System and method for direct coupling blending combustion of biomass fuel in coal-fired power plant

Abstract

The invention provides a system and method for direct coupling and blending combustion of biomass fuel in a coal-fired power plant, and belongs to the field of biomass fuel utilization. Feeding the biomass fuel into a receiving bin; the biomass fuel is conveyed to a middle storage bin through a scraper; biomass fuel is conveyed to the three-way valve through the vibrating feeder and the bucket elevator; biomass fuel is distributed to the first self-sliding pipe or the second self-sliding pipe through the three-way valve; biomass fuel in the articulated chute is mixed with coal of the first coal conveying belt and the second coal conveying belt, and the first coal conveying belt and the second coal conveying belt convey the mixed fuel to different units or raw coal bins; and the coal plough is used for controlling the mixed fuel to enter the corresponding raw coal bunker for blending combustion. The system is high in feeding, conveying and blending combustion automation degree and high in flexibility, and blending combustion units, grinding units and the like can be selected according to needs.

Description

Technical Field

[0001] The present invention belongs to the field of biomass fuel utilization, and in particular relates to a system and method for directly coupling and blending biomass fuel in a coal-fired power plant. Background Art

[0002] Serious issues such as limited fossil energy reserves, environmental pollution during extraction, and greenhouse gas emissions from combustion have not only exacerbated the severity of global climate change, but have also compelled humanity to actively explore and develop cleaner, more sustainable energy solutions. Against this backdrop, biomass energy, as a highly promising renewable, low-carbon, and environmentally friendly energy source, has gradually emerged from among numerous renewable energy sources, garnering widespread attention and significant international attention.

[0003] Biomass pellet fuel, a key form of biomass energy utilization, is a high-density, high-energy-density solid fuel produced by processing abundant biomass raw materials (including but not limited to crop straw, forestry waste, municipal organic waste, and agricultural processing residues) through a series of advanced processes, including fine crushing, efficient compression, and precise molding. This fuel not only has a high calorific value and stable combustion, but is also easy to store and transport over long distances. This significantly expands its application scenarios, making it a valuable alternative to traditional fossil fuels such as coal and oil, and providing strong support for optimizing and adjusting the energy structure.

[0004] However, despite the important role biomass pellet fuel plays in energy transition, its actual use in power plants still faces a series of complex technical challenges. First, the reception, storage, transportation, and blending of biomass pellet fuel require a set of efficient, reliable, and adaptable equipment and technical systems to support it. Because the physical properties of biomass pellet fuel (such as shape, density, and moisture content) are significantly different from those of traditional fossil fuels, traditional fuel reception and transportation systems are often unable to directly meet their needs. Therefore, targeted modifications and optimizations are necessary to ensure the continuity and stability of fuel processing.

[0005] Secondly, the blending ratio and combustion method of biomass briquette fuel in power plants also pose a major technical challenge. To achieve optimal power generation efficiency and environmental performance, the blending ratio and combustion method of biomass briquette fuel with other fuels must be precisely controlled based on the specific characteristics of the biomass briquette fuel and the operational requirements of the power plant. This requires power generation companies to not only have advanced fuel management systems, but also extensive operational experience and a professional technical team to achieve refined management and optimization of the biomass briquette fuel utilization process.

[0006] Furthermore, the utilization of biomass pellet fuel requires comprehensive consideration of its safety and economic viability. Regarding safety, it is crucial to ensure that safety precautions are in place during fuel handling, storage, and transportation to prevent accidents such as fires and explosions. Regarding economic viability, technological innovation and cost control are crucial to reduce the costs of biomass pellet fuel preparation, transportation, and utilization, improve its market competitiveness, and ensure the stable operation and long-term benefits of the system.

