Light-coal coupling power generation system with fused salt heat storage function

Abstract

The utility model provides a light-coal coupling power generation system with fused salt heat storage, and relates to the technical field of power generation. The system comprises a heat storage device which heats feed water through hot molten salt to generate superheated steam to be fed into a steam turbine to do work to drive a generator to generate electricity; the temperature uniformizing device is used for uniformizing the temperature of the cold molten salt and the hot molten salt in the heat storage device; the auxiliary temperature adjusting assembly is used for adjusting the temperature of the cold molten salt and the hot molten salt; the light coal combination device is used for converting light energy into heat energy to heat cold molten salt into hot molten salt, and the hot molten salt is used for heating condensed water to generate main steam; the main steam is conveyed to the steam turbine to do work to drive the power generator to generate power; and the dead steam circulating device is used for recovering and cooling dead steam into condensed water to be conveyed to the light coal combination device. The problem that in the prior art, due to the fact that the temperature of the cold molten salt and the temperature of the hot molten salt stored in the molten salt storage tank are not uniform, power generation is not stable when the stored hot molten salt and cold molten salt are used for power generation is solved.

Description

Technical Field

[0001] This utility model relates to the field of power generation technology, specifically to a photovoltaic-coal coupled power generation system with molten salt thermal storage. Background Technology

[0002] With the continuous growth of global energy demand and the increasing awareness of environmental protection, improving energy efficiency and reducing carbon emissions have become important issues in the energy sector. Concentrated solar power (CSP), as a clean and renewable energy source, has broad application prospects. However, CSP suffers from intermittency and instability, limiting its large-scale application. While coal-fired power generation is technologically mature and has a large power output, it suffers from environmental pollution and low energy efficiency. Therefore, solar-coal co-generation has become a new energy utilization option.

[0003] Molten salt thermal energy storage technology is an advanced thermal energy storage system. Molten salt is a liquid substance formed by heating and melting salt substances. Compared with heat transfer oil, molten salt can achieve higher operating temperatures under the same pressure. Furthermore, molten salt is non-explosive, non-flammable, has good thermal stability, and a high heat transfer coefficient. Molten salt heated by solar energy is stored in molten salt storage tanks. Therefore, these tanks need to have excellent insulation properties, and the molten salt needs to be heated further when the temperature inside the tank is insufficient. Currently, a problem with ordinary molten salt storage tanks, especially large-capacity ones, is uneven temperature distribution within the tank. Temperature differences exist between the top and bottom of the tank, and between the middle and edges. This inconsistent molten salt temperature severely affects the stability of power generation.

[0004] Therefore, there is an urgent need for a system that can solve at least one of the above problems. Utility Model Content

[0005] The purpose of this utility model embodiment is to provide a photovoltaic-coal coupled power generation system with molten salt thermal storage, which solves the problem in the prior art where the power generation is unstable when using the stored hot and cold molten salts due to the uneven temperature of the cold and hot molten salts stored in the molten salt storage tank.

[0006] To achieve the above objectives, this utility model provides a solar-coal coupled power generation system with molten salt thermal storage, connected to a steam turbine and a generator. The solar-coal coupled power generation system with molten salt thermal storage includes:

[0007] The thermal storage device stores cold molten salt and hot molten salt. It is used to supply cold molten salt and heat the feedwater fed into the thermal storage device with the stored hot molten salt to generate superheated steam. The superheated steam is sent to the steam turbine to do work to drive the generator to generate electricity. After the superheated steam does work, it becomes exhaust steam and is discharged from the steam turbine.

[0008] A temperature equalization device, connected to a heat storage device, is used to equalize the temperature of cold molten salt and hot molten salt in the heat storage device.

[0009] An auxiliary temperature control component, connected to the thermal storage device, is used to regulate the temperature of the cold molten salt and hot molten salt stored in the thermal storage device;

[0010] The solar-coal combined unit, connected to a thermal storage unit and a steam turbine, is used to convert solar energy into thermal energy to heat the cold molten salt supplied by the thermal storage unit into hot molten salt. The hot molten salt is then used to heat the condensate to generate main steam, which is sent to the steam turbine to do work and drive the generator to produce electricity. It is also used to burn coal to generate thermal energy to heat the condensate to produce main steam, which is also sent to the steam turbine to do work and drive the generator to produce electricity. After doing work, the main steam becomes exhaust steam and is discharged from the steam turbine.

[0011] The waste steam recirculation unit, connected to the steam turbine and phosphogypsum combination unit, is used to recover and cool the waste steam discharged from the steam turbine into condensate, and then transport the condensate back to the phosphogypsum combination unit.

[0012] Specifically, the solar-coal combination device includes: a solar energy conversion module, a combustion module, and a heat exchange module;

[0013] A solar energy conversion module, connected to a thermal storage device, is used to convert light energy into heat energy to heat the cold molten salt from the thermal storage device into hot molten salt;

[0014] The heat exchange module is connected to the solar energy conversion module, the steam turbine and the exhaust steam recirculation device. It is used to heat the condensate with hot molten salt to generate main steam and send the main steam into the steam turbine to do work.

[0015] The combustion module, connected to the steam turbine and exhaust steam recirculation unit, is used to burn coal to generate heat energy to heat condensate and generate main steam, which is then sent to the steam turbine to perform work.

[0016] Specifically, the thermal storage device includes a pair of molten salt tanks, each molten salt tank including a tank body with a receiving cavity. The tank bodies of the pair of molten salt tanks are both connected to a solar energy conversion module. The receiving cavity of one molten salt tank stores cold molten salt and can supply cold molten salt to the solar energy conversion module. The receiving cavity of the other molten salt tank stores hot molten salt formed after being heated by the solar energy conversion module.

[0017] Specifically, the heat storage device further includes: a first heat exchanger connected to a pair of molten salt storage tanks and a steam turbine. The first heat exchanger uses hot molten salt output from one of the molten salt storage tanks to heat the feedwater entering the first heat exchanger to generate superheated steam, and sends the superheated steam to the steam turbine to do work. After the hot molten salt loses heat, it becomes cold molten salt and enters the other molten salt storage tank.

[0018] Specifically, the auxiliary temperature control component is installed inside the container cavity of the tank and is used to adjust the temperature of the cold molten salt or hot molten salt inside the container cavity.

