A hydrogen and natural gas mixed combustion burner

Abstract

The present invention discloses a hydrogen and natural gas mixed combustion burner, comprising a burner body, a natural gas pipe and a hydrogen pipe. A combustion-supporting gas is introduced into the combustion body. A cyclone blade is provided at the end of the combustion body. The cyclone blade is provided with a combustion-supporting air hole connected with the inner cavity of the combustion body. A boss is provided at the center of the cyclone blade. The inside of the boss is hollow and provided with a hydrogen nozzle. The height of the hydrogen nozzle is less than the height of the boss. The top, outer side and inner side of the boss are all provided with natural gas nozzles. The natural gas pipe is provided inside the combustion body and the end is connected with the natural gas nozzle. The hydrogen pipe is sleeved in the natural gas pipe and the end is connected with the hydrogen nozzle. The burner uses hydrogen and natural gas as fuel for mixed combustion, which can effectively exert the advantages of hydrogen and solve the disadvantages of hydrogen when burned alone.

Description

Technical Field

[0001] The invention relates to the technical field of burners, and in particular to a hydrogen and natural gas mixed combustion burner. Background Art

[0002] Hydrogen is a relatively popular green renewable energy, with the advantages of high calorific value per unit mass and easy and sufficient combustion. However, there are certain defects when hydrogen is directly used in the field of industrial fuel combustion, such as high hydrogen cost, high local combustion temperature, easy generation of large amounts of H2O, and low safety performance. In order to solve the limitations of the application of pure hydrogen in the field of industrial furnace burners, a new combustion technology is urgently needed that can effectively exert the advantages of hydrogen and solve its shortcomings when burned alone. Summary of the invention

[0003] In view of the defects of the above-mentioned prior art, the purpose of the present invention is to provide a hydrogen-natural gas co-firing burner, which uses hydrogen and natural gas as the combustion sources of the burner for co-firing, which can effectively exert the advantages of hydrogen and solve the shortcomings of its single combustion.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] A hydrogen and natural gas mixed combustion burner comprises a burner body, a natural gas pipe and a hydrogen pipe, wherein a combustion-supporting gas is introduced into the combustion body, a cyclone sheet is provided at the end of the combustion body, and the cyclone sheet is provided with a combustion-supporting air hole connected to the inner cavity of the combustion body, a boss is provided at the center of the cyclone sheet, the boss is hollow inside and is provided with a hydrogen nozzle, the height of the hydrogen nozzle is less than the height of the boss, the top, outer side and inner side of the boss are all provided with natural gas nozzles, the natural gas pipe is provided inside the combustion body and the end thereof is connected to the natural gas nozzle, and the hydrogen pipe is sleeved in the natural gas pipe and the end thereof is connected to the hydrogen nozzle.

[0006] Furthermore, the natural gas nozzle at the top of the boss is oriented toward the periphery of the boss and is 30-60° away from the height direction of the boss, and the distance between the natural gas nozzle on the outer side of the boss and the cyclone blade is 8-12 mm.

[0007] Furthermore, the natural gas nozzle on the inner side surface of the boss is oriented toward the inside of the boss and is 30 to 60 degrees with respect to the height direction of the boss.

[0008] Furthermore, the combustion-supporting air holes include positive air holes and side air holes. The positive air holes are arranged inside the cyclone blade and are parallel to the center line of the cyclone blade. The side air holes are arranged on the outer circumference of the cyclone blade and are inclined relative to the center line of the cyclone blade.

[0009] Furthermore, the cyclone blade is embedded in one end of the burner body, and the side air hole is inclined at 10 to 20 degrees relative to the center line of the cyclone blade.

[0010] Furthermore, the burner body includes a burner sleeve and a burner cover, the burner cover is arranged at one end of the burner body away from the cyclone plate, the hydrogen pipe extends out of the burner cover and is connected to a hydrogen inlet, and a natural gas inlet is provided on the burner cover, and the natural gas inlet is connected to the natural gas pipe.

[0011] Furthermore, a combustion-supporting air inlet is provided on the side of the burner body, and the combustion-supporting air inlet communicates with the interior of the burner body and the combustion-supporting air hole.

[0012] Furthermore, an ignition device and a fire detection device are provided at the combustion-supporting air hole, and the ignition device and the fire detection device are both arranged on the outside of the boss, and the ignition device and the fire detection device are symmetrically distributed along the boss.

[0013] Furthermore, a mounting flange and a pressure measuring nozzle are provided outside the burner body.

[0014] Furthermore, a flame-blocking element is installed at the position of the hydrogen inlet, and the flame-blocking element is set to a porous medium structure with a pore diameter less than 0.8 mm.

