A method to alleviate the temperature deviation of the tube wall of the counter-coal-fired boiler

Abstract

The invention relates to a method for alleviating the temperature deviation of the tube wall of a coal-fired boiler, which includes setting a deflector at the elbow of the secondary air wind box pipe; device; install a wind direction steering device at the air inlet of the inner secondary air duct of the burner; install a second air gathering device at the air inlet of the first and second outer secondary air ducts near the side wall; The third air gathering device is installed at the air inlet of the secondary air duct in the first and second burn-out air channels on the side wall. The present invention proposes a scheme for reforming the flow field of the secondary air bellows combined with the reformation of the secondary air passage near the side wall burner (including the burn-out air). Diversion, flaring, confluence, etc. are optimized to smooth the air flow in the air duct, thereby increasing the secondary air volume in the area near the side wall, so as to further alleviate the overheating of the tube wall in the furnace, and effectively control the occurrence of overtemperature tube explosion.

Description

technical field [0001] The invention relates to the field of boiler transformation, in particular to a method for alleviating the temperature deviation of the tube wall of a counter-coal-fired boiler. Background technique [0002] The "Coal Power Energy Conservation and Emission Reduction Upgrading and Transformation Action Plan (2014-2020)" pointed out the direction for the design optimization of newly built units, and provided the main reference technologies for energy conservation and emission reduction in coal-fired power plants, among which improving steam parameters and secondary reheating technology are more important. Mature. To increase the steam parameters is to increase the main steam pressure to 27MPa ~ 28MPa, maintain the main steam temperature at 600°C, and increase the hot reheat steam temperature to 610°C or 620°C. With the improvement of steam parameters, especially the increase of the temperature of hot reheat steam to 620°C, the requirements for materials...

AI Technical Summary

Problems solved by technology

However, due to the structural characteristics of the burner, when the damper of the intermediate burner is closed below 30%, the rigidity of the secondary air volume of the intermediate burner will be insufficient, causing the combustion flame to brush the wall and coke and burn the nozzle

Therefore, in the process of deep optimization and adjustment, after the dampers of the burners on both sides are fully opened and the dampers of the middle burner are closed to 30%, even if the oxygen content on both sides is low and the CO emission concentration is still high, the means of combustion optimization adjustment can no longer meet the requirements. Balancing air distribution needs

At the same time, the optimization and adjustment of the deep combustion of the unit can alleviate the overheating of the pipe wall, but because the combustion process in the furnace is a dynamic process, it is greatly affected by the type of coal, the contamination in the furnace, etc., and the stability of the combustion optimization effect is not enough

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