Solved: In the central receiver concept of solar energy

Chapter , Problem 12.117

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In the central receiver concept of solar energy collection, a large number of heliostats (reflectors) provide a concentrated solar flux of to the receiver, which is positioned at the top of a tower. The receiver wall is exposed to the solar flux at its outer surface and to atmospheric air for which T,o 300 K and ho 25 W/m2 K. The outer surface is opaque and diffuse, with a spectral absorptivity of 0.9 for 3 m and 0.2 for 3 m. The inner surface is exposed to a working fluid (a pressurized liquid) for which T,i 700 K and hi 1000 W/m2 K. The outer surface is also exposed to surroundings for which Tsur 300 K. If the wall is fabricated from a high-temperature material for which k 15 W/mK, what is the minimum thickness L needed to ensure that the outer surface temperature does not exceed Ts,o 1000 K? What is the collection efficiency associated with this thickness? 12.118 Cons