A dual-immersion flow boiling phase change radiator

Abstract

This application provides a dual-immersion type flowing boiling phase change radiator, disposed in an immersion chamber for heat exchange with the liquid in the chamber. It includes a microchannel structure, a first cooling medium pipeline, and a second cooling medium pipeline. The microchannel structure has multiple arrayed fins to form a microchannel group. The first cooling medium pipeline is connected to the inlet of the microchannel group, supplying the cooling medium to it. The outlet of the microchannel group is fully open, connected to the liquid storage chamber of the immersion chamber. A cover plate is provided along the thickness direction of the microchannel structure, and a baffle structure is provided on the cover plate. The second cooling medium pipeline is connected to the baffle structure, supplying the cooling medium into it. The baffle structure guides the cooling medium to flow across the outer surface of the cover plate, which has a porous layer. The dual-layer immersion cooling formed by the microchannel structure and the cover plate improves heat exchange performance, accelerates bubble release, reduces the dryness of the two-phase fluid, and achieves high-power, high-heat-fluidity heat dissipation.

Description

Technical Field

[0001] This application relates to the field of heat dissipation technology for electronic devices, and in particular to a dual-immersion flow boiling phase change heat sink. Background Technology

[0002] With the rapid development of electronic information technology toward high integration and high power density, the heat flux density of chips and other core heat-generating components continues to rise, far exceeding the limits of traditional heat dissipation technologies such as air cooling and liquid cooling.

[0003] In related technologies, the immersion cooling structure is completely submerged in the coolant of the server chassis to dissipate heat from the coolant. The immersion cooling structure includes a microchannel cold plate, which has densely arranged microchannels inside. The cooling medium undergoes a phase change and boils within the microchannels, thereby achieving heat dissipation.

[0004] However, under high-power conditions, the wall temperature of the microchannel is too high, the flow resistance is large, resulting in a low critical heat flux density. The channel outlet is prone to dryness due to excessive dryness. At the same time, when the cooling medium undergoes large-scale vaporization, it is difficult for the bubbles to detach. A large number of bubbles accumulate on the heat exchange surface to form a gas film, which hinders the cooling medium from continuing to contact the heat exchange surface and reduces the heat exchange performance. Summary of the Invention

[0005] This application provides a dual-immersion flow boiling phase change radiator to solve the problem in related technologies where the cooling system has low heat exchange performance and is prone to burn-out under high power conditions.

[0006] This application provides a dual-immersion flow-boiling phase change radiator, configured to be disposed in an immersion chamber for heat exchange with the liquid in the immersion chamber. It includes: a microchannel structure, a first cooling medium pipeline, and a second cooling medium pipeline. The microchannel structure has multiple arrayed fins to form a microchannel group. The first cooling medium pipeline is connected to the inlet of the microchannel group to deliver cooling medium to the microchannel group. The outlet of the microchannel group is a fully open structure to communicate with the liquid storage chamber of the immersion chamber. A cover plate is disposed along the thickness direction of the microchannel structure, and a baffle structure is disposed on the cover plate. The second cooling medium pipeline is connected to the baffle structure to deliver cooling medium into the baffle structure. The baffle structure guides the cooling medium to flow through the outer surface of the cover plate, and the outer surface of the cover plate has a porous layer.

[0007] The dual-immersion flow boiling phase change radiator provided in this application embodiment has the following effects:

[0008] The first stage of submerged flow-boiling phase change heat dissipation is achieved through flow-boiling within a microchannel structure immersed in liquid, while the second stage is achieved through the outer surface of a cover plate immersed in liquid. Specifically, the cooling medium undergoes large-space flow-boiling on the outer surface of the cover plate, reducing the cover plate temperature and thus mitigating the flow-boiling intensity within the microchannel structure. This also cools the two-phase fluid within the microchannel structure, reducing its dryness. Simultaneously, the flowing cooling medium displaces numerous bubbles from the heat exchange surface, achieving efficient bubble removal; it also provides a large amount of fresh cooling medium to the outer surface for heat exchange, ensuring an efficient supply of cooling medium to the vaporization zone.

