Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7721137 | International Journal of Hydrogen Energy | 2013 | 9 Pages |
Abstract
A dynamic model has been developed to characterize dormancy and hydrogen loss from an insulated cryogenic pressure vessel that is filled with 99.79%-para liquid hydrogen to reach supercritical conditions. The model considers the thermodynamics and kinetics of the endothermic para-to-ortho conversion that occurs when the stored H2 heats after the vessel is exposed to ambient conditions for an extended time. The thermal, thermodynamic, and kinetic aspects of the model were validated against experimental data obtained on a 151-L tank designed for service at nominal pressures up to 350Â bar. Depending on the initial pressure, temperature, amount of H2, and the rate of heat gain from the ambient, the endothermic para-to-ortho conversion can extend the loss-free dormancy time by up to 85%. Under conditions in which the endothermic conversion does not materially affect dormancy, it can still significantly reduce the H2 loss rate and it can even introduce a secondary dormancy period.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
J.K. Peng, R.K. Ahluwalia,