Analysis of CNG-Diesel Powered Diesel Engine Combustion, Performance and Exhaust Emission Characteristics

The present study investigates the performance, combustion and emission characteristics results of a 5.5 kW constant speed diesel engine, which was modified to run with both diesel and CNG fuel (diesel+CNG) under combined mode condition. The experiment was conducted with CR: 19.5:1at maximum power condition (at 1500 rpm and 5.5 kW). The brake thermal efficiency (BTE) of the engine was found lower at all different energy ratio, in comparison to diesel fuel (0% energy ratio). The deteriorations in BTE of the engine was observed at 30%, 46% and 51% of gaseous fuel energy ratio under combined mode operation. The engine powered by CNG-Diesel showed lower CO2 and Smoke. However, it showed higher Carbon monoxide, Hydrocarbon and Nitric oxide emissions as compared to diesel fuel.