Diesel particle filters (DPF) have become the standard and essential aftertreatment components for all on-road diesel engines used in the US and Europe. The OBD requirements for DPF are becoming rigorously strict starting from 2015 model year. The pressure sensor or other strategies currently used for DPF diagnostics will most likely become insufficient to meet the new OBD requirements and a post DPF soot sensor might be necessary. This means that it will be even more imperative to develop a DPF design that would not have any soot leaks in its emission lifetime, otherwise the DPF will become a high warranty item. To reach this goal with the lowest cost during the design stage, it is necessary to gain a thorough understanding of DPF hardware design parameters such as material properties, cell structure and canning etc. which determine the thermal strength of DPF devices and DPF calibration parameters such as soot loading, regeneration temperature and temperature ramp rates etc., which determine the thermal stress of DPF devices.
In this paper, the impact of DPF material selection and cell structure on soot loading and back pressure are discussed based on test data. Analysis has been carried out with measured back pressures in transient cycles to understand the fuel economy impact of different DPF materials under regeneration and non regeneration conditions. Furthermore, DPF thermal strength and stress are defined based on temperature data and the impact of design parameters on the probability of DPF failure is discussed.