Low-carbon stable combustion device for hydrogen-ammonia mixed ignition pulverized coal and boiler

Abstract

The invention relates to the technical field of combustion equipment, and discloses a low-carbon stable combustion device and boiler for igniting pulverized coal through hydrogen and ammonia mixing, the device comprises a hydrogen pipeline, and the hydrogen pipeline is sequentially sleeved with a central air pipeline, an ammonia-air mixed gas pipeline and a primary air pipeline; an ignition gun is arranged in the hydrogen pipeline, the ignition end of the ignition gun extends into the hydrogen-ammonia combustion chamber, in the hydrogen-ammonia combustion chamber, hydrogen from the hydrogen pipeline and air from the central air pipeline are mixed and then can be ignited by the ignition gun, hydrogen flames are sprayed out, and the hydrogen flames ignite ammonia premixed gas from the ammonia-air mixed gas pipeline; a pulverized coal combustion chamber is arranged at an outlet of the hydrogen-ammonia combustion chamber, and the primary air pipeline is communicated with the pulverized coal combustion chamber; a secondary combustion chamber is arranged at an outlet of the pulverized coal combustion chamber, and the primary air pipeline is communicated with the secondary combustion chamber. According to the low-carbon stable combustion device, the boiler can keep stable combustion in the ultra-low load operation state, meanwhile, the requirement for low-carbon emission is better met, and the structure is simple.

Description

Technical Field

[0001] The invention relates to the technical field of combustion equipment, and in particular to a low-carbon stable combustion device and a boiler for igniting coal powder by mixing hydrogen and ammonia. Background Art

[0002] The traditional thermal power generation industry faces huge pressure to reduce carbon dioxide emissions. Using non-carbon fuels to replace fossil fuels is one of the effective ways to reduce carbon emissions. The main zero-carbon emission fuels are renewable energy and hydrogen (H2) / ammonia (NH3). Renewable energy generation is the development trend of the power industry in the future, but it is restricted by geographical and environmental conditions, and has strong volatility and intermittent characteristics. When connected to the grid on a large scale, thermal power units need to participate in deep peak regulation. The core issue is to ensure stable combustion of boilers at ultra-low loads.

[0003] At present, when the coal-fired units in service are performing deep peak regulation, they mostly use improvements on existing plasma ignition and micro-oil ignition technologies, and adjust the primary air supply temperature, coal mill outlet temperature, coal powder fineness and concentration, primary air rate, etc., to meet the needs of low-load stable combustion of power station coal-fired boilers. However, plasma ignition has poor adaptability to coal types, and low-volatile coal types are difficult to ignite; micro-oil ignition is prone to oil gun clogging, and the nozzle is prone to coking if the operation time is too long, causing system failures and other problems. In order to solve the problem that the single fuel mainly coal produces huge carbon emissions during the combustion process of the burner in the existing power station boiler, and it is difficult to achieve stable combustion under ultra-low load, it is necessary to develop a new low-carbon stable combustion device.

[0004] Patent application CN106905039A discloses a burner structure for mixed combustion of natural gas and pulverized coal, which is conducive to achieving stable combustion under low boiler load by inputting natural gas into the central air duct. However, the main component of natural gas is CH4, which is not a zero-carbon fuel and will also cause excess carbon emissions.

[0005] H2 and NH3 are the two most promising non-carbon fuels suitable for large-scale applications. They do not produce any carbon emissions when burned at high temperatures. At present, there are burners that ignite coal powder with hydrogen, but the large-scale transportation and storage of hydrogen are costly and difficult. At present, it is uneconomical and unrealistic to mix hydrogen with coal powder for a long time at low load. At present, there are dual-fuel burners for ammonia and coal powder, but ammonia has a high ignition point, low flame propagation speed, and a narrow ignition range. Mixed combustion of ammonia and coal powder cannot stably burn at ultra-low loads. Therefore, it is urgent to develop a combustion device with strong low-carbon stable combustion capability, so that the boiler can maintain stable combustion under ultra-low load operation while better meeting the low-carbon emission requirements. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a low-carbon stable combustion device and boiler for igniting coal powder with a hydrogen-ammonia mixture. The device enables the boiler to maintain stable combustion under ultra-low load operation while better meeting low-carbon emission requirements.

