蓄冰球内定向凝固过程蓄冷特性的实验研究

To further explore the heat transfer characteristics in dynamic cold storage process of the spherical phase change medium and the influence of cooling boundary condition on the solidification process, the solidification process of distilled water in an ice ball was experimentally studied. A visualized experimental system for cold storage was calibrated and set up. A semi-spherical cold storage unit was selected as the test object, enabling the capture of the transient solidification front. The real-time temperature response of the phase change process and the transition of the solidification interface were obtained. The experimental results showed that the solid-liquid interface gradually moved inward in a circular shape over time. The temperature responses of concentric spheres with different radiuses kept the same. The influence of natural convection was weak and could be ignored. The lower the temperature of the cooling boundary condition was, the faster the transition speed of the phase interface would be. Compared with -5 and -6 ℃, the temperature of -7 ℃ can shorten the solidification time by 55% and 28.3%, respectively. This work may provide a reference for improvement and optimization of the cold storage performance in engineering practices.