Immersed cooling and power generation system based on loop heat pipe

Abstract

The invention discloses an immersed cooling and power generation system based on a loop heat pipe, and relates to the technical field of loop heat pipe heat dissipation, liquid cooling server heat dissipation and thermoelectric power generation, the immersed cooling and power generation system comprises a server case, the loop heat pipe, a thermoelectric power generation device and a heat dissipation device, the server case comprises a case cover, a main case body and a heat source; the loop heat pipe comprises an evaporator, a steam pipeline, a condenser and a liquid pipeline; the thermoelectric power generation device comprises a thermoelectric power generation sheet and a substrate; phase change heat transfer in the loop heat pipe and pool boiling heat transfer on the surface of the evaporator are carried out at the same time, so that the comprehensive heat dissipation capacity of immersed cooling is greatly improved; the built-in condenser cools the loop heat pipe and the temperature difference power generation device, and meanwhile, the working fluid in the machine box can be cooled through a fin structure on the surface; the thermoelectric power generation device can generate power continuously and stably by means of the temperature difference provided by the heat from the loop heat pipe and the cold from the liquid cooling plate.

Description

Technical Field

[0001] The present invention relates to the technical fields of loop heat pipe heat dissipation, liquid-cooled server heat dissipation and thermoelectric power generation, and specifically relates to an immersion cooling and power generation system based on a loop heat pipe. Background Art

[0002] With the development of artificial intelligence, people's demand for large language models is increasing day by day, which puts strict requirements on the computing power of chips. In order to improve the computing performance of chips, the scale of chips is constantly increasing, and the heat generation is also increasing accordingly. In 2025, NVIDIA released a new generation of AI graphics processor B200, whose computing speed is 30 times faster than the previous generation B100 chip, while the power consumption of a single chip is as high as 1000W. The safe operating temperature of the chip is only 85°C. Above this temperature, the computing performance of the chip will decline, and even permanent damage will be caused. Therefore, improving the heat dissipation capacity of cooling equipment is very important for the safe operation of the chip.

[0003] The heat dissipation capacity of the traditional air-cooled structure can no longer meet the current heat generation of chips; the traditional water-cooled structure has strong heat transfer ability but is complex in structure, has moving parts, so its reliability is low, and there is a risk of working fluid leakage. Immersion cooling technology uses a cooling working fluid to directly contact the heat source to greatly reduce the thermal resistance, thereby achieving efficient heat transfer.

[0004] A loop heat pipe is an efficient two-phase heat transfer device, which has the advantages of passive operation, high reliability and flexible structure layout. A loop heat pipe consists of an evaporator, a vapor pipeline, a condenser and a liquid pipeline, and is in a vacuum state inside and filled with a certain mass of working fluid. The working fluid absorbs heat in the evaporator and turns into steam, reaches the condenser through the vapor pipeline to release heat, condenses into liquid, and then returns to the evaporator through the liquid pipeline to absorb heat again. Although traditional heat pipes and heat spreaders are also two-phase passive heat transfer devices, the gas phase and the liquid phase will contact each other and cause a carry-over phenomenon, resulting in a lower heat transfer limit for these two devices and being unable to be applied to high heat load scenarios. The structure with a capillary wick penetrating the evaporation section and the condensation section also limits the heat transfer distance. The gas phase channel and the liquid phase channel in the loop heat pipe are separated from each other, thus eliminating the occurrence of the carry-over phenomenon. This makes the heat transfer limit of the loop heat pipe higher, and the capillary wick only exists in the evaporator, making the heat transfer distance of the loop heat pipe longer, and the evaporation section and the condensation section can be flexibly arranged.

[0005] In addition to improving the heat dissipation capacity of the cooling equipment, the power consumption of the cooling equipment also needs to be considered. According to the report of the International Energy Agency, the total power consumption of global data centers in 2022 was 460 TW·h, accounting for 2% of the global total power consumption. It is expected that the total power consumption of global data centers will exceed 1000 TW·h in 2026. Among the various systems in the data center, the energy consumption of the cooling equipment accounts for as high as 38%. In the context of carbon peaking and carbon neutrality, it is crucial to ensure chip heat dissipation while reducing the energy consumption of the cooling equipment. Recycling the waste heat released by the chip for power generation is a method to reduce the energy consumption of the equipment. Among them, the thermoelectric power generation technology is a waste heat recovery technology that directly converts thermal energy into electrical energy using the Seebeck effect. The temperature difference between the hot end and the cold end of the thermoelectric power generation chip will drive the carriers to move from the hot end to the cold end and accumulate at the cold end, thus generating a potential difference inside the material and generating electricity. The thermoelectric power generation chip has the advantages of high reliability, compact structure, and no noise.

