Coal-fired boiler coupled with biomass gas combustion device and combustion system arrangement method thereof

Abstract

The present invention provides a coal-fired boiler coupled with a biomass gas combustion device and a method for arranging its combustion system, and belongs to the technical field of boiler combustion devices and methods for arranging their combustion systems. The biomass gas combustion device of the present invention is arranged in a wind box, a central air duct is fixed in a gas channel, the central air duct and the gas channel are arranged in concentric circles, a secondary air duct is fixed outside the rear end of the gas channel, the secondary air duct and the gas channel are arranged in concentric circles, a secondary air swirl device is fixed at the air inlet end of the secondary air duct, a central air swirl device is arranged at the rear end in the central air duct, a gas swirl device is provided between the rear end of the gas channel and the rear end of the central air duct, and a central air introduction channel is fixed at a position centered in front and behind the gas channel and communicates with the central air duct. Using the method for arranging the combustion system of a coal-fired boiler coupled with a biomass gas combustion device, the biomass gas combustion device is arranged between the upper pulverized coal burner and the OFA burner.

Description

Technical Field

[0001] The invention relates to a coal-fired boiler coupled biomass gas combustion device and a combustion system arrangement method thereof, belonging to the technical field of boiler combustion devices and combustion system arrangement methods thereof. Background Art

[0002] In the biomass gasification coupled coal-fired unit power generation system, the gas composition of the gasifier is unstable and the calorific value fluctuates greatly due to the changes in the type of biomass fuel and the operating conditions of the gasifier itself. After a large amount of low calorific value gas is sprayed into the furnace, if the combustion conditions are not organized well, it may have a great impact on the combustion air dynamic field in the furnace, thereby affecting the fuel burnout, nitrogen oxide emissions and boiler efficiency. At present, the existing biomass gas burners are mainly designed for biomass gas with stable gas composition and fixed calorific value. Most of them have complex structures and are mostly used in gas furnaces that burn pure biomass gas. Generally, they do not have low nitrogen capabilities. Summary of the invention

[0003] In order to promote the progress of domestic biomass co-combustion power generation technology and accelerate the pace of renewable energy transformation, the present invention needs to solve the problem of stable combustion of biomass gas whose composition and calorific value fluctuate in a wide range, and at the same time select a suitable nozzle layout position to avoid a significant adverse effect on the combustion of coal-fired boilers after being sprayed into the furnace. Further, a coal-fired boiler coupled biomass gas combustion device and a combustion system layout method thereof are provided.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] A coal-fired boiler coupled with a biomass gas combustion device comprises: a biomass gas combustion device, a central wind swirl device, a central air cylinder, a gas swirl device, a gas channel, a secondary air duct, a secondary wind swirl device, a secondary air door adjustment mechanism, a secondary air door adjustment rod, a positioner, a secondary air door indication scale, a central wind introduction channel, a central air volume adjustment baffle, a conical blunt body, a central wind baffle block, a secondary air volume adjustment device limit block, a central wind baffle plate adjustment mechanism, a central wind baffle plate opening indication scale, a pointer and a bellows, the biomass gas combustion device is arranged in the bellows, the central wind cylinder is fixed in the gas channel, the central wind cylinder and the gas channel are arranged in concentric circles, the secondary air duct is fixed to the outside of the rear end of the gas channel, the secondary air duct and the gas channel are arranged in concentric circles, the secondary wind swirl device is fixed to the air inlet end of the secondary air duct, the central wind swirl device is arranged at the rear end in the central wind cylinder, a gas swirl device is arranged between the rear end of the gas channel and the rear end of the central wind cylinder, the central wind introduction channel The channel is fixed at a position centered in the front and rear of the gas channel and is connected to the central air duct, a central air volume adjustment baffle is provided in the central air introduction channel, a conical blunt body is arranged on the central air introduction channel, a central air block is fixed on the inner wall of the central air duct corresponding to the outlet of the central air introduction channel, a secondary air volume adjustment device limit block is fixed on the outer wall of the gas channel, a secondary air door adjustment mechanism is arranged on the outer wall of the gas channel near the secondary air inlet, one end of the central air baffle adjustment mechanism is connected to the central air volume adjustment baffle, and the other end of the central air baffle adjustment mechanism is in contact with the central air baffle opening indicator scale, a positioner is fixed on the front end plate of the biomass gas combustion device, one end of the secondary air door adjustment rod is fixedly connected to the secondary air door adjustment mechanism, the other end of the secondary air door adjustment rod is movably connected to the positioner, one end of the pointer is fixed on the other end of the secondary air door adjustment rod, and the other end of the pointer is in contact with the secondary air door indicator scale fixed on the front end plate of the biomass gas combustion device.

