CN220828274U - Mixed flow turbine structure suitable for medium power unit - Google Patents

Abstract

The utility model discloses a mixed flow turbine structure suitable for a medium power unit, and relates to the technical field of turbine structures; the mixing device comprises a shell, wherein a mixing chamber surrounded by a holding ring and a rotor is arranged in the shell, a steam inlet chamber is arranged in the mixing chamber, the steam inlet chamber is provided with a steam inlet and a steam outlet, and an adjusting stage is arranged at the steam outlet and is communicated with the mixing chamber; the regulating stage comprises a stage outer ring, a stage inner ring and a stage movable blade arranged on the rotor, the stage outer ring and the stage inner ring are arranged at the steam outlet, a stage stationary blade is arranged between the stage outer ring and the stage inner ring, and the stage movable blade is arranged at the downstream of the stage stationary blade along the flow direction of the steam; a movable vane top steam seal is arranged between the stage outer ring and the stage movable vane, and an interstage steam seal is arranged between the outer wall of the steam inlet cavity or between the stage inner ring and the rotor. According to the utility model, through the structural form that the single-flow regulating stages are matched with the double-flow pressure stages, the number of the regulating stages can be reduced, the height of the regulating stage blades and the steam inlet degree can be increased, the economy of a unit can be ensured, the cost can be reduced, the steam leakage can be reduced, and the regulating stage efficiency can be improved.

Description

Mixed flow turbine structure suitable for medium power unit

Technical Field

The utility model relates to the technical field of turbine structures, in particular to a mixed flow turbine structure suitable for a medium-power unit.

Background

The turbine is an important energy power equipment in modern countries, and economy, safety and cost are main indexes for measuring the advantages and disadvantages of the turbine.

In recent years, the variety of energy utilization modes has been rapidly developed, and turbine structural forms are also becoming more and more abundant, for example: the multi-stage axial flow turbine is suitable for high-power thermal power and nuclear power units, and is suitable for radial-axial mixed flow leveling of medium-and-small-power steam generator units.

Besides the power level of the unit, the operation mode has a great influence on the turbine structure, and the two modes of throttling steam distribution and nozzle steam distribution are common. The throttling and gas distribution adjusting structure is simple and compact, rated load efficiency is higher, adjusting flexibility is poor, and throttling loss is larger during low-load operation. The nozzle has good steam distribution adjustment flexibility, smaller throttling loss during low-load operation, lower rated load efficiency, and complex structures such as a steam inlet chamber, an adjusting stage, a mixing chamber and the like are required to be matched.

At present, in order to meet the operation requirements of multiple working conditions, a medium-power steam generator set generally adopts a nozzle adjusting mode, and a middle steam inlet structure and a left-right side flow dividing structure are matched with a double-flow adjusting stage; when in actual use, the flow rate of the double-flow regulating stage is lower, the secondary flow loss and the steam inlet loss at the end part of the regulating stage are higher, the pressure and the temperature of working media in the regulating stage are high, the volume flow rate is smaller, the height of regulating stage blades is generally smaller, and the machining precision is lower. Therefore, a new turbine structure is needed to solve the above problems.

Disclosure of utility model

The utility model aims at: aiming at the problems, the mixed flow turbine structure suitable for the medium power unit is provided, the number of the regulating stages can be reduced, the height of the regulating stage blades and the steam inlet degree can be increased, the economy of the unit can be ensured, the cost can be reduced, the steam leakage can be reduced, and the efficiency of the regulating stage can be improved by matching the structural form of the double-flow pressure stage with the single-flow regulating stage.

The technical scheme adopted by the utility model is as follows: the mixed flow turbine structure suitable for the medium power unit comprises a shell, wherein a mixing chamber surrounded by a holding ring and a rotor is arranged in the shell, a steam inlet chamber is arranged in the mixing chamber, the steam inlet chamber is arranged on the shell and is provided with a steam inlet and a steam outlet, a steam inlet pipeline is connected to the steam inlet, and an adjusting stage is arranged at the steam outlet and is communicated with the mixing chamber; the regulating stage comprises a stage outer ring, a stage inner ring and a stage movable blade arranged on the rotor, the stage outer ring and the stage inner ring are coaxially arranged at a steam outlet of the steam inlet chamber, a stage stationary blade is arranged between the stage outer ring and the stage inner ring, and the stage movable blade is arranged at the downstream of the stage stationary blade along the flow direction of steam; and an interstage gland seal is arranged between the outer wall of the steam inlet cavity or between the inner ring of the stage and the rotor.

