Fused salt and water cascade energy storage system and scheduling method

Abstract

The invention provides a fused salt and water cascade energy storage system and a scheduling method, and belongs to the technical field of heat exchange equipment.The fused salt and water cascade energy storage system specifically comprises an air compressor unit, a heat storage and exchange system, a gas storage and a turbine motor, and the heat storage and exchange system comprises a low-temperature fused salt tank, a high-temperature fused salt tank, a low-temperature water tank, a high-temperature water tank, a fused salt heat exchanger and a water heat exchanger; molten salt heat exchangers and water heat exchangers are correspondingly arranged between the air compressor set and the gas storage and between the turbine and the gas storage, and the low-temperature molten salt tank and the high-temperature molten salt tank are connected through the molten salt heat exchangers in the connecting loops between the air compressor set and the gas storage and between the turbine and the gas storage. The low-temperature water tank and the high-temperature water tank are connected with the gas storage and the water heat exchanger in the connection loop between the turbine and the gas storage through the air compressor set, and therefore the heat energy recovery rate is increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat exchange equipment, and particularly relates to a molten salt and water cascade energy storage system and a scheduling method. Background Art

[0002] For an energy system including a compressed air, a turbine, and a molten salt energy storage system, it is difficult to achieve low temperature in the existing molten salt energy storage system. Currently, the existing products on the market can only be used up to 180°C, and the low-temperature part can only be recovered through water. A similar technical solution is given in the invention patent application CN202510430176.9, "A Molten Salt Thermal Energy Storage System Based on Electricity Price Regulation and a Control Method".

[0003] However, in the above technical solution, if only a molten salt and water cascade energy storage system is adopted, there is still a lot of thermal energy that has not been collected after the compressed air passes through the heat exchanger, resulting in energy waste; for water, if the use temperature is too high, the cost of the storage system increases and it is difficult to manufacture the water storage tank.

[0004] Therefore, to solve the above technical problems, the present application provides a molten salt and water cascade energy storage system and a scheduling method. Summary of the Invention

[0005] To achieve the object of the present invention, the present invention adopts the following technical solutions: Specifically, the present application provides a molten salt and water cascade energy storage system, which has a high energy utilization efficiency and flexible regulation.

[0006] To achieve the above object of the invention, a molten salt and water cascade energy storage system provided by the present application includes the following: An air compressor unit, a storage heat exchange system, a gas storage reservoir, and a turbine. The storage heat exchange system includes a low-temperature molten salt tank, a high-temperature molten salt tank, a low-temperature water tank, a high-temperature water tank, a molten salt heat exchanger, and a water heat exchanger. Molten salt heat exchangers and water heat exchangers are respectively provided in the connection circuits between the air compressor unit and the gas storage reservoir, and between the turbine and the gas storage reservoir. The low-temperature molten salt tank and the high-temperature molten salt tank are connected by using the molten salt heat exchanger in the connection circuit between the air compressor unit and the gas storage reservoir, and between the turbine and the gas storage reservoir. The low-temperature water tank and the high-temperature water tank are connected by using the water heat exchanger in the connection circuit between the air compressor unit and the gas storage reservoir, and between the turbine and the gas storage reservoir.

[0007] Furthermore, when the low-temperature molten salt tank and the high-temperature molten salt tank are connected by using the molten salt heat exchanger in the connection circuit between the air compressor unit and the gas storage reservoir, and between the turbine and the gas storage reservoir, valves are provided between the molten salt heat exchanger and the energy release circuit and the energy storage circuit of the low-temperature molten salt tank and the high-temperature molten salt tank.

[0008] A further technical solution lies in that when the low-temperature water tank and the high-temperature water tank are connected by using the water heat exchanger in the connection circuits between the air compressor unit and the gas storage reservoir, and between the turbine and the gas storage reservoir, valves are provided between the water heat exchanger and the low-temperature water tank and the high-temperature water tank in both the energy release circuit and the energy storage circuit.

[0009] A further technical solution lies in that the low-temperature molten salt tank and the high-temperature molten salt tank construct a molten salt and water cascade energy storage system, and the low-temperature water tank and the high-temperature water tank construct a water storage heat exchange system.

[0010] A further technical solution lies in that when the cascade energy storage heat supply and power generation system is in the energy storage mode, it includes the following: The molten salt and water cascade energy storage system and the water storage heat exchange system start to operate. The low-temperature molten salt flows from the low-temperature molten salt tank through the molten salt heat exchanger and returns to the low-temperature molten salt tank, and the low-temperature water flows from the low-temperature water tank through the water heat exchanger and returns to the low-temperature water tank. Subsequently, when the target condition is reached, the air compressor unit starts to operate. Finally, the gas storage reservoir starts to store gas.

[0011] A further technical solution lies in that when the cascade energy storage heat supply and power generation system stops, it includes the following: The air compressor unit stops operating, the molten salt and water cascade energy storage system and the water storage heat exchange system stop operating, the molten salt heat exchanger and the water heat exchanger stop operating, and the high-temperature molten salt tank and the high-temperature water tank enter the static stage.

[0012] It can be understood that when the cascade energy storage heat supply and power generation system is in the energy release mode, it includes the following: The high-temperature molten salt flows from the high-temperature molten salt tank through the molten salt heat exchanger and returns to the low-temperature molten salt tank, and the high-temperature water flows from the high-temperature water tank through the water heat exchanger and returns to the low-temperature water tank. Subsequently, the gas storage reservoir starts to release gas. Finally, the turbine starts to operate.

[0013] Further, when the cascade energy storage heat supply and power generation system is in the startup stage, the molten salt medium in the low-temperature molten salt tank is heated by using the molten salt heat exchanger, and the cold-side molten salt outlet temperature of the molten salt heat exchanger is monitored in real time. When the outlet temperature reaches the designed energy storage temperature of the high-temperature molten salt tank, the control system switches the flow pipeline of the molten salt, and the molten salt in the low-temperature molten salt tank flows into the high-temperature molten salt tank through the molten salt heat exchanger.

[0014] It can be understood that when the low-temperature molten salt tank of the cascade energy storage heat supply and power generation system, as well as the connecting pipelines and valves of the low-temperature molten salt tank are frozen and blocked, it includes the following: The hot water storage heat exchange system immediately stops operating, the control system switches the compressed air circulation line, discharges the high-temperature compressed air into the atmosphere through the exhaust port, and shuts down the air compressor unit at a preset decreasing rate.

