Unit steam extraction industrial steam supply system coupled with high-temperature heat pump and fused salt heat storage and operation method

Abstract

The invention discloses a unit steam extraction industrial steam supply system coupling a high-temperature heat pump and fused salt heat storage and an operation method, and the unit steam extraction industrial steam supply system comprises a steam supply subsystem which is used for controlling steam extraction and steam supply of a unit. The high-temperature heat pump subsystem utilizes unit extraction steam as a heat source, converts electric energy into heat energy, can participate in deep peak regulation of a unit, consumes electric power and improves heat quality at the same time. And the fused salt heat storage subsystem is used for storing high-grade heat generated by the high-temperature heat pump subsystem. And the steam generation subsystem is used for storing steam extraction condensate water and preparing high-temperature steam by utilizing the heat stored by the molten salt subsystem. Flexible adjustment of unit steam extraction and supply is achieved, the industrial steam requirement is met, low-grade extraction steam can be used as a heat source, the influence on unit output can be reduced, unit steam supplementing output increasing and unit load increasing speed increasing can be achieved, redundant power generation can be consumed through the high-temperature heat pump, and the unit load reducing speed can be increased; therefore, flexible adjustment of unit output is realized.

Description

Technical Field

[0001] This invention relates to a unit steam extraction system for industrial steam supply coupled with a high-temperature heat pump and molten salt thermal storage, and its operation method, belonging to the fields of energy conversion and storage, industrial heating and power grid peak shaving technology. Background Technology

[0002] Traditional extraction steam supply technology relies on direct matching of extraction parameters with industrial demand. When parameters do not match, forced adjustments (such as temperature and pressure reduction) or restrictions on extraction volume are required, leading to fluctuations in unit output and loss of thermal efficiency. Furthermore, simple thermal storage peak shaving, due to its low thermal storage temperature and lack of steam replenishment capability, can only passively adjust the extraction volume, making it difficult to balance heating and power generation demands.

[0003] Existing peak shaving technologies rely on a single method (such as extraction steam pressure regulation and electric boiler thermal storage), lacking a two-way regulation mechanism of "using electricity to generate heat and store heat - using heat to supplement steam and increase power". Furthermore, heat pumps are limited by the temperature resistance of the working fluid, and the thermal storage system is disconnected from the unit's extraction steam, making it impossible to achieve deep peak shaving or efficiently absorb excess electricity, and difficult to adapt to grid load fluctuations and the demand for electric and thermal synergy.

[0004] The heat pump, thermal storage, and steam extraction and supply systems operate independently, failing to form a closed-loop coupling of "heat boosting - thermal storage - peak shaving". The information exchange between the systems is not smooth and the coordination is poor. It is impossible to dynamically optimize and control according to the load and heat source, resulting in low comprehensive energy utilization and lagging control, which restricts the unit's flexible operation capability and multi-energy complementarity efficiency.

[0005] In traditional technologies, when a unit reduces load, it can only do so by reducing fuel input or limiting steam extraction, which cannot quickly respond to the grid's demand for significant load reduction. When increasing load, it needs to increase fuel supply to increase steam output, but due to limitations in boiler heat storage capacity, steam parameters increase slowly, limiting the rate of load increase. At the same time, steam extraction and supply are mutually restrictive with unit output regulation. Fluctuations in steam supply directly affect the turbine's work stability, leading to frequent adjustments to fuel and steam extraction balance during load increases and decreases. This not only increases energy consumption but also makes it difficult to achieve the coordination of "stable steam supply" and "rapid peak shaving," failing to meet the grid's high requirements for flexible unit response. Summary of the Invention

[0006] This invention provides a unit steam extraction system and operation method for supplying industrial steam by coupling a high-temperature heat pump and molten salt thermal storage, which solves the problems disclosed in the background art.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A unit steam extraction and industrial steam supply system coupled with a high-temperature heat pump and molten salt thermal storage includes: a steam supply subsystem, a high-temperature heat pump subsystem, a molten salt thermal storage subsystem, and a steam generation subsystem; The steam supply subsystem is used to control the extraction and supply of steam for the unit. The high-temperature heat pump subsystem is used to utilize the steam extracted from the unit as a heat source to convert electrical energy into heat energy and generate high-grade heat. The molten salt thermal storage subsystem is used to store high-grade heat generated by the high-temperature heat pump subsystem. The steam generation subsystem is used to store the condensate from the extracted steam and to generate high-temperature steam using the heat stored in the molten salt subsystem.