[0007] In order to achieve the above-mentioned object, the present invention provides a low-carbon stable combustion device for igniting coal powder by mixing hydrogen and ammonia, the device comprising a hydrogen pipeline, a central air pipeline, an ammonia-air mixed gas pipeline and a primary air pipeline are sequentially sheathed outside the hydrogen pipeline;

[0008] An ignition gun is arranged in the hydrogen pipeline, and an ignition end of the ignition gun extends into the interior of the hydrogen-ammonia combustion chamber. In the hydrogen-ammonia combustion chamber, the hydrogen from the hydrogen pipeline and the air from the central air pipeline are mixed and can be ignited by the ignition gun and spray out a hydrogen flame, and the hydrogen flame ignites the ammonia premixed gas from the ammonia-air mixed gas pipeline;

[0009] A pulverized coal combustion chamber is provided at the outlet of the hydrogen-ammonia combustion chamber, and the primary air duct is connected to the pulverized coal combustion chamber to convey pulverized coal primary air therein;

[0010] A secondary combustion chamber is provided at the outlet of the pulverized coal combustion chamber, and the primary air duct is communicated with the secondary combustion chamber to transport pulverized coal primary air therein.

[0011] Preferably, the device further comprises a support plate, and the primary air duct is fixedly connected to the pulverized coal combustion chamber via the support plate.

[0012] Preferably, the ignition gun, the hydrogen-ammonia combustion chamber and the pulverized coal combustion chamber are coaxially arranged.

[0013] Preferably, the outer surface of the primary air duct is sheathed with a secondary air duct for supplying air to the furnace of the boiler.

[0014] Preferably, a plurality of swirl blades are provided in the secondary air duct.

[0015] Preferably, the secondary air duct is provided to include an inner secondary air duct and an outer secondary air duct, and the inner secondary air duct and the outer secondary air duct are sequentially sleeved on the outer surface of the primary air duct.

[0016] Preferably, the pulverized coal primary air comprises pulverized coal and air.

[0017] A second aspect of the present invention provides a boiler, comprising the low-carbon stable combustion device as described above.

[0018] Preferably, the boiler is an opposed-fired boiler or a tangentially fired boiler.

[0019] Preferably, part or all of the burners in the boiler are the low-carbon stable combustion devices.

[0020] The advantages and beneficial effects of the present invention are:

[0021] 1. The low-carbon stable combustion device provided by the present invention utilizes the high-temperature flame generated by hydrogen combustion to ignite the ammonia premixed gas, and then ignites the coal powder after the hydrogen and ammonia are mixed and burned. This layered combustion-supporting and step-by-step combustion method ensures the timely ignition, stable combustion and efficient burnout of the coal powder, so that the boiler can operate stably under ultra-low load;

[0022] 2. The low-carbon stable combustion device provided by the present invention can adjust the ratio of hydrogen and ammonia blending, so that the boiler can operate normally and stably under a lower load when the thermal power unit participates in deep peak regulation, so that more renewable energy sources such as wind power and photovoltaic power can be incorporated into the power grid, thereby reducing carbon emissions to a greater extent; and the corresponding ratio of hydrogen and ammonia blending can be adjusted for different types of coal such as lean coal, bituminous coal, lignite and different working conditions to achieve the effect of low-carbon stable combustion, with strong adaptability to coal types and wide adaptability to working conditions;

[0023] 3. The ammonia premixed gas in the ammonia-air mixed gas pipeline of the present invention has the function of cooling the pipe wall, thereby preventing the high-temperature flame generated by the hydrogen combustion from burning the pipe wall of the hydrogen pipe. The structure is simple and does not require other auxiliary cooling methods, and the pipeline is safer and has a better cooling effect.

