WO2011069986A1 - Multiple-part inner housing for a steam turbine - Google Patents

Abstract

The invention relates to an inner housing (1) for a flow machine, in particular a steam turbine, wherein the inner housing (1) is formed at least from three inner-housing parts as viewed in the circumferential direction.

Description

description

MULTIPLE INTERIOR HOUSING FOR A STEAM TURBINE

The invention relates to an inner housing for a

Turbomachine and a method for producing an inner housing for a turbomachine.

Under a flow machine, a steam turbine ^¬ is meant, for example. A steam turbine conventionally includes a rotatably mounted rotor and a housing disposed about the rotor. Between the rotor and the inner housing, a flow channel is formed. The housing in a steam turbine must be able to fulfill several functions. On the one hand, the guide vanes are arranged in the flow channel on the housing and, secondly, the inner housing must withstand the pressure and the temperatures of the flow medium for all load and special operating cases. In a steam turbine, the flow medium is steam. Furthermore, the housing must be designed such that supply and Abführun ^¬ conditions, which are also referred to as taps, are possible. Another feature that a case must meet is the possibility of a shaft end passing through the case.

In the case of occurring in operation high voltages, pressures, and temperatures, it is necessary that the materials are geeig ^¬ net is selected and the design is chosen such that the mechanical integrity and functionality it is ^¬ made possible. This requires that high-grade materials be used, especially in the area of the inflow and the first Leitschaufelnuten.

For applications at live steam temperatures above 650 ° C, such as 700 ° C, nickel-based alloys are suitable because they withstand the stresses occurring at high temperatures. However, the use of such is Nickel-based alloy associated with new challenges. For example, the cost of nickel-base alloys is comparatively high and, moreover, the manufacturability of nickel-base alloys, for example due to limited casting possibilities, is limited. As a result, the use of nickel-based materials must be minimized. Furthermore, the nickel-based materials are poor heat conductors. As a result, the temperature gradients over the wall thickness are so rigid that thermal stresses are comparatively high. Furthermore, it must be taken into account that when using nickel-based materials, the temperature difference between the inlet and outlet of the steam turbine can be increased compared to conventional materials.

Various concepts are currently being pursued to provide a steam turbine suitable for high temperatures and high pressures. So it is known, a comprehensive multi-part housing structure in a

Exterior housing structure incorporate according to the article Y.

Tanaka et al. Mitsubishi Heavy Industries, Power Gen Europe, 2003, Dusseldorf, May 06.-08., 2003.

It is also known, an inner housing of two parts from ^¬ zubilden according to DE 10 2006 027 237 AI.

 In DE 342 1067 is also a multi-component

Inner housing structure disclosed and in DE 103 53 451 AI.

Turbomachines such as steam turbines are designed for high steam temperatures and steam pressures. Partly the steam temperatures are above 650 ° C and the vapor pressures over 300bar. Such steam parameters require the use of materials that are thermal and mechanical

Withstand stresses. It is known to use high-alloy chrome steels. Furthermore, it is known to use nickel-based materials. A steam turbine essentially comprises a rotor rotatably mounted about a rotation axis and an inner housing arranged around the rotor and an outer housing arranged around the inner housing. The Inner housing is usually made in two parts, ie, the inner housing has a lower inner housing part and an upper inner housing part, wherein between these two inner housing parts a horizontal parting line is formed. The nickel-based materials used for such steam turbines are comparatively expensive. In addition, the

Production limited to low tonnages during pourability. In addition, are made of one piece

Inner housing parts comparatively heavy and large.

At this point, the invention whose object is to provide an inner housing for a turbomachine, which is easy to manufacture. This object is achieved by an inner housing for a turbomachine according to claim 1.

The invention is based on the aspect that the limitation to two inner housing parts can be omitted and at least three inner housing parts are formed. This will determine the mass and size of each individual

Inner housing parts reduced, resulting in a better

 Handling of the inner housing parts leads. In addition, the inner housing parts can be made easier.

The inner housing is for installation around one

Form axis of rotation aligned rotor and the

Inner housing parts in the circumferential direction with respect to

Divide rotation axis. The subdivision is also possible in the axial direction. However, one is

Subdivision in the circumferential direction with respect to the axis of rotation advantageous because mechanical forces can be better distributed. Furthermore, the outer dimensions of circumferentially divided inner housing parts are smaller than axially divided inner housing parts. The

Inner housing parts are doing with in the circumferential direction

appropriate means interconnected.

