Pulverized coal stable combustion device

Abstract

The present invention provides a pulverized coal stable combustion device, which includes a burner and a stable combustion device. At least part of the stable combustion device is located inside the burner; the stable combustion device includes a housing, a reflux cylinder, an acceleration cylinder, and a pulverized coal pipe assembly. The housing covers the outside of the reflux cylinder, and a strengthening layer is provided between the housing and the reflux cylinder; the reflux cylinder and the acceleration cylinder are connected and defined to form a stable combustion cavity. The pulverized coal pipe assembly has a powder feeding port, and the powder feeding port is arranged in the stable combustion cavity to convey the pulverized coal fluid into the stable combustion cavity. The pulverized coal stable combustion device disclosed by the present invention not only effectively enhances the structural strength and durability of the equipment, but also greatly improves the combustion efficiency and stability of the pulverized coal, bringing new solutions and technological breakthroughs to the industrial combustion field.

Description

Technical Field

[0001] The invention relates to the technical field of coal powder combustion, and in particular to a coal powder combustion stabilizing device. Background Art

[0002] As one of the key equipment in thermal power plants and other industrial furnaces, the operating performance of pulverized coal combustion equipment directly affects the energy efficiency and safety of the entire system. However, during the use of pulverized coal combustion equipment, the stabilizer is in the high-temperature combustion chamber of the burner for a long time, which is prone to high-temperature wear, affecting the structural strength of the stabilizer, and thus reducing the service life of the stabilizer. Summary of the invention

[0003] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

[0004] As a key component of pulverized coal combustion equipment, the flame stabilizer is designed to stabilize the flame and ensure that the pulverized coal burns evenly and efficiently in the combustion chamber. It is usually directly exposed to the high-temperature combustion chamber of the burner, and is subjected to extremely high temperatures and complex thermal stress environments. Under such extreme conditions, the flame stabilizer material is very susceptible to high-temperature oxidation, thermal fatigue, and mechanical wear, which not only weakens the structural strength of the flame stabilizer, but may also cause its shape to change, thereby affecting the stability of the flame and the combustion efficiency.

[0005] In the long run, high-temperature wear will seriously shorten the service life of the flame stabilizer, increase the frequency and cost of equipment maintenance, and may even cause unstable combustion, flameout or more serious safety accidents due to failure of the flame stabilizer, posing a threat to the stable operation of the entire system.

[0006] To this end, an embodiment of the present invention proposes a coal powder combustion stabilization device, which includes a burner and a flame stabilizer, at least part of which is located in the burner; the flame stabilizer includes a cover shell, a reflux cylinder, an acceleration cylinder and a coal powder pipe assembly, the cover shell is arranged on the outside of the reflux cylinder, and a reinforcement layer is provided between the cover shell and the reflux cylinder; the reflux cylinder and the acceleration cylinder are connected to define a combustion stabilization chamber, and the coal powder pipe assembly has a powder delivery port, which is arranged in the combustion stabilization chamber to transport the coal powder fluid into the combustion stabilization chamber.

[0007] In summary, the pulverized coal combustion stabilization device in the embodiment of the present invention not only effectively enhances the structural strength and durability of the equipment, but also greatly improves the combustion efficiency and stability of the pulverized coal, bringing new solutions and technological breakthroughs to the field of industrial combustion.

[0008] In some embodiments, the acceleration cylinder has a first end and a second end disposed opposite to each other, the diameter of the first end is smaller than that of the second end, and the first end is provided with a jet port; the reflux cylinder has a third end and a fourth end disposed opposite to each other, the diameter of the third end is larger than that of the fourth end, and the third end of the reflux cylinder is connected to the second end of the acceleration cylinder.

[0009] In some embodiments, a wear-resistant coating is provided on the outer side of the housing;

[0010] And / or, the reinforcing layer is made of heat-insulating cotton.

[0011] In some embodiments, the pulverized coal pipe assembly includes a first reflux channel and a second reflux channel. The powder feeding port includes a first reflux port located in the first reflux channel and a second reflux port located in the second reflux channel. The first reflux port and the second reflux port are communicated with each other. The openings of the first reflux port and the second reflux port are both arranged facing the inner wall of the reflux cylinder. The straight line where the opening direction of the first reflux port is located and the straight line where the opening direction of the second reflux port is located intersect to inject the pulverized coal fluid into the stable combustion chamber.