[0007] In summary, the use of biomass pellet fuel in power plants is a complex system project involving multiple technologies and management. To address the above issues, we have proposed an innovative biomass pellet fuel transportation and delivery system technology solution. Summary of the Invention

[0008] The purpose of the present invention is to overcome the problem that the fuel blending ratio of traditional fuel receiving and delivery systems cannot be accurately controlled, resulting in low power generation efficiency, and to provide a system and method for directly coupling and burning biomass fuel in coal-fired power plants.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions: A system for directly coupling and co-firing biomass fuel in a coal-fired power plant includes a receiving bin, which is sequentially connected to a scraper, an intermediate storage bin, a vibrating feeder, and a bucket elevator. The outlet of the bucket elevator is connected to a three-way valve, the valve port of the three-way valve is connected to a first self-sliding pipe and a second self-sliding pipe, the first self-sliding pipe leads to a first coal conveyor belt, and the second self-sliding pipe leads to a second coal conveyor belt. A plurality of coal plows are distributed on the first and second coal conveyor belts, and two raw coal bins are installed on both sides of each coal plow.

[0010] An isolation valve is provided at the bottom of the intermediate storage bin to control the outflow of the biomass fuel.

[0011] The vibrating feeder and the bucket elevator are provided with a frequency converter for controlling the feeding speed of the vibrating feeder and the bucket elevator.

[0012] The frequency converter can adjust its operating speed according to a preset blending ratio.

[0013] The feeding output of the frequency converter is 0-50t / h.

[0014] The receiving bin is located below the ground, and the top of the receiving bin is flush with the ground.

[0015] The first coal conveyor belt and the second coal conveyor belt can operate independently or in parallel. All equipment can adapt to frequent start and stop, continuous or intermittent operation modes, and can meet the requirements of normal startup under full load conditions.

[0016] The scraper and bucket elevator are made of wear-resistant and corrosion-resistant materials, and the scraper, intermediate storage bin and bucket elevator all have good sealing properties.

[0017] A method for directly coupling and co-firing biomass fuel in a coal-fired power plant, the specific method is as follows: The biomass fuel is delivered to the receiving bin; the biomass fuel is delivered to the intermediate storage bin through a scraper; the biomass fuel is delivered to the three-way valve through a vibrating feeder and a bucket elevator; the biomass fuel is distributed to the first chute or the second chute through the three-way valve; the biomass fuel in the chute is mixed with the coal from the first coal conveyor belt and the second coal conveyor belt, and the first coal conveyor belt and the second coal conveyor belt deliver the mixed fuel to the corresponding raw coal bunker of the generator set; the mixed fuel is controlled by the coal plow to enter the corresponding raw coal bunker for blending and burning, and the generator set and raw coal bunker can be flexibly selected.

[0018] The start and stop of the vibrating feeder and bucket elevator are linked to the coal conveying belt: when the belt is started, the system begins to feed evenly, thereby achieving the purpose of even blending.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a system and method for directly coupling and co-firing biomass fuel in a coal-fired power plant, comprising a receiving bin, which is sequentially connected to a scraper, an intermediate storage bin, a vibrating feeder and a bucket elevator, an outlet of the bucket elevator being connected to a three-way valve, a valve port of the three-way valve being connected to a first self-flowing pipe and a second self-flowing pipe, the first self-flowing pipe being connected to a first coal conveying belt, the second self-flowing pipe being connected to a second coal conveying belt, a plurality of coal plows being distributed on the first coal conveying belt and the second coal conveying belt, and two raw coal bins being installed on both sides of each coal plow; biomass fuel is fed into the receiving bin; the biomass fuel is transported to the intermediate storage bin by the scraper; the biomass fuel is transported to the three-way valve by the vibrating feeder and the bucket elevator; the biomass fuel is distributed to the first self-flowing pipe or the second self-flowing pipe by the three-way valve; the biomass fuel in the self-flowing pipe is mixed with coal from the first coal conveying belt and the second coal conveying belt, and the first coal conveying belt and the second coal conveying belt transport the mixed fuel to different units or raw coal bins; and the mixed fuel is controlled by the coal plow to enter the corresponding raw coal bin for co-firing. The first chute connects to the first coal conveyor, and the second chute connects to the second coal conveyor. The biomass briquette is positioned after the coal conveyor's metering and sampling devices, eliminating any impact on the coal metering system. This improves blending accuracy and ensures power generation efficiency and environmental performance. This system features a high degree of automation for loading, conveying, and blending, offering strong flexibility, allowing for the selection of blending units and grinding groups as needed.

