COMBUSTION AND EMISSION CHARACTERISTICS OF DIESEL, B100 AND B20 FUEL ON A THERMAL BARRIER COATING ON PISTON CROWN IN DIRECT INJECTION C.I. ENGINE AT OPTIMUM IOP AND IT

The objective of this study is to investigate the performance, combustion and emission characteristics of Jatropha biodiesel and its blend fueled in standard CI engine (without coating piston crown) and thermal barrier coating (with coating of piston crown) CI engine at optimum injector opening pressure (IOP) and injection timing (IT). Tests were performed on a single cylinder, four stroke, direct injection, water cooled, CI engine whose piston crown were coated with a 300µm thickness of zirconium oxide over a 150µm thickness of nickel chromium and aluminum oxide bond coat at optimum IOP and IT (220 bar and 26° btdc). The working conditions for the standard and thermal barrier coating of piston crown CI engine were kept exactly the same to ensure a realistic comparison between the two configurations of the engine. During this investigation, both the engine was fueled with the diesel fuel, biodiesel and its blend of biodiesel and neat diesel fuel in proportions of 20% biodiesel and 80% diesel fuel which are generally called of B20 fuel. In this work various performance parameters such as brake thermal efficiency, brake specific energy consumption, combustion characteristics such as peak cylinder pressure, peak heat release rate, ignition delay and emission parameter such as UBHC, smoke opacity and NOx under varying load conditions are studied and recorded.

The test results indicate that performance, combustion and emission characteristics of the B20 fueled with thermal barrier coating CI engine for all load range has improved. At full load at B20 fuel, emissions such as UBHC and smoke opacity were observed to be lower compared to the standard CI engine. The thermal efficiency and specific energy consumption of B20 fueled at full load conditions of thermal barrier coating CI engine has increased approximately by 1.96% and decreased approximately by 4.2% respectively when compared to standard CI engine.