Cooling architecture for turbine exhaust case

Patent metadata

Field	Value
Publication number	US-9945251-B2
Application number	US-201314443818-A
Country	US
Kind code	B2
Filing date	Dec 17, 2013
Priority date	Dec 29, 2012
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

Cooling a turbine exhaust case (TEC) employed in an industrial gas turbine engine includes supplying cooling airflow from an outer diameter (OD) to an inner diameter (ID) cavity, supplying a secondary airflow having a pressure greater than the pressure of the cooling airflow to the ID cavity for mixing with the cooling airflow to provide a mixed airflow, and directing the mixed airflow in a serpentine cooling path that includes first directing the mixed airflow radially outward via hollow struts to an OD cavity, then radially inward via hollow fairings that surround the hollow struts.

First claim

The invention claimed is:

1. A method of cooling a turbine exhaust case (TEC) employed in an industrial gas turbine engine, the method comprising:
supplying cooling airflow from an outer diameter (OD) to an inner diameter (ID) cavity by directing the cooling airflow through a tube disposed inside of a hollow strut that extends between an outer ring and an inner ring of the TEC;
supplying a secondary airflow having a pressure greater than the pressure of the cooling airflow to the ID cavity for mixing with the cooling airflow to provide a mixed airflow; and
directing the mixed airflow in a serpentine cooling path that includes first directing the mixed airflow radially outward inside the hollow strut to an OD cavity formed between the outer ring of the TEC and a fairing outer ring disposed radially inward of the outer ring of the TEC, then radially inward between the hollow strut of the TEC and a hollow fairing strut that surrounds the hollow strut.

2. The method of claim 1 , wherein directing the mixed airflow further includes exhausting the airflow provided radially inward between the hollow strut of the TEC and the hollow fairing strut in an aft direction for rejoinder with a gaspath airflow.

3. The method of claim 2 , wherein exhausting the airflow in the aft direction for rejoinder with the gaspath airflow provides a low-pressure sink that maintains direction of the mixed airflow radially outward inside the hollow strut and then radially inward between the hollow strut and the hollow fairing strut.

4. A cooling architecture for a turbine exhaust case (TEC) employed in an industrial gas turbine engine, the cooling architecture comprising:
a passage for directing cooling airflow radially inward through the TEC, wherein the passage is formed inside a hollow strut that extends between an outer ring and an inner ring of the TEC;
an inner diameter (ID) cavity disposed radially inward from the inner ring of the TEC that mixes the cooling airflow with a secondary airflow to form a mixed airflow; and
a serpentine cooling path that directs the mixed airflow radially outward inside the hollow strut and outside of the passage, and then radially inward between the hollow strut of the TEC and a hollow fairing strut that surrounds the hollow strut of the TEC.

5. The cooling architecture of claim 4 , wherein the serpentine cooling path further includes an exhaust portion that exhausts airflow provided radially inward between the hollow strut if the TEC and the hollow fairing strut in an aft direction for combination with a gaspath.

6. The cooling architecture of 5 , wherein the exhaust portion is a low pressure sink that maintains circulation of the mixed airflow in a desired direction.

7. The cooling architecture of claim 5 , wherein the exhaust portion includes a seal and/or metering plate to exhaust the mixed airflow at a desired rate.

8. The cooling architecture of claim 4 , wherein the secondary airflow has a pressure greater than the cooling airflow.

9. The cooling architecture of claim 4 , wherein the secondary airflow is bleed air supplied from a compressor stage.

10. The cooling architecture of claim 4 , wherein the cooling airflow is provided by an external heat exchanger.

11. The cooling architecture of claim 4 , wherein the ID cavity is defined between the inner ring and a bearing compartment.

12. The cooling architecture of claim 4 , further including:
a heat shield located between the hollow fairing strut and the hollow strut of the TEC.

13. A turbine exhaust case (TEC) employed in an industrial gas turbine engine comprising:
a frame portion that includes an outer ring, an inner ring disposed radially inward of the outer ring, and a hollow strut connecting the outer ring to the inner ring, wherein an inner diameter (ID) cavity is formed between the inner ring and a bearing compartment disposed radially inward of the inner ring;
a fairing portion that includes a fairing outer ring, a fairing inner ring disposed radially inward of the fairing outer ring, and a hollow fairing strut that connects the fairing outer ring to the fairing inner ring, wherein the hollow fairing strut surrounds the hollow strut;
a passage located within the hollow strut that directs cooling airflow radially inward to the ID cavity;
a second passage located radially inward of the ID cavity that directs pressurized airflow into the ID cavity for mixing with the cooling airflow to form a mixed airflow; and
a serpentine cooling path that directs the mixed airflow radially outward inside the hollow strut to an outer diameter (OD) cavity formed between the outer ring and the fairing outer ring, and then radially inward between the hollow fairing strut and the hollow strut.

14. The TEC of claim 13 , wherein a pressure of the pressurized airflow is greater than a pressure of the cooling airflow, and wherein a pressure of the mixed airflow is greater than the pressure of the cooling airflow.

15. The TEC of claim 13 , wherein the passage is a tube that extends from the outer ring, through the hollow strut and inner ring, for attachment to a top portion of the bearing compartment.

16. The TEC of claim 15 , wherein the tube includes a plurality of apertures for communicating cooling airflow into the ID cavity for mixing with the pressurized airflow.

17. The TEC of claim 13 , further including:
an exhaust portion located on an aft side of the TEC that exhausts the mixed airflow into a gaspath.

18. The TEC of claim 17 , wherein the exhaust portion is a pressure sink that is at a lower pressure than a pressure of the mixed airflow mixed in the ID cavity.

19. The TEC of claim 13 , further including:
a heat shield located between the hollow fairing strut and the hollow strut.

Assignees

• United Technologies Corp

Inventors

• Yeager William
• Tu John S

Classifications

• F01D25/14 Primary

  Casings modified therefor (double casings F01D25/26) · CPC title

• F05D2250/185

  serpentine-like · CPC title

• F02C7/12 Primary

  Cooling of plants (of component parts, see the relevant subclasses, e.g. F01D; cooling of engines in general F01P) · CPC title

• F05D2260/20

  Heat transfer, e.g. cooling · CPC title

• F01D25/30

  Exhaust heads, chambers, or the like · CPC title