[0012] In some embodiments, the pulverized coal pipe assembly includes a reflux cap and a guiding plate. The first reflux channel and the second reflux channel are coaxially arranged in the reflux cap. The first reflux channel is located outside the second reflux channel. The guiding plate is arranged at the communication position of the first reflux port and the second reflux port. An inclined surface is provided on the side of the guiding plate facing the second reflux channel.

[0013] In some embodiments, the pulverized coal pipe assembly includes a supply pipe. A first channel and a second channel are provided in the supply pipe. The first channel is communicated with the first reflux channel, and the second channel is communicated with the second reflux channel. The first channel and the second channel are used to convey different types of pulverized coal fluids to the stable combustion chamber.

[0014] In some embodiments, a secondary air assembly is further included. The secondary air assembly includes a plurality of air ducts that are independent of each other. The air ducts have air supply ports. The air supply ports are arranged at one end of the reflux cylinder, and the powder feeding ports are arranged at the other end of the reflux cylinder. The air supply ports are arranged in a staggered manner relative to the powder feeding ports in the radial direction of the combustion stable combustion chamber.

[0015] In some embodiments, the secondary air assembly further includes a plurality of regulating valves. The plurality of regulating valves are respectively arranged on the air ducts, and the regulating valves are used to regulate the passing flow rate of the air flow in the air ducts.

[0016] In some embodiments, the secondary air assembly further includes a plurality of swirler vanes, and the plurality of swirler vanes are respectively arranged at the air outlet of the air duct. The swirler vanes are used to guide the air flow conveyed by the air duct to form a swirling air flow in the combustion stabilizing chamber.

[0017] In some embodiments, the air duct and the pulverized coal pipe assembly are coaxially arranged, the air duct is arranged outside the pulverized coal pipe assembly, and an annular blunt body is arranged between the air duct and the pulverized coal pipe assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a front view schematic diagram of the pulverized coal combustion stabilizing device provided by an embodiment of the present invention.

[0019] Figure 2 is a side view schematic diagram of the pulverized coal combustion stabilizing device provided by an embodiment of the present invention.

[0020] Figure 3 is Figure 2 a sectional view schematic diagram of the pulverized coal combustion stabilizing device shown along A-A.

[0021] Figure 4 is a structural schematic diagram of the pulverized coal combustion stabilizing device provided by an embodiment of the present invention at the reflux cap.

[0022] Figure 5 is a flow schematic diagram of pulverized coal fluid of the pulverized coal combustion stabilizing device provided by an embodiment of the present invention at the reflux cap.

[0023] Figure 6 is a flow schematic diagram of fluids in the pulverized coal pipe assembly, the cleaning assembly and the secondary air assembly of the pulverized coal combustion stabilizing device provided by an embodiment of the present invention.

[0024] Reference numerals: 100, pulverized coal combustion stabilizing device;

[0025] 10, combustion stabilizing chamber; 11, acceleration cylinder; 111, first end; 112, second end; 113, injection port; 114, high-temperature acceleration zone; 12, reflux cylinder; 121, third end; 122, fourth end; 123, high-temperature reflux zone; 13, strengthening layer; 15, housing;

[0026] 30, cleaning assembly; 311, air outlet; 312, reduced-diameter section; 313, rectifying channel; 314, straight pipe section; 315, wear-resistant coating;

[0027] 50, pulverized coal pipe assembly; 51, powder feeding port; 511, first reflux port; 512, second reflux port; 52, reflux cap; 521, first reflux channel; 522, second reflux channel; 523, guiding plate; 53, supply pipe; 531, first channel; 532, second channel; 533, inner pipe; 534, outer pipe; 535, side branch pipe;

[0028] 70. Secondary air component; 71. Air duct; 711. Air supply port; 721. Inner layer pipe; 722. Middle layer pipe; 723. Outer layer pipe; 724. Main air supply pipe; 725. Axial pipe; 726. Radial pipe; 73. Control valve; 74. Rotating vane; 75. Annular blunt body; 76. End plate. Detailed implementation mode

[0029] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0030] As Figures 1 to 6 shown, the embodiment of the present invention provides a pulverized coal stable combustion device 100, which includes a burner and a stable combustion device. At least part of the stable combustion device is located inside the burner. The stable combustion device includes an acceleration cylinder 11, a reflux cylinder 12, a housing 15 and a pulverized coal pipe assembly 50. The housing 15 covers the outside of the reflux cylinder 12, and a strengthening layer 13 is provided between the housing 15 and the reflux cylinder 12. The reflux cylinder 12 and the acceleration cylinder 11 are connected to define a stable combustion chamber 10. The pulverized coal pipe assembly 50 has a powder feeding port 51, and the powder feeding port 51 is arranged in the stable combustion chamber 10 to convey the pulverized coal fluid into the stable combustion chamber 10.

