A surface combustion burner with controllable air-fuel ratio of water-cooled premixed air and its combustion control method

Abstract

The present invention discloses a surface combustion burner with controllable water-cooled premixed air-fuel ratio and its combustion control method, which includes a combustion head, a mixer, a manual regulating valve, a valve group, a wind pressure switch, a blower, an ignition device and a control system. The combustion head is connected to the mixer through a gas mixing pipeline A, the mixer is connected to the valve group through a natural gas pipeline B, the other end of the mixer is connected to the blower through an air pipeline C, the manual regulating valve is arranged on the natural gas pipeline B, and the wind pressure switch is arranged on the air pipeline C. The present invention has the following advantages and effects: through the design of the control system and related sensors, the air feed amount is controlled by taking the steam pressure and the heat of the combustion head as index signals, and then the opening degree of the valve group is controlled by the control system through the air feed amount index signal to realize the ratio of natural gas. In addition, through the arrangement design of a number of metal sheets with equal intervals on the combustion head, carbon deposition and blockage of the combustion head can be avoided without additional treatment such as dust filtration of the air.

Description

Technical Field

[0001] The present invention relates to a burner, and particularly to a surface burner with a controllable water-cooled premixed air-fuel ratio and a combustion control method thereof. Background Art

[0002] Nitrogen oxides form acid rain and are one of the components of air pollutants. At the same time, they are also one of the main components of smog. Beijing has promulgated a new "Emission Standard of Air Pollutants for Boilers", stipulating that since April 1, 2017, the nitrogen oxide emission limit for all in-use gas boilers is 80 mg / m 3 , and the nitrogen oxide emission limit for newly built gas boilers is 30 mg / m 3 , which poses a low-nitrogen requirement for current combustion devices.

[0003] A burner is a general term for a device that sprays and mixes fuel and air for combustion in a certain way. Common burners will discharge a large amount of nitrogen oxides, which will affect air quality when discharged into the atmosphere and usually need to be treated before discharge. Similarly, waste gas treatment also requires a high cost. Currently, low-nitrogen combustion control technology mainly reduces the formation of nitrogen oxides by reducing the flame temperature. According to the formation mechanism of NOx, it can be divided into thermal nitrogen oxides, fuel nitrogen oxides, and prompt nitrogen oxides. Among them, fuel nitrogen oxides are generated during the oxidation of nitrogen oxides in the fuel and account for more than 90% of the total generation during the entire combustion process. The combustion technology with a controllable water-cooled premixed air-fuel ratio relies on the low temperature of the water-cooled wall to cool the flame to achieve the purpose of low-nitrogen combustion.

[0004] The existing patent CN202110332325.X technology uses the furnace temperature as an index for an electromagnet and the air feed amount to jointly control the opening and closing of the natural gas valve. However, with this technology, the natural gas feed amount cannot be controlled according to the air flow rate to achieve the preset mixing ratio; in the technology of patent CN201910775293.3, the operation steps mention the controllable cooperation ratio of the premixed air-fuel ratio of air and natural gas, but there is no description of how to achieve the controllable cooperation ratio of the premixed air-fuel ratio; in addition, the existing technology has defects in the structural design of the burner head. Since the air participating in combustion contains dust, some carbon deposits will be generated after long-term combustion, and these carbon deposits will block the air flow channels of the existing burner head, resulting in an explosion of the burner, so it needs to be improved. Summary of the Invention

[0005] The object of the present invention is to provide a surface burner with a controllable water-cooled premixed air-fuel ratio and a combustion control method thereof. Compared with traditional burners, this burner can not only adjust the air-fuel ratio, but also avoid explosions caused by blockage of fine carbon deposits during combustion, threatening human safety. On the other hand, it can improve the working efficiency and service life of the burner.