[0019] Specifically, the auxiliary temperature control component includes: an adjustment support and multiple temperature regulators;

[0020] The adjusting support is vertically installed inside the receiving cavity to support multiple temperature regulators;

[0021] Multiple temperature regulators are detachably mounted on the regulating support along the circumference of the regulating support, and the temperature of the cold molten salt or hot molten salt in the containing cavity is adjusted by the multiple temperature regulators.

[0022] Specifically, the auxiliary temperature control component further includes: multiple adjustment mounting rods;

[0023] Multiple adjusting mounting rods are detachably mounted on the adjusting support column along the circumference. Multiple temperature regulators are arranged along the extension direction of each adjusting mounting rod, wherein the multiple temperature regulators on each adjusting mounting rod are arranged in layers.

[0024] Specifically, the temperature equalization device includes: multiple stirring components;

[0025] Each mixing component includes: mixing blades, connecting rod, and mixing actuator;

[0026] The stirring blades are installed inside the receiving cavity of the tank and are used to stir the cold molten salt or hot molten salt inside the tank;

[0027] One end of the connecting rod extends into the receiving cavity of the tank and connects to the stirring blades, while the other end is exposed outside the receiving cavity of the tank and connects to the stirring driver.

[0028] The stirring actuator is located on the outer wall of the tank and is used to drive the connecting rod to rotate the stirring blades to stir the cold or hot molten salt in the tank.

[0029] Specifically, the system further includes: multiple sets of detection components, with at least one set of detection components installed in the accommodating cavity of each molten salt storage tank, the detection components being used to detect the liquid level and temperature inside the tank.

[0030] Specifically, the system further includes an auxiliary heat exchanger connected to the combustion module and a pair of molten salt storage tanks, used to heat cold molten salt from one molten salt storage tank into hot molten salt using the main steam from the combustion module, and to transport the hot molten salt to the other molten salt storage tank for storage.

[0031] This utility model provides a photovoltaic-coal coupled power generation system with molten salt thermal storage. The thermal storage device stores both cold and hot molten salt. The stored hot molten salt heats feedwater to generate superheated steam. This superheated steam is sent to a steam turbine to drive a generator. After performing work, the superheated steam becomes exhaust steam, which is discharged from the turbine and enters an exhaust steam recirculation system. To ensure stable temperature of the hot molten salt supplied to the thermal storage device and thus a stable output of superheated steam, thereby ensuring stable generator power generation, a temperature equalization device and auxiliary temperature control components are connected to the thermal storage device. The temperature equalization device evenly distributes the hot and cold molten salts stored in the thermal storage device. The temperature of the salt is used to equalize the temperature of the cold and hot molten salts in the thermal storage unit. The temperature of the stored cold and hot molten salts is regulated by auxiliary temperature control components to ensure that the output cold and hot molten salts remain within a suitable temperature range. This ensures stable output of superheated steam and guarantees the conversion efficiency of the hot molten salts. The photovoltaic-coal combined unit uses the heat energy converted from solar energy to heat the cold molten salt supplied by the thermal storage unit, turning it into hot molten salt. The hot molten salt can be stored in the thermal storage unit or used in conjunction with condensate. In the condensate heat exchange process, the condensate entering the galvanized coal combination unit absorbs heat from the molten salt and vaporizes into main steam, which is then fed into the turbine to drive the generator. The galvanized coal combination unit can also utilize the heat energy generated from burning coal to heat the condensate and generate main steam. This main steam is also fed into the turbine to drive the generator. After performing its work, the main steam becomes exhaust steam and is discharged from the turbine into the exhaust steam recirculation unit. In this unit, the exhaust steam is cooled and becomes condensate, which is then fed back into the galvanized coal combination unit. Thus, by utilizing the molten salt to heat the feedwater to generate superheated steam and the heat from the galvanized coal combination unit, the condensate is effectively heated and heated. The combined unit utilizes the main steam generated by heating condensate with molten salt and the main steam generated by heating condensate with the heat energy from burning coal. Both can be sent to the steam turbine to do work and drive the generator to generate electricity, thereby ensuring a stable supply of main steam and superheated steam to the steam turbine, avoiding frequent adjustments to the power generation system, and ensuring stable power generation. The photovoltaic-coal coupled power generation system with molten salt thermal storage provided in this application solves the problem of unstable power generation when using stored hot and cold molten salt for power generation due to the uneven temperature of cold and hot molten salt stored in the molten salt storage tank in the prior art. It can also avoid frequent adjustments to the power generation system.

[0032] Other features and advantages of this utility model embodiment will be described in detail in the following detailed description section. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0034] Figure 1This is a schematic diagram of the layout of a photovoltaic-coal coupled power generation system with molten salt thermal storage provided in an embodiment of this utility model;

[0035] Figure 2 This is a schematic diagram of the layout of a photovoltaic-coal coupled power generation system with molten salt thermal storage provided in another embodiment of this utility model;

[0036] Figure 3 This is a schematic diagram of the installation of the auxiliary temperature control component in the tank of a solar-coal coupled power generation system with molten salt thermal storage provided in an embodiment of this utility model;

[0037] Figure 4 This is a schematic diagram of the auxiliary temperature control component in a photovoltaic-coal coupled power generation system with molten salt thermal storage provided in another embodiment of this utility model;

[0038] Figure 5 This is another structural schematic diagram of the tank in the solar-coal coupled power generation system with molten salt thermal storage provided in this embodiment of the utility model;

[0039] Figure 6 This is another structural schematic diagram of the auxiliary temperature regulation component in the photovoltaic-coal coupled power generation system with molten salt thermal storage provided in this embodiment of the utility model.

