ilovepdf merged

Page 1

POWER PRODUCTION FROM RENEWABLE ENERGY AY 2023-24 17th June 2024 Prof. Andrea Giostri Time: 1.5 hours NAME and SURNAME:.................................................................................................................................................. COURSE and CFU:......................................................................................................................................................... Instructions for the examination: 1) Clearly indicate your name on all the sheets you will deliver. 2) The score refers to exercises done in a comprehensive manner with exact numerical results. Numerical results correct but not accompanied by explanations will not be taken into account. The final score can be normalized according to the average results. 3) Answer briefly and clearly only to the asked questions. Calculations and explanations which do not respond to the questions will not be considered for evaluation even if correct. 4) Talking with colleagues and / or cheating will cause the cancellation of the exam. 5) All the needed data for the resolution of exercises lies on this paper. It is NOT ALLOWED to use material other than this (e.g. books, clipboard etc.). Exercise 1 (15 points) – All students Consider a CSP plant based on solar tower technology. The solar field counts 2750 heliostats, each with a reflective area of 110 m 2, and concentrates the solar radiation onto a tubular cylindrical external receiver. The receiver heats up molten salts (cp MS=1.45 kJ/kg-K, ρMS=1800 kg/m 3) and its characteristics and design operating conditions are reported in the table below: Optical efficiency 0.65 Receiver aspect ratio (H/D) 1.5 HTF inlet temperature (°C) 290 Average heat flux absorbed on receiver (kW/m2) 550 HTF outlet temperature (°C)…