Inlet guide vane, compressor, inlet guide vane attachment method, and centrifugal compressor production method

Abstract

An inlet guide vane includes vane main bodies (42) having a pressure surface (S1) and a suction surface (S2) which extend along a radial-direction axial line (Ar). Each of the pressure surface (S1) and the suction surface (S2) has a blade-shaped surface along a surface of an imaginary blade shape (Pv) having a blade-like cross-sectional shape. At least one of the pressure surface (S1) and the suction surface (S2) has a thin portion-forming surface (St) which recedes toward an inside of the imaginary blade shape (Pv) more than the surface of the imaginary blade shape (Pv).

1 . An inlet guide vane comprising:
 vane main bodies having a pressure surface and a suction surface which extend in a radial direction of a rotary shaft,   wherein each of the pressure surface and the suction surface has a blade-shaped surface along a surface of an imaginary blade shape having a blade-like cross-sectional shape, and   at least one of the pressure surface and the suction surface has a thin portion-forming surface which recedes toward an inside of the imaginary blade shape more than the surface of the imaginary blade shape.   
     
     
         2 . The inlet guide vane according to  claim 1 ,
 wherein the vane main body has a front end surface on an end portion on an inside in the radial direction,   the thin portion-forming surface is formed in a front end-side region connected to the front end surface on one of the pressure surface and the suction surface, and   the blade-shaped surface on one of the pressure surface and the suction surface is formed in a base end-side region of the thin portion-forming surface on an outside in the radial direction.   
     
     
         3 . The inlet guide vane according to  claim 2 ,
 wherein the thin portion-forming surface is formed along a blade central line of the imaginary blade shape.   
     
     
         4 . The inlet guide vane according to  claim 2 ,
 wherein the front end surface forms a blade shape along the imaginary blade shape, and   the thin portion-forming surface is formed so as to, as the thin portion-forming surface runs from an edge portion of one of the pressure surface and the suction surface on the front end surface toward the outside in the radial direction, extend toward the other of the pressure surface and the suction surface.   
     
     
         5 . The inlet guide vane according to  claim 2 ,
 wherein one of the pressure surface and the suction surface has a connection surface that is configured to connect a level difference between the blade-shaped surface and the thin portion-forming surface.   
     
     
         6 . The inlet guide vane according to  claim 1 ,
 wherein the thin portion-forming surface is formed on one of the pressure surface and the suction surface so as to be sandwiched by the blade-shaped surface from both the inside in the radial direction and the outside in the radial direction.   
     
     
         7 . The inlet guide vane according to  claim 1 ,
 wherein the imaginary blade shape becomes smaller in a similar shape as the blade-like cross-sectional shape runs from the outside in the radial direction to the inside in the radial direction.   
     
     
         8 . The inlet guide vane according to  claim 1 ,
 wherein, in the imaginary blade shape, the blade-like cross-sectional shape forms a linearly symmetric shape having the blade central line as a symmetric axis.   
     
     
         9 . A compressor comprising:
 the inlet guide vane according to  claim 1 ;   a casing in which a suction port that is configured to support the inlet guide vane is formed; and   an impeller that is configured to compress fluid suctioned from the suction port.   
     
     
         10 . An inlet guide vane attachment method for attaching a plurality of inlet guide vanes to a suction port formed in a casing of a compressor in a circumferential direction of the suction port at intervals,
 wherein, in the inlet guide vane, each of a pressure surface and a suction surface has a blade-shaped surface along a surface of an imaginary blade shape having a blade-like cross-sectional shape, and   at least one of the pressure surface and the suction surface has a thin portion-forming surface which recedes toward an inside of the imaginary blade shape more than a surface of the imaginary blade shape,   the attachment method comprising:   a step of attaching a first inlet guide vane to an inner circumferential side of the casing;   a step of attaching a second inlet guide vane at an interval with respect to the first inlet guide vane in the circumferential direction; and   a step of attaching a third inlet guide vane between the first inlet guide vane and the second inlet guide vane in the circumferential direction,   wherein, in the step of attaching the third inlet guide vane, a portion of the third inlet guide vane on an inside in a radial direction which includes the thin portion-forming surface is inserted into a gap between the first inlet guide vane and the second inlet guide vane, and then the third inlet guide vane is moved to an outside in the radial direction.   
     
     
         11 . A centrifugal compressor production method comprising:
 a step of preparing the casing and the plurality of inlet guide vanes;   the respective steps of the inlet guide vane attachment method according to  claim 10 ; and   a step of attaching a rotary shaft and an impeller to an inner portion of the casing.