Case Study $-4$

Determine the input power to an electric motor $({}_m=90\%)$ supplying a pump

$80\%$ delivering $50\frac{L}{sec}$ of water $(=1000\frac{kg}{m^3}$;$=0\mathrm{.}001\frac{kg}{m}.s)$ from

Tank$-1$ to Tank$-2$ as shown below if the pipeline length is $200m$ long, of

$150mm$ diameter galvanized iron $($assume surface roughness is $0\mathrm{.}15mm)$ for a

pumping losses of $100m$

$[$Ans: $77\mathrm{.}0937kW]$

Note:

Use the formula

$P=\frac{g(Q^{})H_{\text{t}\text{o}\text{t}\text{a}\text{l}}}{{}_m{}_P}$

For finding the input power

if motor & pump efficiencies are given;

Valve is Ball type and fully open;