Industrial gas turbine exhaust system with splined profile tail cone

Patent metadata

Field	Value
Publication number	US-9644497-B2
Application number	US-201314087040-A
Country	US
Kind code	B2
Filing date	Nov 22, 2013
Priority date	Nov 22, 2013
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

An integrated single-piece exhaust system (SPEX) with modular construction that facilitates design changes for enhanced aerodynamics, structural integrity or serviceability. The SPEX defines splined or curved exhaust path surfaces, such as a series of cylindrical and frusto-conical sections that mimic curves. The constructed sections may include: (i) a tail cone assembly fabricated from conical sections that taper downstream to a reduced diameter; or (ii) an area-ruled cross section axially aligned with one or more rows of turbine struts; or both features. Modular inner and outer diameter inlet lips enhance transitional flow between the last row blades and the SPEX, as well as enhance structural integrity. Modular strut collars have large radius profiles between the SPEX annular inner diameter and outer diameter flow surfaces, for enhanced airflow and constant thickness walls for uniform heat transfer and thermal expansion. Scalloped mounting flanges enhance structural integrity and longevity.

First claim

What is claimed is:

1. An industrial gas turbine exhaust system, for coupling to a turbine section of an industrial gas turbine engine apparatus, downstream of a last downstream row of blades in the turbine section, comprising:
an outer exhaust case with a tubular-shape, having an inlet end for coupling to a turbine section of an industrial gas turbine engine apparatus downstream of a last downstream row of blades in the turbine section, and an exhaust end, having:
a centerline of the outer exhaust case, coextensive with an axial centerline defined by the industrial exhaust system,
a contiguous inner circumferential surface of the outer exhaust case, from the inlet end thereof to the exhaust end thereof, said contiguous inner circumferential surface of the outer exhaust case defining sequentially and contiguously from the inlet end to the outlet end thereof:
a first frusto-conical portion of the outer exhaust case, formed at the inlet end, and extending downstream thereof, having a first diverging angle relative to the centerline of the outer exhaust case,
a second frusto-conical portion of the outer exhaust case that adjoins and extends downstream from the first frusto-conical portion of the outer exhaust case, having a second diverging angle relative to the centerline of the outer exhaust case, with the second diverging angle less than the first diverging angle; and
an outer diameter cylindrical portion (OD cylindrical portion) of the outer exhaust case, having a cylindrical radius that is perpendicular relative to the centerline of the outer exhaust case, a first axial end that adjoins and extends downstream from the second frusto-conical portion of the outer exhaust case, and a second axial end that terminates at the exhaust end of the outer exhaust case;

a modular annular-shaped outer diameter stiffening ring (OD ring), coupled to the inlet end of the outer exhaust case, having:
a leading axial end;
a trailing axial end coupled to a leading surface of the inlet end of the outer exhaust case;
a contiguous inner circumferential surface of said OD ring between the leading and trailing axial ends thereof, which abuts and is coextensive with the inner circumferential surface of the outer exhaust case, also defining the turbine exhaust path, said contiguous inner circumferential surface of said OD ring defining sequentially and contiguously from the leading to trailing axial ends thereof:
a chamfered entrance with a converging frusto-conical profile, chamfered entrance formed in and transitioning between the leading axial end and the inner circumferential surface of the OD ring;
an annular-shaped notched shoulder, having a shoulder circumferential surface that adjoins and extends axially from the chamfered entrance towards the trailing axial end of the OD ring and terminating in a shoulder flange, a tip portion of the shoulder flange radially extending towards the axial centerline, the shoulder circumferential surface having a first radius with respect to the axial centerline and the shoulder flange tip portion having a second radius with respect to the axial centerline that is smaller than the first radius;
an annular convex lip, formed in the shoulder flange tip; and
a frusto-conical profile, ramped diverging cone with a frusto-conical profile, contiguous with the annular convex lip, extending axially towards and terminating at the trailing end of the outer diameter ring, and diverging radially away from with respect to the axial centerline;

an inner exhaust case with a tubular-shape, having a contiguous outer circumferential surface circumscribed by the inner circumferential surface of the outer exhaust case in nested, spaced relationship relative to axial centerline of the outer exhaust case, the contiguous outer circumferential surface of the inner exhaust case having:
an inlet end for coupling to a turbine section of an industrial gas turbine engine apparatus downstream of a last downstream row of blades in the turbine section, and
an exhaust end, extending axially downstream of the inlet end of the contiguous outer circumferential surface of the inner exhaust case, terminating axially between the first and second axial ends of the OD cylindrical portion of the outer exhaust case;

a plurality of struts interposed between the inner circumferential surface of the outer exhaust case and the outer circumferential surface of the inner exhaust case; and
a splined, continuous curve tail cone, having:
a first axial end, contiguous with, coupled to, and projecting axially downstream from the exhaust end of the inner exhaust case, said first axial end of the splined, continuous curve tail cone having a first axial end circumference, initiating axially between the first and second axial ends of the OD cylindrical portion of the outer exhaust case;
a second axial end, having a second axial end circumference that is smaller than the corresponding first axial end circumference of the first axial end of the splined, continuous curve tail cone, said second axial end of the splined, continuous curve tail cone terminating axially between the first and second axial ends of the OD cylindrical portion of the outer exhaust case; and
the splined, continuous curve tail cone having first, second, third and fourth sequential, contiguous, conjoined, frusto-conical tail cone segments, with larger diameter of the first tail cone segment forming the first axial end of the tail cone, and smaller diameter of the fourth tail cone segment forming the second axial end of the tail cone; and
said first, second, third, and fourth frusto-conical tail cone segments respectively having the following converging angle ranges relative to the centerline of the outer exhaust case, and length/larger diameter ratio percentage (L/D %) ranges:

Tail Cone Segment
L/D %
Angular Range (Degrees)

First
10%-20%
3-7

Second
10%-20%
 8-12

Third
10%-20%
13-17

Fourth
40%-70%
18-22

an outer circumference; and

a turbine exhaust path, defined between respective inlet and exhaust ends of the inner circumferential surface of the outer exhaust case and the respective outer circumferential surfaces of the inner exhaust case and the splined, continuous curve tail cone.

2. The system of claim 1 , at least one of the outer or inner cases further comprising at least two adjoining frusto-conical sections that increase the exhaust path cross sectional area, for forming an area ruled exhaust path cross section proximal at least one strut.

3. The system of claim 1 , the splined, continuous curve tail cone fabricated from a plurality of coupled, axially arrayed, varying profile annular sections, including frusto-conical fabricated sections that in combination approximate a splined curved outer surface thereof.

4. The system of

Assignees

• Salunkhe Anil L
• Orosa John A
• Shteyman Yevgeniy
• Porter Matthew R
• Han Lijuan
• Delisa Iii Matthew J
• Siemens Energy Inc

Inventors

• Salunkhe Anil L
• Orosa John A
• Shteyman Yevgeniy
• Porter Matthew R
• Han Lijuan
• Delisa Iii Matthew J

Classifications

• F01D25/30 Primary

  Exhaust heads, chambers, or the like · CPC title

• F01D25/162

  Bearing supports · CPC title

• F01D25/243

  Flange connections; Bolting arrangements (F01D25/265 takes precedence) · CPC title

• F01D9/041

  using blades (F01D5/148 takes precedence) · CPC title

• F01D5/143

  Contour of the outer or inner working fluid flow path wall, i.e. shroud or hub contour · CPC title