| 摘要 |
From the instant of changeover, rich regeneration is prolonged beyond the requirement for complete desorption of nitrogen oxides from the catalyst, until rich exhaust gas breaks through. The time DELTA t1, changeover to breakthrough, is measured during lean burn, the time DELTA t2 to oxygen breakthrough is similarly measured. Intervals DELTA t1, DELTA t2 are used independently to assess oxygen and nitrogen oxides storage functionalities. Preferred features: The rich phase is prolonged by 1.0-10 times the interval to the first breakthrough of rich exhaust, using a fresh catalyst. During rich running, the air fuel ratio is adjusted between 0.99 and 0.7. Intervals DELTA t1 and DELTA t2 are measured with a rapid response lambda sensor or a linear lambda sensor. They are alternatively determined using a rapid response lambda sensor before and after the catalyst. |