[0006] The above technical object of the present invention is achieved through the following technical solutions: A surface combustion burner with a controllable air-fuel ratio for water-cooled premixing, including a combustion head, a mixer, a manual regulating valve, a valve group, a wind pressure switch, a blower, an ignition device, and a control system. The combustion head is connected to the mixer through a gas mixing pipeline A. The lower part of the mixer is connected to the valve group through a natural gas pipeline B. The other end of the mixer is connected to the blower through an air pipeline C. The manual regulating valve is arranged on the natural gas pipeline B in the middle of the connection between the mixer and the valve group. The wind pressure switch is arranged on the air pipeline C in the middle of the mixer and the blower.

[0007] The combustion head consists of a combustion mask, water-cooled pipes, and a combustion surface. The combustion mask is communicated with the mixer through a gas mixing pipeline A. There are gaps between the water-cooled pipes. The water-cooled pipes are arranged side by side and pass through the combustion mask. The two ends of the water-cooled pipes are respectively connected to water pipes to form a circulating water path. The combustion surface is rectangular and is formed by arranging a number of metal sheets with equal intervals. The gaps left between the metal sheets serve as channels for the mixed gas to flow through. The ignition device is close to the combustion surface and is on the parallel plane of the combustion head.

[0008] When the manual regulating valve is in the open state and the blower sends in a certain amount of air, the valve group makes an opening action with a corresponding opening degree according to the air volume, and sends in natural gas in a certain proportion to the air. The natural gas and air are uniformly mixed in the mixer and then sent into the combustion head through the gas mixing pipeline A. The uniformly mixed air and natural gas flow through the gaps between the water-cooled pipes until they reach the combustion surface formed by a number of metal sheets with equal intervals. Compared with the traditional mesh design, on the one hand, this combustion surface can avoid explosion caused by blockage of fine carbon deposits during combustion, threatening personal safety. On the other hand, it can improve the working efficiency and service life of the burner.

[0009] A further setting of the present invention is: A vortex wheel and a mixing chamber are arranged in the mixer. The vortex wheel is rotationally matched with the inlet end of the mixing chamber. The mixing chamber is in a cylindrical cone shape. A number of air outlet holes are opened on the cylindrical wall of the mixing chamber. The mixing chamber is also connected to the manual regulating valve and the valve group in sequence through the natural gas pipeline B. The valve group is connected to the natural gas supply end through the natural gas pipeline B.

[0010] A further setting of the present invention is: A number of metal fan blades are arranged on the vortex wheel. The metal fan blades are distributed 360 degrees along one circle of the vortex wheel, and all the metal fan blades are not in the same plane.

[0011] The vortex wheel is driven to send natural gas and air into the mixing chamber. Under the vortex air flow formed by the vortex wheel, the natural gas and air are fully mixed and then discharged through the air outlet holes and sent to the combustion head through the gas mixing pipeline A.

[0012] A further setting of the present invention is that the control system controls the mixer, valve group, air pressure switch, blower and ignition device through signal processing.

[0013] A further setting of the present invention is that the combustion control method of the surface combustion burner with controllable water-cooled premixed air-fuel ratio is as follows:

[0014] 1) Steam pressure acquisition stage: When the external boiler burns, steam is generated. The pressure signal is transmitted to the control system by collecting the steam pressure. The control system issues an instruction to control the blower to realize the control of the air feed amount. The air enters the mixer through the air pipeline C.

[0015] 2) Blower air feed and natural gas feed stage: Open the manual regulating valve. A certain amount of air is fed in step 1. The air pressure is adjusted through the air pressure switch. The action signal of the air pressure switch and the flow signal collected by the flowmeter are transmitted to the control system. The control system and the valve group with the set air-fuel ratio realize the control of the natural gas feed amount. While the control system adjusts the opening of the valve group to control the flow rate, it also receives the pressure signal real-time feedback through the built-in pressure sensor to achieve the preset air and natural gas feed volume ratio and matching pressure. The natural gas enters the mixer through the natural gas pipeline B.

