US 9,810,228 B2
Centrifugal compressor diffuser control
Lin Sun, Tallahassee, FL (US); Jose Alvares, Tallahassee, FL (US); and Mogens Rasmussen, Tallahassee, FL (US)
Assigned to DANFOSS A/S, (DK)
Appl. No. 14/344,407
Filed by Lin Sun, Tallahassee, FL (US); Jose Alvares, Tallahassee, FL (US); and Mogens Rasmussen, Tallahassee, FL (US)
PCT Filed Sep. 14, 2011, PCT No. PCT/US2011/051504
§ 371(c)(1), (2), (4) Date Mar. 12, 2014,
PCT Pub. No. WO2013/039492, PCT Pub. Date Mar. 21, 2013.
Prior Publication US 2015/0010383 A1, Jan. 8, 2015
Int. Cl. F04D 17/10 (2006.01); F04D 27/00 (2006.01); F04D 27/02 (2006.01); F04D 29/46 (2006.01); F25B 1/053 (2006.01); F04D 29/058 (2006.01)
CPC F04D 27/002 (2013.01) [F04D 17/10 (2013.01); F04D 27/001 (2013.01); F04D 27/0246 (2013.01); F04D 29/058 (2013.01); F04D 29/462 (2013.01); F04D 29/464 (2013.01); F25B 1/053 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A centrifugal refrigerant compressor control system comprising:
an impeller connected to a shaft;
a diffuser arranged on a downstream side of the impeller and configured to regulate refrigerant flow exiting the impeller;
a magnetic bearing system supporting the shaft;
a sensing element from the magnetic bearing system configured to produce an output relating to a shaft condition; and
a controller configured to receive the output and determine an undesired impeller operating condition based upon the shaft condition only when a predetermined minimum impeller speed is reached with the diffuser in a fully open state, the controller configured to command the diffuser to a desired state in response to the undesired impeller operating condition.