JP5221760B2 - Reduction method of thermal load of outer housing for turbomachine - Google Patents

Abstract

The turbo-machine has an inner housing (3) arranged around a rotor (2), and an outer housing (4) arranged around the inner housing. The rotor comprises a medium pressure thrust-compensating piston (6) with a lateral area (7) arranged around the piston. A prechamber (10) is formed between the inner housing and the piston, and a damping line (12) feeds vapor into the prechamber in the inner housing. An annular chamber (17) is arranged at the inner housing, and is connected with an evaporation chamber (11). The annular chamber is arranged opposite to the lateral area.

Description

  The present invention is a turbomachine including a rotor formed along the flow direction and rotatable about a rotation axis, an inner housing, and an outer housing, the inner housing being provided around the rotor, The outer housing is provided around the inner housing, and the rotor is provided with an intermediate pressure thrust compensating piston having an outer surface provided around the intermediate pressure thrust compensating piston, and the front chamber is provided with the inner housing and the intermediate pressure thrust. The present invention relates to a turbomachine which is formed between a compensation piston and a first steam pipe for supplying steam to a front chamber is formed in an inner housing.

  A steam turbine as an example of a turbomachine is supplied with high-temperature raw steam and applied with high pressure to convert the thermal energy of the raw steam into mechanical rotational energy. The rotational energy is converted into electrical energy through a generator provided in the turbomachine by transmitting torque. The live steam entering the steam turbine is usually hotter than the steam coming out of the steam turbine again. The steam turbine substantially comprises a rotor, an inner housing, and possibly an outer housing. The heat load of these members differs by reducing the temperature of the steam along the flow direction. For example, in a high-pressure partial turbine, a high heat resistance characteristic is required for the material in the inflow region, and a higher cold resistance characteristic of the material is required in the downstream portion of the high-pressure partial turbine as viewed in the flow direction.

  A single-flow steam turbine is usually provided with a thrust compensating piston, which applies a reaction force to the thrust due to the pressure difference through the cascade to maintain the axial bearing capability. For this purpose, a front chamber to which steam is supplied is formed between the thrust compensation piston and the inner housing, whereby a force acts on the thrust compensation piston and thus the entire rotor. The steam in the front chamber is usually high temperature and high pressure. The rotor, which is rotatably implemented, is sealed against the inner housing via a packing. Even if the packing is good, a part of the steam in the front chamber leaks into the space between the inner housing and the outer housing through the packing. Usually, in the space between the inner housing and the outer housing, there is a low-temperature and low-pressure exhaust steam as compared with the live steam. Due to the relatively hot steam flowing between the thrust compensating piston and the inner housing, the outer housing is subjected to a thermal load at this point. Therefore, a material with higher value is selected as the material for the outer housing.

  However, if high value materials are selected, the entire steam turbine will be costly. It would be desirable if the thermal load caused by the steam flowing between the thrust compensating piston and the inner housing is reduced in the space between the outer housing and the inner housing.

  In this position, the present invention has begun with the problem of providing a cost-effective steam turbine.

This problem is a turbomachine including a rotor formed along a flow direction and rotatable around a rotation axis, an inner housing, and an outer housing, and the inner housing is provided around the rotor, The outer housing is provided around the inner housing, and the rotor is provided with an intermediate pressure thrust compensating piston having an outer surface provided around the intermediate pressure thrust compensating piston, and the front chamber is provided with the inner housing and the intermediate pressure thrust. A first steam pipe for supplying steam to the front chamber is formed in the inner housing. The inner housing is connected to the exhaust steam space in terms of fluid technology. and ring chamber is provided are, ring chamber is provided opposite the outer surface, phosphorus exhaust steam space First hole connecting the chamber in fluid technically is, are provided in the inner housing, a second hole connecting the first bore and the annular chamber is solved by a turbo machine is equipped in the inner housing.

  The present invention proposes that steam having a temperature lower than that of the steam in the front chamber is supplied to the gap between the outer surface of the intermediate pressure thrust compensating piston and the inner housing. The steam flowing into this gap flows on the one hand in the direction of the outer housing and on the other hand in the direction of the front chamber. A part of the steam flowing in the direction of the front chamber flows in reverse to the steam flowing out from the front chamber. Steam in the front chamber is used to generate a force on the thrust compensating piston. This relatively hot steam is prevented from flowing in the direction of the outer housing into the gap between the intermediate pressure thrust compensating piston and the inner housing. This is because steam flowing in the opposite flow direction is supplied through the ring chamber. This relatively cool steam partially flows in the direction of the outer housing, and the thermal burden on the outer housing is lighter than that of the steam in the front chamber. Thereby, the outer housing can be made of a material adapted to lower temperatures at this point. This eliminates the need for the outer housing to select a high-value material suitable for the temperature of the steam in the front chamber. Thereby, this steam turbine can be manufactured more cost-effectively.

