STUDY OF COAL RANK AND FINENESS ON NOx REDUCTION WITH COAL REBURNING TECHNOLOGY
煤种及煤粉细度对炉内再燃过程脱硝和燃尽特性的影响

Coal reburning is a successful advanced technology for reducing NO_x emissions from utility coal-fired boilers. In this work, various rank coals were employed as reburning fuel, the effects of reburning fuel ratio, reacting zone temperature, excess air, residual time and coal fineness on NO_x reduction efficiency were experimentally investigated by using an one-dimension drop-tube furnace. The experimental results show that the coal with high volatile content can reduce NO_x more effectively. For the same coal, in order to achieve high NO_x reduction efficiency, the finer coal finess and suitable residence time of the reburning zone are required. The minimum burn-out height has been put forward to evaluate the right location of the reburning coal injection ports to get a higher carbon burn-out and higher NO_x reduction efficiency.