Rotational flow pulverized coal burner capable of burning oxyhydrogen in mixed mode and wall type hedging pulverized coal boiler

Abstract

The utility model discloses a rotational flow pulverized coal burner capable of burning oxyhydrogen and oxygen in a blending mode and a wall type hedging pulverized coal boiler, and the burner comprises a primary air inlet, a secondary air inlet, a secondary air inlet and a secondary air outlet, the primary air nozzle is an air-coal pipeline communicated with the downstream of the primary air inlet and comprises an inlet section used for mixing oxyhydrogen and an outlet section used for spraying out pulverized coal for combustion, and a secondary air nozzle is arranged on the outer side of the outlet section; the oxyhydrogen gas jacket is embedded in the inlet section of the primary air nozzle, an oxyhydrogen gas jacket nozzle is formed in the inner side of the oxyhydrogen gas jacket, and the outer side of the oxyhydrogen gas jacket communicates with an oxyhydrogen gas pipeline; the pulverized coal guiding bluff body is fixed to the center of the inlet section of the primary air nozzle, and a concentrated-phase pulverized coal outlet of the pulverized coal guiding bluff body is close to the oxyhydrogen gas jacket nozzle. The problems that when an existing pulverized coal burner burns pulverized coal, pulverized coal burning is insufficient, and the low-load stable burning effect is poor are solved, the low-load stable burning effect of pulverized coal of different qualities can be achieved, and extra carbon emission is not increased.

Description

Technical Field

[0001] The utility model relates to the technical field of coal powder combustion, in particular to a swirl coal powder burner and a boiler capable of mixing combustion of hydrogen and oxygen. Background Art

[0002] When using coal-fired power units to generate electricity by pulverized coal combustion, the degree of burnout of the pulverized coal and the stable combustion level of the burner have a great impact on the power generation performance of the unit. Insufficient and unstable combustion will also increase the generation of pollutants.

[0003] The minimum load capacity of conventional coal-fired units is based on the ignition index of the fuel and is subject to the inherent combustion properties of the fuel. When using high-quality fuel, the burner can easily achieve stable combustion at low load. However, a large part of the fuel actually used is low-quality coal with a low ignition index. When it is necessary to burn or blend low-quality coal, conventional burners cannot achieve stable combustion or can only achieve stable combustion under high load conditions. If improvement measures are not taken, the continuous operation of coal-fired power units will be seriously affected. Chinese patent publication number CN111486450A, publication date August 4, 2020, named "A pulverized coal burner" discloses a pulverized coal burner, including a first shell, a plurality of swirl blades, a second shell and a concentrating ring, wherein the concentrating ring is arranged on the inner side of the air inlet end of the first shell, and the plurality of swirl blades are installed on the inner side of the air outlet end of the first shell, and the plurality of swirl blades cause the pulverized coal passing between the first shell and the second shell to form a swirl, and independent pulverized coal channels for dense phase and dilute phase pulverized coal are set, and the characteristics of high-temperature flue gas entrainment are utilized to increase the stable combustion ability of the pulverized coal boiler in the low-load stage to a certain extent. However, the improvement of the pulverized coal burner provided by this patent is still limited to the diversion and utilization of dense and thin pulverized coal, and the improvement effect based on the existing conventional technology is not obvious. The main reason why inferior pulverized coal is difficult to burn stably is insufficient volatile matter or excessive heat-absorbing impurities. When the combustion characteristics of pulverized coal are not improved, only increasing the pulverized coal concentration and the swirl entrainment effect of the airflow still cannot solve this key problem. Utility Model Content

[0004] The utility model overcomes the problems of insufficient combustion of pulverized coal and poor stable combustion effect at low load in existing pulverized coal burners when burning pulverized coal, especially when burning inferior coal, and provides a swirl pulverized coal burner and boiler that can be mixed with hydrogen and oxygen for combustion. By arranging a hydrogen and oxygen jacket and a pulverized coal guide blunt body in the primary air nozzle, the hydrogen and oxygen sprayed from the hydrogen and oxygen jacket nozzle are fully mixed with the dense phase pulverized coal separated by the pulverized coal guide blunt body, and the catalytic property of hydrogen and oxygen on the combustion of pulverized coal is utilized to solve the problem that the calorific value and volatile matter of inferior pulverized coal cannot meet the stable combustion requirement, so that pulverized coal of different qualities can achieve the effect of stable combustion at low load without increasing additional carbon emissions.

