A coal-fired power generation system coupled with steam energy storage and operation method

Abstract

The present invention provides a coal-fired power generation system coupled with steam energy storage and an operation method, which belong to the technical field of coal-fired power generation. The coal-fired power generation system coupled with steam energy storage comprises: a coal-fired power generation component, wherein the coal-fired power generation component comprises: a coal-fired boiler, a high-pressure steam turbine, a medium-pressure steam turbine, a low-pressure steam turbine, a condenser, a deaerator and a high-pressure heater which are connected and arranged; a steam energy storage component, wherein the steam energy storage component comprises: a gas storage tank; the coal-fired power generation system coupled with steam energy storage of the present invention improves the peak-shaving and frequency-regulating capabilities of the coal-fired unit.

Description

Technical Field

[0001] The present invention relates to the technical field of coal-fired power generation, and in particular to a coal-fired power generation system coupled with steam energy storage and an operation method thereof. Background Art

[0002] As the global use of renewable energy such as solar energy and wind energy increases dramatically, its volatility, intermittency and unpredictability have brought huge challenges to the stable and safe operation of the power grid.

[0003] In the existing technology, the minimum stable combustion load restricts the peak-shaving capacity of the boiler system, and the large thermal inertia inside the boiler restricts the frequency regulation capacity of the boiler system. As a result, the peak-shaving and frequency regulation capabilities of the coal-fired units cannot meet the needs of the power grid. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the peak-shaving and frequency-regulating capabilities of coal-fired units in the prior art cannot meet the needs of the power grid, thereby providing a coal-fired power generation system coupled with steam energy storage.

[0005] The present invention also provides an operation method of a coal-fired power generation system coupled with steam energy storage.

[0006] In order to solve the above technical problems, the present invention provides a coal-fired power generation system coupled with steam energy storage, comprising:

[0007] A coal-fired power generation assembly, the coal-fired power generation assembly comprising: a coal-fired boiler, a high-pressure steam turbine, a medium-pressure steam turbine, a low-pressure steam turbine, a condenser and a deaerator, a high-pressure heater and a low-pressure heater, which are connected and arranged;

[0008] The steam inlet of the high-pressure steam turbine is connected to the steam outlet of the coal-fired boiler; the steam outlet of the high-pressure steam turbine is connected to the steam inlet of the medium-pressure steam turbine through the coal-fired boiler; the first-stage steam extraction outlet of the medium-pressure steam turbine is connected to the steam inlet of the high-pressure heater; the second-stage steam outlet of the medium-pressure steam turbine is connected to the steam inlet of the deaerator;

[0009] The steam outlet of the medium-pressure steam turbine is connected to the steam outlet of the low-pressure steam turbine through a pipeline; the steam extraction outlet of the low-pressure steam turbine is connected to the low-pressure heater; the steam outlet of the low-pressure steam turbine is connected to the steam inlet of the condenser through a pipeline; the condensate outlet of the condenser is connected to the condensate inlet of the low-pressure heater through a pipeline; the condensate outlet of the low-pressure heater is connected to the condensate inlet of the deaerator through a pipeline; the feed water outlet of the deaerator is connected to the feed water inlet of the high-pressure heater through a pipeline; the feed water outlet of the high-pressure heater is connected to the feed water inlet of the coal-fired boiler through a pipeline;

[0010] A steam energy storage component, the steam energy storage component comprising: a gas storage tank;

[0011] The steam inlet of the steam storage tank is connected to the main steam outlet of the coal-fired boiler; the steam inlet of the steam storage tank is connected to the reheat steam outlet of the coal-fired boiler; the water working medium inlet of the steam storage tank is connected to the water working medium outlet of the deaerator; the steam outlet of the steam storage tank is connected to the steam inlet of the high-pressure heater; the steam outlet of the steam storage tank is connected to the steam inlet of the deaerator; the steam outlet of the steam storage tank is connected to the steam inlet of the low-pressure steam turbine; the steam outlet of the steam storage tank is connected to the steam inlet of the low-pressure heater.