[0015] Further, when a failure occurs in the high-temperature side hot water storage heat exchange system of the stepped energy storage heating and power generation system, the following contents are included: Start the standby high-pressure hot water tank feed water heat exchanger to provide a heat exchange medium, gradually adjust the gas storage reservoir gas release flow rate according to a preset gas release rate, until the flow rate and temperature requirements of the compressed air in the air compressor unit are met, perform the shutdown process of the turbine, and finally, the molten salt and water stepped energy storage system and the hot water storage heat exchange system stop operating.

[0016] The high-temperature side hot water storage heat exchange system includes a high-temperature water tank, connecting pipes of the high-temperature water tank, valves, and a water heat exchanger.

[0017] In a second aspect, the present application provides a scheduling method for a molten salt and water stepped energy storage system, which is applied to the above-mentioned molten salt and water stepped energy storage system, and specifically includes: S1 Obtain the energy storage regulation data of the molten salt and water stepped energy storage system, determine the energy storage response deviation situation of the low-temperature molten salt system at different operating temperatures based on the energy storage regulation data, and when the energy storage response deviation situation meets the requirements, proceed to the next step; S2 Based on the energy storage regulation data on different dates, determine the energy storage regulation target time period, determine the distribution data of the energy storage regulation target time period on different dates, and when the distribution dispersion degree of the energy storage regulation target time period meets the requirements based on the distribution data, determine the optimization time period of the temperature control strategy in the energy storage regulation target time period based on the distribution data; S3 Based on the energy storage response deviation situation in different optimization time periods, and combined with the duration required for different operating temperatures to reach the target operating temperature for energy storage regulation of the high-temperature molten salt tank, determine the temperature treatment strategy of the low-temperature molten salt tank in different optimization time periods.

[0018] A further technical solution lies in that the energy storage regulation data includes the energy storage regulation times of the molten salt and water stepped energy storage system and the energy storage regulation amounts for different energy storage regulation times.

[0019] A further technical solution lies in that the energy storage response deviation situation at the operating temperature includes the energy storage regulation rate at different operating temperatures and the deviation amount between the energy storage regulation rate requirements and the energy storage regulation rate for different historical energy storage regulation times.

[0020] A further technical solution lies in that the method for determining the temperature treatment strategy of the low-temperature molten salt tank in the optimization time period is as follows: Based on the energy storage response deviation situation in different optimization time periods, determine the energy storage regulation times for which the energy storage regulation rate requirements cannot be met in the optimization time period, and use them as the adjustment deviation times; The duration to reach the target operating temperature for energy storage regulation of a high-temperature molten salt tank at different operating temperatures is used to determine the regulation processing duration at the available temperature for the regulation duration. According to the number of regulation deviations and the regulation processing duration, determine the temperature processing strategy of the low-temperature molten salt tank in the optimized period.

[0021] Specifically, the number of energy storage regulation times that cannot meet the energy storage regulation rate requirement is the number of energy storage regulation times when the energy storage regulation rate is less than the energy storage regulation rate requirement during energy storage regulation.

[0022] Compared with the prior art, the beneficial effects of the present invention include: During the energy storage process, the high-temperature compressed air generated by the air compressor sequentially flows through the molten salt heat exchanger and the water heat exchanger. During the energy release process, the low-temperature compressed air in the gas storage reservoir sequentially flows through the water heat exchanger and the molten salt heat exchanger. The operating temperature range of the heat storage medium molten salt (wide-temperature molten salt) in the molten salt and water cascade energy storage system is 180°C to 600°C, and the operating temperature range of the heat storage medium water (pressurized water) in the hot water heat exchange and storage system is 40°C to 185°C. Combining the two can achieve cascade heat exchange and storage, reducing the compressed air temperature from, for example, 350°C to, for example, 40°C and collecting and storing (basically) all the released thermal energy. By making full use of the respective characteristics of molten salt and water, the maximum energy storage capacity of the heat exchange and storage system can be increased to a greater extent, improving the energy storage and power generation efficiency of the system and reducing the system cost. It is difficult to achieve low temperature for molten salt. It can not only achieve high-temperature power generation, but also achieve energy cascade utilization and reduce costs. The expansion process is correspondingly carried out by heating with the heat storage medium water and the heat storage medium molten salt in turn in the order of increasing temperature, so as to release (basically) all the stored thermal energy.

[0023] The coupling degree between the molten salt and water cascade energy storage system and the hot water heat exchange and storage system inside the "cascade heat storage" system is relatively high, and their behaviors will be more closely related to each other. By designing a control system, it can real-time monitor the inlet and outlet temperatures and flow rates of each pipeline, judge the flow state of the medium in the pipeline, timely respond to problems such as abnormal temperature and abnormal flow, and can control the electronic flow valve to timely achieve flow regulation and flow path switching.

[0024] To prevent emergency situations that seriously endanger the safe operation of the system, such as a complete power outage, molten salt pump failure, and hot water pump failure, standby high-pressure hot water storage tanks and high-pressure compressed air storage tanks can be arranged in the system. These are used as heat sources or power sources in emergencies to enable the system to shut down safely and orderly. The high-pressure hot water storage tanks and high-pressure compressed air storage tanks can further compress the media in the high-temperature water tanks and high-temperature molten salt tanks for storage or collect high-temperature compressed air. The pressure in the high-pressure hot water storage tanks and high-pressure compressed air storage tanks should be high enough, or the gravitational potential energy of the storage tank arrangement should be large enough to ensure that heat supply or pushing the molten salt back to the storage tank can be completed without external force drive during the period of emergency shutdown of the turbine.

[0025] Based on the energy storage response deviation in different optimization periods and the time required for different operating temperatures to reach the target operating temperature for energy storage regulation of the high-temperature molten salt tank, determine the temperature treatment strategy for the low-temperature molten salt tank in different optimization periods. Thus, the optimization adjustment of the temperature treatment strategy for the low-temperature molten salt tank in the optimization periods with large energy storage regulation requirements and high regulation rate requirements is realized, ensuring that the low-temperature molten salt tank can operate within a reasonable temperature range, thereby improving the efficiency of energy storage regulation processing.

[0026] Other features and advantages will be described in the subsequent specification. The objectives and other advantages of the present invention are achieved and obtained through the structures specifically pointed out in the specification and the accompanying drawings.

