Molten Salt Thermal Storage System

Abstract

This invention provides a molten salt thermal energy storage system, relating to the field of molten salt thermal energy storage technology. The system includes a molten salt heating component, an energy conversion component, and a steam generation component. The molten salt heating component heats low-temperature molten salt to obtain high-temperature molten salt, which is then transported to the energy conversion component. The energy conversion component includes a molten salt hot tank, a molten salt cold tank, and a heat exchange unit. The molten salt hot tank stores high-temperature molten salt, which releases heat in the heat exchange unit to obtain low-temperature molten salt, which is then stored in the molten salt cold tank. The molten salt cold tank transports the low-temperature molten salt to the molten salt heating component. The steam generation component includes a feedwater unit. The feedwater output from the feedwater unit absorbs heat in the heat exchange unit to obtain superheated steam, which is then output to the steam turbine through the outlet of the steam generation component. This system exhibits strong adaptability to power market fluctuations, can participate in grid peak shaving response while providing heating, achieves thermal-electric decoupling, improves operational flexibility, and has high operating efficiency.

Description

Technical Field

[0001] This utility model relates to the field of molten salt thermal storage technology, and in particular to a molten salt thermal storage system. Background Technology

[0002] With the promotion of the electricity spot market, the price signal guidance mechanism during periods of tight electricity supply and demand and periods of high renewable energy generation is becoming increasingly important. During periods of tight supply and demand, high price signals incentivize thermal power plants to increase power generation, while during peak periods of renewable energy generation, price signals prompt thermal power plants to reduce output in order to optimize the distribution of grid load.

[0003] However, for energy systems like combined heat and power (CHP) units that can simultaneously generate electricity and heat, their peak-shaving and peak power generation capabilities are limited due to constraints on heating parameters and heat supply. This not only leads to trading losses for CHP units in the spot market but also affects the grid's ability to absorb new energy sources. Especially during periods of high demand requiring rapid response or low demand requiring a significant reduction in output, the inherent limitations of CHP units result in poor adaptability to fluctuations in electricity demand, making it impossible for them to effectively participate in electricity market regulation and optimize energy management and dispatch while providing heat. Utility Model Content

[0004] To address the shortcomings of the existing technologies, this utility model provides a molten salt thermal energy storage system, which solves the technical problem that existing cogeneration or combined heat and power systems cannot participate in electricity market regulation and optimize energy management and dispatch while providing heat, and have poor adaptability to cope with fluctuations in electricity demand.

[0005] This utility model provides a molten salt thermal storage system, including a molten salt heating component, an energy conversion component, and a steam generation component;

[0006] The outlet end of the molten salt heating component is connected to the inlet end of the energy conversion component. The molten salt heating component is used to heat low-temperature molten salt to obtain high-temperature molten salt and transport the high-temperature molten salt to the energy conversion component.

[0007] The energy conversion component includes a molten salt hot tank, a molten salt cold tank, and a heat exchange unit. The inlet end of the molten salt hot tank is connected to the outlet end of the molten salt heating component for storing high-temperature molten salt. The outlet end of the molten salt hot tank is connected to the inlet end of the molten salt cold tank through the heat exchange unit. The high-temperature molten salt in the molten salt hot tank releases heat in the heat exchange unit to obtain low-temperature molten salt, which is then stored in the molten salt cold tank. The outlet end of the molten salt cold tank is connected to the inlet end of the molten salt heating component for transporting the low-temperature molten salt to the molten salt heating component.

[0008] The steam generating assembly includes a water supply unit connected to the heat exchange unit. The water supply unit absorbs heat in the heat exchange unit to obtain superheated steam, which is then output through the outlet of the steam generating assembly.

[0009] Optionally, the molten salt heating assembly includes a heat exchange device and an electric heating device, wherein the heat exchange device and the electric heating device are connected in series or in parallel; when the heat exchange device and the electric heating device are connected in series, the inlet end of the heat exchange device is connected to the outlet end of the molten salt cold tank, the outlet end of the heat exchange device is connected to the inlet end of the electric heating device, and the outlet end of the electric heating device is connected to the inlet end of the molten salt hot tank; when the heat exchange device and the electric heating device are connected in parallel, the inlet end of the heat exchange device and the inlet end of the electric heating device are respectively connected to the outlet end of the molten salt cold tank, and the outlet end of the heat exchange device and the outlet end of the electric heating device are respectively connected to the inlet end of the molten salt hot tank.

