Study on Co-firing characteristics of NH3 and coal in the main burning zone of the coal staged combustion
Jianwei Yuan, P P Wang, Chunrui Ruan, Xiaohuan Huang
Abstract
Abstract The mathematical models including NH 3 and pulverized coal were established, and the co-combustion characteristics of NH 3 /pulverized coal and NO x formation process in the main combustion zone (air consumption coefficient 0.9) of coal staged combustion are studied. The gas temperature distributions and NOx generation characteristics under different ammonia/pulverized coal ratios are investigated. The results show that the ammonia combustion and the NO x production is greatly enhanced by coal combustion when the ammonia and pulverized coal are mixed. For pure ammonia combustion, due to difficult ignition and lower burning rate in the lower gas temperature environment, the NO concentration formed in the furnace and at the outlet are very low; When the proportion of NH 3 is 20%, the NO x concentration at the furnace outlet is the highest; when the ammonia gas ratio is 40%, NO at the outlet is lower than that of pure pulverized coal. In addition to a large amount of NO, there are also a large amount of NO 2 and N 2 O in the high temperature region when ammonia and pulverized coal are mixed.