A boiler hydrogen burner

Abstract

A boiler hydrogen gas burner relates to a burner, including burner air bellow, firebrick, primary fuel gun, tertiary fuel gun group and ignition assembly, burner air bellow is fixedly connected with firebrick through the right end surface burner mounting plate, and the primary fuel gun is fixed at the center of the left end surface mounting plate of burner air bellow, and the gas main line of secondary fuel gun group and ignition assembly are respectively fixed at the upper portion and lower portion of the left end surface mounting plate of burner air bellow, the left end of primary fuel gun is respectively communicated with the gas main line of secondary fuel gun group, the gas main line of tertiary fuel gun group and gas inlet through gas distributor; the utility model adopts the design of three-stage radial fuel injection and tangential injection angle, hydrogen gas is injected in several branches and the diffusion mixing with air is enhanced, the local high temperature zone is weakened, and CO2 is not generated, zero carbon emission is achieved; the problems of high hydrogen gas combustion NOx emission concentration and great environmental protection compliance pressure under traditional non-premixed combustion mode are solved.

Description

Technical Field

[0001] This invention relates to a burner, and more particularly to a boiler hydrogen burner. Background Technology

[0002] With the acceleration of the global low-carbon transition, zero-carbon energy substitution has become a key trend. Hydrogen fuel, due to its combustion product being only water vapor (producing only a small amount of thermal nitrogen oxides), has become a core option for the clean energy transition. However, the physical and chemical properties of hydrogen lead to the following significant technical challenges in its combustion: 1. Hydrogen has a low ignition energy and an extremely high combustion speed (approximately 10 times that of natural gas), resulting in a short and concentrated flame. This leads to localized high-temperature accumulation at the burner outlet, causing damage to furnace tubes and uneven furnace temperature distribution. During low-load operation, the risk of backfire increases sharply due to the reduced airflow velocity, making stable operation over a wide load range difficult. 2. Pollutant emissions are difficult to control. Although hydrogen combustion produces no carbon emissions, it easily generates thermal nitrogen oxides (NOx) at high temperatures. Existing burners lack specific designs to address this issue. 1. High emission concentrations make it difficult to meet environmental protection requirements; 2. Uneven heat distribution and concentrated flames lead to large temperature gradients in the furnace, causing localized overheating of the furnace tubes and shortening the equipment's lifespan; at the same time, low combustion efficiency results in serious energy waste; 3. Poor adaptability to modification: directly modifying existing burners to be compatible with hydrogen fuel requires large-scale changes to the boiler structure, resulting in high modification costs, long cycles, and difficulty in ensuring operational safety; existing burners are mostly designed for traditional fossil fuels and are difficult to adapt to the special combustion characteristics of hydrogen, failing to meet the requirements of industrial boilers for high efficiency, stability, and low emissions. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a boiler hydrogen burner.

[0004] The technical solution adopted in this invention is: A boiler hydrogen burner includes a burner box, refractory bricks, a primary fuel gun, a tertiary fuel gun assembly, and an ignition assembly. The burner box is fixedly connected to the refractory bricks via a burner mounting plate on its right end face. A primary fuel gun is fixed at the center of the mounting plate on the left end face of the burner box. The gas main pipeline of the secondary fuel gun assembly and the ignition assembly are fixed at the upper and lower parts of the mounting plate on the left end face of the burner box, respectively. The left end of the primary fuel gun is connected to the gas main pipeline of the secondary fuel gun assembly, the gas main pipeline of the tertiary fuel gun assembly, and the gas inlet via a gas distributor. The nozzle of the primary fuel gun is provided with an ignition hole C and a combustion hole C. The ignition holes C are perpendicular to the barrel of the primary fuel gun and are arranged in a ring with four holes. There are three combustion holes C evenly distributed, one of which is set at a 30° angle to the ignition hole C and is distributed with a tangential injection angle of 15°. Each nozzle of the secondary fuel gun assembly is provided with a combustion hole B and an ignition hole B. There are two combustion holes C, distributed with a tangential injection angle of 10°-15°, and one ignition hole B, arranged with a tangential injection angle of 0°-3°. Each nozzle of the three-stage fuel gun assembly is equipped with a combustion port A and an ignition port A. There are two combustion ports A, distributed at tangential injection angles of 10°-15°, and two ignition ports A, distributed at tangential injection angles of 0°-3°.