[0008] Furthermore, the steam supply subsystem includes: a steam turbine, a first valve, a second valve, and a third valve; the inlet of the steam turbine is connected to the molten salt thermal storage subsystem, the third valve is connected to the outlet of the steam turbine, one end of the first valve is connected to the third valve, the other end is connected to the inlet of the steam turbine, one end of the second valve is connected to the pipeline between the third valve and the outlet of the steam turbine, and the other end is connected to the high-temperature heat pump subsystem.

[0009] Furthermore, the high-temperature heat pump subsystem includes a steam extraction condenser, a compressor, an expander, and a molten salt heater; the high-temperature side inlet of the steam extraction condenser is connected to a second valve, the high-temperature side outlet is connected to the steam generation subsystem, the low-temperature side inlet is connected to the outlet of the expander, and the low-temperature side outlet is connected to the inlet of the compressor; the high-temperature side inlet of the molten salt heater is connected to the outlet of the compressor, the high-temperature side outlet is connected to the inlet of the expander, and the low-temperature side inlet and outlet are respectively connected to the molten salt thermal storage subsystem.

[0010] Furthermore, the molten salt thermal storage subsystem includes: a fourth valve, a first pump, a second pump, a hot salt tank, a cold salt tank, and a fifth valve; the outlet of the cold salt tank is connected to the low-temperature side inlet of the molten salt heater via the first pump, the inlet of the cold salt tank is connected to the steam generation subsystem via the fifth valve, the inlet of the hot salt tank is connected to the low-temperature side outlet of the molten salt heater via the fourth valve, and the outlet of the hot salt tank is connected to the steam generation subsystem via the second pump.

[0011] Furthermore, the steam generation subsystem includes a sixth valve, a hot water tank, a third pump, a seventh valve, an eighth valve, and a steam generator; the water-side outlet of the steam generator is connected to the inlet of the steam turbine through the seventh valve, the molten salt-side inlet is connected to the second pump, the molten salt-side outlet is connected to the fifth valve, the inlet of the hot water tank is connected to the high-temperature side outlet of the extraction condenser through the sixth valve, the outlet is connected to the water-side inlet of the steam generator through the third pump, one end of the eighth valve is connected to the pipeline between the water-side outlet of the steam generator and the seventh valve, and the other end is connected to the first valve.

[0012] A second aspect of the present invention provides an operating method for a unit that extracts steam to supply industrial steam in conjunction with a coupled high-temperature heat pump and molten salt thermal energy storage, comprising: Operating condition for low-grade steam: The third valve is open, and the first, second, fourth, fifth, sixth, seventh, and eighth valves, the first pump, the second pump, and the third pump are closed; the steam supply subsystem directly supplies the extracted steam from the unit to the user, while the high-temperature heat pump subsystem, the molten salt thermal storage subsystem, and the steam generation subsystem are shut down; the extracted steam from the unit is directly supplied to the user through the third valve.

[0013] Molten salt thermal storage operation: Second valve, fourth valve, sixth valve, and first pump are open; first valve, third valve, fifth valve, seventh valve, eighth valve, second pump, and third pump are closed. The extracted steam from the unit enters the extraction steam condenser through the second valve to release heat and condense. After condensation, it enters the hot water tank through the sixth valve and is stored. At the same time, the high-temperature heat pump working fluid at the expander outlet enters the extraction steam condenser to absorb heat and evaporate. After evaporation, it enters the compressor to be compressed and heated. After being heated and pressurized, it enters the molten salt heater to release heat and cool down. After being expanded in the expander, it expands, does work, and depressurizes. This cycle repeats continuously. The low-temperature molten salt in the cold salt tank, driven by the first pump, enters the molten salt heater to absorb heat and heat up. After being heated, it enters the hot salt tank through the fourth valve for storage.