[0009] Therefore, the double-layer immersion flow boiling phase change heat transfer formed by the microchannel structure and the cover plate can improve heat transfer performance, accelerate bubble detachment, reduce the dryness of the two-phase fluid, and achieve high-power, high-heat-fluid-density heat dissipation. Attached Figure Description

[0010] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0011] Figure 1 Schematic diagram of the structure of the dual-immersion flow boiling phase change radiator provided in the embodiments of this application. Figure 1 ;

[0012] Figure 2 Schematic diagram of the structure of the dual-immersion flow boiling phase change radiator provided in the embodiments of this application. Figure 2 ;

[0013] Figure 3 A schematic diagram of the microchannel structure of the dual-immersion flow boiling phase change radiator provided in this application embodiment. Figure 1 ;

[0014] Figure 4 A schematic diagram of the microchannel structure of the dual-immersion flow boiling phase change radiator provided in this application embodiment. Figure 2 ;

[0015] Figure 5 A schematic diagram of the cover plate of the dual-immersion flow boiling phase change radiator provided in the embodiments of this application. Figure 1 ;

[0016] Figure 6 A schematic diagram of the cover plate of the dual-immersion flow boiling phase change radiator provided in the embodiments of this application. Figure 2 ;

[0017] Figure 7 This is a schematic diagram of the cooling system provided in an embodiment of this application.

[0018] Figure label:

[0019] 100-microchannel structure;

[0020] 101-Microchannel group; 102-Liquid collection tank; 103-Flow divider fins; 110-Dual immersion flow boiling phase change radiator;

[0021] 1011 - Fully open structure; 1021 - First connecting hole;

[0022] 200-cover plate;

[0023] 201 - Enclosure structure; 202 - Sprinkler head; 203 - Outer surface;

[0024] 2011 - Second connecting hole;

[0025] 300 - First cooling medium piping;

[0026] 400 - Second cooling medium piping;

[0027] 500 - Immersion tank;

[0028] 501 - Liquid chamber; 502 - Vapor chamber;

[0029] 600 - Storage tank;

[0030] 700 - Condenser;

[0031] 800 - Miniature Pump.

[0032] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0033] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. In the following description relating to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements.

[0034] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0035] refer to Figure 1 and Figure 2The dual-immersion flow boiling phase change radiator provided in this application embodiment is used to be installed in the immersion tank 500 and exchange heat with the liquid in the immersion tank 500, that is, the coolant.

[0036] The dual-immersion flow boiling phase change radiator includes: a microchannel structure 100, a first cooling medium pipeline 300, and a second cooling medium pipeline 400.

[0037] The microchannel structure 100 has multiple arrayed ribs to form a microchannel group 101. In the length direction of the microchannel structure 100, the microchannel group 101 includes opposite inlets and outlets. The first cooling medium pipeline 300 is connected to the inlet of the microchannel group 101 and is used to deliver the cooling medium into the microchannel group 101. The cooling medium flows through the microchannel group 101 and flows from the inlet to the outlet.

[0038] The cooling medium is a low-boiling-point medium under normal or positive pressure, with a boiling point range of 30℃ to 50℃.

[0039] The microchannel group 101 significantly increases the contact area between the cooling working fluid and the microchannel structure 100 to improve heat exchange efficiency; the distribution area of ​​the microchannel group 101 accounts for 70% to 80% of the total area of ​​the microchannel structure 100, ensuring sufficient heat exchange contact area and improving heat dissipation performance.

[0040] The outlet of the microchannel group 101 is configured as a fully open structure 1011 to communicate with the liquid chamber 501 of the immersion box 500.

[0041] Among them, the microchannel group 101 includes multiple microchannels, each microchannel is composed of two adjacent ribs, and the outlet of each microchannel is open to form a fully open structure 1011.

[0042] The cooling medium flows and exchanges heat within the microchannel structure 100 and undergoes a phase change. Finally, it is discharged into the immersion chamber 500 through a fully open outlet. The fully open outlet makes it easier to discharge the cooling medium that has undergone phase change and heat exchange.

