Biomass-pulverized coal burner and boiler
By setting up inner and outer primary air channels in the burner, and setting up a multi-feed structure and a powder concentration separation structure at the feed end of the inner primary air channel, the problem of separate pathway organization of biomass and pulverized coal in the same burner is solved, the spatial distribution of fuel is improved, and the combustion stability of the burner and the operational reliability of the boiler are enhanced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI POWER EQUIPMENT RESEARCH INSTITUTE CO LTD
- Filing Date
- 2026-05-27
- Publication Date
- 2026-07-14
Smart Images
Figure CN122384071A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of boiler combustion equipment technology, and in particular to a biomass-pulverized coal burner and boiler. Background Technology
[0002] Currently, the coal-fired power industry is continuously promoting low-carbon transformation to achieve carbon peaking and carbon neutrality goals. Among these efforts, biomass co-firing has become a common technological approach. Simultaneously, with the increasing demand for spot trading and peak shaving in the electricity market, coal-fired units are facing higher requirements for fuel organization methods and burner adaptability under different load conditions.
[0003] Existing biomass co-firing methods mainly include direct co-firing and indirect co-firing. Direct co-firing typically involves directly mixing pulverized biomass with pulverized coal for combustion, or using an existing coal grinding system for coupled grinding. This method has low conversion costs and is easy to promote, but when the co-firing ratio increases, the organization of biomass and pulverized coal during transportation and combustion becomes significantly more difficult, easily affecting the stability and uniformity of the combustion process.
[0004] Furthermore, simply mixing biomass and pulverized coal in the primary air duct makes it difficult to rationally control their spatial distribution within the burner, hindering the consideration of the combustion characteristics of different fuels and thus affecting the combustion organization effect. Meanwhile, existing biomass burners are mostly single-burner or direct-flow structures, which can significantly impact the original combustion flow field when burning large proportions of biomass; while using independent burners to introduce pulverized coal and biomass separately makes it difficult to achieve good synergistic combustion within the same combustion space.
[0005] Therefore, there is an urgent need to provide a biomass-pulverized coal burner that can separate biomass and pulverized coal in the same burner and form different fuel spatial distributions, thereby improving the combustion organization state in the burner and increasing the flexibility of fuel organization. Summary of the Invention
[0006] One object of the present invention is to provide a biomass-pulverized coal burner to solve the problems of difficulty in achieving separate pathway organization of biomass powder and pulverized coal in the same burner, and difficulty in rationally controlling the spatial distribution of fuel, thereby improving the fuel organization state within the burner. Another object of the present invention is to provide a boiler.
[0007] To achieve this objective, the present invention adopts the following technical solution: This invention provides a biomass-coal pulverized burner, comprising a central air duct, an inner primary air duct, an outer primary air duct, and a secondary air unit arranged sequentially from the inside out. The inner primary air duct is located between the central air duct and the outer primary air duct, and the outer primary air duct is located between the inner primary air duct and the secondary air unit. The inner primary air duct has a multi-feed structure, including a biomass pulverized material feed passage and a coal pulverized material feed passage that communicate with the inner primary air duct. A first control valve is provided on the biomass pulverized material feed passage, and a second control valve is provided on the coal pulverized material feed passage. A first pulverized material concentration separation structure is provided within the inner primary air duct, and a second pulverized material concentration separation structure is provided within the outer primary air duct, so that the pulverized material concentration distribution in the inner primary air duct differs from that in the outer primary air duct.
[0008] Optionally, the first powder concentration separation structure is disposed on the channel wall of the inner primary air channel near the outer primary air channel and protrudes toward the central air channel, so that the concentration of biomass powder and / or coal powder in the inner primary air channel near the central air channel is higher than the concentration of biomass powder and / or coal powder near the outer primary air channel.
[0009] Optionally, the second powder concentration separation structure is disposed on the channel wall of the outer primary air channel near the inner primary air channel and protrudes toward the secondary air unit, so that the coal powder concentration in the outer primary air channel near the secondary air unit is higher than the coal powder concentration near the inner primary air channel.
[0010] Optionally, at least one of the first powder concentration separation structure and the second powder concentration separation structure is a concentration ring or a louvered concentration device.
