A power generation system

Abstract

The application 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 first feedwater heating system, a steam turbine and a generator; the steam turbine is connected with the generator; the coal-fired boiler comprises a coal-fired boiler first reheater, a coal-fired boiler second reheater, a coal-fired boiler third reheater and a coal-fired boiler heating section; the steam turbine comprises a critical cylinder, 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 second feedwater heating system; the steam generation module comprises an initial reheating section and an initial heating section. The technical scheme realizes high-efficiency combination of the steam generation system and the coal-fired boiler, improves the deep peak regulation capacity and the quick load variation capacity by introducing the steam generation system into the existing or newly-built thermal power generation system, and arranging the steam generation system in series with the coal-fired boiler, and arranging the cylinder which only receives the supercritical steam generated by the coal-fired boiler.

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 overarching goals of current energy development, but for energy security and assurance, the vigorous development of thermal power generation remains necessary. However, thermal power systems are limited by the minimum stable combustion load of coal-fired boilers and the need to prevent overheating of the heating surfaces. Their deep peak-shaving capacity is generally no less than 25% of rated power. Furthermore, large-scale additions to thermal power generation capacity will also result in increased carbon emissions. Therefore, to reduce carbon emissions, the vigorous development of combined power generation technologies combining renewable energy and thermal power generation is an inevitable trend.

[0003] However, due to the physical properties of the heat storage medium in current steam generation systems, for example, steam generation systems using molten salt as the heat storage medium can only produce subcritical steam at a temperature of 550°C. However, after years of development, the superheated steam parameters at the outlet of traditional thermal power generation coal-fired boilers have reached supercritical steam at 600°C. Due to the inconsistent steam parameters produced by coal-fired boilers and steam generation systems, direct combined power generation cannot be achieved, or the power generation efficiency of the combined system is low (according to the Rankine cycle principle, increasing the steam temperature at the turbine inlet 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 response to the defects in the prior art, the purpose of the present invention is to provide a power generation system. By introducing a steam generation system into an existing or newly built thermal power generation system, and setting the steam generation system in series with a coal-fired boiler, and at the same time providing a cylinder that only receives supercritical steam generated by the coal-fired boiler, a high-efficiency combination of the steam generation system and the coal-fired boiler is achieved. 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;

[0006] The thermal power generation system includes a coal-fired boiler, a first feedwater heating system, a steam turbine and a generator; the steam turbine is connected to the generator;

[0007] The coal-fired boiler includes a first reheater of the coal-fired boiler, a second reheater of the coal-fired boiler, a third reheater of the coal-fired boiler and a heating section of the coal-fired boiler; the steam turbine includes a critical cylinder, a high-pressure cylinder and a medium- and low-pressure cylinder;

[0008] The steam generation system includes a heat storage module, a steam generation module and a second feedwater heating system;

[0009] The steam generation module includes an initial reheating section and an initial heating section;

[0010] The output end of the first feedwater heating system is connected to the water working medium input end of the heating section of the coal-fired boiler, the main steam output end of the heating section of the coal-fired boiler is connected to the steam input end of the critical cylinder, the steam discharge end of the critical cylinder is connected to the steam input end of the third reheater of the coal-fired boiler, the steam output end of the third reheater 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 second reheater of the coal-fired boiler, the steam output end of the second reheater of the coal-fired boiler is connected to the steam input ends 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 first reheater of the coal-fired boiler, and the steam output end of the first reheater of the coal-fired boiler is connected to the steam input ends of the medium and low-pressure cylinders;

[0011] The output end of the second 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 third reheater of the coal-fired boiler;

[0012] 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, 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 reheat section, and the heat storage medium output end of the initial reheat section is connected to the low-temperature heat storage medium input end of the heat storage module.

[0013] Furthermore, the first feedwater heating system includes a first feedwater pump, a first low-pressure heating system, a first deaerator, a first deoxygenated water delivery pump and a first high-pressure heating system;

[0014] The output end of the first feedwater pump is connected to the water working medium input end of the first low-pressure heating system, the water working medium output end of the first low-pressure heating system is connected to the water working medium input end of the first deaerator, the water working medium output end of the first deaerator is connected to the water working medium input end of the first deoxygenated water delivery pump, the water working medium output end of the first deoxygenated water delivery pump is connected to the water working medium input end of the first high-pressure heating system, and the water working medium output end of the first high-pressure heating system is connected to the water working medium input end of the heating section of the coal-fired boiler;

[0015] The second feedwater heating system includes a first feedwater heating module and a second feedwater heating module;

[0016] The first feedwater heating module includes a second feedwater pump, a second low-pressure heating system, a second deaerator, a second deoxygenated water delivery pump and a second high-pressure heating system;

