Double-loop heat recovery immersed data center cooling system

Abstract

The invention relates to the technical field of data center heat management, and particularly discloses a double-loop heat recovery immersed data center cooling system, which comprises an immersion cooling cabin, a heat recovery module, a heat recovery module, a heat recovery module and a heat recovery module, wherein the immersion cooling cabin is used for installing a server circuit board in an immersion manner; the cooling liquid circulating system is used for removing core heat of the server; a main circulating loop is formed by a variable-frequency circulating pump, a precision filter, a cooling liquid conveying valve, a spraying device, an immersion cooling cabin, a cooling liquid return valve and a refrigerating unit which are connected in sequence; the waste heat recovery cooling system is independent of the main loop and is connected to the heat storage tank through a heat exchange pipe immersed in cooling liquid, a waste heat adjusting valve and a water pump to form a secondary loop for extracting medium and low temperature waste heat; and the intelligent regulation and control module is used for collecting data and outputting a control instruction. According to the system, through immersed direct heat exchange and independent double-loop design, cooperation of server core heat dissipation and waste heat recovery is achieved, and the heat dissipation efficiency and the energy comprehensive utilization level are improved.

Description

Technical Field

[0001] This invention relates to the field of data center thermal management technology, and in particular to a dual-loop heat recovery immersion data center cooling system. Background Technology

[0002] As the computing power of data center servers continues to increase, their power density has also increased significantly, making traditional air-cooling methods insufficient to meet the demands for efficient heat dissipation. Immersion liquid cooling technology, with its advantages of high heat transfer efficiency and low noise, is gradually becoming the mainstream solution for high-density data center cooling. However, existing immersion cooling systems still have the following shortcomings:

[0003] First, most existing systems use fixed cooling strategies and cannot adjust the cooling intensity in real time according to the dynamic changes in server load. This results in a lag in heat dissipation response when the load changes suddenly, which can easily cause local overheating and affect the stability and lifespan of the equipment.

[0004] Secondly, most common systems adopt a single-loop circulation design with a single heat dissipation path. This not only limits the stability of heat dissipation, but also results in high energy consumption due to the continuous high-speed operation of the circulation pump. There is still room for improvement in overall energy efficiency.

[0005] Third, a large amount of waste heat generated in the system is usually not effectively recovered and utilized, but is directly discharged into the environment, resulting in energy waste, which is not in line with the development trend of green data centers.

[0006] Fourth, existing systems are often not comprehensive enough in terms of safety protection. The monitoring and response mechanisms for emergencies such as coolant leakage, decreased insulation performance, and abnormal pressure are not perfect, which poses certain operational risks.

[0007] Therefore, it is necessary to propose an immersion cooling system that can achieve intelligent dynamic regulation, has dual-loop coordinated heat dissipation, efficiently recovers waste heat, and integrates all-round safety protection to solve the above-mentioned technical problems. Summary of the Invention

[0008] The purpose of this invention is to provide a dual-loop heat recovery immersion data center cooling system to solve the aforementioned technical problems in the prior art.

[0009] To achieve the above objectives, the present invention provides the following solution: a dual-loop heat recovery immersion data center cooling system, comprising: an immersion cooling chamber filled with coolant and in which server circuit boards are installed; a coolant circulation system comprising a variable frequency circulation pump, a precision filter, a coolant delivery valve, a spray device, the immersion cooling chamber, and a coolant return valve connected in sequence by pipelines, the outlet of the coolant return valve being connected to a chiller unit via pipelines, forming a main circulation loop for removing core heat from the server; a waste heat recovery cooling system, independent of the main circulation loop, comprising heat exchange tubes immersed in coolant, the inlet of the heat exchange tubes being connected to a waste heat regulating valve and a water pump in sequence via pipelines, and the outlet being connected to a heat storage tank, forming a secondary loop for extracting and utilizing medium- and low-temperature waste heat; and an intelligent control module comprising multi-dimensional sensing components for collecting system operation data and a control center for processing data and outputting control commands.

