gas burner

Abstract

The present invention provides a gas burner, comprising: a combustion-supporting air channel; an air distribution and adjustment device, the second end of which is located in the combustion-supporting air channel, the first end of which extends to the outside of the first end of the combustion-supporting air channel; a central gas gun, one end of which extends from the combustion-supporting air channel through the air distribution and adjustment device and extends to the outside of the first end of the air distribution and adjustment device; a flame stabilizing device, located outside the first end of the air distribution and adjustment device; a plurality of premixed gas gun assemblies, located on the periphery of the flame stabilizing device; one end of the premixed gas gun assembly extends from the combustion-supporting air channel through the air distribution and adjustment device and extends to the outside of the first end of the air distribution and adjustment device; a plurality of outer gas gun assemblies located on the periphery of the air distribution and adjustment device; one end of the outer gas gun assembly extends from the combustion-supporting air channel to the outside of the first end of the combustion-supporting air channel. The gas burner of the present invention can achieve low-nitrogen combustion and greatly reduce NOx emissions.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial gas burners, in particular to a gas burner. Background Art

[0002] Low nitrogen combustion transformation of natural gas, without using flue gas external circulation technology to achieve NOx (nitrogen oxides) < 30mg / Nm 3 (milligrams per standard cubic meter) emissions are the trend of low nitrogen transformation. Although there are burners on the market that do not use flue gas external circulation that can barely achieve 30mg / Nm 3 However, there are problems with the stability and safety of long-term operation, and it is not possible to achieve 30mg / Nm2 within 80%-100% load. 3 Low nitrogen emissions. Summary of the Invention

[0003] To achieve the above-mentioned and other related purposes, the present invention provides a gas burner, comprising:

[0004] a combustion air passage having a first end and a second end opposite to each other;

[0005] an air distribution regulating device having a first end and a second end opposite to each other, the second end of the air distribution regulating device being located in the combustion-supporting air passage, and the first end of the air distribution regulating device extending outside the first end of the combustion-supporting air passage;

[0006] a central gas gun, one end of which passes through the air distribution and adjustment device from the combustion-supporting air channel and extends to the outside of the first end of the air distribution and adjustment device;

[0007] a flame stabilizing device, the flame stabilizing device being located outside the first end of the air distribution and adjustment device and being located outside the central gas gun;

[0008] a plurality of premixed gas gun assemblies, wherein the plurality of premixed gas gun assemblies are located on the periphery of the flame stabilizing device and are arranged at intervals along the circumference of the flame stabilizing device; one end of the premixed gas gun assembly passes through the air distribution and adjustment device from the combustion-supporting air channel and extends to the outside of the first end of the air distribution and adjustment device;

[0009] A plurality of external combustion gas gun assemblies are located on the periphery of the air distribution and regulation device and are arranged at intervals along the circumference of the air distribution and regulation device; one end of the external combustion gas gun assembly extends from the combustion-supporting air channel to the outside of the first end of the combustion-supporting air channel.

[0010] Optionally, the combustion-supporting air channel includes a combustion-supporting air pipe and a combustion-supporting air constriction, one end of the combustion-supporting air constriction is connected to the combustion-supporting air pipe, and the other end extends to the first end of the combustion-supporting air channel.

[0011] Optionally, the flame stabilizing device is disc-shaped; and a straight-line distance from the combustion air constriction away from the end face of the combustion air pipe to the flame stabilizing device is greater than a diameter of the flame stabilizing device.

[0012] Optionally, the air distribution and regulating device includes an inner air pipe and an inner air constriction; the inner air pipe is located in the combustion-supporting air channel, one end of the inner air constriction is connected to the inner air pipe, and the other end extends from the combustion-supporting air channel to the first end of the air distribution and regulating device; the inner air pipe and the inner air constriction together constitute the inner air channel.

[0013] Optionally, the central gas gun includes a central gas gun body and a central gas gun head located at one end of the central gas gun body; the central gas gun body passes through the air distribution adjustment device from the combustion-supporting air channel and extends to the outside of the first end of the air distribution adjustment device; the central gas gun head is located outside the first end of the air distribution adjustment device and is located on the side of the flame stabilizing device away from the air distribution adjustment device, and the side walls of the central gas gun body, the side walls of the central gas gun head, the inclined surface of the central gas gun head and the front end face of the central gas gun head are all provided with gas nozzles.