[0027] To make the above objectives, features, and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given, and in conjunction with the accompanying drawings, the detailed description is as follows. Brief Description of the Drawings

[0028] By referring to the accompanying drawings and describing its exemplary embodiments in detail, the above and other features and advantages of the present invention will become more obvious; Figure 1 is a framework diagram of a molten salt and water cascade energy storage system; Figure 2 is a schematic diagram of the start-up process in a molten salt and water cascade energy storage system; Figure 3 is a schematic diagram of temperature control during system operation; Figure 4 is a schematic diagram of the abnormal handling strategy when freezing occurs; Figure 5 is a schematic diagram of the abnormal handling strategy when a failure occurs in the hot water storage and heat exchange system on the high-temperature side; Figure 6 is a flowchart of a scheduling method for a molten salt and water cascade energy storage system; Figure 7 is a flowchart for judging whether the energy storage response deviation meets the requirements; Figure 8It is a flowchart of a method for determining the temperature treatment strategy of a low-temperature molten salt tank during the optimization period. Detailed implementation mode

[0029] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this specification. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all of the embodiments. Based on the embodiments of this specification, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of this specification.

[0030] Embodiment 1 Specifically, as Figure 1 shown, a molten salt and water cascaded energy storage system includes the following: An air compressor unit, a storage heat exchange system, a gas storage reservoir, and a turbine. Among them, the storage heat exchange system includes a low-temperature molten salt tank, a high-temperature molten salt tank, a low-temperature water tank, a high-temperature water tank, a molten salt heat exchanger, and a water heat exchanger. Molten salt heat exchangers and water heat exchangers are correspondingly arranged between the connection circuits of the air compressor unit and the gas storage reservoir, and between the connection circuits of the turbine and the gas storage reservoir. The low-temperature molten salt tank and the high-temperature molten salt tank are connected by using the molten salt heat exchanger in the connection circuit between the air compressor unit and the gas storage reservoir, and between the turbine and the gas storage reservoir. The low-temperature water tank and the high-temperature water tank are connected by using the water heat exchanger in the connection circuit between the air compressor unit and the gas storage reservoir, and between the turbine and the gas storage reservoir.

[0031] Furthermore, when the low-temperature molten salt tank and the high-temperature molten salt tank are connected by using the molten salt heat exchanger in the connection circuit between the air compressor unit and the gas storage reservoir, and between the turbine and the gas storage reservoir, valves are arranged between the molten salt heat exchanger and the energy release circuit and the energy storage circuit of the low-temperature molten salt tank and the high-temperature molten salt tank.

[0032] Specifically, when the low-temperature water tank and the high-temperature water tank are connected by using the water heat exchanger in the connection circuit between the air compressor unit and the gas storage reservoir, and between the turbine and the gas storage reservoir, valves are arranged between the water heat exchanger and the energy release circuit and the energy storage circuit of the low-temperature water tank and the high-temperature water tank.

[0033] It can be understood that the low-temperature molten salt tank and the high-temperature molten salt tank construct a molten salt and water cascaded energy storage system, and the low-temperature water tank and the high-temperature water tank construct a water storage heat exchange system.

[0034] Furthermore, when the cascaded energy storage heat supply and power generation system is in the energy storage mode, it includes the following: The molten salt and water cascaded energy storage system and the water storage heat exchange system start to operate. The low-temperature molten salt flows from the low-temperature molten salt tank through the molten salt heat exchanger and returns to the low-temperature molten salt tank, and the low-temperature water flows from the low-temperature water tank through the water heat exchanger and returns to the low-temperature water tank. Subsequently, when the target conditions are reached, the air compressor unit starts to operate. Finally, the gas storage reservoir starts to store gas.

[0035] Specifically, when the cascaded energy storage heat supply and power generation system stops, it includes the following: The air compressor unit stops operating, the molten salt and water cascaded energy storage system and the water storage heat exchange system stop operating, the molten salt heat exchanger and the water heat exchanger stop operating, and the high-temperature molten salt tank and the high-temperature water tank enter the static stage.

[0036] It can be understood that when the cascaded energy storage heat supply and power generation system is in the energy release mode, it includes the following: The high-temperature molten salt flows from the high-temperature molten salt tank through the molten salt heat exchanger and returns to the low-temperature molten salt tank, and the high-temperature water flows from the high-temperature water tank through the water heat exchanger and returns to the low-temperature water tank. Subsequently, the gas storage reservoir starts to release gas. Finally, the turbine starts to operate.

[0037] Furthermore, when the cascaded energy storage heat supply and power generation system is in the startup stage, the molten salt medium in the low-temperature molten salt tank is heated by using the molten salt heat exchanger, and the cold-side molten salt outlet temperature of the molten salt heat exchanger is monitored in real time. When the outlet temperature reaches the designed energy storage temperature of the high-temperature molten salt tank, the control system switches the flow pipeline of the molten salt, and the molten salt in the low-temperature molten salt tank flows into the high-temperature molten salt tank through the molten salt heat exchanger.

[0038] It can be understood that as Figure 2 shown, it is a schematic diagram of the startup process in the molten salt and water cascaded energy storage system. The operating temperature range of the heat storage medium molten salt (wide-temperature lava) is 180°C - 600°C, and the operating temperature range of the heat storage medium water (pressurized water) in the hot water storage heat exchange system is 40°C - 185°C. The temperature of the compressed air filled is 35 - 40°C. Since each system has a different optimal operating temperature range, the temperature matching during system operation is particularly crucial. During the energy storage process, in the initial stage of system operation, the temperature of the molten salt in the low-temperature molten salt tank is relatively low, and its temperature may not reach the designed energy storage temperature of the high-temperature molten salt tank after being heated by the high-temperature compressed air through the molten salt heat exchanger. Therefore, in the initial stage of operation, the molten salt in the molten salt heat exchanger should circulate back to the low-temperature molten salt tank. The control system monitors the cold-side molten salt outlet temperature of the molten salt heat exchanger in real time. When the outlet temperature reaches the designed energy storage temperature of the high-temperature molten salt tank, the control system switches the flow pipeline of the molten salt, and the molten salt flows into the high-temperature molten salt tank. (In the figure, × indicates that the equipment is closed).

