Influence of preheating on performance parameters and combustion characteristics of high grade semi adiabatic diesel engine with cotton seed biodiesel

Vegetable oils are important substitutes for diesel fuel, as their properties are comparable to diesel fuel and also they are renewable in nature. However, drawbacks associated with vegetable oils of high viscosity and low volatility need to be converted into biodiesel. These biodiesels derived from vegetable oils present a very promising alternative for diesel fuel, since they have numerous advantages compared to fossil fuels. They are renewable, biodegradable, provide energy security and foreign exchange savings besides addressing environmental concerns and socio-economic issues. However drawbacks associated with biodiesel of high viscosity and low volatility which cause combustion problems in CI engines, call for engine with hot combustion chamber. They have significant characteristics of higher operating temperature, maximum heat release, and ability to handle lowcalorific value fuel. Investigations were carried out to evaluate the performance and combustion characteristics with low heat rejection combustion chamber with cotton seed biodiesel. It consisted of an air gap insulated piston, an air gap insulated liner and ceramic coated cylinder head with different operating conditions of cotton seed biodiesel. Combustion characteristics were determined by means of Piezo electric pressure transducer, TDC (top dead center) and special pressure-crank angle software package at full load operation. Comparative studies were made for engine with LHR combustion chamber and CE at manufacturer's recommended injection timing (27^obTDC) with biodiesel operation. Engine with LHR combustion chamber with biodiesel showed improved performance at 27^obTDCover CE.