The effectiveness of the heat transfer fluid pipe orientation angle inside a latent heat thermal energy storage system

Abstract

Latent heat thermal energy storage systems exhibit a significant performance over other thermal energy storage systems. The performance of these particular systems during melting/solidification is influenced by their orientation. Therefore, a numerical investigation and experimental validation were conducted. ANSYS Fluent 18.1 is used to develop a numerical model to investigate the effects of the pipe's orientation angle. Parametric analysis of various pipe orientation angles (0°, 30°, 60°, 90°) and various oil inlet temperatures were conducted during the investigation. It was determined that the melting time and absorbed heat flux when the inlet temperature increased from 493 K to 523 K is reduced by 42% and increases by 59%, respectively. Furthermore, the solidification time decreases by 63% when the inlet temperature is reduced from 444 K to 413 K. Increasing the orientation angle of the pipe results in a reduction in the melt fraction by 16.5% as the orientation angle is increased from 0° to 90°. In addition, the orientation angle has a significant effect during the melting, which is influenced by increasing the orientation angle from 0° to 90° by 18.2%. Conversely, the orientation angle has no impact on solid fraction during solidification.