A thermal power unit peak regulation system and method based on a steam accumulator

Abstract

The present application relates to a kind of steam accumulator-based thermal power unit peak shaving system and peak shaving method, including steam turbine, the boiler of steam to steam turbine delivery, and the feedwater assembly of water to boiler to form steam;The boiler includes main steam pipe and reheat steam pipe;The feedwater assembly includes water supply component and heating component, and the heating component is used to heat the water of water supply component inside delivery using the steam extraction of the steam turbine;The thermal power unit peak shaving system further includes steam storage system, and the steam storage system includes steam accumulator, and the steam input end of the steam accumulator is connected with the main steam pipe, and the steam output end of the steam accumulator is connected with at least the heating component, and specifically meet the advantage of unit rapid peak shaving.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal power unit peak regulation, and in particular to a thermal power unit peak regulation system and method based on a steam accumulator. BACKGROUND

[0002] Due to the obvious uncertainty and volatility of new energy, and the fact that thermal power is still the main power source in China, in order to ensure the power balance of the power system, it is necessary to improve the peak regulation capacity of thermal power units to achieve a higher proportion of new energy access.

[0003] However, the current thermal power unit has a slow peak regulation rate, and the modification technology represented by molten salt heat storage and electrochemical energy storage faces the problem of high modification cost. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the defects in the prior art, thereby providing a thermal power unit peak regulation system and method based on a steam accumulator.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] A thermal power unit peak regulation system based on a steam accumulator, comprising a steam turbine, a boiler for delivering steam to the steam turbine, and a feedwater assembly for delivering water to the boiler to form steam; the boiler comprises a main steam pipe and a reheated steam pipe; the feedwater assembly comprises a water delivery assembly and a heating assembly, the heating assembly is used to heat the water delivered in the water delivery assembly by using the extraction steam of the steam turbine; the thermal power unit peak regulation system further comprises a steam storage system, the steam storage system comprises a steam accumulator, the steam input end of the steam accumulator is connected with the main steam pipe, and the steam output end of the steam accumulator is connected with at least the heating assembly.

[0007] Preferably, the steam storage system further comprises a first pipeline assembly; the input end of the first pipeline assembly is connected with the output end of the steam accumulator, and the output end of the first pipeline assembly is connected with the reheated steam pipe.

[0008] Preferably, the steam storage system further comprises a second pipeline assembly; the input end of the second pipeline assembly is connected with the output end of the steam accumulator, and the output end of the second pipeline assembly is connected with the heating assembly.

[0009] Preferably, the heating assembly comprises a plurality of high-pressure heaters, the plurality of high-pressure heaters are connected in sequence along the upstream-to-downstream direction of the water feeding assembly; the second pipeline assembly comprises a second steam pipe, a second check valve, a third steam pipe and a first regulating valve; the third steam pipe is provided in one-to-one correspondence with the high-pressure heaters; the output end of the steam accumulator, the second steam pipe, the third steam pipe and the high-pressure heaters are connected in sequence; the second check valve is arranged on the second steam pipe, and the first regulating valve is arranged on the third steam pipe.

[0010] Preferably, the steam accumulator system further comprises a third pipeline assembly; the third pipeline assembly comprises a fourth steam pipe, a desuperheater and a third check valve; the output end of the main steam pipe, the fourth steam pipe and the input end of the steam accumulator are connected in sequence; the third check valve and the desuperheater are both located on the fourth steam pipe.

[0011] Preferably, the steam turbine comprises a high-pressure cylinder, a medium-pressure cylinder and a low-pressure cylinder; the steam input end of the high-pressure cylinder is connected with the output end of the main steam pipe, the steam input end of the medium-pressure cylinder is connected with the output end of the reheated steam pipe, and the output end of the medium-pressure cylinder is connected with the input end of the low-pressure cylinder; the heating assembly comprises a plurality of high-pressure heaters, the plurality of high-pressure heaters are connected in sequence along the upstream-to-downstream direction of the water feeding assembly; the steam extraction ends of the high-pressure cylinder and the medium-pressure cylinder are both connected with at least one high-pressure heater, and the high-pressure heater connected with the high-pressure cylinder is located downstream of the high-pressure heater connected with the medium-pressure cylinder.