[0016] 3) Mixer mixing stage: The air from the blower enters the mixer from the end of the mixer provided with the vortex wheel. Under the action of the rotation of the metal fan blades, the air is brought into the mixing chamber, and the natural gas enters the mixing chamber from the pipeline B below the mixing chamber. The air and natural gas are mixed in the mixing chamber. Due to the continuous influx of air and natural gas, the volume of the mixed gas in the mixing chamber increases. The mixed gas flows out from the air holes opened in the mixing chamber and is discharged from the other end of the mixer and then flows into the burner head through the mixing gas pipeline A;

[0017] 4) Ignition device ignition stage: In step 2, when the valve group is opened, at this time, the ignition device is signaled by the control system to synchronize the ignition so that the ignition action is not later than the time when the natural gas flows out from the burner head;

[0018] 5) Heat collection and feedback stage: In step 3, a certain proportion of the mixed gas composed of natural gas and air flows into the burner head. On the premise of step 4, this mixed gas is ignited, and the heat generated by the combustion of the mixed gas is collected and feedback to the control system;

[0019] 6) Closed-loop regulation stage: Under the feedback of the heat signal in step 5, if the heat value exceeds the requirement, the control system reduces the air feed amount of the blower, thereby reducing the natural gas feed amount; if the heat value does not reach the requirement, the control system increases the air feed amount of the blower. Without changing the controllable ratio of the premixed air-fuel ratio, the natural gas feed amount increases and the combustion heat of the mixed gas increases;

[0020] It should be noted that this application has a technical effect: in the initial stage when the boiler starts to generate steam and the heat value signal has not yet appeared, the steam pressure signal has a higher priority, and the control system controls the air feed volume of the blower through the steam pressure signal; if there is an obvious change rate in the steam pressure signal, the steam pressure signal becomes a signal with an even higher priority, and at this time the control system controls the air feed volume of the blower according to the steam pressure signal.

[0021] It should be noted that this application also has another technical effect: when the boiler steam is stable, after the ignition device ignites the mixture gas, if the heat value exceeds the set required value, at this time the heat value signal has a higher priority than the steam pressure, and the control system appropriately reduces the air feed volume of the blower according to the heat value signal, and then adjusts the valve group to reduce the natural gas feed volume to achieve a reduction in combustion heat; if the heat value is lower than the set required value, at this time the heat value signal also has a higher priority than the steam pressure, and the control system appropriately increases the air feed volume of the blower according to the heat value signal, and then adjusts the valve group to increase the natural gas feed volume to achieve an increase in combustion heat; through this technology, the heat of the burner head is always stabilized at the set value level.

[0022] A further setting of the present invention is that the range of the air dust content fed by the blower is ≤ 10 mg / m 3 。

[0023] A further setting of the present invention is that after the surface combustion burner with a controllable water-cooled premixed air-fuel ratio adjusts the air-fuel ratio by controlling the air feed volume of the blower (6) and the natural gas feed volume of the valve group (4), the content of nitrogen oxides in the discharged combustion products is controlled to be < 25 mg / Nm 3 。

[0024] In summary, the present invention has the following beneficial effects: through the design of the control system and related sensors, it is realized to control the air feed volume with the steam pressure and the heat of the burner head as the index signals, and then the opening degree of the valve group is controlled by the control system through the air feed volume index signal to achieve the ratio of natural gas, and the preset mixing ratio of air and natural gas is achieved. Using the air feed volume to determine the natural gas feed volume can stably control the air-fuel ratio and is more conducive to the control of the heat of the burner head. In addition, through the arrangement design of a number of equally spaced metal sheets on the burner head, without additional treatments such as dust filtration of the air, it is also possible to avoid the blockage of the air flow gap of the burner head caused by carbon deposition due to incomplete combustion of dust, so that dangerous situations such as explosion no longer occur. The content of nitrogen oxides in the discharged combustion products is < 25 mg / Nm 3 , which is lower than the emissions of the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of a surface combustion burner with a controllable water-cooled premixed air-fuel ratio;

