Low-frequency sunlight-assisted coal-fired boiler power generation system and method

Abstract

The invention provides a low-frequency sunlight-assisted coal-fired boiler power generation system and method, which are applied to the technical field of electrical energy, and the system comprises a spectrum separation device which is used for carrying out spectrum separation processing on incident solar energy to obtain a solar spectrum of a first wave band and a solar spectrum of a second wave band, and transmitting the solar spectrum of the first wave band to a light-concentrating heat-collecting system, and transmitting the solar spectrum of the second wave band to a photovoltaic power generation device, so that the photovoltaic power generation device performs solar power generation by using the solar spectrum of the second wave band. The light-gathering heat-collecting system is used for heating a circulating working medium in the light-gathering heat-collecting system by utilizing the solar spectrum of the first wave band after receiving the solar spectrum of the first wave band, and heating flue gas in a hearth when the coal-fired boiler receives a work load reducing instruction, so that the temperature of the flue gas reaches the lowest temperature threshold value of the denitration device; the problem that the denitration performance is reduced when the coal-fired power generation unit enters the deep peak regulation state can be solved.

Description

Technical Field

[0001] This application relates to the technical field of electric power energy, and in particular to a low-frequency sunlight-assisted coal-fired boiler power generation system and method. Background Art

[0002] The inherently large volatility of new energy poses a severe challenge to the safe and stable operation of the power grid. In common large bases of wind, light, thermal power, and energy storage, specific-capacity coal-fired generating units are used as peak regulation and frequency modulation resources to suppress the impact brought by the volatility of new energy generating units. Especially during the daytime when photovoltaic power is the main output, coal-fired generating units need to frequently enter the deep peak regulation state to yield corresponding power capacity for solar energy.

[0003] However, after the coal-fired generating unit enters the deep peak regulation stage, since the coal-fired generating unit deviates from the designed operating conditions, the coal consumption of the coal-fired generating unit increases sharply. At the same time, the pulverized coal entering the furnace decreases, the flue gas temperature in the tail flue decreases, and the outlet flue gas temperature may be far lower than the minimum operating temperature threshold of the denitration catalyst, resulting in a decline in denitration performance. Although traditional solutions can increase the denitration temperature by means such as adding a flue gas bypass, adding a water bypass, or flow replacement, they will cause a reduction in the boiler efficiency of the coal-fired generating unit under low-load conditions, further reducing the economy of the coal-fired generating unit. Summary of the Invention

[0004] The purpose of this application is to provide a low-frequency sunlight-assisted coal-fired boiler power generation system and method to solve the problem of the decline in denitration performance when the coal-fired generating unit enters the deep peak regulation state.

[0005] In a first aspect, an embodiment of this application provides a low-frequency sunlight-assisted coal-fired boiler power generation system and method. The low-frequency sunlight-assisted coal-fired boiler power generation system includes: a spectral separation device, a concentrating and heat collection system, a denitration device, a coal-fired boiler, and a photovoltaic power generation device.

[0006] The spectral separation device is connected to the concentrating and heat collection system and the photovoltaic power generation device. The spectral separation device is used to perform spectral separation processing on the incident solar energy to obtain a first-band solar spectrum and a second-band solar spectrum, transmit the first-band solar spectrum to the concentrating and heat collection system, and transmit the second-band solar spectrum to the photovoltaic power generation device, so that the photovoltaic power generation device uses the second-band solar spectrum for solar power generation. The first-band solar spectrum is the solar spectrum other than the second-band solar spectrum.

[0007] The coal-fired boiler includes a furnace and a flue. The denitration device is deployed in the flue. The solar concentrating and heat collection system includes a heat exchange device, which is deployed between the furnace and the denitration device. The solar concentrating and heat collection system is used to heat the circulating working fluid in the solar concentrating and heat collection system by using the solar spectrum of the first band after receiving the solar spectrum of the first band, and to heat the flue gas in the furnace when the coal-fired boiler receives a command to reduce the working load, so that the temperature of the flue gas reaches the minimum temperature threshold of the denitration device.

[0008] In the low-frequency sunlight-assisted coal-fired boiler power generation system provided by the embodiments of the present application, the solar spectrum of the second band used by the photovoltaic power generation device is distributed to the photovoltaic power generation device, and the solar spectrum of the first band other than the second band is distributed to the solar concentrating and heat collection system. The solar concentrating and heat collection system uses the solar spectrum of the first band to heat the flue gas in the coal-fired boiler, so that the temperature of the flue gas can reach the minimum temperature threshold for denitration of the denitration device, improving the coal denitration efficiency of the coal-fired boiler in the deep peak shaving stage while saving the coal consumption of the coal-fired boiler.

[0009] A possible implementation manner is that the solar concentrating and heat collection system includes a solar concentrating and heat collection device, a heat storage device, a main path valve, and a heat exchange device. The first end of the solar concentrating and heat collection device is connected to the output end of the spectral separation device, the second end of the solar concentrating and heat collection device is connected to the first end of the heat storage device, the second end of the heat storage device is connected to the first end of the main path valve, the second end of the main path valve is connected to the first end of the heat exchange device, and the second end of the heat exchange device is connected to the third end of the solar concentrating and heat collection device to form a main path loop for the circulation of the medium.

[0010] The solar concentrating and heat collection device is used to convert the solar spectrum of the first band into heat energy by means of coating absorption after receiving the solar spectrum of the first band, so as to heat the circulating working fluid.

