
%0 Journal Article
%A Pailthorpe, BA 
%A Collins, RE 
%A O'Shea, S 
%T Temperature Limitation in Evacuated Solar Collector Tubes
%J Australian Journal of Physics
%D 1987/10/01
%V 40
%N 5
%P 643-658
%K 
%R https://doi.org/10.1071/PH870643
%U https://www.publish.csiro.au/paper/PH870643 
%X A recent innovation in evacuated tubular solar collector technology is described. A desorbable gas, which specifically adsorbs on the graphitic solar selective surface, can reversibly degrade the vacuum by providing a heat conduction path at elevated temperatures. The stagnation temperature of the system is thus limited in a controllable manner without significantly degrading the low temperature performance. A simple theory incorporating the Langmuir adsorption isotherm and the Knudsen free molecule transport regime is used to describe the phenomenon. 
