Coal combustion low-oxygen flameless combustion furnace

Abstract

The utility model relates to coal combustion furnace technical field especially is a kind of coal low oxygen flameless combustion furnace, including furnace wall, cover and heat insulation medium layer, the inside of furnace wall left end, inside right end symmetrical distribution fixed setting has cover, the inside fixed setting of cover has heat insulation medium layer, in the utility model, by the back air injection pipe, flue gas backflow pipe and porous catalytic bed of above-mentioned setting, the jet direction of back air injection pipe inner wall jet hole is along the tangent direction of furnace wall inner wall, so that annular air duct is formed in furnace wall inside, cooperate the hot gas ascending of coal powder combustion, form spiral upwards flue gas dust mixed air duct, high-heat flue gas is introduced into flue gas backflow pipe through pipeline, high-temperature flue gas is blown upwards through the through hole inside the porous catalytic bed, high-temperature flue gas reduces oxygen concentration in combustion zone, has preheating air and reduce oxygen concentration in combustion zone, improve combustion efficiency, reduce fuel consumption, reduce the generation of thermal nitrogen oxides.

Description

Technical Field

[0001] This utility model relates to the field of coal-fired combustion furnace technology, specifically a low-oxygen flameless coal-fired combustion furnace. Background Technology

[0002] The low-oxygen flameless combustion furnace for coal is a highly efficient and clean combustion technology. Through precise control and combustion dynamics, it achieves stable combustion of pulverized coal under low-oxygen conditions, while avoiding the high-temperature concentration zone of traditional flame combustion, thereby significantly reducing nitrogen oxide and dust emissions. Take small and medium-sized low-oxygen flameless combustion furnaces for coal as an example.

[0003] Some small and medium-sized coal-fired low-oxygen flameless combustion furnaces are not very effective in preheating air and reducing the oxygen concentration in the combustion zone, resulting in low combustion efficiency and insufficient control of nitrogen oxide emissions in flue gas. Therefore, a coal-fired low-oxygen flameless combustion furnace is proposed to address the above problems. Utility Model Content

[0004] The purpose of this invention is to provide a low-oxygen flameless combustion furnace for coal, which solves the problems mentioned above regarding the poor effect of some small and medium-sized low-oxygen flameless combustion furnaces for preheating air and reducing oxygen concentration in the combustion zone, as well as the insufficient control of nitrogen oxide pollution emissions in flue gas.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A low-oxygen, flameless coal-fired furnace includes a furnace wall, a casing, and a heat insulation medium layer. The casing is symmetrically and fixedly arranged inside the left and right ends of the furnace wall. The heat insulation medium layer is fixedly arranged inside the casing. A pulverized coal igniter is fixedly arranged inside the heat insulation medium layer. A return air injection pipe and a ceramic heat insulation plate are fixedly arranged on the inner wall of the furnace wall. A heat insulation pad is fixedly arranged inside the ceramic heat insulation plate. An ammonia injection pipe and a sealing shell are fixedly arranged inside the ceramic heat insulation plate and the heat insulation pad. A non-dispersive infrared sensor is fixedly arranged inside the sealing shell. Liquid inlet pipes are fixedly arranged below the right side of the ceramic heat insulation plate and below the right side of the heat insulation pad. Liquid outlet pipes are fixedly arranged above the left side of the ceramic heat insulation plate and above the left side of the heat insulation pad.

[0006] Preferably, a furnace bottom plate is fixedly provided at the bottom end of the furnace wall, a base plate is fixedly provided at the bottom end of the furnace bottom plate, a pulverized coal pressurizing and conveying device is fixedly provided between the base plate and the furnace bottom plate, and a pulverized coal injector is fixedly provided at the top end of the pulverized coal pressurizing and conveying device via a rigid pipe.

[0007] Preferably, a porous catalytic bed is fixedly arranged inside the furnace wall, a pulverized coal injector is fixedly arranged inside the porous catalytic bed, a plurality of through holes are arranged inside the porous catalytic bed, and a flue gas return pipe is fixedly connected to the right end of the furnace wall.