[0015] The beneficial effects of the present invention are:

[0016] (1) The hydrogen pipe is hidden in the natural gas pipe, and the natural gas pipe is placed in the burner body. This "tube-in-tube" structure can separate the combustion air holes, natural gas nozzles and hydrogen nozzles in layers. The structure is compact and occupies little space. It can not only give full play to the advantages of hydrogen combustion, but also solve the shortcomings of hydrogen combustion alone.

[0017] (2) Natural gas is used to block direct contact between hydrogen and air, which enhances the safety of hydrogen combustion. Hydrogen and natural gas are premixed, and the mixed gas is gradually burned in sections above the boss to achieve the effect of graded combustion, effectively suppressing the high NO generated by natural gas combustion. X Phenomenon, effectively reducing the root flame temperature of hydrogen combustion and avoiding gun body damage and flashback. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a front view of the hydrogen and natural gas mixed combustion burner of the present invention;

[0019] Figure 2 It is a schematic diagram of the structure of the hydrogen and natural gas mixed combustion burner of the present invention;

[0020] Figure 3 is a cross-sectional view of the hydrogen and natural gas mixed combustion burner of the present invention;

[0021] Figure 4 It is a schematic diagram of the structure of the cyclone blade and the boss in the present invention;

[0022] Figure 5 It is a schematic diagram of the structure of the cyclone blade in the present invention;

[0023] Figure 6 It is a partial structural schematic diagram of the hydrogen and natural gas mixed combustion burner of the present invention;

[0024] Figure 7 It is a right side view of the hydrogen and natural gas mixed combustion burner of the present invention.

[0025] In the figure:

[0026] 1. Burner body; 110. Burner sleeve; 120. Burner cover; 2. Natural gas pipe; 3. Hydrogen pipe; 4. Cyclone blade; 5. Combustion-supporting air hole; 510. Positive air hole; 520. Side air hole; 6. Boss; 7. Natural gas nozzle; 8. Hydrogen nozzle; 9. Hydrogen inlet; 10. Natural gas inlet; 11. Fire-viewing mirror; 12. Combustion-supporting air inlet; 13. Ignition device; 14. Fire detection device; 15. Mounting flange; 16. Pressure measuring nozzle; 17. Through groove. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects solved by the invention more clearly understood, the invention is further described below in conjunction with the accompanying drawings and embodiments.

[0028] Unless otherwise defined, the technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0029] like Figures 1 to 7 As shown, the present invention provides a hydrogen-natural gas mixed combustion burner, comprising a burner body 1, a natural gas pipe 2 and a hydrogen pipe 3. A combustion-supporting gas is introduced into the burner body 1, and generally, the combustion-supporting gas is air; a cyclone blade 4 is provided at the end of the burner body 1, and a combustion-supporting air hole 5 connected to the inner cavity of the burner body 1 is provided on the cyclone blade 4, and a boss 6 is provided at the center of the cyclone blade 4, the boss 6 is hollow inside and is provided with a hydrogen nozzle 8, the height of the hydrogen nozzle 8 is less than the height of the boss 6, and the top, outer side and inner side of the boss 6 are all provided with natural gas nozzles 7; the natural gas pipe 2 is arranged inside the burner body 1 and the end is connected to the natural gas nozzle 7, and the hydrogen pipe 3 is sleeved in the natural gas pipe 2 and the end is connected to the hydrogen nozzle 8.

[0030] The hydrogen pipe 3 is hidden in the natural gas pipe 2, and the natural gas pipe 2 is placed in the burner body 1. This "tube-wrapped-tube" structure can separate the combustion-supporting air holes 5, the natural gas nozzles 7 and the hydrogen nozzles 8 in layers. The structure is compact and occupies a small space. It can not only give full play to the advantages of hydrogen combustion, but also solve the shortcomings of hydrogen combustion alone. The hydrogen is wrapped in the natural gas. Since the mixing amount of natural gas is greater than the mixing amount of hydrogen, the structure can also play a role in cooling the hydrogen. To further explain, combustion-supporting gas is introduced into the burner body 1, natural gas is introduced into the natural gas pipe 2, and hydrogen is introduced into the hydrogen pipe 3. A cyclone sheet 4 is provided at one end of the burner body 1. The hydrogen pipe 3 is connected to the hydrogen nozzle 8 arranged inside the boss 6. The natural gas pipe 2 is sleeved on the outside of the hydrogen pipe 3. Therefore, the end of the natural gas pipe 2 directly covers the bottom surface of the boss 6 and can be directly connected to all the natural gas nozzles 7. The part of the cyclone sheet 4 not covered by the natural gas pipe 2 will directly contact the inner cavity of the burner body 1 and be connected to the combustion-supporting gas in the burner body 1, so that hydrogen is finally ejected from the center of the boss 6, natural gas is ejected from the top of the boss 6, and combustion-supporting air is ejected from the periphery of the boss 6.

