Abstract: Embodiments of the disclosure provide a method for controlling steam pressure within a turbine component. The method includes calculating a predicted stress on a rotor of the turbine component based on a predicted steam flow with the inlet valve in a minimum load position, a rotor surface temperature, and an inlet steam temperature, and determining whether the predicted stress exceeds a threshold. If the predicted stress exceeds the threshold, the inlet valve adjusts to a warming position. When steam in the discharge passage reaches a target pressure, the exhaust valve partially closes while maintaining the warming position of the inlet valve. If a safety parameter of the turbine component violates a boundary, the exhaust valve partially opens while maintaining the warming position of the inlet valve. When the predicted stress does not exceed the threshold, the inlet valve opens to at least the minimum load position.

Abstract: Embodiments of the disclosure provide a method for controlling steam pressure within a turbine component. The method includes calculating a predicted stress on a rotor of the turbine component based on a predicted steam flow with the inlet valve in a minimum load position, a rotor surface temperature, and an inlet steam temperature, and determining whether the predicted stress exceeds a threshold. If the predicted stress exceeds the threshold, the inlet valve adjusts to a warming position. When steam in the discharge passage reaches a target pressure, the exhaust valve partially closes while maintaining the warming position of the inlet valve. If a safety parameter of the turbine component violates a boundary, the exhaust valve partially opens while maintaining the warming position of the inlet valve. When the predicted stress does not exceed the threshold, the inlet valve opens to at least the minimum load position.

Abstract: Certain embodiments of the disclosure may include systems and methods for boundary control during steam turbine acceleration. According to an example embodiment, the method can include receiving an indication the turbine is in an initial acceleration phase; receiving speed control parameter data from a plurality of sensors; receiving boundary control parameter data from a plurality of sensors; providing a control valve configured for controlling steam flow entering the turbine; determining the control valve position based on received speed control parameter data; determining the control valve position based on received boundary control parameter data; adjusting at least one boundary control parameter to the at least one boundary control parameter limit during turbine startup, wherein the value of a speed control parameter is simultaneously adjusted based on the adjusted at least one boundary control parameter; and adjusting the control valve position based at least on determined parameter data.

Abstract: A method and a system for limiting steam flow entering a steam turbine are provided. The method and system may intentionally unbalance the steam flow apportioned between sections of the steam turbine. The steam turbine comprises at least: a first section, a second section, and a rotor disposed within each section. The method may receive a speed/load command, or the like, which provides reference strokes for a first valve, associated with the first section; and a second valve, associated with the second section. The method may also determine an operational parameter that may limit the reference strokes relative to the speed/load command. The operational parameter may determine the allowable steam flow for each section of steam turbine, independent of the speed/load command.

Abstract: Certain embodiments of the disclosure may include systems and methods for boundary control during steam turbine acceleration. According to an example embodiment, the method can include receiving an indication the turbine is in an initial acceleration phase; receiving speed control parameter data from a plurality of sensors; receiving boundary control parameter data from a plurality of sensors; providing a control valve configured for controlling steam flow entering the turbine; determining the control valve position based on received speed control parameter data; determining the control valve position based on received boundary control parameter data; adjusting at least one boundary control parameter to the at least one boundary control parameter limit during turbine startup, wherein the value of a speed control parameter is simultaneously adjusted based on the adjusted at least one boundary control parameter; and adjusting the control valve position based at least on determined parameter data.

Abstract: A method for increasing the operational flexibility of a turbomachine during a startup phase is provided. The turbomachine may include a first section, a second section, and a rotor disposed within the first section and the second section. The method may determine an allowable range of a physical parameter associated with the first section and/or the second section. The method may modulate a first valve and/or a second valve to allow steam flow into the first section and the second section respectively, wherein the modulation is based on the allowable range of the physical parameter. In addition, the physical parameter allows the method to independently apportion steam flow between the first section and the second section of the turbomachine, during the startup phase.

Abstract: A method for increasing the operational flexibility of a turbomachine during a shutdown phase is provided. The turbomachine may include a first section, a second section, and a rotor disposed within the first section and the second section. The method may determine an allowable range of a physical parameter associated with the first section and/or the second section. The method may modulate a first valve and/or a second valve to allow steam flow into the first section and the second section respectively, wherein the modulation is based on the allowable range of the physical parameter. In addition, the physical parameter allows the method to independently apportion steam flow between the first section and the second section of the turbomachine, during the shutdown phase.

