Potential of a Low Heat Rejection Diesel Engine with Crude Pongamia Oil

Investigations are carried out to evaluate the performance of a low heat rejection (LHR) diesel engine consisting of air gap insulated piston with 3mm air gap, with superni 2/4(an alloy of nickel) crown and air gap insulated liner with superni insert with different operating conditions of crude pongamia oil (CPO) with varied injection pressure and injection timing. Performance parameters of are determined at various magnitudes of brake mean effective pressure. Pollution levels of smoke and oxides of nitrogen (NOx) are recorded at the peak load operation of the engine. Combustion characteristics at peak load operation of the engine are measured with TDC (top dead centre) encoder, pressure transducer, console and special pressure-crank angle software package. Conventional engine (CE) showed deteriorated performance, while LHR engine showed improved performance with CPO operation at recommended injection timing and pressure and the performance of both version of the engine is improved with advanced injection timing and at higher injection pressure when compared with CE with pure diesel operation. Peak brake thermal efficiency increased by 5%, smoke levels decreased by 4% and NOx levels increased by 40% with CPO operation on LHR engine at its optimum injection timing, when compared with pure diesel operation on CE at manufacturer’s recommended injection timing.