Biomass combustor suitable for low-nitrogen combustion technology
By installing biomass conveying channels outside the low-nitrogen coal powder burner, synchronous admixture of coal powder and biomass is achieved, the problems of interference with coal powder transmission and low nitrogen emissions are solved, and the low-nitrogen combustion characteristics are maintained and emission reduction are achieved.
Patent Information
- Application Number
- CN202422843503.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-11-21
AI Technical Summary
In the prior art, the biomass combustion method is likely to interfere with the transportation of coal powder when mixed on the coal powder boiler, and the independent arrangement of the biomass burner will change the height of the main combustion zone of the boiler and affect the low nitrogen emission standards.
Install a biomass delivery channel on the outside of the low-nitrogen coal powder burner, so that it is located inside the cavity of the bellows and the primary perimeter wind nozzle, so as to achieve separation and synchronous transportation of coal powder and biomass to avoid interference with coal powder transport and high occupation of boiler.
It effectively avoids the interference of biomass transportation on coal powder transportation, maintains the combustion characteristics and emission standards of low-nitrogen coal powder burners, and does not require separate arrangement of biomass burners to reduce CO2 and NOx emissions.
Smart Images
Figure CN223153550U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of burners, and specifically relates to a biomass burner suitable for low-nitrogen combustion technology. Background Art
[0002] In coal-fired power plants, in order to reduce NOx emissions to meet environmental protection standards, low-nitrogen combustion technology has been applied to the pulverized coal boiler, generating a main combustion zone, a reduction zone, and a burnout zone in the height direction of the boiler. To meet the requirements of low-nitrogen emissions, during the boiler transformation process, it is necessary to increase the distance between the main combustion zone and the burnout zone to create a relatively large reduction zone in height. However, since the boiler structure has been finalized, to achieve the above requirements, generally, the combustion height of the main combustion zone is compressed. To ensure the rigidity of the primary air, the nozzle of the pulverized coal burner is compressed very little, which causes a part of the total secondary air volume in the main combustion zone to be distributed to the burnout zone. Therefore, it is also necessary to compress the height of the secondary air nozzle, which makes the secondary air nozzles of the pulverized coal boiler after the low-nitrogen combustion technology transformation very small.
[0003] Biomass is a renewable carbon-neutral fuel. Coal-fired power generation coupled with biomass is a comprehensive utilization method of traditional energy and renewable energy. Biomass has the characteristics of higher reactivity, easier ignition and burnout, and low nitrogen oxide emissions. To further reduce the emissions of CO2 and NOx, co-firing biomass in pulverized coal boilers is a future development trend. In the prior art, many forms have been proposed for the layout of biomass combustion methods. Currently, there are mainly two forms. One is to couple with the primary air pipeline outside the furnace and then send it into the furnace through the original primary air pulverized coal burner. However, such a layout method is likely to interfere with the transportation of pulverized coal and has the problem of affecting the combustion characteristics of the burner. The other is to arrange an independent biomass burner separately. However, such a layout method must occupy the space in the height direction of the boiler combustion area, which will inevitably change the height of the main combustion zone, thus affecting the achieved low-nitrogen emission standards. Moreover, since the secondary air nozzles in the main combustion zone of the pulverized coal boiler after the low-nitrogen combustion technology transformation are very small, it is very difficult to arrange an independent biomass burner. Summary of the Utility Model
[0004] To solve or partially solve the problems existing in the related technologies, the utility model provides a biomass burner suitable for low-nitrogen combustion technology. This biomass burner suitable for low-nitrogen combustion technology can effectively avoid the interference of biomass transportation on the transportation of pulverized coal and can effectively avoid affecting the achieved low-nitrogen emission standards of the low-nitrogen pulverized coal burner after the low-nitrogen combustion technology transformation.
[0005] The present application provides a biomass burner suitable for low-nitrogen combustion technology, including a low-nitrogen pulverized coal burner, a wind box, and a primary peripheral wind nozzle. The low-nitrogen pulverized coal burner includes a pulverized coal burner body, and pulverized coal burner nozzles and a pulverized coal channel respectively located at both ends of the pulverized coal burner body. The wind box is arranged on the periphery of the low-nitrogen pulverized coal burner, and the primary peripheral wind nozzle is connected and arranged between the wind box and the furnace.