[0006] Chinese Patent CN114340332B discloses an immersion cooling system. This patent uses two heat transfer methods, natural convection heat transfer and water-cooled heat transfer, to improve the heat dissipation capacity of the server cabinet. However, the number of fans and fins used is relatively large, the structure is relatively complex, and the energy consumption is relatively high. In addition, this patent does not recover the waste heat generated by the chip. Chinese Patent CN115793819A discloses an immersion liquid-cooled server and its waste heat recovery system. This patent uses the vaporized immersion coolant to drive the steam turbine to rotate to achieve power generation. However, the pipeline layout of this device is complex, and the structures of the steam turbine and the generator will generate resistance to the circulation of the coolant. The steam flow rate overflowing from the pool boiling is slow, the rotation speed of the driven steam turbine is limited, and the power generation is also relatively limited. In addition, this patent does not improve the heat dissipation capacity of the immersion liquid cooling at all.

[0007] It can be seen that it is difficult to achieve both high-efficiency heat dissipation and low energy consumption at the same time. Focusing on heat dissipation may lead to high energy consumption of the equipment, while focusing on low energy consumption may lead to unsatisfactory heat dissipation effect. In view of this, how to further improve the heat dissipation capacity of the immersion chassis while maintaining low energy consumption is still one of the problems to be solved in this field. Summary of the Invention

[0008] Aiming at the above-mentioned disadvantages of the existing technology, the purpose of the present invention is to provide an immersion cooling and power generation system based on a loop heat pipe, which can achieve efficient heat dissipation of the server with low energy consumption.

[0009] To achieve the above object, the present invention provides the following technical solutions: An immersion cooling and power generation system based on a loop heat pipe, comprising a server chassis, a loop heat pipe, a thermoelectric power generation device, and a heat dissipation device. The server chassis includes a chassis cover, a main cabinet, and a heat source. The loop heat pipe includes an evaporator, a vapor pipeline, a condenser, and a liquid pipeline. The thermoelectric power generation device includes a thermoelectric power generation chip and a substrate. The heat dissipation device includes an internal condenser, a first hose, an external radiator, a second hose, a coolant pump, a third hose, and an external radiator fan.

[0010] Preferably, the chassis cover is closed with the main cabinet and sealed with an O-ring. The interior of the chassis is filled with a working fluid. A first communication port and a second communication port are provided on the right side of the main cabinet. A heat source is installed on the inner wall of the chassis. The vapor pipeline, the condenser, and the liquid pipeline together form a loop pipe and are connected. The evaporator is connected to the loop pipe to form a closed loop and is filled with a working fluid. The loop heat pipe can transfer a large amount of heat from the heat source to the heat dissipation device.

[0011] Preferably, the evaporator includes a bottom plate, an evaporator outlet, an evaporator inlet, a liquid filling port, a capillary structure, an upper cover, and surface sintered copper powder. The bottom plate and the upper cover are buckled. The capillary structure is placed between the bottom plate and the upper cover. The bottom plate, the capillary structure, and the upper cover are tightly sintered into one body. Then, the gap between the upper cover and the bottom plate is welded to ensure the sealing performance. The evaporator itself can be regarded as a temperature equalizing device, which expands the heat source area of a limited size into a large-area temperature equalizing heat source surface. A layer of surface sintered copper powder is sintered on the outer side of the upper cover and the side wall of the evaporator. The surface sintered copper powder can provide more nucleation sites for the pool boiling of the working fluid in the chassis, thereby transferring a large amount of heat from the heat source to the heat dissipation unit. The bottom surface of the evaporator is closely attached to the heat source on the inner wall of the chassis, and the interface gap is filled with an interface thermal conductive material. The capillary structure includes a sintered wire mesh main capillary core and a sintered wire mesh auxiliary capillary core. The lower surface of the sintered wire mesh main capillary core is attached to the bottom plate, and the upper surface is attached to the upper cover. One end of the sintered wire mesh auxiliary capillary core is attached to the sintered wire mesh main capillary core through a trapezoidal card slot, and the other end extends to the outlet of the condenser, with a length the same as that of the liquid pipeline. The sintered wire mesh auxiliary capillary core can provide additional capillary force to accelerate the rate of the working fluid flowing back to the evaporator. The sintered wire mesh main capillary core and the sintered wire mesh auxiliary capillary core are tightly sintered into one body. The evaporator outlet is welded to the vapor pipeline, and the evaporator inlet is welded to the liquid pipeline. The liquid filling port can be welded with a liquid filling pipe to perform vacuum pumping and liquid filling operations on the loop heat pipe.

