Natural cooling system based on lake water utilization

Abstract

The invention relates to the field of data center cooling, and particularly discloses a natural cooling system based on lake water utilization, which comprises a natural cooling unit, an air cooling unit, a liquid cooling unit, a waste heat utilization unit and a control unit, according to the system, lake water or other surface water can be used as a cold source, the indoor tail end adopts a liquid cooling plate and an air cooling mode to effectively supply cooling capacity, annual natural cooling of the data center is achieved, refrigeration energy consumption is greatly reduced, meanwhile, the tail end exchanges heat efficiently, and the requirement for safe operation of a high-energy-density cabinet can be met.

Description

Technical Field

[0001] This patent relates to the field of data center cooling, and specifically to a natural cooling system based on lake water utilization. Background Art

[0002] Data centers are energy-intensive. Besides the necessary energy consumption of electronic equipment, the cooling system responsible for ensuring the safe and reliable operation of servers accounts for the largest share of energy consumption. Traditional data center cooling systems utilize cooling towers and chillers to produce cooling water on the primary side. On the secondary side, the chilled water exchanges heat with air, and air is supplied via precision air conditioning. This process not only consumes high energy in the chiller compressor, hindering energy efficiency in data centers, but also creates hotspots due to the long indoor air supply distance.

[0003] Now the number of intelligent computing data centers is growing rapidly, and the power density is much greater than that of cloud data centers. The demand for cooling system efficiency has increased significantly. The above-mentioned air cooling system is difficult to meet the demand. Liquid cooling plates can be used to exchange heat with major heat-generating components such as CPUs. The heat of other heat-generating components is taken away by air cooling, so the supply air temperature can be appropriately increased, making it possible to use natural cooling throughout the year. Summary of the Invention

[0004] In response to the above-mentioned defects or improvement needs of the existing technology, this patent provides a natural cooling system based on the utilization of lake water. The system can use lake water or other surface water as a cold source. The indoor terminal adopts liquid cooling plates supplemented by air cooling to effectively supply cold air, thereby realizing natural cooling of the data center throughout the year, greatly reducing the cooling energy consumption. At the same time, the terminal has efficient heat exchange, which can meet the safe operation requirements of high-energy-density cabinets.

[0005] To achieve the above-mentioned object, the present invention provides a natural cooling system based on lake water utilization, comprising: a natural cooling unit, an air cooling unit, a liquid cooling unit, a waste heat utilization unit and a control unit;

[0006] Among them, the natural cooling unit is used to extract deep low-temperature lake water as cooling water to exchange heat with high-temperature chilled water, and transport the high-temperature lake water after heat exchange back to the natural water source; the call number air cooling unit is used to supply air to the cabinet to cool low-heat density components; the liquid cooling unit is used to cool the main heat-generating components in the server; the waste heat utilization unit is used to recover part of the chilled water heat; the control unit is used to detect the operation status of the natural cooling system and make real-time adjustments.

[0007] The natural cooling unit includes a lake water source, a water quality detection device, a heat exchanger, a cooling water pump and a backup water pump. The natural cooling unit is used to extract deep low-temperature lake water from the lake water source as cooling water for heat exchange with high-temperature chilled water, and transport the high-temperature lake water after heat exchange back to the natural water source. The natural cooling unit is equipped with at least one backup water pump; wherein, the lake water source is connected to the primary side inlet of the first heat exchanger through the cooling water pump and the pipeline to form a closed loop.

[0008] As a preferred embodiment of the present invention, the water quality detection device is located inside the lake water source and includes at least a temperature sensor and a turbidity sensor, which are used to upload lake water environment information to the control unit. When the lake water temperature is higher than the set value, the control unit issues an alarm and turns on the supplementary cooling device to ensure that the temperature in the machine room is within a safe range; when the turbidity data exceeds a preset threshold, the control unit triggers an alarm and activates a backup water source. According to actual needs, at least one of an ammonia nitrogen sensor, a total phosphorus sensor, a residual chlorine sensor, etc. can be added to detect different pollutant indicators.

