Mixed combustor and mixed combustion system

Abstract

The invention relates to a mixed combustor and a mixed combustion system.The mixed combustor comprises a conveying part, and the conveying part comprises a hydrogen pipeline, an inert gas pipeline and a primary air pipeline which are sequentially arranged in a sleeved mode from inside to outside; the inlet side of the hydrogen pipeline is communicated with a hydrogen conveying pipeline, the inlet side of the inert gas pipeline is communicated with a first inert gas conveying pipeline, and the inlet side of the primary air pipeline is communicated with a primary air conveying pipeline mixed with pulverized coal; a secondary air channel is further arranged on the periphery of the side, facing the outlet end, of the conveying part and communicates with a secondary air box, and the secondary air channel is further provided with rotational flow blades. According to the mixed burner, part of coal can be replaced by hydrogen, so that the hydrogen and pulverized coal are mixed for burning, carbon emission is reduced, the influence on the environment is reduced, and meanwhile, the safety of hydrogen burning can be guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of combustion equipment, and in particular to a mixed burner and a mixed combustion system. Background Art

[0002] Coal-fired power plants are one of the main sources of carbon dioxide emissions. A large amount of carbon dioxide is released during the combustion of coal, which has a serious impact on the environment. Fuel flexibility transformation, especially the partial replacement of coal with low-carbon fuels to reduce carbon emissions from coal-fired power plants, is an important technology.

[0003] In the existing technology, carbon emissions can be reduced by using green ammonia mixed with pulverized coal to generate electricity. Specifically, green hydrogen is produced by electrolyzing water and green ammonia is synthesized, and coal-fired units are mixed with green ammonia to generate electricity to replace part of the coal. However, there is a large energy attenuation problem from green electricity to green hydrogen and then to green ammonia, and the energy utilization efficiency is low. In addition, ammonia is a toxic gas and is dangerous. The conditions for ammonia storage and transportation are relatively high. If an ammonia leakage accident occurs, it will pose a serious threat to the health of power plant workers. At the same time, ammonia leakage into the environment may also cause harm to surrounding residents and the ecological environment. In addition, ammonia combustion is prone to high risks of nitrogen oxide emissions.

[0004] Hydrogen is used directly as fuel, and there is no need to invest a large amount of money in the construction of green hydrogen synthesis green ammonia process equipment or green hydrogen synthesis green methanol equipment. At the same time, there is no problem of energy and energy quality attenuation when converting green hydrogen to green ammonia or green hydrogen to green methanol. The combustion of high calorific value hydrogen only produces water vapor, which can replace coal combustion to achieve the effect of direct carbon reduction. There is basically no problem of nitrogen oxides that need to be controlled when burning green ammonia. Therefore, hydrogen is an ideal fuel to replace part of coal to reduce carbon emissions, but the safe combustion of hydrogen is a more important issue.

[0005] Therefore, how to replace part of the coal combustion with hydrogen to reduce carbon emissions and reduce the impact on the environment while ensuring the safety of hydrogen combustion is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0006] The purpose of this application is to provide a mixed burner and a mixed combustion system, which can replace part of the coal with hydrogen, so that hydrogen and coal powder are mixed and burned to reduce carbon emissions and reduce the impact on the environment, while also ensuring the safety of hydrogen combustion.

[0007] In order to solve the above technical problems, the present application provides a mixed burner, including a conveying part, the conveying part including a hydrogen pipeline, an inert gas pipeline and a primary air pipeline which are sequentially sleeved from the inside to the outside; the inlet side of the hydrogen pipeline is connected to the hydrogen conveying pipeline, the inlet side of the inert gas pipeline is connected to the first inert gas conveying pipeline, and the inlet side of the primary air pipeline is connected to the primary air conveying pipeline mixed with coal powder; a secondary air channel is also provided on the outer periphery of one side of the conveying part facing the outlet end, the secondary air channel is connected to the secondary air box, and the secondary air channel is also provided with swirl blades.

[0008] During the combustion process, the first valve component and the second valve component are both in an open state, hydrogen is introduced into the hydrogen pipeline, inert gas is introduced into the inert gas pipeline, and primary air mixed with coal powder is introduced into the primary air pipeline. The inert gas surrounds the hydrogen in the middle to prevent the hydrogen from directly contacting the primary air. After the hydrogen is ejected from the outlet end of the hydrogen pipeline, part of the outer hydrogen can first diffuse into the inert gas to mix with the inert gas to reduce the concentration of hydrogen, and then mix with the air of the primary air and burn, thereby avoiding the explosion caused by direct mixing of hydrogen with air, thereby ensuring safety.