[0005] In order to achieve the above purpose, the utility model adopts the following scheme:

[0006] The swirl coal powder burner capable of burning hydrogen and oxygen includes:

[0007] A primary air inlet, which is used to introduce primary air carrying coal powder;

[0008] A primary air nozzle, which is an air-coal pipeline connected to the downstream of the primary air inlet, including an inlet section for mixing hydrogen and oxygen and an outlet section for spraying coal powder for combustion, and a secondary air nozzle is arranged outside the outlet section;

[0009] A hydrogen-oxygen jacket, which is embedded in the inlet section of the primary air nozzle, wherein the inner side of the hydrogen-oxygen jacket is provided with a hydrogen-oxygen jacket nozzle and the outer side is connected with a hydrogen-oxygen pipeline;

[0010] The pulverized coal guide bluff body is fixed at the center of the inlet section of the primary air nozzle, and the dense phase pulverized coal outlet of the pulverized coal guide bluff body is close to the hydrogen and oxygen jacket nozzle.

[0011] Preferably, there are multiple hydrogen and oxygen jacket nozzles, which are evenly spaced along the inner circumference of the hydrogen and oxygen jacket.

[0012] Preferably, the hydrogen and oxygen gas pipeline comprises an annular main pipe and a plurality of branch pipes with valves connected thereto, and the connecting positions of the plurality of branch pipes on the hydrogen and oxygen gas jacket correspond one-to-one to the nozzles of the hydrogen and oxygen gas jacket.

[0013] Preferably, a circular bellows panel is provided outside the burner, the annular mother pipe is provided outside the bellows panel, the annular mother pipe is externally connected to the hydrogen and oxygen gas supply device, one end of the branch pipe is connected to the annular mother pipe, and the other end passes through the bellows panel and is connected to the hydrogen and oxygen jacket.

[0014] Preferably, a premixing section for fully mixing the hydrogen and oxygen gas and pulverized coal is provided between the hydrogen and oxygen gas jacket and the combustion section of the burner.

[0015] Preferably, the secondary air nozzle uses a blade-type swirler.

[0016] The present application also provides a wall-type opposed pulverized coal boiler, which is arranged with a plurality of swirl pulverized coal burners capable of mixing hydrogen and oxygen as provided in any of the above solutions.

[0017] Preferably, the oxygen-hydrogen jacket has a plurality of nozzles which are evenly spaced along the inner circumference of the oxygen-hydrogen jacket, and the oxygen-hydrogen pipeline comprises an annular mother pipe and a plurality of branch pipes with valves connected thereto, and the connecting positions of the plurality of branch pipes on the oxygen-hydrogen jacket correspond one to one with the oxygen-hydrogen jacket nozzles;

[0018] Multiple swirl pulverized coal burners are arranged in multiple layers to form a burner array, the valves of the branch pipes of the swirl pulverized coal burners on the periphery of the array close to the wall are opened, the branch pipe valves of the swirl pulverized coal burners in the middle of the array are opened at intervals, and the lower branch pipe valves of the swirl pulverized coal burners on the bottom layer are opened.

