ENGINE EXHAUST EMISSION CONTROL DEVICE AND EXHAUST EMISSION CONTROL METHOD

摘要

[PROBLEMS] To control NOx emission into the atmospheric air when abnormality occurs in an engine or SCR unit. [MEANS FOR SOLVING PROBLEMS] An engine C/U (51) detects abnormality occurred in an engine to output the abnormality-indicating signal to an SCR-C/U (61). The SCR-C/U (61) increases or decreases a urea water injection amount according to abnormality occurred. The SCR-C/U (61) detects abnormality occurred in an SCR unit to output the abnormality-indicating signal to the engine C/U (51). The engine C/U (51) controls engine components such as an EGR valve to reduce an NOx exhaust amount.