[0031] Specifically, the housing 15, as an external protective layer, tightly wraps around the periphery of the reflux cylinder 12, which not only provides necessary protection for the entire stable combustion device and helps to guide the reasonable distribution of air flow. And a strengthening layer 13 is added between the housing and the reflux cylinder 12, which not only significantly enhances the overall structural strength of the stable combustion device, enabling it to withstand the high temperature and high pressure environment generated during the combustion process, but also effectively reduces the risk of material wear caused by long-term high-temperature operation, and extends the service life of the equipment. The reflux cylinder 12 and the acceleration cylinder 11 jointly define the stable combustion chamber 10, and the powder feeding port 51 of the pulverized coal pipe assembly 50 is arranged in the stable combustion chamber 10, ensuring that the pulverized coal fluid can be sent into this area in the best state, and then, under the cooperation of the reflux cylinder 12 and the acceleration cylinder 11, the full mixing and efficient combustion of pulverized coal are realized.

[0032] In summary, the pulverized coal stable combustion device 100 in the embodiment of the present invention not only effectively enhances the structural strength and durability of the equipment, but also greatly improves the combustion efficiency and stability of pulverized coal, bringing new solutions and technological breakthroughs to the industrial combustion field.

[0033] In this embodiment, a wear-resistant coating 315 is provided on the outer side of the housing 15, so as to improve the wear resistance of the housing, extend the service life of the equipment, and reduce the costs and inconveniences brought about by frequent replacement or maintenance.

[0034] Further, the strengthening layer 13 is made of heat-insulating cotton. On the one hand, it is used to prevent excessive heat from dissipating from the return cylinder 12 to the housing, causing the temperature of the housing to be too high. On the other hand, it can maintain a relatively high temperature inside the return cylinder 12, promoting the rapid ignition and stable combustion of pulverized coal. At the same time, it can also enhance the structural strength of the return cylinder 12.

[0035] As Figure 1 , Figure 2 and Figure 3 shown, in some embodiments, the accelerating cylinder 11 has a first end 111 and a second end 112 that are oppositely arranged. The diameter of the first end 111 is smaller than that of the second end 112, and a jet port 113 is provided at the first end 111. The return cylinder 12 has a third end 121 and a fourth end 122 that are oppositely arranged. The diameter of the third end 121 is larger than that of the fourth end 122, and the third end 121 of the return cylinder 12 is connected to the second end 112 of the accelerating cylinder 11. That is to say, both the accelerating cylinder 11 and the return cylinder 12 are arranged in a structure similar to a cone, so that the stable combustion chamber is a cylindrical structure with a larger diameter in the middle and smaller diameters at both ends, enabling the pulverized coal fluid ejected from the powder feeding port 51 to rotate inside the cylinder and smoothly eject through the jet port 113 of the accelerating cylinder 11.

[0036] Further, the stable combustion chamber 10 can be divided into a high-temperature return area 123 located inside the return cylinder 12 and a high-temperature acceleration area 114 located inside the accelerating cylinder 11. The powder feeding port 51 is located at the connection between the return cylinder 12 and the accelerating cylinder 11, and the opening of the powder feeding port 51 is arranged facing the high-temperature return area 123, so that the pulverized coal fluid moves towards the high-temperature return area 123, rotates in the high-temperature return area 123, and then flows towards the high-temperature acceleration area 114, and then flows out through the jet port 113.

[0037] As Figure 3 , Figure 4 and Figure 5 shown, in some embodiments, the pulverized coal pipe assembly 50 includes a first return channel 521 and a second return channel 522. The powder feeding port 51 includes a first return port 511 located in the first return channel 521 and a second return port 512 located in the second return channel 522. The first return port 511 and the second return port 512 are connected. The openings of the first return port 511 and the second return port 512 are both arranged facing the inner wall of the return cylinder 12. The straight line where the opening direction of the first return port 511 is located and the straight line where the opening direction of the second return port 512 is located intersect, so as to eject the pulverized coal fluid into the stable combustion chamber.

