US 12,378,970 B2
Mass flow interpolation systems and methods of dynamic compressors
Michael D. Oakley, Dayton, OH (US); Michael M. Perevozchikov, Tipp City, OH (US); and Matthew J. Swallow, Versailles, OH (US)
Assigned to Copeland LP, Sidney, OH (US)
Filed by Copeland LP, Sidney, OH (US)
Filed on Sep. 19, 2022, as Appl. No. 17/933,237.
Application 17/933,237 is a continuation of application No. 17/243,787, filed on Apr. 29, 2021, granted, now 12,044,245.
Prior Publication US 2023/0008611 A1, Jan. 12, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. F04D 27/00 (2006.01); F04D 17/12 (2006.01); F04D 29/30 (2006.01)
CPC F04D 27/001 (2013.01) [F04D 17/12 (2013.01); F04D 29/30 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A system comprising:
a dynamic compressor operable to compress a working fluid, the dynamic compressor comprising an impeller, a motor operably connected to the impeller, a variable frequency drive (VFD) coupled to the motor, and a variable inlet guide vane (VIGV); and
a controller connected to the dynamic compressor, the controller comprising a processor and a memory, the memory storing:
a map of a plurality of predetermined operating points of the dynamic compressor, each predetermined operating point including a mass flow of the dynamic compressor at that predetermined operating point; and
instructions that program the processor to:
operate the dynamic compressor to compress the working fluid by controlling a position of the VIGV and controlling a speed of the motor driving the impeller using the VFD;
determine, while operating the dynamic compressor, a current operating point of the compressor;
calculate a mass flow for the current operating point from the map of the plurality of predetermined operating points; and
continue to operate the dynamic compressor to compress the working fluid based at least in part on the calculated mass flow for the current operating point by inputting the calculated mass flow into a control algorithm that calculates an operating point value based at least in part on the calculated mass flow and controlling an unloading device of the dynamic compressor based on the operating point value and a margin.