General Electric Company

John Raymond Hawley

Richard G Farnsworth

Samuel G Hardy

Bruce L Morrison

Albert R Varney, Jr

Robert Sean Talley

Dale M Bickford

A combined cycle power plant includes a gas turbine, a steam turbine and a heat recovery steam generator having a duct burner for supplementary firing. In the unfired mode, gas turbine exhaust is used in the heat recovery steam generator for generating steam for the steam turbine. The power plant includes a main steam output line from the heat recovery steam generator connected to the first stage inlet of the high pressure section of the steam turbine. A bypass loop is connected either to an intermediate pressure connection of the HRSG or from the high pressure line to an admission point downstream of the high pressure inlet nozzle, at a lower pressure than the nominal inlet pressure. By operating the bypass system in conjunction with the duct burning process in the HRSG, the steam inlet pressure to the steam turbine can be maintained at the optimal level during both fired and unfired operation of the HRSG. Another potential benefit is a higher output during fired operation than could otherwise be accomplished with a given steam turbine.

Optimized steam turbine peaking cycles utilizing steam bypass and related process

Redundant pulses generated by independently operable pulse sources in an electricity meter are accumulated as pulse counts in a pair of channels of a multi-channel recorder. The pulse counts are compared to verify the accuracy of the pulses counted by each channel. If the difference between the values of the pulse counts exceeds a predetermined threshold value, a trouble indicator is turned on and a telephone call is initiated by the recorder to notify a data center that a system malfunction has occurred which is disrupting the accumulation of pulses in one of the channels of the recorder. The pulse counts are stored in the recorder as substantially duplicate independent measures of energy usage by a load connected to the electricity meter, to be thereafter retrieved from the recorder to obtain energy survey and billing data. The recorder also maintains a system status error log which records the time and date of each malfunction and the identification of the channel pair where the malfunction occurred. In one embodiment, the operation of the recorder is controlled by a programmable microprocessor. Combinations of independent power sources for powering the recorder and the pulse sources are employed to enhance system reliability by making each of the pulse sources and the recorder substantially independently operable.

Redundant pulse monitoring in electric energy metering system

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Schenectady, NY, United States of America

John Raymond Hawley