[0014] Optionally, the flame stabilizing device is provided with a plurality of swirl blades and a plurality of cooling ventilation holes.

[0015] Optionally, the premixed gas gun assembly includes a premixed gas gun and an air-gas premixed gun; the premixed gas gun and the air-gas premixed gun are coaxially arranged, the air-gas premixed gun is located at the periphery of the premixed gas gun, and the premixed gas gun extends into the air-gas premixed gun; one end of the premixed gas gun and the air-gas premixed gun both pass through the air distribution regulating device from the combustion-supporting air channel and extend to the outside of the first end of the air distribution regulating device.

[0016] Optionally, the premixed gas gun includes a premixed gas gun body and a premixed gas gun head, the air-gas premixed gun is arranged on the periphery of the premixed gas gun body, and one end of the air-gas premixed gun extends to a side of the premixed gas gun head away from the combustion-supporting air channel.

[0017] Optionally, the external gas gun assembly includes an external gas gun and a flue gas-air-gas premixing gun; one end of the external gas gun is located in the combustion-supporting air channel, and the other end extends to the outside of the first end of the combustion-supporting air channel; the flue gas-air-gas premixing gun is located outside the first end of the combustion-supporting air channel, one end is placed on the periphery of one end of the external gas gun, and the other end extends to a side of the external gas gun away from the combustion-supporting air channel; a flue gas inlet is formed between the external gas gun and the flue gas-air-gas premixing gun.

[0018] As described above, the gas burner of the present invention has the following beneficial effects: the gas burner of the present invention does not require the central tube provided on conventional burners. By providing a flame stabilizing device and a central gas gun, although there is no central tube at the front end of the flame stabilizing device, the stability of the central flame can still be guaranteed, thereby igniting the peripheral flame and ensuring stable combustion of the entire gas burner; the gas burner of the present invention does not use a central tube, thereby increasing the area of ​​internal circulation of the flue gas, and the flue gas circulated back from the internal circulation can flow back to the central gas gun, so that the flue gas circulated back from the internal circulation and the combustion-supporting air and gas are mixed in a larger area to form a gas-air-flue gas mixture, which comprehensively reduces the oxygen content of fuel combustion, can perform low-nitrogen combustion, and thus greatly reduces NOx emissions, reaching NOx < 30 mg / Nm in the load range of 30%-100%. 3 emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the cross-sectional structure of the gas burner of the present invention.

[0020] Figure 2 For the Figure 1 Schematic diagram of the end face structure in the A direction.

[0021] FIG3( a ) is a schematic cross-sectional view of the central gas gun in the gas burner of the present invention.

[0022] FIG3( b ) is a schematic diagram of the end structure of the central gas gun in the gas burner of the present invention.

[0023] Figure 4 It is a schematic diagram of the working principle of internal circulation and semi-premixing of flue gas during operation of the gas burner of the present invention.

[0024] Description of labels:

[0025] 1. Center gas gun; 11. Side wall of the center gas gun head; 12. Slant of the center gas gun head; 13. Front face of the center gas gun head; 14. Gas nozzle; 2. Premixed gas gun assembly; 21. Premixed gas gun; 211. Premixed gas gun body; 212. Premixed gas gun head; 22. Air-gas premixed gun; 3. External gas gun assembly; 31. External gas gun; 311. External gas gun head; 32. Flue gas-air-gas premixed gun; 33. Flue gas inlet; 4. Flame stabilizing device; 41. Swirl blades; 42. Cooling vents; 5. Combustion-supporting air channel; 51. Combustion-supporting air pipe; 52. Combustion-supporting air constriction; 6. Air distribution and adjustment device; 61. Inner air pipe; 62. Inner air constriction. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] The preferred embodiments described below are for illustrative purposes only, and those skilled in the art may readily conceive of other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0028] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0029] Low nitrogen combustion transformation of natural gas, without using flue gas external circulation technology to achieve NOx < 30mg / Nm 3 The trend of low nitrogen emissions is to transform the fuel into a fuel with low nitrogen content. Although there are burners on the market that do not use flue gas external circulation and can barely reach 30mg / Nm 3 However, there are problems with the stability and safety of long-term operation, and it is not possible to achieve 30mg / Nm2 within 80%-100% load. 3 Low nitrogen emissions.

