US 11,946,678 B2
System and method for extending the operating range of a dynamic compressor
Michael M. Perevozchikov, Tipp City, OH (US); Matthew J. Swallow, Versailles, OH (US); and Zheji Liu, Tipp City, OH (US)
Assigned to Copeland LP, Sidney, OH (US)
Filed by Copeland LP, Sidney, OH (US)
Filed on Jan. 27, 2022, as Appl. No. 17/585,736.
Prior Publication US 2023/0235935 A1, Jul. 27, 2023
Int. Cl. F25B 49/02 (2006.01); F04D 27/02 (2006.01); F25B 31/02 (2006.01)
CPC F25B 49/022 (2013.01) [F04D 27/0246 (2013.01); F25B 31/026 (2013.01); F25B 2600/022 (2013.01); F25B 2600/0253 (2013.01); F25B 2700/193 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A system comprising:
a dynamic compressor operable to compress a working fluid, the dynamic compressor comprising:
a first compressor stage having a first variable inlet guide vane (VIGV) controllable to selectively introduce pre-whirl into working fluid entering the first compressor stage;
a second compressor stage having a second VIGV controllable to selectively introduce pre-whirl into working fluid entering the second compressor stage; and
a motor configured to drive the first compressor stage and the second compressor stage at a same speed;
a valve in fluid communication with the dynamic compressor to selectively direct a flow of working fluid to an inlet of the second compressor stage without the flow of working fluid passing through the first compressor stage; and
a controller connected to the dynamic compressor, the controller comprising a processor and a memory, the memory storing instructions that program the processor to:
operate the dynamic compressor at a current speed, a first position of the first VIGV, and a second position of the second VIGV to compress the working fluid;
determine, while operating the dynamic compressor, if a condition is satisfied;
continue to operate the compressor at the current speed, the first position of the first VIGV, and the second position of the second VIGV when the condition is not satisfied; and
change the second position of the second VIGV to a third position different than the second position and maintain the first position of the first VIGV when the condition is satisfied, wherein determining if the condition is satisfied comprises determining if the valve is open.