High-reliability negative pressure liquid cooling system and control method thereof

Abstract

The application belongs to the technical field of liquid cooling and heat energy engineering, and particularly relates to a high-reliability negative pressure liquid cooling system and a control method thereof. When the liquid cooling system is started, the controller instructs the vacuum pump to work, and when the accumulator air pressure gauge liquid level control sensor reaches the system preset pressure value, the controller controls the liquid supply pump to work, and the system enters a normal working state. When the circulating system normally operates, the first normally-opened control valve remains in an open state, the second normally-opened control valve remains in a closed state, and the normally-closed bypass valve remains in a closed state. The cooling liquid sequentially flows from the water tank through the first constant pressure valve, the first normally-opened control valve, the third normally-opened control valve, the load, and the liquid supply pump, and finally flows back to the water tank through the second constant pressure valve, so that the liquid cooling circulating system loop is normally operated. Through the application of the accumulator in the negative pressure liquid cooling system, the controller avoids misjudgment of normal pressure fluctuation of the system, and the backflow program is not started by mistake, so that the noise caused by frequent starting of the vacuum pump is reduced.

Description

Technical Field

[0001] This invention belongs to the field of liquid cooling and thermal energy engineering, and particularly relates to a highly reliable negative pressure liquid cooling system and its control method. Background Technology

[0002] Modern electronic devices are developing rapidly, becoming increasingly compact, and their heat flux density is also increasing. Simultaneously, the heat exchange methods of electronic devices have changed significantly, shifting from natural heat exchange and forced ventilation to liquid cooling. Liquid cooling systems primarily employ liquid circulation cooling to exchange heat with the electronic device. The circulating liquid cooling system dissipates heat to the external environment, continuously cooling the electronic device through circulation and providing a stable and suitable operating environment.

[0003] A liquid cooling system typically includes a cold plate, a heat exchanger, piping, a liquid supply pump, and various sensors. At the load end, the cold plate is bonded to the plate to be cooled and has internal fluid channels that transfer heat from the plate to the fluid. The fluid in the cold plate is then transferred to the environment through the piping. The liquid supply pump regulates the flow rate of the coolant in the piping, thereby adjusting the heat exchange capacity of the coolant. Sensors are used to detect pressure, temperature, and other parameters within the liquid cooling system.

[0004] Traditional liquid cooling systems are typically positive pressure systems, meaning the liquid pressure inside the pipes is greater than the ambient pressure outside the pipes. When the pipes are perforated due to corrosion or other reasons, the liquid inside the pipes will leak from the perforation onto the circuit board, causing damage to the load end. For example, if the coolant is water, water leaking from the pipes onto the circuit board may cause the circuit board to short-circuit or burn out.

[0005] In traditional negative pressure liquid cooling systems, a pressure regulating device is installed at the constant pressure point of the liquid cooling circuit. This device adjusts the absolute pressure of the circuit to ensure it is lower than atmospheric pressure. This prevents leakage of water or other cooling fluids even if pipes or valves leak, ensuring system safety. However, in mobile operating environments such as shipborne, airborne, or vehicle-mounted systems, pressure changes caused by vibration, impact, and water hammer effects can lead to false alarms, frequent vacuum pump starts, high noise levels, and low reliability.

[0006] In summary, existing positive pressure liquid cooling systems cannot actively prevent leaks, while traditional negative pressure liquid cooling systems have poor environmental adaptability, frequent vacuum pump starts, high noise, and low reliability. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a highly reliable negative pressure liquid cooling system and its control method. By applying an accumulator to the negative pressure liquid cooling system, the controller avoids misjudging normal fluctuations in system pressure and frequent starts, thereby reducing noise.

