Circulating fluidized bed boiler system for solar frequency division heat compensation and afterwave photovoltaic power generation

Abstract

The invention discloses a circulating fluidized bed boiler system for solar frequency division heat compensation and afterwave photovoltaic power generation. An outlet of a hearth dilute-phase area is communicated with a separator, a circulating material outlet of the separator is communicated with a first opening of a reversing three-way valve, a second opening of the reversing three-way valve is communicated with a return feeder, and the return feeder is communicated with a dense-phase area of a hearth; a third port of the reversing three-way valve is communicated with the photo-thermal absorber, the photo-thermal absorber absorbs heat generated by the photovoltaic photo-thermal frequency division assembly on the part of the spectrum after the frequency division of the solar energy, and the photovoltaic photo-thermal frequency division assembly generates power for the part of the spectrum after the frequency division of the solar energy; a high-temperature flue gas outlet of the separator is communicated with the convection shaft, and steam generated by heat exchange of the convection shaft is supplied to the steam turbine generator. Energy spectrum frequency division of the sun and low-frequency radiation energy are used for auxiliary heat compensation and heat storage of circulating materials of the circulating fluidized bed boiler, high-frequency energy is directly used for photovoltaic power generation, gradient utilization of light and gradient utilization of heat are achieved, and the flexibility of a circulating fluidized bed boiler system and the stability of a power grid are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power generation, and in particular to a circulating fluidized bed boiler system for solar frequency division heating and after-wave photovoltaic power generation. Background Art

[0002] Circulating fluidized bed coal-fired power generation is a clean and efficient thermal power generation technology with the advantage of wide fuel adaptability. Solar photovoltaic power generation is a cost-effective solar power generation technology with the advantage of abundant reserves. However, solar energy is an intermittent renewable energy source. With the integration of solar power generation into the grid, the power grid has to rely on increasing the load regulation range of thermal power generation to smooth out peak loads and fill valleys to create conditions for solar integration.

[0003] At present, circulating fluidized bed boilers are the main units for thermal power generation. In order to ensure the stability of the power grid, circulating fluidized bed boilers are required to have higher rapid load increase and load decrease capabilities, so as to cooperate with renewable energy such as solar energy to ensure the stability of the power grid.

[0004] In the prior art, CN219913039U discloses a circulating fluidized bed unit capable of rapid load adjustment. This unit stores high-temperature materials in the furnace by providing a temporary storage component. When the load needs to be increased rapidly, the high-temperature materials are delivered to the furnace. However, the temporary storage component is located in the dense phase area of the boiler, resulting in larger particles of stored materials. When delivered to the furnace, the effective bed material is small, resulting in poor heat transfer performance. CN117053185A discloses a circulating fluidized bed pressure-shaving system. After pressure-shaving, excess hot materials are introduced into a gasifier to gasify the biomass, thereby converting sensible heat energy into chemical energy for heat storage. Synthesis gas is generated when the load is reduced, and the synthesis gas is burned to rapidly increase the furnace temperature when the load is increased. However, this system is complex and involves combustible gases, requiring a high explosion-proof rating.

[0005] Therefore, how to improve the variable load heat transfer rate of the circulating fluidized bed boiler to improve the peak load regulation capability and ensure the stability of the power grid is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a circulating fluidized bed boiler system with solar frequency division heating and after-wave photovoltaic power generation, which improves the variable load heat transfer rate of the circulating fluidized bed boiler to improve the peak regulation capacity and ensure the stability of the power grid.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation, comprising: a furnace, a separator, a convection shaft, a photovoltaic thermal frequency division component, a photothermal absorber, a return device and a steam turbine generator;

[0009] The outlet of the dilute phase zone of the furnace is connected to the separator, the circulating material outlet of the separator is connected to the first port of the reversing three-way valve, the second port of the reversing three-way valve is connected to the material return device, and the material return device is connected to the dense phase zone of the furnace;

[0010] The third port of the reversing three-way valve is connected to the photothermal absorber, which absorbs heat generated by the photovoltaic-photothermal frequency division component on the partial spectrum after solar energy is divided. The photothermal absorber is adjustably connected to the return device, and the photovoltaic-photothermal frequency division component generates electricity from the partial spectrum after solar energy is divided. The power generation device of the photovoltaic-photothermal frequency division component is connected to the power grid;

[0011] The high-temperature flue gas outlet of the separator is connected to the convection shaft, and the high-temperature flue gas exchanges heat with the convection shaft. The steam generated by the heat exchange in the convection shaft is supplied to the steam turbine generator, and the steam turbine generator is connected to the power grid.

[0012] Preferably, in the above-mentioned circulating fluidized bed boiler system for solar frequency division heating and residual wave photovoltaic power generation, a high-temperature material storage tank and a regulating valve are provided between the photothermal absorber and the return device;

[0013] The high-temperature material storage tank is communicated with the photothermal absorber, and the regulating valve is provided between the high-temperature material storage tank and the material return device to control the connection and disconnection between the high-temperature material storage tank and the material return device.

[0014] Preferably, in the above-mentioned circulating fluidized bed boiler system for solar frequency division heating and residual wave photovoltaic power generation, an external bed is provided between the reversing three-way valve and the photothermal absorber;

[0015] The external bed is in contact with the heat exchange device for heat exchange, the inlet of the external bed is connected to the third port of the reversing three-way valve; the outlet of the external bed is connected to the photothermal absorber.

[0016] Preferably, in the above-mentioned circulating fluidized bed boiler system for solar frequency division heating and residual wave photovoltaic power generation, a screener is provided between the reversing three-way valve and the external bed;

[0017] The discharge port of the screener is communicated with the third port of the reversing three-way valve, the overflow port above the screen of the screener is communicated with the return device, and the overflow port below the screen of the screener is communicated with the inlet of the external bed.