[0012] Preferably, the high-pressure heater comprises a first high-pressure heater, a second high-pressure heater and a third high-pressure heater; along the upstream-to-downstream direction of the water feeding assembly, the first high-pressure heater, the second high-pressure heater and the third high-pressure heater are connected in sequence; the first high-pressure heater is connected with the steam extraction end of the medium-pressure cylinder; the second high-pressure heater is connected with the first steam extraction end of the high-pressure cylinder; the third high-pressure heater is connected with the second steam extraction end of the high-pressure cylinder, and the steam extraction temperature of the second steam extraction end is greater than that of the first steam extraction end.

[0013] A peak regulation method based on the above-mentioned peak regulation system of the thermal power generating unit, comprising the following steps:

[0014] When the unit reduces load, the main steam of the unit is transported to the steam accumulator, and the main steam is converted into high-pressure water and stored in the steam accumulator, so as to reduce the amount of steam entering the steam turbine for work;

[0015] When the unit increases load, the high-pressure water in the steam accumulator is converted into steam to replace at least part of the steam extraction of the steam turbine to supply the water feeding assembly, so as to preheat the water fed into the boiler and increase the amount of steam entering the steam turbine for work.

[0016] Preferably, the method further comprises the step of: when the unit is in the process of load increase, the high-pressure water in the steam accumulator is converted into steam, and the steam is supplied to the reheat steam pipe of the boiler together with the exhaust steam of the high-pressure cylinder to increase the amount of steam entering the steam turbine for work.

[0017] Preferably, the method further comprises the step of: when the unit is in the process of load increase, the steam generated by the steam accumulator is first replaced with the extraction steam of the high-pressure cylinder of the steam turbine from the feedwater assembly, and then the steam generated by the steam accumulator is replaced with the extraction steam of the high-pressure cylinder of the steam turbine from the reheat steam pipe; finally, the steam generated by the steam accumulator is replaced with the extraction steam of the intermediate-pressure cylinder of the steam turbine.

[0018] Preferably, the method further comprises the step of: when the unit is in the process of load decrease, the amount of steam entering the steam accumulator is changed to change the rate of load decrease of the unit; when the unit is in the process of load increase, the amount of steam delivered by the steam accumulator to the heating assembly and the reheat steam pipe is changed to change the rate of load increase of the unit.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] The steam accumulator-based thermal power unit peak shaving system provided in the technical solution has the steam input end of the steam accumulator connected with the main steam pipe, and the steam output end of the steam accumulator connected with at least the heating assembly, so that when the unit has a load decrease demand, the high-temperature and high-pressure hot steam output by the main steam pipe can be delivered to the steam accumulator of the steam accumulator system, so that the main steam is converted into high-pressure water and stored in the steam accumulator, which can not only quickly reduce the amount of steam supplied to the high-pressure cylinder of the steam turbine, thereby quickly reducing the output power of the steam turbine, but also store the energy of the high-temperature and high-pressure steam output by the main steam pipe, thereby avoiding energy waste. Meanwhile, the energy stored in the steam accumulator of the steam accumulator system can be used to preheat the water supplied to the boiler by converting the high-pressure water into steam to replace at least part of the extraction steam of the steam turbine to supply the feedwater assembly when the unit has a load increase demand, which can not only meet the demand for water preheating, but also reduce the amount of extraction steam of the steam turbine, thereby quickly increasing the output power of the steam turbine. Correspondingly, the peak shaving method based on the above-mentioned thermal power unit peak shaving system can achieve rapid peak shaving of the thermal power unit. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the specific embodiments or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0022] Figure 1 One of the example schematic diagrams provided by the present application;

[0023] Reference signs:

