A wide load regulation system for biomass fluidized bed boiler

Abstract

The invention relates to a wide load regulation system of a biomass fluidized bed boiler in the field of boiler technology, comprising a furnace, a separator, a burnout chamber and a flue connected in sequence, and a primary air mechanism and a secondary air mechanism for supplying air to the furnace and the burnout chamber. The invention provides a first air distribution plate for forming a vertical airflow at the bottom and a second air distribution plate for forming a horizontal airflow at the side, and forms a gas-solid phase mixed state similar to turbulence under the combined action of the horizontal airflow and the vertical airflow by the particulate material, effectively improves the combustion efficiency and increases the high load value of the system, and at the same time, because the two air distribution plates jointly divert the primary air, the hood area of ​​the first air distribution plate that plays a major role in fluidization is relatively reduced, and the reduction of the hood area can achieve a predetermined critical fluidization wind speed under the same air volume, so that under low load conditions, that is, when the fluidization air is completely provided by the first air distribution plate, the air intake of the first air distribution plate can match the critical fluidization wind speed required to be achieved, thereby realizing low-nitrogen combustion under low load conditions, relatively reducing the low load value of the system, effectively achieving the purpose of wide load regulation operation of the system, and achieving better energy-saving and emission reduction effects.

Description

Technical Field

[0001] The invention relates to the technical field of boilers, and in particular to a wide load regulation system for a biomass fluidized bed boiler. Background Art

[0002] Biomass power plant projects with combined heat and power and pure heating can bring stable profits, so biomass heating boilers have developed rapidly. However, the load of heating boilers in actual operation varies with the user end, resulting in a large adjustment range of boiler operating load, and the following problems often occur:

[0003] At low load, in order to ensure the fluidization quality of the bed material, the primary air volume of the boiler cannot be reduced synchronously, and the oxygen content of the boiler is high, resulting in high nitrogen oxide emissions, which is difficult to meet environmental protection requirements. To control the oxygen content in the dense phase area of ​​the furnace, the current conventional solution is to use the flue gas recirculation method, mixing a certain proportion of the exhaust fan outlet tail flue gas into the primary air to reduce the oxygen content in the air, while reducing the oxygen content in the furnace and ensuring fluidization. However, since the flue gas of the biomass boiler contains corrosive gases and a certain amount of fine particles remain after dust removal, the service life of the primary fan is severely shortened. In addition, a separate recirculation fan needs to be configured to increase the factory electricity consumption. There are also some existing technologies that reduce the area of ​​the air distribution plate to improve the fluidization quality of the air distribution plate, but this method leads to a weakening of the boiler's load capacity and serious backflow of the furnace flue gas.

[0004] When the load is high or the fuel entering the furnace deviates from the design value, the cyclone separator will overheat and coke will form on the inner wall of the separator, resulting in blockage of the lower cone section of the separator, reduced separator efficiency, poor boiler operation, and other problems. The conventional solution to coke in the separator is to use manual or mechanical coke removal, or to add air cannons at the coke-hanging location, but the coke removal effect is not good, and there is no adjustment method to prevent the separator from overheating. Therefore, it is urgent to develop new technologies to solve the above problems encountered by biomass heating boilers. Summary of the invention

[0005] In view of the defects in the prior art, the object of the present invention is to provide a wide load regulation system for a biomass fluidized bed boiler.

[0006] A wide load regulation system for a biomass fluidized bed boiler provided by the present invention comprises a furnace, a separator, a burnout chamber, a flue, a primary air mechanism and a secondary air mechanism;

[0007] A wind chamber is provided at the bottom of the furnace, a first air distribution plate is provided at the top of the wind chamber, a hood is provided on the first air distribution plate, and a vertical air flow is ejected from the hood toward the top of the furnace, a feed port and a second air distribution plate are provided on the front wall of the furnace, the second air distribution plate is located between the feed port and the first air distribution plate, the second air distribution plate is connected to a wind box located outside the furnace, the second air distribution plate is provided with a nozzle, and a horizontal air flow is ejected from the nozzle toward the rear wall of the furnace, and the primary air mechanism is connected to the wind chamber and the wind box through a pipeline, respectively, and independently controls the air intake volume;

