ES220908 practical test

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POWER PRODUCTION FROM RENEWABLE ENERGY AY 2021-22 8th September 2022 Prof. Silva Time: 1.5 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 explanations will not be taken into account. The final score can be normalized according to the average results. 3) Talking with colleagues and / or cheating will cause the cancellation of the exam. 4) 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 (16 points) Consider a geothermal plant based on vapour-dominated reservoir, direct-steam, single-flash. The geothermal fluid composition on mass base is 95% H20 and the remaining is N2 (MMN2=28 kg/kmol). Temperature of the geother- mal fluid 190°C Turbine isentropic efficiency 87% Pressure of the geothermal fluid 12,6 bar Steam turbine generator effi- ciency 97% Mass flowrate of the geother- mal fluid 44 kg/s Condensing pressure 0,1 bar Enthalpy of the water (mix- ture of liquid and vapour) 2500 kJ/kg Auxiliaries for heat rejection 15 kWel/MWth Non-condensable gas com- pressor isentropic efficiency 81% Non-condensable gas compres- sor motor efficiency 94% Design the lay-out of the plant with all the components (1 points). Calculate the net power output of the geo- thermal plant considering a pressure after lamination valve of 9 bar) (6 points). Determine the net electric efficiency (2 points). Energy Engineering students: Considering a solar multiple equal to 1,2 calculate the solar field area of parabolic trough collectors necessary to increase the geothermal fluid…