The present disclosure relates to dual fuel internal combustion engines with multiple cylinder banks and/or cylinder subsets, and exhaust aftertreatment systems associated therewith. Systems and methods are disclosed that relate to engine operations involving fuelling control for fuel cutout of one or more of the cylinder banks and/or cylinder subsets in response to a fuel cutout event to increase gaseous fuel substitution on the other cylinder banks and/or cylinder subsets to satisfy the torque request and thermal management conditions of the aftertreatment system.

The present disclosure relates to dual fuel internal combustion engines with multiple cylinder banks and/or cylinder subsets, and exhaust aftertreatment systems associated therewith. Systems and methods are disclosed that relate to engine operations involving fuelling control for fuel cutout of one or more of the cylinder banks and/or cylinder subsets in response to a fuel cutout event to increase gaseous fuel substitution on the other cylinder banks and/or cylinder subsets to satisfy the torque request and thermal management conditions of the aftertreatment system.

An object of the present invention is to optimally control a recirculation amount of exhaust gas flowing to an engine that includes an exhaust heat recovery device in a main exhaust pipe thereof and performs exhaust gas recirculation from downstream of the exhaust heat recovery device. An engine control device includes an exhaust heat recovery device, an exhaust gas recirculation pipe, an exhaust gas temperature acquisition unit, and an exhaust gas recirculation amount control unit. The exhaust heat recovery device is provided in a main exhaust pipe of an engine and recovers heat from exhaust gas. The exhaust gas recirculation pipe is branched from the main exhaust pipe downstream of the exhaust heat recovery device and recirculates exhaust gas to the engine. The exhaust gas temperature acquisition unit acquires an exhaust gas temperature downstream of the exhaust heat recovery device. The exhaust gas recirculation amount control unit controls a recirculation amount of exhaust gas flowing through the exhaust gas recirculation pipe based on at least the exhaust gas temperature.

An object of the present invention is to optimally control a recirculation amount of exhaust gas flowing to an engine that includes an exhaust heat recovery device in a main exhaust pipe thereof and performs exhaust gas recirculation from downstream of the exhaust heat recovery device. An engine control device includes an exhaust heat recovery device, an exhaust gas recirculation pipe, an exhaust gas temperature acquisition unit, and an exhaust gas recirculation amount control unit. The exhaust heat recovery device is provided in a main exhaust pipe of an engine and recovers heat from exhaust gas. The exhaust gas recirculation pipe is branched from the main exhaust pipe downstream of the exhaust heat recovery device and recirculates exhaust gas to the engine. The exhaust gas temperature acquisition unit acquires an exhaust gas temperature downstream of the exhaust heat recovery device. The exhaust gas recirculation amount control unit controls a recirculation amount of exhaust gas flowing through the exhaust gas recirculation pipe based on at least the exhaust gas temperature.

An intake and exhaust system of an internal combustion engine includes an exhaust gas recirculation passage (35) communicates a part of an exhaust passage (7) downstream of a turbine with a part of an intake passage (6) upstream of a compressor and a cooling circuit (51), the cooling circuit including a first evaporator (52) provided in a part of the exhaust passage downstream of the turbine and upstream of a junction with the exhaust gas recirculation passage and storing a medium, an ejector pump (54) using vapor from the first evaporator as a driving flow, a condenser (57) for cooling and condensing the vapor ejected from the ejector pump and returning the condensed medium to the first evaporator, and a second evaporator (55) provided in the exhaust gas recirculation passage to cool the exhaust gas passing through the exhaust gas recirculation passage by evaporating a medium stored therein with a negative pressure created by the ejector pump.

An intake and exhaust system of an internal combustion engine includes an exhaust gas recirculation passage (35) communicates a part of an exhaust passage (7) downstream of a turbine with a part of an intake passage (6) upstream of a compressor and a cooling circuit (51), the cooling circuit including a first evaporator (52) provided in a part of the exhaust passage downstream of the turbine and upstream of a junction with the exhaust gas recirculation passage and storing a medium, an ejector pump (54) using vapor from the first evaporator as a driving flow, a condenser (57) for cooling and condensing the vapor ejected from the ejector pump and returning the condensed medium to the first evaporator, and a second evaporator (55) provided in the exhaust gas recirculation passage to cool the exhaust gas passing through the exhaust gas recirculation passage by evaporating a medium stored therein with a negative pressure created by the ejector pump.

An intake and exhaust system of an internal combustion engine includes an exhaust gas recirculation passage (35) communicates a part of an exhaust passage (7) downstream of a turbine with a part of an intake passage (6) upstream of a compressor and a cooling circuit (51), the cooling circuit including a first evaporator (52) provided in a part of the exhaust passage downstream of the turbine and upstream of a junction with the exhaust gas recirculation passage and storing a medium, an ejector pump (54) using vapor from the first evaporator as a driving flow, a condenser (57) for cooling and condensing the vapor ejected from the ejector pump and returning the condensed medium to the first evaporator, and a second evaporator (55) provided in the exhaust gas recirculation passage to cool the exhaust gas passing through the exhaust gas recirculation passage by evaporating a medium stored therein with a negative pressure created by the ejector pump.

An intake and exhaust system of an internal combustion engine includes an exhaust gas recirculation passage (35) communicates a part of an exhaust passage (7) downstream of a turbine with a part of an intake passage (6) upstream of a compressor and a cooling circuit (51), the cooling circuit including a first evaporator (52) provided in a part of the exhaust passage downstream of the turbine and upstream of a junction with the exhaust gas recirculation passage and storing a medium, an ejector pump (54) using vapor from the first evaporator as a driving flow, a condenser (57) for cooling and condensing the vapor ejected from the ejector pump and returning the condensed medium to the first evaporator, and a second evaporator (55) provided in the exhaust gas recirculation passage to cool the exhaust gas passing through the exhaust gas recirculation passage by evaporating a medium stored therein with a negative pressure created by the ejector pump.

Methods and systems for low emission power generation in combined cycle power plants are provided. One system includes a gas turbine system that stoichiometrically combusts a fuel and an oxidant in the presence of a compressed recycle stream to provide mechanical power and a gaseous exhaust. The compressed recycle stream acts as a diluent to moderate the temperature of the combustion process. A boost compressor can boost the pressure of the gaseous exhaust before being compressed into the compressed recycle stream. A purge stream is tapped off from the compressed recycle stream and directed to a C0.sub.2 separator which discharges C0.sub.2 and a nitrogen-rich gas which can be expanded in a gas expander to generate additional mechanical power.

Methods and systems for low emission power generation in hydrocarbon recovery processes are provided. One system includes a gas turbine system configured to stoichiometrically combust a compressed oxidant derived from enriched air and a fuel in the presence of a compressed recycle exhaust gas and expand the discharge in an expander to generate a recycle exhaust stream and drive a main compressor. A boost compressor receives and increases the pressure of the recycle exhaust stream and prior to being compressed in a compressor configured to generate the compressed recycle exhaust gas. To promote the stoichiometric combustion of the fuel and increase the CO.sub.2 content in the recycle exhaust gas, the enriched air can have an increased oxygen concentration.