Low-nitrogen burner for blending natural gas with hydrogen in large proportion

Abstract

The invention discloses a low-nitrogen burner for blending natural gas with hydrogen in a large proportion, and relates to the technical field of burners. The invention aims to solve the problems that an existing combustor can only support mixed combustion of hydrogen with a low proportion, and after the hydrogen mixing proportion exceeds a certain limit, combustion is unstable, the flame temperature is too high, and NOX emission exceeds the standard. The device comprises an on-duty gas pipe, a hydrogen pipeline, an air channel, an on-duty sleeve, an air sleeve, a plurality of on-duty gas branch pipes and a plurality of porous rotational flow blades, the outer side of the gas inlet side of the on-duty gas pipe is coaxially sleeved with the air channel, and the gas outlet end of the hydrogen pipeline penetrates through the air channel and then is connected with the gas inlet side of the on-duty gas pipe; the on-duty sleeve and the air sleeve are sequentially and coaxially arranged on the outer side of the gas outlet side of the on-duty gas pipe in a sleeving mode from inside to outside, the multiple on-duty gas branch pipes are evenly distributed in the on-duty sleeve in the circumferential direction, the gas inlet ends of the on-duty gas branch pipes are communicated with the on-duty gas pipe, and porous rotational flow blades are arranged at the gas outlet ends of the on-duty gas branch pipes. The low-nitrogen combustor is used for low-nitrogen combustion of the combustor.

Description

Technical Field

[0001] The present invention relates to the technical field of burners, and in particular to a low-nitrogen burner that burns natural gas mixed with hydrogen in a large proportion. Background Art

[0002] With increasingly stringent environmental regulations and the advancement of clean energy applications, hydrogen has received widespread attention as a green fuel. Natural gas blended with hydrogen not only expands hydrogen energy application scenarios, but also improves the combustion performance of terminal equipment and reduces emissions of carbon dioxide, nitrogen oxides, and other gases. Its green and low-carbon characteristics make it increasingly popular. Currently, hydrogen blending technology is mainly concentrated in small-proportion hydrogen blending applications, but with increasingly stringent environmental regulations and the advancement of low-carbon energy policies, market demand for large-proportion hydrogen blending technology is gradually increasing. In the long run, with the further reduction of hydrogen production costs, the improvement of hydrogen energy infrastructure, and the continuous increase in market demand, large-proportion hydrogen blending technology will be widely used in the industrial boiler field.

[0003] At present, most burners can only support the combustion of low proportions of hydrogen. When the hydrogen ratio exceeds a certain limit, the high reactivity of hydrogen will lead to unstable combustion and excessively high flame temperature, resulting in NO X Therefore, the key to solving this problem is to develop a low-nitrogen gas burner that can stably achieve the combustion of a large proportion of natural gas mixed with hydrogen. Summary of the Invention

[0004] The present invention aims to solve the problem that the existing burner can only support the combustion of a low proportion of hydrogen. When the hydrogen ratio exceeds a certain limit, the high reactivity of hydrogen will lead to unstable combustion, excessively high flame temperature, and NO X In order to solve the problem of excessive emissions, a low-nitrogen burner that mixes a large proportion of natural gas with hydrogen is proposed.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A low-nitrogen burner that burns a large proportion of natural gas mixed with hydrogen includes a duty gas pipe, a hydrogen pipe, an air channel, a duty sleeve, an air sleeve, multiple duty gas branch pipes and multiple porous swirl blades. The air channel is coaxially sleeved on the outside of the air inlet side of the duty gas pipe, and the outlet end of the hydrogen pipe passes through the air channel and is connected to the air inlet side of the duty gas pipe. The duty sleeve and the air sleeve are coaxially sleeved on the outside of the air outlet side of the duty gas pipe in sequence from the inside to the outside. Multiple duty gas branch pipes are evenly distributed in the duty sleeve along the circumferential direction. The air inlet end of the duty gas branch pipe is connected to the duty gas pipe, and the outlet end of the duty gas branch pipe is provided with porous swirl blades.