[0011] The heat storage device is used to release heat energy to heat the circulating working fluid when the coal-fired boiler receives a command to reduce the working load.

[0012] The main path valve is used to control the passage of the main path loop so that the heated circulating working fluid flows through the heat exchange device when the coal-fired boiler receives a command to reduce the working load and the temperature of the flue gas in the furnace is less than or equal to the minimum temperature threshold.

[0013] Specifically, the heat exchange device is used to heat the flue gas in the furnace by using the heated circulating working fluid when the main path loop is in passage, so that the temperature of the flue gas reaches the minimum temperature threshold of the denitration device.

[0014] A possible implementation manner is that the heat storage device is further used to store the heat energy of the circulating working fluid when the coal-fired boiler receives a command to increase the working load and the temperature of the flue gas in the furnace is greater than the minimum temperature threshold.

[0015] The main road valve is also used to control the interruption of the main road circuit when the coal-fired boiler receives a command to increase the working load and the flue gas temperature in the furnace is greater than the minimum temperature threshold.

[0016] In a possible implementation, the concentrating heat collection system further includes a branch valve. The first end of the branch valve is connected to the second end of the heat storage device and the first end of the main road valve, and the second end of the branch valve is connected to the second end of the heat exchange device and the third end of the concentrating heat collection device. The branch valve forms a branch circuit for the medium circulation with the heat storage device and the concentrating heat collection device.

[0017] The branch valve is used to control the interruption of the branch circuit when the coal-fired boiler receives a command to reduce the working load and the flue gas temperature in the furnace is less than or equal to the minimum temperature threshold.

[0018] In a possible implementation, the branch valve is also used to control the passage of the branch circuit when the coal-fired boiler receives a command to increase the working load and the flue gas temperature in the furnace is greater than the minimum temperature threshold.

[0019] In a possible implementation, the concentrating heat collection system further includes a circulation pump.

[0020] The first end of the circulation pump is connected to the second end of the heat storage device, and the second end of the circulation pump is connected to the first end of the main road valve. The circulation pump is used to drive the circulation of the working medium at a first preset time before the coal-fired boiler receives a command to reduce the working load. Or, the circulation pump is also used to stop working at a second preset time after the coal-fired boiler receives a command to increase the working load.

[0021] In a possible implementation, the low-frequency sunlight-assisted coal-fired boiler power generation system further includes: a soot blowing device.

[0022] The soot blowing device is deployed on the outer surface of the heat exchange device. The soot blowing device is used to determine a soot blowing strategy based on the state parameters of the heat exchange device and blow the dust on the outer surface of the heat exchange device based on the soot blowing strategy. The state parameters include one or more of the following: heat transfer efficiency and working time. The soot blowing strategy includes one or more of the following: soot blowing pressure and soot blowing frequency.

[0023] In a second aspect, an embodiment of the present application provides a low-frequency sunlight-assisted coal-fired boiler power generation method, which is applied to the low-frequency sunlight-assisted coal-fired boiler power generation system according to the first aspect or any possible implementation in the first aspect. The method includes:

[0024] The spectral separation device performs spectral separation processing on the incident solar energy to obtain the solar spectrum of the first band and the solar spectrum of the second band, transmits the solar spectrum of the first band to the concentrating heat collection device, and transmits the solar spectrum of the second band to the photovoltaic power generation device. The solar spectrum of the first band is the solar spectrum other than the solar spectrum of the second band.

[0025] After the concentrating and heat - collecting system receives the solar spectrum in the first band, it uses the solar spectrum in the first band to heat the circulating working fluid in the concentrating and heat - collecting system, and when the coal - fired boiler receives a command to reduce the working load, it heats the flue gas in the furnace of the coal - fired boiler so that the temperature of the flue gas reaches the minimum temperature threshold of the denitration device.

[0026] A possible implementation, the low - frequency sunlight - assisted coal - fired boiler power generation method provided by the embodiments of the present application further includes:

[0027] When the coal - fired boiler receives a command to reduce the working load and the temperature of the flue gas in the furnace of the coal - fired boiler is less than or equal to the minimum temperature threshold, control the main valve in the concentrating and heat - collecting system to close and control the branch valve to disconnect, so that the heated circulating working fluid flows through the heat - exchange device, and the heat - exchange device uses the heated circulating working fluid to heat the flue gas in the furnace so that the temperature of the flue gas reaches the minimum temperature threshold.

[0028] A possible implementation, the low - frequency sunlight - assisted coal - fired boiler power generation method provided by the embodiments of the present application further includes:

[0029] When the coal - fired boiler receives a command to increase the working load and the temperature of the flue gas in the furnace of the coal - fired boiler is greater than the minimum temperature threshold, control the main valve to disconnect and control the branch valve to close, so that solar energy is stored in the heat - storage device of the concentrating and heat - collecting system.

[0030] In a third aspect, the embodiments of the present application provide a low - frequency sunlight - assisted coal - fired boiler power generation device, and this low - frequency sunlight - assisted coal - fired boiler power generation device has the function of implementing the low - frequency sunlight - assisted coal - fired boiler power generation method in the above - mentioned first aspect or any possible implementation. This function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above - mentioned function.

[0031] In a fourth aspect, the embodiments of the present application provide a computer - readable storage medium, and instructions are stored in this computer - readable storage medium. When it runs on a computer, it enables the computer to execute the low - frequency sunlight - assisted coal - fired boiler power generation method in the above - mentioned first aspect or any possible implementation.

