Analysis of Hydrogen Expansion's Potential for Fuel Cell Electric Vehicle's Efficiency

This paper investigates the potential of energetic utilization of hydrogen expansion in a fuel cell electric passenger vehicle. The expansion process is considered and evaluated from the thermodynamic side with different assumptions. The theoretical calculations are used in combination with measured data from a research fuel cell electric vehicle to calculate potential energies that are generatable with hydrogen expansion during driving. In addition, the requirements and boundary conditions for a hydrogen expander are considered and different expansion technologies are compared for their suitability for the application in a fuel cell vehicle. Finally, first results of a model of the hydrogen expansion engine in DYMOLA will be presented.