Ammonia-doped multi-channel pulverized coal burner

Abstract

The application discloses a multi-channel pulverized coal burner with ammonia doping, relates to the field of pulverized coal combustion, and comprises a central channel, a primary air pipe is fixed on the central channel, a secondary air pipe is fixed on the primary air pipe, a tertiary air pipe is fixed on the secondary air pipe, a plurality of circumferentially distributed swirl vanes are fixed between the central channel and the primary air pipe, the swirl vanes are located at one end of the primary air pipe, a pulverized coal auxiliary mixing mechanism is arranged between the primary air pipe and the central channel, and a multi-angle ammonia doping mechanism is arranged between the primary air pipe and the secondary air pipe. The multi-angle ammonia doping mechanism is arranged between the primary air pipe and the secondary air pipe, ammonia gas mixed with secondary air is sprayed out of the multi-angle ammonia doping mechanism, thereby enabling the ammonia-doped secondary air to be accurately sprayed, and enabling the secondary air and the ammonia gas to enter flame zones in different combustion stages of the pulverized coal, so that accurate ammonia spraying for different coal quantities is realized.

Description

Technical Field

[0001] This application relates to the field of pulverized coal combustion, and in particular to ammonia-infused multi-channel pulverized coal burners. Background Technology

[0002] With the continuous increase in energy demand, coal, as an important energy resource, still occupies an important position in the energy structure. Pulverized coal combustion, as a common way of utilizing coal, has the advantages of high combustion efficiency and easy control, and is widely used in power generation, industrial boilers and other fields. However, pulverized coal combustion produces a large amount of pollutants such as nitrogen oxides (NOx), which cause serious environmental pollution. With the continuous and in-depth research on combustion technology, it has been gradually recognized that adding an appropriate amount of ammonia during pulverized coal combustion can effectively reduce the generation of nitrogen oxides. Ammonia can react chemically with nitrogen oxides during combustion, reducing them to nitrogen and water, thereby reducing nitrogen oxide emissions.

[0003] Multi-channel pulverized coal burners are advanced combustion devices widely used in rotary kilns and combustion furnaces in industries such as building materials, metallurgy, chemicals, and power. Their main technical principle is to achieve efficient mixing and combustion of pulverized coal and air through a multi-channel design. These burners typically consist of an internal swirl channel, a middle coal flow channel, an external axial flow channel, and an outermost cooling air channel. Pulverized coal is ejected from the multi-channel burner for combustion, while the external axial flow channel delivers high-pressure air from the channel, causing the local outlet air velocity to approach the wind speed. Under the entrainment effect of this high-speed airflow, a large amount of secondary air enters the combustion zone, significantly increasing the combustion speed and temperature of the pulverized coal.

[0004] When the burner sprays out the secondary air, the spray angle of the secondary air is not restricted. The secondary air mixed with ammonia comes into direct contact with the primary air carrying coal dust. It is impossible to accurately control the amount and location of ammonia incorporation according to different combustion stages and coal consumption, resulting in unsatisfactory ammonia incorporation effect. Utility Model Content

[0005] The purpose of this application is to address the problem mentioned in the background technology that the secondary air ejection angle is not limited, the ammonia-infused secondary air directly contacts the primary air carrying pulverized coal, and it is impossible to accurately control the amount and location of ammonia infusion according to different combustion stages and coal consumption, resulting in unsatisfactory ammonia infusion effect. This application provides an ammonia-infused multi-channel pulverized coal burner.

[0006] To achieve the above objectives, this application specifically adopts the following technical solution: Ammonia-infused multi-channel pulverized coal burner includes a central channel, a primary air duct fixed to the central channel, a secondary air duct fixed to the primary air duct, a tertiary air duct fixed to the secondary air duct, a plurality of circumferentially distributed swirl vanes fixed to the central channel and the primary air duct, the swirl vanes being located at one end of the primary air duct, a pulverized coal auxiliary mixing mechanism being provided between the primary air duct and the central channel, and a multi-angle ammonia infusion mechanism being provided between the primary air duct and the secondary air duct.