Further, the inlet steam flow area of the steam inlet pipeline is smaller than the flow area of the steam inlet.

Further, the blending chamber has a tapered surface that tapers the flow area of the steam flow from the steam inlet to the steam outlet.

Further, the axis of the steam outlet is parallel to the axis of the rotor.

Further, the movable blade top steam seal comprises a top steam seal tooth arranged on the stage outer ring and a plurality of steam seal steps arranged at the top of the stage movable blade, wherein the top steam seal tooth is perpendicular to the step surfaces of the steam seal steps, and each steam seal step position is provided with a top steam seal tooth.

Further, the steam seal steps are arranged in a mirror image mode on the center surface of the top of the stage bucket.

Further, the interstage gland seal includes interstage flat teeth disposed on the rotor between an outer wall or an inner ring of the steam inlet plenum and the rotor.

Further, a steam seal front groove is formed in the rotor and is located at the upstream or one side of the interstage steam seal.

Further, at least one row of pressure movable blades is arranged on the rotor, at least one row of pressure stationary blades is arranged on the holding ring, each row of pressure stationary blades and each row of pressure movable blades are arranged alternately, and the pressure stationary blades are arranged in front of the pressure movable blades.

Further, the pressure stationary blades and the pressure movable blades of the plurality of rows are arranged along the axial direction of the rotor.

In summary, due to the adoption of the technical scheme, the beneficial effects of the utility model are as follows:

1. Compared with a double-flow regulation stage, the single-flow regulation stage structure is adopted, the flow is increased, the heights of the stage stationary blades and the stage movable blades at the regulation stage are effectively increased, so that the flow area is increased, the steam inlet degree is increased, the secondary flow loss and partial steam inlet loss at the end part of the regulation stage are reduced, and the regulation stage efficiency is remarkably improved;

2. Compared with the double-flow regulating stage, the single-flow regulating stage has the advantages that the heights of the stage stationary blades and the stage movable blades are obviously increased, the machining precision is obviously improved, and the regulating stage efficiency is further improved;

3. the number of the adjusting stages is reduced, and the cost of the adjusting stages is obviously reduced;

4. The utility model reduces the number of adjusting stages, shortens the axial span of the unit, reduces the sizes of a rotor, a cylinder and the like, and further reduces the overall cost;

5. According to the utility model, the movable blade top steam seal is arranged at the position of the stage movable blade of the regulating stage, so that the steam leakage quantity at the top of the stage movable blade can be reduced, the regulating stage efficiency is improved, the uniform distribution of the movable blade mass is ensured, and the stability of the movable blade in high-speed rotation is improved;

6. According to the utility model, by arranging the interstage steam seal, the flow of interstage steam leakage can be blocked, so that the quantity of interstage steam leakage is reduced, and the efficiency of the regulation stage is improved.

Drawings

The utility model will now be described by way of example and with reference to the accompanying drawings in which:

FIG. 1 is a schematic diagram of the structure of the present utility model;

FIG. 2 is a schematic diagram of a regulating stage configuration of the present disclosure;

FIG. 3 is a schematic view of a vapor seal structure at the top of a bucket according to the present disclosure;

FIG. 4 is a schematic view of an interstage vapor seal structure of the present disclosure;

The marks in the figure: 1-a housing; 2-holding ring; 21-pressure vane; 3-rotor; 31-pressure moving blades; 4-a steam inlet chamber; 41-steam inlet; 42-steam outlet; 5-a steam inlet pipeline; a 6-blending chamber; 7-a regulation stage; 71-stage vanes; 72-stage moving blades; 73-stage inner ring; a 74-stage outer ring; 8-steam sealing at the top of the movable blade; 81-top gland sealing teeth; 82-steam seal steps; 9-interstage steam sealing; 91-a steam seal front groove; 92-inter-stage flat teeth.

