A coupling molten salt heat storage thermal power unit integrated system
By introducing a molten salt thermal storage system into thermal power units, the problem of insufficient peak-shaving capacity in traditional coal-fired power plants has been solved, enabling flexible adjustment and efficient power generation peak shaving, reducing coal consumption, and making it suitable for upgrading and retrofitting traditional coal-fired power plants.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAN THERMAL POWER RES INST CO LTD
- Filing Date
- 2026-03-23
- Publication Date
- 2026-06-26
AI Technical Summary
Traditional coal-fired power plants struggle to meet the demands for flexible regulation, especially during peak shaving, and are unable to effectively cope with the randomness and volatility of renewable energy generation, resulting in insufficient peak shaving capacity of thermal power units.
The integrated system of thermal power units with coupled molten salt thermal storage transfers the heat of boiler steam to molten salt and stores it in molten salt tanks through a steam molten salt heat exchanger, reducing the amount of steam delivered to the turbine unit. The molten salt thermal storage system is used to regulate the steam flow to achieve flexible peak shaving, and the boiler feedwater temperature is increased through a feedwater molten salt heat exchanger, thereby reducing coal consumption.
It improves the operational flexibility of thermal power units during peak shaving, enhances the ability to respond quickly to load changes, reduces power generation and coal consumption, and facilitates the upgrading and transformation of coal-fired power systems without replacing existing infrastructure.
Smart Images
Figure CN122280668A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of power generation system technology, specifically relating to an integrated system for thermal power units coupled with molten salt thermal storage. Background Technology
[0002] As my country's energy supply system continues to adjust and optimize, non-fossil energy power generation has entered a period of rapid development. The installed capacity of thermal power units is decreasing year by year, while the installed capacity of hydropower, wind power, and solar power is growing rapidly. However, my country's inherent energy structure of "abundant coal, scarce oil, and limited gas" cannot be changed, and most non-fossil energy generating units have limitations such as randomness, volatility, and grid connection instability. Therefore, the consumption of non-fossil energy will inevitably be a gradual process, and coal-fired power units will remain the mainstay of my country's electricity market. Statistics show that by the end of 2023, the installed capacity of thermal power units accounted for 48% of my country's total power generation, and their electricity generation accounted for 66% of the country's total electricity generation. This demonstrates that although renewable energy generation is playing an increasingly important role in my country's power generation structure, thermal power remains the main power source, playing a crucial supporting role in the steady development of my country's power system.
[0003] However, with the increase in renewable energy generation, the long-term, high-load demand that thermal power needs to bear in my country's energy structure is gradually weakening. This means that thermal power is gradually transforming from a primary power source to a supporting and regulating power source; that is, thermal power needs to undertake the task of peak shaving and even deep peak shaving for a long time. But traditional coal-fired power plants are obviously unable to meet the needs of flexible regulation. Therefore, a new integrated system that can improve the peak shaving flexibility of coal-fired power plants is being developed. Summary of the Invention
[0004] The embodiments of the present invention aim to at least solve one of the technical problems existing in the prior art, and provide an integrated system for thermal power units coupled with molten salt thermal storage.
[0005] This invention provides an integrated system for thermal power units coupled with molten salt thermal storage, comprising: A power generation system, comprising: a boiler, a steam turbine unit, and a generator, wherein the steam outlet of the boiler is connected to the steam inlet of the steam turbine unit, and the steam turbine unit is connected to the generator; A thermal energy storage subsystem includes: a steam molten salt heat exchanger, a molten salt hot tank, a molten salt cold tank, and a feedwater molten salt heat exchanger. The hot-side inlet of the steam molten salt heat exchanger is connected to the steam outlet of the boiler, the hot-side outlet of the steam molten salt heat exchanger is connected to the hot-side inlet of the feedwater molten salt heat exchanger, the molten salt cold tank is connected to the cold-side inlet of the steam molten salt heat exchanger, the molten salt hot tank is connected to the cold-side outlet of the steam molten salt heat exchanger, the steam extraction port of the turbine unit is connected to the cold-side inlet of the feedwater molten salt heat exchanger, and the return water port of the boiler is connected to the cold-side outlet of the feedwater molten salt heat exchanger.