[0011] Optionally, the biomass powder feeding passage is connected to the inlet end of the inner primary air channel, and the coal powder feeding passage is an inner primary air branch pipe connected to the inner primary air channel; the biomass powder feeding passage, the inner primary air channel, and the inner primary air branch pipe constitute a three-way feeding structure.
[0012] Optionally, the first control valve and the second control valve are configured to be controlled independently; the second control valve is a regulating valve with continuously adjustable opening, and is used to regulate the amount of pulverized coal entering the inner primary air channel through the pulverized coal feed passage.
[0013] Optionally, a guide surface is provided at the intersection of the pulverized coal feeding passage and the inner primary air channel; the guide surface connects the inner wall of the pulverized coal feeding passage and the inner wall of the inner primary air channel to guide the pulverized coal entering through the pulverized coal feeding passage into the inner primary air channel.
[0014] Optionally, the pulverized coal feeding passage includes a feeding section, an elbow section, and an access section connected in sequence. The access section is connected to the junction of the inner primary air channel. The elbow section is located between the feeding section and the access section, and the inner wall of the elbow section is provided with a wear-resistant lining.
[0015] Optionally, the secondary air unit includes an inner secondary air duct and an outer secondary air duct; wherein the inner secondary air duct is located outside the outer primary air duct, and the outer secondary air duct is located outside the inner secondary air duct.
[0016] Beneficial Effects: The biomass-coal pulverized coal burner provided by this invention adds an inner primary air channel between the central air channel and the outer primary air channel, and sets up a multi-feed structure at the feed end of the inner primary air channel, allowing biomass pulverized coal and coal pulverized coal to enter the inner primary air channel through different feed paths, thereby achieving separate pathway organization of the two fuels within the same burner. Simultaneously, pulverized coal concentration separation structures are set up in both the inner and outer primary air channels, resulting in different concentration distributions of the pulverized coal in the inner and outer primary air channels, thereby improving the spatial distribution of fuel within the burner. This enhances the flexibility of fuel organization and improves the combustion organization effect of the burner.
[0017] The present invention also provides a boiler comprising a furnace and the aforementioned biomass-pulverized coal burner, wherein the biomass-pulverized coal burner is connected to the furnace.
[0018] Beneficial effects: The boiler provided by the present invention includes the above-mentioned biomass-pulverized coal burner. Through the separate feeding path and stratified rich-lean combustion organization of the burner, the boiler can flexibly adjust the fuel ratio and spatial distribution according to different load conditions, effectively improve the combustion stability when co-firing biomass, thereby improving the boiler's operational reliability and combustion efficiency. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the structure of a biomass-pulverized coal burner provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the inner primary air duct provided in an embodiment of the present invention.
[0020] In the picture: 1. Central ventilation duct; 2. Inner primary air duct; 201. Biomass powder feed passage; 202. Coal powder feed passage; 203. First control valve; 204. Second control valve; 205. Junction section; 3. Outer primary air duct; 4. First powder concentration separation structure; 5. Second powder concentration separation structure; 6. Internal secondary air ducts; 7. External secondary air ducts; 8. Nozzle section; 9 ignition units; 10 external secondary air cyclones; 11. Internal secondary air cyclone separator. Detailed Implementation
[0021] Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement the invention, and are not intended to exhaustively describe all possible embodiments of the invention, nor to limit the scope of the invention.
[0022] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" 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 or an electrical connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0023] The present invention provides a biomass-pulverized coal burner (hereinafter, sometimes simply referred to as "burner"), which will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0024] like Figure 1 As shown, an embodiment of the present invention provides a biomass-pulverized coal burner. The burner includes a central air duct 1, an inner primary air duct 2, an outer primary air duct 3, and a secondary air unit arranged sequentially from the inside out. The inner primary air duct 2 is located between the central air duct 1 and the outer primary air duct 3, and the outer primary air duct 3 is located between the inner primary air duct 2 and the secondary air unit.
[0025] The inner primary air duct 2 has a multi-feed structure at its feed end, including a biomass powder feed passage 201 and a coal powder feed passage 202 that can communicate with the inner primary air duct 2. A first control valve 203 is installed on the biomass powder feed passage 201, and a second control valve 204 is installed on the coal powder feed passage 202, allowing biomass powder and / or coal powder to enter the inner primary air duct 2. The inner primary air duct 2 has a first powder concentration separation structure 4, and the outer primary air duct 3 has a second powder concentration separation structure 5, resulting in a different powder concentration distribution between the inner and outer primary air ducts.