[0026] Figure 2 Schematic diagram of the combustion head structure in a surface combustion burner with water-cooled premixed air-fuel ratio controllable

[0027] Figure 3 Schematic diagram of the combustion surface structure in the combustion head of a surface combustion burner with water-cooled premixed air-fuel ratio controllable

[0028] Figure 4 Schematic sectional view of the mixer in a surface combustion burner with water-cooled premixed air-fuel ratio controllable

[0029] Reference numerals: 1. Combustion head, 2. Mixer, 3. Manual regulating valve, 4. Valve group, 5. Wind pressure switch, 6. Blower, 11. Combustion mask, 12. Water-cooled pipe, 13. Combustion surface, 21. Vortex wheel, 22. Mixing chamber, 131. Metal sheet, 132. Gap, 211. Metal fan blade, 221. Air outlet hole Detailed implementation mode

[0030] The present invention will be further described in detail below with reference to the accompanying drawings

[0031] As Figures 1-4 shown, a surface combustion burner with water-cooled premixed air-fuel ratio controllable includes a combustion head 1, a mixer 2, a manual regulating valve 3, a valve group 4, a wind pressure switch 5, a blower 6, an ignition device and a control system. The combustion head 1 is connected to the mixer 2 through a gas mixing pipeline A. The mixer 2 is connected to the valve group 4 through a natural gas pipeline B below, and the other end of the mixer 2 is connected to the blower 6 through an air pipeline C. The manual regulating valve 3 is arranged on the natural gas pipeline B in the middle of the connection between the mixer 2 and the valve group 4, and the wind pressure switch 5 is arranged on the air pipeline C in the middle of the mixer 2 and the blower 6

[0032] Further, the combustion head 1 is composed of a combustion mask 11, water-cooled pipes 12 and a combustion surface 13. The combustion mask 11 is connected to the mixer 2 through a gas mixing pipeline A and is in communication with it. There are gaps between the water-cooled pipes. The water-cooled pipes 12 are arranged side by side through the combustion mask 11. Both ends of the water-cooled pipes 12 are respectively connected to water pipes to form a circulating water path. The combustion surface 13 is rectangular and is arranged by a number of metal sheets 131 with equal intervals. The gaps 132 left between the metal sheets 131 serve as channels for the mixed gas to flow through. The ignition device is close to the combustion surface 13 and is on the parallel plane of the combustion head 1

[0033] When the manual regulating valve is in the open state and the blower 6 feeds a certain amount of air, the valve group 4 makes an opening action with a corresponding opening degree according to the air volume, feeds natural gas in a certain proportion to the air, and the two are uniformly mixed in the mixer and then sent to the burner head 1 through the gas mixing pipeline A. The uniformly mixed air and natural gas flow through the gaps between the water-cooled pipes 12 until they reach the combustion surface 13 formed by a number of metal sheets 131 arranged at equal intervals. Compared with the traditional mesh design, on the one hand, this combustion surface 13 can avoid explosion caused by blockage of fine carbon deposits during combustion, threatening human safety; on the other hand, it can improve the working efficiency and service life of the burner.

[0034] Further, a vortex wheel 21 and a mixing chamber 22 are arranged in the mixer 2. The vortex wheel 21 is rotatably matched with the inlet end of the mixing chamber 22. The mixing chamber 22 is in a cylindrical conical shape, and a number of air outlet holes 221 are opened on the cylindrical wall of the mixing chamber 22. The mixing chamber 22 is also connected to the manual regulating valve 3 and the valve group 4 in sequence through a natural gas pipeline B, and the valve group 4 is connected to the natural gas supply end through the natural gas pipeline B.