[0007] Furthermore, the air inlet end of the duty gas branch pipe is arranged along the radial direction of the duty gas pipe, and the air outlet end of the duty gas branch pipe is arranged along the axial direction of the duty gas pipe and toward the air outlet side of the duty gas pipe.

[0008] Furthermore, the porous swirl blade is vertically fixed to the outer wall of the duty gas pipe. The porous swirl blade is a hollow structure. An axial gas inlet hole is provided on the rear end face of the porous swirl blade. The axial gas inlet hole is connected to the gas outlet end of the duty gas branch pipe. A plurality of axial gas injection holes are distributed on the front end face of the porous swirl blade.

[0009] Furthermore, a plurality of tangential gas injection ports are evenly distributed along the circumferential direction on the port side wall of the gas outlet end of the duty gas pipe.

[0010] Furthermore, two inner and outer circles of main flame gas pipes are coaxially arranged on the outside of the duty gas pipe, and each circle of main flame gas pipes includes multiple evenly distributed main flame gas pipes. The front end of the inner circle of main flame gas pipes is provided with an inner circle mixing pipe, and the front end of the outer circle of main flame gas pipes is provided with an outer circle mixing pipe.

[0011] Furthermore, the main flame gas pipes of the inner circle and the main flame gas pipes of the outer circle are arranged alternately.

[0012] Furthermore, the main flame gas nozzle is provided at the gas outlet end of the main flame gas pipe, and the air inlet sides of the outer ring mixing tube and the inner ring mixing tube are respectively provided with mixing tube suction ports, which are arranged in front of the main flame gas nozzle.

[0013] Furthermore, the air inlet ends of the outer ring mixing tube and the inner ring mixing tube are respectively provided with mixing tube expansion openings, and the mixing tube expansion openings are arranged on the outside of the air outlet end of the main flame gas pipe.

[0014] Furthermore, an air deflector is provided in the middle of the inner wall of the air sleeve, an air sleeve flare is provided at the front end of the air sleeve, an air sleeve suction port is provided at the rear end of the air sleeve, and the air sleeve suction port is arranged outside the air outlet end of the air channel.

[0015] Furthermore, a duty sleeve flare is provided at the front end of the duty sleeve, and the duty sleeve flare is arranged at the front side of the air sleeve flare.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The purpose of the present invention is to provide a low-nitrogen burner that burns a large proportion of natural gas mixed with hydrogen. The hydrogen pipeline is connected to the on-duty gas pipeline, and hydrogen and natural gas are premixed in the on-duty gas pipeline to ensure ignition and combustion stability. After the hydrogen and natural gas are premixed, they are ejected through porous swirl blades to optimize the mixing of fuel and air, avoid the occurrence of local high-temperature areas, and reduce thermal NO. XGeneration.

[0018] The present invention is applicable to small and medium-sized gas boilers, and can achieve large proportion of hydrogen blending while ensuring combustion efficiency and stability, and effectively reducing nitrogen oxides (NO X )emission.

[0019] The present invention accurately controls the mixing ratio of hydrogen and natural gas by regulating the valve, which can reduce NO while ensuring combustion stability. X Emissions, to meet the demand for large proportion of hydrogen blending in natural gas.

[0020] In the present invention, the mixing of hydrogen and natural gas is carried out in the service pipeline. The gas is fully mixed before injection and then ejected through the porous swirl blades to form a more dispersed gas flow, thereby avoiding the instability factor generated by hydrogen in the combustion zone.

[0021] The present invention ensures that the air flow is evenly distributed in the combustion zone through the air guide plate and the porous swirl blades, strengthens the mixing of gas and air, and improves the combustion efficiency. Especially when the hydrogen mixing ratio is high, it can effectively avoid the local high temperature phenomenon and reduce the thermal NO X Generation.

