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Cost-efficient Cathode Air Path for PEM Fuel Cell systems
ISSN: 0148-7191, e-ISSN: 2688-3627
To be published on April 14, 2020 by SAE International in United States
Fuel cell technology will play a major role in reducing transportation-related emissions, especially in sectors where battery-electric powertrains will face severe challenges, e.g. in heavy-duty, long-haul applications, as it decouples system weight from electric driving range. To achieve the required fuel cell stack lifetime, the supply of clean air is essential, especially with low Platinum catalyst loads required to achieve the DOE cost targets. As gases as NOx, SO2 and NH3 can poison the catalyst, leading to - often irreversible - loss in power supply from the stack, these must be captured by use of tailor-made activated carbons. Research on real-life concentrations of these contaminants under different driving patterns and road profiles leads to the knowledge-based design of Cathode Air Filter elements. Cost-efficient Balance-of-Plant components are required to integrate the filter into the full Cathode Air path. To prevent flooding of components like air filter, humidifier, or the stack itself, water separators are integrated at different position inside the system. Air ducts are designed in a way to operate under the different temperature and pressure levels, with plastic technology enabling the integration of sensors and flaps required to manage the air flow. Broadband silencers are applied to reduce or even cancel noises inside the system, e.g. generated by the compressor. Essential components like humidifier and air-cooler integrated into charge-air ducts can easily be incorporated into the system. In the Cathode Air exhaust path, additional water separators are applied to protect turbine blades and to prevent emission of splash water from the tailpipe. Plastic technology enables the functional integration of water reservoirs, collecting separated water. The consistent transfer of competences and components from air supply systems for combustion engines to cathode air supply enables cost- and packaging-optimized system designs, which can be adapted to individual applications in a straightforward manner.