[0030] Technologies that effectively reduce thermal NOx emissions without external flue gas recirculation include internal flue gas recirculation, semi-premixing, premixing, staged combustion, and rich-lean combustion. Staged combustion and rich-lean combustion are both used in burners, and the ratio of rich-lean combustion to rich-lean combustion is currently well established. Both internal flue gas recirculation and semi-premixing technologies are used by manufacturers, but the amount of high-temperature flue gas recirculated by the burner varies significantly, as does the ratio of semi-premixed gas (i.e., the proportion of premixed gas to the total gas).

[0031] Premixing technology, also known as full premixing, involves mixing all the gas and air in the burner before combustion. Semi-premixing technology involves mixing a portion of the gas and air before combustion, leaving the remaining gas to diffuse with the air while burning. Full premixing poses a significant risk of flashover in large burners. However, a large burner with multiple gas guns, where the amount of gas in each gun is relatively small, can be premixed. Premixing can be performed on demand within a safe range.

[0032] While maintaining safety, generally speaking, the more high-temperature flue gas that is recirculated, the lower the oxygen content in the combustion zone, and the better the nitrogen reduction effect. A higher proportion of semi-premixed gas leads to a lower and more uniform flame temperature after combustion, and the less NOx generated. Currently, in burners on the market, semi-premixed gas is often premixed with a mixture of gas and air, and the recirculated flue gas does not reach the center of the burner. This results in high-temperature, high-oxygen combustion in the center, with less direct premixing of gas with air, and a low proportion of semi-premixed gas in the total gas.

[0033] Example 1

[0034] See also Figure 1 and Figure 2The present invention provides a gas burner, which includes: a combustion-supporting air channel 5, wherein the combustion-supporting air channel 5 has a first end and a second end opposite to each other; an air distribution and adjustment device 6, wherein the air distribution and adjustment device 6 has a first end and a second end opposite to each other, the second end of the air distribution and adjustment device 6 is located in the combustion-supporting air channel 5, and the first end of the air distribution and adjustment device 6 extends to the outside of the first end of the combustion-supporting air channel 5; a central gas gun 1, wherein one end of the central gas gun 1 passes through the air distribution and adjustment device 6 from the combustion-supporting air channel 5 and extends to the outside of the first end of the air distribution and adjustment device 6; a flame stabilizing device 4, wherein the flame stabilizing device 4 is located outside the first end of the air distribution and adjustment device 6 side, and are located on the periphery of the central gas gun 1, and there is no central tube outside the flame stabilizing device 4; a plurality of premixed gas gun assemblies 2, a plurality of said premixed gas gun assemblies 2 are located on the periphery of the flame stabilizing device 4, and are arranged at intervals along the circumference of the flame stabilizing device 4; one end of the premixed gas gun assembly 2 passes through the air distribution and regulation device 6 from the combustion-supporting air channel 5, and extends to the outside of the first end of the air distribution and regulation device 6; a plurality of outer gas gun assemblies 3, a plurality of said outer gas gun assemblies 3 are located on the periphery of the air distribution and regulation device 6, and are arranged at intervals along the circumference of the air distribution and regulation device 6; one end of the outer gas gun assembly 3 extends from the combustion-supporting air channel 5 to the outside of the first end of the combustion-supporting air channel 5.

[0035] Specifically, with the central axis of the gas burner as the center, the central gas gun 1, the flame stabilizing device 4, the premixed gas gun assembly 2 and the outer gas gun assembly 3 are coaxially symmetrically arranged from the inside to the outside; the central axis of the central gas gun 1, the central axis of the flame stabilizing device 4, the central axis of the premixed gas gun assembly 2, the central axis of the outer gas gun assembly 3, the central axis of the air distribution and adjustment device 6 and the central axis of the combustion-supporting air channel 5 all coincide with the central axis of the gas burner.

[0036] More specifically, one end of the premixed gas gun assembly 2 extends from the combustion-supporting air passage 5 through the air distribution and regulation device 6 to the outside of the first end of the air distribution and regulation device 6. A portion of the air enters the air-gas premixing gun 22, where the gas and air are premixed. One end of the external gas gun assembly 3 extends from the combustion-supporting air passage 5 to the outside of the first end of the combustion-supporting air passage 5, drawing high-temperature flue gas and air from the surrounding area into the flue gas-air premixing gun 32, where the gas, flue gas, and air are premixed.