[0019] The utility model includes at least the following beneficial effects: (1) the hydrogen and oxygen gas sprayed from the hydrogen and oxygen jacketed nozzle is fully mixed with the dense phase coal powder separated by the coal powder guide blunt body, thereby improving the combustion characteristics of the coal powder and achieving low-load stable combustion for coal materials of various qualities; (2) due to the uniform and sufficient mixing, only a small amount of hydrogen and oxygen needs to be added to reduce the stable combustion load and unburned loss of the burner, thereby improving the energy conversion rate of the thermal power generator set and achieving high economic benefits; (3) the hydrogen and oxygen jacketed nozzle is located upstream of the combustion section of the burner and does not generate an independent hydrogen and oxygen flame. By mixing hydrogen and oxygen to catalyze the combustion of coal powder, the conversion of carbon monoxide to carbon dioxide is promoted, while carbon emissions are not increased and the control of nitrogen oxide concentration is not affected, which is green and environmentally friendly; (4) by setting a plurality of hydrogen and oxygen jacketed nozzles and branch pipes for providing hydrogen and oxygen, the valves of each branch pipe are controlled to open and close, and by adjusting the hydrogen and oxygen supply amount and the gas supply position, the coal powder burner can adapt to the combustion conditions at different positions in the coal powder boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of a technical solution of the utility model;

[0021] Figure 2 A schematic diagram of an opening and closing method of a branch valve of a hydrogen and oxygen pipeline of the utility model;

[0022] Figure 3 This is a schematic diagram of another opening and closing method of the branch valve of the hydrogen and oxygen pipeline of the utility model;

[0023] Figure 4 The utility model is a schematic diagram of a burner arrangement of the wall-type pulverized coal-fired boiler.

[0024] In the figure: primary air inlet 1, primary air nozzle 2, secondary air nozzle 3, hydrogen and oxygen jacket 4, premixing section 5, coal powder guide bluff 6, annular mother pipe 7, valve 8, branch pipe 9, wind box panel 10. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0026] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0027] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the materials can be obtained from commercial channels unless otherwise specified; in the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "set" should be understood in a broad sense, for example, they can be fixedly connected, set, or detachably connected, set, or connected and set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood in specific circumstances. The orientation or position relationship indicated by the terms "transverse", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model.

[0028] like Figure 1 As shown, the utility model provides a swirl coal powder burner capable of burning hydrogen and oxygen, comprising:

[0029] The primary air inlet 1 is used to introduce primary air carrying coal powder; the primary air inlet 1 is a standard configuration of swirl coal powder. As an example, a direct current air inlet duct structure is adopted, and the primary air enters the burner from the air inlet duct. A coal powder pipe is connected to the side of the air inlet duct. The coal powder pipe is supplied with coal powder by the equipped coal mill. The coal powder pipe can optionally adopt an elbow axial powder supply structure to facilitate the arrangement of coal powder concentration reforming equipment. The primary air after passing through the joint of the coal powder pipe carries coal powder and flows to the primary air nozzle 2. The air volume and speed of the primary air and the amount of coal powder carried can be adjusted and controlled by the unit equipment.

[0030] The primary air nozzle 2 is a wind-coal pipeline connected to the downstream of the primary air inlet 1, including an inlet section for mixing hydrogen and oxygen and an outlet section for spraying coal powder for combustion, and a secondary air nozzle 3 is arranged outside the outlet section; after the primary air with coal powder enters the primary air nozzle 2, it is first mixed with the hydrogen and oxygen gas in the inlet section, and the coal powder mixed with hydrogen and oxygen gas continues to move forward and sprays out from the outlet section for combustion, and secondary air is added in the outlet section and subsequent parts to promote the combustion of coal powder. The secondary air includes inner secondary air and outer secondary air. The inner secondary air swirl is regulated by the secondary air baffle to form a stable combustion zone in the combustion section, and the outer secondary air maintains the swirl stability of the combustion zone and provides sufficient oxygen-containing air. The inlet section of the nozzle realizes the premixing of hydrogen and oxygen gas with dense phase coal powder. The premixed mixed fuel is separated from the ignition concentration range of hydrogen fuel and will not form an independent hydrogen flame. It is sent to the outlet section for ignition and spraying before the coal powder diffuses by itself. The outlet section of the nozzle uses non-metallic refractory materials to cope with the temperature of the local high-temperature flame after catalysis.

