Double-immersion type flowing boiling phase change radiator

Abstract

The embodiment of the invention provides a double-immersion type flow boiling phase change radiator which is arranged in an immersion box body, exchanges heat with liquid in the immersion box body, and comprises a micro-channel structure, a first cooling working medium pipeline and a second cooling working medium pipeline, a plurality of fins arranged in an array are arranged in the micro-channel structure to form a micro-channel group, and the first cooling working medium pipeline is communicated with an inlet of the micro-channel group and conveys a cooling working medium to the micro-channel group; the outlet of the micro-channel group is fully open and is communicated with the liquid storage cavity of the immersion box body; the micro-channel structure is provided with a cover plate in the thickness direction of the micro-channel structure, the cover plate is provided with a fence structure, the second cooling working medium pipeline communicates with the fence structure and conveys a cooling working medium into the fence structure, the fence structure is used for guiding the cooling working medium to flow through the outer surface of the cover plate, and the outer surface is provided with a porous layer. Double-layer immersed cooling formed by the micro-channel structure and the cover plate can improve the heat exchange performance, accelerate bubble separation, reduce the dryness of two-phase fluid and realize high-power and high-heat-flux heat dissipation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic device heat dissipation, and in particular to a double-immersion flow boiling phase change heat sink. BACKGROUND

[0002] With the rapid development of electronic information technology towards high integration and high power density, the heat flux density of chips and other core heat generating elements continues to rise, far exceeding the limit of traditional air cooling, liquid cooling and other heat dissipation technologies.

[0003] In related technologies, the immersion cooling structure is completely immersed in the cooling liquid in the server box body to dissipate heat. The immersion cooling structure includes a micro-channel cold plate, and the micro-channel cold plate is internally provided with densely arranged micro-channels. The cooling working medium undergoes phase change boiling in the micro-channels, thereby realizing heat dissipation.

[0004] However, under high power conditions, the micro-channel wall surface temperature is too high, the flow resistance is large, the critical heat flux density is low, and the outlet of the channel is prone to dry-out phenomenon caused by too high dryness; at the same time, when the cooling working medium vaporizes on a large scale, it is difficult for bubbles to detach, a large number of bubbles gather on the heat exchange surface to form a gas film, which hinders the cooling working medium from continuing to contact the heat exchange surface, thereby reducing the heat exchange performance. SUMMARY

[0005] The embodiments of the present application provide a double-immersion flow boiling phase change heat sink to solve the problem of low heat exchange performance and easy dry-out phenomenon of the cooling system under high power conditions in related technologies.

[0006] The embodiments of the present application provide a double-immersion flow boiling phase change heat sink, which is configured to be arranged in an immersion tank and exchange heat with liquid in the immersion tank, and includes a micro-channel structure, a first cooling working medium pipeline and a second cooling working medium pipeline. The micro-channel structure is internally provided with a plurality of array-arranged fins to form a micro-channel group. The first cooling working medium pipeline is in communication with the inlet of the micro-channel group to deliver cooling working medium to the micro-channel group. The outlet of the micro-channel group is provided as a fully open structure to communicate with a liquid storage cavity of the immersion tank. The micro-channel structure is provided with a cover plate along the thickness direction thereof. The cover plate is provided with a surrounding structure. The second cooling working medium pipeline is in communication with the surrounding structure to deliver cooling working medium into the surrounding structure. The surrounding structure is used to guide the cooling working medium to flow through the outer surface of the cover plate. The outer surface of the cover plate is provided with a porous layer.

[0007] The double-immersion flow boiling phase change heat sink provided by the embodiments of the present application has the following effects:

[0008] The first level of immersed flow boiling phase change heat dissipation is formed by flow boiling in the micro-channel structure immersed in the liquid, and the second level of immersed flow boiling phase change heat dissipation is formed by the outer surface of the cover plate immersed in the liquid. Wherein, the cooling working medium occurs large space flow boiling on the outer surface of the cover plate, reduces the temperature of the cover plate, thereby reducing the flow boiling intensity in the micro-channel structure, and cooling the two-phase fluid in the micro-channel structure, and reducing the dryness. At the same time, the flowing cooling working medium can separate a large number of bubbles on the outer surface from the heat exchange surface, realizing efficient bubble separation; and provides a large amount of fresh cooling working medium to the outer surface for heat exchange, ensuring efficient supply of the cooling working medium in the vaporization area.

