An engine includes an exhaust manifold, an intake manifold, and an EGR device configured to supply EGR gas from the exhaust manifold to the intake manifold. An EGR cooler is provided at a side of the exhaust manifold, and a longitudinal direction of the EGR cooler is in an up-down direction of the engine in a used state.

A system is provided. The system includes a controller communicatively coupled to an industrial combustion engine and an exhaust gas recirculation (EGR) system, wherein the EGR system is configured to route exhaust gas generated by the industrial combustion engine from at least one exhaust system to at least one intake system, the EGR system includes multiple EGR circuits, each EGR circuit of the multiple EGR circuits includes an EGR cooler unit including at least two of a high temperature non-condensing cooler, a low temperature condensing cooler, an adiabatic gas/liquid separator, and a reheater. The controller includes a processor and a non-transitory memory encoding one or more processor-executable routines, wherein the one or more routines, when executed by the processor, cause the controller to control operations of both the industrial combustion engine and the EGR system.

A valve device increases or decreases a flow rate of EGR gas. The valve device includes a housing, a bypass valve body, an EGR valve body. The housing includes a first upstream passage into which the EGR gas cooled by an EGR cooler flows, a second upstream passage into which the EGR gas that bypasses the EGR cooler flows, a junction connected to each of a gas-flow downstream side of the first upstream passage and a gas-flow downstream side of the second upstream passage, and a downstream passage connected to the first upstream passage and the second upstream passage via the junction. The bypass valve body opens and closes the second upstream passage. The EGR valve body is provided in the downstream passage, rotates around an EGR valve axis.

In the exhaust gas control system, the electronic control unit is configured to execute first air-fuel ratio control for controlling an air-fuel ratio of an air-fuel mixture in a part of cylinders to a lean air-fuel ratio and controlling an air-fuel ratio of an air-fuel mixture in the other part of the cylinders to a rich air-fuel ratio is executed. The electronic control unit is configured to execute second air-fuel ratio control to perform malfunction diagnosis. The electronic control unit is configured to execute second air-fuel ratio control when the execution of the first air-fuel ratio control is interrupted after the temperature of the three-way catalyst becomes equal to or higher than the diagnosis temperature.

In the exhaust gas control system, the electronic control unit is configured to execute first air-fuel ratio control for controlling an air-fuel ratio of an air-fuel mixture in a part of cylinders to a lean air-fuel ratio and controlling an air-fuel ratio of an air-fuel mixture in the other part of the cylinders to a rich air-fuel ratio is executed. The electronic control unit is configured to execute second air-fuel ratio control to perform malfunction diagnosis. The electronic control unit is configured to execute second air-fuel ratio control when the execution of the first air-fuel ratio control is interrupted after the temperature of the three-way catalyst becomes equal to or higher than the diagnosis temperature.

An internal combustion engine (ICE) and method of control are provided to determine a value of a catalyst temperature and a value of a quantity of a reducing agent stored in the catalyst. The quantity of gas recirculated by an exhaust gas recirculation (EGR) system of the ICE is calculated on the basis of the value of the catalyst temperature and of the value of the quantity of the reducing agent stored in the catalyst. This solution makes it possible to adjust the quantity of gas recirculated by the EGR system on the basis of parameters linked to an efficiency of a selective catalytic reduction (SCR) system associated with the ICE, in order to reduce the global quantity of pollutants produced by the ICE and released in the environment.

An internal combustion engine (ICE) and method of control are provided to determine a value of a catalyst temperature and a value of a quantity of a reducing agent stored in the catalyst. The quantity of gas recirculated by an exhaust gas recirculation (EGR) system of the ICE is calculated on the basis of the value of the catalyst temperature and of the value of the quantity of the reducing agent stored in the catalyst. This solution makes it possible to adjust the quantity of gas recirculated by the EGR system on the basis of parameters linked to an efficiency of a selective catalytic reduction (SCR) system associated with the ICE, in order to reduce the global quantity of pollutants produced by the ICE and released in the environment.

The present disclosure provides a method for controlling EGR rate of a low pressure EGR system, a system and a vehicle. The method calculates a molar concentration of water molecules of exhaust gas processed by EGR cooler, calculates a molar concentration of water molecules, obtains coefficient as to excess air, and calculates a molar volume ratio of air according to the coefficient. Under a maximum limit of humidity, an allowable EGR rate of the exhaust gas processed by the EGR cooler is determined and an allowable EGR rate of the mixed gas before entry into supercharger and/or compressor is also determined, a lower EGR rate between the two allowable rates is set as a maximum for application actual working conditions. The present disclosure solves a problem of condensation caused by an introduction of exhaust gas from the existing gasoline engine.

A control device predicts whether temporary reduction occurs to a charging efficiency of fresh air in an in-cylinder gas by an influence of an EGR rate of the in-cylinder gas, which increases later than increase of a charging efficiency of the in-cylinder gas, if a first arithmetic operation is applied to calculating a target throttle opening degree based on a target charging efficiency which is increasing, in a case of shifting to an acceleration operation, by using a prediction model expressing dynamic characteristics of an internal combustion engine. When it is predicted that temporary reduction occurs to the charging efficiency of the fresh air, the control device calculates the target throttle opening degree by a second arithmetic operation by which an increase speed of a throttle opening degree is restrained more than by the first arithmetic operation, instead of calculating the target throttle opening degree by the first arithmetic operation.

A control device predicts whether temporary reduction occurs to a charging efficiency of fresh air in an in-cylinder gas by an influence of an EGR rate of the in-cylinder gas, which increases later than increase of a charging efficiency of the in-cylinder gas, if a first arithmetic operation is applied to calculating a target throttle opening degree based on a target charging efficiency which is increasing, in a case of shifting to an acceleration operation, by using a prediction model expressing dynamic characteristics of an internal combustion engine. When it is predicted that temporary reduction occurs to the charging efficiency of the fresh air, the control device calculates the target throttle opening degree by a second arithmetic operation by which an increase speed of a throttle opening degree is restrained more than by the first arithmetic operation, instead of calculating the target throttle opening degree by the first arithmetic operation.