A peak shaving power generation system coupling molten salt heat storage and steam turbine supplementary steam

Abstract

The application provides a peak shaving power generation system coupling molten salt heat storage and steam turbine supplementary steam, and relates to the technical field of thermal engineering. The system comprises a low-temperature molten salt tank, a molten salt heater, a high-temperature molten salt tank, a molten salt steam-water heat exchanger, a gas boiler, a steam turbine and a feedwater system. The molten salt heater receives low-temperature molten salt pumped into the low-temperature molten salt tank by a low-temperature molten salt pump during the low electricity consumption period, and heats the low-temperature molten salt by the heat of main steam provided by the gas boiler. The high-temperature molten salt tank receives and stores the high-temperature molten salt obtained by heating. The molten salt steam-water heat exchanger receives high-temperature molten salt pumped into the high-temperature molten salt tank by a high-temperature molten salt pump during the high electricity consumption period, and transfers the heat energy of the high-temperature molten salt to high-pressure feedwater from the feedwater system to generate superheated steam. Part of the superheated steam is sent into a main steam main pipe connected with the gas boiler. The application can effectively improve the steam turbine power generation efficiency, realizes efficient utilization of heat energy and flexible adjustment of power grid load.

Description

Technical Field

[0001] This application relates to the field of thermal energy engineering technology, and in particular to a peak-shaving power generation system that couples molten salt thermal storage with steam turbine supplementation. Background Technology

[0002] Energy storage is a key supporting technology for the energy revolution and an urgent need to address the large-scale integration of renewable energy into the grid and improve the efficiency of regional energy systems. With the large-scale integration of renewable energy into the grid, energy storage technology plays a crucial role in improving the operational efficiency of regional energy systems and regulating electricity load. Currently, energy storage technology and industry have experienced rapid development.

[0003] If the characteristics of peak-valley industrial electricity pricing can be combined with peak-shaving and valley-filling modifications to utilize existing coal gas resources through "on-demand storage and release," purchasing more off-peak electricity and less peak-valley electricity, considerable economic benefits will inevitably be generated. At the same time, this will reduce the impact of power rationing on steel mill production during special periods, ensure a continuous power supply for steel mills, and significantly improve the economic efficiency of enterprises.

[0004] Existing technologies have attempted to utilize molten salt thermal energy storage systems in conjunction with thermal power units to achieve extraction steam storage for peak shaving. These systems can utilize molten salt to achieve large-capacity, high-quality thermal energy storage, improving the flexibility and economy of thermal power units under deep peak shaving conditions. However, existing technologies still have certain limitations. For example, there is a mismatch between the steam production parameters of the molten salt heat release system and the generator unit, which may lead to low heat exchange efficiency and system instability, limiting their applicability and potential for economic improvement in specific scenarios. These problems urgently need to be addressed. Utility Model Content

[0005] To address the problems in the prior art, this application provides a peak-shaving power generation system that couples molten salt thermal storage with steam turbine supplementation, which can solve the problems existing in the prior art.

[0006] In a first aspect, this application provides a peak-shaving power generation system that couples molten salt thermal storage with steam turbine supplementation, including: a molten salt thermal storage and heat exchange system and a steam-water circulation system;

[0007] The molten salt thermal storage and heat exchange system includes a low-temperature molten salt tank, a molten salt heater, a high-temperature molten salt tank, and a molten salt steam-water heat exchanger;

[0008] The steam-water circulation system includes a gas-fired boiler, a steam turbine, and a feedwater system; the steam turbine includes a high-pressure cylinder and a medium- and low-pressure cylinder.

[0009] The molten salt heater receives the low-temperature molten salt pumped into the low-temperature molten salt tank from the low-temperature molten salt tank during off-peak electricity hours, and heats the low-temperature molten salt with the heat from the main steam provided by the gas boiler;

[0010] The high-temperature molten salt tank receives and stores the high-temperature molten salt obtained by heating the molten salt heater;

[0011] During peak electricity consumption periods, the molten salt steam-water heat exchanger receives high-temperature molten salt pumped into the high-temperature molten salt tank and transfers the heat energy of the high-temperature molten salt to the high-pressure feedwater from the feedwater system to generate superheated steam; a portion of the superheated steam is fed into the main steam header connected to the gas-fired boiler.

