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Abstract

Recently the interest in Phase Change Materials (PCMs) has grown significantly amongst researchers [1-9]. Namely, these materials, due to their ability to store large amounts of thermal energy in relatively small temperature intervals, can be effectively used for various thermal energy storage (TES) applications. Nevertheless, accurate knowledge of the thermal properties of PCMs is a prerequisite before design processes and real time deployments of any TES applications.

The T-history method is widely used for the investigation of phase change materials. The majority of the T-history studies reported in the literature during the last 20 years aim to reduce the temperature and the heat storage uncertainty associated with the PCMs measurement [3-9]. Reduction of these uncertainties is important since it should provide better material utilisation. This paper presents an improved measurement technique for the characterisation of PCMs using the T-history method. The main modifications involved in the measurement process are briefly summarized below.

Primarily, suggested improvements include the selection of the thermally controlled environment and the temperature sensing modalities for the T-history setup. This was followed by the development of the adequate instrumentation and data acquisition system. In addition, the mathematical model given by Marin et al. was adjusted for the data analysis in order to take the subcooling phenomenon into account. The calculated results on heat capacity were presented as heat density in given temperature intervals, as suggested by Mehling et al. Moreover, the determination of the total phase change heat in case of both cooling and heating cycles showed that the reduction of relevant temperature and heat storage uncertainties was achieved.

Publication Type:	Conference or Workshop Item (Paper)
Subjects:	T Technology > TK Electrical engineering. Electronics Nuclear engineering
Departments:	School of Science & Technology > Engineering

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