Immersed thermal management system

Abstract

The invention provides an immersed thermal management system, which comprises a closed cavity for placing a heating device; the cooling unit array is located in the closed cavity, the cooling unit array comprises a plurality of cooling units which are arranged at intervals, flowing cooling liquid is arranged in the cooling units, and the heating devices are located between the adjacent cooling units; the gas source is communicated with the closed cavity through a gas pipeline and used for supplying high-heat-conduction gas into the closed cavity, the heating device is immersed in the high-heat-conduction gas, the high-heat-conduction gas flows in the closed cavity, heat generated by the heating device is transmitted to the cooling unit, and the cooling unit is used for cooling the heating device. Therefore, the heating device is cooled.

Description

Technical Field

[0001] The present invention relates to the field of cooling technology, and particularly to an immersion thermal management system. Background Art

[0002] With the rise of AI technologies such as ChatGPT, the high computing power demand for chips and computing devices has further exploded. The demand for high-power servers has increased significantly, and the corresponding heat dissipation and energy-saving requirements have also increased synchronously.

[0003] Traditional cooling solutions include air cooling and liquid cooling. Air cooling uses the flow of air to carry away heat to ensure the stable operation of the server. Liquid cooling can be divided into two types: contact liquid cooling and non-contact liquid cooling according to the different heat exchange methods between the coolant and the server.

[0004] Contact liquid cooling refers to the liquid cooling form in which the coolant is in direct contact with the server, mainly including immersion liquid cooling. Immersion liquid cooling uses the coolant as the heat transfer medium, completely immerses the server in the coolant, and the server is in direct contact with the coolant for heat exchange. According to whether there is a phase change of the coolant during the heat exchange process, it can be divided into two categories: immersion single-phase liquid cooling and immersion phase-change liquid cooling. Immersion single-phase liquid cooling immerses the server in the coolant. The coolant dissipates heat through temperature rise and fall, in cooperation with the heat dissipation system. During the process, the coolant does not undergo a phase change. The heat dissipation efficiency is higher than that of air cooling, and it can adapt to servers with a higher power density. Moreover, the coolant can be recycled. Immersion phase-change liquid cooling immerses the server in the coolant, and the coolant dissipates heat through the transformation between liquid and gas, utilizing the principle of heat absorption during liquid vaporization. The heat dissipation efficiency is higher, and it is suitable for servers with ultra-high power density, but the system is relatively complex.

[0005] Non-contact liquid cooling refers to the liquid cooling form in which the coolant is not in direct contact with the server, such as cold plate liquid cooling. In this method, the liquid cooling plate is attached to the server to be cooled, and heat is dissipated with the help of the heat dissipation system. The heat of the server is indirectly transferred to the coolant enclosed in the circulating pipeline through the liquid cooling plate, and then the heat is carried away by the coolant. This method does not directly contact the server and transfers heat indirectly through the liquid cooling plate, and the maintenance is relatively convenient. It is suitable for ordinary server scenarios with not particularly high heat dissipation requirements.

[0006] With the synchronous significant increase in chip computing power and power consumption, the heat generation of high-power servers has increased. Traditional cooling technologies such as air cooling and liquid cooling are difficult to meet the heat dissipation requirements. Therefore, the cooling industry urgently needs a practical cooling device that can effectively solve the problems of heat dissipation and energy saving. Summary of the Invention

[0007] To solve the above technical problems, embodiments of the present invention provide an immersion thermal management system that integrates the advantages of air cooling, cold plate cooling, and immersion cooling. In a sealed enclosure, heat-generating devices are immersed in a gas cooling medium with good thermal conductivity, and through the reflux circulation of the gas cooling medium, the heat generated by the heat-generating devices is taken away by the cooling unit.

[0008] According to some embodiments of the present invention, there is provided an immersion thermal management system, including: a sealed enclosure for placing heat-generating devices; a cooling unit array located within the sealed enclosure, the cooling unit array including a plurality of cooling units arranged at intervals, with flowing cooling liquid provided within the cooling units, and the heat-generating devices being located between adjacent cooling units; and a gas source connected to the sealed enclosure through a gas pipeline for supplying a highly thermally conductive gas into the sealed enclosure, the heat-generating devices being immersed in the highly thermally conductive gas, and the highly thermally conductive gas flowing within the sealed enclosure to transfer the heat generated by the heat-generating devices to the cooling unit, thereby cooling the heat-generating devices.

[0009] According to some embodiments of the present invention, the immersion thermal management system further includes: a first heat exchanger connected to the cooling unit array through a liquid pipeline for cooling the cooling liquid.

[0010] According to some embodiments of the present invention, the liquid pipeline includes an inlet liquid pipeline and an outlet liquid pipeline. The inlet liquid pipeline is provided with a first pressure sensor for detecting the pressure of the cooling liquid within the inlet liquid pipeline; and / or the outlet liquid pipeline is provided with a first temperature sensor for detecting the temperature of the cooling liquid within the outlet liquid pipeline.

[0011] According to some embodiments of the present invention, the interfaces of the liquid pipeline with each cooling unit of the cooling unit array are located outside the sealed enclosure.

[0012] According to some embodiments of the present invention, the gas pipeline is provided with: a second temperature sensor for detecting the temperature of the highly thermally conductive gas within the gas pipeline; and / or a second pressure sensor for detecting the pressure of the highly thermally conductive gas within the gas pipeline.

[0013] According to some embodiments of the present invention, the gas pipeline is further provided with a second heat exchanger for cooling the highly thermally conductive gas.

[0014] According to some embodiments of the present invention, the highly thermally conductive gas flows within the sealed enclosure in a vertical direction, a plurality of cooling units are arranged at intervals in the vertical direction, and a plurality of heat-generating devices are arranged at intervals in the horizontal direction between adjacent cooling units.

[0015] According to some embodiments of the present invention, each heating device is parallel to the flow direction of the high thermal conductivity gas, and each cooling unit is perpendicular to the flow direction of the high thermal conductivity gas.

[0016] According to some embodiments of the present invention, the high thermal conductivity gas flows horizontally in the sealed cavity, multiple cooling units are arranged at intervals along the vertical direction, and the heating devices are arranged between adjacent cooling units.

