Delay mixing low-NOx burner applicable to multiple fuels

Abstract

The utility model relates to the field of burners, in particular to a delay mixing low-NOx burner suitable for multiple fuels, which comprises a main gas inlet pipe, a main burner core, an auxiliary gas inlet pipe and an auxiliary gas system, the main burner core comprises a main gas pipe, a primary mixing cavity, a mixing disc and a delay wall surface, the primary mixing cavity is provided with a primary air hole, and the auxiliary gas inlet pipe is provided with a secondary air hole. The burner is provided with a main burning system and an auxiliary burning system, two different kinds of gas can be used at the same time, so that burning states of different furnace temperatures are achieved, meanwhile, the main burner core is provided with a plurality of air holes at different positions, and therefore the burning efficiency is improved, and the burning efficiency is improved. The gas and the air are distributed in a multi-stage mode, so that the gas and the air are mixed in a delayed mode, high-temperature areas are reduced to a large extent, the combustion temperature is lowered, and generation of NOx is restrained. The multi-fuel energy-saving device can be applied to various fuels, including clean fuels with higher requirements on stability, controllability and safety.

Description

Technical Field

[0001] The utility model relates to the field of burners, in particular to a multi-fuel delayed mixing low NOx burner. Background Art

[0002] Industrial production is an important part of economic development, but at the same time, industrial production activities are also the largest energy-consuming sector in human activities. In today's increasingly severe global energy crisis and greenhouse effect, we need to move towards reducing NOx emissions and using clean energy.

[0003] For example, a gas-staged low-NOx high-speed burner (publication number: CN220624038U, publication date: 2024-03-19) includes a main gas pipe, an air shell, a mixing cup, a combustion chamber, an auxiliary gas duct, etc. When the gas and the combustion-supporting air are mixed and burned, the combustion-supporting air in the air shell is mixed with the gas in a staged manner through the air staged port on the mixing cup and the gap between the mixing cup and the combustion chamber, thereby realizing staged combustion. The amount of thermal NOx generated is reduced by lowering the temperature of the flame during combustion, and the gas transported by the main gas pipe can be optionally reduced while the gas is transported through several auxiliary gas ducts, thereby expanding the combustion reaction zone, which can further reduce the temperature of the flame during combustion, thereby better reducing the amount of thermal NOx generated.

[0004] However, the burner mixes the fuel gas in stages through the air staging ports on the mixing cup and the gap between the mixing cup and the combustion chamber, and reduces the amount of thermal NOx produced by lowering the temperature of the flame during combustion. This method has a small number of staging times and is not strong enough to suppress the generation of NOx, and it is impossible to significantly reduce the amount of NOx produced while using clean energy. Utility Model Content

[0005] In view of the technical defects existing in the background technology, the utility model proposes a multi-fuel delayed mixing low NOx burner, which solves the above technical problems and meets the actual needs. The specific technical solution is as follows:

[0006] A multi-fuel delayed mixing low NOx burner, comprising a main gas inlet pipe, a main burner core connected to the main gas inlet pipe, an auxiliary gas inlet pipe and an auxiliary gas system connected to the auxiliary gas inlet pipe, an air shell and an air inlet pipe communicating with the inside of the air shell are arranged on the side of the main gas inlet pipe away from the auxiliary gas inlet pipe, and a combustion chamber is arranged on the side of the air shell away from the main gas inlet pipe;

[0007] The main burner core includes a main gas pipe, a primary mixing chamber, a mixing disk and a delay wall which are sequentially connected along the flow direction of the main gas. A main gas nozzle is arranged between the main gas pipe and the primary mixing chamber. A primary air hole is arranged on the cavity wall of the primary mixing chamber. The mixing disk is sequentially provided with secondary air holes, tertiary air holes and quaternary air slots from the center to the edge. The delay wall is provided with five secondary air holes. The main gas pipe and the primary mixing chamber are respectively arranged in the air shell. The mixing disk and the delay wall are respectively arranged in the combustion chamber. An ignition column and an ignition electrode are arranged on the mixing disk.

