Experimental Evaluation of Performance and Emission Characteristics of Minimally Processed Ethanol Fuelled HCCI Engine

摘要

A well known bio-fuel ethanol has been investigated in this work in a HCCI mode. The engine chosen for the experiment is a single cylinder DI diesel engine modified to ignite minimally processed ethanol in a diesel engine under HCCI mode. As the ethanol has higher self ignition temperature the firing of ethanol in regular diesel engine by auto-ignition is not possible. Hence, suitable modification was made in the engine to ignite ethanol in the diesel engine like diesel fuel. The modified engine has on ECM controlled fuel spray and an air preheater in the suction side of the engine. The combined effort of the adiabatic compression in the engine and preheating of air ignites ethanol by auto-ignition and its timing of firing was precisely controlled by changing air intake temperature. This investigation revealed that the engine operated with minimally processed ethanol performed well with little loss of brake thermal efficiency, and, emitted comparatively lower emissions such as NO_x and smoke and proved that the ethanol is best suited fuel for HCCI operation. The water content present in the ethanol helped to control the timing of autoignition and helped to run HCCI engine smoothly.