DPF Soot Estimation Challenges and Mitigation Strategies and Assessment of Available DPF Technologies

Diesel Particulate Filters (DPFs) have been widely used to control the particulate emissions and have become an indispensable feature of the modern diesel engines. However, DPFs also result in additional fuel consumption from added back pressure and periodic regenerations required for oxidizing the accumulated particulate matter. Aftertreatment calibrations are developed with a significant emphasis on the reducing these penalties. It is desirable to accumulate higher levels of particulate matter before regeneration and perform active regenerations at higher temperatures. This capacity is generally limited by the substrate and catalyst properties and also the inaccuracies in the DPF soot accumulation estimation. Several advancements have been made in the DPF material technologies to mitigate these limitations.

This publication describes the performance of various DPF technologies. Silicon Carbide, Aluminum Titnate and Acicular Mullite substrate materials that were tested in controlled test cell environment. The back pressure of the substrates was investigated with varying levels of accumulated particulates in the DPF. The particulate matter storage capacity was determined by examining the substrate integrity and filtration efficiency after conducting standard drop to idle tests. Also, the influence of DPF soot loading characteristics on particulate matter estimation was studied. In addition to this the influence of catalyzed Vs uncoated DPF substrates on particulate matter oxidation in the availability of different levels of exhaust oxygen was investigated. Soot estimation challenges are highlighted and mitigation strategies are provided. It was discovered that although all the technologies have several advantages and improvements over their predecessors, many of the challenges still exist.