Liquid cooling system for data center

Abstract

According to the liquid cooling system for the data center provided by the utility model, Freon is adopted as a heat exchange medium of the liquid cooling system, and a mechanical compression refrigeration direct expansion type air conditioning system (fluorine pump system) is combined with the liquid cooling system, so that the unification of an air cooling part and a liquid cooling part is realized, the pipeline is simple, the manufacturing cost is low, and the overall operation efficiency and the maintenance convenience are higher. The system has good expansibility and can be flexibly adjusted according to the outdoor temperature or the tail end load condition, and the refrigerating capacity of the cold source is correspondingly increased or reduced. The compressor is not directly connected with the evaporator and the CDU plate heat exchanger, but indirectly exchanges heat through the plate heat exchanger, so that the flow of a mechanical compression refrigeration loop is reduced, lubricating oil of the compressor is not easy to accumulate in the condenser I and the loop, the problem of unsmooth oil return of the compressor is avoided, and the service life of the compressor is prolonged. And the design support system is connected in parallel with the expansion mechanical refrigeration module, and the cold source can be flexibly adjusted according to the tail end load.

Description

Technical Field

[0001] This utility model relates to the field of heat dissipation technology for data center cabinets, and more particularly to a liquid cooling system for data centers. Background Technology

[0002] With the rise of high-performance computing technologies such as Large Scale Language Modeling (LLM), the heat density of servers in data centers has increased significantly, and traditional all-air-cooled systems can no longer meet the heat dissipation requirements. Currently, data center cooling technologies mainly include all-air-cooled systems, liquid-cooled + air-cooled systems, and a small number of all-liquid-cooled systems. Liquid-cooled + air-cooled systems typically use liquid cooling to dissipate heat from the CPU and GPU in the server, while air cooling dissipates heat from the hard drives, memory, power distribution systems, and network switches. Liquid cooling systems usually use deionized water or aqueous solutions of ethylene glycol or propylene glycol as the heat exchange medium, transported through a pipe network, while air-cooled systems require Freon systems.

[0003] In existing technical solutions, air-cooling and liquid-cooling systems are used simultaneously in data centers, but they typically require independent layout and operation and maintenance. This makes system maintenance very difficult and increases the complexity of piping layout and system cost. In addition, air-cooling systems cannot fully handle the heat density of data center servers, especially with the rise of large-scale language models (LLM), which has significantly increased the heat generation of data center servers, making all-air-cooling systems unable to meet the requirements for efficient heat dissipation. Utility Model Content

[0004] This invention provides a liquid cooling system for data centers that combines a direct expansion air conditioning system (fluorine pump system) with a liquid cooling system, allowing the air-cooled and liquid-cooled parts to use the same system. It also optimizes refrigerant distribution, simplifies the overall system design, reduces maintenance costs, and improves overall cooling efficiency.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A liquid cooling system for a data center includes a data center rack array, and a mechanical refrigeration compression circuit and a refrigerant pump circulation circuit connected to the data center rack array. The mechanical refrigeration compression circuit includes a compressor, a plate heat exchanger, a throttling device, and a condenser. The compressor's outlet is connected to a first port of the plate heat exchanger via a first pipe, the compressor's outlet is connected to the inlet of the condenser via a second pipe, and the condenser's outlet is connected to a second port of the plate heat exchanger via a third pipe. A throttling device is provided on the third pipe.

[0007] The refrigerant pump circulation loop includes a throttling device, a storage tank, a refrigerant pump, an evaporator, a second plate heat exchanger, and a second condenser. The inlet of the storage tank is connected to the third port of the first plate heat exchanger via a fourth pipeline. The outlet of the storage tank is equipped with the refrigerant pump. The evaporator and the second plate heat exchanger are connected in parallel. The first port of the evaporator is connected to the refrigerant pump via a fifth pipeline. The first port of the second plate heat exchanger is connected to the refrigerant pump via a sixth pipeline. The throttling device is installed on both the fifth and sixth pipelines. The second ports of the evaporator and the second plate heat exchanger merge and are connected to the fourth port of the first plate heat exchanger via a seventh pipeline. The second condenser is connected in parallel with the seventh pipeline.

[0008] As a further preferred embodiment of this utility model, the data center rack array consists of multiple data center servers, and the multiple data center servers are connected to the third port of the plate heat exchanger II through a refrigerant outlet pipe.

