Periodic equivalence ratio modulation method and apparatus for controlling combustion instability
The periodic equivalence ratio modulation (PERM) method and apparatus significantly reduces and/or eliminates unstable conditions within a combustion chamber. The method involves modulating the equivalence ratio for the combustion device, such that the combustion device periodically operates outside of an identified unstable oscillation region. The equivalence ratio is modulated between preselected reference points, according to the shape of the oscillation region and operating parameters of the system. Preferably, the equivalence ratio is modulated from a first stable condition to a second stable condition, and, alternatively, the equivalence ratio is modulated from a stable condition to an unstable condition. The method is further applicable to multi-nozzle combustor designs, whereby individual nozzles are alternately modulated from stable to unstable conditions. Periodic equivalence ratio modulation (PERM) is accomplished by active control involving periodic, low frequency fuel modulation, whereby low frequency fuel pulses are injected into the main fuel delivery. Importantly, the fuel pulses are injected at a rate so as not to affect the desired time-average equivalence ratio for the combustion device.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 20050810
- Resource Relation:
- Other Information: PBD: 9 May 2000
- Country of Publication:
- United States
- Language:
- English
Similar Records
Periodic equivalence ratio modulation method and apparatus for controlling combustion instability
An Experimental Investigation of Fuel Staging In A Model Gas Turbine Combustor