System and method for controlling temperature of cooling water system of compressed carbon dioxide energy storage project

Abstract

The invention discloses a system and method for controlling the temperature of a cooling water system of a compressed carbon dioxide energy storage project, and belongs to the field of compressed carbon dioxide energy storage. The system comprises a cooling tower water supply main pipe, a water return main pipe, a water chilling unit condensation side, a chilled water system pipeline and a bypass pipeline. The system is characterized in that a heating loop is additionally arranged, the loop is led out from a cooling tower water return main pipe or a condensation side water return pipeline, and after a heating water pump and a pipeline type electric heater are sequentially arranged, water flows back to a cooling tower water supply main pipe or a condensation side water supply pipeline; when the water outlet temperature of the cooling tower is 15-32 DEG C in the transition season, the water temperature of the upper tower is heated and adjusted through the electric heater, and the water temperature entering the condensation side of the water chilling unit can be effectively controlled. The cooling tower can be prevented from freezing in winter, the water temperature can be adjusted all the year round, and efficient and stable operation of a cooling water system is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressed carbon dioxide energy storage, and in particular to a system and method for controlling the temperature of a cooling water system of a compressed carbon dioxide energy storage project. BACKGROUND

[0002] Compressed carbon dioxide energy storage is a new long-term energy storage technology that uses the phase change of carbon dioxide between the gaseous and liquid (or supercritical) states to store and release energy, and is suitable for large-scale renewable energy consumption and grid peak shaving. A compressed carbon dioxide energy storage system generally has three stages: charging (energy storage) stage, discharging (energy release) stage, and standing stage. In the energy storage stage, the carbon dioxide is liquefied by cooling and then stored. Currently, conventional compressed carbon dioxide energy storage projects usually use a water chiller combined with a cooling tower to provide chilled water for carbon dioxide cooling. The condenser side of the water chiller, the cooling tower, and related pipelines together form the cooling water system in a compressed carbon dioxide energy storage power station.

[0003] The existing cooling water system uses a combination of a water chiller and a cooling tower to provide chilled water. In summer, the condenser side of the water chiller is connected to the cooling tower to produce 37 / 32℃ cooling water, and the evaporator side produces 15℃ chilled water that is connected to devices such as the condenser and water cooler to cool the carbon dioxide. In winter, the cooling tower is directly connected to the chilled water system to directly produce 15℃ chilled water. According to the performance characteristics of the water chiller, the inlet temperature of the condenser side of the water chiller is allowed to fluctuate within the range of 23~32℃. Therefore, when the temperature of the cooling tower is within the range of 15~23℃, the cooling tower return water cannot enter the water chiller or be directly connected to the chilled water system. To address the requirement that the inlet temperature of the condenser side of the water chiller be maintained within the range of 23~32℃, the current system usually sets up a cooling tower bypass to mix high and low temperature return water to adjust the inlet water temperature. In the carbon dioxide energy storage power stations that have been designed or applied, the way to solve this problem is to set up a cooling tower bypass to connect the cooling tower supply and return water main pipes, mix the lower temperature cooling tower lower tower water with the higher temperature upper tower water, and thus meet the requirements of the water chiller inlet temperature.

[0004] However, the existing system has significant defects: First, the problem of winter freeze protection. Since the medium in the cooling water system is water, the cooling water system of a compressed carbon dioxide energy storage power station constructed in a severe cold or cold region has the risk of freezing, which affects the safe operation of the system. Second, the problem of the water chiller inlet temperature. The bypass mixing adjustment method has limited capacity and poor controllability, and it is difficult to achieve stable and automated temperature control within the temperature range of 15~23℃, which restricts the adaptability and reliability of the system.

[0005] Therefore, combined with the operation mode of the cooling water system of the current compressed carbon dioxide energy storage project and the specific situation that the water temperature entering the water chiller needs to be controlled in winter, it is necessary to develop a system and method for controlling the temperature of the cooling water system of the compressed carbon dioxide energy storage project. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a system and method for controlling the temperature of the cooling water system of the compressed carbon dioxide energy storage project, which increases a water pump, a pipe heater and related pipelines, valves and the like in the conventional compressed carbon dioxide energy storage project cooling water system, meets the antifreezing requirement of the cooling tower in winter, adjusts the water temperature entering the water chiller, and ensures the energy efficiency and stable operation of the system.