[0009] Therefore, the double-layer immersed flow boiling phase change heat transfer formed by the micro-channel structure and the cover plate can improve the heat exchange performance, accelerate bubble separation, reduce the dryness of the two-phase fluid, and realize high-power and high heat flux density heat dissipation. BRIEF DESCRIPTION OF DRAWINGS

[0010] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate an embodiment consistent with the present application and, together with the description, serve to explain the principles of the application.

[0011] Figure 1 Structure diagram of the double immersed flow boiling phase change heat dissipation device provided by the embodiment of the present application Figure 1 ;

[0012] Figure 2 Structure diagram of the double immersed flow boiling phase change heat dissipation device provided by the embodiment of the present application Figure 2 ;

[0013] Figure 3 Structure diagram of the micro-channel structure of the double immersed flow boiling phase change heat dissipation device provided by the embodiment of the present application Figure 1 ;

[0014] Figure 4 Structure diagram of the micro-channel structure of the double immersed flow boiling phase change heat dissipation device provided by the embodiment of the present application Figure 2 ;

[0015] Figure 5 Structure diagram of the cover plate of the double immersed flow boiling phase change heat dissipation device provided by the embodiment of the present application Figure 1 ;

[0016] Figure 6 Structure diagram of the cover plate of the double immersed flow boiling phase change heat dissipation device provided by the embodiment of the present application Figure 2 ;

[0017] Figure 7 Structure diagram of the cooling system provided by the embodiment of the present application.

[0018] REFERENCE NUMERALS

[0019] 100 - micro-channel structure

[0020] 101 - micro-channel group; 102 - header; 103 - flow-splitting fin; 110 - double-immersed flow boiling phase-change heat spreader

[0021] 1011 - fully-opened structure; 1021 - first connecting hole

[0022] 200 - cover plate

[0023] 201 - enclosure structure; 202 - spray head; 203 - outer surface

[0024] 2011 - second connecting hole

[0025] 300 - first cooling working medium pipeline

[0026] 400 - second cooling working medium pipeline

[0027] 500 - immersion tank

[0028] 501 - liquid cavity; 502 - vapor cavity

[0029] 600 - liquid storage tank

[0030] 700 - condenser

[0031] 800 - micro-pump

[0032] The specific embodiments of the present application have been shown and described in the above-described drawings, and will be described in more detail hereinafter. The drawings and the written description are not intended to restrict the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0033] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The same numbers are used in different drawings to represent the same or similar elements. The following description is made with reference to the accompanying drawings in which:

[0034] The technical solutions of the present application and how the technical solutions of the present application solve the above-mentioned technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0035] Reference Figure 1 and Figure 2The double-immersed flow boiling phase-change heat dissipator provided by the embodiments of the present application is arranged in the immersion box 500 and exchanges heat with the liquid, i.e., the cooling liquid, in the immersion box 500.

[0036] The double-immersed flow boiling phase-change heat dissipator comprises a micro-channel structure 100, a first cooling working medium pipeline 300 and a second cooling working medium pipeline 400.

[0037] The micro-channel structure 100 is provided with a plurality of array-arranged fins to form a micro-channel group 101, and the micro-channel group 101 comprises opposite inlets and outlets in the length direction of the micro-channel structure 100. The first cooling working medium pipeline 300 is in communication with the inlet of the micro-channel group 101 and is used to deliver the cooling working medium into the micro-channel group 101. The cooling working medium flows through the micro-channel group 101 from the inlet to the outlet.

[0038] The cooling working medium is a normal-pressure or positive-pressure low-boiling-point working medium, and the boiling point range of the cooling working medium is 30-50 DEG C.

