Communication science et technologie
Volume 2, Numéro 1, Pages 01-10

Simplified Models For Direct And Indirect Contract Cooling Towers And Evaporative Condensers

Authors : Jean Lebrun. C. . Aparecida Silva . Felipe Trebilcock . Eric Winandy .


This paper presents a simplified method of analyzing the combined heat and mass transfer phenomena in direct and indirect contact cooling towers and evaporative condensers.The theoretical basis of the model is Merkel's theory.The cooling towers evaporative condensers and fluid coolers are considered as members of a classical heat exchangers family working in wet regime.Here the air side heat and mass transfer processes are governed by the same basic process.This paper shows that a "unified" theoretical treatment may be applied to all three evaporative exchangers.The key difference inthe theory for each type relates to these exchangers unique characteristic,the global heat transfer coefficient UA,or its correspondent thermal resistances of the process fluid .Specific correlations for the calculation of UA or the equivalent thermal resistances, considering the influence of the water and air flow rates entering the exchangers,are discussed.An example for each case is shown illustrating the validation of the models with catalogue data.


cooling ,mass,UA