[0006] In some embodiments of the present invention, the steam outlet of the boiler is connected to the steam molten salt heat exchanger via a molten salt steam pipeline, and the molten salt steam pipeline is equipped with a steam flow regulating valve.
[0007] In some embodiments of the present invention, the turbine unit includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder. The high-pressure cylinder, the intermediate-pressure cylinder, and the low-pressure cylinder are all coaxially connected to the generator. The steam outlet of the boiler is connected to the steam inlet of the high-pressure cylinder through a main steam pipeline. The reheat steam outlet of the boiler is connected to the steam inlet of the intermediate-pressure cylinder. The steam outlet of the intermediate-pressure cylinder is connected to the steam inlet of the low-pressure cylinder. The extraction ports of the high-pressure cylinder, the intermediate-pressure cylinder, and the low-pressure cylinder are respectively connected to the return water port of the boiler through the feedwater molten salt heat exchanger.
[0008] In some embodiments of the present invention, the power generation system includes a first high-pressure heater, a second high-pressure heater, and a deaerator. The first extraction port of the high-pressure cylinder is connected to the first high-pressure heater, the second extraction port of the high-pressure cylinder is connected to the second high-pressure heater, the condensate outlet of the first high-pressure heater is connected to the condensate inlet of the second high-pressure heater, the condensate outlet of the second high-pressure heater is connected to the condensate inlet of the feedwater molten salt heat exchanger, the condensate outlet of the feedwater molten salt heat exchanger is connected to the inlet of the deaerator, and the outlet of the deaerator is connected to the return water port of the boiler through a first return water pipeline. The first return water pipeline flows sequentially through the feedwater molten salt heat exchanger, the second high-pressure heater, and the first high-pressure heater.
[0009] In some embodiments of the present invention, the power generation system includes a third high-pressure heater, the first extraction port of the intermediate-pressure cylinder is connected to the third high-pressure heater, the condensate outlet of the feedwater molten salt heat exchanger is connected to the condensate inlet of the third high-pressure heater, the condensate outlet of the third high-pressure heater is connected to the inlet of the deaerator, and the first return water pipeline flows sequentially through the third high-pressure heater, the feedwater molten salt heat exchanger, the second high-pressure heater and the first high-pressure heater.
[0010] In some embodiments of the present invention, the second extraction port of the high-pressure cylinder is connected to the reheat steam inlet of the boiler.
[0011] In some embodiments of the present invention, the second extraction port of the intermediate pressure cylinder is connected to the inlet of the deaerator.
[0012] In some embodiments of the present invention, the power generation system further includes a water supply pump, which is located in the first return water pipeline and between the deaerator and the third high-pressure heater.
[0013] In some embodiments of the present invention, the power generation system includes a first low-pressure heater, a second low-pressure heater, a third low-pressure heater, a fourth low-pressure heater, and a condenser. The extraction port of the low-pressure cylinder is connected to the first low-pressure heater, the second low-pressure heater, the third low-pressure heater, the fourth low-pressure heater, and the condenser, respectively. The condensate outlet of the first low-pressure heater is connected to the condensate inlet of the second low-pressure heater, the condensate outlet of the second low-pressure heater is connected to the condensate inlet of the third low-pressure heater, the condensate outlet of the third low-pressure heater is connected to the condensate inlet of the fourth low-pressure heater, and the condensate outlet of the fourth low-pressure heater is connected to the condensate inlet of the condenser. The outlet of the condenser is connected to the inlet of the deaerator through a second return water pipeline, which flows sequentially through the fourth low-pressure heater, the third low-pressure heater, the second low-pressure heater, and the first low-pressure heater.
[0014] In some embodiments of the present invention, the power generation system includes a condensate pump located in the second return water line and between the condenser and the fourth low-pressure heater.