[0008] As a further technical solution of the utility model, one end of the main gas inlet pipe is connected to the auxiliary gas inlet pipe, and the other end is connected to the main gas pipe. One end of the auxiliary gas system passes through the main gas inlet pipe and is connected to the auxiliary gas inlet pipe, and the other end is arranged in the main burner core and connected to the auxiliary gas nozzle. The auxiliary gas nozzle extends out of the main burner core at one end away from the auxiliary gas system and is arranged in the combustion chamber.

[0009] As a further technical solution of the utility model, the main burner core also includes a spoiler disk, which is arranged on the side of the delay wall away from the mixing disk and is arranged in the combustion chamber. A plurality of pressure equalizing holes are distributed on the spoiler disk. The spoiler disk is arranged in a circular ring shape and is provided with an electrode position.

[0010] As a further technical solution of the utility model, the primary air holes are symmetrically distributed along the central axis of the primary mixing chamber, and the main gas pipe, the primary mixing chamber, the mixing disk, the delay wall and the spoiler are arranged along the same central axis.

[0011] As a further technical solution of the utility model, the mixing disk is provided with an ignition flame detection hole, an ignition electrode hole and an ignition column hole. The ignition column is arranged in the ignition column hole. One end of the ignition electrode is arranged in the ignition electrode hole, and the other end passes through the air shell and extends outward.

[0012] As a further technical solution of the utility model, a flame detection device is provided at one end of the air housing close to the main gas inlet pipe.

[0013] As a further technical solution of the utility model, a mounting flange is provided between the combustion chamber and the air shell, a burner brick is provided outside the combustion chamber, the burner brick is arranged on the side of the mounting flange away from the air shell, and the combustion chamber is arranged inside the burner brick.

[0014] As a further technical solution of the utility model, the mixing disk is arranged in a circular ring shape, and the secondary air holes, tertiary air holes and quaternary air grooves respectively pass through the two ends of the mixing disk in the thickness direction, and the secondary air holes, tertiary air holes and quaternary air grooves are evenly distributed along the central axis of the mixing disk, and the secondary air holes and tertiary air holes are swirl holes or straight holes, respectively, and the quaternary air grooves are arranged at the outer edge of the mixing disk, and the quaternary air grooves are straight grooves or swirl grooves.

[0015] The beneficial effects of the utility model are:

[0016] The utility model is provided with two combustion systems of main combustion and auxiliary combustion, which can use two different types of gas at the same time, so as to realize combustion states of different furnace temperatures, and has high flexibility and adaptability. At the same time, the main burner core is designed with multiple air holes at different positions to distribute the gas and air in multiple stages, so as to delay the mixing of the gas and air, minimize the high temperature zone, reduce the combustion temperature, and thus inhibit the generation of NOx.

[0017] The utility model adopts different furnace temperatures, different air holes, and different fuel flame detection methods for different gases with different calorific values ​​or different combustion speeds, and selects the delayed weak mixing or enhanced mixing method by selecting the shape of the air holes according to the situation, so that the utility model can be applied to a variety of fuels, including clean fuels with higher requirements on stability, controllability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a multi-fuel delayed mixing low NOx burner.

[0019] Figure 2 The burner core structure diagram is suitable for a multi-fuel delayed mixing low NOx burner.

[0020] Figure 3 The internal structure diagram of a multi-fuel delayed mixing low NOx burner is shown.

[0021] Figure 4 Schematic diagram of the main burner core structure suitable for a multi-fuel delayed mixing low NOx burner Figure 1 .

[0022] Figure 5 Schematic diagram of the main burner core structure suitable for a multi-fuel delayed mixing low NOx burner Figure 2 .

[0023] Figure 6 This is an exploded diagram of the main burner core structure suitable for a multi-fuel delayed mixing low NOx burner.

[0024] Figure 7 Schematic diagram of a primary mixing chamber suitable for a multi-fuel delayed mixing low NOx burner.

