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Department of Energy Politecnico di Milano Author Francesco Tonini Pag.1 of 4 Date 21/04/2022 Milan, 21st April 2022 Exam Simulation – Thermoeconomics and Energy Modelling 22-04-2022 Total score: 21 points (exercise 1 roughly 2/3 of the total) Exercise 1. Let’s consider the simple cogeneration plant depicted in the figure, characterized by the data provided in Table 1. The plant composed by 4 components; Air Compressor (AC), Combustion Chamber (CC), Gas Turbine (GT) and Heat Exchanger (HE), generating 30 MW of net electric power, and the AC consumes 29.66 MW to perform the compression. The flue gases 5 are released to the environment without any additional cost, and hot water 7 is considered as a useful product. Table 1 Table 2 State Substance Mass Flow Rate [kg/s] T [K] P [bar] Ex [MW] 1 Air 91.28 298.15 1.013 0.00 2 Air 91.28 603.74 10.130 27.54 3 Flue gas 92.92 1520 9.142 101.45 4 Flue gas 92.92 1006.16 1.099 38.78 5 Flue gas 92.92 426.9 1.013 2.77 6 Water 14 298.15 20.00 0.06 7 Steam 14 485.57 20.00 12.81 8 Methane ? 298.15 12.00 84.99 Environment 298.18 1.013 unit cost of Fuel (cF) [€/GJ] 4.57 Z_AC (Investment, O&M) [€/s] 0.21 Z_CC (Investment, O&M) [€/s] 0.019 Z_GT (Investment, O&M) [€/s] 0.21 Z_HE (Investment, O&M) [€/s] 0.073 ẆAC GT Ẇnet 4 HE 3 76 1 5 Cooling water CC AC 8 Air Flue Gas Fuel Department of Energy Politecnico di Milano Author Francesco Tonini Pag.2 of 4 Date 21/04/2022 It is required to: a. Write the exergy balance computing exergy destruction of each component. Calculate the rational and functional exergy efficiencies. Comment on the obtained results. b. Write the auxiliary equations needed to characterize the thermoeconomic system of equations for this plant. Clearly explain the reason why each auxiliary equation is assigned and make sure they…