Ultra-low load flexible peak shaving system and method for thermal power plant

Abstract

The invention provides a thermal power plant ultra-low load flexible peak regulation system and method.The thermal power plant ultra-low load flexible peak regulation system comprises a pulverized coal conveying unit, a combustion unit and a pulverized coal gasification unit, the pulverized coal conveying unit is used for receiving coal briquettes and grinding the coal briquettes into pulverized coal, the combustion unit comprises a boiler, the boiler is connected with the pulverized coal conveying unit, and the pulverized coal gasification unit is used for gasifying the pulverized coal; the pulverized coal gasification unit comprises a pressurization assembly and a gasification assembly, the pressurization assembly is provided with a first inlet, the first inlet is connected with the pulverized coal conveying unit, so that the pulverized coal conveying unit introduces part of pulverized coal into the pressurization assembly through the first inlet, and the pressurization assembly is connected with the gasification assembly; and the gasification assembly is connected with the boiler, so that pulverized coal is gasified through the pressurization assembly and the gasification assembly in sequence and then is introduced into the boiler for combustion. The ultralow-load flexible peak shaving system of the thermal power plant is simple in structure and process, convenient to transform and more stable in low-load peak shaving operation.

Description

Technical Field

[0001] The present invention relates to the technical field of power plant peak regulation, and in particular to an ultra-low load flexible peak regulation system and method for a thermal power plant. Background Art

[0002] In the context of energy structure adjustment, improving the flexibility of thermal power operation is an important direction for the transformation and development of the thermal power industry. Improving the flexibility of thermal power mainly refers to increasing the output variation range of thermal power units and the ability to respond to load changes or dispatch instructions. In most cases, it refers to increasing the stable, clean and efficient operation capabilities of thermal power units at low loads. One of the important transformation contents is the transformation of the combustion unit, that is, to achieve stable combustion under ultra-low loads.

[0003] When the boiler is running at low load, the flame filling degree in the furnace will be worse than that at high load. When the load is reduced to a certain extent, the temperature in the furnace drops, resulting in an increase in the ignition distance per minute of airflow, and the radiation loss of the flame to the furnace wall increases relatively, so it is easy to have unstable combustion or even flameout of the boiler. The stable combustion technology used in related technologies, such as micro-oil small oil gun stable combustion technology, plasma stable combustion technology, and the use of fuel oil or plasma to assist combustion not only increase additional energy consumption, but can only be used as an emergency measure to avoid non-stop accidents such as boiler flameout in special circumstances, and cannot achieve stable combustion under ultra-low load. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, an embodiment of the present invention proposes an ultra-low load flexible peak-shaving system for a thermal power plant, which has a simple structure and process, is easy to transform, and has a more stable low-load peak-shaving operation.

[0005] The ultra-low load flexible peak-shaving system of a thermal power plant according to an embodiment of the present invention comprises:

[0006] A coal powder conveying unit, the coal powder conveying unit is used to receive coal blocks and grind the coal blocks into coal powder;

[0007] A combustion unit, wherein the combustion unit comprises a boiler, and the boiler is connected to the pulverized coal conveying unit so that the pulverized coal conveying unit conveys the pulverized coal to the boiler for combustion;

[0008] Pulverized coal gasification unit, the pulverized coal gasification unit includes a pressurizing component and a gasification component, the pressurizing component has a first inlet, the first inlet is connected to the pulverized coal conveying unit, so that the pulverized coal conveying unit passes part of the pulverized coal into the pressurizing component through the first inlet, the pressurizing component is connected to the gasification component, and the gasification component is connected to the boiler, so that after the pulverized coal is gasified through the pressurizing component and the gasification component in sequence, it is then passed into the boiler for combustion.

