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Politecnico di Milano Department of Energy School of Industrial and Information Engineering Course Energy Systems LM proff. S. CONSONNI, E. MARTELLI, M. ROMANO - Academic Year 2017/18 Energy Systems LM - written test of July 16th, 2018 page 1 of 1 Written Exam 16 July 2018 - QUESTIONS - Time: 1 hour PLEASE NOTICE 1) This part of the exam is closed book. Computers and cell phones are NOT allowed. Talking with colleagues and/or copying will lead to the immediate cancellation of the exam. 2) The final grade is the sum of the points assigned to the answer of each question plus a bonus of max 3 points. The bonus will be given based on whether the answer to each question is complete, as well as the clarity and the details of the explanations. 3) Wherever possible, support your statements with clear drawings and/or graphical representations 4) ANSWER JUST TO THE QUESTIONS asked. CONSIDERATIONS THAT DO NOT ADDRESS THE QUESTIONS MAY LEAD TO THE SUBTRACTION OF POINTS. 5) ORGANIZE YOUR ANSWERS CLEARLY: ANSWER TO 1.A ANSWER TO 1.B ETC. Question 1 (18 points) A) Draw the scheme of a closed loop ideal gas cycle working between a given heat source and a given heat sink and draw the T-s diagram of the cycle B) Provide the definition of cycle efficiency and net specific work and the functional dependency on the cycle parameters C) Draw the scheme of a real gas turbine (open cycle), draw the T-s diagram of the cycle and list the main types of efficiency losses D) Provide the definition of net electric efficiency and net specific work for the real gas turbine and discuss how they change with the cycle parameters E) Given the maximum turbine inlet temperature made possible by turbine materials and the cooling system, describe the main criteria to select the pressure ratio of real gas…