Liquid cooling system and exhaust method thereof

Abstract

The invention provides a liquid cooling system and an exhaust method thereof. The liquid cooling system comprises a heat exchanger, an immersed box body, a pump, an exhaust device and an exhaust pipe, the output end of the immersed box body is connected with the input end of the heat exchanger through an output pipeline; the input end of the immersed box body is connected with the output end of the heat exchanger through a backflow pipeline; the pump is arranged on the output pipeline; the exhaust device is arranged on the backflow pipeline; a throat is arranged in the middle of the exhaust device, so that the pipe diameter of the exhaust device is small in the middle and large at two ends; one end of the exhaust pipe is connected to the highest point of the backflow pipeline through a one-way valve, and the other end of the exhaust pipe communicates with the throat. The exhaust method of the liquid cooling system adopts the liquid cooling system. The negative pressure generated at the throat due to the Venturi effect is utilized, dynamic adjustment of the pump power is combined, air at the highest point of the backflow pipeline and in the plate heat exchanger can be conveniently and rapidly exhausted automatically and efficiently, and the problems of air suck-back and refrigerant leakage of a traditional automatic exhaust valve when a system is closed are effectively avoided.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of liquid cooling, and more particularly relates to a liquid cooling system and an exhaust method thereof. BACKGROUND

[0002] In recent years, with the rapid development of technology iteration and digital economy, high-density, high-computing-power and high-energy-consumption data centers have experienced explosive growth. The throughput and operation of massive data bring unprecedented high energy consumption pressure and thermal management system challenges to the data centers. Under this background, liquid cooling data centers using new liquid cooling technology and liquid cooling servers and other equipment have emerged. Compared with air cooling, liquid cooling can deploy more high-density storage in limited space, more accurately support high-power chip heat dissipation, and guarantee stable operation of the chip at low temperature, while having the characteristics of safety and silence; it can not only effectively reduce the PUE (power utilization efficiency) value of the data center and help IT expansion, but also greatly reduce the operation and maintenance cost because it does not need to use high-cost components such as centrifugal machines, refrigeration pumps, scroll compressors and precision air conditioners.

[0003] The core and key of the liquid cooling technology lies in the design and application of the thermal management system, and the heat exchange efficiency of the primary side and the secondary side of the liquid cooling system is particularly important. The primary side and the secondary side of the refrigerant realize heat exchange through the plate heat exchanger, and the higher the heat exchange efficiency, the smaller the energy loss. The plate heat exchanger is usually installed at the highest point or a lower position in the CDU (cooling distribution unit). When the CDU is running, the residual air or air carried by the refrigerant in the pipeline will gather at the highest point of the pipeline: if the plate heat exchanger is located at a lower position, it will not be affected by the air; but when it is located at the highest point, excessive air will flow into the heat exchanger from the pipeline, reducing the heat exchange volume and seriously affecting the heat exchange efficiency.

[0004] At present, the market usually installs an automatic exhaust valve at the highest point to exhaust the air gathered in the pipeline. However, when the liquid cooling system is closed and stopped, the refrigerant in the pipeline will fall back due to gravity, causing negative pressure in the pipeline, and then a large amount of air from the outside will be sucked into the pipeline through the automatic exhaust valve. When the system is started again, a large amount of air will be exhausted while carrying the refrigerant in the pipeline, resulting in leakage. In order to prevent leakage of the automatic exhaust valve, the valve cap of the exhaust valve exhaust hole needs to be manually unscrewed and screwed off every time the liquid cooling system is closed and started, which greatly increases the workload in the use process. SUMMARY

[0005] The purpose of the embodiments of the application is to provide a liquid cooling system and an exhaust method thereof, so as to solve the technical problems in the prior art that the automatic exhaust valve of the liquid cooling system is easy to cause air backflow and refrigerant leakage when it is closed, and manual operation of the exhaust valve increases the workload.