[0043] The microchannel structure 100 has a cover plate 200 along its thickness direction. The microchannel structure 100 and the cover plate 200 can be integrally formed, or they can be manufactured separately and then welded together by diffusion welding process.

[0044] The overall area of ​​the microchannel structure 100 and the cover plate 200 is the same; or, the difference between the overall area of ​​the microchannel structure 100 and the cover plate 200 does not exceed 1%.

[0045] Both the microchannel structure 100 and the cover plate 200 are made of copper, aluminum or other materials with high thermal conductivity. The thermal conductivity of the material enables the heat from the heat source to be quickly conducted to the microchannel structure 100 and the cover plate 200, thereby improving the heat dissipation performance.

[0046] A baffle structure 201 is provided on the cover plate 200. The baffle structure 201 is located near the edge of the cover plate 200. One wall of the baffle structure 201 is connected to a second cooling medium pipe 400. The second cooling medium pipe 400 is used to deliver cooling medium into the baffle structure 201. The other wall of the baffle structure 201 has a fully open opening, so that the cooling medium delivered by the second cooling medium pipe 400 into the baffle structure 201 flows towards the outer surface 203 of the cover plate 200. The baffle structure 201 can guide the cooling medium to flow through the outer surface 203 of the cover plate 200.

[0047] The outer surface 203 of the cover plate 200 is provided with a porous layer.

[0048] The cooling medium, guided by the enclosure structure 201 to the outer surface 203 of the cover plate 200, flows through the porous layer of the outer surface 203 to achieve submerged flow boiling. The porous layer provides a large number of vaporization nuclei, which causes the cooling medium to undergo large-space flow boiling, thereby reducing the temperature of the cover plate 200, reducing the intensity of flow boiling in the microchannel structure 100, and cooling the two-phase fluid in the microchannel structure 100 to reduce dryness.

[0049] Meanwhile, the flowing cooling medium can flush away a large number of bubbles from the heat exchange surface on the outer surface 203, achieving efficient bubble detachment; it also provides a large amount of fresh cooling medium to the outer surface 203 for heat exchange, ensuring efficient supply of cooling medium to the vaporization zone.

[0050] Furthermore, the microchannel structure 100 and the cover plate 200 form a double-layer immersion-type flow-boiling phase change heat transfer system, working together to complete the heat exchange process. Specifically, the first stage of immersion-type flow-boiling phase change heat transfer is formed by the flow-boiling within the microchannel structure 100 immersed in the liquid, and the second stage of immersion-type flow-boiling phase change heat transfer is formed by the flow sweeping on the outer surface 203 of the cover plate 200 immersed in the liquid. The aforementioned double-layer immersion-type flow-boiling phase change heat transfer system can improve heat transfer performance, accelerate bubble detachment, reduce the dryness of the two-phase fluid, and achieve high-power, high-heat-fluid-density heat dissipation.

[0051] refer to Figure 3 and Figure 4In this embodiment of the application, a liquid collection tank 102 is provided in the microchannel structure 100; the microchannel group 101 and the first cooling medium pipeline 300 are connected through the liquid collection tank 102, and at least one diversion fin 103 is provided in the liquid collection tank 102. The at least one diversion fin 103 is used to divert the cooling medium flowing from the first cooling medium pipeline 300 into the liquid collection tank 102.

[0052] The arrangement of the liquid collection tank 102 and the diversion fins 103 enables the cooling medium to flow evenly through the microchannel group 101, ensuring the uniformity of heat exchange and thus improving the heat exchange efficiency.

[0053] In this embodiment, the inner wall of the liquid collection tank 102 is provided with a first connecting hole 1021, and the first cooling medium pipeline 300 is connected to the first connecting hole 1021 to deliver the cooling medium to the liquid collection tank 102; at least one diversion fin 103 is symmetrically distributed in the liquid collection tank 102 with the hole axis of the first connecting hole 1021 as the axis of symmetry.

