Evaluating Temperature Uniformity In Pasteurization: CFD And Experimental Approach For Viscous Fluids

Ensuring uniform temperature distribution during thermal treatments is crucial for food safety and quality, particularly in the case of high-viscosity products. This study investigates temperature uniformity in a tube-in-tube heat exchanger using a combined Computational Fluid Dynamics (CFD) and experimental approach. CFD provides detailed thermal profiles, while the experimental tests carried out using concentrated orange juice (40 Brix) allow to validate the simulation results and confirm the presence of significant temperature variations across the pipe section. The results highlight the need for more precise thermal control strategies to mitigate risks of localized undertreatment or excessive heating, which can lead to food safety concerns or product degradation. A virtual sensor approach based on simulation results is proposed to this end. This solution would allow estimating internal temperature distributions based on external sensor data, acting as an essential tool for real-time process optimization that could be integrated into Digital Twin frameworks. This approach would enhance pasteurization efficiency, reduce fouling, and ensure consistent product quality. Future work will extend the investigation and application of simulation-based virtual sensors to this and other heat exchanger designs, to enhance and support the implementation of Digital Twin technologies for advanced control of food processes.