[0025] Figure 8 Schematic diagram of a mixing disk suitable for a multi-fuel delayed mixing low NOx burner.

[0026] Fig. 9 A schematic diagram of a delayed wall suitable for a multi-fuel delayed mixing low NOx burner.

[0027] Fig.10 Schematic diagram of a spoiler disk suitable for a multi-fuel delayed mixing low NOx burner.

[0028] Wherein: main gas inlet pipe 1, auxiliary gas inlet pipe 2, air inlet pipe 3, air shell 4, mounting flange 5, burner brick 6, combustion chamber 7, flame detection 8, connecting pipe 9, ignition electrode 10, auxiliary gas system 11, main gas pipe 12, primary mixing chamber 13, primary air hole 131, mixing disk 14, secondary air hole 141, flame detection hole 142, fourth air slot 143, ignition electrode hole 144, tertiary air hole 145, delay wall 15, fifth air hole 151, spoiler 16, equalizing hole 161, electrode position 162, auxiliary gas nozzle 17, main gas nozzle 18, ignition column 19, ignition column hole 191, main burner core 20. DETAILED DESCRIPTION

[0029] The following is combined with Figures 1 to 10 The implementation methods of the present invention are described with relevant embodiments, but the implementation methods of the present invention are not limited to the following embodiments, and the present invention involves relevant necessary components in this technical field, which should be regarded as the known technology in this technical field and can be known and mastered by the technicians in this technical field.

[0030] The utility model provides a multi-fuel delayed mixing low NOx burner, such as Figure 1 As shown, it includes a main gas inlet pipe 1, a main burner core 20 connected to the main gas inlet pipe 1, an auxiliary gas inlet pipe 2 and an auxiliary gas system 11 connected to the auxiliary gas inlet pipe 2. An air shell 4 and an air inlet pipe 3 that penetrates the inside of the air shell 4 are provided on the side of the main gas inlet pipe 1 away from the auxiliary gas inlet pipe 2. A combustion chamber 7 is provided on the side of the air shell 4 away from the main gas inlet pipe 1. The utility model is provided with two sets of combustion systems for main combustion and auxiliary combustion, and two different types of gas can be used at the same time, thereby realizing combustion states of different furnace temperatures, and has high flexibility and adaptability.

[0031] More specifically, the main gas enters the burner through the main gas inlet pipe 1, and the auxiliary gas enters the burner through the auxiliary gas inlet pipe 2. At the same time, the total chemical thermal power of the main gas + auxiliary gas and the total combustion-supporting air volume (the combustion-supporting air enters the burner from the air inlet pipe 3) must meet the chemical combustion equivalence ratio. By adjusting the ratio of the main gas to the auxiliary gas, three different combustion states can be achieved:

[0032] 1) When the main gas supply is 100% and the auxiliary gas is turned off, it is a high-temperature flame and the carbon monoxide content in the flue gas is low, which can be used in low furnace temperature scenarios;

[0033] 2) When the main gas supply is 10%~90% and the rest is auxiliary gas, it meets the medium and high furnace temperature requirements and can take into account the low carbon monoxide content in the flue gas and low NOx emissions;

[0034] 3) When higher furnace temperature and lower NOx requirements are required, the main gas is turned off and the auxiliary gas supply is 100%. At this time, the flameless combustion mode can be entered. The minimum furnace temperature requirement must be higher than the auto-ignition temperature of the gas used for the auxiliary gas.

[0035] like Figure 4 and Fig.10 As shown, the main burner core 20 includes a main gas pipe 12, a primary mixing chamber 13, a mixing disk 14 and a delay wall 15 which are sequentially connected along the flow direction of the main gas. A main gas nozzle 18 is provided between the main gas pipe 12 and the primary mixing chamber 13. A primary air hole 131 is provided on the cavity wall of the primary mixing chamber 13. The mixing disk 14 is sequentially provided with secondary air holes 141, tertiary air holes 145 and quaternary air slots 143 along the center to the edge, and the delay wall 15 is provided with quintuple air holes 151.

