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.

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.

The present invention provides a compressor for refrigeration and air conditioning and a refrigeration and air conditioning device capable of achieving both favorable environmental performance and favorable refrigeration cycle efficiency. In the compressor for refrigeration and air conditioning, a refrigerator oil containing a polyol ester and a refrigerant containing difluoromethane are enclosed. The polyol ester has two or more repetitions of poly[2,2-di(alkanoyloxymethyl)oxytrimethylene] as a structural unit. Further, the polyol ester is composed of only one or both of a cyclic polyol ester, which is obtained by cyclically polymerizing a molecular chain having the structural unit, and a crosslinked polyol ester, which is obtained by crosslinking molecular chains having the structural unit with each other through a crosslinkable structural unit polymerized with the structural unit.

A system for cryocooling an optical sensor on a satellite to a temperature below 200K with minimal vibration comprising a miniature conical rotary screw compressor comprising an inner element configured to only rotate around a first stationary axis and an outer element configured to only rotate around a second stationary axis so that both elements revolve with minimal vibration; with at least one of a) a length of at least one of the inner element and the outer element is between 10 mm and 100 mm; b) a diameter of at least one of the inner element and the outer element is between 2 mm and 45 mm; c) a compression ratio of the rotary screw compressor is between 1:2 and 1:20; and d) a shaft speed of the conical rotary screw compressor is between 1001 and 20000 revolutions per minute.

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 screw compressor includes a compressor housing defining a working chamber, the housing including a plurality of bores; a first rotor having helical threads, the first rotor being housed in a first of the plurality of bores; a second rotor having helical threads intermeshing with the helical threads of the first rotor, the second rotor being housed in a second of the plurality of bores; an inlet port that receives a fluid to be compressed; an outlet port that receives a compressed fluid; and an intermediate discharge port disposed between the compression chamber and the outlet port, the intermediate discharge port including a sealing member and a biasing mechanism, fluid flow being prevented between the compression chamber and the intermediate discharge port when in a flow-blocked state, and fluid flow being enabled from the compression chamber through the intermediate discharge port when in a flow-permitted state.

A screw compressor includes a compressor housing defining a working chamber, the housing including a plurality of bores; a first rotor having helical threads, the first rotor being housed in a first of the plurality of bores; a second rotor having helical threads intermeshing with the helical threads of the first rotor, the second rotor being housed in a second of the plurality of bores; an inlet port that receives a fluid to be compressed; an outlet port that receives a compressed fluid; and an intermediate discharge port disposed between the compression chamber and the outlet port, the intermediate discharge port including a sealing member and a biasing mechanism, fluid flow being prevented between the compression chamber and the intermediate discharge port when in a flow-blocked state, and fluid flow being enabled from the compression chamber through the intermediate discharge port when in a flow-permitted state.

Rotary heat exchangers can include a ride-along compressor, at least a portion of which can be rotated along with the heat exchanger. By rotating at least a portion of the compressor along with the heat exchanger, a sealed fluid circuit containing a two-phase working fluid can be provided. A rotary heat pump or heat engine can include an evaporator and a condenser in the form of back-to-back centrifugal fans. The centrifugal fan blades or other portions of the evaporator and condenser may include internal cavities where the working fluid undergoes a phase change.

A refrigeration cycle apparatus comprises: a refrigerant cycle circuit, a condenser, a pressure-reducing device and an evaporator are sequentially connected by pipes; an injection circuit that branches off from the refrigerant cycle circuit between the condenser and the pressure-reducing device and is connected to the injection flow passage; a flow rate control device provided in the injection circuit or the injection flow passage; and a controller configured to control the flow rate control device. At a time of starting up the compressor, the controller, controls regardless of a temperature of refrigerant discharged from the compressor, the flow rate control device so as to supply refrigerant liquid to the compression chamber via the injection circuit and the injection flow passage until an operating capacity of the compressor reaches a preset operating capacity or until a preset time elapses after starting up the compressor.

A refrigeration cycle device includes at least a condenser, an expansion valve, an evaporator and a plurality of compressors, a sealed casing of each of the compressors is disposed with a rotary compression mechanism part in communication with a low-pressure path and a motor part configured to drive the compression mechanism part, the low-pressure path is in communication with the evaporator, each of the compressors is further provided with an oil storage cavity, and a gas discharge path of at least one compressor is connected with the sealed casing of another compressor.