A boiler combustion temperature regulating mechanism and a biomass combustion fluidized bed boiler

Abstract

This invention relates to the field of boiler technology, and more particularly to a boiler combustion temperature control mechanism and a biomass combustion fluidized bed boiler. The technical solution includes a feeding structure, a regulator, and a power structure. The feeding structure is used to transport biomass fuel and includes a lifting pipe, an upper feeding pipe, a lower feeding pipe, and a humidity sensor. The regulator includes a valve frame, a valve plate, a hydraulic cylinder, a pump casing, a spiral heat exchange tube, and a spiral conveying pipe. It includes a furnace structure and a boiler structure. The furnace structure includes a furnace body; the boiler structure includes an annular boiler. This invention reduces the fuel moisture content and stabilizes the furnace combustion temperature by using a humidity sensor in conjunction with a waste heat drying structure. The annular boiler, suspended in the center of the furnace, expands the heating area, fully utilizes the high-temperature heat source, significantly improves fuel utilization, reduces energy consumption, and ensures efficient and stable boiler operation.

Description

Technical Field

[0001] This invention relates to the field of boiler technology, and in particular to a boiler combustion temperature control mechanism and a biomass combustion fluidized bed boiler. Background Technology

[0002] Fluidized bed boilers are highly efficient and clean combustion equipment that burns solid fuels in a fluidized state. A bed of fuel is arranged inside the furnace, and high-speed airflow causes the bed to boil, ensuring thorough mixing and rapid combustion of the fuel. It has wide fuel adaptability, can burn various fuels such as biomass and coal, has a moderate combustion temperature, low pollutant emissions, and high thermal efficiency, and is widely used in industrial heating and power generation.

[0003] Biomass combustion fluidized bed boilers are key equipment for biomass energy conversion and utilization. The boiler body of existing fluidized bed boilers is mostly fixed to the inner wall of the furnace, and the heating surface is only concentrated on the side wall of the furnace. The high-temperature heat source in the central area of ​​the furnace is difficult to exchange heat effectively with the boiler, resulting in low utilization rate of primary heat source, large heat loss, and limited fuel thermal energy conversion efficiency, making it difficult to meet the demand for high-efficiency heating.

[0004] Meanwhile, existing boilers lack humidity control and pretreatment designs in their feeding stages. Biomass fuel is often fed directly into the furnace without drying, resulting in a generally high moisture content. When high-moisture fuel enters the furnace, it absorbs a large amount of furnace heat to evaporate the moisture, causing a sharp drop and drastic fluctuation in furnace combustion temperature. This makes it impossible to maintain a stable combustion temperature, and the moisture inhibits the combustion reaction, leading to incomplete combustion. This increases fuel consumption and easily produces unburned residue, significantly reducing fuel utilization and hindering the energy-saving and stable operation performance of fluidized bed boilers. Therefore, those skilled in the art have provided a boiler combustion temperature control mechanism and a biomass combustion fluidized bed boiler to solve the problems mentioned in the background art. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the background art by proposing a boiler combustion temperature control mechanism and a biomass combustion fluidized bed boiler.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a boiler combustion temperature control mechanism and a biomass combustion fluidized bed boiler, comprising a feeding structure, a regulator and a power structure, wherein the feeding structure is used to transport biomass fuel, and the feeding structure includes a lifting pipe, an upper feeding pipe, a lower feeding pipe and a humidity sensor, wherein the detection end of the humidity sensor is located inside the lifting pipe, and the lower feeding pipe and the upper feeding pipe are two channels for biomass fuel; The regulator is used to regulate the opening and closing of the lower feed pipe and the upper feed pipe. The regulator includes a valve frame, a valve plate, a hydraulic cylinder, a pump housing, a spiral heat exchange tube, and a spiral conveying pipe. The valve frame is connected to the lower feed pipe and the upper feed pipe. The valve plate is longitudinally slidably installed inside the valve frame. The hydraulic cylinder is fixed at the upper end of the valve frame and its telescopic end is connected to the upper end of the valve plate. The power structure provides a power source for the feeding structure, and the power structure includes a motor and a pump casing.

[0007] Preferably, the motor is fixed at the upper end of the lifting pipe. The motor is a dual-shaft motor, with an upper output shaft at its upper output end. An impeller, rotatably mounted inside the pump casing, is sleeved on the outer wall of the upper output shaft. The motor drives the upper output shaft to rotate the impeller, generating suction force inside the pump casing.

