Cooling Tower Heat Transfer 101

摘要

Many power plants and other industrial facilities utilize open recirculating cooling systems equipped with cooling towers for heat transfer from condensers and other heat exchangers. This article outlines the fundamentals of heat transfer in a cooling tower and important issues for maximizing heat exchange. Evaporation is the key to maximizing efficiency. As air passes through a cooling tower, it induces evaporation. No matter how efficient, a cooling tower can never chill the recirculating water to the wet bulb temperature, and at some point costs and space requirements limit cooling tower size. Evaporation causes dissolved and suspended solids in the cooling water to increase in concentration. Critical to maximum efficiency in a cooling tower is intimate contact between the warm inlet water and the air flowing through the tower. Space limitations prevent a detailed discussion of tower internals, but one technological achievement that has greatly improved heat transfer over the decades is development of film fill.