[0010] Optionally, the immersion cooling chamber is enclosed by a main cabinet, which is a sealed and insulated structure with an insulation layer on its inner wall and a layered server mounting rack inside. The surface of the server mounting rack is coated with a nano-thermal conductive coating.

[0011] Optionally, the surface of the nano-thermal conductive coating is formed with micron-sized flow channels by laser etching.

[0012] Optionally, the side wall of the main cabinet is provided with a visual observation window and a quick maintenance door, and its bottom is provided with a vibration damping pad.

[0013] Optionally, the refrigeration unit is a shell-and-tube heat exchanger with internal baffles for enhancing heat transfer.

[0014] Optionally, the waste heat recovery cooling system further includes a heat pump device and a waste heat exchanger connected to the heat storage tank. The heat pump device is used to improve the temperature grade of the recovered heat energy, and the waste heat exchanger is used to cool the circulating return water.

[0015] Optionally, the multi-dimensional sensing components include: a temperature sensor disposed on the surface of the heat-generating components of the server circuit board and at key locations in the coolant flow path; a flow sensor for monitoring the flow rate of the main circulation loop and the secondary loop; and a pressure sensor for monitoring the pressure in the pipeline and the immersion cooling chamber.

[0016] Optionally, the control center includes an edge computing controller and a wireless communication unit; the edge computing controller has a built-in load-cooling strategy algorithm, which is used to generate and output control commands within the response time based on server load and temperature data. The control commands include adjusting the speed of the variable frequency circulating pump, adjusting the opening of the coolant delivery valve, the coolant return valve and the waste heat regulating valve.

[0017] Optionally, the control logic of the load-cooling strategy algorithm includes:

[0018] When the server load is ≤50%, the variable frequency circulating pump is controlled to run at low speed, and the flow rate of the waste heat recovery cooling system is minimized or shut off.

[0019] When the server load is between 50% and 80%, increase the speed of the variable frequency circulating pump and start the waste heat recovery cooling system at a lower flow rate;

[0020] When the server load is greater than 80% or the temperature at any critical monitoring point is greater than or equal to 42°C, the variable frequency circulating pump is controlled to run at full speed, and the water pumps and valves of the waste heat recovery cooling system are fully opened.

[0021] Optionally, the dual-loop heat recovery immersion data center cooling system further includes a safety protection module for monitoring and protecting the system's coolant level, insulation performance, and pressure status. The safety protection module includes: a level monitor for high-precision monitoring of the coolant level in the immersion cooling chamber and triggering an alarm and replenishment when the level is below a set threshold; a leakage current detection unit for continuous monitoring of the coolant's insulation performance and loop current, and cutting off the server power and triggering an alarm when a leakage risk is detected; and an explosion-proof pressure relief valve installed on the immersion cooling chamber or the main circulation loop for automatic pressure relief when the system pressure exceeds a safety threshold.

[0022] Compared with the prior art, the present invention discloses at least the following beneficial effects:

[0023] This invention fully immerses the server circuit board in coolant through an immersion cooling chamber, achieving direct and efficient heat transfer between heat-generating components and the cooling medium, significantly improving heat dissipation efficiency. The dual-loop structure includes a main circulation loop and an independent waste heat recovery secondary loop. This not only achieves stable removal of core server heat through the coordinated operation of a variable frequency circulating pump, precision filter, spray device, and refrigeration unit, but also effectively extracts and utilizes medium- and low-temperature waste heat through heat exchange tubes and heat storage tanks immersed in the coolant, thereby significantly improving overall energy efficiency while enhancing heat dissipation. The integrated intelligent control module collects system operation data in real time through multi-dimensional sensing components, and the control center dynamically adjusts the flow rate and equipment operating status of each loop based on server load and temperature information, enabling the system to adapt to load changes and achieve precise temperature control and energy-saving operation. Furthermore, the embedded safety module continuously monitors and protects against coolant level, insulation performance, and pressure status, further ensuring the long-term stability and safety of the entire cooling system. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the dual-loop heat recovery immersion data center cooling system of the present invention;

