General Electric Company

Bernd Artur Westphal

Thane Montgomary Drummond

Vivek Venugopal Badami

Paul Kenneth Houpt

Jens Kure-Jensen

Kenneth H-c Chiang

James Baldwin Comly

James H Moore, Jr

Richard G Livingston

Thane Montgomery Drummond

A method and apparatus for determining turbine rotor stresses in real time enables increased operation efficiency and more accurate stress determinations. The system calculates rotor bore and surface temperatures based on the time response of the rotor. The rotor surface temperature is measured using a sensor such as a thermocouple, and the measured rotor surface temperature is used to calculate rotor bore temperature and rotor average temperature based on time constants determined as a function of rotor geometry and material. The rotor surface thermal stress and the rotor bore thermal stress can be determined based on the measured and calculated temperatures.

Method and apparatus determining turbine stress

Method and apparatus for determining turbine stress

A method for automated control of a steam turbine prewarming procedure employs fuzzy logic to generate a control signal for a turbine regulatory function, such as steam supply. The method includes the steps of determining a plurality of turbine condition parameter signals; generating a plurality of regulatory control directions; generating a weighting factor to be assigned to each of said regulatory control directions by means of a fuzzy inference calculation in accordance with an operator-selected fuzzy logic profile, and applying the weighting factors to the regulatory control directions to produce the turbine regulatory function control signal. The turbine regulatory function control signal is applied to a respective function controller in the steam plant such that the selected turbine prewarming profile is implemented.

Automated steam turbine startup method and apparatus therefor

In a steam turbine system including a high pressure turbine section, a reheat turbine section and a low pressure turbine section coupled to a generator, and wherein a boiler supplies steam to the high pressure turbine and wherein a condenser is arranged to receive spent steam from the low pressure turbine and to return the spent steam to the boiler, a process including the steps of: a) during cold start-up, bypassing a portion of the steam generated by the boiler around the high pressure turbine section, reheat turbine section and low pressure turbine section and feeding the bypass portion directly to the condenser, accelerating the turbine to a predetermined speed less than approximately 1000 rpm utilizing control valves at an inlet side of the high pressure turbine section while keeping closed a plurality of intercept valves at an inlet side of the reheat turbine section; and wherein steam pressure to the high pressure turbine section is controlled by a high pressure bypass valve; and b) upon reaching said predetermined speed, fixing the control valves at a learned value corresponding substantially to a valve opening required to reach the predetermined speed; and c) opening the reheat stop valves and and using the intercept valves alone to control turbine speed until a predetermined synchronization speed is reached.

Steam turbine split forward flow

A signal representing the electrical output power of a steam turbine-generator is fed back to a control system. A signal representing the boiler steam pressure is also fed to the control system. A control signal for controlling valves feeding steam to the steam turbine is gain controlled between one and zero in the presence of a negative rate of change of steam pressure less than a predetermined value. At other negative and all positive values of rate of change of steam pressure, the control signal is unaffected. In one embodiment, a linear relationship is employed for controlling the gain for increasingly negative values of the rate of change of steam pressure. At an extreme negative value, the gain is controlled to zero, whereby the a load reference signal remains unchanged.

Steam turbine control with megawatt feedback

Improved method and apparatus for controlling thermal stress on component parts of a steam turbine while providing maximum loading and unloading rates during startup, shutdown, and other periods of load change. From monitored and derived quantities, a loading rate is calculated for each of a plurality of preselected turbine component parts and the lowest rate is selected for control. Simultaneously, and in concert with load change calculation and execution, the steam admission mode of the turbine is automatically directed to either the partial arc mode or the full arc mode as necessary to reduce stress as compared with a preselected and adaptive stress reference value.

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Clifton Park, NY, United States of America

Bernd Artur Westphal