Equilibrium temperature in diesel particulate filter passive regeneration

Experimental investigations of a CI engine's DOC/OC-DPF system analyzed soot oxidation by NO2 on platinum catalysts under oxidizing conditions, considering exhaust gas temperature influence. The soot/NO2 equilibrium temperature, crucial for passive filter regeneration and backpressure minimization, was precisely determined using engine dynamometer tests at high NO to NO2 conversion and constant engine speed. Standardized initial conditions (filter loading, pre-test thermal regeneration) ensured result comparability and minimized experimental error. The developed method simplifies DOC/OC-DPF equilibrium temperature determination, providing a tool for comprehensive filter evaluation regarding dimensions, catalytic composition (precious metals/metal oxides ratio), exhaust system placement, and fuel contaminant (e.g., sulfur compounds) impact on catalyst activity. This method facilitates preliminary assessment of regeneration energy consumption and enables potential reduction in costly emission testing (WLTP/RDE), contributing to efficient research and development.