A numerical and experimental investigation of marine diesel particulate filter regeneration characteristics under varying soot loading, inlet temperature and flow rate conditions

This study investigates the regeneration characteristics of marine diesel particulate filter (DPF) by combining numerical simulation with experimental testing on an externally heated bench. Distinct from conventional automotive DPF research, this study specifically addresses the unique exhaust thermal and flow conditions inherent to marine engines. A marine DPF regeneration model was established to evaluate temperature evolution and pressure drop. The results indicate that regeneration temperatures increase with higher initial soot loading. Both peak and average temperatures rise rapidly during the initial stage, reaching a maximum around 400 s. Concurrently, the pressure drop exhibits an initial increase followed by a decrease, with larger peak magnitudes observed at higher soot loadings. Elevated inlet temperatures increase regeneration temperatures, whereas higher inlet flow rates accelerate and further amplify peak temperatures. Experimentally, regeneration efficiencies exceed 94 % across all soot loadings at an inlet temperature of 873 K, but fall below 80 % at 823 K. Under an inlet temperature 873 K and soot loading ≥ 6 g/L, localized temperature extremes occur, with the most severe peak reaching 1421 K at the substrate outlet center. This localized critical thermal anomaly, rarely emphasized in prior studies, approaches the material’s thermal threshold, posing a significant melting risk. Finally, particulate emission concentrations decrease sharply during rapid oxidation, showing minimal dependence on initial soot loading. These findings provide critical references for optimizing marine DPF regeneration management strategies.