[0038] Among them, the opening direction of the first return port 511 is parallel to the axis of the return cylinder 12, and the opening direction of the second return port 512 is inclined from the center to the edge along the radial direction of the return cylinder 12. It can be imagined that the flow rates of the pulverized coal fluid in the first return channel 521 and the second return channel 522 can be adjusted as needed to change the injection angle of the pulverized coal fluid to meet different usage requirements.

[0039] Furthermore, the pulverized coal pipe assembly 50 further includes a return cap 52 and a guide plate 523. The first return channel 521 and the second return channel 522 are coaxially arranged in the return cap 52. The first return channel 521 is located outside the second return channel 522. The guide plate 523 is arranged at the connection of the first return port 511 and the second return port 512. An inclined surface is provided on the side of the guide plate 523 facing the second return channel 522, so that the pulverized coal fluid in the second return channel 522 is drained along the inclined surface of the guide plate 523 to the connection of the first return port 511 and the second return port 512. Then, the pulverized coal fluid in the first return channel 521 and the pulverized coal fluid in the second return channel 522 converge to form a stream of pulverized coal fluid, and this pulverized coal fluid is sprayed into the stable combustion chamber 10.

[0040] In this embodiment, the included angle between the straight line where the opening direction of the first return port 511 is located and the straight line where the opening direction of the second return port 512 is located can be set to β°. The pulverized coal fluid in the first return channel 521 can be the first fluid, and the pulverized coal fluid in the second return channel 522 can be the second fluid. The first fluid and the second fluid can converge at the connection of the first return port 511 and the second return port 512, and then converge into a stream of pulverized coal mixed fluid for jet spraying. During the above process, by adjusting the flow rates of the first fluid and the second fluid, the jet momentum ratio of the first fluid and the second fluid can be changed, and the mutual entrainment effect between the first fluid and the second fluid can be changed. Finally, the injection angle of the pulverized coal mixed fluid formed after the convergence of the first fluid and the second fluid is between 0° and β°. Among them, Figure 5 As shown by arrow D in the figure, it is the flow direction of the first fluid, and arrow E shows the flow direction of the second fluid.

[0041] Among them, when the total pulverized coal amount in the first return channel 521 and the second return channel 522 remains unchanged, if the flow rate of the first fluid is increased and the flow rate of the second fluid is decreased, the injection angle of the converging pulverized coal mixed fluid will gradually approach β°; if the flow rate of the first fluid is decreased and the flow rate of the second fluid is increased, the injection angle of the converging pulverized coal mixed fluid will gradually approach 0°.

[0042] It should be noted that when the injection angle of the pulverized coal mixed fluid increases, the radial velocity component of the pulverized coal mixed fluid flowing around will increase, and the axial velocity component will decrease, resulting in an accelerated decay of the overall flow velocity of the pulverized coal mixed fluid from right to left, and an earlier turn to flow from left to right, thereby achieving the purpose of reducing the axial length of the high-temperature recirculation zone 123. Similarly, when the injection angle of the pulverized coal mixed fluid decreases, the radial velocity component of the pulverized coal mixed fluid flowing around will decrease, and the axial velocity component will increase, resulting in a slower decay of the overall flow velocity of the pulverized coal mixed fluid from right to left, and a delayed turn to flow from left to right, thereby achieving the purpose of increasing the axial length of the high-temperature recirculation zone 123.

[0043] As Figure 3 shown, in this embodiment, the pulverized coal pipe assembly 50 further includes a supply pipe 53. The supply pipe 53 is provided with a first channel 531 and a second channel 532. The first channel 531 and the second channel 532 are independent of each other. The first channel 531 is communicated with the first recirculation channel 521, and the second channel 532 is communicated with the second recirculation channel 522. The first channel 531 and the second channel 532 are used to convey different types of pulverized coal fluids into the stable combustion chamber 10. It should be noted that different types of pulverized coal fluids can have different flow velocities or different concentrations. In this embodiment, they are pulverized coal fluids with different flow velocities.