[0009] A secondary air channel is also provided on the outer periphery of one side end of the conveying part toward the outlet end. The secondary air channel is an annular channel provided on the outer periphery of the conveying part. Swirl blades are provided in the secondary air channel. The secondary air channel is connected to the secondary air bellows. The secondary air from the secondary air bellows flows through the secondary air channel, generates a rotation motion under the action of the swirl blades, and is sprayed into the furnace through the outlet end of the secondary air channel.

[0010] Since the inert gas can surround the hydrogen from the periphery, the hydrogen concentration in the central area of ​​the outlet end of the conveying part is relatively high, the peripheral inert gas contains relatively low concentration hydrogen, and the primary air at the periphery is mixed with coal powder. That is, from the inside to the outside, there are high-concentration hydrogen, low-concentration hydrogen, primary air mixed with coal powder, and rotating secondary air. In other words, the concentration of hydrogen gradually decreases from the center to the periphery, and the concentration of oxygen gradually decreases from the periphery to the center, thereby effectively ensuring the safety of hydrogen combustion.

[0011] The hydrogen and pulverized coal ejected from the outlet end of the conveying section burn in the furnace to produce a flame. Specifically, during combustion, the rotating secondary air located at the outermost periphery can cause the high-temperature, low-oxygen flue gas downstream of the flame in the furnace to be sucked into the center of the flame to burn with the hydrogen. Since this part of the flue gas is the flue gas after combustion, the oxygen content is relatively low, and the hydrogen combustion process is controllable, thereby ensuring the safety of hydrogen combustion.

[0012] After the hydrogen in the center of the flame burns with the high-temperature, low-oxygen flue gas, a higher-temperature flue gas can be generated. This part of the flue gas diffuses to the periphery and can ignite the low-concentration hydrogen in the inert gas. Then, it can also heat the outer coal powder to make it burn. In other words, the stable heat flow generated by the hydrogen combustion in the central area ensures the timely ignition and stable combustion of the outer coal powder, thereby promoting the burnout effect of the coal powder. In addition, the oxygen in the center of the flame is consumed by the hydrogen combustion, so that the coal powder is in a lower oxygen environment and a higher temperature during the volatilization, analysis and combustion process. In this way, it is more conducive to the conversion of nitrogen in the coal powder into nitrogen through combustion, reducing the generation of nitrogen oxides, thereby reducing the emission of nitrogen oxides and reducing environmental pollution.

[0013] Through the conveying part provided in the present application, a central hydrogen diffusion flame and a peripheral pulverized coal premixed combustion flame can be formed, and the organic combination and interaction of the two ensure the stability and safety of the combustion of hydrogen and pulverized coal.

[0014] The mixed burner is based on the existing swirl pulverized coal burner, coupled with a hydrogen pipeline and an inert gas pipeline to achieve hydrogen-coal mixed combustion. By replacing part of the coal combustion with hydrogen, it can ensure safety while reducing carbon emissions and environmental pollution. In addition, compared with the existing technology of synthesizing green hydrogen into green ammonia or methanol and then mixing them in coal-fired boilers, there is no need to further synthesize green ammonia or methanol through green hydrogen, thereby reducing investment costs and operating costs, and avoiding energy attenuation and grade reduction.

[0015] Optionally, the hydrogen pipeline is further connected to a second inert gas delivery pipeline, the hydrogen delivery pipeline is provided with a first valve component, and the second inert gas delivery pipeline is provided with a third valve component.

[0016] Optionally, the inert gas pipeline is further connected to a compressed air pipeline, the first inert gas delivery pipeline is provided with a second valve component, and the compressed air pipeline is further provided with a fourth valve component.

[0017] Optionally, the number of the secondary air channels is at least two groups, the secondary air channels are arranged in sequence from the inside to the outside, and the outlet end of each secondary air channel is a trumpet-shaped structure.

[0018] Optionally, an extension section is further provided at the outlet end of the secondary air channel located at the outermost side.

[0019] Optionally, at least one group of the swirl blades are axial swirl blades.

[0020] Optionally, at least one group of the swirl blades are tangential swirl blades, and the secondary air passage provided with the tangential swirl blades is further provided with an adjustment portion, and the adjustment portion is used to adjust the rotation angle of each of the swirl blades.

