Pulverized coal burner

Abstract

The invention relates to the technical field of thermal power plant boiler combustion and discloses a pulverized coal burner which comprises a first combustion cylinder, a flow guide pipe, a second combustion cylinder and a combustion stabilizer, the flow guide pipe is provided with an air inlet end and an air outlet end, and the air outlet end is communicated with the first combustion cylinder; the flow guide pipe is used for guiding in mixed airflow carrying pulverized coal and conveying the mixed airflow into the first combustion cylinder, the second combustion cylinder is arranged in the first combustion cylinder, an annular channel is formed between the second combustion cylinder and the first combustion cylinder, and the second combustion cylinder is used for dividing the mixed airflow into first-stage airflow flowing through the second combustion cylinder and second-stage airflow flowing through the annular channel. The combustion stabilizer is arranged on the flow guide pipe and provided with an air outlet part, the air outlet part is located in the flow guide pipe and faces the second combustion cylinder, and the air outlet part is used for spraying out flames and sequentially igniting the first-stage airflow and the second-stage airflow. The pulverized coal burner provided by the embodiment of the invention can ignite in batches and realize stable and sufficient combustion.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of boiler combustion in thermal power plants, and particularly relates to a pulverized coal burner. BACKGROUND

[0002] With the implementation of the national new generation coal power upgrading special action plan, coal power unit low load operation will become the norm. In order to solve the problems of difficult ignition, stable combustion and difficult burnout of coal powder due to low furnace temperature during boiler start-up and low load operation, the related technology has a scheme that the coal powder stable combustion device burns high concentration coal powder to form a central stable flame, and ignites the main coal powder gas flow for combustion. However, since the structure size of the coal powder stable combustion device is larger than that of the traditional plasma igniter or micro-oil igniter, the traditional burner is not suitable for the coal powder stable combustion device, and how to ensure the step-by-step ignition of coal powder and the reasonable internal pressure drop of the burner is also a problem to be solved at present. SUMMARY

[0003] The present application aims to at least solve one of the technical problems in the related art. To this end, the embodiments of the present application propose a pulverized coal burner which can ignite coal powder in batches and achieve stable and sufficient combustion.

[0004] The pulverized coal burner of the embodiments of the present application comprises a first combustion cylinder, a flow guide pipe, a second combustion cylinder and a stable combustion device, the flow guide pipe has an air inlet end and an air outlet end, the air outlet end communicates with the first combustion cylinder, the flow guide pipe is used for guiding the mixed gas flow carrying coal powder into the first combustion cylinder, the second combustion cylinder is arranged in the interior of the first combustion cylinder, an annular channel is formed between the second combustion cylinder and the first combustion cylinder, the second combustion cylinder is used for dividing the mixed gas flow into a first gas flow flowing through the second combustion cylinder and a second gas flow flowing through the annular channel, the stable combustion device is arranged on the flow guide pipe, the stable combustion device has an air outlet portion, the air outlet portion is in the interior of the flow guide pipe and faces the second combustion cylinder, and the air outlet portion is used for spraying a flame and igniting the first gas flow and the second gas flow in turn.

[0005] The pulverized coal burner of the embodiments of the present application divides the mixed gas flow of the flow guide pipe into the first gas flow and the second gas flow, realizes the step-by-step ignition of the two gas flows, reduces the heat required for single ignition, reduces the difficulty of ignition in batches, realizes stable combustion, and the unburned combustible gas in the gas flow can continue to burn with the second gas flow, realizing sufficient combustion. Therefore, easy ignition and sufficient stable combustion can be realized under the conditions of start-up and low load. In addition, in the present embodiment, the second gas flow in the annular channel can wrap the first gas flow burning in the second combustion cylinder, realizing wind wrapping fire, realizing the preheating of the second gas flow and controlling the combustion process, preventing the risk of high-temperature burning of the burner, ash deposition and coking, etc.

[0006] In some embodiments, the pulverized coal burner further comprises a first connecting assembly for mounting the flame stabilizer, the first connecting assembly employing a first sleeve connected with the flow guide pipe, the flame stabilizer being mounted in the first sleeve.

