Provided is an engine control device capable of suppressing deterioration of combustion stability due to a change in engine temperature in an engine which performs lean combustion or EGR combustion. When lean combustion in which an air-fuel mixture leaner than a stoichiometric air-fuel ratio is burned or exhaust gas recirculation combustion in which a diluted air-fuel mixture is burned by re-suctioning exhaust gas discharged from the combustion chamber into the combustion chamber is performed, a ratio of a fuel injection amount during a compression stroke to a total fuel injection amount during one combustion cycle is increased as a temperature of an engine decreases.

Methods and systems are provided for an engine. In one example, a method comprises stopping an engine via a soft-stop method in response to a likelihood of condensate forming being less than or equal to a threshold likelihood. The method further comprises stopping the engine via an exhaust gas evacuation method in response to the likelihood of condensate forming being greater than the threshold likelihood.

A method of controlling a gas engine connected to a turbocharger including a compressor and a turbine includes: performing a knocking control operation of optimizing an ignition timing as a steady operation; and in a case where a load of the gas engine increases during the steady operation, when a degree of increase in the load is relatively small, gradually increasing an actual fuel injection amount while keeping the ignition timing, and when the degree of increase in the load is relatively great, retarding the ignition timing and then gradually increasing the actual fuel injection amount.

A method of controlling a gas engine connected to a turbocharger including a compressor and a turbine includes: performing a knocking control operation of optimizing an ignition timing as a steady operation; and in a case where a load of the gas engine increases during the steady operation, when a degree of increase in the load is relatively small, gradually increasing an actual fuel injection amount while keeping the ignition timing, and when the degree of increase in the load is relatively great, retarding the ignition timing and then gradually increasing the actual fuel injection amount.

Control is performed so as to occur SPCCI combustion in which, after an air-fuel mixture in a first area of a combustion chamber that includes an electrode portion of an ignition device is burned by receiving ignition energy, an air-fuel mixture formed in a second area located on an outer periphery of the first area is self-ignited. Control is also performed such that, in a high load operation region of an SPCCI combustion execution region, an air-fuel ratio in the entire combustion chamber becomes richer than a stoichiometric air-fuel ratio and that an air-fuel ratio of the air-fuel mixture in the first area becomes leaner than an air-fuel ratio of the air-fuel mixture in the second area.

Control is performed so as to occur SPCCI combustion in which, after an air-fuel mixture in a first area of a combustion chamber that includes an electrode portion of an ignition device is burned by receiving ignition energy, an air-fuel mixture formed in a second area located on an outer periphery of the first area is self-ignited. Control is also performed such that, in a high load operation region of an SPCCI combustion execution region, an air-fuel ratio in the entire combustion chamber becomes richer than a stoichiometric air-fuel ratio and that an air-fuel ratio of the air-fuel mixture in the first area becomes leaner than an air-fuel ratio of the air-fuel mixture in the second area.

An internal-combustion-engine warm-up apparatus includes: a post-processing apparatus; a heater arranged upstream of the post-processing apparatus on the exhaust path; a circulation path where air having passed through the post-processing apparatus is fed back to an upstream side of the heater; an air pump that is a blower that feeds air heated by the heater to the post-processing apparatus; a coolant flow path; a heat exchanger; and a control apparatus that controls operation of the heater and the blower, and in a state where the engine is stopped, the control apparatus causes the heater and the air pump to operate, and causes the air heated by the heater to be supplied to the post-processing apparatus and the heat exchanger.

An internal-combustion-engine warm-up apparatus includes: a post-processing apparatus; a heater arranged upstream of the post-processing apparatus on the exhaust path; a circulation path where air having passed through the post-processing apparatus is fed back to an upstream side of the heater; an air pump that is a blower that feeds air heated by the heater to the post-processing apparatus; a coolant flow path; a heat exchanger; and a control apparatus that controls operation of the heater and the blower, and in a state where the engine is stopped, the control apparatus causes the heater and the air pump to operate, and causes the air heated by the heater to be supplied to the post-processing apparatus and the heat exchanger.

A method of operating a two-stroke cycle, opposed-piston engine comprising a pumping device coupled to pump air to cylinders of the engine through a charge air cooler and an aftertreatment system of thermally-activated devices coupled to receive exhaust from the cylinders by which a thermal state of the exhaust sufficient to sustain thermal activation of one or more of the aftertreatment system devices may be maintained during a deceleration or motoring condition of operation by reducing the mass airflow to the engine.

A method of operating a two-stroke cycle, opposed-piston engine comprising a pumping device coupled to pump air to cylinders of the engine through a charge air cooler and an aftertreatment system of thermally-activated devices coupled to receive exhaust from the cylinders by which a thermal state of the exhaust sufficient to sustain thermal activation of one or more of the aftertreatment system devices may be maintained during a deceleration or motoring condition of operation by reducing the mass airflow to the engine.