Industrial gas turbine exhaust system diffuser inlet lip

Patent metadata

Field	Value
Publication number	US-9598981-B2
Application number	US-201314087042-A
Country	US
Kind code	B2
Filing date	Nov 22, 2013
Priority date	Nov 22, 2013
Publication date	Mar 21, 2017
Grant date	Mar 21, 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, comprising:
an inner exhaust case with a tubular-shape having an outer circumferential surface;
an outer exhaust case with a tubular-shape, having an inner circumferential surface of the outer exhaust case, which circumscribes an outer circumferential surface of the inner exhaust case in nested, spaced relationship relative to an axial centerline defined by the industrial gas turbine exhaust system, the nested outer and inner exhaust cases defining respective inlet and exhaust ends thereof;
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;
a turbine exhaust path, defined between respective inlet and exhaust ends of the inner circumferential surface of the outer exhaust case and the outer circumferential surface of the inner exhaust case; and
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 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 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 the axial centerline.

2. The system of claim 1 , further comprising:
a modular annular-shaped inner diameter ring (ID ring), coupled to the inlet end of the inner exhaust case, having:
a leading axial end, including a first flange portion extending radially towards the axial centerline;
a trailing axial end coupled to a leading surface of the inlet end of the inner exhaust case;
an inner circumferential surface of said modular annular-shaped inner diameter ring between the leading and trailing axial ends thereof, which abuts and is coextensive with an outer circumferential surface of the inner exhaust case, also defining the turbine exhaust path; and
a chamfered entrance with a converging, frusto-conical profile, formed in and transitioning between the leading axial end and the inner circumferential surface of said modular annular-shaped inner diameter ring, also defining the turbine exhaust path;
the modular annular-shaped inner diameter ring or the modular annular-shaped outer diameter stiffening ring comprising a metal casting; and the corresponding coupled inner or outer case comprising rolled sheet steel.

3. The system of claim 2 , the modular annular-shaped inner diameter ring comprising a metal casting; and the corresponding coupled outer circumferential surface of the inner exhaust case comprising rolled sheet steel.

4. The system of claim 2 , adapted for attachment to an industrial gas turbine having a last downstream row of blades that create a downstream flow path into the turbine exhaust path, the chamfer defined by the modular annular-shaped inner diameter ring having angle of 10-30 degrees relative to the centerline and sufficient axial length to insure no forward facing step from the downstream flow path into the turbine exhaust path.

5. The system of claim 1 , the modular annular-shaped outer diameter stiffening ring comprising a metal casting; and the corresponding coupled inner circumferential surface of the outer exhaust case comprising rolled sheet steel.

6. The system of claim 1 , the industrial gas turbine exhaust system adapted for attachment to an industrial gas turbine having a last downstream row of blades that define a blade tip angle, the ramped diverging cone of the modular annular-shaped outer diameter stiffening ring defining an angle corresponding to the blade tip angle.

7. An industrial gas turbine apparatus, comprising:
a compressor section;
a combustor section;
a turbine section including a last downstream row of turbine blades that are mounted on a rotating shaft, the shaft having a shaft rotational centerline, the blades having tips defining a blade tip angle, and said last downstream row of blades creating a downstream flow path; and
an industrial gas turbine exhaust system, coupled to the turbine section downstream of the last downstream row of turbine blades, having:
an inner exhaust case with a tubular-shape, having an outer circumferential surface;
an outer exhaust case with a tubular-shape, having an inner circumferential surface of the outer exhaust case, which circumscribes an outer circumferential surface of the inner exhaust case in nested, spaced relationship relative to an axial centerline defined by the industrial gas turbine exhaust system, the axial centerline concentric with shaft rotational centerline, the nested outer and inner exhaust cases defining respective inlet and exhaust ends thereof;
a plurality of struts interposed between the inner circumferential surface of the outer exhaust case with a tubular-shape and an outer circumferential surface of the inner exhaust case with a tubular shape;
a turbine exhaust path, in communication with and downstream of the downstream flow of the last downstream row of turbine blades, the turbine exhaust path defined between respective inlet and exhaust ends of the inner circumferential surface of the outer exhaust case with a tubular-shape and the outer circumferential surface of the inner exhaust case with a tubular shape; and
a modular annular-shaped outer diameter stiffening ring (OD ring), coupled to the inlet end of the outer exhaust case, downstream of the last downstream row of turbine blades, having:
a leading axial end;
a trailing axial end coupled to a leading surface of the inlet end of the outer exhaust case; and
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 circumscribing tips of the last downstream row of turbine blades, and defining sequentially and contiguously from the leading to trailing axial ends thereof:
a converging chamfered entrance with a frusto-conical profile, 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

Assignees

• Salunkhe Anil L
• Orosa John A
• Shteyman Yevgeniy
• Han Lijuan
• Delisa Iii Matthew J
• Riveros Daniel F
• Siemens Energy Inc

Inventors

• Salunkhe Anil L
• Orosa John A
• Shteyman Yevgeniy
• Han Lijuan
• Delisa Iii Matthew J
• Riveros Daniel F

Classifications

• F01D11/001

  for sealing space between stator blade and rotor · CPC title

• F02K1/80

  Couplings or connections · CPC title

• F01D25/30 Primary

  Exhaust heads, chambers, or the like · CPC title

• F05D2250/15

  spiral · CPC title

• F01D5/143

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