Power plant diagnostics and control by unsteady combustion using a modulated plasmatron

Results are presented of an experimental verification of the unstable combustion diagnostic method based on the combustion chamber's response to the harmonic perturbations generated by a (periodically) modulated electric discharge in plasmatron channel. The response was investigated in an almost full-scale combustion chamber: in an oxidizer blow-through without combustion, in centered propane-air combustion and in the distributed combustion of benzene-air mixtures. It is demonstrated that it is possible to determine the basic acoustic combustion chamber characteristics (the resonance frequencies, the attenuation decrement) in the operating regime from the response to the harmonic perturbations produced with the modulated plasmatron, as well as to damp the resonant oscillations in unstable combustion by means of the high-temperature plasmatron jet effect on the combustion zone.