Biomass blending combustion coal-fired power generation system and method based on low-temperature aerobic upgrading

Abstract

The invention discloses a biomass blending combustion coal-fired power generation system and method based on low-temperature aerobic upgrading. The system comprises a biomass bin, and a crushing unit is arranged at a discharge port of the biomass bin; the discharging end of the crushing unit is sequentially connected with a low-temperature aerobic upgrading device, a coal bunker unit and a coal mill through a conveying mechanism; the coal mill is connected with a coal-fired boiler, and the coal-fired boiler is provided with an SCR reactor; a heat source inlet of the low-temperature aerobic upgrading device is connected to a tail flue behind the SCR reactor, and tail flue gas of the SCR reactor is used for heating; tail gas of the low-temperature aerobic upgrading device is conveyed to the coal-fired boiler through the centrifugal fan to be combusted and purified, and the system achieves real-time monitoring and control through the central control system and the monitoring unit. According to the invention, high-efficiency and low-cost treatment can be carried out on the biomass, the problems of moisture content, high volatile components, grindability and the like of the biomass are effectively improved while the high energy recovery rate is reserved, and large-scale stable blending combustion of the biomass in a large coal-fired boiler is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of efficient biomass quality improvement and biomass co-combustion low-carbon transformation of thermal power units, and specifically relates to a biomass co-combustion coal-fired power generation system and method based on low-temperature aerobic quality improvement. Background Art

[0002] Driven by the transformation of the energy structure, the large-scale utilization of biomass energy as a renewable carbon source is of great significance for the low-carbon transformation of coal-fired power plants. Traditional biomass direct combustion power generation has problems such as low fuel energy density, poor combustion efficiency, and high safety risks.

[0003] When unpretreated biomass (such as straw and forestry waste) is directly added to the coal-fired system, it faces multiple technical bottlenecks: the high moisture content of the biomass (30-60%) will significantly reduce the calorific value of the fuel entering the furnace, affecting the furnace efficiency, and it is difficult to crush; the fluffy fiber structure of the biomass makes it difficult to mix evenly with the coal powder, causing combustion fluctuations; the high volatile matter (60-80%) and low ignition point of the biomass easily cause it to spontaneously combust during the pulverization process of the coal mill.

[0004] In summary, the current biomass pretreatment methods cannot effectively improve the moisture content, high volatile matter and grindability of biomass while retaining its high energy recovery rate; thus, it is difficult to achieve large-scale and stable co-combustion of biomass in large coal-fired boilers. Summary of the Invention

[0005] The present invention provides a biomass co-firing coal-fired power generation system and method based on low-temperature aerobic quality improvement, aiming to solve the problem that the current biomass pretreatment method cannot effectively improve its moisture content, high volatile matter and grindability while retaining the high energy recovery rate of biomass; and thus it is difficult to achieve large-scale and stable co-firing of biomass in large coal-fired boilers.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: The present invention provides a biomass-co-fired coal-fired power generation system based on low-temperature aerobic upgrading, comprising a system body and a central control unit configured therewith. The system body comprises a biomass bin for storing biomass raw materials to be processed, and a crushing unit is configured at the discharge port of the biomass bin; the crushing unit is used to crush the biomass raw materials to be processed into crushed materials; The discharge end of the crushing unit is connected to a low-temperature aerobic upgrading device through a conveying mechanism. The discharge end of the low-temperature aerobic upgrading device is connected to a coal bunker unit, which is connected to a coal mill. The coal mill is connected to a coal-fired boiler to provide fuel for the coal-fired boiler. The coal-fired boiler is equipped with an SCR reactor and subsequent units for flue gas purification. The heat source inlet of the low-temperature aerobic upgrading device is connected to the tail flue of the SCR reactor, and the low-temperature aerobic upgrading device is configured to utilize the tail flue gas of the SCR reactor to heat the biomass raw material to be processed; the tail gas outlet of the low-temperature aerobic upgrading device is connected to the coal-fired boiler through a centrifugal fan so that the tail gas can be introduced into the coal-fired boiler in real time for combustion purification; the system body also includes a monitoring unit, and the central control system monitors and controls the system body in real time based on the feedback signal of the monitoring unit.

