EP3266984A2 - Aube mobile et turbine utilisant l'aube mobile - Google Patents

Aube mobile et turbine utilisant l'aube mobile Download PDF

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Publication number
EP3266984A2
EP3266984A2 EP17170642.7A EP17170642A EP3266984A2 EP 3266984 A2 EP3266984 A2 EP 3266984A2 EP 17170642 A EP17170642 A EP 17170642A EP 3266984 A2 EP3266984 A2 EP 3266984A2
Authority
EP
European Patent Office
Prior art keywords
moving blade
distal end
blade
guide
last
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP17170642.7A
Other languages
German (de)
English (en)
Other versions
EP3266984A3 (fr
Inventor
Senoo SHIGEKI
Fukushima HISATAKA
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Power Ltd
Original Assignee
Mitsubishi Hitachi Power Systems Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Hitachi Power Systems Ltd filed Critical Mitsubishi Hitachi Power Systems Ltd
Publication of EP3266984A2 publication Critical patent/EP3266984A2/fr
Publication of EP3266984A3 publication Critical patent/EP3266984A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/14—Form or construction
    • F01D5/20—Specially-shaped blade tips to seal space between tips and stator
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/14—Form or construction
    • F01D5/141—Shape, i.e. outer, aerodynamic form
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
    • F01D11/08—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/22—Blade-to-blade connections, e.g. for damping vibrations
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/30—Fixing blades to rotors; Blade roots ; Blade spacers
    • F01D5/3007—Fixing blades to rotors; Blade roots ; Blade spacers of axial insertion type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/22—Blade-to-blade connections, e.g. for damping vibrations
    • F01D5/225—Blade-to-blade connections, e.g. for damping vibrations by shrouding
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2220/00—Application
    • F05D2220/30—Application in turbines
    • F05D2220/31—Application in turbines in steam turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2220/00—Application
    • F05D2220/30—Application in turbines
    • F05D2220/32—Application in turbines in gas turbines
    • F05D2220/321—Application in turbines in gas turbines for a special turbine stage
    • F05D2220/3215—Application in turbines in gas turbines for a special turbine stage the last stage of the turbine

Definitions

  • the present invention relates to a moving blade and a turbine using the moving blade.
  • a moving blade at a last stage (hereinafter, last-stage moving blade) of a low-pressure turbine tends to be elongated in order to meet requests for a high output and high efficiency of turbines in recent years (see JP-A-2003-65002 and the like).
  • the circumferential speed of the last-stage moving blade increases.
  • the pressure of the working fluid on a downstream side in the flowing direction (hereinafter, downstream side) of the working fluid of the last-stage moving blade is generally determined by the pressure in a condenser disposed on the downstream side of the turbine. Therefore, when the pressure of the working fluid present on the upstream side of the last-stage moving blade is raised, a ratio of an upstream pressure with respect to a downstream pressure of the working fluid of the last-stage moving blade increases.
  • the turbine there is a gap between a moving blade of a turbine rotor, which is a rotating body, and a stationary body that covers the turbine rotor.
  • a part of the working fluid present on the upstream side of the last-stage moving blade can pass the gap.
  • a flow passing the gap between a moving blade distal end and the stationary body opposed to the moving blade distal end without passing a blade section (a profile section) of the moving blade in this way is described as leak flow in this specification.
  • the leak flow is sometimes suppressed by providing a seal fin on opposed surfaces of the moving blade distal end and the stationary body.
  • a very small gap remains between a seal fin distal end and a section opposed to the seal fin distal end. The leak flow cannot be completely suppressed.
  • the present invention has been devised in view of the above and an object of the present invention is to provide a moving blade that can suppress an increase in a pressure loss due to separation of a leak flow from a diffuser wall surface.
  • the present invention is a moving blade disposed in a last stage closest to a diffuser among a plurality of stages of a turbine including a turbine rotor and a stationary body that covers the turbine rotor, the diffuser being connected to an outlet side of working fluid of the stationary body, a distal end of the moving blade being opposed to a seal fin provided in the stationary body, the moving blade including: a blade section; a cover provided at a distal end portion of the blade section; and a guide provided on a moving blade distal end face, which is a surface of the cover opposed to the stationary body.
