Fuel gas combustion device with low pollutant emission

Abstract

The utility model relates to a gas combustion device with low pollutant emission, which solves the problem that the initial emission of NOx of most of gas boilers in use exceeds the standard and is basically 150-200mg / m < 3 > at present, adopts the technical scheme of flue gas internal circulation, fuel grading and air grading, and is characterized in that internal circulation flue gas is mixed with combustion-supporting air, so that the oxygen concentration of a combustion area is reduced, and a heat absorption medium is increased at the same time; according to the technical scheme, fuel and air classification is combined, so that fuel combustion heat release is more dispersed, the average temperature of a combustion area is reduced, and generation of thermal NOx is restrained. The structure of the scheme mainly comprises a combustion-supporting air outlet barrel, a rotational flow eternal flame device is arranged in the center of the air outlet barrel, and a plurality of main flame gas spray pipes are evenly arranged on the periphery of the air outlet barrel; the integrated silicon carbide burner is matched with the air outlet cylinder nozzle and the main flame gas nozzle to form a plurality of Venturi jet device structures, high-speed jet air / gas flows through the structures to form negative pressure to suck flue gas in the furnace to form flue gas internal circulation, and ever-burning flames / main flames are distributed in a scattered mode and ignited step by step to achieve fuel classification and air classification.

Description

Technical Field

[0001] The utility model relates to the technical field of gas combustion, and particularly relates to a gas combustion device with low pollutant emissions. Background Art

[0002] Nitrogen oxides (NOx) are one of the most important pollutants in the atmosphere. They can not only cause photochemical smog pollution, but also trigger acid rain and haze. After being discharged into the atmosphere, NOx will also produce photochemical smog in the atmosphere, and even lead to the destruction of the ozone layer, the greenhouse effect, crop yield reduction, and diseases of the eyes and respiratory tracts of humans and animals. In severe cases, it can even cause death directly, bringing serious harm to the ecological environment and human health.

[0003] Currently, the initial nitrogen oxide emissions of the vast majority of in-use gas boilers are basically in the range of 150 - 200 mg / m 3 .

[0004] The NOx emission standards are becoming increasingly strict, and ultra-low NOx emission gas combustion will become the mainstream. At present, there is a large market demand for ultra-low nitrogen emission gas burners applied to industrial boilers and power station boilers, but currently, it still mainly relies on foreign imports. The high price of imported burners erodes the profits of the gas industry. Therefore, it is of practical significance to independently develop advanced ultra-low nitrogen emission gas burners. Content of the Utility Model

[0005] Purpose of the utility model: To solve the problem of serious over-standard of the initial nitrogen oxide emissions of the vast majority of in-use gas boilers, which are basically in the range of 150 - 200 mg / m 3 , the utility model proposes a gas combustion device with low pollutant emissions.

[0006] The utility model is implemented through the following scheme: A gas combustion device with low pollutant emissions, which includes a swirling long-burning flame gas device, a combustion-supporting air outlet cylinder device, a main flame gas device, an integrated silicon carbide burner, a silicon carbide heat radiation isolation belt, a water-cooled jacket, a water-cooled jacket sealing box, and a combustion-supporting air large air box frame;

[0007] The water-cooled jacket and the middle part of the water-cooled jacket sealing box pass through the combustion-supporting air outlet barrel device. The swirling long-burning flame gas device is arranged in the middle of the combustion-supporting air outlet barrel device, and the main flame gas device is arranged outside the combustion-supporting air outlet barrel device. The main flame gas device includes a main gas supply ring box and a plurality of main fuel gas nozzles; the main gas supply ring box is sleeved outside the combustion-supporting air outlet barrel device, and the main gas supply ring box is fixedly connected to the outer end face of the water-cooled jacket sealing box. One end of the main gas supply ring box is connected to the main gas supply main pipe communicated with it. The plurality of main fuel gas nozzles are evenly distributed along the circumferential direction and are fixedly connected to the inner end face of the water-cooled jacket sealing box, and the plurality of main fuel gas nozzles are all communicated with the main gas supply ring box. One end of the combustion-supporting air outlet barrel device is fixedly connected to the outer end face of the combustion-supporting air large box frame. One end of the swirling long-burning flame gas device and one end of the intake port of the main gas supply main pipe both pass through the outer end face of the combustion-supporting air large box frame. The outer end plate of the water-cooled jacket sealing box is fixedly connected to the inner end face of the combustion-supporting air large box frame. The integrated silicon carbide burner is connected and supported to the end plate of the water-cooled jacket sealing box through a high-temperature-resistant supporting and fixing metal part. The outlets of the plurality of main fuel gas nozzles and the combustion-supporting air outlet barrel device are respectively inserted into the roots of the channels corresponding to the integrated silicon carbide burner. A main fuel gas / circulating flue gas mixing Venturi channel is arranged between the plurality of main fuel gas nozzles and the integrated silicon carbide burner. A combustion-supporting air / circulating flue gas mixing Venturi channel is arranged between the outlet of the combustion-supporting air outlet barrel device and the integrated silicon carbide burner. A flue gas return channel is arranged between the integrated silicon carbide burner and the water-cooled jacket.