[0007] To solve the above technical problems, the technical scheme adopted by the present application is: A system for controlling the temperature of the cooling water system of the compressed carbon dioxide energy storage project, comprising a cooling tower water supply main pipe, a cooling tower water return main pipe, a water chiller condensing side, a chilled water system water supply pipeline and a chilled water system water return pipeline, and a bypass pipeline connected between the cooling tower water supply main pipe and the water return main pipe; further comprising a heating pipeline and a matching valve pipeline system, the heating pipeline is drawn from the cooling tower water return main pipe or the water chiller condensing side water return pipeline, and is sequentially provided with a heating water pump and a pipe type electric heater, and finally returns to the cooling tower water supply main pipe or the water chiller condensing side water supply pipeline; when the water temperature of the cooling tower is between 15-32 DEG C in the transition season, the water temperature of the cooling tower is heated by the pipe type electric heater to meet the water temperature of the cooling tower and the temperature entering the condensing side of the water chiller.

[0008] Further improvement of the technical scheme of the present application is that: the first water supply pipeline connected between the cooling tower water supply main pipe and the water chiller condensing side is sequentially provided with a fourth electric valve and a first electric valve; the first water return pipeline connected between the water chiller condensing side and the cooling tower water return main pipe is sequentially provided with a second electric valve, an eighth electric valve and a fifth electric valve; the chilled water system water supply pipeline is provided with a sixth electric valve; the chilled water system water return pipeline is provided with a seventh electric valve; the bypass pipeline is provided with a third electric valve; the heating pipeline is drawn before the eighth electric valve and flows after the eighth electric valve; the ninth electric valve is provided before the heating water pump, and the eighteenth electric valve is provided after the pipe type electric heater.

[0009] Further improvement of the technical scheme of the present application is that the first electric valve, the second electric valve, the third electric valve, the fourth electric valve, the fifth electric valve, the sixth electric valve, the seventh electric valve, the eighth electric valve, the ninth electric valve and the eighteenth electric valve are connected with the thermometers on the upper and lower towers of the cooling tower to realize automatic switching and adjustment of the opening degree, and automatic operation of the system.

[0010] Further improvement of the technical scheme of the present application is that the heating water pump adopts one active and one standby configuration, including a first heating water pump and a second heating water pump; and the pipeline electric heater adopts one active and one standby configuration, including a first pipeline electric heater and a second pipeline electric heater.

[0011] Further improvement of the technical scheme of the present application is that the tenth electric valve and the eleventh electric valve are arranged before and after the first heating water pump respectively; the twelfth electric valve and the thirteenth electric valve are arranged before and after the second heating water pump respectively; the fourteenth electric valve and the fifteenth electric valve are arranged before and after the first pipeline electric heater respectively; and the sixteenth electric valve and the seventeenth electric valve are arranged before and after the second pipeline electric heater respectively.

[0012] Further improvement of the technical scheme of the present application is that the tenth electric valve, the eleventh electric valve, the twelfth electric valve, the thirteenth electric valve, the fourteenth electric valve, the fifteenth electric valve, the sixteenth electric valve and the seventeenth electric valve are connected with the thermometers on the upper and lower towers of the cooling tower to realize automatic switching and adjustment of the opening degree, and automatic operation of the system.

[0013] Further improvement of the technical scheme of the present application is that the temperature range of the condensing side water inlet of the water chiller is 23-32 DEG C, and the power of the pipeline electric heater can be adjusted to meet the demand of the condensing side water inlet temperature of the water chiller under various temperature conditions.

