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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 2016/17 Energy Systems LM - written test of Feb 6th, 2017 page 1 of 3 Written Exam 06 February 2017 - Problems - Time: 2 hours PLEASE NOTICE 1) Exam is open book, but computers and cell phones are NOT allowed. Talking with colleagues and/or copying will lead to the immediate cancellation of the exam. 2) Answer clearly ONLY to the questions posed by the problem sets. Even if correct, additional considerations and/or calculations will NOT be considered. 3) Fill this sheet with your name and return it together with your solutions. 4) Mark each sheet of the solution with your name and page number. 5) The final grade is the sum of the points assigned to the solution of each problem plus a bonus of max 3 points. The bonus will be given based on whether the solution of each problem is complete, with clear details and explanations. FIRST NAME………………………......……..…FAMILY NAME………….………………………….. Problem 1 (16 points) Consider the cogenerative heat recovery steam cycle in figure. The steam cycle is based on a single evaporation pressure HRSG with reheat and a backpressure turbine configuration. The system produces superheated water for heat users in the steam cycle condenser (D-F streams line) and in dedicated tube bank at the cold end of the HRSG (B-C line). Water heating by the backpressure steam cycle is performed in two heat exchangers: a low temperature one (D-E streams) and a high temperature one (E- F streams). The following design parameters are given: • Hot gas at HRSG inlet (stream a): m=100 kg/s; T=500°C; cp=1.1 kJ/kgK • Superheated steam (5): p=40 bar, T=450°C • Reheated steam (7): p=16 bar, T=450°C…