Cooling system of liquid cooling server

Abstract

The utility model discloses a cooling system of a liquid cooling server, which comprises a water cooling unit, a first circulating pipeline, a second circulating pipeline and an adjusting unit, and a first temperature sensor, a first heat exchanger, a variable frequency pump, a second heat exchanger, a second temperature sensor and the liquid cooling server are sequentially arranged in the first circulating pipeline along the flow direction of a heat-conducting medium; the second circulating pipeline comprises a first main path connected with an outlet of the water cooling unit, a second main path connected with an inlet of the water cooling unit, and a first branch path and a second branch path which are connected between the first main path and the second main path in parallel, and a first heat exchanger and a first temperature control valve are sequentially arranged in the first branch path in the flowing direction of cooling liquid; a second heat exchanger and a second temperature control valve are sequentially arranged in the second branch in the flowing direction of the cooling liquid. The adjusting unit is used for controlling the inlet and return hydraulic pressure difference in the first circulation pipeline. According to the utility model, stable flow and temperature can be provided under the lowest load working condition, the system resistance is reduced, and the system pressure balance is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of refrigeration equipment, in particular to a heat dissipation system of a liquid cooling server. Background Art

[0002] Electronic products are constantly developing in the direction of miniaturization and integration, and the heat dissipation problem is becoming more and more prominent; the heat flux density of GaN chips, IGBT power devices, etc. has reached 1000W / cm2, and the heat flux density of future chips will exceed 2000W / cm2; it has gradually exceeded the air cooling threshold, and the artificial intelligence model has increased the demand for computing power. Large computing power brings high power consumption. Liquid cooling technology has efficient cooling performance. The thermal conductivity of liquid can reach 6 times that of air, and the specific heat capacity of the same volume of liquid is 1000 times that of air. Therefore, liquid cooling not only improves the cooling efficiency and maximizes the use of outdoor natural cold sources, but also solves the heat dissipation problem of high-power density servers. There are currently two commonly used liquid cooling technologies:

[0003] (1) Direct liquid cooling: The cooling liquid flows directly over the surface of the hardware, absorbing and taking away the heat generated by the hardware. There is no intermediary between the liquid and the heat source in the direct liquid cooling system, so the heat dissipation efficiency is higher. The heat can be directly transferred to the liquid. It is mainly used in scenarios with high requirements for heat dissipation efficiency. Direct cooling includes immersion and spray types. The immersion type can be divided into single-phase immersion and phase change immersion according to whether the cooling medium undergoes phase change.

[0004] (2) Indirect liquid cooling: The liquid does not come into direct contact with the hardware, but contacts the hardware through an intermediary component (heat sink or cooling block), through which the cooling medium takes away the heat. Indirect cooling is generally cold plate liquid cooling, which is also the most commonly used method in liquid cooling technology.

[0005] Cold plate liquid cooling technology means that the liquid absorbs heat through the cold plate, and then transfers the heat to the cooling unit away from the server through the liquid pipe, and distributes the cold through the cold distribution unit (CDU). The whole system consists of CDU, water quality filtration and treatment device, water distribution unit, quick-release connector, cold source equipment, water distribution pump pipeline valves, etc.

[0006] However, in actual usage scenarios, the heat load of the customer's cold plate liquid cooling cabinet fluctuates greatly. The existing CDU's plate heat exchangers are matched according to the system's maximum heat load. The conventional design of CDU is to ensure temperature control requirements under the condition of its maximum heat load, ignoring the working scenario under the minimum heat load. When the actual usage scenario encounters the minimum heat load, the CDU's system operating condition is not the best condition under the minimum heat load condition. There is a large system operating resistance and large fluctuations in flow and temperature. Therefore, it is difficult to meet the requirements for flow and temperature control accuracy, and there is a situation where the total return water volume is less than the system's minimum flow rate. At this time, the system is at risk of decompression. Summary of the Invention

[0007] In view of the deficiencies of the prior art, the present utility model provides a heat dissipation system for a liquid-cooled server, which can provide a stable flow rate and temperature under the lowest load condition, reduce the system resistance, and ensure the system pressure balance.

