An adaptive coating based data center immersion liquid cooling system

Abstract

The present application relates to a kind of data center immersion liquid cooling systems based on adaptive coating, comprising: outdoor cold supply unit, room side air cooling unit and rack side immersion cooling unit;Rack side immersion cooling unit includes: rack, mainboard, adaptive coating, liquid cooling plate, thermoluminescent material, heat exchanger one and heat exchanger two;Data center includes multiple racks, mainboard is immersed in cooling working medium in rack, cooling working medium is condensed on the surface of liquid cooling plate after temperature rise, and condensed liquid working medium is re-dropped back to pool to carry out liquid supplement, after heat is taken away by liquid cooling plate, cooling working medium flows into heat exchanger one below thermoluminescent material, so that thermoluminescent material emits visible light or ultraviolet light, to be irradiated on the adaptive coating on the surface of mainboard.Compared with prior art, the present application can simultaneously adjust its characteristics according to different stages of boiling, improve cooling capacity;It can improve the energy utilization efficiency of immersion cooling system.

Description

Technical Field

[0001] This invention relates to the field of data center cooling technology, and in particular to a data center immersion liquid cooling system based on an adaptive coating. Background Technology

[0002] The development of 5G, the Internet of Things (IoT), and artificial intelligence (AI) has accelerated the urgent need for data processing, data storage, and information transmission systems. Global data volume is growing rapidly, leading to a dramatic increase in the number, scale, and computing density of data centers, and consequently, a rapid increase in energy consumption. By 2030, the energy demand of data centers is projected to reach 3000 terawatt-hours. This massive power consumption also translates to enormous cooling demands. Data center heat dissipation bottlenecks include two aspects: the energy efficiency of the cooling system and the heat dissipation efficiency of high-power equipment. Adopting efficient cooling methods to reduce cooling system energy consumption is one of the effective ways to save energy in data centers. Furthermore, traditional air cooling methods are no longer sufficient to meet the rapidly growing cooling demands of data centers accompanying the surge in computing power. Many companies and academics currently use liquid cooling to reduce the cooling load of data centers, but with the rapid development of the AI ​​field, even indirect liquid cooling, i.e., cold plate cooling, cannot meet the cooling needs of some high-power, high-energy-density electronic devices. Therefore, direct immersion cooling methods are being widely studied. Immersion cooling systems are divided into single-phase and two-phase types. Compared to single-phase immersion cooling, two-phase immersion cooling systems, which utilize the latent heat conduction of phase change, can handle the cooling requirements of high-power electronic devices exceeding 200W / cm2. Due to its direct immersion characteristic, it reduces the pumping work generated during the heat exchange process. At the same time, because the immersion medium can remove a large amount of heat without changing its temperature, the cooling system does not require a large temperature difference during heat dissipation, which greatly reduces the energy efficiency of the cooling system. Furthermore, since the electronic devices are directly immersed in the medium, the noise and danger of the system are also greatly reduced.

