# US 11,028,730 B2 · Air oil cooler airflow augmentation system

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- Number: US 11,028,730 B2
- Document ID: US11028730B2
- Status: Granted
- Kind: B2
- Application number: 16/266,948
- Filed: 2019-02-04
- Published: 2019-06-06
- Granted: 2021-06-08
- Earliest claimed: 2013-03-15
- Assignees: Raytheon Technologies Corporation
- Applicants: United Technologies Corporation
- Inventors: Ethan K. Stearns; John Axel Glahn; Daniel J. McKaveney
- Web page: https://patentgrep.com/patent/US11028730B2

## CPC

- F01D 25/20: using lubrication pumps
- F01D 25/12: Cooling
- F01D 25/125: {of bearings}
- F01D 25/18: Lubricating arrangements (of machines or engines in general F01M)
- F01M 1/12: Closed-circuit lubricating systems not provided for in groups F01M1/02 - F01M1/10
- F02C 7/06: Arrangements of bearings (bearings F16C); Lubricating ({of turbo machines F01D25/18; of machines or} engines in general F01M)
- F02C 7/14: of fluids in the plant {, e.g. lubricant or fuel (F02C7/185 takes precedence)}
- F02C 7/185: {Cooling means for reducing the temperature of the cooling air or gas}
- F02C 7/224: Heating fuel before feeding to the burner
- F02C 9/18: by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages {(F02C3/113 takes precedence)}
- F05D 2220/32: in gas turbines
- F05D 2220/323: for aircraft propulsion, e.g. jet engines
- F05D 2240/35: Combustors or associated equipment
- F05D 2260/205: Cooling fluid recirculation, i.e. after cooling one or more components is the cooling fluid recovered and used elsewhere for other purposes
- F05D 2260/213: by the provision of a heat exchanger within the cooling circuit
- F05D 2260/232: characterized by the cooling medium
- F05D 2260/40311: of the epicyclical, planetary or differential type
- F05D 2260/601: using an ejector or a jet pump
- F05D 2260/606: Bypassing the fluid
- F05D 2260/98: Lubrication
- Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F01M: LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
- 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)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

An oil supply system for a gas turbine engine has a lubricant pump delivering lubricant to an outlet line. The outlet line is split into at least a hot line and into a cool line, with the hot line directed primarily to locations associated with an engine that are not intended to receive cooler lubricant, and the cool line directed through one or more heat exchangers at which lubricant is cooled. The cool line then is routed to a fan drive gear system of an associated gas turbine engine. A method and apparatus are disclosed. The heat exchangers include at least an air/oil cooler wherein air is pulled across the air/oil cooler to cool oil. The air/oil cooler is provided with an ejector tapping compressed air from a compressor section to increase airflow across the air/oil cooler.

## Claims

### Claim 1

A lubricant supply system for a gas turbine engine comprising:
a lubricant pump delivering lubricant to an outlet line that splits into at least a hot line and a cool line, said hot line being directed primarily to locations associated with the gas turbine engine that are not intended to receive cooler lubricant, and said cool line being directed to at least one component with an operating temperature lower than the locations associated with the gas turbine engine that are not intended to receive cooler lubricant;
an air/oil cooler that pulls air across said air/oil cooler to cool lubricant in said cool line, wherein at least a portion of the lubricant in said cool line bypasses the air/oil cooler and is passed through a first fuel/oil cooler configured to cool the at least a portion of the lubricant using fuel leading to a combustion section of the gas turbine engine;
an oil/oil cooler configured to cool lubricant from a generator with lubricant from the air/oil cooler; and
a second fuel/oil cooler configured to cool another lubricant exhausted from the oil/oil cooler with the fuel leading to the combustion section.

### Claim 2 (depends on 1)

The system as recited in claim 1, including an ejector within the air/oil cooler for augmenting air flow across the air/oil cooler selectively responsive to an operating condition not providing air flow sufficient for cooling lubricant to desired temperature.

### Claim 3 (depends on 2)

The system as recited in claim 2, including selectively actuating a fan to provide airflow through to the ejector to augment airflow across the air/oil cooler.

### Claim 4 (depends on 2)

The system as recited in claim 2, including selectively providing airflow from a compressor section to provide airflow to the ejector to augment airflow across the air/oil cooler.

### Claim 5 (depends on 1)

The system as set forth in claim 1, wherein a valve is positioned on said cool line and splits said cool line into two lines, with a first line being directed through said first fuel/oil cooler at which the at least a portion of the lubricant is cooled by fuel leading to the combustion section of the gas turbine engine, and the lubricant in the cool line that is not being directed to the first fuel/oil cooler is directed through a second line, said cool line being split into said two lines at a location downstream of a point where said outlet line is split into said hot line and said cool line.

