Numerical study of hydrogen absorption in a metal hydride tank embedded with multiple U-shaped cooling channel

In the present paper, a three-dimensional hydrogen absorption model is applied to a cylindrical LaNi5 hydride bed embedded with multiple U-shaped cooling channels having fins fitted in different orientations. Four number of cooling channels are placed radially at equal distances to achieve uniform heat removal from the bed. The fins are fixed to the coolant channel in transverse and radial directions. The fins volumetrically collect heat from the bed and deliver to the coolant channels. Three metal hydride bed cases are numerically studied, they are with: only coolant channels - case 1, coolant channels fitted with transverse fins - case 2 and coolant channels with transverse and radial fins - case 3. From the simulation results, it is revealed that the presence of fins in the coolant channels significantly improves the heat transfer and hydrogen absorption rate in the bed. The hydrogen absorption in the bed approaches 90% of saturation in 998 s, 867 s and 656 s for case 1, 2 and 3, respectively. Detailed multi-dimensional contours of temperature and hydrogen to metal ratio distributions in the bed are presented for different cases. This study provides a better understanding of heat and mass transfer during the hydrogen absorption in a metal hydride bed.