Unit Coordinated Control for Drum Boilers

The Ovation® expert control system offers Unit Coordinated Control (UCC) that provides a coordinated front-end control strategy that unites the boiler and turbine controls. Coordinated controls generate and regulate the setpoint for unit load (MW). The unit load setpoint or UCC MW Demand may be generated from local operator entry, remote increase/decrease contact inputs, or internally generated contingencies such as runbacks and rundowns.

Unit coordinated control manages unit load (megawatts) and throttle pressure by sending out parallel demand signals to the boiler and turbine control loops through the Boiler Master and Turbine Master M/A Stations, respectively.

The Boiler Master demand is used as a feedforward signal to the loops controlling feedwater, fuel and air flow to improve unit response to load changes.

The Turbine Master demand controls the turbine control valves by sending an analog output signal to the turbine controls. The operator interface to the unit control is through a dedicated graphic and associated pop-up windows which may be accessed at an Operator’s station.

Features

• Provides a coordinated front-end control strategy that unites boiler and turbine controls
• Offers air/fuel cross limiting to regulate the fuel and air input in response to load changes
• Offers typical air flow control stations, furnace pressure control stations (ID fans), and feedwater control stations

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