[0032] In a fifth aspect, the embodiments of the present application provide a computer program product containing instructions. When it runs on a computer, it enables the computer to execute the low - frequency sunlight - assisted coal - fired boiler power generation method in the above - mentioned first aspect or any possible implementation.

[0033] Among them, for the technical effects brought by any design method in the second aspect to the fifth aspect, reference can be made to the technical effects brought by different possible implementations in the first aspect, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 FIG. [ID] is a structural example diagram of a low-frequency solar-assisted coal-fired boiler power generation system provided by an embodiment of the present application;

[0036] Figure 2 FIG. [ID] is another structural example diagram of a low-frequency solar-assisted coal-fired boiler power generation system provided by an embodiment of the present application;

[0037] Figure 3 FIG. [ID] is a flowchart of a low-frequency solar-assisted coal-fired boiler power generation method provided by an embodiment of the present application;

[0038] Figure 4 FIG. [ID] is still another structural example diagram of a low-frequency solar-assisted coal-fired boiler power generation system provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] In order to make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application to be protected, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0041] Most commercial photovoltaic power generation devices use silicon-based photovoltaic panels, and their photoelectric conversion efficiency can reach more than 20%. However, such photovoltaic power generation devices mainly focus on using sunlight in the 400-1100nm band of the solar spectrum for power generation, such as visible light (400-700nm) and near-infrared light (700-1100nm), resulting in the waste of sunlight in other bands, such as ultraviolet (<400nm) and mid- and far-infrared (>1100nm), causing extensive utilization of solar energy.

[0042] Based on this, the embodiments of the present application provide a low-frequency sunlight-assisted coal-fired boiler power generation system and method. The low-frequency sunlight-assisted coal-fired boiler power generation system includes a spectral separation device, a concentrating heat collection system, a denitration device, and a coal-fired boiler.

[0043] Among them, the spectral separation device performs spectral separation processing on the incident solar energy to obtain the solar spectrum of the first band and the solar spectrum of the second band, and transmits the solar spectrum of the first band to the concentrating heat collection system. The solar spectrum of the first band is the solar spectrum other than the solar spectrum of the second band. After receiving the solar spectrum of the first band, the concentrating heat collection system uses the solar spectrum of the first band to heat the circulating working fluid in the concentrating heat collection system, and when the coal-fired boiler receives a command to reduce the working load, heats the flue gas in the furnace so that the temperature of the flue gas reaches the minimum temperature threshold of the denitration device.

[0044] The low-frequency sunlight-assisted coal-fired boiler power generation system provided by the embodiments of the present application distributes the solar spectrum of the second band used by the photovoltaic power generation device to the photovoltaic power generation device, and distributes the solar spectrum of the first band other than the second band to the concentrating heat collection system. The concentrating heat collection system uses the solar spectrum of the first band to heat the flue gas in the coal-fired boiler so that the temperature of the flue gas can reach the minimum temperature threshold for denitration of the denitration device, improving the coal denitration efficiency of the coal-fired boiler in the deep peak shaving stage while saving the coal consumption of the coal-fired boiler.

[0045] On the one hand, the embodiments of the present application provide a low-frequency sunlight-assisted coal-fired boiler power generation system. As Figure 1 shown, the low-frequency sunlight-assisted coal-fired boiler power generation system 100 includes a spectral separation device 101, a concentrating heat collection system 102, a denitration device 103, a coal-fired boiler 104, and a photovoltaic power generation device 105.

[0046] The spectral separation device 101 is connected to the concentrating and heat - collecting system 102 and the photovoltaic power generation device 105. The spectral separation device 101 is used to perform spectral separation processing on the incident solar energy to obtain the solar spectrum of the first band and the solar spectrum of the second band, transmit the solar spectrum of the first band to the concentrating and heat - collecting system 102, and transmit the solar spectrum of the second band to the photovoltaic power generation device 105, so that the photovoltaic power generation device 105 uses the solar spectrum of the second band for solar power generation.

[0047] Among them, the spectral separation device 101 can be a frequency divider.

[0048] The photovoltaic power generation device 105 can be a silicon - based photovoltaic power generation panel or a photovoltaic cell composed of other materials. It converts the solar spectrum of the second band transmitted by the spectral separation device 101 into electrical energy for output.

[0049] Among them, the solar spectrum of the first band is the solar spectrum other than the solar spectrum of the second band.

[0050] It should be noted that the first band and the second band depend on the band of the solar spectrum used by the photovoltaic power generation device 105 for photovoltaic power generation, and this application does not limit this. At the same time, the spectral separation device 101 will preferentially distribute the solar spectrum of the second band, which is most needed by the photovoltaic power generation device 105, to the photovoltaic power generation device 105, and then transmit the solar spectrum of the first band to the concentrating and heat - collecting device.

[0051] For example, when the second band is the solar spectrum of 400 - 1100 nm, the first band can be the solar spectrum less than 400 nm and greater than 1100 nm.

[0052] In this process, the operation of the spectral separation device 101 for performing spectral separation processing on the incident sunlight can, without affecting the normal operation of the photovoltaic power generation device 105, not only separate the solar spectrum of the first band required by the photovoltaic power generation device 105, but also transmit the solar spectrum of the first band that the photovoltaic power generation device 105 does not need to the concentrating and heat - collecting system 102, so that the concentrating and heat - collecting system 102 uses the remaining solar spectrum to heat the concentrating and heat - collecting system 102, improve the denitration efficiency of the coal - fired boiler 104, and improve the utilization rate of solar energy.

