1900

Hydrogen Release from a High-Pressure Gh2 Reservoir in Case of a Small Leak

Abstract

"High-pressure GH2 systems are of interest for storage and distribution of hydrogen. The dynamic blow-down process of a high-pressure GH2 reservoir in case of a small leak is a complex process involving a chain of distinct flow regimes and gas states which needs to be understood for safety investigations.

This paper presents models to predict the hydrogen concentration and velocity field in the vicinity of a postulated small leak. An isentropic expansion model with a real gas equation of state for normal hydrogen is used to calculate the time dependent gas state in the reservoir and at the leak position. The subsequent gas expansion to 0.1 MPa is predicted with a zero-dimensional model. The gas conditions after expansion serve as input to a newly developed integral model for a round free turbulent H2-jet into ambient air. The model chain was evaluated by jet experiments with sonic hydrogen releases from different reservoir pressures and temperatures.

Predictions are made for the blow-down of hydrogen reservoirs with 10, 30 and 100 MPa initial pressure. The evolution of the pressure in the reservoir and of the H2 mass flux at the orifice are presented in dimensionless form, which allows scaling to other system dimensions and initial gas conditions. Computed hydrogen concentrations and masses in the jet are given for the 100 MPa case. A normalized hydrogen concentration field in the free jet is presented which allows for a given leak scenario the prediction of the axial and radial range of burnable H2-air mixtures."


Related subjects: Safety
Countries: Germany
Loading

Article metrics loading...

/content/conference442
2009-09-17
2021-06-24
http://instance.metastore.ingenta.com/content/conference442
Loading
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error