[0018] Preferably, in the above-mentioned circulating fluidized bed boiler system with solar frequency division heating and after-wave photovoltaic power generation, an external bed air chamber is provided at the bottom of the external bed, the external bed air chamber provides fluidizing air to the external bed, and an external bed air outlet is provided on the upper part of the external bed near the side of the heat exchange device, and the external bed air outlet is connected to the first auxiliary combustion air outlet of the furnace;

[0019] and / or,

[0020] An absorber wind chamber is provided at the bottom of the photothermal absorber, and the absorber wind chamber provides fluidizing air to the photothermal absorber. An absorber outlet is provided on the upper side of the photothermal absorber away from the reflected sunlight, and the absorber outlet is connected to the second auxiliary combustion air port of the furnace.

[0021] Preferably, in the above-mentioned circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation, the photovoltaic thermal frequency division component includes:

[0022] Frequency divider, which is a filter that passes short waves and reflects long waves;

[0023] A photovoltaic cell is stacked with the frequency divider, and the frequency divider is located on the surface of the photovoltaic cell, absorbing the solar energy transmitted by the frequency divider and generating electricity. The photovoltaic cell is connected to the power grid.

[0024] Preferably, in the above-mentioned circulating fluidized bed boiler system for solar frequency division heating and after-wave photovoltaic power generation, the divider is a curved surface divider, the photovoltaic cell is a curved surface thin-film photovoltaic cell, the curved surface divider has the same curvature as the curved surface thin-film photovoltaic cell, and is arranged in a stacked manner.

[0025] Preferably, in the above-mentioned circulating fluidized bed boiler system with solar frequency division heating and after-wave photovoltaic power generation, the photovoltaic cells are perovskite thin film cells, copper indium gallium selenide thin film cells, polycrystalline silicon thin film cells or cadmium telluride thin film cells.

[0026] Preferably, in the above-mentioned circulating fluidized bed boiler system for solar frequency division heating and after-wave photovoltaic power generation, the frequency divider is a planar frequency divider, the photovoltaic cell is a planar photovoltaic cell, and the planar frequency divider and the planar photovoltaic cell are stacked.

[0027] Preferably, in the above-mentioned circulating fluidized bed boiler system for solar frequency division heating and after-wave photovoltaic power generation, the frequency divider includes: a silicon dioxide layer, a titanium dioxide layer, a niobium pentoxide layer, and a tantalum pentoxide layer coated on the glass surface.

[0028] Disclosed in an embodiment of the present invention is a circulating fluidized bed boiler system with solar frequency division heating and afterwave photovoltaic power generation. In a load reduction state, the circulating material generated by the separator is collected, and the circulating material generated by the separator of the circulating fluidized bed boiler is heated using the energy suitable for heating obtained by frequency division in the solar electromagnetic radiation spectrum, thereby reducing the material concentration in the furnace and achieving rapid load reduction in the furnace; in a load increase state, the heated circulating material is returned to the furnace, increasing the temperature and material concentration in the furnace, thereby achieving rapid load increase of the circulating fluidized bed boiler and improving the stability of the power grid.

[0029] At the same time, the energy in the solar spectrum that is suitable for power generation is used for solar power generation, which realizes the coupling of solar power generation and solar heating of circulating fluidized bed boilers, which is conducive to improving the utilization of solar energy, reducing power generation costs, and improving the stability of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 This is a schematic structural diagram of a first structure of a circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation disclosed in an embodiment of the present invention;

[0032] Figure 2 for Figure 1 The assembly relationship diagram of photovoltaic and thermal frequency division components;

[0033] Figure 3 This is a schematic structural diagram of a second structure of a circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation disclosed in an embodiment of the present invention;

[0034] Figure 4 for Figure 3 Assembly diagram of photovoltaic and thermal frequency division components

[0035] Figure 5 This is a structural diagram of a reversing three-way valve disclosed in an embodiment of the present invention;

[0036] Figure 6 A schematic structural diagram of a screener disclosed in an embodiment of the present invention;

[0037] Figure 7 Schematic diagram of spectral irradiance. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the quantity of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0040] Circulating fluidized bed coal-fired power generation is a clean and efficient thermal power generation technology with the advantage of wide fuel adaptability. Solar photovoltaic power generation is a cost-effective solar power generation technology with the advantage of abundant reserves. However, solar energy is an intermittent renewable energy source. With the integration of solar power generation into the grid, the power grid has to rely on increasing the load regulation range of thermal power generation to smooth out peak loads and fill valleys to create conditions for solar integration.

[0041] At present, circulating fluidized bed boilers are the main units for thermal power generation. In order to ensure the stability of the power grid, circulating fluidized bed boilers are required to have higher rapid load increase and load decrease capabilities, so as to cooperate with renewable energy such as solar energy to ensure the stability of the power grid.

[0042] Based on the above technical problems, an embodiment of the present application discloses a circulating fluidized bed boiler system with solar frequency division heating and after-wave photovoltaic power generation, which stores heat from part of the solar energy band in the material circulation system of the circulating fluidized bed boiler. When the circulating fluidized bed boiler needs to increase its load, the stored material is released into the furnace of the circulating fluidized bed boiler to increase the concentration of the circulating material in the furnace and quickly replenish heat to the furnace; when the circulating fluidized bed boiler reduces its load, the circulating material is stored to reduce heat release.

