Screening system for coal-fired unit coupling biomass power generation system

Abstract

The invention relates to the field of biomass-fire coal coupling generator sets. The screening system comprises mixing equipment arranged on one side of an inlet of a combustion furnace, a biomass crushing bin, a fire coal crushing bin, a uniform mixing assembly and a humidity measuring assembly, wherein the biomass crushing bin and the fire coal crushing bin are arranged at an inlet of the mixing equipment, the uniform mixing assembly is arranged in the mixing equipment, and the humidity measuring assembly is arranged in the mixing equipment. A shear type crushing roller is arranged in the biomass crushing bin, a hammer type crushing roller is arranged in the fire coal crushing bin, the uniform mixing assembly comprises a biomass uniform mixing piece and a fire coal particle uniform mixing piece, the rotating speed of the biomass uniform mixing piece and the rotating speed of the fire coal particle uniform mixing piece are independently adjusted, and the mixing device comprises a barrel and is internally provided with a partition plate which divides the mixing device into a biomass bin and a fire coal bin. The biomass crushing bin is communicated with the biomass bin, the fire coal crushing bin is communicated with the fire coal bin, and a uniform mixing bin is arranged on the bottom side of the mixing equipment. The biomass fuel and the fire coal are fully mixed, and the particle sizes are kept consistent, so that the problem of insufficient and uniform combustion is solved.

Description

Technical Field

[0001] This application relates to the field of power generation screening systems, and in particular to a screening system used in a coal-fired power unit coupled with a biomass power generation system. Background Technology

[0002] Currently, conventional coal-fired power plants utilize the heat energy from coal combustion to heat water, generating high-temperature, high-pressure steam that drives a turbine to produce electricity. However, conventional coal-fired power generation is costly and highly susceptible to fluctuations in the coal market. Therefore, the common coupling methods between biomass and coal-fired power plants fall into two categories. The first involves converting biomass into combustible gas and mixing it with coal for combustion, using a coal-fired boiler and turbine system to generate electricity. The second method is direct co-firing, where biomass is directly crushed and mixed with coal in a specific ratio to form a blended fuel. This blended fuel is then injected into the furnace through a burner for combustion. The high-temperature combustion heats the boiler's water-cooled walls, generating high-temperature, high-pressure steam that drives the turbine to produce electricity.

[0003] Since gasification coupling involves multiple stages such as gasification, purification, and transportation, the equipment is relatively complex. In contrast, direct co-firing only requires biomass pretreatment to a particle size that matches the coal powder, which has a lower technical threshold and requires less modification and lower cost compared to existing coal-fired units. Therefore, existing technologies often use biomass pre-combustion and direct co-firing for coupled power generation.

[0004] Because biomass raw materials are prone to contain impurities such as stones and metals, and coal may contain incompletely crushed particles, these can easily damage combustion equipment or affect combustion efficiency during co-firing. In addition, when the particle size of biomass fuel and coal is inconsistent, the uneven particle size can easily cause differences in combustion speed, resulting in an unstable combustion process. Therefore, when crushing and mixing biomass raw materials and coal, it is necessary to maintain uniform mixing and consistent particle size. Summary of the Invention

[0005] In order to ensure that biomass fuel and coal are fully mixed and have a consistent particle size, thereby solving the problem of incomplete and uneven combustion, this application provides a screening system for a coal-fired power unit coupled with a biomass power generation system.