[0035] Further, a number of metal fan blades 211 are arranged on the vortex wheel 21. The metal fan blades 211 are distributed at 360 degrees along one circle of the vortex wheel 21, and all the metal fan blades 211 are not in the same plane.

[0036] The vortex wheel 21 is driven to send natural gas and air into the mixing chamber 22. Under the vortex air flow formed by the vortex wheel 21, the natural gas and air are fully mixed and then discharged through the air outlet holes 221 and sent to the burner head 1 through the gas mixing pipeline A.

[0037] Further, the control system controls the actions of the mixer 2, the valve group 4, the air pressure switch 5, the blower 6 and the ignition device through signal processing.

[0038] Further, the combustion control method of the water-cooled premixed air-fuel ratio controllable surface combustion burner is as follows:

[0039] 1) Steam pressure acquisition stage: When the boiler burns, steam is generated. The pressure signal is transmitted to the control system by collecting the steam pressure. The control system issues an instruction to control the blower 6 to achieve the control of the air feed volume. The air enters the mixer 2 through the air pipeline C;

[0040] 2) Blower air supply and natural gas supply stage: Control the blower 6 to supply a certain amount of air, adjust the air pressure through the air pressure switch 5, transmit the action signal of the air pressure switch 5 and the flow signal collected by the flow meter to the control system, and control the natural gas supply amount by the control system and the opening degree of the valve group 4 with the preset air-fuel ratio. While the control system adjusts the opening degree of the valve group 4 to control the flow, it also receives the pressure signal real-time feedback through the built-in pressure sensor to achieve the preset air and natural gas intake ratio and matching pressure. Among them, the natural gas enters the mixer 2 through the natural gas pipeline B.

[0041] 3) Mixer mixing stage: The air from the blower 6 enters the mixer 2 from the end of the mixer 2 where the vortex wheel 21 is provided. Under the action of the rotation of the metal fan blade 211, the air is brought into the mixing chamber 22, and the natural gas enters the mixing chamber 22 from the pipeline B below the mixing chamber 22. The air and natural gas are mixed in the mixing chamber 22. Due to the continuous influx of air and natural gas, the volume of the mixed gas in the mixing chamber 22 increases. The mixed gas flows out from the air holes opened in the mixing chamber 22, and after being discharged from the other end of the mixer 2, it flows into the burner head 1 through the mixing gas pipeline A.

[0042] 4) Ignition device ignition stage: When the valve group 4 is opened, the ignition device is signaled by the control system to synchronously ignite, so that the ignition action is not later than the time when the natural gas flows out from the burner head 1.

[0043] 5) Heat collection and feedback stage: A mixture of a certain proportion composed of natural gas and air flows into the burner head 1. This mixture of gases is ignited, and the heat generated by the combustion of the mixture of gases is collected and fed back to the control system.

[0044] 6) Closed-loop regulation stage: If the heat value exceeds the requirement, the control system reduces the air supply amount of the blower 6, thereby reducing the natural gas supply amount; if the heat value does not meet the requirement, the control system increases the air supply amount of the blower 6. Under the condition that the pre-mixed air-fuel ratio controllable ratio remains unchanged, the natural gas supply amount increases, and the combustion heat of the mixture of gases increases.

[0045] It should be noted that this application has a technical effect: In the initial stage when the external boiler starts to generate steam, the heat value signal has not appeared yet, and the steam pressure signal has a higher priority. The control system controls the air supply amount of the blower 6 through the steam pressure signal; if there is an obvious change rate in the steam pressure signal, the steam pressure signal becomes a signal with a higher priority. At this time, the control system controls the air supply amount of the blower 6 according to the steam pressure signal.

