Performance and Emission Characteristics of LPG-Fuelled Variable Compression Ratio SI Engine

The growing concern about the fast depletion of petroleum-based fuels and the environmental pollution caused by their combustion has been a compelling incentive to many researchers to find ways to use en- vironmentally friendly and renewable sources of energy. Research and experiments on liquefied petroleum gas (LPG) have demonstrated that this fuel is suitable as an alternative to conventional fuel. Its perfor- mance and efficiency parameters are better than the conventional fuel and it can run cleaner at attractive prices and in larger operating range. Among the alternatives found to be superior to the present gasoline is natural gas, hydrogen (H2), and LPG (i.e. liquefied petroleum gas in the form of either propane, C3H8; butane, C4H10; or a mixture of both). In the present paper, LPG in the form of propane as a fuel has been considered. The present paper evaluates the performance and emission characteristics of a single cylinder, 4-stroke, air-cooled, variable compression ratio spark ignition engine when fuelled with LPG at different compression ratios. The results obtained show that the engine running on an LPG fuel system delivered a substantial improvement in power and torque in a high-load condition. Conversion of the engine using LPG as fuel showed an average reduction of CO and HC exhaust gas emissions in comparison to the original fuel.