[0006] This application provides a screening system for a coal-fired power unit coupled with a biomass power generation system, which adopts the following technical solution: A screening system for a coal-fired power unit coupled with a biomass power generation system includes a mixing device located at the inlet of the combustion furnace, a biomass crushing chamber and a coal crushing chamber located at the inlet of the mixing device, a mixing and homogenizing component located within the mixing device, and a moisture measuring component located within the mixing device. The biomass crushing chamber is equipped with a scissor-type crushing roller, and the coal crushing chamber is equipped with a hammer crushing roller. The mixing and homogenizing component includes a biomass mixing element with independently adjustable rotation speed and a coal particle mixing element. The mixing device includes a cylinder, and a partition is provided inside the mixing device to divide the mixing device into a biomass chamber and a coal chamber. The biomass crushing chamber is connected to the biomass chamber, and the coal crushing chamber is connected to the coal chamber. A mixing chamber is located on the bottom side of the mixing device. The biomass crushing chamber has a first feed inlet on its bottom side that communicates with the mixing chamber, and the coal crushing chamber has a second feed inlet on its bottom side that communicates with the mixing chamber. A first sealing plate is movably installed at the first feed inlet, and a second sealing plate is movably installed at the second feed inlet. The biomass crushing chamber is equipped with an adjusting component for adjusting the first sealing plate. After the testing component detects the moisture content of the biomass pellets in the biomass crushing chamber, it adjusts the opening size of the first feed inlet through the adjusting component. The coal pellet mixing component includes a first stirring rod rotatably disposed within the coal bunker and a first stirring blade disposed on the first stirring rod; the biomass mixing component includes a second stirring rod rotatably disposed within the biomass bunker and a second stirring blade disposed on the second stirring rod. The mixing chamber is also equipped with a third stirring rod, as well as horizontal and vertical stirring blades mounted on the third stirring rod. The vertical stirring blades are periodically slidably mounted on the third stirring rod, and the sliding period of the vertical stirring blades is related to the opening size of the first feed inlet.

[0007] By adopting the above technical solution, when mixing biomass fuel pellets and coal pellets, since the biomass fuel pellets are usually larger in size than the coal pellets and the coal pellets are usually uneven in size, and considering the hardness of the biomass fuel pellets and coal pellets, a shear crusher is used to crush the biomass fuel pellets and a hammer crusher is used to crush the coal pellets, thereby achieving separate crushing of biomass fuel pellets and coal pellets.

[0008] Then, the crushed biomass fuel and coal are temporarily stored in the set biomass bins and coal bins. The crushed particles are further dispersed by the set biomass mixing device and coal particle mixing device, thereby reducing the agglomeration generated during crushing and rolling, which affects the subsequent mixing performance and combustion performance.

[0009] Meanwhile, the humidity of the biomass pellets in the biomass bin is detected by the set humidity measuring components and adjustment components, thereby adjusting the size of the first feed inlet to achieve different ratios. Since the moisture content of the biomass pellets is higher than 10% when leaving the factory, the ratio of biomass pellets to coal pellets is 1:2 when the moisture content is between 10% and 15%. As the moisture content gradually increases, more coal is needed to provide heat to evaporate the moisture in high-moisture biomass. Therefore, the higher the moisture content, the lower the proportion of biomass pellets.

[0010] Meanwhile, the higher the moisture content of biomass pellets, the more likely fiber entanglement will occur during conventional mixing, which can easily lead to uneven mixing or clumping. Therefore, it is necessary to cut and disperse the mixture vertically during mixing. By correlating the sliding cycle of the vertical mixing blades with the opening size of the first feed inlet, the uniformity and consistency of the mixing of biomass pellets and coal pellets can be improved, thereby ensuring the uniformity and stability of subsequent combustion.

[0011] Optionally, the moisture measuring component includes a moisture measuring blade rotatably mounted on the first stirring blade, the moisture measuring blade being in active contact with the biomass pellet, an elastic recovery element being provided at the pivot of the measuring blade, a torque sensor being provided at the pivot of the moisture measuring blade, and the first stirring rod and the second stirring rod rotating at the same speed.

[0012] By adopting the above technical solution, the rotation speeds of the first and second stirring rods are set to be consistent, ensuring that the degree of dispersion of biomass pellets and coal pellets is consistent. Furthermore, by using rotating moisture-measuring blades that protrude from the first stirring blades, higher moisture content biomass exerts greater resistance on the moisture-measuring blades during the dispersion process, resulting in a larger value from the torque sensor. This facilitates simple and intuitive detection of the moisture content of biomass pellets, reducing the complexity of conventional drying methods and improving mixing efficiency. Simultaneously, by correlating the moisture content with the opening size of the first feed inlet, the mixing ratio of subsequent biomass fuel pellets and coal pellets can be adjusted to improve subsequent combustion performance.

