Bubble agitation as a new low-intrusive method to crystallize glass-forming materials

Abstract

Xylitol is a very promising Phase Change Material (PCM) for long-term thermal energy storage at low to medium temperatures due to its low melting temperature, its high energy density, its high and stable undercooling allowing long-term storage with reduced thermal losses. However, the activation of the energy discharge process (crystallization activation) is difficult and the subsequent crystallization rates (discharge powers) are very low. To overcome such problems, a simple and efficient technique is proposed. It consists in bubbling undercooled Xylitol using a gas until it crystallizes and the recalescence phase is completed. The mechanisms activating the crystallization are presented in this paper and the bubbling performances are experimentally investigated.