[0007] In some embodiments, the low-temperature aerobic upgrading device adopts a rotary kiln structure, the reaction time of the biomass raw material to be processed in the rotary kiln structure is controlled to be 30-60 minutes, and the rotation speed and inclination angle of the rotary kiln structure are configured to be adjustable; the tail flue gas temperature of the SCR reactor is 280-320°C and the oxygen content is 4-8%.

[0008] In some embodiments, the low-temperature aerobic upgrading device can form a semi-coke product after the biomass raw material to be processed undergoes low-temperature aerobic upgrading. The exhaust gas from the low-temperature aerobic upgrading device is introduced into the secondary air box of the coal-fired boiler through a pipeline and a centrifugal fan to achieve combustion purification in the coal-fired boiler.

[0009] In some embodiments, the crushing unit includes a crushing device, the crushing device is equipped with a dust removal device, the monitoring unit includes a temperature detection component and an explosion-proof alarm component, and the temperature detector and the explosion-proof alarm are arranged in the crushing device.

[0010] In some embodiments, the conveying mechanism is a conveying belt; the input area of ​​the conveying belt is connected to the crushing unit, and the output area is connected to a buffer bin through a coal plow; a screw feeder is provided at the bottom of the buffer bin, which can measure and convey the biomass raw materials to be processed.

[0011] Furthermore, the inner wall of the buffer bin is made of ultra-high molecular polyethylene material, the bottom of the buffer bin is provided with a vibration arch breaking device, and the top is provided with a pulse dust collector and a microwave level meter.

[0012] In some embodiments, the coal bunker unit includes a coal bunker connected to the discharge end of the low-temperature aerobic upgrading device, a coal conveyor is provided below the coal bunker, and the coal mill is connected to the discharge end of the coal conveyor.

[0013] Furthermore, the coal bunker is divided into a raw coal bunker and a biomass semi-coke bunker, and two independently controlled two-way plug-in doors are provided at the bottom of the coal bunker.

[0014] Furthermore, the discharge end of the low-temperature aerobic upgrading device is equipped with a water-cooled screw conveyor and a bucket elevator, which are used to transport the biomass semi-coke processed by the low-temperature aerobic upgrading device to the coal bunker.

[0015] The present invention also provides a method for power generation by blending biomass with coal based on low-temperature aerobic upgrading. The method is based on the above-mentioned system for power generation by blending biomass with coal based on low-temperature aerobic upgrading, and the method comprises the following steps: S1. Check and inspect the system to ensure that all parts of the system are in normal condition; S2. The biomass raw materials to be processed enter the crushing unit from the biomass silo. The crushing unit crushes the biomass raw materials to be processed into fragments, which are then connected to a low-temperature aerobic upgrading device through a conveying mechanism. The low-temperature aerobic upgrading device uses the tail flue gas of the SCR reactor to heat the biomass raw materials to be processed. The tail gas of the low-temperature aerobic upgrading device is introduced into the coal-fired boiler in real time through a centrifugal fan for combustion purification. The central control system realizes real-time monitoring and control of the system body through the monitoring unit. S3. The biomass semi-coke treated in the low-temperature aerobic upgrading device enters the coal bunker unit through the discharge end, and then enters the coal-fired boiler after being processed by the coal mill to provide fuel for the coal-fired boiler.

[0016] The present invention provides a biomass-co-fired coal-fired power generation system and method based on low-temperature aerobic upgrading, which has the following beneficial effects.

