Thermal Analysis of Mobile Thermal Battery with Aluminum Mesh Subjected to Solar-Concentrated Heating

Abstract

Solar thermal heating analysis of a tube in the presence of metallic meshes, resembling the mobile thermal battery, is carried out. The influence of metallic meshes on the heat-transfer rates inside the tube is examined in detail. Structured aluminum meshes are incorporated into the tube while stagnant water is assumed as the working fluid inside the tube. Numerical analysis using the control-volume approach is incorporated to solve the governing equations of heat transfer and fluid flow inside the tube. The dimensionless temperature parameter is introduced to quantify the excessive local heating inside the tube with and without meshes under the solar-concentrated irradiation. It is found that aluminum meshes act like a conduction tree and enhance the heat-transfer rates in water inside the tube. The local excessive heating and large temperature difference are avoided inside the tube when the aluminum meshes are used inside the tube. The influence of natural convection current on the heat-transfer rates is found to be insignificant when the aluminum mesh is present inside the tube. This behavior is associated with the small mesh volumes, which are occupied by water; in this case, small temperature difference in the cell causes small variation in water density while suppressing the natural convection current formed in the cell. Small oscillation in the temperature parameter is observed along the x- and y-axes inside the tube because of the high rates of heat transfer toward water in the region close to the aluminum meshes.