Investigations on the Performance of Diesel in an Air Gap Ceramic Coated Diesel Engine

Abstract

The world's rapidly diminishing petroleum supplies, their raising costs and budding danger of environmental pollution have led to an intensive search for an alternative fuels or increasing the efficiency of the available diesel engines. It is a known fact that about 30% of energy supplied to the diesel engine is lost through the coolant and 30% is wasted through friction and exhaust and other losses, thus leaving only 40% of energy utilization for the useful purposes. If this lost heat rejection is reduced, the thermal efficiency can be improved. With the insulation of the combustion chamber Walls with ceramics, the transfer of heat can be restricted and can be used further for heating the incoming fresh charge and the same thing can be observed with exhaust gases. This increases the combustion efficiency and reduces the emissions. Hence in the present work, a ceramic coated engine is developed by incorporating air gap between the piston skirt and crown, cylinder liner and jacket, ceramic coating on cylinder head and valves. Therefore, a solemn attempt is made in this research work to investigate the performance and emission characteristics of diesel engine with diesel as fuel. Further the performance of the engine depends on the heat in the combustion chamber. This intends depend on piston material and the turbulence generated in the engine. So, further an attempt is made with brass piston insert and brass insert with six grooves which replaces the aluminum piston in the engine. Among all the pistons tested the brass insert with six grooves is proved to be the best in terms of performance and emissions point of view. But with the higher temperatures in the chamber drop in volumetric efficiency and lubricating oil deterioration are the main problems. However they can overcome by turbo compounding and with the development of new lubricants.