[0039] The micro-channel group 101 significantly increases the contact area between the cooling working medium and the micro-channel structure 100 to improve the heat exchange efficiency. The distribution area of the micro-channel group 101 accounts for 70-80% of the total area of the micro-channel structure 100, so that sufficient heat exchange contact area is ensured and the heat dissipation performance is improved.

[0040] The outlet of the micro-channel group 101 is provided with a full-open structure 1011 to be in communication with the liquid cavity 501 of the immersion box 500.

[0041] The micro-channel group 101 comprises a plurality of micro-channels, each of which is composed of two adjacent fins, and the outlet of each micro-channel is open to form the full-open structure 1011.

[0042] The cooling working medium flows and exchanges heat in the micro-channel structure 100 and undergoes phase change, and is finally discharged into the immersion box 500 through the full-open outlet. The full-open outlet makes the cooling working medium after phase change and heat exchange more easily discharged.

[0043] The micro-channel structure 100 is provided with a cover plate 200 along the thickness direction thereof. The micro-channel structure 100 can be integrally formed with the cover plate 200 or can be independently manufactured and then welded into an integral whole through diffusion welding process.

[0044] The overall area of the micro-channel structure 100 and the cover plate 200 is the same, or the difference between the overall areas of the micro-channel structure 100 and the cover plate 200 is not more than 1%.

[0045] The micro-channel structure 100 and the cover plate 200 are made of copper, aluminum or other high-thermal-conductivity materials, which can quickly conduct the heat from the heat source to the micro-channel structure 100 and the cover plate 200, so as to improve the heat dissipation performance.

[0046] The cover plate 200 is provided with a surrounding structure 201, which is arranged close to the edge of the cover plate 200. One wall surface of the surrounding structure 201 is communicated with the second cooling working medium pipeline 400, which is used to deliver the cooling working medium into the surrounding structure 201. Another wall surface of the surrounding structure 201 has an open opening, so that the cooling working medium delivered by the second cooling working medium pipeline 400 into the surrounding structure 201 flows to the outer surface 203 of the cover plate 200. The surrounding structure 201 can guide the cooling working 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 working medium guided by the surrounding structure 201 to the outer surface 203 of the cover plate 200 flows through the porous layer of the outer surface 203, so as to realize the immersed flow boiling. The porous layer provides a large number of vaporization cores, so that the cooling working medium occurs large-space flow boiling, thereby reducing the temperature of the cover plate 200, reducing the flow boiling intensity in the micro-channel structure 100, cooling the two-phase fluid in the micro-channel structure 100 and reducing the dryness.

[0049] Meanwhile, the flowing cooling working medium can flush a large number of bubbles away from the heat exchange surface of the outer surface 203, so as to realize the efficient bubble detachment. The flowing cooling working medium also provides a large number of fresh cooling working medium to the outer surface 203 for heat exchange, so as to ensure the efficient supply of the vaporization area cooling working medium.

[0050] Further, the micro-channel structure 100 and the cover plate 200 form double-layer immersed flow boiling phase change heat exchange, which jointly complete the heat exchange process. The flow boiling in the micro-channel structure 100 immersed in the liquid forms the first-level immersed flow boiling phase change heat dissipation, and the flow flushing of the outer surface 203 of the cover plate 200 immersed in the liquid forms the second-level immersed flow boiling phase change heat dissipation. The above-mentioned double-layer immersed flow boiling phase change heat exchange can improve the heat exchange performance, accelerate the bubble detachment, reduce the two-phase fluid dryness, and realize the high-power and high-heat-flux-density heat dissipation.

[0051] Reference Figure 3 and Figure 4In the embodiment of the present application, the micro-channel structure 100 is provided with a liquid collecting groove 102; the micro-channel group 101 and the first cooling working medium pipeline 300 are communicated through the liquid collecting groove 102, and the liquid collecting groove 102 is provided with at least one flow distribution fin 103, and the at least one flow distribution fin 103 is used for distributing the cooling working medium flowing into the liquid collecting groove 102 from the first cooling working medium pipeline 300.

