Cooling towers: how to get peak efficiency.
There are two types of Cooling towers used to cool water in commercial properties. The types are Cross Flow and Counter Flow. In the Cross Flow Tower, water flows by gravity through honey-combed Fill. Air flows perpendicular to the water, hence the name Cross Flow. Counter Flow Tower, the air moves upward through the fill as the water fall gravity, hence the name Counter Flow.
Condenser water is pumped to the top of the tower, distributed of the tower and piped back to the chiller. Fans move the air through the tower fill and out of the tower.
Some components of the Cooling Tower are:
* Fill - Spreads the water into a very thin layer and allows the air to contact the water for as long as possible
* Drift Eliminators - Material configured to make air pass through changing direction enough times to remove the water picked up in the fill
* Distribution System - The condenser water is distributed throughout the tower and broken up into small droplets
* Fans - Must move air through the tower to achieve the correct change in the condenser water temperature
Cooling Towers produce the desired results if air water produce the required heat transfer. This happens when the following are present: 1. Air
a. Velocity through the Fill and
Drift Eliminators must be slow
as possible to keep the air in
contact with the water for the
b. Fans in Cooling Towers are
either centrifugal or propeller
type 2. Water
a. Flow to the tower should match
the towers' capability. Too
much does not allow the tower
to cool it; too little does not
allow for even distribution
b. Distribution in the tower allows
the water to be broken up into
very small droplets so the air
can mix and cool it.
To increase the amount of heat transfer a Cooling, a process of Evaporative Cooling, a process where some condenser liquid is changed to a vapor. To make this happen, it is necessary to add heat. The heat comes from the remaining liquid which is in turn cooled.
Some ways to improve Cooling Tower Performance: 1. Distribute water and air over the complete heat transfer surface - check for blockages 2. Keep fans running rated conditions
a. Adjust pitch of fan blades
b. See that gear boxes or belt
drives are in top condition 3. Keep pumps operating at peak efficiency 4. Chemically treat condenser water 5. Keep Cooling Tower clean 6. Add filtration system to cut down on blockage in piping condenser and chiller
Remember that a Cooling Tower is a very good filter and it picks up and retains any of the dust in the air or the system.
A recent concern associated with Cooling Towers is the amount of asbestos which was previously used in Towers. If these items are moved, extreme caution and qualified, experienced personnel should be used.
To conclude, it is very important for money saving reason to have the Cooling Tower operate at its peal efficiency If problems are encountered, corrections should be performed by qualified people.