Fuel Cell: System Integration Based on In-Depth Cell Know-How

Authors

Dipl.-Ing. J. Rechberger, W. Resende BSc, Dipl.-Ing. H. Schreier, Dipl.-Wirt.-Ing. F. Berg, AVL List GmbH, Graz

Year

2020

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 813

Summary

The momentum to implement fuel cell solutions in passenger car-, commercial vehicles-, marine- and rail applications is drastically building-up. The key advantages of fuel cell technology are: rapid refill, zero emission (if renewable hydrogen is used) and higher power/energy densities compared to batteries. The requirements in the above-mentioned applications are very different and require specific solutions. In passenger car the requirements are driven by power density and investment cost, contrary in commercial vehicles where durability and TCO (Total cost of ownership) are of upmost importance.
To meet these different challenges, AVL follows a systematic systems engineering approach.
In this approach the vehicle requirements (mostly defined by the use case) are broken down to the powertrain level. On this level already the first optimization loop towards performance and cost is performed via different powertrain architectures and hybridization scenarios.
In a further step the requirements of the powertrain are broken down to all the powertrain elements (fuel cell system, e-drive, battery, transmission, …). This level is the starting point for the fuel cell system development. As the fuel cell system consists of various subsystems and components, the requirements need to be further broken down. This is typically done by fuel cell system simulation and trade-off analyses towards cost, power-density, performance and durability. To meet the different requirements on component & subsystem level, in most cases specific development is needed. Looking into the key component PEM stack, then the requirements for a passenger car application for power density are typically in the range of 4 kW/l and for durability 5.000 h. Contrary in a rail application, where the requirements are dominated by durability up to 30.000 h and a much lower power density in the range of 2 kW/l. These completely different set of requirements forces a specific technology setup and stack concept regarding the design, the selected stack components (e.g. CCM, GLD, MEA, ...) and the materials (e.g. graphite of metallic bipolar plate). In the scope of the presentation the approach of AVL towards requirement engineering from vehicle level to stack/cell level will be
explained based on specific examples and technical solutions to meet the requirements will be shown.