Effect of Injection Pressure on CI Engine Performance Fuelled with Biodiesel and its blends

Use of biodiesel as an alternative to diesel could reduce the dependency on petroleum products and the pollution problem. The physical properties of the fuel such as viscosity, volatility and f lash point also affect the combustion process, thereby engine performance. Specif ically atomization of the fuel during the injection is attributed to higher viscosity of biodiesel. Injec ted fuel droplets get smaller as the injection pressure increases which contributes to better atomization of the fuel. Hence the effect of injection pressure (IP) on the performance of compression ignition (CI) engine fuelled w ith biodiesel and its blends w ith diesel is evaluated. Tests are conducted on CI engine fuelled with diesel at IP of 200 bar to get base line data for comparing engine performance w ith various blends of palm oil methyl ester (POME) and diesel as test fuels at different injection pressures. The results indicate that the performance of engine is improved w ith B60 (60% POME and 40% diesel) at IP of 220 bar compared to other test fuels at different injection pressures. In this paper comparison of test fuel B60 at different injection pressures with diesel at 200 bar is made.It is observed that brake thermal eff iciency is improved and brake specif ic energy consumption is low ered w ith B60 at 220 bar due to improved atomization. It is also observed that carbon monoxide, unburned hydrocarbons are reduced and Nox emissions increased compared to other test fuels at different injection pressures.