[0037] The gas burner of the present invention does not require the central tube provided on conventional burners. By providing the flame stabilizing device 4 and the central gas gun 1, although there is no central tube at the front end of the flame stabilizing device 4, the stability of the central flame can still be guaranteed, thereby igniting the peripheral flame and ensuring stable combustion of the entire gas burner. Since the gas burner of the present invention does not use the central tube, the area of ​​internal circulation of the flue gas is increased. The flue gas circulated back from the internal circulation can flow back to the central gas gun, so that the flue gas circulated back from the internal circulation and the combustion-supporting air and gas are mixed in a larger area to form a gas-air-flue gas mixture, which comprehensively reduces the oxygen content of the fuel combustion, realizes low-nitrogen combustion, and greatly reduces NOx emissions, reaching NOx < 30mg / Nm in the load range of 30%-100%. 3 emissions.

[0038] Example 2

[0039] Please combine Figure 1 and Figure 2 See Figure 3(a), Figure 3(b) to Figure 4 A gas burner is also provided in this embodiment. The structure of the gas burner in this embodiment is substantially the same as that of the gas burner in the first embodiment. Compared with the first embodiment, the gas burner in this embodiment also includes a more detailed structure as described later in this embodiment.

[0040] As an example, the combustion-supporting air passage 5 may include a combustion-supporting air pipe 51 and a combustion-supporting air constriction 52. One end of the combustion-supporting air constriction 52 is connected to the combustion-supporting air pipe 51, and the other end extends to the first end of the combustion-supporting air passage 5. The combustion-supporting air constriction 52 draws high-temperature flue gas back to the area near the first end surface of the combustion-supporting air constriction 52, forming an internal circulation of the flue gas. No burner throat is provided downstream of the combustion-supporting air passage 5.

[0041] As an example, the shape of the flame stabilizing device 4 can be disc-shaped, and there is no central tube outside the flame stabilizing device 4; the straight-line distance from the combustion air constriction 52 away from the end face of the combustion air pipe 5 to the flame stabilizing device 4 is greater than the diameter of the flame stabilizing device 4.

[0042] Specifically, in this embodiment, the diameter of the flame stabilizing device 4 is recorded as D, and the straight-line distance from the combustion air constriction 52 away from the end surface of the combustion air pipe 5 to the flame stabilizing device 4 is greater than the diameter D of the flame stabilizing device 4 .

[0043] As an example, the air distribution and regulating device 6 includes an inner air pipe 61 and an inner air constriction 62; the inner air pipe 61 is located in the combustion-supporting air channel 5, one end of the inner air constriction 62 is connected to the inner air pipe 61, and the other end extends from the combustion-supporting air channel 5 to the first end of the air distribution and regulating device 6; the inner air pipe 61 and the inner air constriction 62 together constitute an inner air channel (not marked).

[0044] Specifically, the angle of the inner air constriction 62 is consistent with that of the combustion air constriction 52, and the diameter of the inner air tube 61 is smaller than that of the combustion air tube 51. The axial distance from the end face of the combustion air constriction 52 to the flame stabilization device 4 is greater than 2D (D is the diameter of the flame stabilization device 4). The air distribution and adjustment device 6 can be moved back and forth to adjust the distance between the inner air constriction 62 and the combustion air constriction 52, thereby adjusting the ratio of inner and outer air, that is, adjusting the air flow rate. When the inner air constriction 62 and the combustion air constriction 52 are tightly fitted, all combustion air flows out of the inner air channel, achieving the maximum air flow rate and smoke entrainment capability.

[0045] As an example, the center gas gun 1 includes a center gas gun body (not marked) and a center gas gun head (not marked) located at one end of the center gas gun body; the center gas gun body passes through the air distribution and regulation device 6 from the combustion-supporting air channel 5 and extends to the outside of the first end of the air distribution and regulation device 6; the center gas gun head is located outside the first end of the air distribution and regulation device 6, and is located on the side of the flame stabilizing device 4 away from the air distribution and regulation device 6. The side wall of the center gas gun body, the side wall 11 of the center gas gun head, the inclined surface 12 of the center gas gun head and the front end face 13 of the center gas gun head are all provided with the gas nozzle 14. The part of the gas nozzle 14 located on the side wall of the center gas gun body is located upstream of the flame stabilizing device 4 and is a premixed gas nozzle, so that part of the center gas and air are premixed. As shown in Figures 3(a) and 3(b), the central gas gun 1 is placed at the center of the gas burner, and a number of radial gas nozzles 14 are evenly distributed on the side wall 11 of the central gas gun head and the inclined surface 12 of the gas gun head. A number of gas nozzles 14 are arranged on the front end face 13 of the central gas gun head as needed, and the central gas gun 1 is extended out of the flame stabilizing device 4.

