# US 8,147,186 B2 · Centrifugal compressor

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- Number: US 8,147,186 B2
- Document ID: US8147186B2
- Status: Granted
- Kind: B2
- Application number: 12/308,246
- Filed: 2008-04-10
- Published: 2010-07-01
- Granted: 2012-04-03
- Earliest claimed: 2007-04-20
- Assignees: Mitsubishi Heavy Industries, Ltd.
- Inventors: Seiichi Ibaraki; Isao Tomita; Yasuaki Jinnai; Takashi Shiraishi; Koichi Sugimoto
- Web page: https://patentgrep.com/patent/US8147186B2

## CPC

- F04D 29/4206: {especially adapted for elastic fluid pumps}
- F04D 29/422: {Discharge tongues (F04D17/04 takes precedence)}
- F04D 29/441: {especially adapted for elastic fluid pumps}
- F04D 29/462: {especially adapted for elastic fluid pumps}
- F04D 29/464: {adjusting flow cross-section, otherwise than by using adjustable stator blades}
- F05D 2250/52: Outlet
- F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

A centrifugal compressor having a wide operating range, being economically efficient and high reliability in terms of a stable operation is provided. A centrifugal compressor including a partition wall for dividing a flow channel in the diffuser section and the volute section into a plurality of channels in the direction of circulation of the fluid so as to define a hub-side flow channel and a shroud-side flow channel; and a flow rate adjusting valve for lowering the flow rate of the fluid flowing in the shroud-side flow channel to increase the flow rate in the hub-side flow channel when the flow rate of the fluid compressed by an impeller is low and not lowering the flow rate of the fluid flowing the shroud-side flow channel to allow the fluid to flow both in the shroud-side flow channel and the hub-side flow channel when the flow rate of the fluid compressed by the impeller is high is employed.

## Claims

### Claim 1

A centrifugal compressor comprising:
a revolving shaft;
an impeller mounted to the revolving shaft;
a casing configured to house the impeller;
a diffuser section connected downstream of the impeller; and
a volute section connected downstream of the diffuser section, and being configured to compress fluid by applying a centrifugal force to the fluid by rotating the impeller;
a parting member configured to divide a flow channel in the diffuser section and the volute section into a plurality of channels in a direction of circulation of the fluid so as to define a hub-side flow channel and a shroud-side flow channel; and
a flow rate adjuster configured to lower the flow rate of the fluid flowing in the shroud-side flow channel and enabling the fluid to flow in the hub-side flow channel at a high flow rate when the flow rate of the fluid compressed by the impeller is low and not lowering the flow rate of the fluid flowing the shroud-side flow channel to enable the fluid to flow both in the shroud-side flow channel and the hub-side flow channel when the flow rate of the fluid compressed by the impeller is high, wherein
the diffuser section includes a hub-side diffuser section in the hub-side flow channel and a shroud-side diffuser section in the shroud-side flow channel,
at least the hub-side diffuser section is provided with vanes, and
a cross-sectional area of the flow channel in the shroud-side diffuser section is larger than the cross-sectional area of the flow channel in the hub-side diffuser section.

### Claim 2 (depends on 1)

The centrifugal compressor according to claim 1, wherein the parting member is a partition wall disposed in the interiors of the diffuser section and the volute section.

### Claim 3 (depends on 1)

The centrifugal compressor according to claim 1, wherein the flow rate adjuster is a flow rate adjusting valve disposed in the vicinity of an exit portion of the volute section.

### Claim 4 (depends on 1)

The centrifugal compressor according to claim 1, wherein the diameter of an inlet for at least one of the hub-side diffuser section and the shroud-side diffuser section is 1.02 to 1.2 times the diameter of the impeller.

### Claim 5 (depends on 2)

The centrifugal compressor according to claim 2, wherein an end surface of the partition wall on an upstream side is inclined from a hub side to a shroud side.

### Claim 6 (depends on 1)

The centrifugal compressor according to claim 1, wherein
the shroud-side diffuser section includes vanes, and
a number of the vanes on the hub-side diffuser section is larger than a number of the vanes on the shroud-side diffuser section.

### Claim 7 (depends on 6)

The centrifugal compressor according to claim 6, wherein
a vane height or a vane angle of the vanes in the hub-side diffuser section is smaller than a van height or a vane angle of the vanes in the shroud-side diffuser section.