阅读说明：本技术 一种发电厂抽汽调节结合小型汽机发电的飞轮储能系统 (Flywheel energy storage system combining steam extraction regulation of power plant and power generation of small-sized steam turbine ) 是由 杨利 余小兵 马汀山 王东晔 王伟 郑天帅 刘学亮 林轶 王春燕 李�昊 赵若昱 于 2021-08-26 设计创作，主要内容包括：本发明公开了一种发电厂抽汽调节结合小型汽机发电的飞轮储能系统,包括高压缸、主发电机及第一发电系统,第一发电系统包括第一切换阀门、第二切换阀门、第三切换阀门、小汽机、整流器及飞轮系统；高压缸的抽汽口经第一切换阀门与第二切换阀门的一端及第三切换阀门的一端相连通,第二切换阀门的另一端与小汽机的入口相连通,小汽机经整流器与飞轮系统相连接,小汽机的排汽口与第三切换阀门的另一端相连通,高压缸与主发电机相连接,该系统能够满足系统对变工况及调峰的需求,且能量储能过程不造成环境污染,成本低,使用寿命长,同时适合大规模应用。(The invention discloses a flywheel energy storage system for power plant steam extraction regulation combined with small-sized steam turbine power generation, which comprises a high-pressure cylinder, a main generator and a first power generation system, wherein the first power generation system comprises a first switching valve, a second switching valve, a third switching valve, a small steam turbine, a rectifier and a flywheel system; the high-pressure cylinder is connected with the main generator, the system can meet the requirements of the system on variable working conditions and peak regulation, the energy storage process does not cause environmental pollution, the cost is low, the service life is long, and the high-pressure cylinder is suitable for large-scale application.)

1. A flywheel energy storage system combining power plant extraction regulation and small-sized steam turbine power generation is characterized by comprising a high-pressure cylinder (1), a main generator (4) and a first power generation system, wherein the first power generation system comprises a first switching valve (11), a second switching valve (14), a third switching valve (15), a small steam turbine (10), a rectifier (8) and a flywheel system (7);

the steam extraction port of the high-pressure cylinder (1) is communicated with one end of a second switching valve (14) and one end of a third switching valve (15) through a first switching valve (11), the other end of the second switching valve (14) is communicated with the inlet of a small steam turbine (10), the small steam turbine (10) is connected with a flywheel system (7) through a rectifier (8), the steam exhaust port of the small steam turbine (10) is communicated with the other end of the third switching valve (15), and the high-pressure cylinder (1) is connected with a main generator (4).

2. The flywheel energy storage system for power generation by combining steam extraction regulation of a power plant and a small steam turbine as claimed in claim 1, further comprising a heat supply station (13) and a fourth switching valve (12), wherein the steam extraction port of the high pressure cylinder (1) is communicated with the inlet of the heat supply station (13) through the fourth switching valve (12), the steam exhaust port of the high pressure cylinder (1) is communicated with the inlet of the heat supply station (13), and the steam exhaust port of the small steam turbine (10) and the outlet of the heat supply station (13) are communicated with the water supply pipeline of an external boiler.

3. The flywheel energy storage system for regulating steam extraction in combination with small-sized steam turbine power generation in power plant according to claim 2, characterized in that the outlet of the heat supply station (13) is connected to the water supply pipeline of the external boiler through the water supply pump (6).

4. The flywheel energy storage system for power plant steam extraction regulation and small-sized turbine power generation combined according to claim 1, further comprising an intermediate pressure cylinder (2), a low pressure cylinder (3), a condenser (5), a second power generation system and a third power generation system, wherein the first power generation system, the second power generation system and the third power generation system have the same structure, a first switching valve (11) in the second power generation system is communicated with a steam outlet of the intermediate pressure cylinder (2), a first switching valve (11) in the third power generation system is communicated with a steam outlet of the low pressure cylinder (3), a steam outlet of the high pressure cylinder (1) is communicated with an inlet of the intermediate pressure cylinder (2), a steam outlet of the intermediate pressure cylinder (2) is communicated with an inlet of the low pressure cylinder (3), a steam outlet of the low pressure cylinder (3) is communicated with an inlet of the condenser (5), and an outlet of the condenser (5) is communicated with an external water supply pipeline of a boiler, the outlet of the small steam turbine (10) in the first power generation system, the outlet of the small steam turbine (10) in the second power generation system and the outlet of the small steam turbine (10) in the third power generation system are communicated with an external condenser.