  • the moving blade distal end face extends in a rotation axis direction of the turbine rotor
  • the guide includes a guide surface located on a side close to the diffuser with respect to the seal fin and formed to incline upward in a direction from the seal fin toward the diffuser.
  • Fig. 1 is a schematic diagram showing the overall configuration of a configuration example of a steam turbine power generation facility applied with a moving blade according to this embodiment.
  • the moving blade according to this embodiment is applied to the steam turbine power generation facility.
  • an application target of the moving blade according to this embodiment is not limited to the steam turbine power generation facility.
  • the moving blade according to this embodiment can also be applied to, for example, a gas turbine power generation facility.
  • a steam turbine power generation facility 100 includes a steam generation source 1, a high-pressure turbine 3, an intermediate-pressure turbine 6, a low-pressure turbine 9, a condenser 11, and a load apparatus 13.
  • the steam generation source (a boiler) 1 heats feed water supplied from the condenser 11 and generates high-temperature/high-pressure steam.
  • the steam generated by the boiler 1 is guided to the high-pressure turbine 3 via a main steam pipe 2 and drives the high-pressure turbine 3.
  • the steam that has driven the high-pressure turbine 3 and has been decompressed flows down in a high-pressure turbine exhaust pipe 4 and is guided to the boiler 1 and heated again to be reheated steam.
  • the reheated steam heated by the boiler 1 is guided to the intermediate-pressure turbine 6 via a reheating steam pipe 5 and drives the intermediate-pressure turbine 6.
  • the steam that has driven the intermediate-pressure turbine 6 and has been decompressed is guided to the low-pressure turbine 9 via an intermediate-pressure turbine exhaust pipe 7 and drives the low-pressure turbine 9.
  • the steam that has driven the low-pressure turbine 9 and has been decompressed flows in a diffuser 10 and is guided to the condenser 11.
  • the condenser 11 includes a cooling water pipe (not shown in the figure).
  • the condenser 11 causes the steam guided to the condenser 11 and cooling water flowing in the cooling water pipe to perform heat exchange and condenses the steam.
  • the condensed water generated by the condenser 11 is sent to the boiler 1 again as feed water by a feed water pump 56.
  • the high-pressure turbine 3, the intermediate-pressure turbine 6, and the low-pressure turbine 9 are coupled on the same axis by a turbine rotor 12.
  • the load apparatus (in this embodiment, a generator) 13 is coupled to the turbine rotor 12.
  • the generator 13 is driven by rotation power of the high-pressure turbine 3, the intermediate-pressure turbine 6, and the low-pressure turbine 9.
  • the rotation power of the high-pressure turbine 3, the intermediate-pressure turbine 6, and the low-pressure turbine 9 is converted into electric power.
  • the configuration is illustrated in which the coupled high-pressure turbine 3, intermediate-pressure turbine 6, and low-pressure turbine 9 drive the generator 13.
  • a configuration may be adopted in which the high-pressure turbine 3, the intermediate-pressure turbine 6, and the low-pressure turbine 9 respectively drive generators and individually convert rotation power into electric power or a configuration may be adopted in which a turbine obtained by coupling any two of the high-pressure turbine 3, the intermediate-pressure turbine 6, and the low-pressure turbine 9 drives a generator and converts rotation power into electric power.
  • the configuration including the high-pressure turbine 3, the intermediate-pressure turbine 6, and the low-pressure turbine 9 is illustrated.
  • a configuration excluding the intermediate-pressure turbine 6 and including the high-pressure turbine 3 and the low-pressure turbine 9 may be adopted.
  • the configuration including the boiler as the steam generation source 1 is illustrated.
  • a configuration including, as the steam generation source 1, a heat recovery steam generator (HRSG) that uses exhaust heat of a gas turbine may be adopted.
  • the steam turbine power generation facility may be a combined cycle power generation facility.
  • the steam generation source 1 may be an atomic power generation facility including an atomic reactor.
  • Fig. 2 is a sectional view showing the internal structure of a main part of the low-pressure turbine 9 applied with the moving blade according to this embodiment.
