Combustion stabilizing device and combustion stabilizing method for preventing slagging

Abstract

The invention discloses a combustion stabilizing device and a combustion stabilizing method for preventing slagging, belongs to the technical field of self-service turbulent combustors, and aims to solve the problems that the interior of a combustion stabilizing cavity of a self-service combustion stabilizing combustor and a water cooling wall of a tangential hearth are prone to slagging and high-temperature corrosion, NOx emission is high during low-load operation, and an anti-slagging air system is insufficient in power. According to the self-service swirling burner, a stable combustion cavity in a traditional self-service swirling burner is mainly optimized, firstly, the traditional stable combustion cavity is optimized to be of an adjustable structure, the adjustable stable combustion cavity is characterized in that the design of an outer anti-slagging air nozzle is integrated in the structure of the adjustable stable combustion cavity, and an inner anti-slagging air nozzle is additionally arranged on the adjustable stable combustion cavity on the basis; the aim of preventing slag bonding on the water cooling wall of the hearth is achieved through the matching design of the outer slag bonding prevention air nozzle and the inner slag bonding prevention air nozzle and the axial adjustment between the stable combustion cavity and the outer slag bonding prevention air nozzle. The self-service swirling burner structure is mainly used in a direct-flow burner and swirling burner collaborative combustion system.

Description

Technical Field

[0001] The invention relates to the technical field of self-swirl burners, and in particular to a combustion stabilizing device and a combustion stabilizing method for preventing slagging. Background Art

[0002] Coordinate the power supply guarantee and pollution reduction and carbon reduction, reasonably build advanced coal-fired power according to development needs, maintain the reasonable margin required for safe and stable operation of the system, accelerate the transformation of coal-fired power from the main power source to the basic guarantee and system regulation power source that provides reliable capacity, peak and frequency regulation and other auxiliary services, give full play to the emergency peak regulation capacity of existing coal-fired power units, and orderly promote the construction of supporting and regulating power sources. Many departments have issued documents requiring power station boilers to flexibly adjust the peak. With the large-scale grid connection of new energy such as wind power and solar power generation, the power grid needs thermal power units to provide flexible peak regulation capabilities. In order to absorb more new energy, thermal power units need to provide a wider load adjustment range, especially those that will be in low-load operation conditions for a long time. The primary problem with low-load operation of thermal power units is to ensure the stability of combustion under ultra-low or low load conditions. Therefore, ensuring the stable operation of boilers under ultra-low or low loads is an urgent problem to be solved in the operation of power station boilers.

[0003] During the low-load operation of power station boilers, the self-help stable combustion burner is a key combustion equipment. Its stable combustion chamber has a larger heat load than the furnace cross section. The heat released after combustion causes the temperature in the stable combustion chamber to rise rapidly and maintain at a high temperature. At the same time, under the action of the internal secondary air, a central reflow zone is formed in the stable combustion chamber, which is conducive to the ignition of coal powder and subsequent stable combustion. This feature enables the flame formed by the self-help stable combustion burner to ignite the primary air powder flame of the DC burner, thereby achieving stable combustion of the four-corner or octagonal cut-circle boiler at an ultra-low load of 20%, significantly improving the peak-shaving capacity of the unit and ensuring the safe operation of the boiler.

[0004] However, the quality of coal in my country is changeable, and the fluctuation of coal prices has led to frequent replacement of coal for power station boilers, and the quality of coal used is uneven, which seriously deviates from the optimal coal parameters designed for boilers. This not only leads to problems such as difficulty in ignition, unstable combustion, and slagging at the burner nozzle, but also directly affects the combustion stability of power station boilers. In addition, due to the high temperature and small space in the stable combustion chamber, and the coal powder particles gather towards the cylinder wall under the action of centrifugal force, it is very easy to accumulate ash and slag in the cylinder wall. Especially when burning inferior coal with a low ash melting point, the slagging in the stable combustion chamber is particularly serious. These ash and slag not only destroy the aerodynamic field in the stable combustion chamber, but also affect the combustion stability of coal powder. In severe cases, they may even cause safety accidents and increase the workload of operators to clean and remove ash. Therefore, preventing ash and slag in the stable combustion chamber and ensuring that coal powder and ash slag are not deposited on the wall is the primary condition for ensuring the long-term stable operation of the stable combustion chamber. At the same time, as an important source of NOx emissions, the NOx emissions of thermal power plants have always received widespread attention. As the national environmental protection policy becomes increasingly strict, NOx emissions from thermal power plants are strictly controlled. At present, the country is vigorously promoting ultra-low emission transformation of thermal power plants. According to the requirements of ultra-low emissions, the NOx emission standard has been reduced to 50mg / m 3 Therefore, it is urgent to control the NOx emissions of pulverized coal boilers in power plants under low load conditions.

[0005] At present, the introduction of anti-slagging wind system helps complete combustion of fuel, reduces NOx emissions, and avoids slagging corrosion. When the temperature is too high during the combustion process, the introduction of an appropriate amount of cooling air to reduce the temperature can reduce the risk of slagging corrosion. However, excessive cooling air volume will reduce the flame temperature, which may lead to incomplete combustion, affect combustion efficiency, and even extinguish the flame. Therefore, the anti-slagging air volume generally accounts for about 20% of the total air volume. However, most of the existing anti-slagging wind technologies use the secondary air in the secondary wind box of the burner as the wind source. As the load decreases, the wind pressure at the blower outlet and the secondary wind box decreases, resulting in too low a secondary wind box pressure. Due to the small flow area, high wind speed, large resistance, and insufficient airflow rigidity of the anti-slagging wind, when it is directly blown into the furnace, it is easy to be sucked by the main airflow in the furnace, resulting in insufficient airflow penetration depth, and unable to effectively improve the reducing atmosphere on the surface of the water-cooled wall, and thus unable to solve the high-temperature corrosion problem of the water-cooled wall.

[0006] In order to solve the problems of easy slagging and high-temperature corrosion in the combustion stabilizing chamber of the self-service combustion stabilizing burner and on the water-cooled wall of the circular furnace, high NOx emissions during low-load operation, and insufficient power of the anti-slagging air system, the present invention proposes a combustion stabilizing method and device to prevent slagging. Summary of the invention

[0007] The present invention aims to solve the problems of easy slagging and high temperature corrosion in the combustion chamber of the self-service combustion stabilizing burner and the water-cooled wall of the tangential furnace, high NOx emission during low-load operation, insufficient power of the anti-slagging wind system, and so on, and thus provides a combustion stabilizing device and a combustion stabilizing method for preventing slagging;

[0008] A combustion stabilization device for preventing slagging comprises a primary air duct, an inner secondary air duct, an adjustable combustion stabilization chamber, an anti-slagging air system and a plurality of inner anti-slagging air nozzles, the inner secondary air duct is coaxially sleeved on the outside of the primary air duct, and the air outlet ends of the primary air duct and the inner secondary air duct are both connected to the air inlet end of the adjustable combustion stabilization chamber, the adjustable combustion stabilization chamber is installed inside a baffle sleeve, a plurality of inner anti-slagging air nozzles are equidistantly arranged on the air inlet end of the adjustable combustion stabilization chamber along the circumferential direction, and a plurality of inner anti-slagging air nozzles are arranged around the inner secondary air duct, each inner anti-slagging air nozzle is connected to the adjustable combustion stabilization chamber, the anti-slagging air system is arranged outside the baffle sleeve, and the air outlet end of the anti-slagging air system is connected to each inner anti-slagging air nozzle and the adjustable combustion stabilization chamber;

[0009] Furthermore, an inner secondary air blade group is provided between the primary air duct and the inner secondary air duct, the inner secondary air blade group is arranged close to the adjustable combustion stabilization chamber, the inner secondary air blade group includes a plurality of inner secondary air blades, and the plurality of inner secondary air blades are equidistantly installed on the inner wall of the inner secondary air duct along the circumferential direction;

[0010] Furthermore, the adjustable combustion stabilizing chamber comprises a combustion stabilizing chamber sleeve, an outer anti-slagging air nozzle and a plurality of adjusting mechanisms, the outer anti-slagging air nozzle is coaxially sleeved on the outside of the combustion stabilizing chamber sleeve, the air inlet end of the combustion stabilizing chamber sleeve is a closed end, the primary air duct, the inner secondary air duct and the plurality of inner anti-slagging air nozzles are arranged on the air inlet end of the combustion stabilizing chamber sleeve, a plurality of adjusting mechanisms are arranged between the combustion stabilizing chamber sleeve and the outer anti-slagging air nozzle, and the combustion stabilizing chamber sleeve realizes axial adjustment along the outer anti-slagging air nozzle through the plurality of adjusting mechanisms;

[0011] Furthermore, an outer anti-slagging wind blade group is provided between the outer anti-slagging wind nozzle and the combustion stabilizing chamber sleeve, and the outer anti-slagging wind blade group includes a plurality of outer anti-slagging wind blades, and the plurality of outer anti-slagging wind blades are equidistantly installed on the inner wall of the outer anti-slagging wind nozzle in the circumferential direction;

[0012] Furthermore, the adjustment mechanism includes a driving unit and a guiding unit, the driving unit and the guiding unit are respectively arranged on both sides of the outer anti-slagging wind blade group, and the driving unit and the guiding unit are both installed on the outer wall of the combustion stabilizing chamber sleeve;

[0013] The driving unit includes a ruler, a pull rod, a bracket and a connecting block. The bracket is installed at the end of the partition sleeve. A pull rod sleeve is inserted in the bracket. An external thread is processed on the outer circumferential surface of the pull rod sleeve, and the pull rod sleeve is detachably connected to the bracket through two limit nuts. A gasket is provided between each limit nut and the bracket. The pull rod is inserted in the pull rod sleeve and slidably connected to the pull rod sleeve. Both ends of the pull rod extend to the outside of the pull rod sleeve, and one end of the pull rod is installed on the outer wall of the combustion stabilizing chamber sleeve through a connecting block. The other end of the pull rod is used as a driving end to pull the pull rod to slide back and forth in the pull rod sleeve. The ruler is fixed on the bracket, and the length extension direction of the ruler is the same as the length extension direction of the pull rod. The driving end of the pull rod is fixedly connected to the marking slider on the ruler through a connecting piece.

