# US 11,994,034 B2 · Gas turbine engine with low pressure compressor stages

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- Number: US 11,994,034 B2
- Document ID: US11994034B2
- Status: Granted
- Kind: B2
- Application number: 16/157,476
- Filed: 2018-10-11
- Published: 2020-04-16
- Granted: 2024-05-28
- Earliest claimed: 2018-10-11
- Assignees: Pratt & Whitney Canada Corp.
- Applicants: Pratt & Whitney Canada Corp.
- Inventors: Ghislain Plante; Ian MacFarlane
- Web page: https://patentgrep.com/patent/US11994034B2

## CPC

- F01D 17/105: {by passing part of the fluid}
- F02C 3/06: the compressor comprising only axial stages (F02C3/10 takes precedence)
- F01D 21/006: {Arrangements of brakes (brakes per se F16D)}
- F02C 3/13: having variable working fluid interconnections between turbines or compressors or stages of different rotors {(controlling flow ratio between different flows of multi-flow jet-propulsion plant, e.g. ducted fan F02K3/075)}
- F02C 3/145: {the combustion chamber being in the reverse flow-type}
- F02C 6/08: the gas being bled from the gas-turbine compressor
- F02C 7/36: Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user ({F02C3/107 - F02C3/13 and} F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H)
- F02C 9/18: by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages {(F02C3/113 takes precedence)}
- F02K 3/075: controlling flow ratio between flows
- F04D 25/02: Units comprising pumps and their driving means
- F04D 27/0269: {by changing flow path between different stages or between a plurality of compressors; load distribution between compressors}
- F05D 2220/3217: for the first stage of a compressor or a low pressure compressor
- F05D 2220/3219: for the last stage of a compressor or a high pressure compressor
- F05D 2260/4023: through a friction clutch
- F05D 2260/606: Bypassing the fluid
- F05D 2260/902: using frictional mechanical forces
- F05D 2270/10: to cope with, or avoid, compressor flow instabilities
- 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)
- F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00)
- 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 low pressure compressor section of a gas turbine engine includes low pressure compressor stages spaced apart along an axis of rotation of the low pressure compressor section. The low pressure compressor section includes at least one of a fluid conduit extending between an air inlet of the gas turbine engine and the low pressure compression stages. The fluid conduit having at least one flow diverter displaceable between a first position and a second position to modulate air through the low pressure compressor stages. And/or a compressor stage disabler is engageable with at least one of the low pressure compressor stages and configured to reduce a rotation thereof.

## Claims

### Claim 1

A gas turbine engine, comprising:
a low pressure compressor section in fluid communication with an air inlet and drivingly engaged by a low pressure turbine section, the low pressure compressor section having low pressure compressor stages spaced apart along an axis of rotation of the low pressure compressor section, the low pressure compressor stages including a first low pressure compressor stage and a second low pressure compressor stage, and the low pressure compressor section further having:
a) a fluid conduit extending between the air inlet and the low pressure compressor stages, the fluid conduit having at least one flow diverter displaceable between a first position and a second position to modulate air flow through the low pressure compressor stages, the fluid conduit including a first fluid conduit segment extending between the air inlet and the first low pressure compressor stage, and a second fluid conduit segment extending between the air inlet and the second low pressure compressor stage, the first and second low pressure compressor stages fluidly connected in parallel to the air inlet via the first and second fluid conduit segments, the first and second fluid conduit segments meeting at a fluid conduit junction upstream of the low pressure compressor stages, the at least one flow diverter positioned at the fluid conduit junction and displaceable between the first position to direct air in parallel from the fluid conduit junction to both the first and second fluid conduit segments, and the second position closing the fluid conduit junction to direct air from the fluid conduit junction only to the first fluid conduit segment; and
b) a brake selectively engageable with at least one of the first and second low pressure compressor stages and configured to reduce a rotation thereof;
a high pressure compressor section in fluid communication with the low pressure compressor stages to receive pressurized air therefrom and drivingly engaged by a high pressure turbine section; and
an output drive shaft drivingly engaged by the low pressure turbine section.

