Session: 04-25: Novel Combustors I

Paper Number: 101364

101364 - Development of a Hydrogen Micro Gas Turbine Combustor: Atmospheric Pressure Testing 

On the way to a carbon-neutral world, the utilization of fossil energy sources must phase out as soon as possible to limit the impact of climate change. This implies the shift from fossil to clean fuels for combustion-driven processes and machines like gas turbines. Next to biofuels, which are limited due to the available amount of biomass, green hydrogen is a promising alternative to substitute natural gas and other fossil fuels. However, the combustion of hydrogen in premixed gas turbine burners is challenging because reactivity, flame temperature, flame speed and gravimetric energy density are much higher compared to natural gas.

In the H2mGT project, funded by the German Federal Ministry of Economic Affairs and Climate Action, a micro gas turbine (mGT) burner with 100% hydrogen firing is developed and validated in the machine. The project is a collaboration between TU Berlin and the manufacturer Euro-K GmbH. The mGT is considered to be the perfect platform for the implementation of hydrogen combustion on the machine level because the thermal power, temperatures and foremost the operating pressure are much closer to laboratory conditions than at large gas turbines. The project consists of three phases: 1. Atmospheric pressure tests with a fused silica combustion chamber; 2. Atmospheric pressure tests with counterflow-cooled steel combustion chamber and secondary air injection; 3. Validation of the burner in the micro gas turbine at elevated pressure levels. This paper will present the results of Phase 1.

The hydrogen burner is based on an earlier swirl-stabilized burner of TU Berlin and was scaled to match the requirements of the mGT with its 130 kW thermal power. The burner design features multiple geometrical parameters to enable the optimization of the flame towards low NO_x emissions. Therefore, a variable swirl intensity, additional axial momentum of air in the mixing tube, a movable center-body and different fuel injection locations are implemented. Phase 1 investigates the parameter space in terms of flame stability, operational range and parameter impact. Temperature, pressure, microphone and emission measurements as well as OH* imaging are carried out. It is found that the flame can be operated over a large range of equivalence ratios and preheating temperatures up to 500°C for many parameter settings. However, at some geometries flashback into the mixing tube is triggered. As expected, the NO_x emissions are mainly influenced by the equivalence ratio, the fuel distribution, and the swirl intensity. Single digit emissions are reached up to an equivalence ratio of 0.4 at atmospheric pressure conditions. The results of Phase 1 will be used in Phase 2, in which the burner geometry will be optimized regarding emissions and pressure loss in a machine-like setup.

Presenting Author: Tom Tanneberger Technische Universität Berlin

Presenting Author Biography: Researcher at the Chair of Fluid Mechanics at Berlin Institute of Technology.
Worked in combustion research for 9 years.
Wrote dissertation about hydrogen/oxygen combustion technology.

Authors:

Tom Tanneberger Technische Universität Berlin
Johannes Mundstock Euro-K GmbH
Christoph Rex Euro-K GmbH
Sebastian Rösch Euro-K GmbH
Christian Oliver Paschereit Technische Universität Berlin