J. B. Hansen, J. Pålsson, J. U. Nielsen, N. Christiansen: Haldor Topsøe A/S, Lyngby, Denmark
E. Ramschak, M. Schüssler, P. Prenninger: AVL List GmbH, Graz, Austria.
Fuel Cell Seminar 2005,14.11.2005 - 15.11.2005, Palm Springs
Since early 2003 Haldor Topsøe A/S and AVL List GmbH are performing a joint development project on SOFC APU technology. The project covers the feasibility study of a SOFC APU truck system, the development and testing of stacks with selected balance of plant (BoP) components and the dynamically operation of a subsystem in Hardware in the Loop (HIL) test bench environment. This paper will focus on the results of recent stack and subsystem tests.
Auxiliary Power Units (APU) for onboard electrical power generation is considered to become an important market, especially in the truck sector, in the coming years. In comparison with state-of-the-art APUs, based on internal combustion diesel engines, fuel cell systems have significant advantages in terms of efficiency, exhaust & noise emissions and also maintenance intervals.
The test bench environment was specifically developed for fuel cell systems by AVL, based on established workflows in the automotive industry. The HIL test bench system combines SOFC and selected BoP hardware components with virtual, i.e. software based components. Components interactions occur therefore like in an entire fuel cell system, even when only selected hardware components are physically installed. The benefits of HIL testing are the reduction of development cycle times with improved outcomes and at the same time lowering development costs.
Recent test results achieved with a 50 cell SOFC stack from Haldor Topsøe, showed very promising performance characteristics. Operated under stable conditions on a simulated pre-reformed gas mixture, the achieved performance was a power output of around 1000We and a fuel utilisation factor of 88 %. The average cell voltage was just below 750 mV. Further, the stack was operated in thermally self sustained mode meaning no additional heating source was used.
Currently the stack is applied for tests of a subsystem consisting besides the stack of an air preheater, a prereformer, a catalytic afterburner and an automotive 42V DC/DC converter connected through real time linked software models to a complete SOFC APU system. Characterisation and successfully testing of the individual system components were made in advance with promising results.