Hydrogen Refilling Optimizations Through 1-D Simulations for Commercial Vehicles 2024-26-0176

Fuel cell electric vehicles (FCEVs) and battery electric vehicles are being touted worldwide by the automotive industry and policy makers as the answer to decarbonizing the transportation sector. FCEVs are especially suited for commercial vehicle applications as they offer very short re-fueling times that is comparable to conventional internal combustion engine vehicles. While this is entirely possible there are host of challenges that include safety, that need to be addressed to make short refilling times possible for commercial vehicles where the hydrogen storage requirement is higher (25 kg or more). This is due to the rise in temperature of the hydrogen in the cylinder due to compression and the negative Joule-Thompson coefficient. The SAE J2601 standard limits the safe temperature limit of hydrogen gas in the cylinder to 85 °C during filling. In countries where the ambient temperature can go above 45°C, like India, this poses a serious challenge and can severely impact the re-filling rates. One way re-filling stations get around this is by cooling the hydrogen gas to as low as -40°C before filling. However, this adds to the cost of the hydrogen re-filling stations which then becomes an additional bottleneck in the development of hydrogen infrastructure. In this work we explore, using 1-D simulations, how different novel re-filling strategies can impact the re-filling time while staying within safe handling limits of hydrogen gas. Different initial conditions for hydrogen gas before filling are studied to understand how refilling can be optimized to meet targeted refilling times while still curtailing cost over runs on the infrastructure side.