摘要
为降低柴油机污染物排放,提出DOC+SCR直筒型催化器系统,利用计算流体动力学(CFD)建立DOC+SCR直筒型催化器的三维数值仿真模型,该模型包括尿素水溶液的蒸发和分解,但忽略催化剂表面的催化还原反应,基于简化模型提出一种NO_x转换效率的计算方法,根据试验结果对数值模型和NO_x转换效率计算方法进行验证.分析计算得到的催化器系统内部流场分布情况,提出多种结构优化方案,结果表明:优化后,特定工况下催化器系统压降由9.98,kPa减小至8.60,kPa,催化器结构因素引起的压降由2.98,kPa降低至1.60,kPa;SCR入口截面还原剂NH_3均匀性指数可提高到93.45%,,在特定工况下NO_x转换效率可达92.87%,.
In order to reduce the pollutant emissions from diesel engines,a DOC+SCR catalytic converter system was proposed.A three-dimensional numerical simulation model of the DOC+SCR catalytic converter was established by using computational fluid dynamics(CFD).The model includes evaporation and decomposition of urea aqueous solution,but ignores the catalytic reduction reaction on the catalyst surface.Based on the simplified model,a calculation method of NOx conversion efficiency was proposed.The numerical model and the NOx conversion efficiency calculation method were verified by test results.Through the numerical simulation of the model,the flow field distribution of the catalytic converter was obtained and several optimization scheme were put forward.The results show that after optimization,in certain conditions,the pressure drop of the catalytic converter system is reduced from 9.98,kPa to 8.60,kPa.Also,the pressure drop caused by the catalyst structure factor is decreased from 2.98,kPa to 1.60,kPa.In addition,the NH3 uniformity index of the SCR can be increased to 93.45%,.The conversion efficiency of NOx can reach up to 92.87%, in certain conditions.
作者
胡广地
马卢平
刘丛志
张露
Hu Guangdi;Ma Luping;Liu Congzhi;Zhang Lu(School of Mechanical Engineering,Southwest Jiaotong University,Chengdu 610031,China;State Key Laboratory of Automotive Safety and Energy,Tsinghua University,Beijing 100084,China)
出处
《内燃机学报》
EI
CAS
CSCD
北大核心
2019年第2期155-163,共9页
Transactions of Csice
基金
四川省重大科技成果转化示范资助项目(2015CC0003)
关键词
柴油机
计算流体动力学
结构优化
NO_x转换效率
diesel engine
computational fluid dynamics
structural optimization
NO_x conversion efficiency
作者简介
马卢平,硕士研究生,E-mail:782651790@qq.com;通信作者:胡广地,博士,教授,E-mail:ghu@swjtu.edu.cn.