[0017] The present invention provides a biomass co-combustion coal-fired power generation system based on low-temperature aerobic upgrading. It realizes biomass aerobic low-temperature upgrading based on flue gas recycling, and uses the flue gas at the tail of the boiler to provide a heat source for biomass upgrading, thereby avoiding additional heat input and saving energy; and improves energy utilization efficiency through direct contact heat exchange between flue gas and biomass. The present invention can reduce the moisture content of biomass, thereby increasing the calorific value of subsequent products; reduce the volatile matter of biomass, and avoid spontaneous combustion during its transportation and pulverizing process; at the same time, it increases the grindability of biomass, and the upgraded biomass can be directly fed into the existing pulverizing and combustion system, which neither affects the output of the coal mill nor avoids the modification of the existing system to the greatest extent, and the construction cost is relatively low. The biomass aerobic low-temperature upgrading process of the present invention can reduce the differences in the biomass itself, expand the range of biomass types that can be used in coal-fired boilers, and improve the flexibility, economy and environmental protection of biomass co-combustion in coal-fired power plants. The method of the present invention can realize continuous aerobic low-temperature upgrading of biomass, and the normal operation of the coal-fired boiler is basically not affected during the transformation. After the transformation, there is no impact on the original coal powder combustion system. This treatment method uses the exhaust gas purification system of the coal-fired boiler to achieve ultra-low emission treatment of the flue gas and upgraded waste gas generated by biomass combustion, has good reliability and environmental protection, and is of practical significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings in the specification are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] Figure 1 This is a structural schematic diagram of a biomass-co-fired coal-fired power generation system based on low-temperature aerobic upgrading according to the present invention.

[0020] Among them, 1. Biomass silo, 2. Crushing device, 3. Dust removal device, 4. Conveyor belt, 5. Buffer silo, 6. Screw feeder, 7. Low-temperature aerobic quality improvement device, 8. Centrifugal fan, 9. Coal silo, 10. Coal conveyor, 11. Coal mill, 12. Coal-fired boiler, 13. SCR reactor, 14. Air preheater. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0023] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0024] In the description of the embodiments of the present invention, it should be noted that if the terms "upper," "lower," "horizontal," "inner," etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the inventive product is typically placed when in use. These terms are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0025] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0026] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections 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.

[0027] How to provide a biomass processing system that can improve the quality of biomass, reduce its moisture and volatile matter, increase its calorific value and grindability, and achieve uniform mixing and combustion of biomass and coal.

[0028] like Figure 1 As shown, the present invention is a biomass co-combustion coal-fired power generation system based on low-temperature aerobic upgrading, comprising a system body and a central control unit configured therein, wherein the system body comprises a biomass bin 1 for storing biomass raw materials to be processed, and a crushing unit is configured at the discharge port of the biomass bin 1; the crushing unit is used to crush the biomass raw materials to be processed into crushed materials; The discharge end of the crushing unit is connected to the low-temperature aerobic upgrading device 7 through a conveying mechanism. The discharge end of the low-temperature aerobic upgrading device 7 is connected to the coal bunker unit, which is connected to the coal mill 11. The coal mill 11 is connected to the coal-fired boiler 12 to provide fuel for the coal-fired boiler 12. The coal-fired boiler 12 is equipped with an SCR reactor 13 and subsequent units for purifying tail flue gas. The heat source inlet of the low-temperature aerobic upgrading device 7 is connected to the tail flue of the SCR reactor 13, and the low-temperature aerobic upgrading device 7 is configured to utilize the tail flue gas of the SCR reactor 13 to heat the biomass raw material to be processed; the tail gas outlet of the low-temperature aerobic upgrading device 7 is connected to the coal-fired boiler 12 through the centrifugal fan 8, so that the tail gas can be introduced into the coal-fired boiler 12 in real time for combustion purification; the system body also includes a monitoring unit, and the central control system realizes real-time monitoring and control of the system body based on the feedback signal of the monitoring unit.