[0009] The ultra-low load flexible peak shaving system of a thermal power plant according to an embodiment of the present invention can gasify part of the pulverized coal fuel in a coal-fired power station to generate combustible gas and be used for stable combustion during the low-load peak shaving operation of the power station, achieving regulation in the range of 10% to 100% of the rated load of the boiler. At the same time, the pulverized coal gasification gas is mixed with pulverized coal for combustion in the boiler, which is also beneficial to reducing the emission of nitrogen oxides.

[0010] In some embodiments, the ultra-low load flexible peak shaving system of a thermal power plant according to an embodiment of the present invention further includes a feeding component, the feeding component includes a material inlet, and the material inlet is used to pass in biomass raw materials so as to make biomass powder by using the feeding component.

[0011] The pressurizing component also has a first inlet, and the feeding component is connected to the first inlet so as to pass the biomass powder made by the feeding component into the pressurizing component.

[0012] In some embodiments, the pulverized coal conveying unit includes a mill and a first pipeline, the first end of the first pipeline is connected to the mill, the second end of the first pipeline is connected to the boiler, a first nozzle is provided at the second end of the first pipeline, at least part of the first nozzle is placed inside the boiler, there are multiple first pipelines, and the pressurizing component is connected to the mill and at least one of the multiple first pipelines.

[0013] In some embodiments, the pressurizing component includes a variable pressure chamber and a pressurizing chamber connected in sequence, the variable pressure chamber is connected to the mill and at least one of the multiple first pipelines, the pressurizing chamber is connected to the gasification component, and the pressurizing chamber has a first ventilation port, and the first ventilation port is used to pass in inert gas so as to pass the pulverized coal in the pressurizing chamber into the gasification component.

[0014] In some embodiments, the pressurizing component further includes a storage bin, and the storage bin is connected to the variable pressure chamber and is located upstream of the variable pressure chamber.

[0015] In some embodiments, the gasification assembly includes a gasifier and a second pipeline. The gasifier is connected to the pressurization chamber. The first end of the second pipeline is connected to the gasifier, and the second end of the second pipeline is connected to the boiler. A second nozzle is provided at the second end of the second pipeline. There are a plurality of the second nozzles, and the plurality of second nozzles correspond to the plurality of first nozzles one by one.

[0016] In some embodiments, the gasifier has a second air inlet for introducing oxygen and steam.

[0017] The method for flexible peak shaving at ultra-low load in a thermal power plant according to an embodiment of the present invention is completed according to the ultra-low load flexible peak shaving system described in any one of the above embodiments, and is characterized by including the following steps:

[0018] S1. Determine the combustion state of the boiler and the pulverized coal conveying amount;

[0019] S2. According to the combustion state and the pulverized coal conveying amount, introduce part of the pulverized coal into the pressurization assembly;

[0020] S3. Perform variable pressure, pressurization, and gasification treatment on the pulverized coal;

[0021] S4. Spray the gasified coal gas into the boiler by using the second nozzle.

[0022] In some embodiments, the method for flexible peak shaving at ultra-low load in a thermal power plant according to an embodiment of the present invention further includes the following steps:

[0023] In step S2, the amount of part of the pulverized coal is 5% to 20% of the pulverized coal conveying amount.

[0024] In some embodiments, the method for flexible peak shaving at ultra-low load in a thermal power plant according to an embodiment of the present invention further includes the following steps:

[0025] S5. Monitor the combustion state of the boiler in real time, and adjust the position and quantity of the second nozzles according to the temperature distribution in the furnace so as to make the temperature distribution in the boiler furnace uniform. Description of the Drawings

[0026] Figure 1 is a schematic structural diagram of the ultra-low load flexible peak shaving system in an embodiment of the present invention.

[0027] Figure 2 is a schematic diagram of the operation principle of the ultra-low load flexible peak shaving system in an embodiment of the present invention.

