Consider a dam with an elevation change H of 113m and a flow

Consider a dam with an elevation change, H, of 113m, and a flow rate Q, of 631m³/s. Its turbines are designed to spin at a rotation rate, , of 68 rpm. The dam uses four parallel penstocks with a length of 150m and a diameter of 5.2m. These have concrete walls, which have an equivalent roughness, , of 1.5mm. The system minor loss coefficient, K, is approximately 1.8.

a)    Estimate the mechanical power production (in MW) for this dam, assuming ideal efficiency for the turbine.

b)    Using the specific speed, which type of turbine would be best for this system?

c)     If generators have 94% conversion efficiency, what is the expected electrical power production? You should now consider the turbine inefficiencies.

Solution

Mechanical Power of Dam = pQgH = 1000*631*9.81*113

= 699.482 MW

Since it is a high head and low specific speed case .... Pelton Turbine will be used in this dam .