Theoretical study of absorbed solar energy in multi-layer absorber coatings for receivers of solar concentrators: part 1. radiation transfer analysis
The use of solar energy to produce electricity is under development. High temperature fluid is heated by flowing through blackened receivers placed at the focus of concentrating collectors. This fluid is used to drive a conventional turbine working on Brayton cycle. The receivers should have high absorptance for short wave radiation and low emissivity at the infra-red radiation. Several receiver coatings have been suggested in the literature. A semiconductor coating has the advantage of being transparent to long wave radiation but it has the disadvantage of having high reflectance. The present work analyzes a multi-layer coating composed on a thin semi-conductor layer covered by two very thin absorbing layers. The coating lies on a thin layer of a low-emitting silver substrate. The multiple reflections and multiple absorptions are considered in deriving a mathematical model. The effect of absorption coefficients and thickness of the three layers, as well as the reflection coefficient of the semiconductor layer, on the solar energy absorbed within the different layers of the coating is studied. A discussion is presented on how to apply the results of this model to evaluate the design of the receivers. 2 refs.
- Research Organization:
- King Abdulaziz Univ, Jeddah, Saudi Arabia
- OSTI ID:
- 5351187
- Report Number(s):
- CONF-800802-; CONF-801104-
- Journal Information:
- AIChE Symp. Ser.; (United States), Vol. 77; Conference: 89. annual meeting of the American Institute of Chemical Engineers, Portland, OR, USA, 17 Aug 1980
- Country of Publication:
- United States
- Language:
- English
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