[0014] High-grade steam supply operation: First valve, fifth valve, eighth valve, second pump, and third pump are open; second valve, third valve, fourth valve, sixth valve, seventh valve, and first pump are closed. The high-temperature molten salt stored in the hot salt tank enters the steam generator under the drive of the second pump, releases heat, and then returns to the cold salt tank through the fifth valve. At the same time, the hot water stored in the hot water tank enters the steam generator under the drive of the third pump, absorbs heat, and becomes high-temperature steam, which is then supplied to the user through the eighth valve and the first valve in sequence.

[0015] Furthermore, when the thermal power unit generates excess power, the second valve, the fourth valve, the sixth valve, and the first pump are opened to start the high-temperature heat pump subsystem. While supplying high-grade steam to users, the steam is extracted to reduce the unit's output. The high-temperature heat pump consumes excess electrical energy to produce high-grade heat and store it in the molten salt thermal storage subsystem.

[0016] Furthermore, during peak electricity demand, when the power generation of the thermal power unit is insufficient, the seventh valve can be opened and the first and eighth valves closed. The steam generation subsystem generates high-temperature steam, which is then input into the unit as supplementary steam to increase the unit's output.

[0017] The beneficial effects achieved by this invention are as follows: Two-way peak shaving of electricity and heat and improvement of grid stability: Construct a two-way regulation mechanism of "electricity-heat-steam". During the off-peak period, the excess electricity is consumed by the high-temperature heat pump to convert the low-grade heat into high-grade heat storage, thereby reducing the power generation output of the unit to absorb the excess power of the grid. During the peak period, the heat released by the molten salt heat storage is used to generate high-temperature steam to supplement the steam turbine, which quickly increases the output of the unit. Deep peak shaving can be achieved without additional fuel, effectively alleviating the contradiction between "heat supply and power generation" and enhancing the flexibility and stability of the grid.

[0018] Significantly Reduces Unit Output Fluctuations and Operating Pressure: In traditional technologies, changes in steam extraction directly affect the amount of steam the turbine can produce, leading to frequent fluctuations in unit output (e.g., limited steam extraction forces a decrease in power generation). This invention utilizes a molten salt thermal storage subsystem for buffering and regulation, prioritizing the use of stored high-grade heat when steam demand changes, thus reducing reliance on real-time steam extraction from the turbine. This "thermal storage priority, extraction assistance" operating mode reduces the impact of steam extraction parameter fluctuations on unit output, significantly improving the stability and reliability of the power generation system, and is particularly suitable for scenarios with frequent changes in grid load and fluctuating industrial steam demand.

[0019] Significantly improve the unit's load change rate: During the rapid load reduction process of the unit, more steam is extracted and the electric-driven high-temperature heat pump is operated to store heat in molten salt, further improving the unit's load reduction rate; During the rapid load increase process of the unit, the molten salt thermal storage system generates steam, and while ensuring the industrial steam consumption, the steam returns to the unit to generate electricity, realizing the unit's rapid load increase and further improving the unit's load increase rate.

[0020] Significantly improves the thermal efficiency of molten salt thermal storage systems: Compared to traditional electric heating that directly converts electrical energy into heat (energy efficiency ratio of approximately 1:1), high-temperature heat pumps consume only a small amount of electricity to drive the working fluid circulation, absorbing a large amount of heat from low-grade heat sources (such as steam extracted from the unit) and raising it to a high temperature. Their energy efficiency ratio (COP) can significantly exceed 1 (typically reaching 3-4 or higher). This energy conversion method greatly reduces the unit thermal energy consumption of molten salt thermal storage systems, significantly improves heating efficiency, and reduces dependence on electricity. For the same amount of thermal energy stored, it can save a significant amount of electricity, providing core support for the efficient operation of molten salt thermal storage.