  • the low-pressure turbine 9 includes the turbine rotor 12 and a stationary body 14 that covers the turbine rotor 12.
  • the diffuser 10 is connected to an outlet side (a most downstream side) of working fluid 22 of the stationary body 14.
  • a rotating direction and a rotation axis direction of the turbine rotor 12 are simply referred to as “rotating direction” and “rotation axis direction” and a radial direction inner side and a radial direction outer side of the turbine rotor 12 are simply referred to as "radial direction inner side” and "radial direction outer side”.
  • the stationary body 14 includes a casing 16, outer diaphragms 17a to 17d, stationary blades 18a to 18d, and inner diaphragms 19a to 19d.
  • the casing 16 is a cylindrical member that forms the outer circumferential wall of the low-pressure turbine 9.
  • the outer diaphragms 17a to 17d, the stationary blades 18a to 18d, the inner diaphragms 19a to 19d, and the turbine rotor 12 are housed in the casing 16.
  • the outer diaphragms 17a to 17d are supported on the inner circumferential surface of the casing 16.
  • the outer diaphragms 17a to 17d are cylindrical members extending in the rotating direction.
  • the outer diaphragms 17a to 17d are configured by combining members formed in a semicircular shape.
  • the outer diaphragms 17a to 17d are formed such that the inner circumferential surfaces thereof spread to the radial direction outer side toward a downstream side.
  • An outer circumferential wall 10A of the diffuser 10 is connected to the end portion on the downstream side of a projecting section 55 of the outer diaphragm 17d provided on the most downstream side among the outer diaphragms 17a to 17d.
  • the configuration is illustrated in which the outer diaphragms 17a to 17d are respectively supported on the inner circumferential surface of the casing 16.
  • a configuration may be adopted in which the outer diaphragms 17a to 17d are integrally formed and supported on the inner circumferential surface of the casing 16.
  • the stationary blades 18a to 18d are provided in plurality along the rotating direction on the inner circumferential surfaces of the outer diaphragms 17a to 17d.
  • the stationary blades 18a to 18d are provided to extend from the inner circumferential surfaces of the outer diaphragms 17a to 17d toward the radial direction inner side.
  • the inner diaphragms 19a to 19d are provided on the radial direction inner side of the outer diaphragms 17a to 17d.
  • the inner diaphragms 19a to 19d are cylindrical members extending in the rotating direction.
  • the inner diaphragms 19a to 19d are configured by combining members formed in a semicircular shape.
  • the stationary blades 18a to 18d are connected to the outer circumferential surfaces of the inner diaphragms 19a to 19d. That is, the stationary blades 18a to 18d are fixed between the outer diaphragms 17a to 17d and the inner diaphragms 19a to 19d.
  • the outer diaphragm 17a, the stationary blade 18a, and the inner diaphragm 19a configure a stationary blade row 15a at a first stage
  • the outer diaphragm 17b, the stationary blade 18b, and the inner diaphragm 19b configure a stationary blade row 15b at a second stage
  • the outer diaphragm 17c, the stationary blade 18c, and the inner diaphragm 19c configure a stationary blade row 15c at a third stage
  • the outer diaphragm 17d, the stationary blade 18d, and the inner diaphragm 19d configure a stationary blade row 15d at a fourth stage (a last stage).
  • An annular space formed between the inner diaphragms 19a to 19d and platforms (explained below) of moving blades 21a to 21d and the outer diaphragms 17a to 17d and covers (explained below) configures a channel (an annular channel) 23 in which the working fluid 22 flows.
  • the inner circumferential wall of the annular channel 23 is formed by the outer circumferential surfaces of the inner diaphragms 19a to 19d and the outer circumferential surfaces of the platforms of the moving blades 21a to 21d.
  • the outer circumferential wall of the annular channel 23 is formed by the inner circumferential surfaces of the outer diaphragms 17a to 17d and surfaces facing the radial direction inner side of the covers.
  • the turbine rotor 12 includes rotor disks 20a to 20d and the moving blades 21a to 21d.
  • the rotor disks 20a to 20d are disk-like members disposed side by side in the rotation axis direction.