[0005] Specifically, the refractory bricks consist of an inner refractory brick and an outer refractory brick with two layers. Both the outer and inner refractory bricks have an expansion angle of 12° at their ends. The three-stage fuel gun assembly is located in the secondary air channel between the inner and outer refractory bricks. The multiple nozzles and ignition assemblies of the two-stage fuel gun assembly are located in the primary air channel inside the inner refractory brick.

[0006] Specifically, a primary cyclone separator is installed on the main gas pipeline and ignition assembly of the secondary fuel gun group, and a secondary cyclone separator is installed on multiple tertiary fuel guns in the tertiary fuel gun group; the blade angle of the primary cyclone separator is set at 32° axially, and the blade angle of the secondary cyclone separator is set at 15° radially.

[0007] Specifically, a flame stabilizer is fixed to the nozzle of the first-stage fuel gun.

[0008] Specifically, a secondary gas inlet and an electronic igniter mounting port are provided on the mounting plate on the left end face of the burner air box. The gas pipeline of the secondary fuel gun is fixed on the secondary gas inlet, and the electronic igniter of the ignition assembly is fixed on the electronic igniter mounting port. An ignition system cooling air inlet is provided below the electronic igniter, and an auxiliary combustion air inlet is provided on one side of the upper part of the burner air box.

[0009] Specifically, a primary gas flow restrictor is installed between the left end of the primary fuel gun and the gas distributor, and a secondary gas control valve is installed between the left end of the gas main pipeline of the secondary fuel gun assembly and the gas distributor.

[0010] Specifically, a secondary gas loop is connected to the main gas pipeline of the secondary fuel gun group, and the gas pipelines of multiple secondary fuel guns in the secondary fuel gun group are evenly spaced and connected to the secondary gas loop.

[0011] Specifically, a three-stage gas ring pipe is connected to the main gas pipeline of the three-stage fuel gun group. The gas pipelines of multiple three-stage fuel guns in the three-stage fuel gun group are evenly spaced and connected to the three-stage gas ring pipe. Multiple three-stage fuel guns are installed inside the refractory bricks through the outer wall of the burner air box. A three-stage gas control valve is installed on the main gas pipeline of the three-stage fuel gun group.

[0012] Due to the adoption of the technical solution described above, the present invention has the following advantages: 1. The boiler hydrogen burner of this invention, by setting the blade angle of the first-stage cyclone separator 7 to axial 32° and the blade angle of the second-stage cyclone separator 8 to radial 15°, can dynamically adjust the swirl intensity according to the load, and form a stable flame zone in conjunction with the flame stabilizing ring. It achieves stable operation at 40%-100% load, with no risk of backfire or blow-out at low loads (30%-40%), increases the critical backfire velocity to 28±3m / s, and the blow-out limit velocity to 42m / s, improving the safety margin by 22%, far exceeding the load adaptability of existing burners. It solves the shortcomings of existing technologies, such as low-load backfire, unstable flame at high loads, and narrow load adaptability range (usually only 60%-100%).

[0013] 2. The boiler hydrogen burner described in this invention adopts a three-stage radial fuel injection and tangential injection angle design, which injects hydrogen in separate streams and enhances diffusion mixing with air, weakening the local high-temperature zone and reducing NOx emissions to 32ppm (@3% O2), a 54% reduction compared to traditional technologies. This easily meets stringent environmental standards, achieving zero CO2 generation and zero carbon emissions. It solves the problem of high NOx emission concentrations (usually exceeding 70ppm@3% O2) and significant environmental compliance pressure caused by hydrogen combustion in traditional non-premixed combustion methods.