[0014] A method for controlling the temperature of a cooling water system of a compressed carbon dioxide energy storage project, comprising the following operation modes: When the outdoor temperature is high in summer, the first electric valve, the second electric valve, the fourth electric valve, the fifth electric valve and the sixth electric valve are opened, and the third electric valve, the seventh electric valve, the eighth electric valve, the ninth electric valve, the tenth electric valve, the eleventh electric valve, the twelfth electric valve, the thirteenth electric valve, the fourteenth electric valve, the fifteenth electric valve, the sixteenth electric valve, the seventeenth electric valve and the eighteenth electric valve are closed; 32 DEG C cooling water enters the condensing side of the water chiller, the temperature rises to 37 DEG C, and then returns to the cooling tower, the temperature is reduced to 32 DEG C after heat dissipation in the cooling tower, and then is sent to the condensing side of the water chiller, and the cycle is repeated; When the outdoor temperature is low in winter, the fourth electric valve, the fifth electric valve, the sixth electric valve, the seventh electric valve, the seventeenth electric valve and the eighteenth electric valve are opened, and the first electric valve, the second electric valve, the third electric valve, the eighth electric valve, the ninth electric valve, the tenth electric valve, the eleventh electric valve, the twelfth electric valve, the thirteenth electric valve, the fourteenth electric valve, the fifteenth electric valve and the sixteenth electric valve are closed, and the cooling tower directly produces 15 DEG C cold water into the chilled water system to cool the condenser and the water cooler to cool the carbon dioxide gas, and after heat exchange, the temperature is increased to 20 DEG C and then returned to the cooling tower for cooling, and the cycle is repeated. When the outdoor temperature is low in winter, the fourth electric valve, the fifth electric valve, the sixth electric valve, the seventh electric valve, the seventeenth electric valve and the eighteenth electric valve are opened, and the first electric valve, the second electric valve, the third electric valve, the eighth electric valve, the ninth electric valve, the tenth electric valve, the eleventh electric valve, the twelfth electric valve, the thirteenth electric valve, the fourteenth electric valve, the fifteenth electric valve and the sixteenth electric valve are closed, and the cooling tower directly produces 15 DEG C cold water into the chilled water system to cool the condenser and the water cooler to cool the carbon dioxide gas, and after heat exchange, the temperature is increased to 20 DEG C and then returned to the cooling tower for cooling, and the cycle is repeated. When the outdoor temperature is low in winter, the fourth electric valve, the fifth electric valve, the sixth electric valve, the seventh electric valve, the seventeenth electric valve and the eighteenth electric valve are opened, and the first electric valve, the second electric valve, the third electric valve, the eighth electric valve, the ninth electric valve, the tenth electric valve, the eleventh electric valve, the twelfth electric valve, the thirteenth electric valve, the fourteenth electric valve, the fifteenth electric valve and the sixteenth electric valve are closed, and the cooling tower directly produces 15 DEG C cold water into the chilled water system to cool the condenser and the water cooler to cool the carbon dioxide gas, and after heat exchange, the temperature is increased to 20 DEG C and then returned to the cooling tower for cooling, and the cycle is repeated.

[0015] Due to the adoption of the above technical scheme, the technical progress achieved by the application is: 1、The application can realize precise control of the water temperature of the compressed carbon dioxide energy storage system cooling water system, and enhance the safety and stability of the system, by the comprehensive utilization of the heating water pump, the pipeline electric heater and other devices and pipelines arranged in the cooling water system of the compressed carbon dioxide energy storage system.

[0016] 2、The present application can realize the anti-freezing of the water in the compressed carbon dioxide energy storage system cooling water system, and reduce the risk of freezing of the cooling water system pipeline by the comprehensive utilization of the heating water pump, the pipeline electric heater and other equipment and pipelines arranged in the compressed carbon dioxide energy storage system cooling water system.

[0017] 3、The present application can realize the automatic control of the water temperature of the compressed carbon dioxide energy storage system cooling water system by the comprehensive utilization of the heating water pump, the pipeline electric heater and other equipment and pipelines arranged in the compressed carbon dioxide energy storage system cooling water system, thereby saving the labor cost. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor. Figure 1 is a flow chart of the conventional compressed carbon dioxide energy storage system cooling water system mentioned in the present application; Figure 2 is a flow chart of a system for controlling the temperature of the compressed carbon dioxide energy storage project cooling water system provided in the embodiments of the present application; 1, first heating water pump; 2, second heating water pump; 3, first pipeline electric heater; 4, second pipeline electric heater; V1, first electric valve; V2, second electric valve; V3, third electric valve; V4, fourth electric valve; V5, fifth electric valve; V6, sixth electric valve; V7, seventh electric valve; V8, eighth electric valve; V9, ninth electric valve; V10, tenth electric valve; V11, eleventh electric valve; V12, twelfth electric valve; V13, thirteenth electric valve; V14, fourteenth electric valve; V15, fifteenth electric valve; V16, sixteenth electric valve; V17, seventeenth electric valve; V18, eighteenth electric valve. DETAILED DESCRIPTION

[0019] It should be noted that the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0020] In the description of the present application, it is to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0021] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "several" is at least two, such as two, three, etc., unless otherwise explicitly and specifically limited.

