A complementary system of data center and compressed carbon dioxide energy storage coupling and operation method

Abstract

The application discloses a complementary system of a data center and compressed carbon dioxide energy storage coupling, which comprises a compressed carbon dioxide energy storage subsystem and a data center cooling subsystem; the compressed carbon dioxide energy storage subsystem comprises a gas storage unit, a compression unit, a cooling unit, a condensation unit, a liquid storage unit, a pumping unit, an evaporation unit, a superheating unit and an expansion power generation unit which are sequentially and circularly connected through pipelines; the data center cooling subsystem comprises a liquid cooling unit for absorbing heat of servers; a cooling liquid outlet of the liquid cooling unit is directly communicated with a hot flow side inlet of the evaporation unit, and a cooling liquid inlet of the liquid cooling unit is directly communicated with a hot flow side outlet of the evaporation unit, so that a closed cooling loop is formed; and a power output end of the expansion power generation unit is connected with an electric device of the data center.

Description

Technical Field

[0001] This invention relates to a CO2 energy storage system for utilizing waste heat in data centers, specifically a complementary system coupled with compressed carbon dioxide energy storage and its operation method. Background Technology

[0002] With the full implementation of the national "Eastern Data, Western Computing" project, my country is planning and constructing a large-scale data center cluster in the Northwest region to fully utilize the region's abundant green power resources, such as wind and solar energy. This strategic layout is of great significance for promoting energy structure optimization and achieving "dual-carbon" goals. However, in actual operation, two prominent contradictions exist between data centers and renewable energy power generation.

[0003] First, there is the contradiction between power supply stability and power generation volatility. Data centers, as critical infrastructure in the digital economy era, require 24 / 7 uninterrupted and stable operation, placing extremely high demands on power supply reliability. However, wind and solar power generation exhibit significant time-sensitivity and volatility—wind power is affected by wind speed variations, and solar power is constrained by day-night cycles and weather conditions, making it difficult to directly provide a continuous and stable power supply for data centers. This contradiction forces data centers to rely on traditional power grids or backup power sources in actual operation, weakening the expected benefits of utilizing green electricity.

[0004] Secondly, there is a contradiction between massive heat dissipation and energy waste. Almost all the electrical energy consumed by data center servers during operation is converted into heat. Based on the current mainstream data center rack power of 10-15kW, the heat load of large data centers can reach tens of megawatts. This massive amount of waste heat not only cannot be effectively utilized, but also requires the configuration of cooling towers, chillers, and refrigerant pump air conditioning for forced heat dissipation. The energy consumption of the cooling system accounts for approximately 30-40% of the total energy consumption of the data center, further exacerbating energy consumption and environmental burden. Although existing technologies have attempted to use data center waste heat for heating, in the Northwest region where heat users are scattered and heat demand is mismatched, it is difficult to achieve efficient waste heat utilization.

[0005] Compressed carbon dioxide (CCCO) energy storage is a rapidly developing new physical energy storage technology in recent years. It features high system stability, large installed capacity, long energy release time, good regional adaptability, and environmentally friendly working fluid, demonstrating broad application prospects in the field of renewable energy consumption. In a conventional CCCO energy storage system, the operation process includes an energy storage stage and an energy release stage: In the energy storage stage, gaseous CO2 is compressed and cooled, further condensed into liquid CO2 for storage. Simultaneously, a heat pump raises the phase change heat released during CO2 liquefaction to approximately 50°C and stores it in an atmospheric pressure hot water storage tank. In the energy release stage, the stored heat is used to heat the liquid CO2, causing it to vaporize and drive a turbine expander to generate electricity.

[0006] like Figure 1 The conventional compressed CO2 energy storage system shown mainly includes a gas storage tank 1, a compressor 2, a cooler 3, a condenser 4, a CO2 liquid storage tank 5, a CO2 liquid pump 6, an evaporator 7, a superheater 8, a turbine expander 9, a heat pump unit 10, an atmospheric pressure water storage tank 11, and a medium pressure water storage tank 12. In actual use, the system also needs to be equipped with necessary auxiliary equipment and facilities such as cooling towers and water pumps, which will not be described in detail here.