[0017] The output end of the second feedwater pump is connected to the water working medium input end of the second low-pressure heating system, the water working medium output end of the second low-pressure heating system is connected to the water working medium input end of the second deaerator, the water working medium output end of the second deaerator is connected to the water working medium input end of the second deoxygenated water delivery pump, the water working medium output end of the second deoxygenated water delivery pump is connected to the water working medium input end of the second high-pressure heating system, the water working medium output end of the second high-pressure heating system is connected to the water working medium input end of the second feedwater heating module, and the water working medium output end of the second feedwater heating module is connected to the water working medium input end of the initial heating section;

[0018] The first water supply pump and the second water supply pump are the same water supply pump, or the first water supply pump and the second water supply pump are two independent water supply pumps;

[0019] The first low-pressure heating system and the second low-pressure heating system are the same low-pressure heating system, or the first low-pressure heating system and the second low-pressure heating system are two independent low-pressure heating systems;

[0020] The first deaerator and the second deaerator are the same deaerator, or the first deaerator and the second deaerator are two independent deaerators.

[0021] Furthermore, the extraction steam input end of the second feedwater heating module is connected to the extraction steam output end of the initial heating section, and the second feedwater heating module uses the extraction steam of the initial heating section to heat the water working medium.

[0022] Furthermore, the initial heating section includes a preheating section, an evaporation section and a superheating section;

[0023] The output end of the second feedwater heating module 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 third reheater of the coal-fired boiler; 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;

[0024] The steam extraction output end of the evaporation section is connected to the steam extraction input end of the second feedwater heating module.

[0025] Furthermore, the second feedwater heating module includes a feedwater heater;

[0026] The water working medium output end of the second high-pressure heating system is connected to the water working medium input end of the feed water heater, and the water working medium output end of the feed water heater is connected to the water working medium input end of the preheating section; the steam extraction output end of the evaporation section is connected to the steam extraction input end of the feed water heater.

[0027] Furthermore, it also includes a condensing device, the exhaust steam discharge end of the medium and low pressure cylinder is connected to the input end of the condensing device through the medium and low pressure cylinder exhaust pipeline, and the output end of the condensing device is respectively connected to the water working medium input end of the first feed water heating system and the water working medium input end of the second feed water heating system.

[0028] Furthermore, the output end of the first feedwater heating system is connected to the water working medium input end of the coal-fired boiler heating section through the first feedwater pipeline, the main steam output end of the coal-fired boiler heating section is connected to the steam input end of the critical cylinder through the sixth pipeline, the steam exhaust end of the critical cylinder is connected to the steam input end of the third reheater of the coal-fired boiler through the critical cylinder exhaust pipeline and the second pipeline in sequence, the steam output end of the third reheater of the coal-fired boiler is connected to the steam input end of the high-pressure cylinder through the fifth pipeline, the steam exhaust end of the high-pressure cylinder is connected to the steam input end of the high-pressure cylinder through the high-pressure cylinder exhaust pipeline and the first high-pressure cylinder exhaust pipeline branch in sequence. The steam input end of the initial reheat section is connected to the steam output end of the initial reheat section through the first pipeline, the steam output end of the initial reheat section is connected to the steam input end of the second reheater of the coal-fired boiler through the first pipeline, the steam output end of the second reheater of the coal-fired boiler is connected to the steam input ends of the medium and low pressure cylinders through the fourth pipeline and the mixing pipeline in sequence, the steam discharge end of the high pressure cylinder is also connected to the steam input end of the first reheater of the coal-fired boiler through the high pressure cylinder exhaust pipeline and the second high pressure cylinder exhaust pipeline branch in sequence, the steam output end of the first reheater of the coal-fired boiler is connected to the steam input ends of the medium and low pressure cylinders through the third pipeline and the mixing pipeline in sequence;

[0029] The output end of the second feedwater heating system is connected to the water working medium input end of the initial heating section through the second feedwater pipeline, and the superheated steam output end of the initial heating section is connected to the steam input end of the third reheater of the coal-fired boiler through the second pipeline;

[0030] Among them, a first pipeline isolation valve is provided on the first pipeline, a second pipeline isolation valve is provided on the second pipeline, and a first high-pressure cylinder exhaust pipeline branch isolation valve is provided on the first high-pressure cylinder exhaust pipeline branch; the second pipeline isolation valve is located between the initial heating section and the critical cylinder exhaust connection point, and the critical cylinder exhaust connection point is the connection point between the critical cylinder exhaust pipeline and the second pipeline.

[0031] Furthermore, the extraction steam output end of the evaporation section is connected to the extraction steam input end of the feedwater heater through the initial heating section saturated steam outlet pipeline, and the initial heating section saturated steam outlet pipeline is provided with an initial heating section saturated steam outlet pipeline isolation valve.

[0032] Furthermore, the heat storage medium in the heat storage module is heated by a tower solar thermal collection system; or,

[0033] 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.

[0034] Furthermore, the heat storage medium in the heat storage module is molten salt.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. In existing thermal power generation systems, a large amount of coal is consumed and a large amount of carbon emissions are generated in order to maintain the normal operation of the thermal power generation system. The present invention proposes a power generation system that 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, thereby effectively reducing the consumption of coal and carbon emissions, thereby solving the problem of high carbon emissions from pure coal-fired boilers.