[0021] Optionally, a flame arrester is further provided on the outlet side of the hydrogen pipeline.

[0022] Optionally, a side wall of the hydrogen pipeline facing the outlet side is further provided with a vent hole connected to the inert gas pipeline, and the pressure in the hydrogen pipeline is greater than the pressure in the inert gas pipeline.

[0023] Optionally, the outlet end of the hydrogen pipeline and the outlet end of the primary air pipeline are straight-cylindrical structures, and the outlet end of the inert gas pipeline and the outlet end of the secondary air channel are both trumpet-shaped structures.

[0024] Optionally, a cone cylinder is fixedly provided in the primary air duct, and the cone cylinder includes a straight cylinder section and a reduced diameter section, the straight cylinder section is fixedly connected to the large diameter end of the reduced diameter section, and the reduced diameter section.

[0025] Optionally, the outer peripheral wall of the inert gas pipeline is further provided with a protective layer along the axial direction, from the small diameter end of the cone to the outlet end of the inert gas pipeline.

[0026] The present application also provides a mixed combustion system, including a combustion furnace and the mixed burner as described above, wherein the combustion furnace is provided with a furnace, and the mixed burner is provided on the front and rear water-cooled walls of the furnace.

[0027] The technical effect of the mixed combustion system having the mixed burner as described above is similar to the technical effect of the mixed burner described above, and will not be described in detail here to save space. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of a mixed combustion system provided in an embodiment of the present application;

[0029] Figure 2 It is a schematic diagram of the internal structure of a hybrid burner provided in an embodiment of the present application;

[0030] Figure 3 It is a schematic diagram of the internal structure of another hybrid burner provided in an embodiment of the present application.

[0031] Attached Figure 1-Figure 3 In the figure, the reference numerals are described as follows:

[0032] 10 mixed burner; 20 furnace; 30 burnout air nozzle; 40 combustion zone water-cooled wall; 50 transition section water-cooled wall; 60 radiation superheater / reheater layout area; 70 ceiling; 80 horizontal flue; 90 rear shaft wall;

[0033] 1 hydrogen pipeline, 11 hydrogen inlet pipe, 12 hydrogen delivery pipeline, 13 first valve component, 14 second inert gas delivery pipeline, 15 third valve component, 16 vent hole, 17 flame arrester;

[0034] 2 inert gas pipeline, 21 first inert gas delivery pipeline, 22 second valve component, 23 compressed air pipeline, 24 fourth valve component, 25 protective layer;

[0035] 3 primary air duct, 31 cone, 311 straight section, 312 reduced diameter section, 32 bracket;

[0036] 4. Level 1 secondary air channel;

[0037] 5 second-level secondary air channel, 51 extension section;

[0038] 61 axial swirl blade, 62 tangential swirl blade, 63 adjustment part.

[0039] 7 Secondary air box. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0041] The embodiments of the present application provide a mixed burner and a mixed combustion system, which mixes hydrogen and pulverized coal for combustion. Hydrogen is a clean and efficient energy source that produces heat and water after combustion. Mixing hydrogen and pulverized coal for combustion can reduce carbon emissions and reduce pollution to the environment.

[0042] like Figure 1 As shown, the mixed combustion system includes a combustion furnace and a burner, wherein the combustion furnace is provided with a furnace 20, and the burner is arranged on two opposite front and rear water-cooled walls of the furnace 20 (the rear water-cooled wall refers to the water-cooled wall close to the rear vertical shaft flue), and at least some of the burners are mixed burners 10 provided in this embodiment, by mixing hydrogen and pulverized coal for combustion, specifically, some of the burners can be mixed burners 10, some of the burners can be pulverized coal burners, or all of the burners can be mixed burners 10, and the combustion furnace is also provided with a burnout air nozzle 30 on the downstream side of the burner, and the burnout air is introduced into the furnace 20 through the burnout air nozzle 30, so that the pulverized coal is burned more fully.

[0043] like Figure 1As shown, the combustion furnace also includes components such as a combustion zone water-cooled wall 40, a transition section water-cooled wall 50, a radiation superheater / reheater arrangement area 60, a ceiling 70, a horizontal flue 80, and a rear shaft wall 90. The combustion zone water-cooled wall 40, the transition section water-cooled wall 50, the radiation superheater / reheater arrangement area 60, the ceiling 70, the horizontal flue 80, and the rear shaft wall 90 are already well-known prior arts to those skilled in the art, and will not be described in detail here to save space.

