Hydrogen in the Natural Gas Network—Relevance for Existing Fire Precautions

Power-to-gas technology can be used to convert excess power from renewable energies to hydrogen by means of water electrolysis. This hydrogen can serve as “chemical energy storage” and be converted back to electricity or fed into the natural gas grid. In the presented study, a leak in a household pipe in a single-family house with a 13 kW heating device was experimentally investigated. An admixture of up to 40% hydrogen was set up to produce a scenario of burning leakage. Due to the outflow and mixing conditions, a lifted, turbulent diffusion flame was formed. This led to an additional examination point and expanded the aim and novelty of the experimental investigation. In addition to the fire safety experimental simulation of a burning leakage, the resulting complex properties of the flame, namely the lift-off height, flame length, shape and thermal radiation, have also been investigated. The obtained results of this show clearly that, as a consequence of the hydrogen addition, the main properties of the flame, such as lifting height, flame temperature, thermal radiation and total heat flux densities along the flame, have been changed. To supplement the measurements with thermocouples, imaging methods based on the Sobel gradient were used to determine the lifting height and the flame length. In order to analyze the determined values, a probability density function was created.