[0008] The present utility model is realized through the following technical solutions:

[0009] A heat dissipation system for a liquid-cooled server, including a water-cooling unit, the heat dissipation system further includes:

[0010] A first circulation pipeline, in which a first temperature sensor, a first heat exchanger, a second heat exchanger, a second temperature sensor and the liquid-cooled server are sequentially arranged along the flow direction of the heat-conducting medium;

[0011] A second circulation pipeline, the second circulation pipeline includes a first main path, a second main path, a first branch path and a second branch path. One end of the first main path is connected to the outlet of the water-cooling unit, and one end of the second main path is connected to the inlet of the water-cooling unit. The first branch path and the second branch path are connected in parallel between the other end of the first main path and the other end of the second main path; in the first branch path, the first heat exchanger and a first temperature control valve are sequentially arranged along the flow direction of the coolant, and the first temperature control valve is used to adjust the valve opening ratio according to the temperature feedback signal of the first temperature sensor. In the second branch path, the second heat exchanger and a second temperature control valve are sequentially arranged along the flow direction of the coolant, and the second temperature control valve is used to adjust the valve opening ratio according to the temperature feedback signal of the second temperature sensor;

[0012] A variable-frequency pump, which is arranged on the first circulation pipeline;

[0013] An adjustment unit, which is connected between the liquid inlet and the liquid outlet of the liquid-cooled server and is used to control the inlet and return liquid pressure difference in the first circulation pipeline.

[0014] Furthermore, the adjustment unit includes a first bypass pipeline and a regulating valve. The two ends of the first bypass pipeline are respectively connected to the liquid inlet and the liquid outlet of the liquid-cooled server, and the regulating valve is arranged on the first bypass pipeline and is used to control the inlet and return liquid pressure difference in the first circulation pipeline.

[0015] Further, the regulating unit includes a second bypass pipeline, a third bypass pipeline, a differential pressure controller, and an electric control valve. The second bypass pipeline and the third bypass pipeline are arranged in parallel between the liquid inlet and the liquid outlet of the liquid-cooled server. The differential pressure controller is arranged on the second bypass pipeline for measuring the differential pressure between the inlet and return liquid. The electric control valve is arranged on the third bypass pipeline and can adjust the opening degree according to the instruction of the differential pressure controller to achieve differential pressure balance.

[0016] Further, the heat dissipation system further includes a first pressure sensor and a second pressure sensor arranged on the first circulation pipeline. The first pressure sensor is arranged close to the liquid outlet of the liquid-cooled server, and the second pressure sensor is arranged close to the liquid inlet of the liquid-cooled server.

[0017] Further, the heat dissipation system further includes a first flow sensor arranged on the first circulation pipeline. The first flow sensor is arranged close to the liquid inlet of the liquid-cooled server.

[0018] Further, the heat dissipation system further includes a liquid storage tank arranged on the first circulation pipeline. The liquid storage tank and the variable frequency pump are arranged in sequence between the first heat exchanger and the second heat exchanger along the flow direction of the heat conduction medium.

[0019] Further, the heat dissipation system further includes a check valve arranged on the first circulation pipeline. The check valve is arranged between the variable frequency pump and the second heat exchanger.

[0020] Further, the heat dissipation system further includes a third temperature sensor and a fourth temperature sensor. The third temperature sensor is arranged on the first main pipeline, and the fourth temperature sensor is arranged on the second main pipeline.

[0021] Further, the heat dissipation system further includes a third pressure sensor, a fourth pressure sensor, and a second flow sensor. The third pressure sensor is arranged on the first main pipeline, and the fourth pressure sensor and the second flow sensor are arranged on the second main pipeline.

[0022] Further, the heat dissipation system further includes a drain pipeline connected to the first circulation pipeline and a gate valve arranged on the drain pipeline. One end of the drain pipeline is connected between the check valve and the second heat exchanger.

