Classified-arrangement step-by-step-amplification tiny-oil ignition combustion device

Abstract

The invention belongs to the technical field of boilers, and relates to a staged-arrangement and staged-amplification tiny-oil ignition combustion device which comprises a primary air pipe, a staged convenient combustion device and a smoke backflow device, combustible powder is arranged in the primary air pipe, and the staged convenient combustion device is arranged in the primary air pipe and comprises a combustible powder concentration assembly and a combustible powder combustion assembly. The combustible powder concentration assembly and the combustible powder combustion assembly are sequentially arranged in the direction from the pipe head of the primary air pipe to the pipe tail of the primary air pipe, and the smoke backflow device is arranged in the pipe tail direction of the primary air pipe and used for reducing the air speed of airflow entering the primary air pipe and enabling the airflow entering the primary air pipe to flow back into the primary air pipe.

Description

Technical Field

[0001] The invention relates to the technical field of boilers, and more particularly to a hierarchically arranged and step-by-step amplified micro-oil ignition and combustion device. Background Art

[0002] The main combustion method of large-scale boilers in coal-fired power plants is pulverized coal combustion. The raw coal is ground into pulverized coal of a certain fineness by a coal mill, and then sent into the furnace of the boiler by air to burn, providing heat source for the boiler. The furnace of the boiler has a large space, and the pulverized coal is suspended and burned in this space. The walls around the furnace are arranged with densely arranged pipes (called water-cooled walls), and water or a mixture of steam and water flows through the pipes, which can absorb the radiant heat of high-temperature combustion in the furnace and protect the furnace wall from being burned. The ash generated during the combustion process settles into the cold ash hopper at the bottom of the furnace, is gradually cooled and solidified, and falls into the slag discharge device to form solid slag; a large number of fine ash particles leave the furnace with the flue gas during the suspended combustion process, flow through a series of convection heating surfaces, and gradually cool down. Finally, they are drawn by the induced draft fan and discharged into the chimney after dust removal, desulfurization and other processes.

[0003] Existing large-scale boilers in coal-fired power plants generally use micro-oil or plasma methods in the low-load and startup stages to maintain stable combustion and avoid large amounts of oil. Therefore, the micro-oil method is used to reduce fuel consumption costs and improve economy. The micro-oil or plasma method has good economy in the startup or low-load stages, but due to its structural characteristics, the micro-oil burner has a large primary air volume, large momentum, and a shift in the combustion center, which can easily lead to coking of the side wall water-cooled wall tubes and high-temperature corrosion. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the use of micro-oil or plasma has good economy in the startup or low-load stage, but due to its structural characteristics, the micro-oil burner has a large primary air volume, large momentum, and a shift in the combustion center, which can easily lead to coking of the side wall water-cooled wall tubes, high-temperature corrosion, etc. In view of the above-mentioned defects of the prior art, a hierarchical arrangement and step-by-step amplification of micro-oil ignition and combustion device is provided.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A hierarchical arrangement and step-by-step amplification of micro-oil ignition and combustion device is constructed, comprising:

[0007] A primary air duct, wherein combustible powder is arranged in the primary air duct;

[0008] A step-by-step combustion device, which is arranged in the primary air duct and includes a combustible powder concentration component and a combustible powder combustion component, and the combustible powder concentration component and the combustible powder combustion component are installed in sequence from the pipe head of the primary air duct to the pipe tail of the primary air duct;

[0009] A smoke reflux device is provided at the tail end of the primary air duct, and is used to reduce the velocity of the airflow entering the primary air duct and allow the airflow entering the primary air duct to flow back into the primary air duct.

[0010] Optionally, the combustible powder concentration assembly includes a first combustible powder concentrator and a second combustible powder concentrator installed in sequence from the pipe head of the primary air duct toward the pipe tail of the primary air duct.

[0011] Optionally, the combustible powder combustion assembly includes a first combustible powder combustion chamber and a second combustible powder combustion chamber, and the first combustible powder concentrator, the second combustible powder concentrator, the first combustible powder combustion chamber and the second combustible powder combustion chamber can be installed in sequence from the head of the primary air duct toward the tail of the primary air duct.

[0012] Optionally, the smoke reflow device includes a conical reflow piece and a connecting fixture, one end of the connecting fixture is connected to the side wall of the reflow piece, and the other end is connected to the inner wall of the primary air duct.

[0013] Optionally, the central axis of the return component is coaxial with the central axis of the primary air duct.