[0006] A combustion system arrangement method using a coal-fired boiler coupled with a biomass gas combustion device, wherein the biomass gas combustion device is arranged between an upper layer pulverized coal burner and an OFA burner.

[0007] Beneficial effects of the present invention:

[0008] 1. The present invention proposes a method for arranging a coal-fired coupled biomass gas combustion system suitable for a hedge boiler. The biomass gas injection position is reasonably arranged between the main combustion zone and the burnout zone. The gas injection position is located in the high-temperature zone of the furnace, which effectively avoids the problem of unstable combustion caused by unstable biomass gas composition and large fluctuations in calorific value, and fully ensures the boiler efficiency. In addition, the NOx reduction zone is between the main combustion zone and the burnout zone, which can effectively control the generation of NOx and ensure a low boiler pollutant emission concentration.

[0009] 2. A coal-fired coupled biomass gas combustion device is proposed. The combustion device can adapt to biomass gas with different components and calorific values, has a wide range of load adaptability, and can adapt to changes in the amount of biomass gas blending in a large range without causing a significant impact on the coal-fired boiler. The combustion device is provided with an inner layer central air channel, a middle layer gas channel and an outer layer air channel. Each layer of the channel is provided with a swirl guide vane and an air volume adjustment device. The swirl guide vane is used to rotate the biomass gas and air to ensure that the biomass gas ignites quickly and burns fully. The air volume adjustment mechanism of each layer can control the central air volume of a single gas burner and the outer layer secondary air volume to achieve the purpose of uniform air distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of a coal-fired boiler coupled with a biomass gas combustion device and a combustion system arrangement method thereof according to the present invention.

[0011] Figure 2 for Figure 1 A-direction view.

[0012] Figure 3 Combustion system layout diagram.

[0013] The reference numerals in the figure are as follows: 1 is a biomass gas combustion device, 2 is a central wind swirl device, 3 is a central wind tube, 4 is a gas swirl device, 5 is a gas channel, 6 is a secondary air duct, 7 is a secondary air swirl device, 8 is a secondary air door adjustment mechanism, 9 is a secondary air door adjustment rod, 10 is a positioner, 11 is a secondary air door indicator scale, 12 is a central wind introduction channel, 13 is a central air volume adjustment baffle, 14 is a conical blunt body, 15 is a central wind baffle block, 16 is a secondary air volume adjustment device limit block, 17 is a central wind baffle adjustment mechanism, 18 is a central wind baffle opening indicator scale, 19 is a pointer, 20 is a bellows, 21 is a central air inlet, 22 is a secondary air inlet, and 23 is a biomass gas inlet. DETAILED DESCRIPTION

[0014] The present invention will be further described in detail below in conjunction with the accompanying drawings: This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method is given, but the protection scope of the present invention is not limited to the following embodiments.

