Application of a general non-dimensional mathematical model to cooling towers

A general non-dimensional mathematical model of evaporative cooling devices is applied to cooling towers. One of the benefits of the non-dimensional approach is that the water-cooling efficiency of a cooling tower can be expressed as a function of only two variables and plotted in a single diagram for each type of cooling tower. For counterflow and parallel flow towers there is an analytic solution of the set of differential equations; crossflow towers require a numerical solution. The resulting rating procedure of the overall performance of a cooling tower is simple and consists of the adjustment of the assumed straight air saturation line to the real air saturation data. All three types of cooling towers can be rated using the same procedure, if a diagram showing the water-cooling efficiency of the respective type is used. The accuracy of this method is checked by the use of published data and is found to be good for the usual operating conditions, failing only when the water-cooling range is very large. (C) Elsevier, Paris.