Working with

Cooling tower systems

Cooling towers typically serve as a heat rejection system for plant chillers, or plant process loads, or both. Most modern designs are galvanized metal, stainless steel, or a combination to mitigate corrosion. Cooling towers are subject to several sources of fouling - fouling on the waterside due to biofouling or scaling, fouling of the tower fill or fouling of the hot deck. Many newer designs incorporate variable speed fans to optimize energy consumption, while constant speed or two speed fan motors can be found on older systems. Operation of towers when ambient temperatures are at or near freezing can be challenging as well to prevent both icing of the tower fill and over cooling.

Typical system issues include:

) Low supply/return temperature temperature differential

2) Pumping problems, particularly low NPSHA to pumps

3) Fouling of tower fill

4) Improper water chemistry and maintenance, resulting in biofouling and scale buildup

5) Mismatch between tower cooling capacity and cooling capacity needs of chiller or other system