Heat transfer characteristics of innovative configurations of double pipe heat exchanger

Abstract

Saving energy resources requires a continuous improvement of the power equipment. The present study aims to develop new designs of double pipe heat exchanger (DPHE) to improve the heating/cooling processes at the lowest possible pumping power. Therefore, thermal performance investigation of three configurations of DPHE has been carried out. These configurations are circular wavy DPHE (DPHEwavy), plain oval DPHE (DPHEov.), and an oval wavy DPHE (DPHEov.wavy). In addition, the conventional DPHE (DPHEconv.) has been employed as a reference heat exchanger, and a validated CFD approach is adopted to perform the current investigation. The findings reveal that, DPHEov.wavy yields the highest Nusselt number (Nu) which is up to 28% with respect to DPHEconv.. In addition, data of pressure drop (ΔP) of DPHEwavy are found the highest followed by those of DPHEconv., whereas DPHEov. is found to yield the lowest ΔP. Furthermore, thermal performance factor (η) has been considered, and DPHEov. is found to own the highest η of all investigated DPHEs. In conclusion, the oval tubes have shown better heat transfer characteristics with respect to their circular counterparts in general, in particular plain oval DPHE. Graphical abstract: [Figure not available: see fulltext.]