Methods and systems are provided for to methods and systems for distributing exhaust gas to a turbine, a turbocharger bypass, and an exhaust gas recirculation (EGR) line via a valve. In one example, a method may include selectively flowing exhaust gas, via a valve coupled to an exhaust passage, to one or more of an exhaust gas recirculation (EGR) passage, an exhaust turbine, and an exhaust catalyst via a bypass passage without flowing through the exhaust turbine based on engine operating conditions.

This engine includes an EGR device. The engine is provided with: an EGR gas temperature sensor; an EGR valve; an EGR control unit; an EGR valve position detection unit; a diagnosis unit; a first timer; a second timer; and a diagnosis control unit. The diagnosis unit diagnoses whether the EGR gas temperature sensor has failed, on the basis of a detected value from the EGR gas temperature sensor. The first timer, when the EGR valve is open, performs counting in accordance with the passage of time. The second timer, if a count value of the first timer is greater than or equal to a first threshold value set in advance, and if a predetermined condition is satisfied, performs counting in accordance with the passage of time. The diagnosis control unit prohibits diagnosis by the diagnosis unit if a count value of the second timer is less than a second threshold value set in advance, and permits the diagnosis if the count value is greater than or equal to the second threshold value.

Methods and systems are provided for to methods and systems for distributing exhaust gas to a turbine, a turbocharger bypass, and an exhaust gas recirculation (EGR) line via a valve. In one example, a method may include selectively flowing exhaust gas, via a valve coupled to an exhaust passage, to one or more of an exhaust gas recirculation (EGR) passage, an exhaust turbine, and an exhaust catalyst via a bypass passage without flowing through the exhaust turbine based on engine operating conditions.

A control apparatus of an internal combustion engine controls a heat exchange cooling water flow rate which is a flow rate of cooling water supplied to an exhaust heat recovery cooler apparatus, to a larger flow rate when the control apparatus executes an EGR control, and the exhaust heat recovery cooler apparatus performs an exhaust heat recovery function, than when the control apparatus executes the EGR control, and the exhaust heat recovery cooler apparatus does not perform the exhaust heat recovery function.

The present disclosure belongs to the technical field of engines, and specifically relates to a gas mixing device and a natural gas engine. The gas mixing device includes a housing, a first mixing core, a first measurement assembly, a second mixing core, and a second measurement assembly. An air inlet and a combustion gas inlet respectively communicate with the first mixing core to form a mixed gas in the first mixing core; the first measurement assembly is connected to the first mixing core, the second mixing core is connected in the housing, the EGR exhaust gas inlet and the first mixing core respectively communicate with the second mixing core, and the second measurement assembly is connected to the EGR exhaust gas inlet. In the gas mixing device according to the embodiment of the present disclosure, the first measurement assembly and the second measurement assembly respectively provide measurement data for obtaining flow rates of the air, combustion gas and EGR exhaust gas. As compared with the speed-density method and the throttle model, the results tend to be more accurate, which facilitates a control of the air-fuel ratio to improve the conversion efficiency of the three-way catalytic converter.

The present disclosure belongs to the technical field of engines, and specifically relates to a gas mixing device and a natural gas engine. The gas mixing device includes a housing, a first mixing core, a first measurement assembly, a second mixing core, and a second measurement assembly. An air inlet and a combustion gas inlet respectively communicate with the first mixing core to form a mixed gas in the first mixing core; the first measurement assembly is connected to the first mixing core, the second mixing core is connected in the housing, the EGR exhaust gas inlet and the first mixing core respectively communicate with the second mixing core, and the second measurement assembly is connected to the EGR exhaust gas inlet. In the gas mixing device according to the embodiment of the present disclosure, the first measurement assembly and the second measurement assembly respectively provide measurement data for obtaining flow rates of the air, combustion gas and EGR exhaust gas. As compared with the speed-density method and the throttle model, the results tend to be more accurate, which facilitates a control of the air-fuel ratio to improve the conversion efficiency of the three-way catalytic converter.

A boosted engine is provided, which includes an engine body formed with a combustion chamber, a spark plug, a fuel injection valve, a booster, a boost controller, and a control unit including an operating range determining module and a compression end temperature estimating module. In a high load range, the fuel injection valve and the spark plug are controlled so that a mixture gas inside the combustion chamber starts combustion through flame propagation by ignition of the spark plug, and unburned mixture gas then combusts by compression ignition, and the boost controller is controlled to bring the booster into a boosting state. When a gas temperature inside the combustion chamber exceeds a given temperature at CTDC, the fuel injection valve is controlled so that a fuel injection end timing occurs on a compression stroke, and the spark plug is controlled so that the mixture gas is ignited after CTDC.

A control method of a vehicle having an exhaust gas recirculation (EGR) system includes efficiently controlling a temperature of recirculated exhaust gas and, even when the temperature of recirculated exhaust gas excessively increases, damage to hardware, such as an intake manifold or parts of the exhaust gas recirculation system can be prevented. The control method includes: detecting the temperature of exhaust gas recirculated to an engine intake system by the EGR system; entering into a protection mode so as to control the temperature of the recirculated exhaust gas; determining a correction value such that the controller controls the temperature of the recirculated exhaust gas; and correcting an engine control value by using the determined correction value and controlling an engine according to the corrected engine control value.

Methods and systems are provided for coordinated operation of electric variable geometry turbocharger (e-VGT), an exhaust gas recirculation (EGR), and electric motor coupled to the e-VGT for expedited catalyst light-off. In one example, a method may include, during a cold-start, decreasing each of an opening of e-VGT vanes and an opening of an EGR valve while operating the electric motor for braking and reducing the e-VGT speed.

A system is disclosed that may include a gas recirculation passageway configured to recirculate gas exiting an engine to an intake of the engine prior to the gas reaching an aftertreatment system associated with the engine. The system may include a valve configured to control a gas recirculation of the gas recirculation passageway. The system may include a controller configured to cause, during a compression braking procedure for the engine, actuation of the valve to produce the gas recirculation when the aftertreatment system is performing an operation that is temperature-dependent.