Power generation system

Abstract

The invention provides a power generation system which comprises a steam generation system and a thermal power generation system. The thermal power generation system comprises a coal-fired boiler, a steam turbine and a generator; the turbine is connected with the generator; the coal-fired boiler comprises a coal-fired boiler heating section and a coal-fired boiler reheater; the steam turbine comprises a high-pressure cylinder and a medium-low-pressure cylinder; the steam generation system comprises a heat storage module, a steam generation module and a feed water heating system; the steam generation module comprises an initial heating section and an initial reheating section. According to the technical scheme, the steam generation system is introduced into an existing or newly-built thermal power generation system, the steam generation system and the coal-fired boiler are connected in series, meanwhile, the bypass system is arranged in a matched mode, high-efficiency combination of the steam generation system and the coal-fired boiler is achieved, and compared with a pure thermal power generation system of the same scale, the scale of the coal-fired boiler is reduced; and the deep peak regulation capability and the rapid load change capability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power generation, and in particular to a power generation system. Background Art

[0002] "Carbon peak" and "carbon neutrality" are the overall goals of current energy development, but for energy security and energy guarantee, it is still necessary to vigorously develop thermal power generation. However, the thermal power generation system is limited by the minimum stable combustion load of coal-fired boilers and the factors of preventing the heating surface from overheating. Its deep peak regulation capacity is generally not less than 25% of the rated power. In addition, large-scale new thermal power installed capacity will also bring more carbon emissions. Therefore, in order to reduce carbon emissions, it is a general trend to vigorously develop the combined power generation technology of new energy power generation and thermal power generation.

[0003] However, due to the physical properties of the heat storage medium in the current steam generation system, for example, the steam generation system using molten salt as the heat storage medium can only produce subcritical steam at a temperature of 550°C, while the superheated steam parameters at the outlet of the coal-fired boiler of traditional thermal power generation have reached supercritical steam at 600°C after years of development. Due to the inconsistency of the steam parameters generated by the coal-fired boiler and the steam generation system, it is impossible to directly complete the combined power generation, or the power generation efficiency of the system after the direct combination is low (according to the Rankine cycle principle, increasing the steam temperature at the inlet of the steam turbine can improve the efficiency of the thermal system). Therefore, how to efficiently couple the steam generation system with the coal-fired boiler is the key to reducing carbon emissions in thermal power generation. Summary of the invention

[0004] In view of the defects in the prior art, the purpose of the present invention is to provide a power generation system, which introduces a steam generation system into an existing or newly built thermal power generation system, and sets the steam generation system in series with a coal-fired boiler, and at the same time sets a bypass system, thereby achieving a high-efficiency combination of the steam generation system and the coal-fired boiler. Compared with a pure thermal power generation system of the same scale, the scale of the coal-fired boiler is reduced, and the deep peak-shaving capability and the rapid load change capability are improved.

[0005] The present invention provides a power generation system, comprising a steam generation system and a thermal power generation system; The thermal power generation system comprises a coal-fired boiler, a steam turbine and a generator; the steam turbine is connected to the generator; The coal-fired boiler includes a coal-fired boiler heating section and a coal-fired boiler reheater; the steam turbine includes a high-pressure cylinder and a medium- and low-pressure cylinder; The steam generation system comprises a heat storage module, a steam generation module and a feedwater heating system; The steam generation module includes an initial heating section and an initial reheating section; The main steam output end of the heating section of the coal-fired boiler is connected to the steam input end of the high-pressure cylinder, the steam discharge end of the high-pressure cylinder is connected to the steam input end of the initial reheat section, the steam output end of the initial reheat section is connected to the steam input end of the coal-fired boiler reheater, the steam output end of the coal-fired boiler reheater is connected to the steam input end of the medium and low pressure cylinders; the steam discharge end of the high-pressure cylinder is also connected to the steam input end of the coal-fired boiler reheater; The output end of the feedwater heating system is connected to the water working medium input end of the initial heating section, and the superheated steam output end of the initial heating section is connected to the steam input end of the coal-fired boiler heating section; the output end of the feedwater heating system is also connected to the water working medium input end of the coal-fired boiler heating section; The water working medium input end of the heating section of the coal-fired boiler and the steam input end of the heating section of the coal-fired boiler are the same port or different ports; The high-temperature heat storage medium output end of the heat storage module is connected to the heat storage medium input end of the initial heating section, and the heat storage medium output end of the initial heating section is connected to the low-temperature heat storage medium input end of the heat storage module; the high-temperature heat storage medium output end of the heat storage module is also connected to the heat storage medium input end of the initial reheating section, and the heat storage medium output end of the initial reheating section is connected to the low-temperature heat storage medium input end of the heat storage module.