Detailed Description

All of the features disclosed in this specification, or all of the steps in a method or process disclosed, may be combined in any combination, except for mutually exclusive features and/or steps.

Any feature disclosed in this specification may be replaced by alternative features serving the same or equivalent purpose, unless expressly stated otherwise. That is, each feature is one example only of a generic series of equivalent or similar features, unless expressly stated otherwise.

Example 1

As shown in fig. 1-4, a mixed flow turbine structure suitable for a medium power unit comprises a shell 1, wherein the shell 1 surrounds the whole structure, two holding rings 2 and a rotor 3 capable of rotating relative to the holding rings 2 are arranged in the shell 1, the two holding rings 2 are matched with the rotor 3 and the inner wall of the shell 1 to form a mixing chamber 6, a steam inlet chamber 4 is arranged in the mixing chamber 6, the steam inlet chamber 4 is an independent space and is isolated from the mixing chamber 6, the steam inlet chamber 4 is arranged on the shell 1, the steam inlet chamber 4 is provided with a steam inlet 41 and a steam outlet 42, a steam inlet pipeline 5 is connected at the steam inlet 41, and an adjusting stage 7 is arranged at the steam outlet 42 and is communicated with the mixing chamber 6; the working medium enters the steam inlet chamber 4 from the steam inlet pipeline 5 and the steam inlet 41, enters the mixing chamber 6 through the adjusting stage 7, then flows to two sides of the mixing chamber 6, and flows out from between the rotor 3 and the holding ring 2; the regulating stage 7 comprises a stage outer ring 74, a stage inner ring 73 and a stage moving blade 72 which is arranged on the rotor 3, wherein the stage moving blade 72 can rotate with the rotor 3; the stage outer ring 74 and the stage inner ring 73 are coaxially arranged at the steam outlet 42 of the steam inlet chamber 4, a stage stationary blade 71 is arranged between the stage outer ring 74 and the stage inner ring 73, and the stage movable blade 72 is arranged at the downstream of the stage stationary blade 71 along the flow direction of the steam; a bucket top gland seal 8 is arranged between the stage outer ring 74 and the stage bucket 72, and an interstage gland seal 9 is arranged between the outer wall of the steam inlet cavity 4 or the stage inner ring 73 and the rotor 3.

In the embodiment, the pressure stationary blade 21 is arranged on the holding ring 2, and the pressure movable blade 31 is arranged on the rotor 3; the working medium enters the steam inlet chamber 4 from the steam inlet pipeline 5 and then enters the regulating stage 7 from the steam outlet 42, and under the cooperation of the stage stationary blades 71 and the stage movable blades 72, the working medium expands at the regulating stage 7, so that the stage movable blades 72 rotate relative to the stage stationary blades 71, the stage stationary blades 71 are fixed, and the stage movable blades 72 rotate with the rotor 3, so that the working medium expands at the position of the regulating stage 7 to do work; after the working medium expands and works at the adjusting stage 7, the pressure and the temperature of the working medium are reduced, the working medium enters the blending chamber 6 to be decelerated again and uniformly mixed, flows to the two sides of the blending chamber 6, enters the pressure stage formed by the pressure stationary blade 21 of the holding ring 2 and the pressure movable blade 31 on the rotor 3, and continues to expand and work to push the movable blade to rotate with the rotor 3; the adjusting stage 7 is of a single-flow structure, compared with a conventional double-flow structure, the flow is doubled, the heights of the stage stationary blades 71 and the stage movable blades 72 at the adjusting stage 7 are effectively increased, so that the flow area is increased, the steam inlet degree is increased, the secondary flow loss and partial steam inlet loss at the end part of the adjusting stage 7 are reduced, and the efficiency of the adjusting stage 7 is obviously improved; furthermore, the number of adjustment stages 7 is reduced, the costs are significantly reduced, and the resulting unit axial span is shortened, the size of the cylinders, rotors 3, etc. is reduced, and the overall cost is further reduced, relative to conventional dual-flow structures.