[0014] Optionally, the connecting fixture includes three connecting rods connecting the return member to the inner wall of the primary air duct.

[0015] Optionally, central axes of the first combustible powder concentrator, the second combustible powder concentrator, the first combustible powder combustion chamber, and the second combustible powder combustion chamber are all coaxial with the primary air duct.

[0016] Optionally, the inner diameter of the first combustible powder combustion chamber is smaller than the inner diameter of the second combustible powder combustion chamber.

[0017] Optionally, the first combustible powder combustion chamber and the second combustible powder combustion chamber are both cylindrical.

[0018] Optionally, the combustible powder is coal powder.

[0019] The beneficial effects of the present invention are:

[0020] The present invention comprises a primary air duct, a step-by-step combustion device, and a flue gas reflux device. Combustible powder is arranged in the primary air duct. The step-by-step combustion device is arranged in the primary air duct and comprises a combustible powder concentration component and a combustible powder combustion component. The combustible powder concentration component and the combustible powder combustion component are installed in sequence from the head of the primary air duct toward the tail of the primary air duct. The flue gas reflux device is arranged in the tail direction of the primary air duct. The flue gas reflux device is used to reduce the wind speed of the air flow entering the primary air duct and make the air flow entering the primary air duct flow back into the primary air duct. When using the present invention, under low load conditions, it is necessary to ignite the primary air duct by a micro-oil ignition method. First, the micro-oil burner adopts a micro-oil gasification oil gun for ignition to form an oil flame with a very high temperature gradient. The core temperature of the oil flame is as high as 1500-2000°C, which provides the necessary heat for the rapid ignition of the combustible powder. By injecting combustion-supporting air into the primary air duct, the oil flame is driven to enter the combustible powder combustion assembly to burn the combustible powder in the combustible powder combustion assembly. After the combustible powder in the combustible powder combustion assembly is burned, the combustible powder burning in the combustible powder combustion assembly will ignite the combustible powder outside the combustible powder combustion assembly. After passing through the combustible powder combustion assembly, the combustion-supporting air will contact the flue gas reflux device, so that the combustion-supporting air is diffused in the primary air duct, so that the combustible powder in the primary air duct is fully burned. Under high load conditions, the furnace temperature is high and the burner outlet has sufficient ignition energy. At this time, there is no need for a micro-oil mode. When the combustion-supporting air passes through the flue gas reflux device at the end of the primary air duct, the combustion-supporting air will encounter resistance and form a flue gas reflux volume after diffusion, which shortens the jet distance of the primary air volume to the center of the furnace, thereby reducing the wind speed of the combustion-supporting air, eliminating the flame center offset, and preventing the occurrence of coking and high-temperature corrosion of the side wall water-cooled wall tubes. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work:

[0022] Figure 1 It is an overall side schematic diagram of the present invention.

[0023] Figure 2 The present invention is Figure 1 Schematic diagram of the cross section taken along line AA.

[0024] Figure 3 It is an overall axonometric schematic diagram of the present invention.

[0025] Figure 4It is the left schematic diagram of the present invention.

[0026] Figure 5 It is a right schematic diagram of the present invention.

[0027] The accompanying drawings are marked as follows:

[0028] 100. Primary air duct;

[0029] 200, step-by-step combustion device; 210, combustible powder concentration assembly; 220, combustible powder combustion assembly; 211, first combustible powder concentrator; 212, second combustible powder concentrator; 221, first combustible powder combustion chamber; 222, second combustible powder combustion chamber;

