Using Exergetic Efficiencies Figure P7.129 and the accompanying table provide...

Using Exergetic Efficiencies

Figure P7.129 and the accompanying table provide steady-state operating data for a direct-contact heat exchanger fitted with a valve. Water is the substance. The mass flow rate of the exiting stream is 20 lb/s. Stray heat transfer and the effects of motion and gravity are negligible. For an overall control volume, (a) evaluate the rate of exergy destruction, in Btu/s, and (b) devise and evaluate an exergetic efficiency. Let T₀ = 60^oF, p₀ = 14.7 lbf/in.²