[0007] In some embodiments, the pulverized coal burner further comprises a second connecting assembly for mounting the second combustion cylinder, the second connecting assembly comprising a connecting part for connecting the second combustion cylinder and the first combustion cylinder, wherein the connecting part comprises at least one of a connecting rod, a bolt, and a connecting plate.

[0008] In some embodiments, the pulverized coal burner further comprises a first tapered section disposed between and for connecting the air inlet end and the first combustion cylinder, the first tapered section having a cross-sectional area gradually decreasing in a direction from the air inlet end towards the first combustion cylinder.

[0009] In some embodiments, the first tapered section has a length L tJS in the axial direction of the second combustion cylinder, and the air outlet part has a length L WH in the axial direction of the second combustion cylinder. In some embodiments, the first tapered section is aligned with the large end of the air outlet part at the connection with the flow guide pipe, and L tJS / L WH = 0.6-1.2. In some embodiments, the first tapered section is aligned with the small end of the air outlet part at the connection with the first combustion cylinder, and 1.4 > L tJS / L WH > 1.2.

[0010] In some embodiments, the pulverized coal burner comprises a straight cylinder section in communication with the air inlet end, the straight cylinder section being for connecting a supply assembly of a power plant to provide the mixed gas flow to the flow guide pipe, and a second tapered section disposed between and for connecting the straight cylinder section and the air inlet end, the second tapered section having a cross-sectional area gradually decreasing in a direction from the air inlet end towards the straight cylinder section.

[0011] In some embodiments, the second combustion cylinder has an inner diameter D t1 , the first combustion cylinder has an inner diameter D t2 , and D t1 / D t2 = 0.4-0.6.

[0012] In some embodiments, the distance between the second combustion cylinder and the air outlet part is L tWH2 , the air outlet part is a conical sleeve with a small end facing the second combustion cylinder, the inner diameter of the small end of the air outlet part is D WH2 , 0.8>L tWH2 / D WH2 >0.2.

[0013] In some embodiments, the flow guide pipe is a bend pipe.

[0014] In some embodiments, the flame stabilizer is fixed on the side wall of the flow guide pipe, the air outlet part has an axis, and the axis of the air outlet part coincides with the axis of the second combustion cylinder.

[0015] In some embodiments, the flame stabilizer comprises at least one of a pulverized coal stabilizer, a fuel oil stabilizer, a gas stabilizer, a plasma igniter, and a micro-oil igniter.

[0016] The pulverized coal burner of the embodiment of the present application divides the mixed gas flow of the flow guide pipe into a primary gas flow and a secondary gas flow, realizes step-by-step ignition of the two gas flows, reduces the heat required for single ignition, reduces the difficulty of ignition in batches, realizes stable combustion, and the unburned combustible gas in the gas flow can continue to burn with the secondary gas flow, realizing full combustion. Therefore, easy ignition and full stable combustion can be realized under the conditions of start-up and low load. In addition, in the embodiment, the secondary gas flow in the annular channel can wrap the primary gas flow burning in the second combustion cylinder, realizing wind wrapping fire, realizing preheating of the secondary gas flow and controlling the combustion process, preventing the risk of high-temperature burning of the burner, ash accumulation and coking, etc. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is the overall perspective view of the pulverized coal burner of the embodiment of the present application.

[0018] Figure 2 is the front view of the pulverized coal burner of the embodiment of the present application.

[0019] Figure 3 is the schematic diagram of the gas flow of the pulverized coal burner of the embodiment of the present application.

[0020] Figure 4 is the size schematic diagram of the pulverized coal burner of the embodiment of the present application.

[0021] Figure 5 is the size schematic diagram of the first tapered section and the flame stabilizer of the pulverized coal burner of the embodiment of the present application.

[0022] Figure 6 is the schematic diagram of the influence of the parameters in the pulverized coal burner on the primary gas flow.

[0023] Figure 7 is a diagram showing the influence of parameters in the powder burner of an embodiment of the present application on pressure drop.

[0024] Figure 8 is a perspective view of one embodiment of the present application.

