Abstract
It’s known that the pulverization-densification mechanism of metal hydride may cause the stress accumulation in metal hydrides reactors. In this paper, this idea is proved based on granulometry and a new idea of cycling compression effect is presented, which is caused by the friction between wall and metal hydrides. Through theoretical analysis, the cycling compression effects is shown to increase the localized packing rate from top to down in vertical-placed reactors and thus lead to the maximum deformation in the bottom of reactors, proving that it is the interaction of pulverization-densification effect and cycling compression effect resulting in the stress problems of vertical-placed reactors. Further study points that the effective methods relieving the cycling compress effect are to decrease hydrogen absorption/desorption cycle number, slenderness ratio of reactor, wall friction factor and initial packing rate, or to lower the thermal conductivity and the volume expansion coefficient of metal hydrides.
Highlights
The pulverization and expansion of metal hydrides during its absorption/desorption cycles could decrease the reliability of the reactor directly and greatly, becoming one of the key obstacles to the development and application of hydrogen energy
It’s known that the pulverization-densification mechanism of metal hydride may cause the stress accumulation in metal hydrides reactors. This idea is proved based on granulometry and a new idea of cycling compression effect is presented, which is caused by the friction between wall and metal hydrides
The cycling compression effects is shown to increase the localized packing rate from top to down in vertical-placed reactors and lead to the maximum deformation in the bottom of reactors, proving that it is the interaction of pulverization-densification effect and cycling compression effect resulting in the stress problems of vertical-placed reactors
Summary
The pulverization and expansion of metal hydrides during its absorption/desorption cycles could decrease the reliability of the reactor directly and greatly, becoming one of the key obstacles to the development and application of hydrogen energy. Ao et al found in their test that the LaNi5 alloy’s volume expansion ratio was up to 24% after absorbing hydrogen, causing the density of alloy from the top to bottom of the bed higher and higher and the stress greater and greater after several cycles [2]. They indicated that the increase of initial packing rate and decrease of the wall thickness could help relieving the stress accumulation. Its mechanism has been described and the factors which perform influence to the effect have been studied
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
