Pulverized coal stable combustion and concentration device for coal-fired power unit

Abstract

The present application relates to a pulverized coal stable combustion and concentration device for a coal-fired power unit. The pulverized coal stable combustion and concentration device for a coal-fired power unit comprises a combustor, a combustion stabilizer, and a concentrator; the concentrator is used for dividing primary air pulverized coal airflow provided by a pulverized coal air source into first airflow, second airflow, and third airflow; the first airflow, the second airflow, and the third airflow are combusted in the combustion stabilizer and the combustor; a first inlet is communicated with the concentrator so as to introduce the first airflow into a pulverized coal pipe assembly; the pulverized coal pipe assembly can divide the first airflow into first sub-airflow and second sub-airflow; the concentration of pulverized coal in the first sub-airflow is less than the concentration of pulverized coal in the second sub-airflow; a first outlet is used for discharging the first sub-airflow into a cavity; a second outlet is used for discharging the second sub-airflow into the cavity; and a secondary air pipe is provided on the outer peripheral side of the inlet end of the combustion stabilizer and is communicated with the cavity. Therefore, the pulverized coal stable combustion and concentration device for a coal-fired power unit in the embodiments of the present application has the advantages of good combustion stability, good environmental protection effect, low production cost and the like.

Description

A coal-fired power unit pulverized coal combustion stabilization and concentration device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Chinese patent application number 202310754085.1, filed on June 25, 2023, priority to and the benefit of Chinese patent application number 202310755873.2, filed on June 25, 2023, priority to and the benefit of Chinese patent application number 202321625121.6, filed on June 25, 2023, priority to and the benefit of Chinese patent application number 202321624454.7, filed on June 25, 2023, priority to and the benefit of Chinese patent application number 202310754088.5, filed on June 25, 2023 The priority and rights of the Chinese patent application, the priority and rights of the Chinese patent application with application number 202321620820.1 and application date June 25, 2023, the priority and rights of the Chinese patent application with application number 202321625146.6 and application date June 25, 2023, the priority and rights of the Chinese patent application with application number 202321620798.0 and application date June 25, 2023, the priority and rights of the Chinese patent application with application number 202321625137.7 and application date June 25, 2023, the entire contents of the above-mentioned Chinese patent applications are hereby incorporated by reference into this application. Technical Field

[0003] The present application relates to the technical field of pulverized coal combustion, and in particular to a pulverized coal combustion stabilization and concentration device for a coal-fired power plant. Background Art

[0004] Coal-fired power plants seeking to improve the stable combustion of pulverized coal burners during low-load and variable-load operation typically rely on adding ignition devices or adding auxiliary fuel. Common ignition and stabilization methods use diesel fuel, which requires large quantities of diesel and is very expensive. Furthermore, the addition of fuel to aid combustion can generate new pollutants, such as sulfides and nitrogen oxides. Pulverized coal burners equipped with plasma ignition devices can improve stable combustion at low loads, but the cathode material in these devices has a very short lifespan, increasing unit operating costs.

[0005] In recent years, a method has emerged in which a resistance wire is used to heat the combustion chamber shell, thereby heating the fuel inside the combustion chamber. However, the heating efficiency of indirectly heating the internal structure of the combustion chamber using a resistance wire is low, and during the heating process, the resistance wire and the combustion chamber shell need to withstand very high temperatures, which places high demands on the materials of the resistance wire and the combustion chamber.

[0006] In summary, how to provide a technology that does not require the input of auxiliary fuel and does not require the addition of an ignition device to improve the stable combustion ability of a pulverized coal burner during low-load and variable-load operation has become an important issue that needs to be urgently solved by researchers and technicians in this field.

[0007] Application Contents

[0008] The present application aims to solve at least one of the technical problems in the related art to a certain extent. To this end, an embodiment of the present application proposes a pulverized coal combustion stabilization and concentration device for a coal-fired power plant.

[0009] The pulverized coal combustion stabilization and concentration device for a coal-fired power plant in the embodiment of the present application includes:

[0010] burners and concentrators;

[0011] a burner, wherein an outlet end of the burner is in communication with the burner, the burner extending in a first direction, the burner comprising a cavity and a pulverized coal pipe assembly at least partially disposed within the cavity, the concentrator being in communication with the pulverized coal pipe assembly so as to introduce a first airflow containing pulverized coal into the pulverized coal pipe assembly;

[0012] The pulverized coal pipe assembly can divide the first airflow into a first sub-airflow and a second sub-airflow and introduce the second sub-airflow into the cavity, wherein the pulverized coal concentration of the first sub-airflow is lower than that of the second sub-airflow, and the introduction position of the second sub-airflow is adjacent to the outlet end of the burner stabilizer relative to the introduction position of the first sub-airflow;

[0013] A secondary air duct is communicated with the cavity.

[0014] Therefore, the pulverized coal combustion stabilization and concentration device for a coal-fired power unit according to the embodiment of the present application has the advantages of good combustion stability, good environmental protection effect and low production cost.

[0015] Furthermore, the pulverized coal combustion stabilization and concentration device for coal-fired power plants according to the embodiment of the present application has the following effects:

[0016] (1) Significant economic advantages

[0017] Compared with traditional micro-oil igniters and plasma igniters, this application has significant economic advantages. It can achieve the effect of using a small amount of coal powder to ignite the majority of surrounding coal powder, completely replacing traditional micro-oil igniters and plasma igniters. It uses coal as fuel for direct ignition, achieving the goal of using a small amount of coal powder to ignite a large amount of surrounding coal powder, and improving the economic efficiency of coal-fired units during the ignition process and peak load regulation process.

[0018] (2) Rapid ignition and strong low-load stable combustion capability

[0019] This application couples multi-stage pulverized coal concentration and multi-stage pulverized coal preheating to enhance ignition and stable combustion. By establishing pulverized coal concentration and lean combustion and two-stage pulverized coal ignition and preheating within the combustion-free stabilizer, and constructing multi-stage (three or more) pulverized coal preheating downstream of the combustion-free stabilizer, the downstream pulverized coal airflow is sequentially ignited. This facilitates rapid ignition during the startup of coal-fired units and stable combustion during flexible peak-shaving, while also promoting burnout during pulverized coal combustion.

[0020] (3) Low NOx generation

[0021] By implementing a rich-lean combustion system and a two-stage high-temperature reduction zone within the unsupported combustion stabilizer, as well as multi-stage rich-lean combustion downstream of the unsupported combustion stabilizer's outlet, a multi-stage, highly reducing atmosphere is created along the flame's high-temperature zone, helping to reduce fuel-induced NOx generation. Furthermore, the presence of these multi-stage high-temperature zones results in a more uniform overall temperature distribution within the unsupported combustion stabilizer and the pulverized coal burner, helping to reduce thermal NOx generation.

[0022] (4) Flexible and practical

[0023] The present application can be applied to a four-corner tangential circular direct current burner, and can also be applied to a wall-type opposed swirl burner. It has wide applicability and is convenient for on-site modification on existing types of burners. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic structural diagram of a pulverized coal combustion stabilization and concentration device for a coal-fired power plant according to an embodiment of the present application.

[0025] FIG2 is a schematic diagram of the internal airflow of the combustion stabilizer and the burner of the pulverized coal combustion stabilization and concentration device of the coal-fired power unit according to an embodiment of the present application.

[0026] FIG3 is a left side view of the combustion stabilizer of the pulverized coal combustion stabilization and concentration device of the coal-fired power unit according to an embodiment of the present application.

[0027] FIG4 is a cross-sectional view of a combustion stabilizer of a pulverized coal combustion stabilization and concentration device for a coal-fired power unit according to an embodiment of the present application.

[0028] FIG5 is a schematic structural diagram of a combustion stabilizer and a burner of a pulverized coal combustion stabilization and concentration device for a coal-fired power unit according to an embodiment of the present application.

[0029] FIG6 is a schematic structural diagram of a concentrator of a pulverized coal combustion stabilization and concentration device for a coal-fired power plant according to an embodiment of the present application.

[0030] FIG7 is a schematic cross-sectional view of AA, BB, CC, and DD in FIG6 .

[0031] FIG8 is a schematic structural diagram of the burner and tertiary air duct of the pulverized coal combustion stabilization and concentration device of the coal-fired power unit according to an embodiment of the present application.

[0032] FIG9 is a structural diagram of a burner and a tertiary air duct of a pulverized coal combustion stabilization and concentration device for a coal-fired power plant according to another embodiment of the present application.

[0033] FIG10 is a schematic diagram of the internal airflow flow of the combustion stabilizer of the pulverized coal combustion stabilization and concentration device of the coal-fired power unit according to an embodiment of the present application.

[0034] FIG11 is a schematic diagram of the internal airflow direction of the burner according to an embodiment of the present application. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present application, but should not be understood as limiting the present application.

[0036] As shown in Figures 1-9, the coal powder combustion stabilization and concentration device 1000 of the coal-fired power unit according to the embodiment of the present application includes a burner 200, a combustion stabilizer 100 and a concentrator 300.

[0037] The outlet end of the combustion stabilizer 100 is in communication with the burner 200. The combustion stabilizer 100 extends along a first direction. The combustion stabilizer 100 includes a cavity and a pulverized coal pipe assembly 11 at least partially disposed within the cavity. The concentrator 300 can be in communication with the pulverized coal pipe assembly 11 to introduce a first airflow containing pulverized coal into the pulverized coal pipe assembly 11.

[0038] The pulverized coal pipe assembly 11 can divide the first airflow into a first sub-airflow and a second sub-airflow and introduce them into the cavity. The pulverized coal concentration of the first sub-airflow is lower than that of the second sub-airflow. The introduction position of the second sub-airflow is adjacent to the outlet end of the stabilizer 100 relative to the introduction position of the first sub-airflow.

[0039] The secondary air duct 13 is communicated with the cavity.

[0040] For the convenience of description, the left-right direction in FIG. 1 is taken as the first direction below.

[0041] For example, the flame stabilizer 100 extends in the left-right direction, the outlet end of the flame stabilizer 100 is the right end of the flame stabilizer 100, a cavity is provided in the flame stabilizer 100, the right end of the pulverized coal pipe assembly 11 is provided in the cavity, the concentrator 300 can be connected to the pulverized coal gas source, and the concentrator 300 is connected to the left end of the pulverized coal pipe assembly 11 so as to introduce the first airflow into the pulverized coal pipe assembly 11.

[0042] When the coal powder stabilization and concentration device 1000 of the coal-fired power unit of the embodiment of the present application is in operation, the concentrator 300 introduces a first airflow into the coal powder pipe assembly 11, and the first airflow is divided into a first sub-airflow and a second sub-airflow with different coal powder concentrations in the coal powder pipe assembly 11, and the coal powder concentration of the first sub-airflow is lower than the coal powder concentration of the second sub-airflow.

[0043] Then, the first sub-airflow and the second sub-airflow flow into the cavity from the pulverized coal pipe assembly 11. The introduction position of the first sub-airflow is on the left side of the introduction position of the second sub-airflow.

[0044] At the same time, secondary air is injected into the cavity at high speed along secondary air duct 13, gradually flowing rightward within the cavity to form a high-speed rotating airflow, and a low-pressure zone is formed in the center of the secondary air flow. As the secondary air gradually flows rightward, some of it flows into the low-pressure zone, forming a high-speed recirculation zone within housing 12.

[0045] Because the second sub-airflow is introduced adjacent to the high-speed recirculation zone, it is more easily entrained into the high-speed recirculation zone during its flow, igniting some of the pulverized coal in the second sub-airflow. This causes the second sub-airflow to swirl and burn within the high-speed recirculation zone, releasing heat and thus forming a dense-phase, high-temperature recirculation zone. This facilitates rapid heating and ignition of the second sub-airflow, releasing a significant amount of heat and forming a dense-phase, high-temperature recirculation zone. Simultaneously, the first sub-airflow is injected at a distance to the left of the second sub-airflow. The first sub-airflow is blocked and carried by the swirling secondary airflow, causing it to deflect and enter the dense-phase, high-temperature recirculation zone between the swirling secondary airflow and the second sub-airflow.

[0046] During this process, although the pulverized coal concentration in the first sub-flow is low and not prone to ignition and combustion, on the one hand, the low concentration of pulverized coal in the first sub-flow is subjected to convection and radiation heat transfer in the high-temperature recirculation zone, which promotes the heating and ignition of the first sub-flow. Furthermore, the first sub-flow is introduced to the left of the second sub-flow, allowing the first sub-flow to reside longer within the housing 12 than the second sub-flow. These two factors together promote the ignition and burnout of the first sub-flow. At this point, the first sub-flow undergoes primary preheating, rapidly heating and igniting, and releasing a significant amount of heat, forming a light-phase high-temperature recirculation zone outside the dense-phase high-temperature recirculation zone.