[0046] It should be noted that this application also has another technical effect: when the external boiler steam is stable, after the ignition device ignites the mixture gas, if the heat value exceeds the set demand value, at this time the heat value signal has a higher priority than the steam pressure signal. The control system appropriately reduces the air feed amount of the blower 6 according to the heat value signal, and then adjusts the valve group 4 to reduce the natural gas feed amount, so as to reduce the combustion heat. If the heat value is lower than the set demand value, at this time the heat value signal also has a higher priority than the steam pressure signal. The control system appropriately increases the air feed amount of the blower 6 according to the heat value signal, and then adjusts the valve group 4 to increase the natural gas feed amount, so as to increase the combustion heat. Through this technology, the heat of the burner head 1 is always stabilized at the set value level.

[0047] Further, the range of the air dust content fed by the blower 6 is ≤10mg / m 3 .

[0048] Further, after the surface burner with controllable water-cooled premixed air-fuel ratio adjusts the air-fuel ratio by controlling the air feed amount of the blower (6) and the natural gas feed amount of the valve group (4), the content of nitrogen oxides in the discharged combustion products is controlled to be <25mg / Nm 3 .

[0049] In this embodiment, through the design of the control system and related sensors, the air feed amount is controlled with the steam pressure and the heat of the burner head as the index signals, and then the opening degree of the valve group is controlled by the control system through the air feed amount index signal, so as to realize the ratio of natural gas and reach the preset mixing ratio of air and natural gas. Using the air feed amount to determine the natural gas feed amount can stably control the air-fuel ratio and is more conducive to the control of the heat of the burner head. In addition, through the arrangement design of several equally spaced metal sheets on the burner head, without additional treatments such as dust filtration of the air, it is also possible to avoid the blockage of the air flow gap of the burner head caused by carbon deposition due to incomplete combustion of dust, so that dangerous situations such as explosion no longer occur. The content of nitrogen oxides in the discharged combustion products is <25mg / Nm 3 , which is lower than the emission level of the prior art.

