Double high concentration zone oil ignition pulverized coal burner

Abstract

The utility model relates to the technical field of coal powder boiler burner, specifically disclose a kind of double high concentration area oil-saving ignition coal powder burner. The double high concentration area oil-saving ignition coal powder burner includes flow guide device and is set in the ignition device of combustion cylinder;The flow guide device includes main cylinder and the turbulence structure of setting in the outer periphery of main cylinder, wherein the main cylinder is connected to the inner wall of the combustion cylinder by support, and the turbulence structure is formed as the structure that projects along radial direction, to be used for disturbing the flow direction of mixed gas. Therefore, it solves the problem that the oil-saving ignition coal powder burner structure design in prior art is opposite to the design of boiler original burner when it is in non-ignition condition, the coal powder concentration distribution mode of "inner thick outer thin" is opposite to the design of "outer thick inner thin", and it is easy to produce significant influence on the wind powder flow field characteristics of burner outlet and hearth interior.

Description

Technical Field

[0001] This utility model relates to the technical field of pulverized coal boiler burners, specifically to a dual high-concentration zone fuel-saving pulverized coal burner. Background Technology

[0002] To save on the large amounts of fuel consumed during startup and stable combustion, large power plant boilers typically employ one or more burners with fuel-saving ignition functions. These burners use fuel-saving ignition heat sources (such as micro-oil guns or plasma generators) to directly ignite pulverized coal, enabling boiler startup and stabilizing combustion during shutdown, low load, and ultra-low load conditions. Because the ignition heat sources used in fuel-saving burners (micro-oil guns, plasma generators, etc.) are smaller and have more precise ignition positions and energy compared to conventional oil guns, a specialized burner structure design is required to complete the ignition process within the burner to achieve direct pulverized coal ignition. Pulverized coal burners with opposing front and rear walls typically employ a segmented ignition and step-by-step amplification method. First, a portion of the high-concentration pulverized coal near the ignition source outlet is ignited, and then the already ignited coal continues to ignite other parts of the coal, ultimately achieving the complete pulverized coal ignition process through the burner, thus achieving the goal of starting the boiler with coal instead of oil.

[0003] Traditional pulverized coal burners typically use fuel oil ignition during startup, which is not only costly but also causes significant environmental pollution, contradicting the trend of energy conservation and emission reduction. With technological advancements, fuel-efficient pulverized coal burners have emerged, with current common designs employing a central concentration ignition and staged amplification method.

[0004] Specifically, to meet the requirement of installing an ignition source at the axial center position of the opposed-wall furnace type, the pulverized coal concentration distribution within the burner exhibits a "rich inside, light outside" characteristic. Through a specialized structural design, the pulverized coal burner of the opposed-wall furnace type employs a segmented ignition and step-by-step amplification method. It first ignites the high-concentration pulverized coal near the ignition source outlet, then uses the already ignited pulverized coal to ignite pulverized coal in other parts, ultimately achieving ignition of all pulverized coal and realizing the goal of starting the boiler with coal instead of oil. However, in non-ignition conditions, this common oil-saving pulverized coal burner structural design, with its "rich inside, light outside" pulverized coal concentration distribution pattern, is the opposite of the original boiler burner's "rich outside, light inside" design. This can easily have a significant impact on the air-coal flow field characteristics at the burner outlet and inside the furnace, thereby affecting the stability and economy of boiler combustion.

[0005] Based on the aforementioned technical deficiencies, it is necessary to optimize and improve the structure of the existing pulverized coal burner so that it can better adapt to the operating conditions of the original boiler burner, thereby reducing the impact on the air-coal flow field at the burner outlet and inside the furnace, and ensuring the stability and economy of boiler combustion. Utility Model Content

[0006] The purpose of this invention is to provide a dual high-concentration zone fuel-saving pulverized coal burner to solve the problem that in the non-ignition condition, the "rich inside, light outside" pulverized coal concentration distribution pattern of the existing fuel-saving pulverized coal burner is opposite to the "rich outside, light inside" design of the original boiler burner, which easily has a significant impact on the air-coal flow field characteristics at the burner outlet and inside the furnace.

