heat exchanger
The corrugated fins 5 are joined to the pair of plates 2 and 3, forming a heat exchanger that improves heat dissipation by alternating grooves 10 on the vertical surfaces 6b and 6c, enhancing heat exchange performance and reducing temperature increases in downstream regions.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- T RAD CO LTD
- Filing Date
- 2026-04-13
- Publication Date
- 2026-06-18
AI Technical Summary
Conventional heat exchangers face challenges in maintaining uniform heat distribution and the heat distribution of the heat exchange performance of a semiconductor element, particularly in the downstream region, leading to inefficient heat dissipation.
The corrugated fin 5 is composed of a pair of top plates that face each other with a gap therebetween, and a peripheral wall that shields the outer periphery of the pair of plates that face each other with a gap therebetween, and a peripheral wall that rises from the outer peripheral edge thereof.
The corrugated fin 5 is composed of a pair of top plates that face each other with a gap therebetween, and a peripheral wall that rises from the outer periphery of the pair of plates that are attached to the ridge portion 6a of the corrugated fin 5, with each wave 6 having a ridge 6a joined to the pair of plates 2 and 3.
Smart Images
Figure 2026100038000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a heat exchanger that dissipates the heat of a heat exchange object to a heat exchange medium, and particularly to a heat sink that dissipates the heat of a heat exchange object such as a semiconductor element.
Background Art
[0002] As a conventional technique, in a heat sink that dissipates the heat of a heat exchange object such as a semiconductor element, heat is conducted from the heat exchange object to the core, and heat transfer is performed from the core to the heat exchange medium, thereby reducing the temperature of the heat exchange object. In such a heat sink, the heat exchange medium flowing inside sequentially exchanges heat with the core according to the flow.
Summary of the Invention
Problems to be Solved by the Invention
[0003] However, the heat exchange medium that has exchanged heat with the heat exchange object in the upstream region of the flow has a temperature increase due to heat exchange when it reaches the downstream region of the flow. Therefore, the heat exchange performance of the heat exchange object located in the downstream region deteriorates. As a result, heat dissipation of the heat exchange object located in the downstream region of the flow of the heat exchange medium is inhibited, and the temperature of the heat exchange object at that position increases. Therefore, in order to solve this problem, a structure of a heat exchanger is provided that suppresses a decrease in the heat exchange performance of a heat exchange object located on the downstream side of the heat exchange medium and suppresses an increase in the temperature of the heat exchange object arranged in the downstream region.
Means for Solving the Problems
[0004] The present invention according to claim 1 has a box-shaped heat exchanger body 1 composed of a pair of top plate plates 2 and bottom plate plates 3 that face each other with a gap therebetween, and a peripheral wall portion 4 that shields the outer periphery of the pair of plates 2 and 3. An inner fin is interposed inside the heat exchanger body 1. The inner fin is a corrugated fin 5 in which a strip-shaped metal plate is folded and bent into a waveform. Each wave 6 of the corrugated fin 5 has a ridge 6a joined to the pair of plates 2 and 3, and the heat exchange object 20 is attached to the opposite side of the fin joining surface of at least one of the plates 2 and 3. In a heat exchanger in which a heat exchange medium 21 flows inside the heat exchanger body 1 along the direction of the corrugated fins 5 and exchanges heat with the object to be heat exchanged 20, On the rising surface 6b and rising surface 6c of each wave 6, the uneven ridges 10 are alternately formed in the thickness direction of the strip-shaped metal plate. Each of the aforementioned grooves 10 has an inclination angle of 10 to 60 degrees with respect to the main flow of the heat exchange medium 21, and adjacent grooves 10 are arranged in the same direction in this heat exchanger. The present invention as described in claim 2 is a heat exchanger as described in claim 1, When the heat exchange object 20 is attached to only one of the pair of plates 2 and 3 joined to the ridge portion 6a of the corrugated fin 5, This heat exchanger is formed such that each of the aforementioned grooves 10 moves away from the heat exchange object 20 as it moves from upstream to downstream of the main flow of the heat exchange medium 21. The present invention as described in claim 3 is a heat exchanger as described in either claim 1 or claim 2, Let A be the distance between adjacent surfaces 6b and 6c of each wave 6 of the corrugated fin 5. When the height of the unevenness of the aforementioned uneven surface 10 is denoted by Wh, This heat exchanger is characterized by having a Wh / A value of 0.1 or more and 0.8 or less. The present invention as described in claim 4 is a heat exchanger as described in claim 3, The heat exchanger is characterized in that the Wh / A value is 0.15 or more and 0.68 or less. . [Effects of the Invention]