[0010] Optionally, the heat exchange device is a vapor cooler; the input end of the vapor cooler is connected to the cogeneration unit, and the output end of the vapor cooler is connected to the heat-consuming end. The vapor cooler is used to heat the low-temperature molten salt to obtain high-temperature molten salt by using the hot re-extraction steam of the cogeneration unit, and output the de-cooled hot re-extraction steam to the heat-consuming end for heat supply.

[0011] Optionally, the heat exchange device is a molten salt heat exchanger; the molten salt heat exchanger is used to heat low-temperature molten salt to obtain high-temperature molten salt using a preset heat source.

[0012] Optionally, the electric heating device is an electric heater; the electric heater is used to electrically heat low-temperature molten salt to obtain high-temperature molten salt.

[0013] Optionally, the heat exchange unit includes a superheater, an evaporator, and a preheater; the outlet end of the molten salt hot tank is connected to the inlet end of the molten salt cold tank in sequence through the superheater, the evaporator, and the preheater.

[0014] Optionally, the steam generation assembly further includes a feedwater pump and connecting pipelines; the feedwater unit is connected in sequence to the preheater, the evaporator and the superheater through the connecting pipelines, and outputs the superheated steam through the connecting pipelines; the feedwater pump is located at the outlet end of the feedwater unit and is used to pressurize the feedwater output by the feedwater unit.

[0015] Optionally, the steam generating assembly further includes a heating unit; the heating unit is disposed at the outlet end of the water supply unit and is used to heat the water supply output by the water supply unit.

[0016] Optionally, the heat exchange unit includes at least one dual-medium heat exchanger; the high-temperature molten salt in the molten salt tank releases heat in the first flow channel of the dual-medium heat exchanger to obtain low-temperature molten salt; the feed water output by the feed water unit absorbs heat in the second flow channel of the dual-medium heat exchanger to obtain superheated steam.

[0017] Optionally, the steam turbine is a pure condensing steam turbine or a back-pressure steam turbine.

[0018] This utility model provides a molten salt thermal storage system, which uses a molten salt hot tank to store high-temperature molten salt. This system allows for the release of heat to generate electricity when electricity demand is high, and the suspension of power generation to prioritize heating or heat storage when demand is low. This enables flexible energy allocation over time, allowing the system to both provide heating and participate in grid peak shaving, thus improving its adaptability to electricity market fluctuations. The heat exchange unit utilizes the heat released from the molten salt to heat feedwater and generate steam for power generation, meeting the steam demands of industrial production. This achieves varying degrees of thermoelectric decoupling, enhancing the system's multifunctionality and operational flexibility. Low-temperature molten salt is recycled to a molten salt cold tank and then returned to the heating components for reuse, making the system an independent energy cycle system. This effectively reduces heat loss, improves overall cycle efficiency, reduces dependence on external heat sources, and supports long-term energy storage operation, extending the system's continuous operating time. The above system exhibits strong adaptability to electricity market fluctuations, can participate in grid peak shaving while providing heating, achieves thermoelectric decoupling, improves operational flexibility, and, as an independent energy cycle system, possesses high operating efficiency.

[0019] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0020] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0022] Figure 1 A schematic diagram of the overall structure of the molten salt thermal storage system provided in one embodiment of this application;

[0023] Figure 2 A schematic diagram of the specific structure of the molten salt thermal storage system in another embodiment provided in this application. Detailed Implementation

