Model-based investigation and evaluation of a hydrogen expansion engine by determining system efficiency as well as market development for heavy-duty hydrogen vehicles

In this paper the economic and technical potential of the energetic use of hydrogen expansion in a fuel cell electric vehicle at a pressure drop from 700 bar in the H
2
storage to 3 bar in the fuel cell stack is investigated. From the economic point of view, the paper focuses on the cost analysis of an H
2
expansion engine with coupled generator as well as the determination and comparison of the total operating costs of a fuel cell vehicle in heavy-duty applications without and with integrated expansion engine. In addition, the new registration numbers of these vehicles are simulated and evaluated based on different model assumptions until 2040. For the technical consideration, detailed physical simulation models are created in Dymola to quantify the efficiency at different operating points, which reduce the efficiency and depend on different loss processes. The results show that energy recovery from onboard hydrogen expansion in hydrogen heavy-duty vehicles is both economically and energetically rewarding.