Numerical Study of Thermal Effect during Hydrogen Storage in Porous Bed

The objective of this work was to develop a numerical model of hydrogen storage process in adsorbent porous bed. This model is based on the use of continuity and energy equations that make use of classical volume averaging rules adopted for flows in porous media. Both quasihomogenous and a full axi-symmetrical 2D models were used to describe the tank geometry. They enabled us to predict time-variations of either volume averaged or full 2D spatial distributions of flow velocity, temperature, adsorption capacity and hydrogen density.Several simulations were carried out to investigate the effect of material properties on the net temperature increase in the storage tank and its consequences on the storage tank performance. The results showed that adsorption process becomes a major contributor to the temperature increase in the bed for adsorbent capacity greater than 2%. For a given charging pressure, storage tanks with higher adsorption capacity require longer charging time. These results indicate that although adsorption process in itself would not be a major source of the thermal heating for the presently available activated carbon, this should not be the case for an adsorbent material that would fulfill the DOE target of 6%.

Keywords:

Numerical , hydrogen storage , adsorption