[0008] The top outlet of the furnace is communicated with the inlet of the separator, the material outlet of the separator is communicated with the furnace, the smoke outlet of the separator is communicated with the inlet of the burnout chamber, the outlet of the burnout chamber is communicated with the flue, a first air duct is arranged in the furnace, the first air duct is located above the feed inlet, and the secondary air mechanism is communicated with the first air duct through a pipeline;

[0009] The material entering from the feed port is fluidized under the action of the first air distribution plate alone or the joint action of the first air distribution plate and the second air distribution plate. The smoke temperature generated in the furnace is adjusted by regulating the air volume entering the first air duct, and the smoke fluid enters the burnout chamber from the separator.

[0010] In some embodiments, the lower part of the furnace includes a column section and a cone section, the lower end of the column section is connected to the wind chamber, and the upper end of the column section is connected to the cone section;

[0011] The inclination angle a of the front wall of the cone section is 20° to 30°, the feed port and the second air distribution plate are located on the cone section, and the vertical height h between the feed port and the second air distribution plate is 1000 to 1500 mm.

[0012] In some embodiments, the first air distribution plate includes a blocking area and a hood area, the blocking area is a non-ventilated area, the hood area is formed by a plurality of hoods in an array, the blocking area is adjacent to the front wall of the furnace, the hood area is adjacent to the rear wall of the furnace, and the hood area occupies 70% to 80% of the area of ​​the first air distribution plate.

[0013] In some embodiments, a check baffle is provided in the second air distribution plate, and the check baffle is close to the nozzle outlet.

[0014] In some embodiments, a second air duct is provided in the burnout chamber, and the secondary air mechanism is connected to the first air duct and the second air duct through pipelines respectively and independently controls the air intake volume.

[0015] In some implementations, the second air ducts arranged in the burnout chamber are multi-layered, and the multi-layered second air ducts are arranged in vertical intervals.

[0016] In some implementations, the ratio of the air intake volume of the first air duct to the air intake volume of the second air duct is 1:3-2:3.

[0017] In some embodiments, a steam pipe is further included, wherein the steam pipe is provided with a plurality of steam nozzles, the steam pipe surrounds the outside of the lower cone section of the separator, and the steam nozzles extend into the lower cone section of the separator and are arranged tangent to the inner surface.

[0018] In some embodiments, the flue includes a first flue and a second flue that are connected in sequence, a superheater is provided in the first flue, and an SCR device and an economizer are provided in the second flue from top to bottom.

[0019] In some embodiments, a flue gas bypass duct is further included, wherein the inlet of the flue gas bypass duct is connected to the outlet of the burnout chamber, and the outlet of the flue gas bypass duct is connected to the inlet of the second flue. When the inlet flue gas temperature of the SCR device is lower than a predetermined standard value, the flue gas bypass duct is opened to introduce high-temperature flue gas.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The wide load regulation system of the biomass fluidized bed boiler of the present invention is provided with a first air distribution plate for forming a vertical airflow at the bottom and a second air distribution plate for forming a horizontal airflow at the side. The particulate material forms a gas-solid mixed state that is approximately turbulent under the combined action of the horizontal airflow and the vertical airflow, thereby effectively improving the combustion efficiency and increasing the high load value of the system. At the same time, since the two air distribution plates jointly divert the primary air, the hood area of ​​the first air distribution plate that plays a major fluidizing role is relatively reduced. The reduction in the hood area can achieve a predetermined critical fluidizing wind speed under the same air volume, so that under low-load conditions, that is, when the fluidizing air is completely provided by the first air distribution plate, the air intake of the first air distribution plate can match the required critical fluidizing wind speed, thereby realizing low-nitrogen combustion under low-load conditions, relatively reducing the low load value of the system, effectively achieving the purpose of wide load regulation operation of the system, and achieving better energy-saving and emission reduction effects.

[0022] 2. The wide load regulation system of the biomass fluidized bed boiler of the present invention improves the fluidization effect of the particulate material and ensures the stable operation of the system within a wide load range by optimizing the design of the structure and arrangement of the first air distribution plate and the second air distribution plate.

