A smokeless coal combustion flame boiler apparatus

Abstract

The utility model relates to flame boiler device field discloses a kind of anthracite combustion flame boiler device, including hearth and the upper hearth being communicated with hearth, hearth includes sequentially connected upper combustion chamber, middle combustion chamber and lower combustion chamber, and the upper hearth outer wall is symmetrically equipped with burnout air inlet, and burnout air inlet is connected with burnout air tank, and the upper combustion chamber outer wall is symmetrically equipped with spout, and the included angle between the incidence angle of spout and vertical direction is set to 12 °-17 °, and the middle combustion chamber outer wall is symmetrically equipped with several lack of gas wind inlets, and the middle combustion chamber outer wall is symmetrically equipped with several grading air inlets, and grading air inlet is connected with grading air tank, and the excess air coefficient in hearth is set to 1.2, can maintain hearth temperature field uniform and stable, avoid local overtemperature or low temperature, cooperate with grading air and burnout air can effectively prevent water-cooling wall and upper hearth heating surface slagging, reduce slagging maintenance frequency, prolong equipment service life.

Description

Technical Field

[0001] This utility model relates to the field of flame boiler devices, specifically to a smokeless coal combustion flame boiler device. Background Technology

[0002] W-flame boiler is a power plant boiler mainly used for burning anthracite, lean coal and other low volatile coal types. The boiler burner is one of the key equipment of the combustion device. It ensures that the air used for coal combustion can be fully mixed when it enters the boiler at a certain speed, and can ignite and burn stably in a timely manner. The prior art discloses a concentrated double-adjustable-air swirl burner and combustion method (Publication No.: CN104390214A). Its components include a deflector pipe connected to an inlet elbow, the inlet elbow connected to a concentrator, the concentrator connected to a combustion chamber, and the combustion chamber connected to an air regulator. The air regulator contains an air regulating sleeve, the inlet elbow contains a tongue-shaped plate, and the concentrator contains a waste gas pipe connected to the tongue-shaped plate. The prior art burner uses a staged air supply method, which is beneficial for the ignition and stable combustion of pulverized coal, enhances the burner's adaptability to changes in the medium, and also helps control the formation of nitrogen oxides in the flame. However, due to market factors, the quality of the coal fed into the furnace (high ash, high sulfur, low calorific value coal) deviates from the design coal type. Power plants are gradually adopting mixed coal combustion technology to reduce production costs, leading to the tendency for NOx formation in W-flame boilers during operation. X To address the problems of high emissions, low combustion efficiency, slagging, and uneven burning, we propose a smokeless coal combustion flame boiler device. Utility Model Content

[0003] This utility model aims to provide a smokeless coal combustion flame boiler device to address the problem that power plants using mixed coal combustion technology to reduce production costs are prone to NO emissions during the operation of W-flame boilers. X Problems include high emissions, low combustion efficiency, slagging, and uneven burning.

[0004] To achieve the above objectives, this utility model adopts the following technical solution: a smokeless coal combustion flame boiler device, comprising a furnace and an upper furnace connected to the furnace, the furnace comprising an upper combustion chamber, a middle combustion chamber, and a lower combustion chamber connected in sequence, and the upper combustion chamber being connected to the upper furnace; the cross-sections of both the upper and lower combustion chambers are configured as isosceles trapezoids, and the angle between the waist of the upper combustion chamber and the inner wall of the middle combustion chamber is set to 110°-120°, and the angle between the waist of the lower combustion chamber and the inner wall of the middle combustion chamber is set to 140°-150°. The upper furnace outer wall is symmetrically provided with burnout air inlets, which are connected to burnout air boxes. The upper combustion chamber outer wall is symmetrically provided with several nozzles that can be connected to the burner's deflector pipes, and the angle between the incident angle of the nozzles and the vertical direction is set to 12°-17°. The middle combustion chamber outer wall is symmetrically provided with several exhaust air inlets, and the burner's exhaust air pipes can be connected to the exhaust air inlets. The middle combustion chamber outer wall is symmetrically provided with several staged air inlets, which are connected to staged air boxes. The excess air coefficient in the furnace is set to 1.2.