[0012] As a preferred solution, a main steam diverter valve is provided between the steam inlet of the gas storage tank and the main steam outlet of the coal-fired boiler; a reheat steam diverter valve is provided between the steam inlet of the gas storage tank and the reheat steam outlet of the coal-fired boiler.

[0013] As a preferred solution, a water feed diverter valve and a water feed pump are provided between the water working medium inlet of the steam storage tank and the water working medium outlet of the deaerator.

[0014] As a preferred solution, an outlet regulating valve is provided at the outlet of the steam storage tank.

[0015] As a preferred solution, a first diverter valve is provided between the steam outlet of the steam storage tank and the steam inlet of the high-pressure heater;

[0016] A second diverter valve is provided between the steam outlet of the steam storage tank and the steam inlet of the deaerator;

[0017] A third diverter valve is provided between the steam outlet of the steam storage tank and the steam inlet of the low-pressure steam turbine;

[0018] A fourth diverter valve is provided between the steam outlet of the steam storage tank and the steam inlet of the low-pressure heater.

[0019] As a preferred embodiment, the steam storage tank is a pressure steam storage tank; the pressure of the compressed steam in the steam storage tank is greater than or equal to 70 Pa.

[0020] As a preferred solution, the steam temperature at the reheat steam outlet of the coal-fired boiler is greater than 520°C, and the pressure is greater than 20 Pa; the steam temperature at the steam outlet of the coal-fired boiler is greater than 520°C, and the pressure is greater than 100 Pa.

[0021] The present invention also provides an operation method of a coal-fired power generation system coupled with steam energy storage, comprising the following steps:

[0022] When the coal-fired unit reduces its load, part of the steam from the coal-fired boiler is diverted into the gas storage tank;

[0023] When the coal-fired unit increases its load, the high-pressure steam in the steam storage tank is released from the steam storage tank.

[0024] As a preferred solution, when the coal-fired unit needs to reduce load, the reheat steam diverter valve is opened first to divert part of the reheat steam into the steam storage tank;

[0025] Open the water feed diverter valve and start the water feed pump, so that part of the water feed is pressurized by the water feed pump and enters the steam storage tank to mix with the superheated steam to become saturated water;

[0026] According to the unit requirements, gradually close the reheat steam diverter valve and gradually open the main steam diverter valve; adjust the feed water diverter valve;

[0027] When the pressure in the steam storage tank approaches the reheat steam pressure, close the reheat steam diverter valve, open the main steam diverter valve, and divert part of the main steam into the steam storage tank;

[0028] When the pressure in the steam storage tank is greater than 70 Pa, close the main steam diverter valve, feed water pump and feed water diverter valve;

[0029] When the unit is running at increased load, open the steam storage tank outlet regulating valve to release high-pressure steam from the steam storage tank, open the second medium-pressure steam turbine extraction throttle valve and the first steam outlet diverter valve,

[0030] High-pressure steam heats the feed water of the high-pressure heater. As the pressure in the steam storage tank decreases, the first diverter valve, the second diverter valve, the third diverter valve, the fourth diverter valve and the first intermediate-pressure steam turbine extraction throttle valve are gradually opened in sequence.

[0031] The technical solution of the present invention has the following advantages:

[0032] 1. A coal-fired power generation system coupled with steam energy storage provided by the present invention comprises a coal-fired power generation component and a steam energy storage component; the steam energy storage component and the coal-fired power generation component are coupled to expand the load variation range of the coal-fired unit; its minimum load can be reduced from 30% THA to a maximum of 21% THA, and the maximum load can be increased from 100% THA to a maximum of 115% THA, and the load variation rate of the coal-fired unit can be increased from the traditional 1-1.5Pe0 / min to 3.5Pe0 / min, which greatly improves the peak load regulation and frequency regulation capability of the coal-fired unit;

[0033] Furthermore, coupling the coal-fired power generation component and the steam energy storage component has little impact on the coal-fired boiler, does not require modification of the boiler, and can directly utilize steam without the need for additional heat exchangers.

[0034] 2. The present invention provides a coal-fired power generation system coupled with steam energy storage, in which a feed water pump is arranged between the steam storage tank and the deaerator; the feed water pump is used to increase the pressure of the feed water entering the steam storage tank, so that the feed water and superheated steam are mixed into saturated water, which greatly increases the heat storage density and reduces the floor space of the steam storage tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is a structural schematic diagram of a coal-fired power generation system coupled with steam energy storage according to the present invention.