[0025] Figure 9 is a front sectional view of the present application. Figure 8

[0026] Figure 10 is a perspective view of a first connecting assembly in the present application. Figure 8

[0027] Figure 11 is a gas flow diagram of the present application. Figure 8

[0028] is a perspective view of another embodiment of the present application. Figure 12

[0029] Figure 13 is a front sectional view of the present application. Figure 12

[0030] Figure 14 is a perspective view of a second connecting assembly in the present application. Figure 12

[0031] Figure 15 is a gas flow diagram of the present application. Figure 12 Reference Signs:

[0032] 1. first combustion cylinder; 2. flow guide pipe; 3. second combustion cylinder; 301. first straight cylinder section; 302. flow guide section; 4. flame stabilizer; 401. gas outlet portion; 5. mixed gas flow; 6. primary gas flow; 7. secondary gas flow; 8. first connecting assembly; 801. first sleeve; 802. clamp; 803. first protrusion; 804. second protrusion; 805. limiting groove; 9. second connecting assembly; 901. connecting portion; 902. guide rod; 903. second sleeve; 904. sealing member; 905. collar; 10. first tapered section; 11. second straight cylinder section; 12. second tapered section. DETAILED DESCRIPTION

[0033] ​​​​​​Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0034] like Figures 1-5 As shown, the pulverized coal burner of this embodiment includes a first combustion chamber 1, a guide pipe 2, a second combustion chamber 3, and a flame stabilizer 4. The guide pipe 2 has an inlet end and an outlet end, and the outlet end is connected to the first combustion chamber 1. The guide pipe 2 is used to introduce a mixed airflow 5 carrying pulverized coal and deliver it into the first combustion chamber 1. The second combustion chamber 3 is disposed inside the first combustion chamber 1, and an annular channel is formed between the second combustion chamber 3 and the first combustion chamber 1. The second combustion chamber 3 is used to split the mixed airflow 5 into a primary airflow 6 flowing through the second combustion chamber 3 and a secondary airflow 7 flowing through the annular channel. The flame stabilizer 4 is disposed on the guide pipe 2 and has an outlet 401. The outlet 401 is located inside the guide pipe 2 and faces the second combustion chamber 3. The outlet 401 is used to eject flames and ignite the primary airflow 6 and the secondary airflow 7 in sequence.

[0035] In this embodiment of the pulverized coal burner, the mixed airflow 5 in the guide pipe 2 is divided into a primary airflow 6 and a secondary airflow 7, enabling the two airflows to be ignited sequentially. This reduces the heat required for a single ignition and lowers the difficulty of ignition by using a batch ignition method. Stable combustion is achieved, and unburned combustible gases in the airflow can continue to burn with the secondary airflow 7, ensuring complete combustion. Therefore, it can be easily ignited and achieve stable combustion under startup and low-load conditions. Furthermore, in this embodiment, the secondary airflow 7 in the annular channel can envelop the primary airflow 6 burning in the second combustion chamber 3, achieving air-fire envelopment. This preheating of the secondary airflow 7 also controls the combustion process, preventing risks such as high-temperature burnout, ash accumulation, and coking of the burner.

[0036] The specific working process is as follows: The air inlet end of the guide pipe 2 is connected to the pulverized coal supply unit of the power plant. The pulverized coal output from the pulverized coal supply unit, such as a mill or coal bunker, is directly transported to the boiler's guide pipe 2 along with the hot primary air through the primary air duct to form a mixed airflow 5. A portion of this mixed airflow enters the burner 4 for pre-combustion. The pulverized coal flowing through the burner 4 is ignited by the ignition device within the burner 4 and kept burning continuously. Subsequently, the mixed airflow 5 enters the guide pipe 2 and is split into a primary airflow 6 and a secondary airflow 7. The outlet 401 of the burner 4, i.e., the flame outlet end, can eject a flame, which is directly facing the primary airflow 6, thus igniting the primary airflow 6. The ignited primary airflow 6 continues to be transported and mixed with the secondary airflow 7, igniting the secondary airflow 7. This achieves a gradual ignition effect. By igniting in batches, the heat required for a single ignition is reduced, and the unburned combustible gas in the mixed airflow 5 can mix with the oxygen in the secondary airflow 7 for secondary combustion, achieving complete combustion.

