A heat transfer circuit that includes a compressor with a gas bearing, a condenser, an expander, an evaporator, a lubricant stream, and a heat source. The lubricant stream receives a portion of the working fluid and supplies the portion of the working fluid to the gas bearing of the compressor. A method of supplying lubricant to a gas bearing of a compressor in a heat transfer circuit includes compressing and further heating at least a portion of the working fluid heated in the evaporator, and supplying the compressed and further heated working fluid to the gas bearing of the compressor. A method of the supplying lubricant to a gas bearing of a compressor in a heat circuit includes generating compressed gaseous working fluid within a lubricant stream.

A refrigerant cycle system includes a primary-side cycle that circulates a first refrigerant, a secondary-side cycle that circulates a second refrigerant, and a cascade heat exchanger that exchanges heat between the first refrigerant and the second refrigerant. The primary-side cycle includes a primary-side connection pipe. The secondary-side cycle includes a secondary-side connection pipe. The primary-side connection pipe includes a primary-side gas connection pipe and a primary-side liquid connection pipe. The secondary-side connection pipe includes a secondary-side gas connection pipe and a secondary-side liquid connection pipe. The pipe diameter of the secondary-side gas connection pipe is smaller than the pipe diameter of the primary-side gas connection pipe, or the pipe diameter of the secondary-side liquid connection pipe is smaller than the pipe diameter of the primary-side liquid connection pipe.

Disclosed is a screw compressor (100), comprising a screw compressor housing (101), a discharge cavity (113), at least one silencing channel, and at least one adjustment piston, wherein the discharge cavity (113) is defined by at least one part of the screw compressor housing (101); the at least one part of the screw compressor housing (101) defining the discharge cavity (113) forms a wall of the discharge cavity (113); at least one hole is provided in the wall of the discharge cavity (113); the at least one adjustment piston can be inserted into the at least one hole and move therein; the at least one silencing channel is formed by the at least one hole and the at least one adjustment piston, and the at least one silencing channel is in fluid communication with the discharge cavity (113); and the position of the at least one adjustment piston in the at least one hole determines the silencing length of the at least one silencing channel.

A heat pump is provided with a compressor; an oil separator provided on a discharge path of the compressor; an accumulator connected to the compressor via a suction path; and a bypass circuit configured to supply a gas refrigerant separated by the oil separator. The bypass circuit is connected to the suction path.

A refrigeration system that induces lubricant-liquid refrigerant mixture flow from a flooded or falling film evaporator by means of the lubricant-liquid refrigerant mixture flow adsorbing heat from an electronic component.

An automatic oil level retention system for a compressor and a method for controlling a same, including: a normal oil return mode and an auxiliary oil return mode. When a lubricating oil liquid level monitored by a liquid level detection unit in real time is above a required liquid level height, the system initiates only the normal oil return mode; and when the lubricating oil liquid level monitored by the liquid level detection unit in real time is below the required liquid level height, the system initiates the auxiliary oil return mode, and the auxiliary oil return mode is closed and the normal oil return mode is initiated after the lubricating oil liquid level monitored in real time is lifted above the required liquid level height.

The heat source controller transmits the drive permission signal (SE) to the utilization controller when the compression element is drivable. The utilization controller opens a utilization expansion valve when heat exchange in a utilization heat exchanger is required, on condition that the utilization controller receive the drive permission signal (SE).

In a screw compressor (20), a male rotor suction end bearing (96) and discharge end bearing (90 1, 90 2, 90 3) mount the male rotor suction end shaft portion (39) and discharge end shaft portion (40). A female rotor suction end bearing (98) and discharge end bearing (92 1, 92 2) mount the female rotor suction end shaft portion (41) and discharge end shaft portion (42). At least one valve (182; 282; 382 1,382 2,382 3; 82; 582-1,582-2; 682-1,682-2; 782-1,782-2) is along a lubricant flowpath and has an energized condition and a de-energized condition. At least one restriction (184; 84-1,84-2; 84-1, 84-2,84-3; 484 1,484-2,84-3; 84 1,84 2,584; 84-1,84-2,684; 84-1,84-2,784) is along the lubricant flowpath. The at least one valve and the at least one restriction are positioned to create a lubricant pressure difference biasing the rotors away from a discharge end of the case.

A refrigerant charge controller for heating, ventilation, or air conditioning (HVAC) equipment includes a processing circuit configured to analyze usage data for the HVAC equipment using a machine learning model to estimate an amount of refrigerant used by the HVAC equipment, identify a refrigerant deficiency based on the amount of refrigerant, and initiate a corrective action in response to identifying the refrigerant deficiency.

A gas recovery system for a compressor, said gas recovery system being equipped with: a distillation column that brings a supply gas in a liquid state into contact with a mixed gas, thereby cooling and liquefying a process gas in the mixed gas, and heating and gasifying the liquid supply gas; a process gas recovery line that is connected to the lower part of the distillation column and recovers the liquid process gas discharged from the distillation column; and a supply gas recovery line that is connected to the upper part of the distillation column and recovers the gaseous supply gas discharged from the distillation column.