Performance, Emissions and Combustion Characteristics of Waste Fried Vegetable Oil in Based Biodiesel in High Grade Low Heat Rejection Diesel Engine

Aims: Aim: Experiments were conducted to evaluate the performance of a LHR diesel engine with air gap insulated piston, air gap insulated liner and ceramic coated cylinder head [ceramic coating of thickness 500 microns was done on inside portion of cylinder head] with different operating conditions [normal temperature and pre-heated temperature] of waste fried vegetable oil based biodiesel with varied injection pressure and injection timing and compared the performance with pure diesel operation on CE.
Study Design: Performance parameters of BTE, BSEC, EGT, VE, CL, Sound intensity were determined at various values of BMEP of the engine.
Methodology: Exhaust emissions of smoke and NOx were recorded at different values of BMEP of the engine. Combustion characteristics at peak load operation of the engine were measured with TDC encoder, pressure transducer, console and special pressure-crank angle software package.
Results: Conventional engine (CE) showed compatible performance, while LHR engine showed improved performance with waste fried vegetable oil based biodiesel at recommended injection timing and pressure. The performance of both versions of the engine was improved with advanced injection timings and at higher injection pressure when compared with CE with pure diesel operation. The optimum injection timing was 33ºbTDC with CE while it was 32ºbTDC for LHR engine with biodiesel operation. Relatively, peak brake thermal efficiency increased by 18%, brake specific energy consumption decreased by 6%, exhaust gas temperature decreased by 75ºC, volumetric efficiency decreased by 5%, coolant load decreased by 30%, sound intensity decreased by 35%, smoke levels decreased by 27% and oxides of nitrogen levels increased by 41% with biodiesel operation on LHR engine at its optimum injection timing, when compared with pure diesel operation on CE at manufacturer’s recommended injection timing.