[0039] During the energy storage process, in the initial stage of system operation, the water temperature in the low-temperature water tank is relatively low. After being heated by the high-temperature compressed air through the water heat exchanger, its temperature may not reach the designed energy storage temperature of the high-temperature water tank. Therefore, in the initial stage of operation, the water in the water heat exchanger should circulate back to the low-temperature water tank. The control system monitors the outlet temperature of the cold side of the water heat exchanger in real time. When the outlet temperature reaches the designed energy storage temperature of the high-temperature water tank, the control system switches the water flow pipeline, and the water flows into the high-temperature water tank. (The control strategy and water flow line are similar to those of the above-mentioned molten salt and water cascade energy storage system). During system operation, as Figure 3 shown, it is a schematic diagram of temperature control during system operation. As described above, the molten salt and water cascade energy storage system and the hot water storage heat exchange system will switch the heat exchange medium flow pipeline to achieve temperature matching. Therefore, due to the temperature fluctuation of the heat exchange medium, the temperature of the compressed air may fluctuate. The control system monitors the temperature value of the compressed air before entering the gas storage tank in real time. If the temperature of the compressed air is higher than the designed gas storage temperature of the gas storage tank, the control system switches the flow pipeline of the compressed air, stores the compressed air with abnormal temperature in the standby compressed air storage tank or discharges it into the atmosphere through the exhaust port. Avoid filling the gas storage tank with high-temperature compressed air, which may affect the safe operation and gas storage capacity of the gas storage tank. (In the figure, × indicates that the equipment is closed).

[0040] It can be understood that when the low-temperature molten salt tank of the cascade energy storage heating and power generation system, as well as the connecting pipelines and valves of the low-temperature molten salt tank are frozen and blocked, the following contents are included: The hot water storage heat exchange system immediately stops operating. The control system switches the compressed air circulation line, discharges the high-temperature compressed air into the atmosphere through the exhaust port, and shuts down the air compressor unit at a preset decreasing rate.

[0041] It should be noted that molten salt is an excellent energy storage medium, but the freezing point of molten salt is much higher than the ambient temperature. Low-temperature molten salt faces the risk of freezing and blocking to varying degrees when passing through equipment, pipelines, and valves. Therefore, on the one hand, the pipelines of the molten salt energy storage system need to adopt appropriate anti-freezing and blocking designs, such as adjusting the pipeline slope, optimizing the pipeline structure, and adding compressed air design. At the same time, steam tracing or electric tracing technology is used to keep the molten salt in a molten state, and the pipelines and equipment are insulated to reduce heat loss. On the other hand, once a freezing and blocking situation occurs, the control system can quickly determine the freezing and blocking position through monitoring the temperature and flow rate of the heat exchange medium.

[0042] As Figure 4As shown in the figure, it is a schematic diagram of the abnormal handling strategy when freezing occurs. During the energy storage process, when freezing occurs in the equipment, pipelines and valves on the low-temperature side, most of the heat of the compressed air cannot be stored by the molten salt and water cascade energy storage system, and the safe operation of the hot water storage heat exchange system and the gas storage reservoir will be affected. When the control system determines through the monitoring of the temperature and flow rate of the heat exchange medium that freezing occurs in the molten salt on the low-temperature side, first, the hot water storage heat exchange system immediately stops operating to prevent the high-temperature compressed gas from abnormally heating the water and causing vaporization, threatening the safety of the hot water storage heat exchange system. Subsequently, the control system switches the compressed air flow path and discharges the high-temperature compressed air into the atmosphere through the exhaust port. This avoids charging the high-temperature compressed air into the gas storage reservoir and affecting the safe operation and storage capacity of the gas storage reservoir. Finally, the compressed air unit shuts down orderly and slowly. (! in the figure indicates a failure, the numbers indicate the control sequence, and × indicates that the equipment is closed).

[0043] Fault handling strategy for the low-temperature side hot water storage heat exchange system. During the energy storage process, when a fault occurs on the low-temperature side of the hot water storage heat exchange system, part of the heat of the compressed air cannot be stored by the hot water storage heat exchange system, and the temperature of the compressed air cannot be reduced to the designed gas storage temperature of the gas storage reservoir, and the safe operation of the gas storage reservoir will be affected. When the control system determines through the monitoring of the temperature and flow rate of the heat exchange medium that a fault occurs on the low-temperature side of the hot water storage heat exchange system, first, the control system switches the compressed air flow path and discharges the high-temperature compressed air into the atmosphere through the exhaust port. This avoids charging the high-temperature compressed air into the gas storage reservoir and affecting the safe operation and storage capacity of the gas storage reservoir. Subsequently, the compressed air unit shuts down orderly and slowly. Finally, the molten salt and water cascade energy storage system stops operating. (The control strategy is similar to the above-mentioned treatment of freezing of the molten salt on the low-temperature side).

[0044] Furthermore, when a fault occurs in the high-temperature side hot water storage heat exchange system of the cascade energy storage heating and power generation system, it includes the following: Start the standby high-pressure hot water tank feed water heat exchanger to provide the heat exchange medium, gradually adjust the gas release flow rate of the gas storage reservoir according to the preset gas release rate, until the requirements for the flow rate and temperature of the compressed air in the air compressor unit are met, perform the shutdown process of the turbine, and finally, the molten salt and water cascade energy storage system and the hot water storage heat exchange system stop operating.

[0045] Among them, the high-temperature side hot water storage heat exchange system includes a high-temperature water tank, the connecting pipelines of the high-temperature water tank, valves, and a water heat exchanger.

[0046] As Figure 5As shown in the figure, it is a schematic diagram of the abnormal handling strategy when a failure occurs in the high-temperature side hot water storage heat exchange system. During the energy release process, when a failure occurs in the high-temperature side hot water storage heat exchange system and the water heat exchanger cannot work properly, the first heating of the low-temperature compressed air cannot be achieved, which will cause the heat exchange conditions of the subsequent molten salt heat exchanger to deviate from the design conditions, resulting in a decrease in the power generation efficiency of the system. In severe cases, it will endanger the safe operation of the molten salt and water cascade energy storage system. The control system determines that a failure has occurred on the high-temperature side of the hot water storage heat exchange system through monitoring the temperature and flow rate of the heat exchange medium. First, start the standby high-pressure hot water tank to provide heat exchange medium for the water heat exchanger. Subsequently, gradually adjust the gas release flow rate of the gas storage reservoir to reduce energy loss. Then, gradually and orderly stop the operation of the turbine expander to meet the flow rate and temperature requirements of the compressed air in the expander and ensure the safe and orderly shutdown of the expander unit. Finally, the molten salt and water cascade energy storage system and the hot water storage heat exchange system stop operating. (! in the figure indicates a failure, numbers indicate the control sequence, and × indicates equipment shutdown).