  • the rotor disks 20a to 20d are sometimes alternately superimposed with spacers (not shown in the figure).
  • the moving blades 21a to 21d are respectively provided on the outer circumferential surfaces of the rotor disks 20a to 20d in plurality at equal intervals along the rotating direction.
  • the moving blades 21a to 21d are provided to extend from the outer circumferential surfaces of the rotor disks 20a to 20d toward the radial direction outer side.
  • the moving blades 21a to 21d are rotated round a rotation axis R together with the rotor disks 20a to 20d by the working fluid 22 flowing in the annular channel 23.
  • the rotor disk 20a and the moving blade 21a configure a moving blade row 53a at the first stage
  • the rotor disk 20b and the moving blade 21b configure a moving blade row 53b at the second stage
  • the rotor disk 20c and the moving blade 21c configure a moving blade row 53c at the third stage
  • the rotor disk 20d and the moving blade 21d configure a moving blade row 53d at the fourth stage (the last stage).
  • the stationary blades 18a to 18d and the moving blades 21a to 21d are alternately provided in the rotation axis direction in the order of the stationary blade 18a, the moving blade 21a, the stationary blade 18b, the moving blade 21b, and the like from an inlet side (a most upstream side) of the working fluid 22 of the stationary body 14 toward the downstream side.
  • the stationary blades 18a to 18d are disposed to be opposed to the moving blades 21a to 21d in the rotation axis direction.
  • one set of a stationary blade row and a moving blade row adjacent to each other in the rotation axis direction configures a blade stage.
  • the stationary blade row 15a at the first stage and the moving blade row 53a at the first stage configure a first blade stage 24a
  • the stationary blade row 15b at the second stage and the moving blade row 53b at the second stage configure a second blade stage 24b
  • the stationary blade row 15c at the third stage and the moving blade row 53c at the third stage configure a third blade stage 24c
  • the stationary blade row 15d at the fourth stage and the moving blade row 53d at the fourth stage configure a fourth blade stage 24d.
  • the fourth blade stage 24d is a last stage disposed on the outlet side of the working fluid 22 of the stationary body 14.
  • the fourth blade stage 24d is disposed in a position closest to the diffuser 10.
  • Blade lengths (lengths in the radial direction) of the moving blades 21a to 21d disposed in the first to fourth blade stages are formed to be larger in the moving blades located further on the downstream side.
  • the blade length of the moving blade (the last-stage moving blade) 21d disposed in the fourth blade stage 24d is formed largest among the moving blades 21a to 21d.
  • the last-stage moving blade 21d has the blade length at which a moving blade distal end circumferential speed Mach number obtained by dividing the rotation circumferential speed of the distal end portion of a blade section 26 (explained below) by the sonic speed of the working fluid 22 flowing at the distal end portion of the blade section 26 exceeds 1.0 during the rotation of the turbine rotor 12.
  • Fig. 3 is a perspective view showing the schematic configuration of the last-stage moving blade 21d.
  • the last-stage moving blade 21d includes a platform 25, the blade section 26, an integral cover 27, and a tie boss 28.
  • the platform 25 has size for covering the entire end face of a root portion (a portion on the radial direction inner side) 29 of the blade section 26.
  • the platform 25 is formed in a lozenge shape when viewed from the radial direction outer side.
  • a blade root attachment (not shown in the figure) projecting to the opposite side of the blade section 26 is provided on the lower surface (a surface on the radial direction inner side) of the platform 25.
  • the blade root attachment is formed in, for example, a reverse Christmas tree shape.
  • the blade root attachment is fit with a groove section (not shown in the figure) formed on the outer circumferential surface of the rotor disk 20d (see Fig. 2 ), whereby the last-stage moving blade 21d is fixed to the rotor disk 20d.
  • the blade root attachment is formed in the reverse Christmas tree shape.
  • the shape of the blade root attachment is not limited to the reverse Christmas tree shape as long as the blade root attachment can be fit with the groove section formed on the outer circumferential surface of the rotor disk 20d and can fix the last-stage moving blade 21d to the rotor disk 20d resisting a centrifugal force generated during the rotation of the turbine rotor 12.
