Erythritol Melt Fraction correlation for tall enclosure PCM based heat sinks

João Fidelio Raymundo Júnior¹; Rejane de Césaro Oliveski¹

¹ Universidade do Vale do Rio dos Sinos

doi:10.20906/CPS/COB-2015-1210

Resumo

Many areas of engineering use thermal energy storage to optimize performance, such as the case of petrochemical and food industries and many liquid heating/cooling systems. Thermal energy storage systems can be used as either a heat source or heat sink. In the applications with intermittent energy generation, such as wasted heat recovery and electronic devices cooling systems, an appropriate thermal storage/release system is essential. The thermal storage/release technology based on the use of phase change materials (PCMs) has raised huge practical interest, due to its great heat accumulation capacity. Phase change phenomena occurring during PCM melting need to be carefully controlled and understood. Such optimization requires extensive thermal and dynamic knowledge of the materials within the tanks. Some studies have been carried out to investigate the thermal and hydrodynamic characteristics of the phase change phenomena involved in these systems. Most of these are experimental and only a few use a numerical approach, and most of them use low melting point PCMs. This study focuses studying and analyzing these phase change characteristics in a tall enclosure heat sink with plate fins through CFD (computational fluid dynamics). The PCM utilized is Erythritol. It has a higher melting point compared to most other PCMs, which has drawn interest in the recent years. The simulations were carried out through CFD, using the FLUENT (v14) software, in a 3D domain, which consists of three materials, the PCM, aluminum and air. The mesh used is structured, hexaedrical and refined near the walls and the PCM-air interface. The mathematical model is made of the mass, momentum and energy conservation equations and was validated using results available in the literature. The walls are impermeable and a non-slip condition is adopted. They also have a constant temperature, except for the bottom wall, which is adiabatic. Three temperature differences (10, 15 and 20 °C) between the PCM initial temperature and domain

Palavras-chave: Phase Change Material; Thermal Energy Storage; Correlation; Erythritol