[0007] The operating mode of the compressed CO2 energy storage system is as follows: Energy storage stage: At room temperature and pressure, CO2 gas is stored in storage tank 1. Using wind, solar, or off-peak electricity, compressor 2 compresses the CO2 to a high-temperature, high-pressure gaseous state. It is then cooled in cooler 3, becoming a high-pressure, room-temperature gaseous state. Simultaneously, the heat of compression is stored in medium-pressure water tank 12. The high-pressure, room-temperature CO2 gas then enters condenser 4, condensing into high-pressure, low-temperature CO2 liquid, which is stored in CO2 liquid storage tank 5. The phase change heat released during condensation is pumped to a higher temperature by heat pump unit 10 and stored in atmospheric pressure water storage tank 11. This completes the energy storage process.

[0008] Energy release stage: High-pressure liquid CO2 is sent to evaporator 7 via liquid pump 6. It is heated to gaseous state by atmospheric pressure hot water stored in atmospheric pressure water tank 11. Then it enters superheater 8 and is heated to high temperature state by medium pressure hot water stored in medium pressure water tank 12. Then the high temperature and high pressure CO2 gas is sent to turbine expander 9 to expand and generate electricity. The exhaust steam after doing work is finally returned to gas storage silo 1 for storage.

[0009] However, the aforementioned conventional compressed carbon dioxide energy storage system has the following technical drawbacks: First, a high-power heat pump unit is required to raise the low-temperature phase change heat to a usable temperature. The investment in heat pump equipment is high and the power consumption during operation is large. Second, a large-capacity atmospheric pressure hot water storage tank is required to store phase change heat. The heat storage equipment occupies a large area and has significant heat loss. Third, there is a problem of heat decay during long-term thermal storage, which affects the system's energy storage efficiency and energy release stability; Fourth, the configuration of heat pumps and thermal storage equipment significantly increases the initial investment and subsequent operation and maintenance costs of the system, reducing its technical and economic efficiency.

[0010] like Figure 2 The conventional data center cooling system shown mainly includes: liquid cooling plate 13, heat exchanger 14, cooling tower 15, and server 16.

[0011] The working principle of the data center heat dissipation system is as follows: the liquid cooling plate 13 covers the surface of the server 16, and the low temperature coolant is introduced into the liquid cooling plate 13. The heat generated by the server 16 during operation is absorbed by the surface heat exchange and turned into high temperature coolant. The high temperature coolant is sent into the heat exchanger 14 to exchange heat with the cold water in the lower tower of the cooling tower 15 and then turns into low temperature coolant. The temperature of the cold water in the lower tower increases and is sent back to the cooling tower 15 for cooling, so that the heat is finally dissipated into the environment.

[0012] The aforementioned conventional data center cooling systems have the following technical defects: First, wind and solar power generation are unstable and cannot continuously and stably provide green electricity for data centers. Second, data center cooling requires significant initial investment and subsequent energy consumption.

[0013] To address the aforementioned issues, existing technologies have attempted to combine data center waste heat with CO2 energy storage systems. For example, Chinese patent CN202311366884.8 discloses a gas-liquid two-state compression CO2 energy storage system and method that matches the power consumption of data center servers. It utilizes the waste heat from the data center's cooling liquid to heat both liquid and gaseous CO2, but still retains a complete heat storage system (cold water tank, hot water tank) and auxiliary cooling equipment (air-cooled heat exchanger), resulting in a complex system structure and a large number of devices. Another example is Chinese patent CN202211405628.0, which discloses a CO2 heat pump energy storage method for data center waste heat recovery. It uses a heat pump to circulate and raise the temperature of the data center's waste heat, coupling it with the energy storage cycle. However, the system includes multiple devices such as a heat pump, cold water tank, and hot water tank, and the introduction of the heat pump increases the energy conversion process and system complexity. Chinese patent CN202411781179.9 discloses a liquid-liquid compressed carbon dioxide energy storage system for recovering waste heat from data centers. It employs a phase change cold / heat storage device and a two-stage compression / expansion structure, resulting in a complex system configuration and high control difficulty. Chinese patent CN202510429056.7 discloses a deeply coupled system for data center energy cooling and carbon dioxide energy storage. It extracts CO2 from the CO2 energy storage cycle as a cooling medium to cool the data center. Its technical approach is "cooling the data center with CO2," rather than utilizing waste heat from the data center as a heat source for energy storage, which differs from the technical path of this invention.

