Ryan Shelby, Mechanical Engineering, University of California at Berkeley

New Technologies Engineering Division

Lawrence Livermore National Laboratory   

Abstract:

Onboard hydrogen storage technology is critical component in the realization of a hydrogen-powered economy.  Currently, there are four technologies suitable for vehicular hydrogen storage: compressed gas, metal hydride materials, carbon-based materials, and cryogenic liquid.  Each technology has a fundamental limitation: volumetric efficiency gravimetric efficiency, adsorption thermodynamics, or evaporation loss respectively.  In this study, a one week cryogenic dormancy test of the 151 liter cryogenic capable pressure vessel was performed using liquid nitrogen (LN₂) as a surrogate for liquid hydrogen (LH₂).  Utilizing the pressure and temperature data from the dormancy test, a thermodynamic model of a cryogenic capable pressure vessel was created and the liquid nitrogen loss of the vessel due to boiloff was documented.  From the thermodynamic analysis, it was determined that the vessel experienced a 5.5 Watt heat leak during the dormancy test and that radiation was responsible for ~90% of the heat leak.  Given this heat leak, it is predicted that the pressure vessel will be sufficient to store 10.7 kg of (L)H₂ for 10 days.