# US 12,000,345 B2 · Surge recovery system and methods

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- Number: US 12,000,345 B2
- Document ID: US12000345B2
- Status: Granted
- Kind: B2
- Application number: 17/867,507
- Filed: 2022-07-18
- Published: 2022-11-03
- Granted: 2024-06-04
- Earliest claimed: 2020-02-06
- Assignees: Rtx Corporation
- Applicants: Raytheon Technologies Corporation
- Inventors: Michael M. Romero; Gary Collopy
- Web page: https://patentgrep.com/patent/US12000345B2

## CPC

- F02C 9/16: Control of working fluid flow (F02C9/48 takes precedence; control of air-intake flow F02C7/057)
- F04D 27/0261: {by varying driving speed}
- F02C 7/32: Arrangement, mounting, or driving, of auxiliaries
- F02C 9/28: Regulating systems responsive to plant or ambient parameters, e.g. temperature, pressure, rotor speed (F02C9/30 - F02C9/38, F02C9/44 take precedence)
- F04D 19/026: {with a plurality of shafts rotating at different speeds (F04D19/022 takes precedence)}
- F04D 25/04: the pump being fluid-driven {(pumps driven by exhaust gases F02B37/00, F02B39/00; turbochargers F02C6/12)}
- F04D 25/06: the pump being electrically driven (F04D25/08 takes precedence)
- F04D 27/0269: {by changing flow path between different stages or between a plurality of compressors; load distribution between compressors}
- F05D 2220/76: an electrical generator
- F05D 2270/101: Compressor surge or stall
- F05D 2270/62: Electrical actuators
- 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 surge control system includes a rotor system with at least one compressor section and at least one turbine section operably coupled to a shaft. The surge control system also includes sensors configured to collect sensor data from the rotor system, an electric motor operably coupled to the rotor system, and a controller. The controller is operable to detect surge event from the sensor data, determine an amount of power to apply to the rotor system, and increase the amount of power provided to the rotor system to recover from the surge event.

## Claims

### Claim 1

A gas turbine engine comprising:
a power source;
a first compressor section;
a first turbine section;
a combustor section between the first compressor section and the first turbine section;
a first spool comprising a first shaft, the first shaft operably coupling the first compressor section and the first turbine section, wherein the first compressor section, the first turbine section, and the first shaft provide a first rotor system;
a controller configured to collect or synthesize data from a sensor from at least one of the first rotor system and the combustor section;
a first electric motor operably coupled to the first rotor system, the first electric motor configured to provide a power assist to the first shaft in response to a surge event in the first compressor section, wherein the controller is configured to:
detect the surge event for the first compressor section of the gas turbine engine;
determining, by a predefined multivariable table dependent on at least one of sensed engine parameters, synthesized engine parameters, or time elapsed since detecting the surge event, an amount of power to apply to the first spool of the gas turbine engine;
increasing a power provided to the first spool by a power extraction from a second spool of the gas turbine engine, the second spool comprising a second compressor section, the power increased by the amount of power determined by the predefined multivariable table;
monitoring a magnitude of the power commensurate with a severity of the surge event and loss in thrust due to the power extraction;
adjusting the magnitude of the power commensurate with the severity of the surge event and loss in thrust due to the power extraction; and
increasing a stability margin of the first compressor section in response to the adjusting.

### Claim 2 (depends on 1)

The gas turbine engine of claim 1, wherein the power source is an auxiliary power unit.

### Claim 3 (depends on 1)

The gas turbine engine of claim 1, wherein the second spool comprises a second electric motor, the second compressor section, a second turbine section, and a second shaft operably coupled to the second compressor section and the second turbine section, wherein the second shaft is parallel with the first shaft, and wherein the second electric motor operably coupled to the second shaft.

### Claim 4 (depends on 3)

The gas turbine engine of claim 3, wherein the second electric motor is configured to act as a generator and extract power from the second shaft in response to the surge event in the first compressor section.

### Claim 5 (depends on 4)

The gas turbine engine of claim 4, wherein extracting the power from the second shaft is used to provide all or a supplement of power into the first shaft.

### Claim 6 (depends on 3)

The gas turbine engine of claim 3, further comprising the second spool, wherein:
the first spool is a high speed spool,
the second spool comprises the second shaft,
the second spool is a low speed spool, and
the high speed spool operates at higher speeds than the low speed spool.

### Claim 7 (depends on 1)

The gas turbine engine of claim 1, wherein the first electric motor is operable to apply torque and speed to the first rotor system to recover from the surge event of the first compressor section.

### Claim 8 (depends on 1)

The gas turbine engine of claim 1, wherein the first electric motor is aligned in parallel with the first shaft.

### Claim 9 (depends on 1)

The gas turbine engine of claim 1, wherein the first electric motor is parallel with the first shaft.

### Claim 10

A method of recovering from a surge event, the method comprising:
detecting the surge event for a first compressor of a first spool of a gas turbine engine;
determining, by a predefined multivariable table dependent on at least one of sensed engine parameters, synthesized engine parameters, or time elapsed since detecting the surge event, an amount of power to apply to the first spool of the gas turbine engine;
increasing a power provided to the first spool by a power extraction from a second spool of the gas turbine engine, the second spool comprising a second compressor, the power increased by the amount of power determined by the predefined multivariable table;
monitoring a magnitude of the power commensurate with a severity of the surge event and loss in thrust due to the power extraction;
adjusting the magnitude of the power commensurate with the severity of the surge event and loss in thrust due to the power extraction; and
increasing a stability margin of the first compressor in response to the adjusting.

### Claim 11 (depends on 10)

The method of claim 10, wherein the power comprises a torque and a speed applied to the first spool.

### Claim 12 (depends on 10)

The method of claim 10, wherein the increasing the stability margin of the first compressor places the first compressor into an operable region in a compressor map.