[0015] The integrated system for coupled molten salt thermal energy storage of the present invention includes a power generation system and a thermal energy storage subsystem. Specifically, the thermal energy storage subsystem includes a steam molten salt heat exchanger, a molten salt hot tank, a molten salt cold tank, and a feedwater molten salt heat exchanger. Part of the steam supplied by the boiler enters the steam molten salt heat exchanger through the hot side inlet. The steam releases heat to the molten salt on the cold side in the steam molten salt heat exchanger and is discharged to the feedwater molten salt heat exchanger through the hot side outlet of the steam molten salt heat exchanger. The low-temperature molten salt in the molten salt cold tank enters the steam molten salt heat exchanger through the cold side inlet. The low-temperature molten salt absorbs heat from the steam in the steam molten salt heat exchanger and is heated to a high-temperature molten salt. The high-temperature molten salt is discharged to the molten salt hot tank through the cold side outlet of the steam molten salt heat exchanger. The higher-temperature steam discharged from the steam molten salt heat exchanger to the feedwater molten salt heat exchanger releases heat within the feedwater molten salt heat exchanger. The lower-temperature steam output from the turbine unit enters the feedwater molten salt heat exchanger through its cold-side inlet, absorbs heat from the higher-temperature steam on the hot side, and is then discharged to the boiler's return water outlet through the cold-side outlet. The steam molten salt heat exchanger transfers some of the boiler steam's heat to the molten salt and stores it in the molten salt heat tank, reducing the amount of steam delivered from the boiler to the turbine unit, thereby reducing the power generation of the power generation system and achieving peak shaving. Simultaneously, the steam molten salt heat exchanger transfers steam with a certain amount of remaining heat to the feedwater molten salt heat exchanger to heat the steam output from the turbine unit, increasing the temperature of the steam entering the boiler's return water outlet and reducing the boiler's coal consumption. Furthermore, this system utilizes a traditional coal-fired boiler as a heat source, eliminating the need to replace existing infrastructure, facilitating the upgrading and transformation of coal-fired power systems, and demonstrating strong feasibility for the transformation to new integrated thermal power systems. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the integrated system of thermal power unit with coupled molten salt thermal storage according to the present invention.
[0017] Figure label: 1. Boiler; 2. High-pressure cylinder; 3. Intermediate-pressure cylinder; 4. Low-pressure cylinder; 5. Generator; 6. First high-pressure heater; 7. Second high-pressure heater; 8. Feedwater molten salt heat exchanger; 9. Third high-pressure heater; 10. Deaerator; 11. Feedwater pump; 12. First low-pressure heater; 13. Second low-pressure heater; 14. Third low-pressure heater; 15. Fourth low-pressure heater; 16. Condensate pump; 17. Condenser; 18. Steam flow regulating valve; 19. Steam molten salt heat exchanger; 20. Molten salt hot tank; 21. Molten salt cold tank. Detailed Implementation
[0018] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the disclosure of the present invention. The described embodiments are some, but not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.
[0019] like Figure 1 As shown, this embodiment of the invention provides an integrated system for thermal power units coupled with molten salt thermal storage, including: a power generation system and a thermal storage subsystem; The power generation system includes: boiler 1, steam turbine unit and generator 5. The steam outlet of boiler 1 is connected to the steam inlet of steam turbine unit, and steam turbine unit is connected to generator 5. The thermal storage subsystem includes: a steam molten salt heat exchanger 19, a molten salt hot tank 20, a molten salt cold tank 21, and a feedwater molten salt heat exchanger 8. The hot-side inlet of the steam molten salt heat exchanger 19 is connected to the steam outlet of the boiler 1, the hot-side outlet of the steam molten salt heat exchanger 19 is connected to the hot-side inlet of the feedwater molten salt heat exchanger 8, the molten salt cold tank 21 is connected to the cold-side inlet of the steam molten salt heat exchanger 19, the molten salt hot tank 20 is connected to the cold-side outlet of the steam molten salt heat exchanger 19, the steam extraction port of the turbine unit is connected to the cold-side inlet of the feedwater molten salt heat exchanger 8, and the return water port of the boiler 1 is connected to the cold-side outlet of the feedwater molten salt heat exchanger 8.