[0017] According to some embodiments of the present invention, each heating device is parallel to the flow direction of the high thermal conductivity gas, and each cooling unit is parallel to the flow direction of the high thermal conductivity gas.

[0018] According to some embodiments of the present invention, the high thermal conductivity gas flows horizontally in the sealed cavity, the cooling unit array includes multiple groups of cooling units, the multiple groups of cooling units are arranged at intervals along the vertical direction, each group of cooling units includes multiple cooling units arranged at intervals along the horizontal direction, and multiple heating devices are arranged at intervals along the vertical direction between adjacent cooling units.

[0019] According to some embodiments of the present invention, each heating device is parallel to the flow direction of the high thermal conductivity gas, and each cooling unit is perpendicular to the flow direction of the high thermal conductivity gas.

[0020] According to some embodiments of the present invention, the immersion thermal management system includes at least two of the sealed cavities, and adjacent sealed cavities communicate with each other.

[0021] According to some embodiments of the present invention, the high thermal conductivity gas flows horizontally in the sealed cavity, the cooling unit array includes multiple groups of cooling units, the multiple groups of cooling units are arranged at intervals along the horizontal direction, each group of cooling units includes multiple cooling units arranged at intervals along the vertical direction, the heating devices are arranged between adjacent cooling units, and the cooling units in adjacent groups are arranged in a staggered manner so that the heating components are arranged in a staggered manner.

[0022] According to some embodiments of the present invention, each heating device is parallel to the flow direction of the high thermal conductivity gas, and each cooling unit is parallel to the flow direction of the high thermal conductivity gas.

[0023] According to some embodiments of the present invention, the gas pipeline is provided with a safety valve, and when the pressure in the sealed cavity is too high, the high thermal conductivity gas in the sealed cavity is discharged through the safety valve.

[0024] According to some embodiments of the present invention, the high thermal conductivity gas includes an inert gas.

[0025] According to some embodiments of the present invention, the inert gas includes helium and neon.

[0026] According to some embodiments of the present invention, the high thermal conductivity gas includes hydrogen and nitrogen.

[0027] According to some embodiments of the present invention, the pressure in the sealed cavity is not less than 0.25 atm, and the flow rate of the high thermal conductivity gas is not less than 0.25 m / s.

[0028] In the immersion type thermal management system according to the present invention, the heat generating device and the cooling unit are arranged in the sealed cavity. The heat generating device is arranged between adjacent cooling units. The sealed cavity is filled with a high thermal conductivity gas. The heat generating device is immersed in the high thermal conductivity gas. The high thermal conductivity gas flows in the sealed cavity to transfer the heat generated by the heat generating device to the cooling unit, thereby cooling the heat generating device.

[0029] According to some embodiments of the present invention, by selecting a high thermal conductivity gas with a high thermal conductivity coefficient as the heat conduction medium, the heat transfer efficiency is improved. By adjusting the flow field change of the high thermal conductivity gas in the sealed cavity, an optimal temperature control effect is achieved.

[0030] According to some embodiments of the present invention, the interfaces of the respective cooling units of the cooling unit array are located outside the sealed cavity. Even if the pipeline leaks, since the interfaces are outside, the leaked cooling liquid will not contact the heat generating device and will not affect its operation.

[0031] According to some embodiments of the present invention, by providing a pressure sensor, the pressure in the sealed cavity can be adjusted to improve the heat transfer efficiency.

[0032] According to some embodiments of the present invention, by selecting an inert gas as the heat conduction medium, the chemical properties of the inert gas are stable and it does not react with the heat generating device, which can prevent element vulcanization, block impurities, improve the stability of the heat generating device, reduce the failure probability, and cut down the maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] By describing the exemplary embodiments of the present disclosure in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present disclosure will become more apparent. Among them, in the exemplary embodiments of the present disclosure, the same reference numerals generally represent the same components.

[0034] Figure 1 Shows a schematic structural diagram of an immersion type thermal management system according to an embodiment of the present invention;

[0035] Figure 2 Shows a schematic structural diagram of an immersion type thermal management system according to another embodiment of the present invention;

[0036] Figure 3 Shows Figure 2Front-side schematic diagram of the immersion thermal management system;

[0037] Figure 4 Shows a schematic structural diagram of an immersion thermal management system according to another embodiment of the present invention;

[0038] Figure 5 Shows a schematic structural diagram of an immersion thermal management system according to another embodiment of the present invention;

[0039] Figure 6 Shows a schematic structural diagram of an immersion thermal management system according to another embodiment of the present invention;

[0040] Figure 7A Shows the temperature field distribution diagram of a heat-generating device cooled by an immersion thermal management system adopting an embodiment of the present invention;

[0041] Figure 7B Shows the temperature field distribution diagram of a heat-generating device cooled by air cooling in the prior art. Detailed implementation

[0042] The implementation and use of the embodiments are discussed in detail below. However, it should be understood that the specific embodiments discussed are merely illustrative of the specific ways of implementing and using the present invention, rather than limiting the scope of the present invention. The expressions of the structural positions of various components during description, such as directions like up, down, top, bottom, etc., are not absolute but relative. When the components are arranged as shown in the figures, these direction expressions are appropriate, but when the positions of the components in the figures change, these direction expressions also change accordingly.

[0043] With the synchronous significant increase in chip computing power and power consumption, the heat generation of high-power servers increases, and traditional cooling technologies such as air cooling and liquid cooling are difficult to meet the heat dissipation requirements.

[0044] Air cooling has the disadvantages of low heat exchange efficiency, poor heat dissipation, high noise, and the open layout causes dust and water vapor to be carried in during the air medium flow, affecting the service life of the server, and is mainly applied to small computing power places.

[0045] Cold plate liquid cooling attaches the liquid cooling plate to the heat-generating devices such as computing power chips on the server through thermal conductive silicone to take away heat. Its structure is complex, and the liquid cooling plate needs to be comprehensively designed according to the server backplane, PCBA, connection method, devices, etc., with high design requirements and high costs. In addition, the cold plate liquid cooling device usually has many pipeline joints, there is a hidden danger of liquid leakage, affecting the service life of the server.