[0029] The biomass co-combustion coal-fired power generation system of the present invention utilizes a biomass silo 1 to store unprocessed biomass raw materials. A fuel processing and co-combustion system is formed by a crushing unit, a conveying mechanism, a low-temperature aerobic upgrading device 7, a coal silo unit, a coal mill 11, and a coal-fired boiler 12. The heat source of the low-temperature aerobic upgrading device 7 is directly derived from the tail gas at the outlet of an SCR (Selective Catalytic Reduction) reactor 13. The tail gas from the low-temperature aerobic upgrading device 7 is then fed back to the coal-fired boiler 12 for decomposition via a centrifugal fan 8 in real time. This system directly utilizes the waste heat from the boiler tail gas to upgrade the biomass, avoiding additional energy consumption. The upgraded tail gas is returned to the boiler for high-temperature decomposition of VOCs and tar, leveraging existing purification systems to achieve ultra-low emissions. The upgraded biomass semi-coke is pulverized by a coal mill 11 and then directly fed into the coal-fired boiler 12, improving efficiency. The central control unit and monitoring units located in various locations of the system monitor and control data to enable real-time monitoring and adjustment of the entire system process, enhancing the stability and reliability of system operation and processing.

[0030] In some embodiments of the biomass-co-fired coal-fired power generation system of the present invention, the low-temperature aerobic upgrading device 7 utilizes a rotary kiln structure. The reaction time of the biomass feedstock to be processed within the rotary kiln is controlled to 30-60 minutes, and the rotation speed and inclination angle of the rotary kiln are adjustable. The exhaust gas temperature at the tail of the SCR reactor 13 is 280-320°C, and the oxygen content is 4-8%. By limiting the upgrading device to a rotary kiln structure and other parameters, the present invention ensures that the biomass volatile matter is reduced by 10-20% and the fixed carbon is increased to 10-15%, resulting in high-calorific value semi-coke (≥20 MJ / kg). Parameter optimization prevents spontaneous combustion of the biomass in the boiler pulverizing system and improves grindability.

[0031] In the biomass co-firing coal-fired power generation system of the present invention, the low-temperature aerobic upgrading device 7 can form a semi-coke product after the biomass raw material to be processed undergoes low-temperature aerobic upgrading. The upgraded tail gas of the low-temperature aerobic upgrading device 7 is introduced into the secondary air box of the coal-fired boiler 12 through a pipeline and a centrifugal fan 8, and after being mixed with the secondary air, it enters the furnace of the coal-fired boiler 12 for combustion and purification. For example, organic components such as VOCs / tar can be completely decomposed at high temperature in the furnace of the coal-fired boiler 12 without the need for additional treatment facilities.

[0032] In the biomass co-firing coal-fired power generation system of the present invention, the crushing unit includes a crushing device 2, the crushing device 2 is equipped with a dust removal device 3, and the monitoring unit includes a temperature detection component and an explosion-proof alarm component. The temperature detector and the explosion-proof alarm are arranged on the crushing device 2. Through the temperature detection component and the explosion-proof alarm component, in cooperation with the control of the central control unit, dust explosion and spontaneous combustion are avoided.

[0033] In the biomass co-firing coal-fired power generation system of the present invention, the conveying mechanism includes a conveyor belt 4; the input area of ​​the conveyor belt 4 is connected to the crushing unit, and the output area is connected to a buffer bin 5 through a coal plow; a screw feeder 6 is provided at the bottom of the buffer bin 5, and the screw feeder 6 can measure and convey the biomass raw materials to be processed. Furthermore, the inner wall of the buffer bin 5 has an ultra-high molecular polyethylene material, and the bottom of the buffer bin 5 is provided with a vibration arch breaking device, and the top is provided with a pulse dust collector and a microwave level meter. The inner wall of the buffer bin 5 of the present invention has an ultra-high molecular polyethylene coating, and through the bottom vibration arch breaking and the top pulse dust removal and microwave level meter, it can achieve anti-blocking and anti-bridging in the bin, and accurately measure the feeding, thereby ensuring the continuous and stable operation of the quality improvement device.

[0034] In the biomass-coal-fired power generation system of the present invention, the coal bunker 9 can be remodeled into a separate compartment, forming a raw coal bunker and a biomass coke bunker, with independent two-way gates at the bottom. The single-sided coal drop port is larger than the original size, allowing for flexible blending of biomass coke and raw coal.