[0013] Optionally, a rotating lead screw is rotatably provided inside the third stirring rod, and an adjusting nut is provided on the vertical stirring blade. The adjusting nut is threaded onto the rotating lead screw. The speed of the rotating lead screw is related to the opening size of the first inlet, and the rotation direction of the rotating lead screw is opposite to the rotation direction of the transverse stirring blade. The larger the opening of the first feed inlet, the slower the rotation speed of the rotating screw. The smaller the opening of the first feed inlet, the faster the rotation speed of the rotating screw.

[0014] By adopting the above technical solution, since the rotation direction of the rotating screw is opposite to that of the transverse stirring blades, that is, the rotation direction of the rotating screw is opposite to that of the third stirring rod, the faster the rotation speed of the rotating screw, the shorter the sliding period of the vertical stirring blades, and the faster the cutting efficiency. The slower the rotation speed of the rotating screw, the longer the sliding period of the vertical stirring blades, and the worse the cutting efficiency. The reason why a constant cutting efficiency is not used to cut biomass fuel pellets is that when the moisture content of biomass pellets is low, excessive cutting will produce more fly ash during biomass pellet cutting, which is easy to clog the combustion equipment and shorten the maintenance and repair cycle of the combustion equipment. At the same time, excessive stirring and cutting can easily cut the fibers, making it difficult to maintain a stable flame during fuel combustion, and even easily causing local overheating or incomplete combustion.

[0015] Optionally, multiple sets of the first feed inlet are provided, and the multiple sets of the first feed inlet are arranged at intervals along the radial direction of the mixing device. The adjusting component includes a first blocking block provided on the first blocking plate. Multiple sets of first communication ports corresponding one-to-one with the first feed inlet are provided on the first blocking plate. A first adjusting block is provided on the first blocking plate. A second adjusting block is provided inside the mixing device. The first adjusting block and the second adjusting block are movably fitted and pressed together. The mixing device is also provided with a rotating component for adjusting the rotation speed of the rotating screw.

[0016] By adopting the above technical solution, the multiple sets of first feed inlets facilitate the feeding of biomass pellets. At the same time, the size of the multiple first feed inlets can be adjusted by the first sealing plate, thereby adjusting the size of the biomass pellets fed. The first sealing plate can be slidably adjusted by the first adjusting block and the second adjusting block. Since the side of the first adjusting block and the second adjusting block that are in contact with each other is inclined, the first adjusting block drives the first sealing plate to slide when the second adjusting block is adjusted.

[0017] Optionally, the rotating component includes a first adjusting wheel coaxially arranged with the first stirring rod and a second adjusting wheel coaxially arranged with the rotating lead screw. A transmission belt is driven between the first adjusting wheel and the second adjusting wheel. Both the first adjusting wheel and the second adjusting wheel are in the form of conical wheels, and the transmission belt is driven in different areas of the first adjusting wheel and the second adjusting wheel, thereby realizing the speed adjustment of the rotating lead screw.

[0018] By adopting the above technical solution, the first adjusting wheel is coaxially arranged with the first stirring rod, and the second adjusting wheel is coaxially arranged with the rotating screw, and connected by a transmission belt. This cleverly utilizes the rotation of the first stirring rod to drive the rotation of the rotating screw, achieving a combination of power transmission and speed regulation. The conical wheel design and the transmission belt's operation in different areas allow for convenient adjustment of the rotating screw's speed by changing the position of the transmission belt on the conical wheel. This adjustment method is simple and reliable, and can flexibly adjust the rotating screw's speed according to changes in parameters such as the moisture content of the biomass pellets. This, in turn, controls the sliding cycle of the vertical mixing blades to adapt to different cutting and dispersing requirements when mixing biomass pellets with coal pellets of varying moisture content, effectively improving the mixing quality.

[0019] Optionally, the mixing device includes a linear power component for sliding adjustment of the second adjusting block, a clamping rod on the second adjusting block for clamping the transmission belt, and a controller electrically connected to the torque sensor and the linear power component.