[0043] In addition, the circulating fluidized bed boiler system for solar frequency-splitting heat supplementation and residual wave photovoltaic power generation involved in this application can also frequency-split the energy spectrum from the sun. The low-frequency infrared radiation energy can be used to supplement and store heat for the circulating materials in the circulating fluidized bed boiler, while the remaining high-frequency visible spectrum energy is directly used for photovoltaic power generation in the circulating fluidized bed boiler, thus achieving an organic combination of cascade utilization of light and heat. In addition, high-temperature particles heated by solar energy are directly introduced into the circulating fluidized bed generator set as a source of heat supplementation and an auxiliary means of heat transfer regulation, reducing dependence on fossil fuels and improving rapid load adjustment capabilities. This belongs to the field of renewable energy photovoltaic power generation technology and high-temperature solid particle energy storage coupled with advanced circulating fluidized bed thermal power generation and renewable energy photovoltaic power generation technology.

[0044] The specific structure of the circulating fluidized bed boiler system for solar frequency division heating and after-wave photovoltaic power generation disclosed in the embodiment of the present application is described below with reference to the accompanying drawings.

[0045] like Figure 1 As shown, the circulating fluidized bed boiler system for solar frequency division heating and residual wave photovoltaic power generation includes: a furnace 100, a separator 200, a convection shaft 300, a photovoltaic thermal frequency division component 400, a thermal absorber 500 and a return device 600.

[0046] The interior of the furnace 100 includes a dense phase zone 11 and a dilute phase zone 12. Along the height direction of the furnace 100, the height of the dilute phase zone 12 is higher than that of the dense phase zone 11. The outlet of the dilute phase zone 12 is connected to the separator 200 through the flue gas channel 101.

[0047] The separator 200 is provided with a central tube 201, which is connected to the convection shaft 300 via the separator rear flue 202. The circulating material outlet of the separator 200 is connected to the inlet of the return device 600 via a reversing three-way valve 601. Specifically, the first port of the reversing three-way valve 601 is connected to the material outlet of the separator 200, and the second port of the reversing three-way valve 601 is connected to the inlet of the return device 600 via a first return pipe 602.

[0048] The outlet of the return device 600 is connected to the dense phase zone 11 of the furnace 100 through the second return pipe 603.

[0049] The photovoltaic-thermal splitter 400 concentrates sunlight and separates the solar electromagnetic radiation spectrum, using part of the solar energy for heating and part for power generation. The solar energy spectrum used for heating is radiated to the photothermal absorber 500, while the solar energy spectrum used for power generation is absorbed by the solar photovoltaic panel and connected to the power grid 800 via the DC / AC converter 700.

[0050] It should be noted that solar power generation includes photovoltaic power generation and concentrated thermal power generation. The principle of concentrated thermal power generation is similar to that of circulating fluidized bed thermal power generation: since 99.9% of the energy in the solar electromagnetic radiation spectrum is concentrated in the infrared, visible, and ultraviolet regions, concentrated thermal power generation can utilize radiation energy in the ultraviolet, visible, and infrared regions and convert it into heat. Solar photovoltaic power generation primarily absorbs energy in the visible light region, but also absorbs some infrared light, generally between 300nm and 1100nm.

[0051] Combine Figure 7As shown, 99.9% of the solar electromagnetic radiation spectrum is concentrated in the infrared, visible, and ultraviolet regions. Solar radiation energy is primarily concentrated in the visible light region (400-760 nm), with lesser amounts of infrared radiation (>760 nm) with wavelengths longer than visible light and ultraviolet radiation (<400 nm). Of all radiation energy, wavelengths between 150 and 4000 nm account for over 99% and are primarily distributed in the visible, red, and ultraviolet regions. The visible region accounts for approximately 50% of total solar radiation energy, the infrared region for approximately 43%, and the ultraviolet region for approximately 7%. The wavelength range of solar radiation received at Earth's surface is approximately 295-2500 nm. Solar radiation with wavelengths shorter than 295 nm and longer than 2500 nm does not reach Earth's surface due to strong absorption by ozone, water vapor, and other atmospheric molecules in the Earth's atmosphere.

[0052] The embodiment of the present application adopts a photovoltaic-thermal frequency division component 400 to separate the spectrum of solar energy. The energy suitable for heating is directly supplied to the photothermal absorber 500 for heating and energy storage, while the energy suitable for photovoltaic power generation is directly used to generate electricity using solar cells, thereby realizing the tiered utilization of solar energy grades.

[0053] The third port of the reversing three-way valve 601 is connected to the top of the external bed 502, and the outlet of the external bed 502 is connected to the inlet of the photothermal absorber 500 through the material conveying device 501; the outlet of the photothermal absorber 500 is connected to the high-temperature material storage tank 505, and the high-temperature material storage tank 505 is connected to the return device 600 through the regulating valve 506.

[0054] Combined with the above connection, it can be seen that when the first port and the second port of the reversing three-way valve 601 are connected, the circulating material separated by the separator 200 passes through the outlet of the separator 200 through the reversing three-way valve 601 and enters the return device 600. When the first port and the third port of the reversing three-way valve 601 are connected, the circulating material separated by the separator 200 enters the external bed 502 through the reversing three-way valve 601, and enters the photothermal absorber 500 through the material conveying device 501. The photothermal absorber 500 is heated by solar energy, thereby heating the circulating material entering the photothermal absorber 500; the heated circulating material enters the high-temperature material storage tank 505 for storage. When the circulating fluidized bed boiler is increasing its load, the high-temperature material storage tank 505 and the return device 600 can be connected through the regulating valve 506, so that the high-temperature circulating material is returned to the furnace 100 along with the circulating material from the separator 200, thereby increasing the temperature in the furnace 100 and achieving rapid load increase of the circulating fluidized bed boiler.

[0055] It should be noted that: when the circulating fluidized bed boiler is in a load reduction state, the first port and the second port of the reversing three-way valve 601 are connected, and the regulating valve 506 is closed; when the circulating fluidized bed boiler is in a load increase state, the first port and the third port of the reversing three-way valve 601 are connected, and the regulating valve 506 is turned on.