[0050] The specific embodiments are only explanations of the present invention, and they do not limit the present invention. Those skilled in the art can make modifications without creative contributions to the specific embodiments according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A combustion control method for a surface combustion burner with controllable air-fuel ratio in water-cooled premixed air, characterized in that The surface combustion burner includes a combustion head (1), a mixer (2), a manual regulating valve (3), a valve group (4), a wind pressure switch (5), a blower (6), an ignition device and a control system. The combustion head (1) is connected to one end of the mixer (2) through a gas mixing pipeline A. The lower part of the mixer (2) is connected to the valve group (4) through a natural gas pipeline B. The other end of the mixer (2) is connected to the blower (6) through an air pipeline C. The manual regulating valve (3) is arranged on the natural gas pipeline B. The wind pressure switch (5) is arranged on the air pipeline C; The combustion head (1) is composed of a combustion mask (11), water-cooled pipes (12) and a combustion surface (13). The combustion mask (11) communicates with the mixer (2) through a gas mixing pipeline A. There are gaps between the water-cooled pipes (12). The water-cooled pipes (12) are arranged side by side through the combustion mask (11). Both ends of the water-cooled pipes (12) are respectively connected to water pipes to form a circulating water path. The combustion surface (13) is rectangular and is formed by arranging a number of metal sheets (131) with equal intervals. The gaps (132) left between the metal sheets (131) serve as channels for the mixed gas to flow through. The ignition device is close to the combustion surface (13) and is on a plane parallel to the combustion head (1); The mixer (2) is internally provided with a vortex wheel (21) and a mixing chamber (22). The vortex wheel (21) is rotationally matched with the air inlet end of the mixing chamber (22). The mixing chamber (22) is in a cylindrical cone shape. A number of air outlet holes (221) are opened on the cylindrical wall of the mixing chamber (22). The mixing chamber (22) is connected to the manual regulating valve (3) and the valve group (4) in sequence through the natural gas pipeline B. The valve group (4) is connected to the natural gas supply end through the natural gas pipeline B; A number of metal fan blades (211) are arranged on the vortex wheel (21). The metal fan blades (211) are distributed at 360 degrees along one circle of the vortex wheel (21). All the metal fan blades (211) are not in the same plane; The vortex wheel (21) is driven so that natural gas and air are sent into the mixing chamber (22). Under the vortex air flow formed by the vortex wheel (21), the natural gas and air are fully mixed and then discharged through the air outlet holes (221) and reach the combustion head (1) through the gas mixing pipeline A; When the manual regulating valve is in the open state and the blower (6) sends in a certain amount of air, the valve group (4) makes an opening action with a corresponding opening according to the air volume, sends in natural gas in a certain proportion to the air, and the two are uniformly mixed in the mixer and then sent into the combustion head (1) through the gas mixing pipeline A. The uniformly mixed air and natural gas flow through the gaps between the water-cooled pipes (12) until they reach the combustion surface (13) formed by arranging a number of metal sheets (131) with equal intervals; The combustion control method includes the following steps: 1) Steam pressure acquisition stage: When the external boiler burns, steam is generated. The pressure signal is transmitted to the control system by collecting the steam pressure. The control system issues an instruction to control the blower (6) to realize the control of the air feed volume. The air enters the mixer (2) through the air pipeline C; 2) Blower air supply and natural gas supply stage: Control the blower (6) to supply a certain amount of air, adjust the air pressure through the air pressure switch (5), transmit the action signal of the air pressure switch (5) and the flow signal collected by the flowmeter to the control system, open the manual regulating valve (3), and control the natural gas supply amount by the control system and the valve group (4) with a set air-fuel ratio. While the control system adjusts the opening of the valve group (4) to control the flow rate, it also receives the pressure signal real-time feedback through the built-in pressure sensor to achieve the preset air and natural gas intake ratio and matching pressure. The natural gas enters the mixer (2) through the natural gas pipeline B; 3) Mixer mixing stage: The air from the blower (6) enters the mixer (2) from the end of the mixer (2) equipped with the vortex wheel (21). Under the action of the rotation of the metal fan blades (211), the air is brought into the mixing chamber (22), and the natural gas enters the mixing chamber (22) from the pipeline B below the mixing chamber (22). The air and natural gas are mixed in the mixing chamber (22). Due to the continuous influx of air and natural gas, the volume of the mixed gas in the mixing chamber (22) increases. The mixed gas flows out through the air holes opened in the mixing chamber (22), and after being discharged from the other end of the mixer (2), it flows into the burner head (1) through the mixing gas pipeline A; 4) Ignition device ignition stage: When the valve group (4) is opened, the ignition device is signaled by the control system to synchronously ignite, so that the ignition action is not later than the time when the natural gas flows out of the burner head (1); 5) Heat collection and feedback stage: A mixture of a certain proportion composed of natural gas and air flows into the burner head (1). This mixture is ignited, and the heat generated by the combustion of the mixture is collected and feedback to the control system; 6) Closed-loop regulation stage: If the heat value collected by the control system exceeds the demand, the control system controls the blower (6) to reduce the air supply amount, and at the same time controls the valve group (4) to reduce the natural gas supply amount, and the combustion heat of the mixture decreases; if the heat value does not reach the demand, the control system controls the blower (6) to increase the air supply amount. Under the condition that the pre-mixed air-fuel ratio controllable ratio remains unchanged, the natural gas supply amount of the valve group increases, and the combustion heat of the mixture increases.

2. The combustion control method according to claim 1, characterized in that: The control system controls the actions of the mixer (2), valve group (4), air pressure switch (5), blower (6) and ignition device through signal processing.

3. The combustion control method according to claim 1, characterized in that: The air fed by the blower (6) has a dust content range of ≤ 10 mg / m 3 .

4. The combustion control method according to claim 1, characterized in that: Adjust the air-fuel ratio by controlling the air feed rate of the blower (6) and the natural gas feed rate of the valve group (4), and control the nitrogen oxide content in the discharged combustion products to be < 25 mg / Nm 3 .

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