[0024] 4. When the boiler is running at ultra-low load, the hot air temperature is low, while hydrogen is easy to ignite and is insensitive to air temperature. The heat released by hydrogen igniting ammonia is used to ignite pulverized coal, so there is no need to set up an air preheater, which simplifies the boiler structure;

[0025] 5. When the boiler is running under normal load conditions, the proportion of ammonia and coal powder in the mixed combustion is limited. The present invention adopts the method of burning ammonia mixed with hydrogen to increase the proportion of ammonia and coal powder in the mixed combustion, so as to further reduce the amount of coal powder, thereby reducing the NO X Under the conditions of emission, reduce carbon emissions to the greatest extent possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a front view of a specific implementation of the low-carbon combustion stabilization device provided by the present invention;

[0027] Figure 2 This is a front view of another specific embodiment of the low-carbon combustion stabilizing device provided by the present invention;

[0028] Figure 3 This is a front view of another specific embodiment of the low-carbon combustion stabilizing device provided by the present invention;

[0029] Figure 4 yes Figure 1 Horizontal arrangement diagram of the low-carbon stable combustion device on a tangentially fired boiler;

[0030] Figure 5 yes Figure 1 A schematic diagram of an arrangement of nozzles of the low-carbon combustion stabilization device;

[0031] Figure 6 yes Figure 1 A schematic diagram of another arrangement of the nozzles of the low-carbon combustion stabilization device;

[0032] Figure 7 yes Figure 1 A schematic diagram of another arrangement of the nozzles of the low-carbon combustion stabilization device;

[0033] Figure 8 yes Figure 2 or Figure 3 A schematic diagram of an arrangement of the low-carbon stable combustion device on the hedge boiler;

[0034] Fig. 9 yes Figure 2 or Figure 3 A schematic diagram of another arrangement of the low-carbon stable combustion device on the hedge boiler;

[0035] Fig.10 yes Figure 2 or Figure 3 A schematic diagram of another arrangement of the low-carbon stable combustion device on the hedge boiler.

[0036] Description of Reference Numerals

[0037] 1-hydrogen pipeline; 2-central air pipeline; 3-ammonia-air mixture pipeline; 4-primary air pipeline; 5-support plate; 6-ignition gun; 7-hydrogen-ammonia combustion chamber; 8-coal powder combustion chamber; 9-secondary combustion chamber; 10-secondary air pipeline; 11-swirl blades; 12-inner secondary air pipeline; 13-inner secondary air swirl blades; 14-outer secondary air pipeline; 15-outer secondary air swirl blades. DETAILED DESCRIPTION

[0038] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0039] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0040] The present invention provides a low-carbon stable combustion device for igniting coal powder by mixing hydrogen and ammonia. Figure 1-3 (The primary air powder in the figure is coal powder primary air), the device comprises a hydrogen pipeline 1, and the central air pipeline 2, the ammonia-air mixed gas pipeline 3 and the primary air pipeline 4 are sequentially sheathed outside the hydrogen pipeline 1;

[0041] An ignition gun 6 is provided in the hydrogen pipeline 1, and an ignition end of the ignition gun 6 extends into the interior of the hydrogen-ammonia combustion chamber 7. In the hydrogen-ammonia combustion chamber 7, the hydrogen from the hydrogen pipeline 1 and the air from the central air pipeline 2 are mixed and ignited by the ignition gun to spray out a hydrogen flame, and the hydrogen flame ignites the ammonia premixed gas from the ammonia-air mixed gas pipeline 3;

[0042] A pulverized coal combustion chamber 8 is provided at the outlet of the hydrogen-ammonia combustion chamber 7, and the primary air duct 4 is connected to the pulverized coal combustion chamber 8 to transport pulverized coal primary air therein;

[0043] A secondary combustion chamber 9 is provided at the outlet of the pulverized coal combustion chamber 8, and the primary air duct 4 is connected to the secondary combustion chamber 9 to transport pulverized coal primary air therein.

[0044] The minimum ignition energy (0.02MJ) of hydrogen is extremely low, the calorific value per unit mass is high, and the flammable range is wide, which means that hydrogen is easy to ignite and can release a large amount of heat; the minimum ignition energy (680MJ) of ammonia is high, which makes it difficult to ignite, and often requires the addition of a combustion aid to assist combustion. In the present invention, by using hydrogen to ignite ammonia, the combustion speed of ammonia and the ratio of ammonia and coal powder are increased, and no carbon-containing fuel is introduced. The hydrogen-ammonia mixed combustion can improve the combustion stability and combustion efficiency, and then ignite the coal powder, and burn step by step in the insulated combustion chamber matched therewith, respectively, so that the combustion energy is amplified step by step, and the stable combustion ability is stronger; at the same time, the hydrogen in the present invention is mainly used to ignite ammonia, so its amount is small and the cost is low.

