Coal dust stable combustion and concentration device for coal power unit

Abstract

This invention relates to a coal-fired power unit pulverized coal combustion stabilization and concentration device. The device includes a burner, a flame stabilizer, and a concentrator. The concentrator splits the primary air-pulverized coal gas flow provided by a pulverized coal gas source into a first gas flow, a second gas flow, and a third gas flow. The first, second, and third gas flows burn within the flame stabilizer and burner. A first inlet is connected to the concentrator to introduce the first gas flow into a pulverized coal pipe assembly. The pulverized coal pipe assembly can split the first gas flow to obtain a first sub-gas flow and a second sub-gas flow. The pulverized coal concentration of the first sub-gas flow is lower than that of the second sub-gas flow. A first outlet discharges the first sub-gas flow into a cavity, and a second outlet discharges the second sub-gas flow into the cavity. A secondary air duct is located on the outer periphery of the inlet end of the flame stabilizer and is connected to the cavity. Therefore, the coal-fired power unit pulverized coal combustion stabilization and concentration device of this invention has advantages such as good combustion stability, good environmental performance, and low production cost.

Description

Technical Field

[0001] This invention relates to the field of pulverized coal combustion technology, and in particular to a device for stable combustion and concentration of pulverized coal in coal-fired power units. Background Technology

[0002] To improve the stable combustion capability of pulverized coal burners under low and variable load conditions, coal-fired power plants typically need to add ignition devices or introduce auxiliary fuels. A common ignition and combustion stabilization method uses diesel fuel, which requires large quantities, resulting in high costs. Furthermore, the use of diesel fuel for combustion assistance introduces new pollutants, such as sulfides and nitrogen oxides. Pulverized coal burners equipped with plasma ignition devices can improve stable combustion under low load conditions; however, the cathode material in plasma ignition devices has a very short lifespan, increasing the unit's operating costs.

[0003] In recent years, a method has emerged that uses resistance wire to heat the combustion chamber shell to heat the fuel inside the combustion chamber. However, the heating efficiency of indirectly heating the internal structure of the combustion chamber using resistance wire is low, and the resistance wire and the combustion chamber shell need to withstand very high temperatures during the heating process, which places high demands on the materials of the resistance wire and the combustion chamber.

[0004] In summary, how to provide a technology that can improve the stable combustion capability of pulverized coal burners during low-load and variable-load operation without the need for auxiliary fuel or additional ignition devices has become an important problem that researchers and technicians in this field urgently need to solve. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention provide a coal-fired power unit pulverized coal stable combustion and concentration device.

[0006] The coal-fired power unit pulverized coal combustion stabilization and concentration device of this invention includes:

[0007] Burners and concentrators;

[0008] A flame stabilizer, the outlet end of which is connected to the burner, the flame stabilizer extending along a first direction, the flame stabilizer including a cavity and a pulverized coal tube assembly at least partially disposed in the cavity, and a concentrator being connected to the pulverized coal tube assembly to introduce a first gas flow containing pulverized coal into the pulverized coal tube assembly;

[0009] The pulverized coal pipe assembly 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 less than that of the second sub-airflow. The introduction position of the second sub-airflow is relatively close to the outlet end of the flame stabilizer relative to the introduction position of the first sub-airflow.

[0010] A secondary air duct, which is connected to the cavity.

[0011] Therefore, the coal-fired power unit pulverized coal stable combustion and concentration device of the present invention has the advantages of good combustion stability, good environmental protection effect and low production cost.

[0012] In some embodiments, the flame stabilizer includes a housing, a first inlet, a first outlet, and a second outlet. The housing has a cavity. 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 flame stabilizer to the outlet end of the flame stabilizer is the first sub-direction.

[0013] The first inlet, the first outlet, and the second outlet are all located on the pulverized coal pipe assembly and are arranged sequentially and at intervals along the first sub-direction. The first inlet is connected to each of the first outlet and the second outlet. The first outlet and the second outlet are both located in the cavity and are both arranged towards the first inlet along the second sub-direction. The outlet end of the flame stabilizer is provided with a flame stabilizer outlet.

[0014] The concentrator is adapted to be connected to a pulverized coal gas source. The concentrator is used to split the primary air pulverized coal gas flow provided by the pulverized coal gas source into a first gas flow, a second gas flow, and a third gas flow. The concentrator can be connected to the first inlet to inject the first gas flow into the pulverized coal pipe assembly, and the concentrator can be connected to the burner to inject the second gas flow and the third gas flow into the burner.

[0015] The first inlet is connected to the concentrator to introduce the first airflow into the pulverized coal pipe assembly. The pulverized coal pipe assembly can split the first airflow to obtain the first sub-airflow and the second sub-airflow. The first outlet is used to discharge the first sub-airflow into the cavity, and the second outlet is used to discharge the second sub-airflow into the cavity.

[0016] A secondary air duct is provided on the outer periphery of the inlet end of the flame stabilizer and communicates with the cavity. The air outlet direction of the secondary air duct is tangent to the inner peripheral wall of the housing.

[0017] In some embodiments, the pulverized coal pipe assembly includes:

[0018] The first pipe has its inlet end and outlet end arranged opposite to each other in the first direction, with the first inlet located at the inlet end of the first pipe.

[0019] A concentration element, wherein the concentration element is annular and the inner peripheral wall of the concentration element defines a concentration adjustment channel, and the cross-sectional area of ​​the concentration adjustment channel gradually decreases and then gradually increases along the first sub-direction;

[0020] The second tube, the condenser and the second tube are both disposed inside the first tube, the condenser and the second tube are arranged sequentially and at intervals in the first sub-direction, the inner peripheral wall of the first tube and the outer peripheral wall of the second tube define a first channel, the inner peripheral wall of the second tube defines a second channel, and the inlet end and the outlet end of the second tube are arranged opposite to each other in the first direction.

[0021] The first return element is sleeved on the outer periphery of the second tube and connected to the outlet end of the second tube. The outlet end of the first tube extends between the first return element and the second tube, so that the inner peripheral wall of the first return element and the outer peripheral wall of the first tube define a return channel. The return channel is connected to the first channel, and the opening of the return channel faces the inlet end of the first tube to form the first outlet.

[0022] The second return element is arranged sequentially and at intervals in the first sub-direction, with a portion of the second return element sleeved on the outer periphery of the first return element to form the second outlet.

[0023] In some embodiments, the housing includes a first segment, a second segment, a third segment, and a fourth segment connected sequentially in the first direction. The secondary air duct is connected to the first segment. The first segment and the third segment are both cylindrical. The cross-sectional area of ​​the second segment gradually increases along the first sub-direction, and the cross-sectional area of ​​the fourth segment gradually decreases along the first sub-direction. The first outlet is located in the second segment, and the second outlet is located in the third segment.

[0024] In some embodiments, the burner includes a combustion tube assembly, the flame stabilizer and the combustion tube assembly are arranged sequentially along the first sub-direction, and the outlet end of the combustion tube assembly is adapted to be connected to a combustion furnace;

[0025] The combustion tube assembly includes an inner tube and an outer tube, with the outer tube sleeved on the outside of the inner tube;

[0026] The inner tube includes a first combustion section and a second combustion section 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 peripheral wall of the first combustion section and the inner peripheral wall of the second combustion section define a third channel.

[0027] The outer tube includes a rectifier section and a guide section arranged sequentially along the first sub-direction. The inlet end of the rectifier section is sealed to the inlet end of the first combustion section, and the inner peripheral wall of the guide section and the outer peripheral wall of the second combustion section define a fourth channel.

[0028] In some embodiments, the burner further includes a feed pipe assembly comprising a first feed pipe and a second feed pipe arranged sequentially and at intervals in the first sub-direction. The first feed pipe is used to connect the concentrator and the first combustion section to introduce the second gas flow into the inner pipe. The second feed pipe is used to connect the concentrator and the rectifier section to introduce the third gas flow into the combustion pipe assembly. The combustion pipe assembly can split the third gas flow into a third sub-gas flow and a fourth sub-gas flow. The third channel is used to allow the third sub-gas flow to enter the second combustion section, and the fourth channel is used to allow the fourth sub-gas flow to pass through so as to merge with the gas flow in the second combustion section.

[0029] In some embodiments, the first feed tube includes:

[0030] A first transition segment extends along the first direction, and the cross-sectional area of ​​the first transition segment gradually decreases along the first sub-direction;

[0031] The first feeding section has an inlet end that extends along a second direction, which is orthogonal to the first direction. The outlet end of the first feeding section extends along the first direction. The first feeding section, the first transition section, and the first combustion section are connected in sequence. The flame stabilizer is connected to the first feeding section. The inlet end of the flame stabilizer is located outside 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. The outlet of the flame stabilizer is located in the first transition section.

[0032] In some embodiments, the concentrator includes:

[0033] A main feed pipe, the inlet end of which is adapted to be connected to a pulverized coal gas source, the main feed pipe extending along a second direction;

[0034] The first branch pipe, the second branch pipe, and the third branch pipe are arranged at intervals, and the outlet end of the main feed pipe is connected to each of the first branch pipe, the second branch pipe, and the third branch pipe.