[0009] As a preferred embodiment of the present invention, the water pump adopts multiple variable frequency water pumps connected in parallel. When the load in the machine room increases or the water temperature of the lake water rises and the flow rate of cooling water (i.e., low-temperature lake water) needs to be increased, the operating frequency of the water pump is increased first to meet the flow requirement. When the current number of water pumps running at the highest frequency still cannot meet the demand, an additional water pump is turned on and the frequency of all running water pumps is adjusted to avoid the newly turned-on water pump from running at a low frequency. When the load in the machine room decreases or the water temperature of the lake water decreases and the flow rate of cooling water (i.e., low-temperature lake water) needs to be reduced, the operating frequency of one of the water pumps is reduced first until it is shut down to avoid multiple water pumps running at a low frequency and reducing their service life.

[0010] As a preferred embodiment of the present invention, the heat exchanger adopts a shell-and-tube heat exchanger, which uses two standard tubes of different sizes to connect to form concentric tubes. The fluids in the inner and outer tubes flow in opposite directions to achieve the purpose of heat exchange. Considering that lake water contains more impurities and is prone to scaling, it is recommended that cooling water be connected to the inner tube inlet to facilitate cleaning and control scaling.

[0011] The air-cooling unit includes a chilled water pump, a backplate heat exchanger, a fan unit, a check valve and a first three-way valve, wherein the first three-way valve includes a first interface, a second interface and a third interface; the backplate heat exchanger is installed on the rear door of the cabinet and is connected to the second interface of the first three-way valve, the first interface of the first three-way valve is connected to the chilled water outlet of the heat exchanger of the natural cooling unit, and the third interface of the first three-way valve is connected to the chilled water inlet of the cold liquid distribution unit in the liquid cooling unit;

[0012] The liquid cooling unit includes a cold liquid distribution unit, a liquid cooling plate, and a second three-way valve, wherein the second three-way valve includes a first interface, a second interface, and a third interface; the chilled water outlet of the cold liquid distribution unit is connected to the second interface of the second three-way valve, the first interface of the second three-way valve is connected to the second interface of the third three-way valve in the waste heat utilization unit, and the third interface of the second three-way valve is connected to the chilled water outlet of the back plate heat exchanger in the air cooling unit;

[0013] The check valve connects the third interface of the first three-way valve and the third interface of the second three-way valve to prevent the chilled water from flowing directly from the first three-way valve to the second three-way valve when the air cooling unit and the liquid cooling unit are connected in parallel, causing waste of cooling capacity.

[0014] As a preferred embodiment of the present invention, the liquid cooling plate adopts a heat pipe liquid cooling plate. This heat dissipation method combines the high heat transfer efficiency of the heat pipe and the circulating heat dissipation advantage of liquid cooling technology. It can quickly take away the heat generated by the equipment and does not require a mechanical pump, further reducing energy consumption.

[0015] As a preferred embodiment of the present invention, the air cooling unit and the liquid cooling unit can be connected in series or in parallel:

[0016] In the default operating mode of the series connection mode, the first and second interfaces of the first three-way valve are open, and the third interface is closed; the first and second interfaces of the second three-way valve are open, and the third interface is closed; the check valve is opened, and the outlet of the backplane heat exchanger of the air cooling unit is connected to the inlet of the cold liquid distribution unit of the liquid cooling unit. Chilled water flows from the heat exchanger of the natural cooling unit into the air cooling unit, and after the temperature is slightly increased, it enters the liquid cooling unit, exchanges heat with the main heat-generating components of the server to form high-temperature chilled water, enters the waste heat utilization unit, and returns to the heat exchanger of the natural cooling unit after heat extraction, and repeats the cycle;

[0017] In the default operating mode of the parallel connection method, the first interface, the second interface, and the third interface of the first three-way valve are open, the first interface, the second interface, and the third interface of the second three-way valve are open, the check valve is closed, the outlet of the air cooling unit and the inlet of the liquid cooling unit are not connected, and the chilled water flows from the heat exchanger of the natural cooling unit into the air cooling unit and the liquid cooling unit at the same time. After heat exchange, the temperature is increased and enters the waste heat utilization unit or directly returns to the heat exchanger of the natural cooling unit, and the cycle is repeated.

