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Simulation of nitrogen emissions in a premixed hydrogen flame stabilized on a low swirl burner.
| Content Provider | CiteSeerX |
|---|---|
| Author | Bell, J. B. Day, M. S. Lijewski, M. J. |
| Abstract | There is considerable interest in developing fuel-flexible, low emissions turbines for power generation. One approach is based on burning a variety of lean premixed fuels with relatively low flame temperatures. Such flames can be stabilized in a low swirl burner configuration, for example, using a variety of fuels such as pure hydrogen and hydrogen-seeded hydrocarbon mixtures. However, many hydrogen-rich fuels are thermodiffusively unstable and burn in cellular flame structures, which can have a significant impact on the local nitrogen chemistry. These cellular burning patterns are characterized by a local enhancement of fuel concentration and a corresponding increase in local flame temperature just downstream. In turn, these regions become sites for enhanced thermal NOx production. The structure of these cells, and their impact on the net emissions of a flame is influenced by the global flame stabilization mechanisms and by local turbulence properties. Here we investigate the role of thermodiffusive instabilities on NOx emissions in the context of a laboratory-scale low swirl burner fueled with a lean hydrogen-air mixture at atmospheric pressure. The simulations show how the cellular burning structures characteristic of lean premixed hydrogen combustion lead to local and global enhancements in the NOx emissions. We quantify the chemical pathways that lead to the formation of NO and N2O, and how they are enhanced within local regions of intense burning. |
| File Format | |
| Access Restriction | Open |
| Subject Keyword | Nitrogen Emission Low Swirl Burner Premixed Hydrogen Flame Stabilized Nox Emission Fuel Concentration Power Generation Lean Premixed Hydrogen Combustion Lead Considerable Interest Lean Premixed Fuel Low Flame Temperature Local Region Enhanced Thermal Nox Production Local Flame Temperature Local Enhancement Local Nitrogen Chemistry Atmospheric Pressure Pure Hydrogen Significant Impact Net Emission Global Flame Stabilization Mechanism Laboratory-scale Low Swirl Burner Low Emission Turbine Cellular Flame Structure Cellular Burning Pattern Chemical Pathway Lean Hydrogen-air Mixture Intense Burning Cellular Burning Structure Low Swirl Burner Configuration Thermodiffusive Instability Many Hydrogen-rich Fuel Hydrogen-seeded Hydrocarbon Mixture Corresponding Increase Local Turbulence Property Global Enhancement |
| Content Type | Text |