[0046] Phase change immersion liquid cooling dissipates heat by the evaporation of liquid refrigerants such as fluorinated liquids. Its system structure is complex; being immersed in the liquid also affects the electrical signals and device reliability of communication equipment. In addition, fluorinated liquids are costly and face environmental protection policy pressures, with a risk of production suspension.

[0047] Single-phase immersion liquid cooling immerses the server in the liquid. The liquid medium will cause a swelling reaction to connectors, printed circuit boards, and devices, which will further lead to device failure; replacing the air medium with a coolant will affect the dielectric performance due to the change in the dielectric constant of the liquid, affecting the signal integrity of connectors and PCBs; the upfront construction and transformation costs are high, etc.

[0048] Therefore, an embodiment of the present invention provides an immersion thermal management system that integrates the advantages of air cooling, cold plate cooling, and immersion cooling. In a sealed enclosure, the heat-generating device is immersed in a gas cooling medium with good thermal conductivity, and the heat generated by the heat-generating device is taken away by the cooling unit through the reflux circulation of the gas cooling medium.

[0049] According to an embodiment of the present invention, an immersion thermal management system is provided. The immersion thermal management system includes: a sealed enclosure for placing the heat-generating device; a cooling unit array located in the sealed enclosure. The cooling unit array includes a plurality of cooling units arranged at intervals. A flowing cooling liquid is provided in the cooling unit, and the heat-generating device is located between adjacent cooling units; and a gas source is connected to the sealed enclosure through a gas pipeline for supplying a high-thermal-conductivity gas into the sealed enclosure. The heat-generating device is immersed in the high-thermal-conductivity gas, and the high-thermal-conductivity gas flows in the sealed enclosure to transfer the heat generated by the heat-generating device to the cooling unit, thereby cooling the heat-generating device.

[0050] Figure 1 The structural schematic diagram of an immersion thermal management system 100 according to an embodiment of the present invention is shown. As Figure 1As shown in the figure, the immersion thermal management system 100 includes a sealed chamber 10, a cooling unit array 20, and a gas source 30. The sealed chamber 10 can be formed by a sealed container for placing a plurality of heat generating devices 40, such as servers. The cooling unit array 20 is located inside the sealed chamber 10. The cooling unit array 20 includes a plurality of cooling units 21 arranged at intervals. A flowing cooling liquid, such as cooling water, is provided inside the cooling unit 21. The initial temperature of the cooling liquid is generally between -20°C and 20°C. The heat generating devices 40 are located between adjacent cooling units 21, and one or more heat generating devices 40 can be arranged between adjacent cooling units 21. The gas source 30, such as a gas source bottle, is used to supply a highly thermally conductive gas into the sealed chamber 10. The heat generating devices 40 are immersed in the highly thermally conductive gas. The highly thermally conductive gas flows inside the sealed chamber 10, transfers the heat generated by the heat generating devices 40 to the cooling units 21, and exchanges heat through the cooling liquid in the cooling units 21 to remove the heat, so as to achieve the purpose of cooling the heat generating devices 40.

[0051] In some embodiments, the distance between the cooling unit 21 and the heat generating device 40 is 5 mm - 40 mm, and the distance between adjacent cooling units 21 can be adjusted according to the size of the heat generating device 40 to be cooled. The cooling unit 21 and the heat generating device 40 can be placed inside the sealed chamber 10 through brackets or the like.

[0052] In some embodiments, the highly thermally conductive gas is an inert gas, such as helium or neon. In some embodiments, the highly thermally conductive gas can also be hydrogen or nitrogen.

[0053] In some embodiments, the immersion thermal management system 100 further includes a first heat exchanger 22. The first heat exchanger 22 is connected to the cooling unit array 20 through a liquid pipeline 23 and is used to exchange heat with the cooling liquid flowing out of the cooling unit 21 to reduce the temperature of the cooling liquid. The material of the liquid pipeline 23 can be a material with high thermal conductivity, such as aluminum alloy or copper, to facilitate heat transfer. The size of the liquid pipeline 23 can be adjusted according to the heat generation amount of the heat generating device 40.

[0054] In some embodiments, the liquid pipeline 23 includes a liquid inlet pipeline 231 and a liquid outlet pipeline 232. A first pressure sensor 24, such as a pressure gauge, is provided on the liquid inlet pipeline 231 of the liquid pipeline 23 for detecting the pressure of the cooling liquid in the liquid inlet pipeline 231 of the liquid pipeline 23. In some embodiments, a first temperature sensor 25, such as a thermometer, is provided on the liquid outlet pipeline 232 of the liquid pipeline 23 for detecting the temperature of the cooling liquid in the liquid outlet pipeline 232 of the liquid pipeline 23. By providing the first pressure sensor 24 and the first temperature sensor 25, it is convenient to monitor the operating state of the system and adjust the pressure, flow rate, etc. of the liquid pipeline 23 in real time. For example, when the monitoring system detects that the temperature of the first temperature sensor 25 is higher than the set value, the flow rate of the cooling liquid is increased through the control device.

[0055] In some embodiments, the liquid pipeline 23 is connected to each cooling unit 21 of the cooling unit array 20 through an interface 233. As shown in the figure, one end of each cooling unit 21 is connected to the liquid inlet pipeline 231 of the liquid pipeline 23 through the interface 233, and the other end is connected to the liquid outlet pipeline 232 of the liquid pipeline 23 through the interface 233. These interfaces 233 are all provided outside the sealed cavity 10. Even if the cooling liquid leaks, the heating device 40 inside the sealed cavity 10 will not be damaged.

[0056] In some embodiments, the gas source 30 communicates with the sealed cavity 10 through a gas pipeline 32. The highly thermally conductive gas flows into the sealed cavity 10 through the gas pipeline 32, transfers the heat generated by the heating device 40 to the cooling unit 21, and then flows back from the sealed cavity 10 to the gas pipeline 32 to form a gas circulation loop.

[0057] In some embodiments, a second pressure sensor 33, such as a pressure gauge, is provided on the gas pipeline 32 for detecting the pressure of the highly thermally conductive gas in the gas pipeline 32. In some embodiments, a second temperature sensor 34, such as a thermometer, is provided on the gas pipeline 32 for detecting the temperature of the highly thermally conductive gas in the gas pipeline 32. When the outlet temperature of the gas pipeline 32 is relatively high, the flow rate of the cooling liquid in the cooling unit 21 can be adjusted and the inlet air pressure, flow rate, etc. of the gas pipeline 32 can be increased.

