GAS RECIRCULATION IN TURBOCHARGED DIESEL ENGINES

摘要

An apparatus for improving' exhaust gas recirculation performance is provided which induces improved exhaust gas recirculation flow during engine operating transients, including transients in which exhaust gas flow conditions are unfavorable. The apparatus includes a fresh air intake passage with a venturi section and an exhaust gas recirculation passage outlet, preferably in the form of a pitot tube, arranged in the fresh air intake passage adjacent to the venturi section such that a pressure-reducing flow in the fresh air is induced as a result of the Coanda effect. Establishing Coanda flow adjacent to the exhaust gas recirculation outlet substantially assists in drawing exhaust gas into the fresh air intake flow in transient operating conditions, including unfavorable exhaust-to-intake pressure difference conditions. The Coanda flow also assists in more rapid and thorough mixing the gases to provide a homogeneous mixture to minimize NOx production during engine operating transients.