[0006] Further, the initial heating section includes a preheating section, an evaporation section and a superheating section; The output end of the feedwater heating system is connected to the water working medium input end of the preheating section, the water working medium output end of the preheating section is connected to the water working medium input end of the evaporation section, the steam output end of the evaporation section is connected to the steam input end of the superheating section, and the superheated steam output end of the superheating section is connected to the steam input end of the coal-fired boiler heating section; The high-temperature heat storage medium output end of the heat storage module is connected to the heat storage medium input end of the superheating section, the heat storage medium output end of the superheating section is connected to the heat storage medium input end of the evaporation section, the heat storage medium output end of the evaporation section is connected to the heat storage medium input end of the preheating section, and the heat storage medium output end of the preheating section is connected to the low-temperature heat storage medium input end of the heat storage module.

[0007] Further, the feedwater heating system includes a condensate pump, a low-pressure heating system, a deaerator, a deoxygenated water delivery pump and a high-pressure heating system; The output end of the condensate pump is connected to the water working medium input end of the low-pressure heating system, the water working medium output end of the low-pressure heating system is connected to the water working medium input end of the deaerator, the water working medium output end of the deaerator is connected to the water working medium input end of the deoxygenated water delivery pump, the water working medium output end of the deoxygenated water delivery pump is connected to the water working medium input end of the high-pressure heating system, and the water working medium output end of the high-pressure heating system is respectively connected to the water working medium input end of the initial heating section and the water working medium input end of the coal-fired boiler heating section.

[0008] Furthermore, the heating source of the feedwater heating system is extraction steam from a steam turbine and / or extraction steam from the steam generating system.

[0009] Furthermore, it also includes a condensing device, the exhaust steam discharge end of the medium and low pressure cylinders is connected to the input end of the condensing device, and the output end of the condensing device is connected to the input end of the condensate pump.

[0010] Furthermore, the main steam output end of the heating section of the coal-fired boiler is connected to the steam input end of the high-pressure cylinder through a main steam pipeline, the steam discharge end of the high-pressure cylinder is connected to the steam input end of the initial reheat section through a high-pressure cylinder exhaust pipeline, the steam output end of the initial reheat section is connected to the steam input end of the coal-fired boiler reheater through a second pipeline, and the steam output end of the coal-fired boiler reheater is connected to the steam input end of the medium and low pressure cylinders through a hot reheat pipeline; The output end of the feedwater heating system is connected to the water medium input end of the initial heating section through a feedwater pipeline, and the superheated steam output end of the initial heating section is connected to the steam input end of the coal-fired boiler heating section through a first pipeline; Wherein, a high-pressure cylinder exhaust steam pipeline control valve is arranged on the high-pressure cylinder exhaust steam pipeline, and a water supply pipeline control valve is arranged on the water supply pipeline.

[0011] Furthermore, it also includes a bypass pipe for the high-pressure cylinder exhaust pipe and a bypass pipe for the water supply pipe; One end of the bypass pipe of the high-pressure cylinder exhaust steam pipeline is connected to the high-pressure cylinder exhaust steam pipeline, and the other end is connected to the second pipeline; the bypass pipe of the high-pressure cylinder exhaust steam pipeline is provided with a bypass pipe control valve of the high-pressure cylinder exhaust steam pipeline; One end of the water supply pipeline bypass pipe is connected to the water supply pipeline, and the other end is connected to the water medium input end of the heating section of the coal-fired boiler; the water supply pipeline bypass pipe is provided with the water supply pipeline bypass pipe control valve; The high-pressure cylinder exhaust steam pipeline control valve is located between the exhaust steam connection point and the initial reheating section, and the exhaust steam connection point is the connection point between the high-pressure cylinder exhaust steam pipeline and the high-pressure cylinder exhaust steam pipeline bypass pipe; the water supply pipeline control valve is located between the water supply connection point and the initial heating section, and the water supply connection point is the connection point between the water supply pipeline and the water supply pipeline bypass pipe.