[0008] Further, a silicon carbide heat radiation isolation belt is arranged at the flue gas return channel between the water-cooled jacket and the integrated silicon carbide burner near the end plate of the water-cooled jacket sealing box.

[0009] Still further, the outlet of the combustion-supporting air outlet barrel device is a frustum-shaped reduced opening structure. Combustion-supporting air triangular intake holes are arranged on the combustion-supporting air outlet barrel device. A combustion-supporting air regulating damper is sleeved outside the combustion-supporting air triangular intake holes. The combustion-supporting air regulating damper is connected to a pull rod and the opening and closing of the combustion-supporting air regulating damper are controlled through the pull rod. The control section of the pull rod passes through the outer end face of the combustion-supporting air large box frame. A scale is arranged near the pull rod. The pull rod and the scale are used in combination to determine the opening and closing state of the auxiliary air regulating damper.

[0010] Further, the top of the combustion-supporting air outlet barrel device is connected to the upper end face of the combustion-supporting air large box frame through a suspension structure.

[0011] Still further, the swirling long-burning flame gas device includes a flame stabilizing cover, a swirling long-burning flame gas main pipe, swirling long-burning flame gas branch pipes, and swirling vanes;

[0012] The swirling long - lasting flame gas main pipe and the ignition device are arranged adjacent to each other vertically. One end of the swirling long - lasting flame gas main pipe and one end of the ignition device pass through the outer end face of the combustion - supporting air large - volume blower frame and are fixed on the outer end face. The flame - stabilizing cover is installed outside the other ends of the swirling long - lasting flame gas main pipe and the ignition device. The swirling blades of the swirling long - lasting flame gas branch pipes are all arranged inside the flame - stabilizing cover. The swirling long - lasting flame gas branch pipes are communicated with the outer wall of the swirling long - lasting flame gas main pipe. The swirling blades are fixed on the flame - stabilizing cover and the swirling long - lasting flame gas main pipe.

[0013] Furthermore, soft refractory caulking material is provided between the water - cooled jacket and the silicon carbide heat - radiation - proof isolation belt.

[0014] Still further, a flame detection device is fixed on the outer end face of the combustion - supporting air large - volume blower frame.

[0015] Furthermore, the integrated silicon carbide burner is integrally cast and sintered.

[0016] Still further, the fixed integrated silicon carbide burner "floats" outside the conical necking of the combustion - supporting air outlet cylinder device and outside multiple main fuel gas nozzles.

[0017] Furthermore, the inner contour of the combustion - supporting air / recirculated flue gas mixing Venturi channel of the integrated silicon carbide burner and the outer contour of the conical necking of the combustion - supporting air outlet device form a Venturi injector structure; the inner contour of the main fuel gas / recirculated flue gas mixing Venturi channel of the integrated silicon carbide burner and the outer contour of the nozzle of the main fuel gas nozzle form a Venturi injector structure.