[0014] 3. The boiler hydrogen burner described in this invention adopts a staged combustion design and a 12° expansion angle of refractory bricks, which extends the combustion time and optimizes the flow field, making the flame length controllable and reducing the furnace temperature gradient by 20%. Combined with uniform heat distribution, the service life of the furnace tubes is extended by 30%, significantly reducing equipment maintenance costs. This invention does not require large-scale modifications to the existing boiler structure, and its adaptability design reduces retrofit costs by 40%. Combined with the declining cost of green hydrogen, the total life-cycle operating cost is reduced by 15%-20%. Simultaneously, the combustion efficiency reaches 99.7%, saving 5%-8% energy compared to traditional burners, resulting in significant long-term economic benefits. Furthermore, it meets the global carbon reduction policies, such as the EU carbon tariff and China's "dual-carbon" target for zero-carbon energy, and can directly replace traditional burners, helping industrial boilers achieve a "zero-carbon transition." It covers the upgrading and retrofitting needs of existing boilers and the matching needs of new boilers, with clear market demand and great potential. Attached Figure Description

[0015] Figure 1 This is an overall schematic diagram of the present invention.

[0016] Figure 2 This is a side view of the present invention.

[0017] Figure 3 This is a layout diagram of the spray guns at each stage of the present invention.

[0018] Figure 4 This is a schematic diagram of the burner air box of the present invention.

[0019] Figure 5 This is a schematic diagram of the structure of the refractory brick of the present invention.

[0020] Figure 6 This is a schematic diagram of the spray direction of each level of the spray gun in this invention.

[0021] Figure 7 This is a schematic diagram of the structure of the first-stage hydrocyclone and the second-stage hydrocyclone of the present invention.

[0022] Figure 8 This is a schematic diagram of the nozzle structure of the three-stage fuel gun of the present invention.

[0023] Figure 9 This is a diagram showing the arrangement of the combustion hole A and ignition hole A on the head of the three-stage fuel gun of the present invention.

[0024] Figure 10 This is a schematic diagram of the nozzle structure of the secondary fuel gun of the present invention.

[0025] Figure 11 This is a diagram showing the arrangement of the combustion hole B and ignition hole B on the secondary fuel gun head of the present invention.

[0026] Figure 12 This is a schematic diagram of the nozzle structure of the first-stage fuel gun of the present invention.

[0027] Figure 13 This is a diagram showing the arrangement of the combustion hole C and ignition hole C on the head of the primary fuel gun of the present invention.

[0028] In the diagram: 1. Secondary gas control valve; 2. Primary gas flow restrictor; 3. Gas inlet; 4. Tertiary gas control valve; 5. Electronic igniter; 6. Ignition system cooling vent; 7. Primary cyclone separator; 8. Secondary cyclone separator; 9. Refractory brick; 10. Combustion vent; 11. Tertiary fuel gun; 12. Secondary fuel gun; 13. Primary fuel gun; 14. Flame stabilizer; 15. Ignition assembly; 16. Secondary gas ring pipe; 7. Gas distributor; 18. Three-stage gas ring pipe; 19. Burner air box; 20. Burner mounting plate; 21. Secondary gas inlet; 22. Electronic igniter mounting port; 23. Inner refractory brick; 24. Outer refractory brick; 25. Primary air duct; 26. Secondary air duct; 27. Combustion hole A; 28. Ignition hole A; 29. ​​Combustion hole B; 30. Ignition hole B; 31. Combustion hole C; 32. Ignition hole C. Detailed Implementation