[0007] By adopting the above technical solution, a multi-angle ammonia mixing mechanism is set between the primary air duct and the secondary air duct, allowing the secondary air mixed with ammonia to be sprayed out from the multi-angle ammonia mixing mechanism. This enables the ammonia-mixed secondary air to be precisely injected, allowing the secondary air and ammonia to enter the flame zone of different combustion stages of pulverized coal, thus achieving precise ammonia injection for different coal burning amounts.

[0008] Furthermore, the multi-angle ammonia blending mechanism includes a support ring disposed between the primary air duct and the secondary air duct. The support ring is fixedly connected to both the primary air duct and the secondary air duct. The support ring is provided with a plurality of air nozzles and a plurality of air holes. The air nozzles correspond to the air nozzles. An angle adjustment component is disposed between the air nozzles and the support ring.

[0009] By adopting the above technical solution, the angle adjustment component drives the air nozzle, which changes the angle of the air nozzle on the support ring. Then, the ammonia-infused secondary air is sprayed out from the air nozzle with the changed angle, so that the ammonia-infused secondary air can be accurately injected, allowing the secondary air and ammonia to enter the flame zone of different combustion stages of pulverized coal, thus achieving precise ammonia injection for different coal consumption.

[0010] Furthermore, the angle adjustment component includes a support ball disposed in the air outlet, the support ball being rotatably connected to the support ring, the support ball having a through hole, the air outlet being fixedly connected to the support ball, and the air outlet corresponding to the through hole on the support ball.

[0011] By adopting the above technical solution, the support ball drives the air nozzle to rotate on the support ring, thereby making it easy to adjust the angle of the air nozzle on the support ring.

[0012] Furthermore, a fixing bolt is provided on one side of the support ball. The fixing bolt passes through the secondary air duct and the tertiary air duct. The fixing bolt is threadedly connected to the tertiary air duct. One end of the fixing bolt abuts against the support ball.

[0013] By adopting the above technical solution, after the support ball changes angle, the fixing bolts are used to abut against the support ball, which makes it easy to fix the support ball and make it easy to fix the angle of the air nozzle.

[0014] Furthermore, the pulverized coal auxiliary mixing mechanism includes a mixing sleeve disposed between the primary air duct and the central channel. The mixing sleeve has several circumferentially distributed air inlets at the end away from the swirl vane and several circumferentially distributed air outlets at the end near the swirl vane. The air inlets and air outlets are connected. A rotating component is disposed between the mixing sleeve and the primary air duct and the central channel.

[0015] By adopting the above technical solution, the primary air carrying coal powder enters from the air inlet and is then sprayed out from the air outlet. Under the compression of the connecting channel between the air inlet and the air outlet, the flow rate of the primary air increases. At the same time, the primary air blows the rotating component, which drives the mixing sleeve to rotate. Thus, under the high-speed blowing of the primary air, the primary air and coal powder are further mixed, improving the uniformity of the coal powder sprayed out by the primary air.

[0016] Furthermore, the rotating assembly includes a rotating ring fixed on the mixing sleeve, and a plurality of circumferentially distributed rotating blades are fixed on the rotating ring.

[0017] By adopting the above technical solution, the primary air blows the rotating blade, which drives the rotating ring one, which in turn drives the mixing sleeve, thus making it easy to rotate the mixing sleeve.

[0018] Furthermore, a second rotating ring is provided at the end of the mixing sleeve away from the first rotating ring. The second rotating ring is fixedly connected to the primary air duct and rotatably connected to the mixing sleeve. Several rotating balls are rotatably connected between the second rotating ring and the mixing sleeve.

[0019] By adopting the above technical solution, the mixing sleeve rotates on the rotating balls on the rotating ring two, thereby enabling the mixing sleeve to rotate stably under support.

[0020] Furthermore, a number of auxiliary nozzles are fixed at one end of the mixing sleeve near the air outlet. The auxiliary nozzles correspond to the air outlet and are arranged at an angle.

[0021] By adopting the above technical solution, primary air is ejected from the port of the auxiliary nozzle, which is set at an angle, thereby assisting the rotation of the mixing sleeve under the recoil force of the primary air ejected from the auxiliary nozzle.