[0012] Preferably, a groove is provided on one side of the substrate to cooperate with the condenser. The condenser is fitted into the groove on the substrate and soldered together to ensure good thermal conductivity. The other side of the substrate is attached to the hot end of the thermoelectric generator, and an interface thermal conductive material is filled in the interface gap. The thermoelectric power generation device continuously and stably generates electricity relying on the heat transferred by the loop heat pipe and the cold quantity transferred by the built-in condenser. The built-in condenser is installed inside the main box body, and the external radiator is installed outside the main box body. The built-in condenser includes fins, a liquid cooling plate, a Y-shaped three-way joint at the liquid cooling plate inlet, and a Y-shaped three-way joint at the liquid cooling plate outlet. The fins are attached to the outer side of the liquid cooling plate and soldered together to ensure good thermal conductivity. The liquid cooling plate is provided with a liquid cooling plate inlet, a liquid cooling plate outlet, and a coolant flow channel inside. The inner side of the liquid cooling plate is attached to the cold end of the thermoelectric generator, and an interface thermal conductive material is filled in the interface gap. The built-in condenser continuously absorbs the heat from the loop heat pipe and the working fluid inside the chassis.

[0013] Preferably, the two sides of the built-in condenser are symmetrically designed. Four round holes are provided on each of the two liquid cooling plates. The built-in condenser, the thermoelectric power generation device, and the condenser are fastened together by screws and nuts. The Y-shaped three-way joint at the liquid cooling plate inlet passes through the first communication port, one end is connected to the two symmetrically arranged liquid cooling plate inlets, and the other end is connected to the third hose. The connection is fixed with a clamp. The Y-shaped three-way joint at the liquid cooling plate outlet passes through the second communication port, one end is connected to the two symmetrically arranged liquid cooling plate outlets, and the other end is connected to the first hose. The connection is fixed with a clamp.

[0014] Preferably, the external radiator is provided with an external radiator inlet and an external radiator outlet. The coolant pump is provided with a coolant pump inlet and a coolant pump outlet. One end of the first hose is connected to the Y-shaped three-way joint at the liquid cooling plate outlet, and the other end is connected to the external radiator inlet. The connection is fixed with a clamp.

[0015] Preferably, one end of the second hose is connected to the external radiator outlet, and the other end is connected to the coolant pump inlet. The connection is fixed with a clamp. One end of the third hose is connected to the Y-shaped three-way joint at the liquid cooling plate inlet, and the other end is connected to the coolant pump outlet. The connection is fixed with a clamp.

[0016] Preferably, the external radiator fan faces the external radiator and is closely arranged. The external radiator dissipates the heat absorbed by the built-in condenser.

[0017] Preferably, the liquid cooling plate, the Y-shaped tee at the liquid cooling plate outlet, the first hose, the external radiator, the second hose, the coolant pump, the third hose, and the Y-shaped tee at the liquid cooling plate inlet form a closed loop, and the loop is filled with coolant.

[0018] A method of using an immersion cooling and power generation system based on a loop heat pipe, comprising the following steps:

[0019] S1: Evacuate the loop heat pipe, fill it with a certain amount of working fluid, and then clamp and seal the liquid filling pipe.

[0020] S2: Closely attach the loop heat pipe to the heat source, and fill the interface gap with an interface thermal conductive material.

[0021] S3: Close the server chassis cover and the main box body, fill the inside of the chassis with coolant as the working fluid, the liquid level of the coolant is lower than the lowest point of the built-in condenser, and the liquid level of the coolant is higher than the highest point of the evaporator.

[0022] S4: Fill the closed loop of the heat dissipation device with coolant.