[0005] The beneficial effects of this scheme are as follows: Both the upper and lower combustion chambers adopt isosceles trapezoidal cross sections, which can guide the flue gas to form a slow-flowing reversal channel, avoiding the pulverized coal airflow from rushing against the furnace wall too quickly or being directly discharged, thus extending the residence time of pulverized coal in the furnace. By setting the angle between the incident angle of the nozzle and the vertical direction to 12°-17°, it avoids insufficient downward rushing of pulverized coal airflow due to an excessively small incident angle, resulting in the flame being concentrated in the upper furnace and the high-temperature area being dispersed. At the same time, it also avoids the airflow deflection caused by an excessively large incident angle, forming a backflow vacuum zone, resulting in insufficient mixing of pulverized coal and high-temperature flue gas. Furthermore, it ensures that the pulverized coal airflow injected from the front and rear arches accurately converges in the middle combustion chamber, forming a symmetrical and stable W-shaped flame. The high-temperature area is concentrated in the middle of the furnace, which not only strengthens pulverized coal ignition but also avoids the flame rushing against the water-cooled wall, further improving combustion efficiency. The exhaust gas inlet is connected to the burner exhaust gas pipe, injecting 10%-15% of the separated pulverized coal (including 50% primary air) into the middle combustion chamber, avoiding premature mixing of high-concentration pulverized coal with oxygen and reducing NO in the early stage of combustion. X During the combustion phase, the staged air box replenishes oxygen through the staged air inlet, after the pulverized coal has completed ignition. Appropriate oxygen supplementation prevents "oxygen deficiency flameout" and avoids NO production caused by a high-oxygen environment in the early stages of combustion. X The surge in NO2, caused by the burnout air box supplementing a small amount of oxygen into the upper furnace through the burnout air inlet, ensures that unburned fine coal powder is fully burned without increasing NO2 in the later stages of combustion. XThe excess air coefficient is too low, which can lead to local oxygen deficiency and incomplete combustion of pulverized coal. Unburned pulverized coal accumulates on the furnace wall and easily forms slag. On the other hand, an excessively high excess air coefficient can cause the furnace temperature to be cooled by excess air, resulting in delayed ignition of pulverized coal, upward shift of the flame center, and overheating of the upper furnace heating surface. Setting the excess air coefficient to 1.2 can maintain a uniform and stable furnace temperature field, avoid local overheating or underheating, and, together with staged air and burnout air, effectively prevent slag formation on the water-cooled wall and the upper furnace heating surface, reduce the frequency of slag cleaning and maintenance, and extend the service life of the equipment.

[0006] Preferably, as an improvement, the angle between the incident angle of each exhaust air inlet and the vertical direction is set to 60°.

[0007] The beneficial effects are as follows: The exhaust gas inlet is located on the outer wall of the middle combustion chamber, which is the reversal zone of the W-shaped flame. That is, the main pulverized coal airflow delivered by the symmetrically arranged nozzles extends downwards here and then begins to revers upwards, forming a high-temperature flue gas recirculation zone. If the incident angle of the exhaust gas inlet is too large, the exhaust gas will directly impact the main pulverized coal airflow, destroying the symmetry of the W-shaped flame. If the incident angle of the exhaust gas inlet is too small, the exhaust gas will quickly sink to the lower combustion chamber, resulting in insufficient mixing with the main pulverized coal airflow and causing local pulverized coal accumulation. By setting the incident angle of the exhaust gas inlet to 60°, the exhaust gas can slowly flow in along the inner wall of the middle combustion chamber, forming a staggered mixing with the main pulverized coal airflow. This avoids airflow interference and ensures that low-concentration pulverized coal is evenly dispersed in the high-temperature recirculation zone.

[0008] Preferably, as an improvement, the angle between the incident angle of each stage air inlet and the vertical direction is set to 65°.

[0009] The beneficial effects are: setting the incident angle to 65° allows the staged air to flow slowly along the inner wall of the combustion chamber, supplementing oxygen after the main pulverized coal airflow is ignited and before it enters the burnout stage, thus avoiding a high-oxygen environment in the early stage of combustion and providing support for the continuous combustion of pulverized coal.

[0010] Preferably, as an improvement, the incident angle of the burnout air inlet is perpendicular to the outer wall of the upper furnace.

[0011] Preferably, as an improvement, the opening degree of the air regulating blades inside the burner is set to 100%, and the opening degree of the air regulating blades outside the burner is set to 50%.