[0058] By providing the second pressure sensor 33 and the second temperature sensor 34, it is convenient to monitor the operating state of the system and adjust the pressure, flow rate, etc. of the gas pipeline 32 in real time. In some embodiments, the gas source 30 further includes a supplementary gas pipeline. For example, when the pressure of the highly thermally conductive gas is lower than the set threshold, air is supplemented through the gas source bottle to maintain the pressure inside the sealed cavity 10. The supplementary gas pipeline solves the problem of chronic gas leakage. The supplementary gas pipeline can also be provided separately. When the pressure inside the sealed cavity 10 is too high, the safety valve on the gas pipeline 32 can be opened to discharge the gas inside the sealed cavity 10 to achieve pressure relief.

[0059] In some embodiments, the gas pipeline 32 is provided with a second heat exchanger 31 for exchanging heat with the highly heat-conductive gas coming out of the sealed chamber 10 to reduce the temperature of the highly heat-conductive gas. In some embodiments, the highly heat-conductive gas transfers heat to the cooling unit 21, and the temperature difference between the highly heat-conductive gas entering the sealed chamber 10 and the highly heat-conductive gas leaving the sealed chamber 10 is not significant. Therefore, the gas source 30 may not include the second heat exchanger 31 either. In some embodiments, the first heat exchanger 22 and the second heat exchanger 31 can share one heat exchanger.

[0060] The gas pipeline 32 includes an inlet pipeline 321 and an outlet pipeline 322. A second pressure sensor 33 is arranged on the inlet pipeline 321, between the sealed chamber 10 and the second heat exchanger 31. A second temperature sensor 34 is arranged on the outlet pipeline 322, between the sealed chamber 10 and the second heat exchanger 31. The gas pipeline 32 also includes a plurality of inlet ports and a plurality of outlet ports, and the plurality of inlet ports are respectively communicated with the sealed chamber 10, and the plurality of outlet ports are respectively communicated with the sealed chamber 10.

[0061] The heat exchanger is a key component for heat exchange between cold and hot fluids. Through a separated double-cycle design, it can effectively cool the main equipment. The first heat exchanger 22 and the second heat exchanger 31 in the embodiments of the present invention can adopt an air-cooled heat exchanger or a liquid-cooled heat exchanger.

[0062] In the air-cooled heat exchanger, the heat medium flows through the inner cavity of the metal pipe, and the air flows through the outer wall of the metal pipe. Through the forced convection of the fan, the air sweeps over the fin surface and takes away the heat, thereby realizing heat exchange. For example, the first heat exchanger 22 and the second heat exchanger 31 in the embodiments of the present invention adopt an air-cooled finned tube condenser. The high-temperature liquid or gaseous refrigerant flows in the copper pipe, and the heat is conducted from the copper pipe to the fins. The outdoor fan operates to make the air flow quickly over the fin surface and take away the heat, cooling the liquid or gaseous refrigerant.

[0063] In the liquid-cooled heat exchanger, the working principle of the liquid-cooled heat exchanger is based on heat conduction and heat convection. The heat-generating device transfers heat to the refrigerant (such as the cooling liquid and the highly heat-conductive gas in the present invention) that is in contact with it directly or indirectly. The refrigerant circulates to take away the heat, and then on the other side of the heat exchanger, the low-temperature cooling medium (such as water, alcohol or other cooling liquids) absorbs the heat transferred by the refrigerant, thereby cooling the heat-generating device and realizing the transfer of heat from the heat-generating device to the cooling medium.

[0064] In the liquid-cooled heat exchanger, the cold and hot fluids are separated by a solid wall surface, and heat transfer is carried out through the wall surface, and the two fluids do not mix with each other. Heat exchangers include shell-and-tube heat exchangers, plate heat exchangers, spiral plate heat exchangers, plate-fin heat exchangers, etc.

[0065] Figures 2-3The structural schematic diagram of an immersion thermal management system 100 according to another embodiment of the present invention is shown. As Figures 2-3 shown, the high - thermal - conductivity gas flows in a substantially vertical direction within the sealed chamber 10, for example, from bottom to top. A plurality of cooling units 21 are arranged at intervals in a substantially vertical direction, and a plurality of heat - generating devices 40 are arranged at intervals in a substantially horizontal direction between adjacent cooling units 21.

[0066] In some embodiments, each heat - generating device 40 is parallel to the flow direction of the high - thermal - conductivity gas, that is, the plane with the largest area of each heat - generating device 40 is parallel to the flow direction of the high - thermal - conductivity gas, that is, arranged along the vertical direction; each cooling unit 21 is perpendicular to the flow direction of the high - thermal - conductivity gas, that is, the plane with the largest area of each cooling unit 21 is perpendicular to the flow direction of the high - thermal - conductivity gas, that is, arranged along the horizontal direction. Through this arrangement, the high - thermal - conductivity gas can quickly carry away the heat generated by the heat - generating device 40 and transfer it to the cooling unit 21.

[0067] The cooling liquid (for example, low - temperature cooling water) in the first heat exchanger 22 (for example, a chiller) flows into the cooling unit 21 through the liquid inlet pipe 231 of the liquid pipeline 23, and then flows back into the first heat exchanger 22 through the liquid outlet pipe 232 of the liquid pipeline 23, forming a liquid circulation loop.

[0068] The high - thermal - conductivity gas in the gas source 30 flows into the sealed chamber 10 through the gas pipeline 32 and then flows back to the gas pipeline 32 from the sealed chamber 10, forming a gas circulation loop. Or, a second heat exchanger 31 is provided on the gas pipeline 32 to cool the gas after heat exchange and then flow it into the sealed chamber 10, forming a gas circulation loop.

[0069] The gas pipeline 32 is provided with a second pressure sensor 33 for detecting the pressure of the high - thermal - conductivity gas in the gas pipeline 32, and the gas pipeline 32 is provided with a second temperature sensor 34 for detecting the temperature of the high - thermal - conductivity gas in the gas pipeline 32.