[0035] The main feed pipe is adapted to introduce the primary air-coal powder gas flow into the concentrator. The concentrator can split the primary air-coal powder gas flow to obtain the first gas flow, the second gas flow, and the third gas flow. The first branch pipe is connected to the first inlet to introduce the first gas flow into the burner. The second branch pipe is connected to the first feed pipe to introduce the second gas flow into the burner. The third branch pipe is connected to the second feed pipe to introduce the third gas flow into the burner.

[0036] In some embodiments, the concentrator further includes a concentrating assembly disposed within the main feed pipe. The concentrating assembly includes a first concentrating block, a second concentrating block, and a flow divider plate. The first concentrating block, the second concentrating block, and the flow divider plate are arranged sequentially and at intervals in the second direction, and the first concentrating block is disposed relative to the flow divider plate adjacent to the inlet end of the main feed pipe.

[0037] The main feed pipe has a first sidewall, a second sidewall, a third sidewall and a fourth sidewall connected in sequence in its circumferential direction. The first sidewall and the third sidewall are arranged opposite to each other in the first direction, and the third sidewall is arranged adjacent to the third branch pipe relative to the first sidewall. The second sidewall and the fourth sidewall are arranged opposite to each other.

[0038] The main feed pipe is provided with a first flow channel to a fourth flow channel arranged in an array. In the first sub-direction, the first flow channel and the second flow channel are arranged in sequence, and the third flow channel and the fourth flow channel are arranged in sequence. The first flow channel is disposed adjacent to the second side wall relative to the third flow channel. The first concentration block is disposed on the third side wall to block the second flow channel and the fourth flow channel. The second concentration block is disposed on the second side wall to block the first flow channel and the second flow channel, or the second concentration block is disposed on the fourth side wall to block the third flow channel and the fourth flow channel.

[0039] The flow divider is cross-shaped to fit the first to the fourth flow channels.

[0040] In some embodiments, the concentrator further includes a baffle disposed on the inner peripheral 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.

[0041] The coal-fired power unit pulverized coal combustion stabilization and concentration device of the present invention has the following effects:

[0042] (1) Significant economic advantages

[0043] Compared to traditional micro-oil igniters and plasma igniters, this invention has significant economic advantages. It can ignite most of the surrounding coal dust with a small amount of coal dust, completely replacing traditional micro-oil igniters and plasma igniters. It uses coal as fuel for direct ignition, achieving the goal of igniting a large amount of surrounding coal dust with a small amount of coal dust, thus improving the economy of coal-fired units during the ignition and peak-shaving processes.

[0044] (2) Rapid ignition and strong low-load stable combustion capability

[0045] This invention combines multi-stage pulverized coal enrichment and multi-stage pulverized coal preheating with ignition and combustion stabilization enhancement measures. It constructs a rich-lean pulverized coal combustion system and a two-stage pulverized coal ignition preheating process within a combustion-free stabilizer, and establishes multi-stage (three or more stages) pulverized coal preheating downstream of the combustion-free stabilizer, sequentially igniting the downstream pulverized coal gas flow. This facilitates rapid ignition during the start-up of coal-fired power units and stable combustion during flexible peak shaving, while also promoting burnout during pulverized coal combustion.

[0046] (3) Low NOx generation

[0047] By constructing a rich-lean combustion system and a two-stage high-temperature reduction zone within the combustion stabilizer without combustion aid, and by constructing a multi-stage rich-lean combustion system downstream of the combustion stabilizer outlet, a multi-stage strong reducing atmosphere is created along the high-temperature zone of the flame, which helps reduce the formation of fuel-type NOx. Furthermore, the presence of these multi-stage high-temperature zones results in a more uniform overall temperature distribution within both the combustion stabilizer and the pulverized coal burner, further contributing to the reduction of thermal NOx formation.

[0048] (4) It is flexible and practical.

[0049] This invention can be applied to both tangential DC burners and wall-mounted counter-current swirl burners, demonstrating wide applicability and facilitating on-site modification of existing burner types. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structure of the coal-fired power unit pulverized coal stabilization and concentration device according to an embodiment of the present invention.

[0051] Figure 2 This is a schematic diagram of the internal airflow of the stabilizer and burner in the pulverized coal stabilization and concentration device of the coal-fired power unit according to an embodiment of the present invention.

[0052] Figure 3 This is a left view of the stabilizer of the coal-fired power unit pulverized coal stabilization and concentration device according to an embodiment of the present invention.

[0053] Figure 4 This is a cross-sectional view of the stabilizer of the coal-fired power unit pulverized coal stabilization and concentration device according to an embodiment of the present invention.

[0054] Figure 5 This is a schematic diagram of the structure of the stabilizer and burner of the coal-fired power unit pulverized coal stabilization and concentration device according to an embodiment of the present invention.

[0055] Figure 6 This is a schematic diagram of the concentrator in the coal-fired power unit pulverized coal stable combustion and concentration device according to an embodiment of the present invention.

[0056] Figure 7 yes Figure 6 Schematic diagram of cross-sections at AA, BB, CC, and DD.

[0057] Figure 8 This is a schematic diagram of the burner and tertiary air duct of the coal-fired power unit pulverized coal stable combustion and concentration device according to an embodiment of the present invention.

[0058] Figure 9 This is a schematic diagram of the burner and tertiary air duct of a coal-fired power unit pulverized coal stable combustion and concentration device according to another embodiment of the present invention.

[0059] Figure label:

[0060] Flame stabilizer 100; Pulverized coal pipe assembly 11; First pipe 111; First inlet 1111; Concentrator 1112; Converging section 11121; Expanding section 11122; Second pipe 112; First return section 113; Second return section 114; First outlet 115; Second outlet 116; First channel 117; Second channel 118; Return channel 119; Shell 12; First section 121; Second section 122; Third section 123; Fourth section 124; Flame stabilizer outlet 125; Secondary air duct 13;

[0061] Burner 200; Combustion tube assembly 21; Inner tube 211; First combustion section 2111; Second combustion section 2112; Outer tube 212; Rectifying section 2121; Guide section 2122; Third channel 213; Fourth channel 214; Feed pipe assembly 22; First feed pipe 221; First feed section 2211; First transition section 2212; Second feed pipe 222; Second transition section 2221; Tertiary air duct 23; First nozzle 231; Second nozzle 232; Blade 234; Third nozzle 233;

[0062] Concentrator 300; First branch pipe 31; Second branch pipe 32; Third branch pipe 33; Main feed pipe 34; First side wall 341; Second side wall 342; Third side wall 343; Fourth side wall 344; First flow channel 345; Second flow channel 346; Third flow channel 347; Fourth flow channel 348; First concentration block 35; Second concentration block 36; Diverter plate 37; Baffle 38. Detailed Implementation

[0063] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0064] like Figure 1-9 As shown, the coal-fired power unit pulverized coal stabilization and concentration device of this embodiment includes a burner 200, a stabilizer 100 and a concentrator 300.

[0065] The outlet end of the flame stabilizer 100 is connected to the burner 200. The flame stabilizer 100 extends along a first direction. The flame stabilizer 100 includes a cavity and a pulverized coal tube assembly 11 that is at least partially disposed in the cavity. The concentrator 300 can be connected to the pulverized coal tube assembly 11 to introduce a first airflow containing pulverized coal into the pulverized coal tube assembly 11.

[0066] 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 less than that of the second sub-airflow. The introduction position of the second sub-airflow is relatively close to the outlet end of the flame stabilizer 100 relative to the introduction position of the first sub-airflow.

[0067] Secondary air duct 13 is connected to the cavity.

[0068] For ease of description, the following will use... Figure 1 The left and right directions are taken as the first direction.

[0069] For example, the flame stabilizer 100 extends in the left and right direction, and the outlet end of the flame stabilizer 100 is the right end of the flame stabilizer 100. The flame stabilizer 100 has a cavity, and the right end of the pulverized coal pipe assembly 11 is located in the cavity. 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.

[0070] When the coal-fired power unit pulverized coal combustion stabilization and concentration device of the present invention is working, the concentrator 300 introduces a first airflow into the pulverized coal pipe assembly 11. In the pulverized coal pipe assembly 11, the first airflow is split into a first sub-airflow and a second sub-airflow with different pulverized coal concentrations. The pulverized coal concentration of the first sub-airflow is less than that of the second sub-airflow.

[0071] Then, the first sub-flow and the second sub-flow flow into the cavity from inside the pulverized coal pipe assembly 11. The inlet position of the first sub-flow is to the left of the inlet position of the second sub-flow.

[0072] Simultaneously, secondary air is injected at high speed into the cavity along the secondary air duct 13, gradually flowing to the right within the cavity and forming a high-speed rotating airflow, creating a low-pressure zone in the central region of the secondary air. As the secondary air gradually flows to the right, some of it flows into the low-pressure zone, thus forming a high-speed recirculation zone within the shell 12.