[0023] 3. The wide load regulation system of the biomass fluidized bed boiler of the present invention divides a branch of the secondary air into the burnout chamber. By adjusting the ratio of the secondary air entering the furnace and the burnout chamber, the complete combustion of the material under high load is met, and the high load value that the system can withstand is increased. It can also effectively reduce the smoke temperature in the furnace and the separator under high load conditions, thereby improving the load regulation capability of the system.

[0024] 4. The wide load regulation system of the biomass fluidized bed boiler of the present invention achieves the purpose of timely and rapid cooling by setting a steam pipe for cooling the separator, thereby preventing the problem of coke hanging and blockage in the separator caused by excessively high smoke temperature.

[0025] 5. The wide load regulation system of the biomass fluidized bed boiler of the present invention ensures the denitrification effect of the SCR device by setting an independently controlled bypass flue gas pipeline between the burnout chamber and the flue. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0027] Figure 1 It is a structural schematic diagram of a wide load regulation system of a biomass fluidized bed boiler according to the present invention;

[0028] Figure 2 It is a structural schematic diagram of the dense phase zone of the furnace of the present invention;

[0029] Figure 3 for Figure 2 A schematic diagram of the enlarged structure of the middle part A;

[0030] Figure 4 It is a left view of the structural schematic diagram of the second air distribution plate;

[0031] Figure 5 is a schematic structural diagram of a first air distribution plate;

[0032] Figure 6 It is a top view of a single-layer steam pipeline of a separator temperature control device; DETAILED DESCRIPTION

[0033] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0034] Example 1

[0035] The present embodiment provides a wide load regulation system for a biomass fluidized bed boiler, which mainly includes a furnace 100, a separator 200, a burnout chamber 300 and a flue 400 which are connected in sequence, and a primary air mechanism 500 and a secondary air mechanism 600 which mainly supply air to the furnace 100 and the burnout chamber 300.

[0036] The furnace 100 is the main combustion chamber of the material, and a wind chamber 110 is provided at the bottom thereof. A first air distribution plate 120 is provided at the top of the wind chamber 110. A plurality of air caps 121 are provided on the first air distribution plate 120. The plurality of air caps 121 are arranged in an array, and at least one slag discharge hole 124 is provided between the air caps 121. The first air distribution plate 120 is the main component for fluidization of the material. The airflow ejected from the air caps 121 flows toward the top outlet direction of the furnace 100 as a whole, that is, it is basically a vertical airflow. A feed port 130 is provided at a predetermined height from the first air distribution plate 120 on the front wall of the furnace 100, and the phase area where the material burns in the furnace 100 is basically divided by the feed port 130, that is, the area from the feed port 130 to the first air distribution plate 120 is a dense phase area, and the area above the feed port 130 is a dilute phase area. A second air distribution plate 140 is installed on the front wall of the furnace 100 between the feed port 130 and the first air distribution plate 120. The second air distribution plate 140 is located below the same side of the feed port 130. The second air distribution plate 140 is connected to a wind box 150 disposed outside the furnace 100. The second air distribution plate 140 is provided with a nozzle 141. The wind entering the second air distribution plate 140 from the wind box 150 is blown out horizontally toward the rear wall of the furnace 100 through the nozzle 141. A first air duct 160 is installed in the furnace 100 above the feed port 130. The primary air mechanism 500 mainly includes a first fan 510 and a first air temperature regulator 520. After the air output from the first fan 510 is adjusted in temperature by the first air temperature regulator 520, it is respectively sent to the wind chamber 110 and the wind box 150 through two parallel and independently controlled branch pipes. The secondary air mechanism 600 mainly includes a second fan 610 and a second air temperature regulator 620. The air output from the second fan 610 is temperature-regulated by the second air temperature regulator 620 and then communicated with the first air duct 160 through a pipeline.