[0006] A biomass conveying channel is installed on the outside of the part of the pulverized coal burner body located in the wind box and the primary peripheral wind nozzle, and the biomass conveying channel is located inside the cavity of the wind box and the primary peripheral wind nozzle. A biomass nozzle is arranged at the position of the biomass conveying channel corresponding to the nozzle of the pulverized coal burner, the biomass nozzle is connected to the furnace, and the end of the biomass conveying channel away from the biomass nozzle is connected to the biomass feed channel.
[0007] In an optional embodiment, the biomass conveying channel is formed by a baffle covering the top outer wall of the pulverized coal burner body and closing the top outer wall of the pulverized coal burner body. The biomass conveying channel is not connected to the low-nitrogen pulverized coal burner, and the biomass conveying channel is parallel to the axis of the low-nitrogen pulverized coal burner.
[0008] In an optional solution, the primary peripheral wind nozzle is arranged in a cone shape with an air inlet area larger than an air outlet area, and the air intake volume of the primary peripheral wind nozzle when a biomass conveying channel is arranged outside the pulverized coal burner body is not less than the air intake volume when no biomass conveying channel is arranged.
[0009] In an optional solution, the width of the biomass conveying channel is consistent with the width of the pulverized coal burner body, and the height of the biomass conveying channel is less than the minimum distance between the top outer wall of the pulverized coal burner body and the inner top wall of the primary peripheral air nozzle.
[0010] In an optional solution, the biomass feed channel is arranged gradually away from the pulverized coal burner body.
[0011] Beneficial effects of the utility model:
[0012] The utility model installs a biomass conveying channel outside the original low-nitrogen pulverized coal burner after being transformed by low-nitrogen combustion technology, and makes the biomass conveying channel located inside the cavity of the air box and the primary perimeter air nozzle. Thus, by utilizing the space between the original low-nitrogen pulverized coal burner and the original primary perimeter air nozzle, a biomass conveying channel is installed inside the cavity of the air box and the primary perimeter air nozzle, and the biomass conveying channel is combined with the original low-nitrogen pulverized coal burner. Without changing the functional structure of the boiler and the low-nitrogen pulverized coal burner after being transformed by low-nitrogen combustion technology, it can separate and synchronously convey pulverized coal and biomass into the furnace for co-combustion. On the one hand, it can effectively avoid the interference of biomass conveying on pulverized coal conveying. On the other hand, there is no need to separately arrange an independent biomass burner, avoiding the occupation of the height space of the boiler combustion area by the independent arrangement of the biomass burner, thus avoiding changing the height of the main combustion zone of the boiler, not changing the combustion characteristics of the low-nitrogen pulverized coal burner, and further effectively avoiding affecting the low-nitrogen emission standard already achieved after the low-nitrogen pulverized coal burner is transformed by low-nitrogen combustion technology.
[0013] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present utility model. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0015] Figure 1 is the front view schematic diagram of the burner in an embodiment of the present application;
[0016] Figure 2 is the cross-sectional schematic diagram of the burner in an embodiment of the present application.
[0017] In the figures, each reference numeral: 1 - low-nitrogen pulverized coal burner, 101 - pulverized coal burner body, 102 - pulverized coal burner nozzle, 103 - pulverized coal channel, 2 - air box, 3 - primary perimeter air nozzle, 4 - biomass conveying channel, 401 - biomass nozzle, 402 - baffle, 5 - biomass feeding channel. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0018] The specific implementation manners of the present application will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are used to illustrate the present application, but are not intended to limit the scope of the present application. Similarly, the following embodiments are only partial embodiments of the present application rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present application.
[0019] In the present application, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium. It may be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.
[0020] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.
[0021] In the prior art, for the layout form of biomass combustion, one is to couple it with the primary air duct outside the furnace and then send it into the furnace through the original primary air pulverized coal burner. However, such a layout is likely to interfere with the transportation of pulverized coal and there is a problem that it will affect the combustion characteristics of the burner; the other is to arrange an independent biomass burner separately. However, such a layout must occupy the space of the height of the boiler combustion area, which will inevitably change the height of the main combustion zone, which will affect the achieved low nitrogen emission standard. Moreover, since the secondary air nozzles in the main combustion zone of the pulverized coal boiler after the low nitrogen combustion technology transformation are very small, it is very difficult to arrange an independent biomass burner anymore.
[0022] In view of the above problems, the present application makes improvements and innovations and proposes the following embodiments.