[0073] Because the second sub-gas flow is introduced near the high-speed recirculation zone, it is more easily entrained into this zone during its flow, igniting some of the pulverized coal. This causes the second sub-gas flow to swirl and burn, releasing heat and forming a dense-phase high-temperature recirculation zone. This facilitates the rapid heating and ignition of the second sub-gas flow, releasing a significant amount of heat. Simultaneously, the first sub-gas flow is injected at a certain distance to the left of the second sub-gas flow. The first sub-gas flow is obstructed and carried by the secondary air in a swirling state, causing it to change direction. The first sub-gas flow then enters the dense-phase high-temperature recirculation zone between the secondary air and the second sub-gas flow.

[0074] In this process, although the coal powder concentration in the first sub-gas stream is low and not easily ignited, on the one hand, the low concentration of coal powder in the first sub-gas stream is subjected to convective and radiative heat transfer in the high-temperature reflux zone, which promotes the heating and ignition of the first sub-gas stream. On the other hand, the introduction position of the first sub-gas stream is to the left of the introduction position of the second sub-gas stream, so that the first sub-gas stream has a relatively longer residence time in the shell 12 compared to the second sub-gas stream. These two aspects will jointly promote the ignition and burnout effect of the first sub-gas stream. At this time, the first sub-gas stream is preheated, rapidly heats up and ignites, and releases a lot of heat, forming a light-phase high-temperature reflux zone outside the dense-phase high-temperature reflux zone.

[0075] Meanwhile, since the second sub-gas flow is injected at a certain distance from the first sub-gas flow, it helps to delay the mixing of rich and lean gas flows. This promotes overall burnout and enhances the rich and lean combustion effect of pulverized coal, thereby reducing NOx formation.

[0076] The coal-fired power unit pulverized coal stable combustion and concentration device of the present invention has the advantages of good combustion stability, good environmental protection effect and low production cost.

[0077] In some embodiments, the flame stabilizer 100 includes a housing 12, a first inlet 1111, a first outlet 115, and a second outlet 116. The housing 12 has a cavity. 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 flame stabilizer 100 to the outlet end of the flame stabilizer 100 is the first sub-direction.

[0078] 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 arranged sequentially and at intervals along the first sub-direction. The first inlet 1111 is connected to each of the first outlet 115 and the second outlet 116. The first outlet 115 and the second outlet 116 are both located in the cavity and are both arranged towards the first inlet 1111 along the second sub-direction. The outlet end of the flame stabilizer 100 is provided with a flame stabilizer outlet 125.

[0079] The concentrator 300 is adapted to be connected to a pulverized coal gas source. The concentrator 300 is used to split the primary air pulverized coal gas flow provided by the pulverized coal gas source into a first gas flow, a second gas flow, and a third gas flow. The concentrator 300 can be connected to a first inlet 1111 to inject the first gas flow into the pulverized coal pipe assembly 11, and the concentrator 300 can be connected to a burner 200 to inject the second gas flow and the third gas flow into the burner 200.

[0080] The first inlet 1111 is connected to the concentrator 300 to introduce a first airflow into the pulverized coal tube assembly 11. The pulverized coal tube assembly 11 can split the first airflow to obtain a first sub-airflow and a second sub-airflow. The first outlet 115 is used to discharge the first sub-airflow into the cavity, and the second outlet 116 is used to discharge the second sub-airflow into the cavity.

[0081] The secondary air duct 13 is located on the outer periphery of the inlet end of the flame stabilizer 100, and the air outlet direction of the secondary air duct 13 is tangent to the inner peripheral wall of the shell 12.

[0082] For ease of description, the following will use... Figure 1 The left and right directions are taken as the first direction, with the right being the first sub-direction and the left being the second sub-direction.

[0083] Both the flame stabilizer 100 and the burner 200 extend in the left-right direction. The burner 200 is located on the right side of the flame stabilizer 100, and the outlet end of the burner 200 is connected to the combustion furnace.

[0084] One end of the concentrator 300 is connected to the pulverized coal gas source, and the other end of the concentrator 300 is connected to the first inlet 1111 of the burner 100 and the burner 200. The concentrator 300 can split the primary air pulverized coal gas flow provided by the pulverized coal gas source into a first flow, a second flow, and a third flow. The pulverized coal concentration in the first flow is greater than that in the second flow, and the pulverized coal concentration in the second flow is greater than that in the third flow.

[0085] The following describes in detail the flame stabilizer 100 of the present invention. The flame stabilizer 100 includes a shell 12, a pulverized coal pipe assembly, and a secondary air duct 13.

[0086] The pulverized coal pipe assembly 11 extends in the left-right direction, and the centerline of the pulverized coal pipe assembly 11 coincides with the centerline of the housing 12. The left end of the pulverized coal pipe assembly 11 is located outside the housing 12, and the right end of the pulverized coal pipe assembly 11 is located inside the housing 12. The pulverized coal pipe assembly 11 is provided with a first inlet 1111, a first outlet 115, and a second outlet 116, and the three are arranged sequentially in the left-right direction. The first inlet 1111 is located on the left side and outside the housing 12, that is, the first inlet 1111 is located at the left end of the burner stabilizer 100. 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 located inside the housing 12 and communicate with the cavity. It should be noted that the openings of the first outlet 115 and the second outlet 116 are both set towards the inlet end of the pulverized coal pipe assembly 11, so that the initial flow direction of the airflow from the first outlet 115 or the second outlet 116 is to the left, thereby facilitating the formation of circulation, and further facilitating the formation of the dense phase high-temperature reflux zone and the light phase high-temperature reflux zone.

[0087] The first airflow is an airflow containing pulverized coal. The first airflow enters the pulverized coal pipe assembly 11 through the first inlet 1111. Inside the pulverized coal pipe assembly 11, the first airflow is split into a first sub-airflow and a second sub-airflow, and the pulverized coal concentration in the first sub-airflow is less than that in the second sub-airflow. The first sub-airflow flows into the cavity for combustion from the first outlet 115, and the second sub-airflow flows into the cavity for combustion from the second outlet 116.

[0088] The inner peripheral wall of the left end of the housing 12 is sealed to the outer peripheral wall of the pulverized coal pipe assembly 11. The right end of the housing 12 is open to form a burner outlet 125. The right end of the burner 100 extends into the burner 200. A secondary air duct 13 is provided at the left end of the burner 100. The secondary air duct 13 is located on the outer peripheral side of the housing 12 and communicates with the cavity to inject secondary air into the cavity. It should be noted that the air outlet direction of the secondary air duct 13 is tangent to the inner peripheral wall of the housing 12. In other words, a secondary air channel is provided inside the secondary air duct 13, and the secondary air channel is tangent to the inner wall surface of the housing 12.

[0089] When the coal-fired power unit pulverized coal combustion stabilization and concentration device of the present invention is working, the concentrator 300 can split the primary air pulverized coal gas flow provided by the pulverized coal gas source into a first gas flow, a second gas flow, and a third gas flow with successively decreasing pulverized coal concentration. The concentrator 300 is connected to the first inlet 1111 so as to introduce the first gas flow into the combustion stabilizer 100. The concentrator 300 is connected to the burner 200 so as to introduce the second gas flow and the third gas flow into the burner 200.

[0090] The first airflow enters the pulverized coal pipe group. Inside the pulverized coal pipe group, the first airflow is split into a first sub-airflow and a second sub-airflow with different pulverized coal concentrations. The pulverized coal concentration of the first sub-airflow is less than that of the second sub-airflow.

[0091] Then, the first sub-flow enters the first channel 117 and flows into the cavity from the first outlet 115, and the second flow enters the second channel 118 and flows into the cavity from the second outlet 116.

[0092] At the same time, the secondary air is injected into the cavity at high speed along the secondary air duct 13. It gradually flows to the right in the cavity and forms a high-speed rotating airflow. Because the secondary air has a large rotational tangential velocity at this time, a low-pressure area is formed in the central area of ​​the secondary air during the high-speed rotating flow.

[0093] As the secondary wind gradually flows to the right, some of it will flow into the low-pressure area, thus forming a high-speed recirculation zone within the shell 12.

[0094] Because the second outlet 116 is located near the high-speed recirculation zone, the second sub-gas stream is injected near the high-speed recirculation zone, making it easier for the second sub-gas stream to be entrained into the high-speed recirculation zone during its flow. The second sub-gas stream swirls and combusts within the high-speed recirculation zone, releasing heat and forming a dense-phase high-temperature recirculation zone. This facilitates the rapid heating and ignition of the second sub-gas stream, releasing a significant amount of heat and forming the dense-phase high-temperature recirculation zone. Simultaneously, the first sub-gas stream is injected at a certain distance to the left of the second sub-gas stream. The first sub-gas stream is obstructed and carried by the secondary wind in the swirling state, causing it to change direction. The first sub-gas stream enters the dense-phase high-temperature recirculation zone between the secondary wind and the second sub-gas stream in the swirling state.

