选择性催化还原混合器及整流器的设计与结构优化  

Design and Structure Optimization of Selective Catalytic Reduction Mixer and Rectifier

作　　者：陈贵升[1] 杨锐敏 和志高 黄震[1] CHEN Guisheng;YANG Ruimin;HE Zhigao;HUANG Zhen(School of Traffic Engineering,Kunming University of Science and Technology,Kunming 650500,China;Dehong Vocational College of Yunnan Province,Dehong 678400,China)

机构地区：[1]昆明理工大学交通工程学院,昆明650500 [2]云南省德宏职业学院,德宏678400

出　　处：《内燃机工程》2020年第2期46-53,61,共9页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金项目(51866004)。

摘　　要：通过搭建柴油机后处理试验台架,运用计算流体力学(CFD)对选择性催化还原系统(SCR)内的反应进行仿真计算,设计4种混合器和3种整流器方案,研究了不同混合器及整流器结构对SCR系统内NH3分布及NOx转化效率的影响。结果表明:混合器能够有效改善SCR内NH3分布均匀度及NOx的转化效率。综合分析,有7个厚度均为2mm的叶片且叶片与径向方向的夹角均为30°的方案M2的混合器结构设计较优;气流受到入口扩张管的扩张作用之后,经过方案D1的整流器,使得SCR系统具有更高的NH3分布均匀度和NOx转化效率。混合器和整流器结合可以实现流场的优化,提高NOx转化效率。A diesel engine aftertreatment test bench was built.A numerical simulation model of selective catalytic reduction(SCR)was established with the computational fluid dynamics(CFD)software,and the reliability of the simulation model was verified.Four mixers and three rectifier schemes were designed and their effects on NH3 distribution and NOx conversion efficiency in SCR system were studied.First the effect of different mixers on NH3 distribution and NOx conversion efficiency in the SCR system was investigated.The results show that the mixer can improve the uniformity of NH3 distribution and the conversion efficiency of NOx in the SCR catalyst,and the M2 mixer having seven blades with a thickness of 2 millimeters and an angle of 30°between the blades and their radial directions is the best.Then,the effects of combination of M2 mixer with different rectifiers on NH3 distribution and NOx conversion efficiency in SCR systems are analyzed.The results show that the combination of the mixer and rectifier can optimize the flow field and improve the NOx conversion efficiency,and D1 rectifier makes the SCR system have higher NH3 distribution uniformity and NOx conversion efficiency.

关 键 词：选择性催化还原 混合器 整流器 NOx转化效率 数值仿真 

分 类 号：TK442[动力工程及工程热物理—动力机械及工程]