Effect of hydrogen and producer gas as secondary fuels on combustion parameters of a dual fuel diesel engine

This study presents experimental investigation into the effects of using hydrogen, producer gas and mixture of producer gas and hydrogen in different proportion as a secondary fuel with diesel as pilot fuel in dual fuel operation. The combustion parameters studied are maximum rate of pressure rise, peak cylinder pressure and heat release rate in first phase of combustion at wide range of load conditions. Experiments were conducted on a 4 cylinder turbocharged and intercooled 62.5 kW gen-set diesel engine at constant speed of 1500 RPM. It was found that the maximum rate of pressure rise increases up to 30% of hydrogen substitution and decreases for onward substitution at all load conditions. Peak cylinder pressure also increases up to 30% of hydrogen substitution for 13% and 40% load conditions whereas, at 80% load it decreases with the increase of hydrogen fraction at all load conditions. When producer gas (PG) alone is used as secondary fuel, the maximum rate of pressure rise decreases over the entire range of its substitution while, the peak cylinder pressure increases initially up to 10% of producer gas substitution and for onward substitution of producer gas, it decreases at all load conditions. The heat release rate in first phase of combustion found to decrease during both types of fuel substitution as compared to diesel fuel. However, in mixed dual fuel mode, for all the different compositions tested, the composition (PG:H-2 = 60:40)% shows lower maximum rate of pressure rise and peak cylinder pressure. Further, at all load conditions decrease in heat release rate is observed and at 80% load condition it is found 47.29 J/degrees CA. (C) 2016 Elsevier Ltd. All rights reserved.