5. The flywheel energy storage system for regulating the steam extraction of a power plant and combining small-sized steam turbine power generation according to claim 4, characterized in that the outlet of the condenser (5) is communicated with the water supply pipeline of the boiler through a water supply pump (6).

6. The flywheel energy storage system for power plant extraction regulation in combination with small steam engines to generate electricity according to claim 4, characterized in that the high pressure cylinder (1), the intermediate pressure cylinder (2) and the low pressure cylinder (3) are arranged coaxially.

7. The flywheel energy storage system combining the steam extraction regulation of the power plant and the small-sized turbine for power generation according to claim 1, further comprising an intermediate pressure cylinder (2), a low pressure cylinder (3), a condenser (5), a second power generation system and a third power generation system, wherein the first power generation system, the second power generation system and the third power generation system have the same structure, a first switching valve (11) in the second power generation system is communicated with a steam outlet of the intermediate pressure cylinder (2), a first switching valve (11) in the third power generation system is communicated with a steam outlet of the low pressure cylinder (3), a steam outlet of the high pressure cylinder (1) is communicated with an inlet of the intermediate pressure cylinder (2), a steam outlet of the intermediate pressure cylinder (2) is communicated with an inlet of the low pressure cylinder (3), a steam outlet of the low pressure cylinder (3) is communicated with an inlet of the condenser (5), and an outlet of the condenser (5) is communicated with an inlet of a heat absorption side of the first steam extraction regenerator (9) through a water feed pump (6), the outlet of the heat absorption side of the first steam extraction heat regenerator (9) is communicated with the water supply pipeline of an external boiler through the heat absorption side of the second steam extraction heat regenerator (9) and the heat absorption side of the third steam extraction heat regenerator (9), the outlet of a small steam turbine (10) in the first power generation system is communicated with the heat release side of a third steam extraction heat regenerator (9), the outlet of the small steam turbine (10) in the second power generation system is communicated with the heat release side of a second steam extraction heat regenerator (9), the outlet of the small steam turbine (10) in the third power generation system is communicated with the heat release side of the first steam extraction heat regenerator (9), the heat release side outlet of the third steam extraction heat regenerator (9) is communicated with the heat release side of the second steam extraction heat regenerator (9), the heat release side outlet of the second steam extraction heat regenerator (9) is communicated with the heat release side of the first steam extraction heat regenerator (9), and the heat release side outlet of the first steam extraction heat regenerator (9) is communicated with a steam condenser (5).

8. The flywheel energy storage system for power plant extraction regulation in combination with small steam engines to generate electricity according to claim 7, characterized in that the main generator (4), the high pressure cylinder (1), the intermediate pressure cylinder (2) and the low pressure cylinder (3) are arranged coaxially.

Technical Field

The invention belongs to the field of power engineering and energy storage, and relates to a flywheel energy storage system for power plant steam extraction regulation combined with small-sized steam turbine power generation.

Background

The electric energy is a secondary energy source, has the most extensive application, the most convenient use and the most friendly environment, and has very important significance for the development of national economy and the improvement of the living standard of people. As China has the advantages of rich coal resources, mature thermal power technology and the like, and thermal power generation is the main electric energy production mode of China at present. By the end of 2018, the thermal power installation amount in China is 11.4 hundred million kW, which accounts for more than 60% of the total installation amount in the country, and the annual power generation amount is 49231 kW.h, which accounts for more than 70% of the total power generation amount in the country. With the rise of new energy and nuclear energy, the occurrence of factors such as environmental pollution and energy shortage, the proportion of thermal power generation in the whole industry is predicted to be continuously reduced, and the proportion of installed thermal power capacity is reduced to 51% in 2030 years and 38% in 2050 years. However, the energy structure of which the primary energy is mainly coal in China determines that the power generation structure of which the power generation machine is mainly coal-fired power generation in China is difficult to change fundamentally for a long time.