[0007] This utility model is achieved through the following technical solution:

[0008] A dual high-concentration zone fuel-saving pulverized coal burner includes an ignition device disposed in a combustion chamber; the burner also includes a flow guiding device, which includes a main cylinder and a turbulence-disrupting structure disposed on the outer periphery of the main cylinder, wherein the main cylinder is connected to the inner wall of the combustion chamber by a support member, and the turbulence-disrupting structure is formed as a radially protruding structure to disrupt the flow direction of the mixed gas.

[0009] Alternatively, the turbulence structure is formed such that, along the flow direction of the mixed gas, the turbulence structure has a turbulence section, a transition section, and a buffer section, wherein the diameter of the turbulence section gradually increases, the diameter of the transition section is constant, and the diameter of the buffer section gradually decreases.

[0010] Alternatively, the turbulence structure is wave-shaped and arranged along the circumferential direction of the main cylinder, and the wave-shaped turbulence structure has crests and troughs.

[0011] Alternatively, the peaks and troughs can both be formed as curves.

[0012] Alternatively, the turbulence structure is formed as a plurality of radially protruding bosses, which are evenly spaced along the circumferential direction of the main cylinder.

[0013] Alternatively, the bosses may be configured to be at least five.

[0014] Alternatively, the outer surface of the boss may be formed as an arc surface.

[0015] Alternatively, the boss has an expansion section and a contraction section, the width of the contraction section gradually decreasing in the circumferential direction along the flow direction of the gas mixture.

[0016] Alternatively, the thickness of the contraction section gradually increases along the flow direction of the gas mixture, and the thickness of the contraction section gradually decreases along the flow direction of the gas mixture.

[0017] Alternatively, the ignition device is fixedly connected to the combustion chamber; and / or, the main chamber is connected to the inner wall of the combustion chamber via a support member, wherein the support member is formed as three support ribs spaced apart along the circumferential direction, and the two ends of the support ribs are respectively fixedly connected to the main chamber and the combustion chamber.

[0018] The advantages of this utility model compared to the prior art are as follows:

[0019] Through the above technical solution, the turbulence structure can distribute the pulverized coal flow through the burner, causing the mixed gas entering the central part of the combustion chamber to continue to concentrate towards the central axis, thus forming a high-concentration pulverized coal airflow region in the center, which is used to achieve the ignition process at the heat source outlet of the fuel-saving ignition device. For the pulverized coal that does not enter the central part of the combustion chamber, it diffuses radially towards the outer wall under the action of the flow guiding device, forming a high-concentration pulverized coal distribution area in the area around the inner ring of the combustion chamber. The burner outlet cross-section can form two high-concentration pulverized coal zones: a central region and a wall-adhering region. In the region between the two high-concentration pulverized coal zones, due to the intervention of the turbulence device, less gas diffuses, and the pulverized coal forms a low-concentration zone.

[0020] Compared to the "rich inside, lean outside" pulverized coal distribution characteristic of conventional ignition burners, the dual high-concentration zone burner structure reduces the central air velocity and central pulverized coal velocity within the central combustion chamber, forming a dual-zone high-concentration pulverized coal distribution characteristic at the heat source outlet center and the outer ring. The central concentration in the first-stage chamber continues to match the primary air velocity, consistently meeting the functional requirements of fuel-saving ignition conditions. The annular high-concentration distribution characteristic of the outer wall-attached zone more closely resembles the "rich outside, lean inside" distribution characteristic of the original burner (non-fuel-saving ignition type). In the non-ignition state, it more closely approximates the design characteristics of the original boiler burner, reducing the alteration and impact of non-ignition conditions on the furnace flow field, which is beneficial for adjusting boiler operating conditions, thus solving existing technical problems. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the exemplary embodiments of this utility model, the drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this utility model and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0022] Figure 1 A cross-sectional structural schematic diagram of a dual high-concentration zone fuel-saving pulverized coal burner provided by this utility model in one embodiment;