[0037] Description of reference numerals:

[0038] 1. Coal-fired boiler; 2. High-pressure steam turbine; 3. Medium-pressure steam turbine; 4. Low-pressure steam turbine; 5. Condenser; 6. Low-pressure steam turbine extraction throttle valve; 7. Low-pressure heater; 8. First medium-pressure steam turbine extraction throttle valve; 9. Deaerator; 10. Second medium-pressure steam turbine extraction throttle valve; 11. High-pressure heater; 12. Main steam diverter valve; 13. Reheat steam diverter valve; 14. Steam storage tank; 15. Feedwater diverter valve; 16. Feedwater pump; 17. Outlet regulating valve; 18. First diverter valve; 19. Second diverter valve; 20. Third diverter valve; 21. Fourth diverter valve. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] This embodiment provides a coal-fired power generation system coupled with steam energy storage, such as Figure 1 As shown, it includes: a coal-fired power generation component and a steam energy storage component;

[0044] The steam inlet of the high-pressure steam turbine 2 is connected to the steam outlet of the coal-fired boiler 1; the steam outlet of the high-pressure steam turbine 2 is connected to the steam inlet of the medium-pressure steam turbine 3 through the coal-fired boiler 1; the first-stage steam extraction outlet of the medium-pressure steam turbine 3 is connected to the steam inlet of the high-pressure heater 11; the second-stage steam outlet of the medium-pressure steam turbine 3 is connected to the steam inlet of the deaerator 9; the steam outlet of the medium-pressure steam turbine 3 is connected to the steam outlet of the low-pressure steam turbine through a pipeline; the steam extraction outlet of the low-pressure steam turbine 4 is connected to the low-pressure heater 7; the steam outlet of the low-pressure steam turbine is connected to the steam inlet of the condenser 5 through a pipeline; the condensate outlet of the condenser is connected to the condensate inlet of the low-pressure heater 7 through a pipeline; the condensate outlet of the low-pressure heater 7 is connected to the condensate inlet of the deaerator 9 through a pipeline; the feed water outlet of the deaerator 9 is connected to the feed water inlet of the high-pressure heater 11 through a pipeline; the feed water outlet of the high-pressure heater 11 is connected to the feed water inlet of the coal-fired boiler 1 through a pipeline.

[0045] The steam inlet of the steam storage tank 14 is connected to the main steam outlet of the coal-fired boiler 1; the steam inlet of the steam storage tank 14 is connected to the reheat steam outlet of the coal-fired boiler 1; the water working medium inlet of the steam storage tank 14 is connected to the water working medium outlet of the deaerator 9; the steam outlet of the steam storage tank 14 is connected to the steam inlet of the high-pressure heater 11; the steam outlet of the steam storage tank 14 is connected to the steam inlet of the deaerator 9; the steam outlet of the steam storage tank 14 is connected to the steam inlet of the low-pressure steam turbine; the steam outlet of the steam storage tank 14 is connected to the steam inlet of the low-pressure heater 7.

[0046] Wherein, the steam turbine is a supercritical pure condensing steam turbine; the steam inlet of the high-pressure steam turbine 2 is connected to the main steam outlet of the coal-fired boiler 1 through a pipeline; the steam outlet of the high-pressure steam turbine 2 is connected to the inlet of the reheat circuit of the coal-fired boiler 1, and the outlet of the reheat circuit of the coal-fired boiler 1 is connected to the steam inlet of the medium-pressure steam turbine; the extraction outlet of the high-pressure steam turbine 2 is connected to the steam inlet of the high-pressure heater 11 through a pipeline; the first-stage extraction outlet of the medium-pressure steam turbine is connected to the steam inlet of the high-pressure heater 11, and a second medium-pressure steam turbine extraction throttle valve 10 is provided on the pipeline connecting the medium-pressure steam turbine and the high-pressure heater 11; the second-stage extraction outlet of the medium-pressure steam turbine is connected to the steam inlet of the deaerator 9 through a pipeline, and a first medium-pressure steam turbine extraction throttle valve 8 is provided on the pipeline connecting the medium-pressure steam turbine and the deaerator 9;

