Experimental and computational analysis of thermal performance of the oval tube closed wet cooling tower

Abstract

Abstract Closed wet cooling towers (CWCTs) characterize by smaller investment and exploitation cost as well as fewer materials and less space. It can be regarded as a cooling tower with the packing replaced by a bank of tubes. However, heat and mass transfer in an oval tube closed wet cooling tower (CWCT) have been little investigated under different operating conditions. The thermal performance characteristics of an oval tube CWCT were conducted. From the experimental results, correlations for the water-film heat transfer coefficient and air–water mass transfer coefficient are obtained. Experimental tests show the water-film heat transfer coefficient is a function of deluge-water temperature, deluge-water mass velocity and air mass velocity, which is different from that in the public literatures. The air–water mass transfer coefficient is a function of air mass velocity. In addition, a mathematical model with three ordinary differential functions is presented to predict the outlet process water temperature. The model is solved by a sectional method. The results show the analytical outlet temperature compares well with the experimental data. The method is suitable for evaluating the performance of an oval tube CWCT.