Coupling system and scheduling method for electric heating-molten salt combined heat and power generation

Abstract

The invention relates to the technical field of efficient utilization of energy, and discloses an electric heating-molten salt combined heat and power generation coupling system and scheduling method.The system comprises a transformer, a relay, a cold and hot molten salt combined heat and power generation circulating system, a waterway unit, a heat consumer unit, a steam turbine and a generator; a heat supply source of the steam turbine is connected with an outlet of the boiler; the steam turbine is provided with two groups of outlet ends, one outlet end is connected with the heat consumer unit, the other outlet end is connected with the input end of the generator, and the output end of the generator is connected with the cold and hot molten salt combined heat and power generation circulating system sequentially through the transformer and the relay; and the output end of the water path unit is connected to the heat consumer unit after passing through the cold and hot molten salt combined heat and power generation circulating system. The adaptive capacity of the combined heat and power generation unit to the dynamic change of the price of the electric power spot market is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of energy-efficient utilization technology, specifically to a coupled system and scheduling method for electric heating-molten salt cogeneration. Background Art

[0002] Cogeneration units play a crucial role in energy supply. They have the dual function of simultaneously supplying power to the grid and heat to users, realizing the cascade utilization and efficient allocation of energy, and occupying an indispensable position in the energy supply system.

[0003] With the continuous reform and development of the electricity market, the electricity spot market has gradually emerged and improved, and electricity prices exhibit dynamic changes, with periods of high and low prices. For combined heat and power (CHP) units, while ensuring a stable supply of heat to users, effectively improving their flexibility in supplying power to the grid, and enabling them to sensitively and accurately adapt to high / low price signals from the electricity spot market, is of paramount importance. This measure will not only significantly enhance the market economy of CHP units themselves, strengthening their competitiveness and profitability in the market, but also provide strong support for the large-scale grid integration of renewable energy, promoting the optimization and sustainable development of the energy structure.

[0004] However, given the current state of technology, when electricity spot market prices fluctuate between high and low, the adaptability of combined heat and power (CHP) units to dynamic changes in electricity spot market prices decreases significantly. Specifically, the units struggle to adjust their power supply strategies and operating modes promptly and appropriately based on real-time price changes, failing to fully capitalize on profit opportunities during periods of high electricity prices, while also failing to effectively optimize operating costs during periods of low electricity prices. This situation directly leads to a significant reduction in the economic viability of CHP systems in the electricity spot market environment, limiting the further development and widespread application of CHP units, and also hindering the healthy and stable operation of the electricity market and the efficient use of energy. Therefore, improving the adaptability of CHP units to dynamic changes in electricity spot market prices has become a critical technical problem that urgently needs to be addressed. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a coupling system and scheduling method for electric heating-molten salt cogeneration, so as to solve the technical problem of how to improve the adaptability of cogeneration units to dynamic changes in electricity spot market prices.

[0006] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a coupled system for electric heating-molten salt cogeneration, including a transformer, a relay, a cold and hot molten salt cogeneration cycle system, a water circuit unit, a heat user unit, a steam turbine, and a generator; The heat source of the steam turbine is connected to the boiler outlet; the steam turbine has two sets of outlet ends, one outlet end is connected to the heat user unit, and the other outlet end is connected to the input end of the generator. The output end of the generator is connected to the cold and hot molten salt cogeneration cycle system through a transformer and a relay in sequence; the output end of the water circuit unit is connected to the heat user unit after passing through the cold and hot molten salt cogeneration cycle system.

[0007] Preferably, the cold and hot molten salt cogeneration cycle system includes a cold molten salt unit, a hot molten salt unit, a molten salt electric heater, and a heat exchange unit group; The output end of the cold molten salt unit is connected to the input end of the molten salt electric heater, the output end of the molten salt electric heater is connected to the input end of the hot molten salt unit, the output end of the hot molten salt unit is connected to the input end of the heat exchange unit group, and the output end of the heat exchange unit group is connected to the input end of the cold molten salt unit, forming a molten salt circulation loop. The output terminal of the generator is connected to the molten salt electric heater via a transformer and a relay in sequence. The output of the water circuit unit is connected to the heat user unit after passing through the heat exchange unit group.

