柴油机氧化催化转化器故障的排气参数敏感度分析

摘要

为了将柴油机排气氧化催化转化器(DOC)的在线故障诊断技术应用于柴油机车载诊断系统(OBD),确定DOC在线故障诊断的特征参数,采用仿真的方法分析了柴油机排气参数对DOC故障的敏感度.研究结果表明,在一定的柴油机工况下,DOC前后的排气温度和排气背压对DOC催化剂老化、载体堵塞以及破损等失效故障都有很强的敏感度,可以作为DOC故障诊断的特征参数.%The sensitivity of exhaust parameters to DOC faults was analyzed by the simulation in order to apply the DOC online fault diagnosis technology to OBD system, and determine the characteristic parameters of online diagnosis. The results show that, under given operation conditions, the exhaust temperature and back pressure before and after DOC are very sensitive to catalyst aging, carrier cramming and disrepair, which can be used as the characteristic parameters of DOC fault diagnosis.