[0018] Beneficial effects:

[0019] First, the present invention divides the fuel gas into two levels, namely the swirling long - lasting flame and the main flame, to achieve fuel staging. The combustion - supporting air is close to the long - lasting flame and far from the main flame. The long - lasting flame gas and the main flame gas come into contact with air and burn in different stages successively, achieving air staging. The long - lasting flame gas burns with rich air, and a large amount of excess air absorbs a large amount of ignition heat, reducing the temperature in the long - lasting flame area. The main flame gas gradually mixes with the combustion - supporting air and burns, lengthening the flame length and reducing the high - temperature area generated by local intense combustion. In addition, the main flame gas pipes are multiple and are arranged dispersedly. The flames are ejected by multiple dispersedly - arranged main flame gas pipes, avoiding flame concentration and flame overlap, reducing the local high - temperature area, and reducing the generation of thermal - type NOx.

[0020] In this solution, the inner contour of the combustion-supporting air / recirculated flue gas mixing Venturi channel of the integrated silicon carbide burner forms a Venturi injector structure with the outer contour of the nozzle of the combustion-supporting air outlet device. The inner contour of the main fuel gas / recirculated flue gas mixing Venturi channel of the integrated silicon carbide burner also forms a Venturi injector structure in cooperation with the outer contour of the nozzle of the main flame gas pipe. When the high-speed jet of air / main fuel gas flows through the above two Venturi injector structures respectively, an entrainment effect is generated, and the entrained negative pressure sucks the flue gas in the furnace to flow back into the above combustion-supporting air / recirculated flue gas mixing Venturi channel and the main fuel gas / recirculated flue gas mixing Venturi channel through the flue gas return channel. The combustion-supporting air is mixed with the recirculated flue gas, reducing the oxygen concentration of the combustion-supporting air, increasing the heat-absorbing working medium, inhibiting fuel combustion, and reducing the fuel combustion speed and combustion temperature; the main fuel gas is mixed with the recirculated flue gas, reducing the fuel concentration, increasing the heat-absorbing working medium, reducing the fuel combustion speed and combustion temperature, thereby inhibiting the generation of NOx. Description of the Drawings

[0021] Figure 1 It is an overall assembly schematic diagram of a low-pollutant-emission gas combustion device of the present invention;

[0022] Figure 2 It is a front view of a low-pollutant-emission gas combustion device of the present invention;

[0023] Figure 3 It is a swirling long-burning flame gas device of the present invention;

[0024] Figure 4 It is a combustion-supporting air outlet cylinder device of the present invention;

[0025] Figure 5 It is a cross-sectional view of an integrated silicon carbide burner, a silicon carbide heat-radiation-proof isolation belt and its heat-resistant support structure of the present invention;

[0026] Figure 6 It is a schematic diagram of the air / fuel gas / flue gas airflow mixing process and each mixing channel of the present invention.

[0027] In the figure: 1 - swirling long - lasting flame gas device; 11 - flame - stabilizing cover; 12 - swirling long - lasting flame gas main pipe; 13 - swirling long - lasting flame gas branch pipe; 14 - swirling vane; 2 - combustion - supporting air outlet duct device; 21 - triangular combustion - supporting air inlet hole; 22 - combustion - supporting air regulating damper; 23 - pull rod and scale; 3 - main flame gas device; 31 - main fuel gas nozzle; 32 - main gas supply ring box; 33 - main gas supply main pipe; 4 - silicon carbide heat - radiation - proof isolation belt; 5 - combustion - supporting air large - box frame; 51 - suspension structure; 6 - water - cooled jacket; 7 - water - cooled jacket seal box; 8 - integrated silicon carbide burner; 81 - supporting and fixing metal part; 9 - ignition device; 10 - flame detection device; a - air flow; b - swirling long - lasting flame gas flow; c - main flame gas flow; d - entrained flue - gas flow; E - flue - gas return channel; F - main fuel gas / entrained flue - gas mixing Venturi channel; G - combustion - supporting air / entrained flue - gas mixing Venturi channel. Detailed implementation mode

[0028] Detailed implementation mode one: A low - pollutant - emission gas combustion device, which comprises a swirling long - lasting flame gas device 1, a combustion - supporting air outlet duct device 2, a main flame gas device 3, an integrated silicon carbide burner 8, a silicon carbide heat - radiation - proof isolation belt 4, a water - cooled jacket 6, a water - cooled jacket seal box 7 and a combustion - supporting air large - box frame 5;