[0044] Specifically, the mixed burner 10 includes a conveying part, which is used to convey hydrogen and primary air mixed with pulverized coal. The outlet end of the conveying part extends into the furnace 20, and the hydrogen and pulverized coal can be burned in the furnace 20.

[0045] like Figure 2 and Figure 3 As shown, the transport part includes a hydrogen pipeline 1, an inert gas pipeline 2, and a primary air pipeline 3 which are arranged in sequence from the inside to the outside, wherein the inlet side of the hydrogen pipeline 1 is connected to the hydrogen transport pipeline 12, the hydrogen transport pipeline 12 is connected to a first valve component 13, the inlet side of the inert gas pipeline 2 is connected to a first inert gas transport pipeline 21, the first inert gas transport pipeline 21 is provided with a second valve component 22, the inlet side of the primary air pipeline 3 is connected to the primary air transport pipeline, and coal powder is mixed in the primary air. The hydrogen transport pipeline 12 can be connected to a hydrogen gas source, or to an external hydrogen and natural gas mixed gas source, so as to adapt to more ways of transporting hydrogen using the natural gas pipeline network, and has good flexibility.

[0046] During the combustion process, the first valve component 13 and the second valve component 22 are both in an open state, hydrogen is introduced into the hydrogen pipeline 1, inert gas is introduced into the inert gas pipeline 2, and primary air mixed with coal powder is introduced into the primary air pipeline 3. The inert gas surrounds the hydrogen in the middle to prevent the hydrogen from directly contacting the primary air. After the hydrogen is ejected from the outlet end of the hydrogen pipeline 1, part of the outer hydrogen can first diffuse into the inert gas to mix with the inert gas to reduce the concentration of hydrogen, and then mix with the air of the primary air and burn, thereby avoiding the explosion caused by direct mixing of hydrogen with air, thereby ensuring safety.

[0047] A secondary air channel is also sleeved on the outer periphery of one side end of the conveying part toward the outlet end (i.e., the side end toward the furnace chamber). The secondary air channel is an annular channel arranged on the outer periphery of the conveying part. Swirl blades are arranged in the secondary air channel. The secondary air channel is connected to the secondary air bellows 7. The secondary air from the secondary air box flows through the secondary air channel, generates a rotational motion under the action of the swirl blades, and is sprayed into the furnace 20 through the outlet end of the secondary air channel.

[0048] Since the inert gas can surround the hydrogen from the periphery, the hydrogen concentration in the central area of ​​the outlet end of the conveying part is relatively high, the peripheral inert gas contains relatively low concentration hydrogen, and the primary air at the periphery is mixed with coal powder. That is, from the inside to the outside, there are high-concentration hydrogen, low-concentration hydrogen, primary air mixed with coal powder, and rotating secondary air. In other words, the concentration of hydrogen gradually decreases from the center to the periphery, and the concentration of oxygen gradually decreases from the periphery to the center, thereby effectively ensuring the safety of hydrogen combustion.

[0049] The hydrogen and pulverized coal ejected from the outlet end of the conveying section burn in the furnace to generate a flame. Specifically, during combustion, the rotating secondary air located at the outermost periphery can cause the high-temperature, low-oxygen flue gas located downstream of the flame in the furnace 20 to be sucked into the center of the flame to burn with the hydrogen. Since this part of the flue gas is the flue gas after combustion, the oxygen content is relatively low, and the hydrogen combustion process is controllable, thereby ensuring the safety of hydrogen combustion.

[0050] After the hydrogen in the center of the flame burns with the high-temperature, low-oxygen flue gas, a higher-temperature flue gas can be generated. This part of the flue gas diffuses to the periphery and can ignite the low-concentration hydrogen in the inert gas. Then, it can also heat the outer coal powder to make it burn. In other words, the stable heat flow generated by the hydrogen combustion in the central area ensures the timely ignition and stable combustion of the outer coal powder, thereby promoting the burnout effect of the coal powder. In addition, the oxygen in the center of the flame is consumed by the hydrogen combustion, so that the coal powder is in a lower oxygen environment and a higher temperature during the volatilization, analysis and combustion process. In this way, it is more conducive to the conversion of nitrogen in the coal powder into nitrogen through combustion, reducing the generation of nitrogen oxides, thereby reducing the emission of nitrogen oxides and reducing environmental pollution.

