中文摘要：

利用实时EGR率测量系统及瞬态工况测控平台对增压中冷柴油机废气再循环（EGR）阶跃工况下的EGR率、进气量、发动机转矩、燃烧过程特征参数、排气烟度及气态有害排放物的响应历程进行了试验研究．试验结果表明：在1600r／min、50％负荷工况，EGR率从0分别阶跃到3％、5％、13％和28％时，EGR率、进气流量及发动机有效转矩响应速度较快且相近，均为0．5s左右；排气烟度和以最高燃烧压力表征的缸内燃烧过程趋于稳定状态历时较长且时间相近，不同EGR率阶跃时均为2．5s左右；以气态有害物排放表征的柴油机排放响应历时最长为6s左右．这说明在EGR阶跃工况下，当EGR率达到稳定时，由于燃烧边界条件存在迟滞效应，从而会导致燃烧过程、有害物排放存在较长的延迟．

英文摘要：

The response characteristics of exhausts gas recirculated （EGR） rate, air-intake quantity, torque output, in-cylinder peak pressure, exhaust gas smoke opacity, and gaseous pollutant emissions under EGR step-change operations of a direct injection （DI） turbo-charged and after-cooled （TCA） automotive diesel engine were studied by real-time EGR rate measuring and transient operation control and measurement systems. When the EGR rate from 0 step-changed to 3%, 5%, 13% or 28% or inversely, the EGR rate, air-intake quantity and torque output responded quickly and stabilized within approximately 0.5 s. The smoke opacity of exhaust gas and the peak in-cylinder pressure stabilized within 2.5 s, and the response periods were independent of EGR rate step-change range. The gaseous pollutant emissions of HC, CO and NOx responded slowly, which took about 6 s to stabilize. All the phenomena indicate that even if the EGR rate becomes steady, the delay of combustion initial boundaries, will result in combustion process and pollutant emissious responding slowly.