Method and apparatus for providing increased thermal conductivity and

Abstract

A method and apparatus are disclosed for providing increased thermal conductivity and heat capacity to a pressure vessel containing a hydride-forming metal material which is capable of absorbing and storing relatively large amounts of hydrogen gas. An elongate pressure vessel, having an opening therein for charging and discharging hydrogen therefrom and valve means in combination with the opening for controlling flow of hydrogen gas to and from the container, is provided with a plurality of elongate, aluminum magnesium, or copper tubes as a tube bundle, with the longitudinal axis of the tubes being parallel to the longitudinal axis of the vessel. The tubes are packed in the vessel so that tubes are in firm contact with adjacent tubes, and the outer tubes of the bundle are in firm contact with the longitudinal inside surfaces of the vessel as well as with adjacent tubes in the bundle. Particulate, hydride-forming, metal material substantially fills the otherwise void spaces within the tube-containing vessel. Thermal conductivity and thermal capacity of the bed of particulate material in the tube-containing vessels are increased by as much as 240% and 15%, respectively, in comparison to equivalent size beds of the same particulate material in non-tube containing vessels. An existing pressure vessel can be retrofitted with thetightly packed tubes by cutting tubes, having an outside diameter smaller than the valve opening in the pressure vessel, to lengths having a longitudinal dimension shorter than the longitudinal dimension of the pressure vessel. The lengths of tubes are inserted, one at a time, into the pressure vessel through the valve opening therein, and the inserted tubes are organized into the tightly packed tube bundle.