STUDY OF ICE SPIKE FORMATION MECHANISM IN THE WATER-BASED PHASE CHANGE ENERGY STORAGE

Compared with paraffin, water-based phase change energy storage (WPCES) is widely used in spacecraft thermal control systems due to the higher latent heat. However, the volume expansion of water can lead to an ice spike that might damage the enclosure of WPCES, which is of great significance to research on the formation mechanism of ice spike. The gas-liquid-solid numerical model with detailed thermophysical properties was used to study the solidification of water in cavities. The formation mechanism of ice spike was investigated by considering the gravitational gravity range of 0〜9.81 m/s² and the aspect ratio of water space range of 0.25〜1. The incremental angle was proposed to describe the moving phase interfaces and results revealed that the solidification process could be divided into four stages by the extremum of incremental angle. In the first stage, a raised air-water interface and a concave solidification interface are formed. In the second stage, a thin ice layer extended inward from the periphery of raised air-water interface, and it thickened gradually in the third stage. In the fourth stage, a small ice spike was formed with a spiked angle of 130°. Compared with the benchmark, the smaller gravitational acceleration generated a 38.21% larger incremental angle, 8.48% longer solidification time, and 44.34% higher ice spike. The larger aspect ratio generated a 60.96% larger incremental angle, 4.6% shorter solidification time, and 45.01% higher ice spike. The solidification with zero-G environment resulted in a higher ice spike, which is dangerous for the enclosure of aerospace application.