WO2010091941A1

WO2010091941A1 - Three-shelled steam turbine

Info

Publication number: WO2010091941A1
Application number: PCT/EP2010/050799
Authority: WO
Inventors: Heinz Dallinger; Benjamin Kloss-Grote; Uwe Zander
Original assignee: Siemens Aktiengesellschaft
Priority date: 2009-02-10
Filing date: 2010-01-25
Publication date: 2010-08-19
Also published as: EP2396517A1; CN102317580B; EP2216512A1; EP2396517B1; CN102317580A

Abstract

The invention relates to a three-shelled turbo machine (1) having a valve (10), wherein the valve (10) is coupled to the three-shelled turbo machine (1) via two sealing arrangements (12, 20) and by means of an intermediate ring (18) in a sealing manner.

Description

description

Three-bladed steam turbine

The invention relates to a turbomachine with a Ven ^¬ til, wherein the turbomachine comprises an inner inner housing, an outer inner housing, a Außengehause, wherein the valve comprises a valve diffuser, wherein the valve is arranged on the inner diffuser, and between the inner housing

Valve diffuser and the inner inner housing a first sealing element is arranged, wherein the valve diffuser has a flange, wherein the flange is connected to the outer housing.

Under a flow machine, for example, a steam turbine is understood. 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 temperatures of the flow medium for all load and special operation cases. At a

Steam turbine is the flow medium steam. Furthermore, the housing must be designed such that supply and Abfuhrun ^¬ conditions, which are also referred to as Zudampfleitungen or taps, are possible. Another function that a home must perform is the ability to drive a shaft end through the housing.

The high voltages, pressures and temperatures that occur during operation require that the materials be selected properly and that the design be selected to provide mechanical integrity and functionality. For this it is necessary that high quality Materials are used, in particular in the field of inflow and the first Leitschaufelnuten.

For applications at live steam temperatures of about 650 ⁰ C, such as 700 ⁰ C, nickel-based alloys are suitable because they withstand the stresses occurring at high temperatures ^¬ conditions. However, the use of such a nickel-based alloy is associated with new challenges. For example, the cost of nickel-based alloys is comparatively high and the manufacturability of nickel

Base alloys, e.g. Limited by limited Gussmoglichkeit. 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 strong 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 increases.

Two-shell steam turbines are known. In a twin-shell steam turbine, the inner casing is arranged around the rotor and the outer casing around the inner casing. As a result of temperature changes, it may cause movements of the Innengehauses relative to the valve. The valve essentially comprises a valve housing and a valve tappet arranged in the valve, as well as shut-off devices not described further here. The valve diffuser is usually designed for guiding the flow medium. If the valve diffuser and the inner housing were rigidly coupled by means of frictional connections with each other, this would lead to tensions and possibly to deformations that are undesirable. Therefore, so-called. Winkelrmgverbmdungen be used. The valve diffuser and the inner housing each have a groove in which an angle ring is arranged. This leads to a

Warming movement can be compensated in both an axial and in a radial direction. In the case of three-shell steam turbines, there is now an additional inner housing between the inner inner housing and the outer housing, which can be referred to as an outer interior housing. The outer Innengehause also leads as a result of thermal changes from a warming movement, which may possibly interfere with the valve diffuser. Another requirement is that the space between the inner Innengehause and the outer Innengehause and the outer Innengehause and the outer housing should be sealed. Nevertheless, mechanical stresses due to warm movements should be avoided.

It would be desirable to have a simple possibility of arranging a valve on a three-shell flow machine such that the valve can be suitably cooled.

The object of the invention is therefore to provide a flow machine with a valve, wherein the valve is coupled to the three-shell flow machine such that thermal see limits are not reached.

This object is achieved by a flow machine with a valve, wherein the flow machine comprises an inner inner ^¬ housing, an outer Innengehause and a Außengehause, wherein the valve comprises a valve diffuser, wherein the valve diffuser is disposed on the inner Innengehause and between the Ventildiffusor and the inner inner housing a first sealing element is arranged, wherein the Ventildif- fusor has a flange, wherein the flange is connected to the Außengehause, wherein an intermediate ring disposed on the outer Innengehause and between the intermediate ring and the outer Innengehause a second sealing element is arranged wherein the intermediate ring is connected to the outer housing.