[0018] The waste heat utilization unit includes a heat exchanger, a third three-way valve and a waste heat utilization device; the third three-way valve includes a first interface, a second interface and a third interface; the first interface of the third three-way valve is connected to the chilled water inlet of the heat exchanger in the waste heat utilization unit, the second interface of the third three-way valve is connected to the first interface of the second three-way valve, and the third interface of the third three-way valve is connected to the chilled water inlet of the heat exchanger in the natural cooling unit;

[0019] The third three-way valve can adjust the opening of each interface according to the waste heat demand: when the waste heat demand is large, the opening of the third interface of the third three-way valve is reduced until it is closed, and the chilled water enters the heat exchanger of the natural cooling unit after heat exchange in the heat exchanger of the waste heat recovery unit; when the waste heat demand is small, the opening of the third three-way valve can be appropriately increased to reduce the flow of chilled water entering the waste heat utilization unit and reduce the recoverable waste heat entering the waste heat utilization unit.

[0020] The control unit includes a first temperature measuring device, a second temperature measuring device, a third temperature measuring device, a fourth temperature measuring device and a signal feedback device; the first temperature measuring device is located at the air inlet of the air cooling unit, and is used to measure the return air temperature; the second temperature measuring device is located at the air outlet of the air cooling unit, and is used to measure the temperature of the air outflow at the air outlet of the air cooling unit; the third temperature measuring device is located at the chilled water inlet of the liquid cooling unit, and is used to measure the liquid inlet temperature; the fourth temperature measuring device is located at the chilled water outlet of the liquid cooling unit, and is used to measure the return liquid temperature; the signal feedback device is used to receive the signals of the above temperature measuring devices and the lake water temperature signal, and output a regulation signal to the cooling water pump, the chilled water pump, the fan unit and the first three-way valve;

[0021] When the temperature measured by the first temperature measuring device is higher than the return air temperature setting value, the fan operating frequency of the air-cooling unit can be increased, thereby increasing the cooling air flow rate, improving the heat exchange efficiency and ensuring that the temperature of the machine room is within a safe range; when the temperature measured by the first temperature measuring device is lower than the return air temperature setting value, the fan operating frequency of the air-cooling unit can be reduced, thereby reducing the cooling air flow rate, avoiding waste of cooling capacity and reducing energy consumption. When the temperature measured by the second temperature measuring device is higher than the setting value, the operating frequency of the chilled water pump, the operating frequency of the cooling water pump, or the number of cooling water pumps in operation can be increased while adjusting the operating frequency to increase the cooling capacity; when the temperature measured by the second temperature measuring device is lower than the setting value, the operating frequency of the chilled water pump, the operating frequency of the cooling water pump, or the number of cooling water pumps in operation can be reduced while adjusting the operating frequency to reduce the cooling capacity;

[0022] When the temperature measured by the third temperature measuring device exceeds the set value of the inlet temperature, the adjustment method needs to be determined according to the connection method of the air cooling unit and the liquid cooling unit; in the series mode, when the temperature measured by the third temperature measuring device is higher than the set value of the inlet temperature, the third interface of the first three-way valve needs to be opened so that part of the chilled water enters the liquid cooling unit directly without passing through the air cooling unit, so as to lower the inlet temperature to meet the operating requirements; when the temperature is adjusted, if the temperature measured by the third temperature measuring device is lower than the set value of the inlet temperature, the opening of the third interface of the first three-way valve needs to be reduced to avoid the inlet temperature being too low to generate condensation water inside the server, which affects the safe operation of the equipment; in the parallel mode In this formula, when the temperature measured by the third temperature measuring device exceeds the set value of the liquid inlet temperature, the operating frequency of the chilled water pump can be adjusted, the operating frequency of the cooling water pump can be reduced, or the number of cooling water pumps in operation can be reduced while adjusting the operating frequency so that the liquid inlet temperature is within the allowable operating range; when the temperature measured by the fourth temperature measuring device is higher than the set value of the return liquid temperature, the coolant flow rate can be appropriately increased. At this time, the heat exchange efficiency of the liquid cold plate is increased, and the return liquid temperature is reduced to a safe range; when the temperature measured by the fourth temperature measuring device is lower than the set value of the return liquid temperature, the coolant flow rate can be appropriately reduced. At this time, the temperature of the outer surface of the pipeline will not be too low, effectively avoiding the generation of condensed water.