[0037] In some specific embodiments, the first combustion chamber 1 is cylindrical and the second combustion chamber 3 is also cylindrical, and the two are coaxially arranged, which can make the airflow flow more smoothly and evenly in the first combustion chamber 1 and the second combustion chamber 3.

[0038] In some embodiments, the pulverized coal burner further includes a first connecting assembly 8 for installing a flame stabilizer 4. The first connecting assembly 8 employs a first sleeve 801, which is connected to the guide pipe 2, and the flame stabilizer 4 is installed inside the first sleeve 801. In this embodiment of the pulverized coal burner, the flame stabilizer 4 is installed via the first sleeve 801, which facilitates the disassembly, inspection, and timely replacement of the flame stabilizer 4.

[0039] In some embodiments, the pulverized coal burner further includes a second connecting assembly 9 for mounting a second combustion cylinder 3. The second connecting assembly 9 includes a connecting portion 901 for connecting the second combustion cylinder 3 and the first combustion cylinder 1. The connecting portion 901 includes at least one of a connecting rod, a bolt, and a connecting plate.

[0040] See appendix Figure 2 In the pulverized coal burner of this embodiment, the guide pipe 2 and the second combustion cylinder 3 are fixedly connected by a connecting plate. The orientation of the connecting plate is consistent with the airflow direction to avoid obstructing the airflow.

[0041] In some embodiments, the pulverized coal burner further includes a first tapering section 10, which is disposed between the air inlet end and the first combustion cylinder 1 and serves to connect the air inlet end and the first combustion cylinder 1. The cross-sectional area of ​​the first tapering section 10 gradually decreases along the direction from the air inlet end toward the first combustion cylinder 1. In the pulverized coal burner of this embodiment, the mixed airflow 5 can smoothly enter the annular channel or the second combustion cylinder 3 along the first tapering section 10.

[0042] In some embodiments, the pulverized coal burner includes a straight section and a second tapered section 12. The straight section is connected to the air inlet and is used to connect the power plant's supply components to provide a mixed airflow 5 to the guide pipe 2. The second tapered section 12 is located between the straight section and the air inlet and is used to connect the straight section and the air inlet. The cross-sectional area of ​​the second tapered section 12 gradually decreases along the direction from the air inlet toward the straight section.

[0043] In some embodiments, the guide pipe 2 is a bent pipe. In the pulverized coal burner of this embodiment, the size of the guide pipe 2 is larger than the size of the flame stabilizer 4. After the flame stabilizer 4 is installed in the guide pipe 2, there is still enough space in the guide pipe 2 for the flow of pulverized coal gas. Furthermore, the guide pipe 2 is a bent pipe, which can reduce the resistance of the mixed gas flow 5 in the guide pipe 2, improve the flowability, and prevent pulverized coal residue in the guide pipe 2.

[0044] In some specific embodiments, the bend is a 90-degree bend. This facilitates pipe connections, the arrangement of the flame stabilizer 4, and reduces the flow resistance of the mixed airflow 5 within the guide pipe 2.

[0045] In some embodiments, the flame stabilizer 4 is fixed to the side wall of the guide pipe 2, and the outlet 401 has an axis that coincides with the axis of the second combustion chamber 3. The pulverized coal burner of this embodiment, through its axis-coincident design, ensures that the flame ejected from the flame stabilizer 4 is directly facing the second combustion chamber 3, thereby completely igniting the pulverized coal within the second combustion chamber 3.

[0046] In some embodiments, the flame stabilizer 4 includes at least one of a pulverized coal flame stabilizer, an oil flame stabilizer, a gas flame stabilizer, a plasma igniter, and a micro-oil igniter. In this embodiment, a pulverized coal flame stabilizer can be used to reduce costs. The flame stabilizer is ignited by an ignition device inside the pulverized coal flame stabilizer and combustion is maintained. This ignites the subsequent primary gas flow 6 and secondary gas flow 7.

[0047] The placement of the pulverized coal burner stabilizer 4 increases the resistance within the guide pipe 2, thus affecting the resistance characteristics of the entire feeding system. Therefore, it is necessary to minimize the resistance of bends and multi-stage combustion chambers to reduce the impact of the pulverized coal burner stabilizer 4 on the feeding system. Specific parameter optimizations are as follows.

