Abstract: Based on Arrhenius equation, a chemical reaction model for passive regeneration of catalyzed diesel particulate filter (CDPF) is established and then calibrated and verified by the bench test on a heavy-duty diesel engine. The calibrated model can well predict the reaction rate of soot oxidation by NO₂ in CDPF. Results show that soot oxidation rate, i.e. passive regeneration rate rises with the increases of the soot loading and temperature of CDPF, and under the operation condition of a 3.8 g/L soot loading and a 550×10^-6 NO_x concentration, the balance temperature of CDPF is around 283 ℃. Higher NO_x emission is beneficial to CDPF passive regeneration and can reduce the soot loading and temperature at DCPF balance point. The regeneration balance curve depends on the preset soot loading of CDPF, as the preset soot loading increases, the regeneration balance curve moves downward, and hence the passive regeneration region enlarges.

Key words: CDPF, passive regeneration, Arrhenius equation, balance temperature