[0029] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments. However, this should not be construed as limiting the scope of protection of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0030] Combined with appendix Figure 1-13The boiler hydrogen burner includes a burner box 19, refractory bricks 9, a primary fuel gun 13, a tertiary fuel gun assembly, and an ignition assembly 15. The burner box 19 is fixedly connected to the refractory bricks 9 via a burner mounting plate 20 on its right end face. A primary fuel gun 13 is fixed at the center of the mounting plate on the left end face of the burner box 19. The gas main pipeline of the secondary fuel gun assembly and the ignition assembly 15 are fixed at the upper and lower parts of the mounting plate on the left end face of the burner box 19, respectively. The left end of the primary fuel gun 13 is connected to the gas main pipeline of the secondary fuel gun assembly, the gas main pipeline of the tertiary fuel gun assembly, and the gas inlet 3 via a gas distributor 17. A primary gas flow restrictor plate 2 is provided between the left end of the primary fuel gun 13 and the gas distributor 17 to ensure that the primary fuel gun 13 maintains a specific load for stable combustion while ensuring the supply of upstream fuel pressure. The nozzle of the primary fuel gun 13 is provided with an ignition hole C32 and a combustion hole C31. There are four ignition holes C32 perpendicular to the barrel of the primary fuel gun 13 and arranged in a ring. There are three combustion holes C31 symmetrically arranged. One of the combustion holes C31 is set at a 30° angle to the ignition hole C32 and is distributed with a tangential injection angle of 15°. The ignition fuel and the combustion fuel are dispersed and burned in a design ratio of 3:7 to achieve gas staged combustion, avoid the central flame concentration, and reduce the generation of thermal nitrogen oxides. A flame stabilizer 14 is fixed on the nozzle of the primary fuel gun 13. The hydrogen flame is concentrated and short. The flame stabilizer ring limits the flame core area through physical structure, forming a stable high-temperature recirculation zone, entraining the surrounding air to maintain the flame shape, and avoiding flame flickering, jumping or blowing out due to airflow disturbance. Each nozzle of the secondary fuel gun assembly is provided with a combustion hole B29 and an ignition hole B30. There are two combustion holes C31, which are distributed with a tangential injection angle of 10°-15°, and one ignition hole B30, which is arranged with a tangential injection angle of 0°-3°. Each nozzle of the three-stage fuel gun assembly is provided with a combustion hole A27 and an ignition hole A28. There are two combustion holes A27, distributed with a tangential injection angle of 10°-15°, and two ignition holes A28, distributed with a tangential injection angle of 0°-3°.

[0031] A secondary gas control valve 1 is installed between the left end of the gas main pipeline of the secondary fuel gun group and the gas distributor 17, and a tertiary gas control valve 4 is installed on the gas main pipeline of the tertiary fuel gun group. The valves are opened by the required load setting. A pressure detection port is set on the rear pipeline to provide feedback on the fuel distribution value of the rear fuel gun. The ignition fuel and combustion fuel are dispersed and burned in a design ratio of 2:8. While the gas fuel is graded at each level, the fuel guns at each level are further graded by the design of the combustion hole and ignition hole on the end gun head. According to the combustion characteristics of hydrogen components, the tangential injection angle and distribution state are set to achieve the purpose of controlling the flame shape and nitrogen oxide emissions.

[0032] Specifically, the refractory brick 9 comprises an inner refractory brick 23 and an outer refractory brick 24, arranged in two layers. Both the outer refractory brick 24 and the inner refractory brick 23 have a 12° expansion angle at their ends. This 12° expansion angle helps elongate the flame shape, reducing thermal nitrogen oxide emissions and improving heat distribution. The fuel gun is evenly distributed inside the refractory brick. The local negative pressure generated by combustion, combined with the swirling device, further accelerates the airflow to maintain the flame shape. The expansion angle structure guides the flame to diffuse outwards, resulting in a more uniform flame distribution and reducing the furnace temperature gradient by 20°. This design avoids localized overheating of the furnace tubes and improves heat utilization efficiency. The three-stage fuel gun assembly is located in the secondary air channel 26 between the inner refractory brick 23 and the outer refractory brick 24. The multiple nozzles and ignition assembly 15 of the two-stage fuel gun assembly are located in the primary air channel 25 within the inner refractory brick 23. The combustion air is divided into two air channels, which, together with the first-stage cyclone separator and the second-stage cyclone separator, provide air distribution to each fuel gun. The nozzles of the second-stage fuel gun face the inner refractory brick to provide an attachment point for the second-stage fuel flame, and the nozzles of the third-stage fuel gun face the outer refractory brick to provide an attachment point for the third-stage fuel flame. Stable combustion can be achieved under different fuel loads.

[0033] Specifically, a primary cyclone separator 7 is installed on the main gas pipeline and ignition assembly 15 of the secondary fuel gun group, and secondary cyclone separators 8 are installed on multiple tertiary fuel guns 11 in the tertiary fuel gun group. The blade angle of the primary cyclone separator 7 is set at 32° axially, and the blade angle of the secondary cyclone separator 8 is set at 15° radially. The cyclone separators are used to enhance the swirling intensity, and the blade angles are matched to make the airflow rotate more violently, increase the air velocity, avoid local high temperature at the burner, protect the burner, extend the burner's service life, and reduce the generation of thermal nitrogen oxides. The boiler burner load adjustment is relatively fast, so to ensure stability when the hydrogen fuel load changes drastically, the swirling intensity can be dynamically adjusted through the 32° axial blade and 15° radial auxiliary blade angle design to achieve stable operation at 40%-100% load.