[0014] The guide unit includes a slide rail and a roller assembly. The slide rail is installed on the inner wall of the outer anti-slagging air nozzle. Limiters are installed at both ends of the slide rail, and the length extension direction of the slide rail is the same as the axial direction of the outer anti-slagging air nozzle. The roller assembly is installed on the outer wall of the combustion stabilizing chamber sleeve. The combustion stabilizing chamber sleeve is slidably arranged on the slide rail inside the outer anti-slagging air nozzle through the roller assembly.

[0015] Furthermore, the anti-slagging air system includes an inner anti-slagging air duct, a primary fan, a blower, an air preheater, a cold primary air duct, a hot primary air duct, an anti-slagging air box, an outer anti-slagging air duct, a hot secondary air duct and a secondary air box. The primary fan and the blower are both arranged on one side of the air preheater, and the air outlet end of the primary fan and the air outlet end of the blower are connected to the air inlet end of the air preheater through a pipeline. The No. 1 air outlet end of the air preheater is connected to the air inlet end of the anti-slagging air box through the hot primary air duct. The anti-slagging air box has two air outlet ends. The No. 1 air outlet end of the anti-slagging wind box is connected to the external anti-slagging wind nozzle through the external anti-slagging wind duct, the No. 2 air outlet end of the anti-slagging wind box is connected to multiple internal anti-slagging wind nozzles through the internal anti-slagging wind duct, the No. 2 air outlet end of the air preheater is connected to the air inlet end of the secondary wind box through the hot secondary air duct, the air outlet end of the secondary wind box is connected to the internal secondary air duct, the cold primary air duct is connected in parallel to the air preheater, one end of the cold primary air duct is connected to the hot primary air duct, and the other end of the cold primary air duct is connected to the air outlet end of the primary fan;

[0016] A cold primary air electric regulating valve is connected in series on the cold primary air duct;

[0017] A hot primary air electric regulating valve is connected in series on the hot primary air duct, and the hot primary air electric regulating valve is located between the connection of the cold primary air duct and the hot primary air duct and the air preheater;

[0018] An external anti-slagging air duct is connected in series in the air flow direction in sequence with an external anti-slagging air electric regulating valve, a No. 1 temperature sensor and a No. 1 wind speed measuring device;

[0019] An inner anti-slagging air electric regulating valve, a No. 2 temperature sensor and a No. 2 wind speed measuring device are sequentially connected in series on the inner anti-slagging air duct along the wind flow direction;

[0020] An internal secondary air electric regulating valve is connected in series on the internal secondary air duct;

[0021] Furthermore, a video fire detection device is provided on the air inlet end of the combustion stabilization chamber sleeve. The video fire detection device is composed of a high temperature probe, a camera system, a cooling protection device, a thruster, a power control box, an air source filter and pressure control box, and a monitor and is connected to the DCS system through a cable:

[0022] Furthermore, a plurality of cylinder wall temperature sensors are installed near the exit of the combustion stabilization chamber sleeve, and the plurality of cylinder wall temperature sensors are arranged in sequence and at equal intervals along the circumference of the combustion stabilization chamber sleeve;

[0023] Furthermore, the center line of the inner anti-slagging air nozzle forms an angle β with the end surface of the air inlet end of the combustion stabilization chamber sleeve, and the angle β ranges from 0 to 30°;

[0024] A method for stabilizing combustion to prevent slagging, the specific process of the method is as follows:

[0025] When the boiler load is higher than 50% of the rated load, it is necessary to consider the high-temperature slagging problem in the combustion stabilization chamber. The specific operation is: the self-service combustion stabilization burner enters the high-load anti-coking and burning mode, loosens the limit nut, and pulls the position of the adjustable combustion stabilization chamber by pulling the pull rod, thereby changing the relative position of the adjustable combustion stabilization chamber sleeve and the external anti-slagging air nozzle, so that L2 = 1.0-2.0De, tightens the limit nut when the pull rod is at the required position, fixes the pull rod, and adjusts the opening of the cold primary air electric regulating door and the hot primary air electric regulating door to make T2 = T3 = 60-120°C; adjusts the opening of the inner anti-slagging air electric regulating door to 40%-100% and the opening of the outer anti-slagging air electric regulating door to 40%-100%, so that u1 = 30-60m / s; u2 = 35-65m / s; after the above operations, ensure that the T1 temperature is 700-900°C;

[0026] When the boiler load is lower than 50% of the rated load (20%-50% of the rated load), a small reflow zone is required in the combustion stabilization chamber to ensure stable combustion while avoiding slagging in the combustion stabilization chamber. The specific operation is: the self-service combustion stabilization burner enters the low-load combustion stabilization mode, loosens the limit nut, and adjusts the position of the combustion stabilization chamber by pulling the pull rod, thereby changing the relative position of the combustion stabilization chamber sleeve and the external anti-slagging air nozzle, so that L2=0.1-1.0De, and tightens the limit nut when the pull rod is in the required position. , fix the pull rod, adjust the opening of the cold primary air electric regulating door and the hot primary air electric regulating door to make T2 = T3 = 200-250 ° C; adjust the opening of the inner anti-slagging wind electric regulating door to 0% and the opening of the outer anti-slagging wind electric regulating door to 0%-50%, so that u1 = 20-30m / s; u2 = 20-35m / s; after the above operation, ensure that the T1 temperature is 900-1000 ° C, and form a central reflow zone of an appropriate range in the stable combustion chamber (0.3De <D<2De;1.5De<L<4De;0.2De<a<0.5De)。

[0027] The beneficial effects of this application compared to the prior art are as follows:

[0028] 1. Effectively prevent slagging in the stable combustion chamber

[0029] Based on a coordinated combustion device and a coordinated combustion method of a direct current burner and a swirl burner, in a self-help stable combustion burner, under high load, the furnace temperature is high, the coal powder airflow can be quickly heated, and the stable combustion chamber has a larger heat load than the furnace cross section. The heat released after combustion causes the temperature in the stable combustion chamber to rise rapidly and maintain at a high temperature. Usually, when the burner is burning, the flame center temperature is between 1400-1700°C, and the cylinder wall temperature can reach above 1500°C. At such a high temperature, the ash in the fuel is mostly melted into a liquid or softened state, and the slagging degree inside the stable combustion chamber is serious. Under low load, the flue gas temperature in the main combustion zone is low, and a certain range of reflow zones need to be generated to entrain high-temperature flue gas to ensure the stable combustion of coal powder. This will cause the coal powder particles to gather toward the cylinder wall under the action of centrifugal force, making it very easy for ash accumulation and slagging to occur inside the cylinder wall. Due to the heat absorption of the water-cooled wall outside the stable combustion chamber, the temperature is lower as it moves from the center of the combustion flame to the outside, closer to the water-cooled wall. Under normal circumstances, as the temperature decreases, the ash will change from liquid to softened and then to solid. If the ash is still in a softened state when it touches the heating surface, it will be cooled and adhere to the heating surface, and it will easily form coke at the exit of the stable combustion chamber. At the same time, the stable combustion chamber is cast with refractory castables. When the burner burns, the refractory castables will gather a lot of heat on the end face of the stable combustion chamber, causing local high temperature. When the temperature rises to the coking temperature, it will cause slagging on the end face of the stable combustion chamber.

[0030] The present invention mainly replaces the traditional refractory casting structure with a heat-resistant steel structure, and combines the internal slagging prevention air and the external slagging prevention air to be introduced into the root and the outlet of the self-stabilizing combustion burner respectively. Under the combined action of the internal and external slagging prevention air (the slagging prevention air temperature is maintained at 60 - 120 °C under high load; the slagging prevention air temperature is maintained at 200 - 250 °C under low load) and the excellent heat conduction performance of the heat-resistant steel, the temperature in the stable combustion cavity of the self-stabilizing combustion burner can be reduced, and the temperature field tends to be stable (the outlet temperature of the stable combustion cavity is maintained at 700 - 900 °C under high load; the temperature of the stable combustion cavity is maintained at 900 - 1000 °C under low load), which can prevent the occurrence of local slagging and coking phenomena, and improve the stability and service life of the self-stabilizing combustion burner.

[0031] The high-speed internal slagging prevention air is sprayed into the stable combustion cavity from multiple internal slagging prevention air nozzles at the bottom of the stable combustion cavity at an angle of β, so that the internal slagging prevention air forms a swirling jet. The swirling internal slagging prevention air forms a strong disturbance on the inner wall of the stable combustion cavity, purges the inner wall of the stable combustion cavity, plays a role in ash cleaning, reduces the ash accumulation in the stable combustion cavity, and avoids slagging caused by excessive ash accumulation on the wall surface.

[0032] Under high load, by pulling the pull rod backward (1.0De - 2.0De), the distance between the adjustable stable combustion cavity sleeve and the external slagging prevention air nozzle becomes longer, and the internal and external slagging prevention air velocities are increased (u1 = 30 - 60 m / s; u2 = 35 - 65 m / s), enhancing the heat exchange capacity, cooling the high-temperature area of the burner, making the temperature distribution more uniform, and preventing the softening and slagging of coal ash caused by local overheating. Under low load, by pulling the pull rod backward (0.1De - 0.2De), the mixing of the external slagging prevention air at different positions and the reduction of the internal and external slagging prevention air velocities (u1 = 0 - 30 m / s; u2 = 20 - 35 m / s) affect the size of the recirculation zone. For coal types that are not prone to slagging, the mixing position of the external slagging prevention air is far, and the recirculation zone is larger (0.8De < D < 2De; 2.5De < L < 4De). At this time, the recirculation zone entrains a large amount of high-temperature flue gas, the pulverized coal ignites early, the combustion time of the pulverized coal in the stable combustion cavity is long, and a large amount of heat is released. At the same time, in cooperation with the closing of the internal slagging prevention air and the reduction of the external slagging prevention air velocity u2 = 20 - 25 m / s, the stable combustion of the pulverized coal is ensured; for coal types that are prone to slagging, the mixing position of the external slagging prevention air is close, and the recirculation zone is smaller (0.3De < D < 0.5De; 1.5De < L < 2.0De). At this time, the recirculation zone entrains a small amount of high-temperature flue gas, the pulverized coal ignites late, the combustion time of the pulverized coal in the stable combustion cavity is short, and less heat is released. At the same time, in cooperation with the internal slagging prevention air velocity u1 = 20 - 30 m / s and the increase of the external slagging prevention air velocity u2 = 30 - 35 m / s, the heat exchange capacity is increased, which can effectively prevent the pulverized coal from slagging in the stable combustion cavity.

