Abstract

Renewable fuels are in biodegradable nature and they tender good energy security and foreign exchange savings. In addition they address environmental concerns and socio-economic issues. The present work presents the experimental investigations carried out on the utilization of such renewable fuel combinations for diesel engine applications. For this a single-cylinder four-stroke water cooled direct injection (DI) compression ignition (CI) engine provided with CMFIS (Conventional Mechanical Fuel Injection System) was rightfully converted to operate with CRDi injection systems enabling high pressure injection of Rubber seed oil methyl ester (RuOME) in the dual fuel mode with induction of varied gas flow rates of hydrogen and hydrogen enriched CNG (HCNG) gas combinations. Experimental investigations showed a considerable improvement in dual fuel engine performance with acceptable brake thermal efficiency and reduced emissions of smoke, hydrocarbon (HC), carbon monoxide (CO) and slightly increased nitric oxide (NOx) emission levels for increased hydrogen and HCNG flow rates. Further CRDi facilitated dual fuel engine showed improved engine performance compared to CMFIS as the former enabled high pressure (900 bar) injection of the RuOME and closer to TDC (Top Dead Centre) as well. Combustion parameters such as ignition delay, combustion duration, pressure-crank angle and heat release rates were analyzed and compared with baseline data generated. Combustion analysis showed that the rapid rate of burning of hydrogen and HCNG along with air mixtures increased due to presence of hydrogen in total and in partial combination with CNG which further resulted into higher cylinder pressures and energy release rates. However, sustained research that can provide feasible engine technology operating on such fuels in dual fuel operation can pave the way for continued fossil fuel usage.