[0009] As a further preferred embodiment of this invention, the refrigerant outlet pipe is a closed loop; the refrigerant cooling systems of each data center server are connected in parallel to each other and are all connected to the refrigerant outlet pipe.

[0010] As a further preferred embodiment of this utility model, a three-way valve is provided on the seventh pipeline, and the three ports of the three-way valve are respectively connected to the fourth port of the first plate heat exchanger, the second port of the second plate heat exchanger, and the first port of the second condenser; a one-way valve is provided at the second port of the second condenser and is connected to the fourth port of the first plate heat exchanger.

[0011] As a further preferred embodiment of this utility model, a cooling fan is provided on one side of the first condenser, and the second condenser shares the cooling fan with the first condenser or is connected to an outdoor spray tower / dry cooler.

[0012] As a further preferred embodiment of this invention, the fluorine pump is used to drive the refrigerant to circulate in the fluorine pump circulation loop to deliver cooling capacity to the data center server; the refrigerant is Freon.

[0013] As a further preferred embodiment of this utility model, the plate heat exchanger is a shell-and-tube heat exchanger.

[0014] As a further preferred embodiment of this utility model, the second plate heat exchanger is a CDU plate heat exchanger.

[0015] As a further preferred embodiment of this invention, the evaporator is used in the air-cooled system to dissipate heat from components such as hard drives, memory, power distribution systems, and network switches in the data center server; the plate heat exchanger is used in the liquid-cooled system to dissipate heat from components such as the CPU and GPU in the data center server. The opening degree of the throttling device is set according to the return air temperature of the evaporator, the pressure and temperature of the refrigerant pump circulation loop, to control the amount of refrigerant entering the air-cooled and liquid-cooled systems; the speed of the refrigerant pump is set according to the pressure and temperature of the refrigerant pump circulation loop; and the speed of the compressor and the opening degree of the throttling device are set according to the pressure and temperature of the mechanical refrigeration compression loop.

[0016] Compared with the prior art, the present invention has the following advantages or beneficial effects:

[0017] 1. Using Freon as the heat exchange medium in the liquid cooling system, this system combines the mechanical compression refrigeration direct expansion air conditioning system (fluorine pump system) with the liquid cooling system, achieving unification of air-cooled and liquid-cooled components. This simplifies the piping, reduces costs, and provides higher overall operating efficiency and ease of maintenance. 2. The system offers good scalability, allowing for flexible adjustments based on outdoor temperature or terminal load conditions. Cooling capacity can be increased or decreased accordingly: When outdoor temperatures are low, the refrigerant circulates via the Freon pump, utilizing only natural cooling without mechanical refrigeration; when outdoor air temperatures are high and cooling can be obtained from the air, natural cooling is used, while mechanical compression refrigeration is activated to supplement cooling; when outdoor air temperatures are high and cooling cannot be obtained from the air, mechanical compression refrigeration is used directly. 3. The compressor is not directly connected to the evaporator or CDU plate heat exchanger, but rather exchanges heat indirectly through the plate heat exchanger. This design reduces the flow of the mechanical compression refrigeration circuit, making it less likely for compressor lubricating oil to accumulate in the condenser and the circuit, thus avoiding the problem of poor oil return in the compressor. The refrigerant in the evaporator and CDU plate heat exchanger is circulated by a refrigerant pump, without using the compressor as a power source. This optimizes the distribution of refrigerant in the evaporator and CDU plate heat exchanger, reduces compressor power consumption, and also makes the terminal load more scalable. Furthermore, this design supports the parallel expansion of the system with mechanical refrigeration modules, and the cold source can be flexibly adjusted according to the terminal load. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the circuit connection in this embodiment;

[0019] Figure 2 This is a schematic diagram of the system structure in this embodiment;

[0020] Figure 3 This is the control logic diagram for the natural cooling source mode;

[0021] Figure 4 This is the control logic diagram for the hybrid cooling mode;

[0022] Figure 5 This is the control logic diagram for mechanical refrigeration mode;

[0023] Figure 6 Control logic diagram for modular expansion scheme;

