Micro-channel radiator for multiple hot spots

Abstract

The invention relates to the technical field of radiators, and particularly discloses a micro-channel radiator for multiple hot spots, which comprises a radiating main body, a rectangular frame edge and a jet liquid inlet partition plate, and is characterized in that the radiating main body is arranged in the rectangular frame edge, and the jet liquid inlet partition plate is arranged on the upper surface of the radiating main body; a jet flow heat exchange cavity is formed in the upper end of the heat dissipation body, a jet flow liquid separation plate is arranged at the upper end of the jet flow heat exchange cavity, jet flow holes are formed in the jet flow liquid separation plate, a jet flow liquid collection cavity is formed between the jet flow liquid separation plate and a jet flow liquid inlet partition plate, and a jet flow area baffle is arranged at the lower end of the jet flow liquid separation plate. The lower end of the side wall of the jet flow heat exchange cavity is provided with a jet flow micro-channel arranged outwards. The double-liquid-inlet design is adopted, two heat exchange modes of jet flow cooling and cross flow cooling are combined, and the heat dissipation efficiency is improved; through the jet flow liquid distribution plate and the jet flow area baffle, accurate distribution and targeted flow adjustment of fluid are achieved, and the heat dissipation uniformity and the temperature uniformity are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of radiators, and in particular discloses a microchannel radiator for multiple hot spots. Background Art

[0002] Heat dissipation with multiple hot spots and non-uniform heat flux density has important application prospects in lasers, plasmas, radar power tubes, etc. With the rapid development of integrated circuit technology, the integration of chips continues to increase, and the heat generation per unit area has increased significantly. Especially in application scenarios such as high-performance computing and artificial intelligence accelerators, multiple heat-intensive areas (hot spots) will form in local areas of the chip. The heat flux density of these hot spots can reach hundreds of watts per square centimeter, posing a severe challenge to the heat dissipation of the chip.

[0003] Microchannel liquid cooling technology is commonly used for chip heat dissipation. For example, the utility model patent with application number 2024105803715 discloses an embedded shunt microchannel heat sink for electronic chips, including a radiator bottom plate and a radiator top plate, with multiple microchannels between the radiator bottom plate and the radiator top plate, and multiple shunt microunits are arranged on the microchannels, and the shunt microunits include recesses arranged on the channels and spoilers between the channels. The microchannel heat sink disclosed in this patent adopts an evenly arranged straight channel structure. Although it can meet the overall heat dissipation requirements of the chip to a certain extent, it still has the following shortcomings: First, the traditional evenly arranged microchannel structure cannot specifically enhance the heat dissipation effect of the hot spot area, resulting in excessively high temperatures in the hot spot area, affecting the performance and reliability of the chip; second, due to the unreasonable distribution of the channels, the temperature uniformity of each area is poor, and it is easy to form a large temperature gradient, causing thermal stress problems.

[0004] At present, some improved solutions for hot spot heat dissipation have also appeared in the industry. Some use a single impact jet structure. For example, the invention patent with application number 2022108175973 discloses a double-layer microchannel heat dissipation structure for non-uniform heat sources, including a jet layer and a vein-type microchannel layer. The vein-type microchannel layer is arranged at the bottom of the jet layer. The vein-type microchannel layer is plate-shaped, and a number of microchannels are arranged on its top surface, and a spoiler column is arranged in the microchannel; although jet heat dissipation can enhance local heat exchange, the fluid dispersion effect after the jet causes the heat exchange efficiency to decay rapidly, and it is easy to form a flow dead zone on the chip surface. In addition, there are also fin structures, but due to the short contact time between the fluid and the solid, it is difficult to fully realize heat exchange. Therefore, in response to the shortcomings of existing radiators, this application proposes a new solution that can effectively solve the heat dissipation needs of multiple hot spots. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems in the prior art of poor temperature uniformity of the heat source surface and excessive temperature gradient leading to decreased chip performance and shortened life. The heat source surface here refers to a heat source area containing multiple hot spots. The present application proposes a microchannel radiator that can improve heat dissipation uniformity and reduce temperature gradient.

[0006] A hot spot refers to an area on a chip package where the heat concentration is significantly higher. A hot spot generates more heat than other areas on the chip. The temperature distribution of the chip can be estimated through a power map.