[0029] The water-cooled jacket 6 and the middle part of the water-cooled jacket sealing box 7 pass through the combustion-supporting air outlet barrel device 2. The swirling long-burning flame gas device 1 is arranged in the middle of the combustion-supporting air outlet barrel device 2. The main flame gas device 3 is arranged outside the combustion-supporting air outlet barrel device 2. The main flame gas device 3 includes a main gas supply ring box 32 and a plurality of main fuel gas nozzles 31. The main gas supply ring box 32 is sleeved outside the combustion-supporting air outlet barrel device 2, and the main gas supply ring box 32 is fixedly connected to the outer end face of the water-cooled jacket sealing box 7. One end of the main gas supply ring box 32 is connected to the main gas supply header pipe 33 communicated with it. The plurality of main fuel gas nozzles 31 are evenly distributed along the circumferential direction and are fixedly connected to the inner end face of the water-cooled jacket sealing box 7, and the plurality of main fuel gas nozzles 31 are all communicated with the main gas supply ring box 32. One end of the combustion-supporting air outlet barrel device 2 is fixedly connected to the outer end face of the combustion-supporting air large box frame 5. One end of the swirling long-burning flame gas device 1 and the intake port end of the main gas supply header pipe 33 both pass through the outer end face of the combustion-supporting air large box frame 5. The outer end plate of the water-cooled jacket sealing box 7 is fixedly connected to the inner end face of the combustion-supporting air large box frame 5. The integrated silicon carbide burner 8 is connected and supported to the end plate of the water-cooled jacket sealing box 7 through a high-temperature-resistant support fixing metal part 81. The outlets of the plurality of main fuel gas nozzles 31 and the combustion-supporting air outlet barrel device 2 are respectively inserted into the roots of the channels corresponding to the integrated silicon carbide burner 8. A main fuel gas / rolled tobacco smoke mixing Venturi channel F is provided between the plurality of main fuel gas nozzles 31 and the integrated silicon carbide burner 8. A combustion-supporting air / rolled tobacco smoke mixing Venturi channel G is provided between the outlet of the combustion-supporting air outlet barrel device 2 and the integrated silicon carbide burner 8. A flue gas reflux channel E is provided between the integrated silicon carbide burner 8 and the water-cooled jacket 6.

[0030] In this embodiment: The combustion-supporting air is close to the pilot flame and far from the main flame. The pilot flame gas and the main flame gas come into contact with air and burn successively in different stages, realizing air staging. The pilot flame gas burns with rich air, and a large amount of excess air absorbs a large amount of ignition heat, reducing the temperature in the pilot flame area. The main flame gas gradually mixes with the combustion-supporting air and burns, elongating the flame length and reducing the high-temperature area generated by local intense combustion. In addition, there are multiple main flame gas pipes which are dispersedly arranged. The flames are ejected from the multiple dispersedly arranged main flame gas pipes, avoiding flame concentration and flame overlap, reducing the local high-temperature area, and reducing the generation of thermal NOx. There is a sealing box between the burner and the water-cooled jacket sealing box. Multiple water-cooled wall tubes pass through the water-cooled jacket sealing box. The water-cooled wall tubes passing through the sealing box are used to cool the combustion outlet of the combustion device with cold water. When the high-speed jet of air / main fuel gas flows through the above two Venturi injector structures respectively, an ejecting effect is generated. The ejecting negative pressure sucks the flue gas in the furnace and returns it into the above combustion-supporting air / flue gas entrained mixing Venturi channel and the main fuel gas / flue gas entrained mixing Venturi channel. The combustion-supporting air is mixed with the entrained flue gas, reducing the oxygen concentration of the combustion-supporting air, increasing the heat-absorbing working medium, inhibiting fuel combustion, reducing the fuel combustion speed and combustion temperature, and the flue gas return channel E is used for the return of the entrained flue gas.

[0031] Other embodiments are the same as the first specific embodiment.

[0032] Specific embodiment two: For a low-pollutant-emission gas combustion device, a silicon carbide heat-radiation isolation belt 4 is provided at the end plate of the flue gas return channel E between the water-cooled jacket 6 and the integrated silicon carbide burner 8, near the water-cooled jacket sealing box 7.

[0033] Other embodiments are the same as the first specific embodiment.