[0012] The cryogenic molten salt tank receives and stores the cryogenic molten salt obtained from the molten salt steam-water heat exchanger.

[0013] Furthermore, another portion of the superheated steam is fed into the intermediate stage of the high-pressure cylinder and the intermediate stage of the medium-low pressure cylinder.

[0014] Furthermore, it also includes: a primary desuperheating and pressure reducing device and a secondary desuperheating and pressure reducing device;

[0015] The first-stage desuperheating and pressure reducing device is connected to the molten salt steam-water heat exchanger and the high-pressure cylinder. After desuperheating and pressure reducing the superheated steam from the molten salt steam-water heat exchanger once, a portion of the superheated steam after desuperheating and pressure reducing is sent to the intermediate stage of the high-pressure cylinder.

[0016] The secondary desuperheater is connected to the primary desuperheater and the intermediate-low pressure cylinder. It performs a secondary desuperheater and pressure reduction on another part of the superheated steam after the primary desuperheater and pressure reduction, and then sends it into the intermediate stage of the intermediate-low pressure cylinder.

[0017] Furthermore, the water supply system includes: a low-pressure heater and a high-pressure heater;

[0018] The low-pressure heater uses the heat from the steam extracted from the medium-low pressure cylinder to heat the condensate, and then delivers the resulting preheated water to the high-pressure heater; the condensate is obtained by condensing the exhaust gas from the medium-low pressure cylinder.

[0019] The high-pressure heater uses the heat from the steam extracted by the high-pressure cylinder to further heat the preheated water, and delivers the resulting high-pressure feedwater to the gas boiler and the molten salt steam-water heat exchanger.

[0020] Furthermore, another portion of the superheated steam is fed into the high-pressure heater and the low-pressure heater as a steam heat source.

[0021] Furthermore, it also includes: a primary desuperheating and pressure reducing device and a secondary desuperheating and pressure reducing device;

[0022] The first-stage desuperheating and pressure reducing device is connected to the molten salt steam-water heat exchanger and the high-pressure heater. After desuperheating and pressure reducing the superheated steam from the molten salt steam-water heat exchanger, a portion of the superheated steam after the first desuperheating and pressure reducing is sent to the high-pressure heater.

[0023] The secondary desuperheating and pressure reducing device is connected to the primary desuperheating and pressure reducing device and the low-pressure heater. It performs a secondary desuperheating and pressure reducing on another part of the superheated steam after the primary desuperheating and pressure reducing, and then sends it into the low-pressure heater.

[0024] Furthermore, the water supply system also includes: a deaerator;

[0025] The deaerator uses the heat from the steam extracted from the medium and low pressure cylinders to deaerate the preheated water, and then sends the deaerated water to the high-pressure heater for further heating.

[0026] Furthermore, a steam bypass channel is provided between the molten salt steam-water heat exchanger and the gas boiler, and a flow limiting valve is provided on the steam bypass channel to limit the maximum flow rate of molten salt steam into the main steam header.

[0027] Furthermore, the maximum flow rate shall not exceed 30% of the main steam flow rate.

[0028] Furthermore, the steam-water circulation system also includes: a condenser;

[0029] The condenser condenses the exhaust gas from the medium and low pressure cylinder into condensate, and the condensate is then pumped to the water supply system via a condensate pump.

