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SOLAR AND BIOMASS POWER PRODUCTION AY 2018-19 6th May 2019 Prof. Giampaolo Manzolini Time: 2 hours 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 expla- nations 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.). 6) Not all the provided inputs are necessary for the problem solving Exercise 1 (16 points) It is required to size a concentrated solar power plant based on parabolic trough collectors using Solar Salts as Heat Transfer Fluid (T min 290 - Tmax 550°C) and steam cycle to convert the thermal energy into electricity (4 points). The solar plant characteristics are reported in the table below: Power cycle net power output 65 MW Piping losses 2.5 MW Power cycle second law effi- ciency 57% Specific solar field thermal losses (power referred to the aperture area 70 W/m2 Ambient temperature 25 °C Design DNI 900 W/m2 Solar multiple 2.25 Mirror Reflectivity 95% Receiver Absorptivity 94% Glass envelope transmissivity 95% Tracking efficiency 95% Result: solar field aperture area 696747 m2 The overall heat transfer coefficient between the glass envelope and the environment is equal to 17 W/m2K and the concentration ratio…