[0026] In the diagram: 1. Heat storage tank; 2. Heat pump unit; 3. Emergency cooling device; 4. Spray device; 5. Main cabinet; 6. Flow sensor; 7. Liquid level monitor; 8. Visual observation window; 9. Variable frequency circulating pump; 10. Coolant delivery valve; 11. Control center; 12. Refrigeration unit; 13. Coolant return valve; 14. Precision filter; 15. Quick access door; 16. Temperature sensor; 17. Explosion-proof pressure relief valve; 18. Pressure sensor; 19. Heat exchanger tube; 20. Server circuit board; 21. Vibration damping pad; 22. Coolant; 23. Waste heat regulating valve; 24. Water pump; 25. Leakage detection unit; 26. Waste heat exchanger; 27. Heat distribution valve. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Reference Figure 1As shown, this embodiment provides a dual-loop heat recovery immersion data center cooling system, including an immersion cooling chamber, a coolant circulation system, a waste heat recovery cooling system, an intelligent control module, and a safety protection module. Each module is connected via pipes, valves, and electrical control circuits, forming a collaborative working system integrating efficient heat dissipation, intelligent control, waste heat recovery, and safety protection. The main cabinet 5 of the immersion cooling chamber serves as the core load-bearing and heat exchange area of ​​the system, and its interior is used for immersing and installing server circuit boards 20. The coolant circulation system is primarily responsible for removing the core heat generated during server operation. The waste heat recovery cooling system extracts and reuses the medium- and low-temperature waste heat from the coolant 22. The intelligent control module dynamically coordinates the operation of the two systems based on real-time data. The safety protection module provides multi-dimensional protection for the stable operation of the entire system.

[0030] In one specific embodiment, the main cabinet 5 of the immersion cooling chamber is made of stainless steel with a sealed and insulated structure, and the inner wall is lined with an insulation layer to reduce heat loss. The immersion cooling chamber is filled with sufficient coolant 22 to ensure that the core heat-generating components of the server circuit board 20 are completely immersed in the coolant 22 during operation, enabling efficient heat exchange through direct liquid-solid contact. In this embodiment, the coolant 22 is an environmentally friendly insulating phase change coolant.

[0031] Based on the above embodiments, the main cabinet 5 is further provided with a layered server mounting rack for neatly and securely mounting multiple server circuit boards 20.

[0032] Furthermore, to improve thermal conductivity and optimize coolant flow, the surface of the server mounting bracket is coated with a nano-thermal conductive coating that combines high thermal conductivity with electrical insulation.

[0033] Furthermore, the surface of the nano-thermal conductive coating is formed with micron-sized flow channels through laser etching technology. These flow channels can guide the coolant 22 to flow more smoothly over the surface of the server's heat-generating chip, avoiding local heat accumulation, thereby increasing the effective heat transfer area and enhancing the heat dissipation effect.

[0034] Furthermore, the side wall of the immersion cooling chamber is equipped with a visual observation window 8, which makes it easy for maintenance personnel to observe the condition inside the chamber. It is also equipped with a quick-access maintenance door 15, which facilitates equipment maintenance and replacement.

[0035] Furthermore, to reduce the impact of vibration on the server, a vibration damping pad 21 is installed at the bottom of the immersion cooling chamber.

[0036] In one specific embodiment, the coolant circulation system constitutes the main heat dissipation loop of the system, which includes a main circulation loop and a heat exchange unit connected thereto. The main circulation loop is formed by connecting the variable frequency circulation pump 9, the precision filter 14, the coolant delivery valve 10, the spray device 4, the immersion cooling chamber, and the coolant return valve 13 through pipelines to form a closed loop.

[0037] Specifically, the coolant 22 that has absorbed the heat from the server collects at the bottom of the submerged cooling chamber, flows out through the coolant return valve 13, and is transported by pipeline to the heat exchange unit, namely the refrigeration unit 12.