[0005] The invention described in claim 1 is a heat exchanger in which a strip of metal sheet is folded and bent into a corrugated shape, and on the rising surface 6b and rising surface 6c of each wave 6 of the corrugated fin 5, irregular grooves 10 are alternately formed in the thickness direction of the strip of metal sheet, each irregular groove 10 has an inclination angle of 10 to 60 degrees with respect to the main flow of the heat exchange medium 21, and adjacent irregular grooves 10 are arranged in the same direction. According to this structure, the heat exchange medium 21 in the grooves of the uneven ridges 10, which are arranged at an angle on the opposing vertical surfaces 6b and vertical surfaces 6c (flow channels) of the heat exchange medium 21, moves along the grooves formed on those surfaces 6b and 6c, as shown in Figure 4(A), and then separates from the grooves at the ridge portion 6a where the inclined grooves disappear (see Figures 4(B) to 4(D)). In contrast, when the heat exchange medium 21, which is not exchanging heat with the heat exchange target object 20 outside the groove in the flow path, flows into the groove and exchanges heat with the heat exchange target object 20, the decrease in the heat exchange performance downstream of the heat exchange medium 21 is suppressed, and an improvement in heat dissipation of the heat exchange target object located in the downstream area can be expected. The invention described in claim 2 is a heat exchanger described in claim 1, wherein when the object to be heat exchanged 20 is attached to only one of the pair of plates 2 and 3 joined to the ridge portion 6a of the corrugated fin 5, each of the grooves 10 is formed to move away from the object to be heat exchanged 20 as it moves from upstream to downstream of the main body of the heat exchange medium 21. This structure allows the heat exchange medium that is not undergoing heat exchange to flow through grooves near the object being heated, which is expected to further improve heat exchange performance. The invention described in claim 3 is a heat exchanger according to either claim 1 or claim 2, wherein when the distance between adjacent surfaces 6b and 6c of each wave 6 of the corrugated fin 5 is A, and the height of the irregularities of the irregularities 10 is Wh, the value of Wh / A is 0.1 or more and 0.8 or less. This configuration allows for use in a range where heat exchange performance is high, even when pressure loss is taken into consideration. The invention described in claim 4 is the heat exchanger described in claim 3, wherein the value of Wh / A is 0.15 or more and 0.68 or less. This configuration allows for use in a range with even higher heat exchange performance than that of the invention described in claim 3. [Brief explanation of the drawing]
[0006] [Figure 1] An exploded perspective view showing the heat exchanger of the present invention. [Figure 2] A cross-sectional view of the heat exchanger taken along the line II-II in Figure 1. [Figure 3] A perspective view of the main part (A), a side view (B), and a front view (C) of the corrugated fin 5 of the first embodiment, showing the structure of the corrugated fin 5 used in the core of the heat exchanger. [Figure 4] This diagram illustrates the heat transfer of the heat exchange medium 21 flowing within the corrugated fins (10 ridges sloping downwards to the right) 5. [Figure 5] An explanatory diagram illustrating the heat transfer of a heat exchange medium 21 flowing through a corrugated fin 5 that does not have a pattern formed on it. [Figure 6] A heat dissipation characteristic diagram showing a comparison between the first embodiment, determined by thermal fluid analysis, and a corrugated fin 5 without a pattern formed on it. [Figure 7] This diagram illustrates the heat transfer of a heat exchange medium 21 flowing through a corrugated fin 5 (with ridges 10 sloping upward to the right) of a second embodiment used in the core of the heat exchanger of the present invention. [Figure 8] A heat dissipation characteristic diagram showing a comparison of the corrugated fin 5 of the first and second embodiments based on thermal fluid analysis. [Figure 9] This figure shows a comparison of the dependence of the circulation rate N on corrugated fins 5 used in the core of the heat exchanger of the present invention and corrugated fins 5 without a pattern formed on them. [Figure 10] A cross-sectional view showing another embodiment of the heat exchanger of the present invention. [Modes for carrying out the invention]
