Cryogenic Composite Seals for Liquid Hydrogen Service Components

Statement of the problem or situation that is being addressed: The DOEĺs Hydrogen and Fuel Cell Technologies Office has identified a need for innovative technologies that enable energy security through reliable and safe hydrogen dispensing. NanoSonic has been developing advanced materials in the form of hydrogen dispending hoses, nozzles, high pressure in-line particulate filters for gaseous delivery, as well as cryotanks for liquid storage. Here, NanoSonic shall further develop our materials for use with liquid hydrogen. Specifically, reactive twin-screw extrusion combined with calendering shall enable the production of new low hydrogen permeable, cryogenically durable, materials for use as advanced seals. How this problem is being addressed: Most polymers do not offer glass transitions low enough to accommodate resilience down to 20K, thus new composites are needed for liquid hydrogen applications. Specifically, a new monolithic material with ultra-low coefficient of thermal expansion shall be developed. Ultra-low Tg custom engineering polymers shall be considered for use in the new compounding. NanoSonic has the infrastructure to develop new high pressure tolerant composites in our extruder to reduce the initial cost of production. What is to be done in Phase I: During Phase I, NanoSonic shall work together with Pacific Northwest National Laboratory to design safe liquid hydrogen seals for tribology testing. The design shall be applicable to the targeted back-to-back fueling rates averaging 10 kg H2/minute, onboard storage pressures of up to 700 bar, and new high-speed cryogenic liquid pumps and compressors. H2 quality, delivery rate, efficiency (leaking), and durability shall be tested at NanoSonic and Pacific Northwest National Laboratory to validate sealing performance and reliability. Material cost shall be commensurate with current systems and no personal protective equipment shall be required for use, so that the technology is readily available to all. During Phase II, field studies with hydrogen service station partners shall commence. The seals shall be tested under dynamic (e.g., in pumps) and static (e.g., face seals) conditions for respective use in pumps and face seals, as well as for use in valve seats, and pressure regulators at temperatures down to 20 K. Commercial applications and other benefits: New cryogenically durable seals for use with liquid hydrogen pumps shall be developed for use at temperatures down to 20 K. The new cryogenic materials shall serve the larger hydrogen dispensing community.