[0031] Figure 4 The positions of several natural gas nozzles 7 on the boss 6 are shown, including the natural gas nozzle 7a located on the outer side of the boss 6, the natural gas nozzle 7b located on the top of the boss 6 and the natural gas nozzle 7c located on the inner side of the boss 6.

[0032] During the combustion process of the burner, in the circumferential outer area of ​​the boss 6, the combustion-supporting gas flowing out from the combustion-supporting air holes 5 first contacts and burns with the natural gas ejected from the natural gas nozzle 7a on the outer side of the boss 6, and then the smoke after combustion and the combustion-supporting gas that has not participated in the above-mentioned combustion process flow to the central area above the boss 6, forming a certain low-oxygen zone above the center of the boss 6; at the same time, since the hydrogen nozzle 8 in the boss 6 is lower than the top of the boss 6, the natural gas ejected from the natural gas nozzle 7c on the inner side of the boss 6 and the hydrogen ejected from the hydrogen nozzle 8 will be premixed in the hollow inside of the boss 6, and the premixed gas gradually rises to the low-oxygen zone above the center of the boss 6. In this area, the hydrogen and natural gas mixture is not fully burned at first, and the flame combustion temperature is low, and it will gradually burn completely in the later combustion area, achieving the effect of staged combustion. This method can effectively suppress the high NO generated by the combustion of natural gas. X Phenomenon, effectively reducing the root flame temperature of hydrogen combustion, and preventing the cyclone blade 4, boss 6 and hydrogen nozzle 8 from being damaged and tempered due to high temperature.

[0033] When hydrogen and natural gas are premixed, the natural gas sprayed from the natural gas nozzle 7c on the inner side of the boss 6 will fill the inside of the boss 6, which can avoid the formation of a negative pressure area inside the boss 6, effectively prevent the flame from flowing back above the boss 6, and improve the safety of hydrogen combustion.

[0034] During the combustion process of the burner, the natural gas ejected from the natural gas nozzle 7b on the top of the boss 6 is located between the hydrogen nozzle 8 and the combustion-supporting air hole 5, which can isolate the hydrogen and the combustion-supporting gas at the top surface of the boss 6 to prevent the hydrogen from directly contacting the combustion-supporting gas. The natural gas ejected from the top of the boss 6 can contact the combustion-supporting air or hydrogen, and will not affect the staged combustion of the mixed gas.

[0035] refer to Figure 4 and Figure 5 The natural gas nozzle 7b at the top of the boss 6 is directed toward the periphery of the boss 6 and is at an angle of 30 to 60 degrees with the height direction of the boss 6. The distance between the natural gas nozzle 7a on the outer side of the boss 6 and the cyclone sheet 4 is 8 to 12 mm. In order to optimize the structure of the natural gas nozzle 7, a plurality of through grooves 17 are evenly arranged along the circumference of the boss 6. The through grooves 17 are inclined relative to the height direction of the boss 6. The circumference of the boss 6 is similar to a gear structure. The natural gas nozzle 7a on the outer side of the boss 6 is arranged in the plurality of through grooves 17 and is at a distance of 8 to 12 mm from the cyclone sheet 4. Relative to the top surface of the boss 6, the natural gas nozzle 7a on the outer side of the boss 6 is closer to the cyclone sheet 4; the natural gas nozzle 7b at the top of the boss 6 is arranged between adjacent through grooves 17 and is inclined relative to the top surface of the boss 6. The natural gas ejected from the top of the boss 6 is inclined toward the periphery of the boss 6.

[0036] The natural gas nozzle 7c on the inner side of the boss 6 is oriented toward the inside of the boss 6 and is at an angle of 30 to 60 degrees with the height direction of the boss 6. In order to optimize the structure of the natural gas nozzle 7c on the inner side of the boss 6, the hollow cross-section inside the boss 6 is U-shaped. Figure 3 Its structure is similar to a "wine glass shape". The natural gas nozzles 7c on the inner side of the boss 6 are distributed along the U-shaped circumference and are beveled at 30 to 60 degrees to the top surface of the boss 6. The inner side of the boss 6 tilts to spray natural gas toward the inside of the boss 6, which is convenient for premixing with the hydrogen sprayed from the inside of the boss 6 and flowing to the top of the boss 6.