[0007] The present invention is achieved through the following technical solutions: A microchannel radiator for multiple hot spots, comprising a radiator body, a rectangular frame edge and a jet liquid inlet baffle, wherein the radiator body is arranged in the rectangular frame edge, and the jet liquid inlet baffle is arranged on the upper surface of the radiator body; A jet heat exchange chamber is provided at the upper end of the heat dissipation body, a jet liquid separator plate is provided at the upper end of the jet heat exchange chamber, a jet hole is provided on the jet liquid separator plate, a jet liquid collecting chamber is formed between the jet liquid separator plate and the jet liquid inlet partition plate, a jet liquid inlet port connected to the jet liquid collecting chamber is provided on the jet liquid inlet partition plate, a jet zone baffle plate for separating the jet heat exchange chamber is provided at the lower end of the jet liquid separator plate, outwardly arranged jet microchannels are provided at the lower ends of the side walls of the jet heat exchange chamber on both sides of the jet zone baffle plate, and the outer ends of the jet microchannels on both sides are connected to the liquid outlet chamber formed between the rectangular frame edge and the side wall of the heat dissipation body, and a converging liquid outlet port connected to the liquid outlet chamber is provided on the rectangular frame edge; The upper end of the heat dissipation body is provided with a cross-flow microchannel arranged side by side and perpendicular to the jet microchannel. One end of the cross-flow microchannel is connected to the liquid outlet cavity, and the other end is connected to the cross-flow liquid collecting cavity formed between the rectangular frame edge and the side wall of the heat dissipation body. The rectangular frame edge is provided with a cross-flow liquid inlet connected to the cross-flow liquid collecting cavity.

[0008] As a further configuration of the above scheme, the jet heat exchange cavity is a rectangular structure, whose width matches the width of the hotspot and whose length matches the length of the heat dissipation body. The structure here is a choice of matrix distribution hotspots and is not specifically limited.

[0009] As a further configuration of the above scheme, there is a jet heat exchange chamber, which is opened in the central area where the hot spots are concentrated or on one side of the central area where the hot spots are concentrated. Here, the hot spots are distributed in an array or unevenly distributed, and the jet heat exchange chamber is arranged in the central area where the hot spots are concentrated or on one side of the central area where the hot spots are concentrated; for example, there are nine hot spots in the heat source area of ​​the chip, which are distributed in an array of three horizontal and three vertical equidistant arrays. At this time, the jet heat exchange chamber is arranged above the middle column of hot spots or in the background area between two adjacent columns of hot spots.

[0010] As a further configuration of the above scheme, a plurality of the jet heat exchange cavities are provided and are respectively opened in a plurality of different heat source areas of a discrete heat source, where the discrete heat source refers to a heat source area including a plurality of hot spots.

[0011] As a further configuration of the above solution, the jet holes on the jet separation plate are provided with a plurality of groups, and each group of jet holes is arranged in a rectangular array.

[0012] As a further configuration of the above solution, the converging liquid outlet and the cross-flow liquid inlet are respectively opened on two opposite side surfaces of the rectangular frame.

[0013] As a further configuration of the above scheme, the inner dimensions of the jet microchannel and the cross-flow microchannel are set to be the same, and fins are provided in both the jet microchannel and the cross-flow microchannel.

[0014] As a further configuration of the above scheme, the plurality of fins are arranged in parallel and spaced apart in the jet microchannel or the cross-flow microchannel, and the shape of the fins is any one of circular, square, triangular, trapezoidal or arcuate.

[0015] As a further configuration of the above solution, a connecting hole is provided in the intersection area of ​​the jet microchannel and the cross-flow microchannel to connect the two up and down.

[0016] As a further configuration of the above solution, the heat dissipation body, the rectangular frame edge and the jet liquid inlet baffle are integral components formed by any of CNC machining, 3D printing and metal welding.

[0017] Beneficial Effects

[0018] The microchannel radiator disclosed in the present invention adopts a double liquid inlet design, combining two heat exchange methods of jet cooling and cross-flow cooling to improve heat dissipation efficiency; through the jet liquid separator plate and the jet zone baffle, precise distribution of the fluid and targeted flow regulation are achieved, effectively improving heat dissipation uniformity and temperature uniformity.