[0003] In current research on immersion cooling, two crucial evaluation parameters exist: critical heat flux (CHF) and heat transfer coefficient (HTC). These are typically achieved by modifying the heat source surface through methods such as etching, deposition, electroplating, and self-assembly to alter surface roughness and hydrophilicity / hydrophobicity, thereby changing parameters like bubble nucleation rate and detachment diameter, effectively enhancing CHF and HTC. Hydrophilicity / hydrophobicity significantly impacts bubble activation and nucleation on the heat source surface. Before the heat source temperature reaches saturation, only sensible heat transfer occurs, and bubbles do not form. Using a hydrophobic composite heat source surface promotes bubble formation, thus lowering the onset of boiling (ONB) and improving the system's initial response efficiency. After modal boiling occurs, the working fluid removes heat from the heat source through the latent heat of phase change. At this point, the hydrophilic surface facilitates rapid liquid film replenishment, further increasing CHF. Therefore, dynamically adjusting the hydrophilicity / hydrophobicity of the heat source surface according to different boiling stages can effectively improve the cooling efficiency and response rate of the immersion cooling system. On the other hand, in most current applications of immersion cooling systems, the heat removed by the cooling medium is directly dissipated to the environment or cooling tower without being utilized. This also results in exergy loss in the cooling system, thereby reducing the energy efficiency of the cooling system. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a data center immersion liquid cooling system based on an adaptive coating, which can passively adjust its own characteristics according to different stages of boiling to improve cooling capacity and improve the energy utilization efficiency of the immersion cooling system.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] This invention utilizes the specific spectral activation properties of TiO2 / SiO2 coatings and the thermoluminescent characteristics of thermoluminescent materials. Through the heat energy generated by the immersion cooling system itself, the thermoluminescent material is excited to produce visible or ultraviolet light. Since the TiO2 / SiO2 coating itself is hydrophobic, it can transform into a superhydrophilic film under this spectral irradiation. This achieves a dynamic adaptive regulation effect, reducing ONB in ​​the initial boiling stage and increasing CHF during the nucleate boiling stage. It effectively improves the operating efficiency, cooling rate, and upper limit of the cooling load of the immersion cooling system.

[0007] This invention provides a data center immersion liquid cooling system based on an adaptive coating, comprising: an outdoor cooling supply unit, a room-side air cooling unit, and a rack-side immersion cooling unit;

[0008] The cabinet-side immersion cooling unit includes: a cabinet, a motherboard, an adaptive coating, a liquid cooling plate, a thermoluminescent material, a heat exchanger one, and a heat exchanger two;

[0009] The data center comprises multiple server racks, with the motherboards within each rack being the primary cooling source. The motherboards are immersed in a cooling medium within the rack. As the cooling medium heats up, it condenses on the surface of a liquid cooling plate. The condensed liquid drips back into the pool for replenishment. The cooling medium in the liquid cooling plate carries away heat and flows into heat exchanger one below the thermoluminescent material, causing the thermoluminescent material to emit visible or ultraviolet light, which then illuminates the adaptive coating on the motherboard surface, enhancing the pool's boiling. The remaining heat then flows into heat exchanger two, transferring heat to heat exchanger three. The cooled liquid is then recirculated back into the liquid cooling plate at the top of the rack.

[0010] The room-side air cooling unit is used to remove excess heat generated by LED lights and other pumps. The room-side air cooling unit includes: a fan, an air inlet, and an air outlet. Outdoor fresh air is sent into the room by the action of the fan and enters the room through the air inlet on the floor of the data center. Hot air is discharged from the top air outlet under the action of forced convection and thermal pressure, and finally discharged to the outside through the air outlet. The LED lights on the light panel provide spectral energy for the thermoluminescent material.

[0011] The outdoor cooling supply unit includes a cooling tower and a cooling fan. The final source of cooling is the cooling tower. Driven by the second water pump, chilled water flows into the cooling tower, and the heat is carried away by the cooling fan.

[0012] Furthermore, during data center operation, the motherboard generates heat, causing the cooling medium in the pool to heat up. Once it reaches saturation temperature, the low-boiling-point cooling medium (such as fluorinated liquid) undergoes a phase change. The cooling medium absorbs the heat generated by the motherboard but its temperature remains unchanged. Nucleation boiling occurs on the surface of the motherboard, generating bubbles. Under the influence of pressure difference and buoyancy, these bubbles rise to the surface of the cooling medium, reaching the vapor-phase condensation zone. They condense on the surface of the liquid cooling plate, transferring heat to the plate. The condensed liquid then drips back into the pool for replenishment. After the liquid cooling plate removes the heat, the cooling medium flows into heat exchanger one below the thermoluminescent material, transferring some heat to the material and causing it to emit visible or ultraviolet light. This light then irradiates the adaptive coating on the motherboard surface, altering its hydrophilicity and hydrophobicity, thereby enhancing pool boiling. Subsequently, the remaining heat, driven by pump one, flows into heat exchanger two, transferring heat to heat exchanger three. The cooled liquid then recirculates back into the liquid cooling plate at the top of the rack, continuously removing the heat generated by the pool boiling cycle.

