Ejecting staged combustion W flame boiler for improving ignition and combustion of pulverized coal

Abstract

The invention relates to an ejecting staged combustion W flame boiler for improving ignition and combustion of pulverized coal. The W flame boiler comprises a furnace hearth which is formed by an upper furnace hearth, a lower furnace hearth, a front furnace arch and a rear furnace arch, a plurality of secondary air nozzle groups which are arranged on the front furnace arch and the rear furnace arch, and a plurality of pulverized coal airflow nozzle groups, wherein the plurality of secondary air nozzle groups and the plurality of pulverized coal airflow nozzle groups are arranged side by side linearly, equidistantly and abreast along a width direction of a furnace, the plurality of pulverized coal airflow nozzle groups can be arranged on the furnace arches at fixed angles, an incident angle of secondary air can be adjusted, a plurality of over-fire air nozzles with adjustable incident angles can be formed in the upper furnace hearth, and two layers of tertiary air nozzles with the adjustable incident angles can be formed in water-cooled walls of front and rear walls of each furnace hearth. By adopting the W flame boiler disclosed by the invention, the combustion of the pulverized coal in the furnace can be effectively improved, the adaptive capacity of the boiler to coal types can be improved, the heat and reheat steam temperature can be effectively adjusted to reach a design value, the emission of NOx and the flue gas temperature can be reduced, slag bonding of the front and rear walls can be prevented, and the thermal fatigue existing in water-cooled walls of a combustion chamber hopper can be avoided.

Description

technical field [0001] The invention relates to the technical field of W-flame boiler combustion, in particular to an ejection staged combustion W-flame boiler which can effectively improve the ignition and combustion of pulverized coal and whose main combustion zone in the W-flame boiler can be adjusted. Background technique [0002] Coal is the most important primary energy in my country at present and for a long time to come, and coal for thermal power generation is one of the main ways of coal utilization in my country. According to my country's fuel policy and energy utilization situation, the proportion of anthracite and lean coal in the coal consumption of power plant boilers is as high as 40% to 50%, and will be further increased in the future. In order to achieve high-efficiency burning of anthracite and lean coal, a W-flame furnace type specially designed for burning anthracite and lean coal has been developed abroad. my country has introduced W-flame boilers from ...

AI Technical Summary

Problems solved by technology

Summarizing the operation of Douba technology and my country's Douba technology W flame boiler, there are many problems, such as late ignition of pulverized coal jet, poor combustion stability, serious slagging (including side walls and front and rear walls, etc.), burnout Poor, NO x High emission (generally 1100~1700mg / m 3 (6% oxygen)), although Chinese scholars have developed a new type of burner with independent property rights in response to the above problems, the operation situation shows that the "W" flame boiler still has reheating steam temperature deviation from the design value, low burnout rate, and stable combustion. Poor performance, high exhaust gas temperature, NO x High carbon content in emissions and ash slag, severe slagging on the front and rear walls, and large flame undershoot cause problems such as thermal fatigue cracking and pipe burst on the water wall of the cold ash hopper

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