[0054] The symmetrically distributed at least one diversion fin 103 can ensure that the cooling working fluid flowing into the liquid collection tank 102 is evenly distributed into the microchannel group 101, ensuring the uniformity of heat exchange and thus improving the heat exchange efficiency.

[0055] The angle and position of the diversion fin 103 can be designed according to the size of the microchannel structure 100.

[0056] In this embodiment, the depth of the liquid collection tank 102 is the same as the depth of the microchannel group 101, so as to reduce the flow resistance at the inlet of the microchannel group 101.

[0057] Alternatively, in another embodiment, the depth of the liquid collection tank 102 gradually increases in the direction of the cooling fluid flow, and the lowest point of the bottom of the liquid collection tank 102 is close to the inlet of the microchannel group 101.

[0058] In other words, the bottom of the liquid collection tank 102 is inclined, and the lowest point of the bottom of the liquid collection tank 102 is connected to the inlet of the microchannel group 101, so as to reduce the flow resistance at the inlet of the microchannel group 101.

[0059] In this embodiment, the porous layer is a foam-like copper metal network structure. The interior of the copper metal network structure is filled with continuous through pores. The porosity of the copper metal network structure is 90%-95%, the thickness is 1mm-2mm, the pore density is 80 PPI-130 PPI, and the average pore diameter is 0.15mm-0.25mm.

[0060] The densely packed, interconnected pores within the foam-like copper metal network structure increase the thermal contact area and allow fluids to flow through with low resistance, thereby enhancing convective heat transfer and improving heat transfer efficiency.

[0061] In this embodiment, the porous layer can also be formed by sintering and solidifying copper powder particles with a particle size of 50μm~150μm, with a thickness of 1mm~2mm and a porosity of 40%-60%.

[0062] The preparation process of the porous layer is as follows: First, copper powder particles with a particle size of 50μm~150μm are placed in a concave mold and sintered and cured at 850℃ to form a structure with the same size as the outer surface 203 of the cover plate 200; then, the cured porous layer is placed on the outer surface 203 of the cover plate 200, pressed with a mold, and then sintered in a sintering furnace at 850℃ for 90 minutes to completely fix the porous layer on the outer surface 203 of the cover plate 200, achieve a tight bond, and ensure heat transfer performance.

[0063] Copper has excellent thermal conductivity. When copper powder particles with a particle size of 50μm to 150μm are used, the porous layer formed by sintering has the best capillary force, which can ensure that the liquid can flow smoothly inside the porous layer, while allowing the generated steam bubbles to easily detach and escape.

[0064] Porosity refers to the percentage of the volume of pores within a porous material relative to the total volume of the material.

[0065] Porous layers within the aforementioned porosity range exhibit excellent capillary force. During boiling, this strong capillary force can continuously and autonomously transport the liquid working fluid in the main channel to the wall area that urgently needs replenishment due to violent evaporation, achieving a good liquid replenishment effect and increasing heat flux density.

[0066] The porous layer has a uniform pore size distribution, which greatly increases the vaporization nuclei, enabling the low-boiling-point working fluid at normal pressure or at positive pressure to boil earlier.

[0067] In this embodiment, the porous layer may also be composed of multiple arrayed microribs, the thickness of which is 1mm to 2mm, the height of which along the thickness direction of the microchannel structure 100 is 1mm to 2mm, and the spacing between the multiple microribs is 2mm to 4mm.

[0068] In the embodiments of this application, the porous layer may also be a graphene coating or a nanoporous layer.

[0069] The graphene coating is prepared by chemical vapor deposition and has high surface wettability and thermal conductivity. The graphene coating can increase the density of vaporization cores, thereby improving the bubble detachment efficiency.

[0070] The nanoporous layer is formed by photolithography or electrochemical etching, with a porosity of over 90%. The nanoporous layer can still maintain efficient boiling under low flow conditions, making it suitable for scenarios with large flow fluctuations.

[0071] In this embodiment, the microchannel has a rectangular cross-section; and / or, the width of the microchannel is 0.5mm to 2mm, and the depth of the microchannel is 1mm to 6mm; and / or, the thickness of the rib is 1mm.

