Session: 04-05 High Hydrogen I

Paper Number: 129213

129213 - Nonpremixed Approaches for Fuel Flexible, Low NOx Combustors in High-Efficiency Gas Turbines 

Lean, premixed combustor designs have almost completely replaced non-premixed combustors for industrial gas turbine applications where NOx emissions are regulated.  Nonetheless, these designs have also introduced turndown constraints, as achieving low CO emissions at part load conflicts with design choices to minimize NOx at high power.  They also have made combustion instabilities far more problematic, and introduced flashback risk.  These challenges are becoming increasingly problematic in a decarbonizing energy sector.  First, combustors must also be able to accommodate hydrogen, whose levels can vary from 0-100%, blended with natural gas.  While hydrogen in and of itself is not problematic, it is quite challenging to develop premixed systems that can operate with both 100% H2 and 100% natural gas.  Second, operational flexibility for gas turbines will become increasingly important, as their role evolves from a primary provider of energy to the grid, to one of providing capacity and resilience, and they must compete for these services with a host of new technologies, including energy storage and fuel cells.  In this environment, having systems that can operate acceptably and with low NOx and CO over an extended power range, say 5% to 100% will become increasingly important. 

This paper explores the potential of staged designs, with rich primary zones, essentially next generation RQL designs, to address these challenges of variable hydrogen, high turndown, and acceptable operability.   We explore how these approaches can break the NOx - CO tradeoff, radically simplify fuel staging designs, reduce combustion instability risk, and handle broad variations in fuel composition including 0-100% hydrogen.  We also show how the key design challenge evolves to NOx management in the quench and lean zone.  This paper will include chemical kinetic reactor network modeling data to support and quantify the proposed design architecture and its potential advantages.  Overall, the purpose of this paper is to propose to the combustion community a re-exploration of modified RQL designs for the next generation of high turndown, high fuel flexibility, low NOx combustion designs.

Presenting Author: Benjamin Emerson Georgia Tech

Presenting Author Biography: Dr. Emerson is a Principal Research Engineer in the Ben T. Zinn Combustion Lab at Georgia Tech. Dr. Emerson’s work at Georgia Tech includes fundamental research and development of clean energy for aviation and power generation, with a large focus on hydrogen and ammonia combustion for ground power, alternative sustainable aviation fuels, combustion dynamics, operability, and emissions. This includes experimental testing of engine-scale hardware at real operating conditions.

Authors:

Benjamin Emerson Georgia Tech
Shivam J. Patel Georgia Institute of Technology
Srujan Gubbi Georgia Institute of Technology
Randal G. McKinney Georgia Institute of Technology
David Wu Georgia Institute of Technology
David R. Noble EPRI
Tim C. Lieuwen Georgia Institute of Technology