[0024] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0025] In one embodiment, such as Figure 1 As shown, a molten salt thermal storage system is provided, including a molten salt heating component, an energy conversion component, and a steam generation component. The outlet end of the molten salt heating component is connected to the inlet end of the energy conversion component. The molten salt heating component is used to heat low-temperature molten salt to obtain high-temperature molten salt and then transport the high-temperature molten salt to the energy conversion component. The energy conversion component includes a molten salt hot tank, a molten salt cold tank, and a heat exchange unit. The inlet end of the molten salt hot tank is connected to the outlet end of the molten salt heating component and is used to store high-temperature molten salt. The outlet end of the molten salt hot tank is connected to the inlet end of the molten salt cold tank through the heat exchange unit. The high-temperature molten salt in the molten salt hot tank releases heat in the heat exchange unit to obtain low-temperature molten salt, which is then stored in the molten salt cold tank. The outlet end of the molten salt cold tank is connected to the inlet end of the molten salt heating component to transport the low-temperature molten salt to the molten salt heating component. The steam generation component includes a feedwater unit, which is connected to the heat exchange unit. The feedwater output from the feedwater unit absorbs heat in the heat exchange unit to obtain superheated steam, which is then output through the outlet end of the steam generation component. The outlet end of the steam generation component is connected to the steam turbine to output the superheated steam to the steam turbine to generate electricity.

[0026] The molten salt thermal storage system provided in this embodiment is equipped with a molten salt hot tank for storing high-temperature molten salt. It can release heat to generate electricity when electricity demand is high, and suspend power generation to prioritize heating or store heat when electricity demand is low. This allows for flexible energy allocation over time, enabling the system to both provide heating and participate in grid peak shaving, thus improving its adaptability to electricity market fluctuations. The heat exchange unit can use the heat released by the molten salt to heat feedwater to generate steam for power generation, meeting the steam demand in industrial production. This achieves varying degrees of thermoelectric decoupling, enhancing the system's multifunctionality and operational flexibility. Low-temperature molten salt is recycled to a molten salt cold tank and then returned to the heating components for reuse, making the system an independent energy cycle system. This effectively reduces heat loss, improves overall cycle efficiency, reduces dependence on external heat sources, and supports long-term energy storage operation, extending the system's continuous operating time. The above system has strong adaptability to electricity market fluctuations, can participate in grid peak shaving while providing heating, achieves thermoelectric decoupling, improves operational flexibility, and, as an independent energy cycle system, has high operating efficiency.

[0027] The molten salt used in this application is a binary salt, that is, a mixture of two different types of salts, usually a mixture of two different nitrates or nitrites, such as sodium nitrate (NaNO3) and potassium nitrate (KNO3), which are mixed in a certain proportion to form a eutectic mixture.

[0028] In one embodiment, the molten salt heating assembly includes a heat exchange device and an electric heating device, which are connected in series or in parallel. When the heat exchange device and the electric heating device are connected in series, the inlet end of the heat exchange device is connected to the outlet end of the molten salt cold tank, the outlet end of the heat exchange device is connected to the inlet end of the electric heating device, and the outlet end of the electric heating device is connected to the inlet end of the molten salt hot tank. When the heat exchange device and the electric heating device are connected in parallel, the inlet ends of the heat exchange device and the electric heating device are respectively connected to the outlet end of the molten salt cold tank, and the outlet ends of the heat exchange device and the electric heating device are respectively connected to the inlet end of the molten salt hot tank.

[0029] In this embodiment, the molten salt heating assembly is specifically equipped with two different types of heating devices: a heat exchange device and an electric heating device. The connection method between the two heating devices is not fixed and can be in series or in parallel. In the series mode, electric heating serves as a supplementary means to ensure that even if the heat exchange device is insufficient to heat the molten salt to the target temperature, the required high temperature state can still be achieved. In the parallel mode, a redundancy mechanism is provided. When one heating device fails or is limited, the other heating device can continue to work, ensuring the continuous and stable operation of the system and enhancing the system's ability to cope with various working conditions. Finally, the two heating devices work together to heat the low-temperature molten salt to the target temperature, obtain high-temperature molten salt, and store it in the molten salt hot tank.

[0030] In one embodiment, such as Figure 2 As shown, the heat exchange device is a evaporator; the input end of the evaporator is connected to the cogeneration unit, and the output end of the evaporator is connected to the heat-consuming end. The evaporator is used to heat the low-temperature molten salt to obtain high-temperature molten salt by using the hot re-extraction steam of the cogeneration unit, and outputs the de-cooled hot re-extraction steam to the heat-consuming end for heat supply.