The thermal power generating unit has the characteristics of good stability, long-time power plant, strong controllability and the like, the related technology is mature, and the thermal power generating unit occupies an important position in the traditional peak regulation mode. However, the problems of safety, economy, adjustability, and the like still exist due to the long response time, the large thermal inertia of the system as a whole, and the like. Particularly in the heat supply season, the thermal power generating unit not only processes the conventional power generation and peak regulation tasks, but also considers the heat supply task, and influences the peak regulation capability and effect of the thermal power generating unit. Especially, after large-scale new energy is accessed, many problems and difficulties are faced to planning, production and operation of a power grid, and many thermal power plants start to flexibly transform thermal power generating units so as to ensure stable operation of the power grid. The response speed of the thermal power generating unit is improved by improving the control strategy of thermal power generating unit equipment and a coordinated control system, and the frequency modulation and peak shaving capacity of the thermal power generating unit is further enhanced to meet the requirement of large-scale new energy grid connection.

The current energy consumption equipment and energy consumption mode make the most of the energy in the world wasted, so it is very important to research how to recover and store the wasted energy. The existing energy storage modes mainly include chemical energy storage, physical energy storage and other energy storage, among the energy storage modes, the chemical energy storage technology is mature and widely applied, but the defects are obvious: short service life, obvious influence on external conditions and environmental friendliness; the defects of the superconducting energy storage are as follows: the cost is high, the requirement on the environment is strict, and the method is not suitable for large-scale application for the moment; the physical energy storage is to store energy by a physical method, so the problem of environmental pollution does not exist, and the physical energy storage is more suitable for the current development requirement, so the requirements of a system on variable working conditions and peak regulation cannot be met.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a flywheel energy storage system for power generation by combining steam extraction regulation of a power plant with a small-sized steam turbine, the system can meet the requirements of the system on variable working conditions and peak shaving, the energy storage process does not cause environmental pollution, the cost is low, the service life is long, and the flywheel energy storage system is suitable for large-scale application.

In order to achieve the purpose, the flywheel energy storage system for power plant steam extraction regulation and small-sized steam turbine power generation comprises a high-pressure cylinder, a main generator and a first power generation system, wherein the first power generation system comprises a first switching valve, a second switching valve, a third switching valve, a small steam turbine, a rectifier and a flywheel system;

the steam extraction port of the high-pressure cylinder is communicated with one end of a second switching valve and one end of a third switching valve through a first switching valve, the other end of the second switching valve is communicated with the inlet of a small steam turbine, the small steam turbine is connected with a flywheel system through a rectifier, the steam exhaust port of the small steam turbine is communicated with the other end of the third switching valve, and the high-pressure cylinder is connected with the main generator.

The steam extraction port of the high-pressure cylinder is communicated with the inlet of the heat supply station through the fourth switching valve, the steam exhaust port of the high-pressure cylinder is communicated with the inlet of the heat supply station, and the steam exhaust port of the small steam engine and the outlet of the heat supply station are communicated with a water supply pipeline of an external boiler.

The outlet of the heat supply station is communicated with the water supply pipeline of the external boiler through a water supply pump.

The steam-gas-turbine-based power generation system comprises a high-pressure cylinder, a low-pressure cylinder, a steam condenser, a first power generation system and a third power generation system, wherein the high-pressure cylinder is communicated with a water inlet of the high-pressure cylinder, the low-pressure cylinder is communicated with a water inlet of the low-pressure cylinder, the steam outlet of the low-pressure cylinder is communicated with a water inlet of an external boiler, and an outlet of the low-pressure turbine in the first power generation system, an outlet of the low-pressure turbine in the second power generation system and an outlet of the low-pressure turbine in the third power generation system are communicated with an external condenser.

The outlet of the condenser is communicated with a water supply pipeline of the boiler through a water supply pump.

The high pressure cylinder, the intermediate pressure cylinder and the low pressure cylinder are coaxially arranged.