[0038] In one specific embodiment, the refrigeration unit 12 preferably employs a shell-and-tube heat exchanger with built-in baffles to enhance the heat transfer efficiency between the coolant 22 and the refrigerant, thereby rapidly cooling the returning high-temperature coolant 22. The cooled low-temperature coolant 22 flows out of the refrigeration unit 12, is regulated by the coolant delivery valve 10, and enters the spray device 4. The spray device 4 evenly sprays or returns the coolant 22 to the upper part of the immersion cooling chamber or the server installation area, completing a full main circulation cooling process. The variable frequency circulation pump 9 provides power for the coolant circulation, and its speed is adjustable; the precision filter 14 is used to filter out impurities that the coolant 22 may carry during circulation, preventing blockage of pipes and spray nozzles.

[0039] In one specific embodiment, the waste heat recovery cooling system is independent of the main circulation loop, forming a secondary loop focused on waste heat extraction and utilization. The core of this system is a heat exchange tube 19, laid beneath the immersion cooling chamber and submerged in coolant 22. The heat exchange tube 19 uses a high-efficiency heat exchange material (such as copper or aluminum alloy) to extract medium- and low-temperature waste heat from the coolant 22 that was not completely removed by the main refrigeration unit 12 (typically more than 50%-60% can be extracted). The inlet of the heat exchange tube 19 is connected sequentially to a waste heat regulating valve 23 and a water pump 24 via pipelines, while the outlet is connected to the heat storage tank 1. The water pump 24 provides circulation power, and the waste heat regulating valve 23 is used to precisely control the flow rate of cold water through the heat exchange tube 19.

[0040] Based on the above embodiments, the thermal storage tank 1 further adopts an insulated energy storage design to store recovered heat energy. A heat pump device 2 and a waste heat exchanger 26 are connected to the thermal storage tank 1. The heat pump device 2 can further raise the temperature of the recovered low-temperature hot water in the thermal storage tank 1 to meet higher-grade heat demand (such as heating or domestic hot water).

[0041] Furthermore, the waste heat exchanger 26 is used to cool the hot water that has been used or is too hot. The cooled water is then pumped back to the inlet of the heat exchange tube 19 through the pipeline and the water pump 24 to start a new round of waste heat extraction cycle, thereby realizing the continuous recovery of waste heat.

[0042] Furthermore, the system in this embodiment is also equipped with a heat distribution valve 27, which dynamically adjusts the proportion of heat distributed from the heat storage tank 1 to different uses according to the real-time heat demand of the data center or surrounding buildings (such as winter heating, domestic hot water supply or driving absorption chillers, etc.), so as to realize the cascade and rational utilization of energy.

[0043] In one specific embodiment, the intelligent control module is the brain of the system, enabling adaptive and efficient operation. It includes multi-dimensional sensing components and a control center 11. The multi-dimensional sensing components are widely deployed throughout the system, specifically including: temperature sensors 16 located on the surface of the server's core heat-generating components; temperature sensors 16 located at the inlet / outlet of the coolant 22 and in different areas within the submerged cooling chamber; flow sensors 6 for monitoring the flow rate of the main / auxiliary loops; and pressure sensors 18 for monitoring the pressure in the pipelines and within the chamber. These sensors have high measurement accuracy; for example, the temperature sensor 16 has an accuracy of ±0.1℃. All sensor data is transmitted to the edge computing controller in real time. The control center 11 includes an edge computing controller and a wireless communication unit.

[0044] Furthermore, the edge computing controller incorporates an advanced load-cooling strategy algorithm, enabling rapid processing of server load data and temperature data at various points (response time ≤ 0.5 seconds), and dynamically outputting optimal control commands. These commands include, but are not limited to: adjusting the speed of the variable frequency circulating pump 9 to change the main circulation flow rate; adjusting the opening of the coolant delivery valve 10, the return valve, and the waste heat regulating valve 23 to control the flow distribution of each loop; and controlling the coolant replenishment amount 22 when necessary.

