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Politecnico di Milano Department of Energy - School of Industrial Engineering Course Energy Systems prof. S. Consonni Academic Year 2017/18 Written Exam 11 February 2019 Theoretical Questions ‐ Time: 1.00 h PLEASE NOTICE 1) Books, lecture notes, cell phones are strictly forbidden. Using them or talking with colleagues and/or copying will lead to the immediate invalidation of the exam. 2) Answer clearly ONLY to the questions. Even if correct, additional considerations will NOT contribute to the final grade – and you have NOT enough time! 3) Fill this sheet with your name and return it with your answers. 4) MARK EACH SHEET OF YOUR ANSWERS with YOUR NAME AND PAGE/SHEET NUMBER. 5) WRITING AND SHEET/PAGE SEQUENCE MUST BE LEFT TO RIGHT AS USED IN WESTERN COUNTRIES. 6) 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 completeness, clarity and details of the explanations. 7) Wherever possible, support your statements with clear drawings and/or graphical representation 8) ORGANIZE YOUR ANSWERS CLEARLY: ANSWER TO 1.a; ANSWER TO 1.b, ETC. FIRST NAME…………………………………….......……FAMILY NAME………………………………………………….. Question 1 (18 points) Consider a large scale coal‐fired steam generator which is part of a steam cycle power plant. a. Describe its configuration and give a schematic representation of the main components b. Draw the T‐Q diagram c. Identify the section most critical from the point of view of thermal stresses, explaining why it is so. d. Explain why such steam generators are generally equipped with a Ljungstrom heat exchanger. e. Explain why small scale boilers producing warm water for residential heating are generally not equipped with such heat exchanger. f. Comment on the differences…