Development of a thermophoretic precipitator for direct capture of particles in diesel engine exhaust and analysis of capture mechanism with CFD simulation

Abstract

In present study, a thermophoretic precipitator (TP) was developed to capture particulate matters in diesel engine exhaust gas without additional energy. The TP was directly connected to the rear end of the engine without any post-treatment for direct capture, and thermophoresis caused through a cooling plate in the center. To compare the capture effect of different temperature gradients, cooling water from 278 to 323 K was used, and the temperature gradient value was varied by wrapping heating tape around the walls. The TP showed significant collection efficiency for particles smaller than about 120 nm. CFD simulations were performed to analyze the capture mechanism of the TP. The discrete phase model was used to track the trajectory of the particles and compare the depostion efficiency at different set temperatures. The CFD results showed that the collection efficiency of the TP was similar within the temperatue range of 17.04 to 17.14 %.