Development of Sensors for Measuring the Enthalpy of PCM Storage Systems

Thermal energy storage systems are considered as key components in actual and future thermal applications. Whereas the determination of the charge level of a sensible heat storage system can be easily carried out by temperature measurements, this task for Phase-Change-Materials PCM additionally consists of the measurement of solid and liquid shares of the storage material. In this paper, two possibilities of measuring the enthalpy of PCM storage systems will be presented. The first method is based on the volumetric change of PCM during the transition phase from solid to liquid, the second method uses different damping properties of solid and liquid materials.