Experimental Investigation of the Effect of Hydrogen Addition on Combustion Performance and Emissions Characteristics of a Spark Ignition High Speed Gasoline Engine

Considering energy crises and pollution problems today much work has been done for alternative fuels for fossil fuels and lowering the toxic components in the combustion products. Expert studies proved that hydrogen one of the prominent alternative energy source which has many excellent combustion properties that can be used for improving combustion and emissions performance of gasoline-fuelled spark ignition (SI) engines. This article experimentally investigated the performance and emission characteristics of a high speed single cylinder SI engine operating with different hydrogen gasoline blends. For this purpose the conventional carburetted high speed SI engine was modified into an electronically controllable engine with help of electronic control unit (ECU) which dedicatedly used to control the injection timings and injection durations of gasoline. Various hydrogen enrichment levels were selected to investigate the effect of hydrogen addition on engine brake mean effective pressure (Bmep), brake thermal efficiency, volumetric efficiency and emission characteristics. The test results demonstrated that combustion performances, fuel consumption and brake mean effective pressure were eased with hydrogen enrichment. The experimental results also showed that the brake thermal efficiency was higher than that for the pure gasoline operation. Moreover, HC and CO emissions were all reduced after hydrogen enrichment. (C) 2014 The Authors.