Using Taguchi method on combustion performance of a diesel engine with diesel/biodiesel blend and port-inducting H2

Abstract

In this study, a Taguchi method is used to determine the optimal combinations of concentrations for a diesel engine with diesel/biodiesel blend using H2 and cooled exhaust gas recirculation (EGR) at the inlet port. The authors determined the optimal operating factors for achieving good combustion performance, low NOX and smoke, at various engine loads and at 1500rpm. Furthermore, the combustion performance and emissions are compared between the optimum combination factors and original baseline diesel engine. Experimental results show that predictions by Taguchi’s parameter design technique are in adequate agreement with the confirmation results, with a confidence interval of 95%, and this technique saves 67% of the time taken to perform the experiment in this research. The best brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC), NOX and smoke at each load is achieved for a combination of B20 (A2), 30% hydrogen (B3) and 40% EGR ratio (C3). Furthermore, the heat release rate with a variable specific heat ratio is calculated from the experimental cylinder pressure. This combination is more suitable for obtaining various parameters that affect the combustion performance such as the BTE, cylinder pressure, and heat release rate, than those of the baseline diesel engine for various loads. In addition, the best combination reduces the BSFC and inhibits both NOX and smoke emissions. At a load of 60%, the reduction rate is 25.4% for BSFC, 74.1% for NOX and 29.6% for smoke.