[0019] The microchannel radiator disclosed in the present invention adopts an upper and lower layered design, and the jet microchannel and the cross-flow microchannel are arranged at different levels, respectively, to avoid mutual interference between the flow channels, and at the same time, the heat exchange effect is further enhanced by arranging fins in the microchannel; and the position of the jet heat exchange cavity can be flexibly designed according to the actual heat source distribution, and at the same time, the number of the jet heat exchange cavity can be designed accordingly according to the number of hot spots of the discrete heat source, so that it can dissipate heat from multiple hot spot areas at the same time, thereby improving the adaptability of the radiator.

[0020] The microchannel radiator of the present invention is also manufactured by adopting an integrated design and a precision processing technology, thereby ensuring the reliability and processing accuracy of the product, and having good practicality and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of Example 1 of the present invention; Figure 2 This is a schematic diagram of a three-dimensional explosion structure of Example 1 of the present invention; Figure 3 It is a schematic diagram of the three-dimensional structure of the heat dissipation body, the jet liquid separation plate, and the jet area baffle in Example 1 of the present invention; Figure 4 It is a schematic diagram of the three-dimensional structure of the side cross section of Example 1 of the present invention; Figure 5 It is a schematic diagram of the side plan structure of embodiment 1 of the present invention; Figure 6 for Figure 5 Schematic diagram of the cross-section structure in the AA direction; Figure 7 for Figure 5 Schematic diagram of the cross-sectional structure in the middle BB direction; Figure 8 This is a schematic diagram of a three-dimensional explosion structure of Example 2 of the present invention; Fig. 9 It is a schematic diagram of the structure of the jet heat exchange cavity corresponding to the chip hot spot in Example 1 and Example 2; Fig.10 This is a schematic diagram of the heat dissipation main structure of comparative example 1; Fig.11 This is a schematic diagram of the heat dissipation main structure of comparative example 2; Fig.12 To compare the performance of the JI-CFHS radiator with the CFHS radiator and the PFHS radiator at different Reynolds numbers (1324~1986) in Experiment 1, the vertical indicators of each figure are (a) the maximum temperature of the heat source surface, (b) the maximum temperature difference of the heat source surface, (c) thermal resistance, and (d) performance coefficient; Fig.13 This is the heat source surface cloud diagram of the JI-CFHS radiator, CFHS radiator and PFHS radiator at Re=1324 in the first experiment for comparison; Fig.14 To compare the performance of the three radiators under the Reynolds numbers (1324-1986) in Experiment 1, the longitudinal indicators of each figure are (a) temperature uniformity, (b) temperature gradient; Fig.15 To compare the performance of the two heat sinks at different Reynolds numbers in Experiment 2, the vertical indicators of each figure are (a) the maximum temperature of the heat source surface, (b) the maximum temperature difference of the heat source surface, and (c) the thermal resistance; Fig.16 This is the heat source surface cloud diagram of different radiators in the comparative experiment 2 at Re=1324; Fig.17 To compare the performance of the two heat sinks at different Reynolds numbers in Experiment 3, the vertical indicators of each figure are (a) maximum temperature of the heat source surface, (b) maximum temperature difference of the heat source surface, (c) thermal resistance, and (d) Nusselt number; Fig.18 This is a cloud diagram of the heat source surface of different radiators in comparison experiment three when Re=1324. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. Figure 1-18 , and describes the application in detail with reference to embodiments.

[0025] For ease of understanding, a chip with 9 hot spots is set as the processing object (such as Fig. 9 As shown), 9 hot spots are evenly distributed in an array of three horizontal and three vertical positions, the chip size is 10mm×10mm, the temperature at the chip hot spot is 80℃~85℃, and the refrigerant used in the test is a non-conductive liquid with a boiling point of 47℃; some settings of the following embodiments, such as the position and structure of the jet inlet, are set for the aforementioned multi-hot spot chip. If the hot spot distribution position on the chip is adjusted, the position and structure of the jet inlet are adjusted accordingly. Therefore, the following embodiments and control examples are only for the convenience of understanding and comparison experiments to verify the effects of the corresponding setting structures.