[0008] Preferably, the lower output end of the motor is provided with a lower output shaft rotatably mounted inside the lifting tube. A swivel joint, rotatably mounted inside the lifting tube, is sleeved on the outer wall of the lower output shaft. The lower end of the lifting tube is connected to a hopper, and one end of the hopper is connected to a feeding channel. A conveying mechanism is provided inside the feeding channel to transport biomass fuel into the hopper for buffering. The motor drives the lower output shaft to rotate, causing the swivel joint to rotate inside the lifting tube, thus lifting and conveying the biomass fuel inside the hopper.

[0009] Preferably, the valve plate has a valve hole one and a valve hole two inside. When valve hole one corresponds to the lower feed pipe, valve hole two is misaligned with the upper feed pipe, and vice versa. The valve plate has symmetrically distributed through holes inside, and the valve frame has a guide rod that slides into the through holes. When valve hole one corresponds to the lower feed pipe, the biomass fuel inside the lifting pipe enters the furnace through the lower feed pipe. When valve hole two corresponds to the upper feed pipe, the biomass fuel inside the lifting pipe enters the spiral conveyor pipe through the upper feed pipe and then enters the furnace through the upper feed end pipe. Preferably, the pump casing suction end is connected to the boiler waste heat, the pump casing output end is provided with an air supply pipe, one end of the air supply pipe is connected to a spiral heat exchange tube, one end of the spiral heat exchange tube is connected to an exhaust pipe, one end of the upper feed pipe is provided with a spiral conveying pipe located inside the spiral heat exchange tube, both ends of the spiral heat exchange tube are closed, the outer wall of the spiral conveying pipe located inside the spiral heat exchange tube has equidistantly distributed heat exchange holes, and the end of the spiral conveying pipe is provided with an upper feed end pipe that penetrates the spiral heat exchange tube.

[0010] A biomass combustion fluidized bed boiler includes a furnace structure and a boiler structure, wherein the furnace structure includes a furnace body. The boiler structure includes an annular boiler.

[0011] Preferably, cyclone separators are provided on both sides of the furnace body. A separation pipe communicating with the cyclone separators is provided at the upper end of the furnace body. A flue gas outlet is reserved at the upper end of the cyclone separator. A bottom hopper is provided at the lower end of the cyclone separator. A return pipe for bed material recirculation is connected between the bottom hopper and the furnace body. The cyclone separators separate the bed material and incompletely burned biomass fuel from the flue gas. The bed material and incompletely burned biomass fuel enter the furnace body through the return pipe. The bottom hopper receives the bed material and incompletely burned biomass fuel, ensuring that the bed material and incompletely burned biomass fuel enter the furnace body in an orderly manner.

[0012] Preferably, the annular boiler is suspended at the center of the furnace body and is hollow inside. A collecting spherical tank is provided above the furnace body. The upper end of the collecting spherical tank is connected to a secondary steam pipe, and the lower end of the collecting spherical tank is connected to a primary steam pipe arranged in a ring array and penetrating the upper part of the annular boiler. The hollow structure inside the annular boiler is effectively heated by the furnace interior. Steam obtained inside the boiler enters the collecting spherical tank through the primary steam pipe and is then transported through the secondary steam pipe.

[0013] Preferably, a diversion tank is provided above the furnace body, and a water supply pipe is connected to the upper end of the diversion pipe. A water delivery pipe, arranged in a ring array and penetrating the lower end of the annular boiler, is connected to the outer wall of the diversion tank. The water delivery pipe transports supplementary water into the diversion tank, and the water is then input from the lower end of the annular boiler through the ring array of water delivery pipes.