[0031] The hydrogen-oxygen jacket 4 is embedded in the inlet section of the primary air nozzle 2, and the hydrogen-oxygen jacket nozzle is arranged inside the hydrogen-oxygen jacket 4, and the hydrogen-oxygen pipeline is connected outside; the hydrogen-oxygen jacket 4 is a tubular structure with a hollow interlayer, and its outer wall is fixed to the inner side of the inlet section of the primary air nozzle 2, and is connected to the hydrogen-oxygen pipeline outward, and hydrogen-oxygen is sprayed inward through the hydrogen-oxygen jacket nozzle to mix with the primary air with coal powder. The hydrogen-oxygen jacket nozzle is locally arranged in the circular cylindrical sector of the jacket, and is arranged before the secondary air nozzle 3. The jacket inlet position isolates the coal powder, and provides the hydrogen-oxygen gas with a speed adjustment length from the hydrogen-oxygen pipeline to the fan ring. The outlet position has a mixing distance from the end of the outlet section of the primary air nozzle 2, and the distance does not reach the secondary diffusion length of the coal powder. The hydrogen-oxygen jacket nozzle can adjust the hydrogen-oxygen gas flow rate, so that the hydrogen-oxygen gas flow rate in the local sector meets the requirement of being fully mixed with the coal powder airflow, and adjusts the flow rate of the local coal powder airflow to a certain extent.

[0032] The pulverized coal guide bluff 6 is fixed at the center of the inlet section of the primary air nozzle 2, and the dense phase pulverized coal outlet of the pulverized coal guide bluff 6 is close to the hydrogen-oxygen jacket nozzle. The bluff of the burner is usually used at a position close to the flame ejection, and the pulverized coal combustion is intensified by entraining the high-temperature flue gas reflux. The pulverized coal guide bluff 6 of the present application is set at the center of the inlet section. There are many common shapes and types of bluffs. As an example, a conical bluff is used, which is fixed at the center of the inlet section of the primary air nozzle 2 by a clamping block. The pulverized coal guide bluff 6 adjusts the flow rate of the primary air pulverized gas flow to achieve a reasonable flow rate of the mixed hydrogen-oxygen gas; on the other hand, it redistributes the pulverized coal concentration to form a dense phase pulverized coal close to the hydrogen-oxygen jacket nozzle, increasing the contact probability between the hydrogen-oxygen gas and the pulverized coal, and maximizing its catalytic effect.

[0033] In the process of using this swirl pulverized coal burner to burn pulverized coal, the equipment bellows runs to blow air into the burner from the primary air inlet 1, and the pulverized coal in the pulverized coal pipe mixes with the air flow to form an air-coal mixture that flows into the primary air nozzle 2 air-coal pipeline. Here, the primary air carries the pulverized coal, which is a common way for burners. The pulverized coal enters the hydrogen-oxygen jacket 4 area of ​​the inlet section of the primary air nozzle 2 with the primary air, and is reorganized into dense phase pulverized coal and dilute phase pulverized coal when encountering the pulverized coal guide blunt body 6. The dilute phase pulverized coal flows rapidly from the acceleration area to the downstream, and the dense phase pulverized coal passes through the hydrogen-oxygen jacket nozzle. Position, the gas in the hydrogen and oxygen jacket 4 is ejected from the jacket nozzle and mixed with the coal powder, the dense phase coal powder mixed with hydrogen and oxygen continues to move forward and burns and ejects at the outlet section of the primary air nozzle 2, and the hydrogen and oxygen realize catalytic combustion in the combustion process mixed with the coal powder airflow, so that the subsequent heat-releasing solid carbon releases heat in advance, increases the initial combustion temperature of the coal powder, and increases the conversion rate of carbon monoxide to carbon dioxide, and the ignited dense phase coal powder and light phase coal powder are mixed and burned, and the secondary air swirl stirs the coal powder airflow and provides the air required for combustion, so that the coal powder burns efficiently and stably. During the operation of the pulverized coal boiler, the primary air with coal powder is continuously input to the swirl pulverized coal burner, and the hydrogen and oxygen mixing structure and the secondary air channel are combined to achieve long-term low-load efficient and stable combustion of the burner.