[0014] In summary, how to achieve stable power supply and efficient heat dissipation in data centers while simplifying system structure and reducing equipment investment and operating costs is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0015] The purpose of this invention is to address the shortcomings of existing technologies by providing a complementary system and operating method that couples a data center with compressed carbon dioxide energy storage, which has a simple system structure and effectively reduces equipment investment and operating costs.

[0016] The technical objective of this invention is achieved through the following technical solution: A complementary system coupling a data center and compressed carbon dioxide energy storage includes a compressed carbon dioxide energy storage subsystem and a data center cooling subsystem. The compressed carbon dioxide energy storage subsystem includes a gas storage unit, a compression unit, a cooling unit, a condensation unit, a liquid storage unit, a pumping unit, an evaporation unit, a superheating unit, and an expansion power generation unit, which are sequentially connected by pipelines. The data center cooling subsystem includes a liquid cooling unit for absorbing heat from servers. The coolant outlet of the liquid cooling unit is directly connected to the heat flow inlet of the evaporation unit, and the coolant inlet of the liquid cooling unit is directly connected to the heat flow outlet of the evaporation unit, forming a closed cooling loop. The power output terminal of the expansion power generation unit is connected to the electrical equipment of the data center.

[0017] Preferably, the compressed carbon dioxide energy storage subsystem further includes a medium-pressure thermal storage unit; the cooling unit is connected to the medium-pressure thermal storage unit through a thermal storage circuit and is used to store the compression heat generated during the compression process; the superheating unit is connected to the medium-pressure thermal storage unit through a heat release circuit and is used to superheat gaseous carbon dioxide using the stored compression heat during the energy release stage.

[0018] Preferably, the rated load N of the expansion power generation unit t Configured to satisfy: N t = 1.1 × (N d + N l + N r In the formula, N d For the power load of the data center, N l For residential electricity load, N r For auxiliary power load in production.

[0019] Preferably, the total volume V of the liquid storage unit l Configuration to satisfy: V l = 1.1 × 24 × G t In the formula, G t The rated flow rate of the expansion power generation unit.

[0020] Preferably, the inlet and outlet temperatures of the coolant in the liquid cooling unit are 40°C to 50°C.

[0021] Preferably, the operating pressure range of the liquid storage unit is 6.0 MPa.a to 7.0 MPa.a.

[0022] Preferably, the operating pressure range of the gas storage unit is 300 Pa.g to 500 Pa.g.

[0023] An operation method for a complementary system based on the above-described coupling of a data center and compressed carbon dioxide energy storage, characterized in that it includes: Energy storage stage: Renewable energy or off-peak electricity is used to drive the compression unit to compress, cool, and condense carbon dioxide in the gas storage unit into liquid and store it in the liquid storage unit; Energy release and cooling phase: The pumping unit is activated to transport liquid carbon dioxide from the storage unit to the evaporation unit; at the same time, the data center cooling subsystem is activated, allowing the high-temperature coolant that has absorbed heat from the server to flow from the liquid cooling unit to the heat flow side of the evaporation unit; after absorbing heat from the high-temperature coolant, the liquid carbon dioxide vaporizes and passes through the evaporation unit and the superheating unit in sequence to enter the expansion power generation unit to generate electricity, which supplies the electrical equipment in the data center; after releasing heat, the high-temperature coolant becomes low-temperature coolant and returns to the liquid cooling unit to continue cooling the server.