[0036] like Figure 2 As shown, the main gas pipe 12 and the primary mixing chamber 13 are respectively arranged in the air housing 4, the mixing disc 14 and the delay wall 15 are respectively arranged in the combustion chamber 7, and the main burner core 20 can work independently without the entire auxiliary gas system, and still belongs to the delayed mixing low NOx burner. The mixing disc 14 is provided with an ignition column 19 and an ignition electrode 10.

[0037] Working principle of main burner core 20:

[0038] After the main gas enters the main burner core 20 through the main gas inlet pipe 1, it is ejected through the main gas nozzle 18 connected to the main gas pipe 12, forming a negative pressure to draw the primary air into the primary mixing chamber 13 from the primary air hole 131. The air-fuel mixture after the primary mixing is ignited at the mixing disk 14 by the spark formed between the ignition electrode 10 and the ignition column 19, and at this time, the second air mixing is carried out through the secondary air hole 141. The ignited two mixed combustion products continue to mix with the air of the tertiary air hole 145 and mix with the air of the fifth air hole 151 again along the flow direction, and finally enter the combustion chamber 7.

[0039] After the air (combustion-supporting air) is diverted from the quaternary air slot 143 on the outside of the mixing disk 14, a portion of it enters the inside of the delay wall 15 through the quintuple air hole 151 on the delay wall 15 for mixed combustion, and the other portion continues to move forward into the combustion chamber 7 and is finally mixed with the combustion products coming out of the center for combustion.

[0040] The utility model designs multiple air holes at different positions on the main burner core 20, and distributes the gas and air in multiple stages, so that the gas and air are mixed with delay, and the main gas is divided through the air holes for multiple times to mix with the air, which greatly reduces the high temperature area, reduces the combustion temperature, and thus inhibits the generation of NOx. The utility model adopts different furnace temperatures, different air holes, and different fuel flame detection methods for different gases with different calorific values ​​or different combustion speeds, and selects the delayed weak mixing or enhanced mixing method according to the situation, so that the utility model can adapt to a variety of fuels, including clean fuels with high requirements for stability, controllability and safety.

[0041] The following are embodiments of the present invention.

[0042] Example 1

[0043] The utility model provides a multi-fuel delayed mixing low NOx burner, such as Figure 1 As shown, it includes a main gas inlet pipe 1, a main burner core 20 connected to the main gas inlet pipe 1, an auxiliary gas inlet pipe 2 and an auxiliary gas system 11 connected to the auxiliary gas inlet pipe 2. An air shell 4 and an air inlet pipe 3 that penetrates the inside of the air shell 4 are provided on the side of the main gas inlet pipe 1 away from the auxiliary gas inlet pipe 2. A combustion chamber 7 is provided on the side of the air shell 4 away from the main gas inlet pipe 1.

[0044] A mounting flange 5 is provided between the combustion chamber 7 and the air housing 4, and the mounting flange 5 is installed at the required furnace installation position. A burner brick 6 is provided outside the combustion chamber 7, and the burner brick 6 is provided on the side of the mounting flange 5 away from the air housing 4, and the combustion chamber 7 is provided inside the burner brick 6. The combustion chamber 7 can be formed by the inner contour of the burner brick 6, or an independent combustion chamber 7 can be installed inside the burner brick 6.

[0045] like Figure 2 As shown, one end of the main gas inlet pipe 1 is connected to the auxiliary gas inlet pipe 2, and the other end is connected to the main gas pipe 12. One end of the auxiliary gas system 11 passes through the main gas inlet pipe 1 and is connected to the auxiliary gas inlet pipe 2, and the other end is arranged in the main burner core 20 and connected to the auxiliary gas nozzle 17. The auxiliary gas nozzle 17 extends out of the main burner core 20 at one end away from the auxiliary gas system 11 and is arranged in the combustion chamber 7. The auxiliary gas inlet pipe 2 and the auxiliary gas nozzle 17 can be made into a segmented type and connected. When a higher temperature is required, the auxiliary gas nozzle 17 can be made of high temperature resistant materials, such as ceramics.