[0026] During operation, biomass powder can enter the inner primary air channel 2 through the biomass powder feeding passage 201, and pulverized coal can enter the inner primary air channel 2 through the pulverized coal feeding passage 202. Both can also enter the inner primary air channel 2 together. The biomass powder and / or pulverized coal entering the inner primary air channel 2 are processed by the first powder concentration separation structure 4 to form a first concentration distribution. The pulverized coal entering the outer primary air channel 3 is processed by the second powder concentration separation structure 5 to form a second concentration distribution. This results in different spatial organization states for the powder in the inner primary air channel 2 and the outer primary air channel 3, and combustion occurs under the action of secondary air supplied by the secondary air unit.
[0027] Therefore, in this embodiment, biomass powder and coal powder can be organized in separate channels within the same burner, improving the spatial distribution of fuel within the burner and enhancing the flexibility of fuel organization.
[0028] In one embodiment, the secondary air unit may include an inner secondary air duct 6 and an outer secondary air duct 7. The inner secondary air duct 6 is located outside the outer primary air duct 3, and the outer secondary air duct 7 is located outside the inner secondary air duct 6. Through this arrangement, the secondary air can cover and replenish the fuel flow around the outer primary air duct 3 from the outside in, thereby improving the airflow organization near the burner outlet.
[0029] In one embodiment, such as Figure 1 As shown, the burner may also include a nozzle 8 for outputting the airflow and powder in each channel to the external combustion space. Figure 1 The arrows indicate the flow direction of the airflow and powder output along the burner axis. Specifically, the airflow and powder in the central air duct 1, the inner primary air duct 2, the outer primary air duct 3, and the secondary air unit are all output through the nozzle 8.
[0030] Optionally, such as Figure 1As shown, an ignition unit 9 can also be installed in the central air duct 1 for burner start-up ignition and auxiliary combustion stabilization; an inner secondary air vortex 11 and an outer secondary air vortex 10 can also be installed in the inner secondary air duct 6 and the outer secondary air duct 7 near the nozzle 8, respectively, for swirling organization of the corresponding secondary air flow to improve airflow mixing and combustion stability near the burner outlet.
[0031] In one embodiment, such as Figure 1 As shown, the first powder concentration separation structure 4 can be set on the channel wall of the inner primary air channel 2 near the outer primary air channel 3 and protrude towards the central air channel 1, so that the concentration of biomass powder and / or coal powder in the inner primary air channel 2 near the central air channel 1 is higher than that in the inner primary air channel 2 near the outer primary air channel 3.
[0032] Specifically, after the biomass powder and / or pulverized coal flow through the first powder concentration separation structure 4, a concentration distribution is formed in the inner primary air channel 2, with a high concentration zone near the central air channel 1 and a low concentration zone near the outer primary air channel 3. In this way, the powder in the inner primary air channel 2 is more concentrated in the central area, which is conducive to forming a more concentrated fuel distribution in the middle area of the burner.
[0033] Furthermore, in one embodiment, such as Figure 1 As shown, the second powder concentration separation structure 5 can be set on the channel wall of the outer primary air channel 3 near the inner primary air channel 2 and protrude toward the secondary air unit, so that the coal powder concentration in the outer primary air channel 3 near the secondary air unit is higher than the coal powder concentration in the inner primary air channel 2.
[0034] Specifically, based on the aforementioned arrangement of the secondary air units, it can be seen that the side closer to the secondary air unit corresponds to the side closer to the inner secondary air passage 6. In other words, the pulverized coal concentration on the side of the outer primary air passage 3 closer to the inner secondary air passage 6 is higher than the pulverized coal concentration on the side closer to the inner primary air passage 2. Thus, the pulverized coal in the outer primary air passage 3 is more concentrated in the area closer to the inner secondary air passage 6, thereby complementing the pulverized coal distribution in the inner primary air passage 2 and improving the fuel space organization near the burner outlet.
[0035] Furthermore, in one embodiment, the first powder concentration separation structure 4 and the second powder concentration separation structure 5 can be disposed in the corresponding channel and fixed to the channel wall by welding.
