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ENERGY CONVERSION A 2015-16 Name/Lastname:__________________________________________ Code n.___________ Exam 06/09/2016 Exercise 1 (10 points) Consider an air-cooled single-level combined cycle characterized by:  TOT in combined cycle configuration: 580°C;  exhaust gas mass flow rate: 300 kg/s;  exhaust gas average specific heat capacity at constant pressure: 1.10 kJ/(kg K);  steam cycle evaporation pressure: 35 bar;  evaporation enthalpy at 35 bar: 1750 kJ/kg;  evaporation temperature at 35 bar: 242°C;  superheated steam average specific heat capacity at constant pressure at 35 bar: 2.3 (kJ/kg K). Moreover, consider the layout solution with a ΔT of subcooling of 0°C at the steam drum inlet, which is achieved by a valve yielding a pressure reduction of 15 bar. In contrast, at the deaerator inlet the ΔT of subcooling is 15°C. Please: i. highlight clearly in your the text all assumed parameters and their assumed values (1 point); ii. sketch the plant layout (2 points); iii. plot the temperature-heat transfer (T-Q) diagram of the HRSG (2 points); iv. calculate the mass flow rate of the generated steam (2 points); v. compute the second-law efficiency loss due to the irreversibility for the heat transfer to the environment at the stack (3 points). Exercise 2 (12 points) Consider the following energy source: an ideal gas flow of 100 kg/s at 500°C and 0.1 bar. The gas is characterized by a molar mass of 50 kg/kmol and an average specific heat at constant volume of 2000 J/kg K. Please: i. highlight clearly in your the text all assumed parameters and their assumed values (1 point); ii. compute the reversible power by way of exergy difference (2 points); iii. propose and sketch a realistic plant for exploiting the source; this plant must satisfy the following techno-…