Thermo-hydraulic performance of parallel multi-shell and multi-helical coiled tube heat exchanger CFD model with Taguchi-grey relational analysis

This study utilized four distinct shell and helical tube heat exchanger layouts to numerically evaluate the thermal and hydraulic efficiency of each arrangement. The numerical research was conducted using ANSYS FLUENT 2022R1. Currently, there has been no research conducted on the investigation of multiple helical coiled tubes enclosed by multiple shell heat exchangers. This study aimed to optimize various tasks using the Grey Relational Analysis approach in combination with the Taguchi method to maximize thermal efficiency and minimize pressure drop. A parallel configuration was used to connect two to three concentric helical tubes, with each helical tube being enclosed by a shell to control the flow of fluid. The P–P-2M − 36 design, consisting of two helical tubes, has the highest enhancement ratio of Uo = 26.75 %, when compared to the P–P-3M − 36 configuration. Similarly, the P–P-2M − 42 configuration enhances Uo by 38.42 % in comparison to the P–P-3M − 42 configuration. These findings demonstrate that a configuration consisting of two helical tubes exhibits a higher enhancement ratio of Uo compared to a configuration consisting of three helical tubes. The P–P-3M − 36 design, which consists of three helical tubes, exhibits a minimum pressure drop of 39.19 % compared to the P–P-2M − 36 configuration. Similarly, the P–P-3M − 42 configuration reduces pressure drop by 37.76 % compared to the P–P-2M − 42 configuration. The P–P-3M − 36 configuration is designed to simultaneously reduce pressure drop and boost heat transfer rate. The model achieves the optimal values for heat transfer rate and pressure drop at a Reynolds number of 55,000.