Steel Cryo-Compressed Hydrogen Vessels for Automotive Applications

Abstract

Abstract. We have modeled the applicability of type 1 (all-metal) austenitic stainless steel (XM-11) vessels for cryo-compressed hydrogen (CcH2) storage. Thermodynamic modeling of refueling and utilization patterns for typical automobiles with a regular driving pattern (constant daily driving distances) is used for calculating fill density, system H2 storage density, and H2 weight fraction. Vessel weight is calculated with design rules obtained from the ASME Boiler and Pressure Vessel Code, and CcH2 refueling is evaluated from experimental measurements previously obtained from a liquid hydrogen (LH2) pump. The results indicate that steel CcH2 vessels have nearly identical H2 system storage density as composite CcH2 vessels, resulting in similar H2 storage capacity. While the heavy weight of steel vessels (100–150 kg heavier than composite vessels) impacts fuel economy and performance, it might be compensated by several advantages: (1) improved vacuum insulation performance and stability resulting from elimination of resins prone to outgassing in contact with the vacuum space, (2) improved vessel durability due to steel strengthening at low temperature and elimination of aluminum–steel transition weld, and (3) avoidance of expensive and energy-intensive carbon fiber leading to reduced cost and CO2 emissions during manufacture and eliminating dependency on carbon fiber supply chain. Applicability to transportation modes with reduced weight sensitivity (e.g., ships and trains) may also be considered for improved performance and reduced cost.