Phase Change Material Subsystem for Temperature Reduction during Fast Fill

Growth in the fuel cell electric vehicle (FCEV) market beyond early adaptors will require significant reductions in the cost of hydrogen fueling. During fueling, hydrogen is pre-cooled to - 40°C to reduce the peak temperature rise in the tank to <85°C. About 15% of the station cost is due to the pre-cooling equipment. Pre-cooling to these temperatures also increases performance requirements of the hydrogen dispensers, which account for 14% of station cost and increased maintenance frequency. A materials-based solution that takes advantage of the latent heat of changing phase from solid to liquid along with engineered high surface heat transfer supports will be developed. Previous approaches to phase change material heat mitigation prevented the tank walls from exceeding 85°C but did not provide adequate surface area to prevent the gas temperature from exceeding 85°C. The current project will address this shortcoming by developing low-cost, high surface area, in-tank supports integrated with a phase change material to efficiently couple the excess gas thermal energy to the phase change material to limit the total gas temperature to <85°C. The resulting product will be a tank insert that absorbs excess heat during refueling such that no pre-cooling equipment at the station is required.