基于OBD监测的国六柴油机NOx排放方法研究

陈栋栋¹，彭丽娟²，高慎勇¹，李云华¹，孙晓宇¹

1.潍柴动力股份有限公司，山东 潍坊  261061；2.林德液压（中国）有限公司，山东 潍坊  261061

摘要：为实现国六柴油机NO_x排放精准有效监测，依据柴油机国六排放标准对车载诊断系统（on board diagnostics，OBD）监测NO_x排放的要求，提出一种以选择性催化还原(selective catalytic reduction，SCR)转化效率为基础的监测与标定方法，结合某柴油机进行标定并验证SCR劣化件的报错情况与正常件的误报错余量。验证结果表明：该方法能够实时准确计算SCR转化效率；并及时有效判定NO_x排放是否超OBD监测限值，符合国六标准对OBD监测NO_x排放的要求；使SCR正常件能够留出合理余量防止误判，使SCR劣化件能够有效甄别并及时触发监控器，实现有效监测的目标。

关键词：国六柴油机；OBD监测；NO_x排放；SCR转化效率

NO_xemission monitoring based on OBD for CHINA VI diesel engine

CHENG Dongdong1, PENG Lijuan2, GAO Shenyong1, LI Yunhua1, SUN Xiaoyu1

1.Weichai Power Co., Ltd., Weifang 261061, China；2.Linde Hydraulics（China）Co., Ltd., Weifang 261061, China

Abstract：In order to accurately and effectively monitor the NO_xemission of CHINA VI diesel engine, a monitoring and calibration method are proposed according to the OBD monitoring for NO_xemission requirements in CHINA VI emission regulations. The error reporting of degraded parts and the error margin of normal parts are verified by calibrating a certain type of diesel engine. The verification results show that the proposed monitoring and calibration method can accurately calculate the SCR conversion efficiency in real time, and determine whether the NO_xemission exceeds the limit of OBD monitoring timely and effectively, so it meets the requirements of OBD monitoring for NO_xemission in the CHINA VI emission regulations.

Keywords:CHINA VI diesel engine；OBD monitoring；NOx emission；SCR conversion efficiency