[0046] As an example, the flame stabilizing device 4 may be provided with a plurality of swirl blades 41 and a plurality of cooling ventilation holes 42 .

[0047] Specifically, the shape of the swirl blade 41 may be arc-shaped, and in other embodiments may also be other shapes, which can be set according to specific circumstances.

[0048] In this embodiment, the swirl blades 41 are arranged in a circle of equal diameter around the flame stabilizing device 4. Ten swirl blades are arranged as an example, but a plurality of swirl blades can be arranged as needed. A plurality of cooling ventilation holes 42 can be provided as needed, and the setting position can be set according to actual needs.

[0049] Furthermore, by providing the flame stabilizing device 4, the present invention can form a low-speed, low-pressure zone in the downstream area of ​​the flame stabilizing device 4, protecting the central flame from the impact of a large amount of upstream airflow, and allowing the high-temperature flue gas to flow back to the vicinity of the flame stabilizing device 4, providing ignition heat for the central gas and stabilizing the central flame. At the same time, the high-temperature flue gas in the central area diffuses outward, stabilizing the peripheral flame. The gas burner of the present invention does not have a central tube. The flame stabilizing device 4 is customized as described above. The size, blades, etc. of the flame stabilizing device 4 must be suitable for the characteristic that there is no central tube at the front end of the flame stabilizing device 4.

[0050] As an example, the premixed gas gun assembly 2 includes a premixed gas gun 21 and an air-gas premixed gun 22; the premixed gas gun 21 and the air-gas premixed gun 22 are coaxially arranged, and the air-gas premixed gun 22 is located on the periphery of the premixed gas gun 21, and the premixed gas gun 21 extends into the air-gas premixed gun 22, and part of the air enters the air-gas premixed gun 22, and the gas and air are premixed; one end of the premixed gas gun 21 and the air-gas premixed gun 22 both pass through the air distribution regulating device 6 from the combustion-supporting air channel 5 and extend to the outside of the first end of the air distribution regulating device 6.

[0051] As an example, the premixed gas gun 21 includes a premixed gas gun body 211 and a premixed gas gun head 212. The air-gas premixed gas gun 22 is arranged on the periphery of the premixed gas gun body 211, and one end of the air-gas premixed gas gun 22 extends to the side of the premixed gas gun head 212 away from the combustion-supporting air channel 5.

[0052] Specifically, the premixed gas gun assembly 2 consists of a premixed gas gun 21 with a constricted front end and an air-gas premixed gun 22. The air-gas premixed gun 22 is positioned from the premixed gas gun body 211 of the premixed gas gun 21 and extends a certain distance from the premixed gas gun head 212 of the premixed gas gun 21. The premixed gas gun 21 and the air-gas premixed gun 22 are coaxially arranged, with the diameter of the air-gas premixed gun 22 being larger than that of the premixed gas gun 21. The premixed gas gun 21 extends a certain distance into the air-gas premixed gun 22. The premixed gas gun assembly 2 is positioned within the air distribution and regulating device 6, extending from one end thereof. The premixed gas gun assemblies 2 can be arranged in multiple layers as needed, with multiple assemblies per layer. In this embodiment, the premixed gas gun assemblies 2 are arranged in a single layer, with ten assemblies arranged as an example. The air-gas premixed gun 22 serves as the gas / air mixing channel. The combustion-supporting air enters the air-gas premixing gun 22, and the gas ejected from the premixing gas gun 21 enters the air-gas premixing gun 22. The gas and air are mixed in the air-gas premixing gun 22 to form an air-gas premixed gas, which is ejected from the air-gas premixing gun 22 into the furnace.

[0053] As an example, the external gas gun assembly 3 includes an external gas gun 31 and a flue gas-air-gas premixing gun 32; one end of the external gas gun 31 is located in the combustion-supporting air channel 5, and the other end extends to the outside of the first end of the combustion-supporting air channel 5; the flue gas-air-gas premixing gun 32 is located outside the first end of the combustion-supporting air channel 5, one end is placed on the periphery of one end of the external gas gun 31, and the other end extends to the side of the external gas gun 31 away from the combustion-supporting air channel 5; a flue gas inlet is formed between the external gas gun 31 and the flue gas-air-gas premixing gun 32, which draws high-temperature flue gas and air from the periphery into the flue gas-air-gas premixing gun 32, and the gas and flue gas are premixed.

