In staged combustion, wherein fuel is fed into a furnace, and less than all of the gaseous oxidant needed to completely combust the fuel is fed with the fuel and combusted, providing uncombusted fuel, and the remaining portion of gaseous oxidant needed to combust the fuel is fed into the furnace through a second port, fuel is fed and combusted at the second port to heat the second port and lessen the tendency of deposits to form at the second port.

In staged combustion, wherein fuel is fed into a furnace, and less than all of the gaseous oxidant needed to completely combust the fuel is fed with the fuel and combusted, providing uncombusted fuel, and the remaining portion of gaseous oxidant needed to combust the fuel is fed into the furnace through a second port, fuel is fed and combusted at the second port to heat the second port and lessen the tendency of deposits to form at the second port.

A method for staged combustion in a combustor assembly includes introducing an oxidant stream and a fuel stream at a first location into a combustion chamber to produce a heated stream. A Liquid water stream and an additional oxidant stream, fuel stream or both are then introduced into the heated stream in at least one location along the heated stream downstream from the first location. The additional oxidant stream, fuel stream or both react in the heated stream to generate additional heat that vaporizes liquid water from the liquid water stream to water vapor.