Question

A high-head hydroelectric scheme consists of a reservoir from which the water is delivered to four Pelton turbines through a low pressure tunnel LT = 10 km long, 4 m in diameter, lined with concrete. The tunnel splits into four steel pipelines (penstocks) 500 m long, 2 m in diameter each terminating in a single nozzle, the area of which is varied by a spear valve. The maximum diameter of each nozzle is 0.9 m. The difference in level between reservoir and jets is 500 m. Roughness sizes of the tunnel and pipelines are 0.1 mm and 0.3 mm respectively.

1.Determine the effective area of the jets for maximum power and the corresponding total power generated. (iii) 2. Determine the difference in level between the water in the surge chamber and in the reservoir under the conditions of maximum power.

Answer 1