[0048] In some embodiments, the diameter of the air intake end is D. tw The inner diameter of the second straight section 11 is D. in D tw >D in .

[0049] In some embodiments, the second combustion chamber 3 is a straight cylinder with a length of L. t1 L t1 It is less than the length of the first combustion chamber 1.

[0050] In some embodiments, the inner diameter of the second combustion chamber 3 is D. t1 The inner diameter of the first combustion chamber 1 is D. t2 D t1 / D t2 =0.4-0.6.

[0051] In some embodiments, the distance between the second combustion chamber 3 and the gas outlet 401 is L. tWH2 The outlet 401 is a conical sleeve with its smaller end facing the second combustion chamber 3. The inner diameter of the larger end of the outlet 401 is D. WH1 The inner diameter of the small end of the air outlet 401 is D. WH2 , 0.8>L tWH2 / D WH2 >0.2.

[0052] In some embodiments, the length of the first tapering section 10 along the axial direction of the second combustion chamber 3 is L. tJS The length of the air outlet 401 along the axis of the second combustion chamber 3 is L. WH ; As attached Figure 5 As shown in Figure .b, when the connection between the first tapering section 10 and the guide pipe 2 is aligned with the large end of the outlet 401, L tJS / L WH =0.6-1.2.

[0053] As attached Figure 5 As shown in Figure .a, when the connection between the first tapering section 10 and the first combustion chamber 1 is aligned with the small end of the air outlet 401, 1.4>L tJS / L WH >1.2.

[0054] The effects of different parameters on the proportion of the first-stage airflow and the overall pressure drop of the burner were analyzed. The comprehensive analysis results, combined with the attached figures, are as follows.

[0055] (1) D t1 / D t2 For the impact, see the appendix. Figure 6 .a and Figure 7 .a.

[0056] 1. D t1 / D t2 The value is linearly positively correlated with the flow rate proportion of the first-order airflow 6.

[0057] 2. D t1 / D t2 As the value increases, the resistance increases, and initially the resistance decreases slowly at D. t1 / D t2The resistance decreases rapidly in the range of 0.4-0.5, and then the rate of decrease slows down.

[0058] Therefore, D t1 / D t2 The value range is 0.4-0.6, and preferably 0.5.

[0059] (2) L tWH2 / D WH2 For the impact, see the appendix. Figure 6 .b and Figure 7 .b.

[0060] 1. L tWH2 / D WH2 When the flow rate is greater than 0.4 (i.e., the distance between the stabilizer 4 and the second combustion chamber 3 increases), the flow rate of the primary airflow 6 increases, and then the growth rate slows down.

[0061] 2. In L tWH2 / D WH2 When the pressure drop is less than 0.2, the pressure drop decreases significantly, and then the rate of decrease slows down.

[0062] Therefore, L in the design tWH2 / D WH2 >0.2, and L tWH2 / D WH2 <0.8, for example, preferably 0.4.

[0063] (3) When the connection between the first tapering section 10 and the guide pipe 2 is aligned with the large end of the outlet 401, L tJS For the impact, see the appendix. Figure 6 .c and Figure 7 .c.

[0064] 1. With L tJS As the angle between the small end of the burner 4 and the wall of the first tapering section 10 gradually decreases, the mixed airflow 5 gradually approaches the wall of the first combustion chamber 1 under the action of inertial force. Therefore, the airflow entering the second combustion chamber 3 gradually decreases, and the flow rate of the primary airflow 6 decreases.

[0065] 2. With L tJS As the pressure increases, the pressure drop first decreases and then increases.

[0066] Therefore, L tJS / L WH The range is 0.6-1.2, preferably 0.8.

[0067] (4) When the connection between the first tapering section 10 and the first combustion cylinder 1 is aligned with the small end of the outlet 401, L tJS For the impact, see the appendix. Figure 6 .d and Figure 7 .d.

[0068] 1. Same as above, that is, as L tJS As the angle between the small end of the burner 4 and the wall of the first tapering section 10 gradually decreases, the mixed airflow 5 gradually approaches the wall of the first combustion chamber 1 under the action of inertial force. Therefore, the airflow entering the second combustion chamber 3 gradually decreases, and the flow rate of the primary airflow 6 decreases.