[0037] 2、The power generation system needs to participate in the peak regulation of the power grid according to the dispatching instructions of the power grid in the actual operation process. The existing thermal power generation system realizes peak regulation by reducing the output load of the coal-fired boiler to the steam turbine generator set. However, the coal-fired boiler has a minimum stable combustion load requirement due to its own characteristics (i.e., below the minimum stable combustion load, the coal in the coal-fired boiler cannot be stably combusted), so the peak regulation capacity of the pure thermal power generation system is limited. In the power generation system provided by the present application, the scale of the coal-fired boiler can be reduced due to the introduction of the steam generation system, so the minimum output load of the power generation system to the power grid can be further reduced compared with the same scale pure thermal power generation system, thereby improving the deep peak regulation capacity of the power generation system of the present application. At the same time, the energy source of the steam generation system comes from renewable energy (such as clean energy provided by solar energy or wind energy, further such as the heat storage medium in the heat storage module is heated by a tower type solar heat 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), so compared with the same scale thermal power generation system, carbon emissions can be effectively reduced. In addition, the steam generation system has the ability of rapid load variation, thereby also improving the rapid load variation ability of the power generation system.

[0038] 3、The main steam parameters produced in the coal-fired boiler do not match the steam parameters produced by the steam generation system (such as a molten salt steam generation system), which cannot be directly connected to the same steam turbine. The present application realizes the efficient combination of the steam generation system and the coal-fired boiler by connecting the steam generation system and the coal-fired boiler in series, and at the same time, setting a cylinder that only receives supercritical steam generated by the coal-fired boiler, thereby solving the problem of how to realize efficient combined operation of the steam generation system and the coal-fired boiler under different design parameters, and solving the problem of the decrease of thermal cycle efficiency caused by the introduction of the steam generation system. In addition, since the present application is basically the same as the traditional thermal power in the part of the cylinder except the innovatively designed cylinder that only receives supercritical steam generated by the coal-fired boiler, the investment cost and the modification cost of the power generation system can be reduced.

[0039] 4、The present application takes full advantage of the fact that the coal-fired boiler can improve the cycle efficiency, and innovatively designs several separate heating surfaces, thereby realizing the further temperature increase of the steam generated by the steam generation system (such as a molten salt steam generation system) in the coal-fired boiler, thereby increasing the efficiency of the power generation system of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0040] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the accompanying drawings:

[0041] Figure 1A schematic structural diagram of a power generation system provided by an embodiment of the present invention.

[0042] In the picture:

[0043] 10. Steam generation system; 11. Initial reheating section; 12. Initial heating section;

[0044] 21. Critical cylinder; 22. High-pressure cylinder; 23. Intermediate and low-pressure cylinders; 24. Generator;

[0045] 30. First water supply heating system; 40. First water supply heating module; 41. Second water supply heating module;

[0046] 50. Condensing device;

[0047] 90. Coal-fired boiler; 91. First reheater of coal-fired boiler; 92. Second reheater of coal-fired boiler; 93. Third reheater of coal-fired boiler; 94. Heating section of coal-fired boiler;

[0048] 110. First pipeline; 111. First pipeline isolation valve;

[0049] 120. Second pipeline; 121. Second pipeline isolation valve;

[0050] 128. Isolation valve for the saturated steam outlet pipe of the initial heating section; 129. Saturated steam outlet pipe of the initial heating section

[0051] 210. Critical cylinder exhaust pipe;

[0052] 220, high-pressure cylinder exhaust pipe; 221, first high-pressure cylinder exhaust pipe branch; 222, second high-pressure cylinder exhaust pipe branch isolation valve; 223, second high-pressure cylinder exhaust pipe branch;

[0053] 230, medium and low pressure cylinder exhaust pipes;

[0054] 300, first water supply pipeline; 301, isolating valve for the water supply and heating system connecting pipeline; 302, water supply and heating system connecting pipeline; 303, first water supply pump; 304, first low-pressure heating system; 305, first deaerator; 306, first deoxygenated water delivery pump; 307, first high-pressure heating system; 400, second water supply pipeline; 401, second deoxygenated water delivery pump; 402, second high-pressure heating system;

[0055] 910, third pipeline; 920, fourth pipeline; 915, mixing pipeline; 930, fifth pipeline; 940, sixth pipeline. DETAILED DESCRIPTION

[0056] The present invention will be described in detail below with reference to specific embodiments. The following examples 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 skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0057] See also Figure 1 , an embodiment of the present application provides a power generation system, comprising a steam generation system 10 and a thermal power generation system;

[0058] The thermal power generation system includes a coal-fired boiler 90, a first feedwater heating system 30, a steam turbine and a generator 24; the steam turbine is connected to the generator 24;

[0059] The coal-fired boiler 90 includes a first reheater 91, a second reheater 92, a third reheater 93 and a heating section 94 of the coal-fired boiler; the steam turbine includes a critical cylinder 21, a high-pressure cylinder 22 and an intermediate- and low-pressure cylinder 23; wherein the intermediate- and low-pressure cylinders refer to the intermediate-pressure cylinder sub-cylinder and the low-pressure cylinder sub-cylinder, or the intermediate- and low-pressure cylinders refer to the whole after the intermediate-pressure cylinder sub-cylinder and the low-pressure cylinder sub-cylinder are combined.