[0020] Furthermore, the vibrating feeder and bucket elevator are equipped with frequency converters, which can control the operating speed of the vibrating feeder and bucket elevator. The start and stop of the vibrating feeder and bucket elevator are linked to the coal conveyor belt: when the belt starts, the system begins to feed evenly, achieving precise blending of biomass fuel.

[0021] Furthermore, mixing biomass raw materials with coal to generate electricity reduces the production of carbon dioxide, which is of great significance to environmental protection.

[0022] Furthermore, the biomass fuel in the present invention is crushed reeds, straw, bamboo, wood, etc., which are compressed and formed (in block, column or granular form). Compared with directly blending raw materials, it is convenient to transport and directly blend, and the moisture is dried during the compression process, so the blending is highly economical.

[0023] Furthermore, the coal is directly fed into the pulverizer through the power plant's coal-fired belt for grinding and then enters the boiler for combustion. This requires minimal system equipment modification, saves investment, and allows for controllable blending ratios.

[0024] Furthermore, all equipment can adapt to frequent start and stop, continuous or intermittent operation modes, and can meet normal startup under full load conditions. They have high reliability and flexibility and can meet diverse work needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a system structure diagram of the present invention; Figure 2 This is a schematic diagram of the structure of the first self-flowing pipe and the second self-flowing pipe in the present invention.

[0027] Explanation of the reference numerals in the figure: 1. Receiving bin; 2. Scraper; 3. Intermediate storage bin; 4. Isolation valve; 5. Vibrating feeder; 6. Bucket elevator; 7. Three-way valve; 8. First automatic chute; 9. Second automatic chute; 10. First coal conveyor belt; 11. Second coal conveyor belt; 12. Coal plow; 13. Raw coal bin. DETAILED DESCRIPTION

[0028] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are 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 understood as limiting the present invention.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0031] In the present invention, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0032] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0033] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0034] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0035] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0036] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0037] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0038] Example 1 A system for directly coupling and co-firing biomass fuel in a coal-fired power plant has the following components: like Figures 1 and 2 As shown, a system for directly coupling and co-firing biomass fuel in a coal-fired power plant includes a receiving bin 1, which is connected to a scraper 2 and an intermediate storage bin 3 in sequence. An isolation valve 4 is provided at the bottom of the intermediate storage bin 3. The intermediate storage bin 3 is connected to a vibrating feeder 5, which transports the biomass fuel to a bucket elevator 6. A three-way valve 7 is provided at the outlet of the bucket elevator 6. The outlet of the three-way valve 7 is connected to a first self-sliding pipe 8 and a second self-sliding pipe 9, respectively. The first self-sliding pipe 8 is connected to a first coal conveying belt 10, and the second self-sliding pipe 9 is connected to a second coal conveying belt 11. A plurality of coal plows 12 are installed on the first coal conveying belt 10 and the second coal conveying belt 11, and each coal plow 12 corresponds to two raw coal bins 13 on both sides.

[0039] The receiving silo 1 is preferably located below ground level, with its inlet flush with the ground at the beginning of the system. It is designed with ample capacity to accommodate large quantities of biomass fuel delivered by truck or other means of transportation. The inlet design of the receiving silo 1 facilitates quick and safe unloading of biomass fuel, while its internal structure ensures that the biomass fuel will not spontaneously combust or deteriorate due to accumulation.

[0040] Preferably, the scraper 2 is made of wear-resistant and corrosion-resistant materials to ensure that the biomass fuel will not be contaminated or lost during the transportation process. It operates stably and can continuously and evenly transport the biomass fuel in the receiving bin 1 to the intermediate storage bin 3.

[0041] Preferably, the isolation valve 4 provided at the bottom of the intermediate storage bin 3 can flexibly control the outflow of the biomass fuel, ensuring that the biomass fuel can be supplied quickly and accurately when needed.