[0023] S5: When working, turn on the coolant pump and the external radiator fan. The working fluid in the evaporator absorbs heat from the heat source and turns into steam, reaches the condenser through the steam pipeline, transfers the heat to the thermoelectric generation device, and then turns into liquid and returns to the evaporator through the liquid pipeline. The liquid cooling plate on the built-in condenser provides cooling for the thermoelectric generation device and indirectly cools the loop heat pipe. The thermoelectric generation device continuously generates electricity relying on the temperature difference provided by the heat from the condenser of the loop heat pipe and the cooling provided by the liquid cooling plate. The coolant in the server chassis absorbs heat from the surface of the evaporator and boils to generate steam, condenses on the fins of the built-in condenser and then returns. The circulating coolant in the built-in condenser absorbs heat from the steam and the loop heat pipe in the chassis and heats up, and is driven by the coolant pump to flow into the external radiator. The external radiator fan provides forced convection to cool the circulating coolant flowing through the external radiator.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] The loop heat pipe can transfer a large amount of heat from the heat source to the thermoelectric generation device and the heat dissipation device relying on its excellent heat transfer performance;

[0026] The evaporator of the loop heat pipe itself can be regarded as a kind of temperature equalizing device, expanding the limited heat source area into a large-area temperature equalized heat source surface on the outer surface of the entire evaporator, and then transferring a large amount of heat from the heat source to the heat dissipation device through the enhanced boiling effect and increased heat transfer area of the sintered copper powder on the outer side of the evaporator;

[0027] Greatly improve the comprehensive heat dissipation capacity of immersion cooling by simultaneously carrying out two methods: phase change heat transfer inside the loop heat pipe and pool boiling heat transfer on the surface of the evaporator;

[0028] While cooling the loop heat pipe and the thermoelectric power generation device, the built-in condenser can cool the working fluid inside the chassis through the fin structure on its surface;

[0029] The thermoelectric power generation device can continuously and stably generate electricity relying on the temperature difference provided by the heat from the loop heat pipe and the cold from the liquid cooling plate;

[0030] The loop heat pipe has the characteristic of passive operation, and applying it to the immersion cooling system will not increase additional energy consumption;

[0031] The combination of the loop heat pipe and immersion cooling can further improve the comprehensive heat dissipation capacity of server liquid cooling, while the thermoelectric power generation device can stably and continuously output electricity to reduce the energy consumption of cooling equipment, solving the problem that it is difficult to balance high heat dissipation and low energy consumption of servers. Description of the Drawings

[0032] Figure 1 It is a schematic structural diagram of the immersion cooling and power generation system based on the loop heat pipe of the present invention;

[0033] Figure 2 It is a schematic structural diagram of the server chassis in the present invention;

[0034] Figure 3 It is a schematic structural diagram of the loop heat pipe and the internal auxiliary wire mesh wick in the present invention;

[0035] Figure 4 It is a schematic structural diagram of the heat dissipation device in the present invention;

[0036] Figure 5 It is a schematic structural diagram of the evaporator in the present invention;

[0037] Figure 6 It is a schematic assembly diagram of the built-in condenser, the first hose and the third hose in the present invention;

[0038] Figure 7 It is a schematic assembly diagram of the first hose, the external radiator, the second hose, the coolant pump, the third hose and the external radiator fan in the present invention;

[0039] Figure 8 It is a schematic internal structure diagram of the liquid cooling plate in the present invention.

[0040] Reference Numerals in the Figures: 1, server chassis; 11, chassis cover; 12, main chassis body; 121, first communication port; 122, second communication port; 13, heat source; 2, loop heat pipe; 21, evaporator; 211, bottom plate; 212, liquid filling port; 213, capillary structure; 2131, sintered wire mesh capillary core; 2132, sintered wire mesh auxiliary capillary core; 214, upper cover; 215, surface sintered copper powder; 22, vapor pipeline; 221, evaporator outlet; 23, condenser; 24, liquid pipeline; 241, evaporator inlet; 3, thermoelectric power generation device; 31, thermoelectric power generation chip; 32, substrate; 4, heat dissipation device; 41, built-in condenser; 411, fin; 412, liquid cooling plate; 4121, liquid cooling plate inlet; 4122, liquid cooling plate outlet; 4123, coolant flow channel; 413, liquid cooling plate inlet Y-shaped tee; 414, liquid cooling plate outlet Y-shaped tee; 42, first hose; 43, external radiator; 431, external condenser inlet; 432, external condenser outlet; 44, second hose; 45, coolant pump; 451, coolant pump inlet; 452, coolant pump outlet; 46, third hose; 47, fan. Detailed Implementation Manner

[0041] Please refer to Figure 1-8 , the present invention provides a technical solution: an immersion cooling and power generation system based on a loop heat pipe, comprising: a server chassis 1, a loop heat pipe 2, a thermoelectric power generation device 3, and a heat dissipation device 4.

