Low-smoke recirculation low-nitrogen combustion device of gas-fired boiler

Abstract

The utility model relates to the technical field of combustors, in particular to a gas-fired boiler low-smoke recirculation low-nitrogen combustion device which comprises a combustion assembly, the combustion assembly comprises a main combustor, a secondary combustor and an inner combustor, the secondary combustor is arranged on the outer side of the main combustor in a surrounding mode, and the inner combustor is located on the inner side of the main combustor. A thick gas pipe, a thin gas pipe and a flue gas pipe are integrally arranged on the left front sides of the main combustor, the secondary combustor and the inner combustor correspondingly, the left end of the flue gas pipe communicates with a flue gas through pipe, and the left end of the thick gas pipe and the left end of an inlet one-way valve communicate with a thick mixing tank and a thin mixing tank correspondingly. And the left ends of the thick mixing tank and the thin mixing tank are assembled and connected with an air diversion bin and a fuel gas diversion bin. Fuel gas and air can be conveniently shunted according to needs, the fuel gas and the air are mixed to form combustion airflow with different concentrations, the combustion airflow is supplied to combustors with different concentrations inside and outside for combustion, and meanwhile flue gas can be conveniently recycled, supplied and combusted according to needs.

Description

Technical Field

[0001] The utility model relates to the technical field of burners, in particular to a low-flue-gas recirculation low-nitrogen combustion device for gas boilers. Background Technique

[0002] With the continuous improvement of environmental protection requirements, reducing the emission of nitrogen oxides during the combustion of gas boilers has become an important research topic. In the current industrial and civil fields, gas boilers are widely used in heating, power generation, etc.; at present, in order to reduce the emission of nitrogen oxides, a variety of technical means have been applied to the combustion system of gas boilers. Among them, some common methods include optimizing the burner structure, adopting staged combustion technology, etc.;

[0003] In this regard, Chinese Patent Application No.: CN202023142960.1 discloses a low-nitrogen combustion device applicable to medium and small gas boilers, which includes a main gas pipeline, a burner outer cylinder, a combustion-supporting air inlet, a plurality of main gas pipes, a central gas pipe, and a air distribution plate. The combustion-supporting air is sprayed into the furnace in two stages through the direct-flow air area and the outer-ring annular direct-flow air area of the air distribution plate; the gas is sprayed out in two stages and scattered in all directions through the central gas gun head and the main gas gun head; the gas sprayed out of the oblique throat contraction ring is mixed with the outer-layer inert flue gas to form an outer-layer inert mixing area, further realizing fuel staging;

[0004] However, the existing combustion device is inconvenient to shunt and mix gas and air as needed to form combustion airflows with different concentrations to supply inner and outer burners with different concentrations for combustion, and at the same time, it is inconvenient to recycle the flue gas as needed to supply combustion, affecting the use efficiency and combustion effect;

[0005] Therefore, in order to solve the above problems, a low-flue-gas recirculation low-nitrogen combustion device for gas boilers is proposed. Summary of the Invention

[0006] The purpose of the utility model is to provide a low-flue-gas recirculation low-nitrogen combustion device for gas boilers to solve the problem that the existing combustion device in the above background technique is inconvenient to shunt and mix gas and air as needed to form combustion airflows with different concentrations to supply inner and outer burners with different concentrations for combustion, and at the same time, it is inconvenient to recycle the flue gas as needed to supply combustion, affecting the use efficiency and combustion effect.

[0007] To achieve the above object, the utility model provides the following technical solutions: a low flue gas recirculation low nitrogen combustion device for a gas boiler, including a combustion assembly, the combustion assembly consists of a main burner, a secondary burner and an inner burner, the secondary burner is arranged around the outside of the main burner, the inner burner is located inside the main burner, and the left front sides of the main burner, the secondary burner and the inner burner are respectively integrally provided with a thick gas pipe, a lean gas pipe and a flue gas pipe. The left end of the flue gas pipe is connected and assembled with a flue gas through pipe. The left ends of the thick gas pipe and the inlet check valve are respectively connected and assembled with a thick mixing tank and a lean mixing tank, and an air shunt bin and a gas shunt bin are assembled and connected to the left ends of the thick mixing tank and the lean mixing tank.