[0008] Furthermore, the cold molten salt unit includes a cold salt storage tank outlet regulating valve, a cold salt drive pump, and a cold salt storage tank; The input end of the cold salt storage tank is connected to the output end of the heat exchange unit group; The output end of the cold salt storage tank is connected to the molten salt electric heater; wherein, a cold salt storage tank outlet regulating valve and a cold salt drive pump are provided between the cold salt storage tank and the molten salt electric heater.

[0009] Furthermore, the hot molten salt unit includes a hot salt storage tank outlet regulating valve, a hot salt drive pump, and a hot salt storage tank; The input end of the hot salt storage tank is connected to the output end of the molten salt electric heater; the output end of the hot salt storage tank is connected to the input end of the heat exchange unit group; wherein, a hot salt drive pump and a hot salt storage tank outlet regulating valve are sequentially provided between the hot salt storage tank and the heat exchange unit group.

[0010] Furthermore, the heat exchange unit group includes a preheater, an evaporator, and a superheater; The salt-side inlet of the superheater is connected to the output end of the hot molten salt unit, and the salt-side outlet of the superheater is connected to the salt-side inlet of the evaporator; the salt-side outlet of the evaporator is connected to the salt-side inlet of the preheater; and the salt-side outlet of the preheater is connected to the input end of the cold molten salt unit.

[0011] Furthermore, the output of the water circuit unit is connected to the heat user unit after passing through the preheater, evaporator, and superheater in sequence.

[0012] Furthermore, a steam supply regulating valve is installed between the output end of the water circuit unit and the heat user unit.

[0013] Secondly, the present invention also provides a scheduling method for an electrically heated-molten salt cogeneration coupled system, based on the aforementioned electrically heated-molten salt cogeneration coupled system, comprising: During the molten salt thermal storage process, the generator adjusts the power output of the transformer and relay to provide the electric energy source for heating the molten salt in the cold and hot molten salt cogeneration cycle system, thus enabling the molten salt to circulate. The output of the water circuit unit is supplied to the heat user unit through the cold and hot molten salt cogeneration cycle system. The corresponding makeup water for this part of the steam supply is supplied to the condenser, completing the water circulation of the entire electric heating-molten salt cogeneration coupling system. At the same time, the heating steam extracted from the turbine is supplied to the heat user unit.

[0014] Preferably, the specific process of the hot and cold molten salt cogeneration cycle system as the power source for heating molten salt and circulating the molten salt is as follows: Cold molten salt is stored in a cold salt storage tank. Driven by a cold salt drive pump and flowing through the outlet regulating valve of the cold salt storage tank, it is sent to an electric heater to be heated into hot molten salt, which is then stored in a hot salt storage tank. During the molten salt heat release process, the hot salt is initially stored in the hot salt storage tank. Driven by a hot salt drive pump and flowing through the outlet regulating valve of the hot salt storage tank, it releases heat in the superheater, evaporator, and preheater in sequence, and finally becomes cold salt and returns to the cold salt storage tank, completing the molten salt cycle of the entire electric heating-molten salt cogeneration coupled system.