[0069] 2. With L tJS As the pressure increases, the pressure drop gradually decreases.

[0070] Therefore, the exit position of the tapering section is chosen as L. tJS / L WH >1.2, for example, preferably 1.2.

[0071] Through the above analysis and simulation, it can be seen that the design of parameters such as the second combustion chamber 3, the first combustion chamber 1, the flame stabilizer 4, the first tapering section 10, and the spacing between them affect the pressure drop of the entire burner and the proportion of the primary airflow 6. This analysis allows for different parameter selections for different coal types, optimizing the pressure drop within the burner to achieve the best flow state and the optimal adjustment of the primary airflow 6 proportion, thus meeting the needs of various coal types.

[0072] Other embodiments of the pulverized coal burner of the present invention are described below.

[0073] like Figures 8-15 In some embodiments, at least one of the flame stabilizer 4 and the second combustion chamber 3 can be moved to adjust the relative distance between them to regulate the flow rates of the primary airflow 6 and the secondary airflow 7. This embodiment achieves the adjustment of the ratio of the primary airflow 6 and the secondary airflow 7 by moving the flame stabilizer 4 or the second combustion chamber 3. This means that the proportion of the primary airflow 6 can be rationally allocated according to the coal powder conditions, adapting to various types of coal powder and achieving ignition and fully stable combustion.

[0074] Specifically, for coal types with easy ignition (ignition temperature ≤800℃), the distance between the flame stabilizer 4 and the second combustion chamber 3 is reduced. This increases the area of ​​the flame stabilizer 4 blocking the second combustion chamber 3, reducing the actual effective area of ​​the second combustion chamber 3, thereby reducing the flow rate of the primary airflow 6 and preventing high-temperature coking and burn-off. Conversely, for coal types with difficult ignition (ignition temperature >800℃), the distance between the flame stabilizer 4 and the second combustion chamber 3 is increased. This increases the actual effective area of ​​the second combustion chamber 3, increasing the flow rate of the primary airflow 6 and the concentration of volatile matter per unit volume, which is beneficial for pulverized coal ignition and stable combustion. This solves the problems of difficult ignition, stable combustion, and complete combustion of pulverized coal, as well as the difficulty of stable combustion at low boiler loads, while also reducing nitrogen oxide emissions.

[0075] In some embodiments, the second combustion chamber 3 includes a first cylindrical section 301 and a guide section 302, which are connected. The guide section 302 is a conical sleeve with its larger diameter end facing the air outlet 401. The air outlet 401 can be placed inside the guide section 302 and is spaced apart from the inner wall surface of the guide section 302. The air outlet 401 is a conical sleeve, and the inclined surface of the air outlet 401 is parallel to the inclined surface of the guide section 302.

[0076] In this embodiment of the pulverized coal burner, the second combustion chamber 3 consists of a first cylindrical section 301 and a guide section 302. The guide section 302 is a conical sleeve with the same shape as the air outlet 401. On one hand, the guide section 302 increases the flow rate of the primary airflow 6 entering the second combustion chamber 3. On the other hand, when the flame stabilizer 4 and the second combustion chamber 3 move relative to each other, the distance between the outer surface of the air outlet 401 and the inner surface of the guide section 302 can be adjusted through the cooperation of the inclined surfaces. By adjusting this distance, the flow rate of the primary airflow 6 is regulated.

[0077] In some embodiments, the first connecting assembly 8 includes a first sleeve 801, on which a clamping screw can be provided to achieve stepless adjustment and limiting of the position of the flame stabilizer 4. This satisfies the need for stepless adjustment of the distance between the flame stabilizer 4 and the second combustion chamber 3, providing more adjustment methods.

[0078] In some embodiments, the first connecting assembly 8 includes a first sleeve 801 and a clamp 802. The first sleeve 801 is connected to the guide pipe 2. The flame stabilizer 4 is installed inside the first sleeve 801 and can move along the axial direction of the first sleeve 801. The clamp 802 is provided on the outer wall surface of the first sleeve 801 and the flame stabilizer 4 and is used to connect the first sleeve 801 and the flame stabilizer 4. The first sleeve 801 is provided with a first protrusion 803 at one end connected to the clamp 802, and the flame stabilizer 4 is provided with a second protrusion 804 at one end connected to the clamp 802. The inner wall surface of the clamp 802 is provided with a limiting groove 805. The first protrusion 803 and the second protrusion 804 can be placed in the limiting groove 805 so that the relative position of the flame stabilizer 4 and the first sleeve 801 remains unchanged.