[0033] 2. It is beneficial to avoid slagging and high-temperature corrosion in the furnace

[0034] Based on a coordinated combustion device and coordinated combustion method of a DC burner and a swirl burner, when the boiler is operating at a load higher than 50% of the rated load, by closing the regulating valve in the internal secondary air channel, there is no rotating secondary air inside the self-service stable combustion burner, and only DC primary air is introduced, wherein the DC primary air rate in the stable combustion chamber is maintained at 20-30%. Affected by the stable combustion chamber, the DC primary and secondary air in the furnace cannot replenish the oxygen required for combustion in the stable combustion chamber in time, resulting in the self-service stable combustion area being in a highly reducing atmosphere as a whole. When the boiler is operating at a load lower than 50% of the rated load (20%-50% rated load), relying on the induced effect of the DC primary air and DC secondary air of the DC burner, the stable combustion chamber of the swirl burner and the secondary air in the swirl are coordinated to form a central reflow zone in the center of the swirl burner, so that the coal powder is concentrated in the reducing atmosphere of the central reflow zone for combustion. The self-service stable combustion area is in a reducing atmosphere as a whole, which accelerates the high-temperature corrosion of the water-cooled wall and causes the ash melting point to drop and cause slagging. In addition, the temperature of the self-stabilizing burner area in the furnace is high, which can reach 1200℃-1500℃. The coal ash is more likely to soften or melt, and slag after contacting the water-cooled wall. At the same time, the accumulation of ash on the water-cooled wall will reduce the heat absorption of the water-cooled wall, and the temperature of the self-stabilizing burner area in the furnace will increase, resulting in coking.

[0035] The external anti-slagging wind used in the present invention is evenly arranged in a ring outside the stable combustion chamber with the burner axis as the center, so that the furnace wall around the burner is in an oxidizing atmosphere. The ash melting point is higher in an oxidizing atmosphere, thereby avoiding slagging caused by the reduction of the ash melting point due to the reduction atmosphere. At the same time, the external anti-slagging wind moves around the stable combustion chamber, and the external anti-slagging wind separates the flue gas with high temperature and high ash concentration from the inner wall of the furnace, reducing the contact between the high-temperature ash and the inner wall of the furnace, and reducing the slagging in the furnace; the temperature of the external anti-slagging wind is low (the temperature is 60-120℃ under high load; the temperature is 200-250℃ under low load), which can effectively reduce the flue gas temperature near the inner wall of the furnace, so that the molten coal particles are cooled before reaching the water-cooled wall, avoiding slagging and high-temperature corrosion caused by excessive temperature near the water-cooled wall. The rotating external anti-slagging wind creates a strong disturbance near the water-cooled wall, sweeping the inner wall of the furnace, playing a role in cleaning ash, reducing ash accumulation in the furnace, and avoiding slagging caused by excessive ash accumulation on the heating surface.

[0036] 3. It is beneficial to reduce NO X Generation

[0037] Thermal NOx refers to nitrogen (N 2 ) and oxygen (O 2) NOx generated at high temperatures, with the increase of temperature, the generation rate of thermal NOx increases rapidly according to the exponential law. Fuel-type NOx refers to NOx generated by the reaction of nitrogen and oxygen in the fuel during combustion, especially when the nitrogen content of the fuel is high, the generation of fuel-type NOx will increase greatly. A large number of experiments have shown that the higher the excess air coefficient, the higher the generation concentration and conversion rate of NOx. Therefore, the main measure to control the generation and conversion rate of thermal NOx is to reduce the combustion temperature, and the main measure to control the generation and conversion rate of fuel-type NOx is to reduce the excess air coefficient. Based on a direct current burner and a swirl burner cooperative combustion device and a cooperative combustion method, its stable combustion chamber has a larger heat load than the furnace cross-section, and the heat released after combustion causes the temperature in the stable combustion chamber to rise rapidly and maintain at a high temperature, resulting in an increase in the generation of thermal NOx. At the same time, in the combustion chamber of the self-service stable combustion burner, only primary air is passed under high load, and secondary air and primary air are passed under low load, and the degree of air classification is low; and after the coal powder is ignited, the temperature rises, the volume of the flue gas expands, and the viscosity increases. The mixing of the secondary air and the primary air is much more difficult than before ignition, resulting in uneven mixing and the generation of a large amount of NOx.

[0038] The present invention divides air into inner secondary air, inner anti-slagging air and outer anti-slagging air, and respectively feeds them through corresponding nozzles, thereby strengthening the air staged combustion degree of the burner. The anti-slagging air is divided into two layers, inner and outer, and gradually mixed evenly, thereby avoiding the problem of NOx increase caused by local high oxygen, and realizing radial air staged combustion in the stable combustion chamber and in the furnace, which is conducive to reducing fuel-type NOx. The inner anti-slagging air is injected at the bottom of the stable combustion chamber, and the outer anti-slagging air is adjusted by a retractable device to adjust the mixing position of the outer anti-slagging air, so as to control the combustion temperature in the stable combustion chamber and reduce the generation of thermal NOx. At the same time, the outer anti-slagging wind rotates into the furnace, increasing the radial jet range of the gas fed into the furnace, accelerating the mixing of the anti-slagging air with the primary air and the mixing of the anti-slagging air with the flue gas in the furnace, thereby avoiding the generation of a large amount of NOx due to uneven mixing.

[0039] 4. According to the different coal qualities used under different loads, the slagging condition and flame combustion state can be checked through the temperature sensor at the outlet of the stable combustion chamber and the video fire detection device. Combined with the monitoring of the temperature and wind speed in the anti-slagging air duct, the size of the internal and external coke release air and the mixing position can be flexibly adjusted, which fully broadens the coal adaptability of the self-service stable combustion burner;

[0040] An invention based on the coordinated combustion of direct current burners and swirl burners uses a non-slagging coal with a softening temperature ST higher than 1390°C as the design coal type. The diameter of the recirculation zone is 0.8De < D < 2De; the length of the recirculation zone is 2.5De < L < 4De, the distance between the burner outlet and the starting point of the recirculation zone is 0.2De < a < 0.3De, and the temperature at the outlet of the stable combustion chamber is above 1500°C. The coal quality in China varies greatly, and the fluctuation of coal prices leads to frequent replacement of the coal used in power station boilers. The quality of the coal used is uneven, seriously deviating from the optimal coal parameters designed for the boilers. This not only causes problems such as difficult ignition, unstable combustion, and slagging at the burner nozzles, but also directly affects the combustion stability of power station boilers. The characteristics of different coal types vary greatly, that is, the slagging characteristics of coal are different. Generally, judged by the softening temperature ST, when the softening temperature ST is higher than 1390°C, the coal type belongs to non-slagging coal, and when the softening temperature ST is lower than 1260°C, the coal type belongs to easy-slagging coal. Therefore, different coal types have different requirements for the temperature, velocity, and mixing position of the anti-slagging air. Under low-load conditions, the temperature in the furnace decreases and the combustion reaction rate slows down. A certain range of recirculation zones are required to ensure stable combustion. When burning easy-slagging coal, if there is a relatively large recirculation zone in the stable combustion chamber, it will cause the ignition position of the pulverized coal to move forward. The combustion time of the pulverized coal in the stable combustion chamber is long, and more energy is released, resulting in too high a temperature in the stable combustion chamber, and then causing slagging at the outlet of the stable combustion chamber. At the same time, when the boiler is operating at a load above 50% of the rated load, only one pulverized coal air flow is passed, and the primary air rate is 20%-30%, making the combustion in an oxygen-deficient state for a long time, which is not conducive to the complete combustion of the pulverized coal.

[0041] The present invention adjusts the mixing position of the external slagging prevention air and the pulverized coal air flow through a telescopic device, and adjusts the opening degrees of the electric regulating valves of the internal and external slagging prevention air. At low loads, by stretching the pull rod (0.1De - 1.0De), the external slagging prevention air is controlled to mix into the stable combustion chamber at different positions, and combined with the adjustment of the opening degree of the electric regulating valve of the external slagging prevention air, the velocity of the external slagging prevention air is controlled at 20 - 35 m / s, thereby affecting the size of the recirculation zone. By adjusting the opening degree of the electric regulating valve of the internal slagging prevention air, the velocity of the internal slagging prevention air is controlled at 0 - 30 m / s to cool the wall surface of the stable combustion chamber, and the slagging prevention air rate is maintained at 10% - 20%, thereby improving the adaptability of coal types. For easily slagging coal types, by extending the relative distance between the stable combustion chamber and the external slagging prevention air nozzle (L2 = 0.6 - 1.0De), and ensuring a certain velocity of the internal and external slagging prevention air (u1 = 20 - 30 m / s; u2 = 25 - 35 m / s), a small and stable central recirculation zone is formed (0.3De < D < 0.5De; 1.5De < L < 2.0De; 0.4De < a < 0.5De); at this time, the amount of high-temperature flue gas entrained by the recirculation zone is small, the pulverized coal ignites late, the combustion time of the pulverized coal in the stable combustion chamber is short, and the heat released is small. At the same time, the temperature at the outlet of the stable combustion chamber is maintained at 900 - 1000 °C. For medium-slagging coal types, by shortening the relative distance between the stable combustion chamber and the external slagging prevention air nozzle (L2 = 0.3 - 0.6De), and ensuring a certain velocity of the internal and external slagging prevention air (u1 = 0 m / s; u2 = 20 - 25 m / s), a moderately stable central recirculation zone is formed (0.5De < D < 0.8De; 2.0De < L < 2.5De, 0.3De < a < 0.4De); ensure that the temperature at the outlet of the stable combustion chamber is 900 - 1000 °C. It can prevent the burner and the pre-combustion chamber nozzle from slagging and burning while ensuring the ignition performance of the pulverized coal. For non-slagging coal types, by shortening the relative distance between the stable combustion chamber and the external slagging prevention air nozzle (L2 = 0.1 - 0.3De), and ensuring a certain velocity of the internal and external slagging prevention air (u1 = 0 m / s; u2 = 20 - 25 m / s), a large and stable central recirculation zone is formed (0.8De < D < 2De; 2.5De < L < 4De). The temperature at the outlet of the stable combustion chamber is 1100 - 1200 °C. At this time, the amount of high-temperature flue gas entrained by the recirculation zone is large, which can ensure the timely ignition of the pulverized coal. And the pulverized coal will not slag and melt in the pre-combustion chamber, effectively preventing slagging. The starting position of the recirculation zone is relatively close to the burner nozzle (0.2De < a < 0.3De), and the pulverized coal is ignited in time.