  • the blade section 26 is attached to the outer circumferential surface of the platform 25 and extends from the outer circumferential surface of the platform 25 to the radial direction outer side.
  • the blade section 26 is formed to be twisted.
  • the integral cover (the cover) 27 is provided at a distal end portion (an end portion in the radial direction outer side) 30 of the blade section 26.
  • the cover 27 includes a suction side integral cover (a first cover) 27A extending in the rotating direction in a suction side section of the last-stage moving blade 21d and a pressure side integral cover (a second cover) 27B extending in the rotating direction in a pressure side section of the last-stage moving blade 21d.
  • the surface of the cover 27 facing the radial direction inner side configures a part of the outer circumferential wall of the annular channel 23 and defines the annular channel 23.
  • the cover 27 comes into contact with covers of last-stage moving blades (adjacent blades) adjacent to each other on both sides in the rotating direction of the last-stage moving blade 21d during the rotation of the turbine rotor 12 and couples the last-stage moving blade 21d and the adjacent blades. Action of the cover 27 during the rotation of the turbine rotor 12 is explained below.
  • the cover 27 When the last-stage moving blade 21d is assembled to the low-pressure turbine 9, when viewed on a cross section cut along a plane including the rotation axis R of the turbine rotor 12 (hereinafter referred to as meridional plane cross section), the cover 27 includes a surface opposed to the inner circumferential surface of the outer diaphragm 17d (the stationary body 14) and extending in the rotation axis direction.
  • the surface facing the radial direction outer side of the cover 27 and opposed to the inner circumferential surface of the outer diaphragm 17d is described as a moving blade distal end face 31 for convenience.
  • the moving blade distal end face 31 is formed in size for covering the entire end face of the distal end portion 30 of the last-stage moving blade 21d. That is, when the last-stage moving blade 21d is assembled to the low-pressure turbine 9, when viewed on the meridional plane cross section, the length in the rotation axis direction of the moving blade distal end face 31 is set larger than the length in the rotation axis direction of the blade section 26 at the distal end portion 30 of the last-stage moving blade 21d.
  • a gap 42 that causes spaces on upstream and downstream sides of the last-stage moving blade 21d to communicate is present between the moving blade distal end face 31 and the inner circumferential surface of the outer diaphragm 17d (see Fig. 2 ).
  • a guide 32 is provided on the moving blade distal end face 31. The guide 32 is explained below.
  • the tie boss 28 is provided between the root portion 29 and the distal end portion 30 of the blade section 26.
  • the tie boss 28 is provided in an intermediate portion in the radial direction of the blade section 26.
  • the tie boss 28 includes a suction side tie boss (a first tie boss) 28A provided on the suction side of the last-stage moving blade 21d and a pressure side tie boss (a second tie boss) 28B provided on the pressure side of the last-stage moving blade 21d.
  • the tie boss 28 comes into contact with a tie boss of an adjacent blade during the rotation of the turbine rotor 12 and couples the last-stage moving blade 21d and the adjacent blade. Action of the tie boss 28 during the rotation of the turbine rotor 12 is explained below.
  • the tie boss 28 is provided in the intermediate portion in the radial direction of the blade section 26.
  • the tie boss 28 may be shifted to the radial direction inner side or the radial direction outer side from the intermediate portion of the blade section 26 according to, for example, torsional rigidity of the blade section 26.
  • Fig. 4 is a perspective view showing a state in which the last-stage moving blade 21d is fixed to the rotor disk 20d.
  • Fig. 5 is a diagram in which Fig. 4 is viewed from the radial direction outer side. Note that, in Fig. 4 , the rotor disk 20d is omitted.
  • a centrifugal force acts on the blade section 26 of the last-stage moving blade 21d from the root portion 29 toward the distal end portion 30. Since the blade section 26 is twisted as explained above, untwist is caused in the blade section 26 by the centrifugal force. Consequently, as shown in Fig. 4 , an untwist moment 33 acts on the distal end portion 30 of the blade section 26, an untwist moment 34 acts on the intermediate portion of the blade section 26, and an untwist moment 35 acts on the root portion 29 of the blade section 26 respectively in directions indicated by arrows.