[0023] Further, the heat dissipation system includes an open system and a closed system;

[0024] When the heat dissipation system is an open system, the heat dissipation system further includes a connecting pipe. One end of the connecting pipe is communicated with the liquid storage tank, and the other end is communicated with the outside atmosphere;

[0025] When the heat dissipation system is a closed system, the heat dissipation system further includes a pressure stabilizing tank and a safety valve arranged on the first circulation pipeline, and the pressure stabilizing tank and the safety valve are arranged between the first heat exchanger and the liquid storage tank in sequence along the flow direction of the heat conducting medium.

[0026] Compared with the prior art, the advantages of the present utility model are as follows:

[0027] 1. By arranging the first heat exchanger and the second heat exchanger, when the load end, i.e., the liquid-cooled server, operates at full load, the first heat exchanger and the second heat exchanger operate together for heat exchange. The heat conducting medium first undergoes heat exchange through the first heat exchanger, and the first temperature control valve adjusts the valve opening ratio through the temperature feedback signal of the first temperature sensor. The heat conducting medium is cooled by the main heat exchanger and enters the liquid storage tank, and then the variable-frequency pump drives the heat conducting medium to continue to enter the plate heat exchanger for heat exchange. The second temperature control valve adjusts the valve opening ratio through the temperature feedback signal of the second temperature sensor. Through the combined action of the first heat exchanger and the second heat exchanger, the heat conducting medium is cooled to the target set temperature, and the flow rate of the heat conducting medium is controlled by the variable-frequency pump; when the minimum heat load condition scenario appears at the load end and only the second heat exchanger can meet the heat exchange requirement, at this time, the first temperature control valve is in the closed state, and the second temperature control valve adjusts the valve opening ratio through the temperature feedback signal of the second temperature sensor to cool the coolant to the target set temperature. This enables the heat dissipation system to provide a stable flow rate and temperature even in the face of low heat load or extremely low heat load conditions at the load end.

[0028] 2. By arranging the adjustment unit between the liquid inlet and the liquid outlet of the liquid-cooled server, it is used to control the inlet and return hydraulic pressure difference in the first circulation pipeline, reduce the system resistance, ensure the system pressure balance, and avoid the risk of excessive system pressure difference that may be caused under the minimum flow rate condition or the minimum heat load condition of the heat dissipation system. Description of the Drawings

[0029] Figure 1 It is the schematic diagram when the heat dissipation system is an open system;

[0030] Figure 2 It is the schematic diagram when the heat dissipation system is a closed system;

[0031] Figure 3 It is the schematic diagram of the adjustment unit in another embodiment.

[0032] 1. Water-cooled unit; 2. First heat exchanger; 3. Second heat exchanger; 4. First temperature sensor; 5. Second temperature sensor; 6. First temperature control valve; 7. Second temperature control valve; 8. Variable frequency pump; 9. Control valve; 10. Differential pressure controller; 11. Electric control valve; 12. First pressure sensor; 13. Second pressure sensor; 14. First flow sensor; 15. Liquid storage tank; 150. Connecting pipe; 16. First three-way valve; 17. Second three-way valve; 18. Check valve; 19. Third temperature sensor; 20. Fourth temperature sensor; 21. Third pressure sensor; 22. Fourth pressure sensor; 23. Second flow sensor; 24. Gate valve; 25. Pressure stabilizing tank; 26. Safety valve; 27. Liquid level gauge; 100. First circulation pipeline; 200. Second circulation pipeline; 201. First main path; 202. Second main path; 203. First branch; 204. Second branch; 300. First bypass pipeline; 400. Second bypass pipeline; 500. Third bypass pipeline; 600. Drainage pipeline; 700. Liquid-cooled server. Detailed implementation manners

[0033] The following further non-limiting detailed description of the technical solution of the utility model is made in conjunction with the preferred embodiments and their accompanying drawings. In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present utility model and should not be construed as a limitation of the present utility model.