[0030] This application provides a peak-shaving power generation system coupling molten salt thermal storage and steam turbine supplementation. The system includes: a molten salt thermal storage and heat exchange system and a steam-water circulation system; the molten salt thermal storage and heat exchange system includes a low-temperature molten salt tank, a molten salt heater, a high-temperature molten salt tank, and a molten salt steam-water heat exchanger; the steam-water circulation system includes a gas-fired boiler, a steam turbine, and a feedwater system; the steam turbine includes a high-pressure cylinder and a medium- and low-pressure cylinder; the molten salt heater receives low-temperature molten salt pumped from the low-temperature molten salt tank during off-peak electricity hours and supplies steam through the gas-fired boiler. The heat from the main steam heats the low-temperature molten salt; the high-temperature molten salt tank receives and stores the high-temperature molten salt heated by the molten salt heater; the molten salt steam-water heat exchanger receives the high-temperature molten salt pumped from the high-temperature molten salt tank during peak electricity consumption periods and transfers the heat energy of the high-temperature molten salt to the high-pressure feedwater from the feedwater system to generate superheated steam; a portion of the superheated steam is sent to the main steam header connected to the gas-fired boiler; the low-temperature molten salt tank receives and stores the low-temperature molten salt obtained from the heat exchange in the molten salt steam-water heat exchanger. The peak-shaving power generation system coupled with molten salt thermal storage and turbine steam replenishment provided in this application effectively improves turbine power generation efficiency, reduces dependence on extracted steam, and achieves efficient utilization of thermal energy and flexible adjustment of grid load.

[0031] Among these measures, the system utilizes coal gas thermal energy storage during off-peak hours to adapt to industrial electricity price differences and achieve economic peak shaving; during peak hours, it supplements steam by producing steam from molten salt or connects steam to the turbine to increase power generation; it uses a desuperheater and pressure reducer to precisely regulate steam to the intermediate cylinder section to ensure stable turbine operation; it adopts a strategy of limiting the proportion of parallel steam flow to the main pipe to control the range of thermal disturbance in the main pipe; and it uses molten salt steam to replace extraction steam for feedwater heating, reducing extraction steam loss and improving work capacity. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the structure of a molten salt thermal storage and heat exchange system provided in one embodiment of this application;

[0034] Figure 2 This is a partial structural schematic diagram of a peak-shaving power generation system that couples molten salt thermal storage with steam turbine supplementation, provided in one embodiment of this application.

[0035] Figure 3 This is a partial structural schematic diagram of a peak-shaving power generation system that couples molten salt thermal storage with steam turbine supplementation, provided in one embodiment of this application.

[0036] Figure 4 This is a schematic diagram of the structure of a peak-shaving power generation system that couples molten salt thermal storage with steam turbine supplementation, provided in one embodiment of this application. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments and their descriptions are used to explain this application, but are not intended to limit this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0038] The peak-shaving power generation system coupled with molten salt thermal storage and steam turbine supplementation provided in this application includes: a molten salt thermal storage and heat exchange system and a steam-water circulation system; the steam-water circulation system includes a gas-fired boiler, a steam turbine, and a feedwater system; the steam turbine includes a high-pressure cylinder and a medium- and low-pressure cylinder;

[0039] Figure 1 This is a schematic diagram of the structure of a molten salt thermal storage and heat exchange system provided in one embodiment of this application, as shown below. Figure 1As shown, the molten salt thermal storage and heat exchange system includes a low-temperature molten salt tank 8, a molten salt heater 10, a high-temperature molten salt tank 9, and a molten salt steam-water heat exchanger 11;

[0040] The molten salt heater 10 receives the low-temperature molten salt fed into the low-temperature molten salt tank 8 by the low-temperature molten salt pump 12 during off-peak electricity hours, and heats the low-temperature molten salt with the heat of the main steam provided by the gas boiler;

[0041] The high-temperature molten salt tank 9 receives and stores the high-temperature molten salt obtained by the molten salt heater 10;

[0042] During peak electricity consumption periods, the molten salt steam-water heat exchanger 11 receives high-temperature molten salt from the high-temperature molten salt tank 9 via the high-temperature molten salt pump 13, and transfers the heat energy of the high-temperature molten salt to the high-pressure feedwater from the feedwater system to generate superheated steam; a portion of the superheated steam (molten salt exothermic steam generation 2) is sent to the main steam header connected to the gas-fired boiler.

[0043] The cryogenic molten salt tank 8 receives and stores the cryogenic molten salt obtained by the molten salt steam-water heat exchanger 11.

