Session: 04-13 Combustor Design I

Paper Number: 152799

Effect of Exhaust Gas Recirculation on Combustion Efficiency in a Swirl-Stabilized Flame With Blends of Natural Gas and Hydrogen 

Reducing the climate impact of power-generation and industrial gas turbines can be achieved through blending of low-carbon fuels as well as carbon capture. In gas turbines, carbon capture is facilitated by the use of exhaust gas recirculation (EGR), where exhaust gases are mixed with the inlet gases to increase the concentration of carbon dioxide in the exhaust to increase the efficiency of carbon capture technologies downstream of the engine. However, increasing the diluent fraction of the combustion gases can decrease flame static stability and lead to significant flame elongation, potentially affecting combustion efficiency and emissions. In this study, we measure the carbon monoxide and unburned hydrocarbons in a single-nozzle model gas turbine combustor at a range of EGR levels and compositions for blends of natural gas and hydrogen to understand the impact of EGR on combustion efficiency. Different blends of diluents that mimic the effects of EGR are tested with oxygen mole fractions from 21% (no diluent injection) down to 15%. Blends of natural gas and hydrogen are tested with up to 40% hydrogen in natural gas by volume. Flame imaging is used to better understand the connection between EGR, fuel composition, flame stabilization, and combustion efficiency. As EGR level increases, the flame becomes longer and more diffuse. Blending hydrogen in natural gas aids flame stabilization and combustion efficiency. The experimental results are complemented by detailed chemical modeling to identify the changes in chemical pathways that are driven by such high levels of diluents and various fuel compositions. We conclude with a discussion of the impact of low combustion efficiency on both cycle efficiency as well as the performance of downstream carbon capture systems.

Presenting Author: Javier Rodriguez Camacho Pennsylvania State University

Presenting Author Biography: Javier Rodriguez Camacho is a PhD candidate in the Department of Mechanical Engineering at the Pennsylvania State University and a graduate researcher in the Reacting Flow Dynamics Laboratory.

Authors:

Javier Rodriguez Camacho Pennsylvania State University
Christopher Birkbeck Pennsylvania State University
Min Kyeong Yoon University of South Carolina
Ana Victoria Kok University of South Carolina
Sang Hee Won University of South Carolina
Jacqueline O'Connor Pennsylvania State University