[0014] Preferably, both the upper feed end pipe and the lower feed pipe penetrate the furnace body, with the upper feed pipe located above the lower feed pipe. The upper feed end pipe and the lower feed pipe are positioned at the same horizontal level through the furnace body. The spiral heat exchange pipe and the spiral conveying pipe are spirally sleeved on the outside of the furnace body, allowing the internally heated and dried biomass fuel to spiral downwards and flow into the lower part of the furnace body, mixing with the bed material. The biomass fuel conveyed through the upper feed pipe undergoes heat treatment inside the bolted conveying pipe, reducing the moisture content of the biomass fuel and improving combustion efficiency.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: When the humidity sensor inside the lifting pipe of this invention detects that the humidity of the biomass fuel reaches a threshold, the opening and closing of the upper and lower feed pipes are adjusted by the valve plate. The biomass fuel is transported through the spiral conveying pipe and enters the furnace body. During this process, the biomass fuel is heat-treated inside the spiral heat exchanger to reduce internal moisture. The waste heat of the fluidized bed boiler is drawn in through the pump casing, and the suction power inside the pump casing shares a power source with the lifting and feeding, which reduces energy consumption and improves the utilization of waste heat, improves combustion efficiency, and increases the combustion temperature inside the furnace after complete combustion. The central area of ​​the annular boiler is where biomass fuel and bed material exchange heat, increasing the heating surface area. This avoids the situation in traditional boilers where the heat source is not fully utilized because the heat source is located on the inner wall of the furnace body and only the inner wall is heated. By using an annular boiler structure, the heating surface area is increased, thereby improving the utilization rate of biomass fuel and reducing fuel consumption. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the main cross-sectional three-dimensional structure of the present invention; Figure 2 This is a front-view three-dimensional structural schematic diagram of the present invention; Figure 3 This is a side-view perspective view of the three-dimensional structure of the present invention; Figure 4 This is a side sectional three-dimensional structural diagram of the furnace body of the present invention; Figure 5 This is a front-view three-dimensional structural diagram of the internal structure of the lifting tube of the present invention; Figure 6 This is a schematic diagram of the three-dimensional structure of the lifting tube of the present invention in cross section. Figure 7 This is a partial side sectional view of the three-dimensional structure of the furnace of the present invention; Figure 8 This is a partial side sectional view of the three-dimensional structure of the annular boiler of the present invention; Figure 9 This is a side view of the boiler structure of the present invention. Figure 10 This is a side view of the three-dimensional structure of the valve plate of the present invention; Figure 11 This is a top-view three-dimensional structural diagram of the spiral heat exchanger tube of the present invention.

[0017] Figure label: 100. Furnace structure; 101. Furnace body; 102. Return pipe; 103. Separation pipe; 104. Cyclone separator; 105. Bottom hopper; 200. Boiler structure; 201. Annular boiler; 202. Gathering spherical tank; 203. Primary steam pipe; 204. Secondary steam pipe; 205. Diversion tank; 206. Water supply pipe; 207. Water delivery pipe; 300. Feeding structure; 301. Hopper; 302. Feeding channel; 303. Lifting pipe; 304. Upper feed pipe; 305. Lower feed pipe; 306. Humidity sensor; 400. Regulator; 401. Valve frame; 402. Valve plate; 403. Valve hole one; 404. Valve hole two; 405. Guide rod; 406. Through hole; 407. Hydraulic cylinder; 408. Pump housing; 409. Air supply pipe; 410. Spiral heat exchange tube; 411. Exhaust pipe; 412. Upper feed end pipe; 413. Spiral conveyor pipe; 500. Power structure; 501. Motor; 502. Upper output shaft; 503. Impeller; 504. Lower output shaft; 505. Winch. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figures 1 to 11 The present invention provides four embodiments: Example 1: A boiler combustion temperature control mechanism includes a feeding structure 300, a regulator 400, and a power structure 500. The feeding structure 300 is used to transport biomass fuel. The feeding structure 300 includes a lifting pipe 303, an upper feeding pipe 304, a lower feeding pipe 305, and a humidity sensor 306. The detection end of the humidity sensor 306 is located inside the lifting pipe 303. The lower feeding pipe 305 and the upper feeding pipe 304 are two channels for biomass fuel. The regulator 400 is used to regulate the opening and closing of the lower feed pipe 305 and the upper feed pipe 304. The regulator 400 includes a valve frame 401, a valve plate 402, a hydraulic cylinder 407, a pump housing 408, a spiral heat exchange tube 410, and a spiral conveying pipe 413. The valve frame 401 is connected to the lower feed pipe 305 and the upper feed pipe 304. The valve plate 402 is longitudinally slidably installed inside the valve frame 401. The hydraulic cylinder 407 is fixed at the upper end of the valve frame 401 and its telescopic end is connected to the upper end of the valve plate 402. The power structure 500 provides a power source for the feeding structure 300. The power structure 500 includes a motor 501 and a pump casing 408.

