Experimental Investigations on Exhaust Emissions of Low Heat Rejection Diesel Engine with Crude Mahua Oil

Abstract

Vegetable oils present a very promising alternative for diesel fuel, since they have numerous advantages compared to fossil fuels. They are renewable, biodegradable and provide energy security, foreign exchange savings besides addressing socio–economic issues. However drawbacks associated with crude vegetable oils 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 low calorific value fuel. Investigations were carried out to determine exhaust emissions with low heat rejection diesel engine with crude mahua oil. It consisted of an air gap insulated piston, an air gap insulated liner and ceramic coated cylinder head with different operating conditions of mahua oil with varied injection timing and injector opening pressure. Exhaust emissions were determined at various values of brake mean effective pressure of the engine. Comparative studies on exhaust emissions were made for LHR engine and CE at manufacturer’s recommended injection timing (27o bTDC) and optimum injection timing with vegetable oil operation. LHR engine with crude oil showed reduction of particulate emissions at 27o bTDC and at optimum injection timing over CE.