In the embodiment, when the working medium is positioned at the adjusting stage 7, the steam leakage quantity at the top of the stage moving blade 72 can be reduced due to the existence of the steam seal 8 at the top of the moving blade; due to the existence of the interstage steam seal 9, the interstage steam leakage can be effectively reduced.

Example 2

Further embodiments are presented which can be implemented on the basis of example 1.

In a possible embodiment, as shown in fig. 1, the flow area of the steam inlet pipe 5 is smaller than the flow area of the steam inlet 41, the working medium enters the steam inlet chamber 4 from the steam inlet pipe 5, and the working medium is decelerated and mixed due to the increase of the flow area; in addition, the steam inlet chamber 4 is annular, and the working medium flows in the steam inlet chamber 4 along the circumferential direction, so that the mixing degree of the working medium is further improved.

In a possible embodiment, as shown in fig. 1, the mixing chamber 6 has a conical surface, which guides the working medium into the steam outlet 42, so that the flow area of the working medium steam gradually decreases from the steam inlet 41 to the steam outlet 42; the flow speed of the working medium steam can be increased, so that the working medium steam has enough kinetic energy; and the flow speed of the working medium is increased, the pressure at the steam outlet 42 is reduced, so that the working medium is gradually released from the steam inlet chamber 4, and the aim of assisting in reducing the pressure of the working medium is fulfilled.

In a practical embodiment, the axis of the steam outlet 42 is parallel to the axis of the rotor 3, so that the rotor 3 is prevented from being impacted by the working medium, and the working medium is parallel to the rotor 3, so that the kinetic energy of the working medium can be fully acted on the stage stationary blades 71 and the stage movable blades 72, and the energy transfer efficiency is improved.

Example 3

Further embodiments are provided that are viable on the basis of any of the embodiments of examples 1-2.

2-3, The bucket top steam seal 8 comprises a top steam seal tooth 81 arranged on the stage outer ring 74 and a plurality of steam seal steps 82 arranged on the top of the stage bucket 72, wherein the top steam seal tooth 81 is arranged perpendicular to the step surface of the steam seal steps 82, and each steam seal step 82 is provided with a top steam seal tooth 81; a tortuous flow path is formed by the steps and the top gland seal teeth 81 to achieve a sealing effect.

Further, in the above embodiment, the plurality of steam seal steps 82 are arranged in mirror images on the center plane of the top of the stage bucket 72, so that the quality distribution of the stage bucket 72 is ensured to be uniform and the stability of the stage bucket 72 in high-speed rotation can be improved on the premise of reducing the steam leakage of the top of the stage bucket 72.

Example 4

Further embodiments are provided that are possible on the basis of any one of the embodiments 1-3.

In a possible embodiment, as shown in fig. 4, the interstage gland 9 includes interstage flat teeth 92 provided on the rotor 3, the interstage flat teeth 92 being located between the outer wall of the steam inlet chamber 4 or the stage inner ring 73 and the rotor 3, and sealing is achieved by a tortuous flow path formed by the flat teeth and the rotor 3.

Further, in the above embodiment, the interstage flat teeth 92 are preferably provided on the outer wall of the steam inlet chamber 4, because the outer wall of the steam inlet chamber 4 is closer to the rotor 3 than the inner ring 73, and the interstage gland 9 is provided between the outer wall of the steam inlet chamber 4 and the rotor 3, the gap size can be reduced, the size of the interstage flat teeth 92 can be reduced, and the stability performance of the interstage gland 9 can be improved.

Further, in the above embodiment, the rotor 3 is provided with a gland front groove 91, which is located at the upstream or one side of the interstage gland 9; the working medium steam flow forms strong vortex at the position of the steam seal front groove 91, further hinders the steam leakage flow, and further reduces the inter-stage steam leakage.

Example 5

Further embodiments are provided that are possible on the basis of any one of the embodiments 1-4.

In a possible specific embodiment, at least one row of pressure blades 31 is arranged on the rotor 3, at least one row of pressure static blades 21 is arranged on the holding ring 2, each row of pressure static blades 21 and pressure static blades 31 are arranged at intervals, and the pressure static blades 21 are arranged in front of the pressure static blades 31; the working medium enters between the pressure stationary blade 21 and the pressure movable blade 31 from the mixing chamber 6, expands and does work, and pushes the pressure movable blade 31 to rotate with the rotor 3.

