US Patent 7788923 Constant EGR rate engine and method

An internal combustion engine (100) includes a first exhaust manifold (120), and a second exhaust manifold (118) fluidly connected to the first exhaust manifold (120) through an exhaust valve (122). An exhaust gas recirculation (EGR) cooler (124) constantly fluidly connects the second exhaust manifold (118) with an intake manifold (112). A turbocharger (102) has a turbine (126) in fluid communication with the first exhaust manifold (120), and a compressor (132) in fluid communication with a supercharger (140). A charge air cooler (150) fluidly connects the supercharger (140) with the intake manifold (112).