[0052] The liquid collecting groove 102 and the flow distribution fin 103 can make the cooling working medium flow through the micro-channel group 101 uniformly, ensure the uniformity of heat exchange, and further improve the heat exchange efficiency.

[0053] In the embodiment of the present application, the inner wall surface of the liquid collecting groove 102 is provided with a first connecting hole 1021, the first cooling working medium pipeline 300 is communicated with the first connecting hole 1021 to transport the cooling working medium to the liquid collecting groove 102, and the at least one flow distribution fin 103 is symmetrically distributed in the liquid collecting groove 102 with the hole axis of the first connecting hole 1021 as the symmetry axis.

[0054] The at least one flow distribution fin 103 distributed symmetrically can ensure that the cooling working medium flowing into the liquid collecting groove 102 is evenly distributed to the micro-channel group 101, ensure the uniformity of heat exchange, and further improve the heat exchange efficiency.

[0055] The setting angle and position of the flow distribution fin 103 can be designed according to the size of the micro-channel structure 100.

[0056] In the embodiment of the present application, the groove depth of the liquid collecting groove 102 is the same as the depth of the micro-channel group 101 to reduce the flow resistance of the inlet of the micro-channel group 101.

[0057] Alternatively, in another embodiment, in the direction of the flow of the cooling working medium, the groove depth of the liquid collecting groove 102 gradually increases, and the lowest point of the groove bottom of the liquid collecting groove 102 is close to the inlet of the micro-channel group 101.

[0058] That is, the groove bottom of the liquid collecting groove 102 is inclined, and the lowest point of the groove bottom of the liquid collecting groove 102 is connected with the inlet of the micro-channel group 101 to reduce the flow resistance of the inlet of the micro-channel group 101.

[0059] In the embodiment of the present application, the porous layer is a foamed copper metal network structure, the inside 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 continuous through pores in the foamed copper metal network structure increase the heat contact area and allow the fluid to flow through with low resistance, can strengthen the convective heat exchange, and improve the heat exchange efficiency.

[0061] In the embodiment of the present application, the porous layer can also be sintered and solidified from copper powder particles with a particle size of 50-150 μm, and has a thickness of 1-2 mm and a porosity of 40-60%.

[0062] The porous layer is prepared as follows: first, copper powder particles with a particle size of 50-150 μm are placed in a concave mold, and sintered and solidified at 850°C to form a structure with the same size as the outer surface 203 of the cover plate 200; then, the solidified porous layer is placed on the outer surface 203 of the cover plate 200, pressed by a mold, and then placed in a sintering furnace at 850°C for 90 minutes to completely fix the porous layer on the outer surface 203 of the cover plate 200, realize tight bonding, and ensure the heat transfer performance.

[0063] Copper has excellent heat conduction performance, and when copper powder particles with a particle size of 50-150 μm are used, the sintered porous layer has the best capillary force, which can ensure smooth flow of the liquid inside the porous layer, and the generated vapor bubbles can easily detach and escape.

[0064] The porosity refers to the percentage of the volume of the pores inside the porous material to the total volume of the material.

[0065] The porous layer with a porosity in the above range has excellent capillary force, which can continuously and autonomously send the liquid working medium in the main channel to the wall surface area in need of replenishment due to severe evaporation during the boiling process, realize good liquid replenishment effect, and improve the heat flux density.

[0066] The porous layer has a uniform pore size distribution to greatly increase the vaporization core, so that the cold plate normal pressure low boiling point working medium or positive pressure low boiling point working medium boils early.

[0067] In the embodiment of the present application, the porous layer can also be composed of a plurality of arrayed micro-ribs, the thickness of the micro-rib is 1-2 mm, the height of the micro-rib along the thickness direction of the micro-channel structure 100 is 1-2 mm, and the spacing of the plurality of micro-ribs is 2-4 mm.