[0040] Explanation of reference numerals in the attached figures

[0041] 1-Solar energy conversion module; 3-Low-temperature molten salt pump; 5-First heat exchanger; 6-First valve; 7-High-temperature molten salt pump; 9-Molten salt pump; 10-Heat exchange module; 11-Preheater; 12-Steam generator; 13-Superheater; 14-Exhaust steam recirculation device; 15-Generator; 16-Low-pressure cylinder; 17-Medium-pressure cylinder; 18-High-pressure cylinder; 19-Combustion module; 20-Second valve; 21-Third valve; 23-High-pressure heater; 22-Deaerator; 24-Low-pressure heater; 25-Auxiliary heat exchanger; 31-Agitator assembly; 310-Agitator blades; 311-Connecting rod; 312-Agitator driver; 41-Tank body; 42-Auxiliary temperature control assembly; 421-Adjusting support; 422-Temperature regulator; 423-Adjusting mounting rod; 410-Inner cylinder; 420-Outer cylinder; 430-Insulation cavity; 92-Heating plate; 100-Concentrator; 101-Absorber. Detailed Implementation

[0042] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0043] Figure 1 This is a schematic diagram of the layout of a solar-coal coupled power generation system with molten salt thermal storage provided in one embodiment; Figure 2This is a schematic diagram of the layout of a solar-coal coupled power generation system with molten salt thermal storage provided in another embodiment. Figure 3 This is a schematic diagram of the installation of auxiliary temperature control components in a solar-coal coupled power generation system with molten salt thermal storage in a tank, according to one embodiment. Figure 4 This is a schematic diagram of the auxiliary temperature regulation component in a solar-coal coupled power generation system with molten salt thermal storage. Figure 5 This is another structural schematic diagram of the tank in a solar-coal coupled power generation system with molten salt thermal storage. Figure 6 This is another structural schematic diagram of the auxiliary temperature regulation component in a solar-coal coupled power generation system with molten salt thermal storage.

[0044] like Figures 1-6 As shown, this utility model provides a solar-coal coupled power generation system with molten salt thermal storage, connected to a steam turbine and generator 15. The solar-coal coupled power generation system with molten salt thermal storage includes:

[0045] The thermal storage device stores cold molten salt and hot molten salt. It is used to supply cold molten salt and heat the feedwater fed into the thermal storage device with the stored hot molten salt to generate superheated steam. The superheated steam is sent to the steam turbine to do work to drive the generator 15 to generate electricity. After the superheated steam does work, it becomes exhaust steam and is discharged from the steam turbine.

[0046] A temperature equalization device, connected to a heat storage device, is used to equalize the temperature of cold molten salt and hot molten salt in the heat storage device.

[0047] The auxiliary temperature control component 42 is connected to the thermal storage device and is used to regulate the temperature of the cold molten salt and hot molten salt stored in the thermal storage device.

[0048] The solar-coal combined unit, connected to a thermal storage unit and a steam turbine, is used to convert solar energy into thermal energy to heat the cold molten salt supplied by the thermal storage unit into hot molten salt. The hot molten salt is then used to heat the condensate to generate main steam, which is sent to the steam turbine to do work and drive the generator 15 to generate electricity. It is also used to burn coal to generate thermal energy to heat the condensate to generate main steam, which is sent to the steam turbine to do work and drive the generator 15 to generate electricity. After doing work, the main steam becomes exhaust steam and is discharged from the steam turbine.

[0049] The waste steam recirculation unit 14 is connected to the steam turbine and phosphogypsum combination unit. It is used to recover and cool the waste steam discharged from the steam turbine into condensate, and then transport the condensate back to the phosphogypsum combination unit.

[0050] This utility model provides a photovoltaic-coal coupled power generation system with molten salt thermal storage. The photovoltaic-coal combination unit burns coal to generate heat energy, which heats the condensate fed into the unit. The heated condensate generates main steam, which is sent to a turbine to perform work. The main steam drives a generator 15 to generate electricity. After performing work in the turbine, the main steam becomes exhaust steam, which is discharged from the turbine and enters the exhaust steam recirculation device 14. The photovoltaic-coal combination unit can also convert solar energy into thermal energy to heat the cold molten salt transported to the thermal storage device, turning it into hot molten salt. The hot molten salt can then be transported to the thermal storage device for storage. In the coal-fired power plant, molten salt can also be used to exchange heat with the incoming condensate. The condensate is heated to become main steam, which enters the turbine to drive generator 15 to generate electricity. After the main steam has done its work, it becomes exhaust steam, which is discharged from the turbine and enters the exhaust steam recirculation device 14. The exhaust steam recirculation device 14 is a condenser, where the exhaust steam is cooled to become condensate. The condensate is then sent back to the coal-fired power plant to exchange heat with the molten salt to generate main steam, or it can be heated by the heat energy generated from burning coal to generate main steam. The molten salt stored in the thermal storage device can be heated... The feedwater entering the molten salt thermal storage unit generates superheated steam. This superheated steam then enters the turbine to drive generator 15 and generate electricity. To ensure a stable output of superheated steam when the molten salt heats the feedwater, a temperature equalization device and an auxiliary temperature regulating component 42 are connected to the thermal storage unit. The temperature equalization device evenly distributes the temperature of the stored cold and hot molten salts, ensuring a temperature balance between the stored hot and cold molten salts. The auxiliary temperature regulating component 42 adjusts the temperatures of the cold and hot molten salts within appropriate ranges to prevent temperature stratification that could affect the temperature distribution of the hot and cold molten salts. The heat exchange efficiency of the cold molten salt ensures that the temperature of the hot molten salt is uniform and within a suitable temperature range. When the hot molten salt exchanges heat with condensate or feedwater, it can stably generate main steam or superheated steam, thereby ensuring a stable supply of main steam or superheated steam to the turbine to drive the generator 15 to generate electricity. The stable gas source ensures stable power generation by the generator 15. The condensate from the exhaust steam circulation device 14 can also be used as feedwater to supply the heat storage device. Softened water that has undergone chemical treatment can also be used as feedwater to supply the heat storage device. This application does not limit the source of the feedwater. The superheated steam provided by the thermal storage device, as well as the main steam generated by heating condensate with molten salt and the main steam generated by heating condensate with the heat energy from burning coal, can all enter the steam turbine to drive the generator 15 to generate electricity. This enriches the steam source of the steam turbine, ensures that the steam turbine can be stably supplied with steam, and thus ensures that the generator 15 generates electricity stably. This avoids frequent adjustments to the solar-coal coupled power generation system. It not only solves the problem of unstable power generation when using stored molten salt and cold molten salt due to uneven temperatures of cold and hot molten salt stored in the molten salt storage tank in the existing technology, but also solves the problem of frequent adjustments to the solar-coal coupled power generation system due to the instability or intermittency of solar energy, which leads to a short lifespan of the solar-coal coupled power generation system.

