Validering av KFX för vätgasjetflammor som träffar ytor

Sammanfattning: Regarding climate change and the future need för renewable energy, hydrogen is considered to be an important component in energy storage systems. However, the use of hydrogen is fraught with risk due to its chemical properties. This thesis deals with the problem of modelling heat transfer from hydrogen jet flames hitting surfaces. This paper aims to assess how well KFX reproduces results of hydrogen jet flames hitting surfaces. The simulations in KFX are based on data from experiments conducted by Merander et al. (n.d). KFX is a CFD-code developed by DNV to analyse the safety of situations with fire risks, such as jet fires, mostly offshore. The consequences that were investigated are the temperature of surfaces and radiation levels at specific measurement points. A total of six simulations were performed, of which the results were compared with each respective experiment. For each case, the angle of the jet flame was varied, horizontally and at an angle of 45˚ (downwards). In addition, the experiments were based on three different geometries with a variation in the level of confinement: one plate, two plates and five plates. The results showed that KFX reproduces results well for the least confined cases (one plate) of the cases in terms of surface temperature. However, in terms of radiation, KFX reproduced good results for two other cases. Due to the irregular results, KFX cannot be considered validated for the heat transfer from hydrogen flames based on the results from this study. Furthermore, a sensitive analysis was performed which showed that the results were not sensitive based on the selected parameters. The parameter that resulted in the greatest variation was the conductivity of the insulation.