The inner housing has a horizontal parting line. This results in that during installation of the inner housing parts a corresponding lower inner housing part can be stored stably and the corresponding upper inner housing part or the upper inner housing parts on the lower

Inner housing parts or the lower inner housing parts

can be arranged.

According to the invention, the inner housing comprises above the

horizontal parting line formed from one piece upper inner housing part and below the horizontal

Parting line two lower inner housing parts. As a rule, the lower inner housing parts are larger than the upper ones

Inner housing parts, which is why the subdivision of the lower

Inner housing part in two parts represents an advantageous solution.

In the dependent claims advantageous developments are given.

In an advantageous development, the two arranged below the horizontal parting line lower

Inner housing parts formed by a vertical parting line.

This means that the two below the horizontal

Teilfuge arranged lower inner housing parts in

 Essentially mirror-symmetrical can be formed. This leads to the fact that for reasons of symmetry the mechanical

Load of the inner housing parts is evenly distributed.

The vertical parting line is opposite to the horizontal parting line

 Parting line arranged rotated by 90 °. In advantageous developments, the first lower

 Inner housing part and the second lower inner housing part substantially the same size and the same weight formed.

Furthermore, the first lower and the second lower inner housing parts each have an inlet connection.

In a further advantageous embodiment, the inner housing comprises four inner housing parts, wherein two

Inner housing parts below the horizontal parting line and two inner housing parts are formed above the horizontal parting line. In addition to the division of the inner housing into three parts, the division into four parts is advantageous. Four parts are essentially almost the same size for symmetry reasons. As a result, costs can be saved in the production because the production of components of almost the same size is less of a challenge than the production of components of different sizes. Of

Further reduce the low unit weights of

Inner housing parts the risk of rejection per inner housing part. The economic risks are thereby reduced.

Overall, this leads to greater manufacturing capacity, i. a supplier base can be broadened.

In a further advantageous development, which have arranged above the horizontal parting line

Inner housing parts on a vertical parting line. Similar to the embodiment with three housing parts, in which the two lower inner housing parts have a vertical parting line, the two upper above the horizontal parting line formed inner housing parts on a vertical parting line. This means that the vertical parting line executed above the horizontal parting line is arranged essentially rotated 90 ° with respect to the horizontal parting line. The

Components of the inner housing parts are characterized almost the same size, which leads to a further cost savings.

In a further advantageous embodiment, the

vertical parting line continuous. This means that the vertical parting line of the two upper inner housing parts and the vertical parting line of the two lower inner housing parts are in alignment. For reasons of symmetry will be

mechanical forces better distributed to the inner housing parts. Furthermore, the deformation is more homogeneous.

In a further advantageous embodiment, the

Inner housing parts made of a nickel-based material

educated. The nickel base material is for the in Steam turbine operation occurring mechanical and

suitable for thermal stresses.

The object directed to the method is achieved by a method for producing an inner housing for a turbomachine, wherein the inner housing is manufactured from at least three inner housing cast components. The advantages arise in accordance with the advantages indicated for the device.

Hereinafter, an embodiment of the invention with reference to the schematic drawing, to the

is expressly referred to all essential to the invention explained. In the drawing shows:

Figure 1 is a side view of one another

 coupled inner casing;

Figure 2 is a sectional view taken along the line A of Figure 1;

 Figure 3 is a perspective view of

 Inner casing;

 Figure 4 is a sectional view taken along line A of four inner housing parts

 Inner casing;

 FIG. 5 shows a schematic view of that in FIG. 4

 illustrated inner housing in one

 Exploded view. FIG. 1 shows a side view of an inner housing 1 of a turbomachine. Such a turbomachine may be, for example, a steam turbine or a gas turbine. The following remarks refer to one

Steam turbine. The inner housing 1 comprises a horizontal parting line 2 and is formed substantially symmetrically about a rotation axis 3. Within the inner housing 1 is a rotor, which is not shown in detail to the

Rotation axis 3 rotatably mounted. Above the horizontal parting line 2, an upper inner housing part 5, 10, 11 and below the horizontal parting line 2, a lower inner housing part 6, 7 is formed. The lower inner housing part 6, 7 under the horizontal parting line 2 has substantially an inflow 4.

FIG. 1 shows both one of three inner housing parts and one of four inner housing parts

Inner housing.

FIG. 2 shows a section through the inner housing 1 from FIG. 1 along the line A. Above the horizontal

Parting line 2, the inner housing 1 comprises an upper

Inner housing part 5 and has below the horizontal

Parting line 2, a first lower inner housing part 6 and a second lower inner housing part 7 on. Between the first lower inner housing part 6 and the second lower

Inner housing part 7 is a vertical parting line 8 is formed. This vertical parting line 8 is substantially at 90 °

formed opposite the horizontal parting line 2. The first lower inner housing part 6 and the second lower

Inner housing part 7 can be firmly connected to each other by screws. It is important that after a first connection, the lower inner housing parts 6 and 7 are not opened, as this can lead to the shift.