[0034] Specific embodiment three: For a low-pollutant-emission gas combustion device, the outlet of the combustion-supporting air outlet tube device 2 is of a frustum-shaped reduced opening structure. Combustion-supporting air triangular intake holes 21 are provided on the combustion-supporting air outlet tube device 2. A combustion-supporting air regulating damper 22 is sleeved outside the combustion-supporting air triangular intake holes 21. The combustion-supporting air regulating damper 22 is connected to a pull rod 23 and the opening and closing of the combustion-supporting air regulating damper 22 is controlled through the pull rod 23. The control section of the pull rod 23 passes through the outer end face of the combustion-supporting air large air box frame 5. A scale 24 is provided near the pull rod 23. The pull rod 3 and the scale 24 are used in combination to determine the opening and closing state of the auxiliary air regulating damper 12.

[0035] In this embodiment: Through the precise distribution of the combustion-supporting air by the combustion-supporting air regulating damper, the adjustment method of the combustion-supporting air regulating damper can be selected as manual or electric / pneumatic.

[0036] One end of the combustion-supporting air outlet duct device is welded and fixed to the outer end plate of the combustion-supporting air large wind box frame 5. A cylindrical combustion-supporting air regulating damper with open ends at both sides that can slide back and forth is tightly sleeved outside the triangular air inlet holes of the air inlet cylinder of the combustion-supporting air outlet duct device. The combustion-supporting air regulating damper adjusts the air intake of the combustion-supporting air outlet duct device by changing the flow area of the triangular air inlet holes of the air inlet cylinder of the combustion-supporting air outlet duct device through sliding back and forth; the sliding back and forth of the combustion-supporting air regulating damper is precisely controlled and the damper opening is determined through a pull rod and a scale passing through the outer end face of the combustion-supporting air large wind box frame; optionally, the sliding back and forth control of the combustion-supporting air regulating damper can be manually controlled; preferably, the sliding back and forth control of the combustion-supporting air regulating damper can be controlled by an electric or pneumatic actuator.

[0037] Other embodiments are the same as the first specific embodiment.

[0038] Specific embodiment four: The top of the combustion-supporting air outlet duct device 2 is connected to the upper end face of the combustion-supporting air large wind box frame 5 through a suspension structure 51.

[0039] In this embodiment: The top of the combustion-supporting air outlet duct device is hoisted inside the combustion-supporting air large wind box frame through a suspension structure.

[0040] Other embodiments are the same as the first specific embodiment.

[0041] Specific embodiment five: A low-pollutant-emission gas combustion device, the swirling long-burning flame gas device 1 includes a flame stabilization cover 11, a swirling long-burning flame gas main pipe 12, swirling long-burning flame gas branch pipes 13, and swirling vanes 14;

[0042] The swirling long-burning flame gas main pipe 12 and the ignition device 9 are arranged adjacent to each other vertically. One end of the swirling long-burning flame gas main pipe 12 and one end of the ignition device 9 pass through the outer end face of the combustion-supporting air large wind box frame 5 and are fixed on the outer end face. The flame stabilization cover 11 is installed outside the other ends of the swirling long-burning flame gas main pipe 12 and the ignition device 9. The swirling long-burning flame gas branch pipes 13 and the swirling vanes 14 are both arranged inside the flame stabilization cover 11. The swirling long-burning flame gas branch pipes 13 are communicated with the outer wall of the swirling long-burning flame gas main pipe 12. The swirling vanes 14 are fixed on the flame stabilization cover 11 and the swirling long-burning flame gas main pipe 12.

[0043] In this embodiment: The long-burning flame gas undergoes rich-air combustion. A large amount of excess air absorbs a large amount of ignition heat, reducing the temperature in the long-burning flame area. The gas entering the swirling long-burning flame gas main pipe is distributed to the swirling long-burning flame gas branch pipes and burns inside the flame stabilization cover.

[0044] Other embodiments are the same as the first specific embodiment.

[0045] Embodiment Six: In a gas combustion device with low pollutant emissions, a soft refractory caulking material is provided between the water-cooled jacket 6 and the silicon carbide heat radiation isolation belt 4.

[0046] In this embodiment: The soft refractory caulking material can fully fill the gap between the two.