[0028] Reference Signs:

[0029] 1. Pulverized coal conveying unit, 11. Coal bin, 12. Conveyor belt, 13. Mill, 14. First pipeline, 15. First nozzle,

[0030] 2. Combustion unit, 21. Boiler

[0031] 3. Pulverized coal gasification unit, 31. Pressurizing component, 311. Variable pressure chamber, 312. Pressurizing chamber, 3121. First ventilation port, 313. Storage bin, 3131. First inlet, 3132. First inlet, 32. Gasification component, 321. Gasifier, 3211. Second ventilation port, 322. Second pipeline, 323. Second nozzle

[0032] 4. Stock preparation component, 41. Material inlet Detailed implementation manners

[0033] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0034] The ultra-low load flexible peak shaving system of a thermal power plant according to the embodiments of the present invention will be described below with reference to the drawings.

[0035] As Figure 1 and Figure 2 shown, the ultra-low load flexible peak shaving system of the embodiment of the present invention includes: a pulverized coal conveying unit 1, a combustion unit 2 and a pulverized coal gasification unit 3.

[0036] The pulverized coal conveying unit 1 is used to receive coal blocks and grind them into pulverized coal. The combustion unit 2 includes a boiler 21, and the boiler 21 is connected to the pulverized coal conveying unit 1 so that the pulverized coal conveying unit 1 conveys the pulverized coal to the boiler 21 for combustion. The pulverized coal gasification unit 3 includes a pressurizing component 31 and a gasification component 32. The pressurizing component 31 has a first inlet 3131, and the first inlet 3131 is connected to the pulverized coal conveying unit 1 so that the pulverized coal conveying unit 1 passes part of the pulverized coal into the pressurizing component 31 through the first inlet 3131. The pressurizing component 31 is connected to the gasification component 32, and the gasification component 32 is connected to the boiler 21 so that after the pulverized coal is gasified successively through the pressurizing component 31 and the gasification component 32, it is then passed into the boiler 21 for combustion.

[0037] Specifically, as Figure 1 shown, the pulverized coal conveying unit 1 includes a coal bin 11 for storing coal and a conveyor belt 12 for conveying coal blocks, and also includes equipment such as a mill 13 for grinding coal blocks into pulverized coal, so as to convey the coal blocks to the grinding equipment by using the conveyor belt 12 for pulverization and convey the pulverized coal to the combustion unit 2 for combustion.

[0038] It can be understood that when the boiler 21 is operating at a low load, in order to avoid an increase in the ignition distance of each sub-airflow due to a decrease in the furnace temperature of the boiler 21, and at the same time avoid a relatively increased loss of heat radiation from the flame to the furnace wall, a small amount of pulverized coal can be extracted from the pulverized coal conveying unit 1 and conveyed to the pulverized coal gasification unit 3, and then passed into the boiler 21 after passing through the pressurizing assembly 31 and the gasification assembly 32 in sequence. Thus, in the furnace of the boiler 21, the flame of the gas combustion can support the stable combustion of the pulverized coal. Since the gas combustion is relatively easy and wide-range load regulation can be achieved, therefore, while the gas supports the combustion of the pulverized coal, the load regulation ability of the combustion is also greatly enhanced.

[0039] In some embodiments, the pulverized coal conveying unit 1 includes a mill 13 and a first pipeline 14. The first end of the first pipeline 14 is connected to the mill 13, the second end of the first pipeline 14 is connected to the boiler 21, a first nozzle 15 is provided at the second end of the first pipeline 14, at least a part of the first nozzle 15 is placed inside the boiler 21, there are multiple first pipelines 14, and the pressurizing assembly 31 is connected to the mill 13 and at least one of the multiple first pipelines 14.

[0040] It can be understood that the pressurizing assembly 31 can be connected to the mill 13 through a pipeline; or, the pressurizing assembly 31 can be connected to the multiple first pipelines 14 (as shown in Figure 1 ); or, the pressurizing assembly 31 is connected to both the mill 13 and the multiple first pipelines 14. That is, according to the actual installation conditions, pipelines can be added at different positions to pass the pulverized coal in the mill 13 or the first pipeline 14 into the pressurizing assembly 31.