[0008] Preferably, the left end of the flue gas return pipe is located between the furnace bottom plate and the porous catalytic bed, and the through hole is configured as a through hole structure that is thicker at the bottom and thinner at the top.

[0009] Preferably, the jetting direction of the jetting holes on the inner wall of the return air jetting pipe is along the tangent direction of the inner wall of the furnace, and the eight return air jetting pipes are arranged in a ring-shaped interval in the upper and lower regions.

[0010] Compared with the prior art, the beneficial effects of this utility model are: 1. In this utility model, through the aforementioned return air injection pipe, flue gas return pipe, and porous catalytic bed, the jet direction of the jet holes on the inner wall of the return air injection pipe is along the tangential direction of the inner wall of the furnace, so that an annular air duct is formed inside the furnace wall. Combined with the rising hot gas from the pulverized coal combustion, a spiral upward flue gas and dust mixing air duct is formed. High-temperature flue gas is introduced into the flue gas return pipe through the pipe, and high-temperature flue gas is blown upward through the perforations set inside the porous catalytic bed. The high-temperature flue gas reduces the oxygen concentration in the combustion zone, which has the functions of preheating air and reducing the oxygen concentration in the combustion zone, improving combustion efficiency, reducing fuel consumption, and reducing the generation of thermal nitrogen oxides. 2. In this utility model, through the aforementioned return air injection pipe, non-dispersive infrared sensor, and ammonia injection pipe, atomized ammonia water is sprayed towards the inner side of the furnace wall. Combined with the spiral upward air duct caused by the return air injection pipe, the atomized ammonia water and the rising flue gas can be fully mixed. The ammonia water reacts with the nitrogen oxides in the flue gas to reduce nitrogen gas, thereby reducing the low-pollution emissions of nitrogen oxides and reducing the amount of ammonia water used for injection. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the substrate, furnace bottom plate, and furnace wall of this utility model; Figure 2 This is a schematic diagram of the pulverized coal pressurization and conveying device and the pulverized coal injector of this utility model; Figure 3 This utility model Figure 2 Schematic diagram at point A; Figure 4 This utility model Figure 2 Schematic diagram at point B; Figure 5 This is a schematic diagram of the ceramic heat insulation board and heat insulation pad of this utility model; Figure 6 This is a schematic diagram of the return air jet pipe of this utility model.

[0012] In the diagram: 1. Substrate; 2. Furnace bottom plate; 3. Furnace wall; 4. Pulverized coal pressurization and conveying device; 5. Porous catalytic bed; 6. Pulverized coal injector; 7. Through hole; 8. Flue gas return pipe; 9. Cover; 10. Insulation medium layer; 11. Pulverized coal igniter; 12. Return air injection pipe; 13. Ceramic heat insulation plate; 14. Heat insulation pad; 15. Ammonia water injection pipe; 16. Encapsulation shell; 17. Non-dispersive infrared sensor; 18. Liquid inlet pipe; 19. Liquid outlet pipe. Detailed Implementation

[0013] The technical solutions of the utility model embodiments will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the utility model, and not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the utility model.

[0014] In the embodiments of the utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the position or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations of the utility model. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Similarly, words such as "an," "a," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. Words such as "comprising" or "including" mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0015] Furthermore, in the embodiments of the utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0016] Please see Figure 1-6 This utility model provides a technical solution: A low-oxygen flameless coal-fired furnace includes a furnace wall 3, a casing 9, and a heat insulation medium layer 10. The casing 9 is symmetrically and fixedly arranged inside the left and right ends of the furnace wall 3. The heat insulation medium layer 10 is fixedly arranged inside the casing 9. A pulverized coal igniter 11 is fixedly arranged inside the heat insulation medium layer 10. A return air injection pipe 12 and a ceramic heat insulation plate 13 are fixedly arranged on the inner wall of the furnace wall 3. A heat insulation pad 14 is fixedly arranged inside the ceramic heat insulation plate 13. An ammonia water injection pipe 15 and a sealing shell 16 are fixedly arranged inside the ceramic heat insulation plate 13 and the heat insulation pad 14. A non-dispersive infrared sensor 17 is fixedly arranged inside the sealing shell 16. An inlet pipe 18 is fixedly arranged below the right side of the ceramic heat insulation plate 13 and below the right side of the heat insulation pad 14. An outlet pipe 19 is fixedly arranged above the left side of the ceramic heat insulation plate 13 and above the left side of the heat insulation pad 14.