[0024] Compared with the prior art, the beneficial effects of the present invention are: This invention deeply couples a compressed carbon dioxide energy storage subsystem with a data center cooling subsystem. On one hand, the compressed carbon dioxide energy storage subsystem converts unstable wind and solar green electricity into a continuous and stable power supply for the data center. On the other hand, the waste heat generated by the data center servers is directly used as a heat source for the vaporization of liquid carbon dioxide, thus simultaneously achieving stable power supply and efficient heat dissipation for the data center. Based on this, by directly connecting the liquid cooling unit and the evaporation unit, the conventional cooling tower and intermediate heat exchanger required by the data center are eliminated. At the same time, the heat pump unit and atmospheric pressure hot water storage tank conventionally required by the compressed carbon dioxide energy storage system are also eliminated. This significantly simplifies the system structure, reduces initial investment and operation and maintenance costs, improves the electricity-electricity efficiency of the energy storage system, and provides a stable cooling solution for the data center that is essentially independent of electrical and environmental factors. It achieves a comprehensive benefit of stable power supply, efficient heat dissipation, simplified equipment, and reduced investment, and is particularly suitable for off-grid or pure green electricity data center scenarios in Northwest China that utilize wind and solar green electricity. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a conventional compressed CO2 energy storage system; Figure 2 This is a schematic diagram of a conventional data center cooling system; Figure 3 This is a schematic diagram of the structure of the present invention; Reference numerals: 1—Gas storage tank; 2—Compressor; 21—Second output pipe; 3—Cooler; 31—Third output pipe; 4—Condenser; 41—Fourth output pipe; 5—CO2 liquid storage tank; 51—Fifth output pipe; 6—CO2 liquid pump; 61—Sixth output pipe; 7—Evaporator; 71—Seventh output pipe; 8—Superheater; 81—Eighth output pipe; 9—Turbine expander; 91—Ninth output pipe; 10—Heat pump unit; 11—Atmospheric pressure water storage tank; 12—Medium pressure water storage tank; 13—Liquid cooling plate; 31—First channel; 132—Second channel; 14—Heat exchanger; 15—Cooling tower; 16—Server; 17—Power plant transformer. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0028] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] Example 1 like Figure 1 — Figure 3 As shown, a complementary system coupling a data center and compressed carbon dioxide energy storage includes a compressed carbon dioxide energy storage subsystem and a data center cooling subsystem for absorbing server heat via liquid cooling units. The compressed carbon dioxide energy storage subsystem includes a gas storage unit, a compression unit, a cooling unit, a condensation unit, a liquid storage unit, a pumping unit, an evaporation unit, a superheating unit, and an expansion power generation unit, which are sequentially connected by pipes. The coolant outlet of the liquid cooling unit is directly connected to the heat flow inlet of the evaporation unit, and the coolant inlet of the liquid cooling unit is directly connected to the heat flow outlet of the evaporation unit, forming a closed cooling loop. The power output terminal of the expansion power generation unit is connected to the electrical equipment of the data center.

[0030] By deeply coupling the compressed carbon dioxide energy storage subsystem with the data center cooling subsystem, the system converts unstable wind and solar green electricity into a continuous and stable power supply for the data center. Simultaneously, the waste heat generated by the data center servers is used as the heat source for the vaporization of liquid carbon dioxide, thus achieving both stable power supply and efficient heat dissipation for the data center. Furthermore, by directly connecting the liquid cooling unit and the evaporation unit, the conventional cooling tower and intermediate heat exchanger required by data centers are eliminated. This also eliminates the heat pump unit and atmospheric pressure hot water storage tank typically required by compressed carbon dioxide energy storage systems. This significantly simplifies the system structure, reduces initial investment and maintenance costs, improves the electricity-electricity efficiency of the energy storage system, and provides a stable cooling solution for data centers that is largely independent of electrical and environmental factors. It achieves a comprehensive benefit of stable power supply, efficient heat dissipation, simplified equipment, and reduced investment, making it particularly suitable for off-grid or pure green electricity data center scenarios utilizing wind and solar green electricity in Northwest China.