With the invention, the way is thus taken to provide an intermediate ring with which an optimal connection of the valve to a three-shell flow machine is possible. For this purpose, the intermediate ring is arranged in such a way in the three-shell Strö ^¬ tion machine that between the outer Innenge- home and the outer housing a seal is possible, whereby a second vapor space formed between the outer inner housing and the outer housing and the first vapor space, which is disposed between the inner Innengehause and the outer Innengehause is sealed. One of the advantages of the invention is that a vapor in the first vapor space, which can be referred to as warm vapor, makes contact with the valve diffuser and therefore cools this valve diffuser. Inside the valve diffuser flows the live steam, which can also be called hot steam and has significantly higher temperature values than the warm steam.

The intermediate ring is in this case flanged to the outer housing, whereby a screwing of the intermediate ring to the outer housing is possible. The intermediate ring is in this case additionally sealed against the outer housing, wherein a second sealing element is taken into account. The production of the

Intermediate ring is relatively simple, since the intermediate ring is formed substantially as a rotationally symmetrical body.

Further advantageous developments are specified in the subclaims.

In a first advantageous development, a first cooling space is formed between the valve housing and the valve diffuser. The valve basically has the task of driving a hot steam into the flow machine. This hot steam thermally loads the valve diffuser so that it should be cooled to withstand the thermal stresses. In order to cool the diffuser outside the Stromungsma- machine, a first ice-cube is ausgebil ^¬ det, which is arranged between the valve housing and the valve diffuser. For this purpose, the valve housing is outside the flow machine after the flange after a certain length connected to the valve diffuser. Em first Kuhlraum thereby forms outside the Stromungsmaschine.

In an advantageous embodiment, the valve housing and the valve diffuser emstuckig trained.

In a further advantageous development, a first vapor space is formed between the inner inner housing and the outer inner housing, wherein between the first vapor space and the first Kuhlraum a stromungstechnische

Connection is formed. Em in the first steam room befindlicher warm steam can thus reach the first Kuhlraum because there is a stromungstechnische connection. This hot steam is lower in temperature and lower in pressure than the hot steam flowing inside the valve diffuser. This means that the valve diffuser is cooled as a result of the warm steam on the length in which the first cooling space is formed.

In an advantageous development, a radially and axially movable first sealing arrangement is arranged between the intermediate ring and the valve diffuser.

In a further advantageous embodiment, a Kuhlmediumzufuhr and a Kuhlmediumabfuhr is formed in the valve housing. This Kuhlmediumzufuhr and Kuhlmediumabfuhr provides a stromungstechnische connection between the first Kuhlraum and the atmosphere outside the Stromungsmaschine ago. By this Kuhlmediumzufuhrung an external Kuhldampf can get into the first Kuhlraum and has the opportunity to get to the first seal assembly. Accordingly, the first cooling space is cooled as a result of the external cooling steam up to this area of the first sealing arrangement. This has the significant advantage that the Kuhlparameter can be adjusted from the outside. However, there is a certain amount of equipment overhead against that. The Kuhlmediumzufuhrung and Kuhlmediumabfuhrung is disposed on a circumference of the Ventilgehauses. It has a number of at least seven Kuhlmediumzufuhrungen and Kuhlmediumabfuhrungen preserves, that is, that flows through the Kuhlmediumzufuhrung a Kuhldampf and Kuhldampf is removed again on the Kuhlmediumabfuhrung.

In a further advantageous development of the interim ^¬ rule ring conduit is arranged and formed such that a stromungstechnische ice-cube connection between the first and a second steam chamber, wherein the second vapor space between the outer and inner housing of the

Outside housing is arranged. Thus, the Kuhlmoglichkeit is supplemented by the ability to obtain a Kuhlmedium from the second steam room and to demand this in the first Kuhlraum. For this purpose, a power-technical connection is established between the second steam space and the first cooling space with the line. Basically, now two variants are conceivable. On the one hand, from the second steam space a cold steam, which has a lower temperature than the warm steam, from the second steam space via the line in the first Kuhlraum requested. As a result, the valve diffuser in the first cooling chamber is cooled accordingly. The Kuhldampf or warm steam in this first Kuhlraum is sucked off again via the Kuhlmediumabfuhrungen.

According to the second variant, basically a flow reversal of the cooling medium is possible. For this purpose, an external Kuhldampf is fed via the Kuhlmediumzufuhr in the first Kuhlraum and passed via the line in the intermediate ring in the second Dampfräum.

Exemplary embodiments of the invention will be described in more detail below with reference to the drawings. These are not intended to illustrate the exemplary embodiment of the invention to scale, but are shown, to which explanations serve, executed in a schematic and / or slightly offset form. With regard to additions to the teachings directly recognizable from the drawings, reference is made to the relevant prior art. In the different figures, the same parts are always provided with the same reference numerals, so that these are usually described only once.