[0070] The gas pipeline 32 is also provided with a safety valve 35. When the second pressure sensor 33 detects that the pressure of the high - thermal - conductivity gas in the gas pipeline 32, that is, the pressure in the sealed chamber 10, is too high, the safety valve 35 is opened to discharge the high - thermal - conductivity gas in the sealed chamber 10.

[0071] The gas pipeline 32 can also be provided with a check valve to prevent the high - thermal - conductivity gas from flowing back. The gas pipeline 32 can also be provided with a ball valve for adjusting the flow rate of the high - thermal - conductivity gas.

[0072] The heat-generating device 40, such as a server, is an object that needs to be cooled and generates heat during operation. The cooling units 21, such as condensers, are arranged at intervals in the sealed cavity 10 to form an array. The heat-generating device 40 is arranged between the cooling units 21. Since the sealed cavity 10 is filled with a highly thermally conductive gas, the heat-generating device 40 is immersed in the highly thermally conductive gas environment. The highly thermally conductive gas contacts the heat-generating device 40 and transfers the heat of the heat-generating device 40 to the cooling unit 21. The cooling liquid in the cooling unit 21 takes away the heat, and the hot cooling liquid flows to the first heat exchanger 22 to continuously transfer the heat out.

[0073] The gas source 30 provides the highly thermally conductive gas for the sealed cavity 10 and provides the circulating power for the gas circulation loop to ensure the continuous circulation of the highly thermally conductive gas in the sealed cavity 10, continuously taking away the heat of the heat-generating device 40. The highly thermally conductive gas enters the sealed cavity 10 from the bottom of the sealed cavity 10 and contacts the heat-generating device 40, and the heat of the heat-generating device 40 is transferred to the highly thermally conductive gas. The highly thermally conductive gas flows out from the top of the sealed cavity 10, and the hot highly thermally conductive gas flows to the second heat exchanger 31 of the gas source 30. After transferring the heat out, it flows back into the sealed cavity 10 to continue cooling the heat-generating device 40, forming a gas circulation loop.

[0074] A sealing ring 12 is provided on the cavity door 11 of the sealed cavity 10 to play a sealing role and provide a sealed environment to prevent the highly thermally conductive gas in the sealed cavity 10 from leaking. A reflux device 13, such as a reflux fan, is provided above the sealed cavity 10 to accelerate the circulation flow of the highly thermally conductive gas, assist the heat dissipation of the highly thermally conductive gas, and accelerate the heat dissipation in the sealed cavity 10 to achieve the effect of rapid cooling. The sealed cavity 10 can also be provided with a flow equalizing device, such as a flow equalizing plate, to make the air flow distribution more uniform to ensure the heat exchange effect.

[0075] Figure 4 The structural schematic diagram of an immersion thermal management system 100 according to an embodiment of the present invention is shown. As Figure 4 shown, the highly thermally conductive gas flows in from one side of the sealed cavity 10 and flows out from the other side of the sealed cavity 10. The highly thermally conductive gas flows in the sealed cavity 10 along a substantially horizontal direction, and a plurality of cooling units 21 are arranged at intervals along a substantially vertical direction. The heat-generating device 40 is arranged between adjacent cooling units 21.

[0076] In some embodiments, each heat-generating device 40 is parallel to the flow direction of the highly thermally conductive gas, that is, the plane with the largest area of each heat-generating device 40 is parallel to the flow direction of the highly thermally conductive gas, that is, arranged along the horizontal direction; each cooling unit 21 is parallel to the flow direction of the highly thermally conductive gas, that is, the plane with the largest area of each cooling unit 21 is parallel to the flow direction of the highly thermally conductive gas, that is, arranged along the horizontal direction.

[0077] In the illustrated embodiment, the high thermal conductivity gas enters and exits from the same side, and the gas flow direction of the high thermal conductivity gas is parallel to the heat generating device 40 and the cooling unit 21. The high thermal conductivity gas enters the sealed cavity 10 from one side through the flow equalizing plate, passes through the heat generating device 40 and the cooling unit 21, and then flows out from the other side. The hot high thermal conductivity gas flows to the second heat exchanger 31, transfers the heat, and then flows back to the sealed cavity 10 to continue cooling the heat generating device 40, forming a gas circulation loop.

[0078] Figure 5 FIG. 4 shows a schematic structural diagram of an immersion thermal management system 100 according to an embodiment of the present invention. As Figure 5 shown, the high thermal conductivity gas flows in the sealed cavity 10 along a substantially horizontal direction. The cooling unit array 20 includes multiple groups of cooling units. Each row of cooling units is a group of cooling units. In the figure, there are three groups of cooling units arranged in the sealed cavity 10 at intervals along a substantially vertical direction. Each group of cooling units includes a plurality of cooling units 21 arranged at intervals along the horizontal direction, and a plurality of heat generating devices 40 are arranged at intervals along the substantially vertical direction between adjacent cooling units 21.

[0079] In some embodiments, each heat generating device 40 is parallel to the gas flow direction of the high thermal conductivity gas. That is to say, the plane with the largest area of each heat generating device 40 is parallel to the gas flow direction of the high thermal conductivity gas, that is, arranged along the horizontal direction; each cooling unit 21 is perpendicular to the gas flow direction of the high thermal conductivity gas. That is to say, the plane with the largest area of each cooling unit 21 is perpendicular to the gas flow direction of the high thermal conductivity gas, that is, arranged along the vertical direction.

[0080] In the illustrated embodiment, the immersion thermal management system 100 includes two sealed cavities 10. The adjacent sealed cavities 10 are interconnected through gas pipelines. Each sealed cavity 10 is provided with a cooling unit array 20. The high thermal conductivity gas flows into the first sealed cavity 10 through multiple air inlets 323 of the gas pipeline 32, flows in the first sealed cavity 10, transfers the heat generated by the heat generating device 40 to the cooling unit 21, and then flows out of the first sealed cavity 10 through multiple air outlets 324. Then, it flows into the adjacent second sealed cavity 10 through the gas pipeline, flows in the adjacent second sealed cavity 10, transfers the heat generated by the heat generating device 40 to the cooling unit 21, and then flows out of the second sealed cavity 10 through multiple air outlets 324, and then flows into the first sealed cavity 10 through the gas pipeline 32, forming a gas circulation loop. By connecting multiple sealed cavities 10 in series and sharing a heat exchanger system, it has good economy and saves space.