[0006] To achieve the above object, the technical scheme adopted by the present application is: provide a kind of liquid cooling system, including heat exchanger, immersion box, pump, exhaust device and exhaust pipe;The output end of the immersion box is connected with the input end of the heat exchanger by output pipeline;The input end of the immersion box is connected with the output end of the heat exchanger by backflow pipeline;The pump is arranged on the output pipeline;The exhaust device is arranged on the backflow pipeline;The middle part of the exhaust device is provided with throat, to make the pipe diameter of the exhaust device middle small two ends big;One end of the exhaust pipe is connected to the highest point of the backflow pipeline by one-way valve, and the other end of the exhaust pipe is communicated with the throat.

[0007] Further, the pressure difference Δp between the highest point of the backflow pipeline and the throat satisfies the following relationship:

[0008]

[0009] Wherein, p1 is the pressure of refrigerant at the highest point of backflow pipeline, v1 is the flow rate of refrigerant at the highest point of backflow pipeline, h1 is the height from the ground at the highest point of backflow pipeline;S1 is the cross-sectional area of pipeline at the highest point of backflow pipeline;P2 is the pressure of refrigerant at the throat, v2 is the flow rate of refrigerant at the throat, h2 is the height from the ground at the throat;S2 is the cross-sectional area of pipeline at the throat;ρ is the density of refrigerant;g is the acceleration of gravity;Q is the flow of refrigerant.

[0010] Further, the highest point of the backflow pipeline is provided with mounting hole;The one-way valve includes flap and limiting portion, one end of the flap is hinged with the pipe wall of the backflow pipeline at the mounting hole, and the limiting portion is connected with the pipe wall of the backflow pipeline at the mounting hole;

[0011] When the one-way valve is opened, the flap swings towards one side of the exhaust pipe;When the one-way valve is closed, the other end of the flap abuts against the limiting portion, and the flap is in a horizontal state.

[0012] Further, the backflow pipeline includes a first backflow pipe and a second backflow pipe, one end of the first backflow pipe is connected with the output end of the heat exchanger, and the other end of the first backflow pipe is connected with the input end of the exhaust device;One end of the second backflow pipe is connected with the output end of the exhaust device, and the other end of the second backflow pipe is connected with the input end of the immersion box.

[0013] Further, the exhaust device includes inlet section, contraction section, throat, expansion section arranged in sequence;The inlet section is communicated with the first backflow pipe;The expansion section is communicated with the second backflow pipe.

[0014] Further, a negative pressure port is provided on the throat, and the negative pressure port is connected with the exhaust pipe.

[0015] Further, the throat has a diameter of 30%-70% of the diameter of the inlet section.

[0016] Further, a pressure sensor is arranged at the highest point of the return pipeline, and the pressure sensor is used to monitor the pressure change at the throat.

[0017] Further, a flow sensor is arranged at the highest point of the return pipeline, and the flow sensor is used to monitor the flow change at the throat.

[0018] The application also provides an exhaust method of the liquid cooling system, which adopts the liquid cooling system, and the exhaust method comprises the following steps of:

[0019] starting the liquid cooling system;

[0020] judging whether there is air aggregation in the heat exchanger;

[0021] if there is air aggregation, increasing the power of the pump to increase the refrigerant flow; the one-way valve is automatically opened, the aggregated air is returned to the immersion tank through the exhaust pipe, the throat and the return pipeline, and then is discharged to the atmosphere with the immersion tank;

[0022] if there is no air aggregation, the power of the pump remains unchanged, and the liquid cooling system continues to work normally.

[0023] The liquid cooling system and the exhaust method thereof have the following beneficial effects: compared with the prior art, the application sets the one-way valve and the exhaust pipe at the highest point of the return pipeline, and connects the exhaust pipe with the throat of the exhaust device, utilizes the negative pressure generated at the throat due to the Venturi effect, and dynamically adjusts the power of the pump, so that the air at the highest point of the return pipeline and the air in the plate heat exchanger can be automatically and efficiently discharged, the problem of air backflow and refrigerant leakage of the traditional automatic exhaust valve when the system is closed is effectively avoided. At the same time, the structure design of the one-way valve ensures that the one-way valve can be reliably closed after the air is exhausted, maintains the normal flow of the refrigerant, and reduces the energy loss. In addition, the liquid cooling system does not need to manually operate the exhaust valve, significantly reduces the operation and maintenance workload, and improves the stability and economy of the liquid cooling system in the application of data center thermal management. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative labor.

