Diffuser for centrifugal compressor
View Patent ↗A diffuser ( 30 ) for a centrifugal compressor ( 60 ) having a flow slot ( 34 ) formed between the leading edge portion ( 36 ) of a diffuser vane ( 32 ) and an adjoining diffuser wall ( 70 ) for the passage of working fluid ( 67 ) over the vane from the pressure side (( 40 ) to the suction side ( 42 ) of the vane. The portion ( 38 ) of the working fluid passing over the vane is injected into the flow boundary region ( 43 ), thereby minimizing the growth of a flow separation zone ( 58 ) along the suction side.
1. A diffuser for a compressor, the diffuser comprising:
opposed walls defining a space disposed downstream of a compressor impeller for receiving a flow of a working fluid from the impeller;
a vane comprising a pressure side and a suction side connected between the opposed walls for directing the working fluid through the space; and
a flow slot formed between the vane and one of the walls, the flow slot extending along a portion of the vane upstream from a throat of the vane for allowing a portion of the flow of working fluid to pass from the pressure side to the suction side of the vane to suppress expansion of a flow separation zone on the suction side of the vane;
wherein the flow slot comprises a groove formed into a surface of the vane prior to that surface being connected to a respective adjacent one of the walls.
2. The diffuser of claim 1 , wherein the flow slot extends to a leading edge of the vane.
3. The diffuser of claim 1 , wherein the slot is formed to extend downstream from a point downstream of a leading edge of the vane to define a support connection between the vane and the one of the walls at the leading edge.
4. The diffuser of claim 1 , wherein the flow slot comprises a height perpendicular to a chord of the vane of no more than 5% of a total height of the vane perpendicular to the chord of the vane.
5. The diffuser of claim 1 , wherein the flow slot comprises a height perpendicular to a chord of the vane of no more than 10% of a total height of the vane perpendicular to the chord of the vane.
6. The diffuser of claim 1 , wherein the flow slot extends along no more than 25% of a chord length of the vane.
7. The diffuser of claim 1 , wherein the flow slot extends along no more than 38% of a chord length of the vane.
8. The diffuser of claim 1 , wherein the flow slot extends along at least 5% of a chord length of the vane.
9. A compressor comprising the diffuser of claim 1 .
10. A diffuser for a compressor, the diffuser comprising:
opposed walls defining a space disposed downstream of a compressor impeller for receiving a flow of a working fluid from the impeller;
a vane comprising a pressure side and a suction side connected between the opposed walls for directing the working fluid through the space; and
a flow opening having an inlet on the pressure side of the vane and an outlet on the suction side of the vane upstream from a throat location on the vane for allowing a portion of the flow of working fluid to pass from the pressure side to the suction side of the vane;
wherein the flow opening comprises a hole drilled between the pressure side and the suction side of the vane.
11. The diffuser of claim 10 , wherein the flow opening is formed in one of the opposed walls.
12. The diffuser of claim 10 , wherein a height of the flow opening perpendicular to a chord of the vane is no more than 5% of a total height of the vane.
13. The diffuser of claim 10 , wherein a height of the flow opening perpendicular to a chord of the vane is no more than 10% of a total height of the vane.
14. The diffuser of claim 10 , wherein the flow opening is formed proximate an intersection of the vane and one of the opposed walls.
15. The diffuser of claim 10 , wherein the flow opening comprises a flow slot formed between the vane and one of the opposed walls.
16. The diffuser of claim 10 , wherein the flow opening extends downstream from a point downstream of a leading edge of the vane to define a support connection between the vane and the opposed walls at the leading edge.
17. A compressor comprising the diffuser of claim 10 .
18. A diffuser for a compressor, the diffuser comprising:
opposed walls defining a space disposed downstream of a compressor impeller for receiving a flow of a working fluid from the impeller;
a vane comprising a pressure side and a suction side connected between the opposed walls for directing the working fluid through the space; and
a flow opening having an inlet on the pressure side of the vane and an outlet on the suction side of the vane upstream from a throat location on the vane for allowing a portion of the flow of working fluid to pass from the pressure side to the suction side of the vane;
wherein the flow opening comprises a first flow opening formed proximate a first of the opposed walls allowing a first portion of the flow of working fluid to pass from the pressure side to the suction side of the vane, and further comprising a second flow opening formed proximate a second of the opposed walls allowing a second portion of the flow of working fluid to pass from the pressure side to the suction side of the vane.