Ultra low NOx combustion for steam generator
AssigneeFives North American Combustion, Inc.
InventorThomas F. Robertson
Life of this patent
Estimating the term…
Abstract
A steam generator has a heat exchange chamber with an upstream end and a downstream end. The steam generator further has a burner that injects primary reactants, including fuel and combustion air, into the chamber at the upstream end. A first branch of a once-through water line is located within the chamber downstream of the burner. A second branch of the once-through water line is connected in parallel with the first branch, and is located within the chamber downstream of the first branch. A fuel injector is arranged to inject staged fuel into the chamber at a staged location downstream of the first branch of the once-through water line.
Claims5
An apparatus comprising:
- a steam generator structure defining a gas flow path reaching through heat exchange chambers including a steam-generating chamber and a preheating chamber downstream of the steam-generating chamber;
- a burner arranged to inject primary reactants, including fuel and combustion air, into the steam-generating chamber;
- a once-through water line having a) a preheating portion reaching through the preheating chamber, b) a first branch that receives preheated water from the preheating portion and reaches within the steam-generating chamber in a first serpentine configuration of turns and sections that reach oppositely back and forth end-to-end between the turns, and c) a second branch that receives preheated water from the preheating portion in parallel with the first branch and reaches within the steam-generating chamber in a second serpentine configuration of turns and sections that reach oppositely back and forth end-to-end between the turns, with the second serpentine configuration located downstream relative to the gas flow path of the first serpentine configuration;
- and a fuel injector arranged to inject staged fuel into the steam-generating chamber at a staged location downstream of the first serpentine configuration.
Dependencies are inferred from the claim text.