A Metal Fibrous Filter for Diesel Hybrid Vehicles 2011-01-0604
Trends towards lower vehicle fuel consumption and smaller environmental impact will increase the share of Diesel hybrids and Diesel Range Extended Vehicles (REV). Because of the Diesel engine presence and the ever tightening soot particle emissions, these vehicles will still require soot particle emissions control systems. Ceramic wall-flow monoliths are currently the key players in the Diesel Particulate Filter (DPF) market, offering certain advantages compared to other DPF technologies such as the metal based DPFs. The latter had, in the past, issues with respect to filtration efficiency, available filtration area and, sometimes, their manufacturing cost, the latter factor making them less attractive for most of the conventional Diesel engine powered vehicles. Nevertheless, metal substrate DPFs may find a better position in vehicles like Diesel hybrids and REVs in which high instant power consumption is readily offered enabling electrical filter regeneration. Electrical filter regeneration is more easily applied to metal filters as the filter substrate itself can act as the resistance heater element. In this work, a metallic substrate filter is presented. The filter was assessed with respect to its filtration efficiency, soot loading behavior under constant and transient engine conditions and its electrical regeneration performance. Its emissions control performance has been evaluated against future particle emission limits. The application of electrical filter regeneration revealed a significant advantage in fuel consumption associated with filter regeneration compared to conventional ceramic filters.