[0044] Specifically, during off-peak electricity hours, the molten salt in the low-temperature molten salt tank 8 is pumped into the molten salt heater 10 via the low-temperature molten salt pump 12. The low-temperature molten salt is heated by the heat from the main steam provided by the gas-fired boiler. The heated high-temperature molten salt is then stored in the high-temperature molten salt tank 9, completing the heat storage process. During peak electricity hours, the high-temperature molten salt in the high-temperature molten salt tank 9 is pumped into the molten salt steam-water heat exchanger 11 via the high-temperature molten salt pump 13. After exchanging heat with the boiler feedwater 3 and cooling down, the low-temperature molten salt is stored in the low-temperature molten salt tank 8. Simultaneously, molten salt releases heat to produce steam 2, completing the heat release process.

[0045] During off-peak electricity demand periods, the steam-water circulation system operates as a conventional steam turbine generator set. During peak electricity demand periods, a portion of the steam generated by the molten salt heat release is fed into the main steam header connected to the gas-fired boiler, increasing the flow of new steam for turbine power generation.

[0046] In one embodiment, another portion of the superheated steam is fed into the intermediate stage of the high-pressure cylinder 4 and the intermediate stage of the medium-low pressure cylinder 5.

[0047] Specifically, another portion of the molten salt exothermic steam 2 flows into the intermediate stage of the high-pressure cylinder 4 and the intermediate stage of the medium-low pressure cylinder 5 of the steam turbine, serving as supplementary steam for the steam turbine and increasing the power generation of the steam turbine generator set during peak electricity consumption periods.

[0048] Figure 2 This is a partial structural schematic diagram of a peak-shaving power generation system that couples molten salt thermal storage with turbine steam replenishment, provided in one embodiment of this application. Figure 2As shown, the peak-shaving power generation system with coupled molten salt thermal storage and turbine steam replenishment provided in this application also includes: a primary desuperheater and pressure reducer 6 and a secondary desuperheater and pressure reducer 7;

[0049] The first-stage desuperheating and pressure reducing device 6 is connected to the molten salt steam-water heat exchanger 11 and the high-pressure cylinder 4. After desuperheating and pressure reducing the superheated steam from the molten salt steam-water heat exchanger 11 once, a portion of the superheated steam after desuperheating and pressure reducing is sent to the intermediate stage of the high-pressure cylinder 4.

[0050] The secondary desuperheating and pressure reducing device 7 is connected to the primary desuperheating and pressure reducing device 6 and the medium-low pressure cylinder 5. It performs secondary desuperheating and pressure reducing on another part of the superheated steam after the primary desuperheating and pressure reducing, and then sends it into the intermediate stage of the medium-low pressure cylinder 5.

[0051] Specifically, after the high-pressure feedwater exchanges heat with molten salt in the molten salt steam-water heat exchanger 11, it generates superheated steam (molten salt releases heat to produce steam 2). Part of the steam flows into the main steam header of the gas-fired boiler steam generator 1, and the other part flows into the intermediate stage of the high-pressure cylinder 4 of the steam turbine after being de-heated and de-pressurized by the first-stage desuperheater and pressure reducer 6, serving as makeup steam for the high-pressure cylinder 4. After being de-heated and de-pressurized by the second-stage desuperheater and pressure reducer 7, the steam flows into the intermediate stage of the intermediate and low-pressure cylinder 5 of the steam turbine, serving as makeup steam for the intermediate and low-pressure cylinder 5.

[0052] Figure 3 This is a partial structural schematic diagram of a peak-shaving power generation system that couples molten salt thermal storage with turbine steam replenishment, provided in one embodiment of this application. Figure 3 As shown, the water supply system includes: a low-pressure heater 15 and a high-pressure heater 14;

[0053] The low-pressure heater 15 uses the heat from the steam extracted from the medium-low pressure cylinder 5 to heat the condensate, and then sends the resulting preheated water to the high-pressure heater 14; the condensate is obtained by condensing the exhaust gas from the medium-low pressure cylinder 5.

[0054] The high-pressure heater 14 uses the heat from the steam extracted by the high-pressure cylinder 4 to further heat the preheated water, and delivers the resulting high-pressure feedwater to the gas boiler and the molten salt steam-water heat exchanger 11.

[0055] In one embodiment, such as Figure 3 As shown, another portion of the superheated steam is fed into the high-pressure heater 14 and the low-pressure heater 15 as a steam heat source.

