Experimental Study and Numerical Interpretation on the Temperature Field of DPF during Active Regeneration with Hydrocarbon Injection

Jun  Zhang, Tsinghua University

Diesel Particulate Filter (DPF) is indispensable for diesel engines to meet the increasingly stringent emission regulations. Both the peak temperature and the maximum temperature gradient of the DPF during active regeneration should be well controlled in order to enhance the reliability and durability of the filter. In this presentation, the temperature field of the DPF during active regeneration with hydrocarbon injection was investigated. 24 thermocouples were inserted into the DPF channels to measure the inner temperature of the filter, and several different thermocouple layouts were tested to capture the peak temperature as well as the maximum temperature gradient of the DPF. Finally, a thermocouple layout which can capture the peak temperature and the maximum temperature gradient of the DPF simultaneously was adopted. With this thermocouple layout, the temperature fields of the DPF during active regeneration with hydrocarbon injection at different initial soot loading, different DPF inlet temperature, and different exhaust mass flow were tested on a diesel engine test bench. The test results show that both the peak temperature and the maximum temperature gradient of the DPF during active regeneration increased with the initial soot loading increasing and DPF inlet temperature increasing, while both of the them decreased when exhaust mass flow risen. A 3D simulation, which takes soot loading process and HC spray into considered, was conducted with AVL FIRE, a commercial CFD software, to interpret the DPF temperature field during active regeneration. The simulation results shows that the soot loading in the DPF is very homogeneous, which indicated that it contributed little to the nonuniformity of the DPF temperature field, while the HC uniformity has a significant effect on the nonuniformity of the DPF temperature field during active regeneration.

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