Performance of a diesel engine run on diesel and natural gas in dual-fuel mode of operation

In view of energy crisis, many types of alternative fuels have been tried all over the world for use in internal combustion (IC) engines. This investigation on the use of natural gas as a substitute fuel is in line with the trend of finding alternative fuels. In this investigation, experiments have been performed to study the performance of a diesel engine with natural-gas-diesel in dual-fuel mode with different diesel proportions of 10-100% in 10% interval. The results show that overall the performance with CNG were lower than 100% diesel operations. At lower loads, the performances were much poorer and higher powers, the performances were much better but still lower than 100% diesel operation. The bsfc at 1.1 kW with 90% CNG operation was 68% higher than 100% diesel operation. However, at 2.8 kW the bsfc at 90% CNG operation was only 7% higher. The exhaust emissions show that in dual-mode, the CO2 and smoke emissions were lower due to lower carbon to hydrogen ratio of CNG. The CO emission was higher due to lower air-fuel ratio as the CNG introduction in the intake air replaced some air in the intake runner. (C) 2019 The Authors. Published by Elsevier Ltd.