[0031] like Figure 3 As shown, the compressed carbon dioxide energy storage subsystem includes a gas storage unit, a compression unit, a cooling unit, a condensation unit, a liquid storage unit, a pumping unit, an evaporation unit, a superheating unit, and an expansion power generation unit, which are connected in sequence through pipelines.

[0032] In this embodiment, the gas storage unit is a gas storage chamber 1; the compression unit is a compressor 2; the cooling unit is a cooler 3; the condensation unit is a condenser 4; the liquid storage unit is a CO2 liquid storage tank 5; the pumping unit is a CO2 liquid pump 6; the evaporation unit is an evaporator 7; the superheating unit is a superheater 8; and the expansion power generation unit is a turbine expander 9.

[0033] Specifically, the compressed carbon dioxide energy storage subsystem includes a gas storage chamber 1, a compressor 2, a cooler 3, a condenser 4, a CO2 liquid storage tank 5, a CO2 liquid pump 6, an evaporator 7, a superheater 8, and a turbine expander 9, which are connected in sequence through pipelines.

[0034] Gas storage chamber 1 is connected to the inlet of compressor 2 via a first output pipe; the outlet of compressor 2 is connected to the inlet of cooler 3 via a second output pipe 21; the outlet of cooler 3 is connected to the inlet of condenser 4 via a third output pipe 31; the outlet of condenser 4 is connected to the inlet of CO2 storage tank 5 via a fourth output pipe 41; the outlet of CO2 storage tank 5 is connected to the inlet of CO2 liquid pump 6 via a fifth output pipe 51; the outlet of CO2 liquid pump 6 is connected to the cold flow side inlet of evaporator 7 via a sixth output pipe 61; the cold flow side outlet of evaporator 7 is connected to the inlet of superheater 8 via a seventh output pipe 71; the outlet of superheater 8 is connected to the inlet of turbine expander 9 via an eighth output pipe 81; and the outlet of turbine expander 9 is connected to the inlet of gas storage chamber 1 via a ninth output pipe 91, forming a complete circulation loop.

[0035] The gas storage chamber 1 is used to store CO2 gas at normal temperature and pressure. Its working pressure is a slightly positive pressure state of 300 Pa.g to 500 Pa.g to prevent external air from seeping in and affecting the purity of the system. The CO2 liquid storage tank 5 is used to store high-pressure liquid CO2. Its working pressure is 6.0 MPa.a to 7.0 MPa.a, controlled below the CO2 critical pressure to ensure that CO2 is stored stably in a liquid state and to avoid the increased equipment requirements and operational complexity caused by the supercritical state.

[0036] like Figure 3 As shown, the compressed carbon dioxide energy storage subsystem also includes a medium-pressure thermal storage unit; the cooling unit is connected to the medium-pressure thermal storage unit through a thermal storage loop and is used to store the compression heat generated during the compression process; the superheating unit is connected to the medium-pressure thermal storage unit through a heat release loop and is used to superheat gaseous carbon dioxide using the stored compression heat during the energy release stage.

[0037] In this embodiment, the medium-pressure heat storage unit includes a medium-pressure water storage tank 12, which is used to store the heat of compression generated during the compression process.

[0038] The connection relationship between the cooler 3 and the medium-pressure water storage tank 12 is as follows: The coolant outlet of the cooler 3 is connected to the heat flow inlet of the medium-pressure water storage tank 12 through a first heat storage pipe; the coolant inlet of the cooler 3 is connected to the heat flow outlet of the medium-pressure water storage tank 12 through a second heat storage pipe, forming a closed loop.