[0015] like Figure 1 and Figure 2As shown, a coal-fired boiler coupled with a biomass gas combustion device involved in this embodiment includes: a biomass gas combustion device 1, a central wind swirl device 2, a central wind tube 3, a gas swirl device 4, a gas channel 5, a secondary air duct 6, a secondary air swirl device 7, a secondary air door adjustment mechanism 8, a secondary air door adjustment rod 9, a positioner 10, a secondary air door indicator scale 11, a central wind introduction channel 12, a central air volume adjustment baffle 13, a conical blunt body 14, a central wind block 15, a secondary air volume adjustment device limit block 16, a central wind baffle adjustment mechanism 17, The central wind damper opening indicator scale 18, the pointer 19 and the wind box 20, the biomass gas combustion device 1 is arranged in the wind box 20, the central wind tube 3 is fixed in the gas channel 5, the central wind tube 3 and the gas channel 5 are arranged in concentric circles, the secondary air duct 6 is fixed to the outside of the rear end of the gas channel 5, the secondary air duct 6 and the gas channel 5 are arranged in concentric circles, the secondary air swirl device 7 is fixed to the air inlet end of the secondary air duct 6, the central wind swirl device 2 is arranged at the rear end of the central wind tube 3, and a gas swirl device 4 is provided between the rear end of the gas channel 5 and the rear end of the central wind tube 3. The central wind introduction channel 12 is fixed at the front and rear center position of the gas channel 5 and is connected to the central wind tube 3. A central wind volume adjustment baffle 13 is provided in the central wind introduction channel 12. A conical blunt body 14 is provided on the central wind introduction channel 12. A central wind baffle block 15 is fixed on the inner wall of the central wind tube 3 corresponding to the outlet of the central wind introduction channel 12. A secondary air volume adjustment device limit block 16 is fixed on the outer wall of the gas channel 5. The secondary air door adjustment mechanism 8 is provided on the outer wall of the gas channel 5 near the secondary air inlet 22. One end of the central wind baffle adjustment mechanism 17 is connected to the central wind introduction channel 12. The air volume adjustment baffle 13 is connected, the other end of the central air baffle adjustment mechanism 17 is in contact with the central air baffle opening indicating scale 18, the positioner 10 is fixed on the front end plate of the biomass gas combustion device 1, one end of the secondary air door adjustment rod 9 is fixedly connected to the secondary air door adjustment mechanism 8, the other end of the secondary air door adjustment rod 9 is movably connected to the positioner 10, one end of the pointer 19 is fixed on the other end of the secondary air door adjustment rod 9, and the other end of the pointer 19 is in contact with the secondary air door indicating scale 11 fixed on the front end plate of the biomass gas combustion device 1.

[0016] There are two secondary air door adjusting rods 9, and the two secondary air door adjusting rods 9 are symmetrically arranged.

[0017] The inlet of the central air cylinder 3 is conical.

[0018] A combustion system arrangement method using a coal-fired boiler coupled with a biomass gas combustion device, such as Figure 3As shown, the biomass gas combustion device 1 is arranged between the upper pulverized coal burner and the OFA burner. According to the different coupled biomass gas amounts, one layer or two layers of biomass gas burner devices are arranged on the front and rear walls. The rotation direction of the biomass gas is designed to be opposite to the rotation direction of the upper pulverized coal burner.

[0019] Working principle:

[0020] The biomass gas combustion device 1 is provided with three layers of annular channels, namely, inner central wind, gas, and outer secondary wind, and each layer of the channels is equipped with a flow control device and a swirl guide device, so that the entire combustion device has flexible adjustment capabilities. The biomass gas is transported to the gas channel 5 through a pipeline. Under the action of the conical blunt body 14, the turbulence caused by the central wind introduction channel 12 is eliminated, and the gas swirl device 4 at the burner nozzle is circumferentially and evenly circumferential ... A central air volume adjustment baffle 13 is provided in the central air inlet channel 12, and is equipped with a central air baffle adjustment mechanism 17 and a central air baffle opening indicator scale 18 for accurately adjusting the central air volume. The outer secondary air directly enters the secondary air duct 6 from the wind box through the secondary air swirl device 7. The angle and number of swirl blades of the central air swirl device 2 and the secondary air swirl device 7 match the design of the gas swirl device 4, and the rotation direction is consistent with the gas rotation direction. The secondary air volume is controlled by the secondary air door adjustment mechanism 8, including the secondary air door adjustment rod 9, the positioner 10, the secondary air door indicator scale 11, and the pointer 19, which can realize accurate adjustment of the secondary air volume.