[0037] The combustion-supporting air holes 5 include a positive air hole 510 and a side air hole 520. The positive air hole 510 is arranged inside the cyclone blade 4 and parallel to the center line of the cyclone blade 4. The side air hole 520 is arranged on the outer circumference of the cyclone blade 4 and is inclined relative to the center line of the cyclone blade 4. The cyclone blade 4 is embedded in one end of the burner body 1, and the side air hole 520 is inclined relative to the center line of the cyclone blade 4 by 10 to 20 degrees.

[0038] By adjusting the size and number of the combustion-supporting air holes 5 and the natural gas nozzles 7, the gas flow rate, the combustion-supporting gas flow rate and the mixed combustion ratio of hydrogen and natural gas of the burner are controlled to adapt to the maximum power required by the burner.

[0039] The burner body 1 includes a burner sleeve 110 and a burner cover 120. The burner cover 120 is arranged at one end of the burner body 1 away from the cyclone blade 4. The hydrogen pipe 3 extends out of the burner cover 120 and is connected to the hydrogen inlet 9. The burner cover 120 is provided with a natural gas inlet 10, which is connected to the natural gas pipe 2. By cleverly designing the structure of the burner cover 120, the hydrogen inlet 9 and the natural gas inlet 10 are separated. The hydrogen inlet 9 and the natural gas inlet 10 are arranged at different positions of the burner cover 120, and do not affect each other, which makes it easier for the two combustion gases to be respectively introduced into the burner sleeve 110.

[0040] A fire-blocking element is installed at the position of the hydrogen inlet 9. The fire-blocking element is set to a porous medium structure, which can be a porous ceramic component or a porous metal component. The hole diameter is controlled within 0.8 mm. On the one hand, the porous medium structure of the fire-blocking element can filter the hydrogen source to prevent impurities from clogging the hydrogen nozzle 8. On the other hand, the fire-blocking element can avoid the problem of flashback combustion caused by low hydrogen purity or too low hydrogen pressure. Since its hole diameter is less than 0.8 mm, when flashback occurs, the flashback flame will be divided into many small flame flows by the porous medium structure when passing through the porous medium structure. Due to the heat transfer effect and the wall effect, the flame will be cooled around the porous medium structure. When the flame temperature drops below the ignition point, the flame will be quenched.

[0041] Therefore, when the flame burning speed is greater than the hydrogen supply pressure or the hydrogen purity is abnormal, even if the hydrogen flashes back, the flashback flame will be quenched in the flame arrester, preventing the pipeline from causing safety hazards due to flashback. In addition, the hydrogen supply pressure can be monitored by setting a pressure sensor alarm on the hydrogen pipe 3. The hydrogen pressure range of the flame arrester is set to 0.05MPa to 1.5MPa. When it is less than the lower limit of this pressure, the pressure sensor alarm will send a signal alarm.

[0042] A combustion-supporting air inlet 12 is provided on the side of the burner body 1, and the combustion-supporting air inlet 12 is connected to the inside of the burner body 1 and the combustion-supporting air holes 5. The combustion-supporting gas enters the inner cavity of the burner body 1 from the combustion-supporting air inlet 12 and flows out from a plurality of combustion-supporting air holes 5. In the inner cavity of the burner body 1, the natural gas pipe 2 is placed in the combustion-supporting gas environment, and the hydrogen pipe 3 is placed in the natural gas environment. Each gas is effectively isolated by the pipe in the burner body 1, and no gas premixing occurs. In the absence of premixing, the circulation of hydrogen in the burner body 1 is safer, and there is no need to worry about the mixing ratio problem, which is safer.

[0043] An ignition device 13 and a fire detection device 14 are provided at the combustion-supporting air hole 5. The ignition device 13 and the fire detection device 14 are both arranged on the outside of the boss 6. The ignition device 13 and the fire detection device 14 are symmetrically distributed along the boss 6. Preferably, the ignition device 13 and the fire detection device 14 both pass through the burner body 1 and extend out of the burner cover 120. The ignition device 13 includes an ignition electrode, and the fire detection device 14 includes a fire detection bent electrode. The ignition electrode and the fire detection bent electrode are arranged outside the burner body 1 and located on the outside of the boss 6.

[0044] refer to Figure 7 The burner body 1 is provided with a mounting flange 15 and a pressure measuring nozzle 16 on the outside. There are two pressure measuring nozzles 16, which are respectively arranged at the burner cover 120 and the combustion air inlet 12. The burner body 1 is provided with a fire viewing mirror 11 on the side away from the cyclone blade 4.