[0047] Failure handling strategy for the molten salt and water cascade energy storage system on the high-temperature side. During the energy release process, when a failure occurs in the molten salt and water cascade energy storage system on the high-temperature side and the molten salt pump cannot work properly, the molten salt heat exchanger cannot work properly, and the secondary heating of the low-temperature compressed air cannot be achieved, resulting in a decrease in power generation efficiency. In addition, a large temperature drop will occur in the turbine expander unit. If the initial temperature of the compressed air is not high enough, moisture will condense in the compressed air, threatening the safe operation of the expander unit. When the control system determines that a failure has occurred on the low-temperature side of the molten salt and water cascade energy storage system through monitoring the temperature and flow rate of the heat exchange medium, first, start the high-pressure compressed air storage tank as a power source to drive the high-temperature molten salt to complete heat exchange, and turn on the electric heater to ensure that the temperature of the compressed air meets the safe operation requirements of the turbine expander. Subsequently, gradually adjust the gas release flow rate of the gas storage reservoir. Then, gradually and orderly stop the operation of the turbine expander to meet the flow rate and temperature requirements of the compressed air in the expander and ensure the safe and orderly shutdown of the expander unit. Finally, the hot water storage heat exchange system stops operating. (The control strategy is similar to the failure handling of the high-temperature side hot water storage heat exchange system above).

[0048] Embodiment 2 Based on the deviation of the energy storage regulation rate demand from the energy storage regulation rate corresponding to different historical energy storage regulation times, determine the regulation rate deviation at different operating temperatures. Based on the regulation rate deviation, determine the regulation rate deviation times at different operating temperatures. When there is no operating temperature at which the regulation rate deviation times meet the requirements, it is determined that the energy storage response deviation situation does not meet the requirements.

[0049] When the proportion of the number of dates in different energy storage regulation target periods is less than the preset proportion threshold, it indicates that the distribution dispersion degree of the energy storage regulation target periods is relatively high, and it can be directly determined that the distribution dispersion degree of the energy storage regulation target periods does not meet the requirements.

[0050] The optimization period of the temperature control strategy in the energy storage regulation target period is the energy storage regulation target period in which the proportion of the number of dates is greater than the second proportion threshold. In a possible embodiment, the energy storage regulation target period in which the proportion of the number of dates is greater than 0.5 is used as the optimization period.

[0051] Based on the energy storage response deviation in different optimization periods, determine the number of energy storage regulation times in which the energy storage regulation rate requirement in the optimization period cannot be met, and use it as the regulation deviation times. When the regulation deviation times do not meet the requirement, that is, when it is greater than the threshold, in order to ensure the regulation reliability of the optimization period, the operating temperature of the low-temperature molten salt tank is directly stabilized at the operating temperature that can meet the energy storage demand of the high-temperature molten salt tank. That is, at this operating temperature, there is no need to first heat the molten salt medium in the low-temperature molten salt tank, and the high-temperature molten salt tank can be directly used for energy storage regulation, that is, the molten salt medium in the low-temperature molten salt tank directly enters the high-temperature molten salt tank; In addition, if the regulation deviation times meet the requirement, the regulation deviation times are relatively small at this time. Therefore, according to the regulation processing duration at the available temperature of the regulation duration, based on the regulation deviation times, based on the ratio of the regulation deviation times to the regulation processing duration, determine the adaptation value of different available temperatures of the regulation duration. The available temperature of the regulation duration with the largest regulation processing duration whose adaptation value is greater than the preset adaptation threshold is used as the temperature processing target of the low-temperature molten salt tank in the optimization period, where the preset adaptation threshold is determined according to the regulation deviation times, and the larger the regulation deviation times, the larger the preset adaptation threshold.

[0052] In a second aspect, as Figure 6 shown, the present application provides a scheduling method for a molten salt and water cascade energy storage system, which is applied to the above-mentioned molten salt and water cascade energy storage system, and specifically includes: S1 Obtain the energy storage regulation data of the molten salt and water cascade energy storage system, and based on the energy storage regulation data, determine the energy storage response deviation of the low-temperature molten salt system at different operating temperatures. When the energy storage response deviation meets the requirement, proceed to the next step; Furthermore, the energy storage regulation data includes the energy storage regulation times of the molten salt and water cascade energy storage system and the energy storage regulation amounts of different energy storage regulation times.

[0053] Specifically, the energy storage response deviation at the operating temperature includes the energy storage regulation rate at different operating temperatures and the deviation amount between the energy storage regulation rate requirement and the energy storage regulation rate of different historical energy storage regulation times.

[0054] It is understandable that when the operating temperature is relatively low, during the startup process of the molten salt and water cascaded energy storage system, in order to avoid too high a temperature of the molten salt medium flowing into the low-temperature molten salt tank, a relatively low heating temperature needs to be adopted, resulting in a relatively low energy storage regulation rate.

[0055] In addition, it should be noted that during the startup process, when using a molten salt heat exchanger to heat the low-temperature molten salt device, as the operating temperature increases, the flow rate of the molten salt medium gradually increases, which makes the heating rate of the molten salt medium gradually increase. Therefore, the difference in the operating temperature will cause a change in the energy storage regulation rate.

[0056] It should be noted that the operating temperature is the operating temperature of the low-temperature molten salt tank of the molten salt and water cascaded energy storage system without heating treatment, that is, the operating temperature during the normal operation process when not in the energy storage regulation process.

[0057] Specifically, as Figure 7 shown, determining that the energy storage response deviation situation meets the requirements specifically includes: Based on the energy storage response deviation situation of the low-temperature molten salt system, determining the energy storage regulation rate of the low-temperature molten salt system at different operating temperatures, and based on the deviation amount between the energy storage regulation rate and the energy storage regulation rate requirements of different historical energy storage regulation times, determining the regulation rate deviation amount at different operating temperatures; Based on the regulation rate deviation amount, determining the regulation rate deviation times at different operating temperatures; According to the regulation rate deviation times, determining whether the energy storage regulation deviation situation meets the requirements.

[0058] It is understandable that when there is no operating temperature at which the regulation rate deviation times meet the requirements, it is determined that the energy storage response deviation situation does not meet the requirements.

[0059] The specific regulation rate deviation times are the historical energy storage regulation times when the regulation rate deviation amount is greater than the preset deviation amount threshold.

[0060] It should be noted that when there is no operating temperature at which the regulation rate deviation times meet the requirements, that is, when the regulation rate deviation times are less than the preset regulation times threshold, the operating temperature of the low-temperature molten salt tank is stabilized at the operating temperature that can meet the energy storage requirements of the high-temperature molten salt tank. That is, at this operating temperature, it is not necessary to first heat the molten salt medium in the low-temperature molten salt tank, and the energy storage regulation can be directly carried out using the high-temperature molten salt tank, that is, the molten salt medium in the low-temperature molten salt tank directly enters the high-temperature molten salt tank.