[0036] Optionally, in one embodiment, at least one of the first powder concentration separation structure 4 and the second powder concentration separation structure 5 can be a concentration ring or a louvered concentration device. Both concentration rings and louvered concentration devices are commonly used powder concentration separation structures in the art, and their specific structural forms will not be described in detail here. In practical applications, a concentration ring, a louvered concentration device, or other structural forms capable of achieving the corresponding concentration-lean distribution effect can be selected according to fuel characteristics, channel size, and manufacturing conditions.
[0037] like Figure 2 As shown, the biomass powder feed passage 201 is connected to the inlet end of the inner primary air channel 2, and the pulverized coal feed passage 202 is configured as an inner primary air branch pipe connected to the inner primary air channel 2. The arrows in the figure indicate the feeding direction of the biomass powder feed passage 201. Thus, the biomass powder feed passage 201, the inner primary air channel 2, and the inner primary air branch pipe together form a three-way feeding structure. With this structure, the biomass powder can enter the middle area of the burner along the main feeding direction of the inner primary air channel 2, and the pulverized coal can be replenished into the inner primary air channel 2 through the inner primary air branch pipe. This provides an independent pulverized coal replenishment path for the inner primary air channel 2 without changing the main pulverized coal conveying function of the outer primary air channel 3.
[0038] Furthermore, in one embodiment, the inner primary air branch pipe can be connected to the upstream section of the inner primary air channel 2, so that the coal powder entering through the coal powder feeding passage 202 has a certain common flow path with the biomass powder entering through the biomass powder feeding passage 201 in the inner primary air channel 2, which is beneficial to subsequent fuel organization.
[0039] Optionally, in some embodiments, the pulverized coal feed passage 202 is connected to the inner primary air passage 2 via a branch pipe connection to reduce the structural size of the inlet and facilitate the arrangement of the burner within the limited installation space. For example, the branch pipe connection can be a T-shaped connection or a Y-shaped connection.
[0040] Furthermore, such as Figure 2 As shown, the first control valve 203 is installed on the biomass powder feed passage 201 to control the entry of biomass powder into the inner primary air passage 2; the second control valve 204 is installed on the pulverized coal feed passage 202 to control the entry of pulverized coal into the inner primary air passage 2. By controlling the two feed paths respectively, the inner primary air passage 2 can selectively introduce biomass powder and pulverized coal, or simultaneously introduce both, according to operational requirements.
[0041] Specifically, when the first control valve 203 is open and the second control valve 204 is closed, biomass powder is introduced into the inner primary air channel 2; when the first control valve 203 is closed and the second control valve 204 is open, pulverized coal is introduced into the inner primary air channel 2; when the first control valve 203 and the second control valve 204 are opened simultaneously, both biomass powder and pulverized coal enter the inner primary air channel 2. Thus, the inner primary air channel 2 can be configured as needed to allow for separate feeding of biomass, separate feeding of pulverized coal, or a combined feeding configuration.
[0042] Furthermore, in some embodiments, the first control valve 203 and the second control valve 204 can be controlled independently. The second control valve 204 can be a continuously adjustable regulating valve, which continuously adjusts the amount of pulverized coal entering the inner primary air channel 2 through the pulverized coal feed passage 202 by adjusting its opening. In this way, the type of fuel and the amount of pulverized coal entering the inner primary air channel 2 can be flexibly adjusted according to the load, biomass calorific value, and blending ratio requirements.
[0043] In this embodiment, the first control valve 203 is preferably an on / off valve, having only two states: open and closed, to control the flow of biomass powder. In other embodiments, the first control valve 203 may also be a regulating valve to adjust the flow of biomass powder.
[0044] Under different operating conditions, the inner primary air duct 2 can perform different fuel organization functions. For example, under low load conditions, the inner primary air duct 2 can serve as a biomass combustion stabilization duct; under high load conditions, the inner primary air duct 2 can serve as a pulverized coal calorific value supplementation duct; under intermediate load conditions, the inner primary air duct 2 can serve as a composite fuel duct where biomass powder and pulverized coal enter together, thereby improving the burner's adaptability to different operating conditions.
