Influence of thermal barrier coating on performance and emission characteristics of a compression ignition engine fueled with delonix regia seed biodiesel

Abstract

The selection of Delonix regia seed biodiesel as a prominent renewable source is attributed to its ability to effectively replace conventional fuel. While the use of Delonix regia seed biodiesel does reduce the emission of harmful exhaust gases, the engine efficiency is not equivalent to that of conventional diesel fuel. The piston and cylinder liners underwent a plasma spray process in which they were coated with equal amounts of a blend of Al2O3 and YSZ. The piston and cylinder-liner were coated with a thermal barrier coating at thicknesses measuring 100 and 200 μm, respectively. The current research focuses on the utilisation of an 80% blend of Delonix Regia biodiesel in a compression ignition (CI) engine, which presents a novel approach in the field. The investigation of Delonix Regia biodiesel as a fuel for CI engines has been the focus of limited scholarly inquiry, with studies primarily restricted to blends containing a maximum of 30% biodiesel. This limitation is primarily attributed to the biodiesel's higher viscosity and lower calorific value. These identified attributes have been observed to have a negative impact on the functioning of the engine, leading to less than optimal results. Therefore, a study was undertaken to evaluate the efficacy of Delonix regia seed biodiesel in a thermal barrier coated CI engine, resulting in favourable engine performance and reduction of pollutants. The results of the comprehensive test indicated that the mean specific fuel consumption decreased by 0.0425kg/kWh and 0.015kg/kWh, while the brake thermal efficiency improved by 3.1% and 1.2% when comparing the usage of an 80% biodiesel blend and diesel fuel in an unmodified compression ignition engine. The levels of carbon monoxide, an environmentally harmful pollutant gas, were observed to decrease by 0.059% in terms of volume. Similarly, the emission of unburned hydrocarbons exhibited a reduction of 28 ppm. Additionally, the smoke opacity was found to decrease by 6.52%. The observed NOx level exhibited an increase of 270 ppm in comparison to that of diesel fuel.