Identification of a state-space model by subspace technique to air pressure control in combustion chambers

In industrial combustion chambers, there are several strategies to control the air-gas (fuel) ratio aiming at better thermal use of the reaction. In all of them, the pressure of the mixed gases must be controlled to do not affect the desired air-gas ratio of the mixture. To model the dynamical behavior of the air pressure control system for use in a combustion chamber, a time-invariant linear state-space model was identified. System identification can be used as an alternative to phenomenological models to describe the dynamical behavior of the system, as well as to the use of CFD (Computational Fluid Dynamics) found in literature for combustion chambers. In this paper, a robust subspace identification technique is used to obtain a mathematical model based on state-space and the results obtained presented and discussed.