A centrifugal compressor assembly for compressing refrigerant in a 250-ton capacity or larger chiller system comprising a motor, preferably a compact, high energy density motor or permanent magnet motor, for driving a shaft at a range of sustained operating speeds under the control of a variable speed drive Another embodiment of the centrifugal compressor assembly comprises a mixed flow impeller and a vaneless diffuser sized such that a final stage compressor operates with an optimal specific speed range for targeted combinations of head and capacity, while a non-final stage compressor operates above the optimum specific speed of the final stage compressor Another embodiment of the centrifugal compressor assembly comprises an integrated inlet flow conditioning assembly comprising a flow conditioning nose, a plurality of inlet guide vanes and a flow conditioning body that positions inlet guide vanes to condition flow of refrigerant into an impeller to achieve a target approximately constant angle swirl distribution with minimal guide vane turning

Centrifugal compressor assembly and method

An integrated expansion turbine/electrical generator assembly (collectively referred to as a "turbo-generator") suitable for use in waste heat recovery and similar applications. The turbo-generator uses a common shaft mounting a one or more stage expansion turbine and a homopolar electrical generator. Magnetic levitating axial and thrust bearings are used to hold the common shaft in its proper position with a fixed housing. The magnetic bearings minimize frictional losses, allowing the common shaft to spin at a very high rotational velocity. Sensor rings continually monitor the common shaft's position. This information is used by control electronics to regulate the magnetic bearings in order to hold the rotating shaft's position. Electrical energy is extracted from the rotating shaft in the form of a direct current. Preferably integrated power-switching electronics are used to generate single or three-phase AC power, which can be phase-matched to an existing power grid or other application.

Rankine cycle heat recovery methods and devices

A turbo compressor that has a compression stage provided with an impeller that rotates; a housing provided with a gear unit accommodation space that accommodates lubricating oil and accommodates a large diameter gear that transmits rotating force to the impeller, an IGV accommodation space in which the ambient pressure is lower than the gear unit accommodation space, and a gap that brings the IGV accommodation space and the air intake side of a first compression stage into communication; a pressure equalizing tube that causes a gas to circulate from the gear unit accommodation space toward the IGV accommodation space; and a second oil separating device that separates, in the IGV accommodation space, the lubricating oil contained in the gas.

Turbo compressor and turbo refrigerator

A cooling system (10) is provided for a motor (50) powering a compressor (32) in a vapor compression system (14). The cooling system (10) including a housing (114) and a cavity (126) within the housing (114). A first fluid circuit (140) has a first connection (112) to receive a refrigerant into the cavity (126), and a second connection (154) to deliver refrigerant from the cavity (126) to a heat exchanger for a heat transfer relationship with a heat-generating component (120).

Motor cooling applications

Permanent magnets that constitute the single magnetic poles are constituted by n permanent magnet segments, the n permanent magnet segments being configured such that shapes and directions of orientation thereof have mirror symmetry relative to a plane that passes through a magnetic pole center and that includes a central axis of the rotor core, and being oriented such that a permanent magnet segment that is further away from the magnetic pole center in a circumferential direction has a smaller angle of orientation, and the permanent magnet segment that is positioned further away from the magnetic pole center in the circumferential direction being produced so as to have an approximately fan-shaped cross-sectional shape in which a radial width is wider than a circumferential width.

Embedded permanent magnet rotary electric machine

A high efficiency, low maintenance single stage or multi-stage centrifugal compressor assembly for large cooling installations. The assembly is highly efficient by virtue of a variable frequency drive (VFD) that drives a permanent magnet motor and matches compressor speed with compressor load, a direct drive impeller that eliminates gearing losses, and magnetic bearings that reduce frictional losses. The back-emf produced by the motor provides an intermediate power source for the magnetic bearings in the event of a loss of electrical power. A cooling system provides direct cooling of the rotor with gas refrigerant, and cooling of the stator with liquid refrigerant. Modular construction allows the compressor to be retrofit with upgrades. An inlet guide vane system operates without need for oil lubrication. The use of light metal castings and elimination of gearing reduces the weight to one-third or less of comparably powered conventional units.

Earl A. Campaigne

Papers

High capacity chiller compressor