The preliminary design of a space station calls for a power
cycle that at steady state receives energy by heat transfer at
TH= 600 K from a nuclear source and rejects energy to space
by thermal radiation according to Eq. 2.33. For the radiative
surface, the temperature is TC, the emissivity is 0.6, and the
surface receives no radiation from any source. The thermal efficiency of the power cycle is one-half that of a reversible
power cycle operating between reservoirs at TH and TC.
(a) For TC= 400 K, determine Wcycle/A, the net power developed per unit of radiator surface area, in kW/m2
, and
the thermal efficiency.
(b) Plot Wcycle/A and the thermal efficiency versus TC, and determine the maximum value of Wcycle/A.
(c) Determine the range of temperatures TC, in K, for which Wcycle/A is within 2 percent of the maximum value obtained in part (b).
The Stefan-Boltzmann constant is 5.67x10^-8 W/m²K4