Glossary
Turndown
The ratio of maximum stable firing rate to minimum stable firing rate. Higher turndown supports wider load variation without cycling.
Excess Air
Air supplied above the stoichiometric requirement. Excess air can reduce CO but increases stack losses when too high.
Flue Gas Recirculation (FGR)
Mixing a portion of flue gas with combustion air to dilute oxygen and lower peak flame temperature, typically reducing NOx.
Low NOx
A design goal and set of technologies that reduce NOx formation, often through staging, recirculation, and controlled mixing.