Melting process in a rectangular thermal storage cavity heated from vertical walls

Thermal energy storage is critical for reducing the mismatch between energy supply and demand as well as plays an important role in energy conservation. The melting process in a rectangular thermal storage cavity is investigated numerically. The numerical model is developed and verified by the experimental results. The cavity aspect ratios are varied from 0.1 to 10. The vertical walls of the cavity are heated uniformly, while the horizontal walls are considered insulated. The computational results show how the transient phase-change process depends on the aspect ratio. It is found that the aspect ratios affect dramatically not only the time of full thermal energy storage but also convection currents inside the cavity. The optimized thermal storage performance is obtained for the aspect ratios a parts per thousand yen1.