[0041] That is to say, as shown in Figure 1 , the conveyor belt 12 conveys the coal blocks to the mill 13 for grinding. The blower can convey the pulverized coal through the multiple first pipelines 14 to the boiler 21, and the first nozzle 15 located at the second end of the first pipeline 14 is arranged at different positions and heights in the boiler 21. The first nozzle 15 can spray the pulverized coal into the furnace for ignition, and organize combustion in the furnace of the boiler 21. The flue gas after combustion enters the flue gas purification device downstream of the boiler 21 and is finally discharged by the induced draft fan.

[0042] In other words, the ultra-low load flexible peak shaving system of the thermal power plant in the embodiment of the present invention can generate combustible gas by gasifying part of the pulverized coal fuel in the coal-fired power station and use it for stable combustion during the low-load peak shaving operation of the power station, achieving regulation in the range of 10% - 100% of the rated load of the boiler 21. At the same time, the mixed combustion of the pulverized coal gasification gas and the pulverized coal in the boiler 21 is also beneficial to reducing the emission of nitrogen oxides.

[0043] In some embodiments, the ultra-low load flexible peak shaving system of the thermal power plant according to the embodiments of the present invention further includes a batching component 4. The batching component 4 includes a material inlet 41 for introducing biomass raw materials, so as to make biomass powder by using the batching component 4. The pressurizing component 31 also has a first inlet 3132, and the batching component 4 is connected to the first inlet 3132 to introduce the biomass powder made by the batching component 4 into the pressurizing component 31.

[0044] It can be understood that, as shown in the figure, the biomass raw materials include biomass powder or biomass carbon powder. The batching component 4 includes equipment such as screening, cleaning, drying, and grinding, so as to be able to make the required biomass powder from the biomass raw materials.

[0045] That is to say, the ultra-low load flexible peak shaving system of the thermal power plant according to the embodiments of the present invention can select some pulverized coal in the pulverized coal conveying unit 1 for gasification according to the combustion condition of the boiler 21, or use the biomass powder processed by the batching component 4 for gasification, realizing the system coupling of coal and biomass, and also avoiding the consumption of coal. Under the condition of ensuring the low-load operation of the boiler 21, the demand for carbon reduction is also met.

[0046] In some embodiments, the pressurizing component 31 includes a variable pressure chamber 311 and a pressurizing chamber 312 connected in sequence. The variable pressure chamber 311 is connected to at least one of the mill 13 and a plurality of first pipelines 14, and the pressurizing chamber 312 is connected to the gasification component 32. The pressurizing chamber 312 has a first ventilation port 3121 for introducing an inert gas, so as to introduce the pulverized coal in the pressurizing chamber 312 into the gasification component 32.

[0047] It can be understood that the variable pressure chamber 311 can be connected to the mill 13, or the variable pressure chamber 311 is connected to a plurality of first pipelines 14, or the variable pressure chamber 311 is connected to both the mill 13 and the first pipelines 14. As Figure 1 shown, the variable pressure chamber 311 is connected to a plurality of first pipelines 14, so that the pulverized coal in the plurality of first pipelines 14 can be introduced into the variable pressure chamber 311 to adjust the pressure of the introduced pulverized coal by using the variable pressure chamber 311. The pulverized coal passing through the variable pressure chamber 311 is introduced into the pressurizing chamber 312 through a pipeline to further pressurize the pulverized coal. Optionally, the inert gas introduced through the first ventilation port 3121 can be nitrogen. The inert gas is introduced into the pressurizing chamber 312 through the first ventilation port 3121, which is convenient for the transportation of pulverized coal and can also prevent the pulverized coal from oxidizing or exploding under high-pressure conditions.

