Emerson Process Management Power & Water Solutions, Inc.

Ranjit Ramesh Rao

Xu Cheng

Frederick Charles Huff

Jacob Nathaniel Adams

Richard J Whalen, Jr

Melanie Jean Novacek

Benjamin F Gerideau, Iii

Frederick C Huff

Benjamin F Gerideau

Methods and apparatus to optimize ramp rates in combined cycle power plants are disclosed herein. An example method disclosed herein includes predicting a first setpoint for a gas turbine in a combined cycle power plant over a prediction horizon and predicting a second setpoint for a steam generator over the prediction horizon. The example method includes identifying a first steam property of steam generated by the steam generator in the combined cycle power plant based on the second setpoint. The example method includes comparing the first steam property to a second steam property of steam associated with a steam turbine in the combined cycle power plant and dynamically adjusting at least one of the first setpoint or the second setpoint based on the comparison.

Methods and apparatus to optimize steam header blending and gas turbine loading in combined cycle power plants

Methods and apparatus to optimize turbine ramp rates are disclosed herein. An example method includes predicting a setpoint for a turbine rotor over a prediction horizon. The example method includes predicting a surface temperature profile of the turbine rotor for the prediction horizon based on the predicted setpoint via an empirical data model. The example method also includes predicting a first stress profile for the turbine rotor based on the surface temperature profile. The example method includes performing a comparison of the first stress value to a second stress value and dynamically adjusting the setpoint based on the comparison.

Methods and apparatus to optimize steam turbine ramp rates

A control system for controlling a steam turbine power plant having multiple steam flow paths that converge to a combined steam path controls the final steam temperature of the steam input into the turbine by controlling one or more temperature control devices in each of the steam flow paths. The control system includes a multivariable controller, such as a multi-input/multi-output (MIMO) controller, that produces two control signals that control each of a set of downstream control valves in the split steam flow paths. The controller receives two inputs in the form of measured or calculated process variables including the final steam temperature and the inter-stage temperature difference between the steam being produced in each of the two split steam paths and performs multi-objective control based on these inputs. However, when one of the downstream control valves is placed into a manual mode, the controller shifts to being a single objective controller to control the final steam temperature of the system and to thereby perform better or more optimal control.

Multi-objective steam temperature control

A control system uses a modeled steam turbine megawatt (power) change attributed to a gas turbine demand change (i.e., a steam turbine to gas turbine transfer function) within a conventional closed loop feedback control scheme to perform control of a combined cycle power plant. This control system implements a form of internal model control and provides better unit megawatt (power) set-point tracking and disturbance variable rejection for overall more robust control, and thus operates to optimize the gas turbine operation of the combined cycle power plant in a manner that provides cost savings over time.

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Gibsonia, PA, United States of America

Ranjit Ramesh Rao