[0095] In this process, although the coal powder concentration in the first sub-gas stream is low and not easily ignited, on the one hand, the low concentration of coal powder in the first sub-gas stream is subjected to convective and radiative heat transfer in the high-temperature reflux zone, which can promote the heating and ignition of the first sub-gas stream. On the other hand, the first outlet 115 is located to the left of the second outlet 116, which allows the first sub-gas stream to have a relatively longer residence time in the shell 12 compared to the second sub-gas stream. These two aspects will jointly promote the ignition and burnout effect of the first sub-gas stream. At this time, the first sub-gas stream is preheated, rapidly heats up and ignites, and releases a large amount of heat, forming a light-phase high-temperature reflux zone outside the dense-phase high-temperature reflux zone.

[0096] Meanwhile, because the second sub-gas stream is injected at a certain distance from the first sub-gas stream, it helps to delay the mixing of the rich and lean gas streams. This promotes overall burnout and enhances the rich-lean combustion effect of pulverized coal, while reducing NO. x generate.

[0097] Then, the flame is ejected at high speed from the burner outlet 125 and enters the burner 200. Inside the burner 200, the flame ejected from the burner outlet 125 mixes with the second and third airflows, thereby further improving the combustion effect.

[0098] In other embodiments, there are multiple secondary air ducts 13, which are arranged at circumferential intervals along the inlet end of the flame stabilizer 100. This facilitates the improvement of secondary air introduction efficiency.

[0099] In some embodiments, such as Figure 4 As shown, the pulverized coal pipe assembly 11 includes a first pipe 111, a second pipe 112, a concentrator 1112, a first reflux member 113, and a second reflux member 114.

[0100] The inlet end and the outlet end of the first pipe 111 are arranged opposite each other in the first direction, and the first inlet 1111 is located at the inlet end.

[0101] The concentrator 1112 is annular and the inner peripheral wall of the concentrator 1112 defines a concentration adjustment channel. The cross-sectional area of ​​the concentration adjustment channel gradually decreases and then gradually increases along the first sub-direction. The concentrator 1112 and the second tube 112 are both located inside the first tube 111. The concentrator 1112 and the second tube 112 are arranged sequentially and at intervals along the first sub-direction.

[0102] The inner peripheral wall of the first tube 111 and the outer peripheral wall of the second tube 112 define a first channel 117, and the inner peripheral wall of the second tube 112 defines a second channel 118. The inlet end and the outlet end of the second tube 112 are arranged opposite to each other in the first direction.

[0103] The first return element 113 is sleeved on 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 into the space between the first return element 113 and the second pipe 112, so that the inner peripheral wall of the first return element 113 and the outer peripheral wall of the first pipe 111 define a return channel 119. The return channel 119 is connected to the first channel 117. The opening of the return channel 119 faces the inlet end of the first pipe 111 to form a first outlet 115.

[0104] In the first sub-direction, the first return element 113 and the second return element 114 are arranged sequentially and at intervals, and a part of the second return element 114 is sleeved on the outer periphery of the first return element 113 to form a second outlet 116.

[0105] For example, the first pipe 111 extends in the left-right direction, the inlet end of the first pipe 111 is the left end of the first pipe 111, the outlet end of the first pipe 111 is the right end of the first pipe 111, and the left end of the first pipe 111 is open to form the first inlet 1111.

[0106] The left end of the first tube 111 extends out of the housing 12 to the left, and the concentrate 1112 is located at the part of the first tube 111 that extends out of the housing 12, so as to facilitate the replacement of the concentrate 1112.

[0107] The second pipe 112 is located inside the first pipe 111, and the concentrator 1112 is located to the left of the second pipe 112 and spaced apart from it. After passing through the concentration adjustment channel, the first airflow is split into a first sub-airflow and a second sub-airflow.

[0108] The inner peripheral wall of the first tube 111 and the outer peripheral wall of the second tube 112 are spaced apart to form a first channel 117, and the inner peripheral wall of the second tube 112 defines a second channel 118.

[0109] The inlet end of the second pipe 112 is the left end of the second pipe 112, and the outlet end of the second pipe 112 is the right end of the second pipe 112. The first return element 113 is connected to the right end of the second pipe 112 and is sleeved on the outer periphery of the second pipe 112. The right end of the first pipe 111 is located between the first return element 113 and the second pipe 112, and the outer periphery of the first pipe 111 and the inner periphery of the first return element 113 are spaced apart to form a return channel 119. The right end face of the first pipe 111 is spaced apart from the right end of the first return section, so that the return channel 119 and the first channel 117 can be connected. The opening of the return channel 119 faces to the left, and the opening of the return channel 119 is the first outlet 115.

[0110] The second return element 114 is located to the right of the first return element 113, and a second outlet 116 with an opening facing to the left is formed between the second return element 114 and the first return element 113.

[0111] Optionally, the first return member 113 includes a first end and a first cylindrical portion. The first cylindrical portion is sleeved on the outer periphery of the first tube 111, and the first end is connected to the outlet end of the second tube 112. 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 left-right direction. The second cylindrical portion is sleeved on the outer periphery of the first cylindrical portion, and a second outlet 116 with an opening facing left is formed between the second cylindrical portion and the first cylindrical portion.

[0112] In other embodiments, the outlet end of the second tube 112 is folded outward and in a second direction to form a first return element 113 on the outer periphery of the second tube 112. The first return element 113 and the second tube 112 are integrally formed, and the outlet end of the second tube 112 is folded outward and to the left to form the first return element 113, thereby facilitating the processing of the second tube 112 and the first return element 113.

[0113] In some embodiments, such as Figure 4As shown, the housing 12 includes a first section 121, a second section 122, a third section 123, and a fourth section 124 connected sequentially in a 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 located in the second section 122, and the second outlet 116 is located in the third section 123.

[0114] For example, the first segment 121, the second segment 122, the third segment 123, and the fourth segment 124 are arranged sequentially from left to right. Secondary air ducts 13 are located on the outer periphery of the first segment 121, and multiple secondary air ducts 13 are arranged at intervals along the circumference of the first segment 121. The first segment 121 and the third segment 123 are both cylindrical; in other words, their cross-sectional areas remain constant. The cross-sectional area of ​​the second segment 122 gradually increases from left to right, and the cross-sectional area of ​​the fourth segment 124 gradually decreases from left to right. A flame stabilizer outlet 125 is located at the right end of the fourth segment 124, which can concentrate the flame within the flame stabilizer 100 and increase its velocity.

[0115] In the coal-fired power unit pulverized coal combustion stabilization and concentration device of this invention, since the cross-sectional area of ​​the second section 122 gradually increases from left to right, the flow velocity of the secondary air decreases while the static pressure gradually increases during the flow of secondary air through the second section 122. Furthermore, the outlet direction of the secondary air duct 13 is tangent to the inner peripheral wall of the shell 12, causing the secondary air to rotate and flow at high speed, forming a low-pressure zone in the central region of the secondary air.

[0116] Under the influence of two factors—a low-pressure zone forming in the central region of the secondary wind, a decrease in the flow velocity of the secondary wind, and a gradual increase in static pressure—as the secondary wind gradually flows to the right, some of it flows into the low-pressure zone, thus forming a high-speed recirculation zone in the second section 122 and the third section 123. Since the second outlet 116 is located adjacent to the high-speed recirculation zone, the second sub-flow is injected near the high-speed recirculation zone, making it easier for the second sub-flow to be entrained into the adjacent high-speed recirculation zone during its flow. The second sub-flow swirls and burns, releasing heat within the adjacent high-speed recirculation zone, which promotes rapid heating and ignition of the second sub-flow and releases a significant amount of heat, forming a dense-phase high-temperature recirculation zone.

[0117] In some embodiments, such as Figure 4As shown, the concentrator 1112 is annular and the inner peripheral wall of the concentrator 1112 defines a concentration adjustment channel. The outer peripheral wall of the concentrator 1112 is in contact with the inner peripheral wall of the first tube 111. The concentrator 1112 includes a tapered section 11121 and a widening section 11122 arranged sequentially 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 widening 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.

[0118] For example, the concentrator 1112 is an annular component, with a concentration regulating channel in the middle through which the first airflow can pass. The outer peripheral wall of the concentrator 1112 is fitted to the inner peripheral wall of the first pipe 111, ensuring that the first airflow can only pass through the concentration regulating channel. The tapering section 11121 is located to the left of the expanding section 11122, adjacent to the first outlet 115. The cross-section of the tapering section 11121 is annular, and its cross-sectional area gradually increases from left to right, causing the cross-sectional area of ​​the concentration regulating channel defined by the inner peripheral wall of the tapering section 11121 to gradually decrease from left to right.

[0119] The cross-section of the expanding section 11122 is also annular, and the cross-sectional area of ​​the expanding section 11122 gradually decreases from left to right, so that the cross-sectional area of ​​the concentration regulation channel defined by the inner peripheral wall of the expanding section 11122 gradually increases from left to right.

