Concentric tube and shell and tube latent heat exchangers filled with phase change material (PCM) in the tube part are interesting latent heat thermal energy storage (LHTES) systems that have attracted researchers' attention due to high energy storage density during the charging (melting) and discharging (solidification) processes. Inadequate phase change process reduces the thermal performance of LHTES systems. An effective design can facilitate and accelerate the phase change process. In this study, a novel toroidal shape is proposed for the inner part of the heat exchanger (tube) and the solidification process inside this tube is investigated. A mathematical model based on the enthalpy-porosity approach is developed and numerically solved by finite volume method to simulate the energy transport processes inside the system. The progression of the discharging process is also numerically visualized. Several transient heat transfer characteristics, e.g., thermal filed, solid fraction, average temperature, and energy released during solidification, are determined and depicted.