Experimental study on heat transfer and flow resistance characteristics of integral rolled spiral finned tube bundles heat exchangers

The integral rolled spiral finned tube (IRSFT) represents a novel variant of low carbon steel heat exchanger components. The unique feature of IRSFT is the integral structure of its fins and base tube, with the fin section exhibiting an isosceles trapezoidal shape, thereby enhancing its heat transfer performance. However, the dearth of comprehensive studies on the heat transfer and flow resistance characteristics of IRSFT has impeded its widespread application in engineering projects. To address this gap, this study undertakes an experimental investigation into the heat transfer and flow resistance properties of IRSFT bundles. The findings reveal that the Nusselt number (Nu) escalates with an increase in both transverse and longitudinal pitch. Furthermore, Nu initially increases and subsequently decreases with a rise in fin pitch and fin height. Concurrently, the Euler number (Eu) diminishes with an increase in fin pitch, fin height, transverse pitch, and longitudinal pitch. Within the parameters of this experimental study, IRSFT demonstrated superior heat transfer performance and reduced flow resistance compared to serrated spiral finned tube and spiral finned tubes. This study also proposes a novel experimental correlation for predicting Nu and Eu for IRSFT bundles, thereby providing a theoretical foundation for the industrial application of IRSFT.