Experimental and numerical investigation on the melting behavior of paraffin in a shell and tube latent heat storage unit

Abstract

In order to reduce the melting time of an improved shell and tube latent heat energy storage unit, the melting behaviors of phase-change material (paraffin) in the unit are investigated through visualization experiments. And a two-dimensional simulation model is established to explore the strengthening mechanism of the melting process by distinct heating methods and non-heat source wall. Results show that the complete melting time of outside heating method is 70.2% less than that of inside heating method at same heat flux. Eliminating the influence of heat transfer area (equal total heat input), the outside heating can generate more extensive and stronger natural convection, and the complete melting time can be shortened by 20.2%. In addition, the heat transfer bridge built by the non-heat source wall between the high temperature liquid phase-change material zone and the dead zone can effectively enhance the natural convection and accelerate the melting process. Especially considering the non-heat source wall, the melting time can be reduced by 44.2% through using the inside heating method.