超细煤粉的细度对再燃还原NO的影响

THE EFFECT OF THE MICRO-PULVERIZED COAL FINENESS ON NITRIC OXIDE REDUCTION BY REBURNING

以烟煤和褐煤混煤的超细煤粉作为再燃燃料,用N2、O2、CO2、NO配制模拟烟气,在立式携带流反应器中进行了煤粉再燃还原NO的实验,研究了超细煤粉的细度对炉内1300℃高温烟气中再燃还原NO的影响.结果表明:①超细煤粉在再燃区内最佳停留时间约为0.8s;② NO的还原效率随着超细煤粉细度提高而增大;③在再燃燃料比为20%～25%、再燃区的初始氧浓度为4%～6%的工况范围内,煤粉细度对NO还原效率的影响显著;④在保证一定的NO排放浓度水平的情况下,使用较细的超细煤粉作为再燃燃料时,可以减少再燃燃料的投入量.

An experiment is proceeded in which, NO is reduced by micro-pulverized coal in an entrained flow reactor, the mixture of bituminous coal and lignite is used as the reburning fuel, and the N2, O2, CO2, NO are mixed to simulate flue gas. The effect of micro-pulverized coal fineness on the NO reduction in 1300℃ flue gas is studied. The results indicate: (1) The optimum duration that the micro-pulverized coal stays in the reduction zone is about 0.8s; (2) The NO reduction efficient increases with the increasing of the fineness of the micro-pulverized coal; (3) When the reburning-fuel rate is about 20% to 25% and the O2 concentration is 4% to 6%, the effect of micro-pulverized coal fineness on the NO reduction is most obvious; (4) When the NO emission level meets what is demanded, using more micro-pulverized coal as reburning fuel ,the amount of the reburning fuel can be decreased.