[0048] Preferably, the pressurizing component 31 further includes a storage bin 313, and the storage bin 313 is connected to the variable pressure chamber 311 and is located upstream of the variable pressure chamber 311. Specifically, as Figure 1As shown in the figure, a storage bin 313 is provided upstream of the variable pressure bin 311 to facilitate the storage of pulverized coal or biomass powder. And according to the working state of the variable pressure bin 311, the flow rate of the storage bin 313 can be adjusted at any time to ensure the normal use of the variable pressure bin 311 and avoid the accumulation of pulverized coal.

[0049] In some embodiments, the gasification assembly 32 includes a gasifier 321 and a second pipeline 322. The gasifier 321 is connected to the pressurization bin 312. The first end of the second pipeline 322 is connected to the gasifier 321, and the second end of the second pipeline 322 is connected to the boiler 21. A second nozzle 323 is provided at the second end of the second pipeline 322. There are multiple second nozzles 323, and the multiple second nozzles 323 correspond to the multiple first nozzles 15 one by one.

[0050] Specifically, as Figure 1 shown, the gasifier 321 is connected to the pressurization bin 312 through a pipeline to receive the pressurized pulverized coal. A reaction area is provided inside the gasifier 321 so that the pulverized coal can react in the reaction area to generate coal gas. The second pipeline connects the gasifier 321 and the boiler 21 so that the coal gas generated by the gasifier 321 can be introduced into the boiler 21 through the second pipeline and the multiple second nozzles 323 for combustion.

[0051] Preferably, the gasifier 321 has a second air inlet 3211, and the second air inlet 3211 is used to introduce oxygen and steam.

[0052] It can be understood that the second air inlet 3211 communicates with the reaction area. In the reaction area, the pressurized pulverized coal is mixed with oxygen and steam and reacts to generate syngas, so that when the syngas burns in the boiler 21, the combustion is more complete and the combustion efficiency is higher. And, by using the multiple second nozzles 323, the flow rate and distribution of the syngas can be adjusted as needed to enhance the peak shaving flexibility and adaptability of the ultra-low load flexible peak shaving system of the thermal power plant in the embodiment of the present invention.

[0053] It should be noted that the ultra-low load flexible peak shaving system of the thermal power plant in the embodiment of the present invention has a small impact on the existing boiler 21 system, the number of additional devices is small, the installation is convenient, and the facilities can operate independently. Among them, the pulverized coal gasification unit 3 in the ultra-low load flexible peak shaving system of the thermal power plant in the embodiment of the present invention can be used for different boiler 21 systems, such as direct blow pulverized coal power station boilers 21, intermediate storage pulverized coal power station boilers 21, etc. In addition, it is also applicable to boilers 21 with different combustion methods, such as pulverized coal boilers 21 with tangential firing in four corners, pulverized coal boilers 21 with wall-mounted opposed firing, etc. That is to say, according to the boiler 21 with different combustion methods, the first nozzles 15 and the second nozzles 323 are arranged at different positions in the boiler 21 according to the on-site situation.

[0054] The following describes the ultra-low load flexible peak shaving method for a thermal power plant according to an embodiment of the present invention with reference to the accompanying drawings.

[0055] The ultra-low load flexible peak shaving method for a thermal power plant according to an embodiment of the present invention is completed by the ultra-low load flexible peak shaving system according to any one of the above embodiments, and is characterized by including the following steps:

[0056] S1. Determine the combustion state of the boiler 21 and the pulverized coal delivery volume. Among them, an oxygen analyzer, a temperature sensor, a flue gas analyzer, etc. can be used to monitor the combustion state of the boiler 21 in real time. A flowmeter can be used to detect the pulverized coal flow rate in the pulverized coal delivery pipeline (i.e., the first pipeline 14). So as to judge the combustion condition of the boiler 21 in real time according to the combustion state of the pulverized coal and the pulverized coal delivery volume.