[0054] Specifically, the flue gas, air, and gas premixing gun 32 is positioned adjacent to the external gas gun head 311 and extends a certain distance from the external gas gun head 311. The external gas gun 31 and the flue gas, air, and gas premixing gun 32 are coaxially arranged. The diameter of the flue gas, air, and gas premixing gun 32 is greater than that of the external gas gun 31. An air and flue gas inlet 33 is formed between the flue gas, air, and gas premixing gun 32 and the external gas gun 31. The external gas gun 31 extends a certain distance into the flue gas, air, and gas premixing gun 32. The upstream portion of the external gas gun 31 is positioned within the combustion-supporting air passage 5, and the external gas gun head 311 extends a certain distance from the combustion-supporting air constriction 52.

[0055] In this embodiment, an air-gas premixing gun 22 is provided outside the premixed gas gun body 211. The air-gas premixing gun 22 is a gas / air mixing channel, that is, a gas / air mixing channel is provided outside the premixed gas gun body 211 to increase the ratio of gas-air semi-premixing and reduce NOx emissions; a flue gas-air-gas premixing gun 32 is provided outside the outer gas gun 31. The flue gas-air-gas premixing gun 32 is a gas / air / flue gas mixing channel. By providing the gas / air / flue gas mixing channel outside the outer gas gun 31, a central tube and a burner throat at the front end are not provided. The pressure overcome by the flue gas circulating back in the flue gas is minimized, so that the recycled flue gas can flow back to the central gas gun 1, thereby increasing the area of ​​​​recirculated flue gas reflux, comprehensively reducing the oxygen content of fuel combustion, and thus greatly reducing NOx emissions.

[0056] Specifically, the external combustion gun assemblies 3 are arranged in multiple layers as needed, with multiple assemblies per layer. In this embodiment, the external combustion gun assemblies 3 are arranged in a single layer, with fourteen assemblies arranged as an example. The flue gas / air / flue gas premixing gun 32 serves as a gas / air / flue gas mixing channel. The gas ejected from the external combustion gun 31 enters the flue gas / air / flue gas premixing gun 32, along with a small amount of combustion-supporting air and high-temperature flue gas. After the gas, air, and flue gas form a gas-air-flue gas mixture in the flue gas / air / flue gas premixing gun 32, it is ejected from the flue gas / air / flue gas premixing gun 32 into the furnace.

[0057] In this embodiment, Figure 4 As shown, when the system is in operation, combustion air enters the gas burner from the combustion air pipe 51, and fuel enters the gas burner from the central gas gun 1, the premixed gas gun 21, and the outer gas gun 31. The combustion air enters the combustion air pipe 51 and flows forward. Part of the combustion air enters the air-gas premixed gun 22. Most of the combustion air is greatly accelerated after passing through the combustion air constriction 52 and the inner air constriction 62. The combustion air flows out at a high speed from the inner air constriction 62 and the area between the inner air constriction 62 and the combustion air constriction 52, sucking in high-temperature flue gas from the periphery and flowing back to the combustion air constriction 52 and the central gas gun 1. The high-temperature flue gas and air form a low-oxygen flue-air mixture. The flue-air mixture continues to flow forward. Part of the flue-air mixture passes through the flame stabilizing device 4, and part of the flue-air mixture enters the flue-air-gas premixed gun 32. Most of the flue-air mixture undergoes a combustion reaction after encountering the gas. The flue gas-air mixture flowing out from the swirl blades 41 and the cooling ventilation holes 42 provides combustion-supporting air for the central fuel gas. At the same time, the flame stabilizing device 4 blocks the impact of a large amount of upstream airflow on the central flame, allowing the central area to burn at low oxygen and low temperature, protecting the central flame from stabilization, and giving the burner excellent stable combustion capability.

