Solidification analysis of a single particle with encapsulated phase change materials

The melting or solidification behavior of a single particle with encapsulated phase change material (PCM) is essential in analyzing the heat transfer effect of encapsulated PCM suspension slurries, particularly in mini-channels or high flow speed applications. Accordingly, the heat diffusion equation of a sphere with a liquid-solid moving interface model is used to analyze the solidification of PCM within a single encapsulated particle. The nonlinearities associated with a moving boundary problem are simplified via the transformation of dimensionless variables of equations. A technique which combines Explicit Euler method and Implicit Euler method in finite difference scheme is thus developed to solve the Stefan problem. The result is compared with an iterative analytical series solution and a good agreement is obtained. The evolution of solidification and the moving front surface are predicted for different size particles with core paraffin encapsulated, and the solidified volume fraction as a function of time is also determined. (C) 2012 Elsevier Ltd. All rights reserved.