The system also comprises a medium pressure cylinder, a low pressure cylinder, a condenser, a second power generation system and a third power generation system, wherein the first power generation system, the second power generation system and the third power generation system have the same structure, a first switching valve in the second power generation system is communicated with a steam exhaust port of the medium pressure cylinder, a first switching valve in the third power generation system is communicated with a steam exhaust port of the low pressure cylinder, a steam exhaust port of a high pressure cylinder is communicated with an inlet of the medium pressure cylinder, a steam exhaust port of the medium pressure cylinder is communicated with an inlet of the low pressure cylinder, a steam exhaust port of the low pressure cylinder is communicated with an inlet of the condenser, an outlet of the condenser is communicated with a heat absorption side inlet of a first steam extraction heat regenerator through a feed water pump, a heat absorption side outlet of the first steam extraction heat regenerator is communicated with a water supply pipe steam passage of an external boiler through a heat absorption side of a second steam extraction heat regenerator and a heat absorption side of a third steam extraction heat regenerator, an outlet of a medium and small engine in the first power generation system is communicated with a heat release side of the third steam extraction heat regenerator, the outlet of the small steam turbine in the second power generation system is communicated with the heat release side of the second steam extraction heat regenerator, the outlet of the small steam turbine in the third power generation system is communicated with the heat release side of the first steam extraction heat regenerator, the heat release side outlet of the third steam extraction heat regenerator is communicated with the heat release side of the second steam extraction heat regenerator, the heat release side outlet of the second steam extraction heat regenerator is communicated with the heat release side of the first steam extraction heat regenerator, and the heat release side outlet of the first steam extraction heat regenerator is communicated with the condenser.

The main generator, the high-pressure cylinder, the intermediate-pressure cylinder and the low-pressure cylinder are coaxially arranged.

The invention has the following beneficial effects:

when the flywheel energy storage system for power plant steam extraction regulation and small-sized steam turbine power generation is in specific operation, the steam extraction of the high-pressure cylinder is sent into the small steam turbine, so that the superheated steam is utilized to do work to the maximum extent, and the part of steam extraction energy is converted into electric power, so that the variable working condition and peak regulation capability of the system are effectively improved, the heat transfer temperature difference in the heat regenerator is reduced, the total power generation efficiency of the system is improved, and the requirements of the system on the variable working condition and the peak regulation are met. In addition, the small steam turbine has a compact structure, can adapt to different working conditions of back pressure and pure condensation so as to meet different variable working condition requirements of the system, directly enters exhaust steam into the condenser when the system peak regulation needs quick load shedding, and greatly reduces the steam amount entering a lower-level cylinder in the main steam turbine, so that the regenerative heater is prevented from operating under severe working conditions, and the service life of the heater is prolonged; finally, the flywheel system is adopted for storing energy, so that the energy storage device has the characteristics of no environmental pollution in the energy storage process, low cost, long service life and suitability for large-scale application, and meanwhile, when the heat and electric load demands of the main system are increased, the steam amount entering the steam turbine is reduced, the flywheel system works in the reverse direction, and kinetic energy is converted into electric energy to be merged into a power grid; when the heat and electric load requirements of the main system are reduced, the amount of steam entering the small steam turbine is increased, the total energy storage amount is increased, the whole system is kept to work at high efficiency, and extra energy is not consumed.

Drawings

FIG. 1a is a diagram of a process T-s of work done before exhaust steam of a small steam turbine enters a regenerative heater;

FIG. 1b is a T-s diagram of the process of doing work after the exhaust steam of the small steam turbine enters the regenerative heater;

FIG. 2 is a schematic structural diagram according to a first embodiment;

FIG. 3 is a schematic structural diagram according to a second embodiment;

fig. 4 is a schematic structural diagram of the third embodiment.