[0056] The circulating fluidized bed boiler system with solar frequency division heating and after-wave photovoltaic power generation in the embodiment of the present application collects the circulating material generated by the separator 200 in the load reduction state, and uses the energy suitable for heating divided from the solar electromagnetic radiation spectrum to heat the circulating material generated by the separator of the circulating fluidized bed boiler, thereby reducing the material concentration in the furnace 100 and achieving rapid load reduction of the furnace 100; in the load increase state, the heated circulating material is returned to the furnace 100 to increase the temperature and material concentration in the furnace 100, thereby achieving rapid load increase of the circulating fluidized bed boiler and improving the stability of the power grid.

[0057] At the same time, the energy in the solar spectrum that is suitable for power generation is used for solar power generation, which realizes the coupling of solar power generation and solar energy heating of circulating fluidized bed boilers, which is conducive to improving the utilization of solar energy and can improve the stability of the power grid.

[0058] In some embodiments, a sifter 504 is provided between the reversing three-way valve 601 and the external bed 502. The inlet of the sifter 504 is connected to the third port of the reversing three-way valve 601, the first outlet of the sifter 504 is connected to the external bed 502, and the second outlet of the sifter 504 is connected to the first return pipe 602.

[0059] The screener 504 can further screen the circulating material separated by the separator 200, and transport the screened undersize material to the external bed 502, and the screened oversize material is returned to the return device 600 through the first return pipe 602.

[0060] It should be noted that the size of the screener 504 can be adjusted according to different needs and is within the protection range. Optionally, the screen of the screener 504 can be replaced, and the mesh size can be adjusted according to the screening characteristics of the separator 200 and the heat absorption characteristics of the photothermal absorber 500. For example, particles with a size less than 0.13 mm can be allowed to enter the photothermal absorber 500 to improve the ability to absorb sunlight and enhance the heat exchange capacity of the supplementary bed material in the furnace 100.

[0061] In the embodiment of the present application, the material entering the external bed 502 is screened to ensure that the circulating material entering the external bed 502 is more uniform, thereby ensuring that the circulating material is heated more evenly in the photothermal absorber 500.

[0062] The external bed 502 disclosed in the embodiments of this application includes, but is not limited to, a bubbling bed heat exchanger. The fluidization velocity within the bubbling bed heat exchanger is between 0.1 m / s and 0.3 m / s. A heat exchange device 503 is disposed within the external bed 502. This heat exchange device 503 may include, but is not limited to, a superheater, a reheater, or a water-cooled wall. The heat exchange device 503 can be used to cool the circulating material within the external bed 502.

[0063] During low-load operation of the circulating fluidized bed boiler, the flow of working fluid into the heat exchange device 503 of the external bed 502 is cut off or reduced, thereby reducing or eliminating heat exchange between the external bed 502 and the heat exchange device 503. The circulating material in the external bed 502 is directly elevated to the photothermal absorber 500, where it absorbs heat. After the temperature of the circulating material is raised to 900°C to 1100°C, it is stored in the high-temperature material storage tank 505.

[0064] The volume of the high temperature material storage tank 505 can be set according to different needs and is not limited here. The high temperature material storage tank 505 needs to store enough high temperature circulating material to ensure that the power grid can still meet the load increase demand normally under the conditions of night or cloudy weather.

[0065] During high-load operation of the circulating fluidized bed boiler, the circulating material within the external bed 502 is cooled using a heat exchanger 503. Optionally, by adjusting the mass flow entering the heat exchanger 503 and the amount of circulating material entering the external bed 502, the high-temperature circulating material within the external bed 502 is cooled to a temperature between 200°C and 500°C. The heat exchanged by the circulating material in the external bed 502 can be used for heating or power generation, achieving cascaded heat utilization. Furthermore, since the circulating material temperature is relatively high during high-load operation of the circulating fluidized bed, maintaining a balanced heat absorption and dissipation across the entire boiler system facilitates subsequent heat absorption by the circulating material. The cooled, relatively cool material is then transported to the photothermal absorber 500 via a material conveying device 501, such as a high-temperature bucket elevator.

[0066] If the temperature of the material stored in the high-temperature material storage tank 505 is higher than the temperature of the material in the dense phase zone 11 of the furnace 100, the circulating material entering the furnace 100 from the high-temperature material storage tank 505 will release heat to the water-cooled wall of the furnace 100 in the furnace 100, thereby directly replenishing heat to the furnace 100 and enhancing the heat transfer effect in the furnace 100. When the temperature of the material stored in the high-temperature material storage tank 505 is lower than the temperature of the material in the dense phase zone 11 of the furnace 100, the circulating material entering the furnace 100 from the high-temperature material storage tank 505 will increase the material concentration in the furnace 100 and enhance the heat transfer effect in the furnace 100. When this part of the circulating material flows to the external bed 502, the circulating material exchanges heat with the heat exchange device 503 of the external bed 502, thereby indirectly replenishing heat outside the furnace 100.

[0067] Through the heating and heat release cycle of the circulating material, a portion of the heat of the solar energy frequency division is input into the furnace 100, playing a role in assisting the coal combustion heating and realizing the partial spectrum heat utilization of the solar energy.

[0068] In some embodiments, both the external bed 502 and the photothermal absorber 500 are bubbling bed heat exchangers, requiring fluidizing air to be supplied from their respective bottom air chambers. Therefore, an external bed air chamber is provided at the bottom of the external bed 502 to provide fluidizing air to the external bed 502, and an absorber air chamber is provided at the bottom of the photothermal absorber 500 to provide fluidizing air to the photothermal absorber 500. Optionally, the fluidization velocity within the bubbling bed heat exchanger is 0.1 m / s to 0.3 m / s.

