DOC/POC/SCR组合后处理技术在非电控柴油机排放上的应用研究  

Study on Emission Characteristics of Non-Electronically Controlled Diesel Engine with DOC/POC/SCR Combined System

作　　者：刘洋[1,2] 孙亮 白书战[1,2] 王刚 张杰 李国祥[1] 

机构地区：[1]山东大学能源与动力工程学院,济南250061 [2]无锡威孚力达催化净化器有限责任公司技术研发中心,无锡214177

出　　处：《内燃机工程》2015年第1期18-22,共5页Chinese Internal Combustion Engine Engineering

基　　金：山东大学基本科研业务费专项资金资助项目(2014QY001-04);山东省中青年科学家奖励基金项目(BS2013NJ012)

摘　　要：在一台经典非电控柴油机上进行了氧化催化剂(diesel oxidation catalyst,DOC)/颗粒氧化转化器(particle oxidation catalyst,POC)/选择性催化还原转化器(selective catalytic reduction,SCR)组合后处理排放控制研究以使其达到国-Ⅴ标准要求,对后处理单元的选择及排布进行了考察。试验结果表明:DOC+POC及SCR单后处理系统仅能使试验发动机排放污染物中颗粒物(PM)或NOx达到国-Ⅴ标准;而DOC/POC/SCR组合后处理系统则可使两种污染物排放均满足标准要求。SCR与DOC+POC排布顺序对污染物去除效率无明显影响。对POC的被动再生研究表明:DOC+POC系统需置于SCR系统前以使排气中NO2量满足POC的连续再生要求,且SCR系统后置也可降低其入口温度,减小温度对涂层的热老化影响。通过陶瓷POC的应用及结构优化设计使得组合后处理系统排气背压控制在25kPa之内,可减少对发动机性能影响。An after treatment study was conducted on a typical non electronically controlled diesel engine using combined system of diesel oxidation catalyst （DOC）/particle oxidation catalyst （POC）/selective catalytic reduction catalyst （SCR） to attain China-Ⅴ emissions standards. The research was focused on the selection and arrangement of treatment units. The experiments results show that employing DOC＋POC or SCR system can only reduce either particulate matters （PM） or NO, to the China-Ⅴ standards level,while adopting DOC/POC/SCR combined system can bring both PM and NO, emissions down to the China-Ⅴ standards level. There is no obvious influence of different sequence arrangement of SCR and DOC＋POC system on pollutants conversion efficiency. However, the passive regeneration of POC can be only fully achieved by placing DOC-POC before SCR system due to sufficient amount of NO2 in exhaust which can be utilized for PM oxidation,and such arrangement can reduce hydrothermal aging effect on SCR catalyst owing to lower inlet temperature. The backpressure of the combined system can be less than 25 kPa through the application of ceramic-based POC and optimal design of packaging structure.

关 键 词：内燃机 非电控柴油机 柴油机氧化催化器 颗粒氧化转化器 选择性催化还原 组合后处理系统 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]