High Temperature Fuel Cell Container Design Guide Lines as Applied to a Solid Oxide Fuel Cell to Power a MK 48 Torpedo

A study was performed on the design of powering a MK 48 torpedo with a solid oxide fuel cell stack. The study involved the design and analysis of a container, compression system, vertical and horizontal supports, and vessel insulation. Detailed analysis was performed on the container using different materials, Inconel alloy 740 and 316 SS. The container was designed for thermal and static pressure loading conditions. Additional analysis includes a deflagration pressure load. Over stress conditions are a major design concern, due to the high operating temperature of the solid oxide fuel cell. Typically large thermal gradients occur near the piping penetrations to the container resulting in a high stress states. The acceptable stress levels are reduced due to the elevated temperatures and also are dependent on the length of operation. Details on applying material temperature dependent strength data and the ASME Boiler and Pressure Vessel Code requirements are provided. A novel approach on relocating the high stress zones due to large temperature gradients is applied to the container design. The use of Inconel alloy 740 and 316 SS were examined for container components and the effects on weight are addressed. Knowing the weight and component geometry an engineer can make a overall cost estimate with manufacturing process information. To minimize cost the container was designed using standard pipe geometry.