EXHAUST GAS THROTTLE VALVE

摘要

A method for driving exhaust gas recirculation comprising the steps of restricting exhaust gas flow into the turbine inlet to create backpressure in the exhaust system under low engine operating conditions, and providing an unrestricted exhaust gas flow to the turbine under normal engine operating conditions. Restriction of exhaust gas flow is accomplished through the use of an exhaust gas throttle valve disposed upstream of the turbine inlet. The valves can be adjustable knife edge flap valves or D-shaped valves situated in each passageway of a divided exhaust manifold, which are closed to varying degrees to generate desired levels of backpressure while allowing exhaust gas to pass though open regions of the partially obstructed flow pathway to reach the engine turbocharger. This allows the turbine to continue to spin, while at the same time exhaust gas back pressure upstream of the turbocharger is used to drive exhaust gas recirculation.