Working fluid circuit for a turbocharged engine having exhaust gas recirculation

Abstract

An engine working fluid circuit for a turbocharged internal combustion engine that employs exhaust gas recirculation. The working fluid circuit includes an exhaust gas passage, a charge air passage, and a turbocharger operatively driven by the exhaust gas flowing from the internal combustion engine and acting to provide pressurized air to the charged air passage. An exhaust gas recirculation passage extends between the exhaust gas passage and the charge air passage bypassing the turbo charger and providing a path for recirculating a predetermined amount of exhaust gas into the charge air. A single charge air cooler is also included that has a first manifold assembly, a second manifold assembly, and a plurality of cooling passages disposed therebetween. The cooling passages act to cool the mixed charge air and recirculated exhaust gas prior to induction into the internal combustion engine. A flow valve is operatively disposed between the first manifold assembly and the second manifold assembly, and is movable between open, bypass, and reverse positions to control the flow of the mixed charge air and recirculated exhaust gas through the cooler. The open position provides forward flow through the cooling passages; the bypass position provides flow that bypasses the cooling passages; and the reverse position provides a reverse cleaning flow through the cooling passages.