[0012] Furthermore, the exhaust steam discharge end of the intermediate and low pressure cylinders is connected to the input end of the condensing device through intermediate and low pressure cylinder exhaust steam pipelines.

[0013] Furthermore, the heat storage medium in the heat storage module is heated by a tower solar thermal collection system; or, The heat storage medium in the heat storage module is heated by an electric heater, and the electric energy required by the electric heater comes from a photovoltaic power generation system or a wind power generation system.

[0014] Furthermore, the heat storage medium in the heat storage module is molten salt.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. In the existing thermal power generation system, in order to maintain the normal operation of the thermal power generation system, a large amount of coal needs to be consumed and a large amount of carbon emissions are generated. The present invention proposes a power generation system, which uses a steam generation system (such as a molten salt steam generation system) and a coal-fired boiler to jointly provide the required energy for the steam turbine generator set in the entire power generation system. Compared with a pure thermal power generation system of the same scale, it can effectively reduce the scale of the coal-fired boiler, and then effectively reduce the consumption of coal, reduce carbon emissions, and solve the problem of high carbon emission levels of pure coal-fired boilers.

[0016] 2. In the actual operation process, the power generation system needs to participate in the peak load regulation of the power grid according to the dispatching instructions of the power grid. The existing thermal power generation system performs peak load regulation by reducing the output load of the coal-fired boiler to the steam turbine generator set. However, due to its own characteristics, the coal-fired boiler has a minimum stable combustion load requirement (that is, below the minimum stable combustion load, the coal in the coal-fired boiler cannot burn stably). Therefore, the peak load regulation capacity of a pure thermal power generation system is limited. In the power generation system provided by the present invention, since the scale of the coal-fired boiler can be reduced due to the introduction of the steam generation system into the power generation system, the minimum output load of the power generation system in the present invention to the power grid can be further reduced compared with the pure thermal power generation system of the same scale, thereby improving the deep peak-shaving capability of the power generation system of the present invention; at the same time, the energy in the steam generation system comes from renewable energy (such as clean energy provided by solar energy or wind energy, and further such as the heat storage medium in the heat storage module is heated by a tower solar thermal collection system or the heat storage medium in the heat storage module is heated by an electric heater and the electric energy required by the electric heater comes from a photovoltaic power generation system or a wind power generation system), therefore, compared with the thermal power generation system of the same scale, carbon emissions can be effectively reduced; in addition, since the steam generation system has the ability to quickly change loads, the ability of the power generation system to quickly change loads can also be improved.

[0017] 3. Since the main steam parameters produced in the coal-fired boiler do not match the steam parameters produced by the steam generating system (such as the molten salt steam generating system), they cannot be directly connected to the same steam turbine. The present invention achieves a high-efficiency combination of the steam generating system and the coal-fired boiler by connecting the steam generating system in series with the coal-fired boiler and coordinating with a bypass system. This solves the problem of how to achieve efficient joint operation of the steam generating system and the coal-fired boiler under different design parameters, and solves the problem of decreased thermal cycle efficiency due to the introduction of the steam generating system.

[0018] 4. The present invention makes full use of the advantage of coal-fired boilers in improving cycle efficiency, and innovatively designs a serial process of a steam generation system (such as a molten salt steam generation system) and a coal-fired boiler, so that the steam generated by the steam generation system can further increase the temperature in the coal-fired boiler, thereby improving the efficiency of the power generation system of the present invention. At the same time, the present invention does not make any equipment changes to the original steam turbine and coal-fired boiler, but only adds a steam generation system, thereby reducing the transformation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 A schematic structural diagram of a power generation system provided by an embodiment of the present invention.

[0020] In the figure: 10. Steam generation system; 11. Initial heating section; 12. Initial reheating section; 21. High-pressure cylinder; 22. Medium- and low-pressure cylinders; 24. Generator; 90. Coal-fired boiler; 91. Heating section of coal-fired boiler; 92. Reheater of coal-fired boiler; 110, first pipeline; 120, second pipeline; 200, high-pressure cylinder exhaust pipeline; 201, high-pressure cylinder exhaust pipeline control valve; 210, high-pressure cylinder exhaust pipeline bypass pipe; 211, high-pressure cylinder exhaust pipeline bypass pipe control valve; 230. Exhaust pipes for medium and low pressure cylinders; 30. Condensation device; 40. Feedwater heating system; 400. Feedwater pipeline; 401. Feedwater pipeline control valve; 410. Feedwater pipeline bypass pipe; 411. Feedwater pipeline bypass pipe control valve; 402. Condensate pump; 403. Low-pressure heating system; 404. Deaerator; 405. Deaerated water delivery pump; 406. High-pressure heating system; 910, main steam pipeline; 920, hot reheat pipeline. DETAILED DESCRIPTION

