12-15 July 2011
Saint George Hotel
Africa/Johannesburg timezone

Comparative Efficiency Study of a Solar Trough Receiver: Hot mirror and Selective coating

13 Jul 2011, 12:15


Oral Presentation Track F - Applied and Industrial Physics Applied


Ms Marie Chantal CYULINYANA (University of the Witwatersrand)


We consider a solar trough system in which cylindrical parabolic mirrors focus the sun’s radiation onto a receiver pipe, heating it. Conventionally, the pipe is enclosed in a glass cover under vacuum and the dominant radiation losses are reduced by the use of a selective coating on the receiver pipe. We study the suitability of applying a ‘hot mirror’ coating on the glass cover instead, which transmits in the visible but reflects well in the infra-red. We compare the performance of the ‘selective’ with a ‘hot mirror’ coating using the results from simulations for a general heat transfer model. It is seen that a hot mirror is a viable alternative, and certainly allows higher temperatures of the working fluid and therefore higher Carnot efficiency. The optimum is a hybrid system, with selective coating applied at the low temperature end of the receiver pipe and the hot mirror being used at higher temperatures.

Consider for a student <br> &nbsp; award (Yes / No)? yes
Level (Hons, MSc, <br> &nbsp; PhD, other)? I am a Msc student
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)? Yes

Primary author

Ms Marie Chantal CYULINYANA (University of the Witwatersrand)


Dr Philippe Ferrer (University of the witwatersrand)

Presentation Materials