[0013] Furthermore, the liquid cooling plate is a cold plate or microchannel cold plate used in conventional data center indirect liquid cooling systems; the adaptive coating is a composite coating that can respond to the excitation spectrum of thermoluminescent materials, and the adaptive coating is a TiO2 or SiO2 coating.

[0014] Furthermore, the adaptive coating is generally hydrophobic, but it can rapidly transform into superhydrophilic after being irradiated with visible or ultraviolet light. After the irradiation stops, it will slowly revert to hydrophobicity. Utilizing this principle, during the initial boiling stage of the cooling medium from a single phase to a gas-liquid two phase, when the temperature of the medium in the pool is low and has not reached the excitation temperature of the thermoluminescent material, and there is no visible or ultraviolet light irradiation, the adaptive coating is hydrophobic. This is conducive to the rapid nucleation and aggregation of bubbles, which can effectively reduce the boiling initiation temperature. When the motherboard temperature reaches or exceeds the saturation temperature, and supercooling or saturated boiling occurs, the heat is rapidly carried away by the liquid cooling plate due to the phase change of the cooling medium, condenses on the surface of the liquid cooling plate, and drips back into the pool. This is the internal pool boiling cycle of the cabinet.

[0015] Furthermore, heat is continuously supplied from the liquid-cooled plate into heat exchanger one. Once the temperature reaches the excitation temperature of the thermoluminescent material, it emits ultraviolet or visible light. Simultaneously, due to the bubbles generated by pool boiling, the excitation light is refracted by the bubbles and irradiates the adaptive coating on the motherboard surface, transforming it into a superhydrophilic surface. Since nucleation boiling is occurring on this surface, the hydrophilic surface facilitates timely replenishment of the liquid phase, increasing the system's critical heat flux density. This invention, through a passive hydrophilic / hydrophobic conversion mechanism based on a single coating, effectively reduces the initial boiling temperature of pool boiling and increases the critical heat flux density. This is beneficial for the rapid response and improved cooling efficiency of data center immersion liquid cooling systems.

[0016] Furthermore, the cabinet-side immersion cooling unit also includes a cooling medium spray nozzle and a cooling chamber; the cooling chamber includes: a fan, a condenser coil, a condenser coil, a water pump, a water pump, a heat exchanger, and a liquid spray nozzle; the cooling tower provides the final cooling capacity to the cooling chamber; the cabinet-side immersion cooling unit does not include a liquid cooling plate;

[0017] Without liquid cooling plates to block the heat, the thermoluminescent material is directly installed on the top of the cabinet, maximizing heat transfer efficiency.

[0018] Furthermore, the vapor-phase cooling medium is drawn away by fan two and sent to condenser coil one in the cooling chamber. The chilled water in the cooling chamber is sprayed out from heat exchanger one by water pump one through the cooling medium spray nozzle. Under the action of spray evaporation cooling, the vapor-phase cooling medium is pre-cooled in condenser coil one. At this time, part of the vapor-phase cooling medium condenses into liquid phase and then flows into condenser coil two. The cooling water sprayed from the liquid spray nozzle accumulates at the bottom of the cooling chamber to form accumulated liquid. The liquid cooling water covers condenser coil two and condenses it a second time. At this time, the cooling medium in condenser coil two is completely condensed into liquid phase. Driven by water pump one, it flows back into the bottom of the cabinet and is sprayed into the gap between the motherboards through the cooling medium spray nozzle to replenish the boiling pool.

