Turbine casing and method for assembling a turbine having a turbine casing

Abstract

A turbine casing has a front casing segment around a turbine longitudinal axis with first and second front casing part-segments, and a rear casing segment, around the longitudinal axis with first and second rear casing part-segments. The rear casing segment is downstream of the front casing segment in the direction of flow and fastened to the front casing segment via a rear vertical flange of the rear casing segment and a front vertical flange of the front casing segment, forming a cross-shaped joint. A protrusion surrounding the longitudinal axis is formed on the front casing segment in a region of the front vertical flange and extends parallel to the longitudinal axis and protrudes from the front vertical flange in the flow direction. A circumferential seal device is on an outer side, facing away from the longitudinal axis, of the protrusion, and seals the protrusion against the rear casing segment.

Claims

1. A turbine casing for a turbine or a steam turbine, comprising: a front casing segment, configured about a turbine longitudinal axis, having a first front casing sub-segment as well as a second front casing sub-segment, and a rear casing segment, configured about the turbine longitudinal axis, having a first rear casing sub-segment as well as a second rear casing sub-segment, wherein the rear casing segment in a flow direction is disposed behind the front casing segment, a split cross joint is configured wherein a rear vertical flange of the rear casing segment is fastened to a front vertical flange of the front casing segment, a protrusion on the front casing segment surrounds the turbine longitudinal axis and is configured in a region of the front vertical flange, said protrusion extending parallel to the turbine longitudinal axis and in the flow direction protruding beyond the front vertical flange, wherein an encircling sealing device, which seals the protrusion in relation to the rear casing segment, is disposed on an external side of the protrusion that faces away from the turbine longitudinal axis, wherein the protrusion is configured so as to be hollow-cylindrical or hollow-conical.

2. The turbine casing as claimed in claim 1, wherein the sealing device is disposed and configured in such a manner so as to seal the protrusion in relation to the rear vertical flange.

3. The turbine casing as claimed in claim 1, wherein at least one encircling groove is configured in the external side of the protrusion, wherein the sealing device has at least one seal ring which has at least one first ring segment and one second ring segment, and wherein the at least one seal ring is at least partially received in the at least one groove and in a sealing manner, contacts the rear casing segment in a radial direction in terms of the turbine longitudinal axis.

4. The turbine casing as claimed in claim 3, wherein the at least one first ring segment and the at least one second ring segment are configured as a gas-tight joint and have end regions that at least partially mutually overlap in a circumferential direction.

5. The turbine casing as claimed in claim 4, wherein at least one first end region of the at least one first ring segment has at least one recess that is configured in the circumferential direction, and at least one second end region of the at least one second ring segment has at least one tongue that projects in the circumferential direction, and wherein the at least one tongue is configured for engaging in a form fitting manner in the at least one recess.

6. The turbine casing as claimed in claim 3, wherein the at least one seal ring has a ring external diameter which at least in a destressed state, is larger than a rear casing segment internal diameter of the rear casing segment.

7. The turbine casing as claimed in claim 1, wherein a bore which fluidically connects an intermediate space, which is configured between the sealing device and the front vertical flange, to a second interior region of the rear casing segment configured in the rear vertical flange, wherein the second interior region, with respect to the flow direction, is disposed behind a first interior region of the rear casing segment that is directly adjacent to the front casing segment.

8. The turbine casing as claimed in claim 1, wherein the first front casing sub-segment is configured as a high-pressure turbine casing lower part of a high-pressure turbine casing of the turbine casing, the second front casing sub-segment is configured as a high-pressure turbine casing upper part of the high-pressure turbine casing, the first rear casing sub-segment is configured as an exhaust steam casing lower part of an exhaust steam casing of the turbine casing, and the second rear casing sub-segment is configured as an exhaust steam casing upper part of the exhaust steam casing.

9. A method for assembling a turbine having the turbine casing as claimed in claim 8, the method comprising: inserting a first ring segment of a seal ring of the sealing device into a groove of the protrusion of the high-pressure turbine casing lower part; connecting the high-pressure turbine casing lower part to the exhaust steam casing lower part so as to form a casing lower part; inserting a second ring segment of the seal ring into the groove of the protrusion of the high-pressure turbine casing upper part; connecting the high-pressure turbine casing upper part to the exhaust steam casing upper part so as to form a casing upper part; and depositing the casing upper part onto the casing lower part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A turbine casing according to the invention as well as a method according to the invention will be explained in more detail hereunder by means of drawings in which, in each case in a schematic manner:

(2) FIG. 1 in a lateral view shows a first embodiment of a turbine casing according to the invention;

(3) FIG. 2 in the longitudinal section shows an enlarged fragment of the turbine casing from FIG. 1;

(4) FIG. 3 in the longitudinal shows an enlarged fragment of a second embodiment of a turbine casing according to the invention;

(5) FIG. 4 in a plan view shows an example seal ring; and

(6) FIG. 5 shows an enlarged fragment of end regions of the seal ring from FIG. 4.

