Observation of Soot Accumulation Conditions in Diesel Particulate Filter and Gas Flow Analysis

Soot (here, total particulate matter; TPM) accumulation in a diesel particulate filter (DPF) was characterized for two different engine conditions (high speed / high load and low speed / low load). Soot weight distribution within the filter was different in two engine conditions the accumulated PM layer was thicker when the engine conditions were low speed / low load even though the accumulated soot amounts were almost equivalent.

Flow field conditions in a DPF were calculated and soot accumulation conditions were assumed from the solution. In the axial direction (with gas flow) uniform soot accumulation was suggested. However, in the radial direction (from center to side), non-uniform accumulation was suggested from the flow field solution and this result was experimentally confirmed.

Temperature distribution in the DPF during uncontrolled soot regeneration was also calculated. The simulation suggested that the highest temperature would be observed in the back middle area of DPF. This result was confirmed by a multiple thermocouple experiment.