[0019] Furthermore, the nozzle angle of the cooling medium spray nozzle is the same as the rising angle of the liquid cooling medium, which can play a heat transfer enhancement role similar to fluid boiling; at the same time, the upward sprayed liquid flow can prevent the accumulation of bubbles between two adjacent main plates, effectively delay the time of film boiling, force convection to enhance liquid replenishment, and push the bubbles to move upward, quickly remove heat, and increase the critical heat flux density.

[0020] Furthermore, the heat from heat exchanger one is removed by heat exchanger two, and the final source of cooling is the cooling tower. Driven by water pump three, chilled water flows into the cooling tower, and the heat is carried away by the cooling fan.

[0021] Furthermore, the room-side air cooling unit removes excess heat generated by the LED lights and other pumps. Outdoor fresh air is delivered into the room by the action of fan three, entering the room through the air inlet on the floor of the data center. Hot air is discharged from the top air outlet under the action of forced convection and thermal pressure, and finally discharged outdoors through the exhaust vent.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) It can passively adjust its own characteristics according to different stages of boiling to improve cooling capacity; the adaptive control mode of the system can passively adjust its own boiling characteristics according to different cold end temperatures at different stages of boiling to improve the initial thermal response capability and cooling capacity of the system in the modal boiling stage; by combining the saturation temperature of the low boiling point immersion working fluid with the thermoluminescence excitation temperature, a unique energy utilization method for the immersion cooling system of the data center is proposed.

[0024] (2) It can improve the energy utilization efficiency of the immersion cooling system; the thermoluminescent material is adapted to the charging and discharging light mode of the data center. When the LED lights are used for illumination, the thermoluminescent material absorbs the visible or ultraviolet light. After being excited by the residual heat of the immersion cooling system, it releases the light and irradiates the TiO2 / SiO2 coating, thus regulating its hydrophilicity and hydrophobicity; the thermoluminescent material is coupled with the immersion spray cooling unit; the evaporation working fluid is extracted and condensed outdoors through a combination of evaporation cooling and liquid cooling, and the cooling working fluid is sent back to the liquid phase of the immersion spray cooling unit, forming a cyclic mode of spraying the bubble rising path and the heat source sidewall; this invention effectively reduces the initial boiling temperature of the pool boiling and increases the critical heat flux density by changing the hydrophilicity and hydrophobicity passive mechanism based on a single coating. This is beneficial to the rapid response and cooling efficiency improvement of the data center immersion liquid cooling system. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the data center immersion liquid cooling system based on adaptive coating in Example 1;

[0026] Figure 2This is a schematic diagram of the cabinet-side immersion cooling unit in Example 1;

[0027] Figure 3 This is a schematic diagram of the data center immersion liquid cooling system based on adaptive coating in Example 2;

[0028] Figure 4 This is a schematic diagram of the cabinet-side immersion cooling unit in Example 2.

[0029] Attached reference numerals: 1. Data center; 2. Motherboard; 3. Cooling medium; 4. Liquid cooling plate; 5. Cabinet; 6. Thermoluminescent material; 7. Heat exchanger one; 8. Water pump one; 9. Heat exchanger two; 10. Heat exchanger three; 11. Water pump two; 12. Cooling tower; 13. Cooling fan; 14. Fan one; 15. Air inlet; 16. Air outlet; 17. Exhaust vent; 18. Light panel; 19. LED light; 20. Vapor phase condensation zone; 21. Adaptive coating; 23. Fan two; 24. Condensation coil one; 25. Condensation coil two; 26. Accumulated liquid; 27. Cooling medium spray nozzle; 28. Liquid spray nozzle; 29. ​​Cooling chamber; 30. Water pump three; 31. Fan three. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0031] Example 1

[0032] This embodiment provides a data center immersion liquid cooling system based on an adaptive coating, such as... Figure 1 As shown, it includes: an outdoor cooling supply unit, a room-side air cooling unit, and a cabinet-side immersion cooling unit;

[0033] like Figure 2 As shown, the cabinet-side immersion cooling unit includes: cabinet 5, motherboard 2, adaptive coating 21, liquid cooling plate 4, thermoluminescent material 6, heat exchanger 1 7 and heat exchanger 2 9;