[0051] In one embodiment, such as Figures 1-2 As shown, the solar-coal combination device includes: a solar energy conversion module 1, a combustion module 19, and a heat exchange module 10;

[0052] Solar energy conversion module 1, connected to the thermal storage device, is used to convert light energy into heat energy to heat the cold molten salt from the thermal storage device into hot molten salt;

[0053] The heat exchange module 10 is connected to the solar energy conversion module 1, the steam turbine and the exhaust steam circulation device 14. It is used to heat the condensate with hot molten salt to generate main steam and send the main steam into the steam turbine to do work.

[0054] Combustion module 19 is connected to the steam turbine and exhaust steam recirculation device 14. It is used to burn coal to generate heat energy to heat condensate to generate main steam, and send the main steam to the steam turbine to do work.

[0055] like Figure 1 As shown, the exhaust steam recirculation device 14 recovers and cools the exhaust steam discharged from the steam turbine into condensate. The condensate is transported in two ways: one condensate is sent to the combustion module 19, and the other condensate is sent to the heat exchange module 10.

[0056] The steam turbine includes a high-pressure cylinder 18, an intermediate-pressure cylinder 17, and a low-pressure cylinder 16. The high-pressure cylinder 18 is connected to a combustion module 19 via a pipeline. The combustion module 19 is a boiler. The combustion module 19 burns coal to generate heat energy, which heats the condensate sent into the combustion module 19 to generate main steam. The main steam from the combustion module 19 sequentially enters the high-pressure cylinder 18, the intermediate-pressure cylinder 17, and the low-pressure cylinder 16 to do work. The low-pressure cylinder 16 is connected to a generator 15. The main steam drives the generator 15 to generate electricity by doing work in the high-pressure cylinder 18, the intermediate-pressure cylinder 17, and the low-pressure cylinder 16. A third valve 21 is installed on the connecting pipeline between the high-pressure cylinder 18 and the combustion module 19. The flow state of the main steam in the connecting pipeline between the high-pressure cylinder 18 and the combustion module 19 is controlled by the third valve 21. When the third valve 21 is open, the main steam in the combustion module 19 enters the high-pressure cylinder 18. When the third valve 21 is closed, the main steam in the combustion module 19 cannot enter the high-pressure cylinder 18.

[0057] like Figure 1As shown, the heat exchange module 10 includes a preheater 11, a steam generator 12, and a superheater 13 connected in sequence. The superheater 13 is connected to the high-pressure cylinder 18 via a pipeline. The condensate entering the heat exchange module 10 flows through the preheater 11, the steam generator 12, and the superheater 13 in sequence. The hot molten salt enters the heat exchange module 10 and flows through the preheater 11, the steam generator 12, and the superheater 13 in sequence. The hot molten salt exchanges heat with the condensate transported by the exhaust steam circulation device 14, thereby gradually increasing the temperature of the condensate so that the condensate vaporizes into main steam. After being discharged from the superheater 13, the main steam enters the high-pressure cylinder 18 through a pipeline, and then enters the intermediate-pressure cylinder 17 and the low-pressure cylinder 16 in sequence. The main steam performs work in the high-pressure cylinder 18, the intermediate-pressure cylinder 17, and the low-pressure cylinder 16 to drive the generator 15 to generate electricity. A second valve 20 is installed on the connecting pipeline between the superheater 13 and the high-pressure cylinder 18 to control the flow state of the main steam in the connecting pipeline between the superheater 13 and the high-pressure cylinder 18. After exchanging heat with condensate in heat exchange module 10, the molten salt cools down and becomes heat-loss molten salt. This heat-loss molten salt is discharged from the superheater 13 of heat exchange module 10. Heat exchange module 10 is connected to solar conversion module 1 via a pipe, and a molten salt pump 9 is installed on the connecting pipe between the two modules. The molten salt in heat exchange module 10 is quickly pumped back into solar conversion module 1 by the molten salt pump 9. The heat-loss molten salt can be reheated in solar conversion module 1 to become hot molten salt again. This hot molten salt, heated by the heat energy of solar conversion module 1, can then be sent back into the heat exchange module. In module 10, molten salt can also be sent to the thermal storage device for storage. When the main steam supplied by the combustion module 19 meets the turbine's requirements, the heat energy converted by the solar energy conversion module 1 heats the cold melt supplied by the thermal storage device to become molten salt, and sends the molten salt back to the thermal storage device for storage. Then, when the main steam supplied by the combustion module 19 cannot meet the turbine's requirements, the molten salt stored in the thermal storage device can be used to heat the feedwater to generate superheated steam. The superheated steam is sent to the turbine to do work. The superheated steam flows through the high-pressure cylinder 18, the intermediate-pressure cylinder 17 and the low-pressure cylinder 16 in sequence to do work and drive the generator 15 to generate electricity.

[0058] In one embodiment, such as Figure 3 As shown, the thermal storage device includes a pair of molten salt storage tanks. Each molten salt storage tank includes a tank body 41 with a receiving cavity. The tank bodies 41 of the pair of molten salt storage tanks are both connected to the solar energy conversion module 1. The receiving cavity of the tank body 41 of one molten salt storage tank stores cold molten salt and can supply cold molten salt to the solar energy conversion module 1. The receiving cavity of the tank body 41 of the other molten salt storage tank stores hot molten salt formed after being heated by the solar energy conversion module 1.

[0059] The solar energy conversion module 1 includes a concentrator 100 and a heat absorber 101;

[0060] The concentrator 100 is used to collect light energy and concentrate it into a designated area of ​​the absorber 101;

[0061] The heat absorber 101 is used to absorb and convert light energy in a designated area into heat energy.

[0062] The molten salt thermal storage device further includes: a first heat exchanger 5, which is connected to a pair of molten salt storage tanks and a steam turbine. The first heat exchanger 5 uses hot molten salt output from one molten salt storage tank to heat the feedwater entering the first heat exchanger 5 to generate superheated steam, and sends the superheated steam to the steam turbine to do work. After the hot molten salt loses heat, it becomes cold molten salt and enters the other molten salt storage tank.