[0022] The present invention uses flue gas recirculation technology and staged combustion technology to effectively reduce the combustion temperature and further reduce thermal NO X Generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a front view of the overall structure of the present invention;

[0024] Figure 2 yes Figure 1 Right view;

[0025] Figure 3 It is a schematic diagram of the connection between the porous swirl blades and the on-duty gas branch pipe and the on-duty gas pipe in the present invention. DETAILED DESCRIPTION

[0026] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] Specific implementation method 1: Combination Figures 1 to 3To illustrate this embodiment, the low-nitrogen burner described in this embodiment, which uses a large proportion of natural gas mixed with hydrogen, includes a duty gas pipe 1, a hydrogen pipeline 2, an air channel 3, a duty sleeve 4, an air sleeve 6, multiple duty gas branch pipes 16 and multiple porous swirl blades 19. The air channel 3 is coaxially sleeved on the outside of the air inlet side of the duty gas pipe 1, and the outlet end of the hydrogen pipeline 2 passes through the air channel 3 and is connected to the air inlet side of the duty gas pipe 1. The duty sleeve 4 and the air sleeve 6 are coaxially sleeved on the outside of the air outlet side of the duty gas pipe 1 from the inside to the outside. Multiple duty gas branch pipes 16 are evenly distributed in the duty sleeve 4 along the circumferential direction. The air inlet end of the duty gas branch pipe 16 is connected to the duty gas pipe 1, and the air outlet end of the duty gas branch pipe 16 is provided with a porous swirl blade 19.

[0028] Hydrogen pipeline 2 is connected to duty gas pipeline 1. A regulating valve precisely controls the hydrogen flow rate, ensuring sufficient premixing of hydrogen and natural gas within duty gas pipeline 1. The hydrogen-to-natural gas mixture ratio can be adjusted based on actual needs, optimizing the fuel composition during combustion and leveraging hydrogen's flammability to ensure stable ignition and combustion.

[0029] After hydrogen and natural gas are mixed, they enter the porous swirl blades 19 through the duty gas branch pipe 16 and are then evenly sprayed into the furnace by the porous swirl blades 19. The porous swirl blades 19 optimize the mixing process of gas and air, ensure that the fuel is evenly distributed in the combustion area, reduce the generation of local high temperature areas, and effectively inhibit NO X Generation.

[0030] Specific implementation method 2: Combination Figures 1 to 3 To illustrate this embodiment, the air inlet end of the duty gas branch pipe 16 in this embodiment is arranged along the radial direction of the duty gas pipe 1, and the air outlet end of the duty gas branch pipe 16 is arranged along the axial direction of the duty gas pipe 1 and toward the air outlet side of the duty gas pipe 1.

[0031] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0032] Specific implementation method three: Combination Figures 1 to 3 To illustrate this embodiment, the porous swirl blade 19 described in this embodiment is vertically fixed to the outer wall of the duty gas pipe 1. The porous swirl blade 19 is a hollow structure. An axial gas inlet hole is provided on the rear end face of the porous swirl blade 19. The axial gas inlet hole is connected to the gas outlet end of the duty gas branch pipe 16. A plurality of axial gas injection holes 17 are evenly distributed on the front end face of the porous swirl blade 19.

[0033] The undisclosed technical features in this embodiment are the same as those in the second embodiment.

[0034] Specific implementation method four: Combination Figures 1 to 3To illustrate this embodiment, a plurality of tangential gas injection ports 18 are uniformly distributed along the circumferential direction on the side wall of the port of the gas outlet end of the duty gas pipe 1 described in this embodiment.

[0035] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0036] Specific implementation method five: Combination Figures 1 to 2 To illustrate this embodiment, two inner and outer circles of main flame gas pipes 10 are coaxially arranged on the outer side of the duty gas pipe 1 in this embodiment. Each circle of main flame gas pipes 10 includes a plurality of evenly distributed main flame gas pipes 10. The front end of the inner circle of main flame gas pipes 10 is provided with an inner circle mixing pipe 15, and the front end of the outer circle of main flame gas pipes 10 is provided with an outer circle mixing pipe 14.

