Numerical Modeling of Turbulent Heat Transfer and Fluid Flow in a Single-source Tank in a Tunnel Pasteurization Process
Y. H. Zheng and R. S. Amano
Beverages in bottles and cans are treated in a pasteurizer to lengthen shelf life. Traditional designers for tunnel pasteurization processes choose multiple heat exchangers. In this paper, a model for the heat transfer and fluid flow in a single source-sink tank in a tunnel pasteurizer, which can be used to predict the operation status of the pasteurization process of the beverages, is described. This modeling is useful to optimize the system by making a few changes to the design, operating conditions, or the types of products to be pasteurized. Moreover, the model can be used to provide data for the optimization of the pasteurization component designs. A single-tank heat exchanger is designed as the hot and cold water supply heat exchanger tank in this study. It is a cylindrical heat exchanger tank consisting of four tube-bundles that provides hot water through the top and cold water through the bottom of the tank. There are two outlets. In the heat exchanger tank, the tube arrays are set along the azimuthal direction in the tank. This is a thermally stratified layered water tank that can control the water temperatures in four zones. The numerical calculations of heat transfer and fluid flow have been performed to determine the temperature distribution in the heat exchanger tank. Simulation results indicate that the modeling temperature distribution of each zone is in good agreement with analytical results.