Session: 03-06 Innovations in Hydrogen and Ammonia-Based Propulsion Systems

Paper Number: 151483

Experimental Investigation of Large-Scale Hydrogen Diffusion Jet Flames 

Due to global warming, the change from fossil fuels to renewable energy carriers is mandatory. In industrial energy applications, such as gas turbines or aircraft engines where energy carriers must have high energy densities, hydrogen is a promising alternative to natural gas or kerosene. Since hydrogen has very different combustion properties than hydrocarbons, safety aspects such as flammability, flame velocity and heat radiation must be taken into account. Because hydrogen is usually stored and transported under pressure, one scenario to be considered is a sudden release of hydrogen from a leakage, with subsequent ignition. In this scenario, the emitted heat radiation from the resulting jet flame to the surroundings has to be determined to define adequate safety measures.

For hydrocarbon flames, different jet flame models are available to assess the hazards resulting from an ignited jet release. Since hydrogen flames significantly differ from hydrocarbon flames in their combustion behavior, it has to be checked if these models are also applicable for hydrogen. To evaluate the accuracy of these models for hydrogen jet flames, real scale tests were carried out at the BAM Test Site Technical Safety (BAM-TTS). Herein, the flame geometry and the heat radiation are recorded for varying release parameters such outlet angles (0°-90°), release pressure (currently up to max. 250 bar) and mass flows (up to max. 0.2 kg/s). A main challenge is the characterization of the flame geometry in an open environment and its impact on the thermal radiation. Parameters such as the Surface Emissive Power of the jet flame and the radiant heat fraction are discussed and determined. While existing heat radiation data from the literature are mostly based on unsteady outflow conditions, the experiments presented here are focused on ensuring a constant mass flow over the release duration, in order to obtain a (quasi) stationary jet flame and allow for a better comparability with the steady state jet flame models. In addition to hydrogen experiments, also hydrocarbon jet flames (methane) were investigated, which can be directly compared to existing hydrocarbon jet flame models.

Presenting Author: Christopher Bernardy Bundesanstalt fuer Materialforschung und -pruefung

Presenting Author Biography: Since 2023/01 – PhD Student at the Bundesanstalt für Materialforschung und -prüfung (BAM) (Federal Institute for Materials Research and Testing), Division: Safety of Energy Carriers
Project: Field of Hydrogen Safety, PhD Topic: Real-scale investigation of hydrogen jet flames
2021/05 -2022/12 – Research Assistant at the Bundesanstalt für Materialforschung und -prüfung (BAM) (Federal Institute for Materials Research and Testing), Division: Safety of Energy Carriers

Academia Background:
Since 2023 – Ph.D. Student at Chair of Nonlinear Thermo-Fluid Mechanics, Institute of Fluid Mechanics and Technical Acoustics at the Technical University of Berlin
2018-2021 – M.Sc. Engineering Science (Focus on Fluid Mechanics and Technical Acoustics) at the Technical University of Berlin
2015-2018 – B.Sc. Engineering Science (Focus on Thermodynamics) at the Technical University of Berlin

Authors:

Christopher Bernardy Bundesanstalt fuer Materialforschung und -pruefung
Abdel Karim Habib Bundesanstalt fuer Materialforschung und -pruefung
Martin Kluge Bundesanstalt fuer Materialforschung und -pruefung
Bernd Schalau Bundesanstalt fuer Materialforschung und -pruefung
Hanjo Kant Bundesanstalt fuer Materialforschung und -pruefung
Marcel Schulze Bundesanstalt fuer Materialforschung und -pruefung
Alessandro Orchini Chair of Nonlinear Thermo-Fluid Mechanics, Technical University of Berlin