[0081] In the illustrated embodiment, the heat generating device 40 is placed horizontally, the gas flow direction of the high thermal conductivity gas is parallel to the heat generating device 40, and the cooling unit 21 is perpendicular to the heat generating device 40. The overall structure is compact and has a large loading capacity, and is suitable for heat generating devices with relatively small heat generation.

[0082] Figure 6 The structural schematic diagram of an immersion thermal management system 100 according to an embodiment of the present invention is shown. As Figure 6 shown, the high thermal conductivity gas flows along a substantially horizontal direction in the sealed cavity 10. The cooling unit array 20 includes multiple groups of cooling units. Each column of cooling units is a group of cooling units. In the figure, there are three groups of cooling units arranged in the sealed cavity 10 at intervals along the substantially horizontal direction. Each group of cooling units includes a plurality of cooling units 21 arranged at intervals along the substantially vertical direction. The heat generating devices 40 are arranged between adjacent cooling units. The cooling units 21 in adjacent groups are arranged in a staggered manner, so that the heat generating components 40 are arranged in a staggered manner.

[0083] In some embodiments, each heat generating device 40 is parallel to the flow direction of the high thermal conductivity gas. That is to say, the plane with the largest area of each heat generating device 40 is parallel to the flow direction of the high thermal conductivity gas, that is, arranged along the horizontal direction; each cooling unit 21 is parallel to the flow direction of the high thermal conductivity gas. That is to say, the plane with the largest area of each cooling unit 21 is parallel to the flow direction of the high thermal conductivity gas, that is, arranged along the horizontal direction.

[0084] In the illustrated embodiment, the heat generating devices 40 are placed horizontally. The flow direction of the high thermal conductivity gas is parallel to the heat generating devices 40 and the cooling units 21. The heat generating devices 40 and the cooling units 21 are arranged at intervals in a staggered manner, which can improve the heat exchange efficiency while increasing the loading capacity, saving the floor space, having good economy, and being suitable for heat generating devices with relatively large heat generation.

[0085] In some embodiments, the thermal conductivity of the gas is related to the thermal motion of gas molecules and the collisions between molecules. Under high pressure conditions, the distance between gas molecules is very small, the mean free path is very short, the collisions between molecules are extremely frequent, the interaction between molecules is enhanced, and the thermal conductivity of the gas will increase with the increase of air pressure, and the heat transfer is more rapid. Therefore, the pressure in the sealed cavity 10 is not less than 0.25 atm. For example, the pressure in the sealed cavity 10 is 0.25 atm to 2 atm.

[0086] In some embodiments, the highly thermally conductive gas is transported to the sealed chamber 10 through a pipeline or a gas storage cylinder, so that the sealed chamber 10 maintains a predetermined pressure. The sealed chamber 10 and the cooling unit 21 are filled with the highly thermally conductive gas. The highly thermally conductive gas circulates and flows back in the sealed chamber 10, efficiently transferring the heat of the heat-generating device 40 to the cooling unit array. The highly thermally conductive gas realizes continuous airflow in the sealed chamber 10 through a circulation pipeline, and uniformly and efficiently realizes the transfer of heat from the heat-generating device 40 to the cooling unit 21. An external heat exchanger can also be connected to the highly thermally conductive gas circulation loop to cool the highly thermally conductive gas, and the highly thermally conductive gas cooled by the heat exchanger is re-transported to the sealed chamber 10 for such a circulation and backflow. Therefore, the flow rate of the highly thermally conductive gas is not less than 0.25 m / s. For example, the flow rate of the highly thermally conductive gas is from 0.25 m / s to 10 m / s.

[0087] In the circulation loop of the highly thermally conductive gas, some auxiliary components can also be provided, such as a flow equalizing plate, a flow guiding plate, etc., to further optimize the flow distribution and heat exchange effect of the highly thermally conductive gas in the sealed chamber.

[0088] In some embodiments, the cooling unit 21 is mainly composed of a copper pipe and fins. The copper pipe, as the core component of the cooling unit array system, is used for the circulation and heat exchange of the liquid refrigerant. The copper pipes are arranged in a serpentine or spiral shape in the cooling unit to increase the flow path and heat exchange area of the liquid refrigerant in the pipe. In order to improve the heat exchange efficiency of the cooling unit 21, fins are installed outside the copper pipes. The fins are usually made of aluminum materials, and have the advantages of light weight, good thermal conductivity, corrosion resistance, etc. There are various shapes of the fins, such as flat fins, corrugated fins, louver fins, etc. The cooling unit 21 is provided with a liquid refrigerant inlet and an outlet for connecting the pipelines of the heat exchange system. The liquid refrigerant inlet and outlet pipeline interfaces are arranged outside the sealed chamber.

[0089] The immersion thermal management system of the present invention has a wide range of applications and can be applied to, for example, data centers, computing devices, servers, switches, communication devices, precision instruments, energy storage power stations, fast charging piles, etc. The immersion thermal management system of the present invention is also applied to electronic devices, such as cooling heat-generating components such as server chips and computer CPUs. The immersion thermal management system of the present invention is also applied to energy storage heat dissipation in the energy storage field, dissipating the heat absorbed from the battery module and improving the reliability of the device.

[0090] Table 1 shows the server temperature range after cooling by the immersion thermal management system according to the embodiments of the invention.

[0091]

[0092] The server temperature range refers to the temperature range formed by the lowest temperature to the highest temperature of the server in the sealed chamber after the thermal management system operates stably.

[0093] According to Newton's law of cooling, the convective heat transfer rate Q (unit: W) per unit time is as follows:

[0094] Q = h·A·(Ts - Tg);

[0095] where h represents the convective heat transfer coefficient (W / (m 2 ·K)), which is related to the gas flow rate, physical properties, and flow state, A represents the effective contact area between the solid and the gas (m 2 ), Ts represents the solid surface temperature (K), and Tg represents the gas inlet temperature (K).