  Advantageous further embodiments are set forth in the dependent claims. In a further advantageous embodiment, an inner blade row formed in the turbomachine is provided between the inner housing and the rotor, and is located downstream of the turbine blade row in the flow direction in terms of fluid technology. A cascade and exhaust steam space connected to the exhaust steam space is formed.

  Thereby, the relatively easy possibility of procuring steam suitable for the space for exhaust steam is mentioned. The steam flowing into the gap between the intermediate pressure thrust compensating piston and the inner housing therefore does not have to be supplied via an external tube, and after the live steam has flowed through the turbine cascade, The part can be procured from the steam turbine itself by being transported to the exhaust steam space. Most of the exhaust steam is conveyed to the reheater as cold reheater steam and heated to a higher temperature.

  In one advantageous further form, the inner housing comprises a separating projection provided downstream of the intermediate pressure thrust compensating piston as viewed in the flow direction.

  In order to be able to exert a force on the medium pressure thrust compensating piston, it is necessary for the steam to be in a closed space, here the front chamber. The pressure created in this front chamber acts directly on the intermediate pressure thrust compensating piston. According to the invention, it is proposed to form this anterior chamber by the separating projection of the inner housing. This provides a cost-effective possibility of producing a suitable pressure for the medium pressure thrust compensating piston.

  In a further advantageous form, the first steam pipe is fluidically connectable to an HZU (euumlaut) steam pipe. HZU (Yumlaut) steam pipe is a hot reheater steam pipe. Steam exiting the high pressure partial turbine is directed to the reheater as cold reheater steam, where it is heated to a higher temperature and supplied again to the intermediate pressure partial turbine as hot reheater steam. By using hot reheater steam, steam at a suitable pressure can be utilized.

  In a further advantageous configuration, the first steam pipe is connected to the space upstream of the intermediate pressure cascade. The steam in this space has a suitable pressure.

  In a further advantageous configuration, the first hole is formed substantially parallel to the rotation axis and the second hole is formed substantially perpendicular to the rotation axis. Thereby, an easy possibility of transporting the steam in the exhaust steam space to the ring chamber is conditioned and provided for manufacture. Holes that are implemented parallel and perpendicular to the axis of rotation can be produced relatively simply and quickly.

  The invention is represented in more detail on the basis of the embodiments in the figures. The following is shown in the figure.

Part of a steam turbine according to the prior art. 2 is a portion of a steam turbine implemented in accordance with the present invention.

  FIG. 1 shows a portion of a steam turbine according to the prior art. The steam turbine includes a rotor 2 that is rotatably supported around a rotating shaft 1. An inner housing 3 is provided around the rotor 2. An outer housing 4 is provided around the inner housing 3. In the compensation piston region 5, the rotor is equipped with a medium pressure thrust compensation piston 6. The intermediate pressure thrust compensating piston 6 has a larger radius than the rotor 2 outside the compensating piston region 5. The intermediate pressure thrust compensating piston 6 has an outer surface 7 on the surface. A gap 8 is formed between the outer side surface 7 and the inner housing 3. The live steam flowing into the steam turbine flows in the flow direction 9 through a turbine cascade region, not shown in detail, comprising guide blades and rotor blades. The steam is relaxed and cooled in the middle in the flow direction 9, and a part of the exhaust steam is carried to the exhaust steam space 11. Hot reheater steam is conveyed to the front chamber 10 via the first steam pipe 12 in the inner housing 3. The hot reheater steam applies pressure to the intermediate pressure thrust compensating piston 6 in the front chamber 10 so that the intermediate pressure thrust compensating piston 10 generates a force in a direction opposite to the flow direction. . However, some of the hot reheater vapor in the front chamber 10 flows into the gap 8 and flows into the inner housing 3, which places a heat load at this point. A packing 14, particularly a labyrinth packing, is provided between the outer surface 7 and the inner housing 3. Similarly, brush packing may be provided.

  The inner housing 3 includes a separation protrusion 15. Similarly, the separation protrusion 15 is sealed against the rotor 2 via the packing 16. The packing 16 may be implemented, for example, as a labyrinth packing or a brush packing.

  The portion of the steam turbine represented in FIG. 2 shows the configuration according to the present invention. The embodiment of FIG. 2 is essentially different from the embodiment of FIG. 1 in that a ring chamber 17 is provided in the inner housing 3 that is fluidically connected to the exhaust steam space 11. For this purpose, a first hole 18 and a second hole 19 are provided in the inner housing 3. Here, the first hole 18 is formed substantially parallel to the rotating shaft 1, and the second hole 19 is formed substantially perpendicular to the rotating shaft 1. The steam in the exhaust steam space 11 is conveyed to the ring chamber 17 through the first hole 18 and the second hole 19. The first portion 20 of the steam flows in the direction of the outer housing 4, and the second portion 21 of the steam flows in the direction of the front chamber 10. Thereby, the steam flowing from the front chamber 10 in the third direction 22 is restrained, so that it can no longer flow to the outer housing 4 with the temperature from the hot recombustor.