[0047] At the same time, since the second sub-flow is injected at a certain distance from the first sub-flow, it is beneficial to delay the mixing of the rich and lean airflows. While promoting overall combustion, it is beneficial to deepen the rich and lean combustion effect of coal powder and reduce NOx generation.

[0048] The pulverized coal combustion stabilization and concentration device 1000 for a coal-fired power plant according to the embodiment of the present application has the following advantages:

[0049] (1) Significant economic advantages.

[0050] Compared to traditional micro-oil igniters and plasma igniters, this application offers significant economic advantages. By igniting only a portion of the pulverized coal in the second sub-airflow, this application can achieve the goal of using a small amount of pulverized coal to ignite the majority of the surrounding pulverized coal. This completely replaces traditional micro-oil igniters and plasma igniters, using coal as fuel for direct ignition, achieving the goal of using a small amount of pulverized coal to ignite a large amount of surrounding pulverized coal. This improves the economic efficiency of coal-fired units during the ignition and peak-shaving processes, and reduces production costs.

[0051] (2) Rapid ignition and strong low-load stable combustion capability

[0052] This application constructs coal powder concentration combustion and secondary coal powder ignition preheating inside the non-combustion stabilizer 100, which helps to quickly ignite the coal-fired unit during startup and stabilize combustion during flexible peak regulation, while promoting the burnout effect during coal powder combustion.

[0053] (3) Reduce NOx generation

[0054] The construction of a rich-lean combustion system and two-stage high-temperature reduction zones within the combustion stabilizer 100 helps reduce fuel-induced NOx generation. Furthermore, the presence of these multiple high-temperature zones creates a more uniform temperature distribution within the combustion stabilizer 100 and the pulverized coal burner 200, helping to reduce thermal NOx generation and improve environmental performance.

[0055] (4) The combustion stabilizer 100 of the pulverized coal combustion stabilizing and concentrating device 1000 of the coal-fired power unit of the embodiment of the present application can be applied to the four-corner cut-circle direct current burner 200, and can also be applied to the wall-type counter-swirling burner 200. It has wide applicability and is convenient for on-site modification on existing types of burners 200.

[0056] Therefore, the pulverized coal combustion stabilization and concentration device 1000 for a coal-fired power plant according to an embodiment of the present application has the advantages of good combustion stability, good environmental protection effect, and low production cost.

[0057] The following describes in detail the combustion stabilizer 100 of the pulverized coal combustion stabilization and concentration device 1000 of the coal-fired power unit according to an embodiment of the present application.

[0058] As shown in FIG3 , FIG4 and FIG10 , the combustion stabilizer 100 of the embodiment of the present application includes a shell 12 , a pulverized coal pipe assembly 11 , a secondary air duct 13 and a concentrator 1112 .

[0059] The housing 12 includes a cavity.

[0060] The pulverized coal pipe assembly 11 extends along a first direction, which includes a first sub-direction and a second sub-direction opposite to the first sub-direction. The direction from the inlet end of the pulverized coal pipe assembly 11 to the outlet end of the pulverized coal pipe assembly 11 is the first sub-direction. At least part of the pulverized coal pipe assembly 11 is arranged in the cavity, and the outer peripheral surface of the pulverized coal pipe assembly 11 is sealed with the shell 12.

[0061] The first channel 117 and the second channel 118 are spaced apart in the pulverized coal pipe assembly 11 . Both the first channel 117 and the second channel 118 are connected to the cavity. The outlet of the first channel 117 is adjacent to the inlet end of the pulverized coal pipe assembly 11 relative to the outlet of the second channel 118 .

[0062] The concentrator 1112 is arranged in the pulverized coal pipe assembly 11. The concentrator 1112 can split the first airflow entering the pulverized coal pipe assembly 11 into a first sub-airflow and a second sub-airflow, and the pulverized coal concentration of the first sub-airflow is less than the pulverized coal concentration of the second sub-airflow. The first channel 117 is used for the first sub-airflow to pass through, and the second channel 118 is used for the second sub-airflow to pass through.

[0063] The secondary air duct 13 is communicated with the cavity.

[0064] For ease of description, the left-right direction in FIG. 4 is taken as the first direction below, wherein rightward is the first sub-direction and leftward is the second sub-direction.

[0065] For example, a cavity is provided in the shell 12, the pulverized coal pipe assembly 11 extends in the left and right directions, the center line of the pulverized coal pipe assembly 11 coincides with the center line of the shell 12, the left end of the pulverized coal pipe assembly 11 is provided outside the shell 12, and the right end of the pulverized coal pipe assembly 11 is provided inside the shell 12.

[0066] The left end of the housing 12 is provided with a sealing plate with a mounting opening in the middle. The pulverized coal pipe assembly 11 is fixed in the housing 12 through the mounting opening, and the outer peripheral wall of the pulverized coal pipe assembly 11 is sealed to the inner peripheral wall of the mounting opening. The right end of the housing 12 is provided with a flame stabilizer outlet 125.

[0067] A first channel 117 and a second channel 118 are provided in the pulverized coal pipe assembly 11 . The first channel 117 and the second channel 118 are spaced apart from each other. Both the first channel 117 and the second channel 118 are connected to the cavity. The outlet of the first channel 117 is provided on the left side of the outlet of the second channel 118 .

[0068] A secondary air channel is defined in the secondary air duct 13 , and the secondary air channel can be communicated with the cavity so as to introduce secondary air into the cavity.

[0069] When the flame stabilizer 100 of the embodiment of the present application is working, the primary air flow provided by the pulverized coal gas source enters the pulverized coal pipe assembly 11. After being concentrated by the concentrator 1112, the first air flow is divided into a first sub-air flow and a second sub-air flow, and the pulverized coal concentration of the first sub-air flow is less than the pulverized coal concentration of the second sub-air flow. The first sub-air flow flows from the first channel 117 into the cavity, and the second sub-air flow flows from the second channel 118 into the cavity.

[0070] At the same time, the secondary air is sprayed into the cavity at high speed along the secondary air duct 13, gradually flows to the right in the cavity and forms a high-speed rotating airflow. Since the secondary air at this time has a large rotating tangential velocity, a low-pressure area is formed in the central area of ​​the secondary air during the high-speed rotating flow process.

[0071] When the secondary air gradually flows to the right, part of the secondary air will flow into the low-pressure area, thereby forming a high-speed recirculation area in the shell 12.

[0072] Because the outlet of the second channel 118 is located adjacent to the high-speed recirculation zone, the second sub-airflow is injected into the cavity adjacent to the high-speed recirculation zone. This allows the second sub-airflow to be more easily entrained into the adjacent high-speed recirculation zone during its flow, igniting some of the pulverized coal in the second sub-airflow. This allows the second sub-airflow to swirl and burn within the adjacent high-speed recirculation zone, releasing heat and igniting all of the pulverized coal in the second sub-airflow, thereby forming a dense-phase high-temperature recirculation zone. This facilitates rapid heating and ignition of the second sub-airflow, releasing a significant amount of heat, and ensuring stable combustion of the pulverized coal within the dense-phase high-temperature recirculation zone. Simultaneously, the first sub-airflow is injected into the cavity at a distance to the left of the second sub-airflow. The first sub-airflow is blocked and carried by the swirling secondary airflow, causing it to deflect and enter the dense-phase high-temperature recirculation zone between the swirling secondary airflow and the second sub-airflow.

[0073] During this process, although the pulverized coal concentration in the first sub-airflow is low and not prone to ignition and combustion, on the one hand, the low concentration of pulverized coal in the first sub-airflow is subjected to convection and radiation heat transfer in the high-temperature recirculation zone, which promotes the heating and ignition of the first sub-airflow. On the other hand, the outlet of the first channel 117 is located to the left of the outlet of the second channel 118, so that the first sub-airflow is located to the left of the second sub-airflow when entering the cavity, thereby ensuring a longer residence time within the housing 12 than the second sub-airflow. These two factors jointly promote the ignition and burnout of the first sub-airflow. At this time, the first sub-airflow is preheated, rapidly heating and igniting, and releasing a large amount of heat, forming a light-phase high-temperature recirculation zone outside the dense-phase high-temperature recirculation zone.

[0074] At the same time, since the second sub-flow is injected at a certain distance from the first sub-flow, it is beneficial to delay the mixing of the rich and lean airflows. While promoting overall combustion, it is beneficial to deepen the rich and lean combustion effect of coal powder and reduce NOx generation.

[0075] Then, the flame is ejected from the burner outlet 125 at high speed.

[0076] The flame stabilizer 100 of the embodiment of the present application has the following advantages:

[0077] (1) Significant economic advantages.

[0078] Compared to traditional micro-oil igniters and plasma igniters, this application offers significant economic advantages. By igniting only a portion of the pulverized coal in the second sub-airflow, this application can achieve the goal of using a small amount of pulverized coal to ignite the majority of the surrounding pulverized coal. This completely replaces traditional micro-oil igniters and plasma igniters, using coal as fuel for direct ignition, achieving the goal of using a small amount of pulverized coal to ignite a large amount of surrounding pulverized coal. This improves the economic efficiency of coal-fired units during the ignition and peak-shaving processes, and reduces production costs.

[0079] (2) Rapid ignition and strong low-load stable combustion capability

[0080] This application constructs coal powder concentration combustion and secondary coal powder ignition preheating inside the non-combustion stabilizer 100, which helps to quickly ignite the coal-fired unit during startup and stabilize combustion during flexible peak regulation, while promoting the burnout effect during coal powder combustion.

[0081] (3) Reduce NOx generation

[0082] The construction of a rich-lean combustion system and two-stage high-temperature reduction zones within the combustion stabilizer 100 helps reduce fuel-induced NOx generation. Furthermore, the presence of these multiple high-temperature zones creates a more uniform temperature distribution within the combustion stabilizer, helping to reduce thermal NOx generation and improve environmental performance.

[0083] Therefore, the combustion stabilizer 100 of the embodiment of the present application has the advantages of good combustion stability, good environmental protection effect and low production cost.

[0084] In some embodiments, as shown in FIG4 , the pulverized coal pipe assembly 11 includes a first inlet 1111, a first outlet 115, and a second outlet 116. The first inlet 1111, the first outlet 115, and the second outlet 116 are all provided on the pulverized coal pipe assembly 11 and are sequentially and spaced apart along the first sub-direction. The first inlet 1111 and the first outlet 115 are connected via a first channel 117, and the first inlet 1111 and the second outlet 116 are connected via a second channel 118. The openings of the first outlet 115 and the second outlet 116 are both provided toward the inlet end of the pulverized coal pipe assembly 11. A stabilizer outlet 125 is provided at the outlet end of the burner 100.

[0085] For example, the pulverized coal pipe assembly 11 is provided with a first inlet 1111, a first outlet 115, and a second outlet 116, which are arranged in sequence along the left-right direction. The first inlet 1111 is provided on the left side of the pulverized coal pipe assembly 11 and outside the housing 12. The first inlet 1111 is connected to the first outlet 115, and the first inlet 1111 is also connected to the second outlet 116. The first outlet 115 and the second outlet 116 are both provided in the housing 12 and communicate with the cavity.

[0086] The openings of the first outlet 115 and the second outlet 116 are both toward the left, so that the initial directions of the first sub-airflow and the second sub-airflow entering the cavity are both toward the left, so as to form a high-temperature reflow zone with the secondary air.

[0087] In some embodiments, as shown in Figure 4, the pulverized coal pipe assembly 11 includes a first pipe 111 and a second pipe 112. The inlet end of the first pipe 111 is provided with a first inlet 1111, the second pipe 112 and the concentrator 1112 are both arranged in the first pipe 111, and the concentrator 1112 and the second pipe 112 are arranged sequentially and spaced apart in the first sub-direction. The inner circumferential wall of the first pipe 111 and the outer circumferential wall of the second pipe 112 define a first sub-channel, and the inner circumferential wall of the second pipe 112 defines a second channel 118.