[0053] The coal - fired boiler 104 includes a furnace and a flue. The denitration device 103 is deployed in the flue. The concentrating and heat - collecting system 102 includes a heat - exchange device. The heat - exchange device is deployed between the furnace and the denitration device 103. The concentrating and heat - collecting system 102 is used to, after receiving the solar spectrum of the first band, use the solar spectrum of the first band to heat the circulating working medium in the concentrating and heat - collecting system 102, and when the coal - fired boiler 104 receives a command to reduce the working load, heat the flue gas in the furnace so that the temperature of the flue gas reaches the lowest temperature threshold of the denitration device 103.

[0054] Among them, the circulating working fluid can be molten salt, high-pressure steam, etc.

[0055] It should be noted that the circulating working fluid can also be other phase change heat storage materials, sensible heat storage materials, etc. The present application does not limit the material type of the circulating working fluid.

[0056] A possible implementation manner is as Figure 2 shown. The concentrating and heat collecting system 102 includes a concentrating and heat collecting device 1021, a heat storage device 1022, a main path valve 1023, and a heat exchange device 1024.

[0057] Among them, the first end of the concentrating and heat collecting device 1021 is connected to the output end of the spectral separation device 101, the second end of the concentrating and heat collecting device 1021 is connected to the first end of the heat storage device 1202, the second end of the heat storage device 1202 is connected to the first end of the main path valve 1023, the second end of the main path valve 1023 is connected to the first end of the heat exchange device 1024, and the second end of the heat exchange device 1024 is connected to the third end of the concentrating and heat collecting device 1021 to form a main path loop for the medium circulation.

[0058] The concentrating and heat collecting device 1021 is configured to convert the solar spectrum of the first band into heat energy by means of coating absorption after receiving the solar spectrum of the first band, so as to heat the circulating working fluid.

[0059] Exemplarily, the concentrating and heat collecting device 1021 can be a concentrating mirror. For example, it can be a low-cost trough-type concentrating mirror (400 - 500 degrees), or a Fresnel-type concentrating mirror (800 - 900 degrees), or other types of concentrating mirrors. It should be noted that the selection of the concentrating and heat collecting device 1021 only needs to be higher than the temperature threshold for denitration of the denitration device 103, for example, higher than 300 degrees, and there is no need for high-cost point concentration.

[0060] It should be noted that the present application does not limit the spectral separation order of the spectral separation device 101 and the concentrating order of the concentrating and heat collecting device 1021.

[0061] For example, the incident sunlight of the full spectrum can also be first focused by the concentrating and heat collecting device 1021 to form a high-energy density light spot, and then the spectral separation device 101 separates the focused light spot, so as to transmit the solar spectrum of the first band to the subsequent functions of the concentrating and heat collecting system 102 and transmit the solar spectrum of the second band to the photovoltaic power generation device 105.

[0062] The heat storage device 1202 is configured to release heat energy to heat the circulating working fluid when the coal-fired boiler 104 receives a command to reduce the working load.

[0063] For example, the heat storage device 1202 can be a steel storage tank for storing the circulating working medium. The heat storage device 1202 can suppress the influence of solar energy volatility on the heating performance of the concentrating solar heat collection system 102.

[0064] The main path valve 1023 is used to control the main path loop when the coal-fired boiler 104 receives a command to reduce the working load and the flue gas temperature in the furnace is less than or equal to the minimum temperature threshold, so that the heated circulating working medium flows through the heat exchange device 1024.

[0065] The main path valve 1023 is also used to control the main path loop to be open when the coal-fired boiler 104 receives a command to increase the working load and the flue gas temperature in the furnace is greater than the minimum temperature threshold.

[0066] Exemplarily, a temperature sensor can be arranged in the furnace of the boiler, and the flue gas temperature in the furnace can be detected by the temperature sensor.

[0067] Among them, the main path valve 1023 can be a ball valve or a butterfly valve, and the present application does not limit this.

[0068] The heat exchange device 1024 is specifically used to heat the flue gas in the furnace with the heated circulating working medium when the main path loop is open, so that the flue gas temperature reaches the minimum temperature threshold of the denitration device 103.

[0069] The heat storage device 1202 is also used to store the thermal energy of the circulating working medium when the coal-fired boiler 104 receives a command to increase the working load and the flue gas temperature in the furnace is greater than the minimum temperature threshold.

[0070] Specifically, the heat exchange device 1024 contains a large number of fins. When the flue gas temperature is less than the minimum temperature threshold of the denitration device 103, the heat exchange device 1024 can exchange heat with the flue gas through the circulating medium to achieve the effect of heating the flue gas, so that the flue gas temperature entering the denitration device 103 meets the denitration requirements of the denitration device 103.

[0071] Exemplarily, the heat exchange device 1024 can be an orifice plate heat exchanger or a shell and tube heat exchanger, and the present application does not limit the specific type of the heat exchange device 1024.

[0072] A possible implementation manner, as Figure 2 shown, the concentrating solar heat collection system 102 further includes a branch valve 1025. The first end of the branch valve 1025 is connected to the second end of the heat storage device 1202 and the first end of the main path valve 1023. The second end of the branch valve 1025 is connected to the second end of the heat exchange device 1024 and the third end of the concentrating solar heat collection device 1021. The branch valve 1025 and the heat storage device 1202 and the concentrating solar heat collection device 1021 form a branch loop for medium circulation.