[0046] The main gas enters the burner through the main gas inlet pipe 1, and the auxiliary gas enters the burner through the auxiliary gas inlet pipe 2. The ratio of the main gas to the auxiliary gas can be adjusted to achieve three different combustion states: 1) When the main gas supply is 100% and the auxiliary gas is turned off, it is a high-temperature flame, and the carbon monoxide content in the flue gas is low, which can be used in low furnace temperature scenarios; 2) When the main gas supply is 10%~90% and the rest is auxiliary gas, it is a medium-to-high furnace temperature requirement, which can take into account the low carbon monoxide content in the flue gas and low NOx emissions; 3) When higher furnace temperature and lower NOx requirements are required, the main gas is turned off and the auxiliary gas supply is 100%. At this time, the flameless combustion mode can be entered, and the minimum furnace temperature requirement must be higher than the auto-ignition temperature of the gas used for the auxiliary gas.

[0047] In the flame mode, when the gas is graded (main gas + auxiliary gas = 100%, and main gas ≠ 0%), it is the combustion state of 1) and 2) above. The auxiliary gas through the auxiliary gas inlet pipe 2 starts to mix and burn with the high-temperature combustion products ejected from the combustion chamber 7 at the auxiliary gas nozzle; in the flameless mode (main gas 0%, auxiliary gas 100%), it is the combustion state of 3) above. The auxiliary gas through the auxiliary gas inlet pipe 2 starts to mix with the air ejected from the combustion chamber 7 at the auxiliary gas nozzle and enters the furnace for diffuse combustion, which can greatly reduce the NOx generation.

[0048] like Figure 4 and Figure 5 As shown, the main burner core 20 includes a main gas pipe 12, a primary mixing chamber 13, a mixing disc 14 and a delay wall 15 connected in sequence along the flow direction of the main gas, and a main gas nozzle 18 is provided between the main gas pipe 12 and the primary mixing chamber 13. Figure 7 As shown, the cavity wall of the primary mixing cavity 13 is provided with primary air holes 131, and the primary air holes 131 are symmetrically distributed along the central axis of the primary mixing cavity 13. The primary air holes 131 can be selected as swirl type tangential mixing to improve ignition performance and low-fire stability.

[0049] like Figure 8 As shown, the mixing disk 14 is provided with secondary air holes 141, tertiary air holes 145 and quaternary air slots 143 in sequence from the center to the edge. The mixing disk 14 is arranged in an annular shape, and the secondary air holes 141, tertiary air holes 145 and quaternary air slots 143 respectively penetrate the two ends of the mixing disk 14 in the thickness direction, and the secondary air holes 141, tertiary air holes 145 and quaternary air slots 143 are evenly distributed along the central axis of the mixing disk 14. The secondary air holes 141 and tertiary air holes 145 can be selected as swirl holes or straight holes, respectively, and the gas flow direction can be selected to be convergent, diffused and parallel to the axial direction of the main burner core 20, depending on the type of gas and the required combustion temperature.

[0050] The quaternary air slot 143 is disposed at the outer edge of the mixing disk 14, and the quaternary air slot 143 is a straight slot or a swirl slot. When the primary air hole 131, the secondary air hole 141, and one of the tertiary air holes 145, and the quaternary air slot 143 are all swirl holes or swirl slots, the same rotation and the reverse rotation can be selected according to the required combustion characteristics. Fig. 9 As shown, the delay wall 15 is provided with a fifth air hole 151. Air from the fourth air slot 143 is distributed on the delay wall 15, and a part of the air passes through the fifth air hole 151 and is mixed with the combustion product again for combustion.