[0079] In some specific embodiments, the first protrusion 803 and the second protrusion 804 are both flanges, and the limiting groove 805 is an annular groove, and there are multiple limiting grooves 805.

[0080] The pulverized coal burner of this invention is shown in the appendix. Figure 2As shown, the flame stabilizer 4 is installed inside the first sleeve 801, and the flame stabilizer 4 and the outer wall surface of the first sleeve 801 are in a clearance fit or a tight fit. The flame stabilizer 4 can move along the axial direction of the first sleeve 801, thereby adjusting the position of the flame stabilizer 4. At this time, the flame stabilizer 4 has two adjustment positions. When the first protrusion 803 and the second protrusion 804 are tightly fitted, the clamp 802 is not needed; the first protrusion 803 and the second protrusion 804 can be directly connected together. When it is necessary to increase the distance between the second combustion chamber 3 and the flame stabilizer 4, after adjusting the distance, the clamp 802 is used to place the first protrusion 803 and the second protrusion 804 into different annular grooves, and then the clamp 802 is fixed. In this way, the distance between the second combustion chamber 3 and the flame stabilizer 4 can be adjusted in stages, and multiple different distance levels can be preset, thus facilitating quick on-site adjustment.

[0081] In some embodiments, the pulverized coal burner further includes a second connecting assembly 9, which is used to install a second combustion cylinder 3 and the second combustion cylinder 3 is movable to adjust the relative distance between the second combustion cylinder 3 and the flame stabilizer 4.

[0082] In some embodiments, the second connecting assembly 9 includes a guide rod 902, one end of which is connected to the second combustion cylinder 3, and the other end of which passes through the side wall of the guide tube 2 and is placed outside the guide tube 2.

[0083] As attached Figures 5-7 As shown, multiple guide rods 902 are installed on the guide pipe 2. One end of each guide rod 902 is placed inside the guide pipe 2 and connected to the second combustion cylinder 3 to support and move the second combustion cylinder 3. The position of the second combustion cylinder 3 can be adjusted by pulling the guide rod 902, thereby adjusting the distance between the second combustion cylinder 3 and the flame stabilizer 4.

[0084] In some embodiments, the second connecting assembly 9 further includes a second sleeve 903, a sealing component 904, and a collar 905. The second sleeve 903 is mounted on the side wall of the guide tube 2. The guide rod 902 passes through the second sleeve 903 and can move along the axial direction of the second sleeve 903. The sealing component 904 is sleeved on the guide rod 902 and can move along the guide rod 902. The sealing component 904 is used to seal the connection between the guide rod 902 and the second sleeve 903. The collar 905 is sleeved on the first sleeve 801. The other end of the plurality of guide rods 902 is connected to the collar 905. The collar 905 is used to drive the plurality of guide rods 902 to move synchronously.

[0085] In some specific embodiments, the sealing component 904 and the second sleeve 903 are connected by threads. The sealing component 904 and the guide rod 902 are in a tight fit or an interference fit, which can realize the movement of the sealing component 904 relative to the guide rod 902, and can also realize the stable connection between the sealing component 904 and the guide rod 902 when stationary.

[0086] In this embodiment of the pulverized coal burner, a collar 905 connects to multiple guide rods 902 to improve the support stability of the second combustion chamber 3. Furthermore, during movement, the multiple guide rods 902 can move synchronously, achieving accurate positioning of the second combustion chamber 3. In this embodiment, the guide rods 902 and the second sleeve 903 are in a clearance fit to facilitate movement. Once the guide rods 902 are in position, they can be connected to the second sleeve 903 via a sealing component 904 to fix their position. The sealing component 904 has a sealing ring inside. By moving the sealing component 904 and connecting it to the second sleeve 903, the guide rods 902 can be fixed, and the connection between the guide rods 902 and the second sleeve 903 can be sealed.

