Answer Happy

Water is pumped from one open tank to another open tank. The difference in height of the liquid surfaces of the tanks is 17 m. The length of the piping is 225 m, the inner diameter of the pipe is 100 mm and the pipe material is cast iron. The piping has two diaphragm valves and four 90° bends (R/D = 1). Connections to tanks are sharp and below the liquid surface. The water temperature is 25 °C. Characteristic of the centrifugal are as follows: v /V/min 100 150 250 400 600 850 1150 Hp/m 35 33,5 30,5 26 20,5 13,5 5 1p 0,7 0,72 0,76 0,78 0,82 0,80 0,78 Pipe material is cast iron k=1 mm, water dynamic viscosity 0.8935*10³ kg/ms, water density 997 kg/m³, Local resistors; 90° bend (R/D=1) 0.51, Diaphragm valve 2.3, sharp output 0.5, sharp input 1.0. Calculate a) Operating point b) efficiency np c) pump shaft power