[0058] Furthermore, the central gas entering the central gas gun 1 is injected into the furnace from different positions, directions, and angles through the gas nozzles 14 on the central gas gun 1. It mixes with the flue gas-air mixture at different positions to form a gas-air mixture. The central gas ejected from the gas nozzles 14 upstream of the flame stabilization device 4 premixes part of the central gas with air to form a gas-air premix. The gas-air mixture and the gas-air premix are ignited by the high-temperature heat source of the ignition gun, resulting in low-NOx combustion and forming a central flame. The inner layer gas entering the premixing gas gun 21 is ejected from the premixing gas gun head 212 and enters the air-gas premixing gun 22, where it mixes with air to form a gas-air mixture. The gas-air mixture is ejected from the air-gas premixing gun 22 into the furnace. Encountering the flue gas-air mixture and the high-temperature flame, it undergoes low-oxygen combustion with a uniform oxygen distribution. This combustion generates essentially no high-temperature zones and very little NOx. The outer layer of fuel gas entering from the outer fuel gas gun 31 is ejected from the outer fuel gas gun head 311 and enters the flue gas-air-gas premixing gun 32 to mix with the flue gas-air mixture to form a flue gas-air-gas mixture. The flue gas-air-gas mixture flows out from the flue gas-air-gas premixing gun 22 and is ignited after encountering the flue gas-air mixture and the high-temperature flame, thereby performing low-oxygen combustion with uniform oxygen distribution. There is basically no high-temperature zone generated during combustion, and very little NOx is generated.

[0059] The gas burner of the present invention is coupled with semi-premixing technology to increase the proportion of semi-premixed gas, that is, to increase the proportion of gas premixed with air before combustion. The premixed gas gun assembly 2 is arranged outside the central gas gun 1, and a combustion-supporting air constriction 52 is arranged in the combustion-supporting air channel 5, and an inner layer air constriction 62 is arranged in the air distribution regulating device 6. This can increase the negative pressure capacity of the fuel burner, and there is no need to set a central tube and a burner throat at the front end, so that the recycled flue gas can flow back to the central gas gun 1, thereby increasing the area of ​​recycled flue gas reflow, reducing the need for high-temperature flue gas to overcome resistance when returning, and allowing more flue gas to flow back to the center of the gas burner. The gas burner does not use external flue gas circulation, and can be stable at NOx < 30mg / Nm within 30%-100% load. 3 emissions.

[0060] In summary, the gas burner of the present application has the following beneficial effects:

[0061] 1. This gas burner does not have a central tube, as is common with conventional burners. This eliminates the central tube and customizes the flame stabilization device 4 and the central gas gun 1. This ensures that, despite the lack of a central tube at the front end of the flame stabilization device 4, the central flame can still be stabilized, thereby igniting the peripheral flames and ensuring stable combustion throughout the gas burner. The elimination of the central tube increases the area for internal flue gas recirculation, allowing the recirculated flue gas to flow back to the central gas gun 1, allowing it to mix with the combustion air and gas over a larger area, forming a gas-air-flue gas mixture for low-nitrogen combustion.

[0062] 2. The combustion air constriction 52 is configured so that both combustion air and gas are ejected from downstream of the combustion air constriction 52, and no burner throat is provided downstream of the combustion air constriction 52. The combustion air constriction 52 is designed to greatly increase the velocity of combustion air flowing out of the combustion air constriction 52, utilizing the high-speed ejected air to draw high-temperature flue gas back to the area outside the combustion air constriction 52. Furthermore, gas is ejected from downstream of the combustion air constriction 52, increasing the negative pressure at the combustion air constriction 52 and improving the gas burner's ability to draw in high-temperature flue gas. No burner throat is provided downstream of the combustion air constriction 52, and no center tube is provided. This minimizes the resistance of the internally circulating flue gas, allowing more flue gas to flow back to the burner area.

[0063] 3. The premixing ratio of gas and air is significantly increased. The gas nozzle on the center lance, located upstream of the flame stabilization device, premixes a portion of the central gas with air. The inner layer of gas is premixed with air directly at the front end, while the outer layer of gas is premixed with the flue gas-air mixture. This premixing prior to combustion results in a more uniform flame, eliminating hot spots and reducing thermal NOx generation.

[0064] The present invention has an innovative structural design of the burner body, without a central tube, which increases the ratio of gas and air premixing. These measures greatly enhance the ability of the gas burner to absorb high-temperature flue gas and enhance the effect of gas and air semi-premixing. Through the internal circulation and premixing of flue gas, it is achieved that NOx < 30mg / Nm in the load range of 30%-100% is achieved only through the gas burner without using flue gas external circulation technology. 3 The customized design of the central gas gun 1 and the flame stabilization device 4 gives the gas burner excellent combustion stability. This gas burner eliminates the central tube, increasing the ratio of direct mixing of gas and air, achieving a major structural breakthrough and promising broad market prospects.

