摘要:
A method for active suppression of hydrodynamic instabilities in a combustion system in which liquid or gaseous fuel is premixed with combustion air and the fuel/air mixture is then burnt. The mass flow of the supplied fuel is modulated on the basis of a selected time function. Simplification and increased functional reliability are achieved by the modulation which is carried out using fluidics.
摘要:
In a gas turbine having a device for the fuel injection, which injects fuel into a mixing device (12), the injected fuel being mixed with combustion air in the mixing device (12), and in which the gas turbine also has a combustion chamber (16) arranged downstream of the mixing device (12), the length of the combustion chamber being LBK and the length of the mixing device being LMix, in order to suppress thermoacoustic vibrations the premix combustion chamber (10) containing the combustion chamber (16) and the mixing device (12) is designed in such a way that an acoustic pressure fluctuation which occurs in the premix combustion chamber (10) at the combustion-chamber outlet (20) is superimposed in phase opposition on an entropy-wave-induced pressure fluctuation at a certain frequency to be damped.
摘要:
In a method for burning a liquid fuel in a combustion system (10) which comprises a combustion chamber (11) and at least one injection nozzle (13) through which liquid fuel is injected into the combustion chamber (11) in the form of a fuel spray (16) and is burnt there with combustion air being added, disturbance-free operation in a simple manner is distinguished in that, in order to actively suppress hydrodynamic instabilities in the combustion chamber (11), the injected fuel spray (16) is modulated by having an electrical voltage applied to it during the injection process, governed by a selected time function.
摘要:
In a method of minimizing thermoacoustic vibrations in gas-turbine combustion chambers, a modulated spraying of liquid or gaseous premix fuel into a premix burner is carried out. The premix fuel is fed by means of two fuel lines (13, 14), and the modulation of the quantity of fed fuel is effected in each case by one fuel valve per fuel line.
摘要:
An apparatus for damping acoustic vibrations in a combustor as well as a corresponding combustor arrangement with the apparatus. The apparatus includes a Helmholtz resonator (4) that can be connected via a connecting channel (2) with a combustor (1). The Helmholtz resonator (4) contains a hollow body (6) the volume of which can be changed by adding or draining a fluid via a supply line (5), or is located adjacent to such a hollow body in such a way that the resonance volume (3) of the Helmholtz resonator (4) is changed when the volume of the hollow body (6) is changed. This apparatus makes it possible to adjust the resonance frequency of a Helmholtz resonator arranged inside a pressure container in accordance with the respective current operating point of the combustor to be damped, without having to pass movable components through the pressure container.
摘要:
In a combustion chamber, the hot gases are prepared sequentially via two stages (20, 40). Arranged at the end of the first stage (20) in the direction of flow is a cross-sectional constriction (30) via which the hot gases (21) prepared in the first stage (20) are passed over into the second stage (40). The Mach number at the outlet (31) of this cross-sectional constriction (30) corresponds to the area ratio of outlet area (A2) over inlet area (A1). This results in a low-reflection configuration in which low-frequency vibrations are absorbed to a significant extent. And acoustic energy reflected from the turbine is substantially reduced.
摘要:
A mixing device for mixing two or more flowing fluids in a flow duct in which the fluids to be mixed flow along a dividing wall (22), includes a plurality of vortex generators mounted on a downstream end of the dividing wall. The vortex generators (9) have surfaces which project into the duct, and around which flow occurs freely. Each vortex generator includes two side surfaces connected at a lead connecting edge which stands perpendicularly to the dividing wall (22) and is the edge acted upon first by the flow. A top surface consists of two sectional top surfaces (1, 2) which are connected to one another via a top connecting edge (10). Downstream rear edges (5, 6) of the sectional top surfaces (1, 2) are oriented at an angle (.gamma.) with the dividing wall (22), as a result of which, the the rear edges (5, 6) lie on an opposite side of the dividing wall (22)), with respect to the side surfaces (11, 13). A base surface consists of two sectional base surfaces which are connected to one another by a base connecting edge and to the sectional top surfaces by the rear edges (5, 6).
摘要:
In a premix burner having a swirl-stabilizing interior space (20) which is essentially formed by sectional shells (11, 12) nested one inside the other in a mutually offset manner as well as by a conically running inner body (13), one feed duct (11c, 12c) each extends upstream of the tangential air-inlet slots (11a, 12a) formed by the offset sectional shells, which feed duct (11c, 12c) is fitted at least with means (11d, 12d) for swirling an air flow (23) and with means for introducing a fuel (24). The introduction of the fuel is preferably arranged downstream of the means for swirling the air flow.
摘要:
The object of the invention is to provide a novel cone burner for gaseous and/or liquid fuels which has a reduced NOx and CO emission. According to the invention, this is achieved in that the sectional cone bodies (1, 2) have a common outlet diffuser (27) at their downstream end. They have a transition region (28) to the outlet diffuser (27), in which the size of the air-inlet slots (7, 8) decreases continuously in the direction (3) of flow. The outlet diffuser (27) is designed to be circular and without air-inlet slots (7, 8).
摘要:
In a double-cone burner, at least one row of nozzles (10) for a gaseous fuel containing highly reactive components and having a medium calorific value are arranged on the periphery of the partial conical bodies (1, 2) of the burner near the burner outlet at a distance of approximately 30% of the nominal burner diameter. In addition, there is a fuel conduit (11) and a distributing passage (17), placed in the region of the nozzles (10), for the highly reactive fuel. The gaseous fuel (15) containing highly reactive components is injected at high velocity through the nozzles (10), which have a diameter which is smaller than 1% of the nominal burner diameter, into the zones of high air velocity and the penetration depth and the direction of the fuel jets are matched to one another in such a way that ignition only takes place behind the burner, after mixing has occurred.