooling channels 18 separated by the inner fin 64 are arranged in parallel in the width direction of the channels between the overlapping surfaces of the upper plate 14 and the lower plate 16, and these multiple cooling channels 18 constitute the parallel channel section 32 of this embodiment.

[0072] The parallel flow channels 32 are formed on both the upper and lower sides of the inner fin 64, respectively. The cooling surface 12 of the upper plate 14 is cooled by the heat transfer medium flowing through the parallel flow channel 32 located above the inner fin 64, while the cooling surface of the lower plate 62 (not shown) is cooled by the heat transfer medium flowing through the parallel flow channel 32 located below the inner fin 64. In this embodiment, the cooling channel 18 has a wall portion composed of two swash plate portions 66, 66 that are continuous via one apex 68 of the inner fin 64, and the upper plate 14 or lower plate 16, and has a substantially triangular cross-section.

[0073] The inner fin 64 has projections 70 formed on it. The projections 70 include an upper projection 70A that protrudes from the upper surface of the inner fin 64 and a lower projection 70B that protrudes from the lower surface of the inner fin 64. The projections 70 also include a first projection 70a with a pair of first inclined portions 38, 38 that slope outwards from the center in the flow path width direction toward the downstream side of the cooling flow path 18, and a second projection 70b with a pair of second inclined portions 40, 40 that slope outwards from the outer sides in the flow path width direction toward the center toward the downstream side of the cooling flow path 18. In combination with these, the inner fin 64 has a first upper projection 70Aa and a second upper projection 70Ab that protrude from the upper surface, and a first lower projection 70Ba and a second lower projection 70Bb that protrude from the lower surface. In short, the upper projection 70A includes the first upper projection 70Aa and the second upper projection 70Ab, and the lower projection 70B includes the first lower projection 70Ba and the second lower projection 70Bb. Furthermore, the first projection 70a includes the first upper projection 70Aa and the first lower projection 70Ba, and the second projection 70b includes the second upper projection 70Ab and the second lower projection 70Bb.

[0074] As shown in Figure 12, the first upper projection 70Aa and the second upper projection 70Ab are arranged alternately in the length direction of the flow path in a single cooling flow path 18. The first upper projection 70Aa and the second upper projection 70Ab, which is arranged adjacent to it downstream, are positioned close to each other and form a pair. As shown in Figure 13, the first upper projection 70Aa has a high protrusion 56 in the center in the width direction and low protrusions 58, 58 at both ends in the width direction. On the other hand, as shown in Figure 14, the second upper projection 70Ab has a low protrusion 58 in the center in the width direction and high protrusions 56, 56 at both ends in the width direction.

[0075] As shown in Figure 12, the first lower projection 70Ba and the second lower projection 70Bb are alternately provided in the length direction of a single cooling channel 18. The first lower projection 70Ba and the second lower projection 70Bb, which is positioned adjacent to it downstream, are arranged in close proximity to each other and form a pair. As shown in Figure 14, the first lower projection 70Ba has a high projection 56 in the center in the width direction and low projections 58, 58 at both ends in the width direction. On the other hand, as shown in Figure 13, the second lower projection 70Bb has a low projection 58 in the center in the width direction and high projections 56, 56 at both ends in the width direction. In this embodiment, the height of each projection 70 gradually changes from the high projection 56 to the low projection 58.

[0076] In the cooling heat exchanger 60 with such a structure, a battery pack (not shown) or the like, which is the object to be cooled, is superimposed on the cooling surface 12 of the upper plate 14 and the cooling surface (not shown) of the lower plate 62, respectively. The heat transfer medium flowing from the supply hole 22 to the discharge hole 24 cools the battery pack by exchanging heat with it via the upper plate 14 or the lower plate 62 as it passes through the multiple cooling channels 18 formed on both the upper and lower sides of the inner fin 64. It is also possible to configure a battery cell in which both sides of each battery pack are cooled by the cooling heat exchanger 60 by stacking the cooling heat exchanger 60 and the battery pack alternately in the vertical direction.

[0077] As the heat transfer medium flowing through the cooling channel 18 is disturbed and agitated when it passes over the protrusions 70 formed on the inner fins 64, it is possible to prevent the heat transfer medium at the upper and lower ends near the battery pack from becoming excessively hot, thereby improving cooling performance. In this embodiment, the height of the first protrusion 70a decreases from the center in the width direction toward both outer sides, and the height of the second protrusion 70b increases from the center in the width direction toward both outer sides. Since these first protrusions 70a and second protrusions 70b are arranged alternately in the length direction of the channel, the heat transfer medium is more likely to flow through the low protrusions 58 with low flow resistance, and an agitation effect of the heat transfer medium in the width direction of the channel can be expected.