[0025] Figure 1 The structure schematic diagram of the liquid cooling system provided by the embodiments of the application is shown in the figure.

[0026] Figure 2 A structural schematic diagram of an exhaust device in a liquid cooling system provided by an embodiment of the present application is shown in the figure.

[0027] Figure 3 A schematic diagram of an exhaust process of a liquid cooling system provided by an embodiment of the present application is shown in the figure.

[0028] Figure 4 A flow chart of an exhaust method of a liquid cooling system provided by an embodiment of the present application is shown in the figure.

[0029] In the figure, each reference sign represents:

[0030] 100 - heat exchanger;

[0031] 200 - immersion tank;

[0032] 300 - pump;

[0033] 400 - exhaust device; 401 - inlet section; 402 - contraction section; 403 - throat; 431 - negative pressure port; 404 - expansion section; 405 - first flange interface; 406 - second flange interface;

[0034] 500 - exhaust pipe;

[0035] 600 - one-way valve;

[0036] 700 - output pipeline;

[0037] 801 - first return pipe; 802 - second return pipe. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below in combination with the figures and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0039] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0040] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0041] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified.

[0042] Please refer to Figure 1 and Figure 3 , the liquid cooling system provided by the embodiment of the present application will be described. The liquid cooling system comprises a heat exchanger 100, an immersion tank 200, a pump 300, an exhaust device 400 and an exhaust pipe 500; the output end of the immersion tank 200 is connected with the input end of the heat exchanger 100 through an output pipeline 700; the input end of the immersion tank 200 is connected with the output end of the heat exchanger 100 through a return pipeline; the pump 300 is arranged on the output pipeline 700; the exhaust device 400 is arranged on the return pipeline; the middle part of the exhaust device 400 is provided with a throat 403, so that the pipe diameter of the exhaust device 400 is small in the middle and large at both ends; one end of the exhaust pipe 500 is connected to the highest point of the return pipeline through a one-way valve 600, and the other end of the exhaust pipe 500 is in communication with the throat 403.

[0043] Compared with the prior art, the liquid cooling system provided by the embodiment of the present application sets the one-way valve 600 and the exhaust pipe 500 at the highest point of the return pipeline, and connects the exhaust pipe 500 with the throat 403 of the exhaust device 400, so that the air in the return pipeline and the plate heat exchanger 100 can be automatically and efficiently exhausted by using the negative pressure generated at the throat 403 due to the Venturi effect, in combination with the dynamic adjustment of the power of the pump 300, thereby effectively avoiding the problems of air backflow and refrigerant leakage of the traditional automatic exhaust valve when the system is closed. At the same time, the structural design of the one-way valve 600 ensures that it can be reliably closed after the air is exhausted, maintaining the normal flow of the refrigerant and reducing energy loss. In addition, the liquid cooling system does not need to manually operate the exhaust valve, significantly reducing the operation and maintenance workload and improving the stability and economy of the liquid cooling system in the application of data center thermal management.

[0044] In the embodiment, the immersion tank 200 is a heat dissipation device specially designed for servers or switches. Please refer toFigure 1 , Figure 1 The direction indicated by the arrow represents the flow direction of the refrigerant. The air exhaust device is arranged on the return pipeline, which can effectively prevent the exhaust air from flowing back into the heat exchanger 100.

[0045] In an embodiment of the present application, the pressure difference Δp between the highest point of the return pipeline and the throat 403 satisfies the following relationship:

[0046]

[0047] wherein p1 is the pressure of the refrigerant at the highest point of the return pipeline, v1 is the flow rate of the refrigerant at the highest point of the return pipeline, h1 is the height above ground at the highest point of the return pipeline; S1 is the cross-sectional area of the pipeline at the highest point of the return pipeline; p2 is the pressure of the refrigerant at the throat 403, v2 is the flow rate of the refrigerant at the throat 403, h2 is the height above ground at the throat 403; S2 is the cross-sectional area of the pipeline at the throat 403; ρ is the density of the refrigerant; g is the acceleration of gravity; and Q is the flow rate of the refrigerant.

