8.3 = Figure P8.3 shows an air compressor with intercooling. The numbers given for each stream represent exergy flows. All costs are levelized costs. The cost per exergy unit of stream 2 is c₂ $10.0/GJ. The costs associated with streams 1 (air) and 5 (feedwater inlet) are zero. The cost rates associated with capital investment and operating and main- tenance expenses are Compressor Ż = $0.01/s Feedwater heater Ziwh = $0.02/s Calculate: (a) the exergy destruction rates and the exergy destruction ratios for the compressor and the feedwater heater; (b) the exergetic efficiencies of the compressor, the feedwater heater, and the overall system shown in Figure P8.3; (c) the cost rate and the cost per exergy unit associated with streams 3 (compressed air), 4 (cooled compressed air), and 6 (preheated feedwater). 6 Preheated Feedwater 1.5 MW Compressed Air 5 Feedwater 0 MW FEEDWATER HEATER 2 MW 2 Power 10 MW 9 MW 4 1 Air Cooled Air (to next compression stage) O MW Figure P8.3 8.7 Overunt system For the system of Figure P8.3, (a) calculate all thermoeconomic vari- ables associated with the air compressor and the feedwater heater, and (b) discuss options for improving the cost effectiveness of the overall system.