Effect of Injector Opening Pressure and Injection Timing on Exhaust Emissions and Combustion Characteristics of High Grade Low Heat Rejection Diesel Engine with Tobacco Seed Oil Based Biodiesel

Abstract

Experiments were conducted to determine exhaust emissions and combustion characteristics of a conventional diesel engine (CE) and high grade low heat rejection diesel engine (LHR) (with air gap insulated piston with superni (an alloy of nickel) crown, air gap insulated liner with superni insert and ceramic coated cylinder head)with different operating conditions [normal temperature and pre-heated temperature] of tobacco seed oil based biodiesel with varied injection timing and injector opening pressure. Exhaust emissions [smoke and oxides of nitrogen] and combustion characteristics [peak pressure, time of occurrence of peak pressure and maximum rate of pressure] were determined at peak load operation of the engine fuelled with tobacco seed oil based biodiesel with different versions of the engine. Comparative studies on exhaust emissions and combustion characteristics were made between different versions of the engine with biodiesel operation with varied engine parameters. Smoke levels decreased and NOx levels increased with LHR engine with biodiesel operation on LHR engine. Advanced injection timing and increase of injector opening pressure reduced exhaust emissions from LHR engine with biodiesel operation.