Analysis of Thermal-Hydraulic Performance and Crystalline Fouling in Plate-Fin Heat Exchangers with Rectangular and Triangular Fins

Plate-Fin Heat Exchangers (PFHEs) offer high heat transfer efficiency in a compact footprint, but they suffer from performance losses due to pressure drop and fouling. This study utilizes high-fidelity three-dimensional Computational Fluid Dynamics (CFD) simulations, validated with a deviation of less than ۲% between turbulence models, to quantify the thermal, hydraulic, and transient fouling performance of offset strip fins. At the channel scale, the most effective fin configuration increased the total heat transfer rate from ۰.۰۵۷ W to ۲.۳۳ W, corresponding to a maximum enhancement of approximately ۳۹۸۷% under constant frontal area and equal pumping power conditions. A critical comparison reveals that triangular fins at MS = ۱ further enhanced heat transfer by ۵۳% compared to rectangular fins, while limiting additional pressure drop to a marginal ۱.۶% through intensified secondary flows and periodic boundary-layer disruption. Fouling simulations revealed a ۲۰% decline in net crystalline deposition rate over ۶۰ minutes, indicating self-limiting behavior as rising wall shear stress and deposit insulation inhibited further accumulation. Increasing inlet velocity from ۰.۰۵ to ۰.۲۰ m/s reduced fouling-induced thermal resistance by ۳۵%, confirming that hydrodynamic control via elevated shear forces is more effective than surface area extension alone. The main novelty of the present work lies in the integrated analysis of geometry‑induced flow disturbance, thermal performance, and fouling evolution in plate‑fin heat exchangers. This combined perspective allows the identification of fin configurations that provide improved heat transfer performance while maintaining acceptable hydraulic penalties and favorable fouling behavior, which has not been systematically addressed in previous numerical investigations of similar compact heat exchanger systems, identifying the triangular MS = ۱ configuration as the optimal design for fouling-prone industrial environments.

کلیدواژه ها:

Plate-Fin heat exchanger ، Fin Geometry ، Thermal-Hydraulic Performance ، Crystalline Fouling ، CFD Simulation ، secondary flow ، Heat transfer enhancement introduction