[0022] The present application will be further described in detail below in conjunction with the drawings and examples: The water cooler is a key heat exchange component in the compressed carbon dioxide energy storage system, which cools the high-temperature and high-pressure carbon dioxide gas to near room temperature through cooling water during the energy storage stage, ensuring that the temperature is suitable for subsequent storage or expansion.

[0023] The condenser is a key heat exchange component in the compressed carbon dioxide energy storage system, which condenses the low-temperature and low-pressure carbon dioxide gas into liquid at the low-pressure side of the system, facilitating subsequent pumping or storage.

[0024] In the current compressed carbon dioxide energy storage power station, the related system process is as follows Figure 1As shown, the cooling water provides cold energy for the chiller condenser and runs in the energy storage stage. When the outdoor temperature is high, the first electric valve V1, the second electric valve V2, the fourth electric valve V4 and the fifth electric valve V5 are opened, and the remaining valves (the third electric valve V3, the sixth electric valve V6 and the seventh electric valve V7) are closed. The 32℃ cooling water enters the chiller condenser side, the temperature rises to 37℃, and then returns to the cooling tower. After heat dissipation in the cooling tower, the temperature decreases to 32℃, and then is sent to the chiller condenser side for repeated circulation. When the outdoor temperature is low, the fourth electric valve V4, the fifth electric valve V5, the sixth electric valve V6 and the seventh electric valve V7 are opened, and the remaining valves (the first electric valve V1, the second electric valve V2 and the first electric valve V3) are closed. The cooling tower directly produces 15℃ cooling water which enters the chilled water system to cool the condenser and the water cooler to cool the carbon dioxide gas. After heat exchange, the temperature rises to 20℃, and then returns to the cooling tower for cooling, and the cycle is repeated. When the cooling tower outlet temperature is between 15-32℃ in the transition season, the first electric valve V1, the second electric valve V2, the third electric valve V3, the fourth electric valve V4 and the fifth electric valve V5 are opened. The cooling water outlet mixes with the tower water to 32℃, and then enters the chiller condenser side. The temperature rises to 37℃, and then returns to the cooling tower. After heat dissipation in the cooling tower, the temperature decreases to 32℃, and then is sent to the chiller condenser side. The original system has certain disadvantages. First, in winter, the medium in the cooling water system is water, and the cooling water system of the compressed carbon dioxide energy storage power station constructed in cold or cold regions has the risk of freezing, which affects the operation of the system. Second, the third electric valve V3 on the bypass pipeline cannot realize stepless adjustment and cannot adjust the opening degree in real time according to the cooling tower outlet temperature. Therefore, when the cooling tower outlet temperature is in the range of 15-32℃, the temperature entering the chiller condenser side cannot be precisely and automatically controlled by the electric valve on the bypass pipeline.

[0025] Therefore, the application adds a heating water pump, a pipeline electric heater and corresponding pipelines to the conventional compressed carbon dioxide energy storage system cooling water system. During the period when the compressed carbon dioxide energy storage system cooling water system does not work, the electric heater heats the water in the pipeline to ensure that the water in the system does not freeze, thereby not affecting the operation of the system. At the same time, when the cooling tower outlet temperature is between 15-32℃ in the transition season, the pipeline electric heater heats the tower water temperature of the cooling tower to meet the cooling tower outlet temperature and the temperature entering the chiller condenser side. The specific scheme is as follows: As Figure 2As shown, a system for controlling the temperature of a compressed carbon dioxide energy storage project cooling water system includes a cooling tower supply water main, a cooling tower return water main, a chiller condenser side, a chilled water system supply water line and a chilled water system return water line, and a bypass line connected between the cooling tower supply water main and the return water main; further including a heating line and a matching valve line system, the heating line being drawn from the cooling tower return water main or the chiller condenser side return water line and sequentially provided with a heating water pump and a pipe-type electric heater, and finally returning to the cooling tower supply water main or the chiller condenser side supply water line; when in the transition season, the cooling tower outlet water temperature is between 15-32℃, the cooling tower upper tower water temperature is heated by the pipe-type electric heater to meet the cooling tower outlet water temperature and the temperature entering the chiller condenser side.

[0026] Further, the first supply water line connected between the cooling tower supply water main and the chiller condenser side is sequentially provided with a fourth electric valve V4 and a first electric valve V1; the first return water line connected between the chiller condenser side and the cooling tower return water main is sequentially provided with a second electric valve V2, an eighth electric valve V8 and a fifth electric valve V5; the chilled water system supply water line is provided with a sixth electric valve V6; the chilled water system return water line is provided with a seventh electric valve V7; the bypass line is provided with a third electric valve V3; the heating line is drawn before the eighth electric valve V8 and added after the eighth electric valve V8; the ninth electric valve V9 is provided before the heating water pump and the eighteenth electric valve V18 is provided after the pipe-type electric heater.

