Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1273970 | International Journal of Hydrogen Energy | 2014 | 11 Pages |
•Thermodynamic simulation model for analysis of high pressure hydrogen refueling.•Energy consumption of cascade refueling systems with different number of tanks.•Multiple tanks at different pressures reduce energy consumption significantly.•Compression accounts for half of the energy usage for a complete refueling cycle.•Three to four tanks are properly the optimal amount in a cascade refueling system.
Hydrogen fueling stations are emerging around and in larger cities in Europe and United States together with a number of hydrogen vehicles. The most stations comply with the refueling protocol made by society of automotive engineers and they use a cascade fueling system on-site for filling the vehicles. The cascade system at the station has to be refueled as the tank sizes are limited by the high pressures. The process of filling a vehicle and afterward bringing the tanks in refueling station back to same pressures, are called a complete refueling cycle. This study analyzes power consumption of refueling stations as a function of number of tanks, volume of the tanks and the pressure in the tanks. This is done for a complete refueling cycle. It is found that the energy consumption decreases with the number of tanks approaching an exponential function. The compressor accounts for app. 50% of the energy consumption. Going from one tank to three tanks gives an energy saving of app. 30%. Adding more than four tanks the energy saving per extra added tank is less than 4%. The optimal numbers of tanks in the cascade system are three or four.