Effect of injection timing and injection pressure on the performance of biodiesel ester of hongeoil fuelled common rail direct injection (CRDI) engine

Abstract

This paper discusses the feasibility study on the utilization of biodiesel ester of Honge oil (EHO) in common rail direct injection (CRDI) engine. Biodiesel of EHO has been obtained by transesterification process and characterization has been done. Existing single cylinder diesel engine fitted with conventional mechanical fuel injection system (CMFIS) was suitably modified to operate on Common Rail Direct Injection (CRDI) facilities where the biodiesel can be injected with higher injection pressures. Experiments were conducted on CRDI engine fuelled with diesel and biodiesel to optimize the injection timing (IT), where the IT varied from 25^o before top dead centre (bTDC) to 5^o after top dead centre (aTDC) keeping injector pressure (IP)of 600 bar, compression ratio (CR) of 17.5 and constant engine speed of 1500 rpm at 80 and 100% loading conditions. Improved brake thermal efficiency (BTE) IT was obtained at 10^o. Further experiments were conducted on CRDI engine fuelled with diesel and EHO to optimize the injector opening pressure (IP) where IPs were varied from 600 bar to 1000 bar keeping optimized IT of 10^o bTDC and revealed that maximum BTE was obtained at 900 bar. From the experimental study, IT of 10^obTDC and IP of 900 bar were concluded as best engine operating parameters to obtain maximum BTE with lower hydrocarbon (HC), carbon monoxide (CO), smoke emissions but oxides of nitrogen (NOx) emissions were higher for the fuels used in the study. Peak pressure and heat release rates were observed maximum for IT of 10^obTDC and IP of 900 bar compared to other ITs and IPs used.

Keywords: Diesel engine, Ester of Honge Oil (EHO), Common Rail Direct Injection (CRDI), Emissions