[0051] Through the conveying part provided in this embodiment, a central hydrogen diffusion flame and a peripheral pulverized coal premixed combustion flame can be formed, and the organic combination and interaction of the two ensure the stability and safety of the combustion of hydrogen and pulverized coal.

[0052] The mixed burner 10 provided in this embodiment is based on the existing swirl pulverized coal burner, coupled with the hydrogen pipeline 1 and the inert gas pipeline 2, to achieve hydrogen-coal mixed combustion, and replace part of the coal combustion with hydrogen, which can ensure safety on the basis of reducing carbon emissions and reducing environmental pollution. In addition, compared with the prior art solution of synthesizing green hydrogen into green ammonia or methanol and then mixing them in a coal-fired boiler, there is no need to further synthesize green ammonia or methanol through green hydrogen, thereby reducing investment costs and operating costs, and can also avoid energy attenuation and grade reduction.

[0053] like Figure 2 and Figure 3As shown, the outlet ends of the hydrogen pipeline 1 and the primary air pipeline 3 are both straight cylindrical structures, while the outlet end of the inert gas pipeline 2 is a trumpet-shaped structure that gradually expands outward along the axial direction, and the outlet end of the secondary air channel is also a trumpet-shaped structure that gradually expands outward along the axial direction, wherein outward refers to the side toward the outlet end, that is, the side toward the furnace 20.

[0054] The outlet end of the hydrogen pipeline 1 is set to a straight cylindrical structure, and the outlet end of the inert gas pipeline 2 is a trumpet-shaped structure. The inert gas will diffuse toward the periphery when injected into the furnace 20, thereby increasing the isolation area of ​​the inert gas between the hydrogen and the primary air, delaying the mixing of the hydrogen and the air in the primary air, avoiding the explosion caused by the sudden mixing of hydrogen and air, and thus improving safety.

[0055] The outlet end of the primary air duct 3 is a straight cylindrical structure, and the outlet end of the inert gas duct 2 and the outlet end of the secondary air channel both extend out of the outlet end of the primary air duct 3. This arrangement ensures that the coal powder mixed in the primary air sprayed from the outlet of the primary air duct 3 will not burn violently due to immediate mixing with the secondary air after being sprayed, thereby avoiding the situation where a large amount of nitrogen oxides is caused by violent combustion, reducing the production of nitrogen oxides and increasing the generation of nitrogen, and having good environmental protection performance.

[0056] The outlet end of the secondary air channel is in a trumpet-shaped structure, which makes it easy for the high-temperature flue gas in the furnace 20 to reach a location not far from the end of the conveying section through the action of the swirl blades and mix with hydrogen, inert gas, primary air, and secondary air, so that the hydrogen and the coal powder mixed in the primary air and the air mixed in the primary air participate in the combustion.

[0057] like Figure 2 and Figure 3 As shown, two groups of secondary air channels are provided. For the convenience of explanation, the two groups of secondary air channels are respectively referred to as the primary secondary air channel 4 and the secondary secondary air channel 5. The primary secondary air channel 4 is provided on the outer periphery of the primary air duct 3 and on the side facing the outlet end, and the secondary secondary air channel 5 is provided on the outer periphery of the primary secondary air channel 4. Each group of secondary air channels forms an annular cavity, and a swirl blade is provided inside. The swirl blade can be a tangential swirl blade 62 or an axial swirl blade 61, and the swirl blades provided in each group of secondary air channels can be the same or different. Figure 2 As shown, the primary secondary air passage 4 and the secondary secondary air passage 5 are both provided with axial swirl blades 61, as shown in FIG. Figure 3 As shown, the primary secondary air channel 4 is provided with axial swirl blades 61, and the secondary secondary air channel 5 is provided with tangential swirl blades 62. Alternatively, both the primary secondary air channel 4 and the secondary secondary air channel 5 are provided with tangential swirl blades 62. The specific setting can be based on actual conditions.

[0058] When the secondary air passage is provided with tangential swirl blades 62, as Figure 2 and Figure 3 The two-stage secondary air passage 5 shown is provided with a tangential swirl blade 62, and the tangential swirl blade 62 is also provided with an adjustment portion 63, and the adjustment portion 63 is used to adjust the angle of the swirl blade to adjust the rotational momentum of the secondary air flow, and then adjust the size of the central recirculation zone of the flame, with good flexibility. Specifically, the specific structure of the adjustment portion 63 and how to adjust the angle of the tangential swirl blade 62 through the adjustment portion 63 are already well-known prior art to those skilled in the art, and will not be described here in order to save space.