[0088] For example, the first tube 111 extends in a left-right direction. The inlet end of the first tube 111 is the left end of the first tube 111, and the outlet end of the first tube 111 is the right end of the first tube 111. The left end of the first tube 111 is open, forming a first inlet 1111. The second tube 112 is disposed within the first tube 111. A concentrator 1112 is disposed to the left of the second tube 112 and spaced apart from the second tube 112. After passing through the concentrator 1112, the first airflow is split into a first sub-airflow and a second sub-airflow. The inner circumferential wall of the first tube 111 is spaced apart from the outer circumferential wall of the second tube 112 to form a first sub-channel, while the inner circumferential wall of the second tube 112 defines a second channel 118. The first outlet 115 is disposed to the left of the second outlet 116, so that when the first and second sub-airflows enter the cavity, the first sub-airflow is to the left of the second sub-airflow. Thus, the spacing between the first and second tubes 111, 112, defines the first and second sub-channels 118, facilitating the passage of the pulverized coal airflow.

[0089] Optionally, the left end of the first tube 111 extends leftward out of the housing 12 , and the concentrator 1112 is located at the portion of the first tube 111 extending out of the housing 12 , thereby facilitating replacement of the concentrator 1112 .

[0090] In some embodiments, as shown in FIG4 , the pulverized coal pipe assembly 11 further includes a first return member 113 and a second return member 114. The first return member 113 is sleeved around the outer periphery of the second pipe 112 and connected to the outlet end of the second pipe 112. The outlet end of the first pipe 111 extends between the first return member 113 and the second pipe 112, so that the inner periphery of the first return member 113 and the outer periphery of the first pipe 111 define a return channel 119 that communicates with the first sub-channel, and the opening of the return channel 119 faces the inlet end of the first pipe 111 to form a first outlet 115. In the first sub-direction, the first return member 113 and the second return member 114 are arranged sequentially and spaced apart, and a portion of the second return member 114 is sleeved around the outer periphery of the first return member 113 to form a second outlet 116.

[0091] For example, the outlet end of the second tube 112 is the right end of the second tube 112. The first return member 113 is connected to the right end of the second tube 112 and is sleeved on the outer circumference of the second tube 112. The outlet end of the first tube 111 is the right end of the first tube 111. The right end of the first tube 111 is located between the first return member 113 and the second tube 112. The outer circumferential wall of the first tube 111 and the inner circumferential wall of the first return member 113 are spaced apart to form a return channel 119. The right end surface of the first tube 111 is spaced apart from the right end of the first return portion, so that the return channel 119 and the first sub-channel can communicate. The opening of the return channel 119 faces leftward to form the first outlet 115.

[0092] The second return member 114 is arranged on the right side of the first return member 113, and a portion of the second return member 114 is arranged on the outer peripheral side of the first return member 113, so that a second outlet 116 opening toward the left is formed between the inner peripheral wall of the second return member 114 and the outer peripheral wall of the first return member 113.

[0093] Thus, after entering the first sub-channel, the first sub-airflow is blocked by the first reflow member 113 and deflected into the reflow channel 119, and then discharged from the first outlet 115. After entering the second channel 118, the second sub-airflow is blocked by the second reflow member 114 and deflected before being discharged from the second outlet 116. The combustion stabilizer 100 of the present embodiment utilizes the first reflow member 113 and the second reflow member 114 so that the initial flow directions of the first and second sub-airflows entering the cavity are both toward the left, thereby facilitating the formation of a high-temperature combustion zone and thereby improving the stability of the combustion stabilizer 100.

[0094] In some embodiments, as shown in Figure 4, the first reflux member 113 includes a first cylindrical portion and a first end portion. The first cylindrical portion is sleeved on the outer peripheral side of the first tube 111, and the first end portion is used to connect the first cylindrical portion and the second tube 112. The first end portion is spaced apart from the end face of the outlet end of the first tube 111 in the first direction so that the first sub-channel and the reflux channel 119 are connected to form a first channel 117.

[0095] For example, the first end portion is an annular plate-like member, the inner circumferential wall of the first end portion is connected to the second tube 112, and the outer circumferential wall of the second end portion is connected to the first cylindrical portion, which extends leftward from the left side of the first end portion. The outlet end of the first tube 111 is the right end of the first tube 111, and the right end of the first tube 111 is spaced apart from the first end portion so that the first sub-channel and the reflux channel 119 are connected, thereby forming the first channel 117.

[0096] Therefore, the first reflow member 113 of the combustion stabilizer 100 of the embodiment of the present application has a simple structure and is easy to process.

[0097] In some embodiments, as shown in Figure 4, the second return member 114 includes a second end and a second cylindrical portion, the second end and the first end are spaced apart in the first direction, the second cylindrical portion extends from the surface of the second end toward the direction of the first end, and the second cylindrical portion is sleeved on the outer peripheral side of the first cylindrical portion so that a second outlet 116 is formed between the inner peripheral wall of the second cylindrical portion and the outer peripheral wall of the first cylindrical portion, the second outlet 116 opening toward the inlet end of the pulverized coal pipe assembly 11.

[0098] For example, the second end is a circular plate-like member, the second cylinder extends to the left from the left side of the second end, and is sleeved on the outer peripheral wall of the first cylinder, the first cylinder and the second cylinder are spaced apart to form a second outlet 116, and the opening of the second outlet 116 faces the left side.

[0099] Therefore, the first reflow member 113 of the combustion stabilizer 100 of the embodiment of the present application has a simple structure and is easy to process.

[0100] In some embodiments, as shown in Figure 4, the shell 12 includes a first section 121, a second section 122, a third section 123 and a fourth section 124 connected in sequence in the first direction, the secondary air duct 13 is connected to the first section 121, the first section 121 and the third section 123 are both cylindrical, the cross-sectional area of ​​the second section 122 gradually increases along the first sub-direction, and the cross-sectional area of ​​the fourth section 124 gradually decreases along the first sub-direction, the first outlet 115 is arranged in the second section 122, and the second outlet 116 is arranged in the third section 123.

[0101] For example, the first section 121, the second section 122, the third section 123, and the fourth section 124 are arranged sequentially from left to right, with the secondary air duct 13 located on the outer periphery of the first section 121. Both the first section 121 and the third section 123 are cylindrical. In other words, the cross-sectional areas of the first section 121 and the third section 123 remain constant, while the cross-sectional area of ​​the second section 122 gradually increases from left to right, and the cross-sectional area of ​​the fourth section 124 gradually decreases from left to right. A flame stabilizer outlet 125 is provided at the right end of the fourth section 124. The fourth section 124 can gather the flame within the flame stabilizer 100 and increase its velocity.

[0102] In the flame stabilizer 100 of the embodiment of the present application, since the cross-sectional area of ​​the second section 122 gradually increases from left to right, the flow rate of the secondary air decreases while the static pressure gradually increases during the secondary air flowing through the second section 122, thereby forming a high recirculation zone.

[0103] In some embodiments, as shown in Figures 4 and 3 , the secondary air duct 13 is disposed on the outer periphery of the first segment 121 and is connected to the first segment 121. The air outlet direction of the secondary air duct 13 is tangential to the inner circumferential wall of the first segment 121. There are multiple secondary air ducts 13, and the multiple secondary air ducts 13 are arranged at intervals along the circumference of the first segment 121.

[0104] For example, the secondary air duct 13 is disposed on the outer periphery of the first section 121 and is connected to the first section 121. The air outlet direction of the secondary air duct 13 is tangential to the inner circumferential wall of the first section 121. In other words, a secondary air channel is provided within the secondary air duct 13, and the secondary air channel is tangential to the inner circumferential wall of the first section 121. There may be multiple secondary air ducts 13, for example, two to six. Optionally, there may be two, three, or six secondary air ducts 13.

[0105] In the combustion stabilizer 100 of the embodiment of the present application, the air outlet direction of the secondary air duct 13 is tangent to the inner circumferential wall of the shell 12, so that the secondary air rotates and flows at a high speed, forming a low-pressure area in the central area of ​​the secondary air.

[0106] In some embodiments, as shown in Figure 4, the concentrator 1112 is annular and the inner circumferential wall of the concentrator 1112 defines a concentration adjustment channel. The outer circumferential wall of the concentrator 1112 is in contact with the inner circumferential wall of the first tube 111. The concentrator 1112 includes a tapered section 11121 and a gradually expanding section 11122 arranged in sequence along the first sub-direction. The cross-sectional area of ​​the tapered section 11121 gradually increases along the first sub-direction, and the cross-sectional area of ​​the gradually expanding section 11122 gradually decreases along the first sub-direction, so that the cross-sectional area of ​​the concentration adjustment channel first gradually decreases and then gradually increases along the first sub-direction.

[0107] For example, concentrator 1112 is an annular member with a concentration adjustment channel defined in its center, through which the first airflow can pass. The outer circumferential wall of concentrator 1112 is affixed to the inner circumferential wall of first tube 111, ensuring that the first airflow can only pass through the concentration adjustment channel. A tapered section 11121 is located to the left of diverging section 11122, adjacent to first outlet 115. The cross-section of tapered section 11121 is annular, and its cross-sectional area gradually increases from left to right, such that the cross-sectional area of ​​the portion of the concentration adjustment channel defined by the inner circumferential wall of tapered section 11121 gradually decreases from left to right.

[0108] The cross section of the gradually expanding section 11122 is also annular, and the cross-sectional area of ​​the gradually expanding section 11122 gradually decreases from left to right, so that the cross-sectional area of ​​the partial concentration adjustment channel defined by the inner peripheral wall of the gradually expanding section 11122 gradually increases from left to right.

[0109] When the flame stabilizer 100 of the embodiment of the present application is working, the first airflow first meets the concentrator 1112. In the process of the coal powder particles in the first airflow colliding with the concentrator 1112, the first airflow gradually gathers near the center line of the first tube 111 in the tapered section 11121, so that the coal powder concentration near the center line of the first tube 111 gradually increases. In the diverging section 11122, the first airflow gradually diffuses near the tube wall of the first tube 111. Since the distance between the concentrator 1112 and the second tube 112 is short, even if the first airflow diffuses near the tube wall of the first tube 111, there is not enough time for the coal powder concentration near the tube wall of the first tube 111 to reach the coal powder concentration near the center line of the first tube 111.

[0110] Therefore, when the first airflow passes through the concentration adjustment channel, it is separated into light and thick airflows due to the action of inertial separation, thereby forming a first sub-airflow with a lower coal powder concentration near the inner wall surface of the first tube 111, and a second sub-airflow with a higher coal powder concentration near the center line of the first tube 111. Then the first sub-airflow enters the first channel 117 outside the second tube 112, and the second sub-airflow enters the second channel 118 inside the second tube 112.

[0111] In some embodiments, as shown in FIG4 , the second tube 112 and the first return member 113 are integrally formed, thereby facilitating processing of the second tube 112 and the first return member 113 .

[0112] The specific working process of the combustion stabilizer 100 of the embodiment of the present application is described below with reference to Figures 3, 4 and 10.

[0113] The first airflow sequentially enters the pulverized coal pipe assembly 11 through the first inlet 1111. The first airflow first encounters the concentrator 1112. As the pulverized coal particles in the first airflow collide with the concentrator 1112, they experience inertial separation, causing the first airflow to separate into dense and thin streams, causing the pulverized coal to accumulate near the centerline of the first pipe 111. This results in a first sub-airflow with a lower pulverized coal concentration near the inner wall of the first pipe 111, and a second sub-airflow with a higher pulverized coal concentration near the centerline of the first pipe 111.

[0114] Then, after the first sub-airflow enters the first channel 117, it is guided by the first return member 113 to flow from the right to the left out of the first outlet 115 and into the second section 122. The second sub-airflow enters the second channel 118 and is guided by the second return member 114 to flow from the right to the left into the third section 123, and gradually flows leftward to the second section 122.

[0115] At the same time, the secondary air is ejected into the cavity at high speed along the secondary air duct 13, forming a high-speed rotating airflow within the first section 121 and flowing into the area near the inner wall of the second section 122. Because the secondary air now has a high tangential velocity, this high-speed rotating flow creates a low-pressure zone in the center of the secondary air flow. Furthermore, because the cross-sectional area of ​​the second section 122 gradually increases from left to right, the secondary air velocity decreases as it flows through the second section 122, while the static pressure gradually increases.

[0116] In summary, a low-pressure area is formed in the central area of ​​the secondary air, the flow velocity of the secondary air decreases, and the static pressure gradually increases. Under the influence of these two factors, when the secondary air gradually flows to the right, part of the secondary air will flow into the low-pressure area, thereby forming a high-speed recirculation area in the second section 122 and the third section 123.

