Scroll structure of centrifugal compressor

Patent metadata

Field	Value
Publication number	US-9541094-B2
Application number	US-201113823607-A
Country	US
Kind code	B2
Filing date	Dec 5, 2011
Priority date	Dec 28, 2010
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

A scroll structure of a centrifugal compressor 1 having a spirally formed scroll passage 13 . The scroll passage 13 includes: a flat connecting portion A at a flow passage joint 23 where a scroll start and a scroll end of the scroll passage 13 meet, this flat connecting portion having a flat cross-sectional shape with a same height as that of an outlet passage of a diffuser; and a transition part 21 where the flat cross-sectional shape of the flat connecting portion A gradually changes back to a circular cross-sectional shape along a circumferential direction.

First claim

The invention claimed is:

1. A centrifugal compressor comprising:
a compressor blade;
a diffuser disposed on a radially outer side of the compressor blade;
an outlet passage; and
a scroll passage formed spirally around the diffuser, said scroll passage including:
a connecting portion disposed at a flow passage joint where a scroll start and a scroll end of the scroll passage meet, the connecting portion having a flat-sided cross-sectional shape with a same height as that of the outlet passage of the diffuser; and
the scroll passage further comprising a transition part disposed on a downstream side of the flat-sided connecting portion, the transition part having a cross-sectional shape which gradually changes, along a circumferential direction of the centrifugal compressor, from the flat-sided cross-sectional shape of the connecting portion to a circular cross-sectional shape.

2. The centrifugal compressor according to claim 1 ,
wherein said transition part has a circumferential length equal to the length required for a fluid which flows into the scroll passage from a diffuser outlet at said flow passage joint to make one spiral turn around the cross section of the scroll passage.

3. The centrifugal compressor according to claim 2 , the compressor comprising:
a compressor wheel including the compressor blade; and
a compressor housing including a tongue portion disposed at said flow passage joint, wherein said transition part of said scroll passage extends circumferentially downstream from the tongue portion for a circumferential angle of 30° .

4. The centrifugal compressor according to claim 1 ,
wherein the cross-sectional shape of the transition part changes from said a flat-sided cross section gradually along the circumferential direction of the centrifugal compressor and becomes a circular cross-sectional shape at the end of the transition part.

5. The centrifugal compressor according to claim 1 ,
wherein the cross-sectional shape of the transition part has a contour including an arc-contour portion which is disposed to face a fluid flow from the outlet passage of the diffuser, and said arc-contour portion is gradually enlarged along the circumferential direction so that a cross-sectional shape of the scroll passage becomes a circular cross-sectional shape formed by the enlarged arc-contour portion at an end of the transition part.

6. The centrifugal compressor according to claim 5 ,
wherein the arc-contour portion has a circular arc center located at an end of the outlet passage of the diffuser outlet.

7. The centrifugal compressor according to claim 5 ,
wherein the arc-contour portion has a circular arc center located at a center position of the scroll passage.

8. The centrifugal compressor according to claim 5 ,
wherein the arc-contour portion has a circular arc center which moves closer to an end of the outlet passage of the diffuser as the cross-sectional shape of the transition part changes from the flat-sided cross-sectional shape to the circular cross-sectional shape along the circumferential direction.

Assignees

• Iwakiri Kenichiro
• Tomita Isao
• Ebisu Motoki
• Suzuki Hiroshi
• Shiraishi Takashi
• Mitsubishi Heavy Ind Ltd

Inventors

• Iwakiri Kenichiro
• Tomita Isao
• Ebisu Motoki
• Suzuki Hiroshi
• Shiraishi Takashi

Classifications

• F04D29/441 Primary

  especially adapted for elastic fluid pumps · CPC title

• F04D29/4206

  especially adapted for elastic fluid pumps · CPC title

• F05D2250/52

  Outlet · CPC title

• F04D29/403 Primary

  especially adapted for elastic fluid pumps · CPC title

• F05D2250/70

  Shape · CPC title