中文摘要：

NOx是大气污染的主要污染源之一，据国家环境保护总局统计，有67％的NOx排放来自煤燃烧，因此控制NOx排放的措施受到日益关注，主要有两类：一类是烟气净化技术，另一类是低NOx燃烧技术。燃料再燃技术是低NOx燃烧技术之一，国内外许多学者进行了大量研究。对于煤粉炉，由于所采用的再燃燃料种类与一次燃料相同，无需考虑对第二种燃料的输送问题，这很有利。

英文摘要：

The experiments on NO reduction by the reburning of pulverized Yanzhou bituminous coal were conducted separately with different amounts of water vapor added in a fixed-bed reactor, through which the effect of water vapor on NO reduction by pulverized coal reburning was studied. It is found that NO reduction by pulverized coal reburning was accelerated by adding water vapor, but NO reduction per unit mass of coal decreased with the increase of water vapor since the burnout of pulverized coal was also accelerated at the same time. Moreover, the rates of CO production, CO2 production and O2 consumption were increased separately by water vapor, and CO2 production was promoted more significantly during the reaction stage dominated by volatile matter, but CO production was promoted more significantly during the reaction stage dominated by char. However, CO2 production and O2 consumption decreased separately and CO production increased when they were counted by per unit mass of pulverized coal. The burnout time of coal reburning could become shorter with increasing water vapor, for example the burnout time was shortened by 25.9% at 2% water vapor, and was shortened by 47.8% at 4% water vapor. Adding a certain amount of water vapor into the reburning zone could not only improve NO reduction by pulverized coal reburning but also increase burnout ratio. The optimum amount of water vapor could be obtained through experiments on the basis of coal properties of coal, NO concentration in the main combustion zone, the proportion of reburning coal, the excess air coefficient of the reburning zone, and economic appraisal in engineering practice.