[0020] In this embodiment, the feeding structure 300 includes a lifting pipe 303, an upper feeding pipe 304, a lower feeding pipe 305, and a humidity sensor 306. The humidity sensor 306 is installed inside the lifting pipe 303 and is used to detect the humidity of biomass fuel in real time. The regulator 400 includes a valve frame 401, a valve plate 402, a hydraulic cylinder 407, a pump housing 408, a spiral heat exchange tube 410, and a spiral conveying pipe 413. The valve frame 401 is connected to the upper and lower feeding pipes 305. The valve plate 402 can slide up and down inside the valve frame 401. The hydraulic cylinder 407 is fixed to the upper end of the valve frame 401, and its telescopic end is connected to the valve plate 402 to control the lifting and lowering of the valve plate 402. The power structure 500 consists of a motor 501 and a pump housing 408. The motor 501 is a dual-shaft motor 501, which is fixed to the upper end of the lifting pipe 303.

[0021] During operation, the feeding channel 302 transports biomass fuel to the silo 301 for buffering. The lower output shaft 504 of the motor 501 drives the auger 505 inside the lifting pipe 303 to rotate, lifting and conveying the fuel upwards. The humidity sensor 306 detects the fuel humidity. When the humidity reaches the set value, the hydraulic cylinder 407 pushes the valve plate 402 to move, aligning valve hole 2 404 with the upper feed pipe 304 and valve hole 1 403 with the lower feed pipe 305, allowing the fuel to flow through the drying channel. When the humidity is low, the valve plate 402 switches, and the fuel directly enters the furnace through the lower feed pipe 305. The upper output shaft 502 of the motor 501 drives the impeller 503 inside the pump casing 408 to rotate, drawing in waste heat from the boiler. The waste heat enters the spiral heat exchanger tube 410 through the gas supply pipe 409, heating and drying the fuel inside the spiral conveying pipe 413. After drying, the fuel flows by gravity into the lower end of the furnace, mixing and burning with the bed material. During operation, the humidity sensor 306 continuously monitors the humidity, and the valve plate 402 automatically switches channels according to the humidity. Waste heat is continuously recycled to ensure stable fuel humidity and consistent furnace entry conditions.

[0022] The humidity sensor 306 and valve plate 402 work together to automatically regulate the humidity of biomass fuel. High-moisture fuel can be dried in advance, avoiding furnace temperature fluctuations caused by direct feeding. Waste heat from the boiler is used to heat the fuel, effectively recovering waste heat, reducing energy waste, and lowering overall energy consumption. A dual-shaft motor 501 simultaneously drives feeding and waste heat extraction, featuring a simple structure, shared power, low equipment cost, and reliable operation. The dried fuel burns more completely in the furnace, improving combustion efficiency, stabilizing furnace temperature, reducing unburned residue, enhancing fuel utilization, and ensuring continuous and stable boiler operation.

[0023] In the existing structure, the feeding channel is single, lacking humidity detection and drying devices. High-moisture fuel is directly fed into the furnace, leading to a drop in furnace temperature and unstable combustion. Waste heat from the boiler is directly emitted without recovery, resulting in significant energy waste. Adding a 306 humidity sensor, a dual-channel feeding system, and a waste heat drying structure solves the problems of uneven fuel humidity, large furnace temperature fluctuations, waste heat waste, and incomplete combustion.

[0024] By coordinating the feeding structure 300, regulator 400, and power structure 500, the automatic control of biomass fuel humidity and waste heat recovery drying are achieved. The process is simple, the components work together stably, and the operating status is controllable. It effectively solves the problems of uncontrollable humidity, waste heat, and unstable combustion in existing equipment, and has strong overall practicality.

[0025] Example 2: The motor 501 is fixed at the upper end of the lifting pipe 303. The motor 501 is a dual-shaft motor. The upper output end of the motor 501 is provided with an upper output shaft 502. An impeller 503, which is rotatably installed inside the pump casing 408, is sleeved on the outer wall of the upper output shaft 502.

[0026] The lower output end of the motor 501 is provided with a lower output shaft 504 that is rotatably installed inside the lifting tube 303. The outer wall of the lower output shaft 504 is sleeved with a swivel piece 505 that is rotatably installed inside the lifting tube 303. The lower end of the lifting tube 303 is connected to a hopper 301. One end of the hopper 301 is connected to a feeding channel 302. The feeding channel 302 is provided with a conveying mechanism to transport biomass fuel into the hopper 301 for buffering.

[0027] Valve plate 402 has valve hole 1 403 and valve hole 2 404 inside. When valve hole 1 403 corresponds to the lower feed pipe 305, valve hole 2 404 is misaligned with the upper feed pipe 304, and vice versa. Valve plate 402 has symmetrically distributed through holes 406 inside. Valve frame 401 has a guide rod 405 that slides into the through hole 406.