[0068] In the embodiment of the present application, the porous layer can also be a graphene coating or a nano-porous layer.

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

[0070] The nano-porous layer is formed by photolithography or electrochemical etching, and has a porosity of more than 90%. The nano-porous layer can still maintain efficient boiling under low flow conditions and is suitable for scenes with large flow fluctuations.

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

[0072] In the embodiment of the present application, in the direction of the cover plate 200 towards the microchannel structure 100, the width of the microchannel gradually expands, that is, the width of the microchannel closer to the heat source area can be 0.5mm-0.8mm, and the depth is 4mm-6mm; the width of the microchannel away from the heat source area can be 1mm-2mm, and the depth is 1mm-4mm; forming a gradient distribution of deep cold area and shallow hot area, dense hot area channels and sparse cold area channels.

[0073] The dense hot area channels make the hot area have more heat exchange area, accommodate more vaporized liquid, thereby reducing the dryness rise speed and avoiding dry burning; the sparse cold area channels make the cold area flow small, reduce the flow resistance, and improve the overall pressure drop uniformity.

[0074] Reference Figure 2 , Figure 5 and Figure 6 In the embodiment of the present application, the second connecting hole 2011 is arranged on the enclosure structure 201, and the second cooling working medium pipeline 400 communicates with the second connecting hole 2011 through the spray head 202 to transport the cooling working medium into the enclosure structure 201.

[0075] The spray head 202 can provide power for the cooling working medium in the second cooling working medium pipeline 400, so that it can flush away a large number of bubbles on the outer surface 203, and realize efficient bubble separation.

[0076] In the embodiment of the present application, the first cooling working medium pipeline 300 and the second cooling working medium pipeline 400 are respectively provided with valves, and the valves are used to adjust the flow of the cooling working medium flowing through the first cooling working medium pipeline 300 and the second cooling working medium pipeline 400.

[0077] The valve is used to dynamically adjust the flow distribution, improve the heat exchange load matching degree of the microchannel structure 100 and the outer surface 203 of the cover plate 200, and thereby improve the overall heat dissipation efficiency.

[0078] Among them, the flow of the cooling working medium entering the microchannel structure 100 is 2-3 times the flow of the cooling working medium flowing through the outer surface 203 of the cover plate 200.

[0079] In the embodiment of the present application, temperature sensors are respectively arranged 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 back to the valves, and the valves are also used to adjust the flow of the cooling working medium flowing through the first cooling working medium pipeline 300 and the second cooling working medium pipeline 400 according to the temperature.

[0080] The combination of the temperature sensor and the valve can avoid local overheating caused by insufficient flow of the micro-channel structure 100 or the cover plate 200 in a high-power working condition.

[0081] In the embodiment of the application, the cooling working medium is a supercooled liquid, and the supercooling degree of the supercooled liquid is 10-15℃.

[0082] The cooling working medium can enter the outer surface 203 of the micro-channel structure 100 and the cover plate 200 with different supercooling degrees to realize supercooled boiling, avoid the operation of a conventional immersion radiator in a saturated boiling transition state, and greatly improve the heat dissipation capacity.

[0083] The supercooled liquid refers to a liquid that has a temperature lower than the freezing point (phase transition temperature) corresponding to the current pressure and still remains in a liquid state under the condition of constant pressure. The supercooled liquid can instantly, efficiently and stably take away a large amount of heat through boiling.

[0084] In the embodiment of the application, the first cooling working medium pipeline 300 and the second cooling working medium pipeline 400 are located on the same side, or on opposite sides, or are arranged orthogonally, and a person skilled in the art can arrange them according to the actual scene.

[0085] Reference Figure 7 The embodiment of the application also provides a cooling system, which comprises the double-immersion flow boiling phase change radiator 110 described above, and further comprises an immersion cabinet 500, a liquid storage tank 600 and a condenser 700.

[0086] The double-immersion flow boiling phase change radiator 110 is arranged in the immersion cabinet 500 and in the liquid cavity 501 of the immersion cabinet 500, and is immersed in the cooling liquid of the liquid cavity 501 to exchange heat with the cooling liquid.