[0008] As a further improvement of this solution, the main burner, the secondary burner and the inner burner are all annularly arranged, and the inside and outside of the main burner, the secondary burner and the inner burner are the same. Inner paddles are assembled inside the main burner, the secondary burner and the inner burner. The inner sides of the inner paddles are supported by inner ring frames, and the three inner ring frames are respectively sleeved and assembled on the inner side walls of the main burner, the secondary burner and the inner burner.

[0009] As a further improvement of this solution, air dividing plates and gas dividing plates are respectively assembled inside the air shunt bin and the gas shunt bin. The upper ends of the air shunt bin and the gas shunt bin are respectively connected and communicated with the thick mixing tank through a lean air pipe and a thick gas pipe. The lower ends of the air shunt bin and the gas shunt bin are respectively connected and communicated with the lean mixing tank through a thick air pipe and a lean gas pipe.

[0010] As a further improvement of this solution, fine and sparse holes one corresponding to the lean air pipe and the thick gas pipe are respectively opened in the upper parts of the air dividing plate and the gas dividing plate, and thick and dense holes one corresponding to the thick air pipe and the lean gas pipe are respectively opened in the lower parts of the air dividing plate and the gas dividing plate. Air check valves are assembled in the middle of the lean air pipe and the thick air pipe, and gas check valves are assembled in the middle of the thick gas pipe and the lean gas pipe.

[0011] As a further improvement of this solution, grooves corresponding to the air inlets are opened on the side walls of the inner paddles, and the five inner paddles are distributed in a regular pentagon shape in the side view section on the side of the inner ring frame. Air inlets corresponding to the thick gas pipe, the lean gas pipe and the flue gas pipe are opened on the left front side walls of the main burner, the secondary burner and the inner burner.

[0012] As a further improvement of this solution, the main burner includes a top cover located at the upper part. Nozzles are fixed on the surface of the top cover, and air holes communicating with the inside of the top cover are opened inside the nozzles. An outer cylinder and an inner cylinder are respectively arranged on the outer side and the inner side of the lower part of the top cover. The inner ring frame is sleeved and assembled on the inner wall of the inner cylinder, and an inner bearing is assembled between the inner ring frame and the inner wall of the inner cylinder. A bottom plate is arranged at the bottom of the outer cylinder and the inner cylinder. Reinforcing ribs are supported and assembled on the inner wall of the bottom plate, and feet are assembled at the bottom of the bottom plate.

[0013] Furthermore, in this solution, the bottom plate is assembled with the outer cylinder and the bottom of the inner cylinder by screws. The outer upper ring and the inner upper ring are integrally provided on both the inner and outer sides of the top cover. The same outer lower ring is integrally provided on the outer side of the upper part of the outer cylinder. The outer upper ring, the outer lower ring, and the inner upper ring are all assembled with the upper part of the inner cylinder by screws. A washer is filled between the bottom plate and the bottom of the outer cylinder and the inner cylinder.

[0014] Furthermore, in this solution, check valves are assembled at the outer ends of the thick gas pipe, the light gas pipe, and the smoke gas pipe. A suction pump is assembled in the middle of the smoke gas pipe. Check valves are assembled at the outer ends of the air shunt chamber, the gas shunt chamber, and the smoke gas pipe.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows: The present utility model facilitates the shunting of gas and air as needed, enabling them to be mixed to form combustion airflows with different concentrations of thick and light to supply the inner and outer burners with different concentrations of thick and light for combustion. At the same time, it also facilitates the recirculation of flue gas as needed for combustion.

[0016] By providing a main burner, a secondary burner, and an inner burner, the present utility model, in cooperation with the thick gas pipe, the light gas pipe, and the smoke gas pipe, facilitates the supply of gas fuel to the main burner, the secondary burner, and the inner burner. Through the nested and surrounding arrangement of the main burner, the secondary burner, and the inner burner, it is convenient to distinguish different burner areas. That is, the main burner is supplied with a thick airflow for combustion through the thick gas pipe, the secondary burner is supplied with a light airflow for combustion through the light gas pipe, and the inner burner is supplied with flue gas for re - combustion through the smoke gas pipe, realizing the staged feeding of gas, air, and flue gas, effectively reducing nitrogen oxide emissions. Through this design, the convenience and practicality of the low - flue - gas recirculation and low - nitrogen combustion device for gas boilers are improved.

