Intake air and recirculated exhaust gas cooling system for a boosted i.c. engine

摘要

The intake air and recirculated exhaust gas cooling system of an eg automotive diesel engine comprises a combined cooler 201 for cooling a gas combination of compressed engine intake air and recirculated exhaust gas (EGR gas). Exhaust gas exits the combustion chamber 204 of an engine 200 and passes into an exhaust passage 203 which directs the exhaust gas to a mixing point 209 via a regulator 211 for varying the amount of exhaust gas that is recirculated and to a turbine 205 of a turbocharger 206. A rotary compressor 208 of the turbocharger 206 compresses the intake air and outputs it to the mixing point 209. The mixing point 209 mixes the compressed engine intake air and recirculated exhaust gas and outputs it to the cooler 201, which cools it and outputs it to an intake manifold 210 of the engine 200 and hence to the combustion chamber 204. Thus a single cooler is used instead of respective coolers for intake air and for EGR gas, saving space and reducing cost.