Studies on effect of fuel preheating and bowl geometry modification in di diesel engine with neem and pumpkin oil biodiesels

Abstract

The strict and severe emissions regulations, superior fuel economy demanded by vehicle users, enforce a strong objective to researchers and engine manufacturers to search for supreme efficiency with the lowest level of emission of pollutants. At the present time, the requisite for an alternative energy source is augmenting extremely owing to its strong usage, diminution of natural resources, human population outburst, oscillation in oil price and so forth. Thus, the researchers search intensively for substitute to replace the fossil fuels of diesel engines. Biodiesel is the most prominent and eco-friendly alternative to the conventional fossil fuel as it is non-hazardous, renewable and biodegradable. Biodiesel comprises of 12% of oxygen which aids complete combustion. Though, the traditional diesel engine combustion is a very effective process, the energy loss in engine after combustion is in the form of exhaust gas and cooling water. Preheating of the biodiesel is essential to improve the efficiency as the density of bio-fuels is relatively high. Some researchers use distinct electrical heater for heating the fuel and then allow for combustion. But, this technique consumes more power and is found to be expensive. Consequently, the individual heat exchanger is developed to use the exhaust heat for preheating of the oil. In the present work, three different heat exchangers are developed and employed to attain the various inlet temperatures of the bio-diesel namely 60, 70 and 80 °C. Piston bowl geometry modification helps in achieving better air-fuel mixing, improved combustion efficiency, increased power output and smooth operation. In the present investigation, two combustion chambers namely Toroidal Combustion Chamber (TCC) and Trapezoidal Combustion Chamber (TRCC) are developed. These combustion chambers can offer better squish movement due to variation in diameter to depth ratio. newline