[0073] The branch valve 1025 is used to control the branch circuit to be open when the coal-fired boiler 104 receives a command to reduce the working load and the flue gas temperature in the furnace is less than or equal to the minimum temperature threshold.

[0074] The branch valve 1025 is also used to control the branch circuit to be closed when the coal-fired boiler 104 receives a command to increase the working load and the flue gas temperature in the furnace is greater than the minimum temperature threshold.

[0075] Wherein, the branch valve 1025 can be a ball valve or a butterfly valve, and the present application does not limit this.

[0076] A possible implementation manner is as Figure 2 shown, the concentrating solar heating system 102 further includes a circulation pump 1026.

[0077] The first end of the circulation pump 1026 is connected to the second end of the heat storage device 1202, and the second end of the circulation pump 1026 is connected to the first end of the main path valve 1023. The circulation pump 1026 is used to drive the circulation working medium to flow at a first preset time before the coal-fired boiler 104 receives a command to reduce the working load. Or, the circulation pump 1026 is also used to stop working at a second preset time after the coal-fired boiler 104 receives a command to increase the working load.

[0078] For example, the circulation pump 1026 can be a liquid variable-frequency circulation pump 1026. The liquid variable-frequency circulation pump 1026 can provide driving force for the circulation working medium to flow in the pipeline, and can also change the flow rate of the circulation working medium by frequency conversion to match the flow demand of the coal-fired boiler 104 in real time, ensure that the flue gas temperature is stably heated to the working temperature of the denitration device 103, realize stable control of the flue gas temperature, and improve the denitration efficiency.

[0079] A possible implementation manner is as Figure 2 shown, the low-frequency solar-assisted coal-fired boiler power generation system further includes: a soot blowing device 106.

[0080] The soot blowing device 106 is deployed on the outer surface of the heat exchange device 1024. The soot blowing device 106 is used to determine a soot blowing strategy based on the state parameters of the heat exchange device 1024, and blow the dust on the outer surface of the heat exchange device 1024 based on the soot blowing strategy. The state parameters include one or more of the following: heat transfer efficiency and working time. The soot blowing strategy includes one or more of the following: soot blowing pressure and soot blowing frequency.

[0081] Exemplarily, a first temperature sensor and a first pressure sensor may be provided at the inlet of the heat exchange device 1024, and a second temperature sensor and a second pressure sensor may be provided at the outlet of the heat exchange device 1024. The first temperature sensor collects the first temperature at the inlet of the heat exchange device 1024, the second temperature sensor collects the second temperature at the outlet of the heat exchange device 1024, the first pressure sensor collects the pressure of the circulating working medium at the inlet of the heat exchange device 1024, and the second pressure sensor collects the pressure of the circulating working medium at the outlet of the heat exchange device 1024. After the heat exchange device 1024 obtains the first temperature, the second temperature, the first pressure, and the second pressure, it uses the first temperature, the second temperature, the first pressure, and the second pressure to determine the heat transfer efficiency of the heat exchange device 1024 at this time.

[0082] When the low-frequency sunlight-assisted coal-fired boiler power generation system operates the heat exchange device 1024, it will record the operating time of the heat exchange device 1024. After the soot blowing device 106 performs a soot blowing operation once, it will restart recording the operating time of the heat exchange device 1024.

[0083] Furthermore, the soot blowing device 106 may determine the soot blowing strategy of the soot blowing device 106 based on the obtained heat transfer efficiency and operating time of the heat exchange device 1024. For example, when the soot blowing device 106 determines, based on the heat transfer efficiency and operating time of the heat exchange device 1024, that the heat exchange device 1024 requires mild soot blowing, it controls the soot blowing device 106 to blow the dust on the surface of the heat exchange device 1024 within the first pressure range at the first operating frequency. When the soot blowing device 106 determines, based on the heat transfer efficiency and operating time of the heat exchange device 1024, that the heat exchange device 1024 requires moderate soot blowing, it controls the soot blowing device 106 to blow the dust on the surface of the heat exchange device 1024 within the second pressure range at the second operating frequency. When the soot blowing device 106 determines, based on the heat transfer efficiency and operating time of the heat exchange device 1024, that the heat exchange device 1024 requires severe soot blowing, it controls the soot blowing device 106 to blow the dust on the surface of the heat exchange device 1024 within the third pressure range at the third operating frequency.

[0084] Among them, the first pressure range is smaller than the second pressure range, the second pressure range is smaller than the third pressure range, the first operating frequency is smaller than the second operating frequency, and the second operating frequency is smaller than the third operating frequency.

[0085] It should be noted that the process of determining that the heat exchange device 1024 is in severe soot blowing based on the heat transfer efficiency and working time of the heat exchange device 1024, and controlling the soot blowing device 106 to blow the dust on the surface of the heat exchange device 1024 at a third working frequency within a third pressure range can be directly determined by the soot blowing device 106 after obtaining the heat transfer efficiency and working time of the heat exchange device 1024, or can be determined by the low-frequency solar-assisted coal-fired boiler power generation system after obtaining the heat transfer efficiency and working time of the heat exchange device 1024, and then determining the soot blowing strategy of the soot blowing device 106 and sending the soot blowing strategy to the soot blowing device 106 to control the soot blowing device 106 to perform the soot blowing operation.