[0045] In the present invention, the hydrogen pipeline 1 introduces hydrogen into the hydrogen-ammonia combustion chamber 7, the central air pipeline 2 introduces air into the hydrogen-ammonia combustion chamber 7, and the ammonia-air mixed gas pipeline 3 introduces ammonia premixed gas into the hydrogen-ammonia combustion chamber 7. In the present invention, ammonia premixed gas refers to a mixed gas of ammonia and air.

[0046] In the present invention, the pulverized coal primary air includes pulverized coal and air, and the pulverized coal is carried by air into the pulverized coal combustion chamber 8 and the secondary combustion chamber 9. Preferably, the pulverized coal primary air is a mixture of air and pulverized coal. The concentration of pulverized coal can be appropriately adjusted according to the load of the boiler.

[0047] It can be understood that, in the present invention, the hydrogen-ammonia combustion chamber 7 is communicated with the pulverized coal combustion chamber 8 ; and the pulverized coal combustion chamber 8 is communicated with the secondary combustion chamber 9 .

[0048] In the present invention, the ignition gun 6, the hydrogen-ammonia combustion chamber 7 and the pulverized coal combustion chamber 8 are coaxially arranged.

[0049] Furthermore, the ignition gun 6, the hydrogen pipeline 1, the central air pipeline 2, the ammonia-air mixture pipeline 3 and the primary air pipeline 4 are coaxially arranged.

[0050] The present invention does not limit the specific structure and position of the hydrogen-ammonia combustion chamber 7, which can be located between the ammonia-air mixed gas pipeline 3, the hydrogen pipeline 1, the central air pipeline 2 and the pulverized coal combustion chamber 8, or at the end of the ammonia-air mixed gas pipeline 3. Figure 1 In a specific embodiment, the hydrogen-ammonia combustion chamber 7 is disposed at the end of the ammonia-air mixture pipeline 3, specifically, the area between the outlet end face of the central air pipeline 2 (or the hydrogen pipeline 1) and the outlet end face of the ammonia-air mixture pipeline 3. It should be noted that by adjusting the flow rate of the ammonia premixed gas, the flow rate of the ammonia-air premixed gas is made greater than the propagation speed of the flame, thereby preventing the flame from propagating toward the inlet of the ammonia-air mixture pipeline 3.

[0051] The secondary combustion chamber 9 of the present invention may be independently provided from the primary air duct 4 and the pulverized coal combustion chamber 8, and may be connected to the pulverized coal combustion chamber 8 and the secondary air duct, or may be provided at the end of the primary air duct 4. In a specific embodiment, the secondary combustion chamber 9 is provided at the end of the primary air duct 4.

[0052] The present invention does not limit the specific position of the ignition end of the ignition gun 6 in the hydrogen-ammonia combustion chamber 7, as long as it can be in good contact with the hydrogen introduced by the hydrogen pipeline 1 and the air introduced by the central wind pipeline 2, so that the hydrogen can be ignited as soon as possible. In a specific embodiment, the outlet end face of the central wind pipeline 2 is almost flush with the outlet end face of the hydrogen pipeline 1, and the ignition gun is arranged at the outlet of the hydrogen pipeline 1, so that the hydrogen pipeline 1 introduces hydrogen into the hydrogen-ammonia combustion chamber 7, and the central wind pipeline 2 introduces air into the hydrogen-ammonia combustion chamber 7. Since the ignition end of the ignition gun 6 is arranged at the outlet of the hydrogen pipeline 1 and the central wind pipeline 2, and the ignition energy of hydrogen is very low, therefore, when the ignition gun 6 is ignited, the hydrogen can be ignited quickly, and the hydrogen combustion adopts a non-premixed combustion mode.

[0053] In a preferred embodiment, the device further comprises a support plate 5, and the primary air duct 4 is fixedly connected to the pulverized coal combustion chamber 8 via the support plate 5. Preferably, four support plates 5 are provided, and the four support plates 5 are arranged at equal intervals.

