Consider a Carnot engine operating between temperatures Th, and Ti, where Ti is intermediate between Th and the ambient temperature Tc (Fig. 19.21). It should be possible to operate a second engine between Th and Tc. Show that the maximum overall efficiency of such a two-stage engine is the same as that of a single engine operating between Th, and Tc (which is why combined-cycle power plants achieve high efficiencies).
FIGURE 19.21 Problem 32
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