[0028] The suction end of the pump casing 408 is connected to the waste heat of the boiler. The output end of the pump casing 408 is provided with an air supply pipe 409. One end of the air supply pipe 409 is connected to a spiral heat exchange tube 410. One end of the spiral heat exchange tube 410 is connected to an exhaust pipe 411. One end of the upper feed pipe 304 is provided with a spiral conveying pipe 413 located inside the spiral heat exchange tube 410. Both ends of the spiral heat exchange tube 410 are closed. The outer wall of a section inside the spiral heat exchange tube 413 is provided with heat exchange holes distributed at equal intervals. The end of the spiral conveying pipe 413 is provided with an upper feed end pipe 412 that penetrates the spiral heat exchange tube 410.

[0029] In this embodiment, the boiler combustion temperature control mechanism mainly includes a dual-shaft motor 501, a lifting pipe 303, a winch 505, a valve frame 401, a valve plate 402, a hydraulic cylinder 407, a pump casing 408, an impeller 503, a spiral heat exchange tube 410, and a spiral conveying pipe 413. The dual-shaft motor 501 is fixedly installed at the upper end of the lifting pipe 303. The motor 501 has two parts: an upper output shaft 502 and a lower output shaft 504. The lower output shaft 504 extends into the lifting pipe 303, and the winch 505 is fixed to the outer wall of the shaft; the upper output shaft 502 extends into the pump casing 408, and the impeller 503 is fixed to the outer wall of the shaft. The lower end of the lifting pipe 303 is connected to the silo 301, and the silo 301 is connected to the feeding channel 302; the valve frame 401 is connected to the upper feeding pipe 304 and the lower feeding pipe 305, and the valve plate 402 slides up and down in the valve frame 401. The valve plate 402 has a valve hole 1 403, a valve hole 2 404 and a through hole 406. A guide rod 405 is provided in the valve frame 401. The guide rod 405 passes through the through hole 406 to ensure that the valve plate 402 slides smoothly; the hydraulic cylinder 407 is fixed at the upper end of the valve frame 401, and the piston rod is connected to the top of the valve plate 402; one end of the pump casing 408 is connected to the waste heat of the boiler, and the other end is connected to the spiral heat exchange tube 410 through the air supply pipe 409. The spiral conveying pipe 413 is installed in the spiral heat exchange tube 410. The tube wall has heat exchange holes. The pore size of the heat exchange holes is smaller than the biomass fuel specification to ensure the passage of hot air.

[0030] During operation, the feeding channel 302 feeds biomass fuel into the silo 301 for buffering. The lower output shaft 504 of the motor 501 drives the winch 505 to rotate, lifting the fuel in the silo 301 upwards and conveying it to the valve frame 401. The humidity sensor 306 detects the fuel humidity. When the humidity is too high, the hydraulic cylinder 407 pushes the valve plate 402 downwards. The valve hole 2 404 is aligned with the upper feed pipe 304, and the valve hole 1 403 is aligned with the lower feed pipe 305, allowing the fuel to enter the spiral conveying pipe 413. The upper output shaft 502 of the motor 501 drives the impeller 503 to rotate, and the pump casing 408 draws in the boiler waste heat. The waste heat enters the spiral heat exchanger 410 through the gas supply pipe 409, heating and drying the fuel in the spiral conveying pipe 413 through the heat exchange holes. After drying, the fuel flows downwards along the pipe and enters the furnace through the upper feed pipe 304. When the humidity is too low, the hydraulic cylinder 407 drives the valve plate 402 upwards, allowing the fuel to directly enter the furnace through the lower feed pipe 305. During operation, motor 501 runs continuously, screed 505 feeds material stably, impeller 503 extracts waste heat stably, and valve plate 402 smoothly switches channels according to humidity. The whole system operates continuously and is in a stable state.

[0031] The dual-shaft motor 501 enables shared power for both material feeding and waste heat extraction, resulting in a simple structure, fewer components, and convenient installation and maintenance, thus reducing equipment investment. The valve plate 402, with its double valve holes and guide rod 405, ensures smooth and reliable switching of the feeding channel, preventing jamming or leakage. Waste heat enters the spiral heat exchanger tube 410 via the pump casing 408 and air supply pipe 409, where it fully exchanges heat with the fuel, effectively recovering waste heat and reducing energy consumption. High-moisture fuel is pre-dried before entering the furnace, resulting in more complete combustion, stable furnace temperature, reduced temperature fluctuations, improved combustion efficiency, reduced unburned material, increased fuel utilization, and ensured long-term stable boiler operation.