[0063] The solar energy conversion module 1 is a dish-type solar energy system, comprising a concentrator 100 and a heat absorber 101. The concentrator 100 focuses sunlight onto a designated area of ​​the heat absorber 101. The concentrator 100 includes multiple sets of parabolic concentrating mirrors, which reflect sunlight onto the designated area of ​​the heat absorber 101. The heat absorber 101 absorbs and converts the sunlight into heat energy in the designated area. The heat absorber 101 is connected to the tank bodies 41 of a pair of molten salt storage tanks in the heat exchange module 10 and the heat storage device. One of the tank bodies 41 stores cold molten salt in its receiving cavity. A cryogenic molten salt pump 3 is installed on the connecting pipe between the devices 101. The cryogenic molten salt in the tank 41 is pumped to the absorber 101 by the cryogenic molten salt pump 3. The heat energy converted by the absorber 101 is used to heat the cryogenic molten salt into hot molten salt. Depending on the actual needs, the hot molten salt can be sent to the heat exchange module 10 or to the tank 41 for storing hot molten salt. When the solar energy conversion module 1 can provide sufficient heat energy, the hot molten salt formed by the solar energy conversion module 1 can be sent in two ways. One way is sent to the heat exchange module 10 to exchange heat with condensate, and the other way is sent to the tank 41 for storing hot molten salt.

[0064] When the main steam supplied by the combustion module 19 is insufficient and the solar energy conversion module 1 cannot stably convert light energy into heat energy, the hot molten salt stored in the thermal storage device can be sent to the first heat exchanger 5, such as... Figure 1 and Figure 2As shown, the first heat exchanger 5 is connected to the tank bodies 41 of a pair of molten salt storage tanks and the high-pressure cylinder 18 of the steam turbine via pipelines. A high-temperature molten salt pump 7 is installed on the connecting pipeline between the tank body 41 storing hot molten salt and the first heat exchanger 5. The high-temperature molten salt pump 7 rapidly pumps the hot molten salt in the tank body 41 to the first heat exchanger 5, while simultaneously supplying feedwater to the first heat exchanger 5. The hot molten salt and feedwater exchange heat in the first heat exchanger 5. The feedwater absorbs the heat from the hot molten salt and becomes superheated steam, which enters the high-pressure cylinder 18 through the pipeline, and then flows sequentially through the intermediate-pressure cylinder 17 and... The low-pressure cylinder 16 is used to drive the generator 15 to generate electricity by superheated steam in the high-pressure cylinder 18, intermediate-pressure cylinder 17 and low-pressure cylinder 16. After doing work in the steam turbine, the superheated steam becomes exhaust steam and is discharged from the steam turbine into the exhaust steam circulation device 14. The hot molten salt loses heat after exchanging heat with the feedwater in the first heat exchanger 5 and becomes cold molten salt, which enters the tank 41 containing the cold molten salt. A first valve 6 is installed on the connecting pipe between the first heat exchanger 5 and the high-pressure cylinder 18. The flow state of the superheated steam in the connecting pipe between the first heat exchanger 5 and the high-pressure cylinder 18 is controlled by the first valve 6.

[0065] In one embodiment, in order to ensure that the cold molten salt or hot molten salt in the receiving cavity of the tank 41 is within the required temperature range, the auxiliary temperature regulating component 42 is disposed in the receiving cavity of the tank 41 to regulate the temperature of the cold molten salt or hot molten salt in the receiving cavity.

[0066] The auxiliary temperature control component 42 includes: an adjustment support 421 and multiple temperature regulators 422;

[0067] The adjusting support 421 is vertically installed in the receiving cavity to support multiple temperature regulators 422;

[0068] Multiple temperature regulators 422 are detachably mounted on the regulating support 421 along the circumference of the regulating support 421, and the temperature of the cold molten salt or hot molten salt in the containing cavity is adjusted by the multiple temperature regulators 422.

[0069] The auxiliary temperature control component 42 also includes: multiple adjustment mounting rods 423;

[0070] Multiple adjusting mounting rods 423 are detachably mounted on the adjusting support column 421 along the circumference of the adjusting support column 421. Multiple temperature regulators 422 are arranged along the extension direction of each adjusting mounting rod 423, wherein the multiple temperature regulators 422 on each adjusting mounting rod 423 are arranged in layers.

[0071] like Figures 3-4As shown, an adjusting support column 421 is vertically installed inside the receiving cavity of the tank body 41. To allow the adjusting mounting rod 423 to be detachably mounted on the adjusting support column 421, multiple mounting slots are formed along the circumference of the adjusting support column 421. Each mounting slot is open at one end and extends in the same direction as the adjusting support column 421. The mounting slots are either dovetail slots or T-slots. Each adjusting mounting rod 423 has a boss that matches the shape and size of the mounting slot. For example, if the mounting slot is a dovetail slot, the boss matches the size and shape of the dovetail slot; if the mounting slot is a T-slot, the boss matches the size and shape of the T-slot. With a perfect fit in size and shape, the boss of the adjusting mounting rod 423 can slide into the mounting groove from one end of the mounting groove opening so that the adjusting mounting rod 423 can be mounted on the adjusting support 421. Multiple temperature regulators 422 are provided on each adjusting mounting rod 423. The multiple temperature regulators 422 on each adjusting mounting rod 423 are arranged in layers to facilitate heating hot molten salt or cold molten salt at different depths in the receiving cavity, ensuring that the temperature of hot molten salt or cold molten salt in the receiving cavity is uniform and quickly maintaining the temperature of hot molten salt and cold molten salt at a suitable temperature. The temperature regulator 422 is an electric heating tube.

[0072] To ensure a uniform temperature of the cold or hot molten salt inside the tank 41, the temperature equalization device includes: multiple stirring components 31;

[0073] Each stirring assembly 31 includes a stirring blade 310, which is disposed in the receiving cavity of the tank 41 for stirring the cold molten salt or hot molten salt in the tank 41.

[0074] Each stirring assembly 31 also includes: a connecting rod 311 and a stirring driver 312;

[0075] One end of the connecting rod 311 extends into the receiving cavity of the tank 41 and is connected to the stirring blade 310, while the other end is exposed outside the receiving cavity of the tank 41 and is connected to the stirring driver 312.

[0076] The stirring driver 312 is located on the outer wall of the tank 41 and is used to drive the connecting rod 311 to rotate the stirring blade 310 to stir the cold molten salt or hot molten salt in the tank 41.

