A Simulation Based Study to Improve Active Diesel Particulate Filter Regeneration through Waste-gate Valve Opening Modulation

Authors : Hasan Üstün BAŞARAN

Pages : 32-41

View : 22 | Download : 10

Publication Date : 2019-06-30

Article Type : Research Paper

Abstract :Nowadays, automotive vehicles are generally equipped with diesel particulate filter insert ignore into journalissuearticles values(DPF); systems in order to meet the strict particulate matter insert ignore into journalissuearticles values(PM); emission legislations. DPFs are highly practical systems; however, they need periodic active regeneration to clean the collected PM on their filters. Those regeneration processes are mostly effective when engine outlet temperature is above 500 o C. At medium load diesel engine operations, exhaust temperatures generally remain below 500 o C which is insufficient to maintain active DPF regeneration. Therefore, the aim of this study is to elevate exhaust temperatures above 500 o C at those engine loads via modulating waste-gate valve opening insert ignore into journalissuearticles values(WGVO);. In the analysis, a medium-duty diesel engine is modeled via using Lotus Engine Simulation insert ignore into journalissuearticles values(LES); software. It is set to operate at 1700 RPM engine speed and within 5.75-7.75 bar brake mean effective pressure insert ignore into journalissuearticles values(BMEP); engine load. WGVO modulation can control the mass flow rate of hot exhaust gas which bypasses the turbine and moves directly to the DPF. Lower exhaust expansion on turbine due to open waste-gate decreases compressor effectiveness and thus reduces volumetric efficiency. Reduced airflow causes an increase in exhaust temperature from 35 o C to 100 o C in the load range. While exhaust system can be warmed up above 500 o C at 6.75 bar BMEP in half open waste-gate mode, this can only be achieved at 7.5 bar BMEP in waste-gate closed mode. The method is highly effective; however, it results in fuel penalty insert ignore into journalissuearticles values(up to % 9.2); due to increased cylinder heat loss which needs to be considered.
Keywords : Diesel Particulate Filter, Active Regeneration, Thermal Management, Exhaust Temperature, Waste gate Valve Opening