[0034] In the current medium-speed mill pulverizing system, taking a typical 600MW unit as an example, for different qualities of coal, the common low-load design conditions for bituminous coal boilers are set as follows: (1) for high-quality coal, 3 mills at 40% load with 5 mills at full load; (2) for low-quality lean coal: 3 mills at 45% load with 5 mills at full load; (3) for low-quality lignite, 3 mills at 40% load with 6 mills at full load. At present, the power grid controls the low-load area of ​​each unit to 25% to 30%. Considering the instability of the pulverizing system and the rapid response capability of the power grid, if the power plant still wants to operate 3 pulverizers under this low-load condition, it is possible to achieve high-quality bituminous coal and high-quality lignite under the premise of using conventional stable combustion methods such as coal powder concentration technology and burner enhanced stable combustion technology, but other relatively inferior fuels will have unstable combustion. In addition, the commonly used "W" flame boiler uses the heat from the later combustion of the fuel to solve the energy utilization method of initial stable combustion. However, even with the "W" flame boiler, it is impossible to achieve effective stable combustion of inferior coal below 40% load.

[0035] The data obtained show that the swirl coal powder burner that can be mixed with hydrogen and oxygen provided by the application can promote the burnout effect of CO without affecting the combustion of other fuels. The low-load stable combustion performance of the swirl burner can be improved with a small dose of hydrogen and oxygen, which can not only alleviate the unfavorable situation that inferior fuel cannot be stably burned, but also obtain the actual control ability of further reducing the low load of the burner. Taking the 600MW large power station boiler as an example, it is a Π-type hedge combustion boiler with supercritical parameters, spiral furnace, one intermediate reheating, balanced ventilation, solid slag removal, all-steel frame, and tight closed arrangement, equipped with 6+1 medium-speed coal mills, each coal mill is equipped with 5 burners. Select 5 burners corresponding to a lower coal mill and replace them with the swirl coal powder burner that can be mixed with hydrogen and oxygen provided by the application, and the matching equipment includes hydrogen and oxygen gas generator, furnace front air supply system, compressed air purge system, corresponding safety control device, electrical instrumentation and control device, etc. The designed hydrogen and oxygen blending amount accounts for about 0.7% of the full load power of the corresponding burner in the corresponding transformation layer, the low load calorific value accounts for about 1.5% to 2%, and the blending volume is about 800Nm 3 / h, the mixing volume of each hydrogen-oxygen swirl burner is about 160Nm 3 / h. After the transformation, the unit can achieve stable combustion at a load of 20% BMCR when three coal mills are put into operation under the condition of burning common lignite. The boiler can operate safely and stably for a long time without increasing the carbon content of fly ash. There is no obvious increase in nitrogen oxides under the corresponding load compared with before the transformation.

[0036] By using this swirl pulverized coal burner, the hydrogen and oxygen gas sprayed from the hydrogen and oxygen jacket nozzle are fully mixed with the dense phase pulverized coal separated by the pulverized coal guide blunt body 6, thereby improving the combustion characteristics of the pulverized coal, solving the problem that the calorific value and volatile matter of inferior pulverized coal cannot meet the stable combustion requirements, and low-load stable combustion can be achieved for coal materials of various qualities; the hydrogen and oxygen gas are sprayed from the side, impact the dense phase pulverized coal in the primary air, and then merge with the primary air flow and move forward, and the hydrogen and oxygen gas are fully mixed with the pulverized coal in the hydrogen and oxygen jacket 4 and at the subsequent end, so that the catalytic combustion characteristics of the hydrogen and oxygen gas are fully brought into play, and only a small amount of hydrogen and oxygen need to be added to greatly reduce the stable combustion of the burner The load and unburned losses are reduced, which improves the energy conversion rate of the thermal power generating set. The increased hydrogen and oxygen cost is far less than the gain on the pulverized coal combustion effect, and the economic benefits are high. The hydrogen and oxygen jacket nozzle is located upstream of the combustion section of the burner, and no independent hydrogen and oxygen flame is generated. The pulverized coal is burned by catalyzing the combustion of hydrogen and oxygen, which promotes the conversion of carbon monoxide to carbon dioxide. At the same time, it does not increase carbon emissions and does not affect the control of nitrogen oxide concentration, which is green and environmentally friendly. By adjusting the hydrogen and oxygen supply amount and the gas supply position, the temperature difference in the burner caused by factors such as being close to the wall is balanced, and the pulverized coal burner can adapt to the combustion conditions at different positions in the pulverized coal boiler.

