FLOW MEASUREMENT AND CONTROL

摘要

PROBLEM TO BE SOLVED: To realize more precise feedback control of EGR and better fuel economy and engine operation. SOLUTION: An exhaust gas recirculation system for an internal combustion engine returns exhaust gas from an exhaust manifold 48 to an intake manifold 44. Before entering the intake manifold 44, the exhaust gas from the exhaust manifold 48 passes first a flow control valve 200 and then a measuring orifice 205. The pressure differential across the orifice 205 is referred to, along with a correction factor based on the pressure differential and the orifice-downstream pressure, for exhaust gas flow measurement and control.