[0120] In the coal-fired power unit pulverized coal combustion stabilization and concentration device of this embodiment of the invention, when the first airflow first encounters the concentration element 1112, the pulverized coal particles in the first airflow gradually gather near the center line of the first pipe 111 in the converging section 11121 during the collision with the concentration element 1112, causing the pulverized coal concentration near the center line of the first pipe 111 to gradually increase. In the expanding section 11122, the first airflow gradually diffuses near the pipe wall of the first pipe 111. Since the distance between the concentration element 1112 and the second pipe 112 is short, even if the first airflow diffuses near the pipe wall of the first pipe 111, there is not enough time for the pulverized coal concentration near the pipe wall of the first pipe 111 to reach the pulverized coal concentration near the center line of the first pipe 111.

[0121] Therefore, when the first gas flow passes through the concentration adjustment channel, it is separated by inertial separation, resulting in a first sub-gas flow with a lower coal powder concentration near the inner wall of the first pipe 111, and a second sub-gas flow with a higher coal powder concentration near the center line of the first pipe 111. Then the first sub-gas flow enters the first channel 117 outside the second pipe 112, and the second sub-gas flow enters the second channel 118 inside the second pipe 112.

[0122] In some embodiments, such as Figure 5 As shown, the burner 200 includes a combustion tube assembly 21. The burner 100 and the combustion tube assembly 21 are arranged sequentially along a first sub-direction. The outlet end of the combustion tube assembly 21 is adapted to be connected to the combustion furnace. The combustion tube assembly 21 includes an inner tube 211 and an outer tube 212. The outer tube 212 is sleeved on the outside of the inner tube 211. The inner tube 211 includes a first combustion section 2111 and a second combustion section 2112 arranged sequentially and communicating with each other 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. The outer tube 212 includes a rectifier section 2121 and a guide section 2122 arranged sequentially along the first sub-direction. The inlet end of the rectifier section 2121 is sealed to the inlet end of the first combustion section 2111. 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.

[0123] For example, the flame stabilizer 100 is located on the left side of the combustion tube assembly 21. The airflow in the flame stabilizer 100 flows to the right into the combustion tube assembly 21. The outlet end of the combustion tube assembly 21 is adapted to be connected to the combustion furnace. The flame stabilizer outlet 125 and the inlet end of the combustion tube assembly 21 are arranged opposite each other in the left-right direction, and the flame stabilizer outlet 125 and the inlet end of the combustion tube assembly 21 are spaced apart.

[0124] The combustion tube assembly 21 includes an inner tube 211 and an outer tube 212, both of which extend in the left-right direction, and are spaced apart from each other.

[0125] The inner tube 211 includes a first combustion section 2111 and a second combustion section 2112. The first combustion section 2111 is located to the left of the second combustion section 2112. The left end of the first combustion section 2111 is arranged opposite to the outlet 125 of the flame stabilizer. The right end of the first combustion section 2111 can extend into the second combustion section 2112. 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.

[0126] The outer tube 212 includes a rectifier section 2121 and a guide section 2122. The rectifier section 2121 is located on the left side of the guide section 2122. The right end of the rectifier section 2121 and the left end of the guide section 2122 are sealed together. 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.

[0127] It should be noted that the left side of the rectifier section 2121 is sealed to the left side of the first combustion section 2111. The rectifier section 2121 is located outside the first combustion section 2111 to form a rectifier cavity outside the first combustion section 2111. The guide section 2122 is located outside the right end of the second combustion section 2112 and the first combustion section 2111 so that the airflow in the rectifier cavity can enter the fourth channel 214 along the channel between the guide section 2122 and the first combustion section 2111.

[0128] In some embodiments, such as Figure 5 As shown, the burner 200 also includes a feed pipe assembly 22, which includes a first feed pipe 221 and a second feed pipe 222 arranged sequentially and at intervals in a first sub-direction. The first feed pipe 221 is used to connect the concentrator 300 and the first combustion section 2111 to introduce the second gas flow into the inner pipe 211, and the second feed pipe 222 is used to connect the concentrator 300 and the rectifier section 2121 to introduce the third gas flow into the combustion pipe assembly 21.

[0129] The combustion tube assembly 21 can split the third airflow into a third sub-airflow and a fourth sub-airflow. The third channel 213 is used to allow the third sub-airflow to enter the second combustion section 2112, and the fourth channel 214 is used to allow the fourth sub-airflow to pass through so as to merge with the airflow in the second combustion section 2112.

[0130] The feeding pipe assembly includes a first feeding pipe 221 and a second feeding pipe 222. The first feeding pipe 221 is located to the left of the second feeding pipe 222. One end of the first feeding pipe 221 can be connected to the concentrator 300, and the other end of the first feeding pipe 221 is connected to the left end of the first combustion section 2111 so as to introduce the second gas flow into the first combustion section 2111.

[0131] One end of the second feed pipe 222 can be connected to the concentrator 300, and the other end of the second feed pipe 222 can be connected to the rectifier section 2121 to introduce the third gas flow into the combustion tube assembly 21. The third gas flow enters the rectifier section 2121, and after being rectified in the rectifier section 2121, it gradually flows to the right. A part of the third gas flow, namely the third sub-gas flow, enters the second combustion section 2112 from the third channel 213 and then mixes with the flame in the second combustion section 2112. The other part of the third gas flow, namely the fourth sub-gas flow, flows to the right from the fourth channel 214 and then enters the inner tube 211 to mix with the flame.

[0132] In some embodiments, such as Figure 5 As shown, the first feeding pipe 221 includes a first transition section 2212 and a first feeding section 2211. The first transition section 2212 extends along a first direction, and the cross-sectional area of ​​the first transition section 2212 gradually decreases along the first sub-direction.

[0133] The inlet end of the first feeding section 2211 extends along the second direction, which 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, the first transition section 2212, and the first combustion section 2111 are connected in sequence. 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. The outlet 125 of the flame stabilizer is located in the first transition section 2212.

[0134] For example, for ease of description, the following will use... Figure 1 The up and down directions are used as the second direction.

[0135] The inlet end of the first feeding section 2211 faces downward and the outlet end of the first feeding section 2211 faces to the right. The second airflow passes through the first feeding section 2211 and the first transition section 2212 in sequence before entering the first combustion section 2111.

[0136] The outlet end of the flame stabilizer 100 is located inside the first feeding section 2211. The housing 12 of the flame stabilizer 100 is sealed to the side wall of the first feeding section 2211, and the portion of the flame stabilizer 100 located inside the first feeding section 2211 is spaced apart from the inner peripheral wall of the first feeding section 2211 so that the second airflow passes between the first feeding section 2211 and the flame stabilizer 100.

[0137] The first transition segment 2212 extends in the left-right direction, and the cross-sectional area of ​​the first transition segment 2212 decreases from left to right.

[0138] Optionally, the centerline of the first feeding section 2211 is arc-shaped.

[0139] In other embodiments, the second feed pipe 222 includes a second transition section 2221 that communicates with the rectifying section 2121, and the cross-sectional area of ​​the second transition section 2221 gradually increases along a second direction. For example, the second transition section 2221 is located below the rectifying section 2121, and the cross-sectional area of ​​the second transition section 2221 gradually increases along an upward direction, thereby facilitating the entry of the third airflow from the second transition section 2221 into the rectifying section 2121.

[0140] In some embodiments, such as Figure 6 As shown, the concentrator 300 includes a main feed pipe 34, a first branch pipe 31, a second branch pipe 32 and a third branch pipe 33. The inlet end of the main feed pipe 34 is adapted to be connected to a pulverized coal gas source, and the main feed pipe 34 extends along a second direction.

[0141] The first branch pipe 31, the second branch pipe 32, and the third branch pipe 33 are arranged at intervals, and the outlet end of the main feed pipe 34 is connected to each of the first branch pipe 31, the second branch pipe 32, and the third branch pipe 33.

[0142] The main feed pipe 34 is adapted to introduce primary air and pulverized coal airflow into the concentrator 300. The concentrator 300 can split the primary air and pulverized coal airflow to obtain a first airflow, a second airflow, and a third airflow. 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. The third branch pipe 33 is connected to the second feed pipe to introduce the third airflow into the burner 200.

[0143] For example, the main feed pipe 34 extends in the vertical direction, and the first branch pipe 31, the second branch pipe 32 and the third branch pipe 33 are arranged alternately from left to right. The lower end of the main feed pipe 34 is connected to the pulverized coal gas source, and the upper end of the main feed pipe 34 is connected to the lower ends of the first branch pipe 31, the second branch pipe 32 and the third branch pipe 33.

[0144] The upper end of the first branch pipe 31 is connected to the first inlet 1111, the upper end of the second branch pipe 32 is connected to the first feed pipe 221, and the upper end of the third branch pipe 33 is connected to the second feed pipe 222. The primary air-coal powder gas flow provided by the pulverized coal gas source enters the main feed pipe 34, and is then divided into a first gas flow, a second gas flow, and a third gas flow by the concentrator 300. The first gas flow enters the pulverized coal pipe assembly 11 through the first inlet 1111. The second gas flow passes through the first feed section 2211 and the first transition section 2212 in sequence before entering the first combustion section 2111. The third gas flow enters the rectifying section 2121 through the second feed pipe 222.