[0023] As a preferred embodiment of the present invention, the air cooling unit and the liquid cooling unit are arranged inside the same semi-enclosed cabinet, and the server and the liquid cooling unit pipes are connected by a removable plug to facilitate installation.

[0024] The present invention has the following beneficial effects:

[0025] 1. This invention uses lake water as cooling water, making full use of natural cooling sources according to local conditions. The system does not require high-energy-consuming chillers, which can effectively reduce the energy consumption of the data center and meet the requirements of green and low-carbon operation.

[0026] 2. The present invention uses a liquid cooling unit to cool high-heat components that account for 60-70% of the heat dissipation, and uses an air cooling unit to cool low-heat components. The two cooling units are installed inside the same cabinet. Through different connection methods, the cooling loads of the air cooling unit and the liquid cooling unit are coordinated to adjust, shortening the cooling distance and avoiding cooling waste.

[0027] 3. The present invention uses multiple temperature detection devices to monitor the system operation in real time, timely control the operation strategy of components such as water pumps, and further reduce energy consumption;

[0028] 4. The present invention takes into account the high outlet water temperature of the liquid cooling unit and introduces a waste heat recovery device. On the one hand, it can reduce the adverse impact of direct discharge of waste heat into natural water sources on the environment. On the other hand, it can reduce energy consumption and carbon emissions, and promote the development of data centers in a more green and environmentally friendly direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 shows a schematic diagram of the cooling system structure of a data center using a lake water-based natural cooling system.

[0030] Explanation of the accompanying symbols: 1. Lake water source; 2. Cooling water pump; 3. First heat exchanger; 4. Chilled water pump; 5. Fan unit; 6. Backplate heat exchanger; 7. Cold liquid distribution unit; 8. Liquid cooling plate; 9. Cabinet; 10. Signal feedback device; 11. Second heat exchanger; 12. First temperature detection device; 13. Second temperature detection device; 14. Third temperature detection device; 15. Fourth temperature detection device; 16. Water quality detection device; 17. First three-way valve; 18. Second three-way valve; 19. Third three-way valve; 20. Waste heat utilization device; 21. Check valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The specific embodiments described are merely intended to illustrate the present invention and are not intended to limit the present invention.

[0032] As shown in Figure 1, this example provides a lake water-based natural cooling system, including: a natural cooling unit for extracting deep low-temperature lake water as cooling water for heat exchange with high-temperature chilled water, and transporting the high-temperature lake water after heat exchange back to the natural water source; an air cooling unit for supplying air to the cabinet to cool low-heat density components; a liquid cooling unit for cooling major heat-generating components such as chips in the server; a waste heat utilization unit for recovering part of the chilled water heat; and a control unit for detecting the system operation status and performing real-time adjustments.

[0033] The natural cooling unit includes a lake water source 1 , a water quality detection device 16 , the lake water source 1 , a cooling water pump 2 and a first heat exchanger 3 .

[0034] In an embodiment of the present invention, water quality detection device 16 is located within lake water source 1 and includes a temperature sensor and a turbidity sensor. This sensor monitors the lake water environment in real time and uploads information to the control unit. Furthermore, the system may include at least one of an ammonia nitrogen sensor, a total phosphorus sensor, and a residual chlorine sensor for detecting pollutant indicators.

[0035] Among them, the first heat exchanger 3 can adopt a shell-and-tube heat exchanger. More specifically, two standard tubes of different sizes can be connected to form concentric shells. The fluids in the inner and outer tubes flow in opposite directions to achieve the purpose of heat exchange. Considering that lake water contains more impurities and is prone to scaling, it is recommended that cooling water be connected to the inner tube inlet to facilitate cleaning and control scaling.

[0036] Among them, the air-cooled unit includes a chilled water pump 4, a fan unit 5, a backplate heat exchanger 6, a check valve 21 and a first three-way valve 17. The first three-way valve 17 includes a first interface, a second interface and a third interface, which are respectively connected to the chilled water outlet of the first heat exchanger 3 of the natural cooling unit, the chilled water inlet of the backplate heat exchanger 6 and the chilled water inlet of the cold liquid distribution unit 7 in the liquid cooling unit.

