Abstract ▼ AI-Helper

To meet severe NOx emission target for USA Tier2 Bin5 and Europe EURO6, most of car makers are considering applying urea selective catalytic reduction systems. The system performance should be monitored through the life and informed to the customer if necessary. This paper investigates the feasibili...

To meet severe NOx emission target for USA Tier2 Bin5 and Europe EURO6, most of car makers are considering applying urea selective catalytic reduction systems. The system performance should be monitored through the life and informed to the customer if necessary. This paper investigates the feasibility of the threshold monitoring with current NOx sensor which must be able to distinguish between a normal and a threshold catalyst with enough separation to allow for variability. It is shown that a 2.5 and 1.75 for USA and 1.75 for Europe threshold monitor is not possible with current NOx sensor technology and what NOx sensor accuracy is necessary for those thresholds. Also, we suggest NOx sensors combination that threshold monitoring is possible for each threshold with current ones. That is, an arbitrary NOx sensor can be positioned inlet of the SCR catalyst together with a nominal sensor outlet of the SCR catalyst.