[0012] The beneficial effects are as follows: The internal air regulating blades control the swirl intensity and air volume of the internal secondary air. When the internal air regulating blades are 100% open, the internal secondary air volume is sufficient and the swirl intensity is moderate, which can efficiently entrain the high-temperature flue gas in the furnace and directly act on the high-concentration coal powder airflow at the burner outlet, quickly raising the coal powder airflow temperature to the ignition point and avoiding problems such as delayed ignition and easy flameout of low-volatile anthracite. The core function of the external secondary air is to supplement oxygen for the coal powder in the middle and later stages of combustion. When the external air regulating blades are 50% open, the external secondary air volume is moderate and can be slowly and evenly mixed into the core area of ​​the flame, avoiding excessive external secondary airflow that causes the flame to be blown away by excessive airflow, or insufficient airflow that causes local oxygen deficiency and incomplete combustion.

[0013] Preferably, as an improvement, it also includes eight sets of combustion components, each set of combustion components including two burners. Each set of combustion components is symmetrically arranged at both ends of the upper combustion chamber near the nozzle, and the deflector of each burner is connected to the corresponding nozzle. The secondary air of each set of burners rotates in the same direction. The secondary air of the four sets of burners on the same side rotates clockwise, and the secondary air of the four sets of burners on the other side rotates counterclockwise. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the flame boiler device according to an embodiment of the present invention; Figure 2 This is a temperature field of the flame boiler device under different internal air regulating blade openings according to an embodiment of the present invention; Figure 3 This is a temperature field of the flame boiler device under different external air regulating blade openings according to an embodiment of the present invention; Figure 4 This is a cloud map showing the NO concentration distribution of the flame boiler in an embodiment of this utility model under different external air regulating blade openings. Detailed Implementation

[0015] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings include: furnace 1, upper furnace 2, upper combustion chamber 3, middle combustion chamber 4, lower combustion chamber 5, burnout air inlet 6, nozzle 7, exhaust gas inlet 8, and staged air inlet 9.

[0016] Example The basic implementation examples are as follows: Figures 1-4 As shown, Figure 1The illustrated anthracite combustion flame boiler device includes a furnace 1 and an upper furnace 2 connected to the furnace 1. The furnace 1 includes an upper combustion chamber 3, a middle combustion chamber 4, and a lower combustion chamber 5 connected in sequence. The upper combustion chamber 3 is connected to the upper furnace 2. The cross-sections of both the upper combustion chamber 3 and the lower combustion chamber 5 are isosceles trapezoids. The angle between the waist of the upper combustion chamber 3 and the inner wall of the middle combustion chamber 4 is set to 110°-120°, and the angle between the waist of the lower combustion chamber 5 and the inner wall of the middle combustion chamber 4 is set to 140°-150°. In this embodiment, the angle between the waist of the upper combustion chamber 3 and the inner wall of the middle combustion chamber 4 is set to 115°, and the angle between the waist of the lower combustion chamber 5 and the inner wall of the middle combustion chamber 4 is set to 145°. Several burnout air inlets 6 are symmetrically fixedly installed at both ends of the upper furnace 2, and the incident angle of each burnout air inlet 6 is perpendicular to the outer wall of the upper furnace 2. In this embodiment, eight burnout air inlets 6 are located at the same end. Each burnout air inlet 6 is connected to a burnout air box, and the burnout air box passes through the burnout air inlets 6. The upper combustion chamber 3 is horizontally supplied with burnout air. Eight nozzles 7, which can be connected to the burner's deflector duct, are symmetrically fixed at both ends of the upper combustion chamber 3. The angle between the incident angle of the nozzle 7 and the vertical direction is set to 12°-17°. In this embodiment, the angle between the incident angle of the nozzle 7 and the vertical direction is set to 15°. Several exhaust air inlets 8 are symmetrically provided at both ends of the middle combustion chamber 4. In this embodiment, there are eight exhaust air inlets 8 located at the same end. The burner's exhaust air pipe can be connected to the exhaust air inlets 8. The angle between the incident angle of each exhaust air inlet 8 and the vertical direction is set to 60°. Several staged air inlets 9 are symmetrically provided on the outer wall of the middle combustion chamber 4. In this embodiment, there are eight staged air inlets 9 located at the same end. The angle between the incident angle of each staged air inlet and the vertical direction is set to 65°. The staged air inlets 9 are connected to staged air boxes. The staged air boxes supply staged air to the middle combustion chamber 4 through the staged air inlets 9.