[0042] Referring to Figure 2 , the server chassis includes a chassis cover 11, a main chassis body 12, and a heat source 13. The chassis cover 11 is closed with the main chassis body 12 and sealed with an O-ring. The interior is filled with a working fluid. A first communication port 121 and a second communication port 122 are opened on the right side of the main chassis body, and the heat source 13 is installed on the inner wall of the chassis.

[0043] Referring to Figure 3 , the loop heat pipe includes an evaporator 21, a vapor pipeline 22, a condenser 23, and a liquid pipeline 24. The vapor pipeline 22, the condenser 23, and the liquid pipeline 24 together form a loop pipe and are connected. The evaporator 21 is connected to the loop pipe to form a closed loop, and the interior is filled with a working fluid.

[0044] Referring to Figure 5 , the evaporator 21 includes a bottom plate 211, an evaporator outlet 221, an evaporator inlet 241, a liquid filling port 212, a capillary structure 213, an upper cover 214, and a surface sintered copper powder 215. The bottom plate 211 and the upper cover 214 are buckled, the capillary structure 213 is placed between the bottom plate 211 and the upper cover 214, and the bottom plate 211, the capillary structure 213, and the upper cover 214 are tightly sintered into one body, and then the gap between the upper cover 214 and the bottom plate 211 is welded to ensure the sealing performance.

[0045] Reference Figure 5 On the upper cover and the outer side of the side wall of the evaporator 21, a layer of surface-sintered copper powder 215 is sintered. The surface-sintered copper powder 215 can provide more nucleation sites for the pool boiling of the working fluid in the chassis 1, thereby enhancing the heat transfer performance of the immersion cooling. The bottom surface of the evaporator 21 is attached to the heat source 13 on the inner wall of the chassis 1, and the interface gap is filled with an interface thermal conductive material.

[0046] Reference Figure 3 and Figure 5 The capillary structure 213 includes a sintered wire mesh main capillary core 2131 and a sintered wire mesh auxiliary capillary core 2132. The lower surface of the sintered wire mesh main capillary core 2132 is attached to the bottom plate 211, and the upper surface is attached to the upper cover 214. One end of the sintered wire mesh auxiliary capillary core 2132 is attached to the sintered wire mesh main capillary core 2131 through a trapezoidal card slot, and the other end extends to the outlet of the condenser 23, with the same length as the liquid pipeline 24. The sintered wire mesh auxiliary capillary core 2132 can provide additional capillary force to accelerate the rate of the working fluid returning to the evaporator 21. The sintered wire mesh main capillary core 2131 and the sintered wire mesh auxiliary capillary core 2132 are sintered tightly into one body.

[0047] Reference Figure 3 and Figure 5 The evaporator outlet 221 is welded to the steam pipeline 22, the evaporator inlet 241 is welded to the liquid pipeline 24, and the liquid filling port 212 can be welded with a liquid filling pipe to perform vacuum pumping and liquid filling operations on the loop heat pipe.

[0048] Reference Figure 1 The built-in condenser 31 is placed inside the main box body 12, and the external radiator 35 is placed outside the main box body 12.

[0049] Reference Figure 6 The thermoelectric power generation device 3 includes a thermoelectric power generation chip 31 and a substrate 32. On one side of the substrate 32, there is a groove for cooperating with the condenser 23. The condenser 23 is cooperated with the groove on the substrate 32 and soldered together to ensure good thermal conductivity. On the other side of the substrate 32, it is attached to the hot end of the thermoelectric power generation chip 31, and the interface gap is filled with an interface thermal conductive material.

