US 6,981,838 B2
Method and apparatus for detecting the occurrence of surge in a centrifugal compressor
Robert J. McKee, San Antonio, Tex. (US); and Carl E. Edlund, Castroville, Tex. (US)
Assigned to Southern Gas Association Gas Machinery Reserach Council, Dallas, Tex. (US)
Filed on Feb. 26, 2002, as Appl. No. 10/83,232.
Prior Publication US 2003/0161715 A1, Aug. 28, 2003
Int. Cl. F04D 29/00 (2006.01)
U.S. Cl. 415—1 48 Claims
OG exemplary drawing
 
1. A method for detecting the occurrence of surge or incipient surge in a centrifugal compressor, the method comprising the steps of:
operating the centrifugal compressor having an inlet passage, an inlet passage wall and an impeller, thereby establishing a bulk fluid flow to the compressor and a local axial fluid flow in a recirculation zone in the inlet passage proximate to the inlet passage wall and proximate to the impeller; and
detecting a decrease in the local axial fluid flow, wherein the decrease in the local fluid flow is greater than any concurrent decrease in the bulk fluid flow to the compressor.