[0024] In the diagram, 1. Compressor, 2. Plate heat exchanger one, 3. Throttling device, 4. Condenser one, 5. Liquid receiver, 6. Refrigerant pump, 7. Evaporator, 8. Plate heat exchanger two, 9. Data center server, 10. Refrigerant outlet pipe, 11. Condenser two, 12. Three-way valve, 13. Check valve, 14. Radiator fan, 20. First pipeline, 21. Second pipeline, 22. Third pipeline, 23. Fourth pipeline, 24. Fifth pipeline, 25. Sixth pipeline, 26. Seventh pipeline. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0026] It should be noted that the terms "part," "other," "first," "second," etc., used in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] Please refer to the appendix. Figure 1 , 2 This utility model provides a liquid cooling system for a data center, as well as a mechanical refrigeration compression circuit and a refrigerant pump circulation circuit connected to the data center rack array. Specifically:

[0028] The mechanical refrigeration compression circuit is used to provide cooling capacity to the system through a vapor compression refrigeration cycle in both hybrid refrigeration and mechanical refrigeration modes. The mechanical refrigeration compression circuit mainly includes: compressor 1, plate heat exchanger 2, throttling device 3, and condenser 4. The outlet of compressor 1 is connected to the first port of plate heat exchanger 2 via a first pipe 20. The outlet of compressor 1 is connected to the inlet of condenser 4 via a second pipe 21. The outlet of condenser 4 is connected to the second port of plate heat exchanger 2 via a third pipe 22. The throttling device 3 is installed on the third pipe 22.

[0029] The refrigerant pump circulation loop is used to drive the refrigerant circulation of Freon to deliver cooling capacity to the server. The refrigerant pump circulation loop mainly includes: a throttling device 3, a liquid receiver 5, a refrigerant pump 6, an evaporator 7, a plate heat exchanger 8, and a condenser 11. The inlet of the liquid receiver 5 is connected to the third port of the plate heat exchanger 2 via a fourth pipe 23. The outlet of the liquid receiver 5 is equipped with the refrigerant pump 6. The evaporator 7 and the plate heat exchanger 8 are connected in parallel. The first port of the evaporator 7 is connected to the refrigerant pump 6 via a fifth pipe 24. The first port of the plate heat exchanger 8 is connected to the refrigerant pump 6 via a sixth pipe 25. Both the fifth pipe 24 and the sixth pipe 25 are equipped with throttling devices 3. The second ports of the evaporator 7 and the plate heat exchanger 8 merge and are connected to the fourth port of the plate heat exchanger 2 via a seventh pipe 26. Condenser 2 11 is used to release the heat absorbed by the refrigerant. It can be assembled together with condenser 1 4 and share the heat dissipation fan 14 for heat dissipation. It can also be connected to an outdoor spray tower or dry cooler.

[0030] The data center rack array consists of multiple data center servers 9, which are connected to the third port of the plate heat exchanger 8 via refrigerant outlet pipe 10. The refrigerant outlet pipe 10 forms a closed loop, and the refrigerant cooling systems of each data center server 9 are interconnected and all connected to the refrigerant outlet pipe 10 to ensure connectivity between different areas.

[0031] Further explanation: A three-way valve 12 is installed on the seventh pipe 26. The three ports of the three-way valve 12 are respectively connected to the fourth port of plate heat exchanger 2, the second port of plate heat exchanger 8, and the first port of condenser 11. A one-way valve 13 is installed at the second port of condenser 11 and is connected to the fourth port of plate heat exchanger 2. When the system switches modes, the refrigerant flow direction can be changed through the three-way valve 12. Further explanation: The refrigerant pump 6 is used to drive the refrigerant to circulate in the refrigerant pump circulation loop to deliver cooling capacity to the data center server 9; preferably, the refrigerant is Freon.

