Metal hydride is promising as safe hydrogen storage. However, the effective thermal conductivity of metal hydride is greatly affected by changes in the porosity of the packed bed. Therefore, this study was conducted to calculate the thermal properties of a metal hydride (LaNi5) by using an inverse problem solution based on temperature measurements from heating experiments. Experiments were conducted at different metal temperatures (25 ℃, 30 ℃, 35 ℃) in order to confirm the differences in the experimental results at different metal temperatures. The porosity in this study is the average porosity of the entire packed bed, which was calculated from the observed images of the packed bed. As a result, the changes in porosity during the most recent cycle ranged from 50 % to 57 %, indicating that the packed bed is relatively stable. The temperature change data from the heating experiments at each porosity (reacted fraction) and at each metal temperature confirm that the thermal properties are different. However, the present process has not been able to find a trend of thermal property changes with differences in porosity (reacted fraction) and metal temperature. Therefore, we plan to reconsider the data processing method to calculate accurate thermal properties in the future.
TAKADA et al. (Wed,) studied this question.