THE SOLUTION AND ANSWERS OF PROBLEMS

- 1 - Energy yield of a h ydroelectric gallery A gallery allows to supply a hydroelectric plant from a 20 m deep mountain lake (see figure) containing water at 8°C. After dri lling, this gallery has a circular section of mean diameter 6 m and a length of 400 m. I t is inclined to the horizontal by an angle of =9° and the its surface roughness is around 24 cm. Fig.1: Schematic drawing of the hydroelectric plant Determine : 1. the kinetic p ower of water inside the gallery 2. the dissipa ted po wer at t he exit of t he gallery 3. the annual plant income bas ed of a 2 ,00 0 h working time 4. It is desired to increase the an nual plan income . Propose a solution and estimate how many years are required to make the cost of your solution profitable 5. Make a parametric study and give the most relevant conclusions Assumption : Le lake level and the water temperature will rem ain constant all over t he year.