Experimental study on the melting and solidification of a phase change material enhanced by heat pipe

• A heat pipe was used to enhance heat transfer in PCM.
• Melting and solidification experiments were performed.
• Using a heat pipe compensates the PCM low thermal conductivity.

In the present paper, the effect of using a heat pipe on the melting and solidification behavior of a phase change material (PCM) in a vertical cylindrical test cell was experimentally studied. The experiments were performed using a constant temperature thermal reservoir to provide constant temperatures above and below the melting point for heating and cooling. The melting and solidification experiments were run in test cells with and without heat pipes. The experimental results indicate that utilizing a heat pipe in PCM test cell dramatically enhance the melting and solidification rate. Heat pipe surface temperature was measured during experiments. It shows heat pipe isothermally transmits heat very well. By applying different reservoir working temperature, it is concluded that a 15 °C increase in reservoir temperature in melting experiment with heat pipe almost decreases the melting time by 53% and a 10 °C decrease in temperature in solidification reduce the solidification time by 49%. The growth of solid layer and solid–liquid interface in PCM during solidification was experimentally investigated.