[0056] In one embodiment, such as Figure 3 As shown, the peak-shaving power generation system with coupled molten salt thermal storage and turbine steam replenishment provided in this application also includes: a primary desuperheater and pressure reducer 6 and a secondary desuperheater and pressure reducer 7;

[0057] The first-stage desuperheating and pressure reducing device 6 is connected to the molten salt steam-water heat exchanger 11 and the high-pressure heater 14. After desuperheating and pressure reducing the superheated steam from the molten salt steam-water heat exchanger 11, a portion of the superheated steam after the first desuperheating and pressure reducing is sent to the high-pressure heater 14.

[0058] The secondary desuperheating and pressure reducing device 7 is connected to the primary desuperheating and pressure reducing device 6 and the low-pressure heater 15. It performs a secondary desuperheating and pressure reducing on another part of the superheated steam after the primary desuperheating and pressure reducing, and then sends it into the low-pressure heater 15.

[0059] Specifically, the superheated steam generated by the molten salt steam-water heat exchanger 11 is partly fed into the main steam header of the boiler, and partly fed into the high-pressure cylinder 4 of the turbine after being de-cooled and de-pressurized by the first-stage desuperheater and pressure reducer 6, serving as the heating steam for the high-pressure heater 14. After being de-cooled and de-pressurized by the second-stage desuperheater and pressure reducer 7, it is fed into the intermediate and low-pressure cylinder 5 of the turbine, serving as the heating steam for the low-pressure heater 15. This reduces the amount of steam extracted from the turbine, increases the amount of steam participating in the turbine's work, and improves the turbine's power generation during peak electricity consumption periods.

[0060] In one embodiment, the superheated steam generated by the molten salt steam-water heat exchanger 11 is partially fed into the main steam header generated by the boiler, and the other part completely replaces the turbine extraction steam as the heating steam for the high-pressure heater 14 and the low-pressure heater 15.

[0061] Figure 4 This is a schematic diagram of the structure of a peak-shaving power generation system that couples molten salt thermal storage with turbine steam replenishment, as provided in one embodiment of this application. Figure 4 As shown, the water supply system also includes: a deaerator 18;

[0062] The deaerator 18 uses the heat from the steam extracted by the medium and low pressure cylinder 5 to deaerate the preheated water, and then sends the deaerated water to the high pressure heater 14 for further heating.

[0063] Specifically, the exhaust steam from the low-pressure cylinder of the steam turbine enters the condenser 16 and is condensed into condensate. The condensate is then pumped by the condensate pump 17 into the low-pressure heater 15 and the deaerator 18 in sequence. The deaerated low-pressure feedwater is then pumped by the feedwater pump 19 into the high-pressure heater 14. Part of the high-pressure feedwater heated by the high-pressure heater 14 enters the gas boiler 20, and the other part enters the molten salt steam-water heat exchanger 11 to complete the steam-water cycle.

[0064] In one embodiment, a steam bypass channel is provided between the molten salt steam-water heat exchanger 11 and the gas boiler 20. A flow-limiting valve is provided on the steam bypass channel to limit the maximum flow rate of molten salt steam into the main steam header.

[0065] In one embodiment, the maximum flow rate does not exceed 30% of the main steam flow rate.

[0066] Specifically, a high-pressure steam bypass channel that can be controlled to open and close is set before the superheated steam generated by the molten salt steam-water heat exchanger 11 flows into the main steam header connected to the gas boiler 20. This controls the flow rate of the molten salt exothermic steam 2 to be less than 30% of the steam header flow rate, ensuring that the temperature change of the steam header is less than ±5℃ after the molten salt exothermic steam 2 flows into the header.

[0067] In one embodiment, such as Figure 4 As shown, the steam-water circulation system also includes: a condenser 16;

[0068] The condenser 16 condenses the exhaust gas from the medium and low pressure cylinder 5 into condensate and then pumps the condensate to the water supply system via the condensate pump 17.