Abstract: A control system for a combined cycle power generation system including a gas turbine engine (GT), a heat recovery steam generator (HRSG), and a steam turbine (ST) includes a display wherein an operator may observe information about predicted operating parameters; a user interface wherein an operator may provide additional operating constraints; and a controller configured to generate input profiles of the GT, the HRSG, and the ST that satisfy the nominal constraints and any additional constraints and to generate the information about the predicted operating parameters. The controller may be configured to detect a stage transition of power generation system operation and update the input profiles. The controller may be configured to generate alternative operating scenarios by mapping alternative control actions to an operating constraint of at least one of the system components.

Abstract: A valve fault test system is disclosed. The system tests for leakage in a valve within a turbine system having a gas turbine and a steam turbine sharing a common shaft, by performing actions including: placing the gas turbine in a control mode; determining a power output for the steam turbine corresponding to the control mode of the gas turbine; preventing steam flow to the steam turbine by providing instructions to close at least one of a steam turbine control valve or a steam turbine stop valve; determining a power output for the steam turbine corresponding to the steam flow being prevented to the steam turbine; and comparing the power output for the steam turbine corresponding to the closed at least one of the control valve or the stop valve to an expected power output for the steam turbine to determine whether a leakage in the valve exceeds a predetermined threshold.

Abstract: A method for increasing the operational flexibility of a turbomachine during a startup phase is provided. The turbomachine may include a first section, a second section, and a rotor disposed within the first section and the second section. The method may determine an allowable range of a physical parameter associated with the first section and/or the second section. The method may modulate a first valve and/or a second valve to allow steam flow into the first section and the second section respectively, wherein the modulation is based on the allowable range of the physical parameter. In addition, the physical parameter allows the method to independently apportion steam flow between the first section and the second section of the turbomachine, during the startup phase.

Abstract: A method for increasing the operational flexibility of a turbomachine is provided. The turbomachine may include a first section, a second section, and a rotor disposed within the first section and the second section. The method may determine an allowable range of a physical parameter associated with the first section and/or the second section. The method may modulate a first valve and/or a second valve to allow steam flow into the first section and the second section respectively, wherein the modulation is based on the allowable range of the physical parameter. In addition, the physical parameter allows the method to independently apportion steam flow between the first section and the second section of the turbomachine, during the loading process.

Abstract: A method and a system for limiting steam flow entering a steam turbine are provided. The method and system may intentionally unbalance the steam flow apportioned between sections of the steam turbine. The steam turbine comprises at least: a first section, a second section, and a rotor disposed within each section. The method may receive a speed/load command, or the like, which provides reference strokes for a first valve, associated with the first section; and a second valve, associated with the second section. The method may also determine an operational parameter that may limit the reference strokes relative to the speed/load command. The operational parameter may determine the allowable steam flow for each section of steam turbine, independent of the speed/load command.

Abstract: A method for increasing the operational flexibility of a turbomachine during a shutdown phase is provided. The turbomachine may include a first section, a second section, and a rotor disposed within the first section and the second section. The method may determine an allowable range of a physical parameter associated with the first section and/or the second section. The method may modulate a first valve and/or a second valve to allow steam flow into the first section and the second section respectively, wherein the modulation is based on the allowable range of the physical parameter. In addition, the physical parameter allows the method to independently apportion steam flow between the first section and the second section of the turbomachine, during the shutdown phase.

Abstract: A control system for a combined cycle power generation system including a gas turbine engine (GT), a heat recovery steam generator (HRSG), and a steam turbine (ST) includes a display wherein an operator may observe information about predicted operating parameters; a user interface wherein an operator may provide additional operating constraints; and a controller configured to generate input profiles of the GT, the HRSG, and the ST that satisfy the nominal constraints and any additional constraints and to generate the information about the predicted operating parameters. The controller may be configured to detect a stage transition of power generation system operation and update the input profiles. The controller may be configured to generate alternative operating scenarios by mapping alternative control actions to an operating constraint of at least one of the system components.

Abstract: A method for operating a rotary machine is provided. The rotary machine includes a stationary member and a rotatable member wherein the rotatable member is configured to rotate at least partially within the stationary member. The method includes determining an off-normal operating condition of the rotary machine facilitating undesirable contact between the rotatable member and the stationary member, monitoring a parameter associated with the off-normal operating condition, and preventing operation of the rotary machine while the monitored parameter is within a predetermined range.