[0072] In this embodiment, the width of the microchannel gradually expands in the direction of the cover plate 200 toward the microchannel structure 100. That is, the width of the microchannel closer to the heat source area can be 0.5mm~0.8mm and the depth can be 4mm~6mm; the width of the microchannel farther away from the heat source area can be 1mm~2mm and the depth can be 1mm~4mm; thus forming a gradient distribution with deep hot areas and shallow cold areas, dense hot channels and sparse cold channels.

[0073] The dense channels in the hot zone allow for a larger heat exchange area, accommodating more vaporized liquid and thus reducing the rate of increase in dryness, preventing the liquid from burning out. The loose channels in the cold zone result in a smaller flow rate, reducing flow resistance and improving the overall pressure drop uniformity.

[0074] refer to Figure 2 , Figure 5 and Figure 6 In this embodiment of the application, a second connection hole 2011 is provided on the enclosure structure 201, and the second cooling medium pipeline 400 is connected to the second connection hole 2011 through the nozzle 202 to deliver the cooling medium into the enclosure structure 201.

[0075] The nozzle 202 can provide power to the cooling medium in the second cooling medium pipeline 400, enabling it to flush away a large number of bubbles on the outer surface 203, thus achieving efficient bubble removal.

[0076] In this embodiment of the application, valves are respectively provided on the first cooling medium pipeline 300 and the second cooling medium pipeline 400. The valves are used to regulate the flow rate of the cooling medium flowing through the first cooling medium pipeline 300 and the second cooling medium pipeline 400.

[0077] By using valves to dynamically adjust the flow distribution, the heat transfer load matching degree between the microchannel structure 100 and the outer surface 203 of the cover plate 200 is improved, thereby enhancing the overall heat dissipation efficiency.

[0078] The flow rate of the cooling medium entering the microchannel structure 100 is 2-3 times that of the cooling medium flowing through the outer surface 203 of the cover plate 200.

[0079] In this embodiment, temperature sensors are respectively provided on the microchannel structure 100 and the cover plate 200. The temperature sensors are used to monitor the temperature of the microchannel structure 100 and the cover plate 200 in real time and feed it back to the valve. The valve is also used to adjust the flow rate of the cooling medium flowing through the first cooling medium pipeline 300 and the second cooling medium pipeline 400 according to the temperature.

[0080] Combining temperature sensors and valves can prevent localized overheating caused by insufficient flow in the microchannel structure 100 or cover plate 200 under high-power conditions.

[0081] In this embodiment, the cooling medium is a subcooled liquid with a subcooling degree of 10°C to 15°C.

[0082] The cooling medium can be introduced into the outer surface 203 of the microchannel structure 100 and the cover plate 200 with different degrees of subcooling to achieve subcooled boiling, which avoids the conventional immersion radiator from operating in the saturated boiling transition state and greatly improves the heat dissipation capacity.

[0083] A supercooled liquid is a liquid that remains liquid even when its temperature is below its freezing point (phase transition temperature) at constant pressure. Supercooled liquids can instantly, efficiently, and stably remove a huge amount of heat through boiling.

[0084] In this embodiment, the first cooling medium pipeline 300 and the second cooling medium pipeline 400 are located on the same side; or on opposite sides, or orthogonally arranged; those skilled in the art can make the arrangement according to the actual scenario.

[0085] refer to Figure 7 This application embodiment also provides a cooling system, which includes the dual-immersion flow boiling phase change radiator 110 described above; it also includes: an immersion tank 500, a liquid storage tank 600 and a condenser 700.

[0086] The dual-immersion flow boiling phase change radiator 110 is installed in the immersion tank 500 and in the liquid chamber 501 of the immersion tank 500, and is immersed in the coolant in the liquid chamber 501 to exchange heat with the coolant.

[0087] The first cooling medium pipeline 300 and the second cooling medium pipeline 400 of the dual immersion flow boiling phase change radiator 110 are both connected to the outlet of the liquid storage tank 600 through pipelines, and a micro pump 800 is installed on the pipeline. The micro pump 800 is used to pump the cooling medium in the liquid storage tank 600 to the first cooling medium pipeline 300 and the second cooling medium pipeline 400.