[0054] In a preferred embodiment, the cross-section of the outlet end of the hydrogen-ammonia combustion chamber 7 is smaller than the cross-section of the inlet end of the pulverized coal combustion chamber 8 .

[0055] Working principle: Please refer to Figure 1The hydrogen pipeline 1 delivers hydrogen to the hydrogen-ammonia combustion chamber 7, the central air pipeline 2 delivers air to the hydrogen-ammonia combustion chamber 7, and the ammonia-air mixed gas pipeline 3 delivers ammonia premixed gas to the hydrogen-ammonia combustion chamber 7. In the hydrogen-ammonia combustion chamber 7, air and hydrogen are mixed near the ignition end, ignited and ejected flames through the ignition end of the ignition gun 6. The flame temperature generated by the hydrogen combustion is as high as 1400℃~1500℃. The high-temperature flame generated by the hydrogen combustion can quickly ignite the ammonia premixed gas located in the hydrogen-ammonia combustion chamber 7. Since the hydrogen-ammonia combustion chamber 7 has a small cross-section, the hydrogen-ammonia combustion chamber 7 has a high heat load, which is conducive to the ignition and combustion of ammonia. The high-temperature flame generated by the hydrogen-ammonia mixture after combustion in the hydrogen-ammonia combustion chamber 7 continues to ignite the high-concentration coal powder primary air from the primary air pipeline 4 in the coal powder combustion chamber 8, and the energy is further amplified. Then, it continues to mix and burn with the unburned coal powder primary air in the secondary combustion chamber 9 (the end of the primary air pipeline 4), and the energy and temperature reach a peak value, so that the combustion of the coal powder particles is further strengthened. Finally, the high-temperature flue gas and coal powder airflow from the secondary combustion chamber 9 are sprayed into the furnace and mixed and burned.

[0056] Hydrogen and ammonia are two "zero-carbon" fuels currently suitable for large-scale applications. Both do not contain carbon, so burning at high temperatures does not produce any carbon emissions. Hydrogen has a high calorific value per unit mass, is easy to ignite, has good combustion properties, and burns quickly; ammonia is cheap to produce, has a high energy density, is easy to liquefy and store, and has low transportation costs. Hydrogen-ammonia mixed combustion can improve combustion stability and efficiency. When the boiler is operating under normal load conditions, the addition of hydrogen can assist the combustion of ammonia, helping to increase the flame propagation speed and flame temperature. Ammonia-mixed combustion has little effect on unit operation, and reduces fuel burnout and NO. X The emission is better than coal-fired conditions. The combustion method of ammonia mixed with hydrogen can effectively improve the process characteristics of ammonia combustion, and the ratio of ammonia and coal powder can be appropriately increased without additional NO X When the boiler is running under ultra-low load conditions, hydrogen is used to ignite ammonia, and then the high-temperature flame generated by the mixed combustion of hydrogen and ammonia ignites the pulverized coal. This layered combustion and step-by-step combustion method ensures the instant ignition, stable combustion and efficient burnout of the pulverized coal, allowing the boiler to operate stably under ultra-low load conditions.

[0057] Please refer to Figure 2 On the basis of the above specific implementation, a secondary air duct 10 is further provided on the outer surface of the primary air duct 4 to introduce air into the furnace of the boiler to supplement the air required for the coal powder injected into the furnace to be burned. The secondary air duct 10 is provided to increase the air replenishment effect, so that the high-temperature flue gas and coal powder air flow are mixed and burned with the secondary swirl air. The secondary air duct 10 is provided based on the principle of air classification, so that the fuel is burned layer by layer, which is conducive to reducing the emission of NOx.

[0058] Further preferably, a plurality of swirl blades 11 are provided in the secondary air duct 10 to increase the disturbance effect on the air. The swirl blades 11 may be fixedly connected to the secondary air duct 10 or movably connected to the secondary air duct 10, so that the angle of the swirl blades 11 can be adjusted, thereby adjusting the intensity of the secondary air swirl.

[0059] Please refer to Figure 3 In another specific implementation, the secondary air duct 10 includes an inner secondary air duct 12 and an outer secondary air duct 14 , and the inner secondary air duct 12 and the outer secondary air duct 14 are sequentially sleeved on the outer surface of the primary air duct 4 .