[0017] By providing a thick mixing tank and a light mixing tank, the present utility model shunts and mixes gas and air in cooperation with the air shunt chamber and the gas shunt chamber. That is, the thick gas flow of gas is mixed with the light air flow and supplied to the main burner for combustion through the thick mixing tank, that is, in the main combustion area, it burns in an oxygen - deficient environment. The light gas flow of gas is mixed with the thick air flow and supplied to the secondary burner for combustion through the light mixing tank, that is, in the secondary combustion area, air is introduced to make the unburned products inside burn fully, and the flue gas also burns successively from the inside out, making the combustion more complete. Through this design, the convenience and practicality of the low - flue - gas recirculation and low - nitrogen combustion device for gas boilers are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a front - view three - dimensional schematic diagram of the overall structure of the present utility model;

[0019] Figure 2 It is a bottom - view three - dimensional schematic diagram of the overall structure of the present utility model;

[0020] Figure 3 This is a three-dimensional schematic diagram of the rear view sectional view of the partial structure of the main burner of the present utility model;

[0021] Figure 4 This is a three-dimensional schematic diagram of the front view sectional view of the partial structure of the air shunt bin and the gas shunt bin of the present utility model;

[0022] Figure 5 This is a three-dimensional assembly explosion diagram of the front view of the partial structure of the main burner of the present utility model;

[0023] In the figure: 100, combustion assembly; 101, top cover; 102, outer cylinder; 103, inner cylinder; 104, bottom plate; 105, nozzle; 106, air hole; 107, gasket; 108, support leg; 109, reinforcing rib; 110, main burner; 111, thick gas pipe; 112, inlet check valve; 120, secondary burner; 121, thin gas pipe; 130, inner burner; 131, flue gas pipe; 140, thick mixing tank; 150, thin mixing tank; 160, air shunt bin; 161, thin air pipe; 162, thick air pipe; 163, air check valve; 170, gas shunt bin; 171, thick gas burner pipe; 172, thin gas burner pipe; 173, gas check valve; 180, flue gas through pipe; 181, suction pump; 190, pre-check valve; 200, inner flap; 201, outer upper ring; 202, outer lower ring; 203, inner upper ring; 210, inner ring frame; 220, inner bearing; 230, air inlet; 240, groove; 300, air dividing plate; 310, fine sparse hole one; 320, thick dense hole one; 400, gas dividing plate; 410, thick dense hole two; 420, fine sparse hole two. Specific embodiments

[0024] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0025] Please refer to Figures 1 - 5 , an embodiment provided by the present utility model:

[0026] Low flue gas recirculation low nitrogen combustion device for gas boiler, including combustion assembly 100. The combustion assembly 100 consists of main burner 110, secondary burner 120 and inner burner 130. The secondary burner 120 is arranged around the outside of the main burner 110, and the inner burner 130 is located inside the main burner 110. On the left front side of the main burner 110, secondary burner 120 and inner burner 130, there are respectively integrally arranged thick gas pipe 111, light gas pipe 121 and flue gas pipe 131. The left end of the flue gas pipe 131 is connected and assembled with flue gas through pipe 180. The left ends of the thick gas pipe 111 and inlet check valve 112 are respectively connected and assembled with thick mixing tank 140 and light mixing tank 150. And the left ends of the thick mixing tank 140 and light mixing tank 150 are assembled and connected with air shunt bin 160 and gas shunt bin 170;

[0027] In a more detailed description of this embodiment, the main burner 110, secondary burner 120 and inner burner 130 are all arranged in a ring shape, and the inside and outside of the main burner 110, secondary burner 120 and inner burner 130 are the same. Inside the main burner 110, secondary burner 120 and inner burner 130, there are respectively assembled inner deflectors 200. The inner sides of the inner deflectors 200 are supported by inner ring frames 210. The three groups of inner ring frames 210 are respectively sleeved and assembled on the inner side walls of the main burner 110, secondary burner 120 and inner burner 130. In this way, it is convenient to rotate and convey the airflow inside the main burner 110, secondary burner 120 and inner burner 130, making the gas dispersion more uniform and convenient;

