A gravity-fed liquid reflux phase change heat transfer system with its own cold source

Abstract

A gravity-fed liquid-recirculating phase change heat transfer system with its own cold source includes a condenser, a flash tank, multiple evaporators, a throttling valve A corresponding to each evaporator, a circulating pump, a compressor, a throttling valve B, a gas collecting pipe, and a liquid supply pipe. The liquid refrigerant outlet of the flash tank is connected to the liquid supply pipe. The refrigerant inlet of each evaporator is connected to the outlet of the corresponding throttling valve A via a pipe, and the inlet of throttling valve A is connected to the liquid supply pipe via a pipe. The refrigerant outlet of each evaporator is connected to the gas collecting pipe. The refrigerant inlet of the circulating pump is connected to the gas collecting pipe, and the refrigerant outlet of the circulating pump is connected to the liquid supply pipe. The refrigerant inlet of the compressor is connected to both the gas collecting pipe and the gaseous refrigerant outlet of the flash tank. The refrigerant outlet of the compressor is connected to the refrigerant inlet of the condenser. The throttling valve B is installed between the condenser and the flash tank.

Description

Technical Field

[0001] This application relates to the field of data center cooling technology, specifically to a gravity-fed liquid recirculation phase change heat transfer system with its own cold source. Background Technology

[0002] With the development of data centers, the amount of heat generated is increasing. Existing computer room air conditioning systems all adopt a thermal management approach that controls the overall temperature of the computer room, resulting in a relatively small heat exchange temperature difference and low heat exchange efficiency.

[0003] The main heat dissipation methods currently used in computer rooms are as follows:

[0004] One method is precision air conditioning with precise air delivery. This method uses air ducts in the computer room to directly deliver the cold air from the precision air conditioner to the server rack. The main advantage is that it allows the cold air to be directly delivered to the server rack, keeping the air intake of the server rack at a relatively ideal low temperature. The disadvantage is that the fan needs to be a high-pressure fan that can overcome the resistance of the air duct, so the fan power consumption is relatively high, which in turn leads to a relatively high power consumption of the precision air conditioner.

[0005] The second method is in-row air conditioning, which delivers cool air directly to the cabinets requiring cooling through specific ducts, increasing the temperature difference between the supply and supply air. This can appropriately raise the supply air temperature and improve the overall performance of the air conditioning system. The main drawback of this method is that it requires the air conditioning system's fans to provide a large pressure head, which increases the energy consumption of the air delivery. In addition, the airflow distribution in the duct is not easy to adjust.

[0006] Thirdly, there is the back panel air conditioning, which places the evaporator of the air conditioning system at the exhaust vent of the cabinet. This can effectively reduce the cooling capacity dissipation of the air conditioning system and provide cooling on demand; however, introducing water into the computer room poses a safety hazard.

[0007] In addition to the three heat dissipation methods mentioned above, gravity-driven heat pipe heat dissipation products are increasingly widely used in the field of computer room heat dissipation due to their advantages such as high efficiency, energy saving, safety, and reliability. However, gravity heat pipes cannot achieve safe and stable high-power heat dissipation during application. Therefore, designing a cooling system that can utilize outdoor natural cold sources while improving the overall performance and reliability of the unit and ensuring the normal and stable operation of data center or communication equipment throughout the year is an urgent problem to be solved in this field. Summary of the Invention

[0008] The purpose of this invention is to overcome the problems existing in the prior art and to provide a gravity-fed liquid recirculation phase change heat transfer system with its own cold source. It can fully utilize the combination of natural cold source and mechanical refrigeration to achieve high-power heat exchange of a single unit. Furthermore, it achieves precise liquid supply to each evaporator through a throttling valve. The design of the circulating pump solves the problem that the gas collection pipe is filled with liquid refrigerant and cannot operate normally when the high-power phase change heat transfer system is shut down and restarted.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows:

[0010] A gravity-fed liquid-supply reflux phase change heat transfer system with its own cold source includes a condenser, a flash tank, multiple evaporators, a throttling valve A corresponding to each evaporator, a circulating pump, a compressor, a throttling valve B, a gas collecting pipe, and a liquid supply pipe. The liquid refrigerant outlet of the flash tank is connected to the liquid supply pipe. The refrigerant inlet of each evaporator is connected to the outlet of the corresponding throttling valve A via a pipe, and the inlet of throttling valve A is connected to the liquid supply pipe via a pipe. The refrigerant outlet of each evaporator is connected to the liquid supply pipe via a pipe. The pipeline is connected to the gas collecting pipe; the refrigerant inlet of the circulating pump is connected to the gas collecting pipe through a pipeline, and the refrigerant outlet of the circulating pump is connected to the liquid supply pipe through a pipeline; the refrigerant inlet of the compressor is connected to the gas collecting pipe, and the refrigerant inlet of the compressor is also connected to the gaseous refrigerant outlet of the flash tank; the refrigerant outlet of the compressor is connected to the refrigerant inlet of the condenser; one end of the throttle valve B is connected to the refrigerant outlet of the condenser, and the other end of the throttle valve B is connected to the inlet of the flash tank.