[0065] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0066] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A gas burner, characterized in that: include: a combustion air passage having a first end and a second end opposite to each other; an air distribution regulating device having a first end and a second end opposite to each other, the second end of the air distribution regulating device being located in the combustion-supporting air passage, and the first end of the air distribution regulating device extending outside the first end of the combustion-supporting air passage; a central gas gun, one end of which passes through the air distribution and adjustment device from the combustion-supporting air channel and extends to the outside of the first end of the air distribution and adjustment device; a flame stabilizing device, the flame stabilizing device being located outside the first end of the air distribution and adjustment device and being located outside the central gas gun; a plurality of premixed gas gun assemblies, wherein the plurality of premixed gas gun assemblies are located on the periphery of the flame stabilizing device and are arranged at intervals along the circumference of the flame stabilizing device; one end of the premixed gas gun assembly passes through the air distribution and adjustment device from the combustion-supporting air channel and extends to the outside of the first end of the air distribution and adjustment device; a plurality of external gas gun assemblies, the plurality of external gas gun assemblies being located on the periphery of the air distribution and regulation device and spaced apart along the circumference of the air distribution and regulation device; one end of the external gas gun assembly extending from the combustion-supporting air passage to the outside of the first end of the combustion-supporting air passage; the combustion-supporting air passage comprising a combustion-supporting air pipe and a combustion-supporting air constriction, one end of the combustion-supporting air constriction being connected to the combustion-supporting air pipe and the other end extending to the first end of the combustion-supporting air passage; The flame stabilizing device is in the shape of a disc; The straight-line distance between the combustion air constriction and the end surface of the combustion air pipe is greater than the diameter of the flame stabilizing device; There is no central tube at the front end of the flame stabilizing device; the smoke circulated back from the inner part can flow back to the central gas gun.

2. The gas burner according to claim 1, characterized in that: The air distribution and regulating device includes an inner air pipe and an inner air constriction; the inner air pipe is located in the combustion-supporting air channel, one end of the inner air constriction is connected to the inner air pipe, and the other end extends from the combustion-supporting air channel to the first end of the air distribution and regulating device; the inner air pipe and the inner air constriction together constitute the inner air channel.

3. The gas burner according to claim 1, characterized in that: The central gas gun includes a central gas gun body and a central gas gun head located at one end of the central gas gun body; the central gas gun body passes through the air distribution and adjustment device from the combustion-supporting air channel and extends to the outside of the first end of the air distribution and adjustment device; the central gas gun head is located outside the first end of the air distribution and adjustment device, and is located on the side of the flame stabilizing device away from the air distribution and adjustment device. The side wall of the central gas gun body, the side wall of the central gas gun head, the inclined surface of the central gas gun head and the front end face of the central gas gun head are all provided with gas nozzles.

4. The gas burner according to claim 1, characterized in that: The flame stabilizing device is provided with a plurality of swirl blades and a plurality of cooling ventilation holes.

5. The gas burner according to claim 1, characterized in that: The premixed gas gun assembly includes a premixed gas gun and an air-gas premixed gun; the premixed gas gun and the air-gas premixed gun are coaxially arranged, the air-gas premixed gun is located at the periphery of the premixed gas gun, and the premixed gas gun extends into the air-gas premixed gun; one end of each of the premixed gas gun and the air-gas premixed gun passes through the air distribution regulating device from the combustion-supporting air channel and extends to the outside of the first end of the air distribution regulating device.

6. The gas burner according to claim 5, characterized in that: The premixed gas gun includes a premixed gas gun body and a premixed gas gun head. The air-gas premixed gun is arranged on the periphery of the premixed gas gun body. One end of the air-gas premixed gun extends to a side of the premixed gas gun head away from the combustion-supporting air channel.

7. The gas burner according to claim 1, characterized in that: The external gas gun assembly includes an external gas gun and a flue gas, air and gas premixing gun; one end of the external gas gun is located in the combustion-supporting air channel, and the other end extends to the outside of the first end of the combustion-supporting air channel; the flue gas, air and gas premixing gun is located outside the first end of the combustion-supporting air channel, one end is sleeved on the periphery of one end of the external gas gun, and the other end extends to a side of the external gas gun away from the combustion-supporting air channel; a flue gas inlet is formed between the external gas gun and the flue gas, air and gas premixing gun.

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