Q. Flue Gas Excess Oxygen Control for steam generator?
Air-gas ratio control provides approximate excess oxygen control. However, an in-situ oxygen probe measures the actual oxygen levels which is used to trim the controls, resulting in fuel gas savings. An analyzer controller, employing a P.I.D. algorithm, uses the probe signal and the operator's setpoint to produce an output. The setpoint of the air-gas ratio controller is trimmed directly by this output.