Method and system for controlling a valve of a turbomachine

摘要

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.

主权项

1. A method of limiting steam flow entering a steam turbine, the method comprising:
providing a steam turbine comprising a rotor disposed within a first section and a second section, wherein a flow path around the rotor allows for steam to fluidly communicate between the first section and the second section; providing a first valve configured for controlling steam flow entering the first section; and a second valve configured for controlling steam flow entering the second section; receiving a command that provides reference strokes for the first valve and the second valve; determining an operational parameter, wherein the operational parameter limits the reference strokes relative to the command; selecting a minimum value between the command and the operational parameter; wherein the minimum value determines reference strokes of the first valve and the second valve; and wherein the operational parameter independently controls the steam flow to and of at least one of the first section or the second section, wherein the independently controls is independent of the command, and the operational parameter is based on a physical requirement that comprises at least one of: a pressure, a temperature, a flow rate, or combinations thereof; and wherein the operational parameter comprises at least one of: axial thrust, rotor stress, steam pressure, or a physical range.