[0020] By adopting the above technical solution, the linear actuator can precisely control the sliding of the second adjusting block, thereby driving the clamping rod to adjust the position of the transmission belt and achieving precise adjustment of the rotational screw speed. The controller, torque sensor, and linear actuator are electrically connected to form an automatic control system. The torque sensor detects the resistance of the moisture-measuring blade in real time and transmits the signal to the controller. The controller, based on a preset program and algorithm, determines the moisture content of the biomass pellets and then controls the linear actuator to adjust the position of the second adjusting block, thereby changing the position of the transmission belt on the conical pulley and achieving automatic adjustment of the rotational screw speed. This automated control method greatly improves the system's intelligence and response speed, enabling rapid and accurate adjustment of mixing parameters based on real-time changes in the moisture content of the biomass pellets. This ensures that the biomass pellets and coal pellets are always in the optimal mixing state, improving the overall efficiency and stability of the screening system.

[0021] Optionally, the second stirring rod is coaxially provided with a first moving wheel, and the third stirring rod is coaxially provided with a second moving wheel, wherein the first moving wheel and the second moving wheel are connected in a driving connection.

[0022] By adopting the above technical solution, the second and third stirring rods can rotate synchronously through the transmission connection between the first and second moving wheels. This synchronous rotation design ensures that the dispersion and mixing process of biomass pellets in the biomass bin and the mixing and dispersion process in the blending bin are coordinated and synchronized. This helps maintain a consistent processing rhythm for biomass pellets at different stages, avoiding over- or under-processing of some biomass pellets due to inconsistent stirring speeds. Simultaneously, this transmission connection method is compact and highly efficient, stably transmitting power from the second to the third stirring rod, ensuring stable movement of the biomass pellets throughout the mixing process, thereby improving the uniformity and consistency of the mixing of biomass pellets and coal pellets.

[0023] Optionally, a limiting groove is provided on the third stirring rod, and the vertical stirring blade is slidably disposed in the limiting groove. The rotating screw is provided with a bidirectional thread corresponding to the position of each vertical stirring blade.

[0024] By adopting the above technical solution, the limiting groove limits the sliding of the vertical mixing blades, ensuring that the blades can only slide up and down within a specified range. This prevents the blades from shifting or wobbling during sliding, ensuring the accuracy and stability of the cutting and dispersing action. The bidirectional thread on the rotating screw, corresponding to the position of each vertical mixing blade, allows the blades to reciprocate up and down along the thread when the screw rotates. This bidirectional thread design makes the sliding of the vertical mixing blades smoother and more stable, effectively cutting and dispersing biomass and coal particles vertically. Furthermore, by controlling the rotation speed and direction of the rotating screw, the sliding cycle and cutting intensity of the vertical mixing blades can be flexibly adjusted to meet the special requirements of mixing biomass and coal particles with different moisture contents, further improving the mixing effect and combustion performance.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. The rotation speeds of the first and second stirring rods are set to be the same to ensure consistent dispersion of biomass pellets and coal pellets. By rotating the moisture-measuring blades, the first stirring blades are positioned higher. During the dispersion of biomass pellets, biomass with higher moisture content exhibits greater resistance to the moisture-measuring blades, resulting in a higher value from the torque sensor. This facilitates simple and intuitive detection of the moisture content of biomass pellets, reducing the complexity of conventional drying methods and improving mixing efficiency. Furthermore, by correlating the moisture content with the opening size of the first feed inlet, the mixing ratio of subsequent biomass fuel pellets and coal pellets can be adjusted to improve subsequent combustion performance.

[0026] 2. By setting up moisture measuring components and adjusting parts, the humidity of biomass pellets in the biomass bin is detected, thereby adjusting the size of the first feed inlet to achieve different ratios. Since the moisture content of biomass pellets at the time of leaving the factory is higher than 10%, when the moisture content is between 10% and 15%, the ratio of biomass pellets to coal pellets is 1:2. As the moisture content gradually increases, since high moisture content biomass requires more coal to provide heat to evaporate the moisture, the higher the moisture content, the lower the proportion of biomass pellets.

