The Development of Light-Weight Hydrogen Bottle and 5kW Proton Exchange Membrane Fuel Cells Stack
Date Issued
2016
Date
2016
Author(s)
Cheng, Wei-Yang
Abstract
This study developed (1) A gas and water control system to operate 5kW Ballard 1310 fuel cell stack; (2) The application for light-weight hydrogen bottle combined carbon fiber. For stack system, fuel, air supply and cooling systems with microcontroller units (MCU) were used in a compact design to fit two 5 kW proton exchange membrane fuel cell (PEMFC) stacks. At the initial stage, the testing facility of the system has a large volume (2.0m×2.0m×1.5m) with a longer pipeline and excessive control sensors for safe testing. After recognizing the performance and stability of stack, the system is reduced to fit in a limited space (0.4m×0.5m×0.8m). Furthermore, the stack performance and safety is studied under different hydrogen recycling modes. Then, two similar 5 kW stacks are directly coupled with diodes to obtain a higher power output and safe operation. The result shows that the efficiency of the 5 kW stack is 43.62% with a purge period of 2 min with hydrogen recycling and that the hydrogen utilization coefficient µf is 66.55%. The maximum power output of the twin-coupled module is about 9.52 kW. Next, this study focused on aluminum alloy 7075-T6 as a hydrogen bottle material with high strength. Gas tungsten arc welding (GTAW) was used as fill weld. However, the welded junction is a vulnerable area in hydrogen bottles. Therefore, this study used different types of carbon fiber winding to improve tensile strength. After SGS testing, the maximum water pressure is 150 kgf cm-2 currently. In the future, two studies will be composed together for a more complete power generation systems.
Subjects
compact design
proton exchange membrane fuel cell
hydrogen bottle
aluminum alloy 7075-T6
gas tungsten arc welding
carbon fiber
Type
thesis