[0032] To avoid the need for two sets of power for feeding and waste heat extraction, which are complex in structure and costly, and the lack of a switching structure in the feeding channel, high-moisture fuel is directly fed into the furnace, resulting in unstable furnace temperature and direct discharge of waste heat, thus wasting energy, the dual-shaft motor 501, dual-channel switching, and waste heat drying are adopted, which solves the problems of power redundancy, single channel, waste heat, and furnace temperature fluctuation.

[0033] Example 3: A biomass combustion fluidized bed boiler includes a furnace structure 100 and a boiler structure 200, wherein the furnace structure 100 includes a furnace body 101. The boiler structure 200 includes an annular boiler 201.

[0034] Cyclone separators 104 are provided on both sides of the furnace body 101. A separation pipe 103 connected to the cyclone separator 104 is provided at the upper end of the furnace body 101. A flue gas outlet is reserved at the upper end of the cyclone separator 104. A bottom hopper 105 is provided at the lower end of the cyclone separator 104. A return pipe 102 for bed material return is connected between the bottom hopper 105 and the furnace body 101.

[0035] In this embodiment, the furnace body 101 serves as the main combustion space of the boiler, with cyclone separators 104 symmetrically installed on both sides. Each cyclone separator 104 is connected to the upper end of the furnace body 101 via a separation pipe 103. The top of each cyclone separator 104 has a flue gas outlet, and the bottom is connected to a hopper 105. The hopper 105 is then connected to the lower part of the furnace body 101 via a return pipe 102, forming a circulation loop for bed material and unburned fuel. During overall installation, the furnace body 101 is centrally located, with the cyclone separators 104 positioned on either side. The separation pipe 103 ensures smooth flue gas outflow, and the return pipe 102 ensures the return of solid materials. All components are securely fixed and tightly connected.

[0036] During operation, biomass fuel is mixed and burned with bed material within the furnace body 101. The high-temperature flue gas, fine bed material particles, and unburned fuel generated by combustion flow upwards together and enter the cyclone separators 104 on both sides through the separation pipe 103. Inside the cyclone separators 104, high-speed rotation generates centrifugal force, throwing the heavier bed material and unburned fuel against the cylinder wall, where they fall into the bottom hopper 105 for temporary storage; the lighter flue gas is discharged from the top flue gas outlet. The bed material and unburned fuel in the bottom hopper 105 are then sent back to the lower part of the furnace body 101 through the return pipe 102 to participate in fluidized combustion again. During operation, flue gas is continuously separated, solid materials are continuously returned, and the bed material in the furnace always maintains a boiling fluidized state, ensuring stable material circulation and continuous combustion.

[0037] The cyclone separators 104 on both sides, in conjunction with the return pipe 102, effectively separate flue gas from solid materials, allowing for the recycling of bed material and unburned fuel, thus reducing fuel waste. The separated flue gas contains fewer impurities, reducing the burden of subsequent processing and improving flue gas emission quality. Material return ensures a stable bed material quantity within the furnace, maintaining good fluidization, resulting in more uniform and complete combustion, and preventing localized high temperatures or flameout. The symmetrical and rational structural layout ensures uniform stress distribution, stable and reliable operation, reduces downtime due to malfunctions, and improves the overall operating efficiency of the boiler.

[0038] With the furnace body 101, cyclone separator 104 and reflux structure as the core, the process flow is simple and the material circulation is smooth.

[0039] Example 4: The annular boiler 201 is suspended at the center of the furnace body 101 and is hollow inside. A converging spherical tank 202 is provided above the furnace body 101. The upper end of the converging spherical tank 202 is connected to a secondary steam pipe 204, and the lower end of the converging spherical tank 202 is connected to a primary steam pipe 203 that is distributed in a ring array and runs through the upper end of the annular boiler 201.

[0040] A diversion tank 205 is provided above the furnace body 101. A water supply pipe 206 is connected to the upper end of the diversion pipe. A water supply pipe 207 arranged in a ring array and penetrating the lower end of the ring boiler 201 is connected to the outer wall of the diversion tank 205.