[0024] 1, steam turbine; 11, high pressure cylinder; 12, intermediate pressure cylinder; 13, low pressure cylinder; 2, boiler; 21, main steam pipe; 22, reheat steam pipe; 3, feed water assembly; 31, feed water supply assembly; 311, feed pipe; 312, condenser; 313, condensate pump; 314, deaerator; 315, feed water pump; 32, heating assembly; 321, first high pressure heater; 322, second high pressure heater; 323, third high pressure heater; 324, low pressure heater; 4, steam accumulator system; 40, steam accumulator; 41, first pipe assembly; 411, first steam pipe; 412, first check valve; 413, fourth regulating valve; 42, second pipe assembly; 421, second steam pipe; 422, second check valve; 423, third steam pipe; 424, first regulating valve; 43, third pipe assembly; 431, fourth steam pipe; 432, desuperheater; 433, third check valve; 434, second regulating valve; 5, fifth steam pipe; 51, third regulating valve. DETAILED DESCRIPTION

[0025] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0026] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] Referring to Figure 1 The embodiment of the present application provides a thermal power unit peak shaving system based on a steam accumulator, which comprises a steam turbine 1, a boiler 2 and a feedwater assembly 3. The boiler 2 is used for delivering steam to the steam turbine 1 to drive the steam turbine 1 to work and generate electricity. The feedwater assembly 3 is used for delivering water to the boiler 2 to form steam.

[0029] Specifically, the steam turbine 1 comprises a high-pressure cylinder 11, a medium-pressure cylinder 12 and a low-pressure cylinder 13. The boiler 2 comprises a main steam pipe 21 and a reheated steam pipe 22. The main steam pipe 21 provides high-temperature and high-pressure hot steam, which is mainly used for the high-pressure cylinder 11 of the steam turbine 1. The reheated steam pipe 22 provides high-temperature and high-pressure hot steam heated by secondary heating, which is mainly used for supplying the medium-pressure cylinder 12 to meet the demand of rapid peak shaving. The feedwater assembly 3 comprises a water delivery assembly 31 and a heating assembly 32. The heating assembly 32 is used for heating the water delivered in the water delivery assembly 31 by the steam extracted from the steam turbine 1, so that the unit peak shaving can be realized and the water entering the boiler 2 can be preheated.

[0030] Referring to Figure 1 In order to further meet the demand of rapid peak shaving of the unit, in the embodiment, the thermal power unit peak shaving system further comprises a steam accumulation system 4. The steam accumulation system 4 comprises a steam accumulator 40. The steam input end of the steam accumulator 40 is connected with the main steam pipe 21. The steam output end of the steam accumulator 40 is connected with at least the heating assembly 32. Through the scheme, when the unit reduces load, the high-temperature and high-pressure hot steam output by the main steam pipe 21 can be delivered into the steam accumulator 40 of the steam accumulation system 4, so that the main steam is converted into high-pressure water and stored in the steam accumulator 40. The steam quantity supplied to the high-pressure cylinder 11 of the steam turbine 1 can be rapidly reduced, so that the output power of the steam turbine 1 can be rapidly reduced. The energy of the high-temperature and high-pressure steam output by the main steam pipe 21 can be stored, so that energy waste can be avoided. Meanwhile, the energy stored in the steam accumulator 40 of the steam accumulation system 4 can be used to convert the high-pressure water into steam to replace at least part of the steam extracted from the steam turbine 1 to supply the feedwater assembly 3 when the unit has the demand of increasing load, so that the water entering the boiler 2 can be preheated. The demand of water preheating can be met. The steam extraction quantity of the steam turbine 1 can be reduced, so that the output power of the steam turbine 1 can be rapidly increased.

[0031] Further, in order to quickly provide steam to the intermediate pressure cylinder 12, and further improve the output power of the intermediate pressure cylinder 12, in the embodiment, the steam storage system 4 further comprises a first pipeline assembly 41; the input end of the first pipeline assembly 41 is connected with the output end of the steam accumulator 40, and the output end of the first pipeline assembly 41 is connected with the reheating steam pipe 22, so that the steam generated by the steam accumulator 40 can be transported to the reheating steam pipe 22 for heating and then supplied to the intermediate pressure cylinder 12, so as to improve the power output of the entire steam turbine 1.

[0032] Further, the first pipeline assembly 41 comprises a first steam pipe 411 and a first check valve 412; one end of the first steam pipe 411 is connected with the steam accumulator 40, and the other end is connected with the reheating steam pipe 22; the first check valve 412 is arranged on the first steam pipe 411 to prevent the steam in the reheating steam pipe 22 from flowing back to the steam accumulator 40.

