Performance and Combustion Characteristics in a Methanol-Fueled IDI Engine.

Abstract

Restraining the initial combustion, promoting the diffused combustion and reducing the cyclic combustion variation are of utmost importance to improving the fuel economy, exhaust gas emissions, and noise of the methanol fueled indirect injection (IDI) diesel engine. The author closely studied methanol fuel combustion in a high speed diesel engine (swirl-chamber system and single cylinder of 82.5mm bore and 92mm stroke), using different ignition systems, such as the spark-assisted method, glow-assisted method, and diesel fuel pilot injected method, to evaluate the engine performance and combustion characteristics. The methanol-fueled engine used in the study had a new combustion chamber with a refined jet passage for the optimum air discharge coefficient as well as for improved diffusion and penetration of jet in the main chamber. The engine cylinder was equipped with a miniature throttle nozzle for improved fuel injection characteristics. The new methanol-fueled combustion system was found to outperform the diesel-fueled conventional combustion system as regard the fuel consumption, smoke emission, and NOx emissions, regardless of which ignition system were employed.