### Claim 6 (depends on 5)

The system as set forth in claim 5, wherein a bypass valve selectively bypasses fuel downstream of said fuel/oil cooler back upstream.

### Claim 7 (depends on 6)

The system as set forth in claim 6, wherein said bypass valve alternatively directs the fuel upstream of the first fuel/oil cooler, or downstream of the first fuel/oil cooler.

### Claim 8 (depends on 1)

The system as set forth in claim 1, wherein the second fuel/oil cooler is at a location upstream of said first fuel/oil cooler.

### Claim 9

A gas turbine engine comprising:
a fan, a compressor section, including a low pressure compressor section and a high pressure compressor section;
a combustor;
a turbine section including both a low pressure turbine and a high pressure turbine section, and said low pressure turbine section driving said low pressure compressor section; and
a fan drive gear system provided such that said low pressure turbine further driving said fan, with said fan and said low pressure compressor being driven at different speeds;
a lubricant system including a lubricant pump delivering lubricant to an outlet line that splits into at least a hot line and a cool line, said hot line being directed primarily to locations associated with the gas turbine engine that are not intended to receive cooler lubricant, and said cool line being directed to at least one component with an operating temperature lower than the locations associated with the gas turbine engine that are not intended to receive cooler lubricant; and
an air/oil cooler wherein air is pulled across said air/oil cooler to cool lubricant in said cool line, wherein at least a portion of the lubricant in said cool line bypasses the air/oil cooler and is passed through a first fuel/oil cooler configured to cool the at least a portion of the lubricant using fuel leading to a combustion section of the associated gas turbine engine;
an oil/oil cooler configured to cool lubricant from a generator with lubricant from the air/oil cooler; and
a second fuel/oil cooler configured to cool another lubricant exhausted from the oil/oil cooler with the fuel leading to the combustion section.

### Claim 10 (depends on 9)

The gas turbine engine as recited in claim 9, including an ejector within the air/oil cooler for augmenting air flow across the air/oil cooler selectively responsive to an operating condition not providing air flow sufficient for cooling lubricant to desired temperature.

### Claim 11 (depends on 10)

The gas turbine engine as recited in claim 10, including selectively actuating a fan to provide airflow through to the ejector to augment airflow across the air/oil cooler.

### Claim 12 (depends on 10)

The gas turbine engine as recited in claim 10, including selectively providing airflow from a compressor section to provide airflow to the ejector to augment airflow across the air/oil cooler.

### Claim 13 (depends on 9)

The gas turbine engine as set forth in claim 9, wherein said locations in the engine that are not intended to receive cooler lubricant include bearings associated with at least the turbine section.

### Claim 14 (depends on 9)

The gas turbine engine as recited in claim 9, wherein a valve is positioned on said cool line and splits said cool line into two lines, with said first line being directed through the first fuel/oil cooler at which the at least a portion of the lubricant is cooled by fuel leading to the combustion section of the gas turbine engine, and the lubricant in the cool line that is not being directed to the first fuel/oil cooler but being directed through a second line and, said cool line is split into said two lines at a location downstream of a point where said outlet line is split into said hot line and said cool line.

### Claim 15 (depends on 14)

The gas turbine engine as recited in claim 14, wherein a bypass valve selectively bypasses fuel downstream of said first fuel/oil cooler back upstream.

### Claim 16 (depends on 15)

The gas turbine engine as recited in claim 15, wherein said bypass valve alternatively directs the fuel upstream of the first fuel/oil cooler, or downstream of the first fuel/oil cooler.

### Claim 17 (depends on 15)

The gas turbine engine as set forth in claim 15, wherein the second fuel/oil cooler is at a location upstream of said first fuel/oil cooler.

### Claim 18 (depends on 8)

The system as recited in claim 8, wherein the oil/oil cooler, the generator and the second fuel/oil cooler are part of an oil cooling system circuit that is not in flow communication with lubricant circulated in the at least one hot line and cool line.

### Claim 19 (depends on 17)

The gas turbine engine as recited in claim 17, wherein the generator is driven by the turbine section.

### Claim 20 (depends on 17)

The gas turbine engine as recited in claim 17, wherein the oil/oil cooler, the generator and the second fuel/oil cooler are part of an oil cooling system circuit that is not in flow communication with lubricant in the at least one hot line and cool line.
