Thermal Characterization of Medium-Temperature Phase Change Materials (PCMs) for Thermal Energy Storage Using the T-History Method.

Paulina Rolka,Roman Kwidzinski,Adam Tomaszewski,Tomasz Przybylinski

doi:10.3390/ma14237371

Paulina Rolka, Roman Kwidzinski + Show 2 more

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https://doi.org/10.3390/ma14237371

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Abstract

To reduce energy consumption and increase energy efficiency in the building sector, thermal energy storage with phase change materials (PCMs) is used. The knowledge of the thermophysical properties and the characteristics of PCMs (like their enthalpy changes and the distribution of stored energy over a specified temperature range) is essential for proper selection of the PCM and optimal design of the latent thermal energy store (LHTES). This paper presents experimental tests of the thermophysical properties of three medium-temperature PCMs: OM65, OM55, RT55, which can be used in domestic hot water installations and heating systems. Self-made test chambers with temperature control using Peltier cells were used to perform measurements according to the T-history method. In this way the temperature range of the phase transition, latent heat, specific heat capacity, enthalpy and the distributions of stored energy of the three PCMs were determined. The paper also presents measurements of the thermal conductivity of these PCMs in liquid and solid state using a self-made pipe Poensgen apparatus. The presented experimental tests results are in good agreement with the manufacturers’ data and the results of other researchers obtained with the use of specialized instruments. The presented research results are intended to help designers in the selection of the right PCM for the future LHTES co-working with renewable energy systems, waste heat recovery systems and building heating systems.

Highlights

Energy consumption in the building sector accounts for 40% of global consumption and is responsible for 36% of greenhouse gas emissions to the atmosphere [1]
The pipe Poensgen apparatus was filled with 46 mL of phase change materials (PCMs) in liquid state for each test, which corresponded to about 36 g RT55, 43 g OM65 and 39 g OM55
The paper presents the results of experimental determination of the thermo-physical properties for selected phase change materials (PCMs) that are obtained with the use of two self-built devices: a calorimeter for T-history method measurements and a pipe Poensgen apparatus to measure thermal conductivity

Summary

Introduction

Energy consumption in the building sector accounts for 40% of global consumption and is responsible for 36% of greenhouse gas emissions to the atmosphere [1]. Just in Europe half of the total energy consumption is used for heating and cooling of residential and non-residential buildings, and about 84% of this energy is still generated from fossil fuels [2]. Today it is necessary to reduce the burning of fossil fuels and increase the use of renewable energy sources. Storage of heat or cold can be done with thermal energy storage (TES) using phase change materials (PCMs). PCMs incorporated in latent heat energy storages (LHTES) are used to store heat from solar collectors [3,4], to store energy from household wind power plants [5], in building heating and cooling systems [6,7], to support heat pumps and waste heat recovery installations [8], to support district heating networks [9,10]. PCMs are used to cool photovoltaic panels [11] and are used in building structural elements like walls [12,13,14], windows [15] and roofs [16]

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