[0078] Furthermore, since the protrusions 70 consist of a first protrusion 70a and a second protrusion 70b which are alternately arranged in the direction of the flow path length, alternating flows are generated toward the center in the flow path width direction and flows toward both outer sides in the flow path width direction, thereby achieving a stirring action in the flow path width direction. As described above, even when the inner fins 64 are provided with protrusions 70, the cooling performance can be improved by the stirring action of the heat transfer medium.

[0079] Although embodiments of the present invention have been described in detail above, the present invention is not limited by its specific description. For example, the first projection and the second projection do not necessarily have to be provided alternately in the direction of the flow path length of the cooling channel. Specifically, for example, if both the first projection and the second projection are provided in the direction of the flow path length of the cooling channel, multiple first projections may be provided in a continuous manner, or multiple second projections may be provided in a continuous manner.

[0080] The first and second projections may have different dimensions, such as width and height. Furthermore, the angle formed by the first inclined portion of the first projection with the flow path length direction does not have to be a complementary angle to the angle formed by the second inclined portion of the second projection with the flow path length direction. In short, the inclination angles of the first and second inclined portions can be set independently of each other. Also, the first and second inclined portions are not limited to linearly extending shapes; they may be bent lines with gradually changing inclination angles, or curved shapes with gradually changing inclination angles, etc.

[0081] The connection point of the pair of first inclined sections located furthest upstream on the first projection may be offset in the direction of the flow path width with respect to the center of the flow path width direction of the cooling channel. Similarly, the connection point of the pair of second inclined sections located furthest downstream on the second projection may be offset in the direction of the flow path width direction with respect to the center of the flow path width direction of the cooling channel.

[0082] In the first embodiment described above, the first projection and the second projection located downstream thereof were paired together, approaching each other in the direction of the flow path length. However, for example, the second projection and the second projection located downstream thereof may be paired together, approaching each other in the direction of the flow path length. The projection located furthest upstream in the cooling flow path may be either the first projection or the second projection. Similarly, the projection located furthest downstream in the cooling flow path may be either the first projection or the second projection. It is not necessary for all first and second projections on the flow path to be paired; projections that are not paired, or projections of different shapes, may be present on the flow path. In short, in this specification, "a first projection and a second projection paired together in close proximity" does not define the relative positional relationship between the first projection and the second projection in the direction of the flow path length, nor does it define the separation distance between the first projection and the second projection in the direction of the flow path length. Preferably, no other different protrusions are provided between the "closely positioned pair of first and second protrusions," and the separation distance in the direction of the flow path length at the central portion in the flow path width direction of the paired first and second protrusions is set to five times or less the flow path width (more preferably three times or less, and even more preferably two times or less).

[0083] The protrusions may be partially provided in the width direction of the cooling channel, and the widthwise ends of the protrusions may be separated from the side walls of the cooling channel. Furthermore, the protrusions may be positioned off-center to one side in the width direction of the cooling channel, and the distances from both ends in the width direction to the side walls of the cooling channel may differ. Also, the protrusions may be provided at equal intervals in the length direction of the cooling channel, or they may be arranged at different intervals to create variations in density. If multiple cooling channels are provided, the first and second protrusions only need to be provided in at least one cooling channel, and the number, arrangement, size, and shape of the protrusions may differ among these multiple cooling channels. Furthermore, the protrusions do not need to be distributed along the entire length direction of the cooling channel; they may be provided partially in that direction. In short, the number, arrangement, size, shape, and spacing of the protrusions can be appropriately changed and set according to the heat generation and temperature distribution of the object being cooled.

[0084] The heights of the multiple protrusions arranged in the longitudinal direction of the cooling channel may vary. For example, if the protrusions are made higher towards the downstream side of the cooling channel, the decrease in cooling performance downstream of the cooling channel can be more effectively suppressed.

[0085] It is also possible to provide multiple protrusions in a single cooling channel, aligned in the direction of the channel width. This prevents the length of the protrusions in the direction of the channel length from increasing without reducing the inclination angle of the inclined portion of the protrusions, for example, when the width of the cooling channel is wide. When multiple protrusions are provided in a line in the direction of the channel width of the cooling channel, these multiple protrusions may be provided continuously and integrally with each other.

[0086] In the second to fourth embodiments, an example was shown in which the first projection has a high projection in the center in the width direction and low projections at both ends in the width direction, and the second projection has a low projection in the center in the width direction and high projections at both ends in the width direction. However, for example, the first projection may have a low projection in the center in the width direction and high projections at both ends in the width direction, and the second projection may have a high projection in the center in the width direction and low projections at both ends in the width direction. Furthermore, in a plurality of first projections, there may be a mixture of those with a high projection in the center in the width direction and those with a low projection, and in a plurality of second projections, there may be a mixture of those with a high projection in the center in the width direction and those with a low projection. In addition, in first and second projections that are arranged in close proximity and form a pair, it is desirable that the arrangement of the high projections and low projections be different from each other, but they may be the same from each other.