[0035] Furthermore, the discharge end of the low-temperature aerobic upgrading device 7 of the present invention is equipped with a water-cooled screw conveyor and a bucket elevator. The water-cooled screw conveyor and the bucket elevator are used to transport the biomass semi-coke treated by the low-temperature aerobic upgrading device 7 to the coal bunker 9. The system can prevent the ignition of the biomass semi-coke due to the waste heat through the design of the water-cooled screw conveyor, and ensure the vertical transportation efficiency through the bucket elevator.

[0036] The present invention also provides a method for power generation by blending biomass with coal based on low-temperature aerobic upgrading. The method is based on a system for power generation by blending biomass with coal based on low-temperature aerobic upgrading, and the method comprises the following steps: S1. Check and inspect the system to ensure that all parts of the system are in normal condition; S2. The biomass raw materials to be processed enter the crushing unit from the biomass bin 1. The crushing unit crushes the biomass raw materials to be processed into fragments, which are then connected to the low-temperature aerobic upgrading device 7 through a conveying mechanism. The low-temperature aerobic upgrading device 7 uses the tail flue gas after the SCR reactor 13 to heat and upgrade the biomass raw materials to be processed. The tail gas of the low-temperature aerobic upgrading device 7 is introduced into the coal-fired boiler 12 through the centrifugal fan 8 for combustion purification. The central control system realizes real-time monitoring and controls the system body according to the monitoring unit. S3. The biomass semi-coke treated by the low-temperature aerobic upgrading device 7 enters the coal bunker unit through the discharge end, and then enters the coal-fired boiler 12 after being treated by the coal mill 11 to provide fuel for the coal-fired boiler 12.

[0037] The following is a detailed description of a biomass-co-fired coal-fired power generation system and method based on low-temperature aerobic upgrading of the present invention through specific embodiments.

[0038] like Figure 1 As shown, the biomass raw materials are transported by truck to the designated biomass warehouse 1 in the power plant for storage. The biomass warehouse 1 adopts a fully enclosed steel structure scaffolding design, and the ground is paved with reinforced concrete and coated with an anti-seepage coating. The storage area is equipped with temperature and humidity sensors and combustible gas detectors, and real-time data is uploaded to the central control system. The biomass is then sent to the crushing device 2 to produce crushed materials. The crushing device is equipped with a dust removal device 3, a vibration screening system, a temperature detection system and an alarm system to prevent accidents such as spontaneous combustion and explosion caused by dust from biomass powder. The exhaust gas from the tail of the dust removal device 3 is sent to high altitude emptying after passing through a matching fan. The discharge port of the crushing device 2 realizes the transportation of biomass to the conveyor belt 4 through a chain plate conveyor.

[0039] The crushed biomass is transported via conveyor belt 4. Coal plows are installed in selected areas of conveyor belt 4, allowing the biomass on the belt to enter buffer silo 5. The inner wall of buffer silo 5 is spray-coated with ultra-high molecular weight polyethylene, and the bottom of buffer silo 5 is equipped with a vibrating arch-breaking device. The top of buffer silo 5 is equipped with a pulse dust collector and a microwave level meter to monitor the material level in real time and control the start and stop of conveyor belt 4. A screw feeder 6 at the bottom of buffer silo 5 adopts a double-helical blade structure and is equipped with a high-precision weighing module to ensure accurate biomass transportation and measurement.

[0040] The biomass then enters the low-temperature aerobic upgrading unit 7, which utilizes a rotary kiln. The upgrading heat source utilizes the tail gas (temperature 280-320°C, oxygen content 4-8%) from the denitrification SCR reactor 13 after the coal-fired boiler 12, directly heating the biomass within the kiln. The upgraded tail gas, driven by a centrifugal fan 8, rapidly returns to the secondary airbox of the coal-fired boiler 12 and enters the furnace for purification. The biomass resides in the low-temperature aerobic upgrading unit 7 for 30-60 minutes (controlled by adjusting the rotational speed and inclination angle). After low-temperature aerobic upgrading, the volatile matter content of the biomass is reduced by 10-20%, while the fixed carbon content is increased to 10-15%, resulting in a semi-coke product (calorific value ≥ 20 MJ / kg). The upgraded exhaust gas (containing VOCs, tar, and dust) is introduced into the secondary airbox of the coal-fired boiler 12 via a pipeline. After mixing with the secondary air, it enters the high-temperature zone of the furnace, completely decomposing the organic components.

