| 摘要 |
An EGR system for an internal combustion engine has a separate, secondary high-temperature cooling loop, in addition to a primary cooling loop. In the secondary cooling loop, coolant flows through a secondary high-temperature exhaust gas cooler, which is located upstream of the primary exhaust gas cooler. A large amount of heat is transferred from the exhaust gases to the coolant in the secondary high-temperature cooling loop. The heat absorbed by the high-temperature coolant is rejected in a secondary high-temperature radiator. Heat absorbed by the primary coolant is rejected in a primary radiator. The two radiators occupy the same amount of frontal area as a single radiator used in a conventional single-stage EGR cooling system, but overall reject more heat to the ambient. In an alternate arrangement, the EGR system for a liquid-cooled internal combustion engine has a single exhaust gas cooler which is cooled by an EGR cooling loop that is independent of the engine cooling system. The EGR cooling loop includes a secondary radiator located adjacent the primary engine cooling radiator, and the two radiators together occupy the same frontal area as a single radiator used in a conventional single-stage EGR cooling system, but overall reject more heat to the ambient. <IMAGE> |