[0117] Since the second outlet 116 is arranged at a position adjacent to the high-speed recirculation zone, the second sub-airflow is sprayed in at a position adjacent to the high-speed recirculation zone, so that the second sub-airflow is more easily sucked into the adjacent high-speed recirculation zone during the flow process. The second sub-airflow swirls and burns and releases heat in the adjacent high-speed recirculation zone, thereby forming a dense-phase high-temperature recirculation zone, which will be conducive to promoting the rapid heating and ignition of the second sub-airflow, and releasing more heat to form a dense-phase high-temperature recirculation zone.

[0118] At the same time, the first sub-airflow is sprayed in at a certain distance from the left side of the second sub-airflow. The first sub-airflow is blocked and carried by the secondary air in the swirl state, thereby changing direction. The first sub-airflow enters the dense phase high-temperature reflux zone between the secondary air in the swirl state and the second sub-airflow.

[0119] During this process, although the pulverized coal concentration in the first sub-flow is low and not prone to ignition and combustion, on the one hand, the low concentration of pulverized coal in the first sub-flow is subjected to convection and radiation heat transfer in the high-temperature recirculation zone, which promotes the heating and ignition of the first sub-flow. Furthermore, the location of first outlet 115 to the left of second outlet 116 ensures that the first sub-flow has a greater residence time within the housing 12 than the second sub-flow. These two factors together promote the ignition and burnout of the first sub-flow. At this point, the first sub-flow undergoes primary preheating, rapidly heating and igniting, while also releasing a significant amount of heat, forming a light-phase high-temperature recirculation zone.

[0120] At the same time, since the second sub-flow is injected at a certain distance from the first sub-flow, it is beneficial to delay the mixing of the rich and lean airflows. While promoting overall combustion, it is beneficial to deepen the rich and lean combustion effect of coal powder and reduce NOx generation.

[0121] Then, the airflows in the dense phase high temperature reflux zone and the dilute phase high temperature reflux zone jointly form a primary flame, which is accelerated by the fourth section 124 and ejected at high speed from the burner stabilizer outlet 125 .

[0122] The flame stabilizer 100 of the embodiment of the present application has the following advantages:

[0123] (1) Significant economic advantages

[0124] Compared with traditional micro-oil igniters and plasma igniters, this application has significant economic advantages. It can achieve the effect of using a small amount of coal powder to ignite the majority of surrounding coal powder, completely replacing traditional micro-oil igniters and plasma igniters. It uses coal as fuel for direct ignition, achieving the goal of using a small amount of coal powder to ignite a large amount of surrounding coal powder, and improving the economic efficiency of coal-fired units during the ignition process and peak load regulation process.

[0125] (2) Rapid ignition and strong low-load stable combustion capability

[0126] This application combines multi-stage pulverized coal concentration and multi-stage pulverized coal preheating to enhance ignition and stable combustion. By establishing pulverized coal concentration-lean combustion and two-stage pulverized coal ignition and preheating within the combustion-free stabilizer 100, and constructing multi-stage (three or more) pulverized coal preheating downstream of the combustion-free stabilizer 100, the downstream pulverized coal airflow is sequentially ignited. This facilitates rapid ignition during the startup of coal-fired units and stable combustion during flexible peak load regulation, while also promoting a more complete burnout effect during pulverized coal combustion.

[0127] (3) Low NOx generation

[0128] By implementing a rich-lean combustion system and two-stage high-temperature reduction zones within the combustion stabilizer 100, as well as multi-stage rich-lean combustion downstream of the combustion stabilizer 100's outlet, a multi-stage highly reducing atmosphere is created along the flame's high-temperature zone, helping to reduce fuel-induced NOx generation. Furthermore, the presence of these multiple high-temperature zones creates a more uniform temperature distribution within the combustion stabilizer 100, helping to reduce thermal NOx generation.

[0129] The burner 200 of the pulverized coal combustion stabilization and concentration device 1000 for a coal-fired power plant according to an embodiment of the present application is described below.

[0130] As shown in Figures 5, 8, 9 and 51, the burner 200 of the embodiment of the present application includes a feed pipe assembly 22 and a combustion tube assembly 21.

[0131] A fifth channel 215 is provided in the feed pipe assembly 22, a combustion chamber is provided in the combustion tube assembly 21, the feed pipe assembly 22 is connected to the combustion tube assembly 21, the combustion tube assembly 21 extends along the first direction, a third channel 213 and a fourth channel 214 are provided in the combustion tube assembly 21, the fifth channel 215, the third channel 213 and the fourth channel 214 are all connected to the combustion chamber, the fifth channel 215, the third channel 213 and the fourth channel 214 are spaced apart in the first direction, the burner stabilizer 100 and the combustion tube assembly 21 are arranged sequentially along the first sub-direction, and the outlet end of the combustion tube assembly 21 is suitable for being connected to the combustion furnace.

[0132] For example, for ease of description, the left-right direction in FIG. 5 is taken as the first direction below.

[0133] The feed pipe assembly 22 is used to supply fuel to the combustion tube assembly 21. A fifth channel 215 is provided in the feed pipe assembly 22. The right end of the combustion tube assembly 21 is suitable for connecting to the combustion furnace so that the flame in the combustion chamber enters the combustion furnace.

[0134] The combustion tube assembly 21 extends in the left-right direction. A third channel 213 and a fourth channel 214 are further provided in the combustion tube assembly 21. A fifth channel 215 is provided on the left side of the third channel 213. The third channel 213 is provided on the left side of the fourth channel 214. The connection between the fifth channel 215 and the combustion chamber is provided on the left side of the connection between the third channel 213 and the combustion chamber. The connection between the third channel 213 and the combustion chamber is provided on the left side of the connection between the fourth channel 214 and the combustion chamber.

[0135] The burner stabilizer 100 is arranged on the left side of the combustion tube assembly 21, and the airflow in the burner stabilizer 100 flows to the right into the combustion tube assembly 21. The outlet end of the combustion tube assembly 21 is suitable for being connected to the combustion furnace, and the burner stabilizer outlet 125 and the inlet end of the combustion tube assembly 21 are arranged relative to each other in the left and right directions, and the burner stabilizer outlet 125 and the inlet end of the combustion tube assembly 21 are spaced apart.

[0136] During operation, the burner of the embodiment of the present application utilizes the fifth channel 215, the third channel 213, and the fourth channel 214 to deliver fuel into the combustion chamber. Furthermore, the fifth channel 215, the third channel 213, and the fourth channel 214 are spaced apart in the left-right direction, allowing fuel to be delivered in three stages, resulting in three-stage preheating combustion. This creates three high-temperature combustion zones within the burner 200, allowing each stage of fuel to be preheated and burned, thereby ensuring full combustion of the pulverized coal and improving the combustion efficiency of the fuel. Furthermore, due to the presence of multiple high-temperature zones, the overall temperature distribution within the burner 200 is relatively uniform, helping to reduce the generation of thermal NOx and improve environmental protection.

[0137] Therefore, the burner of the embodiment of the present application has the advantages of good combustion effect and good environmental protection effect.

[0138] In some embodiments, as shown in FIG5 , the first direction includes a first sub-direction and a second sub-direction opposite to the first sub-direction. The direction from the inlet end of the combustion tube assembly 21 to the outlet end of the combustion tube assembly 21 is the first sub-direction.

[0139] The feed pipe assembly 22 is suitable for connecting the gas source and the combustion tube assembly 21. The feed pipe assembly 22 includes a first feed pipe 221 and a second feed pipe 222 arranged sequentially and spaced apart in the first sub-direction. The fifth channel 215 is arranged in the first feed pipe 221, and the second feed pipe 222 is connected to both the third channel 213 and the fourth channel 214.

[0140] For example, for ease of description, the left-right direction in FIG. 5 is taken as the first direction, wherein rightward is the first sub-direction and leftward is the second sub-direction.

[0141] The feed pipe assembly 22 includes a first feed pipe 221 and a second feed pipe 222. The first feed pipe 221 is arranged on the left side of the second feed pipe 222. One end of the first feed pipe 221 is connected to the pulverized coal gas source, and the other end of the first feed pipe 221 can be connected to the combustion chamber. One end of the second feed pipe 222 is connected to the pulverized coal gas source, and the other end of the second feed pipe 222 is connected to the combustion chamber through the third channel 213 and the fourth channel 214.

[0142] Thus, the fifth channel 215 in the first feeding pipe 221 can be used to supply pulverized coal fuel into the combustion chamber, and the second feeding pipe 222 can be used to supply pulverized coal fuel into the combustion chamber through the third channel 213 and the fourth channel 214 .

[0143] In some embodiments, as shown in Figure 5, the combustion tube assembly 21 includes an inner tube 211, which is provided with a cavity to form a combustion chamber. The inner tube 211 includes a first combustion section 2111 and a second combustion section 2112. The first combustion section 2111 and the second combustion section 2112 are arranged sequentially and connected in the first sub-direction. The outlet end of the first combustion section 2111 extends into the inlet end of the second combustion section 2112, so that the outer peripheral wall of the first combustion section 2111 and the inner peripheral wall of the second combustion section 2112 define a third channel 213.

[0144] For example, the inner tube 211 includes a first combustion section 2111 and a second combustion section 2112, the first combustion section 2111 is located on the left side of the second combustion section 2112, the combustion chamber includes a first combustion chamber and a second combustion chamber, the first combustion chamber is located in the first combustion section 2111, and the second combustion chamber is located in the second combustion section 2112.

[0145] The left end of the first combustion section 2111 is connected to the fifth channel 215, and the right end of the first combustion section 2111 can extend into the second combustion section 2112, and the outer peripheral wall of the first combustion section 2111 and the inner peripheral wall of the second combustion section 2112 are spaced apart to define the third channel 213.

[0146] In some embodiments, as shown in Figure 5, the combustion tube assembly 21 also includes an outer tube 212, which is arranged on the outside of the inner tube 211 and the inner circumferential wall of the outer tube 212 is spaced apart from the outer circumferential wall of the inner tube 211. The outer tube 212 includes a straightening section 2121 and a guide section 2122 arranged in sequence along the first sub-direction. The inlet end of the straightening section 2121 is sealed with the inlet end of the first combustion section 2111, and the inner circumferential wall of the guide section 2122 and the outer circumferential wall of the second combustion section 2112 define a fourth channel 214.

[0147] For example, the outer tube 212 extends in the left-right direction, the straightening section 2121 is arranged on the left side of the guide section 2122, and the guide section 2122 and the second combustion section 2112 are spaced apart so that the inner peripheral wall of the guide section 2122 and the outer peripheral wall of the second combustion section 2112 define a fourth channel 214.

[0148] It should be noted that the left side of the rectifying section 2121 is sealedly connected to the left side of the first combustion section 2111, and the right end of the rectifying section 2121 is sealedly connected to the left end of the guide section 2122. The rectifying section 2121 is sleeved outside the first combustion section 2111, so as to form a rectifying cavity between the outer circumferential wall of the first combustion section 2111 and the inner circumferential wall of the rectifying section 2121. The left end of the third channel 213 communicates with the rectifying cavity, and the right end of the third channel 213 communicates with the inlet of the second combustion chamber. The left end of the fourth channel 214 communicates with the rectifying cavity, and the right end of the fourth channel 214 communicates with the outlet of the second combustion chamber.

[0149] The third channel 213 and the fourth channel 214 are both arranged in the guide section 2122, and the right end of the first combustion section 2111 extends to the right into the guide section 2122, so as to form a diversion channel between the rectification section 2121 and the first combustion section 2111, thereby facilitating the airflow in the rectification cavity to enter the third channel 213 and the fourth channel 214 along the diversion channel.

[0150] Therefore, the burner of the embodiment of the present application defines a rectifying cavity by setting a rectifying section 2121, so that the pulverized coal airflow in the second feed pipe 222 can be adjusted in the rectifying cavity to form a steady flow, and then enter the combustion chamber, thereby facilitating the stable combustion of the pulverized coal airflow in the combustion chamber, thereby improving the stability of the burner.

[0151] In some embodiments, as shown in Figure 5, the first feed pipe 221 includes a first transition section 2212, which is connected to the first combustion section 2111, and the first transition section 2212 extends along the first direction, and the cross-sectional area of ​​the first transition section 2212 gradually decreases along the first sub-direction.

[0152] For example, the first transition section 2212 extends in the left-right direction, with the right end of the first transition section 2212 connected to the first combustion section 2111, and the cross-sectional area of ​​the first transition section 2212 gradually decreases from left to right. Thus, the first transition section 2212 can easily adapt to the first combustion section 2111 and connect to the first combustion section 2111.

