Abstracto

Performance Evaluation of Mohr Oil Based Biodiesel in Low Grade Low Heat Rejection Diesel Engine

T. Ratna Reddy, M.V.S. Murali Krishna, Ch. Kesava Reddy and P.V.K.Murthy

Investigations were carried out to evaluate the performance of a low grade low heat rejection (LHR) diesel engine with ceramic coated cylinder head with 3-mm air gap with different operating conditions [normal temperature and pre-heated temperature] of mohr oil based biodiesel (MOBD) with varied injection pressure and injection timing. Performance parameters of brake thermal efficiency, exhaust gas temperature, volumetric efficiency and sound intensity were determined at various values of brake mean effective pressure (BMEP).Exhaust emissions of smoke and oxides of nitrogen (NOx) were recorded at the various values of BMEP. Combustion characteristics at peak load operation of the engine were measured with TDC (top dead centre) encoder, pressure transducer, console and special pressure-crank angle software package. Conventional engine (CE) showed compatible performance, while LHR engine showed marginally increased performance with MOBD operation at recommended injection timing and pressure. The performance of both version of the engine improved with advanced injection timing and at higher injection pressure when compared with CE with pure diesel operation. The optimum injection timing was 33obTDC for CE while it was 29.5obTDC with LHR engine with MOBD operation. Peak brake thermal efficiency increased by 13%, at peak load operation- brake specific energy consumption (BSEC), coolant load, volumetric efficiency, smoke levels and sound intensity decreased by 4%, 15%, 7%, 27%, 24% respectively while NOx levels increased by 47% with MOBD operation on LHR engine at its optimum injection timing when compared with diesel operation on CE at manufacturer’s recommended injection timing of 27obTDC. (Before top dead centre)