[0021] Multi-system coupling enables flexible industrial steam supply and multi-energy complementarity: By switching the operating conditions of four subsystems—steam supply, heat pump, thermal storage, and steam generation—it supports modes such as direct supply of low-grade steam, preparation of high-grade steam, and thermal storage-assisted steam power generation, meeting the needs of industrial users for steam of different grades and avoiding the energy loss of traditional desuperheating and pressure-reducing steam supply; in regional energy scenarios, it can integrate surplus renewable energy power, industrial waste heat, and unit extraction steam, and realize cross-time heat allocation through molten salt thermal storage, constructing a multi-energy complementary system, quickly responding to heat load fluctuations, and ensuring heating stability and efficiency.

[0022] Significantly improved energy utilization efficiency and system integration: Breaking away from the isolated operation mode of existing technologies, the coupling design of high-temperature heat pumps and molten salt thermal storage greatly improves the utilization rate of low-grade heat sources and thermal storage density, meeting the large-capacity thermal storage requirements for continuous industrial steam supply; multiple subsystems are deeply integrated through valves, pump sets and control logic to form a closed-loop control of "heat enhancement - storage - steam supply - peak shaving", which can automatically optimize the operation mode according to the energy supply and demand status, realize the synergistic efficiency of the whole system, and provide innovative solutions for efficient energy utilization and flexible regulation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the steam extraction system for industrial steam supply of the unit coupled with a high-temperature heat pump and molten salt thermal storage according to the present invention. Figure label: 1. Steam turbine; 2. First valve; 3. Second valve; 4. Third valve; 5. Extraction condenser; 6. Compressor; 7. Expander; 8. Molten salt heater; 9. Fourth valve; 10. First pump; 11. Third pump; 12. Hot salt tank; 13. Cold salt tank; 14. Fifth valve; 15. Sixth valve; 16. Hot water tank; 17. Third pump; 18. Seventh valve; 19. Eighth valve; 20. Steam generator. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention. Example 1

[0025] like Figure 1 As shown, this embodiment provides a unit extraction steam supply system for industrial steam that couples a high-temperature heat pump and molten salt thermal storage. It consists of four subsystems: steam supply, high-temperature heat pump, molten salt thermal storage, and steam generation. The system can flexibly adjust the unit extraction steam supply to meet industrial steam demand. It can use low-grade extraction steam as a heat source, which helps to reduce the impact on the unit output. It can also realize the supplementary steam to the unit to increase the output and improve the unit's load increase rate. The high-temperature heat pump can consume excess power generation and improve the unit's load decrease rate, thereby realizing flexible adjustment of the unit's output.

[0026] The steam supply subsystem consists of turbine 1, first valve 2, second valve 3, and third valve 4, and is used to control the extraction and supply of steam for the unit. The inlet of turbine 1 is connected to the molten salt thermal storage subsystem, the third valve 4 is connected to the outlet of turbine 1, one end of the first valve 2 is connected to the third valve 4, and the other end is connected to the inlet of turbine 1. One end of the second valve 3 is connected to the pipeline between the third valve 4 and the outlet of turbine 1, and the other end is connected to the high-temperature heat pump subsystem.

[0027] The high-temperature heat pump subsystem consists of a steam extraction condenser 5, a compressor 6, an expander 7, and a molten salt heater 8. It utilizes the unit's extracted steam as a heat source, converting electrical energy into heat energy. It can participate in deep peak shaving of the unit, absorbing electricity while improving heat quality. The high-temperature inlet of the steam extraction condenser 5 is connected to the second valve 3, and the high-temperature outlet is connected to the steam generation subsystem. The low-temperature inlet is connected to the outlet of the expander 7, and the low-temperature outlet is connected to the inlet of the compressor 6. The high-temperature inlet of the molten salt heater 8 is connected to the outlet of the compressor 6, and the high-temperature outlet is connected to the inlet of the expander 7. The low-temperature inlet and outlet are respectively connected to the molten salt thermal storage subsystem.

[0028] The molten salt thermal storage subsystem consists of a fourth valve 9, a first pump 10, a second pump 11, a hot salt tank 12, a cold salt tank 13, and a fifth valve 14. It is used to store the high-grade heat generated by the high-temperature heat pump subsystem. The outlet of the cold salt tank 13 is connected to the low-temperature inlet of the molten salt heater 8 via the first pump 10. The inlet of the cold salt tank 13 is connected to the steam generation subsystem via the fifth valve 14. The inlet of the hot salt tank 12 is connected to the low-temperature outlet of the molten salt heater 8 via the fourth valve 9. The outlet of the hot salt tank 12 is connected to the steam generation subsystem via the second pump 11.