[0023] Figure 2A three-dimensional structural schematic diagram of the flow guiding device in a dual high-concentration zone fuel-saving pulverized coal burner provided by this utility model in one embodiment;

[0024] Figure 3 A side view of the flow guiding device in one embodiment of the dual high-concentration zone fuel-saving pulverized coal burner provided by this utility model;

[0025] Figure 4 A cross-sectional structural schematic diagram of the dual high-concentration zone fuel-saving pulverized coal burner provided by this utility model in another embodiment;

[0026] Figure 5 A three-dimensional structural schematic diagram of the flow guiding device in another embodiment of the dual high-concentration zone fuel-saving pulverized coal burner provided by this utility model;

[0027] Figure 6 A side view of the flow guiding device in another embodiment of the dual high-concentration zone fuel-saving pulverized coal burner provided by this utility model;

[0028] Figure 7 A cross-sectional view of the dual high-concentration zone fuel-saving pulverized coal burner provided by this utility model in another embodiment;

[0029] Figure 8 A three-dimensional structural schematic diagram of the flow guiding device in another embodiment of the dual high-concentration zone fuel-saving pulverized coal burner provided by this utility model;

[0030] Figure 9 A side view of the flow guiding device in another embodiment of the dual high-concentration zone fuel-saving pulverized coal burner provided by this utility model;

[0031] Figure 10 A partially enlarged structural schematic diagram of the flow guiding device in another embodiment of the dual high-concentration zone fuel-saving pulverized coal burner provided by this utility model;

[0032] Figure 11 This is a schematic diagram showing the mapping relationship of the dual high-concentration zone fuel-saving pulverized coal burner provided by this utility model in one embodiment. The left part of the drawing is a schematic diagram of the mixing airflow direction of the pulverized coal burner, and the right part of the drawing is a side view of the pulverized coal burner, showing the high-concentration zone and the low-concentration zone of pulverized coal.

[0033] The labels and corresponding component names in the attached diagram are as follows: 1-combustion cylinder, 2-ignition device, 3-flow guiding device, 31-main cylinder, 32-turbulence structure, 3211-turbulence section, 3212-transition section, 3213-buffer section, 3221-peak, 3221-trough, 323-bore, 3231-expansion section, 3232-contraction section, 4-concentration ring, 5-support component, 6-high concentration zone, 7-low concentration zone. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that while the description of these embodiments is intended to aid in understanding the present invention, it does not constitute a limitation thereof. The specific structural and functional details disclosed herein are only for describing exemplary embodiments of the present invention. However, the present invention may be embodied in many alternative forms and should not be construed as being limited to the embodiments described herein.

[0035] According to a specific embodiment of this disclosure, a dual high-concentration zone fuel-saving pulverized coal burner is provided. Among them, Figures 1 to 11 Specific embodiments thereof are shown.

[0036] See Figures 1 to 11 As shown, the dual high-concentration zone fuel-saving pulverized coal burner includes an ignition device 2 disposed in the combustion chamber 1. The burner also includes a flow guiding device 3, which includes a main cylinder 31 and a turbulence-disrupting structure 32 disposed on the outer periphery of the main cylinder 31. The main cylinder 31 is connected to the inner wall of the combustion chamber 1, and the turbulence-disrupting structure 32 is formed as a radially protruding structure to disrupt the flow direction of the mixture.

[0037] During operation, the mixture of pulverized coal and air enters the combustion chamber 1 and flows through the main cylinder 31 of the guide device 3. The main cylinder 31 is securely connected to the inner wall of the combustion chamber 1, providing a preliminary guiding channel for the mixture, allowing it to flow relatively orderly towards the outlet of the ignition device 2. As the mixture continues to move forward, its flow direction is disrupted when it encounters the radially protruding turbulence structure 32 on the outer periphery of the main cylinder 31. The turbulence structure 32 breaks the original laminar flow state of the mixture, causing it to generate turbulent motion. This turbulent motion greatly increases the contact area and mixing uniformity between the pulverized coal and air. On the one hand, more thorough mixing helps the pulverized coal to be quickly ignited near the outlet of the ignition device 2, improving ignition efficiency; on the other hand, turbulent motion also allows the heat generated by combustion to be diffused more evenly, contributing to the stable combustion of the pulverized coal afterwards, reducing incomplete combustion or excessively high or low temperatures, and enhancing combustion stability.