[0037] The outlet of the furnace 100 is connected to the inlet of the separator 200, the flue gas outlet of the separator 200 is connected to the inlet of the burnout chamber 300, and the material outlet of the separator 200 is connected to the furnace 100, and the connection point between the furnace 100 and the material outlet of the separator 200 is basically flush with the feed port 130. The outlet of the burnout chamber 300 is connected to the inlet of the flue 400, and the flue 400 is provided with a corresponding superheater 430, an SCR device 440 and an economizer 450. In this embodiment, the flue 400 is divided into a first flue 410 and a second flue 420, the inlet of the first flue 410 is connected to the outlet of the burnout chamber 300, and the inlet of the second flue 420 is connected to the outlet of the first flue 410. The superheater 430 is arranged in the first flue 410, and the SCR device 440 and the economizer 450 are arranged in the second flue 420 from upstream to downstream.

[0038] The working principle of the wide load regulation system of the biomass fluidized bed boiler provided in this embodiment is as follows: under normal operating conditions, the first fan 510 and the second fan 610 are turned on, and the wind output from the first fan 510 is adjusted to a predetermined temperature by the first wind temperature regulator 520 and then respectively introduced into the wind chamber 110 and the wind box 150, and the air volume introduced into the wind chamber 110 and the wind box 150 is adjusted according to the amount of material. At this time, a horizontal airflow toward the rear wall is ejected from the nozzle 141 of the second air distribution plate 140, and a vertical airflow toward the top outlet of the furnace 100 is ejected from the wind cap 121 of the first air distribution plate 120, and the wind output from the second fan 610 is adjusted to a predetermined temperature by the second wind temperature regulator 620 and then sent to the dilute phase zone through the first air duct 160. After the granular material enters from the feed port 130, the horizontal airflow force blown out by the nozzle 141 is applied to the falling material particles, so that the material particles move in the horizontal direction and disperse in the process of movement. The dispersed material particles have a tendency to form laminar flow, and the vertical airflow force blown out by the wind cap 121 will further disperse the material particles with laminar flow effect, and the material particles form a gas-solid phase mixed state that is close to turbulence under the combined force of the horizontal airflow and the vertical airflow, effectively improving the full combustion effect of the material in the dense phase area. The unburned material particles rise to the dilute phase area with the airflow, and the amount of air required for the unburned material particles to continue to burn is guaranteed by adjusting the airflow volume blown out from the first air duct 160. The flue gas mixed with a small amount of material particles continues to rise from the dilute phase area and enters the separator 200 from the outlet of the furnace 100. After separation in the separator 200, the flue gas separated by the separator 200 enters the burnout chamber 300 through the flue gas outlet to continue to burn the combustibles, and the material particles separated by the separator 200 enter the dense phase area in the furnace 100 from the material outlet again to continue to participate in the combustion. The high-temperature flue gas after combustion in the burnout chamber 300 passes through the first flue 410 and the second flue 420 in turn, and the superheater 430, SCR device 440 and economizer 450 located therein perform corresponding work. Under low-load conditions, the pipeline connected to the wind box 150 is closed, and the nozzle 141 of the second air distribution plate 140 no longer sprays. Due to the small amount of feed, the vertical airflow sprayed by the wind cap 121 of the first air distribution plate 120 can meet the requirements of material fluidization, so that the granular material forms a fluidized state and meets the requirements of full combustion in the dense phase area. During high-load conditions, the first air distribution plate 120 and the second air sealing plate 140 work at full load, and the burnout chamber 300 is increased to bear the combustion workload of the unburned flue gas flow in the furnace 100 .

[0039] In the present embodiment, a first air distribution plate for forming a vertical airflow is arranged at the bottom, and a second air distribution plate for forming a horizontal airflow is arranged at the side. The particulate material forms a gas-solid mixed state that is approximately turbulent under the combined action of the horizontal airflow and the vertical airflow, thereby effectively improving the combustion efficiency and increasing the high load value of the system. At the same time, since the two air distribution plates jointly divert the primary air, the hood area of ​​the first air distribution plate that plays a major fluidizing role is relatively reduced. The reduction in the hood area can achieve a predetermined critical fluidizing wind speed under the same air volume, so that under low-load conditions, when the fluidizing air is completely provided by the first air distribution plate, the air intake of the first air distribution plate can match the required critical fluidizing wind speed, thereby achieving low-nitrogen combustion under low-load conditions, relatively reducing the low-load value of the system, and effectively achieving the purpose of wide load regulation operation of the system, and obtaining better energy-saving and emission reduction effects.