[0007] Next, embodiments of the present invention will be described based on the drawings. The heat exchanger of the present invention has an optimal structure for use in a heat sink or the like that dissipates the heat of a heat exchange object such as a semiconductor element. This heat exchanger has a pair of top plates 2 and bottom plates 3 that face each other with a gap therebetween, and a box-shaped heat exchanger body 1 is formed by a peripheral wall portion 4 that shields the outer peripheries of the pair of plates 2 and 3. As shown in FIG. 1, in the heat exchanger body 1 of this example, the top plate 2 is fitted into the opening of a cup plate formed by the bottom plate 3 and a peripheral wall portion 4 that rises integrally from the outer peripheral edge thereof. The heat exchanger body 1 shown in FIG. 1 is an example and is not limited to this shape. The peripheral wall portion 4 may be separate from the bottom plate 3. Inside the heat exchanger body 1, an inner fin that forms its core is interposed. The inner fin is composed of a corrugated fin 5 in which a strip-shaped metal plate is folded and bent in a waveform. The corrugated fin 5 has a standing upper surface 6b and a standing lower surface 6c facing each other in one wave 6, and a ridge line portion 6a that connects them in a wave shape. As shown in FIG. 2, the ridge line portion 6a of each wave 6 is joined to the pair of top plates 2 and bottom plates 3. In the heat exchanger body 1, a heat exchange object 20 is attached to the outer surface (the surface opposite to the fin bonding surface) of at least one of the pair of plates 2 and 3. In this example, the heat exchange object 20 is attached to the outer surface of the top plate 2. An inlet 22 through which a heat exchange medium 21 flows in and an outlet 23 through which it flows out are provided on the outer surface of the heat exchanger body 1. The heat exchange medium 21 flows along the ridge line direction of the ridge line portion 6a of the wave of the corrugated fin 5 disposed inside the heat exchanger body 1. As an example, a refrigerant such as cooling water can be used as the heat exchange medium 21. As an example, as shown in FIG. 1, when a plurality of heat exchange objects 20 are arranged at intervals along the flow of the heat exchange medium 21 on the outer surface of the top plate 2, the heat generated from the heat exchange object 20 is conducted to the corrugated fin 5 through the top plate 2, and heat transfer is performed from the corrugated fin 5 to the heat exchange medium 21, thereby reducing the temperature of the heat exchange object 20. In such a heat exchanger, the heat exchange medium 20 flowing through its interior exchanges heat with the core more in the downstream area of its flow. FIG. 5 is an explanatory diagram showing the heat transfer of the heat exchange medium 21 flowing through the core using the corrugated fin 5 having no pattern formed on the surfaces of the vertical upper surface 6b and the vertical lower surface 6c as the core. The heat 24 generated from the heat exchange object 20 arranged in the upstream area of the flow of the heat exchange medium 21 (point B in FIG. 5(A)) is transferred to the heat exchange medium 21 flowing near the ridge line portion 6a of the corrugated fin 5 connected thereto through the top plate 2 not shown (see FIG. 5(B)). Among the flow of the heat exchange medium 21, the heated medium 21a that has received the heat 24 flows directly on the side of the top plate 2, and when it reaches the downstream area of the flow of the heat exchange medium 21 (point D in FIG. 5(A)), since its temperature has risen due to heat exchange, the effect of receiving heat from the heat exchange object 20 arranged in the downstream area decreases. As a result, the heat dissipation of the heat exchange object located in the downstream area of the flow of the heat exchange medium 21 is inhibited, and the temperature of the heat exchange object at that position increases. Among the flow of the heat exchange medium 21, the unheated medium 21b that has not received the heat 24 flowing at a position away from the top plate 2 simply passes through the flow path in the corrugated fin 5 and is discharged from the outlet 23. In this embodiment, in order to solve the above problems, it has the following structure. On the surfaces of the vertical