乘用车汽油机实际道路行驶中NO排放穿透现象与机理分析

Analysis on the Penetration Phenomenon and Mechanism of NO Emissions from Gasoline Engines of Passenger Cars in Actual Road Driving

摘要: 为了满足将在中国正式实施的国家六b排放法规的要求，减少实际道路条件下的瞬态排放是其有效措施之一。本文针对实际道路条件下的NO排放特性，以一款在中国市场出售的轻型汽油车为研究对象，使用NO快速采样分析仪作为车载测量设备，对该车实际道路运行下三效催化反应器(TWC)前后的NO排放浓度进行采样和分析。研究发现，换挡瞬态过程是导致瞬时NO_x排放升高的重要因素：换挡的同时若不踩油门踏板，排气管则出现NO_x瞬时峰值。基于对换档和燃油切断条件的数据分析，提出采用NO_x瞬态排放的优化控制策略减少车辆在实际道路上的NO_x排放的方法。

Abstract: In order to meet the requirements of the national 6b emission regulations that will be officially implemented in China, reducing transient emissions under actual road conditions is one of its ef-fective measures. For this article, aiming at the characteristics of NO emission under actual road conditions, a light gasoline vehicle sold in the Chinese market as the research object, the NO fast sampling analyzer is used as a vehicle-mounted measurement device. The NO emission concentra-tion before and after the three-way catalytic reactor is sampled and analyzed on the actual road. Studies have found that the transient process of shifting is an important factor leading to the in-crease of instantaneous NO_x emissions: if you do not step on the accelerator pedal while shifting, the exhaust pipe will have an instantaneous peak of NO_x. Based on the data analysis of gear shift and fuel cut-off conditions, an optimized control strategy for NO_x transient emissions is proposed to reduce the NO_x emissions of vehicles on actual roads.