[0020] The integrated system of thermal power unit coupled with molten salt thermal storage of the present invention includes a power generation system and a thermal storage subsystem. Specifically, the thermal storage subsystem includes a steam molten salt heat exchanger 19, a molten salt hot tank 20, a molten salt cold tank 21, and a feedwater molten salt heat exchanger 8. Part of the steam delivered by the boiler 1 enters the steam molten salt heat exchanger 19 through the hot side inlet. The steam releases heat to the molten salt on the cold side in the steam molten salt heat exchanger 19 and is discharged to the feedwater molten salt heat exchanger 8 through the hot side outlet of the steam molten salt heat exchanger 19. The low-temperature molten salt in the molten salt cold tank 21 enters the steam molten salt heat exchanger 19 through the cold side inlet. The low-temperature molten salt absorbs heat from the steam in the steam molten salt heat exchanger 19 and is heated to a high-temperature molten salt. The high-temperature molten salt is discharged to the molten salt hot tank 20 through the cold side outlet of the steam molten salt heat exchanger 19. The higher-temperature steam discharged from the steam molten salt heat exchanger 19 to the feedwater molten salt heat exchanger 8 releases heat in the feedwater molten salt heat exchanger 8. The lower-temperature steam output from the turbine unit enters the feedwater molten salt heat exchanger 8 through the cold side inlet. After absorbing the heat from the higher-temperature steam on the hot side, the lower-temperature steam is discharged to the return water port of the boiler 1 through the cold side outlet of the feedwater molten salt heat exchanger 8.
[0021] The steam-molten salt heat exchanger 19 transfers a portion of the heat from the steam in boiler 1 to molten salt and stores it in the molten salt heat tank 20, thereby reducing the amount of steam delivered from boiler 1 to the turbine unit and thus reducing the power generation of the power generation system, achieving peak shaving for the power generation system. Simultaneously, the steam-molten salt heat exchanger 19 delivers steam with a certain amount of remaining heat to the feedwater-molten salt heat exchanger 8 to heat the steam output from the turbine unit, increasing the temperature of the steam entering the return water inlet of boiler 1 and reducing the coal consumption of boiler 1. Furthermore, this system utilizes the traditional coal-fired boiler 1 as a heat source, eliminating the need to replace existing infrastructure, facilitating the upgrading and transformation of coal-fired power systems, and demonstrating strong feasibility for the transformation to new integrated thermal power systems.
[0022] During peak shaving, the load of the power generation system is controlled by the main steam flow. When the power demand reaches its peak, the molten salt subsystem is activated. By adjusting the molten salt flow, while ensuring the required molten salt outlet temperature, the extraction steam flow of the thermal storage section is increased, and the main steam flow is reduced, thereby enabling the thermal power unit to respond quickly and effectively to load changes. Through the storage and release of steam thermal energy, the molten salt subsystem not only improves the operational flexibility of the thermal power unit in responding to peak shaving demands but also reduces the amount of steam in the high-pressure cylinder during thermal storage, further increasing the unit's peak capacity.
[0023] In some embodiments of the present invention, the steam outlet of boiler 1 is connected to molten salt steam heat exchanger 19 via a molten salt steam pipeline, and a steam flow regulating valve 18 is provided on the molten salt steam pipeline. By controlling the steam flow rate drawn from the steam pipeline of boiler 1 through the steam flow regulating valve 18, the steam supply of the turbine unit can be precisely controlled, thereby achieving precise peak shaving.
[0024] In some embodiments of the present invention, the turbine unit includes a high-pressure cylinder 2, an intermediate-pressure cylinder 3, and a low-pressure cylinder 4. All three cylinders are coaxially connected to a generator 5. The steam outlet of the boiler 1 is connected to the steam inlet of the high-pressure cylinder 2 via a main steam pipeline. The reheat steam outlet of the boiler 1 is connected to the steam inlet of the intermediate-pressure cylinder 3. The steam outlet of the intermediate-pressure cylinder 3 is connected to the steam inlet of the low-pressure cylinder 4. The extraction ports of the high-pressure cylinder 2, intermediate-pressure cylinder 3, and low-pressure cylinder 4 are connected to the return water port of the boiler 1 via a feedwater molten salt heat exchanger 8. The boiler 1 outputs steam to the high-pressure cylinder 2 to drive the generator 5. The boiler 1 also outputs reheat steam to the intermediate-pressure cylinder 3 to drive the generator 5. The intermediate-pressure cylinder 3 outputs a portion of its steam to the low-pressure cylinder 4 to drive the generator 5.
