Abstract: A sensor 11 detects the acoustic pressure at a first location in a combustion chamber 7 of a test rig 1 and produces an input signal which is a function of the acoustic pressure. A controller 13 receives the input signal and produces an output signal which is a function of the input signal. An acoustic actuator (16-18) receives the output signal and introduces into the combustion chamber 7 at a second location an acoustic pressure which is a function of the output signal. The acoustic actuator may comprise a fuel injector 18 or a loudspeaker.

Abstract: Relating to a model-based active control system for a gas turbine, a method for obtaining the data that are used for deriving an active closed loop controller for the gas turbine includes splitting the combustion system into a number of submodels. The measurement of some submodels is achieved by system identification on a single burner test facility. Other submodels are then determined by using known acoustic models. The different submodels are subsequently combined to form an acoustic network model that is subsequently used to develop a closed loop controller.

Abstract: A premix burner has a swirl generator and two perforated through flow elements are arranged at a defined distance from one another in the inflow region for the combustion air. The through flow elements are preferably arranged in such a way that substantially the entire combustion airstream has to flow through the through flow elements. The degree of perforation of the through flow elements and the distance between these elements are preferably adapted to one another in such a way that a reflection free condition for combustion pulsation frequencies which may be expected is present at the exit from the burner into the combustion chamber.

Abstract: A reheat combustion system for a gas turbine comprises a mixing tube adapted to be fed by products of a primary combustion zone of the gas turbine and by fuel injected by a lance; a combustion chamber fed by the said mixing tube; and at least one perforated acoustic screen. The or each said acoustic screen is provided inside the mixing tube or the combustion chamber, at a position where it faces, but is spaced from, a perforated wall thereof. In use, the perforated wall experiences impingement cooling as it admits air into the combustion system for onward passage through the perforations of the said acoustic screen, and the acoustic screen damps acoustic pulsations in the mixing tube and combustion chamber.

Abstract: A reheat combustion system for a gas turbine comprises a mixing tube adapted to be fed by products of a primary combustion zone of the gas turbine and by fuel injected by a lance; a combustion chamber bed by the said mixing tube; and at least one perforated acoustic screen. The or each said acoustic screen is provided inside the mixing tube or the combustion chamber, at a position where it faces, but is spaced from, a perforated wall thereof. In use, the perforated wall experiences impingement cooling as it admits air into the combustion system for onward passage through the perforations of the said acoustic screen, and the acoustic screen damps acoustic pulsations in the mixing tube and combustion chamber.

Abstract: In the case of swirl-stabilized premix burners (1), an axial mass flow distribution of the fuel introduced which has especially favorable values with respect to characteristics such as NOx emission and maximum amplitudes of pulsations occurring is used. For this purpose, Pareto solutions are determined with respect to the said characteristics, in that a distributing device (5) with control valves is represented by a tree structure with distributing parameters, and values for the distributing parameters on the basis of which the distributing device (5) is set by means of a control unit (10) are iteratively generated in a data-processing system (9) by an evolutionary algorithm. On the basis of the values determined by a measuring unit (11), solutions which are especially favorable with respect to the characteristics mentioned, espectially Pareto-optimal, are selected. The distributing devices or the premix burners of the burner system are then formed in a way corresponding to such a solution.

Abstract: Arranged upstream of each swirl-stabilized premix burner (1) of a burner system there is respectively an adjustable distributing device (5) with control valves (V1, . . . ,V8) and/or on/off valves (V?1, . . . , V?16), by means of which various axial mass flow distributions of the fuel introduced can be set. Preferably, those which have particularly favorable values with respect to characteristics such as NOx emission and maximum amplitudes of pulsations occurring are chosen. For this purpose, Pareto solutions are determined with respect to the said characteristics, in that a distributing device (5) is represented by a tree structure with distributing parameters, and values for the distributing parameters on the basis of which the distributing device (5) is set by means of a control unit are iteratively generated in a data-processing system by an evolutionary algorithm.

Abstract: A device and method for atomizing a liquid medium, including an electrically conductive nozzle body with an internal volume for holding the liquid medium, at least one nozzle opening as well as a high-voltage electrode arranged inside the internal volume coaxially to a longitudinal axis of the nozzle body. The high-voltage electrode is provided in the area of its greatest lateral expansion with a circumferential, sharp edge that extends at a small distance to the nozzle body in order to be able to bring about the electrostatic charging of the passing liquid medium. This construction enables the electrostatic atomization in a simple manner even for multi-hole nozzles, so that the electrostatic atomization also can be used in the field of gas turbine technology for improving the injection in the start-up and partial load range.

Abstract: A device and method for atomizing a liquid medium, including an electrically conductive nozzle body with an internal volume for holding the liquid medium, at least one nozzle opening as well as a high-voltage electrode arranged inside the internal volume coaxially to a longitudinal axis of the nozzle body. The high-voltage electrode is provided in the area of its greatest lateral expansion with a circumferential, sharp edge that extends at a small distance to the nozzle body in order to be able to bring about the electrostatic charging of the passing liquid medium. This construction enables the electrostatic atomization in a simple manner even for multi-hole nozzles, so that the electrostatic atomization also can be used in the field of gas turbine technology for improving the injection in the start-up and partial load range.