[0044] Furthermore, the supply pipe 53 includes an inner pipe 533 and an outer pipe 534. The inner pipe 533 is hollow to form the first channel 531. The outer pipe 534 is sleeved outside the inner pipe 533. A second channel 532 is formed between the outer pipe 534 and the inner pipe 533, which can ensure the independence and non-interference of the two channels, and also provides a strong guarantee for the stable conveyance of the pulverized coal fluid.

[0045] Even further, the supply pipe 53 further includes a side branch pipe 535 communicated with the second channel 532. The side branch pipe 535 is arranged in a cylindrical shape, and the axis of the side branch pipe 535 is perpendicular to the axis of the outer pipe 534. The side branch pipe 535 is used to convey the pulverized coal fluid to the second channel 532.

[0046] As Figure 3As shown, in some embodiments, the pulverized coal stable combustion device 100 further includes a secondary air assembly 70. The secondary air assembly 70 includes a plurality of independent air ducts 71. The air ducts 71 have air supply openings 711. The air supply openings 711 are provided at one end of the return cylinder 12. The first return opening 511 and the second return opening 512 are provided at the other end of the return cylinder 12. The air supply openings 711 face the first return opening 511 and the second return opening 512, and the air supply openings 711 are arranged offset in the radial direction of the stable combustion chamber 10 relative to the first return opening 511 and the second return opening 512. This can not only adjust the radial width of the pulverized coal fluid in the high-temperature return area 123, but also provide assistance to the pulverized coal fluid in the high-temperature return area 123, accelerating the flow velocity of the pulverized coal fluid towards the injection opening 113.

[0047] Specifically, the plurality of air ducts 71 are not simply arranged side by side or randomly distributed, but are arranged coaxially and sleeved with each other. Due to the mutual sleeving between the air ducts 71, the corresponding air supply openings 711 also exhibit the characteristics of being annularly arranged and sleeved with each other. This means that when the air flow passes through these air supply openings 711, they will be evenly blown into the high-temperature return area 123 in the form of an annular wind. This design of the annular wind not only increases the coverage range of the air flow, but also makes the distribution of the air flow in the return cylinder 12 more uniform, thereby further improving the combustion efficiency and stability of the pulverized coal.

[0048] Moreover, the central axis of the air supply opening 711 completely coincides with the axis of the return cylinder 12, which not only ensures that the air flow can be evenly distributed along the axis direction of the return cylinder 12, but also avoids the phenomenon of air flow deviation or disorder during the transportation process. Such a layout not only improves the transportation efficiency of the air flow, but also makes the combustion process more stable and controllable.

[0049] In this embodiment, three air ducts 71 are provided. The pulverized coal pipe assembly 50 may include an inner layer pipe 721, a middle layer pipe 722 and an outer layer pipe 723. The inner layer pipe 721, the middle layer pipe 722 and the outer layer pipe 723 are sequentially arranged in the radial direction of the stable combustion chamber 10. Three air ducts 71 are correspondingly provided between the inner layer pipe 721, the middle layer pipe 722 and the outer layer pipe 723. Among them, the inner layer pipe 721 is sleeved outside the outer pipe 534 of the pulverized coal pipe, and the outer layer pipe 723 passes through the housing, so that the overall structure can be more compact.

[0050] Furthermore, the secondary air assembly 70 further includes a main air supply pipe 724. The main air supply pipe 724 is connected to the air duct 71, so as to provide a stable air flow for the air duct 71. Moreover, the inner layer pipe 721, the middle layer pipe 722, and the outer layer pipe 723 all include an axial pipe 725 and a radial pipe 726. The axial pipe 725 is arranged to extend along the axial direction of the return cylinder 12, and the radial pipe 726 is arranged to extend along the radial direction of the return cylinder 12. The radial pipe 726 is connected between the axial pipe 725 and the main air supply pipe 724, such that the air duct 71 is arranged in a Z shape, making the overall structure more compact.