[0032] The cooling capacity distribution system provided in the above embodiments can automatically switch between the following modes according to the outdoor temperature and load conditions:

[0033] When the outdoor temperature is low (e.g., below 15°C), the system fully utilizes natural cooling and enters natural cooling mode. The mode switching steps are as follows:

[0034] The compressor 1 and the throttling device 3 in the mechanical refrigeration compression circuit are turned off, while the throttling device 3 in the refrigerant pump circulation circuit is turned on. The three-way valve 12 actuates, allowing refrigerant to flow through the condenser 11. The refrigerant is pumped from the refrigerant pump 6, and after its pressure and flow rate are regulated by the throttling device 3, it enters the evaporator 7 and the plate heat exchanger 8, respectively, to dissipate heat for the air-cooled and liquid-cooled systems. The refrigerant absorbs heat and evaporates in the evaporator 7 and plate heat exchanger 8, and releases heat and condenses into a liquid state in the condenser 11, returning to the refrigerant pump 6 to complete the cycle. Specifically, the evaporator 7 is used in the air-cooled system to dissipate heat for components such as the hard drive, memory, power distribution system, and network switch in the data center server 9, while the plate heat exchanger 8 is used in the liquid-cooled system to dissipate heat for components such as the CPU and GPU in the data center server 9.

[0035] During the natural cooling source mode switching process, the system sets the opening degree of the throttling device 3 according to the return air temperature of the evaporator 7, the pressure and temperature of the refrigerant pump circulation loop, so as to control the amount of refrigerant entering the air-cooled and liquid-cooled systems; and sets the speed of the refrigerant pump 6 according to the pressure and temperature of the refrigerant pump circulation loop.

[0036] When the outdoor temperature exceeds 15℃ but does not exceed 25℃, the system simultaneously uses natural cooling and mechanical refrigeration and enters a hybrid cooling mode. The mode switching steps are as follows:

[0037] Open the throttling device 3 in compressor 1 and the mechanical refrigeration compression circuit, and open the throttling device 3 in the refrigerant pump circulation circuit. The three-way valve 12 actuates, allowing the refrigerant to flow through condenser 2 11. Compressor 1 compresses the refrigerant into a high-temperature, high-pressure gas, which releases heat and condenses into a liquid state through condenser 1 4. The refrigerant then enters the throttling device 3 to reduce its pressure, and then absorbs heat and evaporates into a gaseous state through plate heat exchanger 1 2. The gaseous refrigerant returns to compressor 1 to complete the cycle. On the other side, the refrigerant releases heat and condenses into a liquid state in condenser 2 11 and plate heat exchanger 2 8. It is then pressurized by refrigerant pump 6, and after the pressure and flow rate are regulated by throttling device 3, it enters evaporator 7 and plate heat exchanger 2 8 to absorb heat and evaporate. It then releases heat and condenses into a liquid state through condenser 2 11, returning to refrigerant pump 6 to complete the cycle.

[0038] During the switching process of the mixed refrigeration mode, the system sets the opening degree of the throttling device 3 according to the return air temperature of the evaporator 7, the pressure and temperature of the refrigerant pump circulation loop, so as to control the amount of refrigerant entering the air-cooled and liquid-cooled systems; sets the speed of the refrigerant pump 6 according to the pressure and temperature of the refrigerant pump circulation loop; and sets the speed of the compressor 1 and the opening degree of the throttling device 3 according to the pressure and temperature of the mechanical refrigeration compression loop.

[0039] When the outdoor temperature is high (e.g., above 25℃), the system relies solely on the mechanical refrigeration module for cooling and enters mechanical refrigeration mode. The mode switching steps are as follows:

[0040] Open the throttling device 3 in compressor 1 and the mechanical refrigeration compression circuit, open the throttling device 3 in the refrigerant pump circulation circuit, and the three-way valve 12 will activate, preventing the refrigerant from flowing through condenser 11. The refrigerant is pumped out from refrigerant pump 6, and after the pressure and flow rate are regulated by throttling device 3, it enters evaporator 7 and plate heat exchanger 8, respectively, to dissipate heat for the air-cooled and liquid-cooled systems. The refrigerant absorbs heat and evaporates in evaporator 7 and plate heat exchanger 8, and releases heat and condenses into liquid through plate heat exchanger 2, returning to refrigerant pump 6 to complete the cycle.

[0041] During the mechanical refrigeration mode switching process, the system sets the opening degree of the throttling device 3 according to the return air temperature of the evaporator 7, the pressure and temperature of the refrigerant pump circulation loop, so as to control the amount of refrigerant entering the air-cooled and liquid-cooled systems; sets the speed of the refrigerant pump 6 according to the pressure and temperature of the refrigerant pump circulation loop; and sets the speed of the compressor 1 and the opening degree of the throttling device 3 according to the pressure and temperature of the mechanical refrigeration compression loop.