[0086] On the one hand, an embodiment of the present application provides a low-frequency solar-assisted coal-fired boiler power generation method, which can be applied to a low-frequency solar-assisted coal-fired boiler power generation system as shown in Figure 1-2 and as shown in Figure 3 The method includes:

[0087] S301, the spectral separation device 101 performs spectral separation processing on the incident solar energy to obtain the solar spectrum of the first band and the solar spectrum of the second band, transmits the solar spectrum of the first band to the concentrating and heat collecting device 1021, and transmits the solar spectrum of the second band to the photovoltaic power generation device 105.

[0088] Among them, the solar spectrum of the first band is the solar spectrum other than the solar spectrum of the second band.

[0089] S302, after the concentrating and heat collecting system receives the solar spectrum of the first band, it uses the solar spectrum of the first band to heat the circulating working fluid in the concentrating and heat collecting system, and when the coal-fired boiler 104 receives a reduced working load instruction, it heats the flue gas in the furnace of the coal-fired boiler 104 to make the flue gas temperature reach the minimum temperature threshold of the denitration device 103.

[0090] A possible implementation manner is that when the coal-fired boiler 104 receives a reduced working load instruction and the flue gas temperature in the furnace of the coal-fired boiler 104 is less than or equal to the minimum temperature threshold, the main road valve in the concentrating and heat collecting system is controlled to close, and the branch valve 1025 is controlled to disconnect, so that the heated circulating working fluid flows through the heat exchange device 1024, and the heat exchange device 1024 uses the heated circulating working fluid to heat the flue gas in the furnace to make the flue gas temperature reach the minimum temperature threshold.

[0091] Another possible implementation manner is that when the coal-fired boiler 104 receives an increased working load instruction and the flue gas temperature in the furnace of the coal-fired boiler 104 is greater than the minimum temperature threshold, the main road valve is controlled to disconnect, and the branch valve 1025 is controlled to close, so that the solar energy is stored in the heat storage device 1202 of the concentrating and heat collecting system.

[0092] Exemplarily, when the solar radiation intensity is high, the photovoltaic power generation device 105 in the low-frequency solar-assisted coal-fired boiler power generation system preferentially meets the power generation demand. At this time, the coal-fired boiler 104 receives a command to reduce the working load and enters the deep peak shaving state. The spectral separation device 101 transmits the solar spectrum in the second band to the photovoltaic power generation device 105 for solar power generation, and transmits the solar spectrum in the first band other than the second band to the concentrating solar heating system. The circulation pump 1026 starts working in advance before the coal-fired boiler 104 starts to reduce the load. At this time, the branch valve 1025 is opened, and the concentrating solar heating system uses the solar spectrum in the first band to heat the circulating working fluid in the concentrating solar heating system, and the temperature of the circulating working fluid continuously rises. As the load of the coal-fired boiler 104 further decreases, the temperature of the flue gas in the flue of the coal-fired boiler 104 continuously decreases. When the flue gas temperature is lower than the minimum temperature threshold of the denitration device 103, the main valve is opened, and the branch valve 1025 is closed. The heated circulating working fluid flows through the heat exchange device 1024, and the heat exchange device 1024 uses the heated circulating working fluid to heat the flue gas, so that the flue gas temperature reaches above the minimum temperature threshold, enabling the denitration device 103 to continue denitrification.

[0093] When the solar radiation intensity is low, the power generation efficiency of the photovoltaic power generation device 105 decreases at this time, and the coal-fired boiler 104 receives a command to increase the working load and leaves the deep peak shaving state. When the flue gas temperature is higher than the minimum working threshold of the denitration device 103, the working power of the circulation pump 1026 decreases. At this time, the main valve is closed, and the branch valve is opened. The solar energy continues to heat the circulating working fluid and stores the human energy in the circulating working fluid.

[0094] Taking a 330MW coal-fired peak shaving unit as an example, when the coal-fired boiler 104 enters the deep peak shaving stage, the load of the coal-fired boiler 104 is reduced to 20%, that is, 66W. At this time, the temperature of the flue gas in the boiler flue decreases, and the denitration device 103 will face the risk of insufficient flue gas temperature. At this time, taking the flue gas flow rate of 500t / h as the reference value and the flue gas temperature rise of 20°C as the design value, the additional solar heat to be recovered is 2.9MW. Calculated based on the local effective solar radiation of 800W / m2, the solar energy in the remaining band accounts for 24.2% of the total solar energy, and the solar-thermal conversion efficiency is 80%. Approximately 18750m 2 of the concentrating area is required to meet the demand of the denitration device. The photoelectric conversion efficiency is estimated at 18%. The solar power generation power of the supporting photovoltaic cells under this area is 2.70MW. The full-spectrum solar energy has achieved good energy-saving benefits for the denitration of low-load coal-fired boilers.

[0095] The low-frequency sunlight-assisted coal-fired boiler power generation method provided by this application distributes the second-band solar spectrum used by the photovoltaic power generation device 105 to the photovoltaic power generation device 105, and distributes the first-band solar spectrum outside the second band to the concentrating heat collection system. The concentrating heat collection system uses the first-band solar spectrum to heat the flue gas in the coal-fired boiler 104, so that the temperature of the flue gas can reach the minimum temperature threshold for denitrification by the denitrification device 103, improving the coal-fired denitrification efficiency of the coal-fired boiler 104 during the deep peak shaving stage while saving the coal consumption of the coal-fired boiler 104.