[0069] This application utilizes the heat energy generated by the combustion of coal gas during off-peak electricity periods to heat molten salt, storing the heat energy in a high-temperature molten salt storage tank. During peak electricity demand periods, this energy is released, increasing the supply of electricity or steam, which is beneficial for regional power grid load regulation, improving energy utilization efficiency, and yielding significant social benefits. Connecting the steam generated by the molten salt exothermics to the steam bus of the generator set boiler reduces the impact of mismatched steam parameters on the turbine. Simultaneously, the molten salt exothermic steam, after being de-temperatured and depressurized, is fed into the intermediate stage of the turbine or replaces turbine extraction steam, increasing turbine power generation during peak electricity periods and ensuring the matching of the molten salt exothermic steam with the turbine, making the system more efficient, stable, and reliable.

[0070] This application provides a peak-shaving power generation system coupling molten salt thermal storage and steam turbine supplementation. The system includes: a molten salt thermal storage and heat exchange system and a steam-water circulation system; the molten salt thermal storage and heat exchange system includes a low-temperature molten salt tank, a molten salt heater, a high-temperature molten salt tank, and a molten salt steam-water heat exchanger; the steam-water circulation system includes a gas-fired boiler, a steam turbine, and a feedwater system; the molten salt heater receives low-temperature molten salt pumped from the low-temperature molten salt tank during off-peak electricity hours and heats the low-temperature molten salt using heat provided by the gas-fired boiler; the high-temperature molten salt tank is connected to the molten salt heater and receives and stores the heated molten salt; the molten salt steam-water heat exchanger receives high-temperature molten salt pumped from the high-temperature molten salt tank during peak electricity hours and transfers the heat energy of the high-temperature molten salt to high-pressure feedwater from the feedwater system to generate superheated steam; a portion of the superheated steam is fed into the main steam header connected to the gas-fired boiler; the low-temperature molten salt tank is connected to the molten salt steam-water heat exchanger and receives and stores the heat-exchanged molten salt. The peak-shaving power generation system coupled with molten salt thermal storage and turbine steam injection provided in this application effectively improves the power generation efficiency of the turbine, reduces the dependence on steam extraction, and realizes efficient utilization of thermal energy and flexible adjustment of grid load.

[0071] Among these measures, the system utilizes coal gas thermal energy storage during off-peak hours to adapt to industrial electricity price differences and achieve economic peak shaving; during peak hours, it supplements steam by producing steam from molten salt or connects steam to the turbine to increase power generation; it uses a desuperheater and pressure reducer to precisely regulate steam to the intermediate cylinder section to ensure stable turbine operation; it adopts a strategy of limiting the proportion of parallel steam flow to the main pipe to control the range of thermal disturbance in the main pipe; and it uses molten salt steam to replace extraction steam for feedwater heating, reducing extraction steam loss and improving work capacity.

[0072] In the description of this specification, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0073] The terms "an embodiment," "a specific embodiment," "some embodiments," "for example," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. The order of steps involved in the various embodiments is used to illustrate the implementation of this application, and the order of steps is not limited and may be adjusted appropriately as needed.

[0074] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0075] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A peak-shaving power generation system coupling molten salt thermal storage and steam turbine supplementation, characterized in that, include: Molten salt thermal storage and heat exchange system and steam-water circulation system; The molten salt thermal storage and heat exchange system includes a low-temperature molten salt tank, a molten salt heater, a high-temperature molten salt tank, and a molten salt steam-water heat exchanger; The steam-water circulation system includes a gas-fired boiler, a steam turbine, and a feedwater system; the steam turbine includes a high-pressure cylinder and a medium- and low-pressure cylinder. The molten salt heater receives the low-temperature molten salt pumped into the low-temperature molten salt tank from the low-temperature molten salt tank during off-peak electricity hours, and heats the low-temperature molten salt with the heat from the main steam provided by the gas boiler; The high-temperature molten salt tank receives and stores the high-temperature molten salt obtained by heating the molten salt heater; During peak electricity consumption periods, the molten salt steam-water heat exchanger receives high-temperature molten salt pumped into the high-temperature molten salt tank and transfers the heat energy of the high-temperature molten salt to the high-pressure feedwater from the feedwater system to generate superheated steam; a portion of the superheated steam is fed into the main steam header connected to the gas-fired boiler. The cryogenic molten salt tank receives and stores the cryogenic molten salt obtained from the molten salt steam-water heat exchanger.

