Empirical Approach to Tower Sizing

There are several approaches to sizing cooling towers outlined in the literature. Most are empirical or semiempirical in nature. The following outlines 

Specify operating conditions, i.e., water inlet and outlet temperatures and the inlet air wet-bulb temperature. 

Prepare an enthalpy-temperature diagram. Select the exit air enthalpy so that the slope of the line for the air enthalpy is equal to the slope of the curve for the enthalpy of saturated air at the water outlet temperature. 

Prepare a plot of [1/(HS - Hair)] versus water temperature. (Refer to Example 2 in Chapter 5 for illustration.) 

Using Simpson s rule or some other appropriate numerical integration technique, determine the area under the curve obtained from step (3). From the area, the required value for the tower characteristic (KaV/L) can be determined. 

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