[0047] The extraction steam outlet of the low-pressure steam turbine is connected to the low-pressure heater 7 through a pipeline, and a low-pressure steam turbine extraction steam throttle valve 6 is provided on the pipeline connecting the low-pressure steam turbine 4 and the low-pressure heater 7; the steam outlet of the low-pressure steam turbine is connected to the steam inlet of the condenser through a pipeline; the condensate outlet of the condenser is connected to the condensate inlet of the low-pressure heater 7 through a pipeline; the condensate outlet of the low-pressure heater 7 is connected to the condensate inlet of the deaerator 9 through a pipeline; the feed water outlet of the deaerator 9 is connected to the feed water inlet of the high-pressure heater 11 through a pipeline; the feed water outlet of the high-pressure heater 11 is connected to the feed water inlet of the coal-fired boiler 1 through a pipeline.

[0048] The steam inlet of the steam storage tank 14 is connected to the main steam outlet of the coal-fired boiler 1 through a pipeline, and a main steam diverter valve 12 is provided between the steam storage tank and the main steam outlet of the coal-fired boiler 1;

[0049] The steam inlet of the gas storage tank is connected to the reheat steam outlet of the coal-fired boiler 1 through a pipeline, and a reheat steam diverter valve 13 is provided on the pipeline between the gas storage tank and the reheat steam outlet of the coal-fired boiler 1;

[0050] The water medium inlet of the steam storage tank 14 is connected to the water medium outlet of the deaerator 9 through a pipeline; a water feed diverter valve 15 and a water feed pump 16 are provided between the steam storage tank 14 and the deaerator 9; an outlet regulating valve 17 is provided on the steam outlet of the steam storage tank 14;

[0051] Furthermore, a first diverter valve 18 is provided between the steam outlet of the steam storage tank 14 and the steam inlet of the high-pressure heater 11; a second diverter valve 19 is provided between the steam outlet of the steam storage tank 14 and the steam inlet of the deaerator 9; a third diverter valve 20 is provided between the steam outlet of the steam storage tank 14 and the steam inlet of the low-pressure turbine; and a fourth diverter valve 21 is provided between the steam outlet of the steam storage tank 14 and the steam inlet of the low-pressure heater 7.

[0052] The steam storage tank 14 is a pressure-bearing steam storage tank 14. The number of the steam storage tanks 14 may be one or more. The pressure of the compressed steam in the steam storage tank 14 is not less than 70 Pa.

[0053] Furthermore, the main steam temperature in the coal-fired boiler 1 is greater than 520° C., the pressure is greater than 100 Pa, and the reheated steam temperature is greater than 520° C., the pressure is greater than 20 Pa.

[0054] Furthermore, the water pressure entering the steam storage tank 14 through the water supply diverter valve 15 and the water supply pump 16 is not less than 70 Pa.

[0055] Example 2

[0056] This embodiment provides an operation method of a coal-fired power generation system coupled with steam energy storage, comprising the following steps:

[0057] When the coal-fired unit reduces its load, the steam diversion portion of the coal-fired boiler 1 enters the gas storage tank;

[0058] When the coal-fired unit increases its load, the high-pressure steam in the steam storage tank 14 is released from the steam storage tank 14 .

[0059] Furthermore, when the coal-fired unit needs to reduce the load, the reheat steam diverter valve 13 is opened first to divert part of the reheat steam into the steam storage tank 14;

[0060] Open the water feed diverter valve 15 and start the water feed pump 16, so that part of the water feed is pressurized by the water feed pump 16 and enters the steam storage tank 14 to mix with the superheated steam to become saturated water;

[0061] According to the unit requirements, gradually close the reheat steam diverter valve 13 and gradually open the main steam diverter valve 12; adjust the feed water diverter valve 15;

[0062] When the pressure in the steam storage tank 14 approaches the reheat steam pressure, the reheat steam diverter valve 13 is closed, and the main steam diverter valve 12 is opened to divert part of the main steam into the steam storage tank 14;

[0063] By adjusting the opening of the main steam diverter valve 12 and the reheat steam diverter valve 13, the flow rate of steam flowing into the steam storage tank 14 can be adjusted, thereby adjusting the load reduction rate of the control unit;

[0064] The feed water flow entering the steam storage tank 14 is controlled by adjusting the opening of the feed water diverter valve 15, thereby matching the feed water flow with the steam flow, ensuring that the superheated steam and feed water are mixed to form saturated water, thereby increasing the heat storage density.

