A method of measuring a residence time in a gas-turbine engine is disclosed that includes measuring a combustor pressure signal at a combustor entrance and a turbine exit pressure signal at a turbine exit. The method further includes computing a cross-spectrum function between the combustor pressure signal and the turbine exit pressure signal, calculating a slope of the cross-spectrum function, shifting the turbine exit pressure signal an amount corresponding to a time delay between the measurement of the combustor pressure signal and the turbine exit pressure signal, and recalculating the slope of the cross-spectrum function until the slope reaches zero.

The disclosed technology includes carryover burner systems and methods for use with water heating system. The water heating system can include a burner unit having an outer sleeve, and an inner sleeve. The water heating system can also include an ignitor. The outer sleeve can include a carryover region having a first plurality of apertures and a combustion region which can be adjacent to the carryover region, the combustion region including a second plurality of apertures. The inner sleeve can comprise a dispersion region having a third plurality of apertures. The inner sleeve can be located substantially within the outer sleeve.

A system configured to generate heat when supplied with a first fuel or a second fuel can include a fuel supply line operatively connected to a fuel source. A valve assembly can be operatively connected to the fuel supply line. A main burner can be operatively connected to the valve assembly. A thermoelectric generating system can be configured to transform heat to electricity. A first pilot burner can include at least one of a first thermocouple and a first Fe-ion sensor. A second pilot burner can include at least one of a second thermocouple and a second Fe-ion sensor. A printed circuit board (PCB) can be operatively connected to the valve assembly and the first and second pilot burners. The PCB can be configured to control operation of the valve assembly based on information received from at least one of the first and second pilot burners.

A system configured to generate heat when supplied with a first fuel or a second fuel can include a fuel supply line operatively connected to a fuel source. A valve assembly can be operatively connected to the fuel supply line. A main burner can be operatively connected to the valve assembly. A thermoelectric generating system can be configured to transform heat to electricity. A first pilot burner can include at least one of a first thermocouple and a first Fe-ion sensor. A second pilot burner can include at least one of a second thermocouple and a second Fe-ion sensor. A printed circuit board (PCB) can be operatively connected to the valve assembly and the first and second pilot burners. The PCB can be configured to control operation of the valve assembly based on information received from at least one of the first and second pilot burners.

Described herein are embodiments of systems and methods for oxidizing gases. In some embodiments, a reaction chamber is configured to receive a fuel gas and maintain the gas at a temperature within the reaction chamber that is above an autoignition temperature of the gas. The reaction chamber may also be configured to maintain a reaction temperature within the reaction chamber below a flameout temperature. In some embodiments, heat and product gases from the oxidation process can be used, for example, to drive a turbine, reciprocating engine, and injected back into the reaction chamber.

The present invention relates to methods and systems for controlling a combustion reaction and the products thereof. One embodiment includes a combustion control system having an oxygenation stream substantially comprising oxygen and CO.sub.2 and having an oxygen to CO.sub.2 ratio, then mixing the oxygenation stream with a combustion fuel stream and combusting in a combustor to generate a combustion products stream having a temperature and a composition detected by a temperature sensor and an oxygen analyzer, respectively, the data from which are used to control the flow and composition of the oxygenation and combustion fuel streams. The system may also include a gas turbine with an expander and having a load and a load controller in a feedback arrangement.

Described embodiments include a system, method, and apparatus. The system includes a sensor device configured to measure an unburned fuel component in an exhaust stream from a gas-fueled combustion device. The system includes a feedback controller configured to generate a combustion management signal responsive to the measured unburned fuel component and to a target value for the measured unburned fuel component. The system includes a combustion controller configured to regulate an aspect of a combustion component delivered to a burner of the gas-fueled combustion device in response to the combustion management signal. In an embodiment, the system includes a user interface configured to display a quality of combustion information responsive to the measured unburned fuel component in a human perceivable format.

Described embodiments include a system, method, and apparatus. The system includes a sensor device configured to measure an unburned fuel component in an exhaust stream generated by a gas-fueled combustion device. The system includes a combustion analysis circuit configured to generate a quality of combustion information responsive to the measured unburned fuel component. The system includes a user interface configured to display the quality of combustion information in a human perceivable format. In an embodiment, the system includes a combustion component controller configured to regulate an aspect of a combustion component delivered to the gas-fueled combustion device in response to the combustion management selection entered by a human user.

A system for boiler control is provided. The system includes supply units to provide supplies of combustion materials for combustion thereof, a vessel coupled to the supply units in which the combustion materials are combusted, a carbon monoxide (CO) sensor disposed at an outlet of the vessel to sense a quantity of exhaust CO output from the vessel as a product of combustion therein and a control unit. The control unit is coupled to the supply units and the sensor and configured to issue a main servo command and a pulse servo command to one or more of the supply units to control operations of the one or more supply units in accordance with the sensed quantity of the exhaust CO.

A system for boiler control is provided. The system includes supply units to provide supplies of combustion materials for combustion thereof, a vessel coupled to the supply units in which the combustion materials are combusted, a carbon monoxide (CO) sensor disposed at an outlet of the vessel to sense a quantity of exhaust CO output from the vessel as a product of combustion therein and a control unit. The control unit is coupled to the supply units and the sensor and configured to issue a main servo command and a pulse servo command to one or more of the supply units to control operations of the one or more supply units in accordance with the sensed quantity of the exhaust CO.