Combined effects of thermal barrier coating and blending of diesel fuel with biodiesel in diesel engines

Abstract

Alternative fuels and modifications in the engine to increase efficiency are receiving much attention nowadays due to the depletion of world petroleum reserves and increased environmental concerns. The desire to reach higher efficiency, lower specific fuel consumption and reduced emissions in internal combustion engines have become the primary focus of engine researchers and manufacturers over the past three decades. In this scenario, processed cooking oil (Biodiesel) with Thermal barrier coated diesel engine becomes an attractive green alternative to the present compression ignition engines. Biodiesel used in the experiment is a methyl ester of free fatty acid made from used cooking oil. The properties of biodiesel fuel are similar to the diesel fuel so that it can work in existing infrastructure of conventional diesel engines without any engine modification. Yttria-stabilized zirconia is used as the Thermal barrier coating. It was found experimentally that B20 was the optimum blend of Biodiesel with Diesel as it had properties comparable to diesel fuel and had lower polluting emissions [29]. Experiments were performed in a Garuda Greaves diesel engine with and without thermal barrier coating for the present work. From the results of the investigation in the diesel engine without thermal barrier coating, it was found that there has been a decrease in brake power with an increase in brake specific fuel consumption for all blends of biodiesel over the entire load range when compared to the diesel fuel. In the case of engine exhaust gas emissions; lower HC, CO and higher CO2 and NOx emissions have been found for all biodiesel blends when compared to diesel. Moreover, reductions in sound level for all biodiesel blends have been observed when compared to diesel. Thermal barrier coatings (T.B.C) help to overcome the limitations possessed by biodiesel in its performance due to its lower heating value when compared to diesel. It also helps to reduce the emissions further when compared to a diesel engine without thermal barrier coating running on biodiesel. Therefore, it can be concluded that B20 with T.B.C was the best arrangement as it showed lower emissions, better properties, and economy than diesel engine without T.B.C