Study on hydrogen flame acceleration and ddt properties at elevated temperatures and pressures

Abstract

Hydrogen security is an important problem of the severe accident analysis in NPP, and the security of hydrogen detonation is more important. The hydrogen risk mainly focused on the risk of flame acceleration (FA) and deflagration-to-detonation transition (DDT) processes. As the processes involved in combustion and detonation are quite complex, it is difficult to present a detailed description of the whole process. Based on the physical phenomena of flame acceleration, the present paper brief introduces two criteria for hydrogen security analysis of detonation, which are FA σ criteria and DDT λ criteria. From the present paper, effect of initial pressures and temperatures on FA and DDT has been discussed. It describes the limit condition of flame acceleration by the quench/re-ignition of flammable gas mixture theory. So as to promote the flame acceleration criteria at elevated temperatures and pressures from the former one. Last the application for hydrogen safety analysis in GASFLOW code has been recommended.