[0037] In another technical solution, there are multiple oxygen-hydrogen jacket nozzles and they are evenly spaced along the inner circumference of the oxygen-hydrogen jacket 4. By evenly arranging multiple oxygen-hydrogen jacket nozzles, the oxygen-hydrogen gas is sprayed to the pulverized coal from different directions and angles, making the mixing more uniform and sufficient.

[0038] like Figure 1 and Figure 2 As shown, the hydrogen and oxygen pipeline includes an annular main pipe 7 and multiple branch pipes 9 with valves 8 connected thereto, and the connection positions of the multiple branch pipes 9 on the hydrogen and oxygen jacket 4 correspond to the nozzles of the hydrogen and oxygen jacket. By controlling the opening and closing of the valves 8 of different branch pipes 9, hydrogen and oxygen can be selectively sprayed from different angles, and the combustion performance can be compensated for the position where stable combustion is more difficult. For the high-temperature area in the burner, hydrogen and oxygen are not sprayed or a small amount of hydrogen and oxygen is sprayed to reduce consumption, and targeted combustion is carried out for relatively low-temperature areas such as the side close to the wall.

[0039] A circular bellows panel 10 is provided outside the burner, the annular mother pipe 7 is provided outside the bellows panel 10, the annular mother pipe 7 is connected to the hydrogen and oxygen gas supply device outwardly, one end of the branch pipe 9 is connected to the annular mother pipe 7, and the other end passes through the bellows panel 10 and is connected to the hydrogen and oxygen jacket 4. The annular mother pipe 7 can be an annular steel pipe for storing part of the hydrogen and oxygen gas, so as to realize the redistribution of the hydrogen and oxygen gas from a single pipeline to an annular channel evenly distributed in the shape of the burner.

[0040] In another technical solution, Figure 1 As shown, a premixing section 5 for fully mixing hydrogen and oxygen and coal powder is provided between the hydrogen and oxygen jacket 4 and the combustion section of the burner. When leaving the hydrogen and oxygen jacket 4, the coal powder in the primary air flow has been mixed with hydrogen and oxygen, and catalytic combustion can be carried out. The premixing section 5 provided thereafter can further increase the mixing degree and catalytic effect, and achieve a lower negative pressure and more stable low negative pressure stable combustion.

[0041] The secondary air nozzle 3 uses a blade-type swirler, which is more efficient and energy-saving, smaller in size, and makes the structure of the burner more compact.

[0042] This application also provides a wall-type hedge pulverized coal boiler, such as Figure 4 As shown, it is arranged with a plurality of swirl coal powder burners that can be mixed with hydrogen and oxygen as provided in any of the above schemes. Because this boiler uses the swirl coal powder burners that can be mixed with hydrogen and oxygen provided in this application, when dealing with coal materials of different qualities, low negative pressure stable combustion can be achieved by mixing hydrogen and oxygen, thereby improving the overall combustion performance and economic benefits of the coal powder boiler.

[0043] In another technical solution, there are multiple oxygen-hydrogen jacket nozzles and they are evenly spaced along the inner circumference of the oxygen-hydrogen jacket 4. The oxygen-hydrogen pipeline includes an annular mother pipe 7 and multiple branch pipes 9 with valves 8 connected thereto. The connecting positions of the multiple branch pipes 9 on the oxygen-hydrogen jacket 4 correspond one by one to the oxygen-hydrogen jacket nozzles.