[0145] Optionally, in the vertical direction, the second branch pipe 32 is arranged opposite to the main feed pipe 34, that is, the upper end of the main feed pipe 34 extends upward to become the second branch pipe 32.

[0146] In some embodiments, such as Figure 6 and Figure 7 As shown, the concentrator 300 also includes a concentrating assembly, which is disposed in the main feed pipe 34. The concentrating assembly includes a first concentrating block 35, a second concentrating block 36, and a flow divider 37. The first concentrating block 35, the second concentrating block 36, and the flow divider 37 are arranged sequentially and at intervals in the second direction. The first concentrating block 35 is disposed near the inlet end of the main feed pipe 34 relative to the flow divider 37. The main feed pipe 34 has a first sidewall 341 to a fourth sidewall 344 connected sequentially in its circumferential direction. The first sidewall 341 and the third sidewall 343 are arranged opposite to each other in the first direction. The third sidewall 343 is disposed near the third branch pipe 33 relative to the first sidewall 341. The second sidewall 342 and the fourth sidewall 344 are arranged opposite to each other.

[0147] The main feed pipe 34 is provided with a first flow channel to a fourth flow channel 348 arranged in an array. In the first sub-direction, the first flow channel 345 and the second flow channel 346 are arranged in sequence, and the third flow channel 347 and the fourth flow channel 348 are arranged in sequence. The first flow channel 345 is located adjacent to the second side wall 342 relative to the third flow channel 347.

[0148] The first concentration block 35 is disposed on the third side wall 343 and protrudes towards the center line of the main feed pipe 34 to block the second flow channel 346 and the fourth flow channel 348. The second concentration block 36 is disposed on the second side wall 342 to block the first flow channel 345 and the second flow channel 346, or the second concentration block 36 is disposed on the fourth side wall 344 to block the third flow channel 347 and the fourth flow channel 348.

[0149] The manifold 37 is cross-shaped to fit the first to fourth flow channels 348.

[0150] For example, the first concentration block 35, the second concentration block 36, and the diverter plate 37 are arranged sequentially and at intervals in an upward direction.

[0151] like Figure 1 As shown, the front-to-back direction is perpendicular to the up-down and left-to-right directions. The first sidewall 341 to the fourth sidewall 344 are connected in sequence to form a ring-shaped main feed pipe 34. The first sidewall 341 is the left sidewall of the main feed pipe 34, the third sidewall 343 is the right sidewall of the main feed pipe 34, the second sidewall 342 is located between the first sidewall 341 and the third sidewall 343, and the fourth sidewall 344 is located between the first sidewall 341 and the third sidewall 343. The second sidewall 342 and the fourth sidewall 344 are arranged opposite each other in the front-to-back direction.

[0152] 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. The first flow channel 345 and the second flow channel 346 are arranged sequentially along the left-right direction, and the third flow channel 347 and the fourth flow channel 348 are arranged sequentially along the left-right direction. The first flow channel 345 and the third flow channel 347 are arranged sequentially along the front-back direction, and the second flow channel 346 and the fourth flow channel 348 are arranged sequentially along the front-back direction. The first flow channel 345 is located adjacent to the second sidewall 342. In other words, the first flow channel 345 and the second flow channel 346 are located adjacent to the second sidewall 342 relative to the third flow channel 347 and the fourth flow channel 348. When the second sidewall 342 is located in front of the fourth sidewall 344, the first flow channel 345 and the second flow channel 346 are located in front of the third flow channel 347 and the fourth flow channel 348. When the second sidewall 342 is located behind the fourth sidewall 344, the first flow channel 345 and the second flow channel 346 are located behind the third flow channel 347 and the fourth flow channel 348.

[0153] The first concentrate block 35 is detachably fixed to the third sidewall 343 and protrudes towards the centerline of the main feed pipe 34. The first concentrate block 35 is used to block the second flow channel 346 and the fourth flow channel 348. The second concentrate block 36 protrudes towards the centerline of the main feed pipe 34. The second concentrate block 36 is disposed on the second sidewall 342 to block the first flow channel 345 and the second flow channel 346, or the second concentrate block 36 is disposed on the fourth sidewall 344 to block the third flow channel 347 and the fourth flow channel 348.

[0154] The flow divider 37 is located above the second concentration block 36. The flow divider 37 is cross-shaped to form four regions, which correspond to the first flow channel 345 to the fourth flow channel 348 respectively, so that the airflow in the first flow channel 345 to the fourth flow channel 348 can pass through.

[0155] The following describes in detail the working process of the concentrator 300 of the coal-fired power unit pulverized coal stable combustion and concentration device of the present invention, taking the example of the second side wall 342 being located in front of the fourth side wall 344 and the second concentration block 36 being located on the second side wall 342.

[0156] First, the primary air pulverized coal gas flow provided by the pulverized coal gas source enters the main feed pipe 34, and then collides with the first thickening block 35, causing inertial separation of pulverized coal. Since the first thickening block 35 blocks the second flow channel 346 and the fourth flow channel 348, a large amount of primary air pulverized coal gas flow accumulates in the first flow channel 345 and the third flow channel 347. After the primary air pulverized coal gas flow passes through the first thickening block 35, a small amount of pulverized coal gas flow diffuses into the second flow channel 346 and the fourth flow channel 348.

[0157] Then, as Figure 7 As shown in the figure, the distribution of pulverized coal in each channel of the multi-stage pulverized coal concentrator 300 during operation is illustrated. After the primary air pulverized coal flow encounters the second concentrator block 36, further inertial separation of the pulverized coal occurs. Since the second concentrator block 36 blocks the first and second channels 345 and 346 respectively, the third channel 347 is not blocked by either the first or second concentrator block 35, resulting in the highest pulverized coal concentration in the airflow within the third channel 347. The airflow in the first and fourth channels 345 is blocked by either the first or second concentrator block 36, therefore, the pulverized coal concentration in the airflow in the first and fourth channels 345 is lower than that in the third channel 347. The second channel 346 is blocked by both the first and second concentrator blocks 35 and 36, resulting in the lowest pulverized coal concentration in the second channel 346.

[0158] The airflow in the third flow channel 347 passes through the splitter plate 37 and then hits the baffle 38, causing a deflection, and then flows into the first branch pipe 31 near the baffle 38.

[0159] After passing through the splitter plate 37, the airflow in the first flow channel 345 and the fourth flow channel 348 is not disturbed by the baffle plate 38 and thus enters the second branch pipe 32.

[0160] The airflow in the second flow channel 346 passes through the splitter plate 37 and then collides with the baffle plate, causing a deflection, and then flows into the third branch pipe 33 near the baffle plate.

[0161] The airflow in the third channel 347 enters the first branch pipe 31 to form the first airflow. The airflow in the first channel 345 and the fourth channel 348 enters the second branch pipe 32 and mixes to form the second airflow. The airflow in the second channel 346 enters the third branch pipe 33 to form the third airflow. The coal powder concentration in the first airflow, the second airflow and the third airflow decreases in sequence.

[0162] It is understandable that when the fourth sidewall 344 is located in front of the second sidewall 342, the positions of the first flow channel 345 to the fourth flow channel 348 change slightly, but this does not affect the concentration process of the primary air-coal powder gas flow, which will not be elaborated here.

[0163] The airflow in the third channel 347 enters the first branch pipe 31 to form the first airflow. The airflow in the first channel 345 and the fourth channel 348 enters the second branch pipe 32 and mixes to form the second airflow. The airflow in the second channel 346 enters the third branch pipe 33 to form the third airflow. The coal powder concentration in the first airflow, the second airflow and the third airflow decreases in sequence.

[0164] Therefore, through the above structure, the concentrator 300 can split the primary air pulverized coal gas flow into three pulverized coal gas flows of different concentrations: high, medium, and low. Thus, the concentrator 300 of the pulverized coal combustion stabilization and concentrating device for coal-fired power units in this embodiment of the invention has the advantages of a more compact structure and lower pressure loss.

[0165] In other embodiments, the first concentrate block 35 has a trapezoidal projected shape in a plane perpendicular to the front-back direction. The second concentrate block 36 has a trapezoidal projected shape in a plane perpendicular to the left-right direction. This facilitates the passage of primary air pulverized coal airflow and reduces the pressure loss of the primary air pulverized coal airflow.

[0166] In some embodiments, such as Figure 6 As shown, the concentrator 300 also includes a baffle 38, which is disposed 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. In the extension direction of the main feed pipe 34, the baffle 38 is arranged opposite to the third flow channel 347.

[0167] Therefore, 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 arranged opposite to the third flow channel 347, thereby guiding the airflow in the third flow channel 347 into the first branch pipe 31, and thus preventing the airflow in the third flow channel 347 from entering the second branch pipe 32.