[0153] In some embodiments, as shown in Figure 5, the first feeding tube 221 also includes a first feeding section 2211, the inlet end of the first feeding section 2211 extends along the second direction, the second direction is orthogonal to the first direction, the outlet end of the first feeding section 2211 extends along the first direction, the first feeding section 2211 is connected to the first transition section 2212, and the first feeding section 2211 and the first transition section 2212 are connected to form a fifth channel 215.

[0154] For example, for ease of description, the vertical direction in Figure 5 is referred to as the second direction. The inlet of the first feeding section 2211 faces downward, and the outlet of the first feeding section 2211 faces rightward. In other words, the centerline of the first feeding section 2211 is arc-shaped. The pulverized coal airflow passes through the first feeding section 2211 and the first transition section 2212 sequentially before entering the first combustion section 2111. The cavity within the first feeding section 2211 and the cavity within the first transition section 2212 communicate to form a fifth channel 215.

[0155] In some embodiments, the flame stabilizer 100 is connected to the first feeding section 2211, the inlet end of the flame stabilizer 100 is located outside the first feeding section 2211, the outlet end of the flame stabilizer 100 passes through the side wall of the first feeding section 2211 and extends into the first feeding section 2211, and the flame stabilizer outlet 125 is located in the first transition section 2212.

[0156] The outlet end of the flame stabilizer 100 is located in the first feeding section 2211, the shell 12 of the flame stabilizer 100 is sealed and connected to the side wall of the first feeding section 2211, and the part of the flame stabilizer 100 located in the first feeding section 2211 is spaced apart from the inner circumferential wall of the first feeding section 2211 so that the second airflow passes between the first feeding section 2211 and the flame stabilizer 100.

[0157] In some embodiments, as shown in FIG. 5 , the second feeding pipe includes a second transition section 2221 , the second transition section 2221 is connected to the rectifying section 2121 , and a cross-sectional area of ​​the second transition section 2221 gradually increases along the second direction.

[0158] For example, the second transition section 2221 is provided below the rectifying section 2121 , and the cross-sectional area of ​​the second transition section 2221 gradually increases from bottom to top, thereby facilitating improving the efficiency of the pulverized coal airflow entering the rectifying section 2121 .

[0159] In some embodiments, as shown in FIG11 , the burner further includes an air supply pipe. The burner 200 is a square-tangential direct current burner 200 . The air supply pipe is sleeved on the outer peripheral side of the guide section 2122 .

[0160] For example, if the burner 200 is a square-tangent, direct current burner 200, an air supply pipe can be arranged on the outer periphery of the guide section 2122. This air supply pipe is equipped with a direct current first nozzle 231 to provide oxygen-containing airflow to the gas burner, thereby providing the oxygen required for subsequent combustion of the pulverized coal in a staged manner. This promotes complete combustion of the pulverized coal while achieving air-staged combustion to reduce NOx generation. In this case, the cross-sections of the first combustion section 2111, the second combustion section 2112, and the guide section 2122, perpendicular to the axial direction of the burner 200, are all rectangular.

[0161] For a direct current burner 200 used for square tangential combustion, the oxygen-containing gas flow can be arranged at a certain distance around the burner 200 and injected in a direct current manner, that is, the nozzle is a cylindrical structure with a circular or rectangular cross-section.

[0162] In some embodiments, as shown in Figure 8, the burner also includes an air supply pipe, the burner 200 is a wall-type counter-swirl burner 200, and the air supply pipe includes a first pipe and a second pipe. The first pipe is sleeved on the outer peripheral side of the guide section 2122, and the second pipe is sleeved on the outer peripheral side of the first pipe.

[0163] For example, when the burner 200 is a wall-mounted, counter-rotating swirl burner 200, an air supply duct can be arranged outside the guide section 2122. The air supply duct includes an annular third nozzle 233 and a second nozzle 232. The second nozzle 232 is arranged on the outer periphery of the third nozzle 233 to provide an oxygen-containing airflow for the burner 200. Swirl blades 234 are uniformly arranged circumferentially within the third nozzle 233 and the second nozzle 232 to guide the straight airflow into a high-speed rotating jet at the outlet. In this case, the cross-sectional shapes of the first combustion section 2111, the second combustion section 2112, and the guide section 2122 perpendicular to the axial direction of the burner 200 are all circular.

[0164] For the swirl burner 200 used for wall-type counter-hedge, this part of the tertiary air can be injected into the burner 200 in two layers of annular swirls, and two layers of inner and outer annular nozzles are set. The outlet swirl intensity of the airflow in the two layers of nozzles can be adjusted by adjusting the angle of the blade 234. While achieving air grading, the oxygen-containing airflow injected in the swirl will also help to form a low-pressure area at the outlet of the burner 200, forming a high-temperature flue gas reflux, and promoting further combustion of coal powder and stable ignition.

[0165] In some embodiments, the burner further includes a connecting pipe (not shown in the figures), which is used to connect the gas source with the first feeding pipe 221 or the second feeding pipe 222 .

[0166] For example, the pulverized coal gas source and the first feeding pipe 221 are connected through a connecting pipe to feed the pulverized coal into the first combustion chamber. The pulverized coal gas source and the second feeding pipe 222 are connected through a connecting pipe to feed the pulverized coal into the second combustion chamber.

[0167] In other embodiments, a through hole is provided on the side wall of the first feeding section 2211, and the flame stabilizer 100 is installed in the through hole. The shell of the flame stabilizer 100 is sealed to the through hole of the first feeding section 2211. The inlet end of the flame stabilizer 100 is located outside the first feeding section 2211, and the outlet end of the flame stabilizer 100 passes through the through hole in the first feeding section 2211 and extends into the fifth channel 215 within the first feeding section 2211. The outlet of the flame stabilizer 100 is located within the first transition section 2212. The portion of the flame stabilizer 100 located within the first feeding section 2211 is spaced apart from the inner peripheral wall of the first feeding section 2211, so that the pulverized coal gas flow in the fifth channel 215 passes between the first feeding section 2211 and the flame stabilizer 100.

[0168] When the stabilizer 100 is operating, a flame ejects from the stabilizer 100 into the first transition section 2212. The pulverized coal airflow in the first feed section 2211 enters the first transition section 2212 through the gap between the stabilizer 100 and the first feed section 2211. It encounters the flame and is preheated and combusted, forming a high-temperature combustion zone. The flame then flows rightward to the second combustion chamber, where it first encounters the pulverized coal airflow in the third channel 213, where it is preheated and combusted, forming a high-temperature combustion zone. Finally, the flame continues to flow rightward and encounters the airflow in the fourth channel 214, where it is preheated and combusted, forming a high-temperature combustion zone. This preheating and combustion process occurs step by step, allowing each stage of fuel to burn, thereby improving the combustion efficiency of the fuel. Furthermore, due to the presence of multiple high-temperature zones, the overall temperature distribution within the burner 200 is relatively uniform, helping to reduce the generation of thermal NOx and improve environmental protection.

[0169] The concentrator 300 of the pulverized coal combustion stabilization and concentrating device 1000 for a coal-fired power plant according to an embodiment of the present application is described below.

[0170] As shown in FIG6-7 , the concentrator 300 according to the embodiment of the present application includes a main feed pipe 34 and a concentrating assembly.

[0171] The main feed pipe 34 extends along the second direction. The inlet end of the main feed pipe 34 is provided with a main feed port, which is suitable for communicating with the pulverized coal gas source. The outlet end of the main feed pipe 34 is provided with a first port, a second port, and a third port. The second port is arranged opposite to the main feed port in the second direction. The second port is located between the first port and the third port. The first port and the second port are arranged opposite to each other in the first direction, and the first direction is orthogonal to the second direction.

[0172] The concentration component is arranged in the main feed pipe 34. The primary air pulverized coal airflow entering from the main feed port can be automatically divided into a first airflow, a second airflow and a third airflow with successively decreasing pulverized coal concentrations by impacting the concentration component. The first airflow is discharged from the first port, the second airflow is discharged from the second port, and the third airflow is discharged from the third port.

[0173] For example, for the convenience of description, the up-down direction in FIG. 6 is referred to as the second direction, and the left-right direction in FIG. 6 is referred to as the first direction.

[0174] The main feed pipe 34 extends in the up and down direction. The inlet end of the main feed pipe 34 is the lower end of the main feed pipe 34. The lower end of the main feed pipe 34 is provided with a main feed port, which is connected to the pulverized coal gas source so that the primary air pulverized coal airflow enters the main feed pipe 34.

[0175] The outlet end of the main feed pipe 34 is the upper end of the main feed pipe 34. The upper end of the main feed pipe 34 is provided with a first port, a second port, and a third port. The second port is located directly above the main feed port. The first port and the third port are arranged opposite each other in the left-right direction. Furthermore, the first port is located to the left of the second port, and the third port is located to the right of the second port.

[0176] When the primary coal pulverized air strikes the concentrator, it is subjected to inertial separation and automatically condenses into three streams of varying concentrations. The first stream has the highest concentration, the third has the lowest, and the second has a concentration somewhere between the first and third streams. The first stream is discharged through the first port, the second through the second port, and the third through the third port for use by the coal-fired power unit.

[0177] The concentrator 300 of the embodiment of the present application, by arranging a concentrating component in the main feed pipe 34, utilizes the inertia generated by the primary air pulverized coal airflow hitting the concentrating component, so that the primary air pulverized coal airflow can be automatically diverted into three airflows with different coal powder concentrations. During the concentration process, there is no need to provide additional power for the primary air pulverized coal airflow, thereby reducing energy consumption when concentrating the coal powder.

[0178] Therefore, the concentrator 300 according to the embodiment of the present application has the advantage of low energy consumption.

[0179] In some embodiments, as shown in Figure 6, the concentrator 300 also includes a first branch pipe 31, a second branch pipe 32 and a third branch pipe 33. The first branch pipe 31 is connected to the main feed pipe 34 through the first port, the second branch pipe 32 is connected to the main feed pipe 34 through the second port, and the third branch pipe 33 is connected to the main feed pipe 34 through the third port.

[0180] For example, the first airflow can flow out of the first branch pipe 31, the second branch pipe 32 can flow out of the second branch pipe 33, and the third airflow can flow out of the third branch pipe 33. The first branch pipe 31, the second branch pipe 32, and the third branch pipe 33 can direct the pulverized coal airflow to the desired location of the coal-fired power unit. For example, the first branch pipe 31 is connected to the combustion stabilizer, and the second branch pipe 32 and the third branch pipe 33 are connected to the burner. Thus, the first branch pipe 31, the second branch pipe 32, and the third branch pipe 33 can be used to transport the pulverized coal airflow to the desired location, with a simple structure.

[0181] In some embodiments, the first branch pipe 31 is connected to the first inlet 1111 to introduce the first airflow into the burner 200, the second branch pipe 32 is connected to the first feed pipe to introduce the second airflow into the burner 200, and the third branch pipe 33 is connected to the second feed pipe to introduce the third airflow into the burner 200.

[0182] For example, the primary pulverized coal airflow provided by the pulverized coal gas source enters the main feed pipe 34 and is then split by the concentrator 300 into a first airflow, a second airflow, and a third airflow. The first airflow enters the pulverized coal pipe assembly 11 through the first inlet 1111, the second airflow passes through the first feeding section 2211 and the first transition section 2212 in sequence, and then enters the first combustion section 2111. The third airflow passes through the second feeding pipe 222 and enters the rectifying section 2121.

[0183] In some embodiments, as shown in Figure 7, the main feed pipe 34 has a first side wall 341, a second side wall 342, a third side wall 343 and a fourth side wall 344 connected in sequence in its circumferential direction, the first side wall 341 and the third side wall 343 are arranged relatively to each other in the first direction, the first port is provided on the first side wall 341, the third port is provided on the third side wall 343, the second side wall 342 and the fourth side wall 344 are arranged relatively to each other in the third direction, and the third direction is orthogonal to both the second direction and the first direction.

[0184] For example, for ease of description, the front-to-back direction in FIG. 6 is taken as the third direction.

[0185] The first to fourth side walls 341, 344 are connected in sequence to form an annular main feed pipe 34. The first side wall 341 is the left side wall of the main feed pipe 34, the third side wall 343 is the right side wall of the main feed pipe 34, the second side wall 342 is located between the first and third side walls 341, 343, and the fourth side wall 344 is located between the first and third side walls 341, 343. The second and fourth side walls 342, 344 are arranged opposite each other in the front-to-back direction. The second side wall 342 is located in front of the fourth side wall 344, or the second side wall 342 is located behind the fourth side wall 344. As a result, the main feed pipe 34 has a simple structure and is easy to process.

