A comparison of four numerical modeling approaches for enhanced shell-and-tube heat exchangers with experimental validation

摘要

In the present paper, 3-D numerical simulations of a rod-baffle shell-and-tube heat exchanger with four different modeling approaches are developed and validated with experimental results. The four methods of modeling include two in which a small subsection of the heat exchanger is modeled (the unit model, and the periodic model), one in which the heat exchanger is consider as a porous medium (the porous model), and one in which the entire heat exchanger is modeled with CFD (the whole model). The results illustrate that the periodic model, porous model and whole model can have high accuracy in predicting heat transfer, while the unit model has relatively low accuracy. The porous model and whole model also provide good predictions of the pressure drop, but the unit model and periodic model fail to accurately predict pressure drop. The porous model requires accurate heat transfer correlations for the heat exchanger; and such correlations may not be available for new designs. The whole model demands significant computational resources for geometric modeling, grid generation, and numerical calculation. A demonstration of different grid systems for various models is also conducted. In summary, the present work provides a comparison of various modeling approaches and an analysis of trade-offs between numerical accuracy and computational demands for models of shell-and-tube heat exchangers.