Title: Calorimetric measurement of absorptance and emittance of the Sydney University evacuated collector
Abstract: Simple calorimetric techniques have been developed for determining the absorptance and emittance of individual evacuated tubular collectors incorporating a selective surface, and the efficiency, ηo, of evacuated collectors in various mirror systems. The absorptance and efficiency measurements are made in natural sunlight without the use of a solarimeter by establishing an absorptance standard based on Nextel black paint. Calibration of solarimeters using the established absorptance standard is discussed. Emittance measurements are made by measuring radiative heat losses from the absorber tube of a collector. Absorptance and emittance measurements for a number of Sydney University evacuated collectors gave values of absorptance α = (0.92 ± 0.01) and emittance ϵ = 0.05 at 120°C for the selective surface utilized. Efficiency (ηo) measurements for Sydney University collectors in two simple mirror systems are also reported.
Publication Year: 1981
Publication Date: 1981-01-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 22
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