[0030] 300. Smoke reflux device; 310. Reflux member; 320. Connecting fixture; 321. Connecting rod. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0033] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0034] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0035] Embodiments of the present invention Figure 1-Figure 5As shown in, it relates to a hierarchically arranged step-by-step amplified micro-oil ignition and combustion device, including a primary air duct 100, a step-by-step combustion device 200, and a smoke reflow device 300. Combustible powder (not shown in the figure) is arranged in the primary air duct 100. The step-by-step combustion device 200 is arranged in the primary air duct 100 and includes a combustible powder concentration component 210 and a combustible powder combustion component 220. The combustible powder concentration component 210 and the combustible powder combustion component 220 are sequentially installed from the pipe head of the primary air duct 100 toward the pipe tail of the primary air duct 100. The flue gas reflux device 300 is arranged at the tail end of the primary air duct 100. The flue gas reflux device 300 is used to reduce the air velocity of the airflow entering the primary air duct 100 and make the airflow entering the primary air duct 100 flow back into the primary air duct 100. Furthermore, the combustible powder is coal powder. When using the present invention, under low load conditions, it is necessary to ignite the primary air duct 100 by a micro-oil ignition method. First, the micro-oil burner uses a micro-oil gasification oil gun for ignition to form an oil flame with a high temperature gradient. The core temperature of the oil flame is as high as 150 0~2000℃, which provides the necessary heat for the rapid ignition of coal powder. By injecting combustion-supporting air into the primary air duct 100, the oil flame is driven into the combustible powder combustion component 220 to burn the coal powder in the combustible powder combustion component 220. After the coal powder in the combustible powder combustion component 220 is burned, the coal powder burned in the combustible powder combustion component 220 will ignite the coal powder outside the combustible powder combustion component 220, and the combustion-supporting air will contact the flue gas reflux device 300 after passing through the combustible powder combustion component 220, so that the combustion-supporting air is diffused in the primary air duct. In order to assist the combustion of the coal powder outside the combustible powder combustion component 220, the coal powder in the primary air duct can be fully burned. Under high load conditions, the furnace temperature is high and the burner outlet has sufficient ignition energy. At this time, there is no need for a micro-oil mode. When the combustion-supporting air passes through the flue gas reflux device 300 at the end of the primary air duct 100, the combustion-supporting air will encounter resistance, and a flue gas reflux volume will be formed after diffusion, so that the jet distance of the primary air volume is shortened to the center of the furnace, thereby reducing the wind speed of the combustion-supporting air, eliminating the deviation of the flame center, and preventing the coking of the side wall water-cooled wall tubes, high-temperature corrosion, etc.

[0036] In this embodiment, the combustible powder concentration assembly 210 includes a first combustible powder concentrator 211 and a second combustible powder concentrator 212 which are sequentially installed from the pipe head of the primary air duct 100 toward the pipe tail of the primary air duct 100. Furthermore, through the step-by-step action of the first combustible powder concentrator 211 and the second combustible powder concentrator 212, the concentration of coal powder in the primary air duct 100 is gradually increased. High-concentration coal powder is easier to ignite, and the combustion process is more stable, thereby improving the combustion efficiency. In the micro-oil ignition mode, the oil flame can quickly ignite the coal powder in the first combustible powder concentrator 211, and then ignite the coal powder in the entire primary air duct 100 through the step-by-step amplification effect.

[0037] In this embodiment, the combustible powder combustion assembly 220 includes a first combustible powder combustion chamber 221 and a second combustible powder combustion chamber 222. The first combustible powder concentrator 211, the second combustible powder concentrator 212, the first combustible powder combustion chamber 221 and the second combustible powder combustion chamber 222 are installed in sequence from the pipe head of the primary air duct 100 toward the pipe tail of the primary air duct 100. Furthermore, after the oil flame is initially formed and stabilized in the first combustible powder combustion chamber 221, it can further ignite and maintain the combustion in the second combustible powder combustion chamber 222. When the coal powder in the second combustible powder combustion chamber 222 burns, the coal powder outside the second combustible powder combustion chamber 222 can be ignited. This step-by-step amplification effect makes the entire combustion process more stable and efficient, and the step-by-step combustion design helps to reduce unburned coal powder particles and reduce energy losses during the combustion process.

[0038] In this embodiment, the flue gas reflow device 300 includes a conical reflow piece 310 and a connecting fixture 320, one end of the connecting fixture 320 is connected to the side wall of the reflow piece 310, and the other end is connected to the inner wall of the primary air duct 100. The design of the conical reflow piece 310 can guide the flue gas to flow along its conical surface, forming a certain reflux force, which helps to reintroduce part of the high-temperature flue gas into the combustion area and improve the combustion efficiency. Through the flue gas reflow device 300, part of the high-temperature flue gas is reused, reducing the smoke exhaust loss and helping to improve the energy utilization efficiency of the entire device.

[0039] In this embodiment, the central axis of the return piece 310 is coaxial with the central axis of the primary air duct 100. Furthermore, the coaxiality of the central axis of the return piece 310 with the central axis of the primary air duct 100 ensures that the airflow channel between the return piece 310 and the primary air duct 100 is evenly distributed, which helps to reduce the resistance of the airflow during the flow, improve the uniformity and stability of the airflow, and the high-temperature flue gas can be more evenly distributed in the combustion area, providing more ideal conditions for the combustion of coal powder.

