抄録
To evaluate a clean diesel combustion concept, the following technologies were installed on a single cylinder research engine for reducing exhaust emissions: a high boost charging, a high rate and cooled EGR and high injection pressure (Pinj). The Digital Hydraulic Variable Valve Actuation (DHVVA) will also be installed as one of the enabling technologies for the reduction of exhaust emissions utilizing flexible valve lift and timing. The timings of intake valve close (IVC) are significant to increase volumetric efficiency (ηv) and the maximum iv has been obtained at 560 degrees of crank angle. When the maximum iv is realized, the maximum EGR rate is also obtained due to BSNO_x and smoke being at minimum at full load condition. DHVVA can open the exhaust valve in the intake stroke, enabling the introduction of exhaust gas into the cylinder providing internal residual gas difference and reducing pumping losses. DHVVA is effective to increase volumetric while also enabling efficiency and reductions of exhaust emissions and improvement of fuel consumption.