  • an untwist moment 33' acts on a distal end portion 30' of a blade section 26' of a last-stage moving blade 21d' adjacent to the last-stage moving blade 21d in the rotating direction
  • an untwist moment 34' acts on the intermediate portion of the blade section 26'
  • an untwist moment 35' acts on a root portion 29' of the blade section 26' respectively in directions indicated by arrows.
  • Fig. 6 is a partially enlarged view showing the distal end portion 30 of the last-stage moving blade 21d.
  • a seal fin 38 is provided on a surface of the projecting section 55 of the outer diaphragm 17d opposed to the last-stage moving blade 21d (a seal fin is not provided on the moving-blade distal end face 31 of the cover 27).
  • a portion extending in the rotation axis direction and opposed to the last-stage moving blade 21d on the inner circumferential surface of the projecting section 55 of the outer diaphragm 17d is described as a moving blade opposed surface 40 for convenience.
  • the configuration is illustrated in which the outer diaphragm 17d and the projecting section 55 are integrally formed.
  • a configuration may be adopted in which the projecting section 55 is attached to the outer diaphragm 17d by welding or the like as an inner casing on the outer side of the last-stage moving blade 21d.
  • the last-stage moving blade 21d is disposed such that the distal end (the cover 27) of the last-stage moving blade 21d is opposed to the seal fin 38.
  • one seal fin 38 is provided in the rotation axis direction on the moving blade opposed surface 40.
  • a very small gap is present between the distal end portion (the end portion on the radial direction inner side) of the seal fin 38 and the moving blade distal end face 31 in order to avoid contact of the stationary body 14 and the turbine rotor 12.
  • the guide 32 is provided on the moving blade distal end face 31 of the cover 27 to be located on a side close to the diffuser 10 with respect to the seal fin 38.
  • one seal fin 38 is provided in the rotation axis direction on the moving blade opposed surface 40 of the outer diaphragm 17d.
  • the guide 32 only has to be provided to be located on a side close to the diffuser 10 with respect to the seal fin present closest to the diffuser 10 side among the plurality of seal fins.
  • the guide 32 extends in the rotating direction and is provided such that both ends thereof are opposed to the end portions of guides of last-stage moving blades adjacent to each other on both sides in the rotating direction. That is, the end portion on the downstream side in the rotating direction of the guide 32 of the last-stage moving blade 21d is opposed to the end portion on the upstream side in the rotating direction of a guide 32' of the last-stage moving blade 21d' adjacent to the last-stage moving blade 21d in the rotating direction.
  • the guide 32 is provided on the moving blade distal end face 31 of the cover 27 to extend from an end portion on the upstream side to an end portion on the downstream side in the rotating direction.
  • the guide 32 when the last-stage moving blade 21d is assembled to the low-pressure turbine 9, the guide 32 is provided as a projecting section that projects from the moving blade distal end face 31 to the moving blade opposed surface 40 side when viewed on the meridional plane cross section.
  • the guide 32 includes a wall surface 37 and a guide surface 41.
  • the wall surface 37 extends from the moving blade distal end face 31 of the cover 27 toward the moving blade opposed surface 40 of the outer diaphragm 17d.
  • the height (the length in the radial direction from the moving blade distal end face 31) of the wall surface 37 is set smaller than the length in the radial direction from the moving blade distal end face 31 to the distal end portion of the seal fin 38 during the rotation. Consequently, even if relative positions in the rotation axis direction of the last-stage moving blade 21d and the seal fin 38 change because of a hot stretching difference between a rotating section such as the rotor and a stationary section such as the casing, it is possible to prevent the guide 32 from coming into contact with the seal fin 38. It is possible to secure reliability of the low-pressure turbine 9.
  • the guide surface 41 is formed to incline upward in a direction from the seal fin 38 toward the diffuser 10.
  • the guide surface 41 is formed in a convex shape toward the rotation axis from an end portion (an upstream edge portion) on the seal fin 38 side to an end portion (a downstream edge portion) on the diffuser 10 side.