upper surface 6b and the vertical lower surface 6c of the corrugated fin 5 constituting the core, a strip-shaped metal a pattern of uneven stripes 10 in which convex portions 10a and concave portions 10b are alternately formed in a wave shape in the thickness direction of the plate is formed. And the pattern of the uneven stripes 10 is formed on the vertical upper surface 6b and the vertical lower surface 6c except in the vicinity of the ridge line portion 6a of the corrugated fin 5. These uneven ridges 10 have an inclination angle θ of 10 to 60 degrees with respect to the main flow of the heat exchange medium 21, and adjacent protrusions 10a and recesses 10b are inclined in the same direction. The inclination angles of the uneven ridges 10 on the vertical surfaces 6b and vertical surfaces 6c are also inclined in the same direction. Furthermore, in this embodiment, as shown in Figure 3, the inclination of the uneven ridges 10 is formed to slope downward to the right (away from the heat exchange object 20) as the main flow of the heat exchange medium 21 moves from upstream to downstream. As shown in Figure 4(A), the heat exchange medium 21 in the flow path of the corrugated fin 5 receives heat 24 at the upstream position of the heat exchange medium 21 (point B in Figure 4(A)) and becomes a heat-receiving medium 21a. The heat-receiving medium 21a moves along the grooves 10c formed on their surfaces 6b and 6c from the top plate 2 side to the bottom plate 3 side, exchanging heat with the object to be heat-exchanged 20, and then separates from the grooves 10c at the position of the ridge 6a (ridge 6a connected to the bottom plate 3) where the inclined grooves 10c disappear (point D in Figure 4(A)). In contrast, the unheated medium 21b, which has not exchanged heat with the heat exchange target object 20 outside the groove 10c in the flow path, flows into the groove 10c as shown in Figure 4(C), and at point D in Figure 4(A), it is replaced by the heat-receiving medium 21a. The flow of these mediums 21a and 21b circulates between the top plate 2 and the bottom plate 3, enabling heat exchange with the heat exchange target object 20 downstream of the heat exchange medium 21. As a result, the decrease in the overall heat exchange performance of the heat exchanger is suppressed. Figure 6 shows a comparison of the thermal resistance of a heat exchanger using corrugated fins 5 having the pattern of the uneven ridges 10 of the present invention shown in Figure 4 (the uneven ridges 10 form a downward sloping pattern to the right), and a heat exchanger using corrugated fins 5 without the pattern shown in Figure 5. The horizontal axis of the graph in Figure 6 shows the respective parts of the heat exchange object 20 located at the inlet side 20a, the middle section 20b, and the outlet side 20c of the heat exchange medium 21 in Figure 1. Within each heat exchange object 20, there are two heat-generating points along the flow of the heat exchange medium 21, and these six heat-generating points are shown. The vertical axis of the graph in Figure 6 shows the thermal resistance (°C / W) at each part. The experimental conditions were as follows: the heat exchange medium 21 was water, the flow rate Vw was 6 L / min, the water inlet temperature Tw1 was 70°C, and the heat input at each of the six locations was 300 W. As shown in Figure 6, the heat exchanger using the corrugated fin 5 having the pattern of the uneven ridges 10 (the uneven ridges 10 are sloped downwards to the right) of the present invention exhibits better heat dissipation characteristics in various places compared to the heat exchanger using corrugated fin 5 without a pattern. Furthermore, when the thermal resistance on the inlet 22 side is set to 100, the ratio of the thermal resistance on the outlet 23 side is 127.1 (a difference in ratio of 27.1%) for the heat exchanger using corrugated fins 5 having the pattern of the uneven ridges 10 of the present invention (the uneven ridges 10 have a downward sloping pattern to the right), while the ratio is 134.8 (a difference in ratio of 34.8%) for the heat exchanger using corrugated fins 5 without a pattern. Thus, the heat exchanger of the present invention shows a smaller decrease in heat dissipation characteristics on the outlet 23 side. Even when the experimental conditions described above are changed, the absolute value of the thermal resistance shown in the graph in Figure 6 changes, but the trend indicated by that value remains the same. Next, Figure 7 shows a second embodiment of the corrugated fin 5 used in the heat exchanger of the present invention, and explains the heat transfer of the heat exchange medium 21 flowing inside it. The difference between this example and the example in Figure 4 is that the pattern