Abstract: An airway structure, a cylinder cover and a Miller-profile engine are provided. The airway structure includes an intake duct and an intake valve arranged on an intake side, and an exhaust duct and an exhaust side roof arranged on an exhaust side. An angle of an axis of an intake valve stem relative to an assembly bottom surface of the cylinder cover is a1; an angle between a revolution cone surface of an intake valve disc and the axis of the intake valve stem is a2, an angle between a plane where the exhaust side roof is located and the assembly bottom surface is a3, a lower guide surface of the intake duct close to an intake throat is inclined downward at an angle of a4 relative to the assembly bottom surface. The airway structure satisfies: a3-3°?a1-a2?a3+3°; and/or, a4-3°?a1-a2?a4+3°.

Abstract: A control method for the combustion system comprises: a fuel injector conducts first primary spray and second primary spray at intervals, and the fuel injector injects fuel to a first arc ridge during the first primary spray; and the fuel injector sprays fuel to a second arc ridge during the second primary spray. By adopting a combustion chamber having two arc ridges and respectively injecting fuel to the two arc ridges by means of the fuel injector, it can be ensured that the amount of fuel shared by each arc ridge is reduced, gathering the fuel at a single arc ridge can be avoided, and it is beneficial to exert the improvement effect of the arc ridge on a wall impact jet flow velocity field at the tail end of a fuel beam, such that the fuel and gas distribution in a cylinder is facilitated.

Abstract: In a control method for the combustion system, spatial intensities of entrainment effects in a cylinder of fuel sprays of the two injections can be superimposed by means of two main fuel injections, two organizations of the fuel sprays for a flow field in the cylinder are implemented; by determining a duration and a first injection pressure of first main fuel injection, a cylinder pressure can at least reach an upper limit threshold of the cylinder pressure; and during second main fuel injection, in a time period when the cylinder pressure drops from the upper limit threshold of the cylinder pressure to a set cylinder pressure, a change rate of the curve slope of a cylinder pressure change curve at each time point is within a set range of slope change rates, and a rotation angle of a crankshaft is not smaller than a first preset rotation angle.

Abstract: An airway structure, a cylinder cover and a Miller-profile engine are provided. The airway structure includes an intake duct and an intake valve arranged on an intake side, and an exhaust duct and an exhaust side roof arranged on an exhaust side. An angle of an axis of an intake valve stem relative to an assembly bottom surface of the cylinder cover is a1; an angle between a revolution cone surface of an intake valve disc and the axis of the intake valve stem is a2, an angle between a plane where the exhaust side roof is located and the assembly bottom surface is a3, a lower guide surface of the intake duct close to an intake throat is inclined downward at an angle of a4 relative to the assembly bottom surface. The airway structure satisfies: a3?3°?a1-a2?a3+3°; and/or, a4?3°?a1-a2?a4+3°.

Abstract: In a control method for the combustion system, spatial intensities of entrainment effects in a cylinder of fuel sprays of the two injections can be superimposed by means of two main fuel injections, two organizations of the fuel sprays for a flow field in the cylinder are implemented, by determining a duration and a first injection pressure of first main fuel injection, a cylinder pressure can at least reach an upper limit threshold of the cylinder pressure; and during second main fuel injection, in a time period when the cylinder pressure drops from the upper limit threshold of the cylinder pressure to a set cylinder pressure, a change rate of the curve slope of a cylinder pressure change curve at each time point is within a set range of slope change rates, and a rotation angle of a crankshaft is not smaller than a first preset rotation angle.

Abstract: A control method for the combustion system comprises: a fuel injector conducts first primary spray and second primary spray at intervals, and the fuel injector injects fuel to a first arc ridge during the first primary spray; and the fuel injector sprays fuel to a second arc ridge during the second primary spray. By adopting a combustion chamber having two arc ridges and respectively injecting fuel to the two arc ridges by means of the fuel injector, it can be ensured that the amount of fuel shared by each arc ridge is reduced, gathering the fuel at a single arc ridge can be avoided, and it is beneficial to exert the improvement effect of the arc ridge on a wall impact jet flow velocity field at the tail end of a fuel beam, such that the fuel and gas distribution in a cylinder is facilitated.