Low-NOx combustor with internal reflux of flue gas and homogeneous combustion and gas configuration method thereof

Abstract

The invention belongs to the technical field of high-power industrial gas combustors and relates to a low-NOx combustor with internal reflux of flue gas and homogeneous combustion. The combustor is characterized in that a plurality of radial holes are arranged at the upper end of a middle gas gun; gas gun heads are uniformly and axially distributed on the periphery outside a flame plate; gas holes are arranged at the sides of the gas gun heads and have height different from the height of the radial holes at the upper end of the middle gas gun; the wedge-shaped bevels of the ends of the gas gun heads form included angles beta with the combustor in the axial direction and the directions of the gas gun heads form included angles alpha with the radius of the combustor; and the gas gun heads are uniformly arranged in 2-4 groups according to different values of beta and alpha. The combustor in the invention has the following effects: the gases do not overlap after being jetted from the gun heads and are separately and alternately jetted to the boiler furnace; the combustion air and the gases permeate each other layer by layer and are uniformly and rapidly mixed and combusted in the boiler furnace; and the flame at the root is reduced on the premise of ensuring stable flame so that local high temperature is avoided, thus ensuring the generated NOx to be less than 40ppm.

Description

Technical field [0001] The invention belongs to the technical field of high-power industrial gas burners, and relates to a high-power NOx low-emission high-power burner with backflow in flue gas, gas and combustion-supporting air uniformly mixed in the furnace space, and uniform temperature field. Background technique [0002] Industrial burner is a boiler accessory that mixes fuel and combustion air. Emissions, energy consumption, safety and service life are important indicators to measure the performance of industrial burners. Cities such as Beijing and Shanghai have already made it clear that coal-burning is not allowed in industrial boilers, and the emission requirements for burners are also increasing year by year. With the implementation of the national energy conservation and emission reduction policy, my country's burner technology and industrial scale are bound to usher in a new round of great development. [0003] The current industrial gas burners have problems such as...

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Problems solved by technology

[0003] The current industrial gas burners have problems such as high energy consumption, low power, and large NOx emissions.

Especially for diffusion gas burners, the power of the flat flame stabilizer used is less than 8MW; while the blade flow pattern of the swirl type flame stabilizer is mostly oblique straight plate type, with large resistance and poor swirl effect; gas gun The form is also simple. Each gun head has a single opening, most of which are single holes and have the same orientation, so that the gas flows in a single direction, and the air and gas cannot be mixed evenly in the furnace, and it is impossible and difficult to stabilize the flame. Reduce NOx emissions, combustion is easy to produce CO, so that single-unit high-power (above 20MW) burners have disadvantages such as large excess air coefficient and high energy consumption

In addition, most gas burners are also equipped with a certain amount of intermediate primary combustion-supporting air and primary gas, which mainly play the role of generating a central root flame and stabilizing combustion. However, too much primary combustion-supporting air will easily cause the temperature of the roots to be too low, resulting in root damage. The flame is unstable, and even fire-off phenomenon occurs; too little primary combustion-supporting air will easily cause a large amount of Nox due to the high temperature of the flame root, which hinders the development and application of high-power burners

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