US 5,428,951 A · Method and apparatus for active control of combustion devices

Abstract

An improved technique for the active control of various combustion devices. This improved technique employs a flame kernel pulse actuator which produces periodic flame kernels by a spark ignition of a stoichiometric air and fuel mixture upstream of the combustion chamber. The discrete flame kernels are convected in a duct of premixed fuel and air which produce discrete pressure oscillations due to the energy release as each discrete flame propagates. Because the source of the energy release is essentially a chemical reaction, the flame kernel pulse actuator is able to produce a substantial amount of energy release even at the high operating pressures which are often encountered in many operational environments. These pressure oscillations may be adjusted to suppress or augment any combustion induced pressure oscillations as well as act to modulate the mixing layer between the fuel and air, thus controlling the downstream combustion process. The flame kernel pulse actuator comprises an actuator housing, a secondary fuel injection system, and an igniter. The combination of the igniter and fuel injection system produces a plurality of discrete flame kernels which are convected downstream toward the combustion chamber. The present flame kernel pulse actuator further includes a pressure sensor which is positioned so as to measure the acoustic oscillations in the combustion chamber and a controller device which uses the output of the sensor to control the frequency, phase shift, and amplitude of the discrete flame kernels.

Claims18

Dependent claims

A flame kernel pulse actuator for actively controlling the stability of an operating combustion device, said combustion device having an inlet duct, a combustion chamber, a primary fuel injection means, a fuel and air mixture, and an ignition means, said flame kernel pulse actuator comprising:

an actuator housing adapted for attachment within said inlet duct of said combustion device, said housing defining an open aft end facing in a downstream orientation with respect to said combustion device;
an auxiliary fuel injection means adapted for supplying an auxiliary fuel and air mixture within said actuator housing, said auxiliary fuel and air mixture supplied by said auxiliary fuel injection means being separate from the fuel and air mixture required for the operation of the combustion device;
an igniter disposed in said actuator housing which in conjunction with said auxiliary fuel injection means produces a plurality of discrete flame kernels which are convected toward said open aft end of said actuator housing and released into said inlet duct, said discrete flame kernels further releasing a predetermined quantity of energy into said inlet duct and upstream of said combustion chamber, thereby producing discrete pressure oscillations in said inlet duct which propagate towards the combustion chamber;
and
a controlling means for actively controlling the frequency, phase shift, and amplitude of the discrete flame kernels in said inlet duct which affects the frequency, phase shift, and amplitude of said discrete pressure oscillations which in turn affects the stability of said operating combustion device.

2 more elements

A method for actively controlling the stability of a combustion device, said combustion device having an inlet duct, a combustion chamber, a primary fuel injection means, a fuel and air mixture, and an ignition means, said method comprising the steps of:

installing a flame kernel actuating device proximate said inlet duct of said combustion device, said flame kernel actuating device capable of producing a plurality of discrete flame kernels;
producing a series of discrete flame kernels in said inlet duct of said combustion device which are convected toward a combustion chamber of said combustion device, said discrete flame kernels further releasing a predetermined quantity of energy into said inlet duct thereby producing discrete pressure oscillations which affect the stability of said combustion device;
taking measurements of any resulting acoustic oscillations in said combustion device with the use of a sensor, said sensor disposed in said combustion device;
processing said measurements of said sensor with a controller device which is adapted for receiving said measurements, said controller device further operatively connected with said flame kernel actuating device so as to actively control frequency of said flame kernels, phase shift of said flame kernel, and amplitude of said flame kernels, in response to said sensor measurements;
and
adjusting one or more of the parameters consisting of the group;
frequency of said flame kernels, phase shift of the flame kernels, and the amplitude of the flame kernels, to achieve a desired form of regulation of said combustion device.

4 more elements

Dependencies are inferred from the claim text.

Method and apparatus for active control of combustion devices

Life of this patent

Method and apparatus for active control of combustion devices

Life of this patent

Abstract

Claims18