[0008] This invention is achieved through the following technical solution:

[0009] This invention discloses a high-reliability negative pressure liquid cooling system, comprising a controller, a vacuum pump, an accumulator, a barometer, a liquid level control sensor, an accumulator, a first constant pressure valve, a water tank, a first normally open control valve, a second normally open control valve, a second constant pressure valve, a liquid supply pump, a normally closed bypass valve, a load, and a third normally open control valve. The controller is connected via wiring to the liquid supply pump, the vacuum pump, the accumulator, the barometer, the liquid level control sensor, the water tank, the first normally open control valve, the second normally open control valve, and the third normally open control valve. The outlet of the water tank is connected to the first constant pressure valve via a pipeline. The first normally open control valve is split into two paths. One path is connected to the inlet of the accumulator and the third normally open control valve via a pipeline. The other path is connected to the inlet of the second normally open control valve via a pipeline. The outlet pipeline of the third normally open control valve is connected to the inlet of the load. The outlet of the load is connected to the inlet of the liquid supply pump via a pipeline. The outlet of the liquid supply pump is connected to the inlet of the second constant pressure valve via a pipeline. The outlet of the second constant pressure valve is connected to the inlet of the water tank via a pipeline. The gas outlet pipeline of the accumulator barometer liquid level control sensor is connected to the vacuum pump and the gas inlet of the accumulator.

[0010] Furthermore, the outlet of the second normally open control valve is connected to the inlet of the liquid supply pump and the normally closed bypass valve, respectively, and the outlet of the normally closed bypass valve is connected to the outlet of the liquid supply pump and the inlet of the second constant pressure valve through a pipeline.

[0011] Another aspect of this invention discloses a control method for a high-reliability negative pressure liquid cooling system. When the liquid cooling system starts, the controller commands the vacuum pump to operate. After the accumulator pressure gauge liquid level control sensor reaches the system's preset pressure value, the controller controls the liquid supply pump to operate, and the system enters normal operating mode. During normal operation of the circulation system, the first normally open control valve remains open, the second normally open control valve remains closed, and the normally closed bypass valve remains closed. The coolant flows from the water tank sequentially through the first constant pressure valve, the first normally open control valve, the third normally open control valve, the load, and the liquid supply pump. The constant pressure valve eventually returns the liquid to the water tank, ensuring the normal operation of the liquid cooling circulation system loop. When the load-side pipeline is damaged and the leak point is connected to the atmosphere, the negative pressure between the atmospheric pressure and the accumulator forces the liquid in the pipe to the accumulator. When the liquid level in the accumulator rises and the liquid level control sensor of the accumulator pressure gauge reaches the preset value, the controller issues a command based on this signal. The third normally open control valve switches to the closed state, the first normally open control valve switches to the closed state, and the second normally open control valve switches to the open state. At this time, the liquid supply pump simultaneously draws coolant from both the load side and the accumulator side to the water tank.

[0012] Furthermore, in the event of damage to pipelines other than the supply pump or in other emergencies, close all control valves and manually open the normally closed bypass valve.

[0013] Furthermore, when the liquid cooling system is started, the entire system except the water tank is under negative pressure.

[0014] The advantages and positive effects of this invention are:

[0015] (1) By applying an accumulator to a negative pressure liquid cooling system, this invention avoids the controller misjudging normal fluctuations in system pressure and incorrectly starting the reflux program, thus avoiding frequent starts of the vacuum pump and reducing noise caused by frequent starts of the vacuum pump.

[0016] (2) The present invention utilizes a control valve to switch the direction of liquid flow in the pipe when there is a liquid supply pump, thereby switching from the liquid supply state to the liquid recovery protection state, avoiding liquid leakage, reducing system complexity and improving system reliability;

[0017] (3) The present invention improves the environmental adaptability of the negative pressure liquid cooling system under mobile conditions such as shipborne, vehicle-mounted, and airborne. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the high-reliability negative pressure liquid cooling system of the present invention;

[0019] This includes the following reference numerals: 1-Controller, 2-Vacuum pump, 3-Accumulator barometer liquid level control sensor, 4-Accumulator, 5-First constant pressure valve, 6-Water tank, 7-First normally open control valve, 8-Second normally open control valve, 9-Second constant pressure valve, 10-Liquid supply pump, 11-Normally closed bypass valve, 12-Load, 13-Third normally open control valve. Detailed Implementation

[0020] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] Example 1

[0023] A high-reliability negative pressure liquid cooling system includes a controller 1, a vacuum pump 2, an accumulator, a barometer, a liquid level control sensor 3, an accumulator 4, a first constant pressure valve 5, a water tank 6, a first normally open control valve 7, a second normally open control valve 8, a second constant pressure valve 9, a liquid supply pump 10, a normally closed bypass valve 11, a load 12, and a third normally open control valve 13.