of the raised and recessed stripes 10 is formed with an upward sloping angle from the bottom plate 3 side to the top plate 2 side. This example will also be explained under the condition that the object to be heat-exchanged is attached to the top plate 2. In this case, as shown in Figure 7(A), the unheated medium 21b, which has not exchanged heat with the heat exchange target 20, moves towards the top plate 2 as it moves downstream along the groove 10c which slopes upward to the right. At point D in Figure 7(A), it is replaced by the heat-receiving medium 21a. Figure 8 shows a heat exchanger using corrugated fins 5 having the pattern of the first embodiment in Figure 4 (the uneven ridges 10 have a downward sloping pattern relative to the main flow direction of the heat exchange medium 21), and the second embodiment in Figure 7. This shows a comparison of thermal resistance with a heat exchanger using a corrugated fin 5 having the pattern of the embodiment (the uneven ridges 10 are inclined upward to the right relative to the main flow direction of the heat exchange medium 21). The explanation of the horizontal and vertical axes of the graph is the same as in Figure 6, so it will be omitted. The experimental conditions are the same as in Figure 6. As shown in Figure 8, even when using the pattern formed in the second embodiment, the heat exchange medium 21 is circulated, and the heat dissipation performance is improved compared to the corrugated fin 5 without a pattern. However, using the material with the pattern of the first embodiment results in better heat dissipation characteristics. Even when the experimental conditions described above are changed, the absolute value of the thermal resistance shown in the graph in Figure 8 changes, but the trend indicated by that value remains the same. As described above, the present invention proposes improving the overall heat dissipation characteristics of the heat exchanger by circulating the heat-receiving medium 21a and the unreceived medium 21b of the heat exchange medium 21. Generally, increasing the degree of circulation improves heat dissipation characteristics. However, the increase in pressure loss due to circulation also causes a decrease in flow rate, which leads to a decrease in heat dissipation characteristics. The following considerations were made to the extent that the above causes could be adequately avoided. In other words, the optimal value for improving heat dissipation characteristics, taking into account pressure loss with respect to the degree of circulation, was determined through numerical calculations. If the degree of circulation of the heat exchange medium 21 is N, the volume of the pattern of the uneven grooves 10 is Vwave, and the volume of one wave 6 is Vcell, then the degree of circulation N can be expressed by the following formula. (Formula 1) N = (Vwave) / (Vcell) Vwave and Vcell can be expressed by the following equations, respectively, where Swave (see Figure 3(C)) is the cross-sectional area of the uneven pattern 10, and Scell (see Figure 3(C)) is the cross-sectional area of a single wave 6. (Formula 2) Vwave = Swave × (Length of 10 raised / recessed patterns) × (Number of raised parts 10a and recessed parts 10b) × 2 =(Wp×sinθ×Wh / 2)×(B / sinθ)×(L / Wp)×2 =Wh × B × L (Formula 3) Vcell = Scell × L = (A × B) × L Here, Wp is the pitch of the pattern of the grooves 10, Wh is the height of the pattern of the grooves 10, θ is the inclination angle of the pattern of the grooves 10, A is the average width of one wave 6, B is the height of one wave 6, and L is the length of the flow path. Substituting (Equation 2) and (Equation 3) into (Equation 1) and rearranging, the degree of cyclicity N is given by (Equation 4). (Formula 4) N = Wh / A Figures 9(a) and (b) show the results of thermal-fluid analysis confirming the dependence of the footprint heat transfer coefficient and pressure loss on the degree of circulation (N), which are indicators of heat dissipation characteristics. Figure 9(c) shows the heat dissipation characteristic index considering pressure loss as a function of the degree of circulation (N). In Figure 9(a), (b), and (c), the horizontal axis represents the degree of circulation N, respectively. The vertical axis of Figure 9(a) represents the footprint heat transfer coefficient ratio (arb.unit) of the present invention, with the heat transfer coefficient of a heat exchanger using corrugated fins 5 without a pattern (hereinafter referred to as the "comparison") set to 1. The vertical axis of Figure 9(b) represents the pressure loss index (arb.unit). The vertical axis of Figure 9(c) represents the heat dissipation characteristic index (arb.unit) considering pressure loss. In each graph, the solid line represents the