Modeling of underground hydrogen pipelines

Abstract

Hydrogen is a critical component in the production of cleaner fuels. Underground pipelines provide a safe, reliable supply of hydrogen to refineries and the petroleum industry. Proper assessment of the risks associated with underground hydrogen pipelines requires an accurate model of the jet fire consequence. This article will describe experimental and modeling work undertaken in order to define the appropriate methodology for utilizing DNV's PHAST software tool to represent the hydrogen jet fire from the rupture of underground hydrogen pipelines. Two experiments were conducted to measure the flow and radiation from an intentionally ignited rupture of a 6 in. diameter, 60 barg hydrogen pipeline buried 1 m underground. Adjustments to PHAST modeling parameters were required in order to obtain agreement between the measured and predicted radiation and flame length values. The modeling assumptions and parameter adjustments include:Velocity modification to account for interaction of the flow out of the two ends of the ruptured pipe and to model the subsequent discharge from the crater. Specification of the fraction of heat radiated. Specification of the angle of the release.

Numerical computation of a large‐scale jet fire of high‐pressure hydrogen in process plant

“…It is important to validate simulated results with experiments, but experimental results are usually difficult to obtain; thus, we chose the newest Phast version because the program has been extensively validated with real flare and jet fire experiments, such as Chamberlain, Johnson, Bennett, and Thornton field tests . The software was also compared with a H 2 jet fire experiment with modification .…”

Modeling of Hydrogen Dispersion, Jet Fires and Explosions Caused by Hydrogen Pipeline Leakage

“…The trench needs to be considered because when the high-pressure hydrogen pipe line leaks, the momentum of leaking hydrogen impinges on nearby obstacles, forming trench. It is worth noting that, in assessing the risk of buried pipeline leakages, some stud ies disregarded the impact of soil on the jet's momentum, while others incorporated trench experiment considering the substantial momentum of hydrogen leakage jets [18] For buried pipelines, a trench with the dimensions of 2.5 m width, 5 m length, and 2 m depth was assumed. Five leak hole sizes were designed, representing 0.01%, 0.1%, 1% 10%, and 100% leakage areas relative to the pipeline's cross-sectional area, translating to leak hole sizes of 3.3 mm, 10.3 mm, 32.5 mm, 102.8 mm, and 325 mm.…”

“…For jet fires, Froeling et al investigated hydrogen jet fire events for hydrogen transported in natural gas transmission pipelines and proposed comprehensive mathematical transformations of the geometric view factor [15]. Other works used the CFD method or PHAST to study fire length, radiation, and fire damage [16][17][18]. Lowesmith conducted large-scale experiments, finding that, compared to natural gas pipelines, pipelines conveying a natural gas/hydrogen mixture presented a slightly lower hazard in terms of thermal dose [19,20].…”