[0017] A furnace bottom plate 2 is fixedly installed at the bottom end of the furnace wall 3. A base plate 1 is fixedly installed on the bottom support plate of the furnace bottom plate 2. A pulverized coal pressurizing and conveying device 4 is fixedly installed between the base plate 1 and the furnace bottom plate 2. A pulverized coal injector 6 is fixedly installed on the top of the pulverized coal pressurizing and conveying device 4. Through the above arrangement, pulverized coal is sprayed in a scattered manner at the top of the pulverized coal injector 6, and the pulverized coal is ignited by the pulverized coal igniter 11. A porous catalytic bed 5 is fixedly installed inside the furnace wall 3. A pulverized coal injector 6 is fixedly installed inside the porous catalytic bed 5. Several through holes 7 are provided inside the porous catalytic bed 5. A flue gas return pipe 8 is fixedly connected to the right end of the furnace wall 3. The left end of the flue gas return pipe 8 is connected to the furnace bottom plate 2 and the porous catalytic bed 5. In the porous catalytic bed 5, the through holes 7 are arranged with a bottom coarser and top finer through hole structure. Through this arrangement, the inner wall of the through holes 7 is coated with a catalytic reducing agent for nitrogen oxides. High-temperature flue gas is blown upward through the through holes 7 inside the porous catalytic bed 5. The high-temperature flue gas reduces the oxygen concentration in the combustion zone and can simultaneously catalytically reduce the nitrogen oxides contained in the high-temperature flue gas. The jet direction of the jet holes on the inner wall of the return air jet pipe 12 is along the tangent direction of the inner wall of the furnace wall 3. The eight return air jet pipes 12 are arranged in a ring-shaped interval in the upper and lower areas. Through this arrangement, a ring-shaped air duct is formed inside the furnace wall 3. With the rising hot gas from the pulverized coal combustion, a spiral upward flue gas and dust mixing air duct is formed.

[0018] Workflow: This utility model provides a combustion chamber structure for a low-oxygen flameless coal-fired furnace. The return air injection pipe 12 is connected to the gas supply pipe of the existing blower equipment. The jet direction of the jet holes on the inner wall of the return air injection pipe 12 is along the tangent direction of the inner wall of the furnace wall 3. The eight return air injection pipes 12 are distributed in a ring at intervals in the upper and lower areas, so that a ring-shaped air duct is formed inside the furnace wall 3. With the rising hot gas from the pulverized coal combustion, a spiral upward flue gas and dust mixing air duct is formed. After the flue gas and dust are removed by the external cyclone dust collector, the high-heat flue gas is then passed through... The flue gas is introduced into the flue gas return pipe 8 through a pipeline. The inner wall of the perforations 7 of the porous catalytic bed 5 is coated with a catalytic reducing agent for nitrogen oxides. High-temperature flue gas is blown upward through the perforations 7 inside the porous catalytic bed 5. The high-temperature flue gas reduces the oxygen concentration in the combustion zone and simultaneously catalytically reduces the nitrogen oxides contained in the high-temperature flue gas. This has the effects of preheating air and reducing the oxygen concentration in the combustion zone, improving combustion efficiency, reducing fuel consumption, and achieving high energy efficiency and energy saving. It also reduces the generation of thermal nitrogen oxides. The ammonia water injection pipe 15 is similar to the ammonia water supply for nitrogen oxide reduction in existing boiler technology. The ammonia delivery system is connected to the existing liquid cooling circulation system. The system guides and delivers the ammonia, controls its flow, and pressurizes it. This will not be described in detail here. The inlet pipe 18 is connected to the delivery pipe of the existing liquid cooling circulation system, and the outlet pipe 19 is connected to the return pipe of the existing liquid cooling circulation system. This will not be described in detail here. The system continuously supplies coolant from bottom to top to the internal area of ​​the ceramic heat insulation plate 13 between the heat insulation pads 14, continuously cooling the ammonia injection pipe 15 and the encapsulation shell 16. The encapsulation shell 16 is used to insulate the non-dispersive infrared sensor 17. For protection, the non-dispersive infrared sensor 17 is electrically connected to an external display and control device via a control signal line. It is used to monitor the concentration of nitrogen oxides in the combustion chamber area of ​​the furnace wall 3. Based on the obtained concentration information, the ammonia water delivery volume in the ammonia water delivery system is controlled, and atomized ammonia water is sprayed towards the inner side of the furnace wall 3. In conjunction with the spiral upward air duct initiated by the return air injection pipe 12, the atomized ammonia water and the rising flue gas can be fully mixed. The ammonia water reacts with the nitrogen oxides in the flue gas to reduce nitrogen gas, thereby reducing the low-pollution emissions of nitrogen oxides and reducing the amount of ammonia water injected.