[0034] Data center 1 includes multiple server racks 5. The motherboards 2 inside the server racks 5 are the main cooling targets. The motherboards 2 are immersed in the cooling medium 3 inside the server racks 5. After the cooling medium 3 heats up, it condenses on the surface of the liquid cooling plate 4. The condensed liquid drips back into the pool for replenishment. After the liquid cooling plate 4 carries away the heat, the cooling medium 3 flows into heat exchanger 7 below the thermoluminescent material 6, causing the thermoluminescent material 6 to emit visible or ultraviolet light, which then irradiates the adaptive coating 21 on the surface of the motherboard 2, enhancing the boiling of the pool. Subsequently, the remaining heat flows into heat exchanger 9, which transfers the heat to heat exchanger 10. The cooled liquid is then recirculated into the liquid cooling plate 4 at the top of the server racks 5.

[0035] The room-side air cooling unit is used to remove excess heat generated by the LED lights 19 and other pumps. The room-side air cooling unit includes: a fan 14, an air inlet 15, and an air outlet 17. Outdoor fresh air is sent into the room by the fan 14 and enters the room through the air inlet 15 on the ground of the data center 1. Hot air is discharged from the top air outlet 16 under the action of forced convection and thermal pressure, and finally discharged to the outside through the air outlet 17. The LED lights 19 on the light panel 18 provide a spectral energy source for the thermoluminescent material 6.

[0036] The outdoor cooling supply unit includes a cooling tower 12 and a cooling fan 13. The final source of cooling is the cooling tower 12. Driven by the second water pump 11, chilled water flows into the cooling tower 12, and the heat is carried away by the cooling fan 13.

[0037] In a specific implementation, when the data center 1 is running, the motherboard 2 generates heat, causing the cooling medium 3 in the pool to heat up. After reaching saturation temperature, the low-boiling-point cooling medium 3 (such as fluorinated liquid) undergoes a phase change. The cooling medium 3 absorbs the heat generated by the motherboard 2 but its temperature remains unchanged. Nucleation boiling occurs on the surface of the motherboard 2, generating bubbles. Under the action of pressure difference and buoyancy, the bubbles rise to the surface of the cooling medium 3 and reach the gas phase condensation zone 20, where they condense on the surface of the liquid cooling plate 4, transferring heat to the liquid cooling plate 4. The condensed liquid medium drips back into the pool for replenishment. After the liquid cooling plate 4 removes the heat, the cooling medium 3 flows into the heat exchanger 7 below the thermoluminescent material 6, transferring some of the heat to the thermoluminescent material 6, causing it to emit visible or ultraviolet light, which then irradiates the adaptive coating 21 on the surface of the motherboard 2, changing its hydrophilicity and hydrophobicity, thereby enhancing pool boiling. Subsequently, the remaining heat flows into the heat exchanger 9 driven by the water pump 8, transferring the heat to the heat exchanger 10. The cooled liquid is then recirculated into the liquid cooling plate 4 at the top of the cabinet 5, continuously removing the heat generated by the pool boiling cycle.

[0038] In a specific embodiment, the liquid cooling plate 4 is a cold plate or microchannel cold plate used in conventional data center indirect liquid cooling systems; the adaptive coating 21 is a composite coating that can respond to the excitation spectrum of thermoluminescent materials, and the adaptive coating 21 is a TiO2 or SiO2 coating.