[0050] Reference Figure 4 The heat dissipation device includes a built-in condenser 41, a first hose 42, an external radiator 43, a second hose 44, a coolant pump 45, a third hose 46, and an external radiator fan 47;

[0051] Reference Figure 6 and Figure 8, the built-in condenser includes fins 411, a liquid cooling plate 412, a Y-shaped tee 413 at the liquid cooling plate inlet, and a Y-shaped tee 414 at the liquid cooling plate outlet. The fins 411 are attached to the outside of the liquid cooling plate 412 and soldered together to ensure good thermal conductivity. The liquid cooling plate 412 is provided with a liquid cooling plate inlet 4121, a liquid cooling plate outlet 4122, and an internal coolant flow channel 4123. The inner side of the liquid cooling plate 412 is attached to the cold end of the thermoelectric generator 31, and an interface thermal conductive material is filled in the interface gap.

[0052] Refer to Figure 6 , both sides of the built-in condenser 41 are symmetrically designed. Four round holes are provided on each of the two liquid cooling plates 412. The built-in condenser 41, the thermoelectric power generation device 3, and the condenser 23 are fastened together with screws and nuts.

[0053] Refer to Figure 6 , the Y-shaped tee 413 at the liquid cooling plate inlet passes through the first communication port 121. One end is connected to the two symmetrically arranged liquid cooling plate inlets 4121, and the other end is connected to the third hose 46. The connection is fixed with a clamp.

[0054] Refer to Figure 6 , the Y-shaped tee 414 at the liquid cooling plate outlet passes through the second communication port 122. One end is connected to the two symmetrically arranged liquid cooling plate outlets 4122, and the other end is connected to the first hose 42. The connection is fixed with a clamp.

[0055] Refer to Figure 7 , the external radiator 43 is provided with an external radiator inlet 431 and an external radiator outlet 432. The coolant pump 45 is provided with a coolant pump inlet 451 and a coolant pump outlet 452.

[0056] Refer to Figure 7 , one end of the first hose 42 is connected to the Y-shaped tee 414 at the liquid cooling plate outlet, and the other end is connected to the external radiator inlet 431. The connection is fixed with a clamp.

[0057] Refer to Figure 7 , one end of the second hose 44 is connected to the external radiator outlet 432, and the other end is connected to the coolant pump inlet 451. The connection is fixed with a clamp.

[0058] Refer to Figure 7 , one end of the third hose 46 is connected to the Y-shaped tee 413 at the liquid cooling plate inlet, and the other end is connected to the coolant pump outlet 432. The connection is fixed with a clamp.

[0059] Refer to Figure 7 , the external radiator fan 47 faces the external radiator 43 and is closely arranged.

[0060] Refer to Figure 4, the liquid cooling plate 412, the Y-shaped three-way joint 414 at the liquid cooling plate outlet, the first hose 42, the external radiator 43, the second hose 44, the coolant pump 45, the third hose 46, and the Y-shaped three-way joint 413 at the liquid cooling plate inlet form a closed loop, and the loop is filled with coolant.

[0061] In the embodiment, the fins 411, the liquid cooling plate 412, and the substrate 32 are all made of aluminum alloy and nickel-plated on the surface. The evaporator 21, the steam pipeline 22, the condenser 23, and the liquid pipeline 24 are all made of red copper. The sintered wire main wick 2133 and the sintered wire auxiliary wick 2134 are both sintered with red copper wire meshes.

[0062] A usage method of an immersion cooling and power generation system based on a loop heat pipe includes the following steps:

[0063] S1: The loop heat pipe 2 is evacuated, filled with a certain amount of working fluid, and then the liquid filling pipe is clamped off and sealed.

[0064] S2: The loop heat pipe 2 is closely attached to the heat source 13, and the gap is filled with an interface thermal conductive material.

[0065] S3: The server chassis cover 11 is closed with the main box 12. The inside of the chassis 1 is filled with coolant as the working fluid. The height of the coolant liquid level is lower than the lowest point of the built-in condenser 31 and higher than the highest point of the evaporator 21.

[0066] S4: The closed loop of the heat dissipation device 4 is filled with coolant.

