Thermodynamic optimization of contact melting of phase change material inside a horizontal cylindrical capsule

Finite time thermodynamic analysis is applied to the contact melting process of phase change material inside a horizontal cylindrical capsule. With the minimum entropy generation in given time as the objective function the quadratic nonlinear ordinary differential equation that the optimal melting process should be satisfied is derived. The dimensionless liquid height, melt liquid film thickness, Nusselt number, melting rate, optimal wall temperature and entropy generation are obtained by the numerical method. The optimal results are discussed and compared with the unoptimizable analytical results under the condition of constant wall temperature. It is found that the heat transfer and thermodynamics performance of the optimal melting process is better than that of the melting with constant wall temperature.