present invention, and the dashed line represents the comparison. The experimental conditions are the same as in Figure 6. In Figure 9(a), as the degree of circulation (N) increases, the heat dissipation characteristics improve, but the degree of circulation When (N) exceeds a certain value, its rate of increase gradually decreases. On the other hand, in Figure 9(b), the pressure loss increases uniformly. In Figure 9(c), when the circulation degree (N) is in the range of 0 to 0.3, the rate of increase in heat dissipation characteristics is greater than the rate of increase in pressure loss. Therefore, the heat dissipation performance index considering pressure loss improves with increasing circulation degree (N). On the other hand, in the range where the degree of circulation (N) exceeds 0.3, the rate of increase in pressure loss exceeds the rate of increase in heat dissipation characteristics, so the heat dissipation characteristic index considering pressure loss decreases. This can be presumed to be because the decrease in flow rate due to the increase in pressure loss reduces the footprint heat transfer coefficient. From the above, it was found that the improvement in heat dissipation characteristics, considering pressure loss, is maximized when the circulation rate (N) is 0.3. As can be seen from Figure 9(C), the degree of circulation (N) is within the range of Equation 5, and the value of the heat dissipation characteristic is 50% or more of the maximum value. (Formula 5) 0.1 ≤ N ≤ 0.8 Furthermore, the degree of circulation (N) is within the range of Equation 6, and the value of the heat dissipation characteristic is 75% or more of the maximum value. (Equation 6) 0.15 ≤ N ≤ 0.68 In the first and second embodiments of the present invention, the effect of the corrugated fins 5 on a heat exchanger in which the heat exchange object 20 is attached only to one side of the top plate 2 was described, but the same can be said when the heat exchange object 20 is attached only to one side of the bottom plate 3. Furthermore, as shown in Figure 10, the same effect can be obtained even when the heat exchange object 20 is attached to both sides of the top plate 2 and the bottom plate 3. [Explanation of symbols]
[0008] 1 Heat exchanger body 2 Top plate 3. Bottom plate 4 Peripheral wall 5 corrugated fins 6 waves 6a Ridge section 6b Standing surface 6c vertical plane 10 Concave and convex stripes 10a Convex part 10b recess 10c Groove 20 Heat exchange target 20a Entrance side 20b middle part 20c exit side 21 Heat exchange medium 21a Heat-receiving medium 21b Unreceived heat medium 22 Entrance 23 Exit 24 fever
Claims
1. A box-shaped heat exchanger body (1) is formed, comprising a pair of spaced-apart, opposing top plates (2) and bottom plates (3), and a peripheral wall portion (4) that covers the outer periphery of the pair of plates (2, 3). An inner fin is interposed inside the heat exchanger body (1). The inner fin is a corrugated fin (5) formed by folding and bending a strip of metal plate into a wave shape. Each wave (6) of the corrugated fin (5) has a ridge (6a) that is joined to the pair of plates (2, 3), and a heat exchange object (20) is attached to the opposite side of the fin joining surface of at least one of the pair of plates (2, 3). In a heat exchanger in which a heat exchange medium (21) flows inside the heat exchanger body (1) along the direction of the wave ridges of the corrugated fins (5) and exchanges heat with the object to be heat exchanged (20), On the rising surface (6b) and rising surface (6c) of each wave (6), irregular grooves (10) are alternately formed in the thickness direction of the strip-shaped metal plate. Each of the aforementioned grooves (10) has an inclination angle of 10 to 60 degrees with respect to the main flow of the heat exchange medium (21), and adjacent grooves (10) are arranged in the same direction in the heat exchanger.
2. In the heat exchanger according to claim 1, When the heat exchange object (20) is attached to only one of the pair of plates (2, 3) joined to the ridge portion (6a) of the corrugated fin (5), A heat exchanger in which each of the aforementioned grooves (10) moves away from the heat exchange object (20) as it moves from upstream to downstream of the main flow of the heat exchange medium (21).
3. In the heat exchanger according to either claim 1 or claim 2, Let A be the distance between adjacent surfaces (6b, 6c) of each wave (6) of the corrugated fin (5). When the height of the unevenness of the aforementioned uneven surface (10) is Wh, A heat exchanger characterized in that the Wh / A value is 0.1 or more and 0.8 or less.
4. In the heat exchanger according to claim 3, A heat exchanger characterized in that the Wh / A value is 0.15 or more and 0.68 or less.