Hydrogen Safety in Accidental Release Scenarios [abstract]

Abstract

With the intensified energy and environmental concerns, hydrogen is considered to be one of the viable solutions to the increasing demands for clean and secure energy. The transition from fossil fuels to such technologies involves challenges that must be overcome for widespread public use/acceptance. Safety issues need to be fully addressed by developing proper codes and standards that are critical for the design and operation of hydrogen-powered systems. Fire safety of hydrogen applications is generally provided by experience from other traditional fuels whose properties are drastically different from those of hydrogen.

As part of a broader project to establish the first hydrogen fueling station and hydrogen-powered commuter service in the state of Missouri, the transient behavior of hydrogen mixing and the associated flammability limits in air are investigated to support the fire safety and prevention guidelines. Advanced computer simulations are developed and utilized to gain a comprehensive understanding of the unsteady mixing, leakage, and flammability of hydrogen under simple and practical conditions. Different hydrogen accidental release scenarios were studied and compared with that of traditional fuels like methane and ethane. The observed complex temporal and spatial distributions of hydrogen demonstrate the fast formation of flammable zones. These results have implications in the safe and efficient use of hydrogen in various applications (e.g., fuel cells) as well as the ventilation of hydrogen accidental leakage in closed and partially closed environments (e.g., parking garage, storage facilities, road tunnel) and other supplementary infrastructure.