Impact of Oxidation Inhibitors on Performance and Emission Characteristics of a Low Heat Rejection Engine

In this study, for the first time analysis of a low heat rejection engine was carried out along with the addition of oxidation inhibitors. If the combustion chamber components of the engine such as piston, cylinder head, and inlet and outlet valves are insulated with a thermal barrier material, then the engine will be referred as low heat rejection engine. In this study yttria stabilized zirconia was coated on the combustion chamber components for a thickness of about 150 microns. Then the analysis of performance parameters such as brake thermal efficiency and specific fuel consumption and emission characteristics such as emission of carbon monoxide, hydrocarbon and nitrogen oxide was carried out in single cylinder four stroke diesel engine with electrical loading using diesel and pongamia methyl ester as the fuels. The major problem associated with the usage of biodiesels and low heat rejection engine is the increased NOX emission than the normal engine operated with the diesel. This problem has been overcome by the usage of oxidation inhibitors such as ethyl hexyl nitrate (EHN), tert-butyl hydroquinone (TBHQ). The results showed that addition of oxidation inhibitors leads to increase in brake thermal efficiency, reduced specific fuel consumption and reduced NOX emission.