[0042] At high load, by shortening the pull rod (1.0De-2.0De), the external anti-slagging wind is controlled to mix into the stable combustion chamber at the front position, and combined with the opening adjustment of the internal and external anti-slagging wind electric regulating doors, the wind speed of the external anti-slagging wind is controlled at 35-65m / s, and the wind speed of the internal anti-slagging wind is controlled at 30-60m / s. While reducing the outlet temperature of the stable combustion chamber, the rotating external anti-slagging wind is stirred and mixed, which increases the mixing degree between the fuel particles and the airflow, and supplements the oxygen required by the fuel, which is conducive to high-load burnout. The outlet temperature of the stable combustion chamber is maintained at 700-900℃, and the anti-slagging wind rate is 20%-30%.

[0043] Wind speed measuring devices and temperature sensors are respectively set at the inner and outer anti-slagging air ducts, and the wind speed of the anti-slagging air in the inner and outer anti-slagging air ducts can be adjusted in real time by adjusting the opening of the inner anti-slagging air electric regulating door and the outer anti-slagging air electric regulating door. The wind temperature of the anti-slagging air in the inner and outer anti-slagging air ducts can be adjusted in real time by adjusting the opening of the cold primary air electric regulating door and the hot primary air electric regulating door. At low load, in order to ensure the stable combustion effect, the anti-slagging air volume inside and outside is reduced as much as possible, and the anti-slagging air temperature is increased to maintain at 200-250℃; at high load, in order to prevent high-temperature slagging, the anti-slagging air volume inside and outside is increased as much as possible, and the anti-slagging air temperature is reduced to maintain at 60-120℃. When the unit load changes, the temperature, wind speed and make-up air volume can be adjusted in time and accurately to ensure the stable operation of the system and improve the operation flexibility. According to the different slagging of coal types, the video fire detection device and temperature sensor set on the adjustable stable combustion chamber can detect the coking situation in the stable combustion chamber in real time. Through the above combination, the anti-slagging air system can quickly adjust the operating parameters according to the changes in coal types, and enhance the system's adaptability to coal types. It broadens the adaptability of coal types, reduces the fuel cost of units participating in deep peak regulation, and improves the combustion stability of power station boilers.

[0044] 5. Meet the momentum required by the internal and external anti-slagging wind, effectively improving the anti-coking effect;

[0045] Based on the invention of the coordinated combustion of direct current burners and swirl burners, when the unit is deeply peak-shifted, the amount of fuel entering the furnace is small, the amount of air required for combustion is also small, and the primary and secondary air volumes sent to the furnace are reduced accordingly. During deep peak-shifting, generally two or three coal mills are maintained in operation. Since the primary air needs to carry coal powder into the furnace for combustion, there is a minimum requirement for the primary wind speed. As the load of the unit decreases, the primary air volume will no longer decrease after it drops to a certain value. Reducing the total air volume entering the furnace requires reducing the secondary air volume. Therefore, as the load decreases, the wind pressure of the secondary wind box decreases accordingly. When the 350MW boiler is at full load, the secondary wind box pressure is about 600Pa. When the load is 14MW (40% of the rated load), the secondary wind box pressure is only about 80Pa. At this time, the secondary wind box pressure is too small. At present, most of the anti-slagging wind technologies use the secondary air in the secondary wind box of the burner as the wind source, while the secondary air pressure in the power plant boiler is relatively low, and the wind speed of the internal anti-slagging wind is too low to play the role of sweeping the inner wall of the stable combustion chamber to clean the ash. Due to the insufficient rigidity of the airflow, the penetration depth of the internal anti-slagging wind cannot reach the outlet. At the same time, the air volume of the internal anti-slagging wind (accounting for 5%-10% of the total air volume of the stable combustion chamber) is usually small. If the anti-slagging wind volume is increased (more than 10%), it will affect the stability of the flame in the stable combustion chamber. Therefore, in order to ensure the stability of the flame and have a certain sweeping ability, a high-speed airflow needs to be introduced into a small cross-sectional area, which leads to large resistance in the channel. Using the secondary air in the secondary wind box as the wind source, it is impossible to increase enough pressure head to provide power for the internal anti-slagging wind. The coordinated combustion system of the DC burner and the swirl burner relies on the induced effect of the DC primary air and the DC secondary air of the DC burner, and coordinates the combustion stabilization cavity of the swirl burner and the secondary air in the swirl, so that a central reflow zone is formed in the center of the swirl burner as a stable ignition heat source to heat the high-concentration coal powder. At the same time, the flame formed by the combustion of the swirl burner ignites the primary air powder flame of the DC burner. Therefore, the distance between the DC primary air nozzle and the self-service combustion stabilization burner is small (the gap is about 50mm). At the same time, the two sides of the self-service combustion stabilization burner are water-cooled walls. In order to ensure that the water-cooled walls are not modified and the coordinated combustion of the DC burner and the swirl burner is not affected, the gap between the external anti-slagging air nozzle (16) and the combustion stabilization cavity sleeve (15) is 10mm-30mm. Anti-slagging air blades are built in, so the resistance of the external anti-slagging air nozzle is relatively large. The secondary air in the secondary air box is used as the wind source, and it is impossible to increase a sufficient pressure head to provide power for the external anti-slagging wind.

[0046] The present invention adopts an anti-slagging wind system, that is, the hot primary air in the hot primary air duct of the burner is used as the wind source, and an anti-slagging bellows is provided for the anti-slagging wind, which is beneficial to reducing the airflow resistance and making the airflow evenly distributed. At the same time, under low load, the hot primary air temperature is 280-350℃ and the hot primary air pressure is 7.5-9.5kpa. Such a high wind pressure can provide a high-speed airflow of 20-65m / s. On the one hand, it ensures that the rotating internal anti-slagging wind forms a strong disturbance on the inner wall of the stable combustion chamber, sweeps the inner wall of the stable combustion chamber, and plays a role in cleaning. On the other hand, the external anti-slagging wind airflow has a certain swirl intensity at the outlet of the stable combustion chamber, which increases the mixing degree between the fuel particles and the airflow. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a schematic diagram of the arrangement of the self-help combustion stabilization burner involved in this application;

[0048] Figure 2 A schematic top view of the self-help combustion stabilizing burner involved in this application;

[0049] Figure 3 This is a schematic diagram of the arrangement of the slagging prevention and combustion stabilization device described in this application;

[0050] Figure 4 for Figure 3 A partial enlarged view of the middle A;

[0051] Figure 5 This is a test schematic diagram of the slagging prevention and combustion stabilization device described in this application;

[0052] Figure 6 This is a schematic diagram of the video fire detection device described in this application;

[0053] Figure 7 This is a schematic diagram of the temperature sensor described in this application;

[0054] Figure 8 This is a schematic diagram of the process of the anti-slagging air system described in this application;

[0055] Fig. 9 This is a working principle diagram of the wind speed measuring device No. 1 described in this application;

[0056] Fig.10 This is a working principle diagram of the wind speed measuring device No. 2 described in this application;

[0057] Fig.11 This is a schematic diagram of the central recirculation area described in this application;

[0058] Fig.12 This is a schematic diagram of the structure of the combustion stabilizing device for preventing slagging and the DC air duct described in this application. DETAILED DESCRIPTION

[0059] Specific implementation method 1: Combination Figures 1 to 12 The present embodiment is described. In the present embodiment, a combustion stabilization device for preventing slagging is provided. The combustion stabilization device includes a primary air duct 1, an inner secondary air duct 3, an adjustable combustion stabilization chamber 20, an anti-slagging wind system and a plurality of inner anti-slagging wind nozzles 45. The inner secondary air duct 3 is coaxially sleeved on the outside of the primary air duct 1, and the air outlet ends of the primary air duct 1 and the inner secondary air duct 3 are both connected to the air inlet end of the adjustable combustion stabilization chamber 20. The adjustable combustion stabilization chamber 20 is installed inside the partition sleeve 7. A plurality of inner anti-slagging wind nozzles 45 are equidistantly arranged on the air inlet end of the adjustable combustion stabilization chamber 20 along the circumferential direction, and a plurality of inner anti-slagging wind nozzles 45 are arranged around the inner secondary air duct 3, each inner anti-slagging wind nozzle 45 is connected to the adjustable combustion stabilization chamber 20, the anti-slagging wind system is arranged on the outside of the partition sleeve 7, and the air outlet end of the anti-slagging wind system is connected to each inner anti-slagging wind nozzle 45 and the adjustable combustion stabilization chamber 20.