[0045] Furthermore, the wireless communication unit supports multiple industrial communication protocols, enabling it to upload system operating status data, alarm information, and other data to the central monitoring platform of the data center, and receive remote commands to achieve remote monitoring and maintenance of the system.

[0046] In a preferred embodiment, the control logic of the edge computing controller is specifically optimized. When the server load is detected to be ≤50%, the control system determines it to be in a low-load state. At this time, the variable frequency circulation pump 9 of the main circulation loop runs at low speed to meet basic heat dissipation, while the auxiliary waste heat recovery loop flow is closed or minimized to save energy. When the server load rises to the 50%-80% range, the system enters a medium-high load state. The edge computing controller will increase the speed of the variable frequency circulation pump 9 to increase the flow of the main circulation coolant 22, and simultaneously open the waste heat recovery loop, but operate at a lower flow rate to begin extracting waste heat. When the server load is >80%, or the temperature of any critical monitoring point exceeds the safety set threshold (e.g., ≥42°C), the system enters a high-load or emergency heat dissipation state. At this time, the edge computing controller will command the main circulation loop to run at full power (variable frequency pump at full speed), and simultaneously fully open the water pump 24 and valves of the waste heat recovery loop to extract heat at the maximum rate, achieving synergistic peak operation of "enhanced heat dissipation" and "waste heat utilization," and rapidly suppressing temperature rise.

[0047] Furthermore, to ensure the long-term stable and reliable operation of the system, the security module provides comprehensive protection. The safety protection module includes: a liquid level monitor 7, which monitors the coolant 22 level in the submerged cooling chamber in real time with high precision (error ≤ ±5mm). Once the liquid level is lower than the set threshold, it will automatically trigger an alarm and link the backup system to strengthen the supply of coolant 22, ensuring that the server is always in a fully submerged state; a leakage current detection unit 25, which continuously monitors the insulation performance of coolant 22 and abnormal current in the circuit. Once a potential leakage risk is detected, it will immediately cut off the server power supply and trigger an audible and visual alarm to prevent accidents; an explosion-proof pressure relief valve 17, which is installed in the submerged cooling chamber or on critical pipelines and is set with a safe pressure threshold (e.g., 0.3MPa). When the system pressure rises abnormally due to a fault, the valve will automatically open to relieve pressure and protect the equipment structure; and an emergency cooling device 3, which serves as the last line of defense. It has a built-in backup coolant 22 and an independent micro circulation pump. When the intelligent control module detects a fault in the main circulation system or power supply, it can be automatically or manually activated quickly to buy time for the main system maintenance (e.g., maintain critical emergency cooling for 30 minutes) and prevent the server from being damaged due to overheating.

[0048] As can be seen from the above technical solution, the dual-loop heat recovery immersion data center cooling system provided in this embodiment constitutes a complete solution through direct and efficient heat exchange in the immersion cooling chamber, the coordinated and independent design of the dual loops (main cooling loop and waste heat recovery loop), intelligent dynamic control based on edge computing, and multiple security protections covering the entire operation cycle. This system not only meets the rapidly increasing heat dissipation demands of high-power-density data centers, improving heat dissipation efficiency by more than 40%, but also reduces the energy consumption of the circulation system by 25%-30% through frequency conversion regulation and waste heat recovery (utilization rate can reach more than 60%), achieving a balance between efficient heat dissipation and green energy saving, while greatly improving the intelligence and reliability of the data center thermal management system.

[0049] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0050] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A dual-loop heat recovery immersion data center cooling system, characterized in that, include: The immersion cooling chamber is filled with coolant (22) and the server circuit board (20) is submerged in it. The coolant circulation system includes a variable frequency circulation pump (9), a precision filter (14), a coolant delivery valve (10), a spray device (4), the immersion cooling chamber, and a coolant return valve (13) connected in sequence by pipelines. The outlet of the coolant return valve (13) is connected to the refrigeration unit (12) through pipelines, forming a main circulation loop for removing core heat from the server. The waste heat recovery cooling system, which is independent of the main circulation loop, includes a heat exchange tube (19) immersed in coolant (22). The inlet of the heat exchange tube (19) is connected to a waste heat regulating valve (23) and a water pump (24) in sequence through a pipeline, and the outlet is connected to a heat storage tank (1), forming a secondary loop for extracting and utilizing medium and low temperature waste heat. The intelligent control module includes a multi-dimensional sensing component for collecting system operation data and a control center (11) for processing data and outputting control commands.