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

[0088] The immersion cabinet 500 comprises a liquid cavity 501 and a vapor cavity 502 that are connected in communication, and the bubbles formed after heat exchange escape into the vapor cavity 502.

[0089] The immersion cabinet 500 is communicated with the condenser 700 through a pipeline, and the condenser 700 is communicated with the inlet of the liquid storage tank 600 through a pipeline; the vapor formed after heat exchange is transported to the condenser 700, the condenser 700 condenses the vapor into liquid and then transports the liquid to the liquid storage tank 600 for storage, so as to realize recycling.

[0090] It should be noted that the cooling working medium entering the first cooling working medium pipeline 300 and the second cooling working medium pipeline 400 can be from the liquid storage tank 600; or one way from the liquid storage tank 600 and the other way from the saturated liquid in the immersion tank 500 after being introduced and then formed into liquid through the cooling heat exchanger.

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

[0092] The double-immersion flow boiling phase change radiator provided by the application is described in detail through specific embodiments as follows:

[0093] Embodiment 1:

[0094] Reference Figure 1 and Figure 2 The double-immersion flow boiling phase change radiator is composed of a microchannel structure 100, a cover plate 200, a first cooling working medium pipeline 300 and a second cooling working medium pipeline 400. In order to meet the heat dissipation condition and have high heat conduction performance, each component is made of red copper and is tightly attached to the cover plate 200 through precision diffusion welding.

[0095] The cover plate 200 is 3 mm thick, and the microchannel structure 100 is 5-8 mm thick. The welding surfaces of the microchannel structure 100 and the cover plate 200 are subjected to precision milling and grinding wheel polishing to ensure that the flatness is high enough, the surface roughness is controlled within Ra1.6 μm, the surface oxidation layer and impurities are removed, and the overall deviation is not more than 1%, so as to ensure the welding sealing performance of the microchannel structure 100 and the cover plate 200.

[0096] The welding temperature is controlled at 850℃, and the vacuum degree is maintained below 5×10 -3 Pa.

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

[0098] The heat source area is 32mm*50mm, the effective heat dissipation area (i.e. the surface strengthening area of the porous layer) of the cover plate 200 is 50mm*80mm, the length of the surrounding 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 (i.e. the distribution area of the micro-channel group) of the micro-channel structure 100 is 32-50mm*50-70mm, the micro-channels are designed in an equal rectangular cross-section, the width is 1-2mm, the depth is 4-6mm, the thickness of the ribs is 1mm, the length of the liquid collecting groove 102 is 8-10mm, the width is 32-50mm, and the depth is 7mm, and in order to reduce the flow resistance, the connecting part of the liquid collecting groove 102 and the inlet of the micro-channel group is provided with a chamfer with a radius of 1mm.

[0099] The first connecting hole 1021 of the liquid collecting groove 102 is in the shape of a rhombus, three flow splitting fins 103 are arranged at the rhombus-shaped inlet and symmetrically distributed in the liquid collecting groove 102, the side length is 5mm, and the two flow splitting fins 103 and the symmetry axis form an included angle of 45°.

[0100] The micro-channel structure 100 is integrally machined by numerical control, thereby ensuring the overall heat conductivity and strength.

[0101] The working process of the double-immersed flow boiling phase change heat sink is as follows:

[0102] The subcooled cooling working medium enters through the mother pipeline of the heat preservation and is divided into two branches through the three-way joint to connect the first cooling working medium pipeline 300 and the second cooling working medium pipeline 400, and valves are arranged on the first cooling working medium pipeline 300 and the second cooling working medium pipeline 400 to adjust the flow distribution of the two branches, and the flow of the subcooled liquid entering the micro-channel structure 100 is 2-3 times the flow of the subcooled liquid flowing through the outer surface 203 of the cover plate 200.