[0029] The steam generation subsystem consists of a sixth valve 15, a hot water tank 16, a third pump 17, a seventh valve 18, an eighth valve 19, and a steam generator 20. It is used to store extraction steam condensate and to generate high-temperature steam using the heat stored in the molten salt subsystem. The water-side outlet of the steam generator 20 is connected to the inlet of the steam turbine 1 through the seventh valve 18, the molten salt-side inlet is connected to the second pump 11, and the molten salt-side outlet is connected to the fifth valve 14. The inlet of the hot water tank 16 is connected to the high-temperature side outlet of the extraction steam condenser 5 through the sixth valve 15, and the outlet is connected to the water-side inlet of the steam generator 20 through the third pump 17. One end of the eighth valve 19 is connected to the pipeline between the water-side outlet of the steam generator 20 and the seventh valve 18, and the other end is connected to the first valve 2. Example 2

[0030] This embodiment provides an operation method for a unit extracting steam to supply industrial steam, based on embodiment 1, which couples a high-temperature heat pump and molten salt thermal storage. It is divided into three operating conditions: supplying low-grade steam, molten salt thermal storage, and supplying high-grade steam.

[0031] When operating under low-grade steam conditions, and the extraction steam temperature meets the industrial steam temperature requirements, the unit directly supplies extracted steam to the user. The system operation mode is as follows: valve 4 is open, and valves 2, 3, 9, 14, 15, 18, 19, pump 10, pump 11, and pump 17 are closed. The steam supply subsystem directly supplies extracted steam to the user, while the high-temperature heat pump, molten salt thermal storage, and steam generation subsystems are shut down. Extracted steam from the unit is directly delivered to the user via valve 5.

[0032] In molten salt thermal storage operation, the high-temperature heat pump subsystem utilizes extracted steam from the generator unit as a low-temperature heat source, consuming excess power generated by the unit to produce high-grade heat and store it in the molten salt thermal storage subsystem. Second valve 3, fourth valve 9, sixth valve 15, and first pump 10 are open; first valve 2, third valve 4, fifth valve 14, seventh valve 18, eighth valve 19, second pump 11, and third pump 17 are closed. The steam extraction heating subsystem provides a low-temperature heat source for the high-temperature heat pump subsystem, and the high-temperature heat generated by the high-temperature heat pump subsystem is stored in the molten salt thermal storage subsystem. Steam extracted from the unit enters the extraction condenser 5 through the second valve 3, releases heat, and condenses. Then, it enters the hot water tank 16 through the sixth valve 15 for storage. At the same time, the high-temperature heat pump working fluid from the outlet of the expander 7 enters the extraction condenser 5, absorbs heat, evaporates, enters the compressor 6, is compressed, heated, and pressurized, enters the molten salt heater 8 to release heat and cool down, and then enters the expander 7 to expand, do work, and reduce pressure. This cycle repeats continuously. The low-temperature molten salt in the cold salt tank 13, driven by the first pump 10, enters the molten salt heater 8 to absorb heat and heat up, and then enters the hot salt tank 12 for storage through the fourth valve 9.

[0033] In high-grade steam operation mode, the steam generation subsystem utilizes the high-grade heat stored in the molten salt thermal storage subsystem to produce high-temperature steam for users. First valve 2, fifth valve 14, eighth valve 19, second pump 11, and third pump 17 are open; second valve 3, third valve 4, fourth valve 9, sixth valve 15, seventh valve 18, and first pump 10 are closed. The steam generation subsystem produces high-temperature steam for users, and the high-temperature heat pump subsystem is in a shutdown state. The high-temperature molten salt stored in the hot salt tank 12, driven by the second pump 11, enters the steam generator 20, releases heat, and then returns to the cold salt tank 13 via the fifth valve 14. Simultaneously, the hot water stored in the hot water tank 16, driven by the third pump 17, enters the steam generator 20, absorbs heat, and becomes high-temperature steam, which is then supplied to users sequentially via the eighth valve 19 and the first valve 2.