DETAILED DESCRIPTION OF INVENTION

(7) A first embodiment of a turbine casing 1 according to the invention is schematically illustrated in a lateral view in FIG. 1. The turbine casing 1 extends along a turbine longitudinal axis 2 and has a front casing segment 3 configured as a high-pressure turbine casing 19 as well as a rear casing segment 4 configured as an exhaust steam casing 20. The rear casing segment 4 in the flow direction D of the turbine casing 1 is disposed behind the front casing segment 3. The front casing segment 3 has a first front casing sub-segment 3a, configured as a high-pressure turbine casing lower part 19a, as well as a second front casing sub-segment 3b, configured as a high-pressure turbine casing upper part 19b. The first front casing sub-segment 3a and the second front casing sub-segment 3b are releasably connected to one another by way of a horizontal flange (not illustrated) which is configured partially on the first front casing sub-segment 3a and partially on the second front casing sub-segment 3b. The rear casing segment 4 has a first rear casing sub-segment 4a, configured as an exhaust steam casing lower part 20a, as well as a second rear casing sub-segment 4b, configured as an exhaust steam casing upper part 20b. The first rear casing sub-segment 4a and the second rear casing sub-segment 4b are releasably connected to one another by way of a horizontal flange (not illustrated) which is configured partially on the first rear casing sub-segment 4a and partially on the second rear casing sub-segment 4b. The rear casing segment 4 has a first interior region 18a and a second interior region 18b, wherein the second interior region 18b in the flow direction D is disposed behind the first interior region 18a.

(8) The front casing segment 3 at a rear end in the flow direction D has an encircling front vertical flange 7 which surrounds the turbine longitudinal axis 2 and advantageously has separating joints only in the region of the transitions between the first front casing sub-segment 3a and the second front casing sub-segment 3b. The rear casing segment 4 at a front end in the flow direction D has an encircling rear vertical flange 6 which surrounds the turbine longitudinal axis 2 and advantageously has separating joints only in the region of the transitions between the first rear casing sub-segment 4a and the second rear casing sub-segment 4b. A split cross joint 5 is configured in a region which is adjacent to the first front casing sub-segment 3a, the second front casing sub-segment 3b, the first rear casing sub-segment 4a, and the second rear casing sub-segment 4b.

(9) An enlarged fragment of the turbine casing 1 from FIG. 1 is schematically illustrated in FIG. 2. It can be seen in this view that a protrusion 8 which in the flow direction D extends across a width of the rear vertical flange 6 of the rear casing segment 4 is configured on the front vertical flange 7 of the front casing segment 3. The protrusion 8 on an external side 9 that faces away from the turbine longitudinal axis 2 (cf. FIG. 1) has a groove 11 in which a seal ring 12 of a sealing device 10 is disposed and fixed. The seal ring 12 extends in the radial direction R and contacts the rear vertical flange 6. A vertical separating joint between the front vertical flange 7 and the rear vertical flange 6 is thus sealed in relation to an interior of the turbine casing 1. According to the invention, a plurality of seal rings 12 can also be provided.

(10) FIG. 3 schematically shows an enlarged fragment of a second embodiment of a turbine casing 1 according to the invention. In this second embodiment, a bore 16 which runs parallel to the flow direction D and opens into an intermediate space 17 is configured, said intermediate space 17 being configured between the sealing device 10 and the front vertical flange 7. Operating fluid which has made its way past the sealing device 10 can be discharged by way of the bore 16. A further end of the bore 16 opens into the second interior region 18b of the rear casing segment 4. The sealing device 10 in this example has two seal rings 12 which are in each case disposed in a groove 11 of the external side 9 of the protrusion 8. According to the invention, one or a plurality of seal rings 12 can be provided.

(11) FIG. 4 and FIG. 5 show an example seal ring 12, or a fragment of the seal ring 12, respectively, in a plan view in the flow direction D. The seal ring 12 has a first ring segment 12a as well as the second ring segment 12b said ring segments 12a, 12b in end regions 13 being connected, or being capable of being connected, respectively to one another while configuring a gas-tight joint. A first end region 13a of the first ring segment 12a has a tongue 15 which is configured for engaging in a form-fitting manner in a recess 14 of a second end region 13b of the second ring segment 12b.

LIST OF REFERENCE SIGNS

(12) 1 Turbine casing

(13) 2 Turbine longitudinal axis

(14) 3 Front casing segment

(15) 3a First front casing sub-segment

(16) 3b Second front casing sub-segment

(17) 4 Rear casing segment

(18) 4a First rear casing segment

(19) 4b Second rear casing segment

(20) 5 Split cross joint

(21) 6 Rear vertical flange

(22) 7 Front vertical flange

(23) 8 Protrusion

(24) 9 External side

(25) 10 Sealing device

(26) 11 Groove

(27) 12 Seal ring

(28) 12a First ring segment

(29) 12b Second ring segment

(30) 13 End region

(31) 13a First end region

(32) 13b Second end region

(33) 14 Recess

(34) 15 Tongue

(35) 16 Bore

(36) 17 Intermediate space

(37) 18a First interior region

(38) 18b Second interior region

(39) 19 High-pressure turbine casing

(40) 19a High-pressure turbine casing lower part

(41) 19b High-pressure turbine casing upper part

(42) 20 Exhaust steam casing

(43) 20a Exhaust steam casing lower part

(44) 20b Exhaust steam casing upper part

(45) D Flow direction

(46) R Radial direction