[0061] Optionally, determining that the energy storage response deviation situation meets the requirements specifically includes: S11 Determine the energy storage adjustment rate of the low-temperature molten salt system at different operating temperatures based on the energy storage response deviation of the low-temperature molten salt system. Determine the adjustment rate deviation at different operating temperatures based on the deviation between the energy storage adjustment rate and the energy storage adjustment rate requirements of different historical energy storage adjustment times. Determine the adjustment rate deviation times at different operating temperatures based on the adjustment rate deviation. It can be understood that in the above steps, when there is no operating temperature at which the adjustment rate deviation times meet the requirements, that is, when the adjustment rate deviation times are less than the preset adjustment times threshold, the operating temperature of the low-temperature molten salt tank is stabilized at the operating temperature that can meet the energy storage requirements of the high-temperature molten salt tank. That is, at this operating temperature, it is not necessary to first heat the molten salt medium in the low-temperature molten salt tank, and the energy storage adjustment can be directly carried out using the high-temperature molten salt tank, that is, the molten salt medium in the low-temperature molten salt tank directly enters the high-temperature molten salt tank. In addition, it should be noted that even when there is an operating temperature at which the adjustment rate deviation times meet the requirements, if at different operating temperatures, the adjustment rate deviation times with the adjustment rate deviation not within the preset deviation range do not meet the requirements, that is, when the adjustment rate deviation times with a large adjustment rate deviation are all greater than the preset times threshold, it indicates that the operating temperature of the low-temperature molten salt tank needs to be stabilized at the operating temperature that can meet the energy storage requirements of the high-temperature molten salt tank. That is, at this operating temperature, it is not necessary to first heat the molten salt medium in the low-temperature molten salt tank, and the energy storage adjustment can be directly carried out using the high-temperature molten salt tank, that is, the molten salt medium in the low-temperature molten salt tank directly enters the high-temperature molten salt tank. If there are adjustment rate deviation times with the adjustment rate deviation not within the preset deviation range that all meet the requirements and there is an operating temperature at which the adjustment rate deviation times meet the requirements, use it as the available operating temperature and transfer to the next step for further judgment.

[0062] S12 Determine the adjustment processing duration of different operating temperatures based on the fastest duration for different operating temperatures to reach the target operating temperature for energy storage adjustment of the high-temperature molten salt tank. It should be noted that in the above steps, if the adjustment processing durations at different available operating temperatures are all greater than the preset adjustment duration threshold, it indicates that the adjustment durations at different available operating temperatures are too long. Therefore, to meet the energy storage adjustment requirements, it indicates that the operating temperature of the low-temperature molten salt tank needs to be stabilized at the operating temperature that can meet the energy storage requirements of the high-temperature molten salt tank. That is, at this operating temperature, it is not necessary to first heat the molten salt medium in the low-temperature molten salt tank, and the energy storage adjustment can be directly carried out using the high-temperature molten salt tank, that is, the molten salt medium in the low-temperature molten salt tank directly enters the high-temperature molten salt tank. When there is an operating temperature with an adjustment processing duration not greater than a preset adjustment duration threshold, it is used as the available temperature for the adjustment duration and the next step is entered.

[0063] S13 determines whether the energy storage adjustment deviation situation meets the requirements according to the number of adjustment rate deviation times and the adjustment processing duration at different operating temperatures.

[0064] In a possible embodiment, the preset duration threshold at different available temperatures for the adjustment duration is determined by the number of adjustment rate deviation times at different available temperatures for the adjustment duration. When there is no available temperature for the adjustment duration with an adjustment processing duration less than the preset duration threshold, it is determined that the energy storage adjustment deviation situation does not meet the requirements.

[0065] In addition, it should be noted that there is a preset corresponding relationship between the preset duration threshold and the number of adjustment rate deviation times, where the more the number of adjustment rate deviation times, the larger the preset duration threshold.

[0066] S2 determines the energy storage adjustment target period based on the energy storage adjustment data on different dates, determines the distribution data of the energy storage adjustment target period on different dates, and when it is determined that the distribution dispersion degree of the energy storage adjustment target period meets the requirements based on the distribution data, determines the optimization period of the temperature control strategy in the energy storage adjustment target period based on the distribution data; Further, the energy storage adjustment target period is the period in different dates where the total number of historical energy storage adjustments in the period is greater than the preset energy storage adjustment number threshold.

[0067] Specifically, determining that the distribution dispersion degree of the energy storage adjustment target period meets the requirements specifically includes: Determining the proportion of the number of dates of different energy storage adjustment target periods based on the distribution data of the energy storage adjustment target period on different dates; Determining whether the distribution dispersion degree of the energy storage adjustment target period meets the requirements according to the proportion of the number of dates of different energy storage adjustment target periods.

[0068] Specifically, when the proportion of the number of dates of different energy storage adjustment target periods is less than the preset proportion threshold, it indicates that the distribution dispersion degree of the energy storage adjustment target period is relatively high. Therefore, on this basis, it can be directly determined that the distribution dispersion degree of the energy storage adjustment target period does not meet the requirements.

[0069] It should be noted that when the distribution dispersion degree of the energy storage adjustment target period does not meet the requirements, the operating temperature of the low-temperature molten salt tank is stabilized at the operating temperature with the shortest adjustment processing duration and the number of adjustment rate deviation times less than the preset adjustment number threshold in different periods.

[0070] Further, the optimization period of the temperature control strategy in the energy storage regulation target period is the energy storage regulation target period with the proportion of the number of dates greater than the second proportion threshold. In a possible embodiment, the energy storage regulation target period with the proportion of the number of dates greater than 0.5 is used as the optimization period.

[0071] S3 determines the temperature treatment strategy of the low-temperature molten salt tank in different optimization periods based on the energy storage response deviation in different optimization periods and combines different operating temperatures to reach the target operating temperature for energy storage regulation of the high-temperature molten salt tank.

[0072] Specifically, as Figure 8 shown, the method for determining the temperature treatment strategy of the low-temperature molten salt tank in the optimization period is as follows: Based on the energy storage response deviation in different optimization periods, determine the number of energy storage regulation times when the energy storage regulation rate requirement cannot be met in the optimization period, and use it as the adjustment deviation times; Based on the time taken for different operating temperatures to reach the target operating temperature for energy storage regulation of the high-temperature molten salt tank, determine the adjustment processing time at the available temperature of the adjustment time; According to the adjustment deviation times and the adjustment processing time, determine the temperature treatment strategy of the low-temperature molten salt tank in the optimization period.

