Even though most variations of solar collector have been tried and tested at some stage or other an important family of concentrating solar trap has been overlooked. This class of collector has combined together the advantages of some of the other collector types by overcoming their individual disadvantages. A concentrating solar trap acts like a non-focussing radiation funnel which by refraction and reflection concentrates solar energy. This thesis demonstrates that for moderate concentrations this collector geometry has better optical efficiencies and acceptance angles than other known concentrators. The investigation has carried out an optimisation simulation aimed at providing the best possible collector geometry without diurnal tracking for a concentrating solar trap using a super-viscous liquid with a high transmittance coefficient and low thermal conductivity. The resulting computer simulation predicted very favourable results for these physical conditions. An experimental collector was built and tested and a comparison of the computational and experimental results for efficiency under steady state conditions has been carried out which confirms the correctness of the simulation. However until such time as a suitable trap material becomes available this collector is not thought to be commercially viable. However the mechanism for predicting the best collector geometry for any trap transmittance has been developed here and can be used with confidence.
|Date of Award||Sep 1987|