Effect of Injection Pressure on the Performance and Emission Characteristics of VCR engine using Honne Biodiesel as a Fuel

This paper deals with the experimental work which has been carried out to investigate the effect of fuel injection pressure (180, 210 and 240 bar) on the performance and emission characteristics of single cylinder variable compression ratio, CI DI engine fuelled with the blends of Honne biodiesel and diesel. The compression ratio of the engine is set to 18 compared to default value of 17.5. The performance parameters evaluated were brake thermal efficiency, brake specific fuel consumption, exhaust gas temperature and the exhaust emissions measured were carbon monoxide, carbon dioxide, hydrocarbon and oxides of nitrogen. The results with biodiesel and diesel blends are compared with that of diesel. The result indicated that the BSFC for Honne biodiesel is higher by 0.042 Kg/kW hr as compared to that of Diesel oil at IP of 240 bar. A marginal increase in BMEP with increase in IP is observed for all the fuels tested. The variations of thermal performance parameters at different Injection pressures from 180bar to 240bar in steps of 30bar and maintaining a constant compression ratio at 18 and load at 12 kg are presented in Figures 4.33 to 4.41. The injection timing was maintained at constant manufacturers default value of 23 degrees bTDC. Honne biodiesel (B100) gives minimum harmful emissions as compared to all other blends. Further at a higher compression ratio of 18 and injection pressure of 240 bar, fairly reduced emissions are observed irrespective of the fuel used. The NOX emissions increase with increase in IP. The NOX emissions increase as the blend proportion is increased. B20 blend gives better thermal performance compared to other blend of Honne biodiesel, but it causes higher levels of exhaust emissions. (C) 2015 Elsevier Ltd. All rights reserved.