[0025] In some embodiments of the present invention, the power generation system includes a first high-pressure heater 6, a second high-pressure heater 7, and a deaerator 10. The first extraction port of the high-pressure cylinder 2 is connected to the first high-pressure heater 6, the second extraction port of the high-pressure cylinder 2 is connected to the second high-pressure heater 7, the condensate outlet of the first high-pressure heater 6 is connected to the condensate inlet of the second high-pressure heater 7, the condensate outlet of the second high-pressure heater 7 is connected to the condensate inlet of the feedwater molten salt heat exchanger 8, the condensate outlet of the feedwater molten salt heat exchanger 8 is connected to the inlet of the deaerator 10, and the outlet of the deaerator 10 is connected to the return water port of the boiler 1 through a first return water pipeline. The first return water pipeline flows sequentially through the feedwater molten salt heat exchanger 8, the second high-pressure heater 7, and the first high-pressure heater 6. Specifically, the outlet of deaerator 10 is connected to the cold-side inlet of feedwater molten salt heat exchanger 8, the cold-side outlet of feedwater molten salt heat exchanger 8 is connected to the feedwater inlet of the second high-pressure heat exchanger, the feedwater outlet of the second high-pressure heat exchanger is connected to the feedwater inlet and outlet of the first high-pressure heat exchanger, and the feedwater outlet of the first high-pressure heat exchanger is connected to the return water outlet of boiler 1. Specifically, the feedwater output from deaerator 10 flows sequentially through the feedwater molten salt heat exchanger 8, the second high-pressure heater 7, and the first high-pressure heater 6 via the first return water pipeline, and is successively heated by the feedwater molten salt heat exchanger 8, the second high-pressure heater 7, and the first high-pressure heater 6 before finally flowing into boiler 1.
[0026] In some embodiments of the present invention, the power generation system includes a third high-pressure heater 9. The first extraction port of the intermediate-pressure cylinder 3 is connected to the third high-pressure heater 9. The condensate outlet of the feedwater molten salt heat exchanger 8 is connected to the condensate inlet of the third high-pressure heater 9. The condensate outlet of the third high-pressure heater 9 is connected to the inlet of the deaerator 10. The outlet of the deaerator 10 is connected to the return water port of the boiler 1 through a first return water pipeline. The first return water pipeline flows sequentially through the third high-pressure heater 9, the feedwater molten salt heat exchanger 8, the second high-pressure heater 7, and the first high-pressure heater 6. Specifically, the feedwater output from the deaerator 10 flows sequentially through the third high-pressure heater 9, the feedwater molten salt heat exchanger 8, the second high-pressure heater 7, and the first high-pressure heater 6 through the first return water pipeline, and is heated sequentially by the third high-pressure heater 9, the feedwater molten salt heat exchanger 8, the second high-pressure heater 7, and the first high-pressure heater 6 before finally flowing into the boiler 1.
[0027] It should be noted that in this embodiment, the pressure of the first high-pressure heater 6 is greater than the pressure of the second high-pressure heater 7, and the pressure of the second high-pressure collector 7 is greater than the pressure of the third high-pressure heater 9.
[0028] In some embodiments of the present invention, the second steam extraction port of the high-pressure cylinder 2 is connected to the reheat steam inlet of the boiler 1. The steam after work is done in the high-pressure cylinder 2 is input into the boiler 1 through the reheat steam inlet for reheat treatment, and the reheated steam after reheat treatment is output into the intermediate-pressure cylinder 3.
[0029] In some embodiments of the present invention, the second steam extraction port of the intermediate pressure cylinder 3 is connected to the inlet of the deaerator 10 so as to deaerate the steam output from the second steam extraction port of the intermediate pressure cylinder 3 through the deaerator 10.
[0030] In some embodiments of the present invention, the power generation system further includes a feedwater pump 11, which is located in the first return water pipeline and between the deaerator 10 and the third high-pressure heater 9. The feedwater pump 11 powers the feedwater output from the deaerator 10, allowing the feedwater to flow sequentially through the third high-pressure heater 9, the feedwater molten salt heat exchanger 8, the second high-pressure heater 7, and the first high-pressure heater 6, ultimately flowing into the return water inlet of the boiler 1.
