国六重型柴油车劣化排放特性分析

Analysis of Deteriorated Emission Characteristics of China VI Heavy-Duty Diesel Vehicle

摘要: 重型柴油车是我国目前最主要的交通工具，并占据了较高的NO_x和PM排放，基于实际道路行驶测量方法(PEMS)模拟后处理中毒和老化情况下的实车排放，选取了一辆技术路线为：EGR + DOC + DPF + SCR的国六重型柴油车进行不同劣化件组合的排放分析。结果表明：DOC失效比SCR转化效率降低产生的NO_x排放更多；低速行驶时，EGR率过高反而会导致排放增加；目前国六的技术路线能够很大程度上起到净化排气的作用；任何一个部件的异常工作状态都会导致排放明显增加。

Abstract: Heavy duty diesel vehicles are currently the most important means of transportation in China, accounting for a high proportion of NO_x and PM emissions. Based on the actual road driving measurement method (PEMS) simulation of post treatment emissions under poisoning and aging conditions, a national VI heavy duty diesel vehicle with a technical route of EGR + DOC + DPF + SCR was selected for emission analysis of different deteriorated component combinations. The results show that DOC failure produces more NO_x emissions than SCR conversion efficiency reduction; When driving at low speeds, an excessively high EGR rate can actually lead to an increase in emissions; At present, the technical route of National VI can largely play a role in purifying exhaust gas; The abnormal working state of any component will lead to a significant increase in emissions.