[0096] Under steady-state conditions, all the heat generation power P of the solid is carried away by the gas, that is:

[0097] P = Q = h·A·(Ts - Tg);

[0098] Therefore, Ts = Tg + P / (h·A);

[0099] If it is necessary to reduce the solid surface temperature, then reduce the gas inlet temperature Tg, increase the effective contact area A, or increase the gas flow rate (increase the convective heat transfer coefficient h). Increasing the gas pressure will increase the gas thermal conductivity, resulting in an increase in the convective heat transfer coefficient h and a decrease in the solid surface temperature Ts.

[0100] Figure 7A Fig. shows the temperature field distribution diagram of a heat-generating device cooled by the immersion thermal management system according to an embodiment of the present invention, Figure 7B Fig. shows the temperature field distribution diagram of a heat-generating device cooled by air cooling in the prior art.

[0101] Figure 7A Corresponding to Embodiment 1, cooling is performed using the immersion thermal management system shown in Figure 6 . The server is of 4U specification, with a power of 800w. The high-thermal-conductivity gas is helium, the gas pressure is 1 atmosphere, the flow rate is 1m / s, the thermal conductivity of helium is 0.15W / (m·K), the server temperature is stable at about 50°C, the temperature distribution is uniform, and the temperature difference at each position is small.

[0102] Figure 7B Corresponding to air cooling in the prior art, the server is of 4U specification, with a power of 800w, the gas pressure is 1 atmosphere, the flow rate is 2m / s, the server temperature is stable at about 70°C, the cooling effect of the server is poor, and the temperature distribution is uneven, with a large temperature difference at each position.

[0103] According to an embodiment of the present invention, a cooling unit array is arranged in a sealed cavity, and heat-generating devices are distributed among the cooling unit array. In the gas immersion mode, the gas circulates inside the sealed cavity, and can quickly transfer the heat generated by the heat-generating devices to the cooling units. Subsequently, the cooling units cooperate with an external cooling circulation system to efficiently remove the heat. The present invention immerses the heat-generating devices in a gas medium environment, the gas medium circulates and returns, and the heat is taken away by an external heat exchanger. The gas medium has almost no influence on the high-speed signal integrity, and solves the compatibility and signal integrity problems of the liquid medium in traditional immersion liquid cooling; in addition, the gas medium has better permeability than the liquid medium, can quickly enter the gaps of complex devices and components, and its excellent fluidity can quickly take away the heat; furthermore, when the liquid medium flows at a high speed, it has a large impact on the devices on the circuit board and affects the operation stability of the devices. The present invention uses the gas medium to flow. The gas medium has a small density and can maintain a high flow rate, and has little impact on the devices.

[0104] According to an embodiment of the present invention, a gas medium refrigerant with a thermal conductivity several times higher than that of air is used and circulates under a pressurized environment. At the same time, cold plate cooling cooperates with an external cooling circulation system to remove heat, with high heat exchange efficiency and good cooling effect. Although immersion liquid cooling has good heat dissipation effect, the coolant cost is high and the maintenance is complex. Cold plate cooling is limited by the material of the liquid cooling plate and the contact thermal resistance, while the high thermal conductivity gas can quickly absorb the heat of the heat-generating devices and transfer it out. While ensuring the heat dissipation performance, it has lower cost, simpler maintenance, less noise, and good gas fluidity, can distribute the heat more evenly, effectively avoid local overheating, and enable each component of the heat-generating devices to be in a more suitable temperature environment, extending the service life of the equipment.

[0105] According to an embodiment of the present invention, a pressure sensor is arranged in the sealed cavity, and the pressure of the sealed system can be flexibly adjusted on the premise that the server is working normally, thereby improving the heat transfer efficiency. Traditional cooling methods are difficult to actively adjust the ambient pressure to optimize heat dissipation. Air cooling is greatly affected by the ambient air pressure and cannot be actively changed. Immersion liquid cooling and cold plate cooling have low requirements for pressure control and lack effective adjustment means. However, the present invention adjusts the pressure, changes the gas density and thermal conductivity, speeds up the heat transfer speed, and appropriately increases the pressure at high temperature and high load to enhance the heat dissipation ability, and reduces the pressure at low load to save energy and reduce consumption, realizing precise and efficient thermal management, and can adapt to the heat dissipation requirements of heat-generating devices under different working scenarios.

[0106] According to an embodiment of the present invention, the optimal temperature control effect can be achieved by adjusting the flow field changes of the gas medium inside the system. The traditional air-cooled flow field is unevenly distributed, and heat dissipation dead corners are prone to occur. The immersion liquid cooling flow field is relatively fixed, and it is difficult to flexibly adapt to the heat generation differences in different parts of the server. The cold plate cooling convection field adjustment capability is limited. The immersion thermal management system of the present invention can accurately control the gas flow field by designing a gas circuit according to the heat generation conditions of each area of ​​the heat-generating device, so that more cooling gas flows through the heat-concentrated area, ensuring that the temperature of each component is balanced, and comprehensively improving the stability and reliability of server operation.

[0107] According to an embodiment of the present invention, selecting an inert medium gas can effectively ensure that the heating device works more stably and avoid interference with the stability of the heating device caused by sulfides, oxygen, water vapor and dust in the air. Traditional air cooling cannot isolate these impurities from the outside world. They are easy to adhere to the inside of the heating device, corrode electronic components, and affect performance. Although immersion liquid cooling can isolate to a certain extent, the coolant may contain impurities or have a risk of chemical reaction with the hardware. Cold plate cooling is also unable to avoid the influence of external impurities. Inert gases have stable chemical properties and do not react with heating devices. They can create a pure environment inside, prevent component sulfidation, and eliminate erosion by water vapor and dust, greatly improving the working stability of heating devices, reducing the probability of failure, and reducing maintenance costs.

[0108] According to an embodiment of the present invention, the pipe interface of the cooling unit in the present invention is arranged outside the closed cavity. During use, even if leakage occurs, it will not affect the heating device itself. Traditional air cooling does not have this advantage. Once the external cooling device fails, the heat dissipation is directly affected. If the cold plate cooling pipeline leaks, it may also affect the heating device. The immersion thermal management system of the present invention places the pipe interface of the cooling unit externally, isolates the leakage risk from the heating device, and even if there is a problem with the external pipeline, the heating device can still operate normally, thereby improving the safety and reliability of the system, reducing the downtime caused by cooling system failure, and ensuring the continuous and stable operation of the heating device.

