Project Title:Development of fast response flow control valve for gaseous hydrogen fueling of fuel cell vehicles Topic Number: C56-18C

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. Phase I will include a feasibility study of key design concepts of the fast-acting flow control valve which will reduce potential for pressure surge during tank switching. The feasibility study will be augmented by development of a simplified model of the system and dynamic model control/passive valve function during the tank switching process. The results of the simplified model will be used to refine the flow characteristics, and suitability of the control valve stroke speed. The model will utilize computational fluid dynamics to develop necessary design parameters. 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.