Patent ID: 9080466
Filing Date: 2015-07-14
Classification: F01K

Abstract:
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.