[0015] Preferably, the specific process of adjusting the power generation of the transformer and relay is as follows: When the electricity spot market price is low, a portion of the electricity generated by the generator is dispatched to the electric heater through transformers and relays to heat the cold molten salt from the cold salt storage tank, turning it into hot molten salt and storing it in the hot salt storage tank. The whole process causes the amount of electricity generated by the cogeneration unit to be input into the grid to decrease rapidly. When the electricity spot market has high electricity prices, the hot molten salt stored in the hot salt storage tank is quickly driven by the hot salt drive pump and then passes through the hot salt storage tank outlet regulating valve to release heat in the superheater, evaporator and preheater in sequence. The water from the self-feed water pump outlet is heated into high-temperature steam and then supplied to the heat user unit. This reduces the steam extraction for steam turbine heating, so that more steam can do work in the steam turbine and drive the generator to generate electricity, thus rapidly increasing the steam turbine power generation.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides a coupled system for electric heating-molten salt cogeneration. The steam turbine has two outlet terminals: one connected to a heat user unit for heating, and the other connected to a generator input for power generation. This allows the system to flexibly adjust the ratio of steam turbine output to heating and power generation based on electricity spot market price signals. The generator output is connected to the hot and cold molten salt cogeneration cycle system via a transformer and a relay. The output of the water circuit unit is connected to the heat user unit via this cycle system. The hot and cold molten salt cogeneration cycle system can store and regulate energy, storing energy when electricity prices are low and releasing energy when prices are high, achieving spatiotemporal energy transfer. This improves energy utilization efficiency while enhancing the system's adaptability to electricity price changes and improving overall economic efficiency. Furthermore, the cold salt storage tank of the cold molten salt unit stores cryogenic molten salt. During periods of low electricity prices in the spot market, excess electricity generated by the generator is transmitted to the molten salt electric heater via a transformer and relay. The cold molten salt in the cold salt storage tank, driven by a cold salt drive pump and controlled by a regulating valve at the tank outlet, enters the molten salt electric heater, where it is heated into hot molten salt and stored in the hot molten salt unit. During periods of high electricity prices, the hot molten salt in the hot molten salt unit flows into the heat exchange unit group, releasing heat. At peak electricity prices, the stored heat energy is converted into electrical energy or used for heating, achieving a spatial and temporal transfer of energy. The cold salt storage tank outlet regulating valve and the cold salt drive pump work together to precisely control the flow of cold molten salt from the cold salt storage tank to the molten salt electric heater. The hot molten salt in the hot molten salt unit flows into the heat exchange unit group, and the output of the water circuit unit is also connected to the heat exchange unit group. In the heat exchange unit group, the hot molten salt exchanges heat with the water in the water circuit, transferring heat to the water. The heated water is then transported to the heat user unit for heating. Meanwhile, the cooled molten salt after heat exchange flows back to the cold salt storage tank, completing the molten salt circulation loop.

[0017] Furthermore, the hot salt storage tank outlet regulating valve and the hot salt drive pump together constitute the control system for the output of molten salt. The hot salt drive pump provides power for the flow of molten salt from the hot salt storage tank to the heat exchange unit group, while the hot salt storage tank outlet regulating valve can precisely control the flow rate of the molten salt. The hot salt drive pump can provide stable and adjustable pressure, ensuring the continuous and stable flow of molten salt in the pipeline, overcoming pipeline resistance, and smoothly transporting the molten salt from the hot salt storage tank to the heat exchange unit group. Through the coordinated regulation of the hot salt storage tank outlet regulating valve and the hot salt drive pump, the system can precisely control the output of molten salt according to the actual heat demand of the heat exchange unit group.

[0018] Furthermore, after flowing out of the molten salt unit, the hot molten salt sequentially enters the superheater, evaporator, and preheater. In the superheater, the hot molten salt transfers heat to the steam, bringing it to a superheated state. Next, the slightly cooled hot molten salt enters the evaporator, transferring heat to the water and causing it to evaporate into steam. Finally, the even cooled hot molten salt enters the preheater to preheat the water about to enter the system. This staged heat exchange method achieves the cascaded utilization of energy, allowing the hot molten salt to release appropriate energy in different temperature ranges.

[0019] Furthermore, the water in the water circuit unit flows sequentially through the preheater, evaporator, and superheater. In the preheater, the water absorbs the lower-temperature heat released by the molten salt, causing its temperature to rise. After entering the evaporator, the water absorbs heat at an even higher temperature, undergoing a phase change from liquid to gas (steam). Finally, in the superheater, the steam further absorbs heat to reach a superheated state, and is then transported to the heat user unit, ensuring that the heat from the molten salt at different temperature stages can be fully absorbed and utilized by the water.