[0039] In a specific embodiment, the adaptive coating 21 is generally hydrophobic. After being irradiated with visible or ultraviolet light, it can quickly transform into superhydrophilic. After the irradiation stops, it will slowly return to hydrophobicity. Utilizing this principle, during the initial boiling stage of the cooling medium 3 from a single phase to a gas-liquid two phase, the temperature of the medium in the pool is low and has not reached the excitation temperature of the thermoluminescent material 6. There is no visible or ultraviolet light irradiation. The adaptive coating 21 is hydrophobic, which is conducive to the rapid nucleation and aggregation of bubbles and can effectively reduce the boiling initiation temperature. When the temperature of the main board 2 reaches or exceeds the saturation temperature and supercooling or saturated boiling occurs, the heat is quickly carried away by the liquid cooling plate 4 due to the phase change of the cooling medium 3. It condenses on the surface of the liquid cooling plate 4 and drips back into the pool. This is the boiling cycle in the pool inside the cabinet 5.

[0040] In a specific implementation, heat is continuously supplied from the liquid cooling plate 4 into the heat exchanger 7. Once the temperature reaches the excitation temperature of the thermoluminescent material 6, it emits ultraviolet or visible light. Simultaneously, due to the bubbles generated by pool boiling, the excitation light is refracted by the bubbles and irradiates the adaptive coating 21 on the surface of the main board 2, transforming it into a superhydrophilic surface. Since nucleation boiling is occurring on this surface, the hydrophilic surface facilitates timely replenishment of the liquid phase, increasing the system's critical heat flux density. This invention, through a passive hydrophilic / hydrophobic conversion mechanism based on a single coating, effectively reduces the initial boiling temperature of pool boiling and increases the critical heat flux density. This is beneficial for the rapid response and improved cooling efficiency of the data center immersion liquid cooling system.

[0041] Example 2

[0042] Compared with Example 1, such as Figure 3 , 4 As shown, the cabinet-side immersion cooling unit also includes a cooling medium spray nozzle 27 and a cooling chamber 29; the cooling chamber 29 includes: a fan 14, a condenser coil 24, a condenser coil 25, a water pump 8, a water pump 30, a heat exchanger 7, and a liquid spray nozzle 28; the cooling tower 17 provides the final cooling capacity to the cooling chamber 14; the cabinet-side immersion cooling unit does not include the liquid cooling plate 4;

[0043] Without the liquid cooling plate 4 to block it, the thermoluminescent material 6 is directly installed on the top of the cabinet 5, maximizing the heat transfer efficiency.

[0044] like Figure 3As shown, in a specific embodiment, the gaseous cooling medium 3 is drawn away by the second fan 23 and sent to the condenser coil 24 in the cooling chamber 29. The cold water in the cooling chamber 29 is sprayed out from the heat exchanger 7 by the water pump 8 through the cooling medium spray nozzle 27. Under the action of spray evaporative cooling, the gaseous cooling medium 3 is pre-cooled in the condenser coil 24. At this time, part of the gaseous cooling medium 3 condenses into liquid and then flows into the second condenser coil 25. The cooling water sprayed from the liquid spray nozzle 28 accumulates at the bottom of the cooling chamber 29 to form the accumulated liquid 26. The liquid cooling water covers the second condenser coil 25 and condenses it again. At this time, the cooling medium 3 in the second condenser coil 25 is completely condensed into liquid. Driven by the water pump 8, it flows back into the bottom of the cabinet 5 and is sprayed into the gap between the motherboards 2 through the cooling medium spray nozzle 27 to replenish the boiling pool.

[0045] In a specific implementation, the nozzle angle of the cooling medium spray nozzle 27 is the same as the rising angle of the liquid cooling medium, which can play a heat exchange enhancement effect similar to flow boiling; at the same time, the upward sprayed liquid flow can prevent the accumulation of bubbles between two adjacent main plates, effectively delay the time of film boiling, force convection to enhance liquid replenishment, and push the bubbles to move upward, quickly remove heat, and increase the critical heat flux density.

[0046] In a specific implementation, the heat from heat exchanger 7 is removed by heat exchanger 9, and the final source of cooling is cooling tower 12. Driven by water pump 30, chilled water flows into cooling tower 12, and the heat is carried away by cooling fan 13.

