Analyses of Thermal Shock Failure on Large Volume DPF

Ceramic honeycomb wall flow diesel particulate filters (DPF) have been investigated for use in exhaust gas control of diesel vehicles. However, before they can be used, prevention of thermal shock failure during combustion regeneration is necessary.

Studies were conducted on thermal shock failures on 9-inch diameter large volume DPF during regeneration by finite element analyses (FEA). These studies reveal that, within safe limits, maximum thermal stress is almost constant even at different gas flow rates and oxygen concentrations.

Regeneration tests were also conducted on large volume DPF of several materials having different pore size distributions. FEA thermal stress was compared with mechanical strength of the material at safe levels.