Optimization of performance and emission characteristics of common rail direct injection diesel engine using response surface methodology

Abstract

The performance and emission characteristics of a waste plastic oil biodiesel blend-fueled Common Rail Direct Diesel Injection (CRDI) engine with exhaust gas recirculation (EGR) were investigated in the current study using the Box-Behnken Design (BBD) matrix of the Response Surface Methodology (RSM). The optimisation of engine parameters like injection pressure (IP), load and EGR ratio were explored to enhance the working characteristics of CRDI diesel engine. The engine's input parameters were chosen to be IP, load and EGR ratio, and the responses were BSFC, BTE, NOx and HC. Multi-objective optimization has been used for the optimum engine responses using the desirability function. The optimum output engine responses were 21.25% BTE, 0.411 kJ/kW.hr BSFC, 20.31 ppm HC and 883.29 ppm NOx, respectively. At optimal engine running conditions yielded a composites desirability of 0.655. Optimized engine parameters received at an IP of 599.99 bar, the load of 55.04%, and the EGR ratio of 6.41. Confirmation experiments were carried out to validate optimization results by engine input parameters to optimal values. The output responses at optimum input parameters are evaluated experimentally and verified to be within the acceptable range of error (<5%). From this study, it has been concluded that the developed mathematical model can be used effectively to predict the engine characteristics.