Reverse-flow gas turbine engine

Patent metadata

Field	Value
Publication number	US-11408352-B2
Application number	US-202017077310-A
Country	US
Kind code	B2
Filing date	Oct 22, 2020
Priority date	Sep 15, 2016
Publication date	Aug 9, 2022
Grant date	Aug 9, 2022

Abstract

A gas turbine engine has a first spool having a low pressure compressor section in fluid communication with an air inlet, the low pressure compressor section including a first plurality of variable guide vanes therein, and a low pressure turbine section drivingly engaged to the low pressure compressor section. A second spool has a high pressure compressor section in fluid communication with the low pressure compressor section to receive pressurized air therefrom, the high pressure compressor section including a second plurality of variable guide vanes at an entry thereof, and a high pressure turbine section drivingly engaged to the high pressure compressor section, the high pressure turbine section disposed upstream of the low pressure turbine section and in fluid communication therewith. An output drive shaft drivingly engages the low pressure turbine section and is adapted to drivingly engage a rotatable load of the gas turbine engine.

First claim

The invention claimed is:

1. A gas turbine engine, comprising:
a first spool rotatable about an axis, the first spool having
a low pressure compressor section in fluid communication with an air inlet, the low pressure compressor section including a first plurality of variable guide vanes in the low pressure compressor section; and
a low pressure turbine section drivingly engaged to the low pressure compressor section;

a second spool having
a high pressure compressor section in fluid communication with the low pressure compressor section to receive pressurized air therefrom, the high pressure compressor section including a second plurality of variable guide vanes at an entry of the high pressure compressor section; and
a high pressure turbine section drivingly engaged to the high pressure compressor section, the high pressure turbine section disposed upstream of the low pressure turbine section and in fluid communication therewith;

an output drive shaft drivingly engaged to the low pressure turbine section;
a rotatable load;
a gearbox, the output drive shaft drivingly engaging the rotatable load through the gearbox, and the low pressure turbine section located axially between the low pressure compressor section and the gearbox along the axis; and
an accessory gearbox disposed upstream of the air inlet, a tower shaft mechanically coupled to a high pressure shaft extending between the high pressure compressor section and the high pressure turbine section, and an accessory gearbox drive shaft having a first end mechanically coupled to the tower shaft and a second end mechanically coupled to the accessory gearbox.

2. The gas turbine engine as defined in claim 1 , wherein the first spool includes a power shaft extending between the low pressure compressor section and the low pressure turbine section, the power shaft and the output drive shaft being co-axial and interconnected.

3. The gas turbine engine as defined in claim 1 , wherein the accessory gearbox drive shaft extends across the air inlet.

4. The gas turbine engine as defined in claim 1 , further comprising an inter-stage bleed disposed upstream of the high pressure compressor section and downstream of the low pressure compressor section.

5. The gas turbine engine as defined in claim 1 , wherein the output drive shaft has a first segment extending between the low pressure compressor section and the low pressure turbine section, and a second segment extending from the low pressure turbine section to drivingly engage the rotatable load.

6. The gas turbine engine as defined in claim 1 , wherein the rotatable load includes a propeller, and the gas turbine engine is a reverse-flow turboprop engine.

7. A method of operating a gas turbine engine, comprising:
drawing air into a core of the gas turbine engine through a low pressure compressor section through a first plurality of variable guide vanes disposed in the low pressure compressor section and then through a high pressure compressor section located downstream from the low pressure compressor section, the high pressure compressor section including a second plurality of variable guide vanes disposed at an entry of the high pressure compressor section, to provide pressurized air;
igniting a mixture of the pressurized air and fuel to generate combustion gases;
directing the combustion gases through a high pressure turbine section and then through a low pressure turbine section to drive the high pressure turbine section and the low pressure turbine section using the combustion gases;
driving the high pressure compressor section with the high pressure turbine section; and
driving the low pressure compressor section and a rotatable load with the low pressure turbine section, the low pressure turbine section and the high pressure turbine section rotating independently from one another;
wherein the low pressure turbine section drives the rotatable load through a reduction gearbox, and the low pressure turbine section is located axially between the low pressure compressor section and the reduction gearbox along a longitudinal center axis of the gas turbine engine; and
driving an accessory gearbox with the high pressure turbine section, the accessory gearbox disposed upstream of an air inlet in fluid communication with the low pressure compressor section;
wherein a tower shaft is mechanically coupled to a high pressure shaft extending between the high pressure compressor section and the high pressure turbine section, and an accessory gearbox drive shaft has a first end mechanically coupled to the tower shaft and a second end mechanically coupled to the accessory gearbox.

8. The method as defined in claim 7 , wherein driving the low pressure compressor section and the rotatable load includes rotating a drive shaft driving the rotatable load, the drive shaft and the low pressure compressor section rotating at a same rotational speed.

9. The method as defined in claim 7 , wherein driving the high pressure compressor section includes rotating the high pressure compressor section at a first rotational speed, and driving the low pressure compressor section includes rotating the low pressure compressor section at a second rotational speed different from the first rotational speed.

10. The method as defined in claim 7 , wherein driving the accessory gearbox includes driving the accessory gearbox drive shaft.

11. The method as defined in claim 7 , further comprising bleeding pressurized air from the core of the gas turbine engine at a location disposed upstream of the high pressure compressor section and downstream of the low pressure compressor section.

12. The method as defined in claim 7 , wherein driving the rotatable load includes driving comprises a propeller through a reduction gear box.

13. A gas turbine engine, comprising:
a rotatable load;
a gearbox;
an output drive shaft having a front end configurable to drivingly engage the rotatable load through the gearbox;
a low pressure turbine section and a low pressure compressor section drivingly engaged to the output drive shaft, the low pressure turbine section disposed downstream of the low pressure compressor section, the low pressure compressor section including a first plurality of variable guide vanes at an inlet of the low pressure compressor section;
a high pressure shaft rotatable independently of the output drive shaft;
a high pressure turbine section and a high pressure compressor section drivingly engaged to the high pressure shaft, the high pressure compressor section disposed downstream of the low pressure compressor section and in fluid communication therewith, the high pressure compressor section including a second plurality of variable guide vanes at an inlet of the high pressure compressor section, and the high pressure turbine section disposed upstream of the low pressure turbine section and in fluid communication therewith;
wherein, during operation of the engine, air flows through the first plurality of variable guide vanes of the low pressure compressor, and then through the second plurality of variable guide vanes of the high pressure compressor, and combustion gases flow downstream through the high pressure turbine section and the low pressure turbine section; and
wherein the low pressure turbine section is axially between the low pressure compressor section and the gearbox along a longitudinal center axis of the gas turbine engine, and the high pressure turbine section is axially between the high pressure compressor section and the gearbox along the longitudinal center axis; and
an accessory gearbox disposed upstream of the low pressure compressor section, a tower shaft mecha

Assignees

• Pratt & Whitney Canada

Inventors

• Morgan Keith
• PELUSO Robert
• Plante Ghislain
• Gekht Eugene
• Durocher Eric
• Dubreuil Jean
• Mah Stephen
• Beauchesne-Martel Philippe

Classifications

• F02C3/145

  the combustion chamber being in the reverse flow-type · CPC title

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title

• F05D2250/38

  angled, e.g. sweep angle · CPC title

• F04D25/024

  the driving means being assisted by a power recovery turbine · CPC title

• F02C3/067

  having counter-rotating rotors (F02C3/073 takes precedence) · CPC title