Accelerated Aging of First-surface Enhanced Aluminum Solar Reflectors under Damp Heat Conditions
2016 (English)Independent thesis Advanced level (degree of Master (Two Years)), 25 credits / 37,5 HE credits
Student thesis
Abstract [en]
Solar reflectors are one of the main components of concentrating solar power systems. With new products being developed, durability studies become a necessity for assessing the feasibility of commercial application. In this project, accelerated aging of three types of first-surface enhanced aluminum reflectors and one type of second-surface silvered thick glass mirror under damp heat conditions is studied. The project is conducted at the Plataforma Solar de Almería (PSA), in collaboration with German Aerospace Center (DLR), and Center for Energy, Environment and Technology (CIEMAT), Spain.
The study is centered on analyzing the effect of soiling on degradation of reflectors. In addition to conventional methods, space resolved specular reflectometry is utilized for comparative purpose. Damp heat test conditions are simulated in a climatic test chamber. Test is conducted with reference to International Electrotechnical Commission standard IEC 62108 10.7a: damp heat test guidelines. The reflector samples are artificially soiled with natural and synthetic test sands of varying composition. Reflector performance is assessed based on the reduction in monochromatic specular reflectance.
From the tests, a comparative assessment of the candidate reflectors is obtained. Aluminum samples suffered higher degradation than silvered glass mirrors. Aluminum reflectors with polymer top coat permanently retained soil residue. It is observed that presence of chlorides and organic components caused corrosion on all the types of reflectors tested. Surface roughening is the reason for performance deterioration in most of the cases. By comparing different reflectance measurement methods, the significance of total area of the measurement spot in the measurement procedures could be highlighted. It is suggested that for studies involving artificial soiling, the grain size of sand is to be factored in.
Place, publisher, year, edition, pages
2016.
Keywords [en]
Solar reflector, Accelerated aging, Corrosion, ALUMIR Project, CSP, Process heat, Collector design, Solar Energy, Spain, Morocco, United Arab Emirates
National Category
Energy Engineering
Identifiers
URN: urn:nbn:se:du-23044OAI: oai:DiVA.org:du-23044DiVA, id: diva2:963495
2016-09-082016-09-08