Utilization of a linearized model for the redesign of the feedwater control system of a drum boiler power plant

Linearized models of the low-pressure feedwater system of a 235-MW drum boiler power plant are developed. The linearized models are to be used as analytical tools for the plant control engineer and also for their intrinsic value as plant system models. In this application of the models, the hotwell and deaerator level controllers of the low-pressure feedwater system are redesigned for best tank level responses because controller tuning was shown to yield only limited improvement. The control strategy decouples the hotwell and deaerator level control systems. It is shown that the deaerator level control is significantly improved with no loss in the accuracy of the hotwell system.<
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