Dispersion of cryogenic hydrogen through high-aspect ratio nozzles

• Published in: International journal of hydrogen energy Vol. 46; no. 23; pp. 12311 - 12319
• Main Authors: Chowdhury, Bikram Roy, Hecht, Ethan S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 31.03.2021
• Subjects: Aspect ratio; Cryogenic hydrogen; Experiment; Jet; Plume; Jet; Cryogenic hydrogen; Plume; Aspect ratio; Experiment
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2020.09.072

Liquid hydrogen is increasingly being used as a delivery and storage medium for stations that provide compressed gaseous hydrogen for fuel cell electric vehicles. In efforts to provide scientific justification for separation distances for liquid hydrogen infrastructure in fire codes, the dispersion characteristics of cryogenic hydrogen jets (50–64 K) from high aspect ratio nozzles have been measured at 3 and 5 barabs stagnation pressures. These nozzles are more characteristic of unintended leaks, which would be expected to be cracks, rather than conventional round nozzles. Spontaneous Raman scattering was used to measure the concentration and temperature field along the major and minor axes. Within the field of interrogation, the axis-switching phenomena was not observed, but rather a self-similar Gaussian-profile flow regime similar to room temperature or cryogenic hydrogen releases through round nozzles. The concentration decay rate and half-widths for the planar cryogenic jets were found to be nominally equivalent to that of round nozzle cryogenic hydrogen jets indicating a similar flammable envelope. The results from these experiments will be used to validate models for cryogenic hydrogen dispersion that will be used for simulations of alternative scenarios and quantitative risk assessment. •Cryogenic hydrogen was released through high-aspect ratio rectangular nozzles.•Minimal differences in concentration observed along the major and minor axes.•Centerline concentration decay is similar to round jets when normalized.•Centerline temperature increase is similar to round jets when normalized.•Concentration and temperature half-widths are Gaussian and self-similar.