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: A fired heater unit is disclosed having at least one radiant heating section with each of the at least one radiant heating section having a heating element located therein. The unit includes a convection section operatively connected to the at least one radiant heating section, wherein the convection section having at least one vertically oriented convection tube. Each of the at least one convection tube being operatively connected to the at least one radiant heating section. Each of the at least one convection tube includes an inner tube having process fluid flowing therethrough, wherein the process fluid being heated by the at least one radiant heating section, and an outer tube extending along a predetermined portion of the inner tube, wherein the outer tube is spaced from the inner tube to form a flow path therebetween.

Abstract: Fouling of heat exchange surfaces is mitigated by a process in which a mechanical force is applied to a fixed heat exchanger to excite a vibration in the heat exchange surface and produce shear waves in the fluid adjacent the heat exchange surface. The mechanical force is applied by a dynamic actuator coupled to a controller to produce vibration at a controlled frequency and amplitude output that minimizes adverse effects to the heat exchange structure. The dynamic actuator may be coupled to the heat exchanger in place and operated while the heat exchanger is on line.

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: A fired heater unit is disclosed having at least one radiant heating section with each of the at least one radiant heating section having a heating element located therein. The unit includes a convection section operatively connected to the at least one radiant heating section, wherein the convection section having at least one vertically oriented convection tube. Each of the at least one convection tube being operatively connected to the at least one radiant heating section. Each of the at least one convection tube includes an inner tube having process fluid flowing therethrough, wherein the process fluid being heated by the at least one radiant heating section, and an outer tube extending along a predetermined portion of the inner tube, wherein the outer tube is spaced from the inner tube to form a flow path therebetween.

Abstract: Fouling of heat exchange surfaces is mitigated by a process in which a mechanical force is applied to a fixed heat exchanger to excite a vibration in the heat exchange surface and produce shear waves in the fluid adjacent the heat exchange surface. The mechanical force is applied by a dynamic actuator coupled to a controller to produce vibration at a controlled frequency and amplitude output that minimizes adverse effects to the heat exchange structure. The dynamic actuator may be coupled to the heat exchanger in place and operated while the heat exchanger is on line.