[0087] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0088] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0089] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0090] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0091] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0092] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A pulverized coal burner, characterized in that, include: First combustion chamber (1); The guide pipe (2) has an air inlet end and an air outlet end. The air outlet end is connected to the first combustion cylinder (1). The guide pipe (2) is used to introduce the mixed airflow (5) carrying coal powder and deliver it to the first combustion cylinder (1). The second combustion cylinder (3) is located inside the first combustion cylinder (1), and an annular channel is formed between the second combustion cylinder (3) and the first combustion cylinder (1). The second combustion cylinder (3) is used to split the mixed airflow (5) into a primary airflow (6) flowing through the second combustion cylinder (3) and a secondary airflow (7) flowing through the annular channel. A flame stabilizer (4) is provided on the guide pipe (2). The flame stabilizer (4) has an outlet (401). The outlet (401) is located inside the guide pipe (2) and faces the second combustion cylinder (3). The outlet (401) is used to spray out flames and ignite the primary airflow (6) and the secondary airflow (7) in sequence.

2. The pulverized coal burner according to claim 1, characterized in that, It also includes a first connecting component (8), which is used to install the flame stabilizer (4). The first connecting component (8) adopts a first sleeve, which is connected to the guide pipe (2), and the flame stabilizer (4) is installed inside the first sleeve.

3. The pulverized coal burner according to claim 1, characterized in that, It also includes a second connecting assembly (9) for mounting a second combustion cylinder. The second connecting assembly (9) includes a connecting part for connecting the second combustion cylinder (3) and the first combustion cylinder (1). The connecting part includes at least one of a connecting rod, a bolt, and a connecting plate.

4. The pulverized coal burner according to claim 1, characterized in that, It also includes a first tapering section (10), which is located between the air intake end and the first combustion cylinder (1) and is used to connect the air intake end and the first combustion cylinder (1). The cross-sectional area of ​​the first tapering section (10) gradually decreases along the direction from the air intake end toward the first combustion cylinder (1).

5. The pulverized coal burner according to claim 4, characterized in that, The length of the first tapering section (10) along the axial direction of the second combustion chamber (3) is L. tJS The length of the air outlet (401) along the axial direction of the second combustion cylinder (3) is L. WH ; Wherein, the connection between the first tapering section (10) and the guide pipe (2) is aligned with the large end of the air outlet (401), and L tJS / L WH =0.6-1.2; Alternatively, the connection between the first tapering section (10) and the first combustion chamber (1) is aligned with the small end of the air outlet (401), and 1.4>L tJS / L WH >1.

2.

6. The pulverized coal burner according to claim 1, characterized in that, Also includes: A straight section (11) is connected to the air inlet end and is used to connect to the power plant's supply components to provide the mixed airflow (5) to the guide pipe (2). The second tapering section (12) is located between the straight section (11) and the air inlet and is used to connect the straight section (11) and the air inlet. The cross-sectional area of ​​the second tapering section (12) gradually decreases along the direction from the air inlet toward the straight section (11).

7. The pulverized coal burner according to claim 1, characterized in that, The inner diameter of the second combustion chamber (3) is D. t1 The inner diameter of the first combustion chamber (1) is D. t2 D t1 / D t2 =0.4-0.

6.

8. The pulverized coal burner according to claim 1, characterized in that, The distance between the second combustion chamber (3) and the gas outlet (401) is L. tWH2 The air outlet (401) is a conical sleeve with its small end facing the second combustion chamber (3), and the inner diameter of the small end of the air outlet (401) is D. WH2 , 0.8>L tWH2 / D WH2 >0.

2.

9. The pulverized coal burner according to any one of claims 1-8, characterized in that, The guide pipe (2) is a bend; And / or, the flame stabilizer (4) is fixed on the side wall of the guide pipe (2), the gas outlet (401) has an axis, and the axis of the gas outlet (401) coincides with the axis of the second combustion cylinder (3).

10. The pulverized coal burner according to claim 9, characterized in that, The flame stabilizer (4) includes at least one of the following: pulverized coal flame stabilizer, fuel oil flame stabilizer, gas flame stabilizer, plasma igniter, and micro oil igniter.

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