[0186] It can be understood that the first side wall 341 to the fourth side wall 344 are all plate-shaped members, that is, the cross-section of the main feed pipe 34 is rectangular.

[0187] In some embodiments, as shown in Figure 7, the main feed pipe 34 is provided with a first flow channel 345, a second flow channel 346, a third flow channel 347 and a fourth flow channel 348 arranged in an array. In the first direction, the first flow channel 345 and the second flow channel 346 are arranged in sequence, the third flow channel 347 and the fourth flow channel 348 are arranged in sequence, and the first flow channel 345 is arranged adjacent to the second side wall 342 relative to the third flow channel 347.

[0188] For example, the first flow channel 345, the second flow channel 346, the third flow channel 347, and the fourth flow channel 348 are arranged in a 2×2 array, with the first flow channel 345 and the second flow channel 346 arranged sequentially in the left-right direction, the third flow channel 347 and the fourth flow channel 348 arranged sequentially in the left-right direction, the first flow channel 345 and the third flow channel 347 arranged sequentially in the front-to-back direction, and the second flow channel 346 and the fourth flow channel 348 arranged sequentially in the front-to-back direction. The first flow channel 345 is disposed adjacent to the second sidewall 342. In other words, the first flow channel 345 and the second flow channel 346 are disposed adjacent to the second sidewall 342 relative to the third flow channel 347 and the fourth flow channel 348.

[0189] When the second sidewall 342 is disposed in front of the fourth sidewall 344, the first flow channel 345 and the second flow channel 346 are disposed in front of the third flow channel 347 and the fourth flow channel 348. When the second sidewall 342 is disposed behind the fourth sidewall 344, the first flow channel 345 and the second flow channel 346 are disposed behind the third flow channel 347 and the fourth flow channel 348.

[0190] In some embodiments, as shown in FIG6 , the concentration assembly includes a first concentration block 35 , a second concentration block 36 and a diverter plate 37 , wherein the first concentration block 35 , the second concentration block 36 and the diverter plate 37 are arranged sequentially and spaced apart in the second direction, and the first concentration block 35 is arranged adjacent to the total feed port relative to the diverter plate 37 .

[0191] For example, the first concentrator block 35, the second concentrator block 36, and the diverter plate 37 are arranged sequentially and spaced apart from each other from bottom to top. The primary pulverized coal airflow is concentrated once after passing through the first concentrator block 35, concentrated again after passing through the second concentrator block 36, and then diverted through the diverter plate 37 into the first, second, and third airflows.

[0192] In some embodiments, as shown in Figures 6-7, the first concentrated block 35 is provided on the third side wall 343 to block the second flow channel 346 and the fourth flow channel 348, and the second concentrated block 36 is provided on the second side wall 342 to block the first flow channel 345 and the second flow channel 346.

[0193] For example, the first concentrating block 35 is detachably fixed on the third side wall 343 and protrudes toward the center line of the main feed pipe 34. The first concentrating block 35 is used to block the second flow channel 346 and the fourth flow channel 348, so that the primary air pulverized coal flow can only flow from the first flow channel 345 and the third flow channel 347.

[0194] The second concentrating block 36 is protruding toward the center line of the main feed pipe 34 . The second concentrating block 36 is provided on the second side wall 342 to block the first flow channel 345 and the second flow channel 346 , so that the primary air pulverized coal flow can only flow through the third flow channel 347 and the fourth flow channel 348 .

[0195] Or the second concentrating block 36 is provided on the fourth side wall 344 to block the third flow channel 347 and the fourth flow channel 348 , so that the primary air pulverized coal flow can only flow through the first flow channel 345 and the second flow channel 346 .

[0196] In some embodiments, as shown in Figure 6, the first concentrated block 35 is shaped like a trapezoidal table, and the first concentrated block 35 has a first end face and a second end face that are spaced apart in a first direction and parallel to each other, the area of ​​the first end face is larger than the area of ​​the second end face, and the first end face is in contact with the inner surface of the third side wall 343.

[0197] For example, the first concentrating block 35 is a trapezoidal pyramid, with a first end face and a second end face spaced apart in the left-right direction, and the first end face positioned to the right of the second end face. That is, the bottom face of the trapezoidal pyramid is the first end face, and the top face is the second end face. The first end face is positioned in contact with the third sidewall 343. This seals the gap between the first end face and the third sidewall 343, preventing the primary coal powder airflow from flowing between the first end face and the third sidewall 343 and into the second concentrating block 36.

[0198] Optionally, the first concentrating block 35 is sealedly connected to the second side wall 342, and the first concentrating block 35 is sealedly connected to the fourth side wall 344. This seals the gap between the first concentrating block 35 and the second side wall 342, and the gap between the first concentrating block 35 and the fourth side wall 344, thereby preventing the primary pulverized coal airflow from flowing away from the gap between the first concentrating block 35 and the second side wall 342, or the gap between the first concentrating block 35 and the fourth side wall 344.

[0199] Optionally, the first end surface is bonded to the third side wall 343. Alternatively, the first enriched block 35 is detachably connected to the main feed pipe 34, for example, the first enriched block 35 is connected to the main feed pipe 34 by snap-fitting.

[0200] In some embodiments, the second concentrated block 36 is shaped like a trapezoidal platform, and has a third end face and a fourth end face that are parallel to each other and spaced apart in the third direction. The area of ​​the third end face is larger than the area of ​​the fourth end face, and the third end face is in contact with the inner surface of the second side wall 342.

[0201] For example, the second concentrating block 36 is a trapezoidal pyramid, with the third and fourth end faces spaced apart in the front-to-back direction, and the third end face positioned in front of the fourth end face. That is, the bottom face of the trapezoidal pyramid is the third end face, and the top face is the fourth end face. The third end face is positioned in contact with the second sidewall 342. This seals the gap between the third end face and the second sidewall 342, preventing the primary coal dust flow from flowing between the third end face and the second sidewall 342 and reaching the diverter plate 37.

[0202] The first end surface of the first concentrated block 35 is in contact with the inner surface of the third side wall 343, and the third end surface of the second concentrated block 36 is in contact with the inner surface of the second side wall 342. That is, the first concentrated block 35 and the second concentrated block 36 are arranged at 90 degrees.

[0203] Optionally, the second concentrating block 36 is sealedly connected to the first side wall 341, and the second concentrating block 36 is sealedly connected to the third side wall 343. This seals the gap between the second concentrating block 36 and the first side wall 341, and the gap between the second concentrating block 36 and the third side wall 343, thereby preventing the primary coal powder flow from flowing away from the gap between the second concentrating block 36 and the first side wall 341, or the gap between the second concentrating block 36 and the third side wall 343.

[0204] Optionally, the first end surface is bonded to the third side wall 343 , or the first concentrate block 35 is detachably connected to the main feed pipe 34 , for example, the first concentrate block 35 is snap-connected to the main feed pipe 34 .

[0205] In some embodiments, as shown in FIG. 7 , the diverter plate 37 is cross-shaped so as to be compatible with the first to fourth flow channels 345 to 348 .

[0206] For example, the diverter plate 37 is disposed above the second concentrator block 36. The diverter plate 37 is cross-shaped to form four regions, which correspond to the first to fourth flow channels 345 to 348, respectively, so that the airflow in the first to fourth flow channels 345 to 348 can pass through. This further separates the primary air and pulverized coal flow.

[0207] In some embodiments, as shown in Figure 6, the concentrator 300 also includes a baffle 38, which is arranged on the inner peripheral wall of the inlet end of the second branch pipe 32, and the baffle 38 is arranged adjacent to the first branch pipe 31 relative to the third branch pipe 33, and the baffle 38 is arranged opposite to the third flow channel 347 in the extension direction of the main feed pipe 34.

[0208] For example, the baffle 38 is disposed on the left side wall of the second branch pipe 32, adjacent to the first branch pipe 31. The baffle 38 is disposed opposite the third flow channel 347, causing the gas in the third flow channel 347 to be deflected, thereby directing the gas flow in the third flow channel 347 into the first branch pipe 31, thereby preventing the gas flow in the third flow channel 347 from entering the second branch pipe 32.

[0209] In some embodiments, as shown in FIG6 , the sidewall of the first branch pipe 31 adjacent to the second branch pipe 32 extends into the second branch pipe 32 to form a baffle 38 , which is integrally formed with the first branch pipe 31 , thereby facilitating the processing and manufacturing of the baffle 38 .

[0210] In another embodiment, the concentrator 300 further includes a baffle (not shown) disposed on the inner circumferential wall of the inlet end of the second branch pipe 32. The baffle is positioned relative to the first branch pipe 31 and adjacent to the third branch pipe 33. The baffle 38 is positioned opposite the second flow channel 346 in the extending direction of the main feed pipe 34. Thus, the baffle deflects the gas in the second flow channel 346, thereby causing it to flow into the third branch pipe 33.

[0211] A specific embodiment of the present application is described below by taking the second side wall 342 in front of the fourth side wall 344 as an example.

[0212] First, the primary pulverized coal airflow provided by the pulverized coal gas source enters the main feed pipe 34 of the concentrator, and then collides with the first concentrating block 35 to cause pulverized coal inertial separation. Since the first concentrating block 35 blocks the second flow channel 346 and the fourth flow channel 348, a large amount of primary pulverized coal airflow gathers in the first flow channel 345 and the third flow channel 347. After the primary pulverized coal airflow passes through the first concentrating block 35, a small amount of pulverized coal airflow diffuses to the second flow channel 346 and the fourth flow channel 348.

[0213] Figure 7 then illustrates the distribution of pulverized coal within each flow channel of concentrator 300 during operation. After the primary air pulverized coal collides with second concentrating block 36, further pulverized coal separation occurs due to inertia. Since second concentrating block 36 blocks first flow channel 345 and second flow channel 346, third flow channel 347 is unblocked by either first concentrating block 35 or second concentrating block 36. Therefore, the pulverized coal concentration in third flow channel 347 is the highest. Both first and fourth flow channels 345 and 348 are blocked by either the first or second concentrating block 35 or 36. Therefore, the pulverized coal concentration in these two channels is lower than that in third flow channel 347. Second flow channel 346, blocked by both the first and second concentrating blocks 35 and 36, has the lowest pulverized coal concentration.

[0214] The airflow in the third flow channel 347 passes through the diverter plate 37 and then hits the baffle 38 , thereby being deflected and then flowing into the first branch pipe 31 near the baffle 38 .

[0215] After passing through the diverter plate 37 , the airflow in the first flow channel 345 and the fourth flow channel 348 is not disturbed by the baffle 38 and thus enters the second branch pipe 32 .

[0216] After passing through the diverter plate 37 , the airflow in the second flow channel 346 hits the baffle plate, thereby being deflected and then flowing into the third branch pipe 33 near the baffle plate.

[0217] The airflow in the third flow channel 347 enters the first branch pipe 31 to form a first airflow, the airflows in the first flow channel 345 and the fourth flow channel 348 enter the second branch pipe 32 and mix to form a second airflow, and the airflow in the second flow channel 346 enters the third branch pipe 33 to form a third airflow. The coal powder concentrations in the first airflow, the second airflow and the third airflow decrease successively.

[0218] It is understandable that when the fourth side wall 344 is arranged in front of the second side wall 342, the positions of the first flow channel 345 to the fourth flow channel 348 are slightly changed, but it does not affect the concentration process of the primary air pulverized coal airflow, which will not be repeated here.

[0219] In summary, the concentrator 300 of the present embodiment, by installing a concentrating assembly within the main feed pipe 34, utilizes the inertia generated by the primary coal airflow striking the concentrating assembly to automatically split the primary coal airflow into three streams with varying coal concentrations. This eliminates the need for additional power to the primary coal airflow during the secondary concentrating process, thereby reducing energy consumption during coal concentrating. Furthermore, the primary coal airflow is concentrated twice using the first concentrating block 35, the second concentrating block 36, the diverter plate 37, and the baffle 38, resulting in a simple structure and ease of fabrication for the concentrator 300.

[0220] Therefore, the concentrator 300 of the embodiment of the present application has the advantages of low energy consumption and simple structure.

[0221] A specific embodiment of the present application is described below with reference to Figures 1-11.

[0222] First, the primary pulverized coal airflow provided by the pulverized coal gas source enters the main feed pipe 34 of the concentrator 300, and then collides with the first concentrating block 35 to cause inertial separation of the pulverized coal. Since the first concentrating block 35 blocks the second flow channel 346 and the fourth flow channel 348, a large amount of the primary pulverized coal airflow gathers in the first flow channel 345 and the third flow channel 347. After the primary pulverized coal airflow passes through the first concentrating block 35, a small amount of the pulverized coal airflow diffuses to the second flow channel 346 and the fourth flow channel 348.