[0060] The slagging prevention and combustion stabilization device provided in this embodiment is an improvement on the self-help swirl burner 39, which is mainly used in the coordinated combustion system of the direct current burner and the swirl burner. Figure 1 and Figure 2As shown, the DC burner and swirl burner cooperative combustion system consists of a four-corner tangential pulverized coal combustion boiler 42, a DC pulverized coal burner 44 and a self-help stabilizing combustion burner 39. The DC pulverized coal burner 44 in the four-corner tangential pulverized coal combustion boiler 42 is arranged at the four corners of the furnace, and the outlet of the DC pulverized coal burner 44 is composed of a group of rectangular nozzles. The primary pulverized coal airflow and the secondary air required for combustion are sprayed into the furnace in the form of DC jets from different nozzles. The DC primary air nozzles 38 and the DC secondary air nozzles 40 are arranged alternately. The upstream adjacent corner flame is ignited at the root of the downstream DC pulverized coal burner 44 to form an actual flame zone 41, and an imaginary tangential circle 43 is formed in the center of the four-corner tangential circle pulverized coal combustion boiler. Four self-help stabilizing burners 39 are arranged at the four corners between the DC primary air nozzles 38 of the DC pulverized coal burner 44 and the DC secondary air nozzles 40 of the DC pulverized coal burner 44. Relying on the induced effect of the DC primary air and DC secondary air of the DC burner, the stabilizing combustion cavity of the self-help stabilizing burner and the secondary air in the swirl are coordinated to form a center in the center of the self-help stabilizing burner. The core recirculation zone serves as a heat source for stable ignition, heating the high-concentration coal powder. At the same time, the flame 47 formed by the combustion of the self-service stable combustion burner ignites the primary air powder flame 46 of the DC burner. The slagging-preventing stable combustion device provided in this embodiment is mainly to optimize the stable combustion chamber in the traditional self-service stable combustion burner 39. First, the traditional stable combustion chamber is optimized into an adjustable structure. The characteristic of the adjustable stable combustion chamber is that the design of the external anti-slagging air nozzle is integrated into its structure. On this basis, the internal anti-slagging air nozzle 45 is added to the adjustable stable combustion chamber. The purpose of preventing slagging on the water-cooled wall of the furnace is achieved through the coordinated design of the external anti-slagging air nozzle and the internal anti-slagging air nozzle 45 and the axial adjustment between the stable combustion chamber and the external anti-slagging air nozzle.

[0061] Specific implementation method 2: Combination Figures 1 to 12 This embodiment is described. The difference between this embodiment and the first embodiment is that an inner secondary air blade group is provided between the primary air duct 1 and the inner secondary air duct 3. The inner secondary air blade group is provided close to the adjustable combustion stabilization chamber 20. The inner secondary air blade group includes a plurality of inner secondary air blades 5. The plurality of inner secondary air blades 5 are equidistantly installed on the inner wall of the inner secondary air duct 3 along the circumferential direction. The other components and connection methods are the same as those of the first embodiment.

[0062] Specific implementation method three: Combination Figures 1 to 12This embodiment is described. The difference between this embodiment and the second embodiment is that the adjustable combustion stabilizing chamber 20 includes a combustion stabilizing chamber sleeve 15, an outer anti-slagging air nozzle 16 and a plurality of adjustment mechanisms. The outer anti-slagging air nozzle 16 is coaxially sleeved on the outside of the combustion stabilizing chamber sleeve 15. The air inlet end of the combustion stabilizing chamber sleeve 15 is a closed end. The primary air duct 1, the inner secondary air duct 3 and the plurality of inner anti-slagging air nozzles 45 are arranged on the air inlet end of the combustion stabilizing chamber sleeve 15. A plurality of adjustment mechanisms are provided between the combustion stabilizing chamber sleeve 15 and the outer anti-slagging air nozzle 16. The combustion stabilizing chamber sleeve 15 is adjusted axially along the outer anti-slagging air nozzle 16 through the plurality of adjustment mechanisms. The other components and connection methods are the same as those of the second embodiment.

[0063] Specific implementation method four: Combination Figures 1 to 12 This embodiment is described. The difference between this embodiment and the third embodiment is that an outer anti-slagging wind blade group is provided between the outer anti-slagging wind nozzle 16 and the combustion stabilization chamber sleeve 15. The outer anti-slagging wind blade group includes a plurality of outer anti-slagging wind blades 16-1, and the plurality of outer anti-slagging wind blades 16-1 are equidistantly installed in sequence along the circumferential direction on the inner wall of the outer anti-slagging wind nozzle 16. The other components and connection methods are the same as those of the third embodiment.

[0064] In combination with the description of specific implementation mode three and specific implementation mode four, the gap between the combustion stabilizing chamber sleeve 15 and the outer anti-slag wind nozzle 16 is 10mm-30mm, and outer anti-slag wind blades 16-1 are arranged between the outer anti-slag wind nozzle 16 and the combustion stabilizing chamber sleeve 15. 10-20 outer anti-slag wind blades 16-1 are arranged circumferentially, and the outer anti-slag wind blades 16-1 are welded to the outer anti-slag wind nozzle 16 and do not move with the combustion stabilizing chamber sleeve 15.

[0065] Specific implementation method five: Combination Figures 1 to 12 This embodiment is described. The difference between this embodiment and the fourth embodiment is that the adjustment mechanism includes a driving unit and a guiding unit, and the driving unit and the guiding unit are respectively arranged on both sides of the outer anti-slagging wind blade group, and the driving unit and the guiding unit are both installed on the outer wall of the combustion stabilization chamber sleeve 15;

[0066] The driving unit includes a scale 9, a tie rod 10, a bracket 13 and a connecting block 14. The bracket 13 is installed at the end of the partition sleeve 7. A tie rod sleeve is inserted in the bracket 13. An external thread is processed on the outer circumferential surface of the tie rod sleeve, and the tie rod sleeve is detachably connected to the bracket 13 through two limit nuts 11. A gasket 12 is provided between each limit nut 11 and the bracket 13. The tie rod 10 is inserted in the tie rod sleeve and slidably connected to the tie rod sleeve. Both ends of the tie rod 10 extend to the outside of the tie rod sleeve, and one end of the tie rod 10 is installed on the outer wall of the combustion stabilizing chamber sleeve 15 through the connecting block 14. The other end of the tie rod 10 is used as a driving end to pull the tie rod 10 to slide back and forth in the tie rod sleeve. The scale 9 is fixed on the bracket 13, and the length extension direction of the scale 9 is the same as the length extension direction of the tie rod 10. The driving end of the tie rod 10 is fixedly connected to the marking slider on the scale 9 through a connecting piece.

[0067] The guide unit includes a slide rail 17 and a roller assembly 18. The slide rail 17 is installed on the inner wall of the outer anti-slagging wind nozzle 16. Limiters 19 are installed at both ends of the slide rail 17. The length extension direction of the slide rail 17 is the same as the axial direction of the outer anti-slagging wind nozzle 16. The roller assembly 18 is installed on the outer wall of the stable combustion chamber sleeve 15. The stable combustion chamber sleeve 15 is slidably arranged on the slide rail 17 inside the outer anti-slagging wind nozzle 16 through the roller assembly 18. Other components and connection methods are the same as those of the specific embodiment 4.

[0068] In this embodiment, the driving unit is mainly used to drive the combustion stabilizing chamber sleeve 15 to move axially relative to the outer anti-slag wind nozzle 16. Usually, two driving units are provided. The two driving units are arranged equidistantly along the circumference on the outer wall of the combustion stabilizing chamber sleeve 15 to ensure the stability of the drive. A scale 9 is provided in the driving unit, and the relative position of the adjustable combustion stabilizing chamber sleeve 15 and the outer anti-slag wind nozzle 16 can be determined by reading. Generally, there are multiple guide units, and multiple guide units are arranged equidistantly along the circumference between the combustion stabilizing chamber sleeve 15 and the outer anti-slag wind nozzle 16 to ensure the accuracy of the movement of the combustion stabilizing chamber sleeve 15. The guide unit includes two limiters 19, and the limiters 19 are used to realize the size of the adjustable range of the combustion stabilizing chamber 20. At the same time, the design of the slide rail 17 and the roller assembly 18 can also effectively prevent the combustion stabilizing chamber sleeve 15 from colliding with the outer anti-slag wind nozzle 16 to cause wear, and also prevent the connection mechanism 14 from colliding with the outer anti-slag wind blade 16-1 to cause damage.

[0069] Specific implementation method six: Combination Figures 1 to 12The present embodiment is described. The present embodiment is different from the specific embodiment 5 in that the anti-slagging air system includes an inner anti-slagging air duct 4, a primary fan 21, an air supply fan 22, an air preheater 23, a cold primary air duct 24, a hot primary air duct 25, an anti-slagging air box 26, an outer anti-slagging air duct 27, a hot secondary air duct 28 and a secondary air box 29. The primary fan 21 and the air supply fan 22 are both arranged on one side of the air preheater 23, and the air outlet end of the primary fan 21 and the air outlet end of the air supply fan 22 are both connected to the air inlet end of the air preheater 23 through a pipeline, and the No. 1 air outlet end of the air preheater 23 is connected to the air inlet end of the anti-slagging air box 26 through the hot primary air duct 25. The anti-slagging wind box 26 has two air outlet ends. The No. 1 air outlet end of the anti-slagging wind box 26 is connected to the external anti-slagging wind nozzle 16 through the external anti-slagging wind duct 27. The No. 2 air outlet end of the anti-slagging wind box 26 is connected to multiple internal anti-slagging wind nozzles 45 through the internal anti-slagging wind duct 4. The No. 2 air outlet end of the air preheater 23 is connected to the air inlet end of the secondary wind box 29 through the hot secondary air duct 28. The air outlet end of the secondary wind box 29 is connected to the internal secondary air duct 3. The cold primary air duct 24 is connected in parallel to the air preheater 23. One end of the cold primary air duct 24 is connected to the hot primary air duct 25, and the other end of the cold primary air duct 24 is connected to the air outlet end of the primary fan 21.

[0070] A cold primary air electric regulating valve 30 is connected in series to the cold primary air duct 24;

[0071] A hot primary air electric regulating valve 31 is connected in series to the hot primary air duct 25, and the hot primary air electric regulating valve 31 is located between the connection between the cold primary air duct 24 and the hot primary air duct 25 and the air preheater 23;

[0072] An external anti-slagging air duct 27 is serially connected in the air flow direction with an external anti-slagging air electric regulating valve 32, a No. 1 temperature sensor 34 and a No. 1 wind speed measuring device 35;

[0073] The inner anti-slagging air duct 4 is connected in series along the air flow direction with the inner anti-slagging air electric regulating valve 2, the second temperature sensor 36 and the second wind speed measuring device 37;

[0074] An inner secondary air electric regulating valve 33 is connected in series to the inner secondary air duct 3. Other components and connection methods are the same as those of the fifth embodiment.

