Numerical analysis of hydrogen absorption in metal hydride beds

Ill NUMERICAL ANALYSIS OF HYDROGEN ABSORBTION IN METAL HYDRIDE BEDS (M.Sc. Thesis) Muhittin BİLGİLİ GAZI UNIVERSITY INSTUTE OF SCIENCE AND TECHNOLOGY July 2003 ABSTRACT Hydrogen, hydrogen energy, different storage methods of hydrogen energy were summarized and a mathematical model was developed on an alternative method of hydrogen storage in metal hydrides. Two dimensional heat and mass transfer were analyzed for hydrogen absorption in porous metal beds using cylindrical coordinates. For high cooling rates an annular geometry was selected for the porous metal bed, and the bed was cooled by fluid on both internal and external surfaces. Absorption process was analyzed numerically for the porous Lanthanum Nickel (LaNi5) metal bed. The variations of the metal hydride temperature and hydrogen / metal (H/M) atomic ratio were calculated in the radial and axial directions by using a Computational Fluid Dynamics (CFD) program. It has been observed that hydride formation takes place faster near the cold boundaries. The results were also compared with numerical outcomes given in the literature for different geometries.IV Science Code : 920 Key Words : Hydrogen Absorption, Hydrogen Energy, Metal Hydride, Mathematical Modelling. Page Number : 144 Adviser : Prof. Dr. Ö. Ercan ATAER