Dynamic heat transfer analysis on hwangtoh with PCM/eco-material for improving thermal inertia

Abstract

The use of a latent-heat storage composite system for which phase-change materials (PCMs) are used is an effective way of storing thermal energy, and it has the advantages of a high energy-storage density and the isothermal nature of the storage process. Therefore, latent heat storage is considered to be the most effective way to use PCM to charge or discharge thermal energy as latent heat during the phase change period. However, the application of PCMs is difficult in a variety of fields due to their phase instability in the liquid state, and PCMs therefore need shape stabilization. To solve this problem, some investigators have studied the possibility of using a container that can prevent the leaking of liquid from PCMs by using a shape-stabilized PCM (SSPCM), a microencapsulated PCM (MPCM), or incorporated PCM techniques. The SSPCM was prepared by eco-material which are perlite and vermiculite. The selected PCM was n-octadecane, belongs to organic PCM. The thermal properties of the PCM, such as their melting and freezing temperatures and latent heat capacities, were measured using differential scanning calorimetry. The melting and freezing temperatures were measured by drawing a line at the point of maximum slope of the leading edge of the peak, and extrapolating to the base line. The latent heat capacities of the PCM were determined by numerical integration of the area under the peaks that represent the solid-solid and solid-liquid phase transitions. The thermal conductivities of the PCM and hwangtoh composite panels were measured by TCi thermal conductivity analyzer. The TCi developed by C-Therm Technologies Ltd. is a device for conveniently measuring the thermal conductivity of a small sample, by using the Modified Transient Plane Source (MTPS) method.