Abstract
The present work suggests a more complete method for predicting the performance of solar collectors at intermediate temperatures, taking into account absorptance of the solar short-wave radiation in the glass covers and transmittance through them of the IR long wave radiation from the plate and other surfaces. The governing equations for energy balances of the shield and outer cover were developed, using a ray tracing method and radiation characteristics of slabs and coatings. The equations were solved numerically for the shield and cover temperatures, Tg and Tc, and then the net energy, Qnet, was found. Other heat fluxes were also obtained, to understand better the influence of each parameter on the performance. A parametric study has been carried out to study the effects of various coatings: heat mirrors (reflecting IR radiation) and anti-reflective for solar radiation. The influences of collector pressure, concentration, double glazing, and selective coatings on the absorbing plate have also been investigated. An important conclusion from the results is that there is no configuration of coatings which yields higher efficiencies over the whole temperature range. An “optimal” collector must be designed according to the intended consumer temperature.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