[0075] In the present embodiment, the anti-slag wind system is mainly used as a system for supplying air to the external anti-slag wind nozzle 16 and multiple internal anti-slag wind nozzles 45, wherein the No. 1 temperature sensor 34 and the No. 2 temperature sensor 36 are respectively fixed by the support tubes of the outer wall of the outer anti-slag wind duct 27 and the inner wall of the inner anti-slag wind duct 4, and some temperature measuring elements and protective sleeves are extended into the inner wall of the outer anti-slag wind duct 27 and the inner wall of the inner anti-slag wind duct 4 for temperature measurement. The temperature measuring element can transmit the temperature signal to the DSC in real time, and the temperature information in the outer anti-slag wind duct 27 and the inner anti-slag wind duct 4 is monitored by the DSC. The first wind speed measuring device 35 and the second wind speed measuring device 37 are inserted into the pipe perpendicular to the pipe wall of the outer anti-slagging wind pipe 27 and the inner anti-slagging wind pipe 4. When the outer anti-slagging wind and the inner anti-slagging wind flow, the windward side measures the total pressure, and the leeward side measures the static pressure. The total pressure and static pressure of the airflow of the outer anti-slagging wind pipe 27 and the inner anti-slagging wind pipe 4 are collected and transmitted to the wind speed sensor, and the pressure is detected at the +- end connected to the micro differential pressure transmitter. It is connected to the DCS industrial control system to display the wind speed and air volume, so as to control the wind speed to achieve the expected purpose.

[0076] Specific implementation method seven: Combination Figures 1 to 12 This embodiment is described. The difference between this embodiment and the sixth embodiment is that a video fire detection device 6 is also provided on the air inlet end of the combustion stabilization chamber sleeve 15. The video fire detection device 6 is composed of a high temperature probe, a camera system, a cooling protection device, a thruster, a power control box, an air source filter and a pressure control box, and a monitor, and is connected to the DCS system through a cable. The other components and connection methods are the same as those of the sixth embodiment.

[0077] In this embodiment, the probe and the camera system are installed horizontally. When it is necessary to shoot a picture, the thruster is controlled to extend the probe, the camera system and the cooling protection device from the connector into the combustion stabilization chamber, the camera system sends the obtained video signal to the controller, and the controller sends the received video signal to the DSC, and the slagging and flame combustion in the combustion stabilization chamber are monitored by the DSC.

[0078] Specific implementation method eight: Combination Figures 1 to 12 This embodiment is described. The difference between this embodiment and the seventh embodiment is that a plurality of cylinder wall temperature sensors 8 are installed near the outlet of the combustion stabilization chamber sleeve 15, and the plurality of cylinder wall temperature sensors 8 are arranged equidistantly in sequence along the circumference of the combustion stabilization chamber sleeve 15. The other components and connection methods are the same as those of the seventh embodiment.

[0079] In this embodiment, three cylinder wall temperature sensors 8 are usually arranged. The cylinder wall temperature sensors 8 are fixed by a support tube on the outer wall of the stable combustion chamber. Some temperature measuring elements and protective sleeves are extended into the inner wall of the stable combustion chamber to measure the temperature. The temperature measuring elements can transmit the temperature signal to the DSC in real time, and the temperature information of the cylinder wall position at the outlet of the stable combustion chamber is monitored by the DSC.

[0080] Specific implementation method nine: Combination Figures 1 to 12 This embodiment is described. The difference between this embodiment and the eighth embodiment is that the center line of the inner anti-slagging air nozzle 45 forms an angle β with the end surface of the air inlet end of the combustion stabilizing chamber sleeve 15, and the angle β ranges from 0 to 30°. The other components and connection methods are the same as those of the eighth embodiment.

[0081] In the present embodiment, the inner anti-slag wind nozzle 45 is inserted into the end face of the air inlet end of the combustion stabilizing chamber sleeve 15, the inner end of the inner anti-slag wind nozzle 45 is tightly attached to the inner cylinder wall of the combustion stabilizing chamber, the inner diameter of the inner anti-slag wind nozzle 45 is 10mm-30mm, and the distance between the center line of the inner end face of the inner anti-slag wind nozzle 45 and the inner cylinder wall of the combustion stabilizing chamber is 20-40mm.

[0082] The working principle of the combustion stabilizing device for preventing slagging described in the present application is described in conjunction with specific embodiments 1 to 9:

[0083] The pulverized coal-air mixture passes through the primary air duct 1 and enters the adjustable stable combustion chamber 20. The inner secondary air in the inner secondary air duct 3 passes through the inner secondary air blades 5 to form a rotating airflow and enters the adjustable stable combustion chamber 20. The inner anti-slagging wind passes through the inner anti-slagging wind nozzle 45 and is injected into the adjustable stable combustion chamber 20 at high speed close to the inner cylinder wall of the stable combustion chamber. The outer anti-slagging wind in the outer anti-slagging wind nozzle 16 passes through the outer anti-slagging wind blades 16-1 to form a rotating airflow with the same rotation direction as the airflow in the inner secondary air duct 3, and after mixing with the outlet airflow of the stable combustion chamber, it enters the furnace. After the direct primary air-powder airflow enters the stable combustion chamber, under the action of the rotating inner secondary airflow and the limited space of the stable combustion chamber, a stable central recirculation zone is formed in the stable combustion chamber, and the high-temperature flue gas in the suction furnace is heated and ignited by the pulverized coal airflow. The anti-slagging wind is divided into internal and external anti-slagging winds. The high-speed internal anti-slagging wind is injected from multiple internal anti-slagging wind nozzles 45 at the bottom of the stable combustion chamber at an angle of β, so that the internal anti-slagging wind forms a rotating jet. The strong disturbance formed by the rotating internal anti-slagging wind on the inner wall of the stable combustion chamber sweeps the inner wall of the stable combustion chamber, plays a role in cleaning, reduces the ash accumulation in the stable combustion chamber, and avoids slagging caused by excessive ash accumulation on the wall. The rotating external anti-slagging wind moves around the adjustable stable combustion chamber 20, mixes with the high-temperature flue gas at the outlet of the stable combustion chamber, and replenishes the air required for the coal powder to burn out.

[0084] Pull the pull rod 10 to adjust the relative position of the combustion stabilizing chamber sleeve 15 and the external anti-slag wind nozzle 16. The scale 9 on the bracket 12 is used to observe the relative position of the combustion stabilizing chamber sleeve 15 to the external anti-slag wind nozzle 16. Tighten the limit nut 11 at the required position to fix the pull rod 10 on the bracket 12, thereby fixing the distance between the combustion stabilizing chamber sleeve 15 and the external anti-slag wind nozzle 16. By controlling the relative position of the combustion stabilizing chamber sleeve 15 and the external anti-slag wind nozzle 16, the position of the external anti-slag wind mixed into the combustion stabilizing chamber is controlled to prevent slagging at the combustion stabilizing chamber outlet while supplementing the air required for coal powder burnout.

[0085] Working process of the anti-slagging air system: After the primary air is pressurized by the primary fan 21, the outlet is divided into two routes: one route passes through the cold primary air duct 24 and passes through the cold primary air electric regulating door 30, and then mixes with the cold and hot primary air of the other route after passing through the air preheater 23 and the hot primary air electric regulating door 31, and then merges into the anti-slagging wind box 26 after being fully mixed. The high-pressure and high-temperature anti-slagging air is divided into two routes through the anti-slagging wind box 26. One route enters the outer anti-slagging air duct 27 through the outer anti-slagging air electric regulating door 32, and the other route enters the inner anti-slagging air duct 4 through the inner anti-slagging air electric regulating door 2. The outer anti-slagging air electric regulating door 32 and the inner anti-slagging air electric regulating door 2 realize the control of the outer and inner anti-slagging air volumes. After being pressurized by the blower 22, the secondary air enters the air preheater 23 for heating, and enters the secondary air box 29 through the hot secondary air duct 28. The secondary air is regulated by the inner secondary air electric regulating door 33, enters the inner secondary air duct 3, passes through the inner secondary air blades 5, and finally enters the self-help stable combustion burner 39 in a rotating form.

[0086] Specific implementation method ten: Combination Figures 1 to 12 This embodiment is described. This embodiment provides a method for preventing slagging and stabilizing combustion. The specific process of the method is as follows:

[0087] First, we judge based on the softening temperature ST. When the softening temperature ST is higher than 1390℃, the coal is not easy to slag. When the softening temperature ST is lower than 1260℃, the coal is easy to slag. The coal between the two is medium slag. Therefore, different types of coal have different requirements for anti-slag wind temperature, wind speed and mixing position. This is achieved through the following steps:

[0088] For coals prone to slagging, when the boiler load is higher than 50% of the rated load, the problem of high-temperature slagging and burning in the combustion stabilization chamber needs to be considered. The specific operation is as follows: the self-service combustion stabilization burner enters the high-load anti-coking and burning mode, loosens the limit nut 11, and pulls the position of the adjustable combustion stabilization chamber 20 by pulling the tie rod 10, thereby changing the relative position of the combustion stabilization chamber sleeve 15 and the external anti-slagging air nozzle 16, so that L2 = 1.6-2.0De. When the tie rod is at the desired position, tighten the limit nut 10 to fix the tie rod. By adjusting the opening of the cold primary air electric regulating door 30 and the hot primary air electric regulating door 31, T2 = T3 = 60-120 ° C; by adjusting the opening of the inner anti-slagging wind electric regulating door 2 to more than 80%, and the opening of the outer anti-slagging wind electric regulating door 32 to more than 80%, u1 = 50-60m / s; u2 = 55-65m / s; after the above operation, the temperature of T1 is guaranteed to be 700-900 ° C. When the boiler load is lower than 50% of the rated load, a small range of reflux area is required in the stable combustion chamber to ensure stable combustion while avoiding slagging in the stable combustion chamber. The specific operation is: the self-service stable combustion burner enters the low-load stable combustion mode, loosens the limit nut 11, and pulls the position of the adjustable stable combustion chamber 20 by pulling the pull rod 10, thereby changing the relative position of the stable combustion chamber sleeve 15 and the outer anti-slagging wind nozzle 16, so that L2 = 0.6-1.0De. When the rod is at the desired position, tighten the limit nut 10 to fix the rod. By adjusting the opening of the cold primary air electric regulating door 30 and the hot primary air electric regulating door 31, T2 = T3 = 200-250 ° C; by adjusting the opening of the inner anti-slagging wind electric regulating door 2 to 40%-50% and the opening of the outer anti-slagging wind electric regulating door 32 to 40%-50%, u1 = 20-30m / s; u2 = 30-35m / s; through the above operations, the temperature of T1 is guaranteed to be 900-1000 ° C, and a small central reflow zone (0.3De <D<0.5De;1.5De<L<2.0De;0.4De<a<0.5De);