[0037] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0038] The gas outlet port of the outer ring mixing tube 14 is arranged to be tilted forward from outside to inside in the radial direction, and the gas outlet port of the inner ring mixing tube 15 is arranged to be tilted forward from inside to outside in the radial direction.

[0039] The fuel is introduced into different combustion areas through the staged gas supply of the main flame gas pipe 10 and the duty gas pipe 1, effectively controlling the combustion speed and temperature, thereby reducing thermal NO X The main flame gas pipe 10 supplies natural gas, and the duty gas pipe 1 is connected to the hydrogen pipeline 2 to supply a mixture of hydrogen and natural gas.

[0040] Specific implementation method six: combination Figures 1 to 2 To explain this embodiment, the main flame gas pipes 10 of the inner circle and the main flame gas pipes 10 of the outer circle are arranged alternately.

[0041] The undisclosed technical features in this embodiment are the same as those in the fifth embodiment.

[0042] Specific implementation method seven: combination Figure 1 To illustrate this embodiment, the main flame gas pipe 10 of this embodiment is provided with a main flame gas nozzle 11 at the gas outlet end, and the outer ring mixing pipe 14 and the inner ring mixing pipe 15 are respectively provided with mixing pipe suction ports 13 on the gas inlet sides. The mixing pipe suction ports 13 are arranged in front of the main flame gas nozzle 11.

[0043] The undisclosed technical features in this embodiment are the same as those in the fifth embodiment.

[0044] Specific implementation method eight: combination Figure 1To illustrate this embodiment, the air inlet ends of the outer ring mixing tube 14 and the inner ring mixing tube 15 are respectively provided with mixing tube expansion openings 12 , and the mixing tube expansion openings 12 are arranged outside the air outlet end of the main flame gas pipe 10 .

[0045] The undisclosed technical features in this embodiment are the same as those in the seventh embodiment.

[0046] Specific implementation method nine: combination Figure 1 To illustrate this embodiment, an air deflector 9 is provided in the middle of the inner wall of the air sleeve 6 described in this embodiment, an air sleeve expansion opening 8 is provided at the front end of the air sleeve 6, and an air sleeve suction opening 7 is provided at the rear end of the air sleeve 6. The air sleeve suction opening 7 is arranged on the outside of the air outlet end of the air channel 3.

[0047] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0048] An air guide plate 9 is provided in the air sleeve 6 to ensure uniform air flow distribution, optimize the mixing of air and return flue gas, further reduce the oxygen concentration, and inhibit NO X Generation.

[0049] Specific implementation method ten: Combination Figure 1 To illustrate this embodiment, the front end of the duty sleeve 4 in this embodiment is provided with a duty sleeve flare 5 , and the duty sleeve flare 5 is arranged in front of the air sleeve flare 8 .

[0050] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0051] The return flue gas is sucked back through the air sleeve expansion 8, the mixing tube expansion 12, and the mixing tube suction port 13, and part of the flue gas generated by combustion is reintroduced into the combustion zone. The return flue gas helps to reduce the oxygen concentration in the combustion zone, reduce the combustion temperature, and inhibit NO X Generation.

[0052] The present invention adopts flue gas recirculation technology and multi-hole injection staged combustion design, which can avoid the formation of local high temperature areas and significantly reduce thermal NO X In addition, the mixing ratio of hydrogen and natural gas in the burner can be flexibly adjusted as needed to ensure that the burner can maintain a low NOx emission even when a large proportion of hydrogen is added. X emissions and higher combustion efficiency.

