Chapter 5, Problem 5.13P

Interpretation Introduction

Interpretation: The energy cost for the running pump is to be calculated.

Concept introduction:

The Bernoulli’s equation is used to calculate the total head loss.The Bernoulli’s equation is between junctions $\text{a}\text{and}\text{b}$

  $\frac{P_a}{\rho g}+\frac{V_a^2}{2g}+Z_a+H=\frac{P_b}{\rho g}+\frac{V_b^2}{2g}+Z_b+\left(K_f+K_c+K_e\right)\frac{V^2}{2g}+\frac{4fl{V}^2}{2gd}$

The work required for the pup is,

From the energy balance equation the work required for the pump is given as follows:

  $W=\frac{H}{\eta }$

The formula for calculating the power is,

  $\text{P}\text{=}\text{<mover accent="true"><mo>m</mo><mo>˙</mo></mover> ×W}$

The formula for calculating the energy cost per day is,

  $\text{Energy}\text{cost}=\text{P}\times \$\text{P}/\text{yr}\times \text{d}/\text{yr}$