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

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 degrees, 30 degrees, 60 degrees, 90 degrees) 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 degrees to 90 degrees. In addition, the orientation angle has a significant effect during the melting, which is influenced by increasing the orientation angle from 0 degrees to 90 degrees by 18.2%. Conversely, the orientation angle has no impact on solid fraction during solidification.

Automated summary

The effects of pipe orientation angle on the performance of latent heat thermal energy storage systems were investigated. It was found that increasing the orientation angle of the pipe can reduce the melt fraction and increase the melting time and absorbed heat flux. However, the orientation angle has no impact on the solid fraction during solidification.