[0031] In some embodiments of the present invention, the power generation system includes a first low-pressure heater 12, a second low-pressure heater 13, a third low-pressure heater 14, a fourth low-pressure heater 15, and a condenser 17. The extraction port of the low-pressure cylinder 4 is connected to the first low-pressure heater 12, the second low-pressure heater 13, the third low-pressure heater 14, the fourth low-pressure heater 15, and the condenser 17, respectively. The condensate outlet of the first low-pressure heater 12 is connected to the condensate inlet of the second low-pressure heater 13. The condensate outlet of the second low-pressure heater 13 is connected to the condensate inlet of the third low-pressure heater 14. The condensate outlet of the third low-pressure heater 14 is connected to the condensate inlet of the fourth low-pressure heater 15. The condensate outlet of the fourth low-pressure heater 15 is connected to the condensate inlet of the condenser 17. The outlet of the condenser 17 is connected to the inlet of the deaerator 10 through a second return water pipeline. The second return water pipeline flows sequentially through the fourth low-pressure heater 15, the third low-pressure heater 14, the second low-pressure heater 13, and the first low-pressure heater 12. Specifically, the feedwater output from the condenser 17 flows through the second return water pipeline sequentially through the fourth low-pressure heater 15, the third low-pressure heater 14, the second low-pressure heater 13, and the first low-pressure heater 12, and is heated sequentially by the fourth low-pressure heater 15, the third low-pressure heater 14, the second low-pressure heater 13, and the first low-pressure heater 12 before finally flowing into the deaerator 10.
[0032] It should be noted that in this embodiment, the pressure of the first low-pressure heater 12 is greater than the pressure of the second low-pressure heater 13, the pressure of the second low-pressure heater 13 is greater than the pressure of the third low-pressure heater 14, and the pressure of the third low-pressure heater 14 is greater than the pressure of the fourth low-pressure heater 15.
[0033] In some embodiments of the present invention, the power generation system includes a condensate pump 16, which is located in the second return water line between the condenser 17 and the fourth low-pressure heater 15. The condensate pump 16 powers the feedwater output from the condenser, allowing the feedwater to flow sequentially through the fourth low-pressure heater 15, the third low-pressure heater 14, the second low-pressure heater 13, and the first low-pressure heater 12, ultimately flowing into the deaerator 10.
[0034] The integrated system for thermal power units coupled with molten salt thermal storage of the present invention also has the following beneficial effects: 1. The system of this invention achieves rapid response to unit load changes by coupling a thermal storage subsystem to increase the extraction steam flow rate of the thermal storage section while reducing the main steam flow rate. Simultaneously, the extraction of steam from the thermal storage section reduces the steam flow rate in the high-pressure cylinder 2 of the turbine unit, thereby increasing the peak capacity of the power generation system.
[0035] 2. The steam stored in the steam molten salt heat exchanger 19, after exchanging heat with the molten salt, enters the feedwater molten salt heat exchanger 8 to further exchange heat with the feedwater of boiler 1, thereby heating the feedwater of boiler 1 and reducing the coal consumption of boiler 1.
[0036] 3. The system of the present invention still uses the facilities of traditional coal-fired power generation turbine units, without the need to replace the existing basic equipment, which facilitates the upgrading and transformation of coal-fired power systems. It can realize the transformation from traditional coal-fired power plants to new thermal power unit integrated systems through coupling.
[0037] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.
Claims
1. An integrated system for thermal power units coupled with molten salt thermal storage, characterized in that, include: A power generation system, comprising: a boiler, a steam turbine unit, and a generator, wherein the steam outlet of the boiler is connected to the steam inlet of the steam turbine unit, and the steam turbine unit is connected to the generator; A thermal energy storage subsystem includes: a steam molten salt heat exchanger, a molten salt hot tank, a molten salt cold tank, and a feedwater molten salt heat exchanger. The hot-side inlet of the steam molten salt heat exchanger is connected to the steam outlet of the boiler, the hot-side outlet of the steam molten salt heat exchanger is connected to the hot-side inlet of the feedwater molten salt heat exchanger, the molten salt cold tank is connected to the cold-side inlet of the steam molten salt heat exchanger, the molten salt hot tank is connected to the cold-side outlet of the steam molten salt heat exchanger, the steam extraction port of the turbine unit is connected to the cold-side inlet of the feedwater molten salt heat exchanger, and the return water port of the boiler is connected to the cold-side outlet of the feedwater molten salt heat exchanger.
