Development of Fast Response Flow Control Valve for Gaseous Hydrogen Fueling of Fuel Cell Vehicles

Hydrogen fueling of medium- to heavy-duty fuel cell vehicles requires a transfer of 100 kg of hydrogen with targeted fueling time under 10 minutes. During the fueling process, the supply (inlet) pressure to the flow control valve can increase significantly and rapidly due to supply tank switching. These flow conditions challenge the performance of currently available flow control valves. The challenges due to pressure transients during supply tank switching will be addressed by reducing the potential for pressure surge by integrating a unique control valve at each tank discharge. The unique control valve will maintain a target ramp in inlet pressure at the common flow control valve. The system response will be improved further by incorporating necessary flow characteristics in the flow control valve. A passive flow control valve design solution will also be developed. In Phase II, design tools/methodology developed under Phase I will be used to finalize the designs of flow control devices (passive flow rate limiting valve and passive modulating flow control valve) suitable for hydrogen. Prototypes of the final passive flow rate limiting valve and modulating flow control valve will be developed. A matrix of separate effects, functional, and qualification tests will be performed, post-test evaluation will be conducted, design refinements will be incorporated as necessary, and functional tests will be repeated on the prototypes to produce functioning flow control devices. The primary application is in hydrogen fueling stations targeting medium- to heavy-duty fuel cell vehicles. Other industry applications may benefit from a fast-acting control valve capable of maintaining a target flow rate in the presence of large changes in differential pressure. Summary for Members of Congress Hydrogen fueling stations can experience sudden, large increases in pressure during operation. The filling station system and primary control valve designs are targeted for improvement, which will reduce/control the pressure increase to maintain safe refueling.