[0168] In other embodiments, the main feed pipe 34, the first branch pipe 31, the second branch pipe 32 and the third branch pipe 33 converge at one point, thereby facilitating the processing and manufacturing of the concentrator 300.

[0169] In other embodiments, a baffle 38 is disposed at the junction, and the sidewall of the first branch pipe 31 adjacent to the second branch pipe 32 extends toward the junction to form the baffle 38, the surface shape of which is adapted to the inner peripheral wall shape of the first branch pipe 31. This improves the flow guidance effect of the baffle 38, thereby reducing the pressure loss of the airflow within the third flow channel 347.

[0170] The following is based on the appendix Figure 1-9 A specific embodiment of the present invention is described below.

[0171] First, the primary air pulverized coal gas flow provided by the pulverized coal gas source enters the main feed pipe 34 of the concentrator 300. Then, after colliding with the first concentrator block 35, the pulverized coal undergoes inertial separation. Since the first concentrator block 35 blocks the second flow channel 346 and the fourth flow channel 348, a large amount of the primary air pulverized coal gas flow accumulates in the first flow channel 345 and the third flow channel 347. After the primary air pulverized coal gas flow passes through the first concentrator block 35, a small amount of pulverized coal gas flow diffuses into the second flow channel 346 and the fourth flow channel 348.

[0172] Then, after the primary airflow of pulverized coal encounters the second thickener block 36, further inertial separation of pulverized coal occurs. Since the second thickener block 36 blocks the first and second channels 345 and 346 respectively, the third channel 347 is not blocked by either the first or second thickener block 35, resulting in the highest pulverized coal concentration in the airflow within the third channel 347. The airflows in the first and fourth channels 345 and 348 are blocked by either the first or second thickener block 36, therefore, the pulverized coal concentrations in these channels are lower than those in the third channel 347. The second channel 346 is blocked by both the first and second thickener blocks 35 and 36, resulting in the lowest pulverized coal concentration within it.

[0173] The airflow in the third channel 347 enters the first branch pipe 31 to form the first airflow. The airflow in the first channel 345 and the fourth channel 348 enters the second branch pipe 32 and mixes to form the second airflow. The airflow in the second channel 346 enters the third branch pipe 33 to form the third airflow. The coal powder concentration in the first airflow, the second airflow and the third airflow decreases in sequence.

[0174] The first airflow sequentially enters the pulverized coal pipe group through the first branch pipe 31 and the first inlet 1111. The first airflow first encounters the condenser 1112. During the collision with the condenser 1112, the pulverized coal particles in the first airflow are subjected to inertial separation, which causes the first airflow to separate into concentrated and diluted particles. This causes the pulverized coal to accumulate near the centerline of the first pipe 111, thus forming 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.

[0175] Then, the first sub-airflow enters the first channel 117 and, under the action of the first return flow member 113, enters the return flow channel 119, causing the first sub-airflow to flow into the second section 122 in a right-to-left direction. The second sub-airflow enters the second channel 118 and, under the action of the second return flow member 114, causes the second sub-airflow to flow into the third section 123 in a right-to-left direction, and gradually flows to the left into the second section 122.

[0176] Simultaneously, secondary air is injected at high speed into the cavity along the secondary air duct 13, forming a high-speed rotating airflow within the first section 121. This airflow then flows into the area near the inner wall of the second section 122. Due to the large tangential velocity of the secondary air at this point, a low-pressure zone is formed in the central region of the secondary airflow during its high-speed rotating flow. Furthermore, as the cross-sectional area of ​​the second section 122 gradually increases from left to right, the flow velocity of the secondary air decreases while the static pressure gradually increases as it flows through the second section 122.

[0177] In summary, a low-pressure area forms in the central region of the secondary wind, the flow velocity of the secondary wind decreases and the static pressure gradually increases. Under the influence of these two factors, as the secondary wind gradually flows to the right, some of the secondary wind will flow into the low-pressure area, thus forming a high-speed recirculation zone in the second segment 122 and the third segment 123.

[0178] Because the second outlet 116 is located near the high-speed recirculation zone, the second sub-gas flow is injected near the high-speed recirculation zone, making it easier for the second sub-gas flow to be entrained into the high-speed recirculation zone during its flow. The second sub-gas flow swirls and burns in the high-speed recirculation zone, releasing heat and forming a dense phase high-temperature recirculation zone. This will help promote the rapid heating and ignition of the second sub-gas flow and release more heat, forming a dense phase high-temperature recirculation zone.

[0179] At the same time, the first sub-flow is injected at a certain distance to the left of the second sub-flow. The first sub-flow is blocked and carried by the secondary wind in the swirling state, thus changing direction. The first sub-flow enters the dense phase high-temperature recirculation zone between the secondary wind in the swirling state and the second sub-flow.

[0180] In this process, although the coal powder concentration in the first sub-gas stream is low and not easily ignited, on the one hand, the low concentration of coal powder in the first sub-gas stream is subjected to convective and radiative heat transfer in the high-temperature reflux zone, which can promote the heating and ignition of the first sub-gas stream. On the other hand, the first outlet 115 is located to the left of the second outlet 116, which allows the first sub-gas stream to have a relatively longer residence time in the shell 12 compared to the second sub-gas stream. These two aspects will jointly promote the ignition and burnout effect of the first sub-gas stream. At this time, the first sub-gas stream is preheated, rapidly heats up and ignites, and releases a large amount of heat, forming a light-phase high-temperature reflux zone.

[0181] Meanwhile, since the second sub-gas flow is injected at a certain distance from the first sub-gas flow, it helps to delay the mixing of rich and lean gas flows. This promotes overall burnout and enhances the rich and lean combustion effect of pulverized coal, thereby reducing NOx formation.

[0182] Then, the airflow in the dense phase high-temperature reflux zone and the light phase high-temperature reflux zone together form a first-stage flame. After being gathered and accelerated by the fourth stage 124, the first-stage flame is ejected at high speed from the burner outlet 125.

[0183] The second gas flow in the second branch pipe 32 enters the first transition section 2212 after passing through the first feeding section 2211. Then, it mixes with the primary flame ejected from the burner outlet 125 in the first transition section 2212 before entering the first combustion section 2111. The pulverized coal carried by the second gas flow is preheated by the primary flame ejected from the burner 100 and quickly ignites after mixing with the high-temperature flame ejected from the burner 100. It is then subjected to secondary preheating to form a secondary flame and a high-temperature zone.

[0184] Meanwhile, the third airflow enters the rectifying section 2121 after passing through the second transition section 2221. After being stabilized by the rectifying cavity, the third airflow flows to the right and splits 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.

[0185] After passing through the third channel 213, the third sub-gas flow near the inner circumferential wall of the second combustion tube. At this time, the third sub-gas directly mixes and preheats with the secondary flame from the upstream, causing the third sub-gas to ignite rapidly and be preheated by the third stage, forming the third stage flame and high-temperature zone.

[0186] After passing through the fourth channel 214, the fourth sub-gas flow mixes and preheats directly with the third-stage flame from upstream, causing the fourth sub-gas flow to ignite rapidly and be preheated by the fourth stage, forming the fourth-stage flame and high-temperature zone.

[0187] In addition, such as Figure 8 and Figure 9As shown, the burner 200 of the coal-fired power unit pulverized coal stable combustion and concentration device in this embodiment of the invention can be a four-corner tangent DC burner 200 or a wall-mounted counter-current swirl burner 200.

[0188] When the burner 200 is a direct-flow burner with tangent corners, direct-flow first nozzles 231 can be arranged at the upper and lower parts of the guide section 2122 to provide tertiary air into the gasifier for staged supply of oxygen required for subsequent combustion of pulverized coal. This promotes complete combustion of pulverized coal while achieving staged combustion of air to reduce NOx formation. In this case, the cross-sectional shapes of the first combustion section 2111, the second combustion section 2112, and the guide section 2122, which are perpendicular to the axial direction of the burner 200, are all rectangular.

[0189] The tertiary air in this section refers to the secondary air in the burner 100. By supplying air in batches during fuel combustion, staged combustion of air can be achieved, reducing NOx generation. For the direct-flow burner 200 with tangential corners, this tertiary air can be arranged at certain intervals around the burner 200 and injected directly, meaning the nozzle is a cylindrical structure with a circular or rectangular cross-section.

[0190] When the burner 200 is a wall-mounted, counter-flow swirl burner 200, annular third nozzles 233 and second nozzles 232 can be arranged sequentially 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 to the burner 200. Swirl blades 234 are uniformly arranged circumferentially inside the third nozzle 233 and the second nozzle 232 to guide the direct 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, which are perpendicular to the axial direction of the burner 200, are all circular.

[0191] The tertiary air in this section refers to the secondary air in the burner 100. By supplying air in batches during fuel combustion, staged combustion can be achieved, reducing NOx formation. For the wall-mounted counter-current swirl burner 200, this tertiary air can be injected in two annular swirls around the burner 200, with inner and outer annular nozzles. The swirl intensity of the airflow at the outlet of the two nozzles can be adjusted by adjusting the blade angle 234. While achieving air staged combustion, the secondary air injected in the swirls also helps to form a low-pressure zone at the outlet of the burner 200, creating a high-temperature flue gas recirculation, promoting further combustion of pulverized coal and stable ignition.

