SAE J2601/5 High-Flow Prescriptive Fueling Protocols for Gaseous Hydrogen Powered Medium and Heavy-Duty Vehicles

TIR SAE J2601-5 establishes prescriptive general-purpose high-flow fueling protocols and process limits for hydrogen fueling of vehicles with compressed hydrogen storage system (CHSS) volume capacities between 750 and 2500 liters which have been qualified to UN GTR #13. These process limits (including the fuel delivery temperature, the maximum fuel flow rate, the rate of pressure increase, and the ending pressure) are affected by factors such as ambient temperature, fuel delivery temperature, and initial pressure in the vehicle’s compressed hydrogen storage system. TIR SAE J2601-5 includes two sets of fueling protocols: 1) high-flow versions of the Category D protocol described in SAE J2601; and 2) an MC Formula-based fueling protocol which utilizes a dynamic pressure ramp rate continuously calculated throughout the fill. The naming convention of the MC Formula-based fueling protocol is MCF-HF-G (MC Formula - High Flow – General). The protocols allow for fueling with communications or without communications and provide end-of-fill pressure targets. For fueling with communications, the fueling protocols are to be used in conjunction with SAE J2799, Hydrogen Surface Vehicle to Station Communications Hardware and Software. An important factor in the performance of hydrogen fueling is the station’s dispensing equipment cooling capability and the resultant fuel delivery temperature. The fueling protocols utilizes fuel delivery temperatures in the range of -40 °C to -10 °C. There are four fuel delivery temperature categories denoted by a “T” rating - T40, T30, T20, and T10, where T40 is the coldest. Future revisions may expand the fuel delivery temperature range to warmer temperatures. Fueling times are a function of the fuel delivery temperature and CHSS volume. With a T40 rated dispenser and under reference conditions (ambient temperature of 20 °C and initial pressure of 10 MPa, the MCF-HF-G protocol can achieve fueling times of 5 to 7.5 minutes and a % State of Charge (SOC) of 95 to 100% (with communications). With higher fuel delivery temperature dispenser ratings (T30, T20, or T10) and/or at high ambient temperatures, fueling times will be longer. Table 1 below depicts the scope of TIR SAE J2601-5 and potential work items for future revisions within this or other documents of the J2601 series. TIR SAE J2601 provides a fueling protocol which is applicable the 70 MPa pressure class (H70). It is expected that a future revision will include the 35 MPa pressure class (H35). The fueling protocols herein were developed based on a set of key assumptions described in Section 7 and Appendix A. These assumptions should be carefully considered in the development and implementation of an on-board compressed hydrogen storage system. SAE TIR J2601-5 provides prescriptive general-purpose fueling protocols which are appropriate for use in both private and publicly accessible fueling stations. TIR J2601-5 is independent from SAE J2601-2 “Protocol for Gaseous Hydrogen Powered Heavy Duty Vehicles.”