[0034] Based on the above-mentioned high-grade steam supply operation, during off-peak electricity demand, i.e. when the thermal power unit generates excess power, the second valve 3, the fourth valve 9, the sixth valve 15, and the first pump 10 can be opened to start the high-temperature heat pump subsystem. While supplying high-grade steam to users, steam is extracted to reduce the unit output. The high-temperature heat pump consumes excess electrical energy to produce high-grade heat and store it in the molten salt thermal storage subsystem.

[0035] Based on the above-mentioned high-grade steam supply operation, during peak electricity demand, when the power generation of the thermal power unit is insufficient, the seventh valve 18 can be opened and the first valve 2 and the eighth valve 19 can be closed. The steam generation subsystem generates high-temperature steam and inputs it into the unit as supplementary steam to increase the unit's output.

[0036] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

[0037] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A unit steam extraction system for supplying industrial steam by coupling a high-temperature heat pump and molten salt thermal energy storage, characterized in that, include: Steam supply subsystem, high-temperature heat pump subsystem, molten salt thermal storage subsystem, and steam generation subsystem; The steam supply subsystem is used to control the extraction and supply of steam for the unit. The high-temperature heat pump subsystem is used to utilize the steam extracted from the unit as a heat source to convert electrical energy into heat energy and generate high-grade heat. The molten salt thermal storage subsystem is used to store high-grade heat generated by the high-temperature heat pump subsystem. The steam generation subsystem is used to store the condensate from the extracted steam and to generate high-temperature steam using the heat stored in the molten salt subsystem.

2. The unit extraction steam supply system for industrial steam based on the coupled high-temperature heat pump and molten salt thermal storage as described in claim 1, characterized in that, The steam supply subsystem includes: a steam turbine (1), a first valve (2), a second valve (3), and a third valve (4); the inlet of the steam turbine (1) is connected to the molten salt thermal storage subsystem, the third valve (4) is connected to the outlet of the steam turbine (1), one end of the first valve (2) is connected to the third valve (4), and the other end is connected to the inlet of the steam turbine (1), one end of the second valve (3) is connected to the pipeline between the third valve (4) and the outlet of the steam turbine (1), and the other end is connected to the high-temperature heat pump subsystem.

3. The unit extraction steam supply system for industrial steam based on the coupled high-temperature heat pump and molten salt thermal storage as described in claim 2, characterized in that, The high-temperature heat pump subsystem includes a steam extraction condenser (5), a compressor (6), an expander (7), and a molten salt heater (8). The high-temperature side inlet of the steam extraction condenser (5) is connected to the second valve (3), the high-temperature side outlet is connected to the steam generation subsystem, the low-temperature side inlet is connected to the outlet of the expander (7), and the low-temperature side outlet is connected to the inlet of the compressor (6). The high-temperature side inlet of the molten salt heater (8) is connected to the outlet of the compressor (6), the high-temperature side outlet is connected to the inlet of the expander (7), and the low-temperature side inlet and outlet are respectively connected to the molten salt heat storage subsystem.

4. The unit extraction steam supply system for industrial steam based on the coupled high-temperature heat pump and molten salt thermal storage as described in claim 3, characterized in that, The molten salt thermal storage subsystem includes: a fourth valve (9), a first pump (10), a second pump (11), a hot salt tank (12), a cold salt tank (13), and a fifth valve (14); the outlet of the cold salt tank (13) is connected to the low-temperature side inlet of the molten salt heater (8) through the first pump (10), the inlet of the cold salt tank (13) is connected to the steam generation subsystem through the fifth valve (14), the inlet of the hot salt tank (12) is connected to the low-temperature side outlet of the molten salt heater (8) through the fourth valve (9), and the outlet of the hot salt tank (12) is connected to the steam generation subsystem through the second pump (11).

