Thermal and electrical performance of an alkaline fuel cell

Fuel cells have interesting prospects to integrate in alternative energy systems. Alkaline fuel cells have the potential to be manufactured at low cost, as they don’t require noble materials for catalysts. To analyse the thermal-physical behaviour of an alkaline fuel cell (AFC), allowing a well designed integration in a new energy system, a heat and performance study is performed on the AFC stack. An outlook is presented of the different electrical and thermal power outputs and how they can be influenced by the main operating parameters. This will enable the integration of all these power outputs in an optimized energy system. To optimize stack performance, taking both electrical and thermal performance into account, an evaluation method, based on primary energy savings, is presented. Finally, a parameter study is performed, which will enable an improved system design or control strategy for an AFC-based CHP-unit. Most of these improvements are found in a reduction of transmission losses and by increasing input air temperature and humidity, resulting in both higher electric and thermal performance.

► This thermal study examines optimal operation mode, based on primary energy savings.
► Heat recovery on the air output could increase thermal performance up to 180%.
► Operating with hot and wet air on the stack inlet improves thermal performance.
► Reducing heat loss to the environment is the most effective improvement.
► For every electrolyte temperature a current is found to be the lower limit.