[0060] The steam generation system 10 includes a heat storage module (not shown in the figure), a steam generation module and a second feedwater heating system;

[0061] The steam generation module includes an initial reheating section 11 and an initial heating section 12;

[0062] The output end of the first feedwater heating system 30 is connected to the water working medium input end of the coal-fired boiler heating section 94, the main steam output end of the coal-fired boiler heating section 94 is connected to the steam input end of the critical cylinder 21, the steam exhaust end of the critical cylinder 21 is connected to the steam input end of the third reheater 93 of the coal-fired boiler, the steam output end of the third reheater 93 of the coal-fired boiler is connected to the steam input end of the high-pressure cylinder 22, the steam exhaust end of the high-pressure cylinder 22 is connected to the steam input end of the initial reheating section 11, the steam output end of the initial reheating section 11 is connected to the steam input end of the second reheater 92 of the coal-fired boiler, the steam output end of the second reheater 92 of the coal-fired boiler is connected to the steam input end of the intermediate and low-pressure cylinders 23, the steam exhaust end of the high-pressure cylinder 22 is also connected to the steam input end of the first reheater 91 of the coal-fired boiler, and the steam output end of the first reheater 91 of the coal-fired boiler is connected to the steam input end of the intermediate and low-pressure cylinders 23;

[0063] The output end of the second feedwater heating system is connected to the water working medium input end of the initial heating section 12, and the superheated steam output end of the initial heating section 12 is connected to the steam input end of the third reheater 93 of the coal-fired boiler;

[0064] 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 12, the heat storage medium output end of the initial heating section 12 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 reheat section 11, and the heat storage medium output end of the initial reheat section 11 is connected to the low-temperature heat storage medium input end of the heat storage module;

[0065] The heating sources of the first feedwater heating system 30 and the second feedwater heating module 40 are both from the steam turbine, and the specific settings can be adjusted according to demand.

[0066] 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 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.

[0067] In a specific embodiment, the first feedwater heating system 30 includes a first feedwater pump 303 , a first low-pressure heating system 304 , a first deaerator 305 , a first deoxygenated water delivery pump 306 , and a first high-pressure heating system 307 ;

[0068] The output end of the first feedwater pump 303 is connected to the water working medium input end of the first low-pressure heating system 304, the water working medium output end of the first low-pressure heating system 304 is connected to the water working medium input end of the first deaerator 305, the water working medium output end of the first deaerator 305 is connected to the water working medium input end of the first deoxygenated water delivery pump 306, the water working medium output end of the first deoxygenated water delivery pump 306 is connected to the water working medium input end of the first high-pressure heating system 307, and the water working medium output end of the first high-pressure heating system 307 is connected to the water working medium input end of the heating section 94 of the coal-fired boiler;

[0069] The second feedwater heating system includes a first feedwater heating module 40 and a second feedwater heating module 41;

[0070] The first feedwater heating module 40 includes a second feedwater pump, a second low-pressure heating system, a second deaerator, a second deoxygenated water delivery pump 401 and a second high-pressure heating system 402;

[0071] The output end of the second feedwater pump is connected to the water working medium input end of the second low-pressure heating system, the water working medium output end of the second low-pressure heating system is connected to the water working medium input end of the second deaerator, the water working medium output end of the second deaerator is connected to the water working medium input end of the second deoxygenated water delivery pump 401, the water working medium output end of the second deoxygenated water delivery pump 401 is connected to the water working medium input end of the second high-pressure heating system 402, the water working medium output end of the second high-pressure heating system 402 is connected to the water working medium input end of the second feedwater heating module 41, and the water working medium output end of the second feedwater heating module 41 is connected to the water working medium input end of the initial heating section 12;

[0072] The extraction steam input end of the second feedwater heating module 41 is connected to the extraction steam output end of the initial heating section 12, and the second feedwater heating module 41 uses the extraction steam of the initial heating section 12 to heat the water working medium;

[0073] The exhaust steam discharge end of the medium and low pressure cylinder 23 is connected to the input end of the condensing device 50 through the medium and low pressure cylinder exhaust pipeline 230, and the output end of the condensing device 50 is connected to the input end of the first water supply pump 303 and the input end of the second water supply pump respectively.