[0069] Because the temperatures inside the external bed 502 and the solar thermal absorber 500 are both relatively high, the fluidizing air supplied to these two units is heated, generating exhaust gas. Specifically, exhaust gas in the external bed 502 typically appears on the side where it meets the heat exchanger 503, while exhaust gas in the solar thermal absorber 500 typically appears on the side away from the sunlight. Exhaust gas is low-temperature, uncontaminated steam entrained (flash evaporated) in the high-temperature condensate.

[0070] The sidewalls of the furnace 100 disclosed in the embodiment of the present application are provided with a first auxiliary combustion-supporting air port and a second auxiliary combustion-supporting air port. The first auxiliary combustion-supporting air port is used to charge the furnace 100 with a first auxiliary combustion-supporting air S1; the second auxiliary combustion-supporting air port is used to charge the furnace 100 with a second auxiliary main combustion air S2. The first auxiliary combustion-supporting air S1 includes, but is not limited to, exhaust gas from the external bed 502; the second auxiliary main combustion air S2 includes, but is not limited to, exhaust gas from the solar thermal absorber 500.

[0071] Specifically, an external bed air outlet is located on the upper portion of the external bed 502, near the heat exchanger 503, and communicates with the first auxiliary combustion air outlet. An absorber air outlet is located on the upper portion of the solar thermal absorber 500, and communicates with the second auxiliary combustion air outlet. The external bed outlet is used to collect exhaust gas from the side of the external bed 502 near the heat exchanger 503, while the absorber outlet is used to collect exhaust gas from the side of the solar thermal absorber 500 away from reflecting sunlight.

[0072] The above content describes the structure and function of the bypass path between the separator 200 and the return device 600, wherein the bypass path includes: a screen 504, an external bed 502, a material conveying device 501, a photothermal absorber 500, a high temperature material storage tank 505 and a regulating valve 506. Figure 1 The connection relationship and function of the above-mentioned convection shaft 300 will be described.

[0073] A heating surface 301 and a superheater 302 are arranged within the convection shaft 300. The heating surface 301 exchanges heat with the superheater 302, and the working fluid that exchanges heat with the fuel in the furnace 100 flows through the superheater 302. The outlet of the superheater 302 is connected to a steam turbine generator 900. The steam generated by the superheater 302 is supplied to the steam turbine generator 900 for power generation, which is then connected to the power grid 800.

[0074] The high-temperature flue gas separated by separator 200 passes through the central tube 201 of separator 200 and the post-separator flue 202 into the convection shaft 300. After entering the convection shaft 300, the high-temperature flue gas exchanges heat with the superheater 302 through the heating surface 301 of the convection shaft 300, causing the superheater 302 to heat and generate steam, which is used to generate electricity in the steam turbine generator 900.

[0075] When the load demand on the circulating fluidized bed boiler increases, that is, when the circulating fluidized bed boiler needs to increase its load, the opening of the regulating valve 506 is increased, so that the circulating material in the high-temperature material storage tank 505 is fed into the furnace 100, thereby enhancing the heat exchange in the furnace 100, thereby generating more heat exchange medium, and the superheater 302 generates more steam to supply the steam turbine generator 900, thereby generating more power. When the load demand on the circulating fluidized bed boiler decreases, that is, when the circulating fluidized bed boiler needs to decrease its load, the regulating valve 506 is closed, reducing the amount of circulating material entering the furnace 100, reducing the heat exchange in the furnace 100, and thus reducing the heat exchange medium. The amount of steam generated by the superheater 302 is reduced, thereby reducing the power generation of the steam turbine generator 900.

[0076] It should be noted that the steam turbine generator 900 herein comprises a steam turbine and a generator. Steam drives the steam turbine, which in turn drives the generator to generate electricity. The steam turbine generator 900 herein is a conventional power generation facility and is applicable to steam turbine generator systems used in solar molten salt thermal energy storage and small thermal power plants. Therefore, the specific structure and principles of the steam turbine generator 900 are not specifically limited.

[0077] The circulating fluidized bed boiler system with solar frequency-splitting heating and residual wave photovoltaic power generation in the embodiments of the present application utilizes a circulating fluidized bed boiler to simultaneously couple steam power generation and solar photovoltaic power generation. During the circulating fluidized bed boiler's load variations, the steam power generation output can be adjusted to smooth out fluctuations in solar photovoltaic power generation. Specifically, steam-powered cycle power generation is combined with solar photovoltaic power generation, and both are simultaneously integrated into power grid 800. The visible light portion of sunlight is used for photovoltaic power generation, while a portion of the sunlight is used to heat the circulating fluidized bed boiler, thereby reducing power generation costs.

[0078] like Figure 1 and Figure 2In the figure, the photovoltaic / photothermal frequency dividing component 400 is a trough-type focusing photovoltaic / photothermal frequency dividing component, which specifically includes: a curved surface frequency divider 401, a curved surface thin-film photovoltaic cell 402 and a trough-type bracket 403.

[0079] Combining the structure of the photovoltaic-thermal frequency division component 400, it can be seen that Figure 1 and Figure 2 The photovoltaic-thermal frequency dividing component 400 is a trough-type solar concentrator with an arc-surface frequency divider 401 added thereto.

[0080] The curved surface divider 401 is located on the surface layer, and the curved thin-film photovoltaic cell 402 is stacked with the curved surface divider 401. Some sunlight can pass through the curved surface divider 401 and illuminate the curved thin-film photovoltaic cell 402. A trough bracket 403 is supported on the bracket and is used to support the curved thin-film photovoltaic cell 402.

