Abstract: An exhaust gas recirculation (EGR) cooler for cooling exhaust gas includes at least one channel configured to allow the exhaust gas to flow through it, and a casing defining a cooling chamber around the at least one channel. The cooling chamber is configured to enable heat transfer between the exhaust gas and the coolant. The at least one channel has an interior surface and an exterior surface made of a first metal and a second metal, respectively, and configured to be in contact with the exhaust gas and the coolant, respectively. The second metal has a higher thermal conductivity than the first metal. The casing includes a coolant inlet and a coolant outlet configured to enable the coolant to enter and exit the cooling chamber, and an exhaust gas inlet and an exhaust gas outlet configured to enable the exhaust gas to enter and exit the at least one channel.

Abstract: An exhaust gas recirculation (EGR) cooler for cooling exhaust gas includes at least one channel configured to allow the exhaust gas to flow through it, and a casing defining a cooling chamber around the at least one channel. The cooling chamber is configured to enable heat transfer between the exhaust gas and the coolant. The at least one channel has an interior surface and an exterior surface made of a first metal and a second metal, respectively, and configured to be in contact with the exhaust gas and the coolant, respectively. The second metal has a higher thermal conductivity than the first metal. The casing includes a coolant inlet and a coolant outlet configured to enable the coolant to enter and exit the cooling chamber, and an exhaust gas inlet and an exhaust gas outlet configured to enable the exhaust gas to enter and exit the at least one channel.

Abstract: In one approach, a method for measuring exhaust gas recirculation flow in an engine is provided. The method comprises separating EGR flow into at least a first flow and a second flow, passing the separated first flow through a restriction region, where the first flow passes through the restriction region separately from the separated second flow, combining the separated second flow and inducting the combined flows into a cylinder of the engine, where the EGR flow is separated and then combined within a common EGR passage.

Abstract: In one approach, a method for measuring exhaust gas recirculation flow in an engine is provided. The method comprises separating EGR flow into at least a first flow and a second flow, passing the separated first flow through a restriction region, where the first flow passes through the restriction region separately from the separated second flow, combining the separated second flow and inducting the combined flows into a cylinder of the engine, where the EGR flow is separated and then combined within a common EGR passage.

Abstract: A method for controlling a diesel engine exhaust gas recirculation system is described. In particular, a simplified diesel engine system is provided where presence of exhaust gas recirculation of flow is controlled via a two-position valve, while a quantity of exhaust gas recirculation is adjusted by varying the throttle valve. In this way, a reduced cost diesel exhaust gas recirculation system is achieved that provides the functionality of having variable amounts of exhaust gas recirculation.

Abstract: A method for controlling an engine during sensor degradation uses a remaining active sensor. The engine has an exhaust gas recirculation system utilizing pressure sensors upstream and downstream of an orifice. The downstream pressure sensor is coupled to the engine intake manifold and is also used for engine air-fuel ratio control.

Abstract: A method for controlling a diesel engine exhaust gas recirculation system is described. In particular, a simplified diesel engine system is provided where presence of exhaust gas recirculation of flow is controlled via a two-position valve, while a quantity of exhaust gas recirculation is adjusted by varying the throttle valve. In this way, a reduced cost diesel exhaust gas recirculation system is achieved that provides the functionality of having variable amounts of exhaust gas recirculation.

Abstract: A method for controlling an engine during sensor degradation uses a remaining active sensor. The engine has an exhaust gas recirculation system utilizing pressure sensors upstream and downstream of an orifice. The downstream pressure sensor is coupled to the engine intake manifold and is also used for engine air-fuel ratio control.

Abstract: A method for measuring flow through an orifice using an upstream gauge pressure sensor and a downstream absolute pressure sensor determines atmospheric pressure when flow through the orifice is substantially zero, or less than a predetermined value. Then, this estimate, along with the upstream and downstream pressure sensors are used to measure flow through the orifice.

Abstract: A method for estimating pressure surround an engine uses a gauge pressure sensor upstream of an orifice and an absolute pressure sensor downstream of the orifice. In particular, atmospheric pressure can be determined when flow through the orifice is below a predetermined threshold.