Show it:

1 shows a sectional view through a three-shell turbomachine in the inflow section;

2 shows a cross-sectional view of part of a three-shell steam turbine with valve according to a first embodiment;

3 shows a cross-sectional view of a part of a three-shell flow machine with a valve according to a second embodiment and

4 shows a cross-sectional view of a portion of a Strö ^¬ tion machine with a valve according to a third embodiment.

1 shows a three-shell steam turbine as Ausfuh ^¬ tion form of a flow machine 1. The flow machine 1 comprises a rotor not shown in detail, which is rotatably mounted about a rotation axis 2.

The rotation axis 2 is perpendicular to the plane of the drawing. An inner inner housing 3 is arranged around the rotor. Between the inner Innengehause 3 and the rotor, a flow channel is formed in which a hot steam in a flow space 4 is located. The steam in the flow space 4 is a live steam, which can also be called hot steam. To the inner Innengehause 3 an outer Innengehause 5 is arranged. Between the äuße ^¬ ren inner housing 5 and the inner inner housing 3, a first steam chamber 6 is formed. In this first steam room 6 is usually contained the exhaust steam, which after the Stro- Flow channel after the last stage from the inner Innenge- home 3 flows and spread around the inner Innengehause 3 and thereby the inner Innengehause 3 cools.

To the outer Innengehause 5 an outer housing 7 is arranged. Between the outer housing 7 and the outer Innengehause 5, a second steam chamber 8 is formed. Outside the outer housing 7, an atmosphere space 9 is formed in which atmospheric pressure and atmospheric temperature prevails. FIG. 1 also shows a valve 10, which is shown before the connection to the three-shell flow machine 1. The valve 10 has the task to direct a hot steam only in the flow space 4. Accordingly, the steam in valve 10 should not reach the first steam space and not the second steam space, let alone the atmosphere space.

The FIG 2 shows how the valve 10 and the three-shell Strö ^¬ tion machine 1 can be formed so that no steam as possible from the valve 10 in the first vapor space 6 and in the second steam room 8 passes. The valve 10 in this case comprises a valve diffuser 11 which may be tubular and is arranged on the inner Innenge ^¬ home 3 via a first sealing element 12. The first sealing element 12 should be designed in such a way that a hot steam in the valve flow channel 13 does not reach the first steam space 6 from the flow space 4 m. Accordingly, the first sealing element 12 can be an angular ring arrangement which has an angle ring with two legs, one leg being arranged in a groove in the inner inner housing and the other leg in a groove in the valve diffuser 11, wherein the two angle ^¬ legs 90 ° against each other are arranged. The valve 10 is already shown in the installed state in the embodiment shown in FIG.

The valve 10 further comprises a valve housing 14, on which a flange 15 is arranged. About this flange 15, the valve housing 14 is arranged on the outer housing 7. Between the valve diffuser 11 and the valve housing 14, a first cooling chamber 16 is formed. This first cooling space 16 is formed substantially outside the flow machine 1, wherein the first cooling space 16 substantially extends to a connection area 17. The first cooling chamber 16 extends from the connecting region 17, which connects the valve housing 14 with the valve diffuser 11, to the first vapor space 6. Thus, there is the possibility that a warm vapor in the first vapor space 6 enters the first cooling chamber 16 and thus the valve diffuser 11 cools. Therefore, a gap 19 is formed between the valve diffuser 11 and the outer inner housing 5 and between the valve diffuser 11 and an intermediate ring 18.

The intermediate ring 19 is formed L-shaped in cross-section, wherein a leg of the intermediate ring 18 is sealed by a second sealing element 20 against the outer inner housing 5. The second leg of the intermediate ring 18 is arranged frictionally between the outer housing 7 and the flange 15. This can be done for example by a screw, which is represented symbolically by a Verschraublinie 21. The Verschraublinie 21 is to represent symbolically how the direction of a screw should be aligned.

Between the outer housing 7 and the intermediate ring 18, a further sealing element 22 may be formed. Likewise, a further sealing element 23 is arranged between the intermediate ring 18 and the flange 15. Thus, it is prevented that a cold vapor, which is located in the second vapor space 8, passes into the first cooling chamber 16 or into the atmosphere 9.

The valve 10 can be formed in the connection region 17 such that the flange 15, the valve housing 14 and the valve diffuser 11 are formed mateπalemstuckig.

