TURBINE EXHAUST STRUCTURE OF PARTICULAR DESIGN

Abstract

A turbine exhaust structure for an intermediate-pressure exhaust end of a high-and-intermediate-pressure (HIP) module.

Claims

1. A turbine exhaust structure comprising: a casing divided into a first element and a second element, the second element being connected to the first element and comprising at least one outlet, at least one connecting pipe configured to be connected to a second pipe, the connecting pipe having a first end, a first section, a second end and a second section; a central aperture, the central aperture extending from a first face to a second opposite face of the casing; and wherein the at least one outlet of the second element is connected to the connecting pipe first end.

2. A turbine exhaust structure according to claim 1, wherein the first element is connected to the second element along a horizontal joint plane.

3. A turbine exhaust structure according to claim 1, wherein the first element is an upper element and the second element is a lower element.

4. A turbine exhaust structure according to claim 4, wherein the section of a first face of the central aperture is larger than a section of a second opposite face of the central aperture.

5. A turbine exhaust structure according to claim 1, wherein the second element comprises at least two outlets, each outlet connected to a connecting pipe.

6. A turbine exhaust structure according to claim 1, wherein the second element is welded to the connecting pipe.

7. A turbine exhaust structure according to claim 1, wherein the length of the turbine exhaust structure varies from 6 to 12 meters.

8. A turbine exhaust structure according to claim 1, wherein the length of the turbine exhaust structure varies from 9 to 10 meters.

9. A turbine exhaust structure according to claim 1, wherein the width of the turbine exhaust structure varies from 2 to 6 meters.

10. A turbine exhaust structure according to claim 1, wherein the width of the turbine exhaust structure varies from 3 to 4 meters.

11. A turbine exhaust structure according to claim 1, wherein the width of the turbine exhaust structure varies from 2 to 6 meters.

12. A turbine exhaust structure according to claim 1, wherein the width of the turbine exhaust structure varies from 3 to 4 meters.

13. A turbine exhaust structure according to claim 1, wherein the second pipe is an elbow pipe.

14. A turbine exhaust structure according to claim 1, wherein the turbine exhaust structure is an intermediate-pressure exhaust end.

15. A high-and-intermediate-pressure casing comprising a high-pressure casing and a turbine exhaust structure according to claim 1.

Description

DRAWINGS

[0025] Other features and advantages of the present invention will appear from the following description, given by way of examples and in view of the following drawings in which:

[0026] FIG. 1A is an isometric view of a HIP casing used in a known steam turbine;

[0027] FIG. 1B is a schematic view of an intermediate-pressure exhaust end used in a known steam turbine;

[0028] FIG. 2 is an isometric view of a high-and-intermediate-pressure casing comprising a turbine exhaust structure according to one embodiment of the invention;

[0029] FIG. 3 is a vertical flange connection side isometric view of a turbine exhaust structure according to an embodiment of the invention; and

[0030] FIG. 4 is a rear pedestal side isometric view of a turbine exhaust structure according to an embodiment of the invention.

DETAILED DESCRIPTION

[0031] Reference is first made to FIG. 2 which discloses a HIP casing 31 according to an embodiment of the invention. The high-and-intermediate-pressure casing 31 comprises a turbine exhaust structure 30, which is an intermediate-pressure exhaust end 30, and a combined high-pressure/intermediate-pressure casing 32, said casing 32 being connected to the turbine exhaust structure 30 thanks to a vertical flange connection 33.

[0032] It is worth noting that the combined high-pressure/intermediate-pressure casing 32 is identical to the combined high-pressure/intermediate-pressure casing 12 represented on FIG. 1A. In an embodiment, the intermediate-pressure exhaust end 30 is configured to be connected to the different modules used in a known steam turbine. In other words, the interfaces of the intermediate-pressure exhaust end 30 are configured in such a way that the design of the other components, i.e., those constituting a known steam turbine and intended to be associated to an intermediate-pressure exhaust end 30, does not need to be modified.

[0033] For example, the vertical flange connection 33 is identical to the one used in an intermediate-pressure exhaust end of the prior art like the vertical flange connection 13.

[0034] As illustrated on FIGS. 3 and 4, the intermediate-pressure exhaust end 30 comprises a casing 34 divided into a first element 35 and a second element 36, which is connected to the first element. The intermediate-pressure exhaust end 30 also comprises two connecting pipes 37, 38 which are configured to be connected to a second pipe 39 and 40. The second pipe 39, 40 is an elbow pipe.

[0035] The second element 36 comprises two outlets 41, 42 (not shown) of rectangular cross section. The connecting pipe 37, 38 is provided with a first end 371, 381, having a first section, and a second end 372, 382, having a second section. Moreover, the second element 36 is connected to the connecting pipe 37, 38 via a welded connection.

[0036] The outlet 41, 42 is connected to the first end 371, 381 and the second end 372, 382 is configured to be connected to the second pipe 39, 40.

[0037] As illustrated on FIGS. 3 and 4, the first element 35 is an upper element 35. The second element 36 is a lower element 36.

[0038] It is to be noted that the casing 34 has a central aperture 43 which extends from a first face 341, shown on FIG. 3, to a second opposite face 342 of the casing 34, shown on FIG. 4. A first face central aperture 431 has a first section and a second face central aperture 432 has a second section. The first section of the first face central aperture 431 is larger than the second section of the second face central aperture 432.

[0039] Moreover, the upper element 35 is connected to the lower element 36 along a horizontal joint plan by a plurality of studs and nuts 44 via two supports 45 and 46 on the second opposite face 342, as shown on FIG. 4.

[0040] The casing 34 comprises a plurality of outer reinforcements 47 on both the upper element 35 and the lower element 36. The outer reinforcements 47 of the lower element 36 extend radially from both the first face central aperture 431 and the second face central aperture 432. The outer reinforcements 47 of the upper element 35 extend radially from the first face central aperture 431 to the second face central aperture 432 and vice versa. The casing 34 also comprises a plurality of inner reinforcements 48 (not shown) located inside said casing 34.

[0041] In addition, the first face central aperture 431 of the casing 34 is configured to be connected with the combined high-pressure/intermediate-pressure casing 32 due to the vertical flange connection 33 and a plurality of studs and nuts 49, which are around the first face central aperture 431, and a sealing weld.

[0042] As shown on FIGS. 2, 3 and 4, no pipe is connected to the upper element 35.

[0043] Thus, such configuration makes the maintenance operations much easier as compared to the one of the intermediate-pressure casing 11 with the four outlets 16, 17, 18 and 19. Indeed, no pipe needs to be dismantled nor retightened. Specifically, the opening and closing of the HIP casing 31 is easier.

[0044] Furthermore, the turbine exhaust end according to the present invention is very cost-efficient because it allows avoiding the use of Y-shaped pipes which are very difficult to manufacture, thereby reducing quantities of materials to be used. Indeed, it is estimated that the turbine exhaust end according to the present invention allows sparing around 15 tons of materials. Moreover, the turbine exhaust end according to the present invention is also very cost-efficient because said turbine exhaust end is a fabricated structure whereas the one described in FIG. 1A is a foundry structure.

[0045] The interfaces of the intermediate-pressure exhaust end 30 are configured in such a way that the design of the other components constituting a known steam turbine, for example the diaphragms, does not need to be modified.