[0040] Example 2

[0041] This embodiment 2 is formed on the basis of embodiment 1, and through the optimization design of the structure and arrangement of the first air distribution plate and the second air distribution plate, the fluidization effect of the particulate material is improved to ensure the stable operation of the system within a wide load range. Specifically:

[0042] The dense phase section of the furnace 100 includes a column section 101 and a cone section 102 connected in sequence from bottom to top. The feed port 130 and the second air distribution plate 140 are both arranged on the front wall of the cone section 102. At this time, the front wall is an inclined surface, and its inclination angle a is 20° to 30°. The vertical height between the feed port 130 and the second air distribution plate 140 is 1000 to 1500 mm. After entering from the feed port 130, the material falls in a parabolic manner. Since the second air distribution plate 140 is located at a certain distance below and closer to the rear wall relative to the feed port 130, the material falling to the position of the second air distribution plate 140 can be closer to the front side of the nozzle 141 of the second air distribution plate 140 in the horizontal direction, and thus the horizontal airflow ejected by the nozzle 141 can be fully utilized, avoiding the problem of weakening of the horizontal airflow force caused by the parabolic fall of the granular material away from the nozzle 141. In this embodiment, a check baffle 142 is disposed inside the second air distribution plate 140 , and the check baffle 142 is close to the air outlet of the nozzle 141 , so as to effectively prevent the nozzle 141 from being blocked due to the entry of materials.

[0043] Furthermore, the first air distribution plate 120 is designed as an eccentric structure, and the so-called eccentric structure means that the first air distribution plate 120 includes a blocking area 122 and a hood area 123, and the blocking area 122 and the hood area 123 are arranged side by side, so that the hood 121 is not arranged symmetrically with respect to the center axis of the first air distribution plate 120, but is arranged eccentrically to one side. Among them, the blocking area 122 on the first air distribution plate 120 can be covered with casting material, and the area of ​​the hood area 123 on the first air distribution plate 120 accounts for 70%-80%. After the first air distribution plate 120 is installed on the top of the air chamber 110, its blocking area 122 is adjacent to the front wall of the furnace 100, and the hood area 123 is adjacent to the rear wall of the furnace 100. Due to the horizontal airflow formed by the second air distribution plate 140, there are fewer particulate materials near the front wall. Therefore, there is little need to set the wind hood 121 below. In addition, the vertical airflow generated by the wind hood 121 will also affect the outflow of the particulate materials. The problem can be completely avoided by adopting an eccentric structure for the distribution of the wind hood 121 on the first air distribution plate 120. In addition, due to the reduction in the area of ​​the wind hood of the first air distribution plate, it can effectively adapt to the balanced control of material fluidization and the required oxygen amount under low load conditions, thereby ensuring the fluidization effect.

[0044] Example 3

[0045] This embodiment 3 is formed on the basis of embodiment 1 or embodiment 2, and a branch of the secondary air is separated and passed into the burnout chamber. By adjusting the ratio of the secondary air entering the furnace and the burnout chamber, the complete combustion of the material under high load is met, the high load value that the system can withstand is increased, and the smoke temperature in the furnace and the separator under high load conditions can be effectively reduced, thereby improving the load adjustment capacity of the system. Specifically:

[0046] The burnout chamber 300 is also provided with a second air duct 310, which is multi-layered and arranged in the burnout chamber 300 in an upper and lower interval manner. The wind output by the second fan 610 is divided into two independently controlled branches after the temperature is adjusted by the second air temperature regulator 620, and is respectively connected to the first air duct 160 and the second air duct 310. The first air duct 160 provides the air required for partial combustion for the dilute phase zone in the furnace 100, and the second air duct 310 provides the required air for complete combustion in the burnout chamber 300. Under high load conditions, by reducing the air volume ratio entering the first air duct 160, the material in the furnace 100 is not completely burned, and the temperature of the furnace and the smoke entering the separator 200 are reduced. The incompletely burned material is completely burned in the burnout chamber 300 through the stratified ventilation of the second air duct 310, and the high-temperature smoke generated is passed into the flue 400, and the heat is absorbed and utilized by the device arranged in the flue 400. Under high-load conditions, the load value that the system can withstand is increased by increasing the combustion ratio in the burnout chamber, and by reducing the combustion ratio in the furnace, the stable operation of the furnace and separator is guaranteed, and the coke blockage in the separator caused by excessively high smoke temperature is reduced.