[0033] Referring to Figure 1 , in order to realize the transportation of the steam formed by the steam accumulator 40 to the heating assembly 32 to heat the water transported in the water feeding assembly 31, the steam storage system 4 further comprises a second pipeline assembly 42; the input end of the second pipeline assembly 42 is connected with the output end of the steam accumulator 40, and the output end is connected with the heating assembly 32.

[0034] Specifically, in the embodiment, the heating assembly 32 comprises a plurality of high-pressure heaters which are connected in sequence along the upstream-to-downstream direction of the water feeding assembly 31 to increase the heat exchange effect. The second pipeline assembly 42 comprises a second steam pipe 421, a second check valve 422, a third steam pipe 423 and a first regulating valve 424; the third steam pipe 423 is arranged in one-to-one correspondence with the high-pressure heaters; the output end of the steam accumulator 40, the second steam pipe 421, the third steam pipe 423 and the high-pressure heaters are connected in sequence; the second check valve 422 is arranged on the second steam pipe 421, and the first regulating valve 424 is arranged on the third steam pipe 423; and then the first regulating valve 424 can dynamically adjust the amount of steam transported to different high-pressure heaters according to the actual working condition.

[0035] The steam output from the main steam pipe 21 of the boiler 2 is high-temperature and high-pressure steam, in order to convert the main steam (i.e. the steam output from the main steam pipe 21) into high-pressure water; in the embodiment, the steam storage system 4 further comprises a third pipeline assembly 43; the third pipeline assembly 43 comprises a fourth steam pipe 431, a desuperheater 432 and a third check valve 433; the output end of the main steam pipe 21, the fourth steam pipe 431 and the input end of the steam accumulator 40 are connected in sequence; the third check valve 433 and the desuperheater 432 are both arranged on the fourth steam pipe 431; the third check valve 433 is used to prevent the steam from flowing back, and the desuperheater 432 is used to reduce the temperature and pressure of the main steam, so as to facilitate the conversion of the main steam into high-pressure water which is stored in the steam accumulator.

[0036] Further, in order to control the amount of steam delivered to the high pressure cylinder 11 and the steam accumulator 40, in the present embodiment, the third pipeline assembly 43 further comprises a second regulating valve 434, which is arranged on the fourth steam pipe 431.

[0037] In order to increase the heat exchange effect, the heating assembly 32 comprises a plurality of high pressure heaters, which are connected in sequence along the upstream to downstream direction of the water delivery assembly 31; the steam extraction end of the high pressure cylinder 11 and the intermediate pressure cylinder 12 are both connected with a high pressure heater, and the high pressure heater connected with the high pressure cylinder 11 is located downstream of the high pressure heater connected with the intermediate pressure cylinder 12, so as to realize the step-by-step heat exchange of water and improve the heat exchange efficiency. Of course, in other embodiments, the steam extraction end of the high pressure cylinder 11 and the intermediate pressure cylinder 12 can also be connected with a plurality of high pressure heaters, as long as the steam supplied to the high pressure heaters is increased in sequence along the upstream to downstream direction of the water delivery assembly 31.

[0038] Referring to Figure 1 In the present embodiment, the high pressure heater comprises a first high pressure heater 321, a second high pressure heater 322 and a third high pressure heater 323; the first high pressure heater 321, the second high pressure heater 322 and the third high pressure heater 323 are connected in sequence along the upstream to downstream direction of the water delivery assembly 31. Among them, the second high pressure heater 322 is connected with the first steam extraction end of the high pressure cylinder 11; the third high pressure heater 323 is connected with the second steam extraction end of the high pressure cylinder 11, and the steam extraction temperature of the second steam extraction end is higher than that of the first steam extraction end. The first high pressure heater 321 is connected with the steam extraction end of the intermediate pressure cylinder 12; it can be known that the intermediate pressure cylinder 12 also has two steam extraction ends, one of which is connected with the first high pressure heater 321, and the other is connected with the input end of the deaerator 314; the output end of the intermediate pressure cylinder 12 is connected with the input end of the low pressure cylinder 13. In addition, in order to realize the control of the flow, the corresponding connecting pipeline can be provided with a regulating valve.