[0074] The first water supply pump 303 and the second water supply pump are the same water supply pump, or the first water supply pump 303 and the second water supply pump are two independent water supply pumps;

[0075] The first low-pressure heating system 304 and the second low-pressure heating system are the same low-pressure heating system, or the first low-pressure heating system 304 and the second low-pressure heating system are two independent low-pressure heating systems;

[0076] The first deaerator 305 and the second deaerator are the same deaerator, or the first deaerator and the second deaerator are two independent deaerators;

[0077] Each device or structure is connected by a pipeline, and each pipeline is equipped with an isolation valve as required;

[0078] The heat in the thermal storage module is generated from renewable energy sources, preferably solar or wind energy. Specifically, the thermal storage medium in the thermal storage module is heated by a tower solar thermal system; alternatively, the thermal storage medium in the thermal storage module is heated by an electric heater, where the electricity required for the electric heater is generated by a photovoltaic power generation system or a wind power generation system. Preferably, the thermal storage medium in the thermal storage module is molten salt.

[0079] In this embodiment, preferably, the initial heating section 12 includes a preheating section, an evaporation section, and a superheating section;

[0080] The output end of the second feedwater heating module 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 third reheater 93 of the coal-fired boiler; 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;

[0081] The steam extraction output end of the evaporation section is connected to the steam extraction input end of the second feedwater heating module 41;

[0082] The second feedwater heating module 41 includes a feedwater heater;

[0083] The water working medium output end of the second high-pressure heating system 402 is connected to the water working medium input end of the feed water heater, and the water working medium output end of the feed water heater is connected to the water working medium input end of the preheating section; the steam extraction output end of the evaporation section is connected to the steam extraction input end of the feed water heater.

[0084] The condensing device 50 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 first water supply pump 303 and the water working medium input end of the second water supply pump.

[0085] Preferably, the critical cylinder 21 is a single-cylinder design, and the high-pressure cylinder 22 and the medium- and low-pressure cylinders 23 can all be single-cylinder or double-cylinder designs.

[0086] Optionally, the output end of the first feedwater heating system 30 is connected to the water working medium input end of the coal-fired boiler heating section 94 through the first feedwater pipeline 300, the main steam output end of the coal-fired boiler heating section 94 is connected to the steam input end of the critical cylinder 21 through the sixth pipeline 940, the steam exhaust end of the critical cylinder 21 is connected to the steam input end of the third reheater 93 of the coal-fired boiler through the critical cylinder exhaust pipeline 210 and the second pipeline 120 in sequence, the steam output end of the third reheater 93 of the coal-fired boiler is connected to the steam input end of the high-pressure cylinder 22 through the fifth pipeline 930, and the steam exhaust end of the high-pressure cylinder 22 is connected to the high-pressure cylinder 22 through the high-pressure cylinder exhaust pipeline 220 and the first high-pressure cylinder exhaust pipeline branch 221 in sequence. The steam input end of the initial reheat section 11 is connected, the steam output end of the initial reheat section 11 is connected to the steam input end of the second reheater 92 of the coal-fired boiler via the first pipeline 110, the steam output end of the second reheater 92 of the coal-fired boiler is connected to the steam input ends of the medium and low pressure cylinders 23 via the fourth pipeline 920 and the mixing pipeline 915 in sequence, the steam discharge end of the high pressure cylinder 22 is further connected to the steam input end of the first reheater 91 of the coal-fired boiler via the high pressure cylinder exhaust pipeline 220 and the second high pressure cylinder exhaust pipeline branch 223 in sequence, and the steam output end of the first reheater 91 of the coal-fired boiler is connected to the steam input ends of the medium and low pressure cylinders 23 via the third pipeline 910 and the mixing pipeline 915 in sequence;

[0087] The output end of the second feedwater heating system is connected to the water working medium input end of the initial heating section 12 via the second feedwater pipeline 400, and the superheated steam output end of the initial heating section 12 is connected to the steam input end of the third reheater 93 of the coal-fired boiler via the second pipeline 120;

[0088] The exhaust steam discharge end of the intermediate and low pressure cylinders 23 is connected to the input end of the first feedwater pump 303 and the input end of the second feedwater pump through the intermediate and low pressure cylinder exhaust pipe 230; the extraction steam output end of the evaporation section is connected to the extraction steam input end of the feedwater heater through the initial heating section saturated steam outlet pipe 129. The initial heating section saturated steam outlet pipe 129 is provided with an initial heating section saturated steam outlet pipe isolation valve 128;

[0089] Among them, a first pipeline isolation valve 111 is provided on the first pipeline 110, a second pipeline isolation valve 121 is provided on the second pipeline 120, and a first high-pressure cylinder exhaust pipeline branch isolation valve 222 is provided on the first high-pressure cylinder exhaust pipeline branch 221; the second pipeline isolation valve 121 is located between the initial heating section 12 and the critical cylinder exhaust connection point, and the critical cylinder exhaust connection point is the connection point between the critical cylinder exhaust pipeline 210 and the second pipeline 120.

