Numerical and Experimental Analysis of Elliptic Finned-Tube Heat Exchangers under Misted Conditions

The numerical and experimental analysis was carried out to study the thermal-hydrauliccharacteristics in elliptical finned-tube heat exchanger under the dry and air/water spray cooledsystem. Three kinds of major/minor axis ratios (2.5?2.8 and 3) were examined for the ellipticfinned-tube heat exchangers and the results were also compared with the corresponding circularfinned-tube having the same perimeter. The numerical results for the pressure and heat transfercoefficient at various inlet frontal velocities (1~5 m/s) are shown and compared with the availableexperimental data. The numerical results indicated that the pressure drop of circular finned-tubeheat exchanger is 3 times that of the elliptic finned-tube heat exchanger, while the heat transfercoefficient of the circular finned-tube is 1.51 times that of the elliptic finned-tube. The heat transfercoefficient per unit of pressure drop for elliptic finned-tube is 1.6-2.5 times of circular finned-tube.When the air/water spray system is applied, the heat transfer could increase up to more than 30%