[0038] Through the above technical solution, the turbulence structure 32 can distribute the pulverized coal flow through the burner, causing the mixed gas entering the central part of the combustion cylinder 1 to continue to concentrate towards the central axis, thereby forming a high-concentration pulverized coal airflow region in the center, which is used to realize the ignition process of the heat source outlet of the fuel-saving ignition device 2. As for the pulverized coal that does not enter the central part of the combustion cylinder 1, it diffuses radially towards the outer wall under the action of the flow guiding device 3, forming a high-concentration pulverized coal distribution area in the area of ​​the outer ring of the inner hole of the combustion cylinder 1. The cross-section of the burner outlet can form two high-concentration pulverized coal areas: the central area and the wall-adhering area. In the area between the two high-concentration pulverized coal areas, due to the intervention of the turbulence device, less gas diffuses, and the pulverized coal forms a low-concentration area 7.

[0039] Compared to the "rich inside, lean outside" pulverized coal distribution characteristic of conventional ignition burners, the dual high-concentration zone 6-burner structure reduces the central air velocity and central pulverized coal velocity within the combustion chamber, forming a dual-zone high-concentration pulverized coal distribution characteristic at the center and outer ring of the heat source outlet. The central concentration of the first-stage cylinder continues to match the air velocity, consistently meeting the functional requirements of fuel-saving ignition conditions. The annular high-concentration distribution characteristic of the outer wall-attached zone more closely resembles the "rich outside, lean inside" distribution characteristic of the original burner (non-fuel-saving ignition type). In the non-ignition state, it more closely approximates the design characteristics of the original boiler burner, reducing the alteration and impact of non-ignition conditions on the internal flow field, which is beneficial for adjusting boiler operating conditions, thus solving existing technical problems.

[0040] It should be noted that the directional terms used, such as "inner" and "outer," refer to the "inner" and "outer" relative to the outline of the component, facing the component (which can be combined with...). Figure 1 (For understanding purposes) The direction of the axis is "inward," and vice versa. Furthermore, it should be noted that the terms used, such as "first" and "second," are used to distinguish one element from another and do not indicate sequence or importance. Moreover, in the following descriptions with accompanying drawings, the same reference numerals in different drawings represent the same element.

[0041] In one embodiment provided in this disclosure, the turbulence structure 32 is formed as follows: along the flow direction of the mixed gas, the turbulence structure 32 has a turbulence section 3211, a transition section 3212 and a buffer section 3213, wherein the diameter of the turbulence section 3211 gradually increases, the diameter of the transition section 3212 is constant, and the diameter of the buffer section 3213 gradually decreases.

[0042] Based on the structure of the turbulence section 3211, the gas can gradually come into contact with the inclined surface, thereby disrupting the flow direction of the mixed gas. This allows the pulverized coal that has not yet entered the central combustion chamber 1 to diffuse radially towards the outer wall under the action of the turbulence section 3211, forming a high-concentration pulverized coal distribution area on the outer ring of the burner. The transition section 3212 and the buffer section 3213 are beneficial for guiding the flow of the mixed gas and ensuring appropriate residence, indirectly forming the low-concentration zone 7. Compared with the single-structure turbulence structure 32, the segmented design can achieve differentiated turbulence in different flow channel regions, avoiding the problems of increased resistance or insufficient mixing caused by excessive disturbance in the traditional turbulence structure 32. It is better suited to the requirements of pulverized coal concentration distribution and flow field stability of the dual high-concentration zone 6 burner.