[0041] The upgraded biomass semi-coke is discharged via a water-cooled screw conveyor at the kiln tail and transported by a bucket elevator to the coal bunker 9 above the coal conveyor 10. To improve fuel flexibility, the coal bunker 9 was renovated into two compartments: raw coal and biomass, along the upper coal belt. The lower gate of the coal bunker 9 was replaced with two independently controlled two-way gates. The elevation of the newly added two-way gates was raised to ensure that the coal drop opening on one side of the gate was larger than the coal drop opening of the entire coal bunker before the renovation.

[0042] Based on combustion requirements, the biomass semi-coke is fed through a coal conveyor 10 into the boiler's primary pulverizing system, where it is pulverized in a coal mill 11. The biomass powder and pulverized coal are then simultaneously conveyed to the burner of a coal-fired boiler 12 for combustion. The flue gas and upgraded exhaust gas generated by biomass combustion can be purified and utilized for heat recovery using existing equipment in the coal-fired unit, such as the SCR reactor 13 and air preheater 14.

[0043] In summary, the present invention provides a biomass co-combustion coal-fired power generation system and method based on low-temperature aerobic upgrading. Through reasonable configuration and control, the system can effectively process biomass in a low-cost and high-efficiency manner, while retaining a high energy recovery rate, effectively solving problems such as moisture content, high volatile matter and grindability, and realizing large-scale and stable co-combustion of biomass in large coal-fired boilers.

[0044] Finally, it should be noted that the above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in this industry can smoothly implement the present invention as shown in the specification and described above. Any equivalent changes, modifications and evolutions made by using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. A biomass-coal-fired power generation system based on low-temperature aerobic upgrading, characterized in that: The invention comprises a system body and a central control unit configured thereon, wherein the system body comprises a biomass bin (1) for storing biomass raw materials to be processed, and a crushing unit is configured at the discharge port of the biomass bin (1); the crushing unit is used to crush the biomass raw materials to be processed into crushed materials; The discharge end of the crushing unit is connected to a low-temperature aerobic upgrading device (7) via a conveying mechanism, the discharge end of the low-temperature aerobic upgrading device (7) is connected to a coal bunker unit, and the coal bunker unit is connected to a coal mill (11); the coal mill (11) is connected to a coal-fired boiler (12) to provide fuel for the coal-fired boiler (12), and the coal-fired boiler (12) is equipped with an SCR reactor (13) for purifying flue gas and subsequent units; The heat source inlet of the low-temperature aerobic upgrading device (7) is connected to the tail flue of the SCR reactor (13), and the low-temperature aerobic upgrading device (7) is configured to utilize the tail flue gas of the SCR reactor (13) to heat the biomass raw material to be processed; the tail gas outlet of the low-temperature aerobic upgrading device (7) is connected to the coal-fired boiler (12) through the centrifugal fan (8), so as to introduce the tail gas into the coal-fired boiler (12) in real time for combustion purification; the system body also includes a monitoring unit, and the central control system monitors and controls the system body in real time based on the feedback signal of the monitoring unit.

2. The biomass-coal-fired power generation system based on low-temperature aerobic upgrading according to claim 1 is characterized in that: The low-temperature aerobic upgrading device (7) adopts a rotary kiln structure. The reaction time of the biomass raw material to be processed in the rotary kiln structure is controlled to be 30-60 minutes. The rotation speed and inclination angle of the rotary kiln structure are configured to be adjustable. The tail flue gas temperature of the SCR reactor (13) is 280-320°C and the oxygen content is 4-8%.

