Abstract: A steam cycle system comprises a boiler comprising a superheat section, a reheat section, and an economizer section, wherein the boiler is configured to receive a feedwater stream; a steam turbine system comprising a high pressure turbine and a lower pressure turbine, wherein the steam turbine system is configured to receive steam generated by the boiler; a condenser configured to receive at least a portion of the outlet steam from the steam turbine system and output the feedwater stream; a high pressure feedwater heat exchanger configured to receive at least a portion of the feedwater stream, allow for an energy exchange between the portion of the feedwater stream and a steam stream, and output the portion of the feedwater stream to the boiler; a steam extraction line configured to provide a steam flow from an outlet of the high pressure turbine to the high pressure feedwater heater; a feedwater temperature control device configured to control the temperature of the feedwater stream by modulating the energy

Abstract: A multivariable control system for controlling boiler burners. The system includes burner actuators, boiler sensors, a control system coupled to the actuators and the sensors and further includes a memory and a processor, and an application stored in the memory. When executed by the processor, the application executes a multivariable control algorithm to determine actuator manipulated variable values to control in part the burners based on data received from the sensors and based on a plurality of gain values. The application also executes an adaptation algorithm to change an actuator manipulated variable value, to maintain the changed manipulated variable value for a pre-determined period of time, to determine a change in data received from the sensors, to determine a gain value based on the changed manipulated variable value and the change in data received from the sensors, and to provide the determined gain value to the multivariable control algorithm.

Abstract: A method comprises heating a feedwater stream in a feedwater heater, boiling the feedwater stream in a boiler to produce a steam stream, superheating the steam stream in the boiler to produce a superheated steam stream, producing power using the superheated steam stream to produce an outlet steam stream, using a first portion of the outlet steam stream to provide heat for the heating step, and modulating the flow of the first portion of the outlet steam stream below a full flow to allow the superheated steam stream to meet a superheated steam set point.

Abstract: A multivariable control system for controlling boiler burners. The system comprises burner actuators, boiler sensors, a control system coupled to the actuators and the sensors and comprising a memory and a processor, and an application stored in the memory. When executed by the processor, the application executes a multivariable control algorithm to determine actuator manipulated variable values to control in part the burners based on data received from the sensors and based on a plurality of gain values. The application also executes an adaptation algorithm to change an actuator manipulated variable value, to maintain the changed manipulated variable value for a pre-determined period of time, to determine a change in data received from the sensors, to determine a gain value based on the changed manipulated variable value and the change in data received from the sensors, and to provide the determined gain value to the multivariable control algorithm.

Abstract: A method comprises heating a feedwater stream in a feedwater heater, boiling the feedwater stream in a boiler to produce a steam stream, superheating the steam stream in the boiler to produce a superheated steam stream, producing power using the superheated steam stream to produce an outlet steam stream, using a first portion of the outlet steam stream to provide heat for the heating step, and modulating the flow of the first portion of the outlet steam stream below a full flow to allow the superheated steam stream to meet a superheated steam set point.

Abstract: A steam cycle system comprises a boiler comprising a superheat section, a reheat section, and an economizer section, wherein the boiler is configured to receive a feedwater stream; a steam turbine system comprising a high pressure turbine and a lower pressure turbine, wherein the steam turbine system is configured to receive steam generated by the boiler; a condenser configured to receive at least a portion of the outlet steam from the steam turbine system and output the feedwater stream; a high pressure feedwater heat exchanger configured to receive at least a portion of the feedwater stream, allow for an energy exchange between the portion of the feedwater stream and a steam stream, and output the portion of the feedwater stream to the boiler; a steam extraction line configured to provide a steam flow from an outlet of the high pressure turbine to the high pressure feedwater heater; a feedwater temperature control device configured to control the temperature of the feedwater stream by modulating the energy

Abstract: A method and system for controlling and providing guidance in reducing the level of NO.sub.x emissions based on controllable combustion parameters and model calculations while maintaining satisfactory plant performance and not causing other harmful consequences to the furnace. To implement such a system, boiler control values of flow, pressure, temperature, valve and damper positions in addition to emission sensors for data associated with the production of NO.sub.x, O.sub.2, CO, unburned carbon and fuel. This information is received from standard sensors located throughout a boiler which are connected either to a distributed control system (DCS), or another data acquisition system which is time coordinated with the DCS. The DCS passes this information to a computing device which then processes the information by model based optimization simulation programs, also referred to as the NO.sub.x Emissions Advisor.

Abstract: A method and system for controlling and providing guidance in sootblowing based on continuous plant monitoring and model calculations. The continuous monitoring of plant conditions is through a plant distributed control system (DCS) which communicates with a computer. The conventional measurements of a DCS such as flow, pressure and temperature and sootblower status data are input into the computer. These valves are validated for accuracy. To predict the effects of fouling a plant model is utilized. The model predicts the rate and effect of fouling on energy distribution in the boiler. The model then predicts the effect that sootblowing of each section will have on the boiler performance. A comparison of the predicted and observed effects are used to update the fouling model and maintain consistency with the actual performance of the boiler. This information is presented to the boiler operator to assist in enhancing the boiler efficiency and maintain steam temperatures within established control ranges.

Abstract: A power plant may include a steam generator and a steam turbine wherein the steam generator provides steam to the turbine for driving the turbine and exhausted steam from the turbine is condensed in the turbine condenser to be pumped back to the steam generator as feedwater. In order to maintain minimum feedwater pump flows and to provide an alternative flow path should the steam generator require less than the available feedwater flow, a recirculation loop is provided for returning a portion of the feedwater to the turbine condenser. According to the present invention, this return flow to the condenser may be used for deaeration of condensate and for the attemperation of bypass steam.

Abstract: In a power plant, a deaerator is a feedwater conditioning device which provides direct contact feedwater heating as well as providing for oxygen removal to inhibit corrosion. Under some conditions, called transients, rapid depressurization could occur in the deaerator which might result in damage to internal deaerator parts. By limiting the condensate flow into the deaerator, the rate of depressurization can be reduced. A control system is described which will react to a reduction in turbine load by reducing the flow of condensate to the deaerator.