Simulation of Efficiency and Low NO_x Combustion-Supporting Technology by Local Oxygen-Enrichment in Pulverized Coal Boiler

摘要

To solve problems such as low thermal efficiency, high concentration of NO_x emissions and slag bonding of a 150t/h pulverized coal boiler, A new idea of using enriched-oxygen air as the over flame air (OFA) and welted edge air was proposed. With the help of computer numerical simulation technology and using k-ε-g turbulence combustion model for computations of the gas phase and two competing reactions for the coal devolatilization, the velocity and temperature field and concentration of NO_x in the combustion of pulverized coal were simulated. The simulation result shows that the local oxygen-enrichment combustion-supporting technology used in tangential pulverized coal boiler can improve the dynamic field characteristics and combustion stability in the furnace effectively, and has a very positive role on reducing the concentration of NO_x emissions.