[0041] The upper feed end pipe 412 and the lower feed pipe 305 both penetrate the furnace body 101. The upper feed pipe 304 is located above the lower feed pipe 305. The upper feed end pipe 412 and the lower feed pipe 305 penetrate the furnace body 101 at the same horizontal height. The spiral heat exchange pipe 410 and the spiral conveying pipe 413 are spirally sleeved on the outside of the furnace body 101, so that the internally heated and dried biomass fuel spirals downward and flows into the lower end of the furnace body 101 and mixes with the bed material.

[0042] In this embodiment, the annular boiler 201 is a hollow annular structure, suspended at the center of the furnace body 101. The collecting spherical tank 202 is installed above the furnace body 101, with multiple primary steam pipes 203 connected to its lower end. The primary steam pipes 203 penetrate the upper interior of the annular boiler 201 and are connected to the secondary steam pipes 204 at their upper ends. The diversion tank 205 is also arranged above the furnace body 101, with a water supply pipe 206 connected to its top and multiple water delivery pipes 207 connected to its outer wall. The water delivery pipes 207 penetrate the lower interior of the annular boiler 201. During overall assembly, the annular boiler 201 is suspended in the center, with the primary steam pipes 203 and water delivery pipes 207 arranged in a circular array. Both ends are connected to the collecting spherical tank 202 and the diversion tank 205, respectively, and the pipe connections are securely sealed.

[0043] During operation, the biomass fuel combustion inside the furnace body 101 generates high temperatures, and the heat is radiated and conducted to the central annular boiler 201. External water enters the distribution tank 205 from the water supply pipe 206, and then flows evenly into the lower end of the annular boiler 201 through the water supply pipe 207. The water is heated and vaporized inside the annular boiler 201 to generate steam. The steam flows upward and is collected in the collection spherical tank 202 through the primary steam pipe 203, and then output for use through the secondary steam pipe 204. During operation, the water continuously flows from bottom to top through the annular boiler 201, constantly absorbing heat and vaporizing, and the steam is stably collected and output. The annular boiler 201 continuously exchanges heat inside and outside, the heat in the furnace is fully absorbed, and the water-steam circulation is continuous and stable.

[0044] The annular boiler 201 is suspended in the center of the furnace, expanding the heating area and allowing direct absorption of heat from the high-temperature region at the furnace center, thus avoiding heat waste. Water is evenly distributed from the distributor tank 205 and enters the annular boiler 201 through the water supply pipe 207, ensuring uniform heating, stable vaporization, and consistent steam production. The primary steam pipes 203 are arranged in a ring, resulting in high steam collection efficiency and smooth transport. The overall structure is simple, heat exchange is sufficient, heat utilization is improved, energy consumption is reduced, and long-term stable steam production from the boiler is guaranteed.

[0045] Existing boilers often fix the heat exchange structure to the inner wall of the furnace, resulting in only the side walls being heated and the central heat being difficult to utilize, leading to low heat exchange efficiency and significant heat waste. By adopting a centrally suspended annular boiler 201, in conjunction with a distribution tank 205 and a converging spherical tank 202, the problems of small heating surface, central heat waste, uneven heat exchange, and unstable steam are solved. With the central annular boiler 201, distribution tank 205, and converging spherical tank 202 as the core, the water-steam circulation process is simple, the heat exchange area is large, the heat absorption is sufficient, and the operating state is stable, effectively making up for the deficiencies of the existing boiler heat exchange structure.

[0046] The above specific embodiments are merely several preferred embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

[0047] 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 invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A boiler combustion temperature regulating mechanism comprising a feeding structure (300), a regulator (400) and a power structure (500), characterized in that: The feeding structure (300) is used to transport biomass fuel. The feeding structure (300) includes a lifting pipe (303), an upper feeding pipe (304), a lower feeding pipe (305), and a humidity sensor (306). The detection end of the humidity sensor (306) is located inside the lifting pipe (303). The lower feeding pipe (305) and the upper feeding pipe (304) are two channels for biomass fuel. The regulator (400) is used to regulate the opening and closing of the lower feed pipe (305) and the upper feed pipe (304). The regulator (400) includes a valve frame (401), a valve plate (402), a hydraulic cylinder (407), a pump housing (408), a spiral heat exchange tube (410), and a spiral conveying pipe (413). The valve frame (401) is connected to the lower feed pipe (305) and the upper feed pipe (304). The valve plate (402) is longitudinally slidably installed inside the valve frame (401). The hydraulic cylinder (407) is fixed at the upper end of the valve frame (401) and its telescopic end is connected to the upper end of the valve plate (402). The power structure (500) provides a power source for the feeding structure (300), and the power structure (500) includes a motor (501) and a pump casing (408).

