Selective Coatings for Thermosolar Power Plants: From Lab Developments to Industrial Production
(Room Room 104-A)
29 Apr 19
4:20 PM
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4:40 PM
Tracks:
Coatings for Energy Conversion and Related Processes
The optimisation of solar selective coatings (SSC) for solar receivers plays a critical role in the efficiency of a concentrated solar power (CSP) plants. In this work two different SSC has been developed: one of them to operate in vacuum for parabolic through collectors (PTC) and the other to operate in air for linear Fresnel collectors. The final achieved multilayer stack designs were obtained after a combination of PVD parameters optimisation, characterisation and optical simulation of the individual layers. Multi-layered coating for evacuated receivers: SiO2/AlNW/Mo/W deposited using magnetron sputtering showed excellent optical selective properties α = 94.0% and ε400 = 4.8% and long-time thermal stability at the operation temperature of CSP plants. SSC has been scaled up to 4 m long tubes and its efficiency is going to be tested in real plant. Chromium oxynitrides, AlCrO/AlCrON/AlCrN deposited by magnetron sputtering were selected to develop solar selective coating to operate in air due to its exceptional thermal stability and oxidation resistance at high temperatures. Again, excellent optical selective properties, total solar absorptance above 90% and thermal emittance below 10% were measured. Thermal stability of the coatings was tested by means of an accelerated ageing test based on Arrhenius calculations.