[0047] In this embodiment, the air volume ratio of the gas output by the second fan 610 and temperature-adjusted by the second air temperature controller 620 to the first air duct 160 and the second air duct 310 is in the range of 1:3 to 2:3. Preferably, the air volume ratio of the first air duct 160 and the second air duct 310 is 1:2, which can effectively meet the smoke temperature control in the furnace 100 and the complete combustion of the material in the burnout chamber 300.

[0048] Example 4

[0049] This embodiment 4 is formed on the basis of any one of the embodiments 1-3, and by setting a steam pipeline for cooling the separator, the purpose of timely and rapid cooling is achieved, and the problem of coke hanging and blockage in the separator caused by excessively high smoke temperature is prevented. Specifically:

[0050] It also includes a steam pipe 700, on which a plurality of steam nozzles 710 are arranged. The steam pipe 700 is arranged in a circumferential manner outside the cone section at the bottom of the separator 200, and the outlet of the steam nozzle 710 extends to the inside of the separator 200 and is arranged tangent to the inner surface of the cone section. In this embodiment, there are four steam nozzles 710 connected to the steam pipe 700, and the four steam nozzles 710 are evenly distributed along the circumference. By spraying the boiler steam on the inner wall surface of the cone section at the bottom of the separator 200 through the steam nozzle 710 of the steam pipe 700, the smoke temperature at the cone section of the separator 200 can be quickly adjusted, and the coke and ash hanging on the inner wall can be effectively removed, so as to avoid the coke hanging and clogging on the inner wall of the separator, resulting in a decrease in separator efficiency and poor boiler operation. In some embodiments, the steam pipe 700 is arranged in multiple layers according to the height of the cone section of the separator 200, and each layer of the steam pipe 700 is provided with an electric regulating door for independent control.

[0051] Example 5

[0052] This embodiment 5 is formed on the basis of any one of the embodiments 1-4, and an independently controlled bypass flue gas pipeline is provided between the burnout chamber and the flue to ensure the denitration effect of the SCR device. Specifically:

[0053] A flue gas bypass pipe 800 is provided between the burnout chamber 300 and the second flue 420. The inlet of the flue gas bypass pipe 800 is connected to the outlet of the burnout chamber 300, and the outlet thereof is connected to the inlet of the second flue 420. The flue gas bypass pipe 800 is independently controlled to open and close by an electric damper. When the system is running at low load, the overall flue gas temperature of the boiler is low. At this time, the electric damper is opened to send the flue gas at the outlet of the burnout chamber 300 directly to the inlet of the SCR device 430 located upstream of the second flue 420 through the flue gas bypass pipe 800, so as to ensure the working temperature of the SCR device, ensure the SCR denitrification efficiency at low load and extend the service life of the catalyst, so as to achieve high-efficiency and low-pollution combustion.

[0054] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0055] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A wide load regulation system for a biomass fluidized bed boiler, characterized in that: It comprises a furnace (100), a separator (200), a burnout chamber (300), a flue (400), a primary air mechanism (500) and a secondary air mechanism (600); A wind chamber (110) is provided at the bottom of the furnace (100), a first wind distribution plate (120) is provided at the top of the wind chamber (110), a wind cap (121) is provided on the first wind distribution plate (120), and a vertical airflow is ejected from the wind cap (121) toward the top of the furnace (100), a feed inlet (130) and a second wind distribution plate (140) are provided on the front wall of the furnace (100), and the second wind distribution plate (140) is located at the feed inlet (130). 0) and the first air distribution plate (120), the second air distribution plate (140) is in communication with a wind box (150) located outside the furnace (100), the second air distribution plate (140) is provided with a nozzle (141), and a horizontal air flow is sprayed from the nozzle (141) toward the rear wall of the furnace (100), and the primary air mechanism (500) is respectively in communication with the wind chamber (110) and the wind box (150) through a pipeline and independently controls the air intake volume; The top outlet of the furnace (100) is in communication with the inlet of the separator (200), the material outlet of the separator (200) is in communication with the furnace (100), the smoke outlet of the separator (200) is in communication with the inlet of the burnout chamber (300), the outlet of the burnout chamber (300) is in communication with the flue (400), a first air duct (160) is arranged in the furnace (100), the first air duct (160) is located above the feed port (130), and the secondary air mechanism (600) is in communication with the first air duct (160) through a pipeline; The material entering from the feed port (130) is fluidized under the action of the first air distribution plate (120) alone or under the joint action of the first air distribution plate (120) and the second air distribution plate (140). The temperature of the smoke generated in the furnace (100) is adjusted by regulating the air volume entering the first air duct (160), and the smoke fluid enters the burnout chamber (300) from the separator (200).