[0048] After the air exhaust device 400 is installed, the liquid cooling system is started. At this time, the cross-sectional area S1 of the pipeline at the highest point of the return pipeline, the height h1 above ground at the highest point of the return pipeline, the cross-sectional area S2 of the pipeline at the throat 403, and the height h2 above ground at the throat 403 are all fixed values that cannot be changed. Therefore, the pressure difference between the two places is only related to the flow rate of the liquid cooling system. Therefore, in the liquid cooling system, the flow rate of the refrigerant can be changed by adjusting the power of the pump 300, and thus the pressure difference between the highest point of the return pipeline and the throat 403 can be controlled.

[0049] When the liquid cooling system is started, the current pressure difference between the highest point of the return pipeline and the throat 403 can be accurately calculated by real-time monitoring of the flow rate of the refrigerant and combining the fixed values of the parameters in formula (1). If the pressure difference does not reach the preset threshold, the power of the pump 300 can be increased to increase the flow rate of the refrigerant, so that the pressure difference increases; on the contrary, if the pressure difference exceeds the threshold, the power of the pump 300 can be reduced to reduce the flow rate, so that the pressure difference is stabilized within a reasonable range, ensuring that the air exhaust device 400 can efficiently exhaust the gas in the system and maintain the stable operation of the liquid cooling system. This way of controlling the pressure difference by adjusting the flow rate is simple and quick to respond, and can adapt to the needs of the liquid cooling system for air exhaust performance under different working conditions, effectively avoiding problems such as reduced heat dissipation efficiency caused by gas accumulation.

[0050] Specifically, the Bernoulli equation is:

[0051]

[0052] wherein, p is the pressure of a certain point in the refrigerant, v is the flow rate of the refrigerant at the point, h is the height of the point, S is the pipe cross-sectional area of the point, and p is the refrigerant density; g is the acceleration of gravity, and C is a constant.

[0053] For the highest point of the return pipe and the throat 403, according to Bernoulli equation (2), the following can be obtained:

[0054]

[0055] The above formula (3) can be transformed to obtain:

[0056]

[0057] Since:

[0058] Ap = p1-p2 (5)

[0059]

[0060] wherein, Ap is the pressure difference between the highest point of the return pipe and the throat 403, and Q is the flow rate of the refrigerant; the relationship formulas (5) and (6) are substituted into the relationship formula (4), and the relationship formula (1) is obtained.

[0061] In an embodiment of the present application, the highest point of the return pipe is provided with a mounting hole; the one-way valve 600 includes a flapper and a limiting portion, one end of the flapper is hinged to the pipe wall of the return pipe at the mounting hole, and the limiting portion is connected to the pipe wall of the return pipe at the mounting hole; when the one-way valve 600 is opened, the flapper swings towards the side of the exhaust pipe 500; when the one-way valve 600 is closed, the other end of the flapper abuts against the limiting portion, and the flapper is in a horizontal state.

[0062] When the one-way valve 600 is opened, the flapper swings around the hinge point towards the side of the exhaust pipe 500 under the action of the pressure difference, at this time, the refrigerant can enter the exhaust pipe 500 through the gap between the flapper and the pipe wall of the return pipe; and when the one-way valve 600 is closed, the flapper is in a horizontal state under the joint action of its own gravity and the limiting portion, and the other end thereof abuts against the limiting portion tightly, thereby completely plugging the mounting hole to prevent the refrigerant from leaking in the non-exhaust state. This structure design not only ensures the smoothness of the exhaust process, but also ensures the good airtightness of the return pipe when not exhausting, effectively improving the operation stability and reliability of the liquid cooling system.

[0063] In an embodiment of the present application, please refer to Figure 1The reflux pipeline includes a first reflux pipe 801 and a second reflux pipe 802. One end of the first reflux pipe 801 is connected with the output end of the heat exchanger 100, and the other end of the first reflux pipe 801 is connected with the input end of the exhaust device 400. One end of the second reflux pipe 802 is connected with the output end of the exhaust device 400, and the other end of the second reflux pipe 802 is connected with the input end of the immersion tank 200.