2. The dual-loop heat recovery immersion data center cooling system according to claim 1, characterized in that, The immersion cooling chamber is enclosed by a main cabinet (5), which is a sealed and heat-insulating structure with an insulation layer on its inner wall and a layered server mounting rack inside. The surface of the server mounting rack is coated with a nano thermal conductive coating.

3. The dual-loop heat recovery immersion data center cooling system according to claim 2, characterized in that, The surface of the nano-thermal conductive coating is formed with micron-sized flow channels by laser etching.

4. The dual-loop heat recovery immersion data center cooling system according to claim 2, characterized in that, The main cabinet (5) has a visual observation window (8) and a quick maintenance door (15) on its side wall, and a vibration damping pad (21) is provided at its bottom.

5. The dual-loop heat recovery immersion data center cooling system according to claim 1, characterized in that, The refrigeration unit (12) is a shell-and-tube heat exchanger with baffles inside to enhance heat transfer.

6. The dual-loop heat recovery immersion data center cooling system according to claim 1, characterized in that, The waste heat recovery cooling system also includes a heat pump device (2) and a waste heat exchanger (26) connected to the heat storage tank (1). The heat pump device (2) is used to improve the temperature grade of the recovered heat energy, and the waste heat exchanger (26) is used to cool the circulating return water.

7. The dual-loop heat recovery immersion data center cooling system according to claim 1, characterized in that, The multi-dimensional sensing components include: a temperature sensor (16) arranged on the surface of the heat-generating component of the server circuit board (20) and at key locations in the flow path of the coolant (22); a flow sensor (6) for monitoring the flow rate of the main circulation loop and the secondary loop; and a pressure sensor (18) for monitoring the pressure in the pipeline and the immersion cooling chamber.

8. The dual-loop heat recovery immersion data center cooling system according to claim 1, characterized in that, The control center (11) includes an edge computing controller and a wireless communication unit; the edge computing controller has a built-in load-cooling strategy algorithm, which is used to generate and output control commands within the response time based on server load and temperature data. The control commands include adjusting the speed of the variable frequency circulating pump (9), adjusting the opening of the coolant delivery valve (10), the coolant return valve (13) and the waste heat regulating valve (23).

9. The dual-loop heat recovery immersion data center cooling system according to claim 8, characterized in that, The control logic of the load-cooling strategy algorithm includes: When the server load is ≤50%, the variable frequency circulating pump (9) is controlled to run at low speed, and the flow rate of the waste heat recovery cooling system is minimized or shut off; When the server load is between 50% and 80%, increase the speed of the variable frequency circulating pump (9) and start the waste heat recovery cooling system at a lower flow rate; When the server load is greater than 80% or the temperature at any critical monitoring point is greater than 42°C, the variable frequency circulating pump (9) is controlled to run at full speed, and the water pump (24) and valves of the waste heat recovery cooling system are fully opened.

10. The dual-loop heat recovery immersion data center cooling system according to claim 1, characterized in that, It also includes a safety protection module for monitoring and protecting the system's coolant (22) level, insulation performance, and pressure status, the safety protection module comprising: The liquid level monitor (7) is used to monitor the liquid level of the coolant (22) in the immersion cooling chamber with high precision, and to trigger an alarm and replenishment when the liquid level is lower than the set threshold. The leakage detection unit (25) is used to continuously monitor the insulation performance and loop current of the coolant (22), and to cut off the server power and alarm when a leakage risk is detected; An explosion-proof pressure relief valve (17) is installed on the immersion cooling chamber or the main circulation loop to automatically relieve pressure when the system pressure exceeds a safety threshold.

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