[0042] Preferably, the vibrating feeder 5 delivers the biomass fuel uniformly and continuously to the bucket elevator 6 through vibration. The design of the vibrating feeder 5 takes into account the characteristics of the biomass fuel and the delivery requirements, ensuring that the biomass fuel will not be blocked or lost during the delivery process.

[0043] Preferably, the vibrating feeder 5 and the bucket elevator 6 are both equipped with a frequency converter, which can control the operating speed of the vibrating feeder 5 and the bucket elevator 6 to achieve accurate blending of the biomass fuel.

[0044] Preferably, the first coal conveyor belt 10 and the second coal conveyor belt 11 can operate independently or in parallel, and are responsible for conveying the mixed fuel to different units or raw coal bins 13. The design of the coal conveyor belts takes into account wear resistance, corrosion resistance, and anti-slip properties to ensure that no fuel loss or contamination occurs during the conveying process.

[0045] Preferably, the coal plow 12 is mounted on the coal conveyor belt, and controls the fuel to enter the corresponding raw coal bin 13 by lifting or lowering. The design of the coal plow 12 takes into account the characteristics and transportation requirements of the fuel, and can ensure accurate blending and distribution of the fuel during the co-firing process.

[0046] Example 2 A system for directly coupling and co-firing biomass fuel in a coal-fired power plant, the method of use of which is as follows: First, the biomass fuel is delivered to the receiving bin 1 by car or other means of transportation. The biomass fuel in the receiving bin 1 is continuously and evenly transported to the intermediate storage bin 3 for temporary storage via a scraper 2. When the biomass fuel in the intermediate storage bin 3 reaches a certain amount, the isolation valve 4 is opened, and the biomass fuel is evenly and continuously transported to the bucket elevator 6 via a vibrating feeder 5. The bucket elevator 6 lifts the biomass fuel to a certain height and then distributes it via a three-way valve 7. Based on the requirements for blending, the outlet direction of the three-way valve 7 is flexibly adjusted so that the biomass fuel enters the first and second self-flowing pipes 8 and 9 respectively. The biomass fuel flows into the first and second coal conveyor belts 10 and 11 through self-flow, and is mixed with the coal on the coal conveyor belts. The coal conveyor belts operate in parallel or individually according to the requirements of the unit or raw coal bin 13, and the mixed fuel is transported to the corresponding raw coal bin 13 of the generator unit. During the operation of the coal conveyor belts, the fuel is controlled to enter the corresponding raw coal bin 13 by raising or lowering the coal plow 12. The mixed fuel in the raw coal bunker 13 is ground by a coal mill and then mixed and burned. The generator set and the raw coal bunker 13 can be flexibly selected.

[0047] Preferably, the vibrating feeder 5 and bucket elevator 6 are both equipped with frequency converters to achieve an adjustable biomass fuel feeding output of 0-50 t / h. The total capacity of the receiving bin and intermediate storage bin meets the system's maximum hourly output requirements.

[0048] Preferably, the start and stop of the vibrating feeder 5 and bucket elevator 6 are linked to the coal conveyor belt: when the belt starts, the system begins feeding evenly, achieving uniform blending. The blending ratio and the unit to which the blend enters can be controlled by the logic of start and stop and corresponding speed.

[0049] The coal and biomass fuel transported by the coal conveyor belt is controlled by raising or lowering the coal plow 12 (corresponding to each pulverizer's raw coal bunker 13) to enter the corresponding raw coal bunker and, in turn, to one or more corresponding pulverizers. This ensures the safety of the pulverizers and maximizes the economic benefits of co-firing.

[0050] Preferably, all equipment can adapt to frequent start and stop, continuous or intermittent operation modes, and can meet the requirements of normal startup under full load.

[0051] Finally, it should be noted that the above embodiments merely illustrate the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description. It is intended that all variations within the meaning and range of equivalents of the claims be encompassed within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0052] In addition, it should be understood that although this specification describes the embodiments, not every embodiment contains only one independent technical solution. This description is for clarity only. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for the purpose of illustrating the technical concept of the present invention and cannot be used to limit the scope of protection of the present invention. Any changes made based on the technical solution in accordance with the technical concept proposed by the present invention fall within the scope of protection of the claims of the present invention.

