Abstract: A tunable fluid flow control system for controlling combustion dynamics in a combustor is disclosed. The control system includes a fuel supply path having an inlet portion, a first diverted portion, a second diverted portion, and an exit portion. A first diverted portion has a first length and a first diameter. A second diverted portion has a second length and a second diameter and spaced apart from the first diverted portion. The first and second diverted portions converge at a merging location. The exit portion is coupled to the merging location of the first and second diverted portions. At least one flow regulation device is coupled to the inlet portion and configured to divert fuel flow to the first and second diverted portions alternately to generate fuel flow perturbations at the merging location.

Abstract: In method for operating a gas turbine (11), the compressed air is fed to a combustor (18, 19) for the combustion of a coal syngas, and the resulting hot gases are expanded in a subsequent turbine (16, 17). Some of the compressed air is separated into oxygen and nitrogen, and the oxygen is used for producing the syngas. In a first combustor, (18) syngas is combusted and the resulting hot gases are expanded in a first turbine (16), and in a second combustor syngas is combusted, using the gases which issue from the first turbine (16), and the resulting hot gases are expanded in the second turbine (17). The two combustors (18, 19) are operated with undiluted syngas, and the first combustor flame temperature (TF) is lowered compared with the operation with natural gas (TNG), while the second combustor (19) is operated in the normal operation (TNG) for natural gas.