[0051] The mixing disk 14 is provided with an ignition column 19 and an ignition electrode 10. The mixing disk 14 is provided with a flame detection hole 142, an ignition electrode hole 144 and an ignition column hole 191, the ignition column 19 is arranged in the ignition column hole 191, one end of the ignition electrode 10 is arranged in the ignition electrode hole 144, and the other end penetrates the air shell 4 and extends outward.

[0052] In this embodiment, if Fig.10 As shown, the main burner core 20 also includes a spoiler 16, which is arranged on the side of the delay wall 15 away from the mixing disk 14 and in the combustion chamber 7, and has a plurality of pressure equalizing holes 161 distributed on the spoiler 16. The spoiler 16 is arranged in a circular ring shape, and an electrode position 162 is arranged on the inner ring wall of the spoiler 16, and the annular gap between the spoiler 16 and the combustion chamber 7 is added with the outer ring part of the electrode position 162. The electrode position 162 is reserved for the spoiler 16 for use in the electrode detection mode.

[0053] The pressure equalizing holes 161 equalize the pressure of another part of the air from the quaternary air slots 143 and then enter the combustion chamber 7 for final mixed combustion. The inner circle channel of the spoiler 16 plus the inner circle equalizing holes 161 strengthen the flow and equalize the pressure of the combustion products from the cup-shaped combustion space formed by the mixing disc 14 and the delay wall 15, and then enter the combustion chamber 7 for final mixed combustion. (When there are other flame temperature, furnace temperature and NOx requirements, the pressure equalizing holes 161 on the spoiler can be cancelled, and even, in special cases, the spoiler can be removed as a whole.)

[0054] like Figure 3 As shown, the main gas pipe 12 and the primary mixing chamber 13 are respectively arranged in the air shell 4, the mixing disk 14, the delay wall 15 and the spoiler 16 are respectively arranged in the combustion chamber 7, and the main gas pipe 12, the primary mixing chamber 13, the mixing disk 14, the delay wall 15 and the spoiler 16 are arranged along the same central axis to facilitate the installation of the main burner core 20.

[0055] The main burner core 20 can work independently without the need for the entire auxiliary gas system and still belongs to a delayed mixing low NOx burner. Figure 2 and Figure 4 As shown, Figure 2 The auxiliary gas system 11 is arranged inside the main burner core 20, and Figure 4 The main burner core 20 does not have auxiliary gas, and the entire system can be connected with a reduced diameter.

[0056] The utility model is provided with two combustion systems of main combustion and auxiliary combustion, which can use two different types of fuel gas at the same time, so as to realize combustion states of different furnace temperatures, and has high flexibility and adaptability. At the same time, the main burner core 20 is designed with multiple air holes at different positions to distribute the fuel gas and air in multiple stages, so as to delay the mixing of the fuel gas and air, minimize the high temperature zone, reduce the combustion temperature, and thus inhibit the generation of NOx.

[0057] like Figure 3 As shown, a flame detection 8 is provided at one end of the air housing 4 close to the main gas inlet pipe 1, and the flame detection 8 is an electrode flame detection or a UV flame detection. When the main and auxiliary gases used are carbon-free gases (such as hydrogen, ammonia, etc.), a connecting pipe 9 is required to connect the UV flame detection. If the main and auxiliary gases are carbon-containing gases, the flame detection 8 can use both electrode flame detection and UV flame detection. It is worth noting that the type of flame detection 8 is not limited to the type of auxiliary gas.

[0058] The working process of this embodiment:

[0059] 1) The main gas enters the main burner core 20 of the burner from the main gas inlet pipe 1; the auxiliary gas enters the auxiliary gas system 11 from the auxiliary gas inlet pipe 2 and finally enters the furnace from the auxiliary gas nozzle; the air enters the air shell 4 from the air inlet pipe 3 and then starts to be distributed in multiple stages from the mixing disk 14.