[0060] Furthermore, a plurality of inner secondary air swirl blades 13 are provided in the inner secondary air duct 12 ; and a plurality of outer secondary air swirl blades 15 are provided in the outer secondary air duct 14 .

[0061] In the first specific implementation, please refer to Figure 1 As shown, the low-carbon stable combustion device includes an ignition gun 6, and a hydrogen pipeline 1, a central air pipeline 2, an ammonia-air mixture pipeline 3 and a primary air pipeline 4 are sequentially sleeved on the outer surface of the ignition gun 6. The primary air pipeline 4 is fixedly connected to the pulverized coal combustion chamber 8 through a support plate 5, and the number of support plates 5 is 4. The hydrogen pipeline 1 conveys hydrogen to the hydrogen-ammonia combustion chamber 7, the central air pipeline 2 conveys air to the hydrogen-ammonia combustion chamber 7, the ammonia-air mixture pipeline 3 conveys ammonia premixed gas to the hydrogen-ammonia combustion chamber 7, and the primary air pipeline 4 conveys pulverized coal primary air to the pulverized coal combustion chamber 8 and the secondary combustion chamber 9. The ignition end of the ignition gun 6 extends into the interior of the hydrogen-ammonia combustion chamber 7, the hydrogen-ammonia combustion chamber 7 is connected to the pulverized coal combustion chamber 8, the pulverized coal combustion chamber 8 is connected to the secondary combustion chamber 9, and the hydrogen-ammonia combustion chamber 7 and the pulverized coal combustion chamber 8, the central air pipeline 2 and the ignition gun 6 are coaxially arranged. After the hydrogen ignites the ammonia premix in the hydrogen-ammonia combustion chamber 7, it is passed into the pulverized coal combustion chamber 8 to ignite the high-concentration pulverized coal, and then mixed with the unburned pulverized coal airflow in the secondary combustion chamber 9 (the end of the primary air duct 4) for combustion, and finally sprayed into the furnace. In this embodiment, the low-carbon stable combustion device is a low-carbon stable combustion direct current burner.

[0062] In the second specific implementation, please refer to Figure 2As shown, the low-carbon stable combustion device includes an ignition gun 6, on the outer surface of which a hydrogen pipeline 1, a central air pipeline 2, an ammonia-air mixture pipeline 3 and a primary air pipeline 4 are sequentially sleeved, the primary air pipeline 4 is fixedly connected to the pulverized coal combustion chamber 8 through a support plate 5, the number of support plates 5 is 4, a secondary air pipeline 10 is sleeved on the outer surface of the end of the primary air pipeline 4, and a swirl blade 11 is arranged inside the secondary air pipeline 10, the hydrogen pipeline 1 conveys hydrogen to the hydrogen-ammonia combustion chamber 7, the central air pipeline 2 conveys air to the hydrogen-ammonia combustion chamber 7, the ammonia-air mixture pipeline 3 conveys ammonia premixed gas to the hydrogen-ammonia combustion chamber 7, the primary air pipeline 4 conveys pulverized coal primary air to the pulverized coal combustion chamber 8 and the secondary combustion chamber 9, the ignition end of the ignition gun 6 extends into the interior of the hydrogen-ammonia combustion chamber 7, the hydrogen-ammonia combustion chamber 7 is connected to the pulverized coal combustion chamber 8, the pulverized coal combustion chamber 8 is connected to the secondary combustion chamber 9, the hydrogen-ammonia combustion chamber 7 and the pulverized coal combustion chamber 8, the central air pipeline 2 and the ignition gun 6 are coaxially arranged. After the hydrogen ignites the ammonia premix in the hydrogen-ammonia combustion chamber 7, it is passed into the pulverized coal combustion chamber 8 to ignite the high-concentration pulverized coal, and then mixed with the unburned pulverized coal airflow in the secondary combustion chamber 9 (the end of the primary air duct 4) for combustion. The secondary air duct 10 introduces air into the furnace of the boiler and, under the action of the swirl blades 11 in the secondary air duct 10, the air supplement and disturbance effects are increased, so that the high-temperature flue gas and pulverized coal airflow are mixed and burned with the secondary swirl air in the furnace. In this embodiment, the low-carbon stable combustion device is a low-carbon stable combustion swirl burner.