[0037] Among them, the liquid cooling unit includes a cold liquid distribution unit 7, a liquid cooling plate 8 and a second three-way valve 18. The second three-way valve 18 includes a first interface, a second interface and a third interface, which are respectively connected to the second interface of the third three-way valve 18 in the waste heat utilization unit, the chilled water outlet of the cold liquid distribution unit 7 and the chilled water outlet of the back plate heat exchanger 6 in the air cooling unit.

[0038] In the example of the present invention, the liquid cooling plate 8 adopts a heat pipe liquid cooling plate. This heat dissipation method combines the high heat transfer efficiency of the heat pipe and the circulating heat dissipation advantage of liquid cooling technology. It can quickly take away the heat generated by the equipment and does not require a mechanical pump, further reducing energy consumption.

[0039] Among them, the waste heat utilization unit includes a second heat exchanger 11, a third three-way valve 19 and a waste heat utilization device 20. The third three-way valve 19 includes a first interface, a second interface and a third interface, which are respectively connected to the chilled water inlet of the waste heat utilization unit heat exchanger 11, the first interface of the second three-way valve 18 and the chilled water inlet of the second heat exchanger 3.

[0040] In the example of the present invention, the first three-way valve 17, the second three-way valve 18 and the third three-way valve 19 are all electric three-way regulating valves, which directly receive control signals from the regulating device to achieve automatic regulation and control of the fluid medium in the process pipeline.

[0041] In the embodiment of the present invention, the air cooling unit and the liquid cooling unit can be connected in series or in parallel. During operation, the connection mode can be adjusted using a valve according to the waste heat utilization requirements. The specific adjustment modes are as follows:

[0042] When the required waste heat temperature is high, the air cooling unit and the liquid cooling unit are connected in series. At this time, the first interface and the second interface of the first three-way valve 17 are opened, and the third interface is closed. The first interface and the second interface of the second three-way valve 18 are opened, and the third interface is closed. The check valve 21 is opened, and the outlet of the backplane heat exchanger 6 of the air cooling unit is connected to the inlet of the cold liquid distribution unit 7 of the liquid cooling unit. The chilled water flows from the first heat exchanger 3 into the backplane heat exchanger 6, and after the temperature is slightly increased, it enters the cold liquid distribution unit 7, and forms high-temperature chilled water after heat exchange with the main heat-generating components of the server. Under this connection mode, the return water temperature of the chilled water is higher, which can effectively increase the waste heat recovery amount of the second heat exchanger 11.

[0043] When the required waste heat temperature is low, the air cooling unit and the liquid cooling unit are connected in parallel. At this time, the first interface, the second interface and the third interface of the first three-way valve 17 are opened, the first interface, the second interface and the third interface of the second three-way valve 18 are opened, the check valve 21 is closed, and the inlet of the back plate heat exchanger 6 of the air cooling unit is connected in parallel with the inlet of the cold liquid distribution unit 7 of the liquid cooling unit. The chilled water flows from the shell and tube heat exchanger 3 into the back plate heat exchanger 6 and the cold liquid distribution unit 7 at the same time. After heat exchange, the temperature is increased and enters the waste heat utilization unit heat exchanger 11. Under this connection mode, the return water temperature of the chilled water is slightly lower, which can meet different waste heat utilization requirements.

[0044] In this embodiment of the present invention, changes in waste heat recovery heat demand can be met by adjusting the opening of the third three-way valve 19. When the waste heat demand is high, the opening of the second port of the third three-way valve 19 is increased, and the opening of the third port is decreased until the third port is completely closed, thereby increasing the flow of chilled water entering the second heat exchanger 11 of the waste heat recovery unit and thus increasing the amount of waste heat recovered. When the waste heat demand is low, the opening of the third port of the third three-way valve 19 is increased, and the opening of the second port is decreased until the second port is completely closed, thereby reducing the flow of chilled water entering the waste heat recovery unit heat exchanger 11 and thus reducing the amount of waste heat recovered.