[0043] In another embodiment provided in this disclosure, the turbulence structure 32 is wave-shaped and arranged along the circumferential direction of the main cylinder 31. The wave-shaped turbulence structure 32 has crests 3221 and troughs 3221. The wave-shaped turbulence structure 32 is continuously distributed along the circumferential direction of the main cylinder 31, and its crests 3221 and troughs 3221 form a periodic concave-convex surface (such as a sine curve profile). When the mixed airflow passes through the crests 3221, the fluid is forced to flow around the convex surface, and the boundary layer separates at the trailing edge of the crests 3221, forming vortices. This is beneficial for forming a high-concentration coal powder distribution state in the area outside the outer diameter of the main cylinder 31.

[0044] Furthermore, both the peaks 3221 and troughs 3221 are curved. The curved surface allows the gas mixture to pass through smoothly, which helps to reduce dead corners where dust accumulates, thus enabling the gas mixture to form a high-concentration mixing zone after it flows through.

[0045] In another embodiment provided in this disclosure, the turbulence structure 32 is formed as a plurality of radially protruding bosses 323, which are evenly spaced along the circumference of the main cylinder 31. Based on the arrangement of the bosses 323, on the one hand, it is beneficial to play a certain role in disturbing the flow direction of the mixed gas, causing the mixed gas to gather towards the grooves between the bosses 323, thereby forming a high-concentration pulverized coal zone in the combustion cylinder 1, thus better adapting to the "rich outside and lean inside" operating condition of the original boiler burner, and improving the stability and economy of boiler combustion.

[0046] Specifically, at least five protrusions 323 are configured. When the number of protrusions 323, n, is less than 5 (e.g., n=4), the circumferential interval θ>90°, and the distance between adjacent protrusions 323 is relatively large, making it difficult to form a stable high-concentration coal powder zone. However, when n=5, θ=72°, which is beneficial for better coal powder aggregation in the mixed gas. The number of protrusions 323 can be flexibly configured by those skilled in the art within the framework of this disclosure.

[0047] Furthermore, the outer surface of the boss 323 is formed as an arc surface. The arc surface helps to guide the high-speed airflow to form a spiral vortex, and the smooth airflow design also helps to guide the smooth flow of the mixed air.

[0048] Furthermore, the boss 323 has an extension section 3231 and a contraction section 3232. Along the flow direction of the mixed gas, the width of the contraction section 3232 gradually decreases in the circumferential direction. The extension section 3231 causes radial diffusion of the fluid, while the contraction section 3232 can appropriately reduce the flow velocity, helping to form a high-concentration coal powder zone.

[0049] Furthermore, the thickness of the contraction section 3232 gradually increases along the flow direction of the mixed gas, while the thickness of the contraction section 3232 gradually decreases along the flow direction of the mixed gas. This helps to guide the mixed gas to accumulate and form a dynamic reflux zone, thereby ensuring the coal powder concentration in this area.

[0050] In one embodiment provided in this disclosure, the ignition device 2 is fixedly connected to the combustion cylinder 1. Specifically, the ignition device 1 is welded to the combustion cylinder 1 to ensure the connection strength between the two. Furthermore, the combustion cylinder 1 is also provided with reinforcing ribs, the two ends of which are respectively connected to the inner wall of the combustion cylinder and the ignition device 2, thereby providing further support and reinforcement for the ignition device 2, thus ensuring the reliability of the position of the ignition device 2.

[0051] It should be noted that "and / or" in the text refers to A and / or B, which indicates that there are three possible scenarios: only A exists, only B exists, and both A and B exist. Conversely, " / and" in the text refers to A / and B, which indicates that there are two possible scenarios: only A exists and both A and B exist.

[0052] In this disclosure, the main cylinder 31 is connected to the inner wall of the combustion cylinder 1 by a support member 5, wherein the support member 5 is formed as three support ribs spaced apart along the circumferential direction, and the two ends of the support ribs are respectively fixedly connected to the main cylinder 31 and the combustion cylinder 1.

