Patent ID: 6882924
Filing Date: 2005-04-19
Classification: F02C,F16K,G05D,Y10T

Abstract:
1. A turbine valve control system, comprising: a variable flow metering device capable of meeting a plurality of predetermined mass flow rates by varying positioning of the flow metering device; a first sensor for detecting variable positioning of the flow metering device and generating a first output signal that is a function of the positioning of the flow metering device; a second sensor for detecting fluid pressure upstream of the flow metering device and generating a second output signal that is a function of the detected upstream fluid pressure; a third sensor for detecting fluid pressure downstream of the flow metering device and generating a third output signal that is a function of the detected downstream fluid pressure; a fourth sensor for detecting temperature upstream of the flow metering device and generating a fourth output signal that is a function of the detected temperature; memory including first computer program code for calculating a combined coefficient of discharge times area that gives a desired flow for a given valve position, upstream pressure, downstream pressure, and temperature for subsonic flow and second computer program code for calculating a combined coefficient of discharge times area that gives a desired flow for a given valve position, upstream pressure, and temperature for sonic flow; and processing circuitry configured to receive the signals, determine whether flow is subsonic or sonic, and implement a corresponding one of the first and second computer program codes to calculate a combined coefficient of discharge times area that will generate a desired mass flow rate for the flow metering device.