An engineer has presented a piping system layout that includ

An engineer has presented a piping system layout that includes a pump, condenser, and cooling tower for a building cooling application. Size the piping and specify the pump required if the total volume flow rate of water is 450 gpm, the pressure drop in the condenser is 15 ft of water gage, the vertical distance from the pump centerline to the top of the cooling tower is 45 ft, the horizontal distance from the condenser to the tower is 70 ft, and the pump is 15 ft below the tower basin. All the necessary accessories are shown in the sketch provided by the engineer.

Solution

Since volume flow rate measures the amount of volume that passes through an area per time, the quation for the volume flow rate

Q = Volume / time

the volume of a portion of the fluid in a pipe can be written as V = Ad where A i sthe cross sectional area of the fluid and D is width of that portion of fluid,

Q = V / t

= Ad /t

but the term d/ t is just the length of the volume of fluid divided by the time it took the fuild to flow through its length , which is just the speed of the fluid , so we can replace d/t with V in the previous equation and get

q = AV