[0022] In summary, this application includes at least one of the following beneficial effects; 1. In this application, when the ammonia-blended secondary air is about to be injected from between the secondary air duct and the primary air duct, the air nozzle is rotated in advance according to the amount of pulverized coal and the feed of the primary air. The air nozzle drives the support ball, which rotates on the support ring, allowing the air nozzle to tilt to a suitable angle. The fixing bolt is then rotated, moving on the tertiary air duct and contacting the support ball, thus fixing and limiting the support ball and fixing the direction of the air nozzle. After the ammonia-blended secondary air reaches the position of the support ring, it passes through the through hole of the support ball and enters the air nozzle through the through hole, and then is ejected from the air nozzle. This allows the ammonia-blended secondary air to be ejected along the direction of the air nozzle, achieving the goal of precise injection of ammonia-blended secondary air and allowing the secondary air and ammonia to enter the flame zone of different combustion stages of pulverized coal, thus achieving the purpose of precise ammonia injection for different coal quantities.

[0023] 2. In this application, just before the primary air and pulverized coal are ejected, the primary air, carrying pulverized coal, is blown in from the inlet of the mixing sleeve and then out from the outlet. The diameter of the inlet is larger than that of the outlet, while the diameter of the middle part of the connecting channel is smaller than that of both the inlet and outlet. The connecting channel between the inlet and outlet first narrows and then expands, causing the primary air carrying pulverized coal to be compressed when it enters from the inlet, increasing the flow velocity of the primary air. When passing through the connecting channel between the inlet and outlet, the pressure increases as the primary air carrying pulverized coal is ejected from the auxiliary nozzle at the outlet due to the flow velocity and the shape of the connecting channel. Under the recoil force of the primary air ejected from the auxiliary nozzle and the action of the rotating blades driven by the primary air, the mixing sleeve rotates under the support of the rotating ring II. This achieves the purpose of further mixing the primary air and pulverized coal under the blowing of the primary air, thereby improving the uniformity of the pulverized coal ejected by the primary air. Attached Figure Description

[0024] Figure 1 This is a first three-dimensional structural schematic diagram of the ammonia-infused multi-channel pulverized coal burner in this application; Figure 2 This is a schematic diagram of the internal structure of the ammonia-infused multi-channel pulverized coal burner in this application; Figure 3 This application Figure 2 Enlarged view of point A in the middle; Figure 4 This is a partial structural schematic diagram of the pulverized coal auxiliary mixing mechanism in this application.

[0025] Explanation of reference numerals in the attached figures: 1. Central channel; 2. Primary air duct; 3. Secondary air duct; 4. Tertiary air duct; 5. Swirl vane; 6. Coal powder auxiliary mixing mechanism; 61. Mixing sleeve; 62. Air inlet; 63. Air outlet; 64. Rotating assembly; 641. Rotating ring one; 642. Rotating blade; 643. Rotating ring two; 644. Rotating ball; 645. Auxiliary nozzle; 7. Multi-angle ammonia blending mechanism; 71. Support ring; 72. Air nozzle; 73. Air outlet; 74. Angle adjustment assembly; 741. Support ball; 742. Through hole; 743. Fixing bolt. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0027] This application discloses an ammonia-doped multi-channel pulverized coal burner.

[0028] Reference Figure 1 , Figure 2 and Figure 3 Ammonia-infused multi-channel pulverized coal burner includes a central channel 1, a primary air duct 2 fixed on the central channel 1, a secondary air duct 3 fixed on the primary air duct 2, a tertiary air duct 4 fixed on the secondary air duct 3, several circumferentially distributed swirl vanes 5 fixed on the central channel 1 and the primary air duct 2, the swirl vanes 5 being located at one end of the primary air duct 2, a pulverized coal auxiliary mixing mechanism 6 being provided between the primary air duct 2 and the central channel 1, and a multi-angle ammonia infusion mechanism 7 being provided between the primary air duct 2 and the secondary air duct 3.