[0021] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0022] See also Figure 1 , a power generation system provided in an embodiment of the present application includes a steam generation system 10 and a thermal power generation system; The thermal power generation system includes a coal-fired boiler 90, a steam turbine and a generator 24; the steam turbine is connected to the generator 24; The coal-fired boiler 90 includes a coal-fired boiler heating section 91 and a coal-fired boiler reheater 92; the steam turbine includes a high-pressure cylinder 21 and a medium- and low-pressure cylinder 22; wherein the medium- and low-pressure cylinder refers to the medium-pressure cylinder sub-cylinder and the low-pressure cylinder sub-cylinder, or the medium- and low-pressure cylinder refers to the whole after the medium-pressure cylinder sub-cylinder and the low-pressure cylinder sub-cylinder are combined.

[0023] The steam generation system 10 includes a heat storage module, a steam generation module, a bypass system and a feedwater heating system 40; The steam generation module includes an initial heating section 11 and an initial reheating section 12; The bypass system includes exhaust steam bypass and feed water bypass; The main steam output end of the heating section 91 of the coal-fired boiler is connected to the steam input end of the high-pressure cylinder 21, the steam discharge end of the high-pressure cylinder 21 is connected to the steam input end of the initial reheat section 12, the steam output end of the initial reheat section 12 is connected to the steam input end of the coal-fired boiler reheater 92, and the steam output end of the coal-fired boiler reheater 92 is connected to the steam input end of the medium and low pressure cylinder 22; the steam discharge end of the high-pressure cylinder 21 is also connected to the steam input end of the exhaust steam bypass, and the steam output end of the exhaust steam bypass is connected to the steam input end of the coal-fired boiler reheater 92; The output end of the feedwater heating system 40 is connected to the water working medium input end of the initial heating section 11, and the superheated steam output end of the initial heating section 11 is connected to the steam input end of the coal-fired boiler heating section 91; the output end of the feedwater heating system 40 is also connected to the water working medium input end of the feedwater bypass, and the water working medium output end of the feedwater bypass is connected to the water working medium input end of the coal-fired boiler heating section 91; The water medium input end of the coal-fired boiler heating section 91 and the steam input end of the coal-fired boiler heating section 91 are the same port or different ports, which can be selected according to actual needs.

[0024] The high-temperature heat storage medium output end of the heat storage module is connected to the heat storage medium input end of the initial heating section 11, and the heat storage medium output end of the initial heating section 11 is connected to the low-temperature heat storage medium input end of the heat storage module; the high-temperature heat storage medium output end of the heat storage module is also connected to the heat storage medium input end of the initial reheating section 12, and the heat storage medium output end of the initial reheating section 12 is connected to the low-temperature heat storage medium input end of the heat storage module.

[0025] In this embodiment, the heat storage module includes a low-temperature heat storage unit for storing a low-temperature heat storage medium and a high-temperature heat storage unit for storing a high-temperature heat storage medium. In addition, in this embodiment, the low-temperature heat storage unit is a low-temperature storage tank, and the high-temperature heat storage unit is a high-temperature storage tank. Of course, in other embodiments, the low-temperature heat storage unit and the high-temperature heat storage unit may also be two independent spaces separated from each other in one storage tank.

