INFLUENCE OF THE WALL SURFACE ROUGHNESS ON THE SUPERCOOLING DEGREE OF WATER FLOWING INSIDE A HEAT EXCHANGER

摘要

In the application of cold thermal energy storage, ice slurry is a technology with enormous potential. A promising technique for ice slurry generation is the method of supercooled water. Here, either water or an aqueous solution is cooled inside a heat exchanger to below freezing point, yet remains in a liquid state. In a second step, nucleation is initialized to create the ice particles. To avoid ice blockage inside the heat exchanger, the crystallization process is usually done in a releasing unit. In this study, the influence of the wall surface roughness on the supercooling degree of water flowing inside a heat exchanger was investigated. In the process, flowing water was supercooled with a constant cooling rate in the inner tube of a double-tube heat exchanger until ice blockage occurred. Several experiments with various surface roughness values of the heat exchanger wall were carried out. The results of this study show the extent to which flowing water can be supercooled, depending on the described conditions.