To meet the increasingly stringent emission regulations,an important aftertreatment technology(SDPF,the selective catalyt-ic reduction catalysts coated into a diesel particulate filter)was developed,which has the ability to reduce both NOx and particulate in the exhaust gas of diesel engines.Not only that,SDPF finds a solution to the problem of heat loss caused by SCR being far from the en-gine exhaust valve,and can significantly reduce NOx emissions during cold start conditions.In this study,a simulation model was es-tablished to explore the effect of different catalyst coating strategies(two variables are catalyst washcoat loadings and coverage rates)of SDPFs on the emission characteristics and performance of diesel engines.The simulation result showed that,pressure drop rises with increasing catalyst washcoat loading and coverage rate,and excessive catalyst coating led to a decrease in NOx conversion efficiency.The highest conversion efficiency for NOx is obtained when the catalyst washcoat loading reached 70g/L with an average conversion rate of 95.2%,and a coverage rate of catalyst washcoat above 60% could have better NOx reduction performance than full coating(at low engine load conditions).
关键词
柴油发动机/选择性催化还原捕集技术/催化剂涂覆/排放/压降
Key words
diesel engine/SDPF/catalyst washcoat loading/catalyst washcoat coverage rate/emission/pressure drop
万方数据