Acoustic Emission Health Monitoring System for DOT Pressure Cylinders

Recertifying hydrogen pressure cylinders entails significant cost and time. Detecting flaws in cylinders in a timely manner is crucial for averting catastrophic failures and maintaining safety throughout the cylinder’s lifespan. Acoustic emission (AE) exhibits remarkable sensitivity to crack propagation, enabling early detection of crack formation and is currently an approved method for high-pressure DOT cylinder inspection but requires offline testing including overpressurization as part of a carefully-designed test plan. The proposed HydrAE system will provide automated AE evaluation during each normal refill to 100%, leveraging previous datasets and machine learning incorporating multiple AE data parameters to establish a historical index and health assessment model; data will be uploaded to the cloud with automated notifications sent to asset owner/authorities. The HydrAE system will continuously monitor cylinders for abnormal events, such as impacts, between refills with a battery-powered MEMS accelerometer system. The long-term vision for the HydrAE monitoring system is to seamlessly integrate AE technology into hydrogen refilling stations, with only the sensors and low-power impact monitoring system residing on the cylinder. Ultimately, the HydrAE technology would be directly applicable to all DOT pressure cylinders, including composite pressure vessels such as those for hydrogen fuel cell vehicles.