Internal circulation low-nitrogen burner capable of jetting flue gas in peripheral annular cavity

Abstract

The utility model discloses an internal circulation low-nitrogen burner capable of spraying flue gas in a peripheral annular cavity, and relates to an internal circulation low-nitrogen burner capable of spraying flue gas in a peripheral annular cavity. Comprising an annular cavity, a fire gathering cover contraction section, a center fire gathering cover, a center flame stabilizing disc, a center gas pipe, a peripheral annular cavity injection pipe, a peripheral annular cavity injection pipe and a peripheral annular cavity radial injection pipe. The low-nitrogen, stable and high-performance combustor capable of sufficiently combusting fuel is designed by mainly combining various technologies such as fuel grading, air grading, flue gas internal circulation, rich-lean combustion and the like.

Description

Technical Field

[0001] This utility model relates to the field of burner technology, specifically to a low-NOx burner with peripheral annular cavity injection of flue gas and internal circulation. Background Technology

[0002] The core of burner design is to generate high calorific value while maintaining low pollutant emissions under stable operation, requiring optimization of the burner structure. Currently, the main emission reduction technologies used in burner design include staged combustion, rich-lean combustion, diffusion combustion, and flue gas recirculation. However, applying a single combustion technology is insufficient to achieve a balance between low emissions and high calorific value. Further reductions in nitrogen oxide emissions are needed while ensuring robust and complete combustion. Therefore, it is necessary to propose a low-NOx burner with peripheral annular injection and internal flue gas recirculation to address these issues. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a low-NOx burner with peripheral annular injection and internal flue gas circulation. This invention applies fuel staging, air staging, flue gas internal circulation, and rich-lean combustion technologies to the design of forced-draft burners, thereby solving the problems of high NOx emissions, incomplete combustion, and unstable combustion in commonly used industrial boiler gas burners.

[0004] This utility model provides a low-NOx burner with peripheral annular cavity injection flue gas internal circulation, including: an annular cavity chamber, a flame-gathering hood contraction section, a central flame-gathering hood, a central flame stabilizer plate, a central gas pipe, a peripheral annular cavity ejector pipe, a peripheral annular cavity injection pipe, and a peripheral annular cavity radial injection pipe;

[0005] The annular chamber has an arc-shaped front end with several holes connected to the outer annular ejector pipes. Several curved outer annular ejector pipes are axially arranged at the end of the annular chamber, and several radial outer annular ejector pipes are arranged radially at the end of the annular chamber. The front end of the flame-gathering hood's contraction section has an outer annular gas inlet and a central gas inlet. A gas storage chamber is located at the outer annular gas inlet, with several holes welded to the outer annular ejector pipes. The central gas pipe is coaxially arranged within the annular chamber and the flame-gathering hood's contraction section. Multiple central fuel nozzles are located at the end of the central gas pipe, with a central flame stabilizer plate below each nozzle and air nozzles on the plate. A central flame-gathering hood surrounds the central flame stabilizer plate, and the central flame-gathering hood and its contraction section form an air grading system, with some air ejected from the outside of the central flame-gathering hood and the other air ejected from the inside of the central flame-gathering hood.

[0006] Furthermore, the number of peripheral annular ejector tubes is 4 to 8.

[0007] Furthermore, the number of peripheral annular cavity injection pipes is 6 to 16.

[0008] Furthermore, the number of radial injection tubes in the outer annular cavity is 4 to 8.

[0009] Furthermore, the central flame stabilizer has 6 to 30 air nozzles.

[0010] This invention offers the following advantages: The peripheral annular cavity injection flue gas recirculation low-NOx burner provided by this invention utilizes the concave arc at the front end of the annular cavity to entrain a portion of the flue gas, achieving an internal flue gas recirculation effect, reducing combustion temperature, and decreasing the formation of nitrogen oxides. By adjusting the injection volume of peripheral and central fuel gases, rich-lean combustion can be achieved, reducing central fuel injection, lowering the central flame temperature, and reducing nitrogen oxide formation. Simultaneously, a central flame diffuser and flame stabilizer ensure stable combustion. Fuel staging and air staging ensure complete combustion. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the structure of the peripheral annular cavity injection flue gas internal circulation low-NOx burner of this utility model;

[0013] Figure 2 This utility model relates to a low-NOx burner with peripheral annular cavity injection and internal flue gas recirculation. Figure 3 A cross-sectional view along the AA direction;

[0014] Figure 3 This is a front view of the peripheral annular cavity injection flue gas internal circulation low-NOx burner of this utility model;

[0015] Figure 4 This is a top view of the peripheral annular cavity injection flue gas internal circulation low-NOx burner of this utility model.

[0016] Illustration: 1-Outer shell; 2-Cable outlet; 3-Spring tube; 4-High frequency connector; 5-Cable. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be pointed out that the following detailed description is illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0018] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0019] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions has been enlarged, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0020] Please see Figures 1 to 4 This utility model provides a low-NOx burner with peripheral annular cavity injection and internal flue gas recirculation, including a central tube assembly, an annular cavity assembly, and a gas interface section. The central tube assembly includes a central gas pipe 5, a central flame stabilizer 4, and a central flame diffuser 3. The annular cavity assembly includes an annular chamber 1, a peripheral annular cavity injection pipe 7, and a peripheral annular cavity radial injection pipe 8. The gas interface section includes a flame diffuser retraction section 2 and a peripheral annular cavity ejector pipe 6.

