Multi response optimization of NOx emission of a stationary diesel engine

In the present work the combined effect of fuel injection timing, percentage of EGR and fuel injection pressure in controlling the NOx emission of a stationary diesel engine fuelled with diesel was investigated. Three levels were chosen in each factor and NOx emission, smoke concentration and brake fuel conversion efficiency are taken as the response variables. Experiments were designed as per Taguchi’s L9 orthogonal array and tests were conducted with different injection timings, percentage EGR (by volume) and injection pressures. Multi response signal to noise ratio (MRSN) was calculated for the response variables and the optimum combination level of factors was obtained simultaneously using Taguchi’s parametric design. Obtained combination was confirmed experimentally and significant improvement was observed in the response variables.