[0063] In the third specific implementation, please refer to Figure 3As shown, the low-carbon stable combustion device includes an ignition gun 6, on the outer surface of which a hydrogen pipeline 1, a central air pipeline 2, an ammonia-air mixture pipeline 3 and a primary air pipeline 4 are sequentially sleeved, the primary air pipeline 4 is fixedly connected to the pulverized coal combustion chamber 8 through a support plate 5, the number of the support plates 5 is 4, and on the outer surface of the end of the primary air pipeline 4, an inner secondary air pipeline 12 and an outer secondary air pipeline 13 are sequentially sleeved, the inner secondary air pipeline 12 is provided with an inner secondary air swirl blade 13, and the outer secondary air pipeline 14 is provided with an outer secondary air swirl blade 14. Flow blades 15, the hydrogen pipeline 1 transports hydrogen to the hydrogen-ammonia combustion chamber 7, the central air pipeline 2 transports air to the hydrogen-ammonia combustion chamber 7, the ammonia-air mixed gas pipeline 3 transports ammonia premixed gas to the hydrogen-ammonia combustion chamber 7, the primary air pipeline 4 transports coal powder primary air to the coal powder combustion chamber 8 and the secondary combustion chamber 9, the ignition end of the ignition gun 6 extends into the interior of the hydrogen-ammonia combustion chamber 7, the hydrogen-ammonia combustion chamber 7 is connected with the coal powder combustion chamber 8, the coal powder combustion chamber 8 is connected with the secondary combustion chamber 9, the hydrogen-ammonia combustion chamber 7 and the coal powder combustion chamber 8, the central air pipeline 2 and the ignition gun 6 are coaxially arranged. After the hydrogen ignites the ammonia premix in the hydrogen-ammonia combustion chamber 7, it is passed into the pulverized coal combustion chamber 8 to ignite the high-concentration pulverized coal, and then mixed with the unburned pulverized coal airflow in the secondary combustion chamber 9 (the end of the primary air duct 4) for combustion. The inner secondary air duct 12 and the outer secondary air duct 14 introduce air into the furnace of the boiler and, under the action of the inner secondary air swirl blades 13 and the outer secondary air swirl blades 15, the air supplement and disturbance effects are increased, so that the high-temperature flue gas and pulverized coal airflow are mixed and burned with the inner and outer secondary swirl air in the furnace. In this embodiment, the low-carbon stable combustion device is a low-carbon stable combustion swirl burner.

[0064] The present invention also provides a boiler, comprising the low-carbon stable combustion device as described above.

[0065] The present invention is not limited to a specific type of the boiler, for example, it may be an opposed-fired boiler or a tangentially fired boiler.

[0066] Furthermore, part or all of the burners in the boiler are low-carbon stable combustion devices that ignite coal powder with the hydrogen-ammonia mixture.

[0067] The specific type of boiler that the low-carbon combustion stabilization device can be applied to is related to the specific structure of the low-carbon combustion stabilization device. For example, when the low-carbon combustion stabilization device is the structure in the first specific embodiment (low-carbon combustion stabilization direct current burner), it can be applied to boilers that conventionally use direct current burners, such as tangential combustion boilers; when the low-carbon combustion stabilization device is the structure in the second and third specific embodiments (low-carbon combustion stabilization swirl burner), it can be used for boilers that conventionally use swirl burners, such as hedge boilers.

[0068] In a specific embodiment, the low-carbon stable combustion device used is the low-carbon stable combustion direct current burner in the first specific embodiment mentioned above. Take the arrangement of three layers of direct current burners at the four corners and the use of a tangential combustion boiler as an example. Please refer to Figure 4-7 In the tangentially fired boiler, a low-carbon stable combustion direct current burner can be arranged at the lower layer, and ordinary direct current burners can be arranged at the middle and upper layers. Each burner has a secondary air nozzle on both sides. Figure 5 As shown; low-carbon stable combustion direct current burners can also be arranged in the middle and lower layers, and ordinary direct current burners can be arranged in the upper layer, and each burner has a secondary air nozzle on both sides, such as Figure 6 As shown; low-carbon stable combustion direct current burners can also be arranged on all three layers, the upper, middle and lower layers, and each burner has a secondary air nozzle on both sides, such as Figure 7 Of course, in practical applications, the low-carbon combustion stabilization device can be flexibly arranged in layers and mixed with ordinary direct current burners, and the specific arrangement is not limited to this example.

