ADVENT INNOVATIONS LTD CO — Department of Energy STTR Phase I: 10d

Description

To stimulate the U.S. economy and global competitiveness there is a push to reduce dependence on foreign oil imports and establish a domestic power and fuel industry using efficient, reliable clean energy technologies. A promising development is the introduction of fuel cell electric vehicles using hydrogen, which can achieve significantly higher efficiencies than combustion engines resulting in overall less energy use. The hydrogen is stored in high-pressure composite tanks, commonly referred to as composite overwrapped pressure vessels. Damage to the composite overwraps can result from pressure loads over time, environmental induced degradation in operation, or accidental mechanical impacts. To ensure the structural health of the composite overwraps and prevent unexpected failure, online monitoring of the tank would be beneficial. There is particular interest in developing structural health monitoring sensors that can provide a real-time indication of potential damage or degradation of the composite overwraps. In this project, an intelligent sensor system will be developed and specifically optimized for composite overwrapped pressure vessels. The sensor system will be integrated with composite tanks to continuously monitor the structural health, thus providing a critical technology to enable the widespread use of fuel cell electric vehicles. During Phase I, structural health monitoring sensors will be developed to be conformable to the composite tanks and will utilize thin, flexible material such as polyvinylidene fluoride (PVDF) films to measure dynamic strain (impacts, vibration, transient stress waves and deformation). The films will be porous so as to allow resin to flow when embedding during the filament winding and composite curing process and ensure structural integrity. Feasibility studies and tests will be conducted to optimize the sensors for embedding and characterize their performance. The system will use both passive and active sensing modes to detect damage and degradation on-demand to ensure robust and comprehensive online monitoring of composite overwrapped pressure vessels. In addition to transportation applications, hydrogen tanks and fuel cell technologies can also address U.S. energy challenges in other sectors, such as commercial, residential, and industrial, which would all benefit from the proposed sensor system. The structural health monitoring sensors could also be utilized for composite tanks used in applications such as onboard compressed natural gas vehicles, rocket motors, self-contained breathing apparatuses used by first responders or recreational divers, containers for chemical or hazardous material storage, and many others. The technology can be applied to any composite structure, and would be especially useful for structures with curvature, such as windmill blades, aircraft wings and fuselage, etc. The application of the proposed system could keep these structures in-service for longer periods of time, often well beyond their designed service life. As these structures age, the proposed SHM system could meet the needs for regular inspection to enhance the reliability of the structures and ensure public safety in a cost effective manner.