[0040] In this embodiment, the connecting fixing member 320 includes three connecting rods 321 connecting the return member 310 to the inner wall of the primary air duct 100. Furthermore, the presence of the three connecting rods 321 makes the connection between the return member 310 and the inner wall of the primary air duct 100 more firm and stable, and can withstand greater force and pressure, thereby ensuring the stability and safety of the device during operation.

[0041] In this embodiment, the central axes of the first combustible powder concentrator 211, the second combustible powder concentrator 212, the first combustible powder combustion chamber 221 and the second combustible powder combustion chamber 222 are all coaxial with the primary air duct 100. Furthermore, the coaxiality of multiple components ensures that the airflow channels between the components are evenly distributed, reduces the resistance and turbulence of the airflow during the flow, helps to form a stable airflow, and improves the uniformity and stability of the airflow.

[0042] In this embodiment, the inner diameter of the first combustible powder combustion chamber 221 is smaller than the inner diameter of the second combustible powder combustion chamber 222. Furthermore, both the first combustible powder combustion chamber 221 and the second combustible powder combustion chamber 222 are cylindrical.

[0043] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A hierarchical arrangement and step-by-step amplification of micro-oil ignition and combustion device, characterized in that: include: A primary air duct (100), wherein combustible powder is arranged in the primary air duct (100); A step-by-step combustion device (200), the step-by-step combustion device (200) being arranged in the primary air duct (100) and comprising a combustible powder concentration component (210) and a combustible powder combustion component (220), the combustible powder concentration component (210) and the combustible powder combustion component (220) being installed in sequence from the pipe head of the primary air duct (100) toward the pipe tail of the primary air duct (100); A smoke reflow device (300), wherein the smoke reflow device (300) is arranged in the tail direction of the primary air duct (100), and the smoke reflow device (300) is used to reduce the wind speed of the air flow entering the primary air duct (100) and make the air flow entering the primary air duct (100) flow back into the primary air duct (100).

2. A hierarchical arrangement and step-by-step amplification of micro-oil ignition and combustion device according to claim 1, characterized in that: The combustible powder concentrating assembly (210) comprises a first combustible powder concentrator (211) and a second combustible powder concentrator (212) which are sequentially installed from the pipe head of the primary air duct (100) toward the pipe tail of the primary air duct (100).

3. A hierarchical arrangement and step-by-step amplification of micro-oil ignition and combustion device according to claim 2, characterized in that: The combustible powder combustion assembly (220) comprises a first combustible powder combustion chamber (221) and a second combustible powder combustion chamber (222); the first combustible powder concentrator (211), the second combustible powder concentrator (212), the first combustible powder combustion chamber (221) and the second combustible powder combustion chamber (222) are sequentially installed from the pipe head of the primary air duct (100) toward the pipe tail of the primary air duct (100).

4. The hierarchical arrangement and step-by-step amplification of the micro-oil ignition and combustion device according to claim 1 is characterized in that: The smoke reflow device (300) comprises a conical reflow piece (310) and a connecting and fixing piece (320), wherein one end of the connecting and fixing piece (320) is connected to the side wall of the reflow piece (310), and the other end is connected to the inner wall of the primary air duct (100).

5. The hierarchical arrangement and step-by-step amplification of the micro-oil ignition and combustion device according to claim 4 is characterized in that: The central axis of the return member (310) is coaxial with the central axis of the primary air duct (100).

6. A hierarchical arrangement and step-by-step amplification of micro-oil ignition and combustion device according to claim 5, characterized in that: The connecting and fixing member (320) comprises three connecting rods (321) for connecting the return member (310) to the inner wall of the primary air duct (100).

7. The hierarchical arrangement and step-by-step amplification of the micro-oil ignition and combustion device according to claim 3 is characterized in that: The central axes of the first combustible powder concentrator (211), the second combustible powder concentrator (212), the first combustible powder combustion chamber (221), and the second combustible powder combustion chamber (222) are all coaxial with the primary air duct (100).

8. The hierarchical arrangement and step-by-step amplification micro-oil ignition and combustion device according to claim 3 is characterized in that: The inner diameter of the first combustible powder combustion chamber (221) is smaller than the inner diameter of the second combustible powder combustion chamber (222).

9. The hierarchical arrangement and step-by-step amplification micro-oil ignition and combustion device according to claim 3 is characterized in that: The first combustible powder combustion chamber (221) and the second combustible powder combustion chamber (222) are both cylindrical.

10. The hierarchical arrangement and step-by-step amplification micro-oil ignition and combustion device according to claim 1 is characterized in that: The combustible powder is coal powder.

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