[0020] This invention also provides a scheduling method for an electric heating-molten salt cogeneration (CHP) coupling system. This system couples an electric heater and a molten salt thermal storage system to a CHP unit. The electric heater enhances the deep-shortage capability of the CHP unit's power generation, while the molten salt thermal storage system enhances its peak and deep-shortage capabilities. This allows for full adaptation to real-time dynamic changes in electricity spot market prices (high / low), thereby improving the CHP unit's flexible operation and market economy. When electricity spot market prices are high / low, this invention regulates the amount of power generated by the CHP unit and inputs it into the grid through the electric heater and molten salt thermal storage system, improving the unit's adaptability to dynamic changes in electricity spot market prices. Furthermore, this invention achieves thermal-electric decoupling through the electric heater and molten salt energy storage system, expanding the unit's electric and thermal load operating range and increasing the CHP unit's operational flexibility. By actively responding to dynamic changes in electricity spot market prices (high / low), it helps improve the economics of the CHP system in the electricity spot market. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the coupled system of electric heating-molten salt cogeneration in an embodiment of the present invention; In the diagram: 1. Transformer; 2. Relay; 3. Cold salt storage tank outlet regulating valve; 4. Cold salt drive pump; 5. Cold salt storage tank; 6. Preheater; 7. Evaporator; 8. Superheater; 9. Steam supply regulating valve; 10. Hot salt storage tank outlet regulating valve; 11. Hot salt drive pump; 12. Hot salt storage tank; 13. Molten salt electric heater; 14. Heat user unit; 15. Steam turbine; 16. Generator. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] The purpose of this invention is to provide a coupling system and scheduling method for electric heating-molten salt cogeneration, in order to solve the technical problem of how to improve the adaptability of cogeneration units to dynamic changes in electricity spot market prices.

[0025] The present invention will now be described in further detail with reference to the accompanying drawings: Example 1 See Figure 1 In one embodiment of the present invention, a coupled system for electric heating-molten salt cogeneration is provided, including a transformer 1, a relay 2, a cold and hot molten salt cogeneration cycle system, a water circuit unit, a heat user unit 14, a steam turbine 15, and a generator 16; the heat source of the steam turbine 15 is connected to the boiler outlet; the steam turbine 15 has two sets of outlet ends, one outlet end is connected to the heat user unit 14, and the other outlet end is connected to the input end of the generator 16; the output end of the generator 16 is connected to the cold and hot molten salt cogeneration cycle system in sequence through the transformer 1 and the relay 2; the output end of the water circuit unit is connected to the heat user unit 14 after passing through the cold and hot molten salt cogeneration cycle system.

[0026] Specifically, the cold and hot molten salt cogeneration cycle system includes a cold molten salt unit, a hot molten salt unit, a molten salt electric heater 13, and a heat exchange unit group. The output end of the cold molten salt unit is connected to the input end of the molten salt electric heater 13, the output end of the molten salt electric heater 13 is connected to the input end of the hot molten salt unit, the output end of the hot molten salt unit is connected to the input end of the heat exchange unit group, and the output end of the heat exchange unit group is connected to the input end of the cold molten salt unit, forming a molten salt circulation loop. The output end of the generator 16 is connected to the molten salt electric heater 13 in sequence through a transformer 1 and a relay 2. The output end of the water circuit unit is connected to the heat user unit 14 after passing through the heat exchange unit group.

[0027] In this embodiment, the cold molten salt unit stores low-temperature molten salt, which is then transported to the molten salt electric heater 13 via pipeline. In the electric heater, the molten salt absorbs electrical energy and converts it into heat energy, significantly increasing its temperature and completing the transition from a cold to a hot state. The heated high-temperature molten salt flows into the hot molten salt unit for storage, forming a thermal energy reserve. When the system needs to release thermal energy, the hot molten salt flows out of the storage unit and enters the heat exchange unit group. Within the heat exchange unit group, the hot molten salt exchanges heat with the water in the water circuit unit, transferring heat to the water. After its own temperature decreases, it flows back to the cold molten salt unit, completing one complete molten salt cycle. This cycle process achieves the storage and on-demand release of thermal energy, ensuring the stability of the system's heat output. The generator 16 converts mechanical energy into electrical energy, and the generated alternating current first enters the transformer 1. The transformer 1 adjusts the voltage according to system requirements, ensuring that electrical energy is transmitted at an appropriate voltage level.