[0044] The multiple swirl pulverized coal burners are arranged in multiple layers to form a burner array, the valve 8 of the branch pipe 9 on the wall side of the swirl pulverized coal burners on the periphery of the array is opened, the valve 8 of the branch pipe 9 of the swirl pulverized coal burners in the middle of the array is opened at intervals, and the valve 8 of the lower branch pipe 9 of the swirl pulverized coal burners on the bottom layer is opened.

[0045] In a pulverized coal boiler, for any swirl burner, the size of the burner nozzle is fixed. Regardless of the load, the flame boundary is located at the junction of the primary air and the internal secondary air. Under low-load conditions, the corresponding coal input is low, and the energy distribution density per unit flame boundary length decreases. Even if the secondary air can achieve an effective entrainment effect, it is easy to cause ignition delays or even fire extinguishing. The flame boundary conditions of burners at different positions in pulverized coal boilers are also different. Based on the conventional flame temperature distribution in the furnace, igniting the uneven distribution of pulverized coal is ignored. In a multi-layer burner system, it is more difficult for the lower burners to ignite, and the ignition conditions of the burners close to the side walls are also worse. As an example, if Figure 4 As shown in FIG. 1 , the pulverized coal burners arranged in the pulverized coal boiler form a multi-layer array of 3 rows and 4 columns. The heat distribution of the burners close to the wall is uneven. The shaded part located at the periphery of the array in the figure is a relatively low temperature position in the boiler. The temperature close to the wall will be lower than that close to the center, and the pulverized coal combustion condition is worse. Therefore, the branch pipe 9 close to the wall is controlled to be opened to realize the single-side enhanced hydrogen and oxygen supply, such as Figure 2 As shown, the air supply method for the burner close to the left wall is left-side air supply, the valve 8 of the left branch pipe 9 is opened, and the valve 8 of the right branch pipe 9 is closed. The mixing of hydrogen and oxygen and coal powder has the characteristic of local enhancement. Due to the high degree of mixing under the impact of airflow and swirl stirring, part of the hydrogen and oxygen will be mixed into the coal powder on the other side. Although the side close to the center area in the burner is not directly supplied with hydrogen and oxygen, it can also achieve good low-load stable combustion. The burners located at the bottom layer also have the problem of uneven heat distribution, and due to the effect of rising heat flow, the temperature on the lower side of the bottom burner is relatively low. Therefore, the lower branch pipe 9 is opened to provide hydrogen and oxygen. The burners located at the upper layer have a higher overall temperature due to the rising heat flow. Therefore, although they are also at the edge of the array, they do not need to be supplied from one side. The intermittent air supply method of the burners in the central area can be adopted. The burners in the central area radiate with other burners around them, and the temperature is relatively high and uniform. Therefore, there is no need for local enhanced air supply, but intermittent uniform air supply, such as Figure 3As shown, the gas supply method for the burners in the central area is intermittent gas supply, the valves 8 of the branch pipes 9 are opened at intervals, and the total amount of hydrogen and oxygen injected can be appropriately less than that of the burners near the wall or the bottom floor.

[0046] By using the swirl pulverized coal burner that can be mixed with hydrogen and oxygen provided by the present application, the hydrogen and oxygen can be fully mixed with the pulverized coal, and the characteristics of hydrogen and oxygen catalyzing the combustion of pulverized coal can be used to solve the problem that the calorific value and volatile matter of inferior pulverized coal cannot meet the stable combustion requirements, and low-load stable combustion can be achieved for coal materials of various qualities; because the mixed hydrogen and oxygen do not need to reach the concentration of forming an independent flame, and the mixing is uniform and sufficient, only a small amount of hydrogen and oxygen needs to be added to greatly reduce the stable combustion load and unburned loss of the burner, thereby improving the energy conversion rate of the thermal power generating set, and the increased hydrogen and oxygen cost is far less than the gain in the pulverized coal combustion effect, and the economic benefit is high; a small amount of hydrogen and oxygen can also promote the conversion of carbon monoxide to carbon dioxide, while not increasing carbon emissions and not affecting the control of nitrogen oxide concentration, which is green and environmentally friendly; by adjusting the hydrogen and oxygen supply amount and the gas supply position, the temperature difference in the burner caused by factors such as being close to the wall is balanced, and the pulverized coal burner can adapt to the combustion conditions at different positions in the wall-type hedged pulverized coal boiler.

