Enhancement of Heat Transfer rate using Axially Interrupted Rectangular Fins in Double Pipe Heat Exchanger

Abstract

The current investigates the thermo-fluid behavior of a double pipe heat exchanger (DPHE) featuring axially interrupted rectangular fins (AIRF) on the annulus part. The inner tube under this study with AIRF represents an interruption of straight longitudinal fins. This modification introduces periodic breaks along the tube's surface, effectively disrupting the boundary layer of the fluid flow. Consequently, it enables a non-continuous fluid passage along the length of the tube, potentially enhancing heat transfer. The experimentation employs standard liquid water, for investigations conducted under varying cold water mass flow rate 0.136 Kg/s to with 0.374 Kg/s keeping hot water at constant flow rate of 0.34 Kg/s with a fin split interval of four different lengths 7mm,27mm,55mm,100mm. A comprehensive investigation of the AIRF arrangements is carried out in contrast to the plain pipe arrangement, concentrating on fluid flow parameters such as Nusselt number (Nu), friction factor, heat transfer rate, and overall performance factor. The findings reveal that heat transfer rates in an annulus equipped with 7mm AIRF exceed those of a plain pipe by 59.31% under similar fluid flow conditions. The Nusselt number shows 1.5 times increase in the 0.007 m AIRF arrangement compared to the plain pipe. Thermal performance factor for 7mm interrupted length of AIRF outperforms other models.