Thermal performance of a PCM heat sink under different heat loads: An experimental study

Abstract

This paper reports the results of an experimental study to quantify the effect of heat transfer performance of a phase change material (PCM) based plate fin heat sink matrix under constant and intermittent heat loads. n-Eicosane with a melting temperature of 36.5 °C is used as the phase change material. Such heat sinks, in general require heat transfer enhancement techniques, because of the low thermal conductivity associated with PCMs. A plate fin matrix made of aluminum is used in the present study to augment the heat transfer. The performance of the heat sink matrix with and without PCM is compared. Additionally, a heat sink filled with PCM, but without any fin is used for baseline comparisons. A series of experiments was conducted at a constant power level of 5–10 W (corresponding to a flux of 2–4 kW/m2) in steps of 1 W. Extensive experimental investigations were carried out at varying power levels by applying the heat flux intermittently by keeping the input heat constant. A step heat input is also applied for a fixed duration at various usage modes usually encountered in the thermal management of portable electronic devices. Parametric studies have been conducted by changing the PCM volume fraction, which is defined as the ratio of the volume of the PCM to the difference between the total empty volume of the heat sink and the volume occupied by the fins and the effect of these on the thermal performance of the plate fin heat sink matrix for both melting and solidification are elucidated in this study.