[0067] S5: When working, turn on the coolant pump 45 and the external radiator fan 47. The working fluid in the evaporator 21 absorbs heat from the heat source 13 and turns into steam, passes through the steam pipeline 22 to reach the condenser 23, and transfers the heat to the thermoelectric generation device 3, then turns into liquid and returns to the evaporator 21 through the liquid pipeline 24. The liquid cooling plate 412 on the built-in condenser 41 provides cooling for the thermoelectric generation device 3 and indirectly cools the loop heat pipe 2. The thermoelectric generation device 3 continuously generates electricity relying on the temperature difference provided by the heat from the loop heat pipe condenser 23 and the cooling from the liquid cooling plate 412. The coolant in the server chassis 1 absorbs heat from the surface sintered copper powder 216 of the evaporator 21, boils to generate steam, condenses on the fins 411 of the built-in condenser 41 and then flows back. The circulating coolant in the built-in condenser 41 absorbs heat from the steam in the chassis 1 and the loop heat pipe 2, heats up, and is driven by the coolant pump 45 to flow into the external radiator 43. The external radiator fan 47 provides forced convection to cool the circulating coolant flowing through the external radiator 43.

Claims

1. An immersion cooling and power generation system based on a loop heat pipe, comprising a server chassis, a loop heat pipe, a temperature difference power generation device and a heat dissipation device, characterized in that: The server chassis includes a chassis cover, a main chassis body and a heat source; the loop heat pipe includes an evaporator, a steam pipeline, a condenser and a liquid pipeline; the temperature difference power generation device includes a temperature difference power generation sheet and a substrate; the heat dissipation device includes a built-in condenser, a first hose, an external radiator, a second hose, a coolant pump, a third hose and an external radiator fan.

2. The immersion cooling and power generation system based on a loop heat pipe according to claim 1, characterized in that: The chassis cover is closed to the main box body and sealed with an O-ring, the inside of the chassis is filled with working fluid, the right side of the main box body is provided with a first connecting port and a second connecting port, a heat source is installed on the inner wall of the chassis, the steam pipeline, condenser and liquid pipeline together form a loop pipe and are connected, the evaporator is connected to the loop pipe and forms a closed loop, the inside is filled with working fluid, and the loop heat pipe can transfer a large amount of heat from the heat source to the heat dissipation device.

3. The immersion cooling and power generation system based on a loop heat pipe according to claim 2, characterized in that: The evaporator comprises a base plate, an evaporator outlet, an evaporator inlet, a liquid filling port, a capillary structure, an upper cover and surface sintered copper powder. The base plate and the upper cover are buckled together, and the capillary structure is placed between the base plate and the upper cover. The base plate, the capillary structure and the upper cover are tightly sintered into one, and then the gap between the upper cover and the base plate is welded to ensure the sealing. The evaporator itself can be regarded as a temperature equalizing device, which expands the heat source area of ​​a limited size into a large area of ​​uniform temperature heat source surface. A layer of surface sintered copper powder is sintered on the outer side of the upper cover and side wall of the evaporator. The surface sintered copper powder can provide more nucleation sites for pool boiling of the working fluid in the chassis, thereby transferring a large amount of heat from the heat source to the heat dissipation unit. The bottom surface of the evaporator is tightly fitted with the heat source on the inner wall of the chassis, and the interface The surface gap is filled with interface thermal conductive material, the capillary structure includes a sintered wire mesh main capillary core and a sintered wire mesh auxiliary capillary core, the lower surface of the sintered wire mesh main capillary core is bonded to the bottom plate, and the upper surface is bonded to the upper cover, one end of the sintered wire mesh auxiliary capillary core is bonded to the sintered wire mesh main capillary core through a trapezoidal slot, and the other end extends to the outlet of the condenser, and the length is the same as the liquid pipeline, the sintered wire mesh auxiliary capillary core can provide additional capillary force to accelerate the rate at which the working fluid flows back to the evaporator, the sintered wire mesh main capillary core and the sintered wire mesh auxiliary capillary core are tightly sintered into one, the evaporator outlet is welded to the steam pipeline, the evaporator inlet is welded to the liquid pipeline, the filling port can be welded to the filling pipe, and the loop heat pipe is vacuumed and filled with liquid.