2. The integrated system for thermal power units coupled with molten salt thermal storage according to claim 1, characterized in that, The steam outlet of the boiler is connected to the molten salt steam heat exchanger via a molten salt steam pipeline, and the molten salt steam pipeline is equipped with a steam flow regulating valve.
3. The integrated system for thermal power units coupled with molten salt thermal storage according to claim 1, characterized in that, The turbine unit includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder. The high-pressure cylinder, the intermediate-pressure cylinder, and the low-pressure cylinder are all coaxially connected to the generator. The steam outlet of the boiler is connected to the steam inlet of the high-pressure cylinder through a main steam pipeline. The reheat steam outlet of the boiler is connected to the steam inlet of the intermediate-pressure cylinder. The steam outlet of the intermediate-pressure cylinder is connected to the steam inlet of the low-pressure cylinder. The extraction ports of the high-pressure cylinder, the intermediate-pressure cylinder, and the low-pressure cylinder are respectively connected to the return water port of the boiler through the feedwater molten salt heat exchanger.
4. The integrated system for thermal power units coupled with molten salt thermal storage according to claim 3, characterized in that, The power generation system includes a first high-pressure heater, a second high-pressure heater, and a deaerator. The first extraction port of the high-pressure cylinder is connected to the first high-pressure heater, and the second extraction port of the high-pressure cylinder is connected to the second high-pressure heater. The condensate outlet of the first high-pressure heater is connected to the condensate inlet of the second high-pressure heater, and the condensate outlet of the second high-pressure heater is connected to the condensate inlet of the feedwater molten salt heat exchanger. The condensate outlet of the feedwater molten salt heat exchanger is connected to the inlet of the deaerator. The outlet of the deaerator is connected to the return water port of the boiler through a first return water pipeline. The first return water pipeline flows sequentially through the feedwater molten salt heat exchanger, the second high-pressure heater, and the first high-pressure heater.
5. The integrated system for thermal power units coupled with molten salt thermal storage according to claim 4, characterized in that, The power generation system includes a third high-pressure heater. The first extraction port of the intermediate-pressure cylinder is connected to the third high-pressure heater. The condensate outlet of the feedwater molten salt heat exchanger is connected to the condensate inlet of the third high-pressure heater. The condensate outlet of the third high-pressure heater is connected to the inlet of the deaerator. The first return water pipeline flows sequentially through the third high-pressure heater, the feedwater molten salt heat exchanger, the second high-pressure heater, and the first high-pressure heater.
6. The integrated system for thermal power units coupled with molten salt thermal storage according to claim 4, characterized in that, The second extraction port of the high-pressure cylinder is connected to the reheat steam inlet of the boiler.
7. The integrated system for thermal power units coupled with molten salt thermal storage according to claim 4, characterized in that, The second extraction port of the intermediate pressure cylinder is connected to the inlet of the deaerator.
8. The integrated system for thermal power units coupled with molten salt thermal storage according to claim 4, characterized in that, The power generation system also includes a water supply pump, which is located in the first return water pipeline and between the deaerator and the third high-pressure heater.
9. The integrated system for thermal power units coupled with molten salt thermal storage according to claim 4, characterized in that, The power generation system includes a first low-pressure heater, a second low-pressure heater, a third low-pressure heater, a fourth low-pressure heater, and a condenser. The extraction port of the low-pressure cylinder is connected to the first low-pressure heater, the second low-pressure heater, the third low-pressure heater, the fourth low-pressure heater, and the condenser, respectively. The condensate outlet of the first low-pressure heater is connected to the condensate inlet of the second low-pressure heater, the condensate outlet of the second low-pressure heater is connected to the condensate inlet of the third low-pressure heater, the condensate outlet of the third low-pressure heater is connected to the condensate inlet of the fourth low-pressure heater, and the condensate outlet of the fourth low-pressure heater is connected to the condensate inlet of the condenser. The outlet of the condenser is connected to the inlet of the deaerator through a second return water pipeline, which flows sequentially through the fourth low-pressure heater, the third low-pressure heater, the second low-pressure heater, and the first low-pressure heater.
10. The integrated system for thermal power units coupled with molten salt thermal storage according to claim 9, characterized in that, The power generation system includes a condensate pump, which is located in the second return water pipeline and between the condenser and the fourth low-pressure heater.