[0223] After the primary air pulverized coal flow encounters the second concentrator 36, further inertial separation of the pulverized coal occurs. Since the second concentrator 36 blocks both the first and second flow channels 345 and 346, the third flow channel 347 is unblocked by either the first or second concentrator 35 and 36. Therefore, the pulverized coal concentration in the third flow channel 347 is the highest. The airflow in the first and fourth flow channels 345 and 348 is blocked by either the first or second concentrator 35 and 36. Therefore, the pulverized coal concentration in the first and fourth flow channels 345 and 348 is lower than that in the third flow channel 347. Second flow channel 346 is blocked twice by both the first and second concentrators 35 and 36, resulting in the lowest pulverized coal concentration in the second flow channel 346.

[0224] The airflow in the third flow channel 347 enters the first branch pipe 31 to form a first airflow, the airflows in the first flow channel 345 and the fourth flow channel 348 enter the second branch pipe 32 and mix to form a second airflow, and the airflow in the second flow channel 346 enters the third branch pipe 33 to form a third airflow. The coal powder concentrations in the first airflow, the second airflow and the third airflow decrease successively.

[0225] The first airflow passes through first branch pipe 31 and first inlet 1111, entering the pulverized coal pipe assembly. The first airflow first encounters concentrator 1112. As the pulverized coal particles in the first airflow collide with concentrator 1112, they experience inertial separation, causing the first airflow to separate into dense and thin streams. This causes the pulverized coal to accumulate near the centerline of first pipe 111, thereby forming a first sub-airflow with a lower pulverized coal concentration near the inner wall of first pipe 111, and a second sub-airflow with a higher pulverized coal concentration near the centerline of first pipe 111.

[0226] The first sub-airflow then enters the first channel 117 and, under the action of the first return member 113, enters the return channel 119, causing the first sub-airflow to flow from right to left into the second section 122. The second sub-airflow enters the second channel 118 and, under the action of the second return member 114, flows from right to left into the third section 123, gradually flowing leftward to the second section 122.

[0227] At the same time, the secondary air is ejected into the cavity at high speed along the secondary air duct 13, forming a high-speed rotating airflow within the first section 121 and flowing into the area near the inner wall of the second section 122. Because the secondary air now has a high tangential velocity, this high-speed rotating flow creates a low-pressure zone in the center of the secondary air flow. Furthermore, because the cross-sectional area of ​​the second section 122 gradually increases from left to right, the secondary air velocity decreases as it flows through the second section 122, while the static pressure gradually increases.

[0228] In summary, a low-pressure area is formed in the central area of ​​the secondary air, the flow velocity of the secondary air decreases, and the static pressure gradually increases. Under the influence of these two factors, when the secondary air gradually flows to the right, part of the secondary air will flow into the low-pressure area, thereby forming a high-speed recirculation area in the second section 122 and the third section 123.

[0229] Since the second outlet 116 is arranged at a position adjacent to the high-speed recirculation zone, the second sub-airflow is sprayed in at a position adjacent to the high-speed recirculation zone, so that the second sub-airflow is more easily sucked into the adjacent high-speed recirculation zone during the flow process. The second sub-airflow swirls and burns and releases heat in the adjacent high-speed recirculation zone, thereby forming a dense-phase high-temperature recirculation zone, which will be conducive to promoting the rapid heating and ignition of the second sub-airflow, and releasing more heat to form a dense-phase high-temperature recirculation zone.

[0230] At the same time, the first sub-airflow is sprayed in at a certain distance from the left side of the second sub-airflow. The first sub-airflow is blocked and carried by the secondary air in the swirl state, thereby changing direction. The first sub-airflow enters the dense phase high-temperature reflux zone between the secondary air in the swirl state and the second sub-airflow.

[0231] During this process, although the pulverized coal concentration in the first sub-flow is low and not prone to ignition and combustion, on the one hand, the low concentration of pulverized coal in the first sub-flow is subjected to convection and radiation heat transfer in the high-temperature recirculation zone, which promotes the heating and ignition of the first sub-flow. Furthermore, the location of first outlet 115 to the left of second outlet 116 ensures that the first sub-flow has a greater residence time within the housing 12 than the second sub-flow. These two factors together promote the ignition and burnout of the first sub-flow. At this point, the first sub-flow undergoes primary preheating, rapidly heating and igniting, while also releasing a significant amount of heat, forming a light-phase high-temperature recirculation zone.

[0232] At the same time, since the second sub-flow is injected at a certain distance from the first sub-flow, it is beneficial to delay the mixing of the rich and lean airflows. While promoting overall combustion, it is beneficial to deepen the rich and lean combustion effect of coal powder and reduce NOx generation.

[0233] Then, the airflows in the dense phase high temperature reflux zone and the dilute phase high temperature reflux zone jointly form a primary flame, which is accelerated by the fourth section 124 and ejected at high speed from the burner stabilizer outlet 125 .

[0234] The second airflow in the second branch pipe 32 passes through the first feeding section 2211 and enters the first transition section 2212. It then mixes with the primary flame ejected from the burner stabilizer outlet 125 in the first transition section 2212 before entering the first combustion section 2111. The pulverized coal carried by the second airflow is preheated by the primary flame ejected from the burner stabilizer 100 and rapidly ignites after mixing with the high-temperature flame ejected from the burner stabilizer 100, undergoing secondary preheating to form a secondary flame and a high-temperature zone.

[0235] At the same time, the third airflow passes through the second transition section 2221 and enters the rectifying section 2121. After being stabilized by the rectifying cavity, the third airflow flows to the right and is divided into a third sub-airflow and a fourth sub-airflow. The third sub-airflow enters the second combustion tube from the third channel 213, and the fourth sub-airflow enters the second combustion tube from the fourth channel 214.

[0236] After passing through the third channel 213, the third sub-airflow flows near the inner wall of the second combustion tube. At this time, the third sub-airflow is directly mixed and preheated with the secondary flame from upstream, so that the third sub-airflow ignites quickly and is preheated by the third stage, forming a third stage flame and a high temperature zone.

[0237] After passing through the fourth channel 214, the fourth sub-flow is directly mixed and preheated with the third-stage flame from upstream, so that the fourth sub-flow is quickly ignited and preheated by the fourth stage to form a fourth-stage flame and a high-temperature zone.

[0238] In addition, as shown in FIG8 and FIG9 , the burner 200 of the pulverized coal combustion stabilization and concentration device 1000 of the coal-fired power unit according to the embodiment of the present application may be a four-corner cut-circle direct current burner 200 and a wall-type hedge swirl burner 200 .

[0239] If the burner 200 is a tangentially shaped DC burner 200, DC first nozzles 231 can be positioned above and below the guide section 2122 to provide tertiary air within the burner. This provides the oxygen required for subsequent combustion of the pulverized coal in a staged manner, promoting complete burnout of the pulverized coal while also achieving air-staged combustion and reducing NOx generation. In this case, the cross-sections of the first combustion section 2111, the second combustion section 2112, and the guide section 2122, perpendicular to the axial direction of the burner 200, are all rectangular.

[0240] This section of tertiary air refers to the secondary air in the combustion stabilizer 100. By supplying air in batches during the fuel combustion process, it achieves staged combustion and reduces NOx generation. For a DC burner 200 used in a square-tangential circular burner, this portion of tertiary air can be arranged at regular intervals around the burner 200 and injected in a DC manner, meaning the nozzle is a cylindrical structure with a circular or rectangular cross-section.

[0241] When the burner 200 is a wall-type, counter-hung swirl burner 200, an annular third nozzle 233 and a second nozzle 232 can be arranged in sequence from the inside to the outside of the guide section 2122. The second nozzle 232 is located on the outer periphery of the third nozzle 233 to provide tertiary air for the burner 200. Swirl blades 234 are evenly arranged circumferentially within the third nozzle 233 and the second nozzle 232 to guide the straight airflow into a high-speed rotating jet at the outlet. In this case, the cross-sections of the first combustion section 2111, the second combustion section 2112, and the guide section 2122 perpendicular to the axial direction of the burner 200 are all circular.

[0242] The tertiary air in this section refers to the secondary air in the stabilizer 100. By supplying air in batches to participate in the combustion during the fuel combustion process, air-staged combustion can be achieved, reducing the amount of NOx generated. For the swirl burner 200 used for wall-type counter-flow, this part of the tertiary air can be injected into the burner 200 in two layers of annular swirls, and two layers of inner and outer annular nozzles are provided. By adjusting the angle of the blades 234, the outlet swirl intensity of the airflow in the two layers of nozzles can be adjusted respectively. While achieving air stage, the secondary air injected in the swirl will also help to form a low-pressure area at the outlet of the burner 200, forming a high-temperature flue gas reflux, promoting further combustion of the coal powder and stable ignition.

[0243] This application has the following advantages:

[0244] (1) Significant economic advantages

[0245] Compared with traditional micro-oil igniters and plasma igniters, this application has significant economic advantages. It can achieve the effect of using a small amount of coal powder to ignite the majority of surrounding coal powder, completely replacing traditional micro-oil igniters and plasma igniters. It uses coal as fuel for direct ignition, achieving the goal of using a small amount of coal powder to ignite a large amount of surrounding coal powder, and improving the economic efficiency of coal-fired units during the ignition process and peak load regulation process.

[0246] (2) Rapid ignition and strong low-load stable combustion capability

[0247] This application combines multi-stage pulverized coal concentration and multi-stage pulverized coal preheating to enhance ignition and stable combustion. By establishing pulverized coal concentration and lean combustion and two-stage pulverized coal ignition and preheating within the combustion-free stabilizer 100, and constructing multi-stage (three or more) pulverized coal preheating downstream of the combustion-free stabilizer, the downstream pulverized coal airflow is sequentially ignited. This facilitates rapid ignition during the startup of coal-fired units and stable combustion during flexible peak load regulation, while also promoting a more complete burnout during pulverized coal combustion.

[0248] (3) Low NOx generation

[0249] By implementing a rich-lean combustion system and two-stage high-temperature reduction zones within the combustion stabilizer 100, as well as multi-stage rich-lean combustion downstream of the combustion stabilizer 100's outlet, a multi-stage highly reducing atmosphere is created along the flame's high-temperature zone, helping to reduce fuel-induced NOx generation. Furthermore, the presence of these multiple high-temperature zones ensures a more uniform overall temperature distribution within the combustion stabilizer 100 and the pulverized coal burner 200, helping to reduce thermal NOx generation.

[0250] (4) Flexible and practical

[0251] The present application can be applied to a four-corner tangential circular direct current burner 200, and can also be applied to a wall-type counter-swirling swirl burner 200. It has wide applicability and is convenient for on-site modification on existing types of burners 200.

[0252] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 understood as a limitation on the present application.

[0253] 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0254] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0255] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it 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. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0256] In this application, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. 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 can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0257] Although the above embodiments have been shown and described, it is understood that the above embodiments are illustrative and cannot be understood as limitations on the present application. Changes, modifications, substitutions and variations of the above embodiments made by ordinary technicians in this field are all within the scope of protection of the present application.

Claims

1. A coal-fired power unit coal powder stable combustion and concentration device, characterized in that: include: burners and concentrators; a flame stabilizer, wherein an outlet end of the flame stabilizer is in communication with the burner, the flame stabilizer extends in a first direction, the flame stabilizer comprises a cavity and a pulverized coal pipe assembly at least partially disposed in the cavity, and the concentrator can be in communication with the pulverized coal pipe assembly so as to introduce a first airflow containing pulverized coal into the pulverized coal pipe assembly; The pulverized coal pipe assembly can divide the first airflow into a first sub-airflow and a second sub-airflow and introduce the first sub-airflow into the cavity, the pulverized coal concentration of the first sub-airflow is less than the pulverized coal concentration of the second sub-airflow, and the introduction position of the second sub-airflow is adjacent to the outlet end of the flame stabilizer relative to the introduction position of the first sub-airflow; A secondary air duct is communicated with the cavity.

