Siemens Energy, Inc.

Siemens Westinghouse Power Corporation

David D Elwood

Uygar O Selman

Kristian I Wetzl

Brad A Steinebronn

Teri J Robertson

Christopher A Gates

Christopher L Moering

Bruce H Carpenter

Adam D Plant

A system and method of treating an exhaust flow including nitrogen oxides (NOx) in a turbine engine power generation plant is provided. The turbine engine has a selective catalytic reduction system having a catalyst. During steady state operation of the engine, a reducing agent, such as ammonia, is supplied to an injector in an amount based on a measured molar flow of NOx in the exhaust flow. During a disturbance in the operation of the turbine engine, a reducing agent is supplied to the injector in an amount based on a predicted molar flow of NOx in the exhaust flow. In addition, the system can include a biasing feature in which additional reducing agent is supplied to the exhaust flow beyond the predicted molar flow of NOx. The system and method can mitigate NOx during transient engine operation, an operational mode in which emissions are difficult to predict and control.

Feedforward selective catalytic reduction system for turbine engines

A component cooling steam flow control scheme for a combined cycle power plant (). Steam pressure in the steam drum () of a waste heat recovery steam generator () is controlled by selectively positioning a steam bypass valve (). The flow of steam from the steam drum through a cooling steam flow path () is controlled by selectively positioning a steam admission valve () in the cooling steam flow path. At power levels below a predetermined crossover power level (), the cooling steam flow is controlled independently from the steam drum pressure, thus assuring good system controllability at the lower power levels where system control is historically a concern. The steam admission valve is maintained fully open at power levels above the crossover power level, so changes in cooling steam flow at these higher power levels are accomplished by regulating steam drum pressure. System efficiency losses resulting from pressure drop across the steam admission valve are thus minimized at the higher power levels where system efficiency is historically a concern.

Steam cooling control for a combined cycle power plant

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Oviedo, FL, United States of America

David D Elwood