[0026] In a specific embodiment, the initial heating section 11 includes a preheating section, an evaporation section, and a superheating section; The output end of the feedwater heating system 40 is connected to the water working medium input end of the preheating section, the water working medium output end of the preheating section is connected to the water working medium input end of the evaporation section, the steam output end of the evaporation section is connected to the steam input end of the superheating section, and the superheated steam output end of the superheating section is connected to the steam input end of the coal-fired boiler heating section 91; The high-temperature heat storage medium output end of the heat storage module is connected to the heat storage medium input end of the superheating section, the heat storage medium output end of the superheating section is connected to the heat storage medium input end of the evaporation section, the heat storage medium output end of the evaporation section is connected to the heat storage medium input end of the preheating section, and the heat storage medium output end of the preheating section is connected to the low-temperature heat storage medium input end of the heat storage module; The feedwater heating system 40 includes a condensate pump 402, a low-pressure heating system 403, a deaerator 404, a deoxygenated water delivery pump 405 and a high-pressure heating system 406; The output end of the condensate pump 402 is connected to the water working medium input end of the low-pressure heating system 403, the water working medium output end of the low-pressure heating system 403 is connected to the water working medium input end of the deaerator 404, the water working medium output end of the deaerator 404 is connected to the water working medium input end of the deoxygenated water delivery pump 405, the water working medium output end of the deoxygenated water delivery pump 405 is connected to the water working medium input end of the high-pressure heating system 406, and the water working medium output end of the high-pressure heating system 406 is respectively connected to the water working medium input end of the initial heating section 11 and the water working medium input end of the coal-fired boiler heating section 91; The power generation system in this embodiment also includes a condensing device 30, the exhaust steam discharge end of the medium and low pressure cylinder 22 is connected to the input end of the condensing device 30, and the output end of the condensing device 30 is connected to the input end of the condensate pump 402; The heating source of the feedwater heating system 40 comes from the steam turbine and / or the extracted steam in the steam generating system; the specific setting can be designed according to the requirements; Each device or structure is connected by a pipeline, and each pipeline is equipped with an isolation valve as required; The heat in the heat storage module comes from renewable energy; the renewable energy is preferably solar energy or wind energy. Specifically, the heat storage medium in the heat storage module is heated by a tower solar thermal collection system; or, the heat storage medium in the heat storage module is heated by an electric heater, and the electric energy required by the electric heater comes from a photovoltaic power generation system or a wind power generation system. Preferably, the heat storage medium in the heat storage module is molten salt.

[0027] The condensing device 30 in this embodiment includes an exhaust steam condensing device and a condensate tank. The exhaust steam output end of the medium and low pressure cylinder 23 is connected to the input end of the exhaust steam condensing device, the water working medium output end of the exhaust steam condensing device is connected to the water working medium input end of the condensate tank, and the water working medium output end of the condensate tank is connected to the water working medium input end of the condensate pump 402.

[0028] Preferably, the high-pressure cylinder 21 is of single-cylinder design, and the medium- and low-pressure cylinders 22 can be of single-cylinder or double-cylinder design.