[0081] The arc surface frequency divider 401 of the embodiment of the present application is a short-wave pass and long-wave reflective filter. Specifically, the surface layer of the arc surface frequency divider 401 has a multilayer dielectric film including but not limited to a combination of silicon dioxide, titanium dioxide, niobium pentoxide, and tantalum pentoxide.

[0082] Since the arc-surface frequency divider 401 is a filter that allows short waves to pass and long waves to be reflected, when using the arc-surface frequency divider 401 of the embodiment of the present application, sunlight shines on the arc-surface frequency divider 401, and the full-spectrum solar energy is divided into two beams. One beam of concentrated light (mainly in the infrared region) with a wavelength greater than the cutoff wavelength is reflected onto the photothermal absorber 500, and the solar energy absorbed by the photothermal absorber 500 comes from the reflection spectrum of the arc-surface frequency divider 401; the other beam of high-frequency light waves (mainly in the visible light region and the ultraviolet region, etc.) with a wavelength less than the cutoff wavelength is transmitted through the arc-surface frequency divider 401 and projected onto the arc-surface thin-film photovoltaic cell 402 on the lower layer of the arc-surface frequency divider 401 for photovoltaic power generation.

[0083] It should be noted that the cut-off wavelength in this article includes but is not limited to 750 nm.

[0084] The curved thin-film photovoltaic cells 402 include, but are not limited to, perovskite thin-film cells (PSCs), copper indium gallium selenide thin-film cells, polycrystalline silicon thin-film cells, or cadmium telluride thin-film cells.

[0085] Taking curved thin-film photovoltaic cell 402 as an example, a perovskite thin-film cell, the specific structure of curved thin-film photovoltaic cell 402 is described below: Along the light path, curved thin-film photovoltaic cell 402 comprises, in order, a transparent glass layer, a conductive glass layer, an electron transport layer, an active layer, a hole transport layer, and a back electrode layer. The specific principles and connections of curved thin-film photovoltaic cell 402 can be found in existing photovoltaic cells. It should be noted that the ability of the photovoltaic cell to generate electricity is sufficient.

[0086] In Example 2:

[0087] like Figure 3 and Figure 4 The photovoltaic / thermal frequency-dividing assembly 400 can also be a tower-type heliostat photovoltaic / thermal frequency-dividing assembly, which includes a planar photovoltaic cell 404, a planar frequency divider 405, and a planar bracket 406. The planar frequency divider 405 is disposed on the sun-facing side of the planar photovoltaic cell 404, and the planar bracket 406 is disposed on the back-facing side of the planar photovoltaic cell 404.

[0088] Combining the structure of the photovoltaic-thermal frequency division component 400, it can be seen that Figure 3 and Figure 4 The photovoltaic-thermal frequency division component 400 is a tower-type solar concentrator with a flat photovoltaic cell 404 added thereto.

[0089] It can be understood that the planar photovoltaic cell 404 is arranged obliquely and fixed by a planar bracket 406 , and a planar frequency divider 405 is provided on the upper surface of the planar photovoltaic cell 404 .

[0090] The planar frequency divider 405 has a planar structure and is a filter that allows short waves to pass through and reflects long waves. When sunlight shines on the planar frequency divider 405, the full spectrum of solar energy is divided into two beams. One beam of concentrated light with a wavelength greater than the cutoff wavelength is reflected onto the photothermal absorber 500. The solar energy absorbed by the photothermal absorber 500 comes from the reflection spectrum of the planar frequency divider 405; the other beam of high-frequency light waves with a wavelength less than the cutoff wavelength is transmitted through the planar frequency divider 405 and projected onto the planar photovoltaic cell 404 on the lower layer of the planar frequency divider 405 for photovoltaic power generation.

[0091] The structure of the planar frequency divider 405 is the same as that of the arc frequency divider 401 in the above embodiment, and will not be described in detail here. The difference between the two is only in shape. The planar photovoltaic cell 404 includes but is not limited to a single crystal silicon photovoltaic cell or a polycrystalline silicon photovoltaic cell.

[0092] Those skilled in the art will appreciate that the photovoltaic-thermal frequency dividing assembly 400 of the embodiment of the present application includes a frequency divider for dividing the solar energy frequency and a photovoltaic panel for receiving solar energy and generating electricity, all of which are within the scope of protection.

[0093] Since the tower-type heliostat photovoltaic / solar thermal frequency-splitting assembly uses a frequency divider on a solar tower concentrator, and the trough-type focusing photovoltaic / solar thermal frequency-splitting assembly uses a frequency divider on the basis of a trough solar concentrator; the tower-type solar concentrator uses convergent focusing technology, and the trough-type solar concentrator uses trough mirror focusing technology. Therefore, the concentration ratio and reflection and transmission efficiency of the frequency dividers of the two are different. The tower-type heliostat photovoltaic / solar thermal frequency-splitting assembly is easier to arrange planar photovoltaic cells under the frequency divider.

[0094] The present embodiment utilizes a photovoltaic / thermal frequency-splitting assembly 400 to separate the solar energy. For example, this decouples the high-frequency and low-frequency components of the solar energy. The high-frequency spectrum is used directly for photovoltaic power generation, while the low-frequency spectrum is used for heating a circulating fluidized bed boiler for solar thermal power generation. The energy from the solar thermal portion used for heating the circulating fluidized bed boiler is stored in the high-temperature material of the circulating fluidized bed. This heat can be used to generate electricity in the circulating fluidized bed boiler during periods of low sunlight, thereby achieving time-delayed solar power generation, enabling the dispatchable use of solar energy, and coupling renewable energy and traditional fossil energy generation.

[0095] like Figures 1 to 4 As shown, a fuel supply device 102 is provided at the furnace 100 , and the fuel supply device 102 is in communication with the dense phase zone 11 of the furnace 100 for supplying fuel into the furnace 100 .

