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 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.

A variable capacity compressor is provided, including: two cylinders and a middle plate; at least one flow channel provided in the middle plate, wherein one end of the flow channel is connected to an exhaust chamber of any one of the two cylinders, the other end is connected to a suction chamber of the other one of the two cylinders. In present disclosure, by setting a flow channel in the middle plate of the variable capacity compressor, the exhaust chamber of one cylinder is connected to the suction chamber of the other cylinder. When the flow channel is completely closed, the two cylinders operate independently; when the flow channel is opened, the refrigerant in the exhaust chamber flows into the suction chamber through the flow channel, that is, the upper cylinders and the lower cylinder are connected to each other, which can adjust the capacity of the compressor.

A variable capacity compressor is provided, including: two cylinders and a middle plate; at least one flow channel provided in the middle plate, wherein one end of the flow channel is connected to an exhaust chamber of any one of the two cylinders, the other end is connected to a suction chamber of the other one of the two cylinders. In present disclosure, by setting a flow channel in the middle plate of the variable capacity compressor, the exhaust chamber of one cylinder is connected to the suction chamber of the other cylinder. When the flow channel is completely closed, the two cylinders operate independently; when the flow channel is opened, the refrigerant in the exhaust chamber flows into the suction chamber through the flow channel, that is, the upper cylinders and the lower cylinder are connected to each other, which can adjust the capacity of the compressor.

A screw compressor includes two screw rotors and two control sliders that are arranged one behind the other in a slider channel. The control sliders have a combined position with mutually facing end surfaces sealing tightly with each other, and being movable together and have a separated position, with positionable spacing from one another, forming an intermediate space. In a transfer position between the combined and separated positions, the control sliders form an inflow chamber into which the medium to be compressed flows out of one of the compression chambers by passing between the mutually facing end surfaces of the control sliders. One of the control sliders is provided with at least one outflow outlet that is adjacent to the inflow chamber and through which the medium from the inflow chamber enters an outflow opening in the slider channel that overlaps with the outflow outlet in this transfer position.

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.

A method and a device for controlling a capacity change of a compressor, and a smart home appliance. The method includes: determining whether a capacity of the compressor is required to be changed; if yes, determining an intermediate frequency; changing the capacity of the compressor while maintaining the operating frequency of the compressor at the intermediate frequency; and the maintaining the operating frequency of the compressor at the intermediate frequency reduces a sudden change in output of the compressor after the changing the capacity.

A scroll compressor includes a fixed scroll, a movable scroll revolvable with respect to the fixed scroll, and a crankshaft rotatable to cause the movable scroll to revolve. A discharge port is formed in a first scroll of the fixed scroll or the movable scroll. A cutout portion is formed in a second scroll of the fixed scroll or the movable scroll. The cutout portion formed in the second scroll at least partially passes through a profile of the discharge port formed in the first scroll because of revolution of the movable scroll.