EFFECTS OF FIN AND TUBE ALIGNMENT ON THE HEAT TRANSFER PERFORMANCE OF FINNED-TUBE HEAT EXCHANGERS WITH LARGE FIN PITCH

摘要

The objective of this study is to provide experimental data that can be used in the optimal design of finned-tube heat exchangers with large fin pitch. In this study, six types of fined tubes were tested by varying airflow rate. Both the effects of number of tube row, fin pitch, and fin type and the influences of tube and fin alignment on the heat transfer performance are investigated. The air-side heat transfer coefficient is calculated from the measured data. Staggered fin and tube alignments improve heat transfer performance by 7% and 10%, respectively, as compared to the inlined fin alignment. By applying both the staggered fin and tube alignments, the heat transfer performance increases by approximately 20% as compared to the continuous flat plate finned-tube. The heat transfer performance decreases with a rise of tube number. For large fin pitch, the effects of fin pitch on the heat transfer performance are negligible.