[0096] The above mainly introduced the solution provided by the embodiments of this application from the perspective of the working principle of the equipment. It can be understood that in order to implement the above functions, the vehicle controller includes the corresponding hardware structure and / or software module for executing each function. Those skilled in the art should easily realize that, combined with the algorithm steps of each example described in the embodiments disclosed in this article, this application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in the way of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0097] The embodiments of this application also provide a low-frequency sunlight-assisted coal-fired boiler power generation device, and this electroencephalogram device can execute the low-frequency sunlight-assisted coal-fired boiler power generation method and related steps in the above method embodiments.

[0098] The embodiments of this application also provide a computer-readable storage medium, on which instructions are stored, and when the instructions are executed, they execute the low-frequency sunlight-assisted coal-fired boiler power generation method and related steps in the above method embodiments.

[0099] The embodiments of this application also provide a computer program product, and when this computer program product runs on a computer, it causes the computer to execute the low-frequency sunlight-assisted coal-fired boiler power generation method and related steps in the above method embodiments.

[0100] In some embodiments, the method shown in this application can be implemented as computer program instructions encoded in a computer-readable storage medium in a machine-readable format or encoded on other non-transitory media or articles.

[0101] The embodiments of this application also provide a low-frequency sunlight-assisted coal-fired boiler power generation system 100, as Figure 4 shown, this low-frequency sunlight-assisted coal-fired boiler power generation system 100 includes at least one processor 401 and at least one interface circuit 402.

[0102] As an example, when the low-frequency sunlight-assisted coal-fired boiler power generation system 100 includes a processor and an interface circuit, the processor can be Figure 4 the processor 401 shown in the solid-line box in Figure 4 (or the processor 401 shown in the dashed-line box), and the interface circuit can be Figure 4 the interface circuit 402 shown in the solid-line box in Figure 4 (or the interface circuit 402 shown in the dashed-line box). When the low-frequency sunlight-assisted coal-fired boiler power generation system 100 includes two processors and two interface circuits, the two processors include Figure 4 the processor 401 shown in the solid-line box and the processor 401 shown in the dashed-line box in Figure 4 , and the two interface circuits include Figure 4 the interface circuit 402 shown in the solid-line box and the interface circuit 402 shown in the dashed-line box in Figure 4 . There is no limitation on this.

[0103] The processor 401 and the interface circuit 402 can be interconnected by lines. For example, the interface circuit 402 can be used to receive signals. Also, for example, the interface circuit 402 can be used to send signals to other devices (such as the processor 401). By way of example, the interface circuit 402 can read the computer instructions stored in the memory and send the computer instructions to the processor 401. The processor 401 executes the instructions and, in combination with the input / output device, implements each step in the above embodiments, such as implementing Figure 3 each step executed in the method embodiment shown in Figure 3 . Of course, the low-frequency sunlight-assisted coal-fired boiler power generation system may also include other discrete devices, and the embodiments of the present application do not make specific limitations on this.

[0104] Through the description of the above embodiments, those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above division of each functional module is used for illustration. In actual applications, the above functions can be allocated to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

[0105] In several embodiments provided in the present application, it should be understood that the disclosed device and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point, the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces, and the indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0106] The unit described as a separation component may or may not be physically separated. The component shown as a unit may be a single physical unit or multiple physical units, that is, it may be located in one place or distributed to multiple different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0107] In addition, each functional unit in various embodiments of the present application can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0108] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiments of the present application, in essence, or the part that makes a contribution, or all or part of this technical solution, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to enable a device (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: USB flash drives, mobile hard disks, read only memory (ROM), random access memory (RAM), magnetic disks, optical spectra, and other various media that can store program codes.

[0109] The above content is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claimed rights.

Claims

1. A low-frequency solar-assisted coal-fired boiler power generation system, characterized in that: The low-frequency solar light-assisted coal-fired boiler power generation system comprises: a spectrum separation device, a concentrating heat collection system, a denitrification device, a coal-fired boiler and a photovoltaic power generation device; The spectrum separation device is connected to the concentrating and thermal collecting system and the photovoltaic power generation device, and is used for performing spectrum separation processing on incident solar energy to obtain a solar spectrum of a first band and a solar spectrum of a second band, transmitting the solar spectrum of the first band to the concentrating and thermal collecting system, and transmitting the solar spectrum of the second band to the photovoltaic power generation device, so that the photovoltaic power generation device uses the solar spectrum of the second band to generate solar power; the solar spectrum of the first band is the solar spectrum other than the solar spectrum of the second band; The coal-fired boiler includes a furnace and a flue, the denitrification device is deployed in the flue, the concentrating solar collection system includes a heat exchange device, and the heat exchange device is deployed between the furnace and the denitrification device. The concentrating solar collection system is used to heat the circulating working fluid in the concentrating solar collection system using the solar spectrum of the first band after receiving the solar spectrum of the first band, and when the coal-fired boiler receives an instruction to reduce the workload, the flue gas in the furnace is heated to make the flue gas temperature reach the minimum temperature threshold of the denitrification device.