[0028] The adjusted electrical energy is controlled by relay 2. Relay 2, as a switching element of the circuit, can precisely connect or disconnect the circuit according to system operation commands, thereby controlling the power supply to the molten salt electric heater 13. When the system needs to heat the molten salt, relay 2 closes, and electrical energy is delivered to the molten salt electric heater 13 to drive it to work; when the heating process is complete or heating is no longer needed, relay 2 opens, stopping the power supply, ensuring efficient use of electrical energy and safe system operation.

[0029] Water, acting as the heat exchange medium, flows into the heat exchange unit group under system drive. Within the heat exchange unit group, the water undergoes indirect heat exchange with high-temperature molten salt, absorbing the heat released by the molten salt, gradually increasing its temperature and completing the transformation from cold water to hot water. The heated hot water is then transported through pipelines to the heat user unit 14, meeting the user's domestic hot water and heating needs. The heat user unit 14 adjusts the hot water flow and temperature according to actual needs, achieving precise supply and efficient utilization of heat energy.

[0030] In this embodiment, the system can flexibly adjust its operating mode according to the energy demand characteristics of different time periods and seasons. During peak electricity demand periods, the system can prioritize power generation and appropriately reduce molten salt heating; during peak heat demand periods, it can increase molten salt heating and heat exchange intensity to ensure the heat energy supply of heat user unit 14. This flexible operating mode enables the system to better adapt to changes in the energy market and fluctuations in user demand, improving the stability and reliability of energy supply.

[0031] The cold molten salt unit includes a cold salt storage tank outlet regulating valve 3, a cold salt drive pump 4, and a cold salt storage tank 5; the input end of the cold salt storage tank 5 is connected to the output end of the heat exchange unit group; the output end of the cold salt storage tank 5 is connected to the molten salt electric heater 13; the cold salt storage tank outlet regulating valve 3 and the cold salt drive pump 4 are provided between the cold salt storage tank 5 and the molten salt electric heater 13.

[0032] In this embodiment, the outlet regulating valve 3 of the cold salt storage tank adjusts its opening in real time according to the system's operating parameters and requirements, such as molten salt circulation flow rate and heating power, to precisely control the flow rate of molten salt entering the molten salt electric heater 13. This helps ensure that the molten salt can fully absorb electrical energy and be heated evenly in the electric heater, improving heating efficiency, while avoiding uneven heating or energy waste caused by excessive or insufficient flow. The cold salt drive pump 4 provides stable power for the molten salt circulation, ensuring that the molten salt flows in the pipeline at a constant pressure. Stable pressure helps maintain the normal operation of the entire molten salt circulation loop, preventing problems such as pipeline vibration and leakage caused by pressure fluctuations, and ensuring the safety and reliability of the system. The cold salt storage tank 5, as a storage and buffer device for molten salt, can balance the supply and demand of molten salt during system operation. When the heat exchange demand of the heat exchange unit group changes or the heating capacity of the molten salt electric heater fluctuates, the cold salt storage tank 5 can store or release a certain amount of molten salt to ensure the continuous and stable operation of the molten salt circulation loop, avoiding the impact on the overall performance of the system due to interruption or excess of molten salt supply.

[0033] The hot molten salt unit includes a hot salt storage tank outlet regulating valve 10, a hot salt drive pump 11, and a hot salt storage tank 12; the input end of the hot salt storage tank 12 is connected to the output end of the molten salt electric heater 13; the output end of the hot salt storage tank 12 is connected to the input end of the heat exchange unit group; wherein, the hot salt drive pump 11 and the hot salt storage tank outlet regulating valve 10 are sequentially arranged between the hot salt storage tank 12 and the heat exchange unit group.

[0034] In this embodiment, the regulating valve 10 at the outlet of the hot salt storage tank adjusts the valve opening in real time according to the actual heat load demand of the heat user unit 14, precisely controlling the flow rate of the hot molten salt entering the heat exchange unit group. When the heat load is high, the valve opening is increased to increase the flow rate of the hot molten salt, thereby improving the heat exchange capacity and meeting the user's heat demand; when the heat load is low, the valve opening is decreased to reduce the flow rate of the hot molten salt, avoiding heat waste and achieving efficient utilization of heat energy.