[0059] Of course, in this embodiment, there is no restriction on the specific number of secondary air channels, which can be set as one group or as follows: Figure 2 and Figure 3 The two groups shown may also be three or more groups.

[0060] The outlet end of the secondary air channel located at the outermost side is also provided with an extension section 51, such as Figure 2 and Figure 3 As shown, the outlet end of the two-stage secondary air duct 5 is provided with an extension section 51, which is a trumpet-shaped cylinder structure. The extension section 51 is the side of the conveying part closest to the center of the furnace 20, and the center temperature of the furnace 20 is relatively high. This avoids the "flash" effect of the rotating airflow, and facilitates the high-temperature flue gas in the center area of ​​the furnace 20 to be guided to the outlet end of the conveying part through the swirl blades to achieve stable combustion.

[0061] like Figure 2 and Figure 3 As shown, since the inert gas pipeline 2 is arranged on the outer peripheral side of the hydrogen pipeline 1, the hydrogen inlet pipe 11 of the hydrogen pipeline 1 passes through the side wall of the inert gas pipeline 2, and is sealed along the circumferential direction of the hydrogen inlet pipe 11 between the hydrogen inlet pipe 11 and the inert gas pipeline 2. The hydrogen inlet pipe 11 is connected with the above-mentioned hydrogen delivery pipeline 12, and at the same time, the hydrogen inlet pipe 11 is also connected with the second inert gas delivery pipeline 14. The hydrogen delivery pipeline 12 is used to pass hydrogen or a mixture of hydrogen and natural gas into the hydrogen pipeline 1. The hydrogen delivery pipeline 12 is provided with a first valve component 13. The second inert gas delivery pipeline 14 is used to pass inert gas, such as nitrogen, argon, etc., into the hydrogen pipeline 1. The second inert gas delivery pipeline 14 is provided with a third valve component 15. Of course, the hydrogen delivery pipeline 12 and the second inert gas delivery pipeline 14 may be respectively connected to the hydrogen pipeline 1. When the hydrogen delivery pipeline 12 and the second inert gas delivery pipeline 14 are connected to the hydrogen pipeline 1 through the same hydrogen inlet pipe 11, the hydrogen pipeline 1 only needs to pass through the inert gas pipeline 2 through the one hydrogen inlet pipe 11, which can simplify the arrangement of the hydrogen pipeline 1 and the inert gas pipeline 2.

[0062] like Figure 2 and Figure 3 As shown, a flame arrester 17 is also provided on the outlet side of the hydrogen pipeline 1 to prevent the high-temperature flue gas in the furnace 20 from entering the hydrogen pipeline 1, thereby avoiding explosion of the hydrogen pipeline 1 and ensuring safety.

[0063] Under normal working conditions, the first valve component 13 is opened and the third valve component 15 is closed, and hydrogen enters the hydrogen pipeline 1 from the hydrogen delivery pipeline 12 through the first valve component 13, then passes through the flame arrester 17 and is ejected from the outlet end of the hydrogen pipeline 1 to the furnace 20 for combustion.

[0064] When hydrogen is not passed through the hydrogen pipeline 1, the first valve component 13 is closed and the third valve component 15 is opened, and an inert gas such as nitrogen enters the hydrogen pipeline 1 from the second inert gas delivery pipeline 14 through the third valve component 15, and the hydrogen pipeline 1 is protected by the nitrogen. When hydrogen needs to be passed through, the first valve component 13 and the third valve component 15 are gradually adjusted to slowly increase the amount of hydrogen passed through, and slowly reduce the amount of nitrogen passed through, until the third valve component 15 is completely closed.

[0065] like Figure 2 and Figure 3 As shown, the hydrogen pipeline 1 is also provided with a vent hole 16 connected to the inert gas pipeline 2. The vent hole 16 is provided on the side of the hydrogen pipeline 1 facing the outlet end, and is used to premix the hydrogen and the inert gas. Specifically, the design pressure in the hydrogen pipeline 1 can be higher than the design pressure in the inert gas pipeline 2, so that part of the hydrogen can enter the inert gas pipeline 2 through the vent hole 16 before being ejected from the outlet end of the hydrogen pipeline 1, and mix with the inert gas. By mixing in advance, the concentration of hydrogen in the central area of ​​the outlet end of the conveying part can be reduced, and the inert gas area located outside the central area is also mixed with a small amount of hydrogen. The concentration of this part of hydrogen is low, and it can be directly mixed with the air of the primary wind and directly burned. Therefore, the setting of the vent hole 16 can realize the premixing of hydrogen and the inert gas before ejection, while ensuring safety performance and improving combustion performance.