[0045] Among them, the control unit includes a first temperature measuring device 12, a second temperature measuring device 13, a third temperature measuring device 14, a fourth temperature measuring device 15 and a signal feedback device 10; the first temperature measuring device 12 is located at the air inlet of the air cooling unit for measuring the return air temperature; the second temperature measuring device 13 is located at the air outlet of the air cooling unit for measuring the inlet air temperature; the third temperature measuring device 14 is located at the chilled water inlet of the liquid cooling unit for measuring the inlet liquid temperature; the fourth temperature measuring device 15 is located at the chilled water outlet of the liquid cooling unit for measuring the return liquid temperature; the signal feedback device 10 is used to receive the above temperature measuring device signals and the lake water temperature signal, and output a regulation signal to the cooling water pump 2, the chilled water pump 4, the fan unit 5 and the first three-way valve 17. The specific control method is as follows:

[0046] When the temperature measured by the first temperature measuring device 12 is higher than the return air temperature setting value, the operating frequency of the air-cooling unit fan unit 5 can be increased, thereby increasing the cooling air flow rate, improving the heat exchange efficiency and ensuring that the room temperature is within a safe range; when the temperature measured by the first temperature measuring device 12 is lower than the return air temperature setting value, the operating frequency of the air-cooling unit fan unit 5 can be reduced, thereby reducing the cooling air flow rate, avoiding waste of cooling capacity and reducing energy consumption. When the temperature measured by the second temperature measuring device 13 is higher than the setting value, the operating frequency of the chilled water pump 4, the operating frequency of the cooling water pump 2, or the number of cooling water pumps 2 in operation can be increased and the operating frequency can be adjusted simultaneously to increase the cooling capacity; when the temperature measured by the second temperature measuring device 13 is lower than the setting value, the operating frequency of the chilled water pump 4, the operating frequency of the cooling water pump 2, or the number of cooling water pumps 2 in operation can be reduced and the operating frequency can be adjusted simultaneously to reduce the cooling capacity.

[0047] When the temperature measured by the third temperature measuring device 14 exceeds the set value of the inlet temperature, the adjustment method needs to be determined based on the connection method between the air cooling unit and the liquid cooling unit. In the series mode, when the temperature measured by the third temperature measuring device 14 is higher than the set value of the inlet temperature, the third interface of the first three-way valve 17 needs to be opened, so that some chilled water enters the cold liquid distribution unit 7 directly without passing through the backplane heat exchanger 6, thereby lowering the inlet temperature to meet the operating requirements; when the temperature measured by the third temperature measuring device 14 is lower than the set value of the inlet temperature after temperature adjustment, the opening of the third interface of the first three-way valve 17 needs to be reduced to prevent the inlet temperature from being too low and generating condensate inside the server, which affects the safe operation of the equipment. In the parallel mode, when the temperature measured by the third temperature measuring device 14 exceeds the set value of the inlet temperature, the operating frequency of the chilled water pump 4 can be adjusted, the operating frequency of the cooling water pump 2 can be reduced, or the number of cooling water pumps 2 in operation can be reduced while adjusting the operating frequency so that the inlet temperature is within the allowable operating range. When the temperature measured by the fourth temperature measuring device 15 is higher than the return liquid temperature setting value, the coolant flow rate can be appropriately increased. At this time, the heat exchange efficiency of the liquid cooling plate 8 is increased, and the return liquid temperature drops to a safe range; when the temperature measured by the fourth temperature measuring device 15 is lower than the return liquid temperature setting value, the coolant flow rate can be appropriately reduced. At this time, the temperature of the outer surface of the pipeline will not be too low, effectively avoiding the generation of condensed water.

[0048] In an example of the present invention, the air cooling unit and the liquid cooling unit are arranged inside the same semi-enclosed cabinet, and the server and the liquid cooling unit pipeline are connected by a removable plug to facilitate installation.

[0049] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms of specific changes without departing from the scope of protection of the invention and the claims. These all fall within the scope of protection of the present invention.

Claims

1. A natural cooling system based on lake water utilization, characterized in that: The natural cooling system includes: a natural cooling unit, an air cooling unit, a liquid cooling unit, a waste heat utilization unit and a control unit; Among them, the natural cooling unit is used to extract deep low-temperature lake water as cooling water to exchange heat with high-temperature chilled water, and transport the high-temperature lake water after heat exchange back to the natural water source; the call number air cooling unit is used to supply air to the cabinet to cool low-heat density components; the liquid cooling unit is used to cool the main heat-generating components in the server; the waste heat utilization unit is used to recover part of the chilled water heat; the control unit is used to detect the operation status of the natural cooling system and make real-time adjustments.

