Selective Absorbing Surface for Evacuated Solar Collector Tubes

摘要

The absorptance of AlN-Al(absorbing coating)/Al solar spectrum (0.34 ～25 um) selective absorbing surface, containing 8-layer AlN-Al composite materials and with distinctive or non-boundaries between the layers, deposited by sputtering technolgoy and heat-treated at 400 deg C (60min) is about 0.95 and its thermal emittance is close to 0.07 ～ 0.08(80 deg C). But on the condition that the absorptance is unchanged, the thermal emittance dropped to 0.04 for the AlN-Al coating composed of matel volum fractionic 0.42, 0.25 and 0.00 films.