[0090] In an optional embodiment, the first feedwater pump 303 and the second feedwater pump are the same feedwater pump, the first low-pressure heating system 304 and the second low-pressure heating system are the same low-pressure heating system, and the first deaerator 305 and the second deaerator are the same deaerator;

[0091] 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 to a high-temperature heat storage medium using sunlight reflected by the heliostat field. The steam generation system uses a molten salt steam generation system, and the heat storage module uses a molten salt heat storage module. That is, the heat storage medium in the heat storage module is molten salt (a molten state of an inorganic salt, such as a molten state of a mixture of sodium nitrate and potassium nitrate).

[0092] Specifically, in this embodiment, the exhaust steam discharged from the exhaust steam exhaust end of the intermediate and low-pressure cylinders 23 is condensed by the condensing device 50 and then connected to the water working medium input end of the first feedwater pump 303 through the intermediate and low-pressure cylinder exhaust pipe 230. The water working medium output end of the first deaerator 305 is connected to the water working medium input end of the second deoxygenated water delivery pump 401 through the feedwater heating system connecting pipe 302. The feedwater heating system connecting pipe 302 is provided with a feedwater heating system connecting pipe isolation valve 301. At the same time, the water working medium output end of the first deaerator 305 is also connected to the water working medium input end of the first deoxygenated water delivery pump 306.

[0093] The critical cylinder exhaust pipe 210 is connected to the second pipe 120 through a connecting piece, and the third pipe 910, the fourth pipe 920 and the mixing pipe 915 are connected through a three-way pipe fitting;

[0094] The extraction steam input of the first low-pressure heating system 304 is connected to the extraction steam output of the intermediate and low-pressure cylinders 23. The extraction steam input of the first high-pressure heating system 307 is connected to the extraction steam output of the critical cylinder 21 and / or the high-pressure cylinder 22. The extraction steam input of the second high-pressure heating system 402 is connected to the extraction steam output of the critical cylinder 21, the high-pressure cylinder 22, and / or the intermediate and low-pressure cylinders 23. This arrangement allows the extraction steam from the steam turbine to heat the water working medium in the first low-pressure heating system 304, the first high-pressure heating system 307, and the second high-pressure heating system 402.

[0095] In one specific scenario, when the power grid requires deep reduction of 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 and shut down the molten salt steam generation system and take isolation measures as follows: close the first pipeline isolation valve 111, the second pipeline isolation valve 121, the first high-pressure cylinder exhaust pipeline branch isolation valve 222, and the initial heating section saturated steam outlet pipeline isolation valve 129. At this time, only the coal-fired boiler 90 participates in the operation of the power generation system, and the specific process is as follows: the main steam is generated by the coal-fired boiler heating section 94, enters the critical cylinder 21 to do work through the sixth pipeline 940, and then enters the coal-fired boiler third reheater 93 through the critical cylinder exhaust pipeline 210, is heated by the coal-fired boiler third reheater 93, and then enters the high-pressure cylinder 22 to do work through the fifth pipeline 930. The high-temperature steam in the high-pressure cylinder exhaust pipeline 220 is discharged from the high-pressure cylinder 22, enters the coal-fired boiler first reheater 91 through the second high-pressure cylinder exhaust pipeline branch 223, is heated, and then enters the medium and low-pressure cylinder 23 to do work through the third pipeline 910. The steam in the medium and low-pressure cylinder exhaust pipeline 230 is condensed and heated by the first feedwater heating system 30, enters the coal-fired boiler fourth heating section 91 to generate main steam through the first feedwater pipeline 300, and thus completes the process of steam doing work and cooling in the steam turbine. The heating source of the first feedwater heating system 30 is from the steam turbine.

[0096] When in the morning and evening peak or the power grid requires maximum load output, the molten salt steam generation system and the coal-fired boiler 90 are combined to operate. At this time, the molten salt steam generation system and the coal-fired boiler 90 are in series operation, and the water supply side of the molten salt steam generation system and the water supply side of the coal-fired boiler 90 are described as follows:

[0097] 1. The water supply process of the coal-fired boiler 90 side: the water supply of the coal-fired boiler 90 is heated by the first feedwater heating system 30, which specifically includes a first feedwater pump 303, a first low-pressure heating system 304, a first deaerator 305, a first deaerated water delivery pump 306, and a first high-pressure heating system 307. After heating, it is sent to the coal-fired boiler heating section 94 through the first feedwater pipeline 300 for heating.

[0098] 2. The flow process of the water side of the molten salt steam generation system: the water working medium output from the first deaerator 305 enters the first feedwater heating module 40 through the feedwater heating system connecting pipeline 302. Specifically, the first feedwater heating module 40 comprises a second deaerated water delivery pump 401 and a second high-pressure heating system 402, wherein the heat source of the second high-pressure heating system 402 comes from inside the steam turbine. The water working medium output from the first feedwater heating module 40 enters the feedwater heater for further heating, wherein the heating source of the feedwater heater comes from the initial heating section 12. The water working medium heated by the feedwater heater finally enters the initial heating section 12 through the second feedwater pipeline 400.

