Investigation on the flow characteristics of a phase change material slurry in horizontal and U-shaped tubes based on CFD-PBM

Abstract

Ice slurry is broadly used as the medium for refrigerating medium, which can effectively reduce energy consumption. However, the change of ice particle size makes the flow properties of ice slurry more complicated, which limits its application in cooling system. A coupled model combining CFD and PBM techniques is developed in this article to effectively depict the variations in ice particle size and the flow of ice slurry. Based on this model, the flow properties of ice slurry isothermally in horizontally placed straight and U-shaped pipes are studied. It is found that velocity determines the degree of agglomeration and fragmentation of particles. The particle fragmentation effect is enhanced and the particle size is reduced as the flow velocity increases, which promotes the homogeneous particle distribution. With increasing the ice content, the size of particles and particle agglomeration increases. And the ice particle size presents a symmetrical distribution. The larger the initial average particle size, the weaker the agglomeration effect, and conversely the weaker the fragmentation effect. In the bending section of the U-shaped tube, the agglomeration effect between particles becomes stronger as the flow velocity decreases and the ice volume and curvature ratio increase.