[0028] In a more detailed description of this embodiment, air dividing plates 300 and gas dividing plates 400 are respectively assembled inside the air shunt bin 160 and gas shunt bin 170. The upper ends of the air shunt bin 160 and gas shunt bin 170 are respectively connected and communicated with the thick mixing tank 140 through light air pipe 161 and thick gas pipe 171. The lower ends of the air shunt bin 160 and gas shunt bin 170 are respectively connected and communicated with the light mixing tank 150 through thick air pipe 162 and light gas pipe 172. In this way, it is convenient to shunt and mix the supply airflow;

[0029] In a more detailed description of this embodiment, on the upper parts of the air dividing plate 300 and gas dividing plate 400, there are respectively provided fine and sparse holes one 310 and thick and dense holes two 410 corresponding to the light air pipe 161 and thick gas pipe 171. On the lower parts of the air dividing plate 300 and gas dividing plate 400, there are respectively provided thick and dense holes one 320 and fine and sparse holes two 420 corresponding to the thick air pipe 162 and light gas pipe 172. Air check valves 163 are respectively assembled in the middle of the light air pipe 161 and thick air pipe 162. Gas check valves 173 are respectively assembled in the middle of the thick gas pipe 171 and light gas pipe 172. In this way, it is convenient to assist in automatically shunting and separating thick and light airflows, facilitating subsequent operation and supply;

[0030] More specifically in this embodiment, the side wall of the inner flap 200 is provided with a groove 240 corresponding to the air inlet 230, and the five groups of inner flaps 200 are distributed in a regular pentagon shape in the top view section on the side of the inner ring frame 210. The main burner 110, the secondary burner 120, and the left front side walls of the inner burner 130 are all provided with air inlets 230 corresponding to the thick gas pipe 111, the lean gas pipe 121, and the flue gas pipe 131. In this way, it is convenient for the airflow surging into the interior from the air inlet 230 to impact the inner flap 200 and make it rotate, which is convenient for assisting in the dispersion of the internal gas, facilitating uniform gas outlet, and being conducive to full combustion and heating;

[0031] More specifically in this embodiment, the main burner 110 includes a top cover 101 located at the upper part. The surface of the top cover 101 is fixedly provided with a gas nozzle 105, and the inside of the gas nozzle 105 is provided with air holes 106 communicating with the inside of the top cover 101. An outer cylinder 102 and an inner cylinder 103 are respectively arranged on the outer side and the inner side of the lower part of the top cover 101. The inner ring frame 210 is sleeved and assembled on the inner wall of the inner cylinder 103, and an inner bearing 220 is assembled between the inner ring frame 210 and the inner wall of the inner cylinder 103. The bottom of the outer cylinder 102 and the inner cylinder 103 is provided with a bottom plate 104. The inner wall of the bottom plate 104 is supported and assembled with a reinforcing rib 109, and the bottom of the bottom plate 104 is assembled with a support leg 108. In this way, it is convenient for the combined assembly of the main burner 110, the secondary burner 120, and the inner burner 130;

[0032] More specifically in this embodiment, the bottom plate 104 is assembled with the bottoms of the outer cylinder 102 and the inner cylinder 103 by screws. The outer upper ring 201 and the inner upper ring 203 are integrally arranged on both the inner and outer sides of the top cover 101. The outer lower ring 202 of the same kind is integrally arranged on the outer side of the upper part of the outer cylinder 102. The outer upper ring 201, the outer lower ring 202, and the inner upper ring 203 and the upper part of the inner cylinder 103 are all assembled by screws. A washer 107 is filled between the bottom plate 104 and the bottoms of the outer cylinder 102 and the inner cylinder 103. In this way, it is convenient for subsequent disassembly, assembly, maintenance, and repair;

[0033] More specifically in this embodiment, check valves 112 are assembled at the outer ends of the thick gas pipe 111, the lean gas pipe 121, and the flue gas pipe 131. A suction pump 181 is assembled in the middle of the flue gas pipe 180. Check valves 190 are assembled at the outer ends of the air shunt chamber 160, the gas shunt chamber 170, and the flue gas pipe 180. In this way, it is convenient to prevent the backflow of each stage of the pipeline.