2. The peak-shaving power generation system coupled with molten salt thermal storage and turbine steam replenishment as described in claim 1, characterized in that, Another portion of the superheated steam is fed into the intermediate stage of the high-pressure cylinder and the intermediate stage of the medium-low pressure cylinder.

3. The peak-shaving power generation system coupled with molten salt thermal storage and turbine steam replenishment as described in claim 2, characterized in that, Also includes: Primary desuperheating and pressure reducing device and secondary desuperheating and pressure reducing device; The first-stage desuperheating and pressure reducing device is connected to the molten salt steam-water heat exchanger and the high-pressure cylinder. After desuperheating and pressure reducing the superheated steam from the molten salt steam-water heat exchanger once, a portion of the superheated steam after desuperheating and pressure reducing is sent to the intermediate stage of the high-pressure cylinder. The secondary desuperheater is connected to the primary desuperheater and the intermediate-low pressure cylinder. It performs a secondary desuperheater and pressure reduction on another part of the superheated steam after the primary desuperheater and pressure reduction, and then sends it into the intermediate stage of the intermediate-low pressure cylinder.

4. The peak-shaving power generation system coupled with molten salt thermal storage and turbine steam replenishment as described in claim 1, characterized in that, The water supply system includes: a low-pressure heater and a high-pressure heater; The low-pressure heater uses the heat from the steam extracted from the medium-low pressure cylinder to heat the condensate, and then delivers the resulting preheated water to the high-pressure heater; the condensate is obtained by condensing the exhaust gas from the medium-low pressure cylinder. The high-pressure heater uses the heat from the steam extracted by the high-pressure cylinder to further heat the preheated water, and delivers the resulting high-pressure feedwater to the gas boiler and the molten salt steam-water heat exchanger.

5. The peak-shaving power generation system coupled with molten salt thermal storage and turbine steam replenishment as described in claim 4, characterized in that, Another portion of the superheated steam is fed into the high-pressure heater and the low-pressure heater as a steam heat source.

6. The peak-shaving power generation system coupled with molten salt thermal storage and turbine steam replenishment as described in claim 5, characterized in that, Also includes: Primary desuperheating and pressure reducing device and secondary desuperheating and pressure reducing device; The first-stage desuperheating and pressure reducing device is connected to the molten salt steam-water heat exchanger and the high-pressure heater. After desuperheating and pressure reducing the superheated steam from the molten salt steam-water heat exchanger, a portion of the superheated steam after the first desuperheating and pressure reducing is sent to the high-pressure heater. The secondary desuperheating and pressure reducing device is connected to the primary desuperheating and pressure reducing device and the low-pressure heater. It performs a secondary desuperheating and pressure reducing on another part of the superheated steam after the primary desuperheating and pressure reducing, and then sends it into the low-pressure heater.

7. The peak-shaving power generation system coupled with molten salt thermal storage and turbine steam replenishment as described in claim 4, characterized in that, The water supply system also includes: a deaerator; The deaerator uses the heat from the steam extracted from the medium and low pressure cylinders to deaerate the preheated water, and then sends the deaerated water to the high-pressure heater for further heating.

8. The peak-shaving power generation system coupled with molten salt thermal storage and turbine steam replenishment as described in claim 1, characterized in that, A steam bypass channel is provided between the molten salt steam-water heat exchanger and the gas boiler. A flow-limiting valve is provided on the steam bypass channel to limit the maximum flow rate of molten salt steam into the main steam header.

9. The peak-shaving power generation system coupled with molten salt thermal storage and turbine steam replenishment as described in claim 8, characterized in that, The maximum flow rate shall not exceed 30% of the main steam flow rate.

10. The peak-shaving power generation system coupled with molten salt thermal storage and turbine steam replenishment according to claim 1, characterized in that, The steam-water circulation system also includes: a condenser; The condenser condenses the exhaust gas from the medium and low pressure cylinder into condensate, and the condensate is then pumped to the water supply system via a condensate pump.

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