[0047] Other embodiments are the same as Embodiment One.

[0048] Embodiment Seven: In a gas combustion device with low pollutant emissions, a soft refractory caulking material is provided between the water-cooled jacket seal box 7 and the silicon carbide heat radiation isolation belt 4.

[0049] In this embodiment: A soft refractory caulking material is provided between the water-cooled jacket seal box and the silicon carbide heat radiation isolation belt, and the soft refractory caulking material can fully fill the gap between the two.

[0050] Other embodiments are the same as Embodiment One.

[0051] Embodiment Eight: In a gas combustion device with low pollutant emissions, a flame detection device 10 is fixed to the outer end face of the combustion air large wind box frame 5.

[0052] In this embodiment: A flame detection device is fixed to the outer end face of the combustion air large wind box frame, and the burner flame detection device is used to detect the flame of the gas combustion device of the present application.

[0053] Other embodiments are the same as Embodiment One.

[0054] Embodiment Nine: In a gas combustion device with low pollutant emissions, the fixed integrated silicon carbide burner 8 "floats" outside the conical constriction of the combustion air outlet barrel device 2 and multiple main fuel gas nozzles 31.

[0055] In this embodiment: The fixed integrated silicon carbide burner 8 "floats" outside the conical constriction of the combustion air outlet barrel device 2 and multiple main fuel gas nozzles 31, so that there is enough space when the combustion air outlet barrel device discharges air and when the main fuel gas nozzles spray fire.

[0056] Other embodiments are the same as Embodiment One.

[0057] Embodiment Ten: In a gas combustion device with low pollutant emissions, the inner contour of the combustion air / recirculated flue gas mixing Venturi channel G of the integrated silicon carbide burner 8 and the outer contour of the conical constriction of the combustion air outlet device 2 form a Venturi ejector structure; the inner contour of the main fuel gas / recirculated flue gas mixing Venturi channel F of the integrated silicon carbide burner 8 and the outer contour of the nozzle of the main fuel gas nozzle 31 form a Venturi ejector structure.

[0058] In this embodiment: The ejector negative pressure sucks the flue gas in the furnace and returns it through the flue gas reflux channel into the above-mentioned combustion-supporting air / vortex flue gas mixing Venturi channel and the main fuel gas / vortex flue gas mixing Venturi channel. The combustion-supporting air is mixed with the vortex flue gas, reducing the oxygen concentration of the combustion-supporting air, increasing the heat-absorbing working medium, inhibiting fuel combustion, and reducing the fuel combustion rate and combustion temperature; the main fuel gas is mixed with the vortex flue gas, reducing the fuel concentration, increasing the heat-absorbing working medium, reducing the fuel combustion rate and combustion temperature, thereby inhibiting the generation of NOx.

[0059] Other embodiments are the same as the first specific embodiment.

