A dynamic technique for the measurement of thermal conductivity of molten salt based on cylindrical melting model

This paper reports a dynamic testing technique for measuring the effective thermal conductivity of phase change materials close to the melting point aiming at the compensation for the absence of such data. Based on Stefan model, the time dependence of the position of the phase interface in a cylindrical melting process, which implies the thermal conductivity, was successfully determined with the aid of the perturbation method. Thereafter, a series of experiments were conducted on a well-designed testing system with excellent heat insulation to collect relevant data of sodium acetate trihydrate. To bridge the gap between the experimental and the actual values, a 3-dimensional, unsteady, numerical model, taking convection into consideration, was built on CFD code. Under necessary assumptions, this model allowed a better understanding of the role of the convection playing in the experiments. Accurate results of approximation to experimental data were obtained by continually adjusting the iterative value. The maximum deviation was limited in 9 %.