[0034] Working principle: During operation, connect the flue gas outlet pipe to the flue gas connection pipe 180, connect the gas pipeline to the gas distribution chamber 170, and connect the compressed air supply pipe to the air distribution chamber 160. With the cooperation of the front check valve 190, gas check valve 173, air check valve 163, and inlet check valve 112, it is convenient to supply gas to the combustion assembly 100 unidirectionally to prevent backflow. Subsequently, when gas and air pass through the gas distribution chamber 170 and air distribution chamber 160 respectively, they are split by the gas distribution plate 400 and air distribution plate 300, that is, the concentrated gas flow and dilute gas flow are separated through the coarse and dense holes two 410 and fine and sparse holes two 420, and the dilute air flow and concentrated air flow are separated through the fine and sparse holes one 310 and coarse and dense holes one 320. After separating the corresponding concentrated and dilute gas flows, they are mixed in the concentrated mixing tank 140 and dilute mixing tank 150, so that the concentrated gas flow and dilute air flow are mixed inside the concentrated mixing tank 140, and the dilute gas flow and concentrated air flow are mixed inside the dilute mixing tank 150. That is, with the cooperation of the main burner 110, the fuel mixed in the concentrated mixing tank 140 burns in an oxygen-deficient environment with a small amount of air through the main combustion area, and with the cooperation of the secondary burner 120, the fuel mixed in the dilute mixing tank 150 burns with a large amount of air through the secondary combustion area, so that the unburned products inside burn again when passing through, ensuring full combustion. The flue gas also burns from the inside outwards. When burning through the cooperation of the nozzle 105 and air holes 106, when entering air through the air inlet 230, the inner flap 200 is impacted with the cooperation of the groove 240, so that the inner flap 200 pushes the inner ring frame 210 to rotate, thereby driving the corresponding five groups of inner flaps 200 to impact and rotate in sequence, facilitating the uniform dispersion of the internal gas, making the gas outlet more uniform, and facilitating subsequent combustion. The operation ends here.

[0035] The above is only the preferred embodiment of the present invention, and does not impose any form of limitation on the present invention; any ordinary technician in the industry can smoothly implement the present invention according to the illustrations in the specification and the above description; however, any minor changes, modifications, and equivalent variations made by those skilled in the art within the scope of the technical solution of the present invention by using the technical content disclosed above are equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications, and variations made to the above embodiments based on the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A low flue gas recirculation low nitrogen combustion device for a gas boiler, comprising a combustion assembly (100), characterized in that: The combustion assembly (100) comprises a main burner (110), a secondary burner (120) and an inner burner (130). The secondary burner (120) is arranged around the outer side of the main burner (110), and the inner burner (130) is located inside the main burner (110). A thick gas pipe (111), a lean gas pipe (121) and a flue gas pipe (131) are integrally arranged on the left front sides of the main burner (110), the secondary burner (120) and the inner burner (130) respectively. The left end of the flue gas pipe (131) is connected and assembled with a flue gas through pipe (180). The left ends of the thick gas pipe (111) and the inlet check valve (112) are respectively connected and assembled with a thick mixing tank (140) and a lean mixing tank (150), and an air shunt bin (160) and a gas shunt bin (170) are assembled and connected to the left ends of the thick mixing tank (140) and the lean mixing tank (150).

2. The low-nitrogen combustion device with low flue gas recirculation for a gas boiler according to claim 1, wherein: The main burner (110), the secondary burner (120) and the inner burner (130) are all arranged in a ring shape, and the inner and outer sides of the main burner (110), the secondary burner (120) and the inner burner (130) are the same. Inner paddles (200) are assembled inside the main burner (110), the secondary burner (120) and the inner burner (130). An inner ring frame (210) is supported inside the inner paddles (200). The three inner ring frames (210) are respectively sleeved and assembled on the inner side walls of the main burner (110), the secondary burner (120) and the inner burner (130).

