General Electric Company

Bruce L Morrison

Alexander Morson

Earl H Brinkman

John Raymond Hawley

Robert Sean Talley

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

An adjustable labyrinth seal for a steam turbine wherein the packing rings may be displaced from a larger diameter position, affording a relatively larger shaft clearance, to a smaller diameter position, affording a relatively smaller shaft clearance. Steam conduits are provided in the turbine casing communicating with the annular space between the individual packing rings and the grooves in which they are retained. The rings are provided with seals and are so configured as to maintain pressure- retaining contact with the sidewalls of the grooves. Steam, at a pressure in excess of the operating pressure of the individual seal, may be admitted to the annular space of the upstream ring to controllably effect the displacement thereof. Steam, at the turbine inlet pressure, is admitted to the annular spaces of the remaining rings to effect their displacement. In a further embodiment, one or more of the remaining rings may receive pressurized steam from an external source to control precisely the time at which they close.

Positive variable clearance labyrinth seal

An expansion joint for sealing the periphery of a component passing through a bore in a member comprises a component sealing element and a bore sealing element, each having a respectively alignable hole therethrough for defining an opening for receiving the component through the expansion joint. The radial outer surface of the bore sealing element sealingly engages the bore and the radial inner surface of the component sealing member that defines the hole therethrough is radially outwardly relieved over a first portion so that a second portion of the inner surface sealingly contacts the periphery of the component along a line which is everywhere tangent to the component, thereby accommodating skew between the central axis of the component and the central axis of the bore. Lateral surfaces of the component and bore sealing elements are mutually sealingly engaged during assembly.

Growing community of inventors

Schenectady, NY, United States of America

Bruce L Morrison