Study on estimation method of soot loading under dynamic working state

Abstract

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 [Formula: see text] 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 [Formula: see text]. On this basis, a method for estimating the soot loading [Formula: see text] based on the time constant [Formula: see text] 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 [Formula: see text]. It was found that the time constant [Formula: see text] 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 [Formula: see text] and the time constant [Formula: see text]; The proposed estimation method allows for the identification of soot loading down to 1 g/L.