[0029] When using this ammonia-blended multi-channel pulverized coal burner, the central channel 1 is connected to the external air-fuel pipeline, then the primary air duct 2 is connected to the external pulverized coal feeder, and the secondary air duct 3 and tertiary air duct 4 are connected to the external air supply device. During pulverized coal combustion, primary air is supplied through the primary air duct 2, and ammonia is added to the primary air. The primary air carrying pulverized coal is ejected from the primary air duct 2. The primary air carrying pulverized coal passes through the pulverized coal auxiliary mixing mechanism 6, which further mixes the pulverized coal evenly. Then, it is ejected from one end of the primary air duct 2 and mixed with the fuel and air blown out from the central channel 1. Ignition is initiated, and secondary air is supplied through secondary air duct 3. During the supply of secondary air, ammonia is added to the secondary air. The secondary air is then sprayed out from the multi-angle ammonia-adding mechanism 7 on the secondary air duct 3, allowing the ammonia-added secondary air to mix with the primary air and provide oxygen for the pulverized coal in the primary air to burn. The multi-angle ammonia-adding mechanism 7 adjusts the angle of the ammonia-added secondary air. By setting the multi-angle ammonia-adding mechanism 7 between the primary air duct 2 and the secondary air duct 3, the secondary air mixed with ammonia is sprayed out from the multi-angle ammonia-adding mechanism 7, thereby enabling the ammonia-added secondary air to be precisely injected. This allows the secondary air and ammonia to enter the flame zone of different combustion stages of the pulverized coal, achieving precise ammonia injection for different coal burning amounts.

[0030] Reference Figure 1 , Figure 2 and Figure 3 The multi-angle ammonia blending mechanism 7 includes a support ring 71 disposed between the primary air duct 2 and the secondary air duct 3. The support ring 71 is fixedly connected to both the primary air duct 2 and the secondary air duct 3. The support ring 71 is provided with a number of air nozzles 72 and a number of air holes 73. The air nozzles correspond to the air nozzles 72. An angle adjustment component 74 is disposed between the air nozzles 72 and the support ring 71.

[0031] In addition, the angle adjustment component 74 includes a support ball 741 disposed in the air outlet 73. The support ball 741 is rotatably connected to the support ring 71. A through hole 742 is provided on the support ball 741. The air outlet 72 is fixedly connected to the support ball 741. The air outlet 72 corresponds to the through hole 742 on the support ball 741.

[0032] Furthermore, a fixing bolt 743 is provided on one side of the support ball 741. The fixing bolt 743 passes through the secondary air duct 3 and the tertiary air duct 4. The fixing bolt 743 is threadedly connected to the tertiary air duct 4. One end of the fixing bolt 743 abuts against the support ball 741.

[0033] When the ammonia-infused secondary air is about to be ejected from between the secondary air duct 3 and the primary air duct 2, the air nozzle 72 is rotated in advance according to the amount of pulverized coal and the feed of the primary air. This causes the air nozzle 72 to drive the support ball 741, which rotates on the support ring 71. This tilts the air nozzle 72 to a suitable angle. Then, the fixing bolt 743 is rotated, moving on the tertiary air duct 4. The fixing bolt 743 abuts against the support ball 741, fixing and limiting its position, thus fixing the direction of the air nozzle 72. The ammonia-infused secondary air then blows onto the support ring 71. After placement, the air supply hole 73 passes through the through hole 742 of the support ball 741, enters the air supply nozzle 72 through the through hole 742, and then sprays out from the air supply nozzle 72, allowing the ammonia-mixed secondary air to be sprayed out along the direction of the air supply nozzle 72. By setting several air supply nozzles 72 between the primary air duct 2 and the secondary air duct 3, the air supply nozzles 72, supported by the support ball 741, change the angle of the ammonia-mixed secondary air spray on the support ring 71, thereby enabling the ammonia-mixed secondary air to be sprayed accurately, allowing the secondary air and ammonia to enter the flame zone of different combustion stages of pulverized coal, and achieving precise ammonia injection for different coal burning amounts.

[0034] Reference Figure 1 , Figure 2 and Figure 4The pulverized coal auxiliary mixing mechanism 6 includes a mixing sleeve 61 disposed between the primary air duct 2 and the central channel 1. The mixing sleeve 61 has several circumferentially distributed air inlets 62 at the end away from the swirl vane 5 and several circumferentially distributed air outlets 63 at the end of the mixing sleeve 61 close to the swirl vane 5. The air inlets 62 and the air outlets 63 are connected. A rotating component 64 is disposed between the mixing sleeve 61 and the primary air duct 2 and the central channel 1.