[0034] Specifically, a secondary gas pipe port 21 and an electronic igniter mounting port 22 are provided on the mounting plate on the left end face of the burner air box 19. The gas pipe of the secondary fuel gun 12 is fixed on the secondary gas pipe port 21. The electronic igniter 5 of the ignition assembly 15 is fixed on the electronic igniter mounting port 22. An ignition system cooling air port 6 is provided below the electronic igniter 5. An auxiliary combustion air port 10 is provided on one side of the upper part of the burner air box 19.

[0035] Specifically, a secondary gas ring pipe 16 is connected to the main gas pipeline of the secondary fuel gun group, and the gas pipelines of multiple secondary fuel guns 12 in the secondary fuel gun group are evenly spaced and connected to the secondary gas ring pipe 16.

[0036] Specifically, a three-stage gas ring pipe 18 is connected to the main gas pipeline of the three-stage fuel gun group. The gas pipelines of multiple three-stage fuel guns 11 in the three-stage fuel gun group are evenly spaced and connected to the three-stage gas ring pipe 18. The multiple three-stage fuel guns 11 are all installed inside the refractory bricks 9 through the outer wall of the burner air box 19.

[0037] When the boiler hydrogen burner described in this invention is in use, after the gas enters the system, it is detected and controlled by a series of gas valve groups, and the system purging is confirmed to be completed. The electronic igniter 5 starts to ignite. At this time, the secondary gas control valve 1 and the tertiary gas control valve 4 are in the closed state. The air volume is adjusted to match the ignition conditions. The combustion air enters the burner air box 19 through the combustion air inlet 10 and supplies air to the primary fuel gun 13 and the secondary fuel gun 12 through the primary cyclone separator 7. The gas enters the gas inlet 3 through the gas inlet pipe and is fed into the primary fuel gun 13. The gas supply pressure is controlled to be stable. The gas passes through the primary gas flow limiting orifice plate 2 of the primary fuel gun 13 and reaches the end nozzle of the primary fuel gun 13, where it is ignited by the electronic igniter 5. After the system detects that the flame is stable, it enters the high-fire stage according to the program settings. The system increases the air distribution, and the combustion air enters the burner air box 19 through the combustion air inlet 10. The combustion air supplies air to the primary fuel gun 13 and the secondary fuel gun 12 through the primary cyclone separator 7, and supplies air to the tertiary fuel gun group through the secondary cyclone separator 8. At the same time, the secondary gas control valve 1 and the tertiary gas control valve 4 are gradually opened, and fuel enters the secondary fuel gun 12 and each tertiary fuel gun 11 of the tertiary fuel gun group through the gas distributor 17. The gas ejected from the end nozzle of the secondary fuel gun 12 is sprayed towards the inner refractory brick 23, and the gas ejected from the end nozzle of the tertiary fuel gun 11 is sprayed towards the inner refractory brick 23. The exhaust gas is injected towards the outer refractory brick 24. The ratio of secondary fuel to tertiary fuel is 1:1. Based on the feedback from the back-end pressure detection, the combustion load is stabilized. When it is necessary to adjust to the medium fire stage, the secondary and tertiary fuels are gradually reduced, the system reduces the air distribution, and the ratio of secondary fuel to tertiary fuel drops to 2:3. When running in the low fire stage, the secondary and tertiary fuels are gradually reduced, the system reduces the air distribution, and the ratio of secondary fuel to tertiary fuel drops to 1:4. After the load is reduced, the flame will shorten. By adjusting the gas ratio, nitrogen oxide emissions are reduced. When the system stops, first close the secondary gas control valve 1 and the tertiary gas control valve 4, and finally cut off the overall gas supply.

[0038] The parts of this invention not described in detail are prior art.