[0035] The hot salt drive pump 11 provides stable power for the hot molten salt circulation, ensuring that the hot molten salt flows in the pipeline at a constant pressure and flow rate. Stable pressure helps maintain the normal operation of the entire molten salt circulation loop, preventing problems such as pipeline vibration and leakage caused by pressure fluctuations, and ensuring the safety and reliability of the system. At the same time, stable flow rate ensures the stability and uniformity of the heat exchange process, improving heat exchange efficiency.

[0036] The hot salt storage tank 12 serves as a storage and buffering device for molten salt, balancing the supply and demand of molten salt during system operation. When the heating capacity of the molten salt electric heater 13 fluctuates or the heat exchange requirements of the heat exchange unit change, the hot salt storage tank 12 can store or release a certain amount of molten salt, playing a buffering and regulating role, ensuring the continuous and stable operation of the molten salt circulation loop, and avoiding the impact on the overall performance of the system due to interruption or excess of molten salt supply.

[0037] By reasonably controlling the operating parameters of the hot salt storage tank outlet regulating valve 10 and the hot salt drive pump 11, it is possible to avoid excessive flow velocity or pressure of hot molten salt in the pipeline, prevent pipeline wear caused by excessive flow velocity and pipeline rupture caused by excessive pressure, and ensure that the system operates under safe and reliable conditions.

[0038] The heat exchange unit group includes a preheater 6, an evaporator 7, and a superheater 8; the salt-side inlet of the superheater 8 is connected to the output end of the hot molten salt unit, and the salt-side outlet of the superheater 8 is connected to the salt-side inlet of the evaporator 7; the salt-side outlet of the evaporator 7 is connected to the salt-side inlet of the preheater 6; and the salt-side outlet of the preheater 6 is connected to the input end of the cold molten salt unit.

[0039] In this embodiment, the three heat exchangers are arranged in a high-low order. After the hot salt releases heat in the three heat exchangers, it flows by gravity in stages and finally collects into the cold salt storage tank 5.

[0040] The output of the water circuit unit is connected to the heat user unit 14 after passing through the preheater 6, evaporator 7 and superheater 8 in sequence.

[0041] In this embodiment, a steam supply regulating valve 9 is provided between the output end of the water circuit unit and the heat user unit 14.

[0042] In summary, the electric heating-molten salt cogeneration coupling system provided in this embodiment has a steam turbine with two sets of outlet terminals. One end connects to the heat user unit for heating, and the other end connects to the generator input terminal for power generation. This allows the system to flexibly adjust the ratio of steam turbine output to heating and power generation based on electricity spot market price signals. The generator output terminal connects to the hot and cold molten salt cogeneration cycle system via a transformer and a relay. The output terminal of the water circuit unit connects to the heat user unit via this cycle system. The hot and cold molten salt cogeneration cycle system can store and regulate energy, storing energy when electricity prices are low and releasing energy when prices are high, achieving spatiotemporal energy transfer. This improves energy utilization efficiency while enhancing the system's adaptability to electricity price changes and improving overall economic efficiency. Example 2 This embodiment also provides a scheduling method for a coupled system of electric heating-molten salt cogeneration, including: During the molten salt thermal storage process, the generator 16 adjusts the power output of the transformer 1 and the relay 2 to provide the electric power source for heating the molten salt in the cold and hot molten salt cogeneration cycle system, thus performing the molten salt circulation operation. The output of the water circuit unit is supplied to the heat user unit 14 through the cold and hot molten salt cogeneration cycle system. The corresponding makeup water of this steam supply is supplied to the condenser, completing the water circulation of the entire electric heating-molten salt cogeneration coupling system. At the same time, the heating steam extracted from the steam turbine 15 is supplied to the heat user unit 14.

