# US 2020/0393129 A1 · Diffuser pipe with axially-directed exit

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- Number: US 2020/0393129 A1
- Document ID: US20200393129A1
- Status: Published application
- Kind: A1
- Application number: 16/440,213
- Filed: 2019-06-13
- Published: 2020-12-17
- Earliest claimed: 2019-06-13
- Assignees: Pratt & Whitney Canada Corp.
- Applicants: Pratt & Whitney Canada Corp.
- Inventors: Hien DUONG
- Web page: https://patentgrep.com/patent/US20200393129A1

## CPC

- F23R 3/04: Air inlet arrangements
- F23R 3/045: {using pipes}
- F01D 9/02: Nozzles; Nozzle boxes; Stator blades; Guide conduits {, e.g. individual nozzles (nozzle boxes F01D9/047)}
- F01D 9/06: Fluid supply conduits to nozzles or the like
- F01D 17/14: varying effective cross-sectional area of nozzles or guide conduits
- F02C 3/08: the compressor comprising at least one radial stage (F02C3/10 takes precedence)
- F04D 29/2255: {flow-channels with a special cross-section contour, e.g. ejecting, throttling or diffusing effect}
- F04D 29/441: {especially adapted for elastic fluid pumps}
- F04D 29/547: {having a special shape in order to influence fluid flow}
- F05D 2240/12: Fluid guiding means, e.g. vanes
- F05D 2250/20: Three-dimensional
- F05D 2250/52: Outlet
- F05D 2260/96: Preventing, counteracting or reducing vibration or noise
- F23R: GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS (fluidised bed combustion apparatus specially adapted for operation at superatmospheric pressures F23C10/16)
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- 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 compressor diffuser for a gas turbine engine includes diffuser pipes having a tubular body including a generally radial portion, a bend portion and a generally axial portion. The generally axial portion has an exit segment extending parallel to the center axis and terminating at a pipe outlet. The bend portion is disposed radially further from the center axis than the exit segment.

## Claims

### Claim 1

A compressor diffuser for a gas turbine engine having a center axis, the compressor diffuser comprising: diffuser pipes having a tubular body including a generally radial portion, a bend portion and a generally axial portion, the generally axial portion having an exit segment extending parallel to the center axis and terminating at a pipe outlet, the bend portion disposed radially further from the center axis than the exit segment.

### Claim 2 (depends on 1)

The compressor diffuser of claim 1, wherein the exit segment is the same radial distance from the center axis along a length of the exit segment.

### Claim 3 (depends on 1)

The compressor diffuser of claim 1, wherein the tubular body has a length measured from an inlet of the generally radial portion to the pipe outlet, the exit segment having a length of 20% of the length of the tubular body.

### Claim 4 (depends on 1)

The compressor diffuser of claim 1, wherein the generally axial portion curves radially inwardly from the bend portion toward the exit segment.

### Claim 5 (depends on 4)

The compressor diffuser of claim 4, wherein the center axis and radial lines extending therefrom define a plurality of planes, one of the plurality of planes intersecting the tubular body along the generally axial portion to define a planar profile of the generally axial portion, the planar profile having a slope being a change in a radial distance of the planar profile from the center axis over a length along the center axis, the slope of the planar profile being negative where the generally axial portion curves radially inwardly from the bend portion toward the exit segment.

### Claim 6 (depends on 5)

The compressor diffuser of claim 5, wherein the slope of planar profile along the exit segment is zero.

### Claim 7 (depends on 1)

The compressor diffuser of claim 1, wherein the exit segment is curved circumferentially toward the center axis relative to a portion of the tubular body immediately upstream of the exit segment.

### Claim 8 (depends on 1)

The compressor diffuser of claim 1 in combination with a reverse-flow combustor positioned to receive fluid flow from the pipe outlet.

### Claim 9

A gas turbine engine, comprising:
a compressor having an impeller rotatable about a center axis, and having a radial impeller outlet;
a diffuser with diffuser pipes to receive fluid from the radial impeller outlet, and having a tubular body including a generally radial portion, a bend portion and a generally axial portion, the generally axial portion having an exit segment extending parallel to the center axis and terminating at a pipe outlet, the bend portion disposed radially further from the center axis than the exit segment; and
a reverse-flow combustor downstream of the diffuser.

### Claim 10 (depends on 9)

The centrifugal compressor of claim 9, wherein the exit segment is the same radial distance from the center axis along a length of the exit segment.

### Claim 11 (depends on 9)

The centrifugal compressor of claim 9, wherein the tubular body has a length measured from an inlet of the generally radial portion to the pipe outlet, the exit segment having a length of 20% of the length of the tubular body.

### Claim 12 (depends on 9)

The centrifugal compressor of claim 9, wherein the generally axial portion curves radially inwardly from the bend portion toward the exit segment.

### Claim 13 (depends on 12)

The centrifugal compressor of claim 12, wherein the center axis and radial lines extending therefrom define a plurality of planes, one of the plurality of planes intersecting the tubular body along the generally axial portion to define a planar profile of the generally axial portion, the planar profile having a slope being a change in a radial distance of the planar profile from the center axis over a length along the center axis, the slope of the planar profile being negative where the generally axial portion curves radially inwardly from the bend portion toward the exit segment.

### Claim 14 (depends on 13)

The centrifugal compressor of claim 13, wherein the slope of planar profile along the exit segment is zero.

### Claim 15 (depends on 9)

The centrifugal compressor of claim 9, wherein the exit segment is curved circumferentially toward the center axis relative to a portion of the tubular body immediately upstream of the exit segment.

### Claim 16

A method of modifying a vibratory response of a diffuser pipe of a compressor with a center axis, the method comprising: positioning a bend portion of the diffuser pipe radially outwardly from the center axis and from an outlet of the diffuser pipe, and orienting an exit segment of the diffuser pipe to be parallel with the center axis.

### Claim 17 (depends on 16)

The method of claim 16, comprising lengthening the diffuser pipe before the bend portion.

### Claim 18 (depends on 16)

The method of claim 16, wherein orienting the exit segment includes straightening the exit segment to have a same radial distance from the center axis over a length of the exit segment.

### Claim 19 (depends on 16)

The method of claim 16, comprising curving the diffuser pipe radially inwardly from the bend portion to the exit segment.