[0047] In a specific implementation, the room-side air cooling unit removes excess heat generated by the LED lights 19 and other pumps. Outdoor fresh air is delivered into the room by the action of the fan 31 and enters the room through the air inlet 15 on the ground of the data center 1. Hot air is discharged from the top air outlet 16 under the action of forced convection and thermal pressure, and finally discharged to the outside through the exhaust outlet 17.

[0048] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0049] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. An adaptive coating based data center immersion liquid cooling system, characterized in that, include: Outdoor cooling supply unit, room-side air cooling unit, and rack-side immersion cooling unit; The cabinet-side immersion cooling unit includes: cabinet (5), motherboard (2), adaptive coating (21), liquid cooling plate (4), thermoluminescent material (6), heat exchanger one (7) and heat exchanger two (9); the adaptive coating (21) is a composite coating that can respond under the excitation spectrum of thermoluminescent material, and the adaptive coating (21) is a TiO2 or SiO2 coating. The data center (1) includes multiple cabinets (5). The motherboard (2) is immersed in the cooling medium (3) inside the cabinet (5). After the cooling medium (3) is heated, it condenses on the surface of the liquid cooling plate (4). The condensed liquid drips back into the pool for replenishment. Heat is continuously sent from the liquid cooling plate (4) to the heat exchanger (7) below the thermoluminescent material (6), causing the thermoluminescent material (6) to emit visible or ultraviolet light, which then irradiates the adaptive coating (21) on the surface of the motherboard (2) to enhance the boiling of the pool. Subsequently, the remaining heat flows into the heat exchanger (9) and transfers the heat to the heat exchanger (10). The cooled liquid is recirculated back into the liquid cooling plate (4) at the top of the cabinet (5). The room-side air cooling unit is used to remove excess heat generated by the LED lights (19) and water pump (8) located in the room. The room-side air cooling unit includes: fan (14), air inlet (15), and air outlet (17). Outdoor fresh air is sent into the room by the action of fan (14), enters the room through the air inlet (15) on the ground of the data center (1), and hot air is discharged from the top air outlet (16) and finally discharged to the outside through the air outlet (17). The outdoor cooling supply unit includes a cooling tower (12), a cooling fan (13), and a heat exchanger (10). The heat exchanger (10) is connected to the cooling tower (12), and the final source of cooling is the cooling tower (12). Chilled water flows into the cooling tower (12), and the heat is carried away by the cooling fan (13).

2. The adaptive coating based data center immersion liquid cooling system of claim 1, wherein, During operation of the data center (1), the motherboard (2) generates heat, which raises the temperature of the cooling medium (3) in the pool. After reaching the saturation temperature, the low-boiling-point cooling medium (3) undergoes a phase change. The cooling medium (3) absorbs the heat generated by the motherboard (2) but its temperature remains unchanged. Nucleation boiling occurs on the surface of the motherboard (2), generating bubbles. Under the action of pressure difference and buoyancy, the bubbles rise to the surface of the cooling medium (3) and reach the vapor phase condensation zone (20). They condense on the surface of the liquid cooling plate (4) and transfer the heat to the liquid cooling plate (4). The condensed liquid medium drips back into the pool for replenishment. The liquid cooling plate (4) carries the heat away from the pool. After the cooling medium (3) flows into heat exchanger 1 (7) below the thermoluminescent material (6), it transfers some of the heat to the thermoluminescent material (6), causing the thermoluminescent material (6) to emit visible or ultraviolet light, which then shines on the adaptive coating (21) on the surface of the motherboard (2), changing its hydrophilicity and hydrophobicity, thereby enhancing the pool boiling. Subsequently, the remaining heat flows into heat exchanger 2 (9) driven by water pump 1 (8), transferring the heat to heat exchanger 3 (10). The cooled liquid is then recirculated into the liquid cooling plate (4) at the top of the cabinet (5), continuously carrying away the heat generated by the pool boiling cycle.

3. The adaptive coating based data center immersion liquid cooling system of claim 1, wherein, The liquid cooling plate (4) is a cold plate or microchannel cold plate used in conventional data center indirect liquid cooling systems.

