Selection of solar collector network design for industrial applications subject to economic and operation criteria

The aim of this paper is to present a design approach for the selection of the most cost-effective solar thermal plant composed of flat plate solar collectors for a given process. The approach seeks to provide the designer with the necessary elements for decision making, namely minimum total operating costs, minimum required plot area for installation, maximum daily operating time and determination of payback time. The optimisation methodology search uses a cost equation for flat plate solar collectors along with a thermal model linked in a MatLab and General Algebraic Modeling System (GAMS) platform. In stand-alone collector design, tube diameter, tube length and collector width are the variables that have a major impact on the cost; in the case of solar collector fields, the number of collectors in series is the variable with the strongest impact. It is shown that the optimised networks fulfil the thermal duty within the limitation of land area. The designs are carried out for the conditions that guarantee operation throughout the year and exhibit saving of up to 50% and payback times lower than six years. The approach is demonstrated using a case study.