Hydrogen Fuel Cell System Layout Design

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Barmi, Jasjyot
Reimer, John
Schultz, Nicolas
Tasnim, Fariha
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Motor Coach Industries is seeking to expand their propulsion system offerings to include hydrogen fuels cells built within the J4500e electric coach chassis. The objective of the team is to design a hydrogen fuel cell layout that is compatible with the J4500e electric coach, whilst minimizing space claim and maximizing range of operation. This report outlines the final layout design for the hydrogen fuel cell system, which includes the fuel cell stacks, battery pack, and hydrogen storage tanks as the major components. Other project deliverables such as a Piping and Instrumentation Diagram, costs of major components, and a Failure Modes and Effects Analysis are also presented in this report. Customer needs were identified to guide the team towards the optimal solution. The most important project needs were to maximize coach range and minimize hydrogen leakage while adhering to all applicable vehicle standards. Engineering metrics were established based on these needs and were used as evaluation criteria for the final design. For the overall system, hydrogen fuel cell stacks and the amount of batteries were determined first based on an experimental142.1 kW power draw of the coach at 60 mph, and assuming a coach range of 10 hours. Using this information, commercially available hydrogen storage tanks were selected that maximized coach range and adhered to the coach’s internal volume constraints. Using these major components, several layout concepts were screened and scored, and the optimal concept was further developed into the final design. The final design was developed by designing the intake and exhaust of the fuel cell stacks, as well by determining the hydrogen piping between all appropriate components. The intake and exhaust were designed considering the required pressure drop and space claim impacts. The hydrogen piping was designed to minimize fittings required, and by assuring emergency hydrogen venting measures were considered. The final design has two 70 kW Ballard Power Systems HDV870 fuel cells, seven 9.8 kg hydrogen capacity Hexagon Composites Model M tanks, and 1 XALT XMP76P battery pack. These specifications give a theoretical hydrogen fuel cell coach a range of 7 hours at a constant speed of 60...