[0051] Still further, the secondary air assembly 70 further includes a plurality of regulating valves 73. The plurality of regulating valves 73 are respectively arranged on the air duct 71 one by one. The regulating valve 73 is used to regulate the passing flow rate of the air flow in the air duct 71. And by opening and closing the regulating valve 73, the opening and closing of the air flow in the air duct 71 can be realized, so as to change the radial width of the pulverized coal mixed fluid in the high-temperature recirculation zone 123. That is to say, the secondary air assembly 70 can provide multiple layers of air flows that are sequentially wrapped from the inside to the outside. By closing or reducing the regulating valves 73 on the inner layer pipe 721, the middle layer pipe 722, and the outer layer pipe 723, the radial width of the multiple layers of air flows in the radial direction of the return cylinder 12 can be changed, so as to regulate the radial width of the high-temperature recirculation zone 123.

[0052] In some embodiments, the secondary air assembly 70 further includes a plurality of rotating vanes 74. The plurality of rotating vanes 74 are respectively arranged at the air outlet 711 of the air duct 71 one by one. The rotating vane 74 is used to guide the air flow conveyed by the air duct 71 to form a rotating air flow in the stable combustion chamber 10. Among them, the rotating vane 74 is a structure of a plurality of guide vanes uniformly arranged along the circumferential direction of the air duct 71. Each guide vane is arranged at an angle with the axial direction of the air duct 71. This angle can be set to 30° to 80°, so as to make the air flow passing through the rotating vane 74 into a rotating fluid with an axial velocity and a tangential velocity, and then spray it into the high-temperature recirculation zone 123 of the return cylinder 12.

[0053] In some embodiments, the air duct 71 and the pulverized coal pipe assembly 50 are coaxially arranged. The air duct 71 is arranged outside the pulverized coal pipe assembly 50. A ring-shaped blunt body 75 is arranged between the air duct 71 and the pulverized coal pipe assembly 50. The ring-shaped blunt body 75 is located at the first end 111 of the return cylinder 12. Among them, the ring-shaped blunt body 75 can be arranged between the inner layer pipe 721 and the outer pipe 534 of the pulverized coal pipe assembly 50.

[0054] Furthermore, the secondary air assembly 70 further includes an end plate 76. The end plate 76 is a circular flat plate structure. The left end parts of the outer pipe 534, the inner layer pipe 721, the middle layer pipe 722, and the outer layer pipe 723 are connected to the end plate 76, realizing the connection between the pulverized coal pipe assembly 50 and the secondary air assembly 70.

[0055] In some embodiments, the pulverized coal stable combustion device 100 further includes a cleaning assembly 30. The cleaning assembly 30 includes a cleaning flow channel located between the housing and the reflux cylinder 12. The cleaning flow channel has an air outlet 311. The air outlet 311 is provided at the second end 112 of the acceleration cylinder 11. The opening of the air outlet 311 faces the inner wall of the acceleration cylinder 11, so that the airflow in the housing is directed towards the inner wall of the acceleration cylinder 11, thereby allowing the gas in the housing to clean the inner wall of the stable combustion chamber 10 and avoiding coking.

[0056] Specifically, the cleaning assembly 30 jets the airflow towards the inner wall of the acceleration cylinder 11 through the air outlet 311 facing the inner wall of the acceleration cylinder 11, so that this airflow impacts the inner wall of the acceleration cylinder 11, effectively removing foreign matters such as pulverized coal particles adhered to the inner wall of the acceleration cylinder 11. This not only avoids the influence of pulverized coal adhesion on the performance of the acceleration cylinder 11, but also further speeds up the mixed fluid through the scouring action of the airflow, so that the flow velocity of the mixed fluid at the injection port 113 is further increased.

[0057] In some embodiments, a plurality of openings are provided between the reflux cylinder 12 and the acceleration cylinder 11 to form the air outlet 311 for the airflow in the housing to flow into the stable combustion chamber 10. The housing 15 includes a reduced-diameter section 312. The reduced-diameter section 312 is connected to the second end 112 of the acceleration cylinder 11. A rectifying channel 313 is provided between the reduced-diameter section 312 and the reflux cylinder. The flow gap of the rectifying channel 313 is reduced to guide the airflow in the housing, so that this airflow can flow smoothly and orderly towards the inner wall of the acceleration cylinder 11, avoiding the disorder and vortex phenomena that may occur during the airflow movement. At the same time, the gap between the reduced-diameter section 312 and the reflux cylinder 12 becomes smaller, which can also increase the frictional resistance along the flow of this airflow, making the airflow jetted through the air outlet 311 more uniform, and can also increase the jet velocity of this airflow, so that this airflow maintains a high momentum and flows forward along the inner wall of the acceleration cylinder 11.