[0024] The controller 1 is connected to the liquid supply pump 10, vacuum pump 2, accumulator barometer liquid level control sensor 3, water tank 6, first normally open control valve 7, second normally open control valve 8, and third normally open control valve 13 via wiring.

[0025] The outlet of water tank 6 is connected to the first constant pressure valve 5 and the first normally open control valve 7 via pipelines, and then splits into two paths. One path is connected to the accumulator 4 and the inlet of the third normally open control valve 13 via pipelines, and the other path is connected to the inlet of the second normally open control valve 8 via pipelines. The outlet of the second normally open control valve 8 is connected to the inlet of the liquid supply pump 10 and the normally closed bypass valve 11, respectively. The outlet of the normally closed bypass valve 11 is connected to the outlet of the liquid supply pump 10 and the inlet of the second constant pressure valve 9 via pipelines.

[0026] The outlet pipe of the third normally open control valve 13 is connected to the inlet of the load 12. The outlet of the load 12 is connected to the inlet of the liquid supply pump 10 through a pipe. The outlet of the liquid supply pump 10 is connected to the inlet of the second constant pressure valve 9 through a pipe. The outlet of the second constant pressure valve 9 is connected to the inlet of the water tank 6 through a pipe.

[0027] The gas outlet pipe of the accumulator barometer liquid level control sensor 3 is connected to the vacuum pump 2 and the gas inlet of the accumulator 4, respectively.

[0028] Example 2

[0029] A control method for a high-reliability negative pressure liquid cooling system, specifically including:

[0030] When the liquid cooling system starts, controller 1 instructs vacuum pump 2 to operate, causing the pressure on the side of the system away from water tank 6, except for the first constant pressure valve 5 and the second constant pressure valve 9, to be lower than atmospheric pressure, thus placing the system in a negative pressure state except for water tank 6. After the accumulator 4, accumulator barometer, and liquid level control sensor 3 reach the system's preset pressure value, controller 1 controls the liquid supply pump 10 to operate, and the system enters normal operating condition.

[0031] When the circulation system is running normally, the first normally open control valve 7 remains open, the second normally open control valve 8 remains closed, and the normally closed bypass valve 11 remains closed. At this time, the coolant flows from the water tank 6 through the first constant pressure valve 5, the first normally open control valve 7, the third normally open control valve 13, the load 12, and the liquid supply pump 10 in sequence, and finally flows back to the water tank 6 through the second constant pressure valve 9, so as to realize the normal operation of the liquid cooling circulation system loop.

[0032] When the pipeline at load 12 is damaged, the leak point is connected to the atmosphere. The negative pressure between the atmospheric pressure and the accumulator 4 will force the liquid in the pipeline to the accumulator 4.

[0033] As the liquid level in accumulator 4 rises, the pressure in accumulator 4 gradually increases. When the liquid level control sensor 3 of the accumulator barometer reaches the preset value, it sends a command to controller 1 based on this signal. The third normally open control valve 13 switches to the closed state, the first normally open control valve 7 switches to the closed state, and the second normally open control valve 8 switches to the open state. At this time, the liquid supply pump 10 simultaneously draws coolant from the load side 12 and the accumulator 4 side to the water tank 6.

[0034] In case of damage to pipelines other than the liquid supply pump 10 or other emergencies, close all control valves and manually open the normally closed bypass valve 11 to protect the liquid supply pump 10.

[0035] Specifically, due to its inherent characteristics, accumulator 4 can store the energy generated by vacuum pump 2, maintain negative pressure in the pipeline, release it again when needed, and provide a storage space for the liquid. In negative pressure liquid cooling systems, under conditions such as vibration, impact, start-up, shutdown, and water hammer, the pressure inside the pipes fluctuates. Accumulator 4 can temporarily replace the function of vacuum pump 2, maintaining negative pressure and recovering some of the refluxed liquid. This helps prevent controller 1 from misinterpreting normal system pressure fluctuations and incorrectly initiating the reflux procedure, thus avoiding frequent starts of vacuum pump 2.

