Abstract: Method of controlling the operation of a combustion device to provide safe and reliable operation while reducing NOx emission that includes providing a flow of fuel and diluent at a determined volume ratio to a flame in the combustion device; providing a flame stability sensor to generate a measurement of a characteristic of the flame, providing a flow measurement for each of the fuel and diluent, and controlling the determined volume ratio of fuel:diluent using the measurement from the flame stability sensor and/or flow measurements. A combustion system incorporating this method also is included.

Abstract: Systems and methods for detecting an instability associated with at least one burner are disclosed. A detector measures a signal associated with a characteristic of the at least one burner. The signal is converted to a time-varying signal spectrum using at least one processor. An instability is detected based at least in part on the time-varying signal spectrum. The instability can be detected based on an instability indicator calculated based at least in part on the time-varying signal spectrum. A threshold can be associated with the instability indicator such that an instability is detected when the instability indicator is greater than the threshold.

Abstract: Systems and method for identifying an unstable subset of burners from among a plurality of burners in a furnace are also disclosed. At least one measurement is obtained from each of the plurality of burners. An instability associated with the furnace is detected. An unstable signal matrix associated with the instability is computed based on the at least one measurement from each of the plurality of burners. An unstable subset of burners is identified based at least in part on the unstable signal matrix.

Abstract: Systems and methods for multi-channel detection of an instability in a furnace comprising a plurality of detectors are disclosed. Each of a plurality of detectors provides a first measurement related to the plurality of burners when the furnace is operating in a stable condition. A stable signal component representation is determined based on the first measurement from each of the plurality of detectors. Each of a plurality of detectors provides a second measurement related to the plurality of burners when the furnace is operating in an unknown state. An unstable signal component representation is determined based on the stable signal component representation and a second measurement from each of the plurality of detectors. An instability is detected based on the unstable signal component representation and an instability threshold.

Abstract: Method of controlling the operation of a combustion device to provide safe and reliable operation while reducing NOx emission that includes providing a flow of fuel and diluent at a determined volume ratio to a flame in the combustion device; providing a flame stability sensor to generate a measurement of a characteristic of the flame, providing a flow measurement for each of the fuel and diluent, and controlling the determined volume ratio of fuel:diluent using the measurement from the flame stability sensor and/or flow measurements. A combustion system incorporating this method also is included.