FIG. 3 shows an alternative embodiment of the valve connection. The essential difference from the execution of FIG 2 is that in the valve housing 14th now at least two Kuhlmediumzufuhrungen and Kuhlmedium- discharges 24 are formed. The valve housing 14, which is formed essentially around the axis of rotation 2, has at least one cooling medium discharge 24 and a cooling medium supply 24 distributed over the circumference. Furthermore, a radially and axially movable first sealing arrangement 25 is arranged between the valve diffuser 11 and the intermediate ring 18. This first sealing arrangement 25 does not allow any steam to pass between the first steam space 6 and the first cooling space 16. Even with a radial and axial displacement of the valve diffuser 11 with respect to the outer inner housing, inner inner housing and outer housing and the intermediate ring 18, no steam is transmitted. This means that the warm steam in the first steam space 6 spreads only to the first sealing arrangement 25. In order nevertheless to achieve a good cooling capability in the first cooling chamber 16, an external cooling steam in the first cooling chamber 16 is required via the cooling medium supply 24. The Kuhldampf required in this first Kuhlraum 16 is then discharged via Kuhlmediumabfuhrung 24 from the first Kuhlraum 16. The steam parameters of the Kuhldampfes in the first Kuhlraum 16 should be chosen accordingly.

FIG. 4 shows a third embodiment of the valve connection. The essential difference from the embodiment shown in FIG. 3 is that lines 26 are provided in the intermediate ring 18, which lines produce a current-technical connection between the second steam space 8 and the first cooling space 16. This means that a cool vapor located in the second steam space 8 can flow into the first cooling space 16 and thus a suitable cooling possibility is present. In an alternative embodiment, an external Kuhldampf via the Kuhlmediumzufuhrung 24 in the first Kuhlraum 16 and via the lines 26 in the second steam chamber 8 can also pass. The parameters of the cooling steam, such as, for example, pressure and temperature, must be selected in such a way that a direction of flow can take place in the direction of the second steam space 8 of the cooling medium. The loan tions 26 are therefore arranged as shown in FIG 4 right of the first seal assembly 25. The first seal ^¬ arrangement 25 and the second sealing element 20 may be constructed as the first sealing element 12.

Claims

claims

A flow machine (1) having a valve (10), the flow machine (1) comprising an inner inner housing (3), an outer inner housing (5), an outer housing (7), the valve (10) having a valve diffuser (11 ), wherein the valve diffuser (11) is arranged on the inner inner housing (3) and between the valve diffuser (11) and the inner Innengehause (3) a first sealing element (12) is arranged, wherein the valve diffuser (11) has a flange , wherein the flange is connected to the outer housing (7), characterized in that an intermediate ring (18) arranged on the outer Innengehause (5) and between the intermediate ring (18) and outer Innengehause (5) a second sealing element (20) is, wherein the intermediate ring (18) with the outer housing (7) is connected.

Second flow machine (1) according to claim 1, wherein the outer inner housing (5) to the inner inner housing (3) and the outer housing (7) around the outer inner housing (5) is arranged.

3. flow machine (1) according to claim 1 or 2, wherein the valve (10) comprises a valve housing (14) which is arranged around the valve diffuser (11), wherein the valve housing (14) having the flange.

4. flow machine (1) according to claim 3, wherein between the valve housing (14) and the Ventildiffu ^¬ sor (11) a first Kuhlraum (16) is formed.

5. flow machine (1) according to claim 4, wherein the first Kuhlraum (16) comprises a Kuhlraumbereich arranged outside the flow machine (1).

6. flow machine (1) according to one of the preceding claims, wherein the first sealing element (12) and the second sealing element (20) are formed as an angle ring sealing element.

7. flow machine (1) according to one of the preceding claims, wherein the valve housing (14) and the valve diffuser (11) emstuckig are formed.

8. flow machine (1) according to one of the preceding claims, wherein between the inner Innengehause (3) and dam outer Innengehause (5) a first vapor space (6) is formed, wherein between the first vapor space (6) and the first

Cooling space (16) is formed a stromungstechnische connection.

9. flow machine (1) according to one of claims 1 to 7, wherein between the intermediate ring (18) and the valve diffuser

(11) a radially and axially movable first seal arrangement (25) is arranged.

10. flow machine (1) according to claim 5, wherein the Kuhlmediumzufuhrung (24) and a Kuhlmediumabfuhrung (24) is formed in the valve housing (14).

11. flow machine (1) according to claim 10, wherein in the intermediate ring (18) a conduit (26) is arranged and formed such that a stromungstechnische connection between the first Kuhlraum (16) and a second vapor space (8), wherein the second Steam chamber (8) the outer inner housing (5) and the outer housing (7) is arranged.