[0192] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0193] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0194] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0195] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0196] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0197] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A coal-fired power unit pulverized coal combustion stabilization and concentration device, characterized in that, include: Burners and concentrators; A flame stabilizer, the outlet end of which is connected to the burner, the flame stabilizer extending along a first direction, the flame stabilizer including a cavity and a pulverized coal tube assembly at least partially disposed in the cavity, and a concentrator being connected to the pulverized coal tube assembly to introduce a first gas flow containing pulverized coal into the pulverized coal tube assembly; The pulverized coal pipe assembly 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 less than that of the second sub-airflow. The introduction position of the second sub-airflow is relatively close to the outlet end of the flame stabilizer relative to the introduction position of the first sub-airflow. A secondary air duct, which is connected to the cavity; The flame stabilizer includes a housing, a first inlet, a first outlet, and a second outlet. The housing has a cavity. 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 flame stabilizer to the outlet end of the flame stabilizer is the first sub-direction. The first inlet, the first outlet, and the second outlet are all located on the pulverized coal pipe assembly and are arranged sequentially and at intervals along the first sub-direction. The first inlet is connected to each of the first outlet and the second outlet. The first outlet and the second outlet are both located in the cavity and are both arranged towards the first inlet along the second sub-direction. The outlet end of the flame stabilizer is provided with a flame stabilizer outlet. The concentrator is adapted to be connected to a pulverized coal gas source. The concentrator is used to split the primary air pulverized coal gas flow provided by the pulverized coal gas source into a first gas flow, a second gas flow, and a third gas flow. The concentrator can be connected to the first inlet to inject the first gas flow into the pulverized coal pipe assembly, and the concentrator can be connected to the burner to inject the second gas flow and the third gas flow into the burner. The first inlet is connected to the concentrator to introduce the first airflow into the pulverized coal pipe assembly. The pulverized coal pipe assembly can split the first airflow to obtain the first sub-airflow and the second sub-airflow. The first outlet is used to discharge the first sub-airflow into the cavity, and the second outlet is used to discharge the second sub-airflow into the cavity. The secondary air duct is located on the outer periphery of the inlet end of the flame stabilizer, and the air outlet direction of the secondary air duct is tangent to the inner peripheral wall of the shell.

2. The coal-fired power unit pulverized coal combustion stabilization and concentration device according to claim 1, characterized in that, The pulverized coal pipe assembly includes: The first pipe has its inlet end and outlet end arranged opposite to each other in the first direction, with the first inlet located at the inlet end of the first pipe. A concentration element, wherein the concentration element is annular and the inner peripheral wall of the concentration element defines a concentration adjustment channel, and the cross-sectional area of ​​the concentration adjustment channel gradually decreases and then gradually increases along the first sub-direction; The second tube, the condenser and the second tube are both disposed inside the first tube, the condenser and the second tube are arranged sequentially and at intervals in the first sub-direction, the inner peripheral wall of the first tube and the outer peripheral wall of the second tube define a first channel, the inner peripheral wall of the second tube defines a second channel, and the inlet end and the outlet end of the second tube are arranged opposite to each other in the first direction. The first return element is sleeved on the outer periphery of the second tube and connected to the outlet end of the second tube. The outlet end of the first tube extends between the first return element and the second tube, so that the inner peripheral wall of the first return element and the outer peripheral wall of the first tube define a return channel. The return channel is connected to the first channel, and the opening of the return channel faces the inlet end of the first tube to form the first outlet. The second return element is arranged sequentially and at intervals in the first sub-direction, with a portion of the second return element sleeved on the outer periphery of the first return element to form the second outlet.

3. The coal-fired power unit pulverized coal combustion stabilization and concentration device according to claim 1, characterized in that, The housing includes a first section, a second section, a third section, and a fourth section connected sequentially in the first direction. The secondary air duct is connected to the first section. 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, and the cross-sectional area of ​​the fourth section gradually decreases along the first sub-direction. The first outlet is located in the second section, and the second outlet is located in the third section.

4. The coal-fired power unit pulverized coal combustion stabilization and concentration device according to any one of claims 1-3, characterized in that, The burner includes a combustion tube assembly, and the flame stabilizer and the combustion tube assembly are arranged sequentially along the first sub-direction. The outlet end of the combustion tube assembly is adapted to be connected to the combustion furnace. The combustion tube assembly includes an inner tube and an outer tube, with the outer tube sleeved on the outside of the inner tube; The inner tube includes a first combustion section and a second combustion section 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 peripheral wall of the first combustion section and the inner peripheral wall of the second combustion section define a third channel. The outer tube includes a rectifier section and a guide section arranged sequentially along the first sub-direction. The inlet end of the rectifier section is sealed to the inlet end of the first combustion section, and the inner peripheral wall of the guide section and the outer peripheral wall of the second combustion section define a fourth channel.

5. The coal-fired power unit pulverized coal combustion stabilization and concentration device according to claim 4, characterized in that, The burner further includes a feed pipe assembly, which includes a first feed pipe and a second feed pipe arranged sequentially and at intervals in the first sub-direction. The first feed pipe is used to connect the concentrator and the first combustion section to introduce the second gas flow into the inner pipe. The second feed pipe is used to connect the concentrator and the rectifier section to introduce the third gas flow into the combustion pipe assembly. The combustion pipe assembly can split the third gas flow into a third sub-gas flow and a fourth sub-gas flow. The third channel is used to allow the third sub-gas flow to enter the second combustion section, and the fourth channel is used to allow the fourth sub-gas flow to pass through so as to merge with the gas flow in the second combustion section.

6. The coal-fired power unit pulverized coal combustion stabilization and concentration device according to claim 5, characterized in that, The first feed tube includes: A first transition segment extends along the first direction, and the cross-sectional area of ​​the first transition segment gradually decreases along the first sub-direction; The first feeding section has an inlet end that extends along a second direction, which is orthogonal to the first direction. The outlet end of the first feeding section extends along the first direction. The first feeding section, the first transition section, and the first combustion section are connected in sequence. The flame stabilizer is connected to the first feeding section. The inlet end of the flame stabilizer is located outside 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. The outlet of the flame stabilizer is located in the first transition section.

7. The coal-fired power unit pulverized coal combustion stabilization and concentration device according to claim 5 or 6, characterized in that, The concentrator includes: A main feed pipe, the inlet end of which is adapted to be connected to a pulverized coal gas source, the main feed pipe extending along a second direction; The first branch pipe, the second branch pipe, and the third branch pipe are arranged at intervals, and the outlet end of the main feed pipe is connected to each of the first branch pipe, the second branch pipe, and the third branch pipe. The main feed pipe is adapted to introduce the primary air-coal powder gas flow into the concentrator. The concentrator can split the primary air-coal powder gas flow to obtain the first gas flow, the second gas flow, and the third gas flow. The first branch pipe is connected to the first inlet to introduce the first gas flow into the burner. The second branch pipe is connected to the first feed pipe to introduce the second gas flow into the burner. The third branch pipe is connected to the second feed pipe to introduce the third gas flow into the burner.

8. The coal-fired power unit pulverized coal combustion stabilization and concentration device according to claim 7, characterized in that, The concentrator further includes a concentrating component disposed inside the main feed pipe. The concentrating component includes a first concentrating block, a second concentrating block, and a flow divider plate. The first concentrating block, the second concentrating block, and the flow divider plate are arranged sequentially and at intervals in the second direction, and the first concentrating block is disposed relative to the flow divider plate near the inlet end of the main feed pipe. The main feed pipe has a first sidewall, a second sidewall, a third sidewall and a fourth sidewall connected in sequence in its circumferential direction. The first sidewall and the third sidewall are arranged opposite to each other in the first direction, and the third sidewall is arranged adjacent to the third branch pipe relative to the first sidewall. The second sidewall and the fourth sidewall are arranged opposite to each other. 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 sub-direction, the first flow channel and the second flow channel are arranged in sequence, and the third flow channel and the fourth flow channel are arranged in sequence. The first flow channel is disposed adjacent to the second sidewall relative to the third flow channel. The first concentration block is disposed on the third sidewall to block the second flow channel and the fourth flow channel. The second concentration block is disposed on the second sidewall to block the first flow channel and the second flow channel, or the second concentration block is disposed on the fourth sidewall to block the third flow channel and the fourth flow channel. The flow divider is cross-shaped to fit the first to the fourth flow channels.

9. The coal-fired power unit pulverized coal combustion stabilization and concentration device according to claim 8, characterized in that, The concentrator also includes a baffle plate disposed on the inner peripheral wall of the inlet end of the second branch pipe, and the baffle plate is arranged adjacent to the first branch pipe relative to the third branch pipe. In the extension direction of the main feed pipe, the baffle plate is arranged opposite to the third flow channel.

Images