[0109] According to an embodiment of the present invention, in a cold plate system, since the heating device is in an air environment, in order to avoid damage to the heating device due to condensation, the temperature of the cooling water is usually higher than the dew point, which will affect the heat dissipation efficiency of the heating device. In the present invention, since the server is immersed in a dry medium atmosphere in a closed cavity and there is no condensation problem, the temperature of the cooling liquid can be set without restriction to achieve a higher heat transfer efficiency.

[0110] The technical content and features of the present invention have been disclosed above. However, it can be understood that under the creative concept of the present invention, those skilled in the art can make various changes and improvements to the above-disclosed concept, but all fall within the protection scope of the present invention. The description of the above embodiments is illustrative rather than restrictive, and the protection scope of the present invention is determined by the claims.

Claims

1. An immersion thermal management system, characterized in that: include: A closed cavity for placing heating components; a cooling unit array, located in the closed cavity, the cooling unit array comprising a plurality of cooling units arranged at intervals, a flowing cooling liquid being provided in the cooling units, and the heating device being located between adjacent cooling units; and A gas source is connected to the closed cavity through a gas pipeline, and is used to supply high thermal conductivity gas into the closed cavity. The heat generating device is immersed in the high thermal conductivity gas. The high thermal conductivity gas flows in the closed cavity, and the heat generated by the heat generating device is transferred to the cooling unit, thereby cooling the heat generating device.

2. The immersion thermal management system according to claim 1, characterized in that: Also includes: The first heat exchanger is connected to the cooling unit array through a liquid pipeline and is used to cool the cooling liquid.

3. The immersion thermal management system according to claim 2, characterized in that: The liquid pipeline includes a liquid inlet pipeline and a liquid outlet pipeline. The liquid inlet pipeline is provided with a first pressure sensor for detecting the pressure of the cooling liquid in the liquid inlet pipeline; and / or The liquid outlet pipeline is provided with a first temperature sensor for detecting the temperature of the cooling liquid in the liquid outlet pipeline.

4. The immersion thermal management system according to claim 2, characterized in that: The interfaces between the liquid pipeline and each cooling unit of the cooling unit array are located outside the closed cavity.

5. The immersion thermal management system according to claim 1, characterized in that: The gas pipeline is provided with: A second temperature sensor is used to detect the temperature of the high thermal conductivity gas in the gas pipeline; and / or The second pressure sensor is used to detect the pressure of the high thermal conductivity gas in the gas pipeline.

6. The immersion thermal management system according to claim 5, characterized in that: The gas pipeline is also provided with a second heat exchanger for cooling the high thermal conductivity gas.

7. The immersion thermal management system according to any one of claims 1 to 6, characterized in that: The high thermal conductivity gas flows in the closed cavity along the vertical direction, a plurality of cooling units are arranged at intervals along the vertical direction, and a plurality of heating devices are arranged at intervals along the horizontal direction between adjacent cooling units.

8. The immersion thermal management system according to claim 7, characterized in that: Each heat generating device is parallel to the flow direction of the high thermal conductivity gas, and each cooling unit is perpendicular to the flow direction of the high thermal conductivity gas.

9. The immersion thermal management system according to any one of claims 1 to 6, characterized in that: The high thermal conductivity gas flows in the closed cavity along the horizontal direction, a plurality of cooling units are arranged at intervals along the vertical direction, and the heating device is arranged between adjacent cooling units.

10. The immersion thermal management system according to claim 9, characterized in that: Each heat generating device is parallel to the flow direction of the high thermal conductivity gas, and each cooling unit is parallel to the flow direction of the high thermal conductivity gas.

11. The immersion thermal management system according to any one of claims 1 to 6, characterized in that: The high thermal conductivity gas flows in the closed cavity along the horizontal direction, the cooling unit array includes multiple groups of cooling units, and the multiple groups of cooling units are arranged at intervals from each other along the vertical direction. Each group of cooling units includes multiple cooling units arranged at intervals along the horizontal direction, and multiple heat generating devices are arranged at intervals along the vertical direction between adjacent cooling units.

12. The immersion thermal management system according to claim 11, characterized in that: Each heat generating device is parallel to the flow direction of the high thermal conductivity gas, and each cooling unit is perpendicular to the flow direction of the high thermal conductivity gas.

13. The immersion thermal management system according to claim 11, characterized in that: It comprises at least two of the sealed cavities, and the adjacent sealed cavities are communicated with each other.

14. The immersion thermal management system according to any one of claims 1 to 6, characterized in that: The high thermal conductivity gas flows in the closed cavity along the horizontal direction, the cooling unit array includes multiple groups of cooling units, the multiple groups of cooling units are arranged with intervals along the horizontal direction, each group of cooling units includes multiple cooling units arranged with intervals along the vertical direction, the heat generating devices are arranged between adjacent cooling units, and the cooling units in adjacent groups are arranged in an interlaced manner, so that the heat generating components are arranged in an interlaced manner.

15. The immersion thermal management system according to claim 14, characterized in that: Each heat generating device is parallel to the flow direction of the high thermal conductivity gas, and each cooling unit is parallel to the flow direction of the high thermal conductivity gas.

16. The immersion thermal management system according to any one of claims 1 to 6, characterized in that: The gas pipeline is provided with a safety valve, and when the pressure in the closed cavity is too high, the high thermal conductivity gas in the closed cavity is discharged through the safety valve.

17. The immersion thermal management system according to any one of claims 1 to 6, characterized in that: The high thermal conductivity gas includes an inert gas.

18. The immersion thermal management system according to claim 17, characterized in that: The inert gas includes helium and neon.

19. The immersion thermal management system according to any one of claims 1 to 6, characterized in that: The high thermal conductivity gas includes hydrogen and nitrogen.

20. The immersion thermal management system according to any one of claims 1 to 6, characterized in that: The pressure in the closed chamber is not less than 0.25 atm, and the flow rate of the high thermal conductivity gas is not less than 0.25 m / s.

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