| Summary: | 碩士 === 元智大學 === 機械工程學系 === 100 === The temperature and flooding phenomenon during operation can strongly influence fuel cell performance. Non-uniform conditions exist in each segment of fuel cell. Previous studies have investigated these conditions on the mm scale using destructive methods or simulation, but none has been able to obtain exact data from within the cell.
This research applies micro-electro-mechanical systems (MEMS) to develop a micro flexible temperature, pressure and flow sensor. It is composed of main two parts: 1. Fabrication of micro flexible sensors on PI film by MEMS; 2. Embedding micro sensors into a PEMFC, and monitoring local temperature/ pressure/ flow rate of PEMFC and cell performance.
Internal temperature data demonstrate that the downstream exceeds upstream and midstream, because the generated heat is carried by gas from the inlet and downstream, where it undergoes a severe reaction. Monitoring the inner pressure for a long period revealed that the accumulation and elimination of water in flow field may be responsible for increased pressure and the recovery. The flow rate that is supplied by the flow controller in the testing system exceeds those measured by the upstream and downstream sensors. This deviation is consistent wit the results of a fuel cell leak test. The flow rate becomes stable after dozens of seconds from the start of operation.
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