[0060] 2) After the main gas enters the main burner core 20, it is ejected through the main gas nozzle 18 connected to the main gas pipe 12, forming a negative pressure to draw air into the primary mixing chamber 13 from the primary air hole 131. The air-fuel mixture after the primary mixing is ignited at the mixing disk 14 by the spark formed between the ignition electrode 10 and the ignition column 19, and at this time, the second air mixing is carried out through the secondary air hole 141. The ignited two mixed combustion products continue to mix with the tertiary air hole 145, and are mixed with the air of the fifth air hole 151 again along the flow direction, and finally enter the combustion chamber 7 through the spoiler disk 16.

[0061] 3) After the air is diverted from the quaternary air slots 143 on the outside of the mixing disk 14, a portion of the air enters the inside of the delay wall 15 through the quintuple air holes 151 on the delay wall 15 for mixed combustion, and the other portion continues forward through the pressure equalizing holes 161 of the spoiler 16 for pressure equalization and enters the combustion chamber 7 for mixed combustion with the combustion products coming out of the center.

[0062] 4) If the main gas in the main burner core 20 from the main gas inlet pipe 1 is carbon-containing gas, the electrode ignition electrode 10 detection mode can be adopted. If it is carbon-free gas (clean fuel), such as hydrogen or ammonia gas, the electrode ignition UV detection mode is adopted.

[0063] 5) The auxiliary gas gas, in the flame mode gas staging (main gas + auxiliary gas = 100%, and main gas ≠ 0%), starts to mix and burn with the high-temperature combustion products ejected from the combustion chamber 7 at the auxiliary gas nozzle; in the flameless mode (main gas 0% auxiliary gas 100%), starts to mix with the combustion-supporting air ejected from the combustion chamber 7 at the auxiliary gas nozzle and enters the furnace for diffuse combustion, which can greatly reduce the NOx generation.

[0064] Furthermore, clean fuels have high requirements for stability, controllability and safety. For example, hydrogen burns very fast, while ammonia burns very slowly. In view of the different combustion speeds and calorific values ​​of the gases, the utility model adopts different furnace temperatures, different air holes, and the corresponding flame propagation ejection speed design for different gases, different fuel flame detection methods, and selects delayed weak mixing or enhanced mixing methods according to the situation, so that the utility model can be applied to a variety of fuels.

[0065] For example, when the furnace temperature is high, in order to meet environmental protection requirements and produce low NOx flue gas, it is necessary to reduce the flame temperature and use delayed slow mixing. The three groups of air ducts can be straight, and when designed to rotate, they rotate in the same direction. The remaining group of air ducts in the secondary air holes 141 and the tertiary air holes 145 is parallel to the gas flow direction or diverges away. The gas types that use delayed slow mixing are characterized by high calorific value (coke oven gas, natural gas, liquefied gas, etc.) or extremely fast combustion speed (hydrogen, etc.).

[0066] For example, when the furnace temperature is low, the gas burns out to meet the safety requirement. There must be no combustibles in the flue gas. The flame temperature needs to be increased and enhanced mixing is adopted to meet the normal ratio of small fire, which is more stable. The high air-fuel ratio combustion conditions of large air and small gas are also stable. At this time, the primary air hole 131, the secondary air hole 141 and one of the tertiary air holes 145, and the fourth air slot 143, these three groups of air ducts are designed to rotate in the opposite direction. The remaining group of air ducts in the secondary air hole 141 and the tertiary air hole 145 is parallel to the gas flow direction or close to convergence. The gas types that use enhanced mixing are characterized by low calorific value (mixed coal gas, blast furnace gas, converter gas and generator gas, etc.) or extremely slow combustion speed (ammonia, etc.).

