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Magnetic bearing centrifugal refrigeration compressor and refrigerant having minimum specific enthalpy rise

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TLDR
In this paper, a vapor compression refrigeration system using a centrifugal compressor with magnetic bearings and a refrigerant is described. And magnetic bearings eliminate the problem caused by lubricated bearings to support rotating structure during normal compressor operation.
Abstract
A vapor compression refrigeration system, such as a water chiller, uses a centrifugal compressor with magnetic bearings and a refrigerant, specifically HFC-227ea and HFC-227ca, to minimize enthalpy rise across the compressor and/or provide compression in a single stage for low cooling capacity Magnetic bearings eliminate the problem caused by lubricated bearings to support rotating structure during normal compressor operation The centrifugal compressor can be configured with a pre-defined static surge line

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Method and apparatus for optimizing refrigeration systems

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References
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Control method and apparatus for a centrifugal chiller using a variable speed impeller motor drive

TL;DR: In this article, a method of controlling the operation of a centrifugal compressor in a water chiller system is presented, where the compressor's capacity is variable by modulating its speed of rotation or by modifying its inlet guide vane's position.
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Near-azeotropic blends for use as refrigerants

TL;DR: In this paper, near-Azeotropic blends of pentafluoroethane and 1,1, 1-trifluoro-ethane with one or more of chlorodifluoromethane, 1,2, 2, 2-tetrafluoropropane, perfluorocyclopropanes, and 1.
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Turbo molecular pump

TL;DR: In this paper, a turbo molecular pump includes a magnetic bearing system which includes a rotor having an impeller connected to a shaft and a motor, and the axial magnet bearing is disposed in the vicinity where the impeller is connected to the shaft.
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Magnetic bearings for pumps, compressors and other rotating machinery

TL;DR: In this paper, a rotating machine has a rotor comprising a flexible shaft with a plurality of masses distributed along the shaft, and magnetic disks are attached to the housing and coact to support the rotor in only a radial direction or in both radial and axial directions.
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Combined radial and axial magnetic bearings

TL;DR: In this article, a five-axis magnetic bearing is composed of two combined radial and axial magnetic bearing structures, and each bearing structure can be controlled by four stator portions with each actuator being supplied with current signals representing a common mode axial force command and a respective differential radial force command.