[0077] The system also includes multiple sets of detection components. At least one set of detection components is provided in the accommodating cavity of the tank body 41 of each molten salt storage tank. The detection components are used to detect the liquid level and temperature inside the tank body 41.

[0078] like Figure 3As shown, the stirring driver 312 is located on the outside of the tank 41. One end of the connecting rod 311 is connected to the stirring blade 310, and the other end is connected to the drive shaft of the stirring driver 312. The stirring driver 312 drives the connecting rod 311 to rotate, thereby driving the stirring blade 310 to stir the hot molten salt or cold molten salt in the tank 41. By stirring the hot molten salt or cold molten salt in the tank 41 through multiple sets of stirring components 31, the hot molten salt or cold molten salt in the tank can be mixed, thereby ensuring the temperature of the hot molten salt or cold molten salt in the containment cavity is balanced. In this way, the temperature of the hot molten salt can be kept stable when it is supplied, and the reheat steam or main steam can be generated stably when exchanging heat with feedwater or condensate. The steam turbine can also work stably, thereby ensuring the stable power generation of the generator 15.

[0079] Each detection component includes a level gauge and multiple temperature sensors. The multiple temperature sensors are arranged in layers within the containment cavity of the tank 41. The multiple temperature sensors are correspondingly arranged with multiple temperature regulators 422. In this way, the temperature of hot molten salt or cold molten salt at different depths within the containment cavity can be detected by the layered temperature sensors. The temperature regulators 422 of the auxiliary temperature control component 42 can be electrically connected to the temperature sensors of the corresponding layers. The temperature regulators 422 can start or stop working according to the temperature of the hot molten salt or cold molten salt detected by the temperature sensors of the corresponding layers. When the temperature detected by the temperature sensors of different layers within the tank 41 is consistent and within the specified temperature range, all temperature regulators 422 within the tank 41 stop working.

[0080] The level gauge detects the level of hot or cold molten salt in the containment cavity of tank 41.

[0081] In another embodiment, such as Figure 5 As shown, the tank 41 includes an inner cylinder 410 and an outer cylinder 420; the inner cavity of the inner cylinder 410 serves as a receiving cavity;

[0082] The inner cylinder 410 is fitted into the outer cylinder 420, so that a heat insulation cavity 430 is formed between the outer wall of the inner cylinder 410 and the inner wall of the outer cylinder 420. The heat insulation cavity 430 is connected to the flue gas outlet of the combustion module 19.

[0083] Hot or cold molten salt is stored in an inner cylinder 410, which is placed inside an outer cylinder 420. An insulation cavity 430 is formed between the outer wall of the inner cylinder 410 and the outer wall of the outer cylinder 420. The insulation cavity 430 is connected to the flue gas outlet of the combustion module 19 through a first flue gas pipe. Thus, the flue gas generated by the combustion of the combustion module 19 is divided into two paths. One path enters the insulation cavity 430 through the first flue gas pipe. The flue gas generated by the combustion of the combustion module 19 has residual heat. The flue gas entering the insulation cavity 430 can slow down or prevent the loss of temperature of the hot or cold molten salt in the inner cylinder 410. After exchanging heat with the cold or hot molten salt in the insulation cavity 430, the flue gas is discharged from the insulation cavity 430. In order to facilitate the control of the flue gas entering the insulation cavity 430, a control valve is installed on the first flue gas pipe. The flow state and flow rate of the flue gas in the first flue gas pipe are controlled by the control valve.

[0084] In order to place the inner cylinder 410 inside the outer cylinder 420, such as Figure 3 As shown, multiple first support blocks are provided in the heat preservation cavity 430. Each support block is connected to the outer wall of the inner cylinder 410 and the outer wall of the outer cylinder 420. The inner cylinder 410 is supported in the outer cylinder 420 by the multiple first support blocks.

[0085] To prevent the storage level of cold or hot molten salt in the inner cylinder 410 from being too low, which would cause the temperature of the cold or hot molten salt stored in the inner cylinder 410 to drop too quickly, a level gauge installed in the receiving cavity of the tank body 41 is used to detect the liquid level in the receiving cavity. This allows the staff to keep track of the liquid level in the tank body 41 at any time and replenish the molten salt in time when the liquid level in the tank body 41 is too low, thus preventing the stored hot or cold molten salt from dropping too quickly.

[0086] In another embodiment, the auxiliary temperature control component 42 includes: a plurality of heating plates 92, which are arranged in layers in the inner cylinder 410 of the tank 41, and the temperature of the cold molten salt or hot molten salt in the inner cylinder 410 of the tank 41 is adjusted by the plurality of heating plates 92.

[0087] To more quickly adjust the temperature of the cold or hot molten salt in tank 41, multiple heating plates 92 are arranged in layers within the inner cylinder 410 of tank 41. By controlling the activation of the heating plates 92 in different layers, the temperature of the cold or hot molten salt in tank 41 can be quickly adjusted. Figure 6As shown, taking the example of multiple heating plates 92 arranged in layers in one of the tanks 41, in order to install the heating plates 92 in layers in the tank 41, multiple second support blocks are arranged in layers along the circumference of the inner wall of the tank 41. The multiple second support blocks arranged in each layer support the heating plate 92 corresponding to that layer. The heating plate 92 can be an electric heating plate, which is made of multiple electric heating tubes spliced ​​together. The auxiliary temperature control component 42 also includes a temperature controller. The temperature controller is electrically connected to the liquid level gauge and the multiple heating plates 92 in the tank 41. The liquid level gauge detects the liquid level in the tank 41 and sends the liquid level to the temperature controller. The temperature controller controls the heating plate 92 of the corresponding layer below the liquid level to work according to the liquid level in the tank 41 to adjust the temperature of the hot molten salt or cold molten salt in the tank 41. In this way, energy waste can be avoided. At the same time, placing the heating plate 92 in the tank 41 can adjust the temperature of the hot molten salt or cold molten salt more quickly.

[0088] To make rational use of energy, the system also includes an auxiliary heat exchanger 25, which is connected to the combustion module 19 and a pair of molten salt storage tanks. It is used to heat cold molten salt from one molten salt storage tank into hot molten salt using the main steam from the combustion module 19, and then transport the hot molten salt to the other molten salt storage tank for storage.