[0066] The inert gas enters the inert gas pipeline 2 from the first inert gas delivery pipeline 21, passes through the second valve component 22, and is ejected from the outlet end of the inert gas pipeline 2 into the furnace 20. The inert gas mentioned herein, including the inert gas delivered by the first inert gas delivery pipeline 21 and the inert gas delivered by the second inert gas delivery pipeline 14, refers to a gas that does not react with hydrogen at normal pressure, such as low-pressure water vapor or nitrogen. The pressure of low-pressure water vapor is generally 0.2MPa-0.3MPa, and the temperature is 150℃-200℃.

[0067] like Figure 2 and Figure 3As shown, the inert gas pipeline 2 is also connected to a compressed air pipeline 23, which is connected to the inlet side of the inert gas pipeline 2. The first inert gas delivery pipeline 21 is provided with a second valve component 22, and the compressed air pipeline 23 is provided with a fourth valve component 24. When the inert gas stops entering the inert gas pipeline 2, the second valve component 22 can be closed, the fourth valve component 24 can be opened, and the compressed air pipeline 23 passes compressed air into the inert gas pipeline 2 to purge the inert gas pipeline 2 and prevent dust and the like in the furnace 20 from entering the inert gas pipeline 2. Of course, the compressed air pipeline 23 may not be provided, and the continuous passage of inert gas can also prevent dust from entering the inert gas pipeline 2. While the compressed air pipeline 23 achieves a cleaning effect by passing air, it can also reduce costs.

[0068] The end of the inert gas pipeline 2 away from the outlet end passes through the side wall of the primary air pipeline 3 and is connected to the first inert gas delivery pipeline 21 and the compressed air pipeline 23. The inert gas pipeline 2 and the primary air pipeline 3 are sealed along the circumference of the inert gas pipeline 2. In addition, the hydrogen inlet pipe 11 passes through the side wall of the inert gas pipeline 2 extending outside the primary air pipeline 3.

[0069] Specifically, it can be Figure 2 and Figure 3 As shown, the primary air duct 3 is provided with a bending structure, and the inert gas duct 2 is a linear structure, or the inert gas duct 2 is provided with a bending structure and passes through the side wall of the primary air duct 3 by bending.

[0070] The primary air carries the pulverized coal and is transported to the primary air duct 3 via an external pipeline, and is sprayed into the furnace 20 through the outlet end of the primary air duct 3 and then burns.

[0071] like Figure 3As shown, a cone 31 is further provided in the primary air duct 3, and the cone 31 includes a straight section 311 and a reduced diameter section 312, wherein the straight section 312 is fixedly connected to the large diameter end of the reduced diameter section 312 and faces the primary air inlet, and the small diameter end of the reduced diameter section 312 faces the primary air outlet, that is, faces the furnace 20. When the pulverized coal is a type of coal with a low volatile content (such as Vdaf<15%), the primary air passes through the cone 31. The cone 31 can The coal powder in the primary air can be collected, specifically, the primary air is guided by the straight section 311, so that the primary air enters the reduced diameter section 312, and the coal powder is collected in the central area. After this part of the primary air flows out from the small diameter section, the air can quickly diffuse to the periphery, and the coal powder is mostly distributed in the central area, so that when the primary air is ejected from the outlet end of the primary air duct 3, more coal powder is mixed with hydrogen in the central area for combustion, which is conducive to ensuring the stability of the flame and improving the degree of coal powder combustion. Specifically, there is no restriction on how the cone 31 is fixed in the primary air duct 3, such as the cone 31 can be fixed to the inner wall of the primary air duct 3 through the bracket 32, or fixed to the outer wall of the hydrogen duct 1 through the bracket 32.

[0072] In addition, a protective layer 25 is provided along the outer wall of the inert gas pipeline 2, along its axial direction, from the small diameter end of the cone 31 to the outlet end of the inert gas pipeline 2. Since the coal powder is mainly concentrated in the area close to the outer wall side of the inert gas pipeline 2 after the primary air passes through the cone 31, the protective layer 25 can provide protection for the outer wall of the inert gas pipeline 2, avoid damage caused by dust scouring, and thus extend the service life of the inert gas pipeline 2.