4. The adaptive coating based data center immersion liquid cooling system of claim 1, wherein, The adaptive coating (21) is generally hydrophobic. After being irradiated by visible or ultraviolet light, it can quickly become superhydrophilic. After the irradiation stops, it will slowly return to hydrophobicity. In the boiling stage of the cooling medium (3) from single phase to gas-liquid two phase, the temperature of the medium in the pool is low and has not reached the excitation temperature of the thermoluminescent material (6). There is no visible or ultraviolet light irradiation. The adaptive coating (21) is hydrophobic, which is conducive to the rapid nucleation and aggregation of bubbles and can effectively reduce the boiling start temperature. When the temperature of the main board (2) reaches or exceeds the saturation temperature and supercooling or saturated boiling occurs, the heat is quickly carried away by the liquid cooling plate (4) due to the phase change of the cooling medium (3). It condenses on the surface of the liquid cooling plate (4) and drips back into the pool. This is the boiling cycle in the pool of the cabinet (5).

5. The adaptive coating based data center immersion liquid cooling system of claim 1, wherein, Heat is continuously sent from the liquid cooling plate (4) into the heat exchanger (7). After the temperature reaches the excitation temperature of the thermoluminescent material (6), it excites ultraviolet or visible light. At the same time, due to the bubbles generated by the boiling of the pool, the excitation light shines on the adaptive coating (21) on the surface of the main board (2) under the refraction of the bubbles, making it into a superhydrophilic surface. Since nucleation boiling is taking place on its surface at this time, the hydrophilic surface is conducive to the timely replenishment of the liquid phase, and the critical heat flux density of the system is increased.

6. The adaptive coating based data center immersion liquid cooling system of claim 1, wherein, The cabinet-side immersion cooling unit also includes a cooling medium spray nozzle (27) and a cooling chamber (29); the cooling chamber (29) includes: a fan (14), a condenser coil (24), a condenser coil (25), a water pump (8), a water pump (30), a heat exchanger (7), and a liquid spray nozzle (28); the cabinet-side immersion cooling unit does not include a liquid cooling plate (4); Without the liquid cooling plate (4) to block it, the thermoluminescent material (6) is directly installed on the top of the cabinet (5) to maximize the heat transfer efficiency.

7. The adaptive coating based data center immersion liquid cooling system of claim 6, wherein, The gaseous cooling medium (3) is drawn away by the second fan (23) and sent to the first condenser coil (24) in the cooling chamber (29). The cold water in the cooling chamber (29) is sprayed out from the cooling medium spray nozzle (27) from the first heat exchanger (7) driven by the first water pump (8). Under the action of spray evaporative cooling, the gaseous cooling medium (3) is pre-cooled in the first condenser coil (24). At this time, part of the gaseous cooling medium (3) condenses into liquid and then flows into the second condenser coil (25). In the middle, the cooling water sprayed from the liquid spray nozzle (28) accumulates at the bottom of the cooling chamber (29) to form the accumulated liquid (26). The liquid cooling water covers the second condenser coil (25) and condenses it a second time. At this time, the cooling medium (3) in the second condenser coil (25) is completely condensed into liquid phase. Driven by the first water pump (8), it flows back into the bottom of the cabinet (5) and is injected into the gap between the motherboard (2) through the cooling medium spray nozzle (27) to replenish the boiling pool.

8. The adaptive coating based data center immersion liquid cooling system of claim 7, wherein, The nozzle angle of the cooling medium spray nozzle (27) is the same as the rising angle of the liquid cooling medium, which can play a heat exchange enhancement role similar to flow boiling. At the same time, the upward sprayed liquid flow can prevent the bubbles from accumulating between two adjacent main plates, effectively delay the time of film boiling, force convection to enhance liquid replenishment, and push the bubbles to move upward, quickly remove heat, and increase the critical heat flux density.

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