3. The biomass-coal-fired power generation system based on low-temperature aerobic upgrading according to claim 1 is characterized in that: The low-temperature aerobic upgrading device (7) can form a semi-coke product after the biomass raw material to be processed undergoes low-temperature aerobic upgrading. The tail gas of the low-temperature aerobic upgrading device (7) is introduced into the secondary air box of the coal-fired boiler (12) through a pipeline and a centrifugal fan (8), so as to achieve combustion purification in the coal-fired boiler (12).

4. The biomass-coal-fired power generation system based on low-temperature aerobic upgrading according to claim 1 is characterized in that: The crushing unit comprises a crushing device (2), the crushing device (2) is equipped with a dust removal device (3), and the monitoring unit comprises a temperature detection component and an explosion-proof alarm component, the temperature detector and the explosion-proof alarm being arranged on the crushing device (2).

5. The biomass-coal-fired power generation system based on low-temperature aerobic upgrading according to claim 1 is characterized in that: The conveying mechanism comprises a conveying belt (4); an input area of ​​the conveying belt (4) is connected to a crushing unit, and an output area is connected to a buffer bin (5) via a coal plow; a screw feeder (6) is provided at the bottom of the buffer bin (5), and the screw feeder (6) is capable of metering and conveying the biomass raw materials to be processed.

6. The biomass-coal-fired power generation system based on low-temperature aerobic upgrading according to claim 5 is characterized in that: The inner wall of the buffer bin (5) is made of ultra-high molecular polyethylene material, and the bottom of the buffer bin (5) is provided with a vibration arch breaking device, and the top is provided with a pulse dust collector and a microwave level meter.

7. The biomass-coal-fired power generation system based on low-temperature aerobic upgrading according to claim 1 is characterized in that: The coal bunker unit comprises a coal bunker (9), the coal bunker (9) is connected to the discharge end of the low-temperature aerobic upgrading device (7), a coal conveyor (10) is provided below the coal bunker (9), and the coal mill (11) is connected to the discharge end of the coal conveyor (10).

8. The biomass-coal-fired power generation system based on low-temperature aerobic upgrading according to claim 7 is characterized in that: The coal bunker (9) is separated into a raw coal bunker and a biomass semi-coke bunker, and two independently controlled two-way plug-in doors are provided at the bottom of the coal bunker (9).

9. The biomass-coal-fired power generation system based on low-temperature aerobic upgrading according to claim 7 is characterized in that: The discharge end of the low-temperature aerobic upgrading device (7) is equipped with a water-cooled screw conveyor and a bucket elevator, and the water-cooled screw conveyor and the bucket elevator are used to transport the biomass semi-coke processed by the low-temperature aerobic upgrading device (7) to the coal bunker (9).

10. A method for power generation by blending biomass with coal based on low-temperature aerobic upgrading, characterized in that: The method is based on the biomass co-combustion coal-fired power generation system based on low-temperature aerobic upgrading according to any one of claims 1 to 9, and comprises the following steps: S1. Check and inspect the system to ensure that all parts of the system are in normal condition; S2, the biomass raw materials to be processed enter the crushing unit from the biomass bin (1), the crushing unit crushes the biomass raw materials to be processed into crushed materials, and then is connected to the low-temperature aerobic upgrading device (7) through a conveying mechanism; the low-temperature aerobic upgrading device (7) uses the tail flue gas of the SCR reactor (13) to heat and upgrade the biomass raw materials to be processed, and the tail gas of the low-temperature aerobic upgrading device (7) is introduced into the coal-fired boiler (12) through the centrifugal fan (8) for combustion purification, and the central control system realizes real-time monitoring and control of the system body according to the monitoring unit; S3. The biomass semi-coke treated by the low-temperature aerobic upgrading device (7) enters the coal bunker unit through the discharge end, and then enters the coal-fired boiler (12) after being treated by the coal mill (11), providing fuel for the coal-fired boiler (12).

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