The first lower inner housing part 6 and the second lower inner housing part 7 are substantially the same size

educated. For supplying flow medium, both the first lower inner housing part 6 and the second lower inner housing part 7 an inflow 4.

FIG. 3 shows a perspective view of the

Inner housing of Figure 2 in an exploded view. The inner housing 1 is formed from at least three inner housing parts 5, 6 and 7. The inner housing 1 is designed for installation about a rotation axis 3 aligned rotor and the inner housing parts 5, 6 and 7 are in the circumferential direction. 9 divided with respect to the axis of rotation 3. The inner casing 1 is formed of a nickel-based material.

FIG. 4 shows an alternative embodiment of the invention

Inner housing 1. The difference from the inner housing 1 according to FIG. 2 lies in the fact that now also the upper one

Inner housing part 5 is divided into a first upper inner housing part 10 and a second upper inner housing part 11. Here, the first upper inner housing part 10 and the second upper inner housing part 11 is also separated from each other by a vertical parting line 12. The vertical parting line 12 and the vertical parting line 8 are called

continuous vertical parting line formed. This means that the vertical parting line 8 and the vertical parting line 12 are arranged along a line 13. The inner housing 1 is formed such that the horizontal parting line 2 in the intended use of the steam turbine, which includes such an inner housing 1, is arranged substantially horizontally. The vertical parting line 8, 12 and the horizontal

Parting line 2 are hereby rotated by 90 ° from each other

arranged.

The first upper inner housing part 10 and the second upper inner housing part 11 can be firmly connected to each other by screws. Again, make sure that the vertical parting line 12 is not opened after a screw, thereby shifts and

Alignments not to change. FIG. 5 shows a perspective view of the

 Inner housing 1 of Figure 4, the four inner housing parts 6, 7, 10, 11 and is divided in the circumferential direction 9. The invention comprises in the embodiments three or four divided in the circumferential direction 9 inner housing parts 6, 7, 10, 11. In alternative embodiments, the

Inner housing can be formed in more than four inner housing parts.

Claims

claims Inner housing (1) for a turbomachine,  wherein the inner housing (1) consists of at least three  Inner housing parts (5, 6, 7, 10, 11) is formed, wherein the inner housing (1) for installation about a rotational axis (3) aligned rotor is formed and the inner housing parts (5, 6, 7, 10, 11) in  Circumferential direction (9) are divided with respect to the axis of rotation (3),  wherein the inner housing (1) has a horizontal parting line (2),  wherein the inner housing (1) above the horizontal parting line (2) comprises a one-piece upper inner housing part (5) and below the horizontal parting line (2) comprises two inner housing parts (6, 7). Inner housing (1) according to claim 1,  wherein the two below the horizontal parting line (2) arranged inner housing parts (6, 7) by a  vertical parting line (8) are formed. Inner housing (1) according to claim 2,  wherein the two below the horizontal parting line (2) arranged inner housing part (6, 7) are formed substantially the same size. Inner housing (1) according to claim 1, 2 or 3, wherein the two below the horizontal parting line (2) arranged inner housing part (6, 7) each have a Einströmstutzen (4). Inner housing (1) according to one of the preceding  Claims,  the inner housing (1) comprising four inner housing parts (5, 6, 7, 10, 11),  wherein two inner housing parts (6, 7) below the horizontal parting line and two inner housing parts (10, 11) above the horizontal parting line (2) are formed. 6. inner housing (1) according to claim 5,  wherein the inner housing parts (10, 11) arranged above the horizontal parting line (2) have a vertical parting line (12). 7. inner housing (1) according to claim 5 or 6, wherein the below the horizontal parting line (2) arranged inner housing parts (6, 7) have a vertical parting line (8).

Inner housing (1) according to claim 6 and 7,  wherein the vertical parting line (8) and the vertical  Parting line (12) are continuous. 9. inner housing (1) according to one of the preceding  Claims,  wherein the housing parts (5, 6, 7, 10, 11) consists of a  Nickel-based material are formed. 10. A method for producing an inner housing (1) for a turbomachine,  wherein the inner housing (1) is made of at least three inner housing cast components which are interconnected in the circumferential direction. 11. The method according to claim 10,  wherein the inner housing parts (5, 6, 7, 10, 11) made  Nickel-based material can be made.