[0027] Further, the first electric valve V1, the second electric valve V2, the third electric valve V3, the fourth electric valve V4, the fifth electric valve V5, the sixth electric valve V6, the seventh electric valve V7, the eighth electric valve V8, the ninth electric valve V9 and the eighteenth electric valve V18 are all connected with the thermometers on the cooling tower upper tower and lower tower side to realize automatic switching and adjustment of the opening degree and automatic operation of the system.

[0028] Further, the heating water pump is configured with one active and one standby, including a first heating water pump 1 and a second heating water pump 2; the pipe-type electric heater is configured with one active and one standby, including a first pipe-type electric heater 3 and a second pipe-type electric heater 4. The safety and stable operation of the system is ensured, and in special cases, the system can also be operated simultaneously to meet the operation requirements of various working conditions.

[0029] Further, the tenth electric valve V10 and the eleventh electric valve V11 are arranged before and after the first heating water pump 1 respectively; the twelfth electric valve V12 and the thirteenth electric valve V13 are arranged before and after the second heating water pump 2 respectively; the fourteenth electric valve V14 and the fifteenth electric valve V15 are arranged before and after the first pipe type electric heater 3 respectively; the sixteenth electric valve V16 and the seventeenth electric valve V17 are arranged before and after the second pipe type electric heater 4 respectively.

[0030] Further, the tenth electric valve V10, the eleventh electric valve V11, the twelfth electric valve V12, the thirteenth electric valve V13, the fourteenth electric valve V14, the fifteenth electric valve V15, the sixteenth electric valve V16 and the seventeenth electric valve V17 are all connected with the temperature meters on the upper tower and the lower tower of the cooling tower to realize automatic switching and adjustment of the opening degree and automatic operation of the system.

[0031] Further, the water inlet temperature on the condensing side of the water chiller can be in the range of 23-32℃, and the power of the pipe type electric heater can be adjusted to meet the demand of the water inlet temperature on the condensing side of the water chiller under various temperature conditions.

[0032] A method for controlling the temperature of a cooling water system of a compressed carbon dioxide energy storage project, specifically comprising the following operation modes: When the outdoor temperature is high in summer, the first electric valve V1, the second electric valve V2, the fourth electric valve V4, the fifth electric valve V5 and the eighth electric valve V8 are opened, and the remaining valves are closed. 32℃ cooling water enters the condensing side of the water chiller, the temperature rises to 37℃, and then returns to the cooling tower. After heat dissipation in the cooling tower, the temperature decreases to 32℃, and then is sent to the condensing side of the water chiller for repeated circulation.

[0033] When the outdoor temperature is low in winter, the fourth electric valve V4, the fifth electric valve V5, the eighth electric valve V8, the ninth electric valve V9, the sixth electric valve V6 and the seventh electric valve V7 are opened, and the remaining valves are closed. The cooling tower directly produces 15℃ cooling water which enters the chilled water system to cool the carbon dioxide gas in the condenser and the water cooler. After heat exchange, the temperature rises to 20℃, and then returns to the cooling tower for cooling, for repeated circulation.

[0034] When the cooling tower outlet water temperature is between 15-32℃ in the transition season, the first electric valve V1, the second electric valve V2, the fourth electric valve V4, the fifth electric valve V5, the ninth electric valve V9, the tenth electric valve V10, the eleventh electric valve V11, the fourteenth electric valve V14, the fifteenth electric valve V15 and the eighteenth electric valve V18 are opened, and the remaining valves are closed. The condenser side outlet water of the water chiller is first heated to 37℃ by the heating water pump through the pipeline heater and then enters the cooling tower. After heat dissipation in the cooling tower, the temperature is reduced to 32℃ and then sent to the condenser side of the water chiller for repeated circulation.

