Sprinkle & Trickle Irrigation Lectures
Page 59
Merkley & Allen
Lectur
6
Econom
e
ic Pipe Selection Method
I. Introduction
•
The
economic pipe selection method
(Chapter 8 of the textbook) is used to
•
Wit
decreases, causing a corresponding decrease in friction loss
•
•
Ho
balance fixed (initial) costs for pipe with annual energy costs for pumping
h larger pipe sizes the average flow velocity for a given discharge
This reduces the head on the pump, and energy can be saved
wever, larger pipes cost more to purchase
total
Cost
Pipe Size (diameter)
Energy costs =
annualized fixed costs
fixed
o
•
osts, compare with annual energy (pumping) costs
•
We can also graph the results so that pipe diameters can be selected
according to their maximum flow rate
•
We will take into account interest rates and inflation rates to make the
comparison
•
onomics” problem, specially adapted to
e
•
. Determine the annual energy cost of pumping
minimum
t tal
energy
T
c
o balance these costs and find the minimum cost we will annualize the fixed
This is basically an “engineering ec
th
selection of pipe sizes
This method involves the following principal steps:
1. Determine the equivalent annual cost for purchasing each available pipe
size
2

This ** preview** has intentionally

**sections.**

*blurred***to view the full version.**

*Sign up*