Wherein, 1 is a high pressure cylinder, 2 is a medium pressure cylinder, 2, 3 is a low pressure cylinder, 4 is a main generator, 5 is a condenser, 6 is a water supply pump, 7 is a flywheel system, 8 is a rectifier, 9 is a steam extraction heat regenerator, 10 is a small steam turbine, 11 is a first switching valve, 12 is a fourth switching valve, 13 is a heat supply station, 14 is a second switching valve, and 15 is a third switching valve.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

There is shown in the drawings a schematic block diagram of a disclosed embodiment in accordance with the invention. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

Referring to fig. 1a and fig. 1b, the flywheel energy storage system for adjusting the steam extraction of the power plant and combining with the small-sized steam turbine to generate power according to the present invention includes a high-pressure cylinder 1, a main generator 4 and a first power generation system, wherein the first power generation system includes a first switching valve 11, a second switching valve 14, a third switching valve 15, a small steam turbine 10, a rectifier 8 and a flywheel system 7; the steam extraction port of the high pressure cylinder 1 is communicated with one end of a second switching valve 14 and one end of a third switching valve 15 through a first switching valve 11, the other end of the second switching valve 14 is communicated with the inlet of a small steam turbine 10, the small steam turbine 10 is connected with a flywheel system 7 through a rectifier 8, the steam exhaust port of the small steam turbine 10 is communicated with the other end of the third switching valve 15, and the high pressure cylinder 1 is connected with a main generator 4.

When the steam turbine works, the pressure drop of the exhaust steam pressure of the small steam turbine 10 is reduced by 10% -20% compared with the inlet steam pressure, the saturation temperature change of the steam entering the steam extraction heat regenerator 9 is limited, as shown in the working process T-s diagram of the system shown in fig. 1a and 1b, if the parameter of the steam extraction point is at the point b, the steam is overheated, and when the parameter is directly used for regenerative heating, the heat transfer temperature difference is too large, and the heat efficiency of the system is reduced. Therefore, the extracted steam is processed by the steam turbine to work, the steam discharge parameter is reduced to the point c or below, and even enters a near saturated wet steam area, as shown by the point d. The main purpose is to reduce the superheat degree of extracted steam, the latent heat of extracted steam can be fully utilized in the regenerative heating process, the heat transfer temperature difference is reduced, and the system efficiency is further improved;

the small steam turbine power generation system can belong to a straight condensing power generation system, the exhaust pressure is the same as the pressure of the condenser 5, when the output load is required to be reduced for a short time and the total energy storage amount of the flywheel is increased, the second switching valve 14 and the third switching valve 15 can be used for switching, most of the exhaust steam is introduced into the small steam turbine 10 for power generation, and the exhaust steam directly enters the condenser 5, so that the variable working condition requirement of load reduction in a power grid is met, the total energy storage amount of the system is increased, and the system is ensured to be at higher efficiency in the whole operation process;

the small steam turbine 10 provides energy for the flywheel system 7, the steam extraction amount and steam extraction parameters can be heated, the electric load demand is greatly fluctuated, and the electric power generated by the small steam turbine 10 is regulated and stabilized by the rectifier 8 and then supplied to the flywheel system 7 for energy storage;

in addition, when the load shedding of the main steam power generation system needs to cut off a large amount of heat or power supply, the energy of the redundant steam can be transferred through the first switching valve 11, the second switching valve 14 and the third switching valve 15, and the redundant energy is temporarily stored in the flywheel system 7 through the steam extraction work to meet the peak regulation requirement of the system;

the small turbine 10 has the capacity of storing energy to a flywheel and directly connecting to the grid for power generation while generating power, and can be adjusted in real time according to different working conditions and load requirements.

