Ignition and heat radiation of cryogenic hydrogen jets

Friedrich, K. Andreas; Breitung, W.; Stern, G.; Veser, Anke; Кузнецов, М.; Fast, G.; Oechsler, Bruno Francisco; Kotchourko, N.; Jordan, Thomas; Travis, J.R.; Xiao, Jianlin; Schwall, M.; Rottenecker, M.

doi:10.1016/j.ijhydene.2012.07.070

Cited by 51 publications

(17 citation statements)

References 4 publications

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“…Data from two of the ignited releases were analysed in this way, assuming a reflection coefficient for the concrete of 0.55 [3], giving an estimate of the radiative fraction as 0.054. This estimate compares reasonably well with previously reported values for gaseous and LH2 hydrogen releases [4,5].…”

Section: Methods 2 E Radiative Fractionsupporting

confidence: 91%

Ignited releases of liquid hydrogen: Safety considerations of thermal and overpressure effects

Hall

Hooker

Willoughby

2014

International Journal of Hydrogen Energy

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a b s t r a c tIf the 'Hydrogen Economy' is to progress, more hydrogen fuelling stations are required. In the short term and in the absence of a hydrogen distribution network, these fuelling stations will have to be supplied by liquid hydrogen (LH2) road tankers. Such a development will increase the number of tanker offloading operations significantly and these may need to be performed in close proximity to the general public.The aim of this work was to determine the hazards and severity of a realistic ignited spill of LH2 focussing on; flammability limits of an LH2 vapour cloud, flame speeds through an LH2 vapour cloud and subsequent radiative heat levels after ignition. The experimental findings presented are split into three phenomena; jet-fires in high and low wind conditions, 'burn-back' of ignited clouds and secondary explosions7 post 'burn-back'. An attempt was made to estimate the magnitude of an explosion that occurred during one of the releases. The resulting data were used to propose safety distances for LH2 offloading facilities which will help to update and develop guidance for codes and standards.Crown

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Section: Methods 2 E Radiative Fractionsupporting

confidence: 91%

Ignited releases of liquid hydrogen: Safety considerations of thermal and overpressure effects

Hall

Hooker

Willoughby

2014

International Journal of Hydrogen Energy

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“…4. It is unclear why this correlation from Friedrich et al [9] is so conservative, over-predicting the maximum ignition distance for the conditions from the current experimental data as well as other reported data [13,21,23].…”

Section: Maximum Ignition Distancecontrasting

confidence: 54%

“…shown by the yellow line in the plot [34]. A correlation based on power-law is proposed to predict the radiative fraction as a function of global flame residence time, given as (9) Now focusing on the radiant fraction data from the current study, the highest radiant fractions are seen for the lowest temperature releases. The speed of sound decreases as the temperature decreases.…”

Section: Maximum Ignition Distancementioning

confidence: 93%

“…Some of the data on maximum ignition distances for under-expanded hydrogen jets reported in the literature [13,21,23], are compared with the current data set in the figure, with operating conditions and maximum ignition heights shown in Table 2. Friedrich et al [9] reported that the maximum ignition distance leading to a jet flame for cryogenic hydrogen jets can be expressed by the relationship . This correlation is shown as the blue dashed line in Fig.…”

Section: Maximum Ignition Distancementioning

confidence: 99%

“…In a controlled laboratory conditions, Friedrich et al [9] performed release and combustion experiments for cryogenic hydrogen jets with release temperatures between 34 -65 K and pressures from 0.7 -3.5 MPa in the ICESAFE (Integrated Cable Energy Safety Analysis Facility and Equipment) facility located at the Karlsruhe Institute of Technology. Hydrogen concentration decay rate measurements preserved the linear dependence when plotted against a density-scaled release diameter.…”

Section: Introductionmentioning

confidence: 99%

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Ignition and flame characteristics of cryogenic hydrogen releases

Panda

Hecht

2017

International Journal of Hydrogen Energy

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In this work, under-expanded cryogenic hydrogen jets were investigated experimentally for their ignition and flame characteristics. The test facility described herein, was designed and constructed to release hydrogen at a constant temperature and pressure, to study the dispersion and thermo-physical properties of cryogenic hydrogen releases and flames. In this study, a nonintrusive laser spark focused on the jet axis was used to measure the maximum ignition distance. The radiative power emitted by the corresponding jet flames was also measured for a range of release scenarios from 37 K to 295 K, 2-6 bar abs through nozzles with diameters from 0.75-1.25 mm. The maximum ignition distance scales linearly with the effective jet diameter (which scales as the square root of the stagnant fluid density). A 1-dimensional (stream-wise) cryogenic hydrogen release model developed previously at Sandia National Laboratories (although this model is not yet validated for cryogenic hydrogen) was exercised to predict that the mean mole fraction at the maximum ignition distance is approximately 0.14, and is not dependent on the release conditions. The flame length and width were extracted from visible and infra-red flame images for several test cases. The flame length and width both scale as the square root of jet exit Reynolds number, as reported in the literature for flames from atmospheric temperature

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