Systems and methods for lubricant management of a compressor in an HVACR system are disclosed. A heat transfer circuit can utilize a working fluid to provide heating or cooling includes a compressor for compressing the working fluid and a heat source configured to increase a suction temperature of the working fluid entering the compressor. One or more lubricant rheological properties in a compressor system based on measurements taken at or near a bearing cavity of the compressor are determinable. A lubricant reservoir can be in thermal communication with a discharge flow path of the compressor. An internal heat exchanger can be disposed within a compressor for improving viscosity of the lubricant to be cycled back into the compressor. A heater can be located on a fluid line between a lubricant separator and a lubricant inlet. Condenser fans can be controlled.

A screw compressor includes a screw rotor having a plurality of screw grooves, a plurality of gate rotors each including gates that mesh with the screw rotor, and a casing. The screw rotor is rotatably inserted in the casing. The casing has a cylindrical wall through which the gates pass. The screw compressor has a plurality of compression chambers inside the cylindrical wall. The plurality of compression chambers are defined by the screw rotor and the gates. The compression chambers include a first compression chamber and a second compression chamber. A fluid introduced into the casing at a suction pressure is compressed to an intermediate pressure higher than the suction pressure in the first compression chamber. The fluid at the intermediate pressure is compressed to a discharge pressure higher than the intermediate pressure in the second compression chamber.

A compressor is disclosed which can include a first stage and a second stage. In one form the compressor includes contact cooled compressor stages. The compressor can include a rod useful to inject a lubricant for purposes of cooling/lubricating/sealing the rotating components of the compressor. In one form the rod is an elongate rod with openings which permit a lubricant such as oil to be injected. The injected oil can be atomized via the openings. The rod can be positioned in the interstage space between the first and second stages, and can include a variety of openings.

A compressor is disclosed which can include a first stage and a second stage. In one form the compressor includes contact cooled compressor stages. The compressor can include a rod useful to inject a lubricant for purposes of cooling/lubricating/sealing the rotating components of the compressor. In one form the rod is an elongate rod with openings which permit a lubricant such as oil to be injected. The injected oil can be atomized via the openings. The rod can be positioned in the interstage space between the first and second stages, and can include a variety of openings.

A refrigeration system includes a rotary pressure exchanger fluidly coupled to a low pressure branch and a high pressure branch. The rotary pressure exchanger is configured to receive the refrigerant at high pressure from the high pressure branch, to receive the refrigerant at low pressure from the low pressure branch, and to exchange pressure between the refrigerant at high pressure and the refrigerant at low pressure, and wherein a first exiting stream from the rotary pressure exchanger includes the refrigerant at high pressure in the supercritical state or the subcritical state and a second exiting stream from the rotary pressure exchanger includes the refrigerant at low pressure in the liquid state or the two-phase mixture of liquid and vapor.

A scroll compressor including an orbiting scroll having a small diameter compared to a case in which an oil groove is provided in a ring shape and constantly communicates with an outlet of an oil passage. The scroll compressor includes a fixed scroll and an orbiting scroll configured to orbit in engagement with the fixed scroll. The fixed scroll includes an outlet of an oil passage configured to communicate with an oil tray storing lubricant, the outlet of the oil passage connected to a sliding surface of the orbiting scroll. The orbiting scroll includes a plurality of oil grooves configured not to communicate with each other so as to supply the lubricant to a sliding surface of the fixed scroll, the plurality of oil grooves configured to communicate with the outlet at least once and not to communicate with the outlet at least once while the orbiting scroll rotates once.

A scroll compressor including an orbiting scroll having a small diameter compared to a case in which an oil groove is provided in a ring shape and constantly communicates with an outlet of an oil passage. The scroll compressor includes a fixed scroll and an orbiting scroll configured to orbit in engagement with the fixed scroll. The fixed scroll includes an outlet of an oil passage configured to communicate with an oil tray storing lubricant, the outlet of the oil passage connected to a sliding surface of the orbiting scroll. The orbiting scroll includes a plurality of oil grooves configured not to communicate with each other so as to supply the lubricant to a sliding surface of the fixed scroll, the plurality of oil grooves configured to communicate with the outlet at least once and not to communicate with the outlet at least once while the orbiting scroll rotates once.

A compressor is disclosed which can include a first stage and a second stage. In one form the compressor includes contact cooled compressor stages. The compressor can include a rod useful to inject a lubricant for purposes of cooling/lubricating/sealing the rotating components of the compressor. In one form the rod is an elongate rod with openings which permit a lubricant such as oil to be injected. The injected oil can be atomized via the openings. The rod can be positioned in the interstage space between the first and second stages, and can include a variety of openings.

A compressor is disclosed which can include a first stage and a second stage. In one form the compressor includes contact cooled compressor stages. The compressor can include a rod useful to inject a lubricant for purposes of cooling/lubricating/sealing the rotating components of the compressor. In one form the rod is an elongate rod with openings which permit a lubricant such as oil to be injected. The injected oil can be atomized via the openings. The rod can be positioned in the interstage space between the first and second stages, and can include a variety of openings.

A compressor is disclosed which can include a first stage and a second stage. In one form the compressor includes contact cooled compressor stages. The compressor can include a rod useful to inject a lubricant for purposes of cooling/lubricating/sealing the rotating components of the compressor. In one form the rod is an elongate rod with openings which permit a lubricant such as oil to be injected. The injected oil can be atomized via the openings. The rod can be positioned in the interstage space between the first and second stages, and can include a variety of openings.