[0058] Furthermore, the housing, the reflux cylinder 12, and the acceleration cylinder 11 are all provided in a cylindrical shape, and a plurality of openings are evenly arranged along the cylinder wall of the acceleration cylinder 11, so that the airflow jetted from the housing through the air outlet 311 is more evenly distributed on the cylinder wall of the acceleration cylinder 11, avoiding problems such as excessive local scouring or insufficient cleaning caused by uneven airflow distribution, and ensuring that every area of the inner wall of the acceleration cylinder 11 can be fully cleaned and covered by the airflow.

[0059] Furthermore, the housing includes a straight pipe section 314, which is connected to the reduced-diameter section 312 and sleeved outside the reflux cylinder 12. On the one hand, it provides a stable and smooth channel for the airflow inside the housing, avoiding problems such as increased airflow resistance and reduced flow velocity caused by pipeline bending or deformation, and ensuring that the airflow inside the housing can flow smoothly towards the acceleration cylinder 11 at a relatively high speed, thereby improving the cleaning effect and the acceleration performance of the gas. On the other hand, the straight pipe section 314 is sleeved outside the reflux cylinder 12, making the structure of the entire pulverized coal stable combustion device 100 more compact and efficient. It not only improves the space utilization rate but also reduces the overall size and weight of the equipment, making the pulverized coal stable combustion device 100 more convenient and flexible during installation and operation.

[0060] As Figure 6 shown, the arrow D indicates the flow direction of the pulverized coal fluid in the first channel; the arrow E indicates the flow direction of the pulverized coal fluid in the second channel; the arrow F indicates the flow direction of the airflow in the secondary air assembly; the arrow G indicates the flow direction of the airflow in the cleaning assembly; the arrow H indicates the rotation direction of the pulverized coal fluid in the high-temperature reflux zone; the length M is the axial length of the high-temperature reflux zone; the length N is the radial length of the high-temperature reflux zone. During the use of the above pulverized coal stable combustion device 100, one of the two pulverized coal fluids flows towards the first reflux port 511 through the first channel 531 and the first reflux channel 521, and the other of the two pulverized coal fluids flows towards the second reflux port 512 through the second channel 532 and the second reflux channel 522. The two pulverized coal fluids converge into a pulverized coal mixed fluid at the connection of the first reflux port 511 and the second reflux port 512 and are sprayed into the high-temperature reflux zone 123 inside the reflux cylinder 12 from right to left along the axis of the reflux cylinder 12;

[0061] Meanwhile, the secondary air assembly 70 divides the secondary air into three airflows through the air supply main pipe 724 and injects them into the inner layer pipe 721, the middle layer pipe 722, and the outer layer pipe 723 respectively. Then, under the rotational guiding action of the rotating vane 74 and along the axis of the reflux cylinder 12, they are injected into the high-temperature reflux zone 123 inside the reflux cylinder 12 from left to right. Thus, three layers of rotating airflows wrapped from the inside to the outside can be formed on the left side of the reflux cylinder 12, which can not only provide oxygen for pulverized coal combustion but also enhance the entrainment effect of the high-temperature airflow by constructing a low-pressure area inside the rotating airflow, further promoting the formation and maintenance of the high-temperature reflux zone 123. At the same time, by closing or reducing the regulating valves 73 on the inner layer pipe 721, the middle layer pipe 722, and the outer layer pipe 723, the width of the multi-layer airflow in the radial direction of the reflux cylinder 12 can be changed, thereby adjusting the radial width of the high-temperature reflux zone 123.

[0062] In addition, the airflow within the cleaning assembly 30 can pass through the cleaning air duct 71 and the air outlet 311, and be injected into the acceleration cylinder 11 from left to right along the axial direction of the return cylinder 12, and flow at high speed along the inner wall of the acceleration cylinder 11, so as to wrap and carry the jet flame located at the center out, ensuring good rigidity of the central flame.

[0063] When the acceleration cylinder 11 and the injection port 113 are ingeniously arranged inside the burner, these high-temperature flames can quickly ignite the pulverized coal airflow located around the injection port 113, thus achieving efficient and stable combustion of the pulverized coal.