[0031] Specifically, the steam cooler not only needs to cool the steam, but also needs to utilize the waste heat of the steam for heating. During the operation of the molten salt cogeneration unit, a portion of high-temperature and high-pressure hot re-extraction steam is extracted. The hot re-extraction steam passes through the inside of the steam cooler, and part of the heat from the hot re-extraction steam is used to heat the molten salt, which causes the temperature to drop. Although the temperature of the hot re-extraction steam decreases, the steam, which still has a high calorific value, is transported to downstream heat-consuming ends, such as industrial users and district heating systems, to continue to be used for heating. The high-temperature molten salt obtained by heating with the heat from the hot re-extraction steam needs to be further heated or stored in a molten salt hot tank.

[0032] In this embodiment, the waste heat of steam that might otherwise be wasted is recovered by the evaporator to heat the molten salt, realizing the reuse of waste heat and avoiding energy loss. At the same time, the steam after cooling can still be used for heating, forming a multi-level energy utilization chain and significantly improving the overall thermal efficiency of the system. Compared with simply relying on external fuel for heating, the method of heating low-temperature molten salt by the evaporator is more energy-efficient and environmentally friendly, and helps to build a closed-loop molten salt circulation system to ensure a continuous supply of high-temperature molten salt.

[0033] In one embodiment, the heat exchange device is a molten salt heat exchanger; the molten salt heat exchanger is used to heat low-temperature molten salt to obtain high-temperature molten salt using a preset heat source.

[0034] Specifically, molten salt heat exchangers use molten salt as the heat transfer medium. Molten salt itself has good thermal stability and high heat capacity, and is widely used in processes that require high-temperature operation. When low-temperature molten salt flows through the molten salt heat exchanger, it exchanges heat with an externally preset heat source, absorbs heat, and rises to become high-temperature molten salt.

[0035] In this embodiment, the molten salt heat exchanger can be adapted to different heat source forms, enhancing the system's adaptability and application range. It is particularly suitable for clean energy access scenarios. Furthermore, the molten salt heat exchanger has a mature structure, stable operation, and is suitable for long-term operation under high temperature and high pressure environments.

[0036] In one embodiment, the electric heating device is an electric heater; the electric heater is used to electrically heat the low-temperature molten salt to obtain high-temperature molten salt.

[0037] In this embodiment, the electric heater has a fast response speed and can provide very precise temperature control, ensuring that the molten salt can reach the required high temperature. When there are multiple clean energy supply options, the electric heater can be connected to clean energy through the power grid, which increases the system's flexibility and sustainability, makes the operation more stable and reliable, and reduces maintenance needs and failure risks.

[0038] Furthermore, the heat exchange unit includes a superheater, an evaporator, and a preheater; the outlet end of the molten salt hot tank is connected to the inlet end of the molten salt cold tank in sequence through the superheater, evaporator, and preheater.

[0039] Furthermore, the steam generation assembly also includes a feedwater pump and connecting pipelines; the feedwater unit is connected to the preheater, evaporator and superheater in sequence through the connecting pipelines, and outputs superheated steam through the connecting pipelines; the feedwater pump is located at the outlet end of the feedwater unit and is used to pressurize the feedwater output by the feedwater unit.

[0040] In this embodiment, the high-temperature molten salt discharged from the molten salt hot tank needs to release heat through the heat exchange unit. At the same time, the feed water output from the water supply unit needs to flow through the heat exchange unit to absorb heat and generate superheated steam.

[0041] In one embodiment, the heat exchange unit specifically includes a superheater, an evaporator, and a preheater connected in sequence. Regarding the process of high-temperature molten salt releasing heat, the main function of the superheater is to further heat the medium that has already been converted into saturated steam, causing its temperature to exceed its boiling point and become superheated steam. After flowing out of the molten salt tank, the high-temperature molten salt first passes through the superheater, releasing heat to the working medium that has already been converted into saturated steam, heating it to a superheated state to obtain superheated steam. The evaporator is responsible for completely converting the preheated feedwater into saturated steam. In this process, the liquid absorbs enough heat to reach its boiling point and transforms into a gaseous state. After the superheater, the high-temperature molten salt enters the evaporator, continuing to release heat to the preheated feedwater, making the feedwater... The feedwater boils and transforms into saturated steam. The preheater's function is to preheat the feedwater, raising its temperature without causing it to boil, which helps reduce the workload of the subsequent evaporator and improves the overall system's thermal efficiency. After passing through the superheater and evaporator, the high-temperature molten salt's temperature drops but remains at a high level. It then enters the preheater to preheat the feedwater that is about to enter the evaporator. The preheated feedwater's temperature is close to its boiling point, preparing it for the subsequent evaporation process. As for the process of feedwater absorbing heat, the feedwater first enters the preheater, absorbing heat to approach its saturation temperature. It then enters the evaporator, absorbing more heat and transforming from a liquid state into saturated steam. Finally, it enters the superheater, where the steam continues to absorb heat and rise in temperature to become high-temperature, high-pressure superheated steam.