[0029] In an optional embodiment, the heat storage medium in the heat storage module is heated by a tower solar thermal collection system; the tower solar thermal collection system includes a heliostat field and a heat absorber, the low-temperature heat storage medium output end of the heat storage module is connected to the heat storage medium input end of the heat absorber, and the heat storage medium output end of the heat absorber is connected to the high-temperature heat storage medium input end of the heat storage module; the heat absorber is used to heat the low-temperature heat storage medium in the heat absorber into a high-temperature heat storage medium by using sunlight reflected by the heliostat field; the steam generation system adopts a molten salt steam generation system, and the heat storage module adopts a molten salt heat storage module, that is, the heat storage medium in the heat storage module is molten salt (molten state of inorganic salt, such as molten state of a mixture of sodium nitrate and potassium nitrate); The main steam output end of the heating section 91 of the coal-fired boiler is connected to the steam input end of the high-pressure cylinder 21 through the main steam pipeline 910, the steam discharge end of the high-pressure cylinder 21 is connected to the steam input end of the initial reheat section 12 through the high-pressure cylinder exhaust pipeline 200, the steam output end of the initial reheat section 12 is connected to the steam input end of the coal-fired boiler reheater 92 through the second pipeline 120, and the steam output end of the coal-fired boiler reheater 92 is connected to the steam input end of the medium and low pressure cylinder 22 through the hot reheat pipeline 920; The output end of the feed water heating system 40 is connected to the water medium input end of the initial heating section 11 through the feed water pipeline 400, and the superheated steam output end of the initial heating section 11 is connected to the steam input end of the coal-fired boiler heating section 91 through the first pipeline 110; The exhaust steam bypass includes a high-pressure cylinder exhaust steam pipeline bypass pipe 210, and the feed water bypass includes a feed water pipeline bypass pipe 410; one end of the high-pressure cylinder exhaust steam pipeline bypass pipe 210 is connected to the high-pressure cylinder exhaust steam pipeline 200, and the other end is connected to the second pipeline 120; when the water working medium input end of the coal-fired boiler heating section 91 and the steam input end of the coal-fired boiler heating section 91 are the same port, one end of the feed water pipeline bypass pipe 410 is connected to the feed water pipeline 400, and the other end is connected to the first pipeline 110; when the water working medium input end of the coal-fired boiler heating section 91 and the steam input end of the coal-fired boiler heating section 91 are different ports, one end of the feed water pipeline bypass pipe 410 is connected to the feed water pipeline 400, and the other end is connected to the water working medium input end of the coal-fired boiler heating section 91; The extraction steam input end of the low-pressure heating system 403 is connected to the extraction steam output end of the medium-low pressure cylinder 22, and the extraction steam input end of the high-pressure heating system 406 is connected to the extraction steam output end of the evaporation section, the high-pressure cylinder 21 and / or the medium-low pressure cylinder 22; Among them, a high-pressure cylinder exhaust steam pipeline control valve 201 is provided on the high-pressure cylinder exhaust steam pipeline 200, a feed water pipeline control valve 401 is provided on the feed water pipeline 400, a high-pressure cylinder exhaust steam pipeline bypass pipe control valve 211 is provided on the high-pressure cylinder exhaust steam pipeline bypass pipe 210, and a feed water pipeline bypass pipe control valve 411 is provided on the feed water pipeline bypass pipe 410; the high-pressure cylinder exhaust steam pipeline control valve 201 is located between the exhaust steam connection point and the initial reheating section 12, and the exhaust steam connection point is the connection point between the high-pressure cylinder exhaust steam pipeline 200 and the high-pressure cylinder exhaust steam pipeline bypass pipe 210; the feed water pipeline control valve 401 is located between the feed water connection point and the initial heating section 11, and the feed water connection point is the connection point between the feed water pipeline 400 and the feed water pipeline bypass pipe 410.

[0030] In a specific scenario, when the power grid requires a deep reduction in the power generation load, since the coal-fired boiler 90 is not allowed to be frequently started and stopped, it is necessary to keep the coal-fired boiler 90 running while the molten salt steam generation system is shut down and isolated. The isolation measures are as follows: close the feed water pipeline control valve 401 and the high-pressure cylinder exhaust pipeline control valve 201, open the high-pressure cylinder exhaust pipeline bypass pipe control valve 211 and the feed water pipeline bypass pipe control valve 411. At this time, only the coal-fired boiler 90 participates in the operation of the power generation system, and its specific process is: the main steam is generated by the heating section 91 of the coal-fired boiler, enters the high-pressure cylinder 21 through the main steam pipeline 910 to work, and then enters the coal-fired boiler reheater 92 through the high-pressure cylinder exhaust pipeline 200, is heated by the coal-fired boiler reheater 92, enters the medium and low pressure cylinder 22 through the hot reheat pipeline 920 to work, and is discharged through the medium and low pressure cylinder exhaust pipeline 230. The steam in the medium and low pressure cylinder exhaust pipe 230 is condensed and heated by the feed water heating system 40, and then flows through the feed water pipe 400 and the feed water pipe bypass pipe 410 in sequence, and finally enters the coal-fired boiler heating section 91 to be heated to generate main steam, thus completing the circulation of the water working medium.

[0031] When the power grid is at peak hours in the morning and evening or requires maximum load output, the molten salt steam generation system operates in conjunction with the coal-fired boiler 90. At this time, the molten salt steam generation system and the coal-fired boiler 90 operate in series, and the specific process is as follows: The process of the water medium side in the joint operation is as follows: First, the water medium in the water supply pipeline 400 is heated in the initial heating section 11 and the coal-fired boiler heating section 91 in turn, and finally enters the high-pressure cylinder 21 through the main steam pipeline 910 from the steam outlet of the coal-fired boiler heating section 91, and is discharged from the high-pressure cylinder exhaust pipeline 210 after doing work, and the discharged steam enters the initial reheater 12. After that, after being heated in the initial reheater 12 and the coal-fired boiler reheater 92 in turn, it enters the medium and low pressure cylinder 22 through the hot reheat pipeline 920 to do work, and the exhaust steam after doing work enters the exhaust condensation device and the condensate water tank through the medium and low pressure cylinder exhaust pipeline 230 for condensation.

