Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.