Consider the central receiver of 12.117 to be a

Chapter , Problem 12.118

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Consider the central receiver of 12.117 to be a cylindrical shell of outer diameter D 7 m and length L 12 m. The outer surface is opaque and diffuse, with a spectral absorptivity of 0.9 for 3 m and 0.2 for 3 m. The surface is exposed to quiescent ambient air for which T 300 K. Atmosph (a) Consider representative operating conditions for which solar irradiation at GS 80,000 W/m2 is uniformly distributed over the receiver surface and the surface temperature is Ts 800 K. Determine the rate at which energy is collected by the receiver and the corresponding collector efficiency. (b) The surface temperature is affected by conditions internal to the receiver. For GS 80,000 W/m2 , compute and plot the rate of energy collection and the collector efficiency for 600 Ts 1000 K. 1