Variable volume ratio compressors may be controlled using a switching parameter based on compressor speed and suction density to improve the matching of compressor volume ratio to desired discharge conditions. Delay periods may be implemented in the determination of when to change volume ratio to control the frequency of changes to the volume ratio. The switching parameter may be a product of the compressor speed and suction density. The volume ratio of the compressor may be controlled by switching valves directing pressure to a piston of a variable volume ratio system of the compressor.

A control device for an internal combustion engine is provided which enables control of dilution of oil by fuel and water drops, i.e., control of the amount of so-called oil dilution. The control device for an internal combustion engine that is lubricated or cooled by oil includes: a variable displacement oil pump capable of varying the amount of discharge of the oil; an air-fuel ratio sensor for sensing an air-fuel ratio of the internal combustion engine; and an ECU for controlling the amount of discharge of the variable displacement oil pump. The ECU controls the amount of discharge of the variable displacement oil pump, based on the air-fuel ratio sensed by the air-fuel ratio sensor.

A control device for an internal combustion engine is provided which enables control of dilution of oil by fuel and water drops, i.e., control of the amount of so-called oil dilution. The control device for an internal combustion engine that is lubricated or cooled by oil includes: a variable displacement oil pump capable of varying the amount of discharge of the oil; an air-fuel ratio sensor for sensing an air-fuel ratio of the internal combustion engine; and an ECU for controlling the amount of discharge of the variable displacement oil pump. The ECU controls the amount of discharge of the variable displacement oil pump, based on the air-fuel ratio sensed by the air-fuel ratio sensor.

A compressor and an air conditioner are provided. The compressor includes a main shaft, a first cylinder and a second cylinder. The main shaft sequentially passes through the first cylinder and the second cylinder and can rotate therein, to compress refrigerant entering the first cylinder and the second cylinder. The second cylinder has an inner cavity capable of receiving the main shaft. A volume variation control cavity in communication with the inner cavity is provided in a side wall of the inner cavity, and a sliding vane is provided inside the volume variation control cavity. The volume variation control cavity can be selectively connected to a gas inlet and a gas outlet of the compressor, to change gas pressure in the volume variation control cavity, and drive the sliding vane to abut against or be separated from the main shaft by the gas pressure in the volume variation control cavity.

Disclosed are a variable-capacity control structure, a compressor and a variable-capacity control method thereof. The variable-capacity control structure includes: a variable-capacity assembly and a sliding vane restraint unit; the variable-capacity assembly is provided outside a housing of a compressor to which the variable-capacity control structure is attached, and is configured to act in a setting order; the sliding vane restraint unit is provided inside a pump body of the compressor, and is configured to cause a variable-capacity cylinder assembly in the compressor to be in a working state or an idling state under controlling the variable-capacity assembly to act in the setting order. By the solution of the present disclosure, advantages that vibration is reduced, compressor is not easy to shut down and pipeline is not easy to break are implemented.

Disclosed are a variable-capacity control structure, a compressor and a variable-capacity control method thereof. The variable-capacity control structure includes: a variable-capacity assembly and a sliding vane restraint unit; the variable-capacity assembly is provided outside a housing of a compressor to which the variable-capacity control structure is attached, and is configured to act in a setting order; the sliding vane restraint unit is provided inside a pump body of the compressor, and is configured to cause a variable-capacity cylinder assembly in the compressor to be in a working state or an idling state under controlling the variable-capacity assembly to act in the setting order. By the solution of the present disclosure, advantages that vibration is reduced, compressor is not easy to shut down and pipeline is not easy to break are implemented.

A screw compressor, method of operating, and refrigerant circuit are disclosed. The screw compressor includes a suction inlet that receives a working fluid to be compressed. A compression mechanism is fluidly connected to the suction inlet that compresses the working fluid. A discharge outlet is fluidly connected to the compression mechanism that outputs the working fluid following compression by the compression mechanism. A valve assembly is configured to vary a location at which the compression mechanism compresses the working fluid, the valve assembly being disposed to modify a suction location of the screw compressor.

A screw compressor, method of operating, and refrigerant circuit are disclosed. The screw compressor includes a suction inlet that receives a working fluid to be compressed. A compression mechanism is fluidly connected to the suction inlet that compresses the working fluid. A discharge outlet is fluidly connected to the compression mechanism that outputs the working fluid following compression by the compression mechanism. A valve assembly is configured to vary a location at which the compression mechanism compresses the working fluid, the valve assembly being disposed to modify a suction location of the screw compressor.

Variable volume ratio compressors may be controlled using a switching parameter based on compressor speed and suction density to improve the matching of compressor volume ratio to desired discharge conditions. Delay periods may be implemented in the determination of when to change volume ratio to control the frequency of changes to the volume ratio. The switching parameter may be a product of the compressor speed and suction density. The volume ratio of the compressor may be controlled by switching valves directing pressure to a piston of a variable volume ratio system of the compressor.

Variable volume ratio compressors may be controlled using a switching parameter based on compressor speed and suction density to improve the matching of compressor volume ratio to desired discharge conditions. Delay periods may be implemented in the determination of when to change volume ratio to control the frequency of changes to the volume ratio. The switching parameter may be a product of the compressor speed and suction density. The volume ratio of the compressor may be controlled by switching valves directing pressure to a piston of a variable volume ratio system of the compressor.