[0099] The operation flow process of the steam side under combined operation is as follows: the high-temperature steam generated by the heating section 94 of the coal-fired boiler enters the critical cylinder 21 through the sixth pipeline 940, is discharged from the critical cylinder exhaust pipeline 210 after work, is mixed with the high-temperature steam generated by the initial heating section 12, and then enters the third reheater 93 of the coal-fired boiler for heating. The heated steam enters the high-pressure cylinder 22 through the fifth pipeline 930, and the steam after work is discharged from the high-pressure cylinder exhaust pipeline 220 and then divided into two branches, one of which is: entering the initial reheating section 11 for heating through the first high-pressure cylinder exhaust pipeline branch 221; the other is: entering the first reheater 91 of the coal-fired boiler for heating through the second high-pressure cylinder exhaust pipeline branch 223, wherein the steam heated by the initial reheating section 11 enters the second reheater 92 of the coal-fired boiler for further heating through the first pipeline 110, and the heated steam is sent out through the fourth pipeline 920 and mixed with the steam in the third pipeline 910, then enters the medium-low pressure cylinder 23 for work through the mixing pipeline 915, and the exhaust steam of the medium-low pressure cylinder 23 is discharged through the medium-low pressure cylinder exhaust pipeline 230.

[0100] At this point, the coal-fired boiler 90 and the molten salt steam generation system complete the combined operation, and as the load of the molten salt steam generation system continuously increases, the power generation capacity of the entire power generation system also increases.

[0101] The specific embodiments of the present application are described above. It should be understood that the present application 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 essential content of the present application. The embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other without conflict.

Claims

1. A power generation system, characterized in that: including a steam generation system (10) and a thermal power generation system; The thermal power generation system includes a coal-fired boiler (90), a first feedwater heating system (30), a steam turbine, and a generator (24); the steam turbine is connected to the generator (24); The coal-fired boiler (90) includes a first reheater (91) of the coal-fired boiler, a second reheater (92) of the coal-fired boiler, a third reheater (93) of the coal-fired boiler, and a heating section (94) of the coal-fired boiler; the steam turbine includes a critical cylinder (21), a high-pressure cylinder (22), and a medium- and low-pressure cylinder (23); The steam generation system (10) comprises a heat storage module, a steam generation module and a second feedwater heating system; The steam generation module comprises an initial reheating section (11) and an initial heating section (12); The output end of the first feedwater heating system (30) is connected to the water working medium input end of the coal-fired boiler heating section (94), the main steam output end of the coal-fired boiler heating section (94) is connected to the steam input end of the critical cylinder (21), the steam discharge end of the critical cylinder (21) is connected to the steam input end of the third reheater (93) of the coal-fired boiler, the steam output end of the third reheater (93) of the coal-fired boiler is connected to the steam input end of the high-pressure cylinder (22), and the steam discharge end of the high-pressure cylinder (22) is connected to the initial The steam input end of the reheating section (11) is connected, the steam output end of the initial reheating section (11) is connected to the steam input end of the second reheater (92) of the coal-fired boiler, the steam output end of the second reheater (92) of the coal-fired boiler is connected to the steam input end of the medium and low pressure cylinder (23), the steam discharge end of the high pressure cylinder (22) is also connected to the steam input end of the first reheater (91) of the coal-fired boiler, and the steam output end of the first reheater (91) of the coal-fired boiler is connected to the steam input end of the medium and low pressure cylinder (23); The output end of the second feedwater heating system is connected to the water working medium input end of the initial heating section (12), and the superheated steam output end of the initial heating section (12) is connected to the steam input end of the third reheater (93) of the coal-fired boiler; 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 (12), the heat storage medium output end of the initial heating section (12) 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 (11), and the heat storage medium output end of the initial reheating section (11) 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 first feedwater heating system (30) comprises a first feedwater pump (303), a first low-pressure heating system (304), a first deaerator (305), a first deoxygenated water delivery pump (306) and a first high-pressure heating system (307); The output end of the first feedwater pump (303) is connected to the water working medium input end of the first low-pressure heating system (304), the water working medium output end of the first low-pressure heating system (304) is connected to the water working medium input end of the first deaerator (305), the water working medium output end of the first deaerator (305) is connected to the water working medium input end of the first deoxygenated water delivery pump (306), the water working medium output end of the first deoxygenated water delivery pump (306) is connected to the water working medium input end of the first high-pressure heating system (307), and the water working medium output end of the first high-pressure heating system (307) is connected to the water working medium input end of the coal-fired boiler heating section (94); The second feedwater heating system comprises a first feedwater heating module (40) and a second feedwater heating module (41); The first feedwater heating module (40) comprises a second feedwater pump, a second low-pressure heating system, a second deaerator, a second deoxygenated water delivery pump (401) and a second high-pressure heating system (402); The output end of the second feedwater pump is connected to the water working medium input end of the second low-pressure heating system, the water working medium output end of the second low-pressure heating system is connected to the water working medium input end of the second deaerator, the water working medium output end of the second deaerator is connected to the water working medium input end of the second deoxygenated water delivery pump (401), the water working medium output end of the second deoxygenated water delivery pump (401) is connected to the water working medium input end of the second high-pressure heating system (402), the water working medium output end of the second high-pressure heating system (402) is connected to the water working medium input end of the second feedwater heating module (41), and the water working medium output end of the second feedwater heating module (41) is connected to the water working medium input end of the initial heating section (12); The first water supply pump (303) and the second water supply pump are the same water supply pump, or the first water supply pump (303) and the second water supply pump are two independent water supply pumps; The first low-pressure heating system (304) and the second low-pressure heating system are the same low-pressure heating system, or the first low-pressure heating system (304) and the second low-pressure heating system are two independent low-pressure heating systems; The first deaerator (305) and the second deaerator are the same deaerator, or the first deaerator (305) and the second deaerator are two independent deaerators.

