Effect of Pilot Fuel Quantity on the Performance and Emission of a Dual Producer Gas–Diesel Engine

Quantity of pilot fuel is an important parameter for controlling the combustion process in a dual fuel engine. However, very few researches have investigated this effect in details in a dual producer gas-diesel engine. In this study, the combustion characteristics, engine performances, and exhaust gas emissions are investigated. The single cylinder, direct injection, diesel engine coupled with dynamometer is used as the engine test bed. The producer gas is generated from 50 kWth double throat downdraft gasifier using charcoal as the raw material. In the test, the engine speed is constant at 1500 rpm while the bmep loads are varied between 0 - 535 kPa. Three pilot fuel quantities being 0.22, 0.29 and 0.35 kg/h are supplied. Experimental results show that the increasing amount of pilot fuel improves thermal efficiency and reduces the CO emission at low engine load conditions. However, the diesel saving is always decreased when the pilot fuel quantity exceeds its optimum condition.