[0039] Further, the first steam extraction end of the high pressure cylinder 11 can also be connected with the reheated steam pipe 22 through a pipeline.

[0040] Further, in the present embodiment, the heating assembly 32 further comprises a low pressure heater 324, and the steam input end of the low pressure heater 324 is connected with one of the steam extraction ends of the low pressure cylinder 13 through a fifth steam pipe 5, so as to heat the water delivered in the water delivery assembly 31 by using the steam extracted from the low pressure cylinder 13. The third regulating valve 51 can be arranged on the fifth steam pipe 5, so as to adjust the amount of steam extracted from the low pressure cylinder 13 by the low pressure heater 324.

[0041] Referring to Figure 1In order to realize the reuse of the exhaust steam of the low-pressure cylinder 13, in the embodiment, the water feeding assembly 31 comprises a delivery pipe 311, a condenser 312, a condensate pump 313, a deaerator 314 and a feed water pump 315.

[0042] It can be known that the delivery pipe 311 is provided with a plurality of delivery pipes 311 arranged in sequence from the exhaust steam end of the low-pressure cylinder 13 to the boiler 2, and the plurality of delivery pipes 311 are sequentially connected to the exhaust steam end of the low-pressure cylinder 13, the condenser 312, the condensate pump 313, the low-pressure heater 324, the deaerator 314, the feed water pump 315, the first high-pressure heater 321, the second high-pressure heater 322, the third high-pressure heater 323 and the boiler 2 to form a water feeding path of the boiler 2.

[0043] It can be known that the system in actual application is as follows:

[0044] The steam accumulator 40 stores and releases heat energy through the mutual conversion of steam and high-pressure water. Specifically:

[0045] When the unit needs to quickly reduce load, the second regulating valve 434 is adjusted to be opened, and the steam (main steam) generated by the main steam pipe 21 of the boiler 2 is divided into two paths, one of which enters the high-pressure cylinder 11 of the steam turbine 1 to do work, and the other of which enters the desuperheater 432 through the third check valve 433, and then the steam is desuperheated and depressurized to a preset temperature and a preset pressure state, and is delivered to the steam accumulator 40 for storage, thereby quickly reducing the steam amount entering the high-pressure cylinder 11 of the steam turbine 1, so as to quickly reduce the output power of the steam turbine 1.

[0046] When the unit needs to quickly increase load, the high-pressure water in the steam accumulator 40 is converted into steam, and the formed steam is also divided into two paths, one of which enters the reheated steam pipe 22 to be heated to superheated steam through the first steam pipe 411 and the first check valve 412, and then is delivered to the intermediate-pressure cylinder 12 of the steam turbine 1 to do work; the other of which sequentially passes through the second steam pipe 421, the second check valve 422, the third steam pipe 423 and the first regulating valve 424 to enter the corresponding high-pressure heater to heat the water delivered in the delivery pipe 311. Under the joint action of the two paths of steam, the steam amount of the high-pressure cylinder 11 and the intermediate-pressure cylinder 12 of the steam turbine 1 is quickly increased, so as to quickly increase the output power of the steam turbine 1.

[0047] It is worth mentioning that the water delivered in the delivery pipe 311 can come from the exhaust steam condensation of the low-pressure cylinder 13 or from external water supply.

[0048] Based on the above-mentioned thermal power unit peak regulation system, the embodiment further provides a peak regulation method, which specifically comprises the following steps:

[0049] When the unit is in load reduction, the main steam of the unit is delivered to the steam accumulator 40, and the main steam is converted into high-pressure water stored in the steam accumulator 40 to reduce the amount of steam entering the steam turbine 1 to do work;

[0050] When the unit is in load increase, the high-pressure water in the steam accumulator 40 is converted into steam to replace at least part of the extraction steam of the steam turbine 1 to supply the feedwater assembly 3 to preheat the water sent to the boiler 2 and increase the amount of steam entering the steam turbine 1 to do work. Specifically, the high-pressure water in the steam accumulator 40 is converted into steam to replace the extraction steam of the feedwater assembly 3 from the high-pressure cylinder 11 of the steam turbine 1, or to replace the extraction steam of the heating assembly 32 from the low-pressure cylinder 13 of the steam turbine 1.

