Performance and Emission Characteristics of Direct Injection C.I Engine Retrofitted with Mono-CNG System

Abstract

Diesel engines are widely used in logistics and haulage as vehicular prime movers. In the mechanized and fast-moving forward world of today, the consumption of petroleum products has become an important yardstick of a country’s prosperity. This ever-increasing consumption has led the world to face the twin challenge of energy shortage and environmental deterioration. Natural gas has been one of the highly considered alternative fuels for both spark ignition (S.I) and compressed ignition (C.I.) engines. The advantages and benefits of CNG have made it the preferred choice as alternative fuel in the transportation sector. This present study focused on the effects of retrofitted direct injection C.I. engine with mono-CNG system to its performance and exhaust emissions. The engine speed was varied from 850 rpm to 2500 rpm, with load test conditions of 0Nm, 27.12Nm and 53.23Nm, using an engine dynamometer. Results indicated that CNG has the potential to provide better fuel consumption compared to diesel fuel. Meanwhile, the characteristics of exhaust gas emissions such as smoke opacity and CO2 gave promising results compared to CO, HC and NOX, for diesel combustion.