2. The low-frequency solar-assisted coal-fired boiler power generation system according to claim 1 is characterized in that: The solar concentrator and heat collector system comprises a solar concentrator and heat collector device, a heat storage device, a main valve and a heat exchange device; the first end of the solar concentrator and heat collector device is connected to the output end of the spectrum separation device, the second end of the solar concentrator and heat collector device is connected to the first end of the heat storage device, the second end of the heat storage device is connected to the first end of the main valve, the second end of the main valve is connected to the first end of the heat exchange device, and the second end of the heat exchange device is connected to the third end of the solar concentrator and heat collector device to form a main circuit for medium circulation; The concentrating heat collecting device is used to convert the solar spectrum of the first wavelength band into heat energy by means of coating absorption after receiving the solar spectrum of the first wavelength band, so as to heat the circulating working medium; The heat storage device is used to release heat energy to heat the circulating working medium when the coal-fired boiler receives the instruction to reduce the workload; The main valve is used to control the main circuit passage when the coal-fired boiler receives the workload reduction instruction and the flue gas temperature in the furnace is less than or equal to the minimum temperature threshold, so that the heated circulating medium flows through the heat exchange device; The heat exchange device is specifically used to heat the flue gas in the furnace using the heated circulating medium when the main circuit is in circulation, so that the flue gas temperature reaches the minimum temperature threshold of the denitration device.

3. The low-frequency solar-assisted coal-fired boiler power generation system according to claim 2 is characterized in that: The heat storage device is also used to store the heat energy of the circulating working medium when the coal-fired boiler receives an instruction to increase the workload and the flue gas temperature in the furnace is greater than the minimum temperature threshold; The main valve is also used to control the main circuit to be disconnected when the coal-fired boiler receives the instruction to increase the workload and the flue gas temperature in the furnace is greater than the minimum temperature threshold.

4. The low-frequency solar-assisted coal-fired boiler power generation system according to claim 2 is characterized in that: The solar concentrating and heat collecting system further comprises a branch valve; a first end of the branch valve is connected to a second end of the heat storage device and a first end of the main valve, a second end of the branch valve is connected to a second end of the heat exchange device and a third end of the solar concentrating and heat collecting device, and the branch valve, the heat storage device and the solar concentrating and heat collecting device form a branch circuit for medium circulation; The branch valve is used to control the branch circuit to be disconnected when the coal-fired boiler receives the instruction to reduce the workload and the flue gas temperature in the furnace is less than or equal to the minimum temperature threshold.

5. The low-frequency solar-assisted coal-fired boiler power generation system according to claim 4 is characterized in that: The branch valve is also used to control the branch circuit passage when the coal-fired boiler receives the workload increase instruction and the flue gas temperature in the furnace is greater than the minimum temperature threshold.

6. The low-frequency solar-assisted coal-fired boiler power generation system according to claim 2, characterized in that: The concentrated solar heat collection system also includes a circulation pump; The first end of the circulation pump is connected to the second end of the heat storage device, and the second end of the circulation pump is connected to the first end of the main valve. The circulation pump is used to drive the circulation working medium to flow at a first preset time before the coal-fired boiler receives the instruction to reduce the workload; or, the circulation pump is also used to stop working at a second preset time after the coal-fired boiler receives the instruction to increase the workload.

7. The low-frequency solar-assisted coal-fired boiler power generation system according to claim 1, characterized in that: The low-frequency solar light-assisted coal-fired boiler power generation system further includes: a soot blowing device; The sootblowing device is deployed on the outer surface of the heat exchange device; the sootblowing device is used to determine a sootblowing strategy based on the state parameters of the heat exchange device, and to blow away dust on the outer surface of the heat exchange device based on the sootblowing strategy; the state parameters include one or more of the following: heat transfer efficiency and working time; the sootblowing strategy includes one or more of the following: sootblowing pressure and sootblowing frequency.

8. A low-frequency solar-assisted coal-fired boiler power generation method, characterized in that: Applicable to the low-frequency solar-assisted coal-fired boiler power generation system as described in claims 1-8; the method comprises: The spectrum separation device performs spectrum separation processing on the incident solar energy to obtain a solar spectrum of a first waveband and a solar spectrum of a second waveband, transmits the solar spectrum of the first waveband to the concentrating and heat collecting device, and transmits the solar spectrum of the second waveband to the photovoltaic power generation device; the solar spectrum of the first waveband is the solar spectrum other than the solar spectrum of the second waveband; After receiving the solar spectrum in the first band, the concentrating solar collection system uses the solar spectrum in the first band to heat the circulating working fluid in the concentrating solar collection system, and when the coal-fired boiler receives an instruction to reduce the workload, the flue gas in the furnace of the coal-fired boiler is heated to make the flue gas temperature reach the minimum temperature threshold of the denitrification device.

9. The method according to claim 8, characterized in that The method further comprises: When the coal-fired boiler receives an instruction to reduce its workload and the flue gas temperature in the furnace of the coal-fired boiler is less than or equal to the minimum temperature threshold, the main valve in the concentrated solar thermal system is controlled to be closed, and the branch valve is controlled to be opened, so that the heated circulating working fluid flows through the heat exchange device, and the heat exchange device uses the heated circulating working fluid to heat the flue gas in the furnace so that the flue gas temperature reaches the minimum temperature threshold.

10. The method according to claim 8 or 9, characterized in that: The method further comprises: When the coal-fired boiler receives an instruction to increase its workload and the flue gas temperature in the furnace of the coal-fired boiler is greater than the minimum temperature threshold, the main valve is controlled to be disconnected and the branch valve is controlled to be closed so that the solar energy is stored in the heat storage device of the concentrated solar thermal system.

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