[0057] S2. According to the combustion state and the pulverized coal delivery volume, part of the pulverized coal is introduced into the pressurizing assembly 31. A conveying fan can be used to convey the pulverized coal to the pressurizing assembly 31, and the pressurizing assembly 31 can perform variable pressure treatment on the pulverized coal to facilitate the subsequent gasification of the pulverized coal.

[0058] S3. Perform variable pressure, pressurization and gasification treatment on the pulverized coal. High-pressure inert gas (such as nitrogen, etc.) is used to send the pulverized coal to the burner of the gasifier 321, and a certain amount of oxygen and steam are introduced into the burner, so that the pulverized coal can complete the pressurized gasification process in the gasifier 321.

[0059] S4. Use the second nozzle 323 to spray the gasified coal gas into the boiler 21. The generated coal gas is introduced into the second nozzle 323 under pressure, and the second nozzle 323 is used to introduce the coal gas into the boiler 21. The coal gas is ignited and burned in the furnace of the boiler 21, and the flame formed by the coal gas plays a supporting role in the combustion of the pulverized coal. By adjusting the pulverized coal feed amount or the coal gas feed amount, flexible load adjustment of the boiler 21 can be realized.

[0060] In some embodiments, the ultra-low load flexible peak shaving method for a thermal power plant according to an embodiment of the present invention further includes the following steps: In step S2, the amount of part of the pulverized coal is 5% - 20% of the pulverized coal delivery volume. It can be understood that under the load combustion state of the boiler 21, according to the combustion condition of the pulverized coal, 5% - 20% of the pulverized coal delivery volume is selected for pulverized coal gasification, which basically has no influence on the pulverized coal delivery and combustion of the boiler 21, and the total heat input to the boiler 21 is basically unchanged. However, through the mixed combustion with the gasified gas, the ignition and stable combustion of the pulverized coal are promoted, and thus the load adjustment of the boiler 21 in the range of 10% - 100% of the rated load is realized.

[0061] In addition, it should be noted that the ultra-low load flexible peak shaving method for thermal power plants in the embodiments of the present invention can also use other materials to replace pulverized coal for gasification. For example, biomass raw materials can be used, that is, the biomass powder processed by the feeding component 4 is used for gasification, which not only realizes the system coupling of coal and biomass, but also avoids the consumption of coal.

[0062] In some embodiments, the ultra-low load flexible peak shaving method for thermal power plants in the embodiments of the present invention further includes the following steps: S5. Monitor the combustion state of the boiler 21 in real time, and adjust the position and quantity of the second nozzles 323 according to the temperature distribution in the furnace chamber, so as to make the temperature distribution in the furnace chamber of the boiler 21 uniform.

[0063] It can be understood that, according to the combustion state of the boiler 21, the gas is classified. The gas classification can mainly be arranged according to the temperature distribution in the furnace chamber, and the setting position and arrangement quantity of the second nozzles 323 are correspondingly adjusted to ensure that the combustible gas injected into the furnace chamber by the second nozzles 323 promotes the combustion of pulverized coal and ensures the stable operation of the power plant at low load. For example, reduce the gas volume in the high-temperature area at the outlet of the pulverized coal burner (the second nozzle 323), and increase the gas in the low-temperature areas such as above the flame of the boiler 21 or the over-fire air (OFA), so as to make the temperature in the furnace chamber of the boiler 21 uniform and reduce the initial emission concentration of nitrogen oxides.

[0064] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0065] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0066] In the present invention, unless otherwise clearly defined and limited, terms such as "installed", "connected", "linked", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0068] In the present invention, terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0069] Although the above embodiments have been shown and described, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions, and variations made by those of ordinary skill in the art to the above embodiments are within the protection scope of the present invention.