Claims

1. A system for directly coupling and co-firing biomass fuel in a coal-fired power plant, characterized in that: The invention comprises a receiving bin (1), wherein the receiving bin (1) is connected to a scraper (2), an intermediate storage bin (3), a vibrating feeder (5) and a bucket elevator (6) in sequence, wherein the outlet of the bucket elevator (6) is connected to a three-way valve (7), wherein the valve port of the three-way valve (7) is connected to a first self-sliding pipe (8) and a second self-sliding pipe (9), wherein the first self-sliding pipe (8) is connected to a first coal conveying belt (10), and the second self-sliding pipe (9) is connected to a second coal conveying belt (11), wherein a plurality of coal plows (12) are distributed on the first coal conveying belt (10) and the second coal conveying belt (11), and wherein two raw coal bins (13) are installed on both sides of each coal plow (12).

2. A system for direct coupling and co-firing biomass fuel in a coal-fired power plant according to claim 1, characterized in that: An isolation valve (4) is provided at the bottom of the intermediate storage bin (3) for controlling the outflow of the biomass fuel.

3. A system for direct coupling and co-firing biomass fuel in a coal-fired power plant according to claim 1, characterized in that: The vibrating feeder (5) and the bucket elevator (6) are provided with frequency converters for controlling the feeding speeds of the vibrating feeder (5) and the bucket elevator (6).

4. A system for direct coupling and co-firing biomass fuel in a coal-fired power plant according to claim 3, characterized in that: The frequency converter can adjust its operating speed according to a preset blending ratio.

5. A system for direct coupling and co-firing biomass fuel in a coal-fired power plant according to claim 3, characterized in that: The feeding output of the frequency converter is 0-50t / h.

6. A system for direct coupling and co-firing biomass fuel in a coal-fired power plant according to claim 1, characterized in that: The receiving bin (1) is located below the ground, and the top of the receiving bin (1) is flush with the ground.

7. A system for direct coupling and co-firing biomass fuel in a coal-fired power plant according to claim 1, characterized in that: The first coal conveying belt (10) and the second coal conveying belt (11) are capable of operating independently or in parallel; All equipment can adapt to frequent start and stop, continuous or intermittent operation, and can meet the requirements of normal start-up under full load.

8. A system for direct coupling and co-firing biomass fuel in a coal-fired power plant according to claim 1, characterized in that: The scraper (2) and bucket elevator (6) are made of wear-resistant and corrosion-resistant materials, and the scraper (2), the intermediate storage bin (3) and the bucket elevator (6) all have good sealing properties.

9. A method for direct coupling and co-firing biomass fuel in a coal-fired power plant as claimed in claims 1 to 8, characterized in that: The specific method is as follows: The biomass fuel is fed into a receiving bin (1); the biomass fuel is transported to an intermediate storage bin (3) by a scraper (2); the biomass fuel is transported to a three-way valve (7) by a vibrating feeder (5) and a bucket elevator (6); the biomass fuel is distributed to a first self-flowing pipe (8) or a second self-flowing pipe (9) by the three-way valve (7); the biomass fuel in the self-flowing pipe is mixed with coal from a first coal conveying belt (10) and a second coal conveying belt (11); the first coal conveying belt (10) and the second coal conveying belt (11) transport the mixed fuel to a corresponding raw coal bin (13) of a generator set; the mixed fuel is controlled to enter a corresponding raw coal bin (13) for blending and burning by a coal plow (12); the generator set and the raw coal bin (13) can be flexibly selected.

10. A method for direct coupling and co-firing biomass fuel in a coal-fired power plant according to claim 9, characterized in that: The start and stop of the vibrating feeder (5) and the bucket elevator (6) are interlocked with the coal conveying belt: when the belt is started, the system starts to feed evenly, thereby achieving the purpose of even blending.

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