[0089] The solar-coal coupled power generation system with molten salt thermal storage also includes a heating component connected to the exhaust steam recirculation device 14 and the combustion module 19, used to heat the condensate fed into the combustion module 19.

[0090] like Figure 2As shown, an auxiliary pipe is connected between the auxiliary heat exchanger 25 and the third valve 21. This allows the main steam generated by the combustion module 19 from burning coal to flow in two streams after passing through the third valve 21. One stream of main steam enters the high-pressure cylinder 18 to perform work, while the other stream flows through the auxiliary pipe into the auxiliary heat exchanger 25. By controlling the third valve 21, the flow of main steam into the auxiliary heat exchanger 25 and / or the high-pressure cylinder 18, as well as the flow state of the main steam in the connecting pipe between the high-pressure cylinder 18 and the combustion module 19 and in the auxiliary pipe, can be controlled. Simultaneously, the cryogenic molten salt pump 3 pumps the molten salt stored in the tank 41 to the auxiliary heat exchanger 25. The molten salt and main steam then interact in the auxiliary heat exchanger 25. The auxiliary heat exchanger 25 absorbs heat from the main steam to become hot molten salt. After being discharged from the auxiliary heat exchanger 25, the hot molten salt enters the molten salt storage tank for storage. After the main steam loses heat in the auxiliary heat exchanger 25, it is discharged from the auxiliary heat exchanger 25. Thus, the excess main steam generated by the combustion module 19 is sent to the auxiliary heat exchanger 25 to heat the cold molten salt to become hot molten salt, which is then stored in the tank 41 for storing hot molten salt. After the cold molten salt absorbs heat from the main steam to become hot molten salt, it is stored. When the hot molten salt releases heat, the stored hot molten salt is pumped into the first heat exchanger 5 by the high-temperature molten salt pump 7 to release heat and heat the feedwater entering the first heat exchanger 5 to become superheated steam. The superheated steam is sent to the high-pressure cylinder 18 of the steam turbine to do work and drive the generator 15 to generate electricity.

[0091] To save energy, the heating assembly includes a high-pressure heater 23 and a low-pressure heater 24;

[0092] The low-pressure heater 24 is connected to the exhaust steam recirculation device 14 and the high-pressure heater 23, and is used to preheat the condensate fed into the combustion module 19;

[0093] The high-pressure heater 23 is connected to the combustion module 19 and is used for secondary heating of the condensate discharged from the low-pressure heater 24.

[0094] The condensate discharged from the self-exhaust steam recirculation device 14 is sent to the combustion module 19. In order to save energy consumed by the combustion module 19 in heating the condensate and to improve the vaporization efficiency of the condensate, the condensate discharged from the self-exhaust steam recirculation device 14 is first heated by the low-pressure heater 24 and the high-pressure heater 23 in sequence before entering the combustion module 19. The low-pressure heater 24 first preheats the condensate discharged from the self-exhaust steam recirculation device 14, and then the high-pressure heater 23 reheats the condensate discharged from the low-pressure heater 24. The condensate has already increased in temperature before entering the combustion module 19. After entering the combustion module 19, it can be heated into main steam with less energy, which not only saves energy but also improves the working efficiency of the combustion module 19.

[0095] To meet the water requirements of the combustion module 19, a deaerator 22 is installed between the low-pressure heater 24 and the high-pressure heater 23. The deaerator 22 removes oxygen and other gases from the condensate water supplied to the combustion module 19 to prevent oxidation and corrosion in the pipeline and combustion module.

[0096] This utility model provides a photovoltaic-coal coupled power generation system with molten salt thermal storage. The thermal storage device stores both cold and hot molten salt. The stored hot molten salt heats feedwater to generate superheated steam. This superheated steam is sent to a steam turbine to drive a generator. After performing work, the superheated steam becomes exhaust steam, which is discharged from the turbine and enters an exhaust steam recirculation system. To ensure stable temperature of the hot molten salt supplied to the thermal storage device and thus a stable output of superheated steam, thereby ensuring stable generator power generation, a temperature equalization device and auxiliary temperature control components are connected to the thermal storage device. The temperature equalization device evenly distributes the hot and cold molten salts stored in the thermal storage device. The temperature of the salt is used to equalize the temperature of the cold and hot molten salts in the thermal storage unit. The temperature of the stored cold and hot molten salts is regulated by auxiliary temperature control components to ensure that the output cold and hot molten salts remain within a suitable temperature range. This ensures stable output of superheated steam and guarantees the conversion efficiency of the hot molten salts. The photovoltaic-coal combined unit uses the heat energy converted from solar energy to heat the cold molten salt supplied by the thermal storage unit, turning it into hot molten salt. The hot molten salt can be stored in the thermal storage unit or used in conjunction with condensate. In the condensate heat exchange process, the condensate entering the galvanized coal combination unit absorbs heat from the molten salt and vaporizes into main steam, which is then fed into the turbine to drive the generator. The galvanized coal combination unit can also utilize the heat energy generated from burning coal to heat the condensate and generate main steam. This main steam is also fed into the turbine to drive the generator. After performing its work, the main steam becomes exhaust steam and is discharged from the turbine into the exhaust steam recirculation unit. In this unit, the exhaust steam is cooled and becomes condensate, which is then fed back into the galvanized coal combination unit. Thus, by utilizing the molten salt to heat the feedwater to generate superheated steam and the heat from the galvanized coal combination unit, the condensate is effectively heated and heated. The combined unit utilizes the main steam generated by heating condensate with molten salt and the main steam generated by heating condensate with the heat energy from burning coal. Both can be sent to the steam turbine to do work and drive the generator to generate electricity, thereby ensuring a stable supply of main steam and superheated steam to the steam turbine, avoiding frequent adjustments to the power generation system, and ensuring stable power generation. The photovoltaic-coal coupled power generation system with molten salt thermal storage provided in this application solves the problem of unstable power generation when using stored hot and cold molten salt for power generation due to the uneven temperature of cold and hot molten salt stored in the molten salt storage tank in the prior art. It can also avoid frequent adjustments to the power generation system.

[0097] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the various possible combinations will not be described separately in this embodiment.

[0098] Furthermore, various different implementation methods of this utility model can be arbitrarily combined, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.