[0027] 3. The limiting groove provides precise guidance for the sliding of the vertical mixing blades, ensuring that the blades can only slide up and down within a specified range. This prevents blade offset or wobbling during sliding, guaranteeing the accuracy and stability of the cutting and dispersing action. The bidirectional thread on the rotating screw, corresponding to the position of each vertical mixing blade, allows the blades to reciprocate up and down along the thread when the screw rotates. This bidirectional thread design makes the sliding of the vertical mixing blades smoother and more stable, effectively cutting and dispersing biomass and coal particles vertically. Furthermore, by controlling the rotation speed and direction of the rotating screw, the sliding cycle and cutting intensity of the vertical mixing blades can be flexibly adjusted to meet the specific requirements of mixing biomass and coal particles with different moisture contents, further improving the mixing effect and combustion performance. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the overall structure of a screening system used in a coal-fired power unit coupled with a biomass power generation system according to this application.

[0030] Figure 2 This is a schematic diagram of the connection structure of the mixing device in this application.

[0031] Figure 3 This is a schematic diagram of the connection structure of the adjusting component and the rotating component in this application.

[0032] Figure 4 This is a schematic diagram of the internal structure of the mixing device in this application.

[0033] Reference numerals: 1. Mixing equipment; 11. Biomass crushing bin; 111. Shear crushing roller; 12. Coal crushing bin; 121. Hammer crushing roller; 13. Baffle plate; 14. Biomass bin; 15. Coal bin; 16. First feed inlet; 17. Second feed inlet; 18. First sealing plate; 19. Second sealing plate; 2. Mixing assembly; 21. Biomass mixing component; 211. Second stirring rod; 212. Second stirring blade; 22. Coal particle mixing component; 221. First stirring rod; 222. First stirring blade 23. Horizontal stirring blade; 24. Vertical stirring blade; 25. Third stirring rod; 26. Limiting groove; 3. Moisture measuring component; 31. Moisture measuring blade; 32. Elastic recovery component; 33. Torque sensor; 4. Rotating screw; 41. Adjusting nut; 5. Adjusting component; 51. First sealing block; 52. First connecting port; 53. First adjusting block; 54. Second adjusting block; 6. Rotating component; 61. First adjusting wheel; 62. Second adjusting wheel; 63. Transmission belt; 64. Linear power component; 65. Clamping rod. Detailed Implementation

[0034] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail below.

[0035] This application discloses a screening system used in a coal-fired power unit coupled with a biomass power generation system.

[0036] Reference Figure 1 A screening system for a coal-fired power unit coupled with a biomass power generation system includes a mixing device integrally installed on one side of the combustion furnace inlet. This mixing device has a cylindrical structure, with partitions inside dividing it into a biomass bin and a coal bin, providing independent temporary storage spaces for biomass fuel and coal. At the inlet of the mixing device, a biomass crushing bin and a coal crushing bin are respectively installed. The biomass crushing bin is equipped with a scissor crusher, and the coal crushing bin is equipped with a hammer crusher. Since biomass fuel particles are typically larger than coal particles, and coal particles are non-uniform in size, and considering the difference in hardness between the two, the scissor crusher is better suited to the characteristics of biomass fuel particles, achieving effective crushing; the hammer crusher is used to crush coal particles, thus achieving separate crushing of biomass fuel particles and coal particles, providing raw materials of suitable particle size for subsequent mixing.

[0037] A mixing assembly is provided within the mixing equipment, including a biomass mixing component and a coal pellet mixing component. The coal pellet mixing component includes a first stirring rod rotatably disposed within the coal bunker and first stirring blades fixed to the first stirring rod. The rotation axis of the first stirring rod is aligned with the height direction of the mixing equipment. Multiple sets of first stirring blades are provided, and these multiple sets of first stirring blades are spaced apart along the height direction of the first stirring rod.

