A method for reducing NOx emissions during operation of an internal combustion engine in commerce which, when burning hydrocarbon fuel as a primary fuel, in the absence of any secondary fuel, has a characteristic stoichiometric ration. The method includes the following: in the absence of electrolytic activity, providing and entraining a quenching species in a gaseous medium and then interacting the quenching species with constituents present during oxidation of the primary fuel in a combustion chamber of the engine.

Provided is a control device and a control method of a high-efficiency internal combustion engine capable of stabilizing combustion and suppressing NO.sub.x emissions without unnecessarily increasing a mounting load on an ECU. Therefore, the control device of the internal combustion engine for controlling the internal combustion engine includes an ignition plug that ignites an air-fuel mixture of fuel and air in the combustion chamber, a combustion pressure estimation sensor that detects a combustion pressure in the combustion chamber, and a crank angle sensor that detects a crank angle of a crankshaft. An MBT region is set based on an ignition delay period from an ignition timing of the ignition plug calculated from a detection value of the combustion pressure estimation sensor and a detection value of the crank angle sensor to a combustion start timing in the combustion chamber, and a combustion period from the combustion start timing to a set amount combustion end timing when a set amount of combustion ends. An ignition timing of the ignition plug is controlled so as to fall within the set MBT region.

An engine system is provided, which includes an engine, a swirl control valve, an EGR passage, an EGR gas adjusting mechanism, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder when it closes. When an engine load is at or below a given threshold, the controller controls the swirl control valve to close. While the engine load is the threshold or below, the controller controls the EGR gas adjusting mechanism such that, at a fixed engine speed, an increase rate of an EGR gas amount with respect to an increase in the engine load is lower in a first load range than in a second load range, the first load range being on a higher load side of the second load range and including the threshold.

The present disclosure relates to exhaust treatment systems and engine systems. In one implementation, an engine system comprises an engine comprising an intake manifold and an exhaust manifold, the engine configured to combust a fuel-air mixture received via the intake manifold and produce a flow of exhaust gases via the exhaust manifold. The engine system also comprises a turbocharger comprising a turbine, an exhaust passageway fluidly connecting the exhaust manifold of the engine to the turbine and an intake passageway fluidly connected to the intake manifold of the engine for supplying the fuel-air mixture, a catalyzed member positioned along the exhaust passageway between the engine and the turbine, and an exhaust gas recirculation (EGR) loop fluidly connected downstream of the catalyzed member and fluidly connected to the exhaust passageway and the intake passageway.

An engine system is provided, which includes an engine, a swirl control valve, an EGR passage, an EGR gas adjusting mechanism, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder when it closes. When an engine load is at or below a given threshold, the controller controls the swirl control valve to close. While the engine load is the threshold or below, the controller controls the EGR gas adjusting mechanism such that, at a fixed engine speed, an increase rate of an EGR gas amount with respect to an increase in the engine load is lower in a first load range than in a second load range, the first load range being on a higher load side of the second load range and including the threshold.

One embodiment is a system comprising an engine including a dedicated EGR cylinder configured to provide EGR to the engine via an EGR loop, a non-dedicated cylinder, a plurality of injectors structured to inject fuel into the dedicated EGR cylinder and the non-dedicated EGR cylinder, and an electronic control system operatively coupled with the fueling system and the ignition system. The electronic control system is configured to evaluate engine operating parameters including an engine load and an engine speed. The electronic control system is responsive to variation of the engine operating parameters to control operation of the fueling system to vary combustion in the at least one dedicated cylinder between rich of stoichiometric and stoichiometric.

One embodiment is a system comprising an engine including a dedicated EGR cylinder configured to provide EGR to the engine via an EGR loop, a non-dedicated cylinder, a plurality of injectors structured to inject fuel into the dedicated EGR cylinder and the non-dedicated EGR cylinder, and an electronic control system operatively coupled with the fueling system and the ignition system. The electronic control system is configured to evaluate engine operating parameters including an engine load and an engine speed. The electronic control system is responsive to variation of the engine operating parameters to control operation of the fueling system to vary combustion in the at least one dedicated cylinder between rich of stoichiometric and stoichiometric.

One embodiment is a system comprising an engine including a dedicated EGR cylinder configured to provide EGR to the engine via an EGR loop, a non-dedicated cylinder, a plurality of injectors structured to inject fuel into the dedicated EGR cylinder and the non-dedicated EGR cylinder, and an electronic control system operatively coupled with the fueling system and the ignition system. The electronic control system is configured to evaluate engine operating parameters including an engine load and an engine speed. The electronic control system is responsive to variation of the engine operating parameters to control operation of the fueling system to vary combustion in the at least one dedicated cylinder between rich of stoichiometric and stoichiometric.

A control device for a compression ignition engine is provided. At least in a high-load range where an engine load is higher than a given value, among an operating range where a partial compression ignition combustion is performed, an EGR valve is opened, and a first injection in which fuel is injected at least from an intake stroke to the first half of a compression stroke is carried out. While an engine body is operated in the high-load range, when a torque down request and a request for reducing external EGR gas amount introduced into the cylinder are issued, the opening of the EGR valve is reduced, and a second injection in which fuel is injected in the second half of the compression stroke is carried out, and a ratio of a fuel amount of the second injection to the total fuel amount injected in a combustion cycle is increased.

A control device of a hybrid vehicle, the hybrid vehicle including an engine, a motor as a traveling power source, and a battery in which electric power to be supplied to the motor is charged, includes: a transient operation controller performing, when absolute values of an outputtable electric power and a chargeable electric power of the battery are small at a time of a transient operation of the engine, a transient operation of controlling an operating point of the engine within a wide range from low output to high output, at a position where a thermal efficiency is lower than the thermal efficiency at a time of a steady operation, and of controlling the engine to be in a combustion state where a margin to a combustion limit is greater than the margin in the steady operation.