[0043] The specific process of the hot and cold molten salt cogeneration cycle system, which uses electricity to heat the molten salt and circulate it, is as follows: Cold molten salt is stored in cold salt storage tank 5. Driven by cold salt drive pump 4 and flowing through cold salt storage tank outlet regulating valve 3, it is sent to electric heater 13 to be heated into hot molten salt, and finally stored in hot salt storage tank 12. During the molten salt heat release process, the hot salt is initially stored in hot salt storage tank 12. Driven by hot salt drive pump 11 and flowing through hot salt storage tank outlet regulating valve 11, it releases heat in superheater 8, evaporator 7 and preheater 6 in sequence, and finally becomes cold salt and returns to cold salt storage tank 5, completing the molten salt cycle of the entire electric heating-molten salt cogeneration coupled system.

[0044] The specific process of adjusting the power generation of transformer 1 and relay 2 is as follows: When the electricity spot market price is low, a portion of the electricity generated by generator 16 is dispatched to electric heater 13 through transformer 1 and relay 2 to heat the cold molten salt from cold salt storage tank 5, turning it into hot molten salt and storing it in hot salt storage tank 12. The whole process causes the electricity generated by the cogeneration unit to decrease rapidly. When the electricity spot market has high electricity prices, the hot molten salt stored in the hot salt storage tank 12 is quickly driven by the hot salt drive pump 11 and passes through the hot salt storage tank outlet regulating valve 11. It then releases heat in the superheater 8, evaporator 7 and preheater 6 in sequence, heating the water from the self-feed water pump outlet into high-temperature steam, which is then supplied to the heat user unit 14. This reduces the extraction of steam from the steam turbine for heating, allowing more steam to do work in the steam turbine and drive the generator 16 to generate electricity, thus rapidly increasing the steam turbine's power generation.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A coupling system for electric heating-molten salt cogeneration, characterized in that, It includes a transformer (1), a relay (2), a cold and hot molten salt cogeneration cycle system, a water circuit unit, a heat user unit (14), a steam turbine (15), and a generator (16). The heat source of the steam turbine (15) is connected to the boiler outlet; the steam turbine (15) has two sets of outlet ends, one outlet end is connected to the heat user unit (14), and the other outlet end is connected to the input end of the generator (16). The output end of the generator (16) is connected to the cold and hot molten salt cogeneration cycle system through the transformer (1) and the relay (2) in sequence; the output end of the water circuit unit is connected to the heat user unit (14) after passing through the cold and hot molten salt cogeneration cycle system.

2. The coupled system for electric heating-molten salt cogeneration according to claim 1, characterized in that, The cold and hot molten salt cogeneration cycle system includes a cold molten salt unit, a hot molten salt unit, a molten salt electric heater (13), and a heat exchange unit group; The output end of the cold molten salt unit is connected to the input end of the molten salt electric heater (13), the output end of the molten salt electric heater (13) is connected to the input end of the hot molten salt unit, the output end of the hot molten salt unit is connected to the input end of the heat exchange unit group, and the output end of the heat exchange unit group is connected to the input end of the cold molten salt unit, forming a molten salt circulation loop. The output terminal of the generator (16) is connected to the molten salt electric heater (13) in sequence via a transformer (1) and a relay (2); The output end of the water circuit unit is connected to the heat user unit (14) after passing through the heat exchange unit group.

3. The coupled system for electric heating-molten salt cogeneration according to claim 2, characterized in that, The cold molten salt unit includes a cold salt storage tank outlet regulating valve (3), a cold salt drive pump (4), and a cold salt storage tank (5). The input end of the cold salt storage tank (5) is connected to the output end of the heat exchange unit group; The output end of the cold salt storage tank (5) is connected to the molten salt electric heater (13); wherein, a cold salt storage tank outlet regulating valve (3) and a cold salt drive pump (4) are provided between the cold salt storage tank (5) and the molten salt electric heater (13).

