Session: 04-41 Combustion dynamics - hydrogen flames I

Paper Number: 125999

125999 - Impact of Diluents on Flame Stability With Blends of Natural Gas and Hydrogen 

Two main decarbonization pathways for natural-gas fueled gas turbine engines include the blending of hydrogen into natural gas and post-combustion carbon capture. The addition of hydrogen into natural gas changes several combustion properties, including flame speeds and stretch sensitivity. The use of post-combustion carbon capture systems is typically facilitated by the implementation of exhaust gas recirculation (EGR), where exhaust gases are injected into the inlet of the engine, resulting in a higher concentration of CO2 at the outlet and, hence, increasing the efficiency of a range of carbon capture technologies. In this work, we explore the impact of both these combustion strategies – hydrogen blending and EGR – on the stability of a swirl-stabilized, central-piloted flame. Mixtures of natural gas with hydrogen blended up to 40% by volume are tested at a range of different diluent compositions mimicking different EGR treatments. In all cases, a constant adiabatic flame temperature is maintained to mimic the operation of a gas turbine a given load point. For each fuel composition, diluents are added to vary the reactant oxygen level from baseline air down to 15% O2 by volume. A variable-length, single-nozzle combustor with industry-relevant hardware is used for testing, where the length of the combustor is varied to understand the dynamic stability characteristics of the system at each fuel and EGR composition. Dynamic pressure measurements in the combustor and fuel and air delivery systems are used to determine the dynamic stability of the system, while CH* chemiluminesence imaging is used to determine the flame shape and static stability of the flame. Experimental results are supported with companion chemical modeling, which is used to calculate unstretched laminar flame speed, stretched laminar flame speeds, and extinction strain rates.

Presenting Author: Javier Rodriguez Camacho Pennsylvania State University

Presenting Author Biography: Javier Rodriguez Camacho is a PhD candidate at the Pennsylvania State University.

Authors:

Javier Rodriguez Camacho Pennsylvania State University
Dang Le Solar Turbines Incorporated
James Blust Solar Turbines Incorporated
Jacqueline O'Connor Pennsylvania State University