[0035] When the outdoor temperature is extremely low, the compressed carbon dioxide energy storage system is in a static or energy release working condition, and the cooling water system pipeline has a freezing risk, the third electric valve V3, the fourth electric valve V4, the fifth electric valve V5, the ninth electric valve V9, the tenth electric valve V10, the eleventh electric valve V11, the fourteenth electric valve V14, the fifteenth electric valve V15 and the eighteenth electric valve V18 are opened, and the remaining valves are closed. The cooling water system enters the anti-freezing mode. The lower tower water of the cooling tower first enters the heating water pump through the bypass of the third electric valve V3, and then enters the cooling tower after being heated by the electric heater. The cycle is repeated to ensure that the cooling water system pipeline does not freeze and does not affect the next operation of the system.

[0036] Through the above-mentioned operation modes, the water temperature of the compressed carbon dioxide energy storage system cooling water system can be precisely automatically controlled, the system operation requirements can be met, the risk of freezing of the cooling water system pipeline can be reduced, and the safe and stable operation of the system can be ensured.

[0037] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A system for controlling the temperature of a cooling water system in a compressed carbon dioxide energy storage project, comprising a cooling tower supply water header, a cooling tower return water header, a chiller unit condenser side, a chilled water system supply water pipeline, a chilled water system return water pipeline, and a bypass pipeline connecting the cooling tower supply water header and the return water header; characterized in that: It also includes a heating pipeline and a matching valve pipeline system. The heating pipeline is led out from the cooling tower return water header or the chiller unit condenser side return water pipeline, and is equipped with a heating water pump and a pipeline electric heater in sequence, and finally flows back to the cooling tower supply water header or the chiller unit condenser side supply water pipeline. When it is the transition season and the cooling tower outlet water temperature is between 15 and 32°C, the pipeline electric heater heats the water temperature in the cooling tower to meet the cooling tower outlet water temperature and the temperature entering the chiller unit condenser side.

2. The system for controlling the temperature of the cooling water system in a compressed carbon dioxide energy storage project according to claim 1, characterized in that: A fourth electric valve (V4) and a first electric valve (V1) are sequentially installed on the first water supply pipeline connecting the cooling tower water supply header to the condenser side of the chiller unit; a second electric valve (V2), an eighth electric valve (V8), and a fifth electric valve (V5) are sequentially installed on the first return water pipeline connecting the condenser side of the chiller unit to the cooling tower return water header; a sixth electric valve (V6) is installed on the chilled water system water supply pipeline; a seventh electric valve (V7) is installed on the chilled water system return water pipeline; a third electric valve (V3) is installed on the bypass pipeline; a heating pipeline is led out before the eighth electric valve (V8), and the heating pipeline returns after the eighth electric valve (V8); a ninth electric valve (V9) is installed before the heating water pump, and an eighteenth electric valve (V18) is installed after the pipeline electric heater.

3. The system for controlling the temperature of the cooling water system in a compressed carbon dioxide energy storage project according to claim 2, characterized in that: The first electric valve (V1), the second electric valve (V2), the third electric valve (V3), the fourth electric valve (V4), the fifth electric valve (V5), the sixth electric valve (V6), the seventh electric valve (V7), the eighth electric valve (V8), the ninth electric valve (V9), and the eighteenth electric valve (V18) are all interlocked with the thermometers on the upper and lower sides of the cooling tower to achieve automatic switching and adjustment of the opening, thus realizing the automatic operation of the system.

4. The system for controlling the temperature of the cooling water system in a compressed carbon dioxide energy storage project according to claim 1, characterized in that: The heating water pumps are configured with one in use and one on standby, including a first heating water pump (1) and a second heating water pump (2); the pipeline electric heaters are configured with one in use and one on standby, including a first pipeline electric heater (3) and a second pipeline electric heater (4).

5. The system for controlling the temperature of the cooling water system in a compressed carbon dioxide energy storage project according to claim 4, characterized in that: A tenth electric valve (V10) and an eleventh electric valve (V11) are respectively installed before and after the first heating water pump (1); a twelfth electric valve (V12) and a thirteenth electric valve (V13) are respectively installed before and after the second heating water pump (2); a fourteenth electric valve (V14) and a fifteenth electric valve (V15) are respectively installed before and after the first pipeline electric heater (3); and a sixteenth electric valve (V16) and a seventeenth electric valve (V17) are respectively installed before and after the second pipeline electric heater (4).

6. The system for controlling the temperature of the cooling water system in a compressed carbon dioxide energy storage project according to claim 5, characterized in that: The tenth electric valve (V10), the eleventh electric valve (V11), the twelfth electric valve (V12), the thirteenth electric valve (V13), the fourteenth electric valve (V14), the fifteenth electric valve (V15), the sixteenth electric valve (V16), and the seventeenth electric valve (V17) are all interlocked with the thermometers on the upper and lower sides of the cooling tower to achieve automatic switching and adjustment of the opening, thus realizing the automatic operation of the system.

