Study on estimation method of soot loading under dynamic working state

Accurately obtaining the soot loading in the Diesel particulate filter (DPF) is important for DPF, and current online real-time estimation methods only go up to about 2 g/L. In this paper, the DPF structure is simplified into a gas-capacity combined with gas-resistance, and the theoretical analysis of the simplified structure is carried out through the equivalent circuit analysis method. The time constant t c corresponding to the DPF during the dynamic working state of the diesel engine is solved, and further analysis reveals that it is related to the incoming flow temperature T and the soot loading m s . On this basis, a method for estimating the soot loading m s based on the time constant t c is proposed. Subsequently, experiments on engine load characteristics at different speed working states were carried out, and the dynamic process of DPF was analyzed at different soot loading m s . It was found that the time constant t c can be characterized by the difference in temperature stabilization time between the inlet and outlet; The smaller the incoming temperature T, the more significant the relationship between the soot loading m s and the time constant t c ; The proposed estimation method allows for the identification of soot loading down to 1 g/L.