燃用神华煤2 028 t/h亚临界锅炉超低NOx 燃烧优化试验研究

为摸清燃用神华煤锅炉深度空气分级超低NO_x燃烧规律,实现防结渣、高效燃烧和超低NO_x排放一体化目标,以多目标综合优化技术为基础进行定向调整试验。主要是通过制粉系统和辅助风系统配风方式优化后,机组热效率由94.00%提升至94.14%,SCR入口处NO_x排放由129.0 mg/m³降为108.3 mg/m³;空气预热器入口处CO体积分数由338×10^-6降为50×10^-6,同时飞灰可燃物质量分数和大渣可燃物质量分数均有大幅降低。完整吹灰次数也由每班1次减少为每天1次,炉内清洁程度明显加强。

Experimental Study on Combustion Optimization for Ultra Low NOx Emissions in 2 028 t/h Sub-Critical Boilers Firing Shenhua-Coal

In order to figure out the mechanism of ultra-low NO_x combustion in deep staged air in the boilers firing Shenhua coal and achieve the integrative goals of anti slagging, high efficiency combustion and ultra-low NO_x emission, the directional adjustment test based on the multi-objective optimization technique is conducted. Through the optimization on the air distribution of the coal pulverizing system and auxiliary air system, the thermal efficiency is improved from 94% to 94.14%, the NO_x emissions at the entrance of SCR is reduced from 129 to 108.3 mg/m³, and the CO concentration of air pre-heater inlet also drops from 338 to 50 ppm with the unburned carbon contents both in fly ash and slag significantly decreased. The soot-blowing also is reduced from 3 times to 1 time one day, and the furnace cleanliness is enhanced significantly.