Severe Soot Oxidations in Gasoline Particulate Filter Applications 2018-01-1699
With the start of EU6 in 2017 gasoline particulate filters (GPF) have been introduced to production vehicles. It is expected that by 2019 all gasoline direct injection engines sold in Europe will be equipped with a GPF. A similar trend is observed in China with a slight delay compared to Europe, but covering all gasoline engines, including those with port fuel injection technology.
With the introduction of GPFs, new requirements are introduced to the management of gasoline engines and their aftertreatment. One requirement is to protect the aftertreatment components from excessive temperatures and damage as result of uncontrolled soot oxidations. While the general fundamentals are similar to those in diesel applications, significant differences exist in the relevant details. In gasoline applications, for example, one of the worst case scenarios with respect to severe soot oxidations is a fuel cutoff during which oxygen is introduced, whereas the drop to idle, critical in diesel applications, is not of concern.
In this contribution, we will evaluate the sensitivity of the soot oxidation in gasoline particulate filters to various operating parameters. We will discuss results obtained by a combination of a broad set of data from fuel cutoff experiments performed on engine bench under different operating conditions as well as detailed numerical simulations. Different limiting cases and regimes as well as simplified methods to describe them will be introduced and discussed. The results will be relevant for developing software functionalities to manage the soot, to protect the filter component as well as for calibrations.