[0039] The connection relationship between the superheater 8 and the medium-pressure water storage tank 12 is as follows: The heating liquid inlet of the superheater 8 is connected to the heat flow side outlet of the medium-pressure water storage tank 12 through a first heat release pipe; the heating liquid outlet of the superheater 8 is connected to the heat flow side inlet of the medium-pressure water storage tank 12 through a second heat release pipe, forming a closed loop.

[0040] like Figure 3 As shown, the data center cooling subsystem includes a server 16 and a liquid cooling unit. In this embodiment, the liquid cooling unit is a liquid cooling plate 13. The liquid cooling plate 13 covers the surface of the server 16 and is used to absorb the heat generated by the server 16 during operation.

[0041] The connection relationship between the liquid cooling plate 13 and the evaporator 7 is as follows: The coolant outlet of the liquid cooling plate 13 is directly connected to the hot flow side inlet of the evaporator 7 through the first channel 131; the coolant inlet of the liquid cooling plate 13 is directly connected to the hot flow side outlet of the evaporator 7 through the second channel 132, forming a closed cooling circuit.

[0042] In this embodiment, the coolant of the liquid cooling plate 13 is deionized water to improve heat exchange efficiency and reduce investment costs.

[0043] The inlet and outlet temperatures of the liquid cooling unit are between 40°C and 50°C. Specifically, the inlet and outlet temperatures of the coolant are set to 40°C / 50°C, meaning the inlet temperature of the liquid cooling plate 13 is 40°C and the outlet temperature is 50°C. This temperature range meets the server's heat dissipation requirements (the server's tolerance temperature should be allowed to fluctuate upwards as much as possible) and provides a stable heat source for the vaporization of liquid CO2, simplifying the structural design of the evaporator 7. The outlet temperature should not be lower than 35°C, otherwise it will be detrimental to the evaporation and vaporization process of liquid CO2 and will increase the structural design complexity of the evaporator 7.

[0044] like Figure 3 As shown, the power output terminal of the expansion power generation unit is connected to the power-consuming equipment of the data center.

[0045] In this embodiment, the power equipment used by the data center is a power plant transformer 17.

[0046] The power output terminal of the turbine expander 9 is connected to the power plant transformer 17, and the output terminal of the power plant transformer 17 is connected to the server 16, supplying the data center with the electrical energy generated by the turbine expander 9.

[0047] Complementary systems coupling data centers with compressed carbon dioxide energy storage are primarily suitable for data centers operating on off-grid or purely green electricity systems, requiring continuous power supply from the energy storage system. In practical applications, the minimum installed capacity design requirement for the turbine expander is: Rated load N of turbine expander 9 t Configured to satisfy: N t = 1.1 × (N d + N l + N r ); In the formula, N d For the power load of the data center, N l For residential electricity load, N r For auxiliary power load in production.

[0048] This formula ensures that the capacity of the turbine expander 9 is sufficient to cover all the power needs of the data center and its supporting facilities, and reserves a 10% margin to ensure the stability of the power supply during load fluctuations.

[0049] The total volume V of CO2 storage tank 5 l Configuration to satisfy: V l = 1.1 × 24 × G t ; In the formula, G t This is the rated flow rate of the turbine expander 9.

[0050] This formula ensures that the CO2 storage tank 5 can store enough liquid CO2 for 24 hours of continuous energy release, and reserves a 10% margin to support the data center's uninterrupted power supply around the clock.

[0051] Example 2 A method for operating a complementary system coupling a data center and compressed carbon dioxide energy storage includes: Energy storage stage: Renewable energy or off-peak electricity is used to drive the compression unit to compress, cool, and condense carbon dioxide in the gas storage unit into liquid and store it in the liquid storage unit; Specifically, the energy storage phase operation method: During the energy storage phase, the compressor 2 is driven by wind, solar, or off-peak electricity to store energy in the form of CO2 compression energy and latent heat of condensation.