[0053] The structure of the enrichment ring 4 can converge the air-fuel mixture, causing a localized increase in fuel concentration in the ignition zone. At the moment of ignition, the higher fuel concentration makes it easier to reach the combustible limit, thereby improving the ignition success rate, especially at low loads or during startup. Thus, the fit between the enrichment ring 4 and the inner hole of the combustion chamber 1 defines the position of the ignition device 2, ensuring it is always within the optimal ignition zone (such as a region with high turbulence intensity and suitable temperature).

[0054] The support member 5 is formed as three circumferentially spaced support ribs, creating a stable triangular structure that helps to evenly bear the radial force and thermal stress between the combustion cylinder 1 and the main cylinder 31, avoiding deformation or breakage caused by single-point stress. Compared to continuous support or multiple support ribs, the design of three support ribs reduces airflow obstruction. The spaced gaps allow the mixture to pass through more smoothly, reducing flow pressure loss and preventing excessive resistance from affecting the burner's airflow and back pressure.

[0055] The above specific embodiments further illustrate the purpose, technical solution and beneficial effects of this utility model. It should be understood that the above are only specific embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

[0056] Finally, it should be noted that this utility model is not limited to the above-described optional embodiments, and anyone can derive other various forms of products under the guidance of this utility model. The above specific embodiments should not be construed as limiting the scope of protection of this utility model, which should be determined by the claims, and the description can be used to interpret the claims.

Claims

1. A dual high-concentration zone fuel-saving pulverized coal burner, comprising an ignition device disposed in a combustion chamber, characterized in that, The burner also includes a flow guiding device, which includes a main cylinder and a flow disturbance structure disposed on the outer periphery of the main cylinder. The main cylinder is connected to the inner wall of the combustion cylinder by a support member, and the flow disturbance structure is formed as a radially protruding structure to disrupt the flow direction of the mixture.

2. The dual high-concentration zone fuel-saving pulverized coal burner according to claim 1, characterized in that, The turbulence structure is formed as follows: along the flow direction of the mixed gas, the turbulence structure has a turbulence section, a transition section and a buffer section, wherein the diameter of the turbulence section gradually increases, the diameter of the transition section is constant, and the diameter of the buffer section gradually decreases.

3. The dual high-concentration zone fuel-saving pulverized coal burner according to claim 1, characterized in that, The turbulence structure is wave-shaped and arranged along the circumference of the main cylinder. The wave-shaped turbulence structure has crests and troughs.

4. The dual high-concentration zone fuel-saving pulverized coal burner according to claim 3, characterized in that, Both the peaks and troughs are curved.

5. The dual high-concentration zone fuel-saving pulverized coal burner according to claim 1, characterized in that, The turbulence structure is formed as a plurality of radially protruding bosses, which are evenly spaced along the circumference of the main cylinder.

6. The dual high-concentration zone fuel-saving pulverized coal burner according to claim 5, characterized in that, The number of bosses is at least five.

7. The dual high-concentration zone fuel-saving pulverized coal burner according to claim 5, characterized in that, The outer surface of the boss is formed as an arc surface.

8. The dual high-concentration zone fuel-saving pulverized coal burner according to claim 5, characterized in that, The boss has an expanding section and a contracting section, and the width of the contracting section gradually decreases in the circumferential direction along the flow direction of the gas mixture.

9. The dual high-concentration zone fuel-saving pulverized coal burner according to claim 8, characterized in that, The thickness of the contraction section gradually increases along the flow direction of the gas mixture, and the thickness of the contraction section gradually decreases along the flow direction of the gas mixture.

10. The dual high-concentration zone fuel-saving pulverized coal burner according to claim 1, characterized in that, The ignition device is fixedly connected to the combustion cylinder; And / or, the main cylinder is connected to the inner wall of the combustion cylinder by a support member, wherein the support member is formed as three support ribs spaced apart along the circumferential direction, and the two ends of the support ribs are respectively fixedly connected to the main cylinder and the combustion cylinder.

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