Characterization of Combustion and NO x Emissions with Respect to Overfire Air Damper Opening in a Down-Fired Pulverized-Coal Furnace

作者：Min Kuang, Zhengqi Li, Xinjing Jing, Xianyang Zeng, Loufeng Zhao, Zhongqian Ling · 发表于：Energy & Fuels · 年份：2013 · DOI：10.1021/ef401205k · 被引用次数：13 · 研究领域：Thermochemical Biomass Conversion Processes、Combustion and flame dynamics、Radiative Heat Transfer Studies

The application of deep-air-staging combustion technology to significantly reduce NO x emissions and simultaneously control combustible loss to acceptable levels is already well established in tangential-fired and wall-arranged furnaces. However, this technology has not yet been widely applied to down-fired furnaces, and thus there is a requirement to investigate the potential benefits. This work presents an experimental investigation of the combustion and NO x emission characteristics in a newly operated down-fired 600 MW e furnace equipped with a deep-air-staging combustion configuration. Full-load industrial-size measurements were performed by acquiring various data such as gas temperatures and species concentrations in the furnace, CO and NO x emissions in flue gas, and carbon in fly ash. Overfire air (OFA) damper opening settings of 15%, 30%, 50%, and 70% were tested in turn so as to evaluate the OFA effect, following which the staged-air damper was opened from 30% to 50% to assess its ability to improve the poor burnout associated with low NO x operating conditions. It was found that, as OFA was opened, gas temperatures in the burner zone and along the flame travel path (prior to penetration of the flame into the hopper region) exhibited an initial increase and subsequently decreased. Similar to trends that have been seen in most tangential-fired and wall-arranged furnaces, opening OFA continuously increased the exhaust gas temperature, CO levels in flue gas, and carbon...