Entropic analysis of a double helical tube heat exchanger including circular depressions on both inner and outer tube

In this research, entropic analysis of a double helical tube heat exchanger including circular depressions on both inner tube and outer tube is provided. Experimentally validated 3D numerical simulation is employed to reach the aim of this study. Entropic characteristics of four cases are investigated and reported. In case a both inner tube and outer tube are smooth. In case b, circular depressions are created on only inner tube while in case c both tubes contain circular depression. Case d is the same as case c while the depression arrangement is different from case c. Dimensionless entropy generation and dimensionless Nu number are used to evaluate the proposed designs based on the first and second laws of thermodynamics. Moreover, heat transfer improvement (HTI) factor is adopted to consider the impacts of said two parameters simultaneously. Results demonstrate that, although creating circular depressions on both tubes significantly improves the heat transfer characteristics of the heat exchanger, it increases the entropy generation level of heat exchanger as well. Case d in which the location of any circular depression of the outer tube is placed between any two continuous depressions of the inner tube, gives the highest thermal performance and also entropy generation.

Automated summary

This research provides an entropic analysis of a double helical tube heat exchanger with circular depressions on both inner and outer tubes, using experimentally validated 3D numerical simulation. The study investigates the entropic characteristics of four different cases, showing that creating circular depressions on both tubes significantly improves heat transfer but also increases entropy generation. Case d, where the outer tube depressions are located between continuous inner tube depressions, demonstrates the highest thermal performance and entropy generation.