3. The low-nitrogen combustion device for gas boilers with low flue gas recirculation according to claim 1, characterized in that: An air dividing plate (300) and a gas dividing plate (400) are respectively assembled inside the air shunt bin (160) and the gas shunt bin (170). The upper ends of the air shunt bin (160) and the gas shunt bin (170) are respectively connected and communicated with the thick mixing tank (140) through a lean air pipe (161) and a thick gas pipe (171). The lower ends of the air shunt bin (160) and the gas shunt bin (170) are respectively connected and communicated with the lean mixing tank (150) through a thick air pipe (162) and a lean gas pipe (172).

4. The low-nitrogen combustion device for gas boilers with low flue gas recirculation according to claim 3, characterized in that: Fine and sparse holes one (310) corresponding to the lean air pipe (161) and thick and dense holes two (410) corresponding to the thick gas pipe (171) are respectively formed in the upper parts of the air dividing plate (300) and the gas dividing plate (400). Coarse and dense holes one (320) corresponding to the thick air pipe (162) and fine and sparse holes two (420) corresponding to the lean gas pipe (172) are respectively formed in the lower parts of the air dividing plate (300) and the gas dividing plate (400). Air check valves (163) are assembled in the middle of the lean air pipe (161) and the thick air pipe (162). Gas check valves (173) are assembled in the middle of the thick gas pipe (171) and the lean gas pipe (172).

5. The low-nitrogen combustion device for a gas boiler with low flue gas recirculation according to claim 2, characterized in that: The side wall of the inner flap (200) is provided with a groove (240) corresponding to the air inlet (230), and the five groups of inner flaps (200) are distributed in a regular pentagon shape in the top view section on the side of the inner ring frame (210). The left front side walls of the main burner (110), the secondary burner (120) and the inner burner (130) are all provided with air inlets (230) corresponding to the thick gas pipe (111), the lean gas pipe (121) and the flue gas pipe (131).

6. The low-nitrogen combustion device for gas boilers with low flue gas recirculation according to claim 2, characterized in that: The main burner (110) includes a top cover (101) located at the upper part. Nozzles (105) are fixedly arranged on the surface of the top cover, and air holes (106) communicating with the inside of the top cover (101) are arranged inside the nozzles (105). An outer cylinder (102) and an inner cylinder (103) are respectively arranged on the outer side and the inner side of the lower part of the top cover (101). The inner ring frame (210) is sleeved and assembled on the inner wall of the inner cylinder (103), and an inner bearing (220) is assembled between the inner ring frame (210) and the inner wall of the inner cylinder (103). The bottom of the outer cylinder (102) and the inner cylinder (103) is provided with a bottom plate (104). Reinforcing ribs (109) are supported and assembled on the inner wall of the bottom plate (104), and feet (108) are assembled at the bottom of the bottom plate (104).

7. The low-nitrogen combustion device for a gas boiler with low flue gas recirculation according to claim 6, characterized in that: The bottom plate (104) is assembled with the bottoms of the outer cylinder (102) and the inner cylinder (103) by screws. Outer upper ring circles (201) and inner upper ring circles (203) are integrally arranged on the inner and outer sides of the top cover (101). An outer lower ring circle (202) of the same kind is integrally arranged on the outer side of the upper part of the outer cylinder (102). The outer upper ring circle (201), the outer lower ring circle (202) and the inner upper ring circle (203) and the upper part of the inner cylinder (103) are all assembled by screws. Washers (107) are filled between the bottom plate (104) and the bottoms of the outer cylinder (102) and the inner cylinder (103).

8. The low-nitrogen combustion device for gas boilers with low flue gas recirculation according to claim 1, characterized in that: Check valves (112) are assembled at the outer ends of the thick gas pipe (111), the lean gas pipe (121) and the flue gas pipe (131). A suction pump (181) is assembled in the middle of the flue gas pipe (180). Check valves (190) are assembled at the outer ends of the air shunt chamber (160), the gas shunt chamber (170) and the flue gas pipe (180).

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