[0051] Further, the method further comprises the following steps:

[0052] When the unit is in load increase, the high-pressure water in the steam accumulator 40 is converted into steam to replace the extraction steam of the feedwater assembly 3 from the high-pressure cylinder 11 of the steam turbine 1, or to replace the extraction steam of the heating assembly 32 from the low-pressure cylinder 13 of the steam turbine 1.

[0053] Further, when the unit is in load increase, the steam generated by the steam accumulator 40 is first used to replace the extraction steam of the feedwater assembly 3 from the high-pressure cylinder 11 of the steam turbine 1, and then used to replace the extraction steam of the reheating steam pipe 22 from the high-pressure cylinder 11 of the steam turbine 1; finally, the steam generated by the steam accumulator 40 is used to replace the extraction steam of the intermediate-pressure cylinder 12 of the steam turbine 1.

[0054] The method further comprises the following steps:

[0055] When the unit is in load reduction, the flow rate of the steam entering the steam accumulator 40 is changed to change the rate of load reduction of the unit. Specifically, the flow rate of the steam entering the steam accumulator 40 can be changed by adjusting the opening degree of the second regulating valve 434.

[0056] When the unit is in load increase, the flow rate of the steam delivered by the steam accumulator 40 to the heating assembly 32 and the reheating steam pipe 22 is changed to change the rate of load increase of the unit. Specifically, the flow rate of the steam delivered by the steam accumulator 40 to the heating assembly 32 and the reheating steam pipe 22 can be changed by adjusting the opening degrees of the first regulating valve 424 and the fourth regulating valve 413.

[0057] The above embodiments are only preferred embodiments of the present application, and cannot be used to limit the protection scope of the present application. Any non-essential changes and replacements made by those skilled in the art based on the present application shall fall within the protection scope of the present application.

Claims

1. A steam accumulator-based peak shaving system for a thermal power unit, comprising a steam turbine (1), a boiler (2) for supplying steam to the steam turbine (1), and a feedwater assembly (3) for feeding water to the boiler (2) to form steam; characterized in that, the boiler (2) comprises a main steam pipe (21) and a reheat steam pipe (22); the feedwater assembly (3) comprises a feedwater assembly (31) and a heating assembly (32) for heating water fed in the feedwater assembly (31) by means of extraction steam of the steam turbine (1); the thermal power unit further comprises a steam accumulator system (4), the steam accumulator system (4) comprising a steam accumulator (40), a steam input end of the steam accumulator (40) being connected to the main steam pipe (21), and a steam output end of the steam accumulator (40) being connected to at least the heating assembly (32).

2. The steam accumulator based peak shaving system for thermal power plant according to claim 1, wherein, the steam accumulator system (4) further comprises a first pipe assembly (41); an input end of the first pipe assembly (41) is connected to an output end of the steam accumulator (40), and an output end of the first pipe assembly (41) is connected to the reheat steam pipe (22).

3. The steam accumulator based peak shaving system for thermal power plant according to claim 1, wherein, the steam accumulator system (4) further comprises a second pipe assembly (42); an input end of the second pipe assembly (42) is connected to an output end of the steam accumulator (40), and an output end of the second pipe assembly (42) is connected to the heating assembly (32).

4. The steam accumulator based peak shaving system for thermal power plant according to claim 3, characterized in that, the heating assembly (32) comprises a plurality of high-pressure heaters, the plurality of high-pressure heaters being connected in sequence along an upstream-to-downstream direction of the feedwater assembly (31); the second pipe assembly (42) comprises a second steam pipe (421), a second non-return valve (422), a third steam pipe (423), and a first regulating valve (424); the third steam pipe (423) is provided in one-to-one correspondence with the high-pressure heaters; the output end of the steam accumulator (40), the second steam pipe (421), the third steam pipe (423), and the high-pressure heaters are connected in sequence; the second non-return valve (422) is provided on the second steam pipe (421), and the first regulating valve (424) is provided on the third steam pipe (423).