[0045] Optionally, in some embodiments, the junction 205 of the pulverized coal feed passage 202 and the inner primary air channel 2 may also be provided with a guide surface. The guide surface connects the inner wall of the pulverized coal feed passage 202 and the inner wall of the inner primary air channel 2, allowing the pulverized coal entering through the pulverized coal feed passage 202 to be introduced into the inner primary air channel 2 along a smoother path. In this way, the change in the flow direction of the pulverized coal in the junction area can be more gradual, which helps to reduce the direct scouring of the junction 205 and the local inner wall of the inner primary air channel 2 by the pulverized coal, and improves the flow state when the pulverized coal is added to the inner primary air channel 2.
[0046] Furthermore, in some embodiments, the pulverized coal feeding passage 202 includes a feeding section, an elbow section, and an inlet section connected in sequence. The inlet section is connected to the junction 205 of the inner primary air channel 2. The elbow section is located between the feeding section and the inlet section, and the inner wall of the elbow is provided with a wear-resistant lining. When pulverized coal flows at high speed through the pulverized coal feeding passage 202, the flow direction changes at the elbow, making the inner wall of the elbow and the area connected to the inner primary air channel 2 more susceptible to erosion and wear. By providing a wear-resistant lining on the inner wall of the elbow, the wear of the pulverized coal feeding passage 202 and the corresponding parts of the inner primary air channel 2 caused by the high-speed flow of pulverized coal can be reduced, thereby reducing the amount of maintenance work.
[0047] Specifically, the wear-resistant liner can be a ceramic liner, a silicon carbide liner, or a liner made of other wear-resistant materials.
[0048] In some other embodiments, the flow area of the central air duct 1 can be designed to be relatively small. For example, the flow area of the central air duct 1 can be reduced by 20% to 50% compared to the central air duct flow area of a pulverized coal burner of the same power rating. This helps to reduce the intensity of oxidation in the central region and better coordinates with the combustion organization of biomass pulverized material in the inner primary air duct 2. The above numerical ranges are preferred empirical ranges and can be adjusted according to specific operating conditions in actual applications.
[0049] The present invention also provides a boiler, which includes a furnace and the aforementioned burner. The burner is connected to the furnace, allowing the airflow and pulverized feed in the burner to enter the furnace for combustion. By employing this burner, the boiler can flexibly adjust the fuel distribution according to changes in operating conditions.
[0050] When the boiler is under different load conditions, the first control valve 203 and the second control valve 204 can adopt different control methods to adjust the type and amount of fuel entering the inner primary air channel 2.
[0051] Specifically, under intermediate load conditions, both biomass powder and pulverized coal can enter the inner primary air channel 2, and the opening of the two control valves can be adjusted according to the calorific value of the biomass to maintain the boiler load. Under high load conditions, the first control valve 203 can be closed and the second control valve 204 can be opened, so that the fuel entering the inner primary air channel 2 is mainly pulverized coal. Under low load conditions, the first control valve 203 can be opened and the second control valve 204 can be closed, while the coal feed rate corresponding to the outer primary air channel 3 is adjusted, so that biomass powder enters the inner primary air channel 2. Thus, the fuel organization method can be adjusted according to changes in boiler load.
[0052] Optionally, the intermediate load condition corresponds to 30% to 80% of the boiler load, the high load condition corresponds to a boiler load higher than 80%, and the low load condition corresponds to a boiler load lower than 30%. The above load thresholds are preferred empirical values. In actual applications, they can be adjusted according to boiler capacity, coal characteristics, biomass calorific value, blending ratio, and operating conditions. Correspondingly, the control methods of the first control valve 203 and the second control valve 204 under each operating condition can also be adjusted accordingly.
[0053] In summary, the biomass-coal pulverizer provided by this invention, by setting an inner primary air channel 2 between the central air channel 1 and the outer primary air channel 3, and by setting a multi-feed structure at the feed end of the inner primary air channel 2, allows biomass powder and coal powder to enter the inner primary air channel 2 as needed. Simultaneously, by setting powder concentration separation structures in the inner primary air channel 2 and the outer primary air channel 3 respectively, different concentration distributions of the powder are formed in the two primary air channels. Therefore, separate pathway organization and stratified combustion of biomass powder and coal powder can be achieved within the same burner. A boiler based on this burner can allow the airflow and powder in the burner to enter the furnace for combustion, thereby improving the fuel organization effect and increasing the flexibility of fuel organization in the boiler.