[0073] Specifically, the number of energy storage regulation times when the energy storage regulation rate requirement cannot be met is the number of energy storage regulation times when the energy storage regulation rate is less than the energy storage regulation rate requirement during energy storage regulation.

[0074] It can be understood that when the adjustment deviation times do not meet the requirements, that is, when they are greater than the threshold, in order to ensure the adjustment reliability of the optimization period, the operating temperature of the low-temperature molten salt tank is directly stabilized at the operating temperature that can meet the energy storage requirements of the high-temperature molten salt tank. That is, at this operating temperature, there is no need to first heat the molten salt medium of the low-temperature molten salt tank, and the energy storage regulation can be directly carried out using the high-temperature molten salt tank, that is, the molten salt medium of the low-temperature molten salt tank directly enters the high-temperature molten salt tank.

[0075] In addition, if the adjustment deviation times meet the requirements, the adjustment deviation times are relatively small at this time. Therefore, based on the adjustment processing time at the available temperature of the adjustment time, and based on the ratio of the adjustment deviation times and the adjustment processing time, determine the adaptation values for different available temperatures of the adjustment time. The available temperature of the adjustment time with the largest adjustment processing time and the adaptation value greater than the preset adaptation threshold is used as the temperature treatment target of the low-temperature molten salt tank in the optimization period, where the preset adaptation threshold is determined according to the adjustment deviation times. The larger the adjustment deviation times, the larger the preset adaptation threshold.

[0076] In another embodiment, the method for determining the temperature treatment strategy of the low-temperature molten salt tank during the optimization period is as follows: S41 Based on the energy storage response deviation conditions in different optimization periods, determine the number of energy storage regulation times when the energy storage regulation rate requirement in the optimization period cannot be met, and use it as the regulation deviation times. Based on the time required for different operating temperatures to reach the target operating temperature for energy storage regulation of the high-temperature molten salt tank, determine the regulation processing time at the available temperature of the regulation time. It should be noted that when the number of regulation deviations does not meet the requirements, that is, when it is greater than the threshold, in order to ensure the regulation reliability during the optimization period, the operating temperature of the low-temperature molten salt tank is directly stabilized at the operating temperature that can meet the energy storage requirements of the high-temperature molten salt tank. That is to say, it is necessary to stabilize the operating temperature of the low-temperature molten salt tank at the operating temperature that can meet the energy storage requirements of the high-temperature molten salt tank. At this operating temperature, it is not necessary to first heat the molten salt medium of the low-temperature molten salt tank, and the high-temperature molten salt tank can be directly used for energy storage regulation, that is, the molten salt medium of the low-temperature molten salt tank directly enters the high-temperature molten salt tank.

[0077] In addition, if the number of regulation deviations meets the requirements, the number of regulation deviations at this time is small. Therefore, based on the regulation processing time at the available temperature of the regulation time, and based on the ratio of the number of regulation deviations to the regulation processing time, determine the adaptation values for different available temperatures of the regulation time. When there is no available temperature of the regulation time with an adaptation value greater than the preset adaptation threshold, it means that the operating temperature of the low-temperature molten salt tank needs to be stabilized at the operating temperature that can meet the energy storage requirements of the high-temperature molten salt tank. At this operating temperature, it is not necessary to first heat the molten salt medium of the low-temperature molten salt tank, and the high-temperature molten salt tank can be directly used for energy storage regulation, that is, the molten salt medium of the low-temperature molten salt tank directly enters the high-temperature molten salt tank.

[0078] If there is an available temperature of the regulation time with an adaptation value greater than the preset adaptation threshold, then use the available temperature of the regulation time with an adaptation value greater than the preset adaptation threshold as the available control target and proceed to the next step.

[0079] S42 Based on the energy storage regulation rate requirements in different numbers of regulation deviations and the energy storage regulation rates at different available temperatures of the regulation time, determine the adaptation deviation times in the number of regulation deviations when using the available temperature of the regulation time. It can be understood that the adaptation deviation times are the number of energy storage deviation times when the energy storage regulation rate at the available temperature of the regulation time is less than the energy storage regulation rate requirement and the amount is greater than the preset rate threshold.

[0080] In addition, it should be further noted that when there is an available control target whose adaptation deviation times meet the requirements, that is, an available control target with the adaptation deviation times less than the threshold, the available control target with the minimum adaptation deviation times is directly used as the temperature processing target of the low-temperature molten salt tank during the optimization period.

[0081] In addition, it should be noted that when there is no available control target whose adaptation deviation times meet the requirements, and the adaptation deviation times under different available control targets are all greater than the preset adaptation deviation times threshold, at this time, the adjustment rates of different available control targets cannot meet the requirements. Therefore, on this basis, the operating temperature of the low-temperature molten salt tank needs to be stabilized at an operating temperature that can meet the energy storage requirements of the high-temperature molten salt tank. At this operating temperature, it is not necessary to first heat the molten salt medium of the low-temperature molten salt tank, and the energy storage adjustment can be directly carried out using the high-temperature molten salt tank, that is, the molten salt medium of the low-temperature molten salt tank directly enters the high-temperature molten salt tank. And when there is an available adjustment target whose adaptation deviation times are not greater than the preset adaptation deviation times threshold, it is used as the screening adjustment target and directly transferred to the next step.

[0082] S43 Determine the temperature processing strategy of the low-temperature molten salt tank during the optimization period according to the adjustment deviation times, the adjustment processing duration at different available temperatures of the adjustment duration, and the adaptation deviation times.

[0083] In a possible embodiment, the adjustment power adaptation value is determined by the ratio of the adaptation deviation times to the adjustment deviation times. According to the sum of the adjustment power adaptation value and the adaptation value, the comprehensive adaptation value is determined. The screening adjustment target with the largest comprehensive adaptation value is used as the temperature processing target of the low-temperature molten salt tank during the optimization period.

[0084] In another embodiment, the adjustment power adaptation value is determined by the ratio of the adaptation deviation times to the adjustment deviation times. The screening adjustment target with the largest product of the adjustment power adaptation value and the adaptation value is used as the temperature processing target of the low-temperature molten salt tank during the optimization period.

[0085] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the key points of each embodiment are the differences from other embodiments. In particular, for the device, equipment, and non-volatile computer storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiments.