[0023] In one embodiment, please refer to Figure 1 - Figure 2A biomass burner suitable for low-nitrogen combustion technology is provided, comprising a low-nitrogen pulverized coal burner 1, a wind box 2, and a primary peripheral wind nozzle 3. The low-nitrogen pulverized coal burner 1 comprises a pulverized coal burner body 101, and pulverized coal burner nozzles 102 and pulverized coal channels 103 respectively located at both ends of the pulverized coal burner body 101. The wind box 2 is arranged at the periphery of the low-nitrogen pulverized coal burner 1, and the primary peripheral wind nozzle 3 is connected and arranged between the wind box 2 and the furnace; a biomass conveying channel 4 is installed on the outer side of the pulverized coal burner body 101 located in the wind box 2 and the primary peripheral wind nozzle 3, and the biomass conveying channel 4 is located in the cavity of the wind box 2 and the primary peripheral wind nozzle 3. A biomass nozzle 401 is arranged at the position of the biomass conveying channel 4 corresponding to the pulverized coal burner nozzle 102, and the biomass nozzle 401 is connected to the furnace, and the end of the biomass conveying channel 4 away from the biomass nozzle 401 is connected to the biomass feeding channel 5.
[0024] By installing a biomass conveying channel 4 on the outside of the original low-nitrogen pulverized coal burner 1 that has been transformed by the low-nitrogen combustion technology, and making the biomass conveying channel 4 located inside the cavity of the wind box 2 and the primary peripheral wind nozzle 3, and connecting the biomass feeding channel 5 at the outer end of the biomass conveying channel 4, the pulverized coal burner nozzle 102 is the outlet for the pulverized coal to be sprayed into the furnace, and the biomass nozzle 401 is the outlet for the biomass to be sprayed into the furnace, so that the pulverized coal conveyed by the pulverized coal channel 103 and the biomass conveyed by the biomass feeding channel 5 are synchronously fed into the furnace of the boiler through the pulverized coal burner nozzle 102 and the biomass nozzle 401 respectively under the action of the wind box 2, so as to complete the mixed combustion of pulverized coal and biomass, part of the pulverized coal can be replaced by biomass, which can effectively reduce the emissions of CO2 and NOx, and is beneficial to improving the atmospheric environment.
[0025] In this way, by utilizing the space between the original low-nitrogen pulverized coal burner 1 and the original primary boundary wind nozzle 3, a biomass conveying channel 4 is added to the cavity of the wind box 2 and the primary boundary wind nozzle 3, and the biomass conveying channel 4 is combined with the original low-nitrogen pulverized coal burner 1. Under the premise of not changing the functional structure of the boiler and the low-nitrogen pulverized coal burner 1 after the low-nitrogen combustion technology transformation, it is possible to separate the pulverized coal and the biomass and simultaneously convey them into the furnace for mixed combustion. On the one hand, it can effectively avoid the interference of the transportation of biomass on the transportation of pulverized coal. On the other hand, there is no need to arrange an independent biomass burner separately, which avoids the occupation of the height space of the boiler combustion area by the independent arrangement of the biomass burner, thereby avoiding changing the height of the main combustion zone of the boiler, and will not change the combustion characteristics of the low-nitrogen pulverized coal burner 1, and thus can effectively avoid affecting the low-nitrogen emission standard that has been achieved by the low-nitrogen pulverized coal burner 1 after the low-nitrogen combustion technology transformation.
[0026] In some embodiments, the biomass conveying channel 4 is formed by enclosing the outer wall of the top of the pulverized coal burner body 101 with a baffle 402, and the biomass conveying channel 4 is not communicated with the low-nitrogen pulverized coal burner 1. In this way, the outer wall of the top of the pulverized coal burner body 101 is used as the bottom of the biomass conveying channel 4, and there is no need to additionally provide a baffle 402 on the top of the pulverized coal burner body 101, which is beneficial to reducing the space occupied by the baffle 402 forming the biomass conveying channel 4, so as to make full use of the space between the original low-nitrogen pulverized coal burner 1 and the original primary perimeter air nozzle 3 to ensure the through-flow rate of the biomass conveying channel 4. In addition, the material consumption of the baffle 402 forming the biomass conveying channel 4 can be effectively reduced to reduce the installation difficulty and the material cost. By making the biomass conveying channel 4 parallel to the axis of the low-nitrogen pulverized coal burner 1, the smoothness of biomass conveying in the biomass conveying channel 4 can be effectively improved.