[0065] When the pressure in the steam storage tank 14 is greater than 70 Pa, the main steam diverter valve 12, the feed water pump 16 and the feed water diverter valve 15 are closed.

[0066] When the unit is running at increased load, the outlet regulating valve 17 of the steam storage tank 14 is opened to release the high-pressure steam from the steam storage tank 14, and the second medium-pressure steam turbine extraction throttle valve 10 and the first steam outlet diverter valve are opened.

[0067] High-pressure steam replaces turbine extraction steam to heat the feed water of the high-pressure heater 11. As the pressure in the steam storage tank 14 decreases, the first diverter valve 18, the second diverter valve 19, the third diverter valve 20, the fourth diverter valve 21 and the first medium-pressure turbine extraction throttle valve 8 are gradually opened in sequence, mainly to ensure that the pressure of the steam at the outlet of the steam storage tank 14 matches the steam pressure required at the turbine release point, thereby improving the steam utilization rate.

[0068] Compared with the existing technology, this solution has the following advantages:

[0069] (1) Compared with traditional coal-fired units, coupling steam energy storage with coal-fired units expands the load variation range of coal-fired units. Its minimum load can be reduced from 30% THA to 21% THA, and its maximum load can be increased from 100% THA to 115% THA. The load variation rate of coal-fired units can be increased from the traditional 1-1.5 Pe0 / min to 3.5 Pe0 / min, greatly improving the peak load regulation and frequency regulation capabilities of coal-fired units.

[0070] (2) Coupling steam energy storage with coal-fired units has little impact on coal-fired boilers, does not require boiler modification, and directly utilizes steam without the need for additional heat exchangers;

[0071] (3) Use the feed water pump to increase the pressure of the feed water entering the steam storage tank, so that the feed water and superheated steam are mixed into saturated water, which greatly increases the heat storage density and reduces the footprint of the steam storage tank;

[0072] (4) When the unit increases its load, the high-pressure steam in the steam storage tank is released to the turbine extraction steam and the low-pressure cylinder inlet according to the pressure step, replacing the turbine extraction steam to heat the feed water. While increasing the turbine output power, it also reduces the heat exchange irreversibility of the heat recovery system, further improving the utilization efficiency of thermal energy.

[0073] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A coal-fired power generation system coupled with steam energy storage, characterized in that: include: A coal-fired power generation component, the coal-fired power generation component comprising: a coal-fired boiler, a high-pressure steam turbine, a medium-pressure steam turbine, a low-pressure steam turbine, a condenser and a deaerator, a high-pressure heater and a low-pressure heater, which are connected and arranged; The steam inlet of the high-pressure steam turbine is connected to the steam outlet of the coal-fired boiler; the steam outlet of the high-pressure steam turbine is connected to the steam inlet of the medium-pressure steam turbine through the coal-fired boiler; the first-stage steam extraction outlet of the medium-pressure steam turbine is connected to the steam inlet of the high-pressure heater; the second-stage steam outlet of the medium-pressure steam turbine is connected to the steam inlet of the deaerator; The steam outlet of the medium-pressure steam turbine is connected to the steam outlet of the low-pressure steam turbine through a pipeline; the extraction steam outlet of the low-pressure steam turbine is connected to the steam inlet of the low-pressure heater; the steam outlet of the low-pressure steam turbine is connected to the steam inlet of the condenser through a pipeline; the condensate outlet of the condenser is connected to the condensate inlet of the low-pressure heater through a pipeline; the condensate outlet of the low-pressure heater is connected to the condensate inlet of the deaerator through a pipeline; the feed water outlet of the deaerator is connected to the feed water inlet of the high-pressure heater through a pipeline; the feed water outlet of the high-pressure heater is connected to the feed water inlet of the coal-fired boiler through a pipeline; A steam energy storage component, the steam energy storage component comprising: a steam storage tank; The steam inlet of the steam storage tank is connected to the main steam outlet of the coal-fired boiler; the steam inlet of the steam storage tank is connected to the reheat steam outlet of the coal-fired boiler; the water working medium inlet of the steam storage tank is connected to the water working medium outlet of the deaerator; the steam outlet of the steam storage tank is connected to the steam inlet of the high-pressure heater; the steam outlet of the steam storage tank is connected to the steam inlet of the deaerator; the steam outlet of the steam storage tank is connected to the steam inlet of the low-pressure steam turbine; the steam outlet of the steam storage tank is connected to the steam inlet of the low-pressure heater; An outlet regulating valve is provided at the outlet of the steam storage tank; A first diverter valve is provided between the steam outlet of the steam storage tank and the steam inlet of the high-pressure heater; A second diverter valve is provided between the steam outlet of the steam storage tank and the steam inlet of the deaerator; A third diverter valve is provided between the steam outlet of the steam storage tank and the steam inlet of the low-pressure steam turbine; A fourth diverter valve is provided between the steam outlet of the steam storage tank and the steam inlet of the low-pressure heater.