[0042] In this process, the preheated feedwater is pressurized by a feedwater pump to ensure its smooth entry and flow throughout the steam generation path. The feedwater pump not only provides the necessary pressure to propel the water forward but also precisely controls the amount of water entering each heat exchanger to maintain system balance and stability. This application does not specify the exact installation location of the feedwater pump, such as... Figure 2 As shown, it can be set at the evaporator. In order to ensure that the feed water can enter the evaporator smoothly and carry out the evaporation process at high efficiency, it is necessary to pressurize the feed water by a water pump. This helps to overcome the pipeline resistance and ensure that the feed water enters the evaporator at an appropriate pressure.

[0043] In one embodiment, the steam generating assembly further includes a heating unit; the heating unit is disposed at the outlet end of the water supply unit and is used to heat the water supply output by the water supply unit.

[0044] In this embodiment, the feedwater from the coal-fired power unit or the chemically treated feedwater is preheated to 240°C to 270°C before entering the preheater. By preheating the feedwater to a higher temperature in advance, the heat input required by subsequent equipment such as the preheater and evaporator can be significantly reduced, thereby reducing the workload of the system and improving the overall thermal efficiency. Furthermore, the sudden entry of low-temperature feedwater without preheating into the heat exchange unit may cause overheating in local areas, posing a potential threat to the equipment. Preheating in advance can ensure that the equipment operates under more uniform conditions, extend its service life, and improve the stability of the system.

[0045] In one embodiment, the heat exchange unit includes at least one dual-medium heat exchanger; the high-temperature molten salt in the molten salt tank releases heat in the first flow channel of the dual-medium heat exchanger to obtain low-temperature molten salt; the feed water output from the feed water unit absorbs heat in the second flow channel of the dual-medium heat exchanger to obtain superheated steam.

[0046] Specifically, a dual-medium heat exchanger is a heat exchange device with two independent flow channels for the flow of two different media. The first flow channel is for high-temperature molten salt from a molten salt hot tank, which releases heat as it flows through the heat exchanger, and after its temperature drops, it becomes low-temperature molten salt and eventually flows into a molten salt cold tank. The second flow channel is for feedwater from a feedwater unit, which absorbs the heat released by the high-temperature molten salt as it flows through the heat exchanger, gradually heating up and converting into superheated steam. The two media exchange heat indirectly through the heat transfer walls inside the heat exchanger.

[0047] In this embodiment, the dual-medium heat exchanger completes the heat exchange of two media within a single device, replacing the function of multiple heat exchange devices in a traditional system. This reduces the number of devices and the floor space required, which is beneficial for modular system design. Furthermore, since the molten salt and feedwater exchange heat within the same heat exchanger, the heat transfer path is short and the heat exchange area is large, which helps to improve the overall heat exchange efficiency. Consequently, the heating curve of the feedwater in the second flow channel can be optimized based on the molten salt temperature distribution, achieving more efficient energy transfer. Compared to the traditional multi-stage heat exchanger series method, the use of a dual-medium heat exchanger can reduce the number of pipe connections, valves, and control system complexity, thereby reducing maintenance difficulty and failure rate, and improving the stability and reliability of system operation.

[0048] Furthermore, the steam turbine is either a pure condensing steam turbine or a back-pressure steam turbine.