[0089] For medium slagging coal, when the boiler load is higher than 50% of the rated load, the high-temperature slagging problem in the combustion stabilization chamber needs to be considered. The specific operation is as follows: the self-service combustion stabilization burner enters the high-load anti-coking and burning mode, loosens the limit nut 11, and pulls the position of the adjustable combustion stabilization chamber 20 by pulling the pull rod 10, thereby changing the relative position of the adjustable combustion stabilization chamber sleeve 15 and the external anti-slagging air nozzle 16, so that L2 = 1.3-1.6De. When the pull rod is at the desired position, tighten the limit nut 10 to fix the pull rod. By adjusting the opening of the cold primary air electric regulating door 30 and the hot primary air electric regulating door 31, T2 = T3 = 60-120 ° C; by adjusting the opening of the inner anti-slagging wind electric regulating door 2 to 60%-80% and the opening of the outer anti-slagging wind electric regulating door 32 to 60%-80%, u1 = 40-50m / s; u2 = 45-55m / s; after the above operation, the T1 temperature is guaranteed to be T1 = 700-900 ° C. When the boiler load is lower than 50% of the rated load, a reflux zone of an appropriate range is required in the stable combustion chamber to ensure stable combustion while avoiding slagging in the stable combustion chamber. The specific operation is: the self-service stable combustion burner enters the low-load stable combustion mode, loosens the limit nut 11, and pulls the position of the adjustable stable combustion chamber 20 by pulling the pull rod 10, thereby changing the relative position of the stable combustion chamber sleeve 15 and the outer anti-slagging wind nozzle 16, so that L2 = 0.3-0.6De. When the rod is at the desired position, tighten the limit nut 10 to fix the rod. By adjusting the opening of the cold primary air electric regulating door 30 and the hot primary air electric regulating door 31, T3 = 200-250 ° C; by adjusting the opening of the inner anti-slagging wind electric regulating door 2 to 0% and the opening of the outer anti-slagging wind electric regulating door 32 to 30%-40%, u2 = 25-30m / s; through the above operation, the temperature of T1 is guaranteed to be 900-1000 ° C, and a central reflow zone (0.5De <D<0.8De;2.0De<L<2.5De;0.3De<a<0.4De);

[0090] For coals that are not prone to slagging, when the boiler load is higher than 50% of the rated load, the high-temperature slagging problem in the combustion stabilization chamber needs to be considered. The specific operation is as follows: the self-service combustion stabilization burner enters the high-load anti-coking and burning mode, loosens the limit nut 11, and pulls the position of the adjustable combustion stabilization chamber 20 by pulling the pull rod 10, thereby changing the relative position of the adjustable combustion stabilization chamber sleeve 15 and the external anti-slagging air nozzle 16, so that L2 = 1.0-1.3De. When the pull rod is at the desired position, tighten the limit nut 10 to fix the pull rod. By adjusting the opening of the cold primary air electric regulating door 30 and the hot primary air electric regulating door 31, T2=T3=60-120℃; by adjusting the opening of the inner anti-slagging wind electric regulating door 2 to 40%-60% and the opening of the outer anti-slagging wind electric regulating door 32 to 40%-60%, u1=30-40m / s; u2=35-45m / s; after the above operation, the T1 temperature is guaranteed to be T1=700-900℃. When the boiler load is lower than 50% of the rated load, a large range of reflux area is required in the stable combustion chamber to ensure low-load stable combustion. The specific operation is: the self-service stable combustion burner enters the low-load stable combustion mode, loosens the limit nut 11, and pulls the position of the adjustable stable combustion chamber 20 by pulling the pull rod 10, thereby changing the relative position of the stable combustion chamber sleeve 15 and the outer anti-slagging wind nozzle 16, so that L2=0.1-0.3De. When the rod is at the desired position, tighten the limit nut 10 to fix the rod. By adjusting the opening of the cold primary air electric regulating door 30 and the hot primary air electric regulating door 31, T3 = 200-250 ° C; by adjusting the opening of the inner anti-slagging wind electric regulating door 2 to 0% and the opening of the outer anti-slagging wind electric regulating door 32 to less than 30%, u2 = 20-25m / s; after the above operation, the temperature of T1 is guaranteed to be 900-1000 ° C, and a large-scale central reflow zone (0.8De <D<2De;2.5De<L<4De;0.2De<a<0.3De)。

[0091] In the above text, L1 is the length of the combustion stabilization chamber sleeve; L2 is the distance between the combustion stabilization chamber and the outlet of the external anti-slagging air nozzle, which can be read by a ruler, and the initial zero position is that the combustion stabilization chamber and the external anti-slagging air nozzle are flush; De is the inner secondary air diameter; L is the length of the recirculation zone, and D is the diameter of the recirculation zone; a is the distance between the burner outlet and the starting point of the recirculation zone; T1 is the average temperature measured by three temperature sensors evenly arranged around the outlet; T2 is the temperature measured by the temperature sensor arranged on the inner anti-slagging air duct; T3 is the temperature measured by the temperature sensor arranged on the outer anti-slagging air duct; u1 is the wind speed measured by the wind speed measuring device arranged on the inner anti-slagging air duct; u2 is the wind speed measured by the wind speed measuring device arranged on the outer anti-slagging air duct. The adjustment of the inner anti-slagging air opening, the adjustment of the outer anti-slagging air opening, the input of the anti-slagging air system, and the adjustable movement position of the combustion stabilization chamber can be controlled according to the measured value of the flue gas temperature in the combustion stabilization chamber and the signal transmitted by the video fire detection.

[0092] The present invention has been disclosed as above with preferred implementation cases, but it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent implementation cases with equivalent changes by using the above-disclosed structures and technical contents without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above implementation cases based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

[0093] Example:

[0094] The present application provides a combustion stabilization device and combustion stabilization method for preventing slagging, which has been applied to a 600MW subcritical pressure drum boiler. The boiler adopts a four-corner tangential combustion method, and four self-help combustion stabilization burners are arranged at the four corners between the DC primary air nozzle and the DC secondary air nozzle of the B layer of the DC pulverized coal burner in the four-corner tangential furnace. Powder is taken from the branch pipeline of the B layer pulverizing system, and air is taken from the secondary air box. After the transformation, the minimum stable combustion load of the boiler without oil injection is 20%. When burning the type of coal actually burned at present, the average NOx emission concentration is about 385-400mg / Nm 3 After one year of stable operation, when the furnace was shut down for maintenance, it was found that there were obvious coke blocks or coke slag in the B / C burner area. Large coke blocks often fall into the furnace, and the slag remover is often stuck by the coke slag or the chain is directly hit by the large coke blocks; coke blocks often block and sinter in the stable combustion chamber, which seriously affects the combustion stability in the furnace and the safety of the powder pipe operation. In order to detect and deal with coking in time, the furnace is often shut down for maintenance, which increases the workload of operators to clean and remove ash and slag. According to the method described in this patent, a stable combustion method to prevent slagging is designed, and a model of the self-service stable combustion burner is established in the laboratory. The size ratio of the model burner to the prototype burner is 1:4. A single-phase cold modeling test system is built, and the burner outlet flow field is measured. The test results are as follows:

[0095] 1) The relative position of the combustion chamber outlet and the external anti-slagging wind nozzle is 0.6-1.0De. The external anti-slagging wind speed is 30-35m / s, and the internal anti-slagging wind speed is 20-30m / s. Under this condition, a small-scale stable central reflow zone is formed, the reflow zone diameter D = 0.3-0.5De, the reflow zone length L = 1.5-2.0De, and the distance between the burner outlet and the starting point of the reflow zone is 0.4De<a<0.5De.

[0096] 2) The relative position of the combustion chamber outlet and the external anti-slagging wind nozzle is 0.3-0.6De. The wind speed of the external anti-slagging wind is 25-30m / s. Under this condition, a stable central reflow zone with an appropriate range is formed, the reflow zone diameter D = 0.5-0.8De, the reflow zone length L = 2.0-2.5De, and the distance between the burner outlet and the starting point of the reflow zone is 0.3De < a < 0.4De.

[0097] 3) The relative position of the combustion chamber outlet and the external anti-slagging wind nozzle is 0.1-0.3De. The wind speed of the external anti-slagging wind is 20-25m / s. Under this condition, a large-scale stable central reflow zone is formed, the reflow zone diameter D = 0.8-2.0De, the reflow zone length L = 2.5-4.0De, and the distance between the burner outlet and the starting point of the reflow zone is 0.3De < a < 0.2De.

[0098] The method described in this patent is applied to the above-mentioned 600MW subcritical pressure drum boiler, which burns a mixture of anthracite, lean coal and bituminous coal (the coal quality characteristics are similar to lean coal). The recirculation zone in the combustion chamber of the self-service combustion stabilizing burner under low load is changed according to the change of coal type, thereby meeting the requirements for stable operation of the boiler under different loads and different coal types. The specific method is: when the boiler is operating at a load of 50% or less, the adjustment of the internal and external anti-slagging air openings and the movable position of the adjustable combustion stabilizing chamber in actual operation are determined according to the cold test results (1)-(4).

[0099] A 600MW subcritical pressure drum boiler using the device and method of the present invention has a NOx emission value of 380mg / Nm after modification when burning the current coal. 3 The following improves the adaptability of coal types, solves the problem of concentrated falling of large coke blocks in the burner area of ​​the B / C layer of the boiler, reduces the hidden dangers of large fluctuations in the negative pressure of the furnace, flickering of the fire detection, and even boiler extinguishing caused by the concentrated falling of large coke blocks inside the boiler furnace, and greatly improves the safety and stability of boiler operation. At the same time, there is no slagging or burning in the stable combustion chamber of the self-service stable combustion burner, which reduces the workload of operators to clean and remove ash and slag. Considering that there is no burner burning and no fire extinguishing accidents, the annual economic benefits are increased by about 10 million yuan.