7. The system for controlling the temperature of the cooling water system in a compressed carbon dioxide energy storage project according to claim 1, characterized in that: The acceptable range of condensate inlet water temperature for chiller units is 23–32°C. The condensate inlet water temperature requirements of chiller units under various temperature conditions can be met by adjusting the power of the in-line electric heater.

8. A method for controlling the temperature of a cooling water system in a compressed carbon dioxide energy storage project using the system described in any one of claims 1-7, characterized in that: Including the following operating modes: When the outdoor temperature is high in summer, the first electric valve (V1), the second electric valve (V2), the fourth electric valve (V4), the fifth electric valve (V5), and the sixth electric valve (V6) are opened, while the third electric valve (V3), the seventh electric valve (V7), the eighth electric valve (V8), the ninth electric valve (V9), the tenth electric valve (V10), the eleventh electric valve (V11), the twelfth electric valve (V12), the thirteenth electric valve (V13), the fourteenth electric valve (V14), the fifteenth electric valve (V15), the sixteenth electric valve (V16), the seventeenth electric valve (V17), and the eighteenth electric valve (V18) are closed. Cooling water at 32°C enters the chiller unit's condenser side, its temperature rises to 37°C, and then it returns to the cooling tower. After being cooled by the cooling tower, its temperature drops to 32°C and it is then sent back to the chiller unit's condenser side, repeating the cycle. When the outdoor temperature is low in winter, the fourth electric valve (V4), the fifth electric valve (V5), the sixth electric valve (V6), the seventh electric valve (V7), the seventeenth electric valve (V17), and the eighteenth electric valve (V18) are opened, while the first electric valve (V1), the second electric valve (V2), the third electric valve (V3), the eighth electric valve (V8), the ninth electric valve (V9), the tenth electric valve (V10), the eleventh electric valve (V11), the twelfth electric valve (V12), the thirteenth electric valve (V13), the fourteenth electric valve (V14), the fifteenth electric valve (V15), and the sixteenth electric valve (V16) are closed. The cooling tower directly produces 15°C cold water, which enters the chilled water system to serve as a condenser and water cooler to cool carbon dioxide gas. After heat exchange, the water is heated to 20°C and then returned to the cooling tower for cooling, and the cycle repeats. When it is the transitional season and the outlet water temperature of the cooling tower is between 15 and 32℃, the first electric valve (V1), the second electric valve (V2), the fourth electric valve (V4), the fifth electric valve (V5), the seventh electric valve (V7), the eighth electric valve (V8), the ninth electric valve (V9), the twelfth electric valve (V12), the thirteenth electric valve (V13), and the sixteenth electric valve (V16) are open, and the third electric valve (V3), the sixth electric valve (V6), the tenth electric valve (V10), the eleventh electric valve (V11), the fourteenth electric valve (V14), the fifteenth electric valve (V15), the seventeenth electric valve (V17), and the eighteenth electric valve (V18) are closed. The water outlet from the condenser side of the chiller unit is first heated to 37℃ by the heating water pump and the pipeline heater before entering the cooling tower. After being cooled by the cooling tower, the temperature drops to 32℃ and is then sent to the condenser side of the chiller unit, and the cycle repeats. When the outdoor temperature is extremely low and the compressed carbon dioxide energy storage system is in a static or releasing state, and there is a risk of freezing in the cooling water system pipelines, the third electric valve (V3), fourth electric valve (V4), fifth electric valve (V5), seventh electric valve (V7), eighth electric valve (V8), ninth electric valve (V9), twelfth electric valve (V12), thirteenth electric valve (V13), and sixteenth electric valve (V16) are opened, while the first electric valve (V1), second electric valve (V2), sixth electric valve (V6), tenth electric valve (V10), eleventh electric valve (V11), fourteenth electric valve (V14), fifteenth electric valve (V15), seventeenth electric valve (V17), and eighteenth electric valve (V18) are closed. The cooling water system enters the anti-freeze mode. The water in the cooling tower first enters the heating water pump through the bypass pipeline where the third electric valve (V3) is located, and then enters the cooling tower after being heated by the pipeline electric heater. This cycle is repeated to ensure that the cooling water system pipelines do not freeze and will not affect the next operation of the system.

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