[0026] Example 1 Embodiment 1 discloses a microchannel heat sink for multiple hot spots. Figure 1 and attached Figure 2The main part includes a heat dissipation body 1, a rectangular frame 2 and a jet liquid inlet baffle 3. The rectangular frame 2 is a rectangular structure surrounded by four side covers. The heat dissipation body 1 is rectangular in shape and is arranged inside the rectangular frame 2. Its lower surface is designed to be a flat surface for direct contact with the heat source for heat exchange. The jet liquid inlet baffle 3 is arranged on the upper surface of the heat dissipation body 1.

[0027] A jet inlet 301 is provided at one-third of the length of the jet inlet partition 3, and a cross-flow inlet 201 and a converging liquid outlet 202 are provided on two opposite sides of the rectangular frame edge 2, and the diameter of the converging liquid outlet 202 is larger than that of the cross-flow inlet 201, so that the jet liquid and the cross-flow liquid can be discharged from the converging liquid outlet 202 at the same time to take away the absorbed heat.

[0028] Reference Figure 3-7 A jet heat exchange cavity 101 is provided on the upper surface of the heat dissipation body 1 directly below the jet liquid inlet 301. The jet heat exchange cavity 101 is in the shape of a long strip and parallel to one side of the heat dissipation body 1, that is, it corresponds to the background area between two adjacent columns of hot spots. At the same time, the lower end of the jet heat exchange cavity 101 extends downward to the bottom wall of the heat dissipation body 1. Jet microchannels 102 extending outward are provided at the lower ends of both side walls of the jet heat exchange cavity 101, and the outer ends of the jet microchannels 102 on both sides are connected to the liquid outlet cavity 103 formed between the rectangular frame edge 2 and the side wall of the heat dissipation body 1. A jet separator plate 4 is arranged on the top of the jet heat exchange chamber 101, and a plurality of jet holes 401 are arranged at intervals and in a rectangular array. The lower surface area of ​​the jet inlet partition plate 3 corresponding to the jet separator plate 4 is recessed upward by a certain distance, so that when the jet inlet partition plate 3 is attached to the upper surface of the heat dissipation body 1, a corresponding jet collection chamber 6 can be formed, and the jet inlet port 301 is connected to the jet collection chamber 6. A jet zone baffle plate 7 is arranged on the lower surface of the jet separator plate 4, and the jet zone baffle plate 7 is arranged perpendicular to the jet microchannel 102, so that the jet heat exchange chamber 101 can be divided into two sections under the blocking effect of the jet zone baffle plate 7, and the jet liquid inside the two sections enters the corresponding jet microchannel 102 respectively, and enters the liquid outlet chamber 103 after passing through the jet microchannel 102, and finally discharged from the converging liquid outlet 202.

[0029] At the upper end of the heat dissipation body 1, there are arranged cross-flow microchannels 104 arranged side by side, and the cross-flow microchannels 104 are arranged parallel to the length direction of the jet heat exchange cavity 101 (i.e., perpendicular to the direction of the jet microchannel 102), and one end of all cross-flow microchannels 104 is connected to the liquid outlet cavity 103, and the converging liquid outlet 202 is connected to the liquid outlet cavity 103. The other ends of all cross-flow microchannels 104 are connected to the cross-flow liquid collection cavity 105 formed between the rectangular frame edge 2 and the side wall of the heat dissipation body 1, and the cross-flow liquid inlet 201 is connected to the cross-flow liquid collection cavity 105.

[0030] Finally, in this embodiment 1, fins 8 are also arranged in the jet microchannel 102 and the cross-flow microchannel 104. The internal dimensions of the jet microchannel 102 and the cross-flow microchannel 104 are kept consistent. The fins 8 are arranged as a cylinder, whose diameter is smaller than the width of the jet microchannel 102 and the cross-flow microchannel 104, and whose height is also smaller than the height of the two microchannels. In the specific arrangement, a plurality of fins 8 are arranged in parallel and at intervals, and their positions correspond to the hot spot areas of the heat source.

[0031] In addition, it should be noted that the heat dissipation body 1, the rectangular frame edge 2 and the jet liquid inlet baffle 3 in this embodiment 1 are formed into an integral component by precision CNC processing, 3D printing, metal welding and the like. The integrated brazing process can make the structure of the microchannel radiator more solid and reliable, and reduce the risk of secondary melting of the brazing material and material degradation caused by secondary brazing. It can be formed in one piece by 3D printing, and the welding surface structure can be optimized by machining and polishing. Since the microchannel radiator is an integrated welded structure and has no multiple welding surfaces as a whole, the strength of the radiator can be effectively improved, and the relevant performance of the radiator can be tested in a short time, so as to achieve rapid iteration and upgrade.