[0047] The number of devices and processing scales described here are used to simplify the description of the utility model. Applications, modifications and variations of the utility model are obvious to those skilled in the art.

[0048] Although the implementation scheme of the utility model has been disclosed as above, it is not limited to the applications listed in the specification and implementation modes. It can be fully applied to various fields suitable for the utility model. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. Swirl coal powder burner that can be mixed with hydrogen and oxygen, It is characterized in that include: A primary air inlet, which is used to introduce primary air carrying coal powder; A primary air nozzle, which is an air-coal pipeline connected to the downstream of the primary air inlet, including an inlet section for mixing hydrogen and oxygen and an outlet section for spraying coal powder for combustion, and a secondary air nozzle is arranged outside the outlet section; A hydrogen-oxygen jacket, which is embedded in the inlet section of the primary air nozzle, wherein the inner side of the hydrogen-oxygen jacket is provided with a hydrogen-oxygen jacket nozzle and the outer side is connected with a hydrogen-oxygen pipeline; The pulverized coal guide bluff body is fixed at the center of the inlet section of the primary air nozzle, and the dense phase pulverized coal outlet of the pulverized coal guide bluff body is close to the hydrogen and oxygen jacket nozzle.

2. The swirl coal powder burner capable of mixing hydrogen and oxygen according to claim 1, It is characterized in that There are a plurality of oxygen-hydrogen jacket nozzles which are evenly spaced along the inner circumference of the oxygen-hydrogen jacket.

3. The swirl coal powder burner capable of mixing hydrogen and oxygen according to claim 2, It is characterized in that The hydrogen and oxygen gas pipeline comprises an annular main pipe and a plurality of branch pipes with valves connected thereto, and the connecting positions of the plurality of branch pipes on the hydrogen and oxygen gas jacket correspond one to one with the nozzles of the hydrogen and oxygen gas jacket.

4. The swirl coal powder burner capable of mixing hydrogen and oxygen according to claim 3, It is characterized in that A circular bellows panel is arranged outside the burner, the annular mother pipe is arranged outside the bellows panel, the annular mother pipe is connected to the hydrogen and oxygen gas supply device outwardly, one end of the branch pipe is connected to the annular mother pipe, and the other end passes through the bellows panel and is connected to the hydrogen and oxygen jacket.

5. The swirl coal powder burner capable of mixing hydrogen and oxygen according to claim 1, It is characterized in that A premixing section for fully mixing the hydrogen and oxygen gas and pulverized coal is provided between the hydrogen and oxygen gas jacket and the combustion section of the burner.

6. The swirl coal powder burner capable of mixing hydrogen and oxygen according to claim 1, It is characterized in that The secondary air nozzle uses a blade-type swirler.

7. Wall-type opposed pulverized coal boiler, It is characterized in that A plurality of swirl pulverized coal burners capable of mixing hydrogen and oxygen as described in any one of claims 1 to 6 are arranged.

8. The wall-type opposed pulverized coal boiler according to claim 7, It is characterized in that The oxygen-hydrogen jacket has a plurality of nozzles which are evenly spaced along the inner circumference of the oxygen-hydrogen jacket. The oxygen-hydrogen pipeline comprises an annular main pipe and a plurality of branch pipes with valves connected thereto. The connection positions of the plurality of branch pipes on the oxygen-hydrogen jacket correspond one to one with the oxygen-hydrogen jacket nozzles. Multiple swirl pulverized coal burners are arranged in multiple layers to form a burner array, the valves of the branch pipes of the swirl pulverized coal burners on the periphery of the array close to the wall are opened, the branch pipe valves of the swirl pulverized coal burners in the middle of the array are opened at intervals, and the lower branch pipe valves of the swirl pulverized coal burners on the bottom layer are opened.

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