[0039] The embodiments selected herein for the purpose of disclosing the inventive objectives are currently considered suitable; however, it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of this concept and invention.

Claims

1. A boiler hydrogen burner, comprising a burner wind box, refractory bricks, a primary fuel gun, a secondary fuel gun assembly, and an ignition assembly, characterized in that: The boiler hydrogen burner air box is fixedly connected to the refractory bricks via the burner mounting plate on the right end face. A primary fuel gun is fixed at the center of the mounting plate on the left end face of the burner air box. The gas main pipeline and ignition assembly of the secondary fuel gun group are fixed at the upper and lower parts of the mounting plate on the left end face of the burner air box, respectively. The left end of the primary fuel gun is connected to the gas main pipeline of the secondary fuel gun group, the gas main pipeline of the tertiary fuel gun group, and the gas inlet via a gas distributor. The nozzle of the primary fuel gun is provided with an ignition hole C and a combustion hole C. The ignition holes C are perpendicular to the barrel of the primary fuel gun and are arranged in a ring with four holes. There are three combustion holes C evenly distributed, one of which is set at a 30° angle to the ignition hole C and is distributed with a tangential injection angle of 15°. Each nozzle of the secondary fuel gun assembly is provided with a combustion hole B and an ignition hole B. There are two combustion holes C, distributed with a tangential injection angle of 10°-15°, and one ignition hole B, arranged with a tangential injection angle of 0°-3°. Each nozzle of the three-stage fuel gun assembly is equipped with a combustion port A and an ignition port A. There are two combustion ports A, distributed at tangential injection angles of 10°-15°, and two ignition ports A, distributed at tangential injection angles of 0°-3°.

2. The boiler hydrogen burner according to claim 1, characterized in that: The refractory bricks include an inner refractory brick and an outer refractory brick with two layers. Both the outer and inner refractory bricks have an expansion angle of 12° at their ends. The three-stage fuel gun assembly is located in the secondary air channel between the inner and outer refractory bricks. The multiple nozzles and ignition assemblies of the two-stage fuel gun assembly are located in the primary air channel inside the inner refractory brick.

3. The boiler hydrogen burner according to claim 1, characterized in that: A primary cyclone separator is installed on the main gas pipeline and ignition assembly of the secondary fuel gun group, and a secondary cyclone separator is installed on multiple tertiary fuel guns in the tertiary fuel gun group; the blade angle of the primary cyclone separator is set at 32° axially, and the blade angle of the secondary cyclone separator is set at 15° radially.

4. The boiler hydrogen burner according to claim 1, characterized in that: A secondary gas inlet and an electronic igniter mounting port are provided on the mounting plate on the left end face of the burner air box. The gas pipeline of the secondary fuel gun is fixed on the secondary gas inlet, and the electronic igniter of the ignition assembly is fixed on the electronic igniter mounting port. An ignition system cooling air inlet is provided below the electronic igniter, and an auxiliary combustion air inlet is provided on one side of the upper part of the burner air box.

5. The boiler hydrogen burner according to claim 1, characterized in that: A primary gas flow restrictor is installed between the left end of the primary fuel gun and the gas distributor, and a secondary gas control valve is installed between the left end of the gas main pipeline of the secondary fuel gun assembly and the gas distributor.

6. The boiler hydrogen burner according to claim 1, characterized in that: A flame stabilizer is fixed to the nozzle of the first-stage fuel gun.

7. The boiler hydrogen burner according to claim 1, characterized in that: A secondary gas loop is connected to the main gas pipeline of the secondary fuel gun assembly. The gas pipelines of multiple secondary fuel guns in the secondary fuel gun assembly are evenly spaced and connected to the secondary gas loop.

8. The boiler hydrogen burner according to claim 1, characterized in that: A three-stage gas ring pipe is connected to the main gas pipeline of the three-stage fuel gun group. The gas pipelines of multiple three-stage fuel guns in the three-stage fuel gun group are evenly spaced and connected to the three-stage gas ring pipe. Multiple three-stage fuel guns are installed inside the refractory bricks through the outer wall of the burner air box. A three-stage gas control valve is installed on the main gas pipeline of the three-stage fuel gun group.

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