4. The coupling system for electric heating-molten salt cogeneration according to claim 2, characterized in that, The hot molten salt unit includes a hot salt tank outlet regulating valve (10), a hot salt drive pump (11), and a hot salt tank (12). The input end of the hot salt storage tank (12) is connected to the output end of the molten salt electric heater (13); the output end of the hot salt storage tank (12) is connected to the input end of the heat exchange unit group; wherein, a hot salt drive pump (11) and a hot salt storage tank outlet regulating valve (10) are sequentially provided between the hot salt storage tank (12) and the heat exchange unit group.

5. The coupling system for electric heating-molten salt cogeneration according to claim 2, characterized in that, The heat exchange unit group includes a preheater (6), an evaporator (7), and a superheater (8); The salt-side inlet of the superheater (8) is connected to the output end of the hot molten salt unit, and the salt-side outlet of the superheater (8) is connected to the salt-side inlet of the evaporator (7); the salt-side outlet of the evaporator (7) is connected to the salt-side inlet of the preheater (6); and the salt-side outlet of the preheater (6) is connected to the input end of the cold molten salt unit.

6. The coupling system for electric heating-molten salt cogeneration according to claim 5, characterized in that, The output end of the water circuit unit is connected to the heat user unit (14) after passing through the preheater (6), evaporator (7) and superheater (8) in sequence.

7. The coupling system for electric heating-molten salt cogeneration according to claim 6, characterized in that, A steam supply regulating valve (9) is provided between the output end of the water circuit unit and the heat user unit (14).

8. A scheduling method for an electrically heated-molten salt cogeneration coupled system, based on the electrically heated-molten salt cogeneration coupled system according to any one of claims 1-7, characterized in that, include: During the molten salt heat storage process, the generator (16) adjusts the power generation of the transformer (1) and the relay (2) to use the cold and hot molten salt cogeneration cycle system as the source of electricity for heating the molten salt and carry out the molten salt circulation work; the output end of the water circuit unit is supplied to the heat user unit (14) through the cold and hot molten salt cogeneration cycle system, and the water supply corresponding to this part of the steam supply is supplied to the condenser to complete the water circulation of the entire electric heating-molten salt cogeneration coupling system. At the same time, the heating extraction steam in the steam turbine (15) is supplied to the heat user unit (14).

9. The scheduling method for a coupled system of electric heating-molten salt cogeneration according to claim 8, characterized in that, The specific process of the hot and cold molten salt cogeneration cycle system, which uses electricity to heat molten salt and circulate it, is as follows: Cold molten salt is stored in a cold salt storage tank (5). After being driven by a cold salt drive pump (4) and flowing through the outlet regulating valve (3) of the cold salt storage tank, it is sent to an electric heater (13) to be heated into hot molten salt and finally stored in a hot salt storage tank (12). During the molten salt heat release process, the hot salt is initially stored in the hot salt storage tank (12). After being driven by a hot salt drive pump (11) and flowing through the outlet regulating valve (11) of the hot salt storage tank, it releases heat in the superheater (8), evaporator (7) and preheater (6) in sequence, and finally becomes cold salt and returns to the cold salt storage tank (5), completing the molten salt cycle of the entire electric heating-molten salt cogeneration coupling system.

10. The scheduling method for an electrically heated-molten salt cogeneration coupled system according to claim 8, characterized in that, The specific process of adjusting the power generation of the transformer (1) and the relay (2) is as follows: When the electricity spot market price is low, a portion of the electricity generated by the generator (16) is dispatched to the electric heater (13) through the transformer (1) and relay (2) to heat the cold molten salt from the cold salt storage tank (5), so that it becomes hot molten salt and is stored in the hot salt storage tank (12). The whole process causes the electricity generated by the cogeneration unit to be input into the grid to decrease rapidly. When the spot electricity market has a high electricity price, the hot molten salt stored in the hot salt storage tank (12) is quickly driven by the hot salt drive pump (11) and then passes through the hot salt storage tank outlet regulating valve (11) to release heat in the superheater (8), evaporator (7) and preheater (6) in sequence. The water from the self-feed water pump outlet is heated into high-temperature steam and then supplied to the heat user unit (14). This reduces the extraction of steam from the steam turbine for heating, so that more steam can do work in the steam turbine and drive the generator (16) to generate electricity, thus rapidly increasing the steam turbine power generation.

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