[0053] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A low-nitrogen burner that uses a large proportion of natural gas mixed with hydrogen, characterized by: The invention comprises a duty gas pipe (1), a hydrogen pipe (2), an air channel (3), a duty sleeve (4), an air sleeve (6), a plurality of duty gas branch pipes (16) and a plurality of porous swirl blades (19). The air channel (3) is coaxially sleeved on the outside of the duty gas pipe (1) on the air inlet side. The outlet end of the hydrogen pipe (2) passes through the air channel (3) and is connected to the air inlet side of the duty gas pipe (1). The duty sleeve (4) and the air sleeve (6) are coaxially sleeved on the outside of the air outlet side of the duty gas pipe (1) in sequence from the inside to the outside. The plurality of duty gas branch pipes (16) are evenly distributed in the duty sleeve (4) along the circumferential direction. The air inlet end of the duty gas branch pipe (16) is connected to the duty gas pipe (1). The outlet end of the duty gas branch pipe (16) is provided with a porous swirl blade (19).

2. The low-nitrogen burner according to claim 1, wherein: The air inlet end of the duty gas branch pipe (16) is arranged along the radial direction of the duty gas pipe (1), and the air outlet end of the duty gas branch pipe (16) is arranged along the axial direction of the duty gas pipe (1) and is arranged toward the air outlet side of the duty gas pipe (1).

3. The low-nitrogen burner for burning natural gas with a large proportion of hydrogen according to claim 2, characterized in that: The porous swirl blade (19) is vertically fixed to the outer wall of the duty gas pipe (1). The porous swirl blade (19) is a hollow structure. An axial gas inlet hole is provided on the rear end face of the porous swirl blade (19). The axial gas inlet hole is connected to the gas outlet end of the duty gas branch pipe (16). A plurality of axial gas injection holes (17) are uniformly distributed on the front end face of the porous swirl blade (19).

4. The low-nitrogen burner for burning natural gas with a large proportion of hydrogen according to claim 1, characterized in that: A plurality of tangential gas injection ports (18) are evenly distributed along the circumferential direction on the side wall of the port at the gas outlet end of the duty gas pipe (1).

5. The low-nitrogen burner for burning natural gas with a large proportion of hydrogen according to claim 1, characterized in that: Two inner and outer circles of main flame gas pipes (10) are coaxially arranged on the outer side of the duty gas pipe (1), each circle of main flame gas pipes (10) comprises a plurality of evenly distributed main flame gas pipes (10), an inner circle of main flame gas pipes (10) is provided at the front end thereof with an inner circle of mixing pipes (15), and an outer circle of main flame gas pipes (10) is provided at the front end thereof with an outer circle of mixing pipes (14).

6. The low-nitrogen burner for burning natural gas with a large proportion of hydrogen according to claim 5, characterized in that: The main flame gas pipes (10) of the inner circle and the main flame gas pipes (10) of the outer circle are arranged alternately.

7. The low-nitrogen burner for burning natural gas with a large proportion of hydrogen according to claim 5, characterized in that: The main flame gas nozzle (11) is provided at the gas outlet end of the main flame gas pipe (10), and the outer ring mixing pipe (14) and the inner ring mixing pipe (15) are respectively provided with mixing pipe entrainment ports (13) on the gas inlet side. The mixing pipe entrainment ports (13) are arranged in front of the main flame gas nozzle (11).

8. The low-nitrogen burner for burning natural gas with a large proportion of hydrogen according to claim 7, characterized in that: The air inlet ends of the outer ring mixing tube (14) and the inner ring mixing tube (15) are respectively provided with mixing tube expansion openings (12), and the mixing tube expansion openings (12) are arranged outside the air outlet end of the main flame gas pipe (10).

9. The low-nitrogen burner for burning natural gas with a large proportion of hydrogen according to claim 1, characterized in that: An air deflector (9) is provided in the middle of the inner wall of the air sleeve (6), an air sleeve expansion opening (8) is provided at the front end of the air sleeve (6), and an air sleeve suction opening (7) is provided at the rear end of the air sleeve (6). The air sleeve suction opening (7) is arranged on the outside of the air outlet end of the air channel (3).

10. The low-nitrogen burner for burning natural gas with a large proportion of hydrogen according to claim 1, characterized in that: The front end of the duty sleeve (4) is provided with a duty sleeve flare (5), and the duty sleeve flare (5) is arranged on the front side of the air sleeve flare (8).

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