[0088] The immersion chamber 500 includes a liquid chamber 501 and a steam chamber 502 that are connected to each other. After heat exchange, the bubbles formed escape into the steam chamber 502.

[0089] The immersion tank 500 is connected to the condenser 700 through a pipeline, and the condenser 700 is connected to the inlet of the liquid storage tank 600 through a pipeline. The steam generated after heat exchange is transported to the condenser 700, which condenses the steam into liquid and then transports it to the liquid storage tank 600 for storage, so as to achieve recycling.

[0090] It should be noted that the cooling medium entering the first cooling medium pipeline 300 and the second cooling medium pipeline 400 can both come from the liquid storage tank 600; or one can come from the liquid storage tank 600 and the other can come from the liquid formed after the saturated liquid in the immersion tank 500 is drawn out and passes through the cooling heat exchanger.

[0091] In this embodiment, the first cooling medium pipeline 300 and the second cooling medium pipeline 400 can be connected by the same main pipeline or by two independent main pipelines.

[0092] The following detailed description of the dual-immersion flow boiling phase change radiator provided in this application is provided through specific embodiments:

[0093] Example 1:

[0094] refer to Figure 1 and Figure 2 The dual-immersion flow boiling phase change radiator consists of a microchannel structure 100, a cover plate 200, a first cooling medium pipeline 300, and a second cooling medium pipeline 400. In order to meet the heat dissipation requirements and give it high thermal conductivity, all components are made of copper and the microchannel structure 100 and the cover plate 200 are tightly bonded by precision diffusion welding.

[0095] The cover plate 200 is 3mm thick, and the microchannel structure 100 is 5-8mm thick. The welding surfaces of the microchannel structure 100 and the cover plate 200 are precision milled and ground with a grinding wheel to ensure that the flatness is high enough and the surface roughness is controlled within Ra1.6 μm. The surface oxide layer and impurities are removed, and the overall deviation does not exceed 1% to ensure the welding seal of the microchannel structure 100 and the cover plate 200.

[0096] Welding temperature controlled at 850℃, vacuum degree maintained at 5×10 -3 Below Pa.

[0097] The first cooling medium pipeline 300 and the second cooling medium pipeline 400 are both connected to the microchannel structure 100 and the cover plate 200 by welding.

[0098] The heat source area is 32mm×50mm, the effective heat dissipation area of ​​the cover plate 200 (i.e., the surface reinforcement area of ​​the porous layer) is 50mm×80mm, the length of the enclosure structure 201 is 13mm, the height is 8mm, and the width is the same as that of the cover plate 200; the effective heat dissipation area of ​​the microchannel structure 100 (i.e., the distribution area of ​​the microchannel group) is 32~50mm×50~70mm, the microchannel adopts an equal rectangular cross-section design, the width is 1~2mm, the depth is 4~6mm, the thickness of the rib is 1mm, the length of the liquid collection tank 102 is 8~10mm, the width is 32~50mm, and the depth is 7mm. In order to reduce the flow resistance, the connection part between the liquid collection tank 102 and the inlet of the microchannel group has a chamfer with a radius of 1mm.

[0099] The first connecting hole 1021 of the liquid collection tank 102 is rhomboid in shape. Three diversion fins 103 are provided at the rhomboid inlet and are symmetrically distributed in the liquid collection tank 102. The side length is 5mm, and the diversion fins 103 on both sides form a 45° angle with the axis of symmetry.

[0100] The microchannel structure 100 is machined in one piece using CNC machining, ensuring overall thermal conductivity and strength.

[0101] The working process of this dual-immersion flow boiling phase change radiator is as follows:

[0102] The subcooled working fluid enters through the insulated main pipeline via the immersion tank 500 and is divided into two branches via a tee connector, which are connected to the first cooling working fluid pipeline 300 and the second cooling working fluid pipeline 400 respectively. Valves are provided on the first cooling working fluid pipeline 300 and the second cooling working fluid pipeline 400 to regulate the flow distribution between the two branches. The flow rate of the subcooled liquid entering the microchannel structure 100 is 2-3 times the flow rate of the subcooled liquid flowing through the outer surface 203 of the cover plate 200.

