Effect of Flow Speed on Ignition Characteristics of Hydrogen/air Mixtures

A fuel cell vehicle has a purging system for exhausting contaminated hydrogen gas. Notwithstanding the allowable hydrogen emissions levels in the purging system are regulated by the GTR, a further research on the safety requirement of emissions concentrations is therefore needed for the vehicle design into a more rational system. In the present study, the effects of flow speed, concentration, humidity on ignition characteristics of hydrogen/air mixtures were experimentally investigated. The results demonstrate that the value of Lower Flammable Limit increased with an increase in the velocity of hydrogen/air mixtures and slightly increased with a decrease in oxygen concentration.