The simulation and experimental research of particulate matter sensor on diesel engine with diesel particulate filter

In this paper a new leakage current sensor is installed on a diesel engine to detect the failure of diesel particulate filter (DPF). The software Fluent is used to determine the optimum installing position of the PM sensor downstream the DPF. Six types of installation positions were studied in this research, visualizing each velocity distribution position of the system. The optimum exhaust sensor absorption position (position II) was determined through axial and radial adjustments. Afterwards, the pressure distribution of the whole system and the particulate distribution in the sensor at location II were further analyzed. Also, the output signal of the sensor at different operation conditions were experimentally analyzed and tested on an engine test bench. Besides, the signal output of voltage downstream the damaged DPFs, agrees well with the smoke intensity values, which validates the viability of the PM concentration transient test of the PM sensor system. Influences of different exhaust temperature on sensor signal output were investigated with the aid of an electrical heating system, at constant engine operating conditions. Unfortunately, the experiment showed that the temperature had a negative effect on the signal output, which makes the sensitivity of the sensor lower.