Testing Research on Effects of Ignition System Parameters on Emission Performance of Gasoline Engine Fueled with Compressed Natural Gas

Abstract

Tests for the effects of ignition system parameters on HC, CO and NOx have been done on a 1.5 liter natural aspirate engine fueled with compressed natural gas. The factors ignition coil charging time and ignition advanced angle have been mainly focused for the idle emission, steady emission, transient emission and exhaust gas temperature. The results indicate that boosting ignition coil charging time, HC emission declines at idle speed. When the engine is operating at power performance points, increasing ignition advanced angle, HC and NOx are rising, while CO emission level keeps unchanged. With the delay of ignition advanced angle, transient HC emission is a little higher, while NOx emission is decreasing largely. Higher exhaust gas temperature can be got to promote quick catalyst ignition by means of increasing ignition coil charging time and delaying ignition advanced angle.