  Here, the ring chamber 17 is provided to face the outer surface 7. Furthermore, a filler 23 for sealing the first hole 18 is provided. Here, the direction of the ring chamber 17 can be changed to the inner housing 3. With the arrangement according to the invention, represented according to FIG. 2, hot recombustor vapor in the first steam pipe 12, which has a lower pressure than cold recombustor vapor, is blocked from the outer housing 4. The recess 25 in the rotor 2 is called a small intermediate floor. In order to ensure reliable start-up of the steam turbine, the packing 16 is well sealed with a small intermediate floor 24, for example by an abrasive layer or brush packing. The first hole 18 and the second hole 19 should be made so as not to collide with the first steam pipe 12. During idle operation, the temperature of the exhaust steam rises, but remains clearly below the steam temperature in the first steam pipe 12, referred to as the hot recombustor temperature. The pressure before and after the intermediate pressure thrust compensating piston 6 is almost the same during this driving state. Due to the axial configuration of the ring chamber 17, the exhaust steam flows mainly into the front chamber 10. During this driving state, the outer housing 4 is subjected to a load similar to that of the outer housing of FIG.

  Therefore, the ring chamber 17 prevents the temperature of the hot recombustor steam in the first steam pipe 12 from affecting the material of the outer housing. Thereby, a cost-effective steam turbine can be produced.

DESCRIPTION OF SYMBOLS 1 Rotating shaft 2 Rotor 3 Inner housing 4 Outer housing 5 Compensation piston area 6 Medium pressure thrust compensation piston 7 Outer surface 8 Gap 9 Flow direction 10 Front chamber 11 Space for exhaust steam 12 First steam pipe 13
DESCRIPTION OF SYMBOLS 14 Packing 15 Separation protrusion 16 Packing 17 Ring chamber 18 1st hole 19 2nd hole 20 1st part of steam 21 2nd part of steam 22 3rd direction 23 Filling 24 Intermediate floor 25 Recessed part

Claims (11)

A turbomachine comprising a rotor (2) formed along a flow direction (9) and rotatable about a rotation axis (1), an inner housing (3), and an outer housing (4),
The inner housing (3) is provided around the rotor (2),
The outer housing (4) is provided around the inner housing (3),
The rotor (2) comprises an intermediate pressure thrust compensating piston (6) comprising an outer surface (7) provided around an intermediate pressure thrust compensating piston (6),
A front chamber (10) is formed between the inner housing (3) and the intermediate pressure thrust compensating piston (6);
A first steam pipe (12) for supplying steam to the front chamber (10) is formed in the inner housing (3);
A ring chamber (17) provided in the inner housing (3) connected in fluid technology to the exhaust steam space (11);
In the turbomachine provided with the ring chamber (17) facing the outer surface (7),
A first hole (18) fluidically connecting the exhaust steam space (11) with the ring chamber (17) is provided in the inner housing (3);
A turbomachine characterized in that a second hole (19) for connecting the first hole (18) to the ring chamber (17) is provided in the inner housing (3). The inner housing (3) is provided with a separation protrusion (15) provided downstream of the intermediate pressure thrust compensating piston (6) when viewed in the flow direction (9). The turbo machine according to 1 . The turbomachine according to claim 2 , wherein the front chamber (10) is provided between the separation protrusion (15) and the intermediate pressure thrust compensation piston (6). The turbomachine according to any one of claims 1 to 3 , wherein the first steam pipe (12) is fluidically connectable to a hot recombustor steam pipe. The turbomachine according to any one of claims 1 to 3 , wherein the first steam pipe (12) is fluidically connectable to a space upstream of the intermediate pressure cascade.   The first hole (18) is formed substantially parallel to the rotation axis (1), and the second hole (19) is formed substantially perpendicular to the rotation axis (1). The turbomachine according to claim 1. Said first hole (18), wherein the first hole (18) in any one of claims 1 to 6, characterized in that it comprises filling for closing the fluid technology (23) Turbomachine. The turbomachine according to any one of claims 1 to 7 , wherein a labyrinth packing is provided between the inner housing (3) and the intermediate pressure thrust compensating piston (6). The turbomachine according to any one of claims 1 to 8 , wherein a packing (16) is provided between the separation protrusion (15) and the rotor (2). The turbomachine according to claim 9 , wherein the packing is formed as a labyrinth packing. The turbomachine according to claim 9 , wherein the packing is formed as a brush packing.

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