Feedforward selective catalytic reduction system for turbine engines

摘要

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.

主权项

1. A method of treating an exhaust flow including nitrogen oxides in a turbine engine, the turbine engine having a selective catalytic reduction system having a catalyst, the turbine engine operating under steady state conditions, the method comprising the steps of:
predicting a molar flow of nitrogen oxides in the exhaust flow; measuring a molar flow of nitrogen oxides in the exhaust flow; detecting a disturbance in the steady state operation of the turbine; determining the difference between the measured molar flow of nitrogen oxides in the exhaust flow and the predicted molar flow of nitrogen oxides in the exhaust flow to yield an error factor; applying the error factor to the predicted molar flow of nitrogen oxides in the exhaust flow so that the predicted molar flow equals the measured molar flow; and responsive to detecting a disturbance, supplying a reducing agent to the exhaust flow upstream of the catalyst relative to the direction of exhaust flow and based on the predicted molar flow of nitrogen oxides with the error factor applied in the exhaust flow.