摘要
采用计算流体力学和化学反应动力学相结合的方法,建立了某型号车用柴油机Urea-SCR排气后处理系统的数值模型,运用FIRE软件对某Urea-SCR催化器系统内3种典型工况下的尿素液滴的分布特性和内部流动特征进行了研究,并重点分析了空速和NO_2体积分数这2个因素对NO_x转化效率的影响.结果表明:NO_x转化效率随空速的增大而降低,当空速大于35 000 h^(-1)时,转化效率低于25%;NO_x转化效率随着V(NO2)/V(NO_x)比值的增加先增大后减小,当控制V(NO_2)/V(NO_x)的比值在0.5左右时,A25和B50工况下的NO_x转化效率最大值分别为50%和59%.
The numerical model of a diesel Urea-SCR aftertreatment system was set up by the methods of CFD and chemical reaction dynamic. Based on the FIRE software,the distribution and the internal flow characteristics of urea droplets in a Urea-SCR catalyst system were analyzed under three typical operating conditions,and the effects of ghsv and NO_2 content on NO_xconversion efficiency were specially investigated. The results show that the NO_xconversion efficiency is reduced with the increasing of ghsv.When the ghsv is faster than 35 000 h^(-1),the conversion efficiency is lower than 25%. With the increasing of ratio of V( NO_2) /V( NO_x),the NO_xconversion efficiency is increased with latter decreasing. When the ratio of V( NO_2) /V( NO_x) is controlled at about 0. 5,the maximum NO_x conversion efficiencies are 50% and 59% under the working conditions of A25 and B50,respectively.
出处
《江苏大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2016年第4期386-393,共8页
Journal of Jiangsu University：Natural Science Edition
基金
国家自然科学基金重点资助项目(51276084)
江苏省科技支撑(工业)计划项目(BE2010198)
江苏高校优势学科建设工程项目(2010)
江苏省普通高校研究生科研创新计划项目(CXZZ11_0560)