[0038] The biomass mixing unit includes a second stirring rod rotatably disposed inside the biomass bin and a second stirring blade disposed on the second stirring rod. The rotation axis of the second stirring rod is also consistent with that of the first stirring rod. The second stirring blade is also provided in multiple sets, just like the first stirring blade. The multiple sets of second stirring blades are also evenly distributed at intervals along the height direction of the second stirring rod.

[0039] The rotational speeds of the first and second stirring rods can be synchronized or adjusted independently by the two motors. Synchronous adjustment solves the power source problem, while the independent speed adjustment design can further disperse the crushed biomass fuel and coal particles, effectively reducing the agglomeration phenomenon generated during crushing and rolling, avoiding agglomeration from affecting subsequent mixing and combustion performance, and ensuring that the two types of particles achieve a good dispersion state in their respective chambers. In this application, the independent speed adjustment method is adopted to save power source.

[0040] Simultaneously, a moisture measuring component is installed within the mixing equipment. The moisture measuring blades of this component are rotatably mounted on the first stirring blade, moving in close contact with the biomass pellets. An elastic return element and a torque sensor are located at the rotating shaft of the moisture measuring blades, and the rotational speeds of the first and second stirring rods are set to be the same. This design ensures consistent dispersion of the biomass pellets and coal pellets. During the dispersion process, biomass with higher moisture content exerts greater resistance on the moisture measuring blades, resulting in a higher value detected by the torque sensor. This allows for simple and intuitive detection of the biomass pellet's moisture content, significantly improving mixing efficiency compared to the complex process of conventional drying methods for moisture content detection.

[0041] A first feed inlet, connected to the mixing chamber, is located on the bottom side of the biomass silo, while a second feed inlet, also connected to the mixing chamber, is located on the bottom side of the coal silo. A first sealing plate is movably installed at the first feed inlet, and a second sealing plate is movably installed at the second feed inlet. An adjusting element for adjusting the first sealing plates is installed inside the biomass crushing silo. Multiple sets of first feed inlets are spaced apart along the radius of the mixing equipment. The adjusting element includes a first sealing block mounted on the first sealing plate. The first sealing plate has multiple sets of first connecting openings corresponding one-to-one with the first feed inlets. A first adjusting block is installed on the first sealing plate, and a second adjusting block is installed inside the mixing equipment. The first and second adjusting blocks are movably fitted and pressed together. This design allows for more flexible and precise control of the flow rate of biomass particles entering the mixing chamber, based on the actual conditions of the biomass particles at different locations within the biomass crushing silo, such as moisture content and particle size characteristics in different areas. This lays the foundation for subsequent rational proportioning and uniform mixing.

[0042] After the moisture measuring component detects the moisture content of the biomass pellets in the biomass crushing chamber, the opening size of the first feed inlet is adjusted via the regulating component. Since the biomass pellets have a moisture content higher than 10% when they leave the factory, the ratio of biomass pellets to coal pellets is 1:2 when the moisture content is between 10% and 15%. As the moisture content gradually increases, higher moisture content biomass requires more coal to provide heat for evaporating the moisture; therefore, the higher the moisture content, the lower the proportion of biomass pellets. Therefore, based on the detected moisture content information, the size of the first feed inlet is precisely adjusted to achieve different ratios, thereby improving subsequent combustion performance.

[0043] A mixing chamber is located at the bottom of the mixing device. A third stirring rod rotates within the mixing chamber, and this third stirring rod has both horizontal and vertical stirring blades. A rotating screw rotates within the third stirring rod. An adjusting nut is attached to the vertical stirring blade, threaded onto the rotating screw. The vertical stirring blade slides periodically on the third stirring rod, and its sliding period is related to the size of the first inlet opening. The speed of the rotating screw is also related to the size of the first inlet opening, and the rotation direction of the rotating screw is opposite to that of the horizontal stirring blades. A larger opening in the first inlet results in a slower rotating screw speed; conversely, a smaller opening results in a faster rotating screw speed. This is because the rotating screw rotates in the opposite direction to the horizontal stirring blades, and vice versa. A faster rotating screw speed results in a shorter sliding period for the vertical stirring blades, leading to higher cutting efficiency; conversely, a slower rotating screw speed results in a longer sliding period for the vertical stirring blades, leading to lower cutting efficiency. When the moisture content of biomass pellets is low, over-cutting will produce more fly ash, which can easily clog combustion equipment and shorten maintenance cycles. Furthermore, excessive agitation and cutting can break fibers, making it difficult to maintain a stable flame during fuel combustion, and may even lead to localized overheating or incomplete combustion. Therefore, this design, which adjusts the cutting efficiency based on moisture content, effectively avoids these problems and improves mixing quality and combustion performance.