[0086] The above description has been made of specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve the desired result. Additionally, the processes depicted in the drawings do not necessarily require the particular order or sequential order shown to achieve the desired result. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0087] The above is only one or more embodiments of this specification and is not intended to limit this specification. For those skilled in the art, various changes and modifications can be made to one or more embodiments of this specification. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of this specification shall be included within the scope of the claims of this specification.

Claims

1. A molten salt and water cascaded energy storage system, characterized in that It includes the following: An air compressor unit, a heat storage and heat exchange system, a gas storage tank, and a turbine. The heat storage and heat exchange system includes a low-temperature molten salt tank, a high-temperature molten salt tank, a low-temperature water tank, a high-temperature water tank, a molten salt heat exchanger, and a water heat exchanger. A molten salt heat exchanger and a water heat exchanger are correspondingly arranged between the connection circuits of the air compressor unit and the gas storage tank and between the connection circuits of the turbine and the gas storage tank. The low-temperature molten salt tank and the high-temperature molten salt tank are connected by using the molten salt heat exchanger in the connection circuits between the air compressor unit and the gas storage tank and between the turbine and the gas storage tank. The low-temperature water tank and the high-temperature water tank are connected by using the water heat exchanger in the connection circuits between the air compressor unit and the gas storage tank and between the turbine and the gas storage tank.

2. The molten salt and water cascaded energy storage system according to claim 1, wherein, When the low-temperature molten salt tank and the high-temperature molten salt tank are connected by using the molten salt heat exchanger in the connection circuits between the air compressor unit and the gas storage tank and between the turbine and the gas storage tank, valves are arranged between the molten salt heat exchanger and the low-temperature molten salt tank and the high-temperature molten salt tank in both the energy release circuit and the energy storage circuit.

3. The molten salt and water cascade energy storage system according to claim 1, characterized in that When the low-temperature water tank and the high-temperature water tank are connected by using the water heat exchanger in the connection circuits between the air compressor unit and the gas storage tank and between the turbine and the gas storage tank, valves are arranged between the water heat exchanger and the low-temperature water tank and the high-temperature water tank in both the energy release circuit and the energy storage circuit.

4. The molten salt and water cascade energy storage system according to claim 1, characterized in that When the cascade energy storage heating and power generation system is in the energy storage mode, it includes the following: The molten salt and water cascade energy storage system and the water heat storage and heat exchange system start to operate. The low-temperature molten salt flows from the low-temperature molten salt tank through the molten salt heat exchanger and returns to the low-temperature molten salt tank. The low-temperature water flows from the low-temperature water tank through the water heat exchanger and returns to the low-temperature water tank. Subsequently, when the target conditions are reached, the air compressor unit starts to operate. Finally, the gas storage tank starts to store gas.

5. The molten salt and water cascade energy storage system according to claim 1, characterized in that, When the cascade energy storage heating and power generation system is in the energy release mode, it includes the following: The high-temperature molten salt flows from the high-temperature molten salt tank through the molten salt heat exchanger and returns to the low-temperature molten salt tank. The high-temperature water flows from the high-temperature water tank through the water heat exchanger and returns to the low-temperature water tank. Subsequently, the gas storage tank starts to release gas. Finally, the turbine starts to operate.

6. The molten salt and water cascade energy storage system according to claim 1, characterized in that, When the cascade energy storage heating and power generation system is in the startup stage, the molten salt medium in the low-temperature molten salt tank is heated by using the molten salt heat exchanger, and the cold-side molten salt outlet temperature of the molten salt heat exchanger is monitored in real time. When the outlet temperature reaches the designed energy storage temperature of the high-temperature molten salt tank, the control system switches the flow pipeline of the molten salt, and the molten salt in the low-temperature molten salt tank flows into the high-temperature molten salt tank through the molten salt heat exchanger.

7. The molten salt and water cascade energy storage system according to claim 1, characterized in that When the low-temperature molten salt tank of the cascade energy storage heating and power generation system, as well as the connecting pipelines and valves of the low-temperature molten salt tank, are frozen and blocked, it includes the following: The hot water heat storage and heat exchange system immediately stops operating. The control system switches the compressed air circulation line, discharges the high-temperature compressed air into the atmosphere through the exhaust port, and shuts down the air compressor unit at a preset decreasing rate.

8. The molten salt and water cascaded energy storage system according to claim 1, wherein When a failure occurs in the high-temperature side hot water heat storage and heat exchange system of the cascade energy storage heating and power generation system, it includes the following: Start the feed water heat exchanger of the standby high-pressure hot water tank to provide the heat exchange medium, gradually adjust the gas discharge flow rate of the gas storage reservoir according to the preset air release rate, until the flow rate and temperature requirements of the compressed air in the air compressor unit are met, and then perform the shutdown process of the turbine. Finally, the molten salt and water cascade energy storage system and the hot water storage heat exchange system stop operating.

9. A scheduling method for a molten salt and water cascaded energy storage system, which is applied to a molten salt and water cascaded energy storage system according to any one of claims 1-8, and is characterized in that, Specifically, it includes: Obtain the energy storage adjustment data of the molten salt and water cascade energy storage system, determine the energy storage response deviation of the low-temperature molten salt system at different operating temperatures based on the energy storage adjustment data, and enter the next step when the energy storage response deviation meets the requirements; Based on the energy storage adjustment data on different dates, determine the energy storage adjustment target time period, determine the distribution data of the energy storage adjustment target time period on different dates, and when the distribution dispersion degree of the energy storage adjustment target time period meets the requirements based on the distribution data, determine the optimization time period of the temperature control strategy in the energy storage adjustment target time period based on the distribution data; Based on the energy storage response deviation in different optimization time periods and combined with the duration for different operating temperatures to reach the target operating temperature for energy storage adjustment of the high-temperature molten salt tank, determine the temperature treatment strategy of the low-temperature molten salt tank in different optimization time periods.

10. The scheduling method of the molten salt and water cascade energy storage system according to claim 9, characterized in that, The method for determining the temperature treatment strategy of the low-temperature molten salt tank in the optimization time period is: Based on the energy storage response deviation in different optimization time periods, determine the number of energy storage adjustment times when the energy storage adjustment rate requirement in the optimization time period cannot be met, and use it as the adjustment deviation times; Based on the duration for different operating temperatures to reach the target operating temperature for energy storage adjustment of the high-temperature molten salt tank, determine the adjustment processing duration at the available temperature of the adjustment duration; According to the adjustment deviation times and the adjustment processing duration, determine the temperature treatment strategy of the low-temperature molten salt tank in the optimization time period.

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