Example one

Referring to fig. 2, the present embodiment further includes an intermediate pressure cylinder 2, a low pressure cylinder 3, a condenser 5, a second power generation system and a third power generation system, wherein the first power generation system, the second power generation system and the third power generation system have the same structure, a first switching valve 11 in the second power generation system is communicated with a steam exhaust port of the intermediate pressure cylinder 2, a first switching valve 11 in the third power generation system is communicated with a steam exhaust port of the low pressure cylinder 3, a steam exhaust port of the high pressure cylinder 1 is communicated with an inlet of the intermediate pressure cylinder 2, a steam exhaust port of the intermediate pressure cylinder 2 is communicated with an inlet of the low pressure cylinder 3, a steam exhaust port of the low pressure cylinder 3 is communicated with an inlet of the condenser 5, an outlet of the condenser 5 is communicated with an inlet of a heat absorption side of the first steam extraction heat regenerator 9 through a water feed pump 6, an outlet of the heat absorption side of the first steam extraction heat regenerator 9 is communicated with a water supply pipeline of an external boiler through a heat absorption side of the second steam extraction heat regenerator 9 and a heat absorption side of the third steam extraction heat regenerator 9, the outlet of a small steam turbine 10 in the first power generation system is communicated with the heat release side of a third steam extraction heat regenerator 9, the outlet of the small steam turbine 10 in the second power generation system is communicated with the heat release side of a second steam extraction heat regenerator 9, the outlet of the small steam turbine 10 in the third power generation system is communicated with the heat release side of the first steam extraction heat regenerator 9, the outlet of the heat release side of the third steam extraction heat regenerator 9 is communicated with the heat release side of the second steam extraction heat regenerator 9, the outlet of the heat release side of the second steam extraction heat regenerator 9 is communicated with the heat release side of the first steam extraction heat regenerator 9, and the outlet of the heat release side of the first steam extraction heat regenerator 9 is communicated with a steam condenser 5; the main generator 4, the high pressure cylinder 1, the intermediate pressure cylinder 2 and the low pressure cylinder 3 are coaxially arranged.

The initial steam parameters in this example are: the pressure is 9.81MPa, the temperature is 540 ℃, the flow of superheated steam is 225t/h, the steam extraction parameters of the high-pressure cylinder 1 and the intermediate pressure cylinder 2 are not lower than 1MPa, and because the original steam turbine power generation system is large in size, the rapid adjustment of the steam flow, the temperature and the like is difficult to complete by means of a self-adjusting mode under the variable load conditions such as peak shaving and the like. Even if the system can achieve the adjusting effect through a self-adjusting mode, the short-time and time-varying working condition of the system still causes the problems of reduced operation efficiency, overhigh thermal shock of the system and the like, so an energy storage system needs to be designed aiming at the situation, 500kW (2-10min) is added according to the maximum output power of a single flywheel, and 30 flywheel energy storage arrays are arranged according to needs to ensure that when the load of a power grid changes, although the steam heat parameters of the original system cannot meet the short-time and large-range adjustment, the flywheel system 7 can obtain more excellent variable working condition parameters. The variable working condition requirement of the power grid is met, the redundant energy is stored or released on the premise that the overall efficiency is basically unchanged, the efficient utilization of primary energy is guaranteed, and the flexibility and the reliability of the system are improved.

When the boiler normally works, high-temperature and high-pressure steam output by the boiler sequentially enters the high-pressure cylinder 1, the intermediate-pressure cylinder 2 and the low-pressure cylinder 3, the high-pressure cylinder 1, the intermediate-pressure cylinder 2 and the low-pressure cylinder 3 are coaxially arranged and then connected with the main generator 4, and electric power generated by the main generator 4 is directly transmitted in a grid-connected mode. Steam is discharged from the low-pressure cylinder 3 and enters the condenser 5, the steam is condensed into saturated water and then enters the water feeding pump 6 to be pressurized and sequentially passes through the first steam extraction heat regenerator 9, the steam obtained from each stage of steam extraction heats the water supply step by step, the water supply enters the boiler to be further heated, and finally enters the next cycle, and the steam extraction at each stage can directly enter the steam extraction heat regenerator 9 instead of entering the steam turbine under the general condition.

When the working condition is changed and the output work needs to be reduced, the first switching valve 11 and the third switching valve 15 are adjusted to increase the steam extraction amount, so that the steam work is reduced, the coal consumption is reduced, and the purpose of changing the working condition is achieved. However, the variable working condition performance of some units is poor due to the unstable control system, for example, the performance of the DEH system is reduced, the peak modulation capability of the main steam turbine is reduced, the output control performance is poor, the instability and the risk of modulation of the system are increased, the thermal efficiency of the system is reduced due to the excessive deviation from the rated working condition, and the energy conservation and emission reduction are not facilitated. Therefore, the rectifier 8, the flywheel system 7 and the small steam turbine 10 are arranged, only the second switching valve 14 needs to be opened, the third switching valve 15 needs to be closed, most of steam flowing through the first switching valve 11 flows into the small steam turbine 10, electricity is directly generated through the small generator, electric energy is further converted into kinetic energy of the flywheel system 7 through the rectifying device, the energy is stored in the flywheel system 7, the stability of the main steam turbine during adjustment of the variable working conditions of the system is guaranteed, the dynamic characteristic of a boiler heating system is optimized, the efficiency of the whole system is guaranteed to be maintained near the rated efficiency, and the energy exceeding the load of the power grid is stored in the flywheel system 7 for next adjustment of the peak valley of the power grid. According to the basic parameters of the main steam engine and the flywheel system 7, the variable working condition efficiency of the system can be improved by 1% -3%, and the overshoot time is reduced by more than 50%. The small steam turbine 10 and the flywheel system 7 can be arranged at high, medium and low pressure steam extraction positions according to system characteristics so as to meet different variable working condition characteristic requirements.