[0052] The specific operation process is as follows: Compression process: The ambient temperature and pressure CO2 gas in the gas storage chamber 1 enters the compressor 2 through the first output pipe. The compressor 2 consumes electrical energy to compress the CO2 into a high temperature and high pressure gaseous state (pressure about 6.0-7.0 MPa, temperature about 150-230℃).

[0053] Cooling and heat storage process: High-temperature and high-pressure CO2 gas enters the cooler 3 through the second output pipe 21, where it exchanges heat with the coolant from the medium-pressure water storage tank 12, releasing the heat of compression and becoming high-pressure, room-temperature gaseous CO2 (temperature approximately 30-40℃). After absorbing heat, the coolant's temperature rises, and it returns to the medium-pressure water storage tank 12 for storage, to be used in the energy release stage.

[0054] Condensation process: High-pressure, ambient-temperature CO2 gas enters the condenser 4 through the third output pipe 31, releasing latent heat of condensation into the environment, condensing into high-pressure, low-temperature liquid CO2 (temperature approximately 15-25℃), which is then stored in the CO2 storage tank 5. A unique feature of this embodiment is that it eliminates the need for a heat pump unit and an atmospheric-pressure water storage tank to recover and store the phase change heat released during the condensation process, thereby simplifying the equipment and reducing investment.

[0055] Energy storage complete: High-pressure liquid CO2 is stored in CO2 storage tank 5, completing the energy storage process.

[0056] Energy release and cooling phase: The pumping unit is activated to transport liquid carbon dioxide from the storage unit to the evaporation unit; at the same time, the data center cooling subsystem is activated, allowing the high-temperature coolant that has absorbed heat from the server to flow from the liquid cooling unit to the heat flow side of the evaporation unit; after absorbing heat from the high-temperature coolant, the liquid carbon dioxide vaporizes and passes through the evaporation unit and the superheating unit in sequence to enter the expansion power generation unit to generate electricity, which supplies the electrical equipment in the data center; after releasing heat, the high-temperature coolant becomes low-temperature coolant and returns to the liquid cooling unit to continue cooling the server.

[0057] Specifically, the operation method of the energy release and cooling stage; the energy release and cooling stage simultaneously achieves two core functions: first, to use the stored liquid CO2 to expand and generate electricity, providing stable power for the data center; second, to use the waste heat of the server to heat the liquid CO2, which not only solves the server heat dissipation problem, but also provides a heat source for CO2 vaporization.

[0058] The specific operation process is as follows: Liquid CO2 delivery: Start the CO2 liquid pump 6 to deliver the high-pressure liquid CO2 in the CO2 storage tank 5 to the cold flow side of the evaporator 7 through the fifth output pipe 51 and the sixth output pipe 61.

[0059] Data center heat dissipation cycle: When the data center cooling subsystem is activated, the low-temperature coolant (approximately 40°C) in the liquid cooling plate 13 absorbs the heat generated by the operation of the server 16, and its temperature rises to approximately 50°C, becoming a high-temperature coolant. The high-temperature coolant flows into the heat flow side of the evaporator 7 through the first channel.

[0060] Heat exchange and vaporization: In evaporator 7, high-pressure liquid CO2 on the cold flow side exchanges heat with high-temperature coolant on the hot flow side. After absorbing heat, the liquid CO2 evaporates and vaporizes, becoming high-pressure gaseous CO2 (temperature approximately 35-45℃); after releasing heat, the high-temperature coolant's temperature drops to approximately 40℃, and it returns to the liquid cooling plate 13 through the second channel to continue dissipating heat for server 16, forming a closed loop.

[0061] Superheating and Expansion Power Generation: The high-pressure CO2 after gasification enters the superheater 8 through the seventh output pipe 71, absorbing the compression heat from the medium-pressure water storage tank 12, further raising its temperature to approximately 130-200℃. It then enters the turbine expander 9 through the eighth output pipe 81. The high-temperature, high-pressure CO2 expands and performs work in the turbine expander 9, driving the generator to generate electricity. The generated electricity is supplied to the server 16 and auxiliary equipment through the power plant transformer 17.