[0035] In addition, the rotating assembly 64 includes a rotating ring 641 fixed on the mixing sleeve 61, and a plurality of circumferentially distributed rotating blades 642 are fixed on the rotating ring 641.

[0036] Furthermore, a second rotating ring 643 is provided at the end of the mixing sleeve 61 away from the first rotating ring 641. The second rotating ring 643 is fixedly connected to the primary air duct 2 and rotatably connected to the mixing sleeve 61. Several rotating balls 644 are rotatably connected between the second rotating ring 643 and the mixing sleeve 61.

[0037] Furthermore, a number of auxiliary nozzles 645 are fixed at one end of the mixing sleeve 61 near the air outlet 63. The auxiliary nozzles 645 correspond to the air outlet 63 and are set at an angle.

[0038] Primary air carrying pulverized coal is blown between primary air duct 2 and central channel 1. Just before the primary air and pulverized coal are about to be ejected, the primary air carrying pulverized coal is blown in through the inlet 62 of the mixing sleeve 61 and then out through the outlet 63 of the mixing sleeve 61. The diameter of the inlet 62 is larger than that of the outlet 63. The diameter of the middle part of the connecting channel is smaller than the diameters of both the inlet 62 and the outlet 63. The channel connecting the inlet 62 and the outlet 63 first narrows and then expands, causing the primary air carrying pulverized coal to be compressed when it enters through the inlet 62, increasing the flow velocity of the primary air. When passing through the connecting channel between the inlet 62 and the outlet 63, the flow velocity and the shape of the connecting channel... Under the action of the primary air, the pressure increases when the primary air carrying coal powder is ejected from the auxiliary nozzle 645 of the outlet 63. Under the recoil force of the primary air ejected from the auxiliary nozzle 645 and the action of the primary air blowing the rotating blade 642, the mixing sleeve 61 rotates under the support of the rotating ring 643, allowing the ejected primary air and coal powder to mix further. By allowing the ammonia-mixed primary air to carry coal powder through the air inlet 62 and air outlet 63 of the mixing sleeve 61, the flow rate of the primary air is increased by using the connecting channel between the air inlet 62 and air outlet 63, thereby allowing the primary air and coal powder to mix further under the blowing of the primary air, improving the uniformity of the primary air carrying coal powder ejected.

[0039] Working principle: When using this ammonia-blended multi-channel pulverized coal burner, connect the central channel 1 to the external air-fuel pipeline, then connect the primary air pipeline 2 to the external pulverized coal feeder, and connect the secondary air pipeline 3 and tertiary air pipeline 4 to the external air supply device. Based on the amount of pulverized coal and the primary air feed, rotate the air supply nozzle 72 beforehand, causing the air supply nozzle 72 to drive the support ball 741. The support ball 741 rotates on the support ring 71, allowing the air supply nozzle 72 to tilt to a suitable angle. Then rotate the fixing bolt 743, causing the fixing bolt 743 to move on the tertiary air pipeline 4. The fixing bolt 743 abuts against the support ball 741, fixing and limiting the support ball 741, thus fixing the direction of the air nozzle 72. During pulverized coal combustion, primary air is supplied through the primary air duct 2, and ammonia is added to the primary air. Before the primary air carrying pulverized coal is ejected from the primary air duct 2, the primary air carrying pulverized coal is blown in through the air inlet 62 of the mixing sleeve 61, and then blown out through the air outlet 63 of the mixing sleeve 61. The diameter of the air inlet 62 is larger than that of the air outlet 63, and the diameter of the middle part of the connecting channel is larger than the diameter of the air inlet 62 and the air outlet 63. The diameters must be small. The channel connecting the air inlet 62 and the air outlet 63 first narrows and then expands, so that the primary air carrying coal dust is compressed when it enters through the air inlet 62, increasing the flow velocity of the primary air. When passing through the connecting channel between the air inlet 62 and the air outlet 63, under the action of the flow velocity and the shape of the connecting channel, the pressure of the primary air carrying coal dust when it is ejected from the auxiliary nozzle 645 of the air outlet 63 increases. Under the recoil force of the primary air ejected from the auxiliary nozzle 645 and the action of the primary air blowing the rotating blade 642, the mixing sleeve 61 rotates in a circular motion. Supported by the 643, the primary air and pulverized coal are further mixed. The primary air, carrying pulverized coal, is then ejected from the primary air duct 2 and mixed with the fuel and air blown out from the central channel 1, and ignited. At the same time, after the ammonia-infused secondary air reaches the support ring 71, it passes through the through hole 742 of the support ball 741 from the air supply hole 73, enters the air supply nozzle 72 from the through hole 742, and is then ejected from the air supply nozzle 72. The ammonia-infused secondary air is ejected along the direction of the air supply nozzle 72, allowing the ammonia-infused secondary air to enter the flame zone of different combustion stages of pulverized coal.