[0011] Furthermore, it also includes a first check valve, which is connected between the circulation pump and the supply pipe.

[0012] Furthermore, it also includes a second check valve, which is installed between the outlet of the gaseous refrigerant in the flash tank and the compressor.

[0013] Furthermore, the flash tank is positioned higher than the evaporator, allowing the refrigerant inside the flash tank to flow back to each evaporator by gravity through the liquid supply pipe.

[0014] Furthermore, the circulating pump is a fluorine pump or a two-phase flow pump.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] The gravity-fed liquid recirculation phase change heat transfer system of this invention, with its own cold source, utilizes a flash tank and throttling valve A to achieve high-power heat dissipation from a single gravity heat pipe, driven entirely by gravity. Each evaporator is precisely supplied with liquid and operates at its optimal state. Furthermore, the design of the circulating pump makes the entire system more stable, resolving the problem of liquid refrigerant filling the gas collection pipe during restart after a sudden system shutdown, which prevents phase change heat transfer. The entire system is safe and reliable; system backup options are flexible, making it suitable for data centers with varying redundancy requirements. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the gravity-fed liquid reflux phase change heat transfer system with its own cold source, as described in this invention.

[0018] In the diagram: 1. Condenser; 2. Flash tank; 3. Evaporator; 4. Throttling valve A; 5. Circulation pump; 61. First check valve; 62. Second check valve; 7. Liquid supply pipe; 8. Gas collection pipe; 9. Compressor; 10. Throttling valve B. Detailed Implementation

[0019] The present invention will be further illustrated below with reference to embodiments. These are merely preferred embodiments and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0020] Please refer to Figure 1 As shown, the present invention provides a gravity-fed liquid reflux phase change heat transfer system with its own cold source, including a condenser 1, a flash tank 2, multiple evaporators 3, a throttling valve A4 corresponding to each evaporator, a circulating pump 5, a compressor 9, a throttling valve B10, a liquid supply pipe 7, and a gas collection pipe 8.

[0021] The liquid refrigerant outlet of the flash tank 2 is connected to the liquid supply pipe 7; the refrigerant supply port of each evaporator 3 is connected to the outlet of the throttle valve A4 corresponding to each evaporator via a pipe, and the inlet of the throttle valve A4 is connected to the liquid supply pipe 7 via a pipe; the refrigerant outlet port of each evaporator 3 is connected to the gas collecting pipe 8 via a pipe; the refrigerant inlet of the circulating pump 5 is connected to the gas collecting pipe 8 via a pipe, and the refrigerant outlet of the circulating pump 5 is connected to the liquid supply pipe 7 via a pipe; the refrigerant inlet of the compressor 9 is connected to the gas collecting pipe 8, and the refrigerant inlet of the compressor 9 is also connected to the gaseous refrigerant outlet of the flash tank 2; the refrigerant outlet of the compressor 9 is connected to the refrigerant inlet of the condenser 1; one end of the throttle valve B10 is connected to the refrigerant outlet of the condenser 1, and the other end of the throttle valve B10 is connected to the inlet of the flash tank 2.

[0022] Furthermore, it also includes a first check valve 61, which is connected between the circulation pump 5 and the supply pipe 7.

[0023] Furthermore, it also includes a second one-way valve 62, which is installed between the outlet of the gaseous refrigerant in the flash tank 2 and the compressor 9.

[0024] The flash tank 2 is positioned higher than the evaporator 3, so that the refrigerant cooled inside the flash tank 2 flows back to each evaporator 3 under the action of gravity through the liquid supply pipe 7.

[0025] The throttle valve A4 is an electronic throttle valve, which accurately supplies liquid by detecting the temperature of the corresponding evaporator 3, so that the evaporator 3 is in the optimal working state.

[0026] The circulating pump 5 is a fluorine pump or a two-phase flow pump. When there is a large amount of liquid refrigerant in the gas collection pipe 8 of the whole system, making the whole system unable to work normally, the circulating pump 5 is turned on to pump the liquid refrigerant or gas-liquid mixture stored in the gas collection pipe 8 back to the flash tank 2.

