Abstract:
The effect of fin pitch, number of tube rows and fin thickness on the air-sideperformance of fin-and-tube heat exchangers are presented in the present study. The fin-and-tubeheat exchangers used in this study are cross-flow type having wavy fin geometry. Air flows outside and hot water flows inside copper tube with 9.53 mm outside diameter and 0.3 rnm thick.The fins of heat exchanger are made of aluminiu~n. A total of 6 samples of w a y fin-and-tube, including 0.1 15 and 0.250 mm of fins thickness, 2-6 of number of tube rows and 1.4 1 - 1.8 1 mmof fin pitch are tested. The heat exchangers are tested in the open circuit wind tunnel. The experimental procedures are conducted by setting the hot water flowing inside the heatexchanger tube at a specific value and varying the air velocity. The results of heat transfer performance are presented as Colburn factor and the results of air-flow perfonnance are presented as friction factor. The experimental data illustrate, that the effect of fin pitch on theair-side heat transfer performance are insignificant, the heat transfer performance decreases \vithincreasing the number of tube rows and slightly increases with increasing fin thickness. The fiction factor decreases with decreasing fin pitch and increasing fin thickness and the number of tube rows. Correlations of Colbum factor and friction fictor are developed for practical use. The proposed Colbum factor correlation and friction factor correlation deviate from measured data in the range of f 10 percent and GO percent, respectively.