5. The steam accumulator based peak shaving system for thermal power plant according to claim 1, wherein, the steam accumulator system (4) further comprises a third pipe assembly (43); the third pipe assembly (43) comprises a fourth steam pipe (431), an attemperator (432), and a third non-return valve (433); an output end of the main steam pipe, the fourth steam pipe (431), and an input end of the steam accumulator (40) are connected in sequence; the third non-return valve (433) and the attemperator (432) are both provided on the fourth steam pipe (431).

6. The system according to any one of claims 1-5, characterized in that, the steam turbine (1) comprises a high-pressure cylinder (11), a medium-pressure cylinder (12), and a low-pressure cylinder (13). The steam input end of the high-pressure cylinder (11) is connected with the output end of the main steam pipe (21), the steam input end of the intermediate-pressure cylinder (12) is connected with the output end of the reheated steam pipe (22), and the output end of the intermediate-pressure cylinder (12) is connected with the input end of the low-pressure cylinder (13); The heating assembly (32) comprises a plurality of high-pressure heaters, and the plurality of high-pressure heaters are connected in sequence along the upstream-to-downstream direction of the water feeding assembly (31); The steam extraction ends of the high-pressure cylinder (11) and the intermediate-pressure cylinder (12) are both connected with at least one high-pressure heater, and the high-pressure heater connected with the high-pressure cylinder (11) is located downstream of the high-pressure heater connected with the intermediate-pressure cylinder (12).

7. The steam accumulator based peak shaving system for thermal power plant according to claim 6, wherein, The high-pressure heater comprises a first high-pressure heater (321), a second high-pressure heater (322) and a third high-pressure heater (323); Along the upstream-to-downstream direction of the water feeding assembly (31), the first high-pressure heater (321), the second high-pressure heater (322) and the third high-pressure heater (323) are connected in sequence; The first high-pressure heater (321) is connected with the steam extraction end of the intermediate-pressure cylinder (12); The second high-pressure heater (322) is connected with the first steam extraction end of the high-pressure cylinder (11); The third high-pressure heater (323) is connected with the second steam extraction end of the high-pressure cylinder (11), and the steam extraction temperature of the second steam extraction end is greater than that of the first steam extraction end.

8. A peak regulation method based on the peak regulation system of any one of claims 1 to 7, characterized in that, The method comprises the following steps: When the unit load is reduced, the main steam of the unit is delivered to the steam accumulator (40), and the main steam is converted into high-pressure water and stored in the steam accumulator (40), so as to reduce the amount of steam entering the steam turbine (1) to do work; When the unit load is increased, the high-pressure water in the steam accumulator (40) is converted into steam, which is supplied to the water feeding assembly (3) instead of at least part of the steam extraction of the steam turbine (1), so as to preheat the water fed into the boiler (2) and increase the amount of steam entering the steam turbine (1) to do work.

9. The peak shaving method of claim 8, wherein, The method further comprises the following steps: When the unit load is increased, the high-pressure water in the steam accumulator (40) is converted into steam, and the steam is supplied to the reheated steam pipe (22) of the boiler (2) together with the exhaust steam of the high-pressure cylinder (11), so as to increase the amount of steam entering the steam turbine (1) to do work.

10. The peak shaving method of claim 9, wherein, The method further comprises the following steps: When the unit load is increased, the steam generated by the steam accumulator (40) is first used to replace the steam extraction of the high-pressure cylinder (11) of the steam turbine (1) for the water feeding assembly (3), then the steam generated by the steam accumulator (40) is used to replace the steam extraction of the high-pressure cylinder (11) of the steam turbine (1) for the reheated steam pipe (22), and finally the steam generated by the steam accumulator (40) is used to replace the steam extraction of the intermediate-pressure cylinder (12) of the steam turbine (1).

11. The peak shaving method of claim 8, wherein, The method further comprises the following steps: When the unit load is reduced, the steam flow rate entering the steam accumulator (40) is changed to change the rate of unit load reduction; When the unit load is increased, the steam flow rate delivered by the steam accumulator (40) to the heating assembly (32) and the reheated steam pipe (22) is changed to change the rate of unit load increase.

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