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Department of Energy Politecnico di Milano Author Pag.1 of 13 Date 20/01/2020 Milan, 15th January 2020 Exam – Advanced Thermodynamic and Thermoeconomics 15-01-2020 Exercise 1. (15pt) Let’s consider a part of an open gas cycle plant. As it can be seen in Figure 1, the parts under study are: the combustion chamber (CC), the first stage of the gas turbine (GT-1) and the second stage (GT-2). The inlet 1 is compressed air while flow 2 is the fuel. In the combustion chamber , a combustion takes place and it gives off hot flue gases. First stage of gas turbine produces power and a hot fluid used in an industrial process while stream 4, still flue gases, is reused to feed the second stage turbine. The last component produces useful power 𝑊𝑊̇ 𝐺𝐺𝐺𝐺−1. With reference to the data provided, it is required to: a. Write the exergy balance and compute exergy destruction of each component. Calculate the rational and functional exergy efficiencies. Comment on the results. b. Write the Thermoeconomic system of equations for each component and derive the analytical expressions of the cost structure of the products. Highlight the auxiliary equations needed to solve the thermoeconomic system and make sure they are coherent with the “functional” use of the components. c. Solve the system and provide the unit costs of the products for each component [€/MWh]. Then collect all the numerical results into a table giving evidence to the three components of the cost structure for each component. Comment on the results obtained. Table 1 State Ex [MW] 1 Compressed air 22 2 Fuel 215 3 Flue gases 177 4 Flue gases 97 5 Flue gases 22 6 Flue gases 25 7 𝑊𝑊̇ 𝐺𝐺𝐺𝐺−1 40 8 𝑊𝑊̇ 𝐺𝐺𝐺𝐺−2 65 Table 2 Unit cost of Fuel [€/MWh] 38 Unit cost of Compressed air [€/MWh] 6 Z – CC (Investment, O&M) [€/h] 300 Z – GT-1…