[0032] The feedwater heating system 40 heats and pressurizes the water medium output from the condensing device 30 and then enters the initial heating section 11 through the feedwater pipeline 400, wherein the heat source of the feedwater heating system 40 comes from the steam turbine and the extraction steam in the molten salt steam generation system.

[0033] In the combined operation mode, if the load and temperature of the coal-fired boiler heating section 91 need to be regulated, it is possible not only to control the combustion of the coal, but also to adjust the flow of the relatively low-temperature water medium in the bypass pipe 410 of the water supply pipe into the coal-fired boiler heating section 91 by adjusting the opening of the bypass pipe control valve 411 of the water supply pipe, thereby achieving load and temperature regulation of the coal-fired boiler heating section 91. Similarly, if local dry burning occurs in the coal-fired boiler reheater 92, causing its temperature to be too high, the flow of the relatively low-temperature steam in the bypass pipe 210 of the high-pressure cylinder exhaust pipe into the second pipeline 120 is adjusted by adjusting the opening of the bypass pipe control valve 211 of the high-pressure cylinder exhaust pipe, thereby achieving load and temperature regulation of the coal-fired boiler reheater 92.

[0034] As the load of the molten salt steam generation system and the load of the coal-fired boiler continue to increase, the power generation capacity of the entire power generation system also increases.

[0035] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A power generation system, characterized in that: It includes a steam generation system (10) and a thermal power generation system; The thermal power generation system comprises a coal-fired boiler (90), a steam turbine and a generator (24); the steam turbine is connected to the generator (24); The coal-fired boiler (90) comprises a coal-fired boiler heating section (91) and a coal-fired boiler reheater (92); the steam turbine comprises a high-pressure cylinder (21) and medium- and low-pressure cylinders (22); The steam generation system (10) comprises a heat storage module, a steam generation module and a feedwater heating system (40); The steam generation module comprises an initial heating section (11) and an initial reheating section (12); The main steam output end of the coal-fired boiler heating section (91) is connected to the steam input end of the high-pressure cylinder (21), the steam discharge end of the high-pressure cylinder (21) is connected to the steam input end of the initial reheat section (12), the steam output end of the initial reheat section (12) is connected to the steam input end of the coal-fired boiler reheater (92), the steam output end of the coal-fired boiler reheater (92) is connected to the steam input end of the medium- and low-pressure cylinders (22); the steam discharge end of the high-pressure cylinder (21) is also connected to the steam input end of the coal-fired boiler reheater (92); The output end of the feedwater heating system (40) is connected to the water working medium input end of the initial heating section (11), and the superheated steam output end of the initial heating section (11) is connected to the steam input end of the coal-fired boiler heating section (91); the output end of the feedwater heating system (40) is also connected to the water working medium input end of the coal-fired boiler heating section (91); The water working medium input end of the coal-fired boiler heating section (91) and the steam input end of the coal-fired boiler heating section (91) are the same port or different ports; The high-temperature heat storage medium output end of the heat storage module is connected to the heat storage medium input end of the initial heating section (11), and the heat storage medium output end of the initial heating section (11) is connected to the low-temperature heat storage medium input end of the heat storage module; the high-temperature heat storage medium output end of the heat storage module is also connected to the heat storage medium input end of the initial reheating section (12), and the heat storage medium output end of the initial reheating section (12) is connected to the low-temperature heat storage medium input end of the heat storage module.

2. A power generation system according to claim 1, characterized in that: The initial heating section (11) comprises a preheating section, an evaporation section and a superheating section; The output end of the feedwater heating system (40) is connected to the water working medium input end of the preheating section, the water working medium output end of the preheating section is connected to the water working medium input end of the evaporation section, the steam output end of the evaporation section is connected to the steam input end of the superheating section, and the superheated steam output end of the superheating section is connected to the steam input end of the coal-fired boiler heating section (91); The high-temperature heat storage medium output end of the heat storage module is connected to the heat storage medium input end of the superheating section, the heat storage medium output end of the superheating section is connected to the heat storage medium input end of the evaporation section, the heat storage medium output end of the evaporation section is connected to the heat storage medium input end of the preheating section, and the heat storage medium output end of the preheating section is connected to the low-temperature heat storage medium input end of the heat storage module.

