US 8,037,713 B2 · Centrifugal compressor assembly and method

Abstract

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.

Claims24

Dependent claims

A compressor assembly for compressing a refrigerant in a chiller system comprising:

a. a centrifugal compressor having a 250-ton capacity or larger, said centrifugal compressor having a compressor housing with a compressor inlet for receiving the refrigerant and a compressor outlet for delivering the refrigerant;
b. a shaft;
c. an impeller in fluid communication with said compressor inlet and said compressor outlet, said impeller mounted to said shaft and being operable to compress refrigerant;
d. a compact, high energy density motor for driving the shaft at a range of sustained operating speeds less than about 20,000 revolutions per minute;
and
e. a variable speed drive configured to vary operation of the motor within the range of sustained operating speeds
wherein each compressor further comprises an external volute forming a circumferential flow path around said compressor housing in fluid communication with a vaneless diffuser, wherein the external volute has a centroid radius greater than a centroid radius of a diffuser.

4 more elements

A compressor assembly for compressing a refrigerant in a chiller system comprising:

a. a centrifugal compressor having a 250-ton capacity or larger, said centrifugal compressor having a compressor housing with a compressor inlet for receiving the refrigerant and a compressor outlet for delivering the refrigerant;
b. a shaft;
c. an impeller in fluid communication with said compressor inlet and said compressor outlet, said impeller mounted to said shaft and being operable to compress refrigerant;
d. a compact, high energy density motor for driving the shaft at a range of sustained operating speeds less than about 20,000 revolutions per minute;
and
e. a variable speed drive configured to vary operation of the motor within the range of sustained operating speeds
wherein the compact, high energy density motor comprises a permanent magnet motor and wherein the compressor comprises two stage compressors having a non-final stage compressor and a final stage compressor, each compressor housing having a compressor inlet for receiving the refrigerant and compressor outlet for delivering the refrigerant, wherein said permanent magnet motor is mounted in a motor housing between the non-final stage compressor and the final stage compressor.

4 more elements

Dependencies are inferred from the claim text.

Centrifugal compressor assembly and method

Life of this patent

Centrifugal compressor assembly and method

Life of this patent

Abstract

Claims24