230830 practical test

Pagina 1

POWER PRODUCTION FROM RENEWABLE ENERGY AY 2022-23 30th August 2023 Prof. Andrea Giostri Time: 1.5 hours NAME a nd SURNAME:.................................................................................................................................................. C OURSE 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) Consider a DSG (“Direct Steam Generation”) concentrating solar power plant based on parabolic trough where liquid water (h=198.5 kJ/kg) enters the solar field and superheated steam (h=3492.7 kJ/kg) is produced (no thermal energy storage). Compute the thermal power provided to the power block by the solar field and the water mass flow rate (2 points), the solar-to-electric efficiency (4 points) and the total aperture area of the solar field (2 points) knowing that the plant is sized to produce 75 MW of net electric power with power block net efficiency…