[0032] When the microchannel heat sink disclosed in the present embodiment 1 is used, the heat source hot spot area of ​​the heat generating device (such as a chip) is aligned with the jet heat exchange cavity 101 so that it fits with the lower surface of the heat dissipation body 1, and then coolant is introduced simultaneously from the jet inlet 301 and the cross-flow inlet 201. The coolant entering from the jet inlet 301 first enters the jet liquid collecting cavity 6, and is split and sprayed into the bottom of the jet heat exchange cavity 101 through the jet hole 401 on the jet liquid separation plate 4, and then is evenly split by the jet area baffle 7, and flows outward along the corresponding jet microchannel 102 into the liquid outlet cavity 103, and finally discharged from the converging liquid outlet 202. The coolant entering from the cross-flow liquid inlet 201 first enters the cross-flow liquid collecting chamber 105, then flows along the cross-flow liquid collecting chamber 105 into the liquid outlet chamber 103, and finally is discharged from the converging liquid outlet 202, so that the liquid flow inside the entire microchannel radiator presents a layered two-in, one-out asymmetric layout.

[0033] Comparative Example 1 On the basis of Example 1, Fig.10 As shown, two sets of upper and lower parallel rectangular microchannels 106 are arranged in the heat dissipation body 1 , and the rectangular microchannels 106 have the same structure and distribution as the jet microchannels 102 .

[0034] Control group 2 On the basis of Example 2, Fig.11As shown, a rectangular microchannel 2 107 is provided in the upper part of the heat dissipation body 1 , and a rectangular microchannel 3 108 is provided in the vertical direction below the rectangular microchannel 2 107 ; the rectangular microchannel 2 107 and the rectangular microchannel 3 108 have the same structure and distribution as the jet microchannel 102 .

[0035] A comparative test 1 was set up to verify the heat dissipation effect of the radiator in Example 1. The radiator in Example 1 was an impingement jet-cross flow microchannel radiator, i.e., a JI-CFHS radiator; the radiator in the control group 1 was a double-layer microchannel radiator, i.e., a PFHS radiator; the radiator in the control group 2 was a hybrid microchannel radiator, i.e., a CFHS radiator; The performance of the three radiators at different Reynolds numbers (1324~1986) is compared. Fig.12 As shown, from Fig.12 As can be seen in (a), the Tmax of the JI-CFHS radiator is significantly lower than that of the PFHS radiator and the CFHS radiator. This is attributed to the fact that the coolant jet inlet of the JI-CFHS is located directly above the middle hotspot, and the coolant after the jet flows to the hotspots on both sides, shortening the flow path of the lower coolant. The fins in the hotspot area can effectively exchange heat with the coolant.

[0036] from Fig.12 As can be seen in (b), the impingement jet-cross flow (JI-CFHS) microchannel effectively reduces the temperature difference on the heat source surface, which is attributed to the array impingement jet inlet design in the middle of the JI-CFHS radiator, which effectively reduces the maximum temperature of the heat source surface and slows down the heat transfer deterioration along the coolant flow direction. At the same time, it also avoids overcooling at the cross flow inlet of the JI-CFHS radiator.

[0037] from Fig.12 It can be seen from (c) that with the increase of Re, the coolant flow rate increases and the thermal resistance decreases. The jet-cross flow structure has the lowest thermal resistance and the best heat transfer capacity.

[0038] from Fig.12 It can be seen from (d) that the PEC of the JI-CFHS microchannel decreases with the increase of the Reynolds number. This is because with the change of Reynolds number, the increase in the NU number of the JI-CFHS microchannel is smaller than the increase rate of the pressure difference. The PEC value of JI-CFHS increases by 51%~56% relative to CFHS.

