Low power autoselective regeneration of monolithic wall flow diesel particulate filters

This paper presents research into a novel autoselective electric discharge method for regenerating monolithic wall flow diesel particulate filters using low power over the entire range of temperatures and oxygen concentrations experienced within the exhaust systems of modern diesel engines. The ability to regenerate the filter independently of exhaust gas temperature and composition significantly reduces system complexity compared to other systems. In addition, the system does not require catalyst loading and uses only mass- produced electronic and electrical components, thus reducing the cost of the after-treatment package. Purpose built exhaust gas simulation test rigs were used to evaluate, develop and optimise the autoselective regeneration system. On-engine testing demonstrated the performance of the autoselective regeneration process under real engine conditions. Typical regeneration performance is presented and discussed with the aid of visual observations, particulate mass measurements, back pressure measurements and energy consumption. The research demonstrates the potential of the novel autoselective method for diesel particulate filter regeneration. The autoselective process does not require an exhaust by-pass and enables the system to be low power, catalyst-free and exhaust temperature independent.