[0045] The cyclone blades 4, bosses 6, hydrogen nozzles 8, natural gas pipes 2 and hydrogen pipes 3 in the burner are all installed on the burner body 1 by threaded connection. Parts can be replaced and disassembled and reassembled according to different power requirements of the burner.

[0046] The present invention utilizes natural gas to block direct contact between hydrogen and air, thereby enhancing the safety of hydrogen combustion. In addition, hydrogen is premixed with natural gas before combustion, which can not only reduce the combustion density of hydrogen and prevent high temperature at the root of the flame during hydrogen combustion, but also achieve staged combustion during the combustion process, thereby avoiding gun body damage and flashback.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should fall within the protection scope of the present invention.

Claims

1. A hydrogen and natural gas mixed combustion burner, characterized in that: The invention comprises a burner body (1), a natural gas pipe (2) and a hydrogen pipe (3), wherein a combustion-supporting gas is introduced into the burner body (1), a cyclone plate (4) is provided at the end of the burner body (1), and a combustion-supporting air hole (5) is provided on the cyclone plate (4) and is connected to the inner cavity of the burner body (1), a boss (6) is provided at the center of the cyclone plate (4), the boss (6) is hollow inside and is provided with a hydrogen nozzle (8), the height of the hydrogen nozzle (8) is less than the height of the boss (6), the top, outer side and inner side of the boss (6) are all provided with natural gas nozzles (7), the natural gas nozzle (7) on the inner side of the boss (6) is oriented toward the inside of the boss (6), the natural gas pipe (2) is provided inside the burner body (1) and its end is connected to the natural gas nozzle (7), and the hydrogen pipe (3) is sleeved inside the natural gas pipe (2) and its end is connected to the hydrogen nozzle (8).

2. A hydrogen and natural gas mixed combustion burner according to claim 1, characterized in that: The natural gas nozzle (7) at the top of the boss (6) is oriented toward the periphery of the boss (6) and is 30 to 60 degrees with respect to the height direction of the boss (6). The distance between the natural gas nozzle (7) on the outer side of the boss (6) and the cyclone blade (4) is 8 to 12 mm.

3. The hydrogen and natural gas mixed combustion burner according to claim 1, characterized in that: The direction of the natural gas nozzle (7) on the inner side of the boss (6) is 30 to 60 degrees with respect to the height direction of the boss (6).

4. The hydrogen and natural gas mixed combustion burner according to claim 1, characterized in that: The combustion-supporting air holes (5) include a positive air hole (510) and a side air hole (520), wherein the positive air hole (510) is arranged inside the cyclone plate (4) and is parallel to the center line of the cyclone plate (4), and the side air hole (520) is arranged on the outer circumference of the cyclone plate (4) and is inclined relative to the center line of the cyclone plate (4).

5. The hydrogen and natural gas mixed combustion burner according to claim 4, characterized in that: The cyclone blade (4) is embedded in one end of the burner body (1), and the side air hole (520) is inclined at 10 to 20 degrees relative to the center line of the cyclone blade (4).

6. The hydrogen and natural gas mixed combustion burner according to claim 1, characterized in that: The burner body (1) comprises a burner sleeve (110) and a burner cover (120); the burner cover (120) is arranged at one end of the burner body (1) away from the cyclone blade (4); the hydrogen pipe (3) extends out of the burner cover (120) and is connected to a hydrogen inlet (9); a natural gas inlet (10) is provided on the burner cover (120); and the natural gas inlet (10) is connected to the natural gas pipe (2).

7. The hydrogen and natural gas mixed combustion burner according to claim 1, characterized in that: A combustion-supporting air inlet (12) is provided on the side of the burner body (1), and the combustion-supporting air inlet (12) communicates with the interior of the burner body (1) and the combustion-supporting air hole (5).

8. The hydrogen and natural gas mixed combustion burner according to claim 1, characterized in that: An ignition device (13) and a fire detection device (14) are provided at the combustion-supporting air hole (5); the ignition device (13) and the fire detection device (14) are both provided on the outside of the boss (6); and the ignition device (13) and the fire detection device (14) are symmetrically distributed along the boss (6).

9. The hydrogen and natural gas mixed combustion burner according to claim 1, characterized in that: The burner body (1) is provided with a mounting flange (15) and a pressure measuring nozzle (16) outside.

10. The hydrogen and natural gas mixed combustion burner according to claim 1, characterized in that: A flame arrester element is installed at the position of the hydrogen inlet (9), wherein the flame arrester element is configured as a porous medium structure with a pore diameter of less than 0.8 mm.

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