[0096] A primary air supply device 105 is provided at the bottom of the furnace 100 to form fluidizing air in the furnace 100 , and a secondary air supply device 104 is arranged in the freeboard zone 12 to drive the flue gas in the furnace 100 .

[0097] In some embodiments, a heat absorbing screen 103 is suspended in the freeboard zone 12 of the furnace 100. The heat absorbing screen 103 absorbs heat in the furnace 100 and is used to heat the steam in the furnace 100, thereby improving the thermal efficiency of the circulating fluidized bed boiler and reducing energy waste.

[0098] like Figure 5 As shown, the reversing three-way valve 601 disclosed in the embodiment of the present application includes but is not limited to a flap valve mechanism, and can also be an electromagnetic reversing valve.

[0099] The flap valve mechanism includes: a valve body 6011 , a first flap 6012 , a second flap 6013 , a flap rotating shaft 6014 , a first limit plate 6015 and a second limit plate 6016 .

[0100] One end of the valve body 6011 is provided with a first port 6017 , and the other end is provided with a second port 6018 and a third port 6019 .

[0101] The valve body 6011 is internally provided with a first flap 6012, a second flap 6013, a flap shaft 6014, a first limiting plate 6015, and a second limiting plate 6016. The first flap 6012 and the second flap 6013 are both rotatably connected to the flap shaft 6014. Optionally, the first flap 6012 and the second flap 6013 are relatively fixed, with an angle of approximately 90° between them. One of the first limiting plate 6015 and the second limiting plate 6016 is located between the second port 6018 and the third port 6019, while the other is located on the sidewall of the valve body 6011. For example, the first limiting plate 6015 is located on the sidewall of the valve body 6011, while the second limiting plate 6016 is located on the bottom wall of the valve body 6011, between the second port 6018 and the third port 6019. It should be noted that the first limit plate 6015 is located on the side wall of the valve body 6011 adjacent to the bottom wall, the first flap 6012 moves between the first limit plate 6015 and the second limit plate 6016, and the rotation angle of the first flap 6012 is about 90°.

[0102] During the flipping process of the first flip plate 6012 and the second flip plate 6013, the second opening 6018 can be connected to the first opening 6017, or the third opening 6019 can be connected to the first opening 6017. When the first flip plate 6012 abuts the first limiting plate 6015, the first flip plate 6012 includes but is not limited to being arranged horizontally and blocking the second opening 6018; when the second flip plate 6013 abuts the second limiting plate 6016, the second flip plate 6013 includes but is not limited to being arranged vertically, connecting the third opening 6019 and the first opening 6017.

[0103] During the flipping process of the first flap 6012 and the second flap 6013, there is a state in which the first port 6017 and the second port 6018 are fully connected. At this time, the circulating material of the separator 200 can be completely introduced into the return material device 600; there is a state in which the first port 6017 and the third port 6019 are fully connected. At this time, the circulating material of the separator 200 can be completely introduced into the screener 504; there is also a state in which the first port 6017 is connected with the second port 6018 and the third port 6019. At this time, part of the circulating material of the separator 200 flows into the screener 504, and the other part flows into the return material device 600. The amount of circulating material entering the return material device 600 and the screener 504 can be changed according to the opening of the second port 6018 and the third port 6019, that is, it is related to the rotation position of the first flap 6012 and the second flap 6013.

[0104] By adjusting the recycled material entering the screener 504 , the amount of the recycled material can be matched with the ability of the solar thermal absorber 500 to absorb solar thermal energy.

[0105] The reversing three-way valve 601 disclosed in the embodiment of the present application has a simple structure, and reversing can be achieved by rotating the first flap 6012 and the second flap 6013; the reversing three-way valve 601 of the present application is a mechanical structure, and through mechanical control, the possibility of misoperation can be reduced.

[0106] like Figure 6 As shown, the sifter 504 has: a material drop port 5041 , a screen 5042 , an overflow port 5043 above the screen, and an overflow port 5044 below the screen.

[0107] Among them, the discharge port 5041 is connected to the third port 6019 of the reversing three-way valve 601, and the screen 5042 is located inside the screener 504. Optionally, the screen 5042 divides the interior of the screener 504 into an upper screen chamber and an lower screen chamber, wherein the upper screen overflow port 5043 is connected to the upper screen chamber, and the upper screen overflow port 5043 is connected to the first return pipe 602, that is, the upper screen overflow port 5043 is the second outlet of the screener 504 in the above embodiment; the lower screen overflow port 5044 is connected to the lower screen chamber, and the lower screen overflow port 5044 is connected to the external bed 502, that is, the lower screen overflow port 5044 is the first outlet of the screener 504 in the above embodiment.

[0108] Optionally, the screen 5042 is arranged at an angle so that the material on the screen 5042 moves along the inclined screen 5042 under the action of gravity, thereby improving the screening effect of the material. The overflow port 5043 on the screen is located at the lower end of the screen chamber so that the material on the screen can enter the overflow port 5043 on the screen after being screened by the screen 5042 under the action of gravity and the guidance of the screen 5042.

[0109] The bottom plate of the screener 504 is an inclined surface, and the undersize overflow port 5044 is located at a lower end of the undersize chamber so that the undersize material enters the undersize overflow port 5044 under the action of gravity and the guidance of the bottom plate of the screener 504 .

[0110] The screener 504 disclosed in the embodiment of the present application has a simple structure and can realize automatic transportation of materials, which is conducive to simplifying the structure and reducing costs.

