Optimized Design of the Insulating Gas Layer in Solar Thermal Collectors
Abstract
The aim of the investigations shown here is to further investigate the convective heat losses in insulation gas layers. These investigations are relevant for the design of the thickness of the insulation gas layer, as this is a main factor influencing the reduction of convective losses. The example used here of the solar glass collector is an extension of the insulating glass collector. The studies on the solar glass collector led to the results shown here, too. In recent studies based on CFD simulations and experimental measurements, deviations from the standard calculation approach by Hollands (1976) are identified and corrected with a correction function. The results shown here apply this correction function to the dimensioning of the thickness of the insulation gas layer. The convective heat transfer coefficient in the gas layer differs up to approx. 30% regarding Hollands (1976).