PFI汽油车GPF再生特性研究

GPF regeneration characteristics of PFI gasoline vehicle

研究PFI轻型汽油车实际道路行驶GPF再生工况特点,分析再生参数,如过量空气系数λ、GPF入口排气温度T_(in)与车辆运行工况的关系,研究再生时CO_(2)和PM排放特性。发现在40~100 km/h中高车速、1400~2200 r/min中等转速区,加速或减速运行,易满足λ≥1.05、T_(in)≥450℃的再生条件,高速路段满足再生条件的运行时间占比可达19.18%,市郊路段8.56%,市区路段3.26%。分析了两种典型再生工况,一种为减速断油被动再生,为从中高车速急减速到低速,减速度–2.45 m/s^(2),初始T_(in)约700℃,λ值从1.01急速增大到1.30;另一种为急加速主动再生,为从中等车速急加速到高速,加速度达1.0 m/s^(2),λ增大到1.35,T_(in)增加到750℃。再生期间PM排放浓度均增大,CO_(2)排放在加速再生期间增大、减速再生期间保持平稳。

This paper studied the characteristics of GPF regeneration operating modes of PFI light duty gasoline vehicle on road,analyzed the relationship among vehicle operating modes and GPF's regeneration parametersλ,inlet temperature of GPF T_(in),and CO_(2)and PM emission characteristics during regeneration.It is concluded that it can easily met the regeneration conditions ofλ≥1.05,T_(in)≥450℃when vehicle runs at 40 km/h to 100 km/h,1400 r/min to 2200 r/min,and acceleration or deceleration operation.It is found the proportion of operation time to meet the regeneration conditions can reach 19.18%in highway,8.56%in suburban,and 3.26%in urban.This test explores two typical regeneration modes,one is the rapid deceleration regeneration at the medium and high vehicle speed,the deceleration reaches–2.45 m/s^(2),the initial is about 700℃,and theλincreases from 1.01 to 1.30.The other situation is rapid acceleration regeneration at medium vehicle speed,acceleration reaches 1.0 m/s^(2),λincreases to 1.35,and T_(in)increases above 750℃.The PM emission concentration increases during regeneration,the CO_(2)emission increases during the accelerated regeneration,but keeps relatively stable during deceleration regeneration.