[0087] The high and low protrusions do not necessarily have to be set at the center and both ends of the protrusion in the width direction; they may be set in the middle of the width direction. Furthermore, while it is desirable for the height of the protrusion to change gradually from the high to the low protrusion, it may also change in steps, for example. In addition, when the height of the protrusion changes gradually from the high to the low protrusion, the rate of change in height may be constant or may vary.

[0088] In the third embodiment, the inner fin was brazed to the upper and lower plates at its top. However, joining the top to the upper and lower plates is not mandatory. For example, the top could be superimposed on the upper and lower plates in a non-adherent state to easily form a parallel flow path, or the top could be separated from the upper and lower plates, with only one cooling flow path formed on each of the upper and lower sides of the inner fin. The inner fin only needs to separate the upper and lower cooling flow paths and is not necessarily limited to the zigzag plate shape exemplified in the third embodiment.

[0089] The cooling channel does not necessarily need to be multiple channels extending in parallel; it may be just one. Furthermore, the cooling channel may extend in a straight line, bend along its length, or be curved overall.

[0090] The object to be cooled is not necessarily limited to batteries for electric vehicles; for example, it could be a stationary type battery for industrial use, etc. Also, for example, one battery pack may be placed on the cooling surface of one heat exchanger, or one battery pack may be placed across multiple heat exchangers.

[0091] 10 Cooling heat exchanger (first embodiment) 12 Cooling surface 14 Upper plate 16 Lower plate 18 (18a to 18e) Cooling channel 20 Outer peripheral wall 22 Supply hole 24 Discharge hole 26 Partition wall 28 Enclosed area 32 Parallel channel section 34 (34a, 34b) Single channel section 36 Protrusion 36a First protrusion 36b Second protrusion 38 First inclined section 40 Second inclined section 50 Cooling heat exchanger (second embodiment) 52 Lower plate 54 Protrusion 54a First protrusion 54b Second protrusion 56 High protrusion 58 Low protrusion 60 Cooling heat exchanger (third embodiment) 62 Lower plate 64 Inner fin 66 Slanted plate section 68 Top section 70 Protrusion 70A Upper protrusion 70B Lower protrusion 70a First projection 70b Second projection 70Aa First upper projection 70Ab Second upper projection 70Ba First lower projection 70Bb Second lower projection

Claims

1. A cooling heat exchanger having a cooling channel formed inside through which a cooling heat transfer medium flows, for cooling an object to be cooled superimposed on a cooling surface provided on the surface, wherein the wall of the cooling channel is provided with a first projection having a first inclined portion that extends inclined from the upstream side to the downstream side as it goes toward both sides in the width direction, and a second projection having a second inclined portion that extends inclined from the downstream side to the upstream side as it goes toward both sides in the width direction, arranged in the direction of the length of the channel.

2. The cooling heat exchanger according to claim 1, wherein the first projection and the second projection are arranged alternately in the direction of the length of the cooling channel.

3. The cooling heat exchanger according to claim 1 or 2, wherein the first projection and the second projection each have a low protruding portion and a high protruding portion.

4. The cooling heat exchanger according to claim 3, wherein the first projection has a central portion in the flow path width direction that is either the high projection or the low projection, and both end portions that are either the low projection or the high projection, and the second projection has a central portion in the flow path width direction that is either the low projection or the high projection, and both end portions that are either the high projection or the low projection.

5. The cooling heat exchanger according to claim 3 or 4, wherein the height of the first projection and the second projection gradually changes from the low projection to the high projection.

6. A cooling heat exchanger according to any one of claims 1 to 5, comprising a parallel flow path section in which a plurality of the cooling flow paths are arranged in parallel.

7. The cooling heat exchanger according to any one of claims 1 to 6, wherein the width dimension of the first projection and the second projection is 50% or more of the flow path width of the cooling channel.

8. The cooling heat exchanger according to any one of claims 1 to 7, wherein the first projection and the second projection are provided continuously over the entire width of the cooling channel and are continuously connected to the side wall of the cooling channel.

9. A cooling heat exchanger according to any one of claims 1 to 8, wherein the widthwise center of the first projection overlaps with the second projection in the projection in the direction of the flow path length of the cooling channel, and the widthwise center of the second projection overlaps with the first projection in the projection in the direction of the flow path length of the cooling channel.

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