[0049] In this embodiment, the pure condensing steam turbine typically operates under high pressure and high temperature conditions, achieving high thermoelectric conversion efficiency. By completely converting the discharged steam into water through the condenser, more latent heat can be recovered, further improving the overall energy efficiency of the system. It is particularly suitable for scenarios requiring a large power supply. In contrast, the back-pressure steam turbine is not equipped with a condenser, and the discharged steam maintains a certain pressure and temperature, which can be directly used for heating or other industrial processes, thereby achieving combined heat and power (CHP). This improves the overall energy utilization rate. Furthermore, for applications with simultaneous electricity and heat load demands, the back-pressure steam turbine can flexibly adjust the ratio of power generation and heat supply according to actual needs, achieving optimal energy allocation.

[0050] The molten salt thermal storage system provided in this application is as follows: Figure 2 As shown, its specific workflow is as follows:

[0051] First, hot re-extraction steam (approximately 1.5MPa to 5MPa, 530℃ to 600℃) is extracted from the cogeneration unit. Then, a heat exchange device is used to exchange heat between the hot re-extraction steam and the low-temperature molten salt. Specifically, the heat exchange device is a vapor cooler. After absorbing heat, the temperature of the low-temperature molten salt increases, while the pressure of the hot re-extraction steam remains unchanged and the temperature decreases to approximately 300℃ to 450℃ before continuing to supply heat to the heat-consuming end. This process replaces the traditional desuperheater and pressure reducer, improving energy utilization efficiency.

[0052] Secondly, a heat exchange device, specifically an electric heater, is used to further heat the high-temperature molten salt. The power source for the electric heater can be new energy electricity, off-peak electricity, or factory electricity. Furthermore, the electric heater and the steam cooler can also be connected in parallel to heat the salt together. The high-temperature molten salt, which is heated by steam coupling electric heating, is transported to the molten salt hot tank, where the temperature is approximately 520℃~550℃.

[0053] Afterwards, the high-temperature molten salt in the hot molten salt tank releases heat and cools down through the heat exchange unit, and is stored in the cold molten salt tank. The temperature of the cold molten salt tank is about 275℃~315℃. Meanwhile, the feedwater from the coal-fired power unit or the chemically treated feedwater is preheated to 240℃~270℃. The preheated feedwater is then pumped into the preheater, evaporator and superheater in sequence to absorb the heat released by the high-temperature molten salt, and finally generate high-temperature and high-pressure superheated steam (16.7MPa, 538℃). The superheated steam is sent to the main steam inlet of the cogeneration unit, which increases the power generation capacity of the unit.

[0054] The high-temperature, high-pressure superheated steam generated by the exothermic reaction of molten salt eventually enters a pure condensing or back-pressure steam turbine to generate electricity.

[0055] The above-mentioned molten salt thermal storage system was put into production and use. The specific operating data is as follows: During the molten salt thermal storage process, the main steam parameters of the cogeneration unit are 16.7 MPa and 538℃, and the extracted hot re-extraction steam parameters are 2.2 MPa, 538℃, and 250 t / h. After heat exchange by the heat exchange device, the temperature is reduced to 390℃ and supplied to the outside. The thermal storage power of the heat exchange device is about 22.8 MW, and the thermal storage power of the coupled electric heating molten salt is 2.1 MW. The obtained high-temperature molten salt is stored in the molten salt hot tank. The temperature of the molten salt hot tank is 548℃, the temperature of the molten salt cold tank is 305℃, and the molten salt flow rate is 237.6 t / h.

[0056] During the molten salt exothermic process, 350.2 t / h of high-temperature molten salt flows out from the molten salt hot tank and passes sequentially through the preheater, evaporator, and superheater. This heats the 17 MPa, 260℃, 56 t / h feedwater output from the feedwater unit to superheated steam at 16.7 MPa and 538℃, which is then sent to the main steam inlet of the cogeneration unit, increasing the unit's power generation capacity. According to calculation and analysis, the overall efficiency of the molten salt thermal storage system provided in this application is 43.1%.

