Modeling of cryogenic compressed hydrogen jet flames

Abstract

Hydrogen will likely be stored and transported at high densities to have sufficient hydrogen on-site for efficient distribution. Cryogenic compressed hydrogen (CcH2) is a high-density hydrogen storage method combining cryogenic temperatures and high pressures. Hydrogen releases from such high-density sources will result in high-momentum jets and jet flames if the jets ignite. This study modelled CcH2 jet flames for stagnation pressures of 2∼5 bar and stagnation temperatures of 55∼150 K. The numerical models were validated by experimental data from the literature. The results show that the flame length increases with increasing pressure but decreases with increasing temperature. The CcH2 jet flames are longer than their room-temperature counterparts with the same mass flow rate. Then, the CcH2 jet flame lengths were correlated with the mass flow rate and stagnation temperature. Correlations were also developed for predicting trajectory temperatures and the radial temperature distributions in the CcH2 jet flames. The present study provides a scientific basis for developing cryogenic hydrogen safety codes and standards and quantitative risk assessment models.