[0067] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A multi-fuel delayed mixing low NOx burner, comprising a main gas inlet pipe (1), a main burner core (20) connected to the main gas inlet pipe (1), an auxiliary gas inlet pipe (2), and an auxiliary gas system (11) connected to the auxiliary gas inlet pipe (2), It is characterized in that An air casing (4) and an air inlet pipe (3) communicating with the interior of the air casing (4) are provided on a side of the main gas inlet pipe (1) away from the auxiliary gas inlet pipe (2); a combustion chamber (7) is provided on a side of the air casing (4) away from the main gas inlet pipe (1); The main burner core (20) comprises a main gas pipe (12), a primary mixing chamber (13), a mixing disc (14) and a delay wall (15) which are connected in sequence along the flow direction of the main gas. A main gas nozzle (18) is provided between the main gas pipe (12) and the primary mixing chamber (13). A primary air hole (131) is provided on the cavity wall of the primary mixing chamber (13). The mixing disc (14) is provided with secondary air holes (141), tertiary air holes (145) and quaternary air slots (143) in sequence from the center to the edge. The delay wall (15) is provided with quintuple air holes (151). The main gas pipe (12) and the primary mixing chamber (13) are respectively arranged in an air shell (4). The mixing disc (14) and the delay wall (15) are respectively arranged in a combustion chamber (7). An ignition column (19) and an ignition electrode (10) are provided on the mixing disc (14).

2. The multi-fuel delayed mixing low NOx burner according to claim 1, It is characterized in that One end of the main gas inlet pipe (1) is connected to the auxiliary gas inlet pipe (2), and the other end is connected to the main gas pipe (12); one end of the auxiliary gas system (11) passes through the main gas inlet pipe (1) and is connected to the auxiliary gas inlet pipe (2), and the other end is arranged in the main burner core (20) and is connected to the auxiliary gas nozzle (17); one end of the auxiliary gas nozzle (17) away from the auxiliary gas system (11) extends out of the main burner core (20) and is arranged in the combustion chamber (7).

3. The multi-fuel delayed mixing low NOx burner according to claim 1, It is characterized in that The main burner core (20) further comprises a spoiler disk (16), the spoiler disk (16) being arranged on a side of the delay wall (15) away from the mixing disk (14) and the spoiler disk (16) being arranged in the combustion chamber (7), a plurality of pressure equalizing holes (161) being distributed on the spoiler disk (16), the spoiler disk (16) being arranged in a circular ring shape and the spoiler disk (16) being provided with an electrode position (162).

4. The multi-fuel delayed mixing low NOx burner according to claim 3, It is characterized in that The primary air holes (131) are symmetrically distributed along the central axis of the primary mixing chamber (13), and the main gas pipe (12), the primary mixing chamber (13), the mixing disk (14), the delay wall surface (15) and the spoiler disk (16) are arranged along the same central axis.

5. The multi-fuel delayed mixing low NOx burner according to claim 1, It is characterized in that The mixing disk (14) is provided with a flame detection hole (142), an ignition electrode hole (144) and an ignition column hole (191); the ignition column (19) is arranged in the ignition column hole (191); one end of the ignition electrode (10) is arranged in the ignition electrode hole (144), and the other end penetrates the air shell (4) and extends outward.

6. The multi-fuel delayed mixing low NOx burner according to claim 1, It is characterized in that A flame detection device (8) is provided at one end of the air housing (4) close to the main gas inlet pipe (1).

7. The multi-fuel delayed mixing low NOx burner according to claim 1, It is characterized in that A mounting flange (5) is provided between the combustion chamber (7) and the air casing (4), a burner brick (6) is provided outside the combustion chamber (7), the burner brick (6) is arranged on a side of the mounting flange (5) away from the air casing (4), and the combustion chamber (7) is arranged inside the burner brick (6).

8. The multi-fuel delayed mixing low NOx burner according to claim 1, It is characterized in that The mixing disk (14) is arranged in a circular ring shape; the secondary air holes (141), the tertiary air holes (145) and the quaternary air slots (143) respectively penetrate the two ends of the mixing disk (14) in the thickness direction; the secondary air holes (141), the tertiary air holes (145) and the quaternary air slots (143) are respectively evenly distributed along the central axis of the mixing disk (14); the secondary air holes (141) and the tertiary air holes (145) are respectively swirl holes or straight holes; the quaternary air slots (143) are arranged at the outer edge of the mixing disk (14); and the quaternary air slots (143) are straight slots or swirl slots.

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