Comparative study of Box–Behnken and central composite designs to investigate the effective parameters of ammonia–water absorption refrigerant system

In this paper, the statistical analyses of the ammonia-water absorption refrigerant system (ARS) are presented. For this purpose, different surface response methods, including the Central composite design (CCD) and Box- Behnken design (BBD), have been studied and compared first to obtain the best response. An attempt is made to study the effect of some factors (mass flow rate, isentropic efficiency of pump, pressure ratio, maximum pressure of cycle, concentration difference of strong and weak solution, concentration of strong solution and effectiveness factor of heat exchanger and pure ammonia concentration) on the system’s response. Based on the design of experiment analysis, regression models are presented to quantify the effects of these parameters on coefficient of performance (COP) and cooling load of the ammonia-water absorption refrigerant cycle. The proposed correlations obtained by the analysis have remarkably satisfactory performance for all simulation data. The error analysis is applied to find the maximum error of 0.482% in numerical computations for ARS by CCD method in midpoint values of parameters.