[0064] In the embodiment, the first reflux pipe 801 and the second reflux pipe 802 form a complete reflux path through the exhaust device 400. The segmented design not only facilitates the installation and maintenance of the exhaust device 400, but also dynamically adjusts the flow and pressure of the reflux refrigerant through the exhaust device 400, ensuring stable flow of the refrigerant during reflux. At the same time, the first reflux pipe 801 introduces the refrigerant output by the heat exchanger 100 into the exhaust device 400, and after being treated by the exhaust device 400, the degassed refrigerant is transported to the immersion tank 200 by the second reflux pipe 802, effectively avoiding the accumulation of air in the reflux pipeline and improving the heat exchange efficiency of the entire liquid cooling system.

[0065] In an embodiment of the present application, please refer to Figure 2 The exhaust device 400 includes an inlet section 401, a contraction section 402, a throat 403, and an expansion section 404 arranged in sequence. The inlet section 401 is in communication with the first reflux pipe 801. The expansion section 404 is in communication with the second reflux pipe 802.

[0066] In the embodiment, the inlet section 401, the contraction section 402, the throat 403, and the expansion section 404 of the exhaust device 400 are connected in sequence to form a Venturi tube structure. When the refrigerant enters the inlet section 401 from the first reflux pipe 801, the pipe cross-sectional area gradually decreases as the refrigerant flows through the contraction section 402, and the flow rate of the refrigerant continuously increases. At the throat 403, the flow rate reaches a maximum, and at this time, according to Bernoulli's principle, the pressure at the throat 403 is at a minimum, forming a stable negative pressure area to provide power for the exhaust pipe 500 to suck in air. Subsequently, the refrigerant enters the expansion section 404, the pipe cross-sectional area gradually increases, the flow rate gradually decreases, and the pressure gradually recovers, so that the refrigerant can smoothly flow into the second reflux pipe 802, reducing the influence of pressure fluctuations caused by sudden changes in flow rate on the system. This structural design can efficiently utilize the Venturi effect, ensuring normal reflux of the refrigerant while significantly enhancing the air suction capacity of the exhaust device 400.

[0067] In an embodiment of the present application, please refer to Figure 2 The exhaust device 400 further includes a first flange interface 405 and a second flange interface 406. The first flange interface 405 is used to connect the first reflux pipe 801 and the inlet section 401. The second flange interface 406 is used to connect the expansion section 404 and the second reflux pipe 802.

[0068] In this embodiment, the first flange interface 405 and the second flange interface 406 adopt a standard flange structure design, and the flange surface is provided with a sealing groove, which can embed a rubber sealing ring resistant to refrigerant corrosion, to ensure the sealing performance of the interface and prevent refrigerant leakage. During installation, the first flange interface 405 is fastened and connected with the corresponding flange of the first return pipe 801 through bolts, so that the inlet section 401 forms a rigid communication with the first return pipe 801, avoiding loosening of the interface due to pipeline vibration. Similarly, the second flange interface 406 is connected with the second return pipe 802 in the same way. This flange connection structure not only facilitates quick assembly and disassembly of the exhaust device 400 and the return pipeline, and facilitates maintenance and replacement of internal components of the exhaust device 400 in the later period, but also can effectively withstand the pressure and impact force generated by the refrigerant flow in the pipeline, ensuring the structural stability of the entire liquid cooling system.

[0069] In an embodiment of the present application, please refer to Figure 2 , the throat 403 is provided with a negative pressure port 431 connected with the exhaust pipe 500.

[0070] In this embodiment, the negative pressure port 431 can accurately connect the exhaust pipe 500 with the negative pressure area of the throat 403, ensuring that the exhaust pipe 500 can be directly connected to the position with the lowest pressure, thereby maximizing the air suction efficiency. The position of the negative pressure port 431 is preferably set in the middle region of the throat 403, where the flow rate is most stable and the negative pressure value is most balanced, which can avoid fluctuations in suction capacity caused by uneven distribution of flow rate in the throat 403. In addition, the connection between the negative pressure port 431 and the exhaust pipe 500 adopts a sealing structure, such as a rubber sealing ring or a welding process, to prevent refrigerant leakage from the connection gap during flow, further improving the sealing performance and safety of the system.

[0071] In an embodiment of the present application, the pipe diameter of the throat 403 is 30%-70% of the pipe diameter of the inlet section 401.