[0019] Although embodiments of the utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the utility model, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A coal-fired low-oxygen flameless combustion furnace, comprising a furnace wall (3), a casing (9), and a heat insulation medium layer (10), characterized in that: A cover (9) is symmetrically and fixedly arranged inside the left and right ends of the furnace wall (3). A heat insulation medium layer (10) is fixedly arranged inside the cover (9). A pulverized coal igniter (11) is fixedly arranged inside the heat insulation medium layer (10). A return air injection pipe (12) and a ceramic heat insulation plate (13) are fixedly arranged on the inner wall of the furnace wall (3). A heat insulation pad (14) is fixedly arranged inside the ceramic heat insulation plate (13). An ammonia water injection pipe (15) and a sealing shell (16) are fixedly arranged inside the ceramic heat insulation plate (13) and the heat insulation pad (14). A non-dispersive infrared sensor (17) is fixedly arranged inside the sealing shell (16). An inlet pipe (18) is fixedly arranged below the right side of the ceramic heat insulation plate (13) and below the right side of the heat insulation pad (14). An outlet pipe (19) is fixedly arranged above the left side of the ceramic heat insulation plate (13) and above the left side of the heat insulation pad (14).

2. The low-oxygen flameless combustion furnace for coal as described in claim 1, characterized in that: A furnace bottom plate (2) is fixedly installed at the bottom of the furnace wall (3), a base plate (1) is fixedly installed at the bottom of the furnace bottom plate (2), a pulverized coal pressurizing and conveying device (4) is fixedly installed between the base plate (1) and the furnace bottom plate (2), and a pulverized coal injector (6) is fixedly installed on the top hard pipe of the pulverized coal pressurizing and conveying device (4).

3. The low-oxygen flameless combustion furnace for coal according to claim 2, characterized in that: A porous catalytic bed (5) is fixedly installed inside the furnace wall (3). A pulverized coal injector (6) is fixedly installed inside the porous catalytic bed (5). Several through holes (7) are provided inside the porous catalytic bed (5). A flue gas return pipe (8) is fixedly connected to the right end of the furnace wall (3).

4. The low-oxygen flameless combustion furnace for coal as described in claim 3, characterized in that: The left end of the flue gas return pipe (8) is located between the furnace bottom plate (2) and the porous catalytic bed (5), and the through hole (7) is a through hole structure with a thicker bottom and a thinner top.

5. The low-oxygen flameless combustion furnace for coal according to claim 1, characterized in that: The jetting direction of the jetting holes on the inner wall of the return air jetting pipe (12) is along the tangent direction of the inner wall of the furnace wall (3), and the eight return air jetting pipes (12) are arranged in a ring-shaped interval in the upper and lower regions.

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