Claims

1. A photo-coal coupled power system with molten salt thermal storage, connected to a steam turbine and a generator (15), characterized in that, The light coal coupled power generation system with molten salt heat storage comprises: a heat storage device storing cold molten salt and hot molten salt, for supplying the cold molten salt, heating feed water entering the heat storage device by the stored hot molten salt to generate superheated steam, and sending the superheated steam into a steam turbine to do work to drive a generator (15) to generate power, the superheated steam becoming exhaust steam after doing work and being discharged from the steam turbine; a temperature equalizing device connected with the heat storage device, for equalizing the temperature of the cold molten salt and the temperature of the hot molten salt in the heat storage device; an auxiliary temperature adjusting assembly (42) connected with the heat storage device, for adjusting the temperature of the cold molten salt and the hot molten salt stored in the heat storage device; a light coal combined device connected with the heat storage device and the steam turbine, for converting light energy into heat energy to heat the cold molten salt supplied by the heat storage device into hot molten salt, and heating condensate into main steam by the hot molten salt, the main steam being sent into the steam turbine to do work to drive the generator (15) to generate power, and for burning coal to generate heat energy to heat condensate into main steam, the main steam being sent into the steam turbine to do work to drive the generator (15) to generate power, wherein the main steam becomes exhaust steam after doing work and is discharged from the steam turbine; an exhaust steam circulation device (14) connected with the steam turbine and the light coal combined device, for recovering and cooling the exhaust steam discharged from the steam turbine into condensate, and sending the condensate into the light coal combined device again.

2. The photo-coal coupled power system with molten salt heat storage according to claim 1, characterized in that, The light coal combined device comprises a solar energy conversion module (1), a combustion module (19) and a heat exchange module (10); the solar energy conversion module (1) is connected with the heat storage device, for converting light energy into heat energy to heat the cold molten salt from the heat storage device into hot molten salt; the heat exchange module (10) is connected with the solar energy conversion module (1), the steam turbine and the exhaust steam circulation device (14), for heating condensate into main steam by the hot molten salt, and sending the main steam into the steam turbine to do work; the combustion module (19) is connected with the steam turbine and the exhaust steam circulation device (14), for burning coal to generate heat energy to heat condensate into main steam, and sending the main steam into the steam turbine to do work. The heat storage device comprises a pair of molten salt storage tanks; 3. The photo-coal coupled power system with molten salt heat storage according to claim 2, characterized in that, each molten salt storage tank comprises a tank body (41) having a containing cavity, the tank bodies (41) of the pair of molten salt storage tanks are connected with the solar energy conversion module (1), wherein the containing cavity of the tank body (41) of one molten salt storage tank stores cold molten salt and can supply the cold molten salt to the solar energy conversion module (1), and the containing cavity of the tank body (41) of the other molten salt storage tank stores hot molten salt formed after being heated by the solar energy conversion module (1). The heat storage device further comprises a first heat exchanger (5) connected with the pair of molten salt storage tanks and the steam turbine, the first heat exchanger (5) heats feed water entering the first heat exchanger (5) by the hot molten salt output from one molten salt storage tank to generate superheated steam, and sends the superheated steam into the steam turbine to do work, the hot molten salt becoming cold molten salt after losing heat and entering the other molten salt storage tank.

4. The photo-coal coupled power system with molten salt heat storage according to claim 3, characterized in that, The auxiliary temperature adjusting assembly (42) is arranged in the containing cavity of the tank body (41), for adjusting the temperature of the cold molten salt or the hot molten salt in the containing cavity.

5. The photo-coal coupled power system with molten salt heat storage according to claim 3, characterized in that, The auxiliary temperature adjusting assembly (42) comprises adjusting struts (421) and a plurality of temperature adjusters (422).

6. The photo-coal coupled power system with molten salt heat storage according to claim 5, characterized in that, ​ The adjusting support (421) is vertically arranged in the accommodating cavity and is used for supporting the plurality of temperature adjusters (422); The plurality of temperature adjusters (422) are detachably arranged on the adjusting support (421) along the circumference of the adjusting support (421), and the temperature of the cold molten salt or the hot molten salt in the accommodating cavity is adjusted by the plurality of temperature adjusters (422).

7. The photo-coal coupled power system with molten salt heat storage according to claim 6, characterized in that, The auxiliary temperature adjusting assembly (42) further comprises a plurality of adjusting mounting rods (423); The plurality of adjusting mounting rods (423) are detachably arranged on the adjusting support (421) along the circumference of the adjusting support (421), and the plurality of temperature adjusters (422) are arranged along the extending direction of each adjusting mounting rod (423), wherein the plurality of temperature adjusters (422) on each adjusting mounting rod (423) are arranged in layers.

8. The photo-coal coupled power system with molten salt heat storage according to claim 3, characterized in that, The temperature equalizing device comprises a plurality of stirring assemblies (31); Each stirring assembly (31) comprises a stirring blade (310), a connecting rod (311) and a stirring driver (312); The stirring blade (310) is arranged in the accommodating cavity of the tank body (41) and is used for stirring the cold molten salt or the hot molten salt in the tank body (41); One end of the connecting rod (311) is connected with the stirring blade (310) and extends into the accommodating cavity of the tank body (41), and the other end of the connecting rod (311) is exposed outside the accommodating cavity of the tank body (41) and is connected with the stirring driver (312); The stirring driver (312) is arranged on the outer sidewall of the tank body (41) and is used for driving the connecting rod (311) to rotate to stir the cold molten salt or the hot molten salt in the tank body (41).

9. The photo-coal coupled power system with molten salt heat storage according to claim 3, characterized in that, The system further comprises a plurality of detection assemblies, at least one detection assembly is arranged in the accommodating cavity of the tank body (41) of each molten salt storage tank, and the detection assembly is used for detecting the liquid level and the temperature in the tank body (41).

10. The photo-coal coupled power system with molten salt heat storage according to claim 2, characterized in that, The system further comprises an auxiliary heat exchanger (25) connected with the combustion module (19) and the pair of molten salt storage tanks, which is used for heating the cold molten salt from one molten salt storage tank into hot molten salt by using the main steam from the combustion module (19) and delivering the hot molten salt to the other molten salt storage tank for storage.

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