Example two

Referring to fig. 3, the present embodiment further includes an intermediate pressure cylinder 2, a low pressure cylinder 3, a condenser 5, a second power generation system and a third power generation system, the first power generation system is the same as the second power generation system and the third power generation system in structure, a first switching valve 11 in the second power generation system is communicated with a steam exhaust port of an intermediate pressure cylinder 2, a first switching valve 11 in the third power generation system is communicated with a steam exhaust port of a low pressure cylinder 3, a steam exhaust port of a high pressure cylinder 1 is communicated with an inlet of the intermediate pressure cylinder 2, a steam exhaust port of the intermediate pressure cylinder 2 is communicated with an inlet of the low pressure cylinder 3, a steam exhaust port of the low pressure cylinder 3 is communicated with an inlet of a condenser 5, an outlet of the condenser 5 is communicated with a water supply pipeline of an external boiler, and an outlet of a small steam turbine 10 in the first power generation system, an outlet of the small steam turbine 10 in the second power generation system and an outlet of the small steam turbine 10 in the third power generation system are communicated with an external condenser; the outlet of the condenser 5 is communicated with a water supply pipeline of the boiler through a water supply pump 6; the high pressure cylinder 1, the intermediate pressure cylinder 2 and the low pressure cylinder 3 are coaxially arranged.

When the power of the steam power system is low, the steam extraction heat recovery system is not arranged, and as shown in fig. 3, the backpressure state of the small steam turbine 10 is changed into the pure steam condensation state, so that the flywheel system 7 can be matched with the low-power steam condenser unit, and meanwhile, the small steam turbine 10 has higher power generation efficiency under the same inlet steam parameter, so that the energy storage power of the flywheel system 7 is improved, and the requirement of variable working conditions in a wider range can be met.

EXAMPLE III

Referring to fig. 4, the present embodiment further includes a heat supply station 13 and a fourth switching valve 12, wherein the steam extraction port of the high pressure cylinder 1 is communicated with the inlet of the heat supply station 13 through the fourth switching valve 12, the steam extraction port of the high pressure cylinder 1 is communicated with the inlet of the heat supply station 13, and the steam extraction port of the small steam turbine 10 and the outlet of the heat supply station 13 are communicated with the water supply pipeline of the external boiler; the outlet of the heating plant 13 is communicated with the water supply pipeline of the external boiler through the water supply pump 6.

For an industrial park, the thermal power plant is responsible for both generating electricity and supplying heat, so a bypass is needed to be added, and the fourth switching valve 12 controls the amount of thermal steam, as shown in fig. 4. The extraction steam volume of the steam turbine has the following main effects:

1) providing higher parameter steam for supplying heat to the heating plant 13;

2) when the system is in a variable working condition and the load is reduced, steam is introduced into the small steam turbine 10 through the second switching valve 14, redundant steam does work in the steam turbine to generate electricity, and the energy is stored in the flywheel system 7 through rectification and secondary work;

3) if the power grid peak shaving needs to increase the output power, the kinetic energy is converted into electric power through the flywheel system 7 and the rectifier 8 and is output to the power grid;

4) when the system heating station 13 is in failure and the system is rapidly load shedding at the moment, the fourth switching valve 12 needs to be turned off emergently, the first switching valve 11 and the third switching valve 15 are opened, and the steam extraction amount is increased so as to ensure the safe and stable operation of the system.