LP EGR Influence on Performance of Turbocharged Direct Injection Gasoline Engine

Low-pressure exhaust gas recirculation (EGR) is one of the several technologies that are being investigated to deliver future reduction of CO₂ and to match legislative emission standards. This paper now presents the influence of low-pressure EGR that is applied to a TDGI engine and the effects of EGR on fuel consumption and emission is studied. By dyno steady-state testing and vehicle simulation, a fuel consumption reduction of 6.18% is achieved under WLTC. The result will interest many professionals working in this field. Stringent legislative measures/national and international legislation/laws are forcing the automotive industry to reduce the fuel consumption and emission. To comply with those regulations and to stay competitive on the global market, it is necessary to adopt new technology. Cooled exhaust gas recirculation (CEGR) is an effective way to improve fuel economy and to reduce NO_x. LP EGR technology was applied to a 1.5-L three-cylinder TDI engine during this study which is specified below. Design of experiment methods was used to adopt the best combination of CR11, valve timing, modifying piston geometry, and the camshaft. To reduce combustion duration, the ignition coil was upgraded from 75  to 90 MJ. Performed vehicle steady state simulation to realize fuel consumption reduction at WLTC cycle. Engine dyno test under steady state operating condition with CR11, able to achieve fuel consumption reduction of 6.18% at WLTC cycle compared to the base engine. At low-speed and high-load (1920 rpm@18 bar) test, result shows maximum fuel consumption reduction of 16.5%, as EGR lowers the knocking tendency, which enables to advance the ignition timing. Increasing EGR rate reduces NO_x, but increases HC.