Thermal System Management

The Finite Element (FE) simulations performed at the Center for Computational Physics (CCP) of the Zurich University of Applied Sciences in Winterthur (ZHW) aim at investigating new concepts for the thermal management of the OneBat micro-SOFC-system. Due to their large surface-to-volume ratio, the high temperatures required to operate a SOFC are more difficult to control in microsystems than in conventional ones. In the OneBat system, the stack operates at about 550°C, while the housing temperature has to be kept below 35°C. The main tasks in this work package are:

• Designing a static insulation, a concept to efficiently block thermal radiation and a efficient heat exchanger to achieve the specific system temperatures
• Integration of the heat exchanger, the gas reformer and the post combustor into the thermal system design
• Developing concepts to reduce the thermo-mechanical stresses
• Scale-Up of the thermal design to different power outputs
• Theoretical predictions of optimum operating conditions including optimal mass flow rates for the fuel reformer and the definition of the final dimensions of the entire system

For all calculations, our in-house multi-physics FE-code Seses is used (www.ccp.zhwin.ch/seses).

Top: Geometry of a rotational-symmetric thermal-flow FE-model including stack, heat exchanger and static insulation components. Below: Calculated temperature and heat-flux distributions under stationary operation conditions.