4. The immersion cooling and power generation system based on a loop heat pipe according to claim 1, characterized in that: A groove matched with the condenser is provided on one side of the substrate, and the condenser is matched with the groove on the substrate and soldered together to ensure good thermal conductivity. The other side of the substrate is attached to the hot end of the temperature difference power generation sheet and the interface gap is filled with interface thermal conductive material. The temperature difference power generation device relies on the heat transferred by the loop heat pipe and the cold transferred by the built-in condenser to continuously and stably generate electricity. The built-in condenser is installed inside the main box, and the external radiator is installed outside the main box. The built-in condenser includes fins, a liquid cooling plate, a Y-shaped tee at the inlet of the liquid cooling plate, and a Y-shaped tee at the outlet of the liquid cooling plate. The fins are attached to the outer side of the liquid cooling plate and soldered together to ensure good thermal conductivity. The liquid cooling plate is provided with a liquid cooling plate inlet, a liquid cooling plate outlet and an internal coolant flow channel. The inner side of the liquid cooling plate is attached to the cold end of the temperature difference power generation sheet and the interface gap is filled with interface thermal conductive material. The built-in condenser continuously absorbs heat from the loop heat pipe and the working fluid in the chassis.

5. The immersion cooling and power generation system based on a loop heat pipe according to claim 4, characterized in that: The two sides of the built-in condenser are symmetrically designed, and four circular holes are left on each of the two liquid cooling plates. The built-in condenser, the temperature difference power generation device and the condenser are fastened together by screws and nuts. The Y-shaped tee at the inlet of the liquid cooling plate passes through the first connecting port, one end is connected to the two symmetrically arranged liquid cooling plate inlets, and the other end is connected to the third hose, and the connection is fixed with a clamp. The Y-shaped tee at the outlet of the liquid cooling plate passes through the second connecting port, one end is connected to the two symmetrically arranged liquid cooling plate outlets, and the other end is connected to the first hose, and the connection is fixed with a clamp.

6. The immersion cooling and power generation system based on a loop heat pipe according to claim 5, characterized in that: The external radiator is provided with an external radiator inlet and an external radiator outlet, the coolant pump is provided with a coolant pump inlet and a coolant pump outlet, one end of the first hose is connected to the Y-shaped tee at the liquid cooling plate outlet, and the other end is connected to the external radiator inlet, and the connection is fixed with a clamp.

7. The immersion cooling and power generation system based on a loop heat pipe according to claim 6, characterized in that: One end of the second hose is connected to the external radiator outlet, and the other end is connected to the coolant pump inlet, and the connection is fixed with a clamp. One end of the third hose is connected to the Y-shaped tee at the liquid cooling plate inlet, and the other end is connected to the coolant pump outlet, and the connection is fixed with a clamp.

8. The immersion cooling and power generation system based on a loop heat pipe according to claim 1, characterized in that: The external radiator fan is disposed toward and closely adjacent to the external radiator, and the external radiator dissipates the heat absorbed by the built-in condenser.

9. The immersion cooling and power generation system based on a loop heat pipe according to claim 1, characterized in that: The liquid cooling plate, the liquid cooling plate outlet Y-shaped tee, the first hose, the external radiator, the second hose, the coolant pump, the third hose and the liquid cooling plate inlet Y-shaped tee form a closed loop, and the loop is filled with coolant.

10. A method for using an immersion cooling and power generation system based on a loop heat pipe according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1: Evacuate the loop heat pipe, fill it with a certain amount of working fluid, and then pinch off the liquid-filled pipe to seal it; S2: The loop heat pipe is closely attached to the heat source, and the interface gap is filled with the interface thermal conductive material; S3: The server chassis cover is closed with the main chassis body, the chassis is filled with coolant as the working fluid, the coolant level is lower than the lowest point of the built-in condenser, and the coolant level is higher than the highest point of the evaporator; S4: The closed circuit of the heat dissipation device is filled with coolant; S5: When working, turn on the coolant pump and the external radiator fan. The working fluid in the evaporator absorbs heat from the heat source and turns into steam. It reaches the condenser through the steam pipeline and transfers the heat to the temperature difference power generation device. Then it turns into liquid and flows back to the evaporator through the liquid pipeline. The liquid cooling plate on the built-in condenser provides cooling for the temperature difference power generation device and indirectly cools the loop heat pipe. The temperature difference power generation device relies on the temperature difference provided by the heat from the loop heat pipe condenser and the cooling from the liquid cooling plate to continuously generate electricity. The coolant in the server chassis absorbs heat from the surface of the evaporator and boils to generate steam, which condenses on the fins of the built-in condenser and then flows back. The circulating coolant in the built-in condenser absorbs heat from the steam in the chassis and the loop heat pipe to heat up, and is driven by the coolant pump to flow into the external radiator. The external radiator fan provides forced convection to cool the circulating coolant flowing through the external radiator.

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