Analysis of Thermo-Mechanical Stresses and Strains for a Novel Design of Insulating Glass Flat-Plate Collector
Abstract
Insulating glass flat-plate collectors have been investigated more intensively during the last decade as this innovative design approach promises to lower heat generation cost for solar thermal applications. The latest investigations in that field indicate that high temperatures and mechanical stresses may affect durability and stability of the collector sealings that are required for an efficient operation of the solar thermal module. A novel design was proposed recently that has not yet been studied regarding its thermo-mechanical loads, stresses, and strains. The objective of this study was to determine typical load profiles for such collectors and – through finite element analysis – determine stresses and strains on the collector sealings. An answer should be given as to whether the novel design improves the thermo- mechanical resilience of the collector and whether the chosen design can withstand typical load conditions for solar district heating. The results show that stagnation is likely to cause gas leakages but unlikely to cause mechanical failure of the collector. Furthermore, it was shown that thermo-mechanical loads during normal operation are uncritical, which is why the novel insulating glass flat-plate collector design is considered superior over the previous. Although a lifetime of 20 to 25 years is very likely to be achieved for the collector, we strongly suggest avoiding stagnation for the collector to avoid gas leakage and resulting decrease in thermal performance.
Keywords
Thermo-mechanical analysis, Stress, Strain, Finite element analysis, Insulating glass, Solar thermal, Flat- plate collector, Durability