Prediction of heat transfer coefficient and friction factor of mini channel shell and tube heat exchanger using numerical analysis and experimental validation

Minichannels are a key technology that results in energy, space, material, and cost savings in shell and tube heat exchangers (STHEs) because they improve performance by increasing compactness and reducing the dimensions, volume, and mass, as well as the amount of working fluids used. This paper employed the Computational Fluid Dynamics (CFD) method to investigate the effect of minichannels on the thermal and hydrodynamic performance of a STHE. The reliability and accuracy of numerical results were corroborated with experimental results. Numerical solutions were performed under constant heat flux conditions at 2650 < Re < 9500, the range in which internal flows are considered transition and turbulent flows. The results showed that the higher the Reynolds (Re) number, the higher the convective heat transfer coefficient (CHTC) and pressure drop. The performance benchmark (psi) is defined as the variations in CHTC per unit of pressure drop. The results showed that the higher the Re number, the lower the psi. Based on numerical solutions regarding psi, the flow in the minichannel tube reached optimal conditions both thermally and hydrodynamically at Re approximately equal to 5900. The deviation between the numerical and experimental CHTCs ranged from -15 % to +15 %, while that between the numerical and experimental friction factors ranged from -13 % to +13 %. These results can be used for engineering designs and applications.

Automated summary

This study investigated the effect of minichannels on the performance of STHEs, finding that optimal thermodynamic and hydrodynamic conditions were reached in the minichannel tube at Re of approximately 5900. The numerical solutions showed acceptable deviations from experimental results, providing valuable guidance for engineering designs and applications.