  • ⁇ is a ratio of specific heat of working fluid.
  • working fluid wet steam
  • ⁇ is, for example, 1.1 to 1.14.
  • ⁇ is set to 1.135.
  • M1 is a Mach number of the supersonic leak flow 43 flowing into the gap 42.
  • the inclination angle ⁇ is determined using Expression (2) such that the inclination angle ⁇ satisfies Expression (1), the height of the wall surface 37 is determined, and the guide 32 is designed and manufactured.
  • the manufactured guide 32 is attached to the moving blade distal end face 31 of the cover 27 by welding or the like to be located on a side close to the diffuser 10 with respect to the seal fin 38 provided on the moving blade opposed surface 40 when viewed on the meridional plane cross section.
  • a main flow of the working fluid 22 flows into spaces among the stationary blades 18a of the stationary blade row 15a at the first stage, accelerates while turning along the shape of the stationary blades 18a, and flows out from the spaces among the stationary blades 18a.
  • the main flow flowing out from the spaces among the stationary blades 18a flows into spaces among the moving blades 21a of the moving blade row 53a at the first stage disposed on the downstream side of the stationary blade row 15a at the first stage and drives to rotate the turbine rotor 12.
  • the main flow flowing out from the spaces among the moving blades 21a flows into spaces among the stationary blades 18b of the stationary blade row 15b at the second stage disposed on the downstream side of the moving blade row 53a at the first stage.
  • the main flow flows into the diffuser 10 provided on the downstream side of the last-stage moving blade 21d while repeating the turning by the stationary blades, imparting of an acceleration component, and the rotation driving of the moving blades.
  • a part of the working fluid 22 passes a very small gap present between the distal end portion of the seal fin 38 and the cover 27 and flows into the gap 42 as the leak flow 43.
  • the supersonic leak flow 43 passing the upstream edge portion of the guide surface 41 and flowing along the guide surface 41 interferes with the oblique shock wave W to be decelerated and is turned to the radial direction outer side by the oblique shock wave W. Thereafter, the leak flow 43 flows into the diffuser 10 from the gap 42.
  • the leak flow 43 is turned to the outer side, a channel area is reduced rather than being expanded as shown in Fig. 6 .
  • the leak flow 43 is gradually decelerated and is decelerated to be a subsonic flow without involving a large pressure loss.
  • Fig. 8 is a partially enlarged view showing the distal end portion 30 of a last-stage moving blade 44d according to this embodiment.
  • portions equivalent to the portions in the first embodiment are denoted by the same reference numerals and signs and explanation of the portions is omitted as appropriate.
  • the last-stage moving blade 44d according to this embodiment is different from the last-stage moving blade 21d according to the first embodiment in that the shape of a guide 45 is different.
  • the other components are the same as the components of the last-stage moving blade 21d according to the first embodiment.
  • the guide 45 when the last-stage moving blade 44d is assembled to the low-pressure turbine 9, as shown in Fig. 8 , when viewed on the meridional plane cross section, the guide 45 is provided as a concave section recessed from the moving blade distal end face 31 of the cover 27 to the rotation axis side (the blade section 26 side of the last-stage moving blade 44d).
  • the guide 45 includes a wall surface 46 and a guide surface 47.
  • the wall surface 46 is formed to extend from the moving blade distal end face 31 of the cover 27 to the rotation axis side.
  • the depth (length from the moving blade distal end face 31 toward the radial direction inner side) of the wall surface 46 is set smaller than the thickness (length in the radial direction) of the cover 27.
  • the guide surface 47 is formed to incline upward in the direction from the seal fin 38 toward the diffuser 10 and connects the end portion on the radial direction inner side of the wall surface 46 and the moving blade distal end face 31.
  • a line extending in the rotation axis direction passing the upstream edge portion of the guide surface 47 is represented as a reference line X
  • an inclination angle of the oblique shock wave W with respect to the reference line X is represented as ⁇
  • length in the radial direction from the moving blade opposed surface 40 to the reference line X is represented as d when viewed on the meridional plane cross section
  • the inclination angle ⁇ is determined from Expressions (1) and (2)
  • the depth of the wall surface 46 