Claims

1. An ammonia-infused multi-channel pulverized coal burner, comprising a central channel (1), characterized in that: A primary air duct (2) is fixed on the central channel (1), a secondary air duct (3) is fixed on the primary air duct (2), a tertiary air duct (4) is fixed on the secondary air duct (3), and several circumferentially distributed swirl vanes (5) are fixed on the central channel (1) and the primary air duct (2). The swirl vanes (5) are located at one end of the primary air duct (2). A pulverized coal auxiliary mixing mechanism (6) is provided between the primary air duct (2) and the central channel (1), and a multi-angle ammonia blending mechanism (7) is provided between the primary air duct (2) and the secondary air duct (3).

2. The ammonia-infused multi-channel pulverized coal burner according to claim 1, characterized in that: The multi-angle ammonia blending mechanism (7) includes a support ring (71) disposed between the primary air duct (2) and the secondary air duct (3). The support ring (71) is fixedly connected to both the primary air duct (2) and the secondary air duct (3). The support ring (71) is provided with a plurality of air nozzles (72) and a plurality of air holes (73) are opened on the support ring (71). The air holes (73) correspond to the air nozzles (72). An angle adjustment component (74) is provided between the air nozzles (72) and the support ring (71).

3. The ammonia-blended multi-channel pulverized coal burner according to claim 2, characterized in that: The angle adjustment assembly (74) includes a support ball (741) disposed in the air outlet (73), the support ball (741) being rotatably connected to the support ring (71), the support ball (741) having a through hole (742), the air outlet (72) being fixedly connected to the support ball (741), and the air outlet (72) corresponding to the through hole (742) on the support ball (741).

4. The ammonia-blended multi-channel pulverized coal burner according to claim 3, characterized in that: A fixing bolt (743) is provided on one side of the support ball (741). The fixing bolt (743) passes through the secondary air duct (3) and the tertiary air duct (4). The fixing bolt (743) is threadedly connected to the tertiary air duct (4). One end of the fixing bolt (743) abuts against the support ball (741).

5. The ammonia-infused multi-channel pulverized coal burner according to claim 1, characterized in that: The pulverized coal auxiliary mixing mechanism (6) includes a mixing sleeve (61) disposed between the primary air duct (2) and the central channel (1). The mixing sleeve (61) has several circumferentially distributed air inlets (62) at the end away from the swirl vane (5), and several circumferentially distributed air outlets (63) at the end of the mixing sleeve (61) close to the swirl vane (5). The air inlets (62) and air outlets (63) are connected. A rotating component (64) is disposed between the mixing sleeve (61) and the primary air duct (2) and the central channel (1).

6. The ammonia-blended multi-channel pulverized coal burner according to claim 5, characterized in that: The rotating assembly (64) includes a rotating ring (641) fixed on the mixing sleeve (61), and a plurality of circumferentially distributed rotating blades (642) are fixed on the rotating ring (641).

7. The ammonia-blended multi-channel pulverized coal burner according to claim 6, characterized in that: The mixing sleeve (61) is provided with a rotating ring two (643) at the end away from the rotating ring one (641). The rotating ring two (643) is fixedly connected to the primary air duct (2). The rotating ring two (643) is rotatably connected to the mixing sleeve (61). A number of rotating balls (644) are rotatably connected between the rotating ring two (643) and the mixing sleeve (61).

8. The ammonia-infused multi-channel pulverized coal burner according to claim 5, characterized in that: A plurality of auxiliary nozzles (645) are fixed at one end of the mixing sleeve (61) near the air outlet (63). The auxiliary nozzles (645) correspond to the air outlet (63) and are arranged at an angle.

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