General Electric Company

Thane Montgomary Drummond

Bernd Artur Westphal

Jens Kure-Jensen

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

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

A control system including a controller for reading temperature values from sensors in a gas turbine, determining the reliability of the sensors, and issuing a fuel control signal for use in controlling the turbine is disclosed. The fuel control signal has a calculated value which is a function of the turbine operating temperature derived from the values of temperature signals generated by the sensors.

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Roanoke, VA, United States of America

Thane Montgomary Drummond