煤粉气化合成气再燃降低NO_x排放的特性研究

Study on NO_x reduction with syngas reburning

通过数值模拟和实验方法研究了煤粉气化合成气的再燃脱硝能力,先后探讨了再燃区温度、再燃区停留时间、再燃燃料比例和过量空气系数等关键因素对降低NOx排放的影响规律。研究结果表明,煤粉气化合成气的再燃脱硝能力随着温度的升高而加强;随着再燃区停留时间的增加而加强,当停留时间超过0.8s后,NOx的还原效率提高幅度趋于平缓;随着再燃燃料比例的增加而增强,超过20%后NOx还原效率提高的幅度变缓;随着再燃区过量空气系数的增加,合成气的脱硝效果逐渐降低。

Numerical simulation and experimental study were conducted on NOx reduction with two kinds of typical pulverized coal syngases as reburning fuels.The influence of some key factors,such as reburning temperature,residence time in reburning zone,reburning fuel fraction and stoichiometric ratio on NOx reduction were studied.The research results indicate that NOx reduction efficiency of syngas increases as temperature and residence time in reburning zone rise.After the residence time is over 0.8 s,NOx reduction efficiency increases slowly.The NOx reduction efficiency of syngas increases as reburning fuel fraction rises.But after the reburning fuel fraction is over 20%,NOx reduction efficiency increases slowly.And NOx reduction efficiency of syngas decreases as the stoichiometric ratio in reburning zone rises.