[0017] It also includes eight combustion assemblies, each consisting of two burners. The burners are configured as concentrated EI-XCL dual-adjustable swirl burners. Each combustion assembly is symmetrically located at both ends of the upper combustion chamber 3 near the nozzle 7, and the deflector ducts of each burner are connected to the corresponding nozzle 7. The secondary air rotation direction of each burner is the same. The secondary air of the four burners on the front side rotates clockwise, and the secondary air of the four burners on the rear side rotates counterclockwise. The wind speeds corresponding to the inner and outer air-adjusting blades of each burner at different openings are shown in the table below:

[0018] like Figure 2The temperature field of the flame boiler shown is under different internal air regulating blade openings. It can be seen intuitively that when the internal air regulating blade opening is set to 100%, a strong swirling effect can be generated. Under this opening, the high-temperature area near the burner nozzle 7 inside the furnace 1 is more reasonably distributed, which is conducive to the entrainment of high-temperature flue gas in the furnace 1. For anthracite with low volatile matter, this can quickly increase the temperature of the pulverized coal airflow, enabling it to reach the ignition point and solving the problem of difficult ignition of anthracite.

[0019] like Figure 3 The temperature field of the flame boiler shown is under different external air regulating blade openings. It can be seen intuitively that when the external air regulating blade opening is 50%, the airflow distribution in the furnace 1 is relatively stable. There will be no flame deflection or airflow turbulence caused by excessively fast or slow external secondary air velocity. This ensures the stable formation of the W-shaped flame and avoids unstable combustion caused by airflow problems, such as flame shaking or extinguishing, thus ensuring the stable operation of the flame boiler.

[0020] like Figure 4 The NO concentration distribution cloud map of the flame boiler under different external air regulating blade openings shows that when the external air regulating blade opening is 50%, the NO concentration distribution in furnace 1 is relatively uniform and the overall concentration is low. This indicates that when the external air regulating blade opening is 50%, the core flame temperature can be stabilized within the optimal combustion temperature range of anthracite, which satisfies the high-temperature environment required for complete combustion and avoids excessive NO production due to local overheating.

[0021] Therefore, in this embodiment, the opening degree of the internal air regulating blades of each burner is set to 100%, the opening degree of the external air regulating blades of each burner is set to 50%, the corresponding internal secondary air velocity is 16.15 m / s, the external secondary air velocity is 8.07 m / s, and the excess air coefficient in the furnace 1 is set to 1.2.

[0022] Both the upper combustion chamber 3 and the lower combustion chamber 5 adopt an isosceles trapezoidal cross section, which can guide the flue gas to form a slow-flowing reversal channel, avoiding the pulverized coal airflow from rushing against the furnace wall too quickly or being directly discharged, and extending the residence time of pulverized coal in the furnace 1. By setting the angle between the incident angle of the nozzle 7 and the vertical direction to 15°, it avoids the pulverized coal airflow from being insufficiently downward due to an incident angle that is too small, resulting in the flame being concentrated in the upper furnace 2 and the high-temperature area being dispersed. At the same time, it also avoids the airflow from being deflected due to an incident angle that is too large, forming a backflow vacuum zone, and the pulverized coal and high-temperature flue gas not being mixed sufficiently. The angle range of 12°-17° can ensure that the pulverized coal airflow injected from the front and rear arches accurately converges in the middle combustion chamber 4, forming a symmetrical and stable W-shaped flame. The high-temperature area is concentrated in the middle of the furnace 1, which not only strengthens the pulverized coal ignition, but also avoids the flame rushing against the water-cooled wall, further improving the combustion efficiency. The exhaust gas inlet 8 is connected to the burner exhaust gas pipe, which injects 10%-15% of the separated pulverized coal into the middle combustion chamber 4, avoiding the premature mixing of high-concentration pulverized coal with oxygen and reducing NO in the early stage of combustion.X During the combustion of pulverized coal, the staged air box replenishes oxygen through the staged air inlet 9. At this point, the pulverized coal has completed ignition. Appropriate oxygen supplementation can prevent flameout due to oxygen deficiency and also avoid NO production caused by the high oxygen environment in the early stages of combustion. X The surge in NO2, caused by the burnout air box supplementing a small amount of oxygen into the upper furnace 2 through the burnout air inlet 6, ensures that unburned fine coal powder is fully burned without increasing NO2 in the later stages of combustion. X Production volume. The exhaust gas inlet 8 is located on the outer wall of the middle combustion chamber 4, which is the reversal zone of the W-shaped flame. That is, the main pulverized coal airflow delivered by the symmetrically arranged nozzles 7 extends downward and then begins to reversal upward, forming a high-temperature flue gas recirculation zone. If the incident angle of the exhaust gas inlet 8 is too large, the exhaust gas will directly impact the main pulverized coal airflow, destroying the symmetry of the W-shaped flame. If the incident angle of the exhaust gas inlet 8 is too small, the exhaust gas will quickly sink to the lower combustion chamber 5, resulting in insufficient mixing with the main pulverized coal airflow and causing local pulverized coal accumulation. By setting the incident angle of the exhaust gas inlet 8 to 60°, the exhaust gas can slowly flow in along the inner wall of the middle combustion chamber 4, forming a staggered mixing with the main pulverized coal airflow. This avoids airflow interference and ensures that low-concentration pulverized coal is evenly dispersed in the high-temperature recirculation zone.

