Controlling ammonia flow in a selective catalytic reduction system during transient non-steady-state conditions

摘要

A selective catalytic reduction (SCR) system is defined that uses the measured concentration of reactant slip in the exhaust gas after SCR processing to control the amount of reactant injected during non-steady-state operational conditions. The SCR system works with a reactant slip detector located in the post-SCR processing section of the exhaust flue. The reactant slip detector measures the concentration of reactant in the exhaust gases and, based on that concentration, the amount of reactant injected into the pre-SCR processing exhaust gases is controlled.