Stress in SOFC Fuel Cells caused by heat up and cool down

What is it about?

Fuel Cells are tools used to create electricity from hydrogen or other fuels, similar to Diesel generators, but without the noise and vibrations. They also are more efficient than fuel burning generators, and they mostly use hydrogen as a fuel. Both of these facts are important in a power economy which tries to avoid the use of fossil fuels. One form of fuel cells are the so called Solid Oxide Fuel Cells or SOFCs. Compared to other fuel cell types they have advantages like fuel flexibility, no need for precious metal catalysts and a particularly high efficiency, meaning more electrical energy can be produced from the same amount of fuel. However, SOFCs also have a disadvantage compared to other fuel cell types, which is the high operating temperature. SOFCs only produce electricity if they are hot enough, typically at temperatures from 700 to 800 degrees Celsius. Ceramic materials and special metals have to be used in the design of SOFCs making them fragile. SOFCs easily break when not handled with care, especially when heated up and cooled down. Changes of temperature causes thermal stress inside the different parts of these fuel cells. This research article tells a story about the stress inside SOFCs heating and cooling them in a way typical for their operation. The stress in the different fuel cell parts is found out by simulations on a computer with the help of special software called ABAQUS, a so called finite element analysis software. To find out how reliable the simulation results about stress and strain are, we have done heat up and cool down experiments in a lab, and compared the thermal expansion in this experiment with the thermal expansion calculated by the computer simulation.

Featured Image