[0023] The specific implementation process is as follows: Coal from three mining sites—Daxinan Mining, Jingkai Nuoda Xing'an, and Aneng—is blended in a 1:1:1 mass ratio to form a mixed coal with a calorific value of approximately 3537 kcal / kg. This blended coal exhibits high combustion efficiency, meeting the power plant's current operating conditions while also utilizing low-quality coal. After blending, the mixed coal is fed into the coal mill at a mass flow rate of 90.7 t / h, maintaining an excess air coefficient of 1.2. The blower is adjusted to achieve a total air volume of 1031 km³. 3 / h, the burnout air box horizontally delivers burnout air to the upper furnace 2 through the burnout air inlet 6, the exhaust air box sends exhaust air into the middle combustion chamber 4 at an incident angle of 60° through the exhaust air inlet 8, the staged air box sends staged air into the middle combustion chamber 4 at an incident angle of 65° through the staged air inlet 9, and the burner enters the furnace 1 through the nozzle 7 at an incident angle of 15°. Then, while keeping the air volume of the burnout air inlet 6, exhaust air inlet 8, staged air inlet 9 and nozzle 7 constant, the total air volume entering the internal and external air regulating channels of the burner remains constant. The opening of the internal air regulating blades of the burner is set to 100%, and the opening of the external air regulating blades of the burner is set to 50%.

[0024] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A smokeless coal combustion flame boiler apparatus, characterized by: The furnace includes a furnace chamber and an upper furnace chamber connected to the furnace chamber. The furnace chamber includes an upper combustion chamber, a middle combustion chamber, and a lower combustion chamber connected in sequence. The upper combustion chamber is connected to the upper furnace chamber. The cross-sections of the upper and lower combustion chambers are both set as isosceles trapezoids. The angle between the waist of the upper combustion chamber and the inner wall of the middle combustion chamber is set to 110°-120°, and the angle between the waist of the lower combustion chamber and the inner wall of the middle combustion chamber is set to 140°-150°. The outer wall of the upper furnace chamber is symmetrically provided with burnout air inlets, which are connected to burnout air boxes. The outer wall of the upper combustion chamber is symmetrically provided with several nozzles that can be connected to the burner's deflector pipes. The angle between the incident angle of the nozzles and the vertical direction is set to 12°-17°. The outer wall of the middle combustion chamber is symmetrically provided with several exhaust air inlets, which can be connected to the burner's exhaust air pipes. The outer wall of the middle combustion chamber is symmetrically provided with several staged air inlets, which are connected to staged air boxes. The excess air coefficient in the furnace chamber is set to 1.

2.

2. A bituminous coal fired flame boiler apparatus as claimed in claim 1 wherein: The angle between the incident angle of each exhaust air inlet and the vertical direction is set to 60°.

3. A bituminous coal fired flame boiler apparatus as claimed in claim 2 wherein: The angle between the incident angle of each graded air inlet and the vertical direction is set to 65°.

4. A bituminous coal fired flame boiler apparatus as claimed in claim 3 wherein: The angle of incidence of the burnout air inlet is perpendicular to the outer wall of the upper furnace.

5. A bituminous coal fired flame boiler apparatus as claimed in claim 4 wherein: The opening degree of the air regulating blades inside the burner is set to 100%, and the opening degree of the air regulating blades outside the burner is set to 50%.

6. A bituminous coal fired flame boiler apparatus as claimed in claim 5 wherein: It also includes eight sets of combustion components, each set of combustion components includes two burners. Each set of combustion components is symmetrically arranged at both ends of the upper combustion chamber near the nozzle, and the deflector of each burner is connected to the corresponding nozzle. The secondary air of each set of burners rotates in the same direction. The secondary air of the four sets of burners on the same side rotates clockwise, and the secondary air of the four sets of burners on the other side rotates counterclockwise.

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