DOC催化剂配方对重型柴油机气态污染物排放的影响  

EFFECT OF DOC CATALYST FORMULATION ON GASEOUS EMISSION CHARACTERISTICS OF HEAVY-DUTY DIESEL ENGINES

作　　者：楼狄明[1] 施雅风 张允华[1] 耿小雨 LOU Di-ming;SHI Ya-feng;ZHANG Yun-hua;GENG Xiao-yu(School of Automotive Studies, Tongji University, Shanghai 201804, China)

机构地区：[1]同济大学汽车学院

出　　处：《环境工程》2019年第8期117-121,共5页Environmental Engineering

基　　金：云南省科技厅高新处工业领域重点科技计划项目(2018ZE001)

摘　　要：基于重型柴油机台架试验,研究了氧化催化器(diesel oxidation catalytic,DOC)的催化剂配方对安装了DOC+催化型颗粒捕集器(catalyzed diesel particulate filter,CDPF)后处理系统的重型柴油机排放特性的影响。结果表明:催化剂配方对发动机排气参数和经济性没有影响;较高的贵金属负载量和Pt占比能有效降低还原性污染物的起燃温度,但随着排气温度的提高,各方案转化率相差不大;CO与HC在较低排气温度下存在竞争吸附关系,因而贵金属负载量和配比对HC所呈现的规律与CO相反;较高的贵金属负载量和Pt占比能提高平衡温度下NO2的生成率,同时较高的Pd占比能提高催化剂热稳定性;CDPF具有进一步氧化NO的能力。Based on the bench test of a heavy-duty diesel engine,different catalyst parameters of diesel oxidation catalytic( DOC) were studied for the impact of gaseous emission characteristics of the engine with DOC+catalyzed diesel particulate filter( CDPF) after-treatment system. The results showed that the catalyst formulations had no effect on engine exhaust parameters and running cost;higher rare metal loading and Pt ratio could effectively reduce the light-off temperature of CO and HC,but there was little difference in the conversion rate of each scheme with increase of exhaust gas temperature. Competitive adsorption existed between CO and HC under a lower exhaust gas temperature,but the influencing law of rare metal loading and formulation on HC was in opposite to that of CO. Higher rare metal loading and Pt proportion could rise the production rate of NO2 under the balancing temperature,and higher Pd proportion could rise the heat-stability of the catalysts. CDPF had the capacity of deeper oxidizing of NO.

关 键 词：重型柴油机 催化剂 DOC+CDPF 气态污染物 

分 类 号：X734.2[环境科学与工程—环境工程]