[0073] Specifically, the protective layer 25 can be provided only at the position from the small diameter end of the cone 31 to the outlet end of the inert gas pipeline 2, or the outer wall of the inert gas pipeline 2 can be provided with the protective layer 25 in the axial direction. In addition, the protective layer 25 can be a protective sleeve provided on the outer wall of the inert gas pipeline 2, or a protective coating provided on the outer peripheral wall of the inert gas pipeline 2.

[0074] The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A hybrid burner, characterized in that: The conveying part comprises a hydrogen pipeline (1), an inert gas pipeline (2) and a primary air pipeline (3) which are sequentially sleeved from the inside to the outside; The inlet side of the hydrogen pipeline (1) is in communication with a hydrogen delivery pipeline (12), the inlet side of the inert gas pipeline (2) is in communication with a first inert gas delivery pipeline (21), and the inlet side of the primary air pipeline (3) is in communication with a primary air delivery pipeline mixed with pulverized coal; A secondary air channel is also provided on the outer periphery of the conveying portion on the side facing the outlet end, the secondary air channel is communicated with the secondary air box (7), and the secondary air channel is also provided with swirl blades.

2. The hybrid burner according to claim 1, characterized in that: The hydrogen pipeline (1) is also connected to a second inert gas delivery pipeline (14); the hydrogen delivery pipeline (12) is provided with a first valve component (13); and the second inert gas delivery pipeline (14) is provided with a third valve component (15).

3. The hybrid burner according to claim 1, characterized in that: The inert gas pipeline (2) is also connected to a compressed air pipeline (23); the first inert gas delivery pipeline (21) is provided with a second valve component (22); and the compressed air pipeline (23) is also provided with a fourth valve component (24).

4. The hybrid burner according to claim 1, characterized in that: The number of the secondary air channels is at least two groups, and the secondary air channels are arranged in sequence from the inside to the outside, and the outlet end of each secondary air channel is a trumpet-shaped structure.

5. The hybrid burner according to claim 4, characterized in that: An extension section (51) is also provided at the outlet end of the secondary air channel located at the outermost side.

6. The hybrid burner according to claim 4, characterized in that: At least one group of the swirl blades is an axial swirl blade (61).

7. The hybrid burner according to claim 6, characterized in that: At least one group of the swirl blades is a tangential swirl blade (62), and the secondary air passage provided with the tangential swirl blades (62) is also provided with an adjustment portion (63), the adjustment portion (63) being used to adjust the rotation angle of each of the swirl blades.

8. The hybrid burner according to any one of claims 1 to 7, characterized in that: A flame arrester (17) is also provided on the outlet side of the hydrogen pipeline (1).

9. The hybrid burner according to any one of claims 1 to 7, characterized in that: A side wall of the hydrogen pipeline (1) facing the outlet is also provided with a vent hole (16) connected to the inert gas pipeline (2), and the pressure in the hydrogen pipeline (1) is greater than the pressure in the inert gas pipeline (2).

10. The hybrid burner according to any one of claims 1 to 7, characterized in that: The outlet end of the hydrogen pipeline (1) and the outlet end of the primary air pipeline (3) are straight cylinder structures, and the outlet end of the inert gas pipeline (2) and the outlet end of the secondary air channel are trumpet-shaped structures.

11. The hybrid burner according to any one of claims 1 to 7, characterized in that: A cone cylinder (31) is also fixedly provided in the primary air duct (3), the cone cylinder (31) comprising a straight cylinder section (311) and a reduced diameter section (312), the straight cylinder section (311) being fixedly connected to the large diameter end of the reduced diameter section (312), and the small diameter end of the reduced diameter section (312) being arranged towards the side of the outlet end.

12. The hybrid burner according to claim 11, characterized in that: The outer peripheral wall of the inert gas pipeline (2) is also provided with a protective layer (25) along the axial direction of the outer wall between the small diameter end of the cone (31) and the outlet end of the inert gas pipeline (2).

13. A mixed combustion system, characterized in that: It comprises a combustion furnace and a mixed burner as claimed in any one of claims 1 to 12, wherein the combustion furnace is provided with a furnace (20), and the mixed burner is provided on the front and rear water-cooled walls of the furnace (20).

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