[0064] In summary, under the combined action of the pulverized coal pipe assembly 50, the secondary air assembly 70, and the cleaning assembly 30, a high-temperature recirculation zone 123 can be formed inside the return cylinder 12, and high-temperature flames are generated. Then, under the acceleration of the acceleration cylinder 11, a high-temperature jet flame is ejected at high speed through the injection port 113, so as to ignite the pulverized coal airflow that has not burned and is located around the injection port 113 inside the burner, thus achieving efficient and continuous combustion of the pulverized coal.

[0065] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0066] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0067] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or communicable with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is less than that of the second feature.

[0069] In the present invention, the terms "one embodiment", "some embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0070] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A pulverized coal combustion stabilization device, characterized in that: It comprises a burner and a flame stabilizer, at least part of which is located in the burner; the flame stabilizer comprises a cover, a reflux cylinder, an acceleration cylinder and a pulverized coal pipe assembly, the cover is arranged on the outside of the reflux cylinder, and a reinforcement layer is arranged between the cover and the reflux cylinder; the reflux cylinder and the acceleration cylinder are connected to define a stabilizing combustion chamber, the pulverized coal pipe assembly has a powder delivery port, and the powder delivery port is arranged in the stabilizing combustion chamber to deliver the pulverized coal fluid into the stabilizing combustion chamber; The pulverized coal pipe assembly includes a first reflow channel and a second reflow channel, and the powder delivery port includes a first reflow port located in the first reflow channel and a second reflow port located in the second reflow channel. The first reflow port and the second reflow port are connected, and the opening of the first reflow port and the opening of the second reflow port are both arranged toward the inner wall of the reflow cylinder. The straight line where the opening direction of the first reflow port is located and the straight line where the opening direction of the second reflow port is located intersect, so as to spray the pulverized coal fluid into the stable combustion chamber.

2. The pulverized coal combustion stabilization device according to claim 1, characterized in that: The acceleration cylinder has a first end and a second end that are arranged opposite to each other, the diameter of the first end is smaller than the diameter of the second end, and the first end is provided with a jet port; the reflux cylinder has a third end and a fourth end that are arranged opposite to each other, the diameter of the third end is larger than the diameter of the fourth end, and the third end of the reflux cylinder is connected to the second end of the acceleration cylinder.

3. The pulverized coal combustion stabilization device according to claim 1, characterized in that: The outer side of the cover shell is provided with a wear-resistant coating; And / or, the reinforcement layer is made of thermal insulation cotton.

4. The pulverized coal combustion stabilization device according to claim 1, characterized in that: The pulverized coal pipe assembly includes a reflux cap and a guide plate. The first reflux channel and the second reflux channel are coaxially arranged in the reflux cap. The first reflux channel is located on the outside of the second reflux channel. The guide plate is arranged at the connection point between the first reflux port and the second reflux port. The guide plate is provided with an inclined surface on the side facing the second reflux channel.

5. The pulverized coal combustion stabilization device according to claim 1, characterized in that: The pulverized coal pipe assembly includes a supply pipe, in which a first channel and a second channel are provided. The first channel is connected to the first return channel, and the second channel is connected to the second return channel. The first channel and the second channel are used to transport different types of pulverized coal fluids into the combustion stabilization chamber.

6. The pulverized coal combustion stabilization device according to claim 1, characterized in that: It also includes a secondary air component, which includes a plurality of independent air ducts, each of which has an air supply port, wherein the air supply port is arranged at one end of the reflux cylinder, and the powder supply port is arranged at the other end of the reflux cylinder, and the air supply port is staggered relative to the powder supply port in the radial direction of the combustion stabilization chamber.

7. The pulverized coal combustion stabilization device according to claim 6, characterized in that: The secondary air component further includes a plurality of regulating valves, which are arranged on the air duct in a one-to-one correspondence, and the regulating valves are used to adjust the flow rate of the air flow in the air duct.

8. The pulverized coal combustion stabilization device according to claim 6, characterized in that: The secondary air component also includes a plurality of rotors, which are arranged one by one at the air supply port of the air duct. The rotors are used to guide the airflow transported by the air duct to form a rotating airflow in the combustion stabilization chamber.

9. The pulverized coal combustion stabilization device according to claim 6, characterized in that: The air duct and the pulverized coal pipe assembly are coaxially arranged, the air duct is arranged outside the pulverized coal pipe assembly, and an annular blunt body is arranged between the air duct and the pulverized coal pipe assembly.

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