2. The coal-fired power generation system coupled with steam energy storage according to claim 1, characterized in that: A main steam diverter valve is provided between the steam inlet of the steam storage tank and the main steam outlet of the coal-fired boiler; a reheat steam diverter valve is provided between the steam inlet of the steam storage tank and the reheat steam outlet of the coal-fired boiler.

3. The coal-fired power generation system coupled with steam energy storage according to claim 1, characterized in that: A water feed diverter valve and a water feed pump are provided between the water working medium inlet of the steam storage tank and the water working medium outlet of the deaerator.

4. The coal-fired power generation system coupled with steam energy storage according to claim 1, characterized in that: The steam storage tank is a pressure-bearing steam storage tank; the pressure of the compressed steam in the steam storage tank is greater than or equal to 70 Pa.

5. The coal-fired power generation system coupled with steam energy storage according to claim 1, characterized in that: The steam temperature at the reheat steam outlet of the coal-fired boiler is greater than 520°C, and the pressure is greater than 20 Pa; the steam temperature at the steam outlet of the coal-fired boiler is greater than 520°C, and the pressure is greater than 100 Pa.

6. An operation method of a coal-fired power generation system coupled with steam energy storage, applicable to the coal-fired power generation system coupled with steam energy storage as described in any one of claims 1 to 5 above, characterized in that: The following steps are involved: When the coal-fired unit reduces its load, part of the steam from the coal-fired boiler is diverted into the steam storage tank; When the coal-fired unit increases its load, the high-pressure steam in the steam storage tank is released from the steam storage tank.

7. The method for operating a coal-fired power generation system coupled with steam energy storage according to claim 6, characterized in that: When the coal-fired unit needs to reduce the load, first open the reheat steam diverter valve to divert part of the reheat steam into the steam storage tank; Open the water feed diverter valve and start the water feed pump, so that part of the water feed is pressurized by the water feed pump and enters the steam storage tank to mix with the superheated steam to become saturated water; According to the unit requirements, gradually close the reheat steam diverter valve and gradually open the main steam diverter valve; adjust the feed water diverter valve; When the pressure in the steam storage tank approaches the reheat steam pressure, close the reheat steam diverter valve, open the main steam diverter valve, and divert part of the main steam into the steam storage tank; When the pressure in the steam storage tank is greater than 70 Pa, close the main steam diverter valve, feed water pump and feed water diverter valve; When the unit is running at increased load, open the steam storage tank outlet regulating valve to release high-pressure steam from the steam storage tank, open the second medium-pressure steam turbine extraction throttle valve and the first steam outlet diverter valve, High-pressure steam heats the feed water of the high-pressure heater. As the pressure in the steam storage tank decreases, the first diverter valve, the second diverter valve, the third diverter valve, the fourth diverter valve and the first intermediate-pressure steam turbine extraction throttle valve are gradually opened in sequence.

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