[0072] It can be understood that the larger the pipe diameter of the throat 403, the smaller the flow rate and pressure change of the refrigerant flowing through the throat 403. Therefore, the size of the pipe diameter of the throat 403 is usually related to the flow rate of the refrigerant and the height of the installation position. When the flow rate of the refrigerant is faster and the installation height is lower, the flow rate and pressure change of the refrigerant through the throat 403 are larger, and at this time, the flow rate and pressure change can be reduced by increasing the pipe diameter size of the throat 403. Limiting the pipe diameter of the throat 403 to be within the range of 30%-70% of the pipe diameter of the inlet section 401 is based on the comprehensive optimization results of Venturi effect and system energy consumption.

[0073] When the throat 403 is too small (e.g., less than 30%), although a stronger negative pressure can be generated, the flow resistance of the refrigerant will significantly increase, the power consumption of the pump 300 will greatly increase, and pipeline vibration and noise problems may be caused. When the throat 403 is too large (e.g., greater than 70%), the flow rate is insufficient, the negative pressure effect is weakened, and the one-way valve 600 cannot be effectively opened, which affects the exhaust efficiency. Through a large number of experiments, it is verified that the pipe diameter ratio of 30%-70% can control the flow resistance within a reasonable range while ensuring sufficient negative pressure, so as to balance the exhaust performance and system energy consumption. For example, when the pipe diameter of the inlet section 401 is 100 mm, the pipe diameter of the throat 403 can be selected as about 50 mm (i.e., a ratio of 50%), so that stable negative pressure can be generated to meet the exhaust demand, and the additional energy consumption of the pump 300 can be controlled within 5%, so that the economy and reliability of the system are considered.

[0074] In an embodiment of the present application, a pressure sensor is arranged at the highest point of the return pipeline, and the pressure sensor is used to monitor the pressure change at the throat 403.

[0075] It can be understood that when air is accumulated, the cross-sectional area of the refrigerant flowing through this area is equivalent to being reduced, which causes the pressure of the refrigerant to change. Therefore, by arranging the pressure sensor at the highest point of the return pipeline, the pressure fluctuation of this area can be captured in real time, and key data support is provided for the judgment of the exhaust state of the system. When the pressure sensor monitors that the pressure at the highest point of the return pipeline decreases or periodically fluctuates, a comparative analysis can be performed in combination with the theoretical pressure difference calculated by formula (1). If the actual pressure deviates from the theoretical value by more than a preset range, it indicates that there may be air accumulation in this area, and the system can automatically trigger the flow regulation mechanism according to this, increase the refrigerant flow by increasing the power of the pump 300, and then increase the pressure difference between the highest point of the return pipeline and the throat 403, so as to ensure that the one-way valve 600 can be opened in time and the accumulated air can be discharged.

[0076] In an embodiment of the present application, a flow sensor is arranged at the highest point of the return pipeline, and the flow sensor is used to monitor the flow change at the throat 403.

[0077] It can be understood that air accumulation at the highest point of the return pipeline will also cause the flow of the refrigerant in this area to change. When air accumulates, it will occupy part of the pipeline space, causing the effective cross-sectional area of the refrigerant participating in the flow to decrease. In the case where the power of the pump 300 remains unchanged, the flow value monitored by the flow sensor will show an upward trend or abnormal fluctuation. By collecting flow data in real time and combining the monitoring results of the pressure sensor, the air accumulation state of the highest point of the return pipeline can be more comprehensively judged.

[0078] The working principle of the liquid cooling system provided in the embodiments of the present application is as follows:

[0079] When the liquid cooling system is started, the pump 300 drives the refrigerant to flow out of the immersion tank 200, and then sequentially passes through the heat exchanger 100 and the heat generating component to exchange heat. The refrigerant after absorbing heat has a higher temperature, and then enters the return pipeline. The refrigerant in the return pipeline first flows through the first return pipeline 801, forms a stable flow at the inlet section 401 of the exhaust device 400 of the Venturi structure, then passes through the contraction section 402 to accelerate, and generates a negative pressure area at the throat 403. At this time, if the highest point of the return pipeline changes due to the accumulation of gas, the pressure sensor and the flow sensor can capture the relevant data in real time, and combine the preset pressure difference threshold to change the refrigerant flow by adjusting the power of the pump 300, so that a sufficient pressure difference is formed between the highest point of the return pipeline and the throat 403. When the pressure difference reaches the opening condition of the one-way valve 600, the flapper swings to one side of the exhaust pipe 500 around the hinge point, and the accumulated gas is sucked into the exhaust device 400 through the exhaust pipe 500 under the action of negative pressure, and then flows back into the immersion tank 200 together with the return refrigerant and further dissipates into the atmosphere; at the same time, after the refrigerant mixes with air, its flowability is greatly improved, which is more conducive to the heat dissipation efficiency of the liquid cooling system. After the exhaust is completed, the pressure difference decreases, and the flapper is reset to close under the action of gravity and the limiting part to prevent refrigerant leakage.

[0080] When the liquid cooling system is turned off, the refrigerant in the return pipeline falls back to generate negative pressure. At this time, the flapper of the one-way valve 600 remains closed under the joint action of the external atmospheric pressure and the negative pressure in the pipeline, so that the air outside will not be sucked into the return pipeline, and therefore the refrigerant leakage phenomenon will not occur.

[0081] In this process, the exhaust device 400 of the Venturi structure efficiently utilizes the principle of fluid mechanics to realize automatic exhaust, and the cooperative monitoring of the pressure and flow sensors ensures the precise control of the exhaust process. The segmented return pipeline design provides convenience for system maintenance and performance optimization. The three work together to enable the liquid cooling system to operate stably for a long time and effectively guarantee the heat dissipation demand of the heat generating component.

[0082] The application also provides an exhaust method of a liquid cooling system, which adopts the above liquid cooling system. Please refer to Figure 4 The exhaust method comprises the following steps:

[0083] Starting the liquid cooling system;

[0084] Judging whether there is air accumulation in the heat exchanger 100;

[0085] If there is air accumulation, increasing the power of the pump 300 to increase the refrigerant flow; the one-way valve 600 is automatically opened, the accumulated air flows back to the immersion tank 200 through the exhaust pipe 500, the throat 403 and the return pipeline, and then flows out of the immersion tank 200 into the atmosphere;

[0086] If there is no air accumulation, the power of the pump 300 remains unchanged, and the liquid cooling system continues to operate normally.

[0087] In this embodiment, the step of determining whether the heat exchanger 100 has air accumulation is specifically realized by real-time acquisition of pressure difference and refrigerant flow data in the system through the pressure and flow sensors. When the sensor detects that the pressure difference reaches the preset threshold and the flow fluctuates abnormally, the system automatically determines that there is air accumulation; otherwise, if the pressure difference is stable in the normal range and the flow remains smooth, it is determined that there is no air accumulation. When the power of the pump 300 is increased, the system will adjust in steps according to the difference between the current pressure difference and the target threshold to avoid the impact of sudden power change on the system, while monitoring the opening state of the one-way valve 600 and the exhaust flow in real time to ensure that the air can be quickly and completely exhausted. In the process of air flowing back to the immersion tank 200 through the exhaust pipe 500, the throat 403 of the Venturi structure, and the return pipe, the throat 403 of the Venturi structure will generate a local negative pressure, further accelerating the separation and flow of air and refrigerant, and improving the exhaust efficiency. The immersion tank 200 is a non-closed device that can automatically exhaust the air carried by the backflow refrigerant to the atmosphere, and the separated pure refrigerant can participate in the system circulation again to ensure the continuous and stable operation of the liquid cooling system.

[0088] It can be understood that when the air is exhausted, the power of the pump 300 is reduced to avoid the risk of increased energy consumption and overheating of the equipment caused by the continuous high-power operation of the pump 300. At this time, the system will gradually adjust the power of the pump 300 to the normal operating range according to the real-time data fed back by the pressure sensor and the flow sensor, so that the refrigerant flow returns to a stable state. With the decrease of the power of the pump 300, the pressure difference between the highest point of the return pipe and the throat 403 will also decrease accordingly, and when the pressure difference decreases to the closing threshold of the one-way valve 600, the flapper of the one-way valve 600 resets under the action of its own gravity and the limiting part, reseals the installation hole, and prevents refrigerant leakage. At the same time, the system continues to monitor the pressure and flow parameters through the sensors to ensure that air cannot accumulate again, thereby realizing the stable and circulating operation of the liquid cooling system in a low-energy state. This dynamic adjustment mechanism can not only ensure the rapid exhaust of air through high-power driving in the exhaust stage, but also automatically reduce the power after the exhaust is completed, taking into account the exhaust efficiency and energy saving needs of the system, and prolonging the service life of the equipment.