[0039] from Fig.13It can be seen from the content that in the cross-flow microchannel of the CFHS radiator and the downstream microchannel of the PFHS radiator, the temperature of the heat source surface gradually increases along the flow direction of the fluid. The highest temperature of the PFHS radiator is located at the three hot spots close to the fluid outlet (i.e., the far right), and the highest temperature of the CFHS radiator is located at the hot spot on the upper right. This is because the hot spot on the upper right is located at the intersection of the outlets of the upper and lower layers. The highest temperature points of the microchannel structure of the JI-CFHS radiator are located at the three hot spots in the middle position. This is because the cold fluid in the middle position impacts the solid-liquid interface in the form of a jet, enhancing the local heat transfer performance. The fluid flowing through the hot spots on both sides is the combined effect of the impact jet of the lower layer and the cross flow of the upper layer, and the flow path of the fluid in the lower structure is shorter, which effectively slows down the increase in fluid temperature. Compared with the microchannels of the CFHS radiator and the PFHS radiator, the average temperature of the microchannels of the JI-CFHS radiator is relatively low.

[0040] from Fig.14 It can be seen from (a) that the temperature uniformity coefficients of the three radiators decrease with the increase of Reynolds number, indicating that the increase of Reynolds number has a positive effect on temperature uniformity. The temperature uniformity coefficient of the JI-CFHS radiator decreases the most with the increase of Reynolds number, and the Reynolds number has the most obvious effect on improving the temperature uniformity of the JI-CFHS radiator; the temperature uniformity coefficient of the JI-CFHS radiator is 16.94%~19.41% lower than that of the CFHS radiator, and 17.39%~19.79% lower than that of the PFHS radiator; indicating that the mixed structure design of jet impact and cross flow can effectively improve temperature uniformity; from Fig.14 It can be seen in (b) that the maximum temperature gradient of JI-CFHS decreases the most. The maximum temperature gradient of JI-CFHS radiator is 10.74%~14.38% lower than that of CFHS radiator and 9.41%~13.46% lower than that of PFHS radiator.

[0041] Example 2 Example 2 discloses a microchannel heat sink that is further improved and designed based on the technical solution in Example 1. The similarities between it and Example 1 will not be described again.

[0042] The position of the jet heat exchange cavity 101 can be flexibly designed and adjusted according to actual heat dissipation requirements. In this embodiment, it is set at half of the length of the radiator, that is, the central area where the hot spots are concentrated.

[0043] A comparative test 2 was set up to verify the influence of the jet inlet position on the heat dissipation performance. Example 1 and Example 2 were selected for comparative test. The correspondence between the jet heat exchange cavity and the hot spot is shown in FIG. Fig. 9 As shown, Example 2 corresponds to Fig. 9 and Fig.15Inlet1, Example 1 corresponds to Fig. 9 and Fig.15 Inlet2, the heat source surface temperature cloud diagram is as follows Fig.16 shown.

[0044] from Fig.15 It can be seen from (a) that the maximum temperature Tmax at Inlet 2 is significantly lower than the maximum temperature Tmax at the jet inlet located at Inlet 1. In Example 2, the jet heat exchange chamber is located directly above the middle hot spot, which is in the stagnant zone of the jet, while in Example 1, the jet heat exchange chamber is located in the middle of the two rows of hot spots, and the hot spot is in the wall jet zone. The impact of the wall jet zone on heat transfer is smaller than that in the stagnant zone, but double-layer flow is superimposed on all hot spots of the Inlet 2 structure, and the superimposed effect of the double-layer cross flow and the wall jet zone on temperature is greater than the heat transfer effect of the jet stop zone in Inlet 1.

[0045] from Fig.15 It can be seen in (b) that Inlet 2 effectively reduces the temperature difference on the heat source surface, which is attributed to the JI-CFHS heat sink impacting Inlet 2, effectively reducing the maximum temperature of the heat source surface and slowing down the heat transfer deterioration along the coolant flow direction.

[0046] from Fig.15 As can be seen in (c), the thermal resistance of the Inlet 2 structure is lower than that of the Inlet 1 structure.

[0047] from Fig.16 It can be seen that the highest temperature point of Inlet 1 is located at the three hot spots in the middle, while the highest temperature point of Inlet 2 is located at the hot spot far away from the impinging jet inlet. This is because the impinging jet inlet is located in the middle of the two rows of hot spots. The hot spots close to the impinging jet are affected by the superposition of the impinging jet wall flow and the double-layer cross flow on heat dissipation, and the temperature is much lower than the temperature of the hot spot at Inlet 1 facing the impinging jet. As the fluid flows, the hot spot temperature of the heat source surface gradually increases along the direction of fluid flow, and the highest temperature is located at the hot spot on the lower right. This is because the hot spot on the lower right is located at the intersection of the outlets of the upper and lower layers. The heat exchange in the impinging jet-cross flow microchannel of Inlet 2 is more sufficient, and the heat source surface temperature of the impinging jet-cross flow microchannel of Inlet 2 is more uniform.

