An experimental and modeling study of ash deposition and migration in diesel particulate filters

Abstract

Ash accumulation in wall-flow filters impacts key performance aspects such as pressure drop, filtration efficiency and catalytic reactivity. In this context, the capability to predict ash deposition and transport behavior is essential to ensure proper system performance under various operating conditions, throughout the useful lifetime of the particulate filter. Despite a large number of previous experimental studies, physically based ash migration models to predict ash transport and its impact on the performance of a wall-flow filter are still not available. The development, calibration and validation of a phenomenological semi-predictive model is presented in this work, based on extensive burner rig and transient engine tests. Combustion-derived ash was collected in several bare DPFs, while the filters’ pressure drop was monitored and the plug ash length was estimated via borescope and CT-scan tests. An example of how the developed model can be used to study design variations at an early development phase is included.