Low-nitric-oxide direct-current pulverized coal combustor adaptive to meager coal boiler

Abstract

The invention relates to a low-nitric-oxide direct-current pulverized coal combustor adaptive to a meager coal boiler, which can achieve stable and economical combustion, and also reduces nitric oxide emission to the lowest level, so that the low-nitrogen combustion modifying technique of the meager coal boiler is improved. The low-nitric-oxide direct-current pulverized coal combustor adaptive to the meager coal boiler comprises main combustor groups which are arranged on four corners of a hearth of the meager coal boiler in a four-angle tangential circle combustion mode, are matched with a water-cooling wall high-temperature-prevention corrosion system of the hearth, and are identical in structure; each main combustor group comprises pulverized coal combustors arranged at intervals and secondary air spray ports; the upper parts of the main combustor groups are provided with corresponding separation burnout air groups; a layer of precombustion chamber back flow combustor is arranged in each n-layer of pulverized coal combustors; the jet flow rotation direction of the main combustor groups is the anticlockwise direction; the rotation direction of secondary air ports close to the upper parts of the precombustion chamber back flow combustors is the clockwise direction, and the imaginary tangential circle diameter is greater than the imaginary tangential circle diameter of the main combustors; separation burnout air groups include upper groups and lower groups; and the jet flow of the lower groups is in an imaginary tangential circle mode, and the jet flow of the upper groups is in an opposed combustion mode.

Description

technical field [0001] The invention relates to a direct-flow pulverized coal combustion device, in particular to a low-nitrogen oxide direct-flow pulverized coal combustion device suitable for lean coal boilers. Background technique [0002] Nitrogen oxides (NOx) are pollutants that endanger human health and damage the atmospheric environment. Among them, coal-fired power plants are the most important emission source, accounting for 67% of NOx emissions, and the proportion will increase as the installed capacity of thermal power plants increases. In order to control the emission level of NOx pollutants from coal-fired power plants in my country, The country has successively promulgated more stringent emission standards for air pollutants from thermal power plants, and put forward stricter nitrogen oxide emission levels, and no longer set different standards for coal types, that is to say, whether it is bituminous coal boilers or lean coal, or even Even anthracite boilers mus...

AI Technical Summary

Problems solved by technology

[0019] According to the above analysis, it can be found that the current low-nitrogen direct-flow pulverized coal burner is more suitable for better ignition characteristics. Coal types with higher volatile content, such as bituminous coal or lignite, will produce more coal with poor ignition characteristics, such as lean coal. Negative impacts are mainly manifested in: (1), the carbon content of fly ash and slag increases, and the boiler economy decreases

(2) Boiler low-load combustion stability is reduced

(3) The reducing atmosphere on the wall surface of the water cooling wall is relatively high, and the water cooling wall is prone to high temperature corrosion

If these problems are not solved, when the low-nitrogen combustion transformation of the lean coal boiler is carried out, it will not only affect the low-nitrogen transformation effect of the boiler, but also seriously affect the safe and economical operation of the boiler.

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