Diesel engine performance fuelled with manifold injection of ethanol and water-in-diesel emulsion blends

Abstract

Growing environmental concerns and rigorous emission rules have fuelled the search for an alternate fuel with cutting-edge engine modifications that can reduce pollutants from compression ignition (CI) engines. Adding water to diesel reduces the nitric oxide (NOx) and particulate matter (PM) emissions while increasing combustion efficiency is a promising standby approach that could help to meet global energy demands as well. Furthermore, injection of alcohol ensures the complete combustion of the fuel mixtures. In this case, two different emulsions with different water-to-diesel ratios are used to inject ethanol into the intake manifold at injection timing (IT) of 5°ATDC with injection duration (ID) of 3-ms (27°CA) to investigate the effects of the ethanol on the performance of modified diesel engine. The test results suggest that higher brake thermal efficiency (BTE) of 31.25% is obtained with 20% water in diesel emulsion along with manifold injected ethanol at 80% load conditions. 10.3% of increment in the BTE was noticed with engine operation on water-in diesel emulsion with ethanol manifold injection compared to baseline diesel operation. Lower smoke emission of 41 HSU was obtained when engine is fuelled with emulsion of 20% water in diesel with manifold injected ethanol at 80% load condition. The smoke emissions were deteriorated by 27.9% with ethanol injection comparatively to that obtained with baseline diesel operation. Declined emissions of NOx, carbon monoxide (CO) and hydrocarbon (HC) by 10.8%, 24.3% and 21% at 80% load were figured out when engine fuelled with an emulsion of 20% water in diesel with manifold injected ethanol compared to baseline diesel operation. Use of a 20% water-in-diesel emulsion with multiple injection of ethanol, delivered at the optimized IT and ID, yields better engine performance and emissions in CI engines.