A thermal battery mimicking a concentrated volumetric solar receiver

A mobile thermal battery is a new concept in renewable energy technologies and provides effective and innovative solutions for solar energy utilization in various applications. A thermal battery mimics a volumetric solar receiver, which uses phase change material and metallic meshes in the energy storing medium. In the present study, performance analysis of a mobile thermal battery is presented. LiNO3 is used as the phase change material and aluminum meshes are incorporated to enhance the heat diffusion inside the receiver. The concentrated solar heating is incorporated resembling the actual field data. In order to achieve uniform heating of the phase change material inside the receiver, the rotation of the receiver is introduced along its symmetry axis. It is found that the aluminum meshes improve the heat diffusion significantly and enhances the melting rate of the phase change material inside the receiver. This, in turn, minimizes the local excessive heating and early initiation of the phase change process inside the thermal battery. The rotation of the receiver reduces the maximum temperature of the working fluid through suppressing local excess heating. In addition, receiver rotation lowers the maximum and minimum temperature difference inside the receiver; however, with increasing rotational speed, a small delay is observed for the time completing the phase change process inside the receiver. (C) 2016 Elsevier Ltd. All rights reserved.