[0111] In combination with the above description, it can be seen that the circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation disclosed in the embodiment of the present application has the following advantages:

[0112] 1. Combining the steam power cycle power generation of the circulating fluidized bed boiler with solar photovoltaic power generation, and connecting the two power generation methods to the grid at the same time, part of the energy of visible light is directly used for photovoltaic power generation, and part of the energy is used for heating the circulating fluidized bed boiler, realizing the utilization of solar energy and reducing the cost of power generation;

[0113] 2. Combining the fossil energy of circulating fluidized bed boilers with the renewable energy of solar energy can not only reduce CO2 emissions, but also be used for peak load regulation of the power grid;

[0114] 3. Using circulating materials to store heat from solar-assisted heating, and using the stored heat to supplement heat in the circulating fluidized bed boiler, the heated circulating materials are used to improve the heat transfer coefficient in the furnace. This operation is convenient and efficient, and can respond to the rapid load reduction / increase requirements of the power grid to stabilize solar power generation.

[0115] 4. The hot air and exhaust gas generated by fluidized granular materials can be directly used as auxiliary combustion air for fluidized bed boilers, realizing energy utilization, reducing the generation of auxiliary combustion air, and reducing costs;

[0116] 5. The circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation is suitable for upgrading or rebuilding coal-fired circulating fluidized bed power generation systems in western areas with abundant solar energy resources and open areas.

[0117] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0118] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation, characterized in that: include: A furnace (100), a separator (200), a convection shaft (300), a photovoltaic and thermal frequency division component (400), a photothermal absorber (500), a returner (600), and a steam turbine generator (900); The outlet of the dilute phase zone of the furnace (100) is connected to the separator (200), the circulating material outlet of the separator (200) is connected to the first port of the reversing three-way valve (601), the second port of the reversing three-way valve (601) is connected to the material return device (600), and the material return device (600) is connected to the dense phase zone of the furnace (100); The third port of the reversing three-way valve (601) is in communication with the photothermal absorber (500), the photothermal absorber (500) absorbs heat generated by the photovoltaic photothermal frequency division component (400) on the partial spectrum after the solar energy is divided, the photothermal absorber (500) is in adjustably communication with the return device (600), the photovoltaic photothermal frequency division component (400) generates electricity from the partial spectrum after the solar energy is divided, and the power generation device of the photovoltaic photothermal frequency division component (400) is connected to the power grid; The high-temperature flue gas outlet of the separator (200) is in communication with the convection shaft (300), and the high-temperature flue gas exchanges heat with the convection shaft (300). The steam generated by the heat exchange in the convection shaft (300) is supplied to the steam turbine generator (900), and the steam turbine generator (900) is connected to a power grid.

2. The circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation according to claim 1 is characterized in that: A high-temperature material storage tank (505) and a regulating valve (506) are provided between the photothermal absorber (500) and the return material device (600); The high-temperature material storage tank (505) is connected to the photothermal absorber (500), and the regulating valve (506) is arranged between the high-temperature material storage tank (505) and the return device (600) to control the connection and disconnection between the high-temperature material storage tank (505) and the return device (600).

3. The circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation according to claim 1 is characterized in that: An external bed (502) is provided between the reversing three-way valve (601) and the photothermal absorber (500); The external bed (502) is in contact with the heat exchange device (503) for heat exchange, and the inlet of the external bed (502) is connected to the third port of the reversing three-way valve (601); the outlet of the external bed (502) is connected to the photothermal absorber (500).

4. The circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation according to claim 3 is characterized in that: A sifter (504) is provided between the reversing three-way valve (601) and the external bed (502); The discharge port of the sifter (504) is connected to the third port of the reversing three-way valve (601), the overflow port (5043) above the sieve of the sifter (504) is connected to the return device (600), and the overflow port (5044) below the sieve of the sifter (504) is connected to the inlet of the external bed (502).

5. The circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation according to claim 3 is characterized in that: An external bed air chamber is provided at the bottom of the external bed (502), and the external bed air chamber provides fluidizing air to the external bed (502). An external bed air outlet is provided on the upper part of the external bed (502) near the heat exchange device (503), and the external bed air outlet is communicated with the first auxiliary combustion air outlet of the furnace (100); and / or, An absorber air chamber is provided at the bottom of the photothermal absorber (500), and the absorber air chamber provides fluidizing air to the photothermal absorber (500). An absorber outlet is provided on the upper side of the photothermal absorber (500) away from the side reflecting sunlight, and the absorber outlet is connected to the second auxiliary combustion air port of the furnace (100).

6. The circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation according to any one of claims 1 to 5, characterized in that: The photovoltaic-thermal frequency division component (400) comprises: Frequency divider, which is a filter that passes short waves and reflects long waves; A photovoltaic cell is stacked with the frequency divider, and the frequency divider is located on the surface of the photovoltaic cell, absorbing the solar energy transmitted by the frequency divider and generating electricity. The photovoltaic cell is connected to the power grid.

7. The circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation according to claim 6 is characterized in that: The frequency divider is a curved surface frequency divider (401), and the photovoltaic cell is a curved surface thin-film photovoltaic cell (402). The curved surface frequency divider (401) and the curved surface thin-film photovoltaic cell (402) have the same curvature and are arranged in a stacked manner.

8. The circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation according to claim 7 is characterized in that: The photovoltaic cell is a perovskite thin film cell, a copper indium gallium selenide thin film cell, a polycrystalline silicon thin film cell or a cadmium telluride thin film cell.

9. The circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation according to claim 6, characterized in that: The frequency divider is a planar frequency divider (405), the photovoltaic cell is a planar photovoltaic cell (406), and the planar frequency divider (405) and the planar photovoltaic cell (406) are stacked.

10. The circulating fluidized bed boiler system with solar frequency division heating and residual wave photovoltaic power generation according to claim 6, characterized in that: The frequency divider comprises: A silicon dioxide layer, a titanium dioxide layer, a niobium pentoxide layer, and a tantalum pentoxide layer coated on the glass surface.

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