A method of manufacturing a suction pipe for a multi-compressor device having a plurality of inlets, the suction pipe comprising a primary portion and a plurality of secondary portions arranged to receive fluid from the primary portion for supplying fluid in parallel to the inlets of a multi-compressor device. The method includes designing the suction pipe by: selecting a first dimension for the primary portion of the suction pipe, calculating a first fluid velocity for fluid in the primary portion based on the first dimension, and comparing the first fluid velocity to a first predetermined threshold; selecting a second dimension for the secondary portions, calculating a second fluid velocity for fluid in the secondary portions based on the second dimension, and comparing the second fluid velocity to a second predetermined threshold; and calculating a ratio of the first fluid velocity to the second fluid velocity.

A scroll compressor is provided. The scroll compressor has a housing, a partition plate, a rack, a movable scroll plate, a stationary scroll plate and a pressure relief low-speed rotation structure. The partition plate is in the interior of the housing and divides the interior of the housing into a suction space and a discharge space, and has a first through to communicate the suction space with the discharge space. The rack is in the suction space and spaced apart from the partition plate. The movable scroll plate is movably provided on the rack. The stationary scroll plate is provided on the rack and cooperates with the movable scroll plate, and has a second through hole communicating with the discharge space. The pressure relief low-speed rotation structure is provided on the stationary scroll plate and configured to communicate the second through hole with the discharge space.

A scroll compressor may include a casing having a low pressure portion and a high pressure portion, a refrigerant suction pipe that communicates with the low pressure portion and a refrigerant discharge pipe that communicates with the high pressure portion, a drive motor installed inside of the low pressure portion, an orbiting scroll coupled to the drive motor to perform an orbiting motion, a non-orbiting scroll engaged with the orbiting scroll to form a compression chamber, and a refrigerant guide provided on the non-orbiting scroll to guide a refrigerant suctioned into the low pressure portion to be suctioned into the compression chamber, whereby an increase in specific volume of refrigerant suctioned into the compression chamber may be suppressed, and thus, an amount of refrigerant suctioned into the compression chamber may increase, thereby improving efficiency of the compressor.

An expander and a fluid circulation system comprising same are disclosed. The expander comprises a housing, an expansion mechanism, an exhaust pipe, an oil sump and a lubricant discharge channel. The expansion mechanism is provided in the housing to expand a high-pressure fluid into a low-pressure fluid. The exhaust pipe discharges the low-pressure fluid out of the expander and comprises an end portion assembled in a first opening of the housing and provided with an exhaust port; the low-pressure fluid enters the exhaust pipe via the exhaust port. The oil sump stores a lubricant in the housing. The lubricant discharge channel discharges the lubricant in the oil sump into the exhaust pipe and/or an external system pipeline and comprises an inlet end having an inlet located at a predetermined oil level of the oil sump and an outlet end having an outlet.

A suction fitting coupled to a scroll compressor that has an outer housing with an inside diameter and a suction port defined in a wall of the outer housing. A suction duct is disposed inside the outer housing at a spaced distance from the wall of the outer housing. The suction duct defines an entrance port aligned with the suction port. The suction fitting includes a first member being generally cylindrical, and a second member being generally cylindrical. The second member is disposed inside the first member with a portion of the second member extending into the outer housing through the suction port, spanning the spaced distance to the suction duct, and coupling with the entrance port of the suction duct. Neither the first member nor the second member includes a suction screen for filtering out solid contaminants in a flow of refrigerant.

A pumping system is provided, including a rough-vacuum pump; a Roots vacuum pump including a pumping stage having a stator inside which two Roots rotors are configured to rotate synchronously in opposite directions to drive a gas to be pumped between an inlet orifice and an outlet orifice; and a pipeline connecting the outlet orifice to an intake of the rough-vacuum pump, a shortest distance between an edge of the outlet orifice and each of the Roots rotors in the pumping stage being less than 3 cm, and the outlet orifice being situated at the end of an upstream tube of the pipeline that passes into the pumping stage.

A horizontal compressor includes a case; a high and low pressure separating plate dividing an inner space of the case into a high-pressure chamber and a low-pressure chamber; a compressor in the high-pressure chamber configured to be operated by a motor to compress refrigerant; a suction pipe in the case to communicate with the low-pressure chamber and through which the refrigerant is sucked; and an internal suction pipe to pass through the high and low pressure separating plate, one end of the internal suction pipe connected to the compressor and another end of the internal suction pipe to communicate with the low-pressure chamber so that the refrigerant in the low-pressure chamber flows into the compressor, wherein the internal suction pipe includes a connecting pipe adjacent to a lower surface of the case parallel to a central axis of the case.

A scroll compressor may include a casing having a low pressure portion and a high pressure portion, a refrigerant suction pipe that communicates with the low pressure portion and a refrigerant discharge pipe that communicates with the high pressure portion, a drive motor installed inside of the low pressure portion, an orbiting scroll coupled to the drive motor to perform an orbiting motion, a non-orbiting scroll engaged with the orbiting scroll to form a compression chamber, and a refrigerant guide provided on the non-orbiting scroll to guide a refrigerant suctioned into the low pressure portion to be suctioned into the compression chamber, whereby an increase in specific volume of refrigerant suctioned into the compression chamber may be suppressed, and thus, an amount of refrigerant suctioned into the compression chamber may increase, thereby improving efficiency of the compressor.

A heat source unit of a refrigerant cycle apparatus includes a compressor, a pipe, and a fixing member. The compressor includes two or three connection portions of a first connection portion connecting a suction pipe, a second connection portion connecting a discharge pipe, and a third connection portion connecting an injection pipe. The pipe includes a vertical portion. At least a part of the vertical portion extends vertically from each of the two or three connection portions. The fixing member fixes at least two of the vertical portions of two or three of the pipes of the suction pipe, the discharge pipe, and the injection pipe. Each of the connection portions of the pipes fixed by the fixing member is located on a first straight line as seen in a top view.

A compressor includes a casing that stores lubricant at a bottom, a compression mechanism disposed in the casing to suck and compress a refrigerant, and an oil return member forming an oil return flow path that extends in a top-to-bottom direction to guide the lubricant discharged from the compression mechanism downward. The oil return flow path includes a uniform-cross-section flow path, and a varying-cross-section flow path continuous with a lower end of the uniform-cross-section flow path. A lower end of the varying-cross-section flow path forms an outlet of the oil return flow path and lies along an inner surface of the casing. A the lower end of the varying-cross-section flow path has a greater width than an upper end of the varying-cross-section flow path, and the lower end of the varying-cross-section flow path has a smaller thickness than the upper end of the varying-cross-section flow path.