[0034] As Figure 1As shown in the figure, a heat dissipation system of a liquid-cooled server according to an embodiment of the present invention includes a water-cooling unit 1, a first circulation pipeline 100, and a second circulation pipeline 200. In the first circulation pipeline 100, a first temperature sensor 4, a first heat exchanger 2, a second heat exchanger 3, a second temperature sensor 5, and a liquid-cooled server 700 are sequentially arranged along the flow direction of the heat-conducting medium; the second circulation pipeline 200 includes a first main path 201, a second main path 202, a first branch path 203, and a second branch path 204. One end of the first main path 201 is connected to the outlet of the water-cooling unit 1, one end of the second main path 202 is connected to the inlet of the water-cooling unit 1, and the first branch path 203 and the second branch path 204 are connected in parallel between the other end of the first main path 201 and the other end of the second main path 202; in the first branch path 203, a first heat exchanger 2 and a first temperature control valve 6 are sequentially arranged along the flow direction of the coolant, and the first temperature control valve 6 is used to adjust the valve opening ratio according to the temperature feedback signal of the first temperature sensor 4. In the second branch path 204, a second heat exchanger 3 and a second temperature control valve 7 are sequentially arranged along the flow direction of the coolant, and the second temperature control valve 7 is used to adjust the valve opening ratio according to the temperature feedback signal of the second temperature sensor 5. In this embodiment, both the first heat exchanger 2 and the second heat exchanger 3 are plate heat exchangers. The first heat exchanger 2 is the main heat exchanger, and the second heat exchanger 3 is the auxiliary heat exchanger. Through the design of the main + auxiliary double plate heat exchangers, the volume of the large heat exchanger can be miniaturized, meeting the usage scenarios of the extreme lowest heat load conditions, and the temperature control accuracy can be improved, reaching ±0.05°C.

[0035] The heat dissipation system further includes a variable-frequency pump 8 and a liquid storage tank 15. The variable-frequency pump 8 and the liquid storage tank 15 are both arranged on the first circulation pipeline 100, and the liquid storage tank 15 and the variable-frequency pump 8 are sequentially arranged between the first heat exchanger 2 and the second heat exchanger 3 along the flow direction of the heat-conducting medium. A liquid level gauge 27 is arranged in the liquid storage tank 15. Under the condition of low heat load or extreme lowest heat load of the load end, that is, the liquid-cooled server 700, the first heat exchanger 2 does not participate in heat load exchange, and the liquid storage tank 15 is equivalent to a cold storage tank, which can improve the heat exchange efficiency of the second heat exchanger 3. In addition, the variable-frequency pump 8 can also be replaced with the form of a fixed-frequency pump + a flow control valve.

[0036] The heat dissipation system further includes a check valve 18 arranged on the first circulation pipeline 100. The check valve 18 is arranged between the variable-frequency pump 8 and the second heat exchanger 3 to prevent the heat-conducting medium in the first circulation pipeline 100 from flowing back.

[0037] The heat dissipation system further includes a drain pipeline 600 connected to the first circulation pipeline 100 and a gate valve 24 arranged on the drain pipeline 600. One end of the drain pipeline 600 is connected between the check valve 18 and the second heat exchanger 3.