[0027] In some embodiments, the primary perimeter air nozzle 3 is tapered with an inlet area larger than the outlet area. In this way, the installation of the biomass conveying channel 4 can be completed without changing the functional structure of the boiler and the low-nitrogen pulverized coal burner 1 after the low-nitrogen combustion technology transformation, and without changing the characteristics of the primary perimeter air nozzle 3 for supplying air to the furnace, and it is ensured that the air intake volume of the primary perimeter air nozzle 3 when the biomass conveying channel 4 is provided outside the pulverized coal burner body 101 is not less than the air intake volume when the biomass conveying channel 4 is not provided. In this way, it can be effectively ensured that the addition of the biomass conveying channel 4 will not change the combustion characteristics of the low-nitrogen pulverized coal burner 1.
[0028] In some embodiments, the width of the biomass conveying channel 4 is consistent with the width of the pulverized coal burner body 101, so that the biomass conveyed from the biomass feed channel 5 and the pulverized coal conveyed from the pulverized coal channel 103 can be evenly mixed and burned after entering the furnace; the height of the biomass conveying channel 4 is less than the minimum distance between the outer wall of the top of the pulverized coal burner body 101 and the inner top wall of the primary perimeter air nozzle 3, so as to ensure that after the biomass conveying channel 4 is arranged in the space between the original low-nitrogen pulverized coal burner 1 and the original primary perimeter air nozzle 3, the presence of the biomass conveying channel 4 will not affect the characteristics of the primary perimeter air nozzle 3 for supplying air to the furnace, and further, it can be effectively ensured that the addition of the biomass conveying channel 4 will not change the combustion characteristics of the low-nitrogen pulverized coal burner 1.
[0029] In some embodiments, the biomass feed channel 5 is arranged gradually away from the pulverized coal burner body 101, so as to facilitate the separate feeding of biomass and pulverized coal.
[0030] Finally, it should also be noted that although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention, and all such changes should be included within the protection scope of this application.
Claims
1. A biomass burner suitable for low-nitrogen combustion technology, comprising a low-nitrogen pulverized coal burner (1), a wind box (2), and a primary peripheral wind nozzle (3), wherein the low-nitrogen pulverized coal burner (1) comprises a pulverized coal burner body (101), and a pulverized coal burner nozzle (102) and a pulverized coal channel (103) respectively located at two ends of the pulverized coal burner body (101), the wind box (2) is arranged at the periphery of the low-nitrogen pulverized coal burner (1), and the primary peripheral wind nozzle (3) is arranged in communication between the wind box (2) and the furnace, characterized in that: A biomass conveying channel (4) is installed on the outer side of the part of the pulverized coal burner body (101) located inside the wind box (2) and the primary peripheral wind nozzle (3), and the biomass conveying channel (4) is located inside the cavity of the wind box (2) and the primary peripheral wind nozzle (3). A biomass nozzle (401) is arranged at a position of the biomass conveying channel (4) corresponding to the pulverized coal burner nozzle (102), and the biomass nozzle (401) is connected to the furnace. The end of the biomass conveying channel (4) away from the biomass nozzle (401) is connected to a biomass feeding channel (5).
2. A biomass burner suitable for low-nitrogen combustion technology according to claim 1, characterized in that: The biomass conveying channel (4) is formed by a baffle (402) covering the top outer wall of the pulverized coal burner body (101) and is sealed with the top outer wall of the pulverized coal burner body (101); the biomass conveying channel (4) is not connected to the low-nitrogen pulverized coal burner (1), and the biomass conveying channel (4) is parallel to the axis of the low-nitrogen pulverized coal burner (1).
3. A biomass burner suitable for low-nitrogen combustion technology according to claim 1 or 2, characterized in that: The primary peripheral air nozzle (3) is arranged in a conical shape with an air inlet area larger than an air outlet area, and the air intake volume of the primary peripheral air nozzle (3) when a biomass conveying channel (4) is arranged outside the pulverized coal burner body (101) is not less than the air intake volume when the biomass conveying channel (4) is not arranged.
4. The biomass burner suitable for low-nitrogen combustion technology according to claim 3, characterized in that: The width of the biomass conveying channel (4) is consistent with the width of the pulverized coal burner body (101), and the height of the biomass conveying channel (4) is less than the minimum distance between the top outer wall of the pulverized coal burner body (101) and the inner top wall of the primary peripheral air nozzle (3).
5. A biomass burner suitable for low-nitrogen combustion technology according to claim 1, characterized in that: The biomass feed channel (5) is arranged gradually away from the pulverized coal burner body (101).