[0103] The subcooled cooling working medium enters the micro-channel structure 100 and the outer surface 203 of the cover plate 200 through the first cooling working medium pipeline 300 and the second cooling working medium pipeline 400 to perform flow boiling heat exchange, the working medium entering the micro-channel structure 100 flows and exchanges heat in the micro-channel group along the length direction and is discharged from the fully open outlet into the immersion tank 500 to perform gas-liquid separation; the subcooled cooling working medium entering the outer surface 203 of the cover plate 200 flows through the porous layer of the outer surface 203 to realize immersed flow boiling, a large number of bubbles of the porous layer are flushed away from the heat exchange surface by the flowing working medium to realize efficient bubble detachment, the flowing working medium flows into the surface to introduce subcooled liquid and promote efficient supply of the liquid in the vaporization area, and the two-phase liquid leaving the surface realizes gas-liquid separation.

[0104] In the micro-channel group, the micro-channels and the ribs significantly increase the contact area of the cooling working medium and the micro-channel structure 100 to improve the heat exchange efficiency, and the fully open outlet makes the working medium after phase change heat exchange more easily discharged.

[0105] On the outer surface 203 of the cover plate 200, the porous layer provides a large number of vaporization cores, and the cooling working medium undergoes large-space flow boiling phenomenon, and the surface fluid flow can effectively take the bubbles away from the heat exchange surface and provide a large amount of fresh working medium 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 micro-channel structure 100, and cools the two-phase fluid in the micro-channel structure 100, and reduces the dryness.

[0106] The upper and lower two layers of the immersed flow boiling phase change heat exchanger work together to complete the heat exchange process.

[0107] Performance tests show that the double-immersed flow boiling phase change heat sink has excellent heat dissipation performance under the test conditions of using normal pressure low boiling point working fluid:

[0108] In the case of a chip module heat source area of 32 mm x 50 mm, the power when generating heat attenuation is 2000 W-3000 W, and the heat flux density can reach 100 W / cm 2 -200 W / cm 2 , which is more than 100% higher than the traditional immersed boiling heat exchange system.

[0109] It should be noted that the present embodiment is particularly suitable for cooling scenarios of high-power high heat flux chips (such as 1000-2600 W level GPUs). In actual application, by adjusting the flow distribution ratio of the inlet branch pipeline, precise matching of the heat load of different micro-channel regions and immersed regions can be realized.

[0110] It should be further noted that the technical solutions of the present embodiment are also applicable to the heat dissipation needs of other high-power electronic devices, such as power MOSFET, CPU, GPU, etc. Any deformation application based on the basic design idea of the present embodiment, as long as it adopts the core technical features of the present invention, should belong to the protection scope of the present application.

[0111] Finally, it should be noted that: other embodiments of the present application will be easily thought of by those skilled in the art after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application that follow the general principles of the present application and include known or customary technical means in the art that are not disclosed by the present application, and is not limited to the precise structure described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof.

Claims

1. A dual-submerged-flow boiling phase change heat sink configured to be disposed in a submerged cabinet (500) and exchange heat with a liquid in the submerged cabinet (500), characterized in that, The double-immersed flow boiling phase-change heat dissipator comprises a micro-channel structure (100), a first cooling working medium pipeline (300) and a second cooling working medium pipeline (400). The micro-channel structure (100) is provided with a plurality of array-arranged fins to form a micro-channel group (101), the first cooling working medium pipeline (300) is communicated with an inlet of the micro-channel group (101) to deliver cooling working medium to the micro-channel group (101), and an outlet of the micro-channel group (101) is provided with a full-open structure (1011) to be communicated with a liquid cavity (501) of the immersion tank (500). The micro-channel structure (100) is provided with a cover plate (200) along a thickness direction thereof, the cover plate (200) is provided with an enclosure structure (201), the second cooling working medium pipeline (400) is communicated with the enclosure structure (201) to deliver cooling working medium to the enclosure structure (201), the enclosure structure (201) is used for guiding the cooling working medium to flow through an outer surface (203) of the cover plate (200), and the outer surface (203) of the cover plate (200) is provided with a porous layer.