Claims

1. A combustion stabilizing device for preventing slagging, characterized in that: The combustion stabilization device comprises a primary air duct (1), an inner secondary air duct (3), an adjustable combustion stabilization chamber (20), an anti-slagging air system and a plurality of inner anti-slagging air nozzles (45); the inner secondary air duct (3) is coaxially sleeved on the outside of the primary air duct (1), and the air outlet ends of the primary air duct (1) and the inner secondary air duct (3) are both connected to the air inlet end of the adjustable combustion stabilization chamber (20); the adjustable combustion stabilization chamber (20) is installed inside the partition sleeve (7), and the plurality of Internal anti-slagging air nozzles (45) are equidistantly arranged along the circumferential direction on the air inlet end of the adjustable combustion stabilization chamber (20), and a plurality of internal anti-slagging air nozzles (45) are arranged around the internal secondary air duct (3), each internal anti-slagging air nozzle (45) is connected to the adjustable combustion stabilization chamber (20), the anti-slagging air system is arranged outside the partition sleeve (7), and the air outlet end of the anti-slagging air system is connected to each internal anti-slagging air nozzle (45) and the adjustable combustion stabilization chamber (20).

2. A combustion stabilization device for preventing slagging according to claim 1, characterized in that: An inner secondary air blade group is provided between the primary air duct (1) and the inner secondary air duct (3), the inner secondary air blade group is arranged close to the adjustable combustion stabilization chamber (20), the inner secondary air blade group includes a plurality of inner secondary air blades (5), and the plurality of inner secondary air blades (5) are installed on the inner wall of the inner secondary air duct (3) at equal intervals along the circumferential direction.

3. A combustion stabilization device for preventing slagging according to claim 2, characterized in that: The adjustable combustion stabilizing chamber (20) comprises a combustion stabilizing chamber sleeve (15), an external anti-slagging air nozzle (16) and a plurality of adjustment mechanisms, wherein the external anti-slagging air nozzle (16) is coaxially sleeved on the outside of the combustion stabilizing chamber sleeve (15), the air inlet end of the combustion stabilizing chamber sleeve (15) is a closed end, the primary air duct (1), the internal secondary air duct (3) and the plurality of internal anti-slagging air nozzles (45) are all arranged on the air inlet end of the combustion stabilizing chamber sleeve (15), a plurality of adjustment mechanisms are arranged between the combustion stabilizing chamber sleeve (15) and the external anti-slagging air nozzle (16), and the combustion stabilizing chamber sleeve (15) can be adjusted axially along the external anti-slagging air nozzle (16) through the plurality of adjustment mechanisms.

4. A combustion stabilizing device for preventing slagging according to claim 3, characterized in that: An external anti-slagging wind blade group is provided between the external anti-slagging wind nozzle (16) and the combustion stabilization chamber sleeve (15), wherein the external anti-slagging wind blade group comprises a plurality of external anti-slagging wind blades (16-1), and the plurality of external anti-slagging wind blades (16-1) are equidistantly installed in sequence along the circumferential direction on the inner wall of the external anti-slagging wind nozzle (16).

5. The combustion stabilizing device for preventing slagging according to claim 4, characterized in that: The regulating mechanism comprises a driving unit and a guiding unit, the driving unit and the guiding unit are respectively arranged on both sides of the outer anti-slagging wind blade group, and the driving unit and the guiding unit are both installed on the outer wall of the combustion stabilizing chamber sleeve (15); The driving unit comprises a scale (9), a pull rod (10), a bracket (13) and a connecting block (14); the bracket (13) is installed at the end of the partition sleeve (7); a pull rod sleeve is inserted in the bracket (13); an external thread is processed on the outer circumferential surface of the pull rod sleeve, and the pull rod sleeve is detachably connected to the bracket (13) through two limit nuts (11); a gasket (12) is provided between each limit nut (11) and the bracket (13); the pull rod (10) is inserted in the pull rod sleeve and is slidably connected to the pull rod sleeve; Both ends of the rod (10) extend to the outside of the tie rod sleeve, and one end of the tie rod (10) is installed on the outer wall of the combustion stabilization chamber sleeve (15) through a connecting block (14), and the other end of the tie rod (10) is used as a driving end to pull the tie rod (10) to slide back and forth in the tie rod sleeve. The scale (9) is fixed on the bracket (13), and the length extension direction of the scale (9) is the same as the length extension direction of the tie rod (10). The driving end of the tie rod (10) is fixedly connected to the marking slider on the scale (9) through a connecting piece; The guide unit comprises a slide rail (17) and a roller assembly (18); the slide rail (17) is mounted on the inner wall of the outer anti-slag air nozzle (16); limiters (19) are mounted on both ends of the slide rail (17); and the length extension direction of the slide rail (17) is the same as the axial direction of the outer anti-slag air nozzle (16); the roller assembly (18) is mounted on the outer wall of the combustion stabilizing chamber sleeve (15); and the combustion stabilizing chamber sleeve (15) is slidably arranged on the slide rail (17) inside the outer anti-slag air nozzle (16) through the roller assembly (18).

6. The combustion stabilization device for preventing slagging according to claim 3, characterized in that: The anti-slagging air system comprises an inner anti-slagging air duct (4), a primary air fan (21), an air supply fan (22), an air preheater (23), a cold primary air duct (24), a hot primary air duct (25), an anti-slagging air box (26), an outer anti-slagging air duct (27), a hot secondary air duct (28) and a secondary air box (29). The primary air fan (21) and the air supply fan (22) are both arranged on one side of the air preheater (23), and the air outlet end of the primary air fan (21) and the air outlet end of the air supply fan (22) are both connected to the air inlet end of the air preheater (23) through a pipeline. The No. 1 air outlet end of the air preheater (23) is connected to the air inlet end of the anti-slagging air box (26) through the hot primary air duct (25). The anti-slagging air box (26) has two The air outlet end is connected to the air preheater (23) through the hot secondary air duct (28), the air outlet end of the secondary air box (29) is connected to the inner secondary air duct (3), the cold primary air duct (24) is connected to the air outlet end of the primary fan (21); one end of the cold primary air duct (24) is connected to the hot primary air duct (25), and the other end of the cold primary air duct (24) is connected to the air outlet end of the primary fan (21); A cold primary air electric regulating valve (30) is connected in series to the cold primary air duct (24); A hot primary air electric regulating valve (31) is connected in series to the hot primary air duct (25), and the hot primary air electric regulating valve (31) is located between the connection between the cold primary air duct (24) and the hot primary air duct (25) and the air preheater (23); An external anti-slagging air duct (27) is serially connected in sequence along the air flow direction of the air, along with an external anti-slagging air electric regulating valve (32), a No. 1 temperature sensor (34) and a No. 1 wind speed measuring device (35); An inner anti-slagging air duct (4) is serially connected in sequence along the air flow direction of the air, along with an inner anti-slagging air electric regulating valve (2), a second temperature sensor (36) and a second wind speed measuring device (37); An inner secondary air electric regulating valve (33) is connected in series to the inner secondary air duct (3).

7. The combustion stabilization device for preventing slagging according to claim 3, characterized in that: A video fire detection device (6) is also provided on the air inlet end of the combustion stabilization chamber sleeve (15). The video fire detection device (6) is composed of a high temperature probe, a camera system, a cooling protection device, a thruster, a power supply control box, an air source filter and pressure control box, and a monitor, and is connected to the DCS system through a cable.

8. The combustion stabilization device for preventing slagging according to claim 3, characterized in that: A plurality of cylinder wall temperature sensors (8) are installed near the outlet of the combustion stabilization chamber sleeve (15), and the plurality of cylinder wall temperature sensors (8) are arranged in sequence and at equal intervals along the circumference of the combustion stabilization chamber sleeve (15).

9. The combustion stabilizing device for preventing slagging according to claim 3, characterized in that: The center line of the internal anti-slagging air nozzle (45) forms an angle β with the end surface of the air inlet end of the combustion stabilizing chamber sleeve (15), and the angle β has a value range of 0 to 30 degrees.

10. A combustion stabilization method using the combustion stabilization device for preventing slagging according to any one of claims 1 to 9, characterized in that: The specific process of the method is as follows: When the boiler load is higher than 50% of the rated load, it is necessary to consider the problem of high-temperature slagging in the combustion stabilization chamber. The specific operation is as follows: the self-service combustion stabilization burner (39) enters the high-load anti-coking and burning mode, loosens the limit nut (11), and pulls the position of the adjustable combustion stabilization chamber (20) by pulling the pull rod (10), thereby changing the relative position of the adjustable combustion stabilization chamber sleeve (15) and the external anti-slagging air nozzle (16) so that L2 = 1.0-2.0De, and tightens the limit nut (10) when the pull rod is at the desired position. ), fix the pull rod, adjust the opening of the cold primary air electric regulating valve (30) and the hot primary air electric regulating valve (31) to make T2 = T3 = 60-120°C; adjust the opening of the inner anti-slagging air electric regulating valve (2) to 40%-100% and the opening of the outer anti-slagging air electric regulating valve (32) to 40%-100%, so that u1 = 30-60m / s; u2 = 35-65m / s; after the above operations, ensure that the temperature T1 is 700-900°C; When the boiler load is lower than 50% of the rated load (20%-50% of the rated load), a small reflow zone is required in the combustion stabilization chamber to ensure stable combustion while avoiding slagging in the combustion stabilization chamber. The specific operation is as follows: the self-service combustion stabilization burner enters the low-load combustion stabilization mode, loosens the limit nut (11), and pulls the position of the adjustable combustion stabilization chamber (20) by pulling the pull rod (10), thereby changing the relative position of the combustion stabilization chamber sleeve (15) and the external anti-slagging air nozzle (16) so that L2=0.1-1.0De, and tightens the limit nut (11) when the pull rod is at the required position. 10) Fix the pull rod, and adjust the opening of the cold primary air electric regulating valve (30) and the hot primary air electric regulating valve (31) to make T2 = T3 = 200-250°C; adjust the opening of the inner anti-slagging air electric regulating valve (2) to 0% and the opening of the outer anti-slagging air electric regulating valve (32) to 0%-50%, so that u1 = 20-30m / s; u2 = 20-35m / s; through the above operations, ensure that the temperature T1 is between 900-1000°C, and form a central reflow zone (0.3De <D<2De;1.5De<L<4De;0.2De<a<0.5De)。

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