Optimization of a solar-powered adsorptive ice-maker by a mathematical method

In this paper, the simulation results of an adsorptive system driven by solar energy, to be used for freezing and cold storage, are presented. The system, consisting of an activated carbon reactor connected to a solar collector and to an evaporator/cold box, is able to produce and store 5 kg of ice/day, in a north Mediterranean climate. The simulations were carried out by a dynamic mathematical model which uses measured climatic data and that is based on energy balances of the components of the system. A parametric analysis, based on a Full Factorial Design (FFD) - a known statistical method used to evaluate the effects and interactions of different independent variables on a dependent variable - was accomplished. The results obtained evidenced that the most influencing parameters on the system performance are the transmittance/absorptivity coefficient of the solar collector and the heat transfer coefficient between the solar collector and the adsorbent material. Finally, the application of the Steepest Ascent Method (SAM) allowed to optimize the solar-powered adsorptive system, in terms of performance, and to determine the corresponding optimal values of the key parameters.