[0089] The above only describes the preferred embodiments of the present application and should not be used to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A liquid cooling system, characterized in that: include: heat exchangers; An immersion box, wherein the output end of the immersion box is connected to the input end of the heat exchanger via an output pipe; the input end of the immersion box is connected to the output end of the heat exchanger via a return pipe; a pump, the pump being arranged on the output pipe; An exhaust device is provided on the return pipe; a throat is provided in the middle of the exhaust device so that the diameter of the exhaust device is smaller in the middle and larger at both ends; An exhaust pipe, one end of which is connected to the highest point of the return pipe through a one-way valve, and the other end of which is communicated with the throat.

2. The liquid cooling system according to claim 1, wherein: The pressure difference Δp between the highest point of the return pipe and the throat satisfies the following relationship: Among them, p1 is the pressure of the refrigerant at the highest point of the return pipe, v1 is the flow velocity of the refrigerant at the highest point of the return pipe, h1 is the height from the ground at the highest point of the return pipe; S1 is the pipe cross-sectional area at the highest point of the return pipe; p2 is the pressure of the refrigerant at the throat, v2 is the flow velocity of the refrigerant at the throat, h2 is the height from the ground at the throat; S2 is the pipe cross-sectional area at the throat; ρ is the refrigerant density; g is the acceleration of gravity; Q is the flow rate of the refrigerant.

3. The liquid cooling system according to claim 1, wherein: A mounting hole is provided at the highest point of the return pipe; the one-way valve includes a baffle and a limiting portion, one end of the baffle is hinged to the pipe wall of the return pipe at the mounting hole, and the limiting portion is connected to the pipe wall of the return pipe at the mounting hole; When the one-way valve is opened, the baffle swings toward one side of the exhaust pipe; when the one-way valve is closed, the other end of the baffle abuts against the limiting portion, and the baffle is in a horizontal state.

4. The liquid cooling system according to claim 1, wherein: The return pipe includes a first return pipe and a second return pipe, one end of the first return pipe is connected to the output end of the heat exchanger, and the other end of the first return pipe is connected to the input end of the exhaust device; one end of the second return pipe is connected to the output end of the exhaust device, and the other end of the second return pipe is connected to the input end of the immersion box.

5. The liquid cooling system according to claim 4, wherein: The exhaust device includes an inlet section, a contraction section, a throat, and an expansion section arranged in sequence; the inlet section is connected to the first return pipe; and the expansion section is connected to the second return pipe.

6. The liquid cooling system according to claim 1, wherein: A negative pressure port is provided on the throat, and the negative pressure port is connected to the exhaust pipe.

7. The liquid cooling system according to claim 5, wherein: The diameter of the throat is 30%-70% of the diameter of the inlet section.

8. The liquid cooling system according to claim 2, wherein: A pressure sensor is provided at the highest point of the return pipe, and the pressure sensor is used to monitor the pressure change at the throat.

9. The liquid cooling system according to claim 2, wherein: A flow sensor is provided at the highest point of the return pipe, and the flow sensor is used to monitor the flow change at the throat.

10. A method for exhausting a liquid cooling system, using the liquid cooling system according to claims 1 to 9, characterized in that: The exhaust method comprises: Starting the liquid cooling system; determining whether air accumulation exists in the heat exchanger; If air is gathered, the power of the pump is increased to increase the refrigerant flow rate; the one-way valve automatically opens, and the gathered air flows back into the immersion box through the exhaust pipe, throat, and return pipe, and then is discharged into the atmosphere along with the immersion box; If there is no air accumulation, the power of the pump remains unchanged and the liquid cooling system continues to operate normally.

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