[0062] CO2 recovery: The exhaust gas (low-pressure, ambient temperature CO2) after the work is done is returned to the gas storage chamber 1 through the ninth output pipe 91 for storage, completing a complete energy release cycle.

[0063] The technical solutions provided by the embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of the present invention. The descriptions of the embodiments above are only for helping to understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the embodiments of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A complementary system coupling a data center and compressed carbon dioxide energy storage, characterized in that, This includes a compressed carbon dioxide energy storage subsystem and a data center cooling subsystem; The compressed carbon dioxide energy storage subsystem includes a gas storage unit, a compression unit, a cooling unit, a condensation unit, a liquid storage unit, a pumping unit, an evaporation unit, a superheating unit, and an expansion power generation unit, which are connected in sequence through pipelines. The data center cooling subsystem includes a liquid cooling unit for absorbing heat from the servers; The coolant outlet of the liquid cooling unit is directly connected to the hot flow inlet of the evaporation unit, and the coolant inlet of the liquid cooling unit is directly connected to the hot flow outlet of the evaporation unit, forming a closed cooling circuit. The power output terminal of the expansion power generation unit is connected to the power-consuming equipment of the data center.

2. The complementary system of data center and compressed carbon dioxide energy storage coupling according to claim 1, characterized in that, The compressed carbon dioxide energy storage subsystem also includes a medium-pressure thermal storage unit; The cooling unit is connected to the medium-pressure heat storage unit through a heat storage circuit and is used to store the heat of compression generated during the compression process. The superheating unit is connected to the medium-pressure thermal storage unit through a heat release circuit, and is used to superheat gaseous carbon dioxide using the stored compression heat during the energy release phase.

3. The complementary system of data center and compressed carbon dioxide energy storage coupled according to claim 1, characterized in that, The rated load N of the expansion power generation unit t Configured to satisfy: N t = 1.1 × (N d + N l + N r ); In the formula, N d For the power load of the data center, N l For residential electricity load, N r For auxiliary power load in production.

4. The complementary system of data center and compressed carbon dioxide energy storage coupling according to claim 1, characterized in that, The total volume V of the liquid storage unit l Configuration to satisfy: V l = 1.1 × 24 × G t ; In the formula, G t The rated flow rate of the expansion power generation unit.

5. The complementary system of data center and compressed carbon dioxide energy storage coupling according to claim 1, characterized in that, The inlet and outlet temperatures of the coolant in the liquid cooling unit are 40°C to 50°C.

6. The complementary system of data center and compressed carbon dioxide energy storage coupling according to claim 1, characterized in that, The operating pressure range of the liquid storage unit is 6.0 MPa.a to 7.0 MPa.a.

7. The complementary system of data center and compressed carbon dioxide energy storage coupling according to claim 1, characterized in that, The operating pressure range of the gas storage unit is 300 Pa.g to 500 Pa.g.

8. A method for operating a complementary system based on the coupling of a data center and compressed carbon dioxide energy storage as described in any one of claims 1 to 7, characterized in that, include: Energy storage stage: Renewable energy or off-peak electricity is used to drive the compression unit to compress, cool, and condense carbon dioxide in the gas storage unit into liquid and store it in the liquid storage unit; Energy release and cooling phase: The pumping unit is activated to transport liquid carbon dioxide from the storage unit to the evaporation unit; at the same time, the data center cooling subsystem is activated, allowing the high-temperature coolant that has absorbed heat from the server to flow from the liquid cooling unit to the heat flow side of the evaporation unit; the liquid carbon dioxide absorbs heat from the high-temperature coolant and vaporizes, passing through the evaporation unit and superheating unit in sequence before entering the expansion power generation unit to generate electricity, which supplies the electrical equipment in the data center; after releasing heat, the high-temperature coolant becomes low-temperature coolant and returns to the liquid cooling unit to continue cooling the server.

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