[0044] To achieve automatic adjustment of the screw rotation speed, a rotating component is installed inside the mixing chamber. This rotating component includes a first adjusting wheel coaxially mounted with the first stirring rod and a second adjusting wheel coaxially mounted with the screw rotation. A transmission belt connects the first and second adjusting wheels, both of which are conical pulleys, and the transmission belt operates in different areas of the first and second adjusting wheels. By changing the position of the transmission belt on the conical pulleys, the screw rotation speed can be easily adjusted. A linear motion component is installed within the mixing equipment to slide and adjust the second adjusting block. The second adjusting block has a clamping rod that clamps the transmission belt. A controller is also installed within the mixing equipment, electrically connected to a torque sensor and the linear motion component. The torque sensor detects the resistance experienced by the moisture-sensing blades in real time and transmits the signal to the controller. The controller, based on a preset program and algorithm, determines the moisture content of the biomass pellets and then controls the linear motion component to adjust the position of the second adjusting block, thereby changing the position of the transmission belt on the conical pulleys and achieving automatic adjustment of the screw rotation speed. This automated control method greatly improves the system's intelligence and response speed, enabling it to quickly and accurately adjust mixing parameters based on real-time changes in the moisture content of biomass pellets, ensuring that biomass pellets and coal pellets are always in the optimal mixing state.

[0045] Furthermore, a first coaxially rotating wheel is mounted on the second stirring rod, and a second coaxially rotating wheel is mounted on the third stirring rod, with the first and second coaxially rotating wheels connected by a transmission. This synchronous rotation design ensures that the dispersion and mixing process of biomass pellets in the biomass bin is coordinated and synchronized with the mixing and dispersion process in the blending bin. This helps maintain a consistent processing rhythm for the biomass pellets at different stages, avoiding over- or under-processing of some biomass pellets. Simultaneously, this transmission connection method is compact and highly efficient, stably transmitting power from the second stirring rod to the third stirring rod, ensuring stable movement of the biomass pellets throughout the mixing process. A limiting groove is provided on the third stirring rod, within which the vertical stirring blades slide. The rotating screw has a bidirectional thread corresponding to the position of each vertical stirring blade. The limiting groove provides precise guidance for the sliding of the vertical mixing blades, ensuring accurate and stable sliding of the blades and avoiding deviation or shaking; the bidirectional thread design allows the vertical mixing blades to reciprocate up and down along the bidirectional thread when the rotating screw rotates, making the sliding more stable and smooth, and effectively cutting and dispersing biomass pellets and coal pellets vertically, further improving the mixing effect and combustion performance.

[0046] The above are all optional embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A screening system for a coal-fired power plant coupled with a biomass power generation system, characterized in that: The system includes a mixing device located on one side of the inlet of the combustion furnace, a biomass crushing chamber and a coal crushing chamber located at the inlet of the mixing device, a mixing and homogenizing component located within the mixing device, and a moisture measuring component located within the mixing device. The biomass crushing chamber is equipped with a shear crushing roller, and the coal crushing chamber is equipped with a hammer crushing roller. The mixing and homogenizing component includes a biomass mixing element with independently adjustable rotation speed and a coal particle mixing element. The mixing device includes a cylinder, and a partition is provided inside the mixing device to divide the mixing device into a biomass chamber and a coal chamber. The biomass crushing chamber is connected to the biomass chamber, and the coal crushing chamber is connected to the coal chamber. A mixing chamber is located on the bottom side of the mixing device. The biomass bin has a first feed inlet connected to the mixing bin on its bottom side, and the coal bin has a second feed inlet connected to the mixing bin on its bottom side. A first sealing plate is movably installed at the first feed inlet, and a second sealing plate is movably installed at the second feed inlet. The biomass crushing bin is equipped with an adjusting component for adjusting the first sealing plate. After the testing component detects the moisture content of the biomass pellets in the biomass crushing bin, it adjusts the opening size of the first feed inlet through the adjusting component. The coal pellet mixing component includes a first stirring rod rotatably disposed within the coal bunker and a first stirring blade disposed on the first stirring rod; the biomass mixing component includes a second stirring rod rotatably disposed within the biomass bunker and a second stirring blade disposed on the second stirring rod. The mixing chamber is also equipped with a third stirring rod, as well as horizontal and vertical stirring blades mounted on the third stirring rod. The vertical stirring blades are periodically slidably mounted on the third stirring rod, and the sliding period of the vertical stirring blades is related to the opening size of the first feed inlet.