[0021] This embodiment has the following advantages:

[0022] 1. A biomass gas combustion device suitable for coal-fired boilers is proposed. The combustion device can adapt to biomass gases with different components and calorific values, has a wide range of load adaptability, and can adapt to changes in the amount of biomass gas blending within a large range without causing a significant impact on the coal-fired boiler.

[0023] 2. A method for arranging the gas combustion system of biomass gasification coupled with a large coal-fired boiler is proposed. By selecting a suitable injection position and coordinating the low nitrogen performance of the gas combustion device itself, the purpose of coupled nitrogen reduction is achieved.

[0024] The fixed connection and the phase connection described in the above embodiments are both welding.

[0025] The above are only preferred specific embodiments of the present invention, which are all different implementations based on the overall concept of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A coal-fired boiler coupled with a biomass gas combustion device, comprising: Biomass gas combustion device (1), central air swirl device (2), central air tube (3), gas swirl device (4), gas channel (5), secondary air duct (6), secondary air swirl device (7), secondary air door adjustment mechanism (8), secondary air door adjustment rod (9), positioner (10), secondary air door indicator scale (11), central air introduction channel (12), central air volume adjustment baffle (13), conical blunt body (14), central air block (15), secondary air volume adjustment device limit block (16), central air baffle adjustment mechanism (17), central air baffle opening indicator scale (18), pointer (19) and bellows (20), characterized in that the biomass gas combustion device (1) is arranged in a wind box (20), the central wind tube (3) is fixed in the gas channel (5), the central wind tube (3) and the gas channel (5) are arranged in a concentric circle, the secondary air duct (6) is fixed outside the rear end of the gas channel (5), the secondary air duct (6) and the gas channel (5) are arranged in a concentric circle, the secondary air swirl device (7) is fixed at the air inlet end of the secondary air duct (6), the central air swirl device (2) is arranged at the rear end of the central wind tube (3), a gas swirl device (4) is arranged between the rear end of the gas channel (5) and the rear end of the central wind tube (3), and the central air is introduced into the gas channel. The gas passage (12) is fixed at a front-to-back center position of the gas passage (5) and communicates with the central air tube (3); a central air volume adjustment baffle (13) is provided in the central air introduction passage (12); a conical blunt body (14) is provided on the central air introduction passage (12); a central air baffle block (15) is fixed on the inner wall of the central air tube (3) corresponding to the outlet of the central air introduction passage (12); a secondary air volume adjustment device limit block (16) is fixed on the outer wall of the gas passage (5); a secondary air door adjustment mechanism (8) is provided on the outer wall of the gas passage (5) near the secondary air inlet (22); one end of the central air baffle adjustment mechanism (17) is connected to the central air tube (3); The central air damper adjustment mechanism (17) is connected to the central air damper opening indicator scale (18), the other end of the central air damper adjustment mechanism (17) is in contact with the central air damper opening indicator scale (18), the positioner (10) is fixed on the front end plate of the biomass gas combustion device (1), one end of the secondary air damper adjustment rod (9) is fixedly connected to the secondary air damper adjustment mechanism (8), the other end of the secondary air damper adjustment rod (9) is movably connected to the positioner (10), one end of the pointer (19) is fixed to the other end of the secondary air damper adjustment rod (9), and the other end of the pointer (19) is in contact with the secondary air damper indicator scale (11) fixed on the front end plate of the biomass gas combustion device (1).

2. The coal-fired boiler coupled biomass gas combustion device according to claim 1 is characterized in that: There are two secondary air valve regulating pull rods (9), and the two secondary air valve regulating pull rods (9) are symmetrically arranged.

3. The coal-fired boiler coupled biomass gas combustion device according to claim 2 is characterized in that: The inlet of the central air cylinder (3) is conical.

4. A combustion system arrangement method using a coal-fired boiler coupled with a biomass gas combustion device according to claim 1, 2 or 3, characterized in that: The biomass gas combustion device (1) is arranged between the upper pulverized coal burner and the OFA burner.

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