2. The wide load regulation system for biomass fluidized bed boiler according to claim 1 is characterized in that: The lower part of the furnace (100) comprises a column section (101) and a cone section (102); the lower end of the column section (101) is connected to the wind chamber (110), and the upper end of the column section (101) is connected to the cone section (102); The inclination angle a of the front wall of the cone section (102) is 20° to 30°, the feed port (130) and the second air distribution plate (140) are located on the cone section (102), and the vertical height h between the feed port (130) and the second air distribution plate (140) is 1000 to 1500 mm.

3. The wide load regulation system for biomass fluidized bed boiler according to claim 2 is characterized in that: The first air distribution plate (120) includes a blocking area (122) and a hood area (123), wherein the blocking area (122) is a non-ventilated area, and the hood area (123) is formed by a plurality of hoods (121) in an array, wherein the blocking area (122) is adjacent to a front wall of the furnace (100), and the hood area (123) is adjacent to a rear wall of the furnace (100), and the hood area (123) occupies 70% to 80% of the area of ​​the first air distribution plate (120).

4. The wide load regulation system for biomass fluidized bed boiler according to claim 2 is characterized in that: A non-return baffle (142) is provided inside the second air distribution plate (140), and the non-return baffle (142) is close to the outlet of the nozzle (141).

5. The wide load regulation system for biomass fluidized bed boiler according to claim 1, characterized in that: A second air duct (310) is provided in the burnout chamber (300), and the secondary air mechanism (600) is connected to the first air duct (160) and the second air duct (310) respectively through pipelines and independently controls the air intake volume.

6. The wide load regulation system for biomass fluidized bed boiler according to claim 5, characterized in that: The second air duct (310) arranged in the burnout chamber (300) is multi-layered, and the multi-layered second air duct (310) is arranged at intervals up and down.

7. The wide load regulation system for biomass fluidized bed boiler according to claim 5, characterized in that: The ratio of the air intake volume of the first air duct (160) to that of the second air duct (310) is 1:3-2:

3.

8. The wide load regulation system for biomass fluidized bed boiler according to claim 1, characterized in that: It also includes a steam pipe (700), wherein the steam pipe (700) is provided with a plurality of steam nozzles (710), and the steam pipe (700) surrounds the outside of the lower conical section of the separator (200), and the steam nozzles (710) extend into the lower conical section of the separator (200) and are arranged tangent to the inner surface.

9. The wide load regulation system for biomass fluidized bed boiler according to claim 1, characterized in that: The flue (400) comprises a first flue (410) and a second flue (420) which are connected in sequence, wherein a superheater (430) is arranged in the first flue (410), and an SCR device (440) and an economizer (450) are arranged in the second flue (420) from top to bottom.

10. The wide load regulation system for biomass fluidized bed boiler according to claim 9, characterized in that: It also includes a flue gas bypass pipe (800), the inlet of the flue gas bypass pipe (800) is connected to the outlet of the burnout chamber (300), and the outlet of the flue gas bypass pipe (800) is connected to the inlet of the second flue (420). When the inlet flue gas temperature of the SCR device (440) is lower than a predetermined standard value, the flue gas bypass pipe (800) is opened to introduce high-temperature flue gas.

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