To address challenges related to refueling with compressed hydrogen, a simple, analytical method has been developed that allows a hydrogen station to directly and accurately calculate an end-of-fill temperature in a hydrogen tank and thereby maximize the fill quantity and minimize the refueling time. This is referred to as the MC Fueling Method, where MC represents total heat capacity. The MC Method incorporates a set of thermodynamic parameters for the tank system that are used by the station in a simple analytical equation along with measured values of dispensed hydrogen temperature and pressure at the station. These parameters can be communicated to the hydrogen station either directly from the vehicle or from a database that is accessible by the station. Because the MC Method is based on direct measurements of actual thermodynamic conditions at the station, and quantified thermodynamic behavior of the tank system, highly accurate tank filling results can be achieved.
The MC Method can be used as the fueling protocol for an Identification Fill (ID Fill), which uses tank-specific MC parameters, or for a MC Non-Communication Fill, which uses the MC parameters of the boundary condition tanks used to derive the fueling speed and pressure targets for the lookup tables in SAE TIR J2601.
This paper details the actual application of and fueling results from an MC Method-based ID Fill at the Shell Pipeline Station in Torrance, CA and computational fueling results of an MC Non-Communication fill. Factors affecting the real world implementation of this fueling method are explained and the adaptation of the method to station capabilities is demonstrated. Fueling test results show that an ID Fill improves upon the non-communication fueling performance of the SAE TIR J2601 lookup tables. Computation results also show that an MC Non-Communication Fill provides safety equivalent to and performance superior to the lookup tables while providing a much simpler and more flexible approach to H2 fueling.
Using the MC Method in SAE J2601 can provide the framework for a universally usable ID Fill fueling protocol as well as a simpler and more flexible equation-based approach to non-communication fueling.