Claims

1. A thermal power plant ultra-low load flexible peak regulation system, characterized in that: include: A coal powder conveying unit, the coal powder conveying unit is used to receive coal blocks and grind the coal blocks into coal powder; A combustion unit, wherein the combustion unit comprises a boiler, and the boiler is connected to the pulverized coal conveying unit so that the pulverized coal conveying unit conveys the pulverized coal to the boiler for combustion; A pulverized coal gasification unit, the pulverized coal gasification unit includes a pressurizing component and a gasification component, the pressurizing component has a first inlet, the first inlet is connected to the pulverized coal conveying unit, so that the pulverized coal conveying unit passes part of the pulverized coal into the pressurizing component through the first inlet, the pressurizing component is connected to the gasification component, and the gasification component is connected to the boiler, so that the pulverized coal is gasified by passing through the pressurizing component and the gasification component in turn, and then passed into the boiler for combustion.

2. The ultra-low load flexible peak-shaving system for thermal power plants according to claim 1 is characterized in that: It also includes a material preparation component, which includes a material inlet, and the material inlet is used to pass biomass raw materials so that biomass powder can be made by using the material preparation component. The pressurizing component also has a first inlet, and the material preparation component is connected to the first inlet so that the powdered fuel made by the material preparation component can be introduced into the pressurizing component.

3. The ultra-low load flexible peak-shaving system for thermal power plants according to claim 1 is characterized in that: The pulverized coal conveying unit includes a mill and a first pipeline, wherein the first end of the first pipeline is connected to the mill, the second end of the first pipeline is connected to the boiler, the second end of the first pipeline is provided with a first nozzle, at least part of the first nozzle is placed in the boiler, there are multiple first pipelines, and the pressurizing assembly is connected to the mill and at least one of the multiple first pipelines.

4. The ultra-low load flexible peak-shaving system for thermal power plants according to claim 3 is characterized in that: The pressurizing component includes a pressure changing chamber and a pressurizing chamber connected in sequence, the pressure changing chamber is connected to the mill and at least one of the plurality of first pipelines, the pressurizing chamber is connected to the gasification component, the pressurizing chamber has a first air vent, and the first air vent is used to introduce inert gas so as to pass the coal powder in the pressurizing chamber into the gasification component.

5. The ultra-low load flexible peak-shaving system for thermal power plants according to claim 4 is characterized in that: The pressurizing assembly further includes a storage bin connected to the voltage transformation bin and located upstream of the voltage transformation bin.

6. The ultra-low load flexible peak-shaving system for thermal power plants according to claim 4 is characterized in that: The gasification component includes a gasifier and a second pipeline, the gasifier is connected to the pressurizing chamber, the first end of the second pipeline is connected to the gasifier, the second end of the second pipeline is connected to the boiler, and the second end of the second pipeline is provided with a second nozzle, and there are multiple second nozzles, and the multiple second nozzles correspond one-to-one to the multiple first nozzles.

7. The ultra-low load flexible peak-shaving system for a thermal power plant according to claim 6, characterized in that: The gasifier has a second air vent, and the second air vent is used for introducing oxygen and steam.

8. A method for flexible peak-shaving at ultra-low load in a thermal power plant, wherein the method is implemented by a flexible peak-shaving system for ultra-low load in a thermal power plant according to any one of claims 1 to 7, and is characterized in that: The following steps are involved: S1. Determine the boiler combustion state and coal powder delivery rate; S2. According to the combustion state and the coal powder delivery amount, part of the coal powder is introduced into the pressurizing component; S3, performing pressure transformation, pressurization and gasification treatment on the pulverized coal; S4. Use the second nozzle to spray the gasified coal gas into the boiler.

9. The ultra-low load flexible peak-shaving method for a thermal power plant according to claim 8, characterized in that: The following steps are also included: In step S2, the partial amount of pulverized coal is 5% to 20% of the pulverized coal conveying amount.

10. The ultra-low load flexible peak-shaving method for a thermal power plant according to claim 9, characterized in that: The following steps are also included: S5. Monitor the combustion state of the boiler in real time, and adjust the position and number of the second nozzles according to the temperature distribution in the furnace to make the temperature distribution in the boiler furnace uniform.

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