STUDY OF PROTON EXCHANGE MEMBRANE FUEL CELLS (PZT-PEMFCS) WITH NOZZLE AND DIFFUSER

摘要

Previous theoretical studies have shown that piezoelectric proton exchange membrane fuel cells (PZT-PEMFCs) might solve water flooding problems and increase cell performance. The innovative design of PZT-PEMFCs results in more oxygen being compressed into the catalyst layer. This enhances the electrochemical reaction and the current density, especially at a high PZT vibration frequency (64 Hz). In this investigation, a single, valveless PZT-PEMFC experimental fuel cell is built. The results are then compared with those of previous theoretical studies. This study includes an analysis of PZT vibration frequencies, and cell operation temperatures. A Nafion 212 membrane with a reaction area of 2 cm × 2 cm is used to measure the voltage and average current density under different temperatures and vibration frequencies. When the PZT device moves upward and increases the chamber volume, a diffuser directs most of the air to the outlet. In the valveless PZT-PEMFC, both a nozzle and diffuser are used. This innovative design may direct air flow into the cathode channel through the diffuser and prevent air backflow. The nozzle/diffuser design in this study can direct a single directional air flow without valves. The experimental results indicate that the direction in which the cell is mounted have a negligible effect on cell performance due to air flow through the nozzle. The diffuser is not influenced by gravity. The optimal operating temperature for the PZT-PEMFC of this study is 50°C, as higher temperatures dry out the membrane electrode assembly (MEA). The optimal vibration frequency of the PZT-PEMFC is 180Hz, as higher frequencies cause more air intake and solve the problem of water flooding in the cathode channel. This study also concludes that the innovative design of PZT-PEMFCs may equal the performance of an open cathode stack configuration and can be applied in a fuel cell stack without an external air supply device.