[0103] The subcooled working medium enters the microchannel structure 100 and the outer surface 203 of the cover plate 200 through the first cooling working medium pipe 300 and the second cooling working medium pipe 400 respectively for flow boiling heat exchange. The working medium entering the microchannel structure 100 flows and exchanges heat along the length of the microchannel group and undergoes phase change, and is discharged from the fully open outlet into the immersion tank 500 for gas-liquid separation. The subcooled working medium entering the outer surface 203 of the cover plate 200 flows through the porous layer of the outer surface 203 to achieve immersion flow boiling. A large number of bubbles in the porous layer are flushed away from the heat exchange surface by the flowing working medium, achieving efficient bubble detachment. The flow of the flowing working medium also introduces subcooled liquid to the surface, promoting efficient supply of liquid in the vaporization zone. The two-phase liquids leaving the surface achieve gas-liquid separation.

[0104] In the microchannel group, the microchannels and fins significantly increase the contact area between the cooling working fluid and the microchannel structure 100, improving heat exchange efficiency. At the same time, the fully open outlet makes it easier for the working fluid that has undergone phase change heat to be discharged.

[0105] On the outer surface 203 of the cover plate 200, the porous layer provides a large number of vaporization nuclei, and the cooling working fluid undergoes large-space flow boiling. The surface fluid flow can effectively carry the bubbles away from the heat exchange surface and provide a large amount of fresh working fluid for heat exchange. The flow boiling on the outer surface 203 of the cover plate 200 reduces the temperature of the cover plate 200, reduces the flow boiling intensity in the microchannel structure 100, and cools the two-phase fluid in the microchannel structure 100, reducing dryness.

[0106] The heat exchange process is completed through the combined action of two submerged flow boiling phase change heat transfer layers.

[0107] Performance tests show that this dual-immersion flow boiling phase change radiator exhibits excellent heat dissipation performance under test conditions using low-boiling-point working fluid at normal pressure:

[0108] With a chip module heat source area of ​​32 mm × 50 mm, the power at which thermal decay occurs is 2000 W-3000 W, and the heat flux density can reach 100 W / cm². 2 -200 W / cm 2 It improves upon traditional immersion boiling heat exchange systems by more than 100%.

[0109] It should be noted that this embodiment is particularly suitable for cooling scenarios of high-power, high-heat-flux-density chips (such as 1000-2600 W-level GPUs). In practical applications, by adjusting the flow distribution ratio of the inlet branch pipes, precise matching of the heat load of different microchannel regions and immersion regions can be achieved.

[0110] It should also be noted that the technical solutions of the embodiments of this application are also applicable to the heat dissipation needs of other high-power electronic devices, such as power MOSFETs, CPUs, GPUs, etc. Any modifications based on the basic design concept of this embodiment, as long as they adopt the core technical features of this invention, should fall within the protection scope of this application.

[0111] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A double-immersion flow-boiling phase change radiator, configured to be disposed in an immersion tank (500) for heat exchange with a liquid in the immersion tank (500), characterized in that, include: Microchannel structure (100), first cooling medium pipeline (300), and second cooling medium pipeline (400); The microchannel structure (100) is provided with multiple arrayed ribs to form a microchannel group (101). The first cooling medium pipeline (300) is connected to the inlet of the microchannel group (101) to deliver the cooling medium to the microchannel group (101). The outlet of the microchannel group (101) is set as a fully open structure (1011) to communicate with the liquid chamber (501) of the immersion box (500). The microchannel structure (100) is provided with a cover plate (200) along its thickness direction. A baffle structure (201) is provided on the cover plate (200). The second cooling medium pipeline (400) is connected to the baffle structure (201) to deliver the cooling medium into the baffle structure (201). The baffle structure (201) is used to guide the cooling medium to flow through the outer surface (203) of the cover plate (200). The outer surface (203) of the cover plate (200) is provided with a porous layer.