2. A boiler combustion temperature regulating mechanism according to claim 1, wherein: The motor (501) is fixed at the upper end of the lifting tube (303). The motor (501) is a dual-shaft motor. The upper output end of the motor (501) is provided with an upper output shaft (502). An impeller (503) that is rotatably installed inside the pump casing (408) is sleeved on the outer wall of the upper output shaft (502).

3. A boiler combustion temperature regulating mechanism according to claim 1, wherein: The lower output end of the motor (501) is provided with a lower output shaft (504) rotatably installed inside the lifting tube (303). The outer wall of the lower output shaft (504) is sleeved with a swivel piece (505) rotatably installed inside the lifting tube (303). The lower end of the lifting tube (303) is connected to a hopper (301). One end of the hopper (301) is connected to a feeding channel (302). The feeding channel (302) is provided with a conveying mechanism to transport biomass fuel into the hopper (301) for buffering.

4. A boiler combustion temperature regulating mechanism according to claim 1, wherein: The valve plate (402) has a valve hole 1 (403) and a valve hole 2 (404) inside. When the valve hole 1 (403) corresponds to the lower feed pipe (305), the valve hole 2 (404) is misaligned with the upper feed pipe (304), and vice versa. The valve plate (402) has symmetrically distributed through holes (406) inside. The valve frame (401) is provided with a guide rod (405) that slides into the through hole (406).

5. The boiler combustion temperature control mechanism according to claim 1, characterized in that: The pump casing (408) has its suction end connected to the waste heat of the boiler. The pump casing (408) has its output end equipped with an air supply pipe (409). One end of the air supply pipe (409) is connected to a spiral heat exchange tube (410). One side of the end of the spiral heat exchange tube (410) is connected to an exhaust pipe (411). One end of the upper feed pipe (304) is equipped with a spiral conveying pipe (413) located inside the spiral heat exchange tube (410). Both ends of the spiral heat exchange tube (410) are closed. The spiral conveying pipe (413) has heat exchange holes evenly distributed on the outer wall of a section inside the spiral heat exchange tube (410). The end of the spiral conveying pipe (413) is equipped with an upper feed end pipe (412) that penetrates the spiral heat exchange tube (410).

6. A biomass combustion fluidized bed boiler, characterized in that: The boiler combustion temperature control mechanism according to any one of claims 1-5 is used, including a furnace structure (100) and a boiler structure (200), wherein the furnace structure (100) includes a furnace body (101). The boiler structure (200) includes an annular boiler (201).

7. A biomass combustion fluidized bed boiler according to claim 6, characterized in that: Cyclone separators (104) are provided on both sides of the furnace body (101). A separation pipe (103) connected to the cyclone separator (104) is provided at the upper end of the furnace body (101). A flue gas outlet is reserved at the upper end of the cyclone separator (104). A bottom hopper (105) is provided at the lower end of the cyclone separator (104). A return pipe (102) for bed material return is connected between the bottom hopper (105) and the furnace body (101).

8. A biomass combustion fluidized bed boiler according to claim 7, characterized in that: The annular boiler (201) is suspended at the center of the furnace body (101) and is hollow inside. A converging spherical tank (202) is provided above the furnace body (101). The upper end of the converging spherical tank (202) is connected to a secondary steam pipe (204), and the lower end of the converging spherical tank (202) is connected to a primary steam pipe (203) that is arranged in a ring array and runs through the upper end of the annular boiler (201).

9. A biomass combustion fluidized bed boiler according to claim 8, characterized in that: A diversion tank (205) is provided above the furnace body (101). A water supply pipe (206) is connected to the upper end of the diversion pipe. A water supply pipe (207) arranged in a ring array and penetrating the lower end of the ring boiler (201) is connected to the outer wall of the diversion tank (205).

10. A biomass combustion fluidized bed boiler according to claim 9, characterized in that: The upper feed end pipe (412) and the lower feed pipe (305) both penetrate the furnace body (101). The upper feed pipe (304) is located above the lower feed pipe (305). The upper feed end pipe (412) and the lower feed pipe (305) penetrate the furnace body (101) at the same horizontal height. The spiral heat exchange pipe (410) and the spiral conveying pipe (413) are both spirally sleeved on the outside of the furnace body (101), so that the internally heated and dried biomass fuel spirals downward and flows into the lower end of the furnace body (101) and mixes with the bed material.

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