10 09 18

Pagina 1

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 September 10th, 2018 p a g e 1 o f 1 Written Exam 10 September 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 graphs 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 E T C . Question 1 (18 points) A) Draw the plant configuration of steam cycle with:  a high-temperature regenerator fed with high pressure steam;  a de-aerator fed with medium-pressure steam;  a low-temperature regenerator fed with low-pressure steam Assign a number to the most relevant points along the cycle (turbine inlet, high-pressure bleed, de-aerator bleed, etc.) B) Draw a qualitative T-Q diagram of the two regenerators and of the de-aerator, identifying the input/output flows with same numbers adopted in the figure that answers to A). C) Explain why regeneration is beneficial to the cycle efficiency D) Discuss how the condensate flows exiting the high-temperature regenerator and the low- temperature regenerator can be handled to send them back into…