Source of Emissions during Closed Loop Operation in a PFI Fueled Stoichiometric Gasoline Engine

摘要

It is concluded that: FTP: 1. the range of λ amplitudes are generally fairly narrow; 2. the effect of transients on the λ variation is typically a reduction in the frequency of the variations, not the amplitude; cold start the data shows the CO catalytic conversion does start at approximately 19 seconds; inlet thermocouple temperatures reach over 200°C within 3 seconds which is about 16 seconds earlier than the catalyst shows CO conversion evidence. The global conclusion from this analysis is that the process of calibration is a complex interaction of multiple variables which must be considered when developing a TWC laboratory protocol. 1. both the catalyst body temperatures and exhaust temperatures often exceed the inlet thermocouple temperatures; again frequency is the major change in the λ response from the UEGO sensor, not amplitude; there is no obvious correlation with λ and the CO and NOx inlet concentrations.