[0060] This solution arranges a swirling long-burning flame gas main pipe, swirling long-burning flame gas branch pipes, and circumferentially arranged main fuel gas nozzles distributed dispersedly, achieving the staging of the combustion of the main flame fuel and the long-burning flame fuel, avoiding the concentration of gas flames, thereby reducing local high-temperature areas and achieving the purpose of reducing the generation of thermal NOx; the combustion-supporting air is precisely distributed through the combustion-supporting air large air box frame and the auxiliary air regulating damper, flows through the combustion-supporting air outlet barrel device and the combustion-supporting air jet constriction, and is ejected into the combustion-supporting air / flue gas mixing channel of the integrated silicon carbide burner at a high speed. The air jet constriction and the structure of the burner form the structure of a Venturi injector. When the high-speed jet of air flows through this structure, a negative pressure is generated, thereby sucking the flue gas refluxed from the flue gas reflux channel. The sucked flue gas enters the burner through the auxiliary air flue gas entrainment inlet and mixes with the air, and then is sprayed into the furnace through the flared structure at the outer end of the burner to assist in fuel combustion. The flue gas sucked into the combustion-supporting air reduces the oxygen concentration in the combustion-supporting air body, reduces the intensity of fuel combustion, and to a certain extent reduces the temperature of the combustion high-temperature area and the high-temperature area, thereby reducing the generation of thermal NOx. The flared structure at the outer end of the burner also slows down the contact between the combustion-supporting air and the main fuel gas, achieving air staging; the gas flows through the main flame gas main pipe and the main flame gas supply ring box and is evenly supplied to the circumferentially arranged main flame gas pipes and jets into the main fuel / flue gas mixing channel of the burner at a high speed. Here, the structure of the main flame gas pipe and the burner also forms the structure of a Venturi injector. When the high-speed jet of fuel flows through this structure, a certain negative pressure is generated, thereby sucking the flue gas refluxed from the flue gas reflux channel. The sucked flue gas is evenly mixed with the fuel in the main fuel / flue gas mixing channel and then sprayed into the furnace for combustion. The sucked flue gas participates in the main fuel combustion process as an endothermic working medium and absorbs a large amount of heat generated by ignition, so the flame temperature is reduced, thereby achieving the purpose of reducing NOx generation; the long-burning fire fuel gas is ejected through the jet holes at the front end of the long-burning flame gas main pipe and the tangential jet holes at the end of the long-burning flame gas branch pipes, contacts and mixes with the air passing through the long-burning flame air swirl vanes and burns to play a role in stabilizing the combustion of the burner; in addition, the burner and the heat radiation isolation belt are both made of integral silicon carbide high-temperature resistant materials, aiming to isolate the direct action of the high-temperature flame heat radiation in the furnace on the metal of the burner body; the main load-bearing structure flange is the main load-bearing part of the burner, and the main structural components of the burner are all connected to this main load-bearing flange through welding or mechanical connection. The burner water-cooling jacket also achieves an overall sealing effect through mechanical connection with the water-cooling jacket sealing box. The burner as a whole is hung on the combustion-supporting air large air box frame through the combustion device suspension structure.

[0061] The present invention combines the technologies of air staging and fuel staging combustion with the technology of flue gas internal recirculation, reducing the local oxygen concentration in the combustion reaction zone of the fuel and directly lowering the flame temperature; air staging and fuel staging can effectively reduce the local high-temperature flame zone and significantly reduce the generation of NOx, and is applicable to gas industrial boilers and gas power station boilers.

Claims

1. A low pollutant emission gas combustion device, characterized in that: It comprises a swirl permanent flame gas device (1), a combustion air outlet tube device (2), a main flame gas device (3), an integrated silicon carbide burner (8), a silicon carbide heat radiation protection isolation belt (4), a water cooling jacket (6), a water cooling jacket sealing box (7) and a combustion air bellows frame (5); The middle of the water cooling jacket (6) and the water cooling jacket sealing box (7) passes through the combustion air outlet duct device (2), the swirl long-burning flame gas device (1) is arranged in the middle of the combustion air outlet duct device (2), the main flame gas device (3) is arranged outside the combustion air outlet duct device (2), and the main flame gas device (3) includes a main gas supply ring box (32) and a plurality of main fuel gas nozzles (31); the main gas supply ring box (32) is mounted on the combustion air outlet duct device (2) The main gas supply ring box (32) is fixedly connected to the outer end surface of the water cooling jacket sealing box (7), one end of the main gas supply ring box (32) is connected to the main gas supply main pipe (33) connected thereto, a plurality of main fuel gas nozzles (31) are evenly distributed along the circumferential direction and fixedly connected to the inner end surface of the water cooling jacket sealing box (7), and the plurality of main fuel gas nozzles (31) are all connected to the main gas supply ring box (32), one end of the combustion air outlet duct device (2) is connected to the combustion air large wind box frame (5) The outer end surface is fixedly connected, one end of the swirl permanent flame gas device (1) and one end of the air inlet of the main gas supply main pipe (33) both pass through the outer end surface of the combustion air bellows frame (5), the outer end plate of the water cooling jacket sealing box (7) is fixedly connected to the inner end surface of the combustion air bellows frame (5), the integrated silicon carbide burner (8) is connected and supported by the end plate of the water cooling jacket sealing box (7) through a high temperature resistant supporting and fixing metal piece (81), a plurality of main fuel gas nozzles (31) and the combustion air outlet pipe device (2 ) are respectively inserted into the root of the channel corresponding to the integrated silicon carbide burner (8), a main fuel gas / entrained smoke gas mixing Venturi channel (F) is provided between the plurality of main fuel gas nozzles (31) and the integrated silicon carbide burner (8), a combustion air / entrained smoke gas mixing Venturi channel (G) is provided between the air outlet of the combustion air outlet tube device (2) and the integrated silicon carbide burner (8), and a smoke return channel (E) is provided between the integrated silicon carbide burner (8) and the water cooling jacket (6).

