A method for determining an estimate of the specific gravity of a fuel for a gas turbine engine is disclosed. The gas turbine engine includes a fuel control valve and one or more fuel injectors. The method includes determining a first estimate of the specific gravity based on an orifice flow model of the fuel control valve. The method also includes determining a second estimate of the specific gravity based on a combined orifice flow model of the one or more fuel injectors. The method further includes recursively filtering the first estimate and the second estimate to determine a third estimate of the specific gravity.

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.

This disclosure relates to systems and methods of predicting physical parameters for a combustion fuel system. In one embodiment of the disclosure, a method of predicting physical parameters of a combustion fuel system includes causing water injection in at least one combustor. The water injection is associated with at least one time and performed during gaseous fuel operations or after liquid fuel operations. The method includes measuring exhaust spread data associated with the water injection and allows correlating the exhaust spread data to at least one physical parameter associated with a nozzle or a valve of the fuel system. The method further includes storing the exhaust spread data, the at least one physical parameter, and the at least one time to a database. The method further provides stored historical data from the database to an analytical model. The analytical model is operable to predict, based at least partially on the stored historical data, at least one future physical parameter associated with a future time.

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.

A combustion chamber system has pilot and main fuel manifolds, and pilot and main fuel nozzles. Each pilot nozzle is connected to the pilot manifold. Each main nozzle is connected to the main manifold. A greater total amount of fuel is supplied to the pilot nozzles than to the main nozzles. A greater amount of fuel is supplied to pilot nozzles at, or in, a first region of the combustion chamber than to pilot fuel nozzles at, or in, a second region. A greater amount of fuel is supplied to the main nozzles at, or in, the first region than to the main nozzles at, or in, the second to improve combustion efficiency, weak extinction and relight of the combustion chamber in a first mode of operation. A greater total amount of fuel is supplied to the main nozzles than to the pilot nozzles in a second mode of operation.

In accordance with one embodiment, a system is presented. The system includes a casing, a combustor disposed within the casing, and a sensing device located on the casing and configured to sense a plurality of acoustic emission waves and generate an electrical signal based on the sensed plurality of acoustic emission waves. The system further includes a processing subsystem operationally coupled to the sensing device and configured to determine one or more features based on the electrical signal, and determine a presence or an absence of fretting wear in the combustor based at least on the one or more features.

An apparatus for controlling a gas turbine combustor having a diffusion combustion burner and a premix combustion burner comprising: a rotating speed detector for detecting a rotating speed of gas turbine, a recorder for recording the detected value of the rotating speed of gas turbine detected by the rotating speed detector, an arithmetic unit for calculating a change with time of the rotating speed of gas turbine in accordance with details of the detected value of the rotating speed of gas turbine recorded in the recorder, and a fuel control unit for judging a starting situation of reduction in the rotating speed of gas turbine on the basis of the change with time of the rotating speed of gas turbine calculated by the arithmetic unit and controlling respectively a fuel flow rate for the diffusion combustion burner to be fed to the diffusion combustion burner installed in the gas turbine combustor and a fuel flow rate for the premix combustion to be fed to the premix combustion burner.

Systems and methods for controlling mode transfers of a turbine combustor are provided. According to one embodiment, a system may include a controller to control a combustor, and a processor communicatively coupled to the controller. The processor may be configured to receive current operating conditions, target operating limits, and combustor transfer functions. The combustor transfer functions may be evaluated to estimate operating limits associated with one or more combustion modes under the current operating conditions. The estimated operating limits associated with the one or more combustor modes may be compared to the target operating limits, and, based on the comparison, at least one of the combustion modes may be selected. The combustor may then be selectively transferred to the selected combustion mode.

A jet engine has an inlet which takes in air, a combustor which combusts fuel by using the air, and a fuel control section which controls supply of the fuel. The combustor has a fuel supplying section which supplies the fuel, injectors which inject the fuel. Each injector contains openings which inject the fuel. The fuel supplying section supplies the fuel to the injector in a flow rate according to a command of an autopilot. The fuel control section controls the injectors such that the number of the openings which inject the fuel or flow-path cross-section areas of the pipes which send the fuel in case of the low-speed is more than the number of the openings which inject the fuel or the flow-path cross-section areas of the pipes which send the fuel in case of the high-speed.

A method of controlling an operating temperature of a first combustion zone of a combustor of a rotary machine includes determining a current operating temperature and a target operating temperature of a first combustion zone using a digital simulation. The method further includes determining a derivative of the current operating temperature with respect to a current fuel split using the digital simulation. The fuel split apportions a total flow of fuel to the combustor between the first combustion zone and a second combustion zone. The method also includes calculating a calculated fuel split that results in a calculated operating temperature approaching the target operating temperature. The method further includes channeling a first flow of fuel to the first combustion zone and a second flow of fuel to the second combustion zone.