Collector Efficiency Calculation Tool for the Plastic Collectors with Temperature Limitation
Abstract
The goal of several projects in Europe is to develop and design collectors made out of polymers. A main boundary condition for such polymer collectors is the possibility to use as cheap as possible polymer material, which can typically withstand temperatures only up to about 90°C. Therefore solutions for limiting the temperatures during stagnation are looked for. One possible solution is a collector with integrated thermosiphon cooling, which limits the temperature during stagnation, but also allows the design of a collector with highest possible efficiency during operation. For supporting the development work a calculation tool is under development. It is a 1-D model which calculates all heat flows within a collector for a finite number of elements along the manifolds and strips in the absorber resulting in a theoretical efficiency curve. Actually the tool is validated against collector test certificates and can be used for parametric studies changing geometry and materials of the collector. This paper presents the validation results compared to a tested collector and some parametric studies. The possible influence of simulations on the design process is emphasized.
Keywords
Solar thermal, Solar collector, Polymer collectors, Collector efficiency, Simulation tool