2. The device for stabilizing and concentrating pulverized coal for coal-fired power generation units according to claim 1, characterized in that: The flame stabilizer comprises: a housing, the housing comprising the cavity; The pulverized coal pipe assembly extends along a first direction, the first direction includes a first sub-direction and a second sub-direction opposite to the first sub-direction, the direction from the inlet end of the pulverized coal pipe assembly to the outlet end of the pulverized coal pipe assembly is the first sub-direction, at least part of the pulverized coal pipe assembly is arranged in the cavity, and the outer peripheral surface of the pulverized coal pipe assembly is sealed and connected to the shell; a first channel and a second channel, wherein the first channel and the second channel are spaced apart in the pulverized coal pipe assembly, the first channel and the second channel are both connected to the cavity, and an outlet of the first channel is adjacent to an inlet end of the pulverized coal pipe assembly relative to an outlet of the second channel; a concentrator, the concentrator being arranged in the pulverized coal pipe assembly, the concentrator being capable of splitting the first airflow entering the pulverized coal pipe assembly into the first sub-airflow and the second sub-airflow, the first channel being used for allowing the first sub-airflow to pass through, and the second channel being used for allowing the second sub-airflow to pass through; A secondary air duct is communicated with the cavity.

3. The device for stabilizing and concentrating pulverized coal for coal-fired power plants according to claim 2, characterized in that: The pulverized coal pipe assembly comprises a first inlet, a first outlet, and a second outlet, wherein the first inlet, the first outlet, and the second outlet are all arranged on the pulverized coal pipe assembly and are arranged sequentially and at intervals along a first sub-direction, the first inlet and the first outlet are connected through the first channel, the first inlet and the second outlet are connected through the second channel, and the openings of the first outlet and the second outlet are both arranged toward the inlet end of the pulverized coal pipe assembly; The outlet end of the flame stabilizer is provided with a flame stabilizer outlet.

4. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 3, characterized in that: The pulverized coal pipe assembly comprises: a first tube, wherein the first inlet is provided at an inlet end of the first tube; A second tube, the second tube and the concentrator are both arranged in the first tube, the concentrator and the second tube are arranged sequentially and spaced apart in the first sub-direction, the inner circumferential wall of the first tube and the outer circumferential wall of the second tube define a first sub-channel, and the inner circumferential wall of the second tube defines the second channel.

5. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 4, characterized in that: The pulverized coal pipe assembly also includes: a first reflux member, the first reflux member being sleeved on the outer peripheral side of the second tube and connected to the outlet end of the second tube, the outlet end of the first tube extending between the first reflux member and the second tube, so that the inner peripheral wall of the first reflux member and the outer peripheral wall of the first tube define a reflux channel communicating with the first sub-channel, and the opening of the reflux channel faces the inlet end of the first tube to form the first outlet; The second return member is arranged in sequence and at intervals with the first return member in the first sub-direction, and a part of the second return member is sleeved on the outer peripheral side of the first return member to form the second outlet.

6. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 5, characterized in that: The first reflux member includes a first barrel and a first end portion, the first barrel portion is sleeved on the outer peripheral side of the first tube, the first end portion is used to connect the first barrel portion and the second tube, and the first end portion is spaced apart from the end face of the outlet end of the first tube in the first direction so that the first sub-channel and the reflux channel are connected to form the first channel.

7. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 6, characterized in that: The second reflux member includes a second end portion and a second barrel portion, the second end portion and the first end portion are spaced apart in the first direction, the second barrel portion extends from the surface of the second end portion toward the direction of the first end portion, and the second barrel portion is sleeved on the outer peripheral side of the first barrel portion so that the second outlet opening toward the inlet end of the pulverized coal pipe assembly is formed between the inner peripheral wall of the second barrel portion and the outer peripheral wall of the first barrel portion.

8. The pulverized coal combustion stabilization and concentration device for a coal-fired power plant according to any one of claims 3 to 7, characterized in that: The shell includes a first section, a second section, a third section and a fourth section which are sequentially connected in the first direction, the first section and the third section are both cylindrical, the cross-sectional area of ​​the second section gradually increases along the first sub-direction, the cross-sectional area of ​​the fourth section gradually decreases along the first sub-direction, the first outlet is arranged in the second section, and the second outlet is arranged in the third section.

9. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 8, characterized in that: The secondary air duct is arranged on the outer peripheral side of the first section and connected to the first section, and the air outlet direction of the secondary air duct is tangent to the inner peripheral wall of the first section; There are multiple secondary air ducts, and the multiple secondary air ducts are arranged at intervals along the circumference of the first section.

10. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to any one of claims 4 to 7, characterized in that: The concentrator is annular and the inner circumferential wall of the concentrator defines a concentration adjustment channel. The outer circumferential wall of the concentrator is in contact with the inner circumferential wall of the first tube. The concentrator includes a tapered section and a gradually expanding section arranged in sequence along the first sub-direction. The cross-sectional area of ​​the tapered section gradually increases along the first sub-direction, and the cross-sectional area of ​​the gradually expanding section gradually decreases along the first sub-direction, so that the cross-sectional area of ​​the concentration adjustment channel first gradually decreases and then gradually increases along the first sub-direction.

11. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to any one of claims 5 to 7, characterized in that: The second tube and the first reflux member are integrally formed.

12. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to any one of claims 3 to 11, characterized in that: The burner comprises: A feeding pipe assembly, wherein a fifth channel is provided in the feeding pipe assembly; A combustion tube assembly, wherein a combustion chamber is provided in the combustion tube assembly, the feed tube assembly is connected to the combustion tube assembly, the combustion tube assembly extends along a first direction, a third channel and a fourth channel are provided in the combustion tube assembly, the fifth channel, the third channel and the fourth channel are all connected to the combustion chamber, the fifth channel, the third channel and the fourth channel are spaced apart in the first direction, the outlet end of the combustion tube assembly is suitable for being connected to a combustion furnace, and the flame stabilizer and the combustion tube assembly are arranged in sequence along the first sub-direction.

13. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 12, characterized in that: The feed pipe assembly is suitable for connecting the gas source and the combustion tube assembly, and includes a first feed pipe and a second feed pipe which are arranged sequentially and spaced apart in the first sub-direction, the fifth channel is arranged in the first feed pipe, and the second feed pipe is connected to both the third channel and the fourth channel.

14. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 13, characterized in that: The combustion tube assembly includes an inner tube, a cavity is provided in the inner tube to form the combustion chamber, the inner tube includes a first combustion section and a second combustion section, the first combustion section and the second combustion section are arranged sequentially and connected in the first sub-direction, the outlet end of the first combustion section extends into the inlet end of the second combustion section, so that the outer circumferential wall of the first combustion section and the inner circumferential wall of the second combustion section define the third channel.

15. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 14, characterized in that: The combustion tube assembly also includes an outer tube, which is sleeved on the outside of the inner tube and the inner circumferential wall of the outer tube is spaced apart from the outer circumferential wall of the inner tube. The outer tube includes a straightening section and a guide section arranged in sequence along the first sub-direction, an inlet end of the straightening section is sealed and connected to an inlet end of the first combustion section, and the inner circumferential wall of the guide section and the outer circumferential wall of the second combustion section define a fourth channel.

16. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 15, characterized in that: The first feeding pipe includes a first transition section, the first transition section is connected to the first combustion section, the first transition section extends along the first direction, and the cross-sectional area of ​​the first transition section gradually decreases along the first sub-direction.

17. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 16, characterized in that: The first feeding pipe also includes a first feeding section, an inlet end of the first feeding section extends along a second direction, the second direction is orthogonal to the first direction, an outlet end of the first feeding section extends along the first direction, the first feeding section is connected to the first transition section, and the first feeding section and the first transition section are connected to form the fifth channel.

18. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 17, characterized in that: The flame stabilizer is connected to the first feeding section, the inlet end of the flame stabilizer is arranged on the outside of the first feeding section, the outlet end of the flame stabilizer passes through the side wall of the first feeding section and extends into the first feeding section, and the flame stabilizer outlet is located in the first transition section.

19. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 17, characterized in that: The second feeding pipe includes a second transition section, the second transition section is communicated with the rectifying section, and the cross-sectional area of ​​the second transition section gradually increases along the second direction.

20. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to any one of claims 15 to 19, characterized in that: The burner further comprises an air supply pipe. The burner is a four-corner tangential circular direct current burner. The air supply pipe is sleeved on the outer peripheral side of the guide section.

21. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to any one of claims 15 to 19, characterized in that: The burner also includes an air supply pipe. The burner is a wall-type counter-swirl burner. The air supply pipe includes a first pipe and a second pipe. The first pipe is sleeved on the outer peripheral side of the guide section, and the second pipe is sleeved on the outer peripheral side of the first pipe.

22. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to any one of claims 13 to 19, characterized in that: The burner further comprises a connecting pipe, and the connecting pipe is used to connect the gas source with the first feeding pipe or the second feeding pipe.

23. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to any one of claims 17 to 19, characterized in that: The concentrator comprises: A main feed pipe, the main feed pipe extends along the second direction, a main feed port is arranged at the inlet end of the main feed pipe, the main feed port is suitable for being connected to a pulverized coal gas source, a first port, a second port and a third port are arranged at the outlet end of the main feed pipe, the second port and the main feed port are arranged opposite to each other in the second direction, the second port is located between the first port and the third port, and the first port and the second port are arranged opposite to each other in the first direction; A concentrating component is arranged in the main feed pipe. The primary air pulverized coal airflow entering from the main feed port can be automatically divided into a first airflow, a second airflow and a third airflow with successively decreasing pulverized coal concentrations by impacting the concentrating component. The first airflow is discharged from the first port, the second airflow is discharged from the second port, and the third airflow is discharged from the third port.

24. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 23, characterized in that: The concentrator further includes a first branch pipe, a second branch pipe and a third branch pipe, wherein the first branch pipe is connected to the main feed pipe through the first port, the second branch pipe is connected to the main feed pipe through the second port, and the third branch pipe is connected to the main feed pipe through the third port.

25. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 24, characterized in that: The first branch pipe is connected to the first inlet so as to introduce the first airflow into the burner, the second branch pipe is connected to the first feed pipe so as to introduce the second airflow into the burner, and the third branch pipe is connected to the second feed pipe so as to introduce the third airflow into the burner.

26. The pulverized coal combustion stabilization and concentration device for coal-fired power generation units according to claim 24 or 25, characterized in that: The main feed pipe has a first side wall, a second side wall, a third side wall and a fourth side wall connected in sequence in its circumferential direction, the first side wall and the third side wall are arranged relatively to each other in the first direction, the first port is provided on the first side wall, the third port is provided on the third side wall, the second side wall and the fourth side wall are arranged relatively to each other in a third direction, and the third direction is orthogonal to both the second direction and the first direction.

27. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 26, characterized in that: The main feed pipe is provided with a first flow channel, a second flow channel, a third flow channel and a fourth flow channel arranged in an array. In the first direction, the first flow channel and the second flow channel are arranged in sequence, the third flow channel and the fourth flow channel are arranged in sequence, and the first flow channel is arranged adjacent to the second side wall relative to the third flow channel.

28. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 27, characterized in that: The concentration assembly includes a first concentration block, a second concentration block and a diverter plate, wherein the first concentration block, the second concentration block and the diverter plate are arranged sequentially and at intervals in the second direction, and the first concentration block is arranged adjacent to the total feed port relative to the diverter plate.

29. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 28, characterized in that: The first concentrated block is disposed on the third side wall to block the second flow channel and the fourth flow channel, and the second concentrated block is disposed on the second side wall to block the first flow channel and the second flow channel.

30. The device for stabilizing and concentrating pulverized coal in a coal-fired power plant according to claim 29, characterized in that: The first concentrated block is in the shape of a trapezoidal table and has a first end face and a second end face which are parallel to each other and spaced apart in a first direction. The area of ​​the first end face is larger than that of the second end face, and the first end face is in contact with the inner surface of the third side wall.

31. The pulverized coal combustion stabilization and concentration device for a coal-fired power plant according to any one of claims 28 to 30, characterized in that: The second concentrated block is in the shape of a trapezoidal table and has a third end face and a fourth end face which are parallel to each other and spaced apart in a third direction. The area of ​​the third end face is larger than that of the fourth end face, and the third end face is in contact with the inner surface of the second side wall.

32. The pulverized coal combustion stabilization and concentration device for a coal-fired power plant according to any one of claims 28 to 31, characterized in that: The diverter plate is cross-shaped so as to be compatible with the first flow channel to the fourth flow channel.

33. The pulverized coal combustion stabilization and concentration device for a coal-fired power plant according to any one of claims 27 to 32, characterized in that: The concentrator also includes a baffle, which is arranged on the inner circumferential wall of the inlet end of the second branch pipe, and the baffle is arranged adjacent to the first branch pipe relative to the third branch pipe, and the baffle is arranged opposite to the third flow channel in the extension direction of the main feed pipe.

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