Effects of Lean Burn and Stoichio. Burn Combustion on Multi-cylinder SI Engine Using Hydrogen and CNG Blends

This paper shows the effect of 0, 5, 10 and 15 % of hydrogen by energy in compressed natural gas during lean burn and stoichio. burn combustion. All trials are performed at wide open throttle position on 3-cylinder, water-cooled 796 cc S.I engine using sequential port fuel injection system at equivalence ratio of 0.7 and 1.0. Carbon-based emission decreased with increase in hydrogen addition. MBT spark timing increased with increase in speed and decreased with increase in equivalence ratio. At 12A degrees CA spark advance and 2500 rpm, 5 % hydrogen addition shows rise in brake thermal efficiency with optimum NOx. NOx emission increased with increase in hydrogen addition and decreased with MBT spark timing. Heat release rate and maximum rate of pressure rise increased remarkably with 5 % hydrogen addition due to increase in burning velocity. Maximum brake thermal efficiency of 25 % is observed for 5 % hydrogen addition with increase in power output at stoichiometric condition.