2. A natural cooling system based on lake water utilization according to claim 1, characterized in that: The natural cooling unit comprises a lake water source (1), a water quality detection device (16), a first heat exchanger (3), a cooling water pump (2) and a backup water pump. The natural cooling unit is used to extract deep low-temperature lake water from the lake water source (1) as cooling water to exchange heat with high-temperature chilled water, and to transport the high-temperature lake water after heat exchange back to the natural water source. The natural cooling unit is equipped with at least one backup water pump. The lake water source (1) is connected to the primary side inlet of the first heat exchanger (3) through a cooling water pump (2) and a pipeline to form a closed loop; The water quality detection device (16) is located inside the lake water source (1), and includes at least a temperature sensor and a turbidity sensor, and the water quality detection device (16) also includes at least one of an ammonia nitrogen sensor, a total phosphorus sensor, and a residual chlorine sensor for detecting pollutant indicators.

3. The natural cooling system based on lake water utilization according to claim 2, characterized in that: The air cooling unit includes a chilled water pump (4), a back plate heat exchanger (6), a fan unit (5), a check valve (21) and a first three-way valve (17); the liquid cooling unit includes a cold liquid distribution unit (7), a liquid cooling plate (8) and a second three-way valve (18); The secondary side outlet of the first heat exchanger (3) of the natural cooling unit is connected to the chilled water pump (4) and the first interface of the first three-way valve (17) in sequence, the second interface of the first three-way valve (17) is connected to the chilled water inlet of the back plate heat exchanger (6), and the third interface of the first three-way valve (17) is connected to the chilled water inlet of the cold liquid distribution unit (7); The air cooling unit and the liquid cooling unit are connected in series or in parallel, the chilled water outlet of the back plate heat exchanger (6) is simultaneously connected to the inlet of the check valve (21) and the third interface of the second three-way valve (18), and the outlet of the check valve (21) is sequentially connected to the chilled water inlet of the cold liquid distribution unit (7) and the second interface of the second three-way valve (18).

4. The natural cooling system based on lake water utilization according to claim 3 is characterized in that: The liquid cooling plate (8) is a heat pipe type liquid cooling plate.

5. The natural cooling system based on lake water utilization according to claim 1, characterized in that: The waste heat utilization unit includes a second heat exchanger (11), a third three-way valve (19) and a waste heat utilization device (20); Wherein, the third three-way valve (19) includes a first interface, a second interface and a third interface; the first interface of the third three-way valve (19) is connected to the chilled water inlet of the second heat exchanger (11) of the waste heat utilization unit, the second interface of the third three-way valve (19) is connected to the first interface of the second three-way valve (18), and the third interface of the third three-way valve (19) is connected to the secondary side chilled water inlet of the first heat exchanger (3) of the natural cooling unit. The third three-way valve (19) is used to adjust the opening of each interface according to the waste heat demand.

6. The natural cooling system based on lake water utilization according to claim 3, characterized in that: The control unit comprises a first temperature measuring device (12), a second temperature measuring device (13), a third temperature measuring device (14), a fourth temperature measuring device (15) and a signal feedback device (10); the first temperature measuring device (12) is located at the air inlet of the air cooling unit and is used to measure the return air temperature; the second temperature measuring device (13) is located at the air outlet of the air cooling unit and is used to measure the temperature of the air outflow at the air outlet of the air cooling unit; the third temperature measuring device (14) is located at the chilled water inlet of the liquid cooling unit and is used to measure the liquid inlet temperature; the fourth temperature measuring device (15) is located at the chilled water outlet of the liquid cooling unit and is used to measure the return liquid temperature; the signal feedback device (10) is used to receive the above temperature measuring device signals and the lake water temperature signal, and output the adjustment signal to the cooling water pump (2), the chilled water pump (4), the fan unit (5) and the first three-way valve (17).

7. A natural cooling system based on lake water utilization according to any one of claims 1 to 6, characterized in that: The air cooling unit and the liquid cooling unit are arranged inside the same half-enclosed cabinet.

8. A natural cooling system based on lake water utilization according to any one of claims 1 to 6, characterized in that: The natural water source is a lake water source or other surface water source.

Images