2. A low pollutant emission gas combustion device according to claim 1, characterized in that: A silicon carbide heat radiation protection isolation zone (4) is provided at the end plate of the flue gas reflow channel (E) between the water cooling jacket (6) and the integrated silicon carbide burner (8) close to the water cooling jacket sealing box (7).

3. A low pollutant emission gas combustion device according to claim 1, characterized in that: The outlet of the combustion-supporting air outlet duct device (2) is a truncated cone-shaped conical structure. A triangular combustion-supporting air inlet hole (21) is arranged on the combustion-supporting air outlet duct device (2). A combustion-supporting air regulating damper (22) is arranged outside the triangular combustion-supporting air inlet hole (21). The combustion-supporting air regulating damper (22) is connected to a pull rod (23) and the opening and closing of the combustion-supporting air regulating damper (22) is controlled by the pull rod (23). The control section of the pull rod (23) passes through the outer end surface of the combustion-supporting air bellows frame (5). A scale (24) is arranged near the pull rod (23). The pull rod (23) and the scale (24) are used in combination to determine the opening and closing state of the combustion-supporting air regulating damper (22).

4. A low pollutant emission gas combustion device according to claim 1, characterized in that: The top of the combustion-supporting air outlet tube device (2) is connected to the upper end surface of the combustion-supporting air large wind box frame (5) via a supporting structure (51).

5. A low pollutant emission gas combustion device according to claim 4, characterized in that: The swirl ever-burning flame gas device (1) comprises a combustion stabilizing hood (11), a swirl ever-burning flame gas main pipe (12), a swirl ever-burning flame combustion branch pipe (13) and a swirl blade (14); The swirl ever-burning flame gas main pipe (12) and the ignition device (9) are arranged adjacent to each other in the upper and lower parts. One end of the swirl ever-burning flame gas main pipe (12) and one end of the ignition device (9) pass through the outer end surface of the combustion air bellows frame (5) and are fixed on the outer end surface. The combustion stabilizing hood (11) is installed outside the other end of the swirl ever-burning flame gas main pipe (12) and the other end of the ignition device (9). The swirl ever-burning flame combustion branch pipe (13) and the swirl blade (14) are both arranged in the combustion stabilizing hood (11). The swirl ever-burning flame combustion branch pipe (13) is connected to the outer wall of the swirl ever-burning flame gas main pipe (12). The swirl blade (14) is fixed on the combustion stabilizing hood (11) and the swirl ever-burning flame gas main pipe (12).

6. A low pollutant emission gas combustion device according to claim 1, characterized in that: A soft refractory filler is provided between the water cooling jacket (6) and the silicon carbide heat radiation protection isolation belt (4).

7. A low pollutant emission gas combustion device according to claim 1, characterized in that: A flame detection device (10) is fixed to the outer end surface of the combustion air bellows frame (5).

8. A low pollutant emission gas combustion device according to claim 1, characterized in that: The integrated silicon carbide burner (8) is made by integral casting and sintering.

9. A low pollutant emission gas combustion device according to claim 1, characterized in that: The fixed integrated silicon carbide burner (8) is "suspended" outside the truncated cone-shaped conical opening of the combustion air outlet tube device (2) and a plurality of main fuel gas nozzles (31).

10. A low pollutant emission gas combustion device according to claim 1, characterized in that: The inner contour of the combustion air / entrained smoke gas mixing Venturi channel (G) of the integrated silicon carbide burner (8) and the outer contour of the table-shaped contraction of the combustion air outlet tube device (2) form a Venturi ejector structure; the inner contour of the main fuel gas / entrained smoke gas mixing Venturi channel (F) of the integrated silicon carbide burner (8) and the outer contour of the nozzle of the main fuel gas nozzle (31) form a Venturi ejector structure.

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