2. The dual-immersion flow boiling phase change radiator according to claim 1, characterized in that, The microchannel group (101) includes multiple microchannels, each of which is composed of two adjacent ribs, and the outlet of each microchannel is open to form the fully open structure.

3. The dual-immersion flow boiling phase change radiator according to claim 1, characterized in that, The microchannel structure (100) is provided with a liquid collection tank (102). The microchannel group (101) and the first cooling medium pipeline (300) are connected through the liquid collection tank (102). The liquid collection tank (102) is provided with at least one diversion fin (103), which is used to divert the cooling medium flowing into the liquid collection tank (102) from the first cooling medium pipeline (300).

4. The dual-immersion flow boiling phase change radiator according to claim 3, characterized in that, The inner wall of the liquid collection tank (102) is provided with a first connecting hole (1021), and the first cooling medium pipeline (300) is connected to the first connecting hole (1021) to deliver cooling medium to the liquid collection tank (102). The at least one diversion fin (103) is symmetrically distributed in the liquid collection tank (102) with the hole axis of the first connecting hole (1021) as the axis of symmetry.

5. The dual-immersion flow boiling phase change radiator according to claim 3, characterized in that, The depth of the liquid collection tank (102) is the same as the depth of the microchannel group (101); or, In the direction of the flow of the cooling working fluid, the depth of the collection tank (102) gradually increases, and the lowest point of the bottom of the collection tank (102) is close to the inlet of the microchannel group (101).

6. The dual-immersion flow boiling phase change radiator according to claim 1, characterized in that, The porous layer is a foam-like copper metal network structure, the interior of which is filled with continuous, interconnected pores. The porosity of the copper metal network structure is 90%-95%, the thickness is 1mm-2mm, the pore density is 80 PPI-130 PPI, and the average pore size is 0.15mm-0.25mm; or... The porous layer is formed by sintering and solidifying copper powder particles with a particle size of 50μm~150μm, with a thickness of 1mm~2mm and a porosity of 40%-60%. or, The porous layer is composed of multiple arrayed microribs, the thickness of which is 1mm to 2mm, the height of which along the thickness direction of the microchannel structure (100) is 1mm to 2mm, and the spacing between the multiple microribs is 2mm to 4mm.

7. The dual-immersion flow boiling phase change radiator according to claim 1, characterized in that, The microchannel has a rectangular cross-section; and / or, The width of the microchannel is 0.5mm to 2mm, and the depth of the microchannel is 1mm to 6mm; and / or, The thickness of the rib is 1 mm.

8. The dual-immersion flow boiling phase change radiator according to claim 1, characterized in that, The enclosure structure (201) is provided with a second connection hole (2011), and the second cooling medium pipeline (400) is connected to the second connection hole (2011) through a nozzle (202) to deliver the cooling medium into the enclosure structure (201).

9. The dual-immersion flow boiling phase change radiator according to claim 1, characterized in that, Valves are provided on the first cooling medium pipeline (300) and the second cooling medium pipeline (400), respectively, and the valves are used to regulate the flow rate of the cooling medium flowing through the first cooling medium pipeline (300) and the second cooling medium pipeline (400).

10. The dual-immersion flow boiling phase change radiator according to claim 9, characterized in that, Temperature sensors are respectively provided on the microchannel structure (100) and the cover plate (200). The temperature sensors are used to monitor the temperature of the microchannel structure (100) and the cover plate (200) in real time and feed it back to the valve. The valve is also used to adjust the flow rate of the cooling medium flowing through the first cooling medium pipeline (300) and the second cooling medium pipeline (400) according to the temperature feedback from the temperature sensor.

11. The dual-immersion flow boiling phase change radiator according to claim 1, characterized in that, The cooling medium is a low-boiling-point medium under normal or positive pressure, and the boiling point range of the cooling medium is 30℃~50℃.

12. The dual-immersion flow boiling phase change radiator according to claim 1, characterized in that, The cooling medium is a subcooled liquid, and the subcooling degree of the subcooled liquid is 10℃~15℃.

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