General Electric Company

William George Carberg

Jatila Ranasinghe

Rajeeva Kumar

Richard Robert Trewin

Raub Warfield Smith

Karl Dean Minto

William Forrester Seely

Charles Michael Jones

Gordon Raymond Smith

Darrin Glen Kirchhof

Nicholas Philip Poccia

Laurence Ambrose Kenny, Iii

William Francis Lopes

Peter Paul Polukort

Mark R Ford, Jr

William G Gorman

George L Touchton, Iii

Karl Kurt Rocco Westphal

Diwakar Balasubramanyam

Systems and methods for controlling exhaust steam temperatures from a finishing superheater are provided. In certain embodiments, the system includes a controller which includes control logic for predicting an exhaust temperature of steam from the finishing superheater using model-based predictive techniques (e.g., based on empirical data or thermodynamic calculations). Based on the predicted exhaust temperature of steam, the control logic may use feed-forward control techniques to control the operation of an inter-stage attemperation system upstream of the finishing superheater. The control logic may determine if attemperation is required based on whether the predicted exhaust temperature of steam from the finishing superheater exceeds a set point temperature as well as whether the inlet temperature of steam into the finishing superheater drops below a set point temperature of steam. The attemperation system may include a characterizing function to linearize the valve operation controlled by the control logic to inject cooled, high-pressure feedwater into the steam upstream of the finishing superheater, which may, in turn, control the exhaust temperature of steam from the finishing superheater. The disclosed embodiments may also be applied to any systems where an outlet temperature of a fluid from a heat transfer device may be controlled.

Inter-stage attemperation system and method

A heat recovery steam generation system is provided. The heat recovery steam generation system includes at least one superheater in a steam path for receiving a steam flow and configured to produce a superheated steam flow. The system also includes an inter-stage attemperator for injecting an attemperation fluid into the steam path. The system further includes a control valve coupled to the inter-stage attemperator. The control valve is configured to control flow of attemperation fluid to the inter stage attemperator. The system also includes a controller coupled to the control valve and the inter-stage attemperator. The controller further includes a feedforward controller and a trimming feedback controller. The feedforward controller is configured to determine a desired amount of flow of the attemperation fluid and the trimming feedback controller is configured to compensate for inaccuracies in the determined amount of flow of the attemperation fluid to determine a net desired amount of flow of attemperation fluid through the control valve into an inlet of the inter-stage attemperator based upon an outlet temperature of steam from the superheater. The controller also determines a control valve demand based upon the flow to valve characteristics. The controller further manipulates the control valve of the inter-stage attemperator, and injects the desired amount of attemperation flow via the inter-stage attemperator to perform attemperation upstream of an inlet into the superheater.

Single loop attemperation control

The mister includes a plurality of manifolds extending between opposite sides of a duct. Each manifold carries a plurality of nozzles at laterally spaced positions along the length of the manifold. The manifolds are spaced one behind the other in the direction of air flow in the duct and the pipes connecting the nozzles of the intermediate and upstream manifolds bypass the downstream manifolds to provide the nozzles in a common plane perpendicular to the direction of air flow in the duct. This arrangement affords a uniformity of spray and, hence, a uniformity of humidified air to the inlet of the compressor.

Spray nozzle grid configuration for gas turbine inlet misting system

An inlet bleed heater for flowing heated air to the inlet of a compressor is fabricated wholly at a factory site. The heater interconnects a manifold which receives extraction air from the compressor to down tubes in the inlet air duct to supply heated extraction air to the ambient inlet air via piping with bellows. The bellows accommodate thermal expansion and contraction of the manifold and the down tubes. The pipe and bellows lie within the height envelope of the bleed heater, facilitating transportation of the heater on its side within overall height and width limitations permitted for road travel.

Inlet bleed heater for heating inlet air to a compressor and methods of fabricating and transporting the heater

A combined water-wash and wet-compression system for a gas turbine includes a compressor having an inlet defining a flow direction; and a plurality of manifolds arranged in proximity to the inlet and arranged transversely of the flow direction; a plurality of dual-function nozzles connected to the manifolds. Each dual-function nozzle is adapted to supply, selectively, either relatively small droplets for introduction into the compressor for intercooling, or relatively large droplets for impingement on components of the compressor for cleaning the components. A method of introducing a liquid into a compressor inlet for providing water wash for cleaning components of the compressor, and for providing wet compression for intercooling is also disclosed.