[0057] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A molten salt thermal storage system, characterized in that, Includes molten salt heating components, energy conversion components, and steam generation components; The outlet end of the molten salt heating component is connected to the inlet end of the energy conversion component. The molten salt heating component is used to heat low-temperature molten salt to obtain high-temperature molten salt and transport the high-temperature molten salt to the energy conversion component. The energy conversion component includes a molten salt hot tank, a molten salt cold tank, and a heat exchange unit. The inlet end of the molten salt hot tank is connected to the outlet end of the molten salt heating component for storing high-temperature molten salt. The outlet end of the molten salt hot tank is connected to the inlet end of the molten salt cold tank through the heat exchange unit. The high-temperature molten salt in the molten salt hot tank releases heat in the heat exchange unit to obtain low-temperature molten salt, which is then stored in the molten salt cold tank. The outlet end of the molten salt cold tank is connected to the inlet end of the molten salt heating component for transporting the low-temperature molten salt to the molten salt heating component. The steam generation assembly includes a feedwater unit and a steam turbine. The feedwater unit is connected to the heat exchange unit. The feedwater output from the feedwater unit absorbs heat in the heat exchange unit to obtain superheated steam, which is then output through the outlet end of the steam generation assembly. The outlet end of the steam generation assembly is connected to the steam turbine to output the superheated steam to the steam turbine to generate electricity.

2. The molten salt thermal storage system according to claim 1, characterized in that, The molten salt heating assembly includes a heat exchange device and an electric heating device, wherein the heat exchange device and the electric heating device are connected in series or in parallel. When the heat exchange device and the electric heating device are connected in series, the inlet end of the heat exchange device is connected to the outlet end of the molten salt cold tank, the outlet end of the heat exchange device is connected to the inlet end of the electric heating device, and the outlet end of the electric heating device is connected to the inlet end of the molten salt hot tank. When the heat exchange device and the electric heating device are connected in parallel, the inlet end of the heat exchange device and the inlet end of the electric heating device are respectively connected to the outlet end of the molten salt cold tank, and the outlet end of the heat exchange device and the outlet end of the electric heating device are respectively connected to the inlet end of the molten salt hot tank.

3. The molten salt thermal storage system according to claim 2, characterized in that, The heat exchange device is a vapor cooler; The input end of the evaporator is connected to the cogeneration unit, and the output end of the evaporator is connected to the heat-consuming end. The evaporator is used to heat the low-temperature molten salt to obtain high-temperature molten salt by using the hot re-extraction steam of the cogeneration unit, and outputs the de-cooled hot re-extraction steam to the heat-consuming end for heat supply.

4. The molten salt thermal storage system according to claim 2, characterized in that, The heat exchange device is a molten salt heat exchanger; The molten salt heat exchanger is used to heat low-temperature molten salt to obtain high-temperature molten salt using a preset heat source.

5. The molten salt thermal storage system according to claim 2, characterized in that, The electric heating device is an electric heater; The electric heater is used to electrically heat low-temperature molten salt to obtain high-temperature molten salt.

6. The molten salt thermal storage system according to claim 1, characterized in that, The heat exchange unit includes a superheater, an evaporator, and a preheater; The outlet end of the molten salt hot tank is connected to the inlet end of the molten salt cold tank in sequence through the superheater, the evaporator and the preheater.

7. The molten salt thermal storage system according to claim 6, characterized in that, The steam generation assembly also includes a water pump and connecting pipelines; The water supply unit is connected in sequence to the preheater, the evaporator and the superheater through the connecting pipe, and outputs the superheated steam through the connecting pipe; The water supply pump is located at the outlet end of the water supply unit and is used to pressurize the water output by the water supply unit.

8. The molten salt thermal storage system according to claim 1 or 7, characterized in that, The steam generation assembly also includes a heating unit; The heating unit is located at the outlet end of the water supply unit and is used to heat the water supplied by the water supply unit.

9. The molten salt thermal storage system according to claim 1, characterized in that, The heat exchange unit includes at least one dual-medium heat exchanger; The high-temperature molten salt in the molten salt hot tank releases heat in the first flow channel of the dual-medium heat exchanger to obtain low-temperature molten salt; The water supplied by the water supply unit absorbs heat in the second flow channel of the dual-medium heat exchanger to obtain superheated steam.

10. The molten salt thermal storage system according to claim 1, characterized in that, The steam turbine is a pure condensing steam turbine or a back-pressure steam turbine.

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