A Comparative Study of the Performance of a Low Heat Rejection Engine with Three Different Levels of Insulation with Vegetable Oil Operation

Investigations are carried out to evaluate the performance of a low heat rejection (LHR) diesel engine consisting of different versions such as ceramic coated cylinder head engine-LHR-1; Air gap insulated piston and air gap insulated linerLHR-2; and Ceramic coated cylinder head, air gap insulated piston and air gap insulated liner –LHR-3 with normal temperature condition of linseed oil with varied injection pressure. Performance parameters 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 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 and LHR engines showed improved performance at recommended injection timing of 27 o bTDC and recommend injection pressure of 190 bar with vegetable oil operation, when compared with CE with pure diesel operation. Peak brake thermal efficiency increased by 12.5%, compatible smoke levels and NOx levels increased by 49% with LHR-3 engine at an injection pressure of 190 bar when compared with pure diesel operation on CE at an injection pressure of 190 bar.