19 06 2023 Practical text

Pagina 1

POWER PRODUCTION FROM RENEWABLE ENERGY AY 2022-23 19th June 2023 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) A CSP plant based on solar tower adopts molten salts as Heat Transfer Fluid (T min=300°C – Tmax=555°C) and a steam cycle for the conversion of thermal power into electricity. The power plant and the heliostat field design characteristics are reported in the table below: Calculate (i) the solar receiver thermal efficiency and the solar multiple ( 4 points). Compute (i i) the receiver average external temperature knowing the receiver specific thermal losses (see above table) and assuming the convective/radiative heat transfer coefficient with the environment…