[0036] In particular, by controlling the opening and closing of the first normally open control valve 7 and the second normally open control valve 8, only one liquid supply pump 10 is used to realize the flow direction conversion of the liquid cooling system, which reduces the system complexity and improves the system reliability.

[0037] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept, and these all fall within the protection scope of the present invention.

Claims

1. A control method for a high-reliability negative pressure liquid cooling system, characterized in that, The high-reliability negative pressure liquid cooling system includes a controller (1), a vacuum pump (2), an accumulator barometer liquid level control sensor (3), an accumulator (4), a first constant pressure valve (5), a water tank (6), a first normally open control valve (7), a second normally open control valve (8), a second constant pressure valve (9), a liquid supply pump (10), a normally closed bypass valve (11), a load (12), and a third normally open control valve (13). The controller (1) is connected via lines to the liquid supply pump (10), the vacuum pump (2), the accumulator barometer liquid level control sensor (3), the water tank (6), the first normally open control valve (7), the second normally open control valve (8), and the third normally open control valve (9). 13) Connection: The outlet of the water tank (6) is connected to the first constant pressure valve (5) and the first normally open control valve (7) via pipelines, and then splits into two paths. One path is connected to the inlet of the accumulator (4) and the third normally open control valve (13) via pipelines. The other path is connected to the inlet of the second normally open control valve (8) via pipelines. The outlet pipeline of the third normally open control valve (13) is connected to the inlet of the load (12). The outlet of the load (12) is connected to the inlet of the liquid supply pump (10) via pipelines. The outlet of the liquid supply pump (10) is connected to the inlet of the second constant pressure valve (9) via pipelines. The outlet of the second constant pressure valve (9) is connected to the inlet of the water tank (6) via pipelines. The gas outlet of the accumulator barometer liquid level control sensor (3) is connected to the vacuum pump (2) and the gas inlet of the accumulator (4) through pipelines. The outlet of the second normally open control valve (8) is connected to the inlet of the liquid supply pump (10) and the normally closed bypass valve (11) through pipelines. The outlet of the normally closed bypass valve (11) is connected to the outlet of the liquid supply pump (10) and the inlet of the second constant pressure valve (9) through pipelines. The control method of the high-reliability negative pressure liquid cooling system is as follows: when the liquid cooling system is started, the controller (1) commands the vacuum pump (2) to work. After the accumulator barometer liquid level control sensor (3) reaches the preset pressure value of the system, the controller (1) controls the liquid supply pump (10) to work. When the system enters normal working state, the first normally open control valve (7) remains open, the second normally open control valve (8) remains closed, and the normally closed bypass valve (11) remains closed. The coolant flows from the water tank (6) through the first constant pressure valve (5), the first normally open control valve (7), the third normally open control valve (13), the load (12), and the liquid supply pump (10) in sequence, and finally flows back to the water tank (6) through the second constant pressure valve (9), thus realizing the normal operation of the liquid cooling circulation system loop. When the pipeline at the load (12) end is damaged and the leak point is connected to the atmosphere, the negative pressure between the atmospheric pressure and the accumulator (4) will press the liquid in the pipe to the accumulator (4).When the liquid level in the accumulator (4) rises and the liquid level control sensor (3) of the accumulator pressure gauge reaches the preset value, the controller 1 issues a command based on this signal. The third normally open control valve (13) switches to the closed state, the first normally open control valve (7) switches to the closed state, and the second normally open control valve (8) switches to the open state. At this time, the liquid supply pump (10) simultaneously draws coolant from the load (12) side and the accumulator (4) side to the water tank (6).

2. The control method according to claim 1, characterized in that, In case of damage to pipelines other than the supply pump (10) or other emergencies, close all control valves and manually open the normally closed bypass valve (11).

3. The control method according to claim 1, characterized in that, When the liquid cooling system is started, the system is under negative pressure except for the water tank (6).

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