Cryogenic Hydrogen Storage for Mobility: from Station to Wheels; On the Impact of Powertrain Operating Pressure on Usable Capacity

Authors

J. Hergott, Forvia, Bavans; Dr. G. Petitpas, Air Liquide, Les Loges en Josas:

Year

2023

Print Info

Production/Publication ÖVK

Summary

Onboard cryogenic hydrogen storage is a great solution for safe, long range, emission free heavy duty-applications. It enables large onboard capacities, together with affordable and fast refueling. A few cryogenic solutions are being investigated, such as low pressure (< 10 bar) liquid hydrogen (LH2), subcooled liquid hydrogen (sLH2) and cryogenic compressed hydrogen (CcH2). Although similar in nature, they offer differences in terms of dormancy, operating conditions, effective capacities and refueling architecture that are worth considering. This paper explores the influence of powertrain (e.g. fuel cell or internal combustion engine) operating pressure on the usable fuel for sLH2 and CcH2 storage systems, under the assumption of a 6 bar or a 30 bar operation for full flow, for a fuel cell or an engine, respectively. It is shown that due to increasing temperatures at low H2 densities (below 10 g/L or so), a great amount of energy can be stored in the vessel’s wall which results in a lower maximum capacity uptake during subsequent direct refueling; hereby reducing the usable H2 amount for the vehicle. Relationships between state of charge prior to refueling and usable H2 capacities are given. It is shown that up to 50% more H2 uptake capacity can be achieved by reducing the minimum operating pressure in the cryogenic vessel from 30 to 6 bar.

ISBN

978-3-9504969-2-5