Solar Thermal Collector’s Degradation – Influence of Corrosivity Inside and Outside the Collectors
Abstract
Influence of atmospheric corrosivity on solar thermal collector’s degradation was studied by exposure of flat plate collectors to two different corrosivity environments, one urban Outdoor Exposure Testing (OET) site with medium corrosivity (C2-C3) and a very high/extreme corrosivity (industrial and marine) (C5-CX) atmosphere highly polluted and simultaneously with highly airborne salinity. Results of thermal performance measurements after two years of exposure in the two OET sites are presented, as well as the evaluation of the corrosion rate inside the collectors, with zinc as reference material, atmospheric contaminants, temperature and relative humidity. For the measurement of temperature and relative humidity inside the collectors, in house produced data acquisition system and sensors were used and are shortly described. Collectors were dismantled and optical properties of the absorbers were measured.