General Electric Company
After treatment bypass for internal combustion engine during cold start and idle operation

Abstract:

Methods of operating an internal combustion engine that has two exhaust paths, the first path having an aftertreatment system. One method includes: operating the engine at idle; directing the exhaust flow through the first exhaust path; detecting an exhaust temperature below a predetermined temperature and/or operation of the engine at idle; and diverting all, or some, of the exhaust flow through the second exhaust path, based on the detecting. Another method includes detecting an engine condition that is indicative of an oil accumulation above a threshold and diverting the exhaust flow through the second exhaust path, based on detecting this engine condition. An exhaust subsystem that includes a controller that employs these methods is disclosed.