### Claim 2 (depends on 1)

The gas turbine engine as defined in claim 1, wherein each of the low pressure compressor stages defines a pressure ratio across said low pressure compressor stages, the pressure ratio for each of the low pressure compressor stages being the same.

### Claim 3 (depends on 1)

The gas turbine engine as defined in claim 1, wherein each of the low pressure compressor stages is configured to draw a quantity of air from the air inlet, the quantity of air for each of the low pressure compressor stages being the same.

### Claim 4 (depends on 1)

The gas turbine engine as defined in claim 1, wherein upon the brake being disengaged from the at least one of the low pressure compressor stages, the output drive shaft drivingly engages all the low pressure compressor stages.

### Claim 5 (depends on 1)

The gas turbine engine as defined in claim 1, wherein the brake is engageable with the at least one of the low pressure compressor stages to stop a rotation of the at least one of the low pressure compressor stages.

### Claim 6

A method of operating a compressor of a gas turbine engine, comprising:
drawing air into a core of the gas turbine engine from an air inlet and through axially spaced-apart low pressure compressor stages, and then through a high pressure compressor section to provide pressurized air; and
while drawing air into the core:
varying a flow of the air through a fluid conduit junction upstream of the low pressure compressor stages, wherein the fluid conduit junction is provided between a first fluid conduit segment and a second conduit segment of a fluid conduit, the first fluid conduit segment extending between the air inlet and one of the low pressure compressor stages, the second fluid conduit segment extending between the air inlet and another one of the low pressure compress stages, the fluid conduit having a flow diverter positioned at the fluid conduit junction, and wherein varying the flow of the air comprises displacing the flow diverter between a first position to direct air from the fluid conduit junction to both the first and second fluid conduit segments, and a second position closing the fluid conduit junction to direct air from the fluid conduit junction only to the first fluid conduit segment; and
varying an increase in pressure of the air across the low pressure compressor stages.

### Claim 7 (depends on 6)

The method as defined in claim 6, wherein providing the air drawn into the core from the air inlet to all of the low pressure compressor stages includes providing a same quantity of air to all of the low pressure compressor stages.

### Claim 8 (depends on 6)

The method as defined in claim 6, wherein providing the air drawn into the core from the air inlet to all of the low pressure compressor stages includes operating the low pressure compressor stages to have a same pressure ratio.

### Claim 9 (depends on 6)

The method as defined in claim 6, wherein varying the increase in pressure of the air across the low pressure compressor stages includes braking one of the low pressure compressor stages.

### Claim 10

A low pressure compressor section of a gas turbine engine, comprising: low pressure compressor stages spaced apart along an axis of rotation of the low pressure compressor section, the low pressure compressor section having:
a fluid conduit extending between an air inlet of the gas turbine engine and the low pressure compressor stages, the fluid conduit having at least one flow diverter displaceable between a first position and a second position to modulate air flow through the low pressure compressor stages, the fluid conduit including a first fluid conduit segment extending between the air inlet and one of the low pressure compressor stages, and a second fluid conduit segment extending between the air inlet and another one of the low pressure compressor stages, the first and second fluid conduit segments meeting at a fluid conduit junction upstream of the low pressure compressor stages, the at least one flow diverter positioned at the fluid conduit junction and displaceable between the first position to direct air from the fluid conduit junction to both the first and second fluid conduit segments, and the second position closing the fluid conduit junction to direct air from the fluid conduit junction only to the first fluid conduit segment; and
a compressor stage disabler drivingly engaged with at least one of the low pressure compressor stages and configured to reduce a rotation thereof.

### Claim 11 (depends on 10)

The low pressure compressor section as defined in claim 10, wherein the compressor stage disabler is a brake engageable with the at least one of the low pressure compressor stages to stop a rotation of the at least one of the low pressure compressor stages.