[0027] The working principle and process of a gravity-fed reflux phase change heat transfer system with its own cooling source are as follows:

[0028] During normal heat exchange, the circulating pump 5 is closed. The liquid supply pipe 7 is vertically positioned below the flash tank 2 and connected to the lower part of the flash tank 2. Under the influence of gravity, the cold refrigerant flows from the flash tank 2 through the liquid supply pipe 7 and the expansion valve A4 into each evaporator 3. The expansion valve A4 regulates the amount of refrigerant in the evaporator 3 by detecting the temperature of the corresponding evaporator 3, so that the evaporator 3 is in the optimal working state. The evaporator 3 exchanges heat with the high-temperature indoor environment, and the refrigerant in the evaporator 3 vaporizes. Then, the gaseous refrigerant enters the compressor 9 through the gas collecting pipe 8. At the same time, the gaseous refrigerant inside the flash tank 2 is processed by the second unit. The refrigerant from the compressor 9 also enters the compressor 9 through valve 62. The high-temperature and high-pressure refrigerant from the compressor 9 enters the condenser 1 to exchange heat with the external environment. After releasing heat, the gaseous refrigerant condenses into liquid refrigerant or a gas-liquid mixture. The refrigerant cooled in the condenser 1 enters the flash tank 2 through the throttle valve B10 for gas-liquid separation. Then, the gaseous refrigerant in the flash tank 2 enters the compressor 9 through the second one-way valve 62. The liquid refrigerant in the flash tank 2 flows into the evaporator 3 through the liquid supply pipe 7 and each throttle valve A4 under the action of gravity. This cycle repeats to complete the heat exchange and achieve heat dissipation from the heat source.

[0029] When the gravity-fed liquid refrigerant phase change heat transfer system with its own cold source is in operation or about to start, if there is a large amount of liquid refrigerant in the gas collecting pipe 8, which prevents the entire system from working properly, the circulation pump 5 is turned on to pump the liquid refrigerant or gas-liquid mixture stored in the gas collecting pipe 8 back to the flash tank 2. This continues until all the liquid refrigerant in the gas collecting pipe 8 is pumped out, at which point the circulation pump 5 stops working, and the gravity-fed liquid refrigerant phase change heat transfer system with its own cold source resumes normal heat exchange mode.

[0030] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A gravity-fed liquid-recirculating phase change heat transfer system with its own cold source, characterized in that: The system includes a condenser, a flash tank, multiple evaporators, a throttling valve A corresponding to each evaporator, a circulating pump, a compressor, a throttling valve B, a gas collecting pipe, and a liquid supply pipe. The liquid refrigerant outlet of the flash tank is connected to the liquid supply pipe. The refrigerant inlet of each evaporator is connected to the outlet of the corresponding throttling valve A via a pipe, and the inlet of throttling valve A is connected to the liquid supply pipe via a pipe. The refrigerant outlet of each evaporator is connected to the gas collecting pipe via a pipe. The refrigerant inlet of the circulating pump is connected to the gas collecting pipe via a pipe, and the refrigerant outlet of the circulating pump is connected to the liquid supply pipe via a pipe. The refrigerant inlet of the compressor is connected to the gas collecting pipe, and the refrigerant inlet of the compressor is also connected to the gaseous refrigerant outlet of the flash tank. The refrigerant outlet of the compressor is connected to the refrigerant inlet of the condenser. One end of the throttling valve B is connected to the refrigerant outlet of the condenser, and the other end of the throttling valve B is connected to the inlet of the flash tank.

2. The gravity-fed liquid-recirculating phase change heat transfer system with its own cold source as described in claim 1, characterized in that: It further includes a first check valve, which is connected between the circulation pump and the supply line.

3. The gravity-fed liquid-supplying reflux phase change heat transfer system with its own cold source as described in claim 1, characterized in that: It further includes a second check valve, which is installed between the outlet of the gaseous refrigerant in the flash tank and the compressor.

4. The gravity-fed liquid-supplying reflux phase change heat transfer system with its own cold source as described in claim 1, characterized in that: The flash tank is positioned higher than the evaporator, allowing the refrigerant inside the flash tank to flow back to each evaporator by gravity through the liquid supply pipe.

5. The gravity-fed liquid-recirculating phase change heat transfer system with its own cold source as described in claim 1, characterized in that: The circulating pump is a fluorine pump or a two-phase flow pump.

Images