Combined water-wash and wet-compression system for a gas turbine compressor and related method

To provide auxiliary steam, a low pressure valve is opened in a combined cycle system to divert low pressure steam from the heat recovery steam generator to a header for supplying steam to a second combined cycle's steam turbine seals, sparging devices and cooling steam for the steam turbine if the steam turbine and gas turbine lie on a common shaft with the generator. Cooling steam is supplied the gas turbine in the combined cycle system from the high pressure steam turbine. Spent gas turbine cooling steam may augment the low pressure steam supplied to the header by opening a high pressure valve whereby high and low pressure steam flows are combined. An attemperator is used to reduce the temperature of the combined steam in response to auxiliary steam flows above a predetermined flow and a steam header temperature above a predetermined temperature. The auxiliary steam may be used to start additional combined cycle units or to provide a host unit with steam turbine cooling and sealing steam during full-speed no-load operation after a load rejection.

Apparatus and methods for supplying auxiliary steam in a combined cycle system

A cooled cooling air (CCA) system is provided for application with gas turbine cycles. In an embodiment of the invention, the CCA system includes a shell and tube heat exchanger in which water flow is provided inside the tube(s) and air flow is provided on the shell side. Water exiting the heat exchanger is partially evaporated. Accordingly, the resulting two phase water/steam flow is admitted to a separator where the steam and water are separated. The saturated steam is flowed to the HRSG whereas the separator water is recycled to the heat exchanger.

Cooling air system and method for combined cycle power plants

Transient conditions, such as startup, shutdown, and contingencies, in gas turbine power plants are difficult to manage; oftentimes in designs employing a fuel moisturization system, such conditions require the use of backup fuel or a temporary fuel stream flare. The present invention enables the use of cold, dry fuel during startup and smoothly transitions to the use of moisturized, superheated fuel at high load without using a backup fuel. A bypass line allows fuel to enter a fuel superheater without passing through a fuel saturator. This enables the independent operation of the fuel superheater from the fuel saturator. Additionally, dry fuel is heated in the fuel superheater before moisturized fuel enters the fuel superheater. Gradually, a transition from dry fuel to moisturized fuel occurs before the gas turbine system operates at premixed combustion mode of operation.

Fuel gas moisturization control system for start-up, high load operation and shutdown

A steam and gas turbine (STAG) plant employs a catalyst in a heat recovery steam generator to react injected ammonia with NO.sub.x from the combustor of the gas turbine to reduce atmospheric emission of NO.sub.x from the system. Rapid control of ammonia injection is achieved using a prediction of the NO.sub.x being generated in dependence upon the operating conditions of the combustor. A trimming signal from a measurement of NO.sub.x being emitted from the heat recovery steam generator downstream of the catalyst is employed to complete the NO.sub.x control loop.

Catalytic pollution control system for gas turbine exhaust

In a combined cycle power plant comprising a steam turbine and gas turbine connected through a heat recovery steam generator, the start-up mode for a steam turbine is based upon the shell metal temperature of the steam turbine. In some combined cycle plants, the output of the gas turbine is reduced so as to more closely match the output steam temperature of the heat recovery steam generator to the steam turbine metal temperature. This arrangement can be disadvantageous for several reasons and so it is proposed that a spray attemperator or desuperheater be incorporated between the heat recovery steam generator outlet and the steam turbine inlet. Moreover, control means are indicated for controlling the fluid input into the attemperator.

Start-up attemperator

The disclosure relates to automated drain valves for pressurized fluid conduits such as steam conduits. Recognizing that there is a direct relationship between steam temperature and steam pressure at the saturation line; the saturation line is used to derive a variable set point for an automated drain system and method. The saturation temperature is compared with the actual temperature to determine the positioning of the conduit drain valves.

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Saratoga Springs, NY, United States of America

William George Carberg