Patent ID: 7380400
Filing Date: 2008-06-03
Classification: F02B,F02D,F02M,Y02T

Abstract:
1. A method for controlling a diesel engine having an intake manifold and an exhaust manifold, the engine further having a turbocharger coupled between the intake and exhaust manifolds of the engine, a low pressure exhaust gas recirculation system with a first end coupled to the exhaust manifold downstream of the turbocharger and a second end coupled to the intake manifold upstream of the turbocharger, said low pressure exhaust gas recirculation system having a first valve coupled thereto for regulating flow, a high pressure exhaust gas recirculation system with a first end coupled to the exhaust manifold upstream of the turbocharger and a second end coupled to the intake manifold downstream of the turbocharger said high pressure exhaust gas recirculation system having a second valve coupled thereto for regulating flow, a first throttle coupled in the intake manifold between said second end of said high pressure exhaust gas recirculation system and said second end of said low pressure exhaust gas recirculation system, and a second throttle coupled upstream of said second end of said low pressure exhaust gas recirculation system, the method comprising: adjusting said first valve and said first throttle to regulate flow in the high pressure system; adjusting said second valve and said second throttle to regulate flow in the low pressure system; decreasing opening of the first throttle while increasing opening of the first valve when pressure across the high pressure exhaust gas recirculation system is less than a first threshold; and decreasing opening of the second throttle while increasing opening of the second valve when pressure across the low pressure exhaust gas recirculation system is less than a second threshold.