Pressure boosted IC engine with exhaust gas recirculation

摘要

A method and apparatus for boosting the pressure of air charge 136 to an internal combustion engine 201 which has exhaust gas recirculation 238. The engine comprises an air inlet passage 135 leading to combustion chambers 10 and an exhaust outlet passage 6 leading from combustion chambers 10 to a turbocharger 116. The turbocharger 116 has an exhaust gas driven turbine impeller 114 linked to a compressor 126 for compressing inlet air 28. An exhaust gas recirculation system 222 recirculates gas from the exhaust outlet passage 6 to the air inlet passage 135, and an exhaust gas bypass passage 244 diverts exhaust gas 250 from the turbine impeller 114. A single control valve 160 receives exhaust gas from the exhaust outlet passage 6 and is used to control the relative proportions of exhaust gas i) recirculated to the air inlet passage 135 via the EGR system 222, ii) routed to the exhaust bypass passage 244 and iii) routed to the impeller 114.