It should be noted that, the multiple rows of pressure movable blades 31 and pressure stationary blades 21 are alternately arranged, so that the working medium can expand gradually to do work, and the rotor 3 is pushed to rotate.

Further, the rows of the pressure vanes 21, 31 are each arranged along the axial direction of the rotor 3.

The utility model is not limited to the specific embodiments described above. The utility model extends to any novel one, or any novel combination, of the features disclosed in this specification, as well as to any novel one, or any novel combination, of the steps of the method or process disclosed.

Claims (10)

1. A mixed flow turbine structure suitable for medium power unit, its characterized in that: the mixing device comprises a shell (1), wherein a mixing chamber (6) surrounded by a holding ring (2) and a rotor (3) is arranged in the shell (1), a steam inlet chamber (4) is arranged in the mixing chamber (6), the steam inlet chamber (4) is arranged on the shell (1), the steam inlet chamber (4) is provided with a steam inlet (41) and a steam outlet (42), a steam inlet pipeline (5) is connected at the steam inlet (41), and an adjusting stage (7) is arranged at the steam outlet (42) and is communicated with the mixing chamber (6); the regulating stage (7) comprises a stage outer ring (74), a stage inner ring (73) and a stage movable blade (72) arranged on the rotor (3), wherein the stage outer ring (74) and the stage inner ring (73) are coaxially arranged at a steam outlet (42) of the steam inlet chamber (4), a stage stationary blade (71) is arranged between the stage outer ring (74) and the stage inner ring (73), and the stage movable blade (72) is arranged at the downstream of the stage stationary blade (71) along the steam flow direction; a movable blade top steam seal (8) is arranged between the stage outer ring (74) and the stage movable blade (72), and an interstage steam seal (9) is arranged between the outer wall of the steam inlet cavity (4) or the stage inner ring (73) and the rotor (3).

2. The mixed flow turbine structure of claim 1, wherein: the inlet steam flow area of the steam inlet pipeline (5) is smaller than the flow area of the steam inlet (41).

3. The mixed flow turbine structure of claim 1, wherein: the mixing chamber (6) has a conical surface which tapers the flow area of the steam flow from the steam inlet (41) to the steam outlet (42).

4. The mixed flow turbine structure of claim 1, wherein: the axis of the steam outlet (42) is parallel to the axis of the rotor (3).

5. The mixed flow turbine structure of claim 1, wherein: the movable blade top steam seal (8) comprises top steam seal teeth (81) arranged on a stage outer ring (74) and a plurality of steam seal steps (82) arranged at the top of the stage movable blade (72), the top steam seal teeth (81) are arranged perpendicular to step surfaces of the steam seal steps (82), and the top steam seal teeth (81) are arranged at the positions of each steam seal step (82).

6. The mixed flow turbine structure of claim 5, wherein: the steam seal steps (82) are arranged in a mirror image mode on the center surface of the top of the stage moving blade (72).

7. The mixed flow turbine structure of claim 1, wherein: the interstage gland seal (9) comprises interstage flat teeth (92) arranged on the rotor (3), and the interstage flat teeth (92) are positioned between the outer wall or the stage inner ring (73) of the steam inlet cavity (4) and the rotor (3).

8. The mixed flow turbine structure of claim 7, wherein: a steam seal front groove (91) is formed in the rotor (3) and is located at the upstream or one side of the interstage steam seal (9).

9. The mixed flow turbine structure according to any one of claims 1-8, wherein: at least one row of pressure movable blades (31) is arranged on the rotor (3), at least one row of pressure stationary blades (21) is arranged on the holding ring (2), each row of pressure stationary blades (21) and pressure movable blades (31) are alternately arranged, and the pressure stationary blades (21) are arranged in front of the pressure movable blades (31).

10. The mixed flow turbine structure of claim 9, wherein: the pressure static blades (21) and the pressure movable blades (31) are arranged along the axial direction of the rotor (3).