煤粉粒度对煤粉燃烧NO_x排放的影响

The effect of pulverized coal size on nitrogen oxides emission performance from pulverized coal combustion

通过数值模拟和试验研究 ,探讨了煤粉在一维热态试验炉内燃烧时 ,煤粉粒度对NOx 排放特性的影响规律 .研究结果表明 :NOx 的排放浓度与煤粉粒度的关系中 ,存在一个煤粉粒度临界值 .当煤粉粒度小于临界值时 ,随煤粉粒度的减小 ,NOx 的排放浓度减小 ;当煤粉粒度大于临界值时 ,随煤粉粒度的减小 ,NOx 的排放浓度增大 ;无论在氧化性气氛中 ,还是在还原性气氛中 ,煤粉超细化后NOx 的释放浓度均减小 ;煤粉高度细化后 ,褐煤NOx 的排放浓度明显减少 ,无烟煤则变化不大 .

Mathematical simulation and experimental study for the influence of pulverized coal size on NO_x emission performance in a bench scale furnace have been done. The results show that there exists a critical diameter (dc). If d<dc, the NO_x concentration reduces with the decrease of pulverized coal size. If d>dc, the NO_x concentration reduces with the increase of the pulverized coal size. The concentration of NO_x is reduced for superfine pulverized coal whether in the oxidative circumstance or in the reductive circumstance. The quantity of NO_x released from superfine pulverized coal decreased obviously for lignite, but decreased little in some sort for anthracite. Overall reasonable agreement between the simulating and experimental results for NO_x release behavior is obtained.