[0048] Since the hotspot positions on the heat source surface are unevenly distributed and unpredictable, in order to improve the adaptability of the microchannel radiator, the jet heat exchange chamber 101 even adopts an adjustable design in practical applications. Specifically, when the heat source is concentrated in the central area, the jet heat exchange chamber 101 can be located at the center of the heat dissipation body 1, and a symmetrical jet zone baffle 7 is arranged; when the heat source is unevenly distributed, the jet heat exchange chamber 101 can be offset to the hotspot-intensive area, and the jet zone baffle 7 adopts an asymmetric design; when there are multiple discrete hotspots, the jet heat exchange chamber 101 adopts a segmented design and cooperates with a jet zone baffle 7 with independent control of multiple areas.

[0049] In addition, to ensure that different positions can achieve the ideal heat dissipation effect, the jet liquid separation plate 4 adopts an adjustable opening ratio design, and the aperture distribution of the jet hole 401 is optimized according to the position of the heat exchange cavity to ensure flow uniformity; the jet microchannel 102 adopts the same rectangular cross-section design and the same spacing position to achieve the best fluid guiding effect. Through the above-mentioned targeted optimization design, this embodiment 2 can effectively cope with various heat source distribution conditions and achieve the most optimized heat dissipation effect.

[0050] A control group 3 is set up. On the basis of Example 1, no jet zone baffle is set on the lower surface of the jet separation plate 4, and the same points as Example 1 are not described again.

[0051] Comparative experiment 3 was set to verify the effect of baffle setting on heat dissipation performance. Example 1 and control group 3 were selected for comparative experiment. Example 1 corresponds to Fig.17 Baffled Structure in the control group 3 Fig.17 UnbaffledStructure.

[0052] from Fig.17 As can be seen in (a), the Tmax of the JI-CFHS radiator with baffles is significantly lower than that of the JI-CFHS radiator without baffles. This is attributed to the baffle separating the impingement jet area into two independent sub-areas, controlling the fluid flow distribution on both sides. Due to the uneven distribution of hot spots on both sides, the fluid flow in the area with more hot spots is larger, resulting in a significant reduction in the temperature of the hot spots located downstream.

[0053] from Fig.17 As can be seen in (b), the JI-CFHS microchannel with baffles can more effectively reduce the temperature difference on the heat source surface. This is attributed to the baffles accurately controlling the fluid flow distribution on both sides, effectively reducing the maximum temperature of the heat source surface and slowing down the heat transfer deterioration along the coolant flow direction. At the same time, it also avoids overcooling at the cross-flow inlet of the JI-CFHS radiator and increases the minimum temperature at the cross-flow inlet.

[0054] from Fig.17It can be seen from (c) that the thermal resistance of the JI-CFHS heat sink with baffles is lower than that without baffles. This is because the maximum temperature of the heat source surface with the baffle structure is lower than the maximum temperature of the heat source surface without the baffle structure.

[0055] from Fig.17 It can be seen in (d) that the average Nusselt number of the JI-CFHS heat sink with baffles is higher than that without baffles.

[0056] from Fig.18 It can be seen that the temperature of the highest heat source surface of the baffle structure is lower, and the area of ​​the high temperature area is much smaller than that of the structure without baffles.

[0057] Example 3 Example 3 discloses a microchannel heat sink that is further improved and designed based on the technical solution in Example 1. The similarities between it and Example 1 will not be described again.

[0058] In this embodiment 3, a number of connecting holes are arranged between the upper and lower corresponding jet microchannels 102 and the cross-flow microchannels 104, and the specific location, number and size of the connecting holes can be designed and adjusted according to the actual heat dissipation requirements. Specifically, the connecting holes are arranged in the area where the jet microchannel 102 and the cross-flow microchannel 104 intersect, so as to realize the fluid connection between the two independent liquid channel systems. When the local area of ​​the heat source is overheated, by adjusting the opening of the connecting holes, the coolant in part of the cross-flow microchannel 104 enters the jet microchannel 102 through the connecting holes, thereby enhancing the heat exchange effect of the local area. The number and distribution density of the connecting holes can be arranged in a targeted manner according to the temperature distribution of the heat source. Through the connection design of the cross-flow microchannel and the jet microchannel, this embodiment 3 can realize the complementary advantages of the two flow modes and further improve the heat exchange efficiency and temperature field uniformity of the radiator.