2. The double-immersed flow boiling phase-change heat dissipator according to claim 1, wherein The micro-channel group (101) comprises a plurality of micro-channels, each of the micro-channels is composed of two adjacent fins, and an outlet of each of the micro-channels is opened to form the full-open structure. The micro-channel structure (100) is provided with a collecting groove (102); 3. The dual-submersion flow boiling phase change heat sink of claim 1, wherein, The micro-channel group (101) and the first cooling working medium pipeline (300) are communicated through the collecting groove (102), and the collecting groove (102) is provided with at least one flow-dividing fin (103) for dividing the cooling working medium flowing from the first cooling working medium pipeline (300) into the collecting groove (102).

4. The double-immersed flow boiling phase-change heat dissipator according to claim 3, wherein An inner wall surface of the collecting groove (102) is provided with a first connecting hole (1021), the first cooling working medium pipeline (300) is communicated with the first connecting hole (1021) to deliver cooling working medium to the collecting groove (102); The at least one flow-dividing fin (103) is symmetrically distributed in the collecting groove (102) with the hole axis of the first connecting hole (1021) as a symmetric axis.

5. The double-immersed flow boiling phase-change heat dissipator according to claim 3, wherein The groove depth of the collecting groove (102) is the same as the depth of the micro-channel group (101); or In the direction of the cooling working medium flow, the groove depth of the collecting groove (102) gradually increases, and the lowest point of a groove bottom of the collecting groove (102) is close to the inlet of the micro-channel group (101).

6. The double-immersed flow boiling phase-change heat dissipator according to claim 1, wherein ​ The porous layer is a foam-like copper metal network structure, the inside 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 size is 0.15mm-0.25mm; or, The porous layer is sintered and solidified by copper powder particles with a particle size of 50μm-150μm, the thickness is 1mm-2mm, and the porosity is 40%-60%; Or, The porous layer is composed of a plurality of array-arranged micro-ribs, the thickness of the micro-rib is 1mm-2mm, the height of the micro-rib along the thickness direction of the micro-channel structure (100) is 1mm-2mm, and the pitch of the plurality of micro-ribs is 2mm-4mm.

7. The dual-submerged flow boiling phase change heat sink according to claim 1, wherein, The cross section of the micro-channel is a rectangular cross section; and / or, The width of the micro-channel is 0.5mm-2mm, and the depth of the micro-channel is 1mm-6mm; and / or, The thickness of the rib is 1mm.

8. The dual-submerged flow boiling phase change heat sink according to claim 1, wherein, A second connecting hole (2011) is arranged on the enclosure structure (201), the second cooling working medium pipeline (400) is communicated with the second connecting hole (2011) through a spray head (202) to transport the cooling working medium into the enclosure structure (201).

9. The dual-submerged flow boiling phase change heat sink according to claim 1, wherein, Valves are respectively arranged on the first cooling working medium pipeline (300) and the second cooling working medium pipeline (400), and the valves are used to adjust the flow of the cooling working medium flowing through the first cooling working medium pipeline (300) and the second cooling working medium pipeline (400).

10. The dual-submerged flow boiling phase change heat sink according to claim 9, wherein, Temperature sensors are respectively arranged on the micro-channel structure (100) and the cover plate (200), the temperature sensors are used to monitor the temperature of the micro-channel structure (100) and the cover plate (200) in real time and feed back to the valves, and the valves are also used to adjust the flow of the cooling working medium flowing through the first cooling working medium pipeline (300) and the second cooling working medium pipeline (400) according to the temperature fed back by the temperature sensors.

11. The dual-submersion flow boiling phase change heat sink of claim 1, wherein, The cooling working medium is a normal pressure or positive pressure low-boiling-point working medium, and the boiling point range of the cooling working medium is 30℃-50℃.

12. The dual-submerged flow boiling phase change heat sink according to claim 1, wherein, The cooling working medium is a supercooled liquid, and the supercooling degree of the supercooled liquid is 10℃-15℃.

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