[0054] It is understood that in this invention, when the number of components or members is not specifically limited, the number can be one or more, where multiple refers to two or more. For cases where the number of components or members shown in the drawings and / or described in the specification is, for example, two, three, four, etc., this specific number is generally exemplary and not limiting, and can be understood as multiple, i.e., two or more; however, this does not mean that the invention excludes the case of one.
[0055] It should be understood that the above-described embodiments, examples, or examples are merely exemplary and are not intended to limit the present invention. Those skilled in the art can make various modifications and changes to the above-described embodiments, examples, or examples under the guidance of the present invention, without departing from the scope of the present invention.
Claims
1. A biomass-pulverized coal burner, characterized in that, It includes a central air duct (1), an inner primary air duct (2), an outer primary air duct (3), and a secondary air unit arranged sequentially from the inside out; wherein, the inner primary air duct (2) is located between the central air duct (1) and the outer primary air duct (3), and the outer primary air duct (3) is located between the inner primary air duct (2) and the secondary air unit; The inner primary air channel (2) is provided with a multi-feed structure, which includes a biomass powder feeding passage (201) and a coal powder feeding passage (202) that can communicate with the inner primary air channel (2). The biomass powder feeding passage (201) is provided with a first control valve (203), and the coal powder feeding passage (202) is provided with a second control valve (204). The inner primary air channel (2) is provided with a first powder concentration separation structure (4), and the outer primary air channel (3) is provided with a second powder concentration separation structure (5), so that the powder concentration distribution in the inner primary air channel (2) is different from that in the outer primary air channel (3).
2. The biomass-pulverized coal burner according to claim 1, characterized in that, The first powder concentration separation structure (4) is disposed on the channel wall of the inner primary air channel (2) near the outer primary air channel (3) and protrudes toward the central air channel (1) so that the concentration of biomass powder and / or coal powder in the inner primary air channel (2) near the central air channel (1) is higher than the concentration of biomass powder and / or coal powder in the outer primary air channel (3).
3. The biomass-pulverized coal burner according to claim 1, characterized in that, The second powder concentration separation structure (5) is set on the channel wall of the outer primary air channel (3) near the inner primary air channel (2) and protrudes toward the secondary air unit so that the coal powder concentration in the outer primary air channel (3) near the secondary air unit is higher than the coal powder concentration in the inner primary air channel (2).
4. The biomass-pulverized coal burner according to claim 2 or 3, characterized in that, At least one of the first powder concentration separation structure (4) and the second powder concentration separation structure (5) is a concentration ring or a louvered concentration device.
5. The biomass-pulverized coal burner according to claim 1, characterized in that, The biomass powder feeding passage (201) is connected to the inlet end of the inner primary air passage (2), and the coal powder feeding passage (202) is an inner primary air branch pipe connected to the inner primary air passage (2). The biomass powder feeding passage (201), the inner primary air passage (2), and the inner primary air branch pipe constitute a three-way feeding structure.
6. The biomass-pulverized coal burner according to claim 5, characterized in that, The first control valve (203) and the second control valve (204) are configured to be controlled independently; The second control valve (204) is a continuously adjustable regulating valve and is used to regulate the amount of coal powder entering the inner primary air channel (2) through the coal powder feed passage (202).
7. The biomass-pulverized coal burner according to claim 5, characterized in that, The junction (205) of the pulverized coal feeding passage (202) and the inner primary air passage (2) is provided with a guide surface; The guide surface connects the inner wall of the pulverized coal feeding passage (202) and the inner wall of the inner primary air passage (2) to guide the pulverized coal entering through the pulverized coal feeding passage (202) into the inner primary air passage (2).
8. The biomass-pulverized coal burner according to claim 5, characterized in that, The coal powder feeding passage (202) includes a feeding section, an elbow section and an access section connected in sequence. The access section is connected to the junction (205) of the inner primary air passage (2). The elbow section is located between the feeding section and the access section, and the inner wall of the elbow section is provided with a wear-resistant lining.
9. The biomass-pulverized coal burner according to claim 1, characterized in that, The secondary air unit includes an inner secondary air channel (6) and an outer secondary air channel (7). The inner secondary air channel (6) is located outside the outer primary air channel (3), and the outer secondary air channel (7) is located outside the inner secondary air channel (6).
10. A boiler, characterized in that, It includes a furnace and a biomass-coal burner as described in any one of claims 1 to 9, wherein the biomass-coal burner is in communication with the furnace.