3. A power generation system according to claim 1, characterized in that: The feedwater heating system (40) comprises a condensate pump (402), a low-pressure heating system (403), a deaerator (404), a deoxygenated water delivery pump (405) and a high-pressure heating system (406); The output end of the condensate pump (402) is connected to the water working medium input end of the low-pressure heating system (403), the water working medium output end of the low-pressure heating system (403) is connected to the water working medium input end of the deaerator (404), the water working medium output end of the deaerator (404) is connected to the water working medium input end of the deoxygenated water delivery pump (405), the water working medium output end of the deoxygenated water delivery pump (405) is connected to the water working medium input end of the high-pressure heating system (406), and the water working medium output end of the high-pressure heating system (406) is respectively connected to the water working medium input end of the initial heating section (11) and the water working medium input end of the coal-fired boiler heating section (91).

4. A power generation system according to claim 1, characterized in that: The heating source of the feedwater heating system (40) is extraction steam from the steam turbine and / or extraction steam from the steam generating system.

5. A power generation system according to claim 3, characterized in that: It also includes a condensing device (30), wherein the exhaust steam discharge end of the medium and low pressure cylinder (22) is connected to the input end of the condensing device (30), and the output end of the condensing device (30) is connected to the input end of the condensate pump (402).

6. A power generation system according to claim 1, characterized in that: The main steam output end of the coal-fired boiler heating section (91) is connected to the steam input end of the high-pressure cylinder (21) through a main steam pipeline (910); the steam discharge end of the high-pressure cylinder (21) is connected to the steam input end of the initial reheat section (12) through a high-pressure cylinder exhaust pipeline (200); the steam output end of the initial reheat section (12) is connected to the steam input end of the coal-fired boiler reheater (92) through a second pipeline (120); and the steam output end of the coal-fired boiler reheater (92) is connected to the steam input end of the medium- and low-pressure cylinders (22) through a hot reheat pipeline (920); The output end of the feedwater heating system (40) is connected to the water working medium input end of the initial heating section (11) via a feedwater pipeline (400), and the superheated steam output end of the initial heating section (11) is connected to the steam input end of the coal-fired boiler heating section (91) via a first pipeline (110); Wherein, a high-pressure cylinder exhaust steam pipeline control valve (201) is provided on the high-pressure cylinder exhaust steam pipeline (200), and a water supply pipeline control valve (401) is provided on the water supply pipeline (400).

7. A power generation system according to claim 6, characterized in that: It also includes a bypass pipe (210) for a high-pressure cylinder exhaust pipe and a bypass pipe (410) for a water supply pipe; One end of the high-pressure cylinder exhaust steam pipeline bypass pipe (210) is connected to the high-pressure cylinder exhaust steam pipeline (200), and the other end is connected to the second pipeline (120); the high-pressure cylinder exhaust steam pipeline bypass pipe (210) is provided with the high-pressure cylinder exhaust steam pipeline bypass pipe control valve (211); One end of the water supply pipeline bypass pipe (410) is connected to the water supply pipeline (400), and the other end is connected to the water working medium input end of the coal-fired boiler heating section (91); the water supply pipeline bypass pipe (410) is provided with the water supply pipeline bypass pipe control valve (411); The high-pressure cylinder exhaust steam pipeline control valve (201) is located between the exhaust steam connection point and the initial reheating section (12), and the exhaust steam connection point is the connection point between the high-pressure cylinder exhaust steam pipeline (200) and the high-pressure cylinder exhaust steam pipeline bypass pipe (210); the feed water pipeline control valve (401) is located between the feed water connection point and the initial heating section (11), and the feed water connection point is the connection point between the feed water pipeline (400) and the feed water pipeline bypass pipe (410).

8. A power generation system according to claim 5, characterized in that: The exhaust steam discharge end of the medium and low pressure cylinder (22) is connected to the input end of the condensing device via a medium and low pressure cylinder exhaust steam pipeline (230).

9. A power generation system according to any one of claims 1 to 8, characterized in that: The heat storage medium in the heat storage module is heated by a tower solar thermal collection system; or, The heat storage medium in the heat storage module is heated by an electric heater, and the electric energy required by the electric heater comes from a photovoltaic power generation system or a wind power generation system.

10. A power generation system according to any one of claims 1 to 8, characterized in that: The heat storage medium in the heat storage module is molten salt.

Images