3. A power generation system according to claim 2, characterized in that: The extraction steam input end of the second feedwater heating module (41) is connected to the extraction steam output end of the initial heating section (12), and the second feedwater heating module (41) uses the extraction steam of the initial heating section (12) to heat the water working medium.

4. A power generation system according to claim 3, characterized in that: The initial heating section (12) includes a preheating section, an evaporation section and a superheating section; The output end of the second feedwater heating module 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 third reheater (93) of the coal-fired boiler; 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 steam extraction output end of the evaporation section is connected to the steam extraction input end of the second feedwater heating module (41).

5. A power generation system according to claim 4, characterized in that: The second feedwater heating module (41) includes a feedwater heater; The water working medium output end of the second high-pressure heating system (402) is connected to the water working medium input end of the feed water heater, and the water working medium output end of the feed water heater is connected to the water working medium input end of the preheating section; the steam extraction output end of the evaporation section is connected to the steam extraction input end of the feed water heater.

6. A power generation system according to claim 1, characterized in that: The system further comprises a condensing device (50), wherein the exhaust steam discharge end of the intermediate and low pressure cylinders (23) is connected to the input end of the condensing device (50) via an intermediate and low pressure cylinder exhaust steam pipeline (230), and the output end of the condensing device (50) is respectively connected to the water working medium input end of the first feed water heating system (30) and the water working medium input end of the second feed water heating system.

7. A power generation system according to claim 1, characterized in that: The output end of the first feedwater heating system (30) is connected to the water working medium input end of the coal-fired boiler heating section (94) through the first feedwater pipeline (300), the main steam output end of the coal-fired boiler heating section (94) is connected to the steam input end of the critical cylinder (21) through the sixth pipeline (940), the steam discharge end of the critical cylinder (21) is connected to the steam input end of the third reheater (93) of the coal-fired boiler through the critical cylinder exhaust pipeline (210) and the second pipeline (120) in sequence, the steam output end of the third reheater (93) of the coal-fired boiler is connected to the steam input end of the high-pressure cylinder (22) through the fifth pipeline (930), and the steam discharge end of the high-pressure cylinder (22) is connected to the initial high-pressure cylinder (22) through the high-pressure cylinder exhaust pipeline (220) and the first high-pressure cylinder exhaust pipeline branch (221) in sequence. The steam input end of the reheat section (11) is connected, the steam output end of the initial reheat section (11) is connected to the steam input end of the second reheater (92) of the coal-fired boiler through the first pipeline (110), the steam output end of the second reheater (92) of the coal-fired boiler is connected to the steam input end of the medium and low pressure cylinder (23) through the fourth pipeline (920) and the mixing pipeline (915) in sequence, the steam discharge end of the high pressure cylinder (22) is also connected to the steam input end of the first reheater (91) of the coal-fired boiler through the high pressure cylinder exhaust pipeline (220) and the second high pressure cylinder exhaust pipeline branch (223) in sequence, the steam output end of the first reheater (91) of the coal-fired boiler is connected to the steam input end of the medium and low pressure cylinder (23) through the third pipeline (910) and the mixing pipeline (915) in sequence; The output end of the second feedwater heating system is connected to the water working medium input end of the initial heating section (12) via the second feedwater pipeline (400), and the superheated steam output end of the initial heating section (12) is connected to the steam input end of the third reheater (93) of the coal-fired boiler via the second pipeline (120); The first pipeline (110) is provided with a first pipeline isolation valve (111), the second pipeline (120) is provided with a second pipeline isolation valve (121), and the first high-pressure cylinder exhaust pipeline branch (221) is provided with a first high-pressure cylinder exhaust pipeline branch isolation valve (222); the second pipeline isolation valve (121) is located between the initial heating section (12) and the critical cylinder exhaust connection point, and the critical cylinder exhaust connection point is the connection point between the critical cylinder exhaust pipeline (210) and the second pipeline (120).

8. A power generation system according to claim 5, characterized in that: The extraction steam output end of the evaporation section is connected to the extraction steam input end of the feedwater heater via the initial heating section saturated steam outlet pipeline (129), and the initial heating section saturated steam outlet pipeline (129) is provided with an initial heating section saturated steam outlet pipeline isolation valve (128).

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.

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