2. The screening system used in the coal-fired power unit coupled with biomass power generation system according to claim 1, characterized in that: The moisture measuring component includes a moisture measuring blade rotatably mounted on the first stirring blade. The moisture measuring blade is in active contact with the biomass pellet. An elastic recovery element is provided at the pivot of the moisture measuring blade. A torque sensor is provided at the pivot of the moisture measuring blade. The first stirring rod and the second stirring rod rotate at the same speed.

3. The screening system used in the coal-fired power unit coupled with biomass power generation system according to claim 1, characterized in that: The third stirring rod is rotatably equipped with a rotating lead screw, and the vertical stirring blade is provided with an adjusting nut. The adjusting nut is threaded onto the rotating lead screw. The speed of the rotating lead screw is related to the opening size of the first inlet. The rotation direction of the rotating lead screw is opposite to the rotation direction of the horizontal stirring blade. The larger the opening of the first feed inlet, the slower the rotation speed of the rotating screw. The smaller the opening of the first feed inlet, the faster the rotation speed of the rotating screw.

4. The screening system used in the coal-fired power unit coupled with biomass power generation system according to claim 1, characterized in that: The first feed inlet has multiple sets, which are spaced apart along the radial direction of the mixing device. The adjusting component includes a first blocking block on the first blocking plate. The first blocking plate has multiple sets of first connecting ports corresponding to the first feed inlets. The first blocking plate is provided with a first adjusting block. The mixing device is provided with a second adjusting block. The first adjusting block and the second adjusting block are movably fitted and pressed together. The mixing device is also provided with a rotating component for adjusting the rotation speed of the rotating screw.

5. The screening system used in the coal-fired power unit coupled with biomass power generation system according to claim 1, characterized in that: The rotating component includes a first adjusting wheel coaxially arranged with the first stirring rod and a second adjusting wheel coaxially arranged with the rotating lead screw. A transmission belt is provided between the first adjusting wheel and the second adjusting wheel. Both the first adjusting wheel and the second adjusting wheel are in the form of conical wheels, and the transmission belt is provided in different areas of the first adjusting wheel and the second adjusting wheel, thereby realizing the adjustment of the rotation speed of the rotating lead screw.

6. The screening system used in the coal-fired power unit coupled with biomass power generation system according to claim 1, characterized in that: The mixing device is equipped with a linear power component for sliding adjustment of the second adjusting block. The second adjusting block is equipped with a clamping rod that clamps the transmission belt. The mixing device is also equipped with a controller that is electrically connected to the torque sensor and the linear power component.

7. The screening system used in the coal-fired power unit coupled with biomass power generation system according to claim 1, characterized in that: The second stirring rod is coaxially provided with a first moving wheel, and the third stirring rod is coaxially provided with a second moving wheel. The first moving wheel and the second moving wheel are connected in a driving connection.

8. The screening system used in the coal-fired power unit coupled with biomass power generation system according to claim 1, characterized in that: The third stirring rod has a limiting groove, and the vertical stirring blade is slidably disposed in the limiting groove. The rotating screw is provided with a bidirectional thread corresponding to the position of each vertical stirring blade.

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