[0069] In another specific embodiment, the low-carbon stable combustion device used is the low-carbon stable combustion swirl burner in the second specific embodiment or the third specific embodiment. This embodiment takes the front and rear walls of the boiler with 15 swirl burners each, arranged in three layers, with 5 swirl burners installed on each layer, and a total of 30 swirl burners as an example, the low-carbon stable combustion swirl burner is arranged on the lower layer, and the ordinary swirl burners are arranged on the middle and upper layers, and the arrangement method is as follows: Figure 8 As shown; low-carbon stable combustion swirl burners can also be arranged in the middle and lower layers, and ordinary swirl burners can be arranged in the upper layer, such as Fig. 9 As shown; hydrogen low-carbon stable combustion swirl burners can also be arranged on the upper, middle and lower layers, such as Fig.10 In practical applications, the low-carbon combustion stabilization device can be flexibly arranged in layers and mixed with the ordinary swirl burner, and the specific arrangement is not limited to this example.

[0070] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A low-carbon stable combustion device for igniting coal powder by mixing hydrogen and ammonia, characterized in that: The device comprises a hydrogen pipeline (1), wherein a central air pipeline (2), an ammonia-air mixed gas pipeline (3) and a primary air pipeline (4) are sequentially sheathed outside the hydrogen pipeline (1); An ignition gun (6) is provided in the hydrogen pipeline (1), and an ignition end of the ignition gun (6) extends into the interior of the hydrogen-ammonia combustion chamber (7). In the hydrogen-ammonia combustion chamber (7), the hydrogen from the hydrogen pipeline (1) and the air from the central air pipeline (2) are mixed and ignited by the ignition gun (6) to emit a hydrogen flame, and the hydrogen flame ignites the ammonia premixed gas from the ammonia-air mixed gas pipeline (3); A pulverized coal combustion chamber (8) is provided at the outlet of the hydrogen-ammonia combustion chamber (7), and the primary air duct (4) is in communication with the pulverized coal combustion chamber (8) to convey pulverized coal primary air therein; A secondary combustion chamber (9) is provided at the outlet of the pulverized coal combustion chamber (8), and the primary air duct (4) is in communication with the secondary combustion chamber (9) to convey pulverized coal primary air therein.

2. The low-carbon combustion stabilization device according to claim 1 is characterized in that: The device also includes a support plate (5), and the primary air duct (4) is fixedly connected to the pulverized coal combustion chamber (8) via the support plate (5).

3. The low-carbon combustion stabilization device according to claim 1 is characterized in that: The ignition gun (6), the hydrogen-ammonia combustion chamber (7) and the coal powder combustion chamber (8) are coaxially arranged.

4. The low-carbon combustion stabilization device according to claim 1, characterized in that: The outer surface of the primary air duct (4) is sleeved with a secondary air duct (10) for supplying air to the furnace of the boiler.

5. The low-carbon combustion stabilization device according to claim 4, characterized in that: A plurality of swirl blades (11) are arranged in the secondary air duct (10).

6. The low-carbon combustion stabilization device according to claim 4, characterized in that: The secondary air duct (10) comprises an inner secondary air duct (12) and an outer secondary air duct (14), and the inner secondary air duct (12) and the outer secondary air duct (14) are sequentially sleeved on the outer surface of the primary air duct (4).

7. The low-carbon combustion stabilization device according to claim 1, characterized in that: The pulverized coal primary air includes pulverized coal and air.

8. A boiler, characterized in that: The boiler comprises the low-carbon stable combustion device as described in any one of claims 1-7.

9. The boiler according to claim 8, characterized in that The boiler is an opposed-fired boiler or a tangentially fired boiler.

10. The boiler according to claim 8, characterized in that Part or all of the burners in the boiler are the low-carbon stable combustion devices.

Images