Instability detecting device for turbo compressors

Abstract

An instability detecting device, used for easily and simply detecting a rotating stall and/or a surge frequently occurring during an operation of a turbo compressor, is disclosed. The detecting device of this invention has a detector ( 20 ) consisting of a body ( 22 ). First and second pressure tubes ( 25 ) and ( 26 ) are axially set in the body ( 22 ) while parallely extending on the same plane, with first and second pressure discharge ports ( 25 a ) and ( 26 a ) of the first and second pressure tubes exposed to the outside of the body ( 22 ) at an end surface of the body ( 22 ). A partition wall ( 28 ) is arranged on the end surface of the body ( 22 ) while crossing the end surface and separating the first and second pressure discharge ports ( 25 a ) and ( 26 a ) from each other. The detector ( 20 ) is attached to the inlet suction port ( 14 ) of a compressor's impeller ( 12 ) such that the partition wall ( 28 ) extends in parallel to a rotation axis of the impeller ( 12 ), and/or to an outlet discharge port of a compressor's impeller such that said partition wall extends in parallel to a discharge flow from impeller. The detector ( 20 ) thus senses a pressure difference between the first and second pressure discharge ports ( 25 a ) and ( 26 a ), and detects an operation of the compressor within an unstable operational region.

What is claimed is:  
     
         1 . An instability detecting device for turbo compressors, comprising: 
 a detector consisting of:    a body;    first and second pressure tubes axially set in said body while parallely extending on the same plane, with first and second pressure discharge ports of said first and second pressure tubes exposed to the outside of said body at an end surface of the body; and    a partition wall arranged on said end surface of the body while crossing the end surface and separating the first and second pressure discharge ports of the pressure tubes from each other,    whereby said detector is attached to an inlet suction port of a compressor's impeller such that said partition wall extends in parallel to a rotation axis of said impeller, and/or to an outlet discharge port of a compressor's impeller such that said partition wall extends in parallel to a discharge flow from impeller, said detector thus sensing a pressure difference between the first and second pressure discharge ports of the pressure tubes and detecting an operation of the compressor within an unstable operational region.    
     
     
         2 . The instability detecting device according to  claim 1 , wherein said detector is connected to a monitor allowing an operator to know operational conditions of the compressor so as to detect an operation of the compressor within the unstable operational region.  
     
     
         3 . The instability detecting device according to  claim 1 , wherein said detector is provided with means for alerting an operator of an operation of said compressor within the unstable operational region.