[0021] The front end of the annular chamber 1 is designed in an arc shape to entrain some flue gas, reduce combustion temperature, and decrease nitrogen oxide emissions. Several holes are provided on the arc, which connect to the outer annular chamber injector 6 to inject peripheral fuel into the annular chamber. An arc-shaped baffle is installed inside the annular chamber to improve fuel mixing within the chamber. Several curved outer annular chamber injector pipes 7 are axially arranged at the end of the annular chamber 1, causing peripheral fuel to be injected outwards. Several radial outer annular chamber injector pipes 8 are radially arranged at the end of the annular chamber 1 to ensure stable combustion of the central flame. The front end of the flame-gathering hood contraction section 2 is provided with an outer annular chamber fuel inlet and a central fuel inlet. A fuel storage chamber is provided at the outer annular chamber fuel inlet, and several holes are opened for welding to the outer annular chamber injector 6. The central fuel pipe 5 is coaxially arranged within the annular chamber 1 and the flame-gathering hood contraction section 2. Multiple central fuel nozzles are opened at the end of the central fuel pipe 5, and a central flame stabilizer 4 is installed below the nozzles.

[0022] An air nozzle is provided on the central flame stabilizer plate 4; a central flame hood 3 is provided around the central flame stabilizer plate 4, the central flame hood 3 is welded to the central flame stabilizer plate 4, and the central flame stabilizer plate 4 is welded to the central gas pipe 5.

[0023] The central flame diffuser 3 and the converging section 2 of the flame diffuser form an air staged combustion chamber. Part of the air is ejected from the periphery of the central flame diffuser 3, and another part is ejected from the inside of the central flame diffuser 3. The end of the converging section 2 of the flame diffuser narrows, injecting air into the combustion chamber. The air injection port formed between the central flame diffuser 3 and the converging section 2 is the first-stage air injection, and the air injected inside the central flame diffuser 3 is the second-stage air injection. This air staged combustion chamber ensures complete combustion, reduces the temperature of the central flame, and decreases nitrogen oxide emissions. At the gas interface section, an outer gas injection chamber is installed and welded to the outer annular injection pipe 6. The central pipe assembly is fixed by a bracket, facilitating disassembly of the central pipe assembly. The air injection between the converging section 2 of the flame diffuser and the central flame diffuser ensures complete combustion of the outer gas.

[0024] In one preferred embodiment, the number of peripheral annular ejector tubes 6 is 4 to 8.

[0025] In one preferred embodiment, the number of peripheral annular injection pipes 7 is 6 to 16.

[0026] In one preferred embodiment, the number of radial injection pipes 8 in the outer annular cavity is 4 to 8.

[0027] In one preferred embodiment, the central flame stabilizer 4 has 6 to 30 air nozzles.

[0028] In summary, due to the combined effects of multiple nitrogen reduction technologies, including fuel staging, air staging, and rich-lean combustion, two types of flames are formed: a central flame and a peripheral diffusion flame. This achieves complete combustion at the optimal excess air coefficient, resulting in very low nitrogen oxide (NOx) formation. Simultaneously, the concave arc surface at the front of the annular chamber can entrain some flue gas, lowering the combustion temperature and further reducing NOx emissions. Through the combined effects of these multiple nitrogen reduction technologies, an ultra-low NOx level is achieved.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in sequences other than those illustrated or described herein.

[0031] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A low-NOx burner with peripheral annular cavity injection and internal flue gas recirculation, characterized in that, include: It includes an annular chamber (1), a flame-gathering shroud retractable section (2), a central flame-gathering shroud (3), a central flame stabilizer (4), a central gas pipe (5), an outer annular ejector pipe (6), an outer annular injection pipe (7), and an outer annular radial injection pipe (8); The front end of the annular chamber (1) is arc-shaped, with several holes on the arc, which are connected to the outer annular ejector pipe (6); the end of the annular chamber (1) is axially provided with several curved outer annular ejector pipes (7), and the end of the annular chamber (1) is radially provided with several outer annular radial ejector pipes (8); the front end of the flame-gathering hood contraction section (2) is provided with an outer annular gas inlet and a central gas inlet, and a gas storage chamber is provided at the outer annular gas inlet, with several holes welded to the outer annular ejector pipe (6); the central The central gas pipe (5) is coaxially arranged in the annular chamber (1) and the flame-gathering shroud contraction section (2); multiple central fuel nozzles are opened at the end of the central gas pipe (5), and a central flame stabilizer (4) is arranged below the nozzles. An air nozzle is arranged on the central flame stabilizer (4); a central flame-gathering shroud (3) is arranged around the central flame stabilizer (4). The central flame-gathering shroud (3) and the flame-gathering shroud contraction section (2) form an air classification. A part of the air is ejected from the outside of the central flame-gathering shroud (3), and another part of the air is ejected from the inside of the central flame-gathering shroud (3).

2. The low-NOx burner with peripheral annular cavity injection and internal flue gas recirculation as described in claim 1, characterized in that, The number of peripheral annular ejector tubes (6) is 4 to 8.

3. The low-NOx burner with peripheral annular cavity injection and internal flue gas recirculation as described in claim 1, characterized in that, The number of peripheral annular cavity injection pipes (7) is 6 to 16.

4. The low-NOx burner with peripheral annular cavity injection and internal flue gas recirculation as described in claim 1, characterized in that, The number of radial injection pipes (8) in the outer annular cavity is 4 to 8.

5. The low-NOx burner with peripheral annular cavity injection and internal flue gas recirculation as described in claim 1, characterized in that, The central flame stabilizer (4) has 6 to 30 air nozzles.

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