Question

Question 2 [Total Marks 25 High Temperature Solar Thermal Systems a) Describe the principle of operation of a central receiver concentrating solar thermal system Include a discussion of the method of collecting sunlight, working fluid, generating electricity and storage. Include appropriate diagram(s) in your description 10 Marks Describe the key differences between solar trough and parabolic dish solar thermal b) collectors. Why is the receiver for a parabolic dish located a long way above the rim of the collector, while the receiver for the trough sits much lower? 5 Marks] A parabolic dish collector, operating in air, has an inlet half-angle of 45° and a dispersion angle of 0.5。. If 960w.m? are falling onto the collector, what is the maximum intensity of light that could be found at the receiver? The actual concentration ratio is likely to be a lot lower: what factors limit the concentration ratio that can actually be achieved? c) I5 Marks] Cmax = 4stn2 (0.268 + 5) The overall efficiency of a solar thermal power system consists of the product of two d) efficiencies, the efficiency of heat collection and the efficiency with which the heat is used to produce power. How do each of these efficiencies vary with temperature, and why do these trends exist? What is the consequence of these temperature effects on the overall efficiency of the system? 5 Marks]

Answer 1

Gwen utPry22% -) point on the ellipse he dtae dc)betweon ando Can be x 2