[0042] In the above embodiments, the compressor is not directly connected to the evaporator and CDU plate heat exchanger, but rather undergoes indirect heat exchange through the plate heat exchanger. This design reduces the flow of the mechanical compression refrigeration circuit, making it less likely for compressor lubricating oil to accumulate in the condenser and the circuit, thus avoiding the problem of poor oil return in the compressor. The refrigerant in the evaporator and CDU plate heat exchanger circulates via a refrigerant pump, without using the compressor as a power source. This optimizes the distribution of refrigerant in the evaporator and CDU plate heat exchanger, reduces compressor power consumption, and also allows for greater scalability of the terminal load. Figure 6 As shown, this design supports the parallel expansion of mechanical refrigeration modules in the system, and the cold source can be flexibly adjusted according to the terminal load.

[0043] In addition to the embodiments described above, this utility model may have other implementations. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by this utility model.

Claims

1. A liquid cooling system for a data center, comprising a data center rack array, and a mechanical refrigeration compression circuit and a refrigerant pump circulation circuit connected to the data center rack array, characterized in that, The mechanical refrigeration compression circuit includes a compressor (1), a plate heat exchanger (2), a throttling device (3), and a condenser (4); the outlet of the compressor (1) is connected to the first port of the plate heat exchanger (2) through a first pipeline (20), the outlet of the compressor (1) is connected to the inlet of the condenser (4) through a second pipeline (21), the outlet of the condenser (4) is connected to the second port of the plate heat exchanger (2) through a third pipeline (22), and a throttling device (3) is provided on the third pipeline (22). The fluorine pump circulation loop includes a throttling device (3), a liquid storage tank (5), a fluorine pump (6), an evaporator (7), a second plate heat exchanger (8), and a second condenser (11); the inlet of the liquid storage tank (5) is connected to the third port of the first plate heat exchanger (2) through a fourth pipe (23), the outlet of the liquid storage tank (5) is equipped with the fluorine pump (6), the evaporator (7) is connected to the second plate heat exchanger (8) in parallel, and the first port of the evaporator (7) is connected to the third port of the first plate heat exchanger (2) through a fifth pipe (11). 24) Connected to the fluorine pump (6), the first port of the second plate heat exchanger (8) is connected to the fluorine pump (6) through the sixth pipe (25), the fifth pipe (24) and the sixth pipe (25) are both equipped with the throttling device (3), the second port of the evaporator (7) and the second plate heat exchanger (8) merge and are connected to the fourth port of the first plate heat exchanger (2) through the seventh pipe (26), and the second condenser (11) is connected in parallel with the seventh pipe (26).

2. The liquid cooling system for a data center according to claim 1, characterized in that, The data center rack array consists of multiple data center servers (9), and the multiple data center servers (9) are connected to the third port of the plate heat exchanger (8) through a refrigerant outlet pipe (10).

3. A liquid cooling system for a data center according to claim 2, characterized in that, The refrigerant outlet pipe (10) is a closed loop; the refrigerant cooling systems of each of the data center servers (9) are connected in parallel to each other and are all connected to the refrigerant outlet pipe (10).

4. A liquid cooling system for a data center according to claim 1, characterized in that, The seventh pipeline (26) is equipped with a three-way valve (12), and the three ports of the three-way valve (12) are respectively connected to the fourth port of the first plate heat exchanger (2), the second port of the second plate heat exchanger (8), and the first port of the second condenser (11); a one-way valve (13) is provided at the second port of the second condenser (11) and is connected to the fourth port of the first plate heat exchanger (2).

5. A liquid cooling system for a data center according to claim 1, characterized in that, A cooling fan (14) is provided on one side of the condenser one (4), and the condenser two (11) shares the cooling fan (14) with the condenser one (4) or is connected to an outdoor spray tower / dry cooler.

6. A liquid cooling system for a data center according to claim 2, characterized in that, The fluorine pump (6) is used to drive the refrigerant to circulate in the fluorine pump circulation loop to deliver cooling capacity to the data center server (9); the refrigerant is Freon.

7. A liquid cooling system for a data center according to claim 1, characterized in that, The plate heat exchanger (2) adopts a shell-and-tube heat exchanger.

8. A liquid cooling system for a data center according to claim 1, characterized in that, The plate heat exchanger 2 (8) adopts a CDU plate heat exchanger.

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