5. The unit extraction steam supply system for industrial steam based on the coupled high-temperature heat pump and molten salt thermal storage as described in claim 4, characterized in that, The steam generation subsystem includes a sixth valve (15), a hot water tank (16), a third pump (17), a seventh valve (18), an eighth valve (19), and a steam generator (20). The water-side outlet of the steam generator (20) is connected to the inlet of the steam turbine (1) through the seventh valve (18), the molten salt-side inlet is connected to the second pump (11), and the molten salt-side outlet is connected to the fifth valve (14). The inlet of the hot water tank (16) is connected to the high-temperature outlet of the extraction condenser (5) through the sixth valve (15), and the outlet is connected to the water-side inlet of the steam generator (20) through the third pump (17). One end of the eighth valve (19) is connected to the pipeline between the water-side outlet of the steam generator (20) and the seventh valve (18), and the other end is connected to the first valve (2).

6. The operating method of the unit extraction steam supply industrial steam system coupled with a high-temperature heat pump and molten salt thermal storage as described in claim 4, characterized in that: The third valve (4) is open, and the first valve (2), second valve (3), fourth valve (9), fifth valve (14), sixth valve (15), seventh valve (18), eighth valve (19), first pump (10), second pump (11), and third pump (17) are closed; the steam supply subsystem directly supplies the unit's extracted steam to the user, and the high-temperature heat pump subsystem, molten salt thermal storage subsystem, and steam generation subsystem are in a shutdown state; the unit's extracted steam is directly supplied to the user through the third valve (5).

7. The operating method of the unit extraction steam supply industrial steam system coupled with a high-temperature heat pump and molten salt thermal storage as described in claim 4, characterized in that: The second valve (3), the fourth valve (9), the sixth valve (15), and the first pump (10) are opened, while the first valve (2), the third valve (4), the fifth valve (14), the seventh valve (18), the eighth valve (19), the second pump (11), and the third pump (17) are closed. The unit's extracted steam enters the extraction steam condenser (5) through the second valve (3), releases heat and condenses, and then enters the hot water tank (16) through the sixth valve (15) for storage. At the same time, the high-temperature heat pump working fluid at the outlet of the expander (7) enters the extraction steam condenser (5), absorbs heat and evaporates, and then enters the compressor (6) to be compressed, heated and pressurized. After entering the molten salt heater (8) to release heat and cool down, it enters the expander (7) to expand, do work and reduce pressure. This cycle repeats. The low-temperature molten salt in the cold salt tank (13) enters the molten salt heater (8) under the drive of the first pump (10), absorbs heat and heats up, and then enters the hot salt tank (12) through the fourth valve (9) for storage.

8. The operating method of the unit extraction steam supply industrial steam system coupled with a high-temperature heat pump and molten salt thermal storage as described in claim 7, characterized in that: The first valve (2), the fifth valve (14), the eighth valve (19), the second pump (11), and the third pump (17) are opened, while the second valve (3), the third valve (4), the fourth valve (9), the sixth valve (15), the seventh valve (18), and the first pump (10) are closed. The high-temperature molten salt stored in the hot salt tank (12) enters the steam generator (20) under the drive of the second pump (11) and releases heat. Then, it returns to the cold salt tank (13) through the fifth valve (14). At the same time, the hot water stored in the hot water tank (16) enters the steam generator (20) under the drive of the third pump (17), absorbs heat and heats up to become high-temperature steam. Then, it passes through the eighth valve (19) and the first valve (2) in sequence to supply the user.

9. The operating method of the unit extraction steam supply industrial steam system coupled with a high-temperature heat pump and molten salt thermal storage as described in claim 8, characterized in that: When the thermal power unit generates excess power, the second valve (3), the fourth valve (9), the sixth valve (15), and the first pump (10) are opened to start the high-temperature heat pump subsystem. While supplying high-grade steam to users, the steam is extracted to reduce the unit output. The high-temperature heat pump consumes excess electrical energy to produce high-grade heat and store it in the molten salt heat storage subsystem.

10. The operating method of the unit extraction steam supply industrial steam system coupled with a high-temperature heat pump and molten salt thermal storage as described in claim 8, characterized in that: During peak electricity demand, when the power generation of the thermal power unit is insufficient, the seventh valve (18) is opened and the first valve (2) and the eighth valve (19) are closed. The steam generation subsystem generates high-temperature steam, which is then input into the unit as supplementary steam to increase the unit's output.

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