Question

A pipeline is constructed to transfer drinking water from the top of a lake to a open top storage tank of a village. The distance from the lake to the storage tank is 15 km and the elevation of the storage tank is 500 m above the lake. The water demand of the village is 4.15 liters per second. The diameter and roughness of the pipe are 15 cm and 0.26 mm, respectively. There are four valves (K=2) and two 90o elbows (K=1.5) along the pipe. You can take the density and viscosity of water as 998 kg/m3 and 1.002 * 10-3 kg/m s, respectively; you can neglect the inlet and exit losses and the kinetic energy correction factor effects. Determine the power (kW) of the pump needed to transfer the water from the lake to the storage tank. If the cost of electricity is 0.48 TL/kWh, determine the annual cost of electricity if the pump works continuously.

Answer 1

The loss due to valve and elbow is minor and friction losses in pipe is major losses. The total head required to uplift the water from lake to tank is summation of all the losses plus the elevation difference between the lake and tank. From total head we will find power required .see the solution.