Simulation and optimization of plate heat exchanger geometry for low-shear cooling of high-fat cream

Plate heat exchangers (PHEs) are widely used in dairy processing, where precise thermal control is essential for maintaining product quality, microbial safety, and energy efficiency. Cooling high-fat cream (∼35 wt%) presents a particular challenge due to its temperature-dependent rheology and sensitivity to mechanical shear, which may influence texture, fat stability, and sensory properties. In this study, three-dimensional computational fluid dynamics (CFD) models were developed to investigate the thermal and hydraulic performance of flat, single-wave, and double-wave PHE geometries for low-shear cream cooling. The simulations were performed using COMSOL Multiphysics 4.0a and validated through a dual-validation strategy combining published benchmark data with plant-scale measurements obtained from a GEA VT-20 plate heat exchanger operating at Kalleh Dairy Company. The numerical predictions showed good agreement with experimental and industrial data, with a root-mean-square error of 1.06°C for cream outlet temperature prediction. Comparative analysis revealed that the double-wave geometry provided the most favorable balance between cooling performance and shear management, producing more uniform shear-rate distributions generally below 120 s⁻¹ while maintaining cream outlet temperatures close to 2°C. Based on the combined evaluation of heat-transfer performance, pressure drop, and shear exposure, an optimal operating velocity range of 0.10–0.15 m·s⁻¹ was identified under the investigated conditions. The proposed CFD framework provides a reliable basis for geometry selection and process optimization in shear-sensitive dairy applications and can be extended to other temperature-dependent non-Newtonian food fluids.