[0059] In addition, the fins 8 in this embodiment 3 can select different cross-sectional shapes according to actual heat dissipation requirements, including but not limited to square, triangle, trapezoid or arc. The setting of the fins 8 not only significantly increases the heat exchange area, but also can produce a turbulence effect during the fluid flow process, effectively breaking the fluid boundary layer and improving the convective heat transfer coefficient.

[0060] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A microchannel heat sink for multiple hot spots, characterized in that: It includes a heat dissipation body, a rectangular frame edge and a jet liquid inlet baffle, wherein the heat dissipation body is arranged in the rectangular frame edge, and the jet liquid inlet baffle is arranged on the upper surface of the heat dissipation body; A jet heat exchange chamber is provided at the upper end of the heat dissipation body, a jet liquid separator plate is provided at the upper end of the jet heat exchange chamber, a jet hole is provided on the jet liquid separator plate, a jet liquid collecting chamber is formed between the jet liquid separator plate and the jet liquid inlet partition plate, a jet liquid inlet port connected to the jet liquid collecting chamber is provided on the jet liquid inlet partition plate, a jet zone baffle plate for separating the jet heat exchange chamber is provided at the lower end of the jet liquid separator plate, outwardly arranged jet microchannels are provided at the lower ends of the side walls of the jet heat exchange chamber on both sides of the jet zone baffle plate, and the outer ends of the jet microchannels on both sides are connected to the liquid outlet chamber formed between the rectangular frame edge and the side wall of the heat dissipation body, and a converging liquid outlet port connected to the liquid outlet chamber is provided on the rectangular frame edge; The upper end of the heat dissipation body is provided with a cross-flow microchannel arranged side by side and perpendicular to the jet microchannel. One end of the cross-flow microchannel is connected to the liquid outlet cavity, and the other end is connected to the cross-flow liquid collecting cavity formed between the rectangular frame edge and the side wall of the heat dissipation body. The rectangular frame edge is provided with a cross-flow liquid inlet connected to the cross-flow liquid collecting cavity.

2. The microchannel heat sink for multiple hot spots according to claim 1, characterized in that: The jet heat exchange cavity is provided with one, and is opened in the central area where the hot spots are concentrated or on one side of the central area where the hot spots are concentrated.

3. The microchannel heat sink for multiple hot spots according to claim 1, characterized in that: The jet heat exchange chamber is provided in plurality and is respectively opened in a plurality of different heat source areas of the discrete heat source.

4. The microchannel heat sink for multiple hot spots according to claim 1, characterized in that: The jet holes on the jet separation plate are provided with a plurality of groups, and each group of the jet holes is arranged in a rectangular array.

5. The microchannel heat sink for multiple hot spots according to claim 1, characterized in that: The converging liquid outlet and the cross-flow liquid inlet are respectively arranged on two opposite side surfaces of the rectangular frame.

6. The microchannel heat sink for multiple hot spots according to claim 1, characterized in that: The inner dimensions of the jet microchannel and the cross-flow microchannel are set to be the same, and fins are arranged in both the jet microchannel and the cross-flow microchannel.

7. The microchannel heat sink for multiple hot spots according to claim 6, characterized in that: A plurality of the fins are arranged in parallel and spaced apart in the jet microchannel or the cross-flow microchannel, and the shape of the fins is any one of circular, square, triangular, trapezoidal or arcuate.

8. The microchannel heat sink for multiple hot spots according to claim 1, characterized in that: A connecting hole for connecting the jet microchannel and the cross-flow microchannel up and down is provided in the intersection area of ​​the jet microchannel and the cross-flow microchannel.

9. The microchannel heat sink for multiple hot spots according to claim 1, characterized in that: The heat dissipation body, the rectangular frame edge and the jet liquid inlet baffle are integral components formed by any one of CNC machining, 3D printing and metal welding.

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