[0038] In this embodiment, the heat dissipation system includes an open system and a closed system. When the heat dissipation system is an open system, refer to Figure 1, the heat dissipation system further includes a connecting pipe 150. One end of the connecting pipe 150 is connected to the liquid storage tank 15, and the other end is connected to the outside atmosphere. The purpose is to solve the safety hazard caused by the increase in the internal pressure of the first circulation pipeline 100 when the temperature of the heat-conducting medium rises and the volume expands. When the heat dissipation system is a closed system, refer to Figure 2 , the heat dissipation system further includes a pressure stabilizing tank 25 and a safety valve 26 arranged on the first circulation pipeline 100. The pressure stabilizing tank 25 and the safety valve 26 are arranged in sequence between the first heat exchanger 2 and the liquid storage tank 15 along the flow direction of the heat-conducting medium. The pressure stabilizing tank 25 and the safety valve 26 can further maintain the liquid pressure in the first circulation pipeline 100. The function of the pressure stabilizing tank 25 is to absorb the expansion amount when the temperature of the heat-conducting medium rises and the volume expands, prevent the internal pressure of the first circulation pipeline 100 from rising too fast, and release the liquid in the airbag when the temperature of the heat-conducting medium drops and the volume contracts, and supplement it into the first circulation pipeline 100 of the heat dissipation system, so as to reduce the pressure relief times and liquid supplement times of the safety valve 26, thereby maintaining the balance of the internal pressure of the first circulation pipeline 100.

[0039] When the pressure in the first circulation pipeline 100 exceeds the set value of the safety valve 26, the safety valve 26 will automatically open to discharge the heat-conducting medium to reduce the pressure. This automatic adjustment mechanism ensures that the medium pressure in the equipment and pipeline always remains within the allowable range, thereby preventing accidents and losses caused by excessive pressure.

[0040] The heat dissipation system further includes an adjustment unit. The adjustment unit is connected between the liquid inlet and outlet of the liquid-cooled server 700 and is used to control the inlet and return liquid pressure difference in the first circulation pipeline 100. In an embodiment of the present invention, the adjustment unit includes a first bypass pipeline 300 and a regulating valve 9. The two ends of the first bypass pipeline 300 are respectively connected to the liquid inlet and outlet of the liquid-cooled server 700, and the regulating valve 9 is arranged on the first bypass pipeline 300 to control the inlet and return liquid pressure difference in the first circulation pipeline 100. If the required liquid supply flow rate of the heat-conducting medium is less than the minimum liquid supply flow rate of the variable frequency pump 8 at this time or the pressure difference measured between the first pressure sensor 12 and the second pressure sensor 13 > the set pressure difference, then the opening of the regulating valve 9 needs to be increased so that the first flow sensor 14 reaches the required target flow rate value or the pressure difference measured between the first pressure sensor 12 and the second pressure sensor 13 is reduced to within the set pressure difference range. In another embodiment of the present invention, refer to Figure 3, the regulating unit includes a second bypass pipeline 400, a third bypass pipeline 500, a differential pressure controller 10 and an electric control valve 11. The second bypass pipeline 400 and the third bypass pipeline 500 are arranged in parallel between the liquid inlet and the liquid outlet of the liquid-cooled server 700. The differential pressure controller 10 is arranged on the second bypass pipeline 400 for measuring the differential pressure between the inlet and return liquid pressures. The electric control valve 11 is arranged on the third bypass pipeline 500 and can adjust the opening degree according to the instruction of the differential pressure controller 10 to achieve differential pressure balance. When the differential pressure measured between the first pressure sensor 12 and the second pressure sensor 13 > the set differential pressure, the differential pressure controller 10 issues an instruction to increase the opening degree of the valve of the electric control valve 11. Otherwise, the opening degree is reduced, so as to balance the internal pressure of the heat dissipation system.

[0041] The heat dissipation system further includes a first pressure sensor 12 and a second pressure sensor 13 arranged on the first circulation pipeline 100. The first pressure sensor 12 is arranged near the liquid outlet of the liquid-cooled server 700, and the second pressure sensor 13 is arranged near the liquid inlet of the liquid-cooled server 700.

[0042] The heat dissipation system further includes a first flow sensor 14 arranged on the first circulation pipeline 100. The first flow sensor 14 is arranged near the liquid inlet of the liquid-cooled server 700.

[0043] The heat dissipation system further includes a third temperature sensor 19 and a fourth temperature sensor 20. The third temperature sensor 19 is arranged on the first main path 201, and the fourth temperature sensor 20 is arranged on the second main path 202.

[0044] The heat dissipation system further includes a third pressure sensor 21, a fourth pressure sensor 22 and a second flow sensor 23. The third pressure sensor 21 is arranged on the first main path 201, and the fourth pressure sensor 22 and the second flow sensor 23 are arranged on the second main path 202.

[0045] The heat dissipation system further includes a first three-way valve 16 and a second three-way valve 17. The first main path 201, the first branch path 203 and the second branch path 204 are connected through the first three-way valve 16, and the second main path 202, the first branch path 203 and the second branch path 204 are connected through the second three-way valve 17.

[0046] During operation, when the load side, i.e., the liquid-cooled server 700, is running at full load, both the first heat exchanger 2 and the second heat exchanger 3 are in operation. The heat-conducting medium first undergoes heat exchange through the main heat exchanger, i.e., the first heat exchanger 2. The first temperature control valve 6 adjusts the valve opening ratio through the temperature feedback signal of the first temperature sensor 4, thereby controlling the heat exchange rate of the first heat exchanger 2. The heat-conducting medium is cooled by the main heat exchanger and enters the liquid storage tank 15, and is then driven by the variable-frequency pump 8 to continue entering the plate heat exchanger 2 for heat exchange. The second temperature control valve 7 adjusts the valve opening ratio through the temperature feedback signal of the second temperature sensor 5, thereby controlling the heat exchange rate of the second heat exchanger 3, so that the heat-conducting medium is cooled to the target set temperature, and the flow rate of the heat-conducting medium is controlled by the variable-frequency pump 8. When the minimum heat load condition scenario appears at the load side and only the second heat exchanger 3 can meet the heat exchange requirement, at this time, the first temperature control valve 6 is in the closed state, and the second temperature control valve 7 adjusts the valve opening ratio through the temperature feedback signal of the second temperature sensor 5 to cool the coolant to the target set temperature. If the required supply flow rate of the heat-conducting medium is less than the minimum supply flow rate of the variable-frequency pump 8 at this time or the pressure difference measured between the first pressure sensor 12 and the second pressure sensor 13 > the set pressure difference, then the regulating valve 9 needs to be adjusted so that the first flow sensor 14 reaches the required target flow rate value or the pressure difference measured between the first pressure sensor 12 and the second pressure sensor 13 is reduced to within the set pressure difference range.

[0047] The above-described embodiments merely represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

Claims

1. A heat dissipation system for a liquid-cooled server, comprising a water cooling unit (1), characterized in that: The heat dissipation system further comprises: A first circulation pipeline (100), wherein a first temperature sensor (4), a first heat exchanger (2), a second heat exchanger (3), a second temperature sensor (5), and the liquid cooling server (700) are sequentially arranged in the first circulation pipeline (100) along the flow direction of the heat-conducting medium; A second circulation pipeline (200), the second circulation pipeline (200) comprising a first main line (201), a second main line (202), a first branch line (203) and a second branch line (204), one end of the first main line (201) being connected to the outlet of the water cooling unit (1), one end of the second main line (202) being connected to the inlet of the water cooling unit (1), the first branch line (203) and the second branch line (204) being connected in parallel between the other end of the first main line (201) and the inlet of the second main line (202). the first branch (203) is provided with the first heat exchanger (2) and the first temperature control valve (6) in sequence along the flow direction of the coolant, the first temperature control valve (6) being used to adjust the valve opening ratio according to the temperature feedback signal of the first temperature sensor (4), and the second branch (204) is provided with the second heat exchanger (3) and the second temperature control valve (7) in sequence along the flow direction of the coolant, the second temperature control valve (7) being used to adjust the valve opening ratio according to the temperature feedback signal of the second temperature sensor (5); A variable frequency pump (8), the variable frequency pump (8) being arranged on the first circulation pipeline (100); A regulating unit, the regulating unit being connected between a liquid inlet and a liquid outlet of the liquid cooling server (700) and being used to control the inlet and return hydraulic pressure difference in the first circulation pipeline (100).

2. The heat dissipation system of the liquid cooling server according to claim 1, characterized in that: The regulating unit comprises a first bypass pipeline (300) and a regulating valve (9); two ends of the first bypass pipeline (300) are respectively connected to a liquid inlet and a liquid outlet of the liquid cooling server (700); and the regulating valve (9) is arranged on the first bypass pipeline (300) and is used to control the inlet and return hydraulic pressure difference in the first circulation pipeline (100).

3. The heat dissipation system of the liquid cooling server according to claim 1, characterized in that: The regulating unit comprises a second bypass pipeline (400), a third bypass pipeline (500), a pressure difference controller (10) and an electric regulating valve (11); the second bypass pipeline (400) and the third bypass pipeline (500) are arranged in parallel between a liquid inlet and a liquid outlet of the liquid cooling server (700); the pressure difference controller (10) is arranged on the second bypass pipeline (400) for measuring the inlet and return hydraulic pressure difference; the electric regulating valve (11) is arranged on the third bypass pipeline (500) and can adjust the opening according to the instruction of the pressure difference controller (10) to achieve pressure difference balance.

4. The heat dissipation system of the liquid cooling server according to claim 1, characterized in that: The heat dissipation system further comprises a first pressure sensor (12), a second pressure sensor (13) and a first flow sensor (14) arranged on the first circulation pipeline (100), wherein the first pressure sensor (12) is arranged close to a liquid outlet of the liquid cooling server (700), the second pressure sensor (13) is arranged close to a liquid inlet of the liquid cooling server (700), and the first flow sensor (14) is arranged close to a liquid inlet of the liquid cooling server (700).

5. The heat dissipation system of the liquid cooling server according to claim 1, characterized in that: The heat dissipation system further comprises a liquid storage tank (15) arranged on the first circulation pipeline (100), and the liquid storage tank (15) and the variable frequency pump (8) are arranged in sequence between the first heat exchanger (2) and the second heat exchanger (3) along the flow direction of the heat transfer medium.

6. The heat dissipation system of the liquid cooling server according to claim 1, characterized in that: The heat dissipation system further comprises a one-way valve (18) arranged on the first circulation pipeline (100), wherein the one-way valve (18) is arranged between the variable frequency pump (8) and the second heat exchanger (3).

7. The heat dissipation system of the liquid cooling server according to claim 1, characterized in that: The heat dissipation system further comprises a third temperature sensor (19) and a fourth temperature sensor (20), wherein the third temperature sensor (19) is arranged on the first main path (201), and the fourth temperature sensor (20) is arranged on the second main path (202).

8. The heat dissipation system of a liquid-cooled server according to claim 1, characterized in that: The heat dissipation system further comprises a third pressure sensor (21), a fourth pressure sensor (22) and a second flow sensor (23); the third pressure sensor (21) is arranged on the first main path (201), and the fourth pressure sensor (22) and the second flow sensor (23) are arranged on the second main path (202).

9. The heat dissipation system of the liquid cooling server according to claim 6, characterized in that: The heat dissipation system further comprises a drain pipeline (600) connected to the first circulation pipeline (100) and a gate valve (24) arranged on the drain pipeline (600); one end of the drain pipeline (600) is connected between the one-way valve (18) and the second heat exchanger (3).

10. The heat dissipation system of the liquid cooling server according to claim 5, characterized in that: The heat dissipation system includes an open system and a closed system; When the heat dissipation system is an open system, the heat dissipation system further comprises a connecting pipe (150), one end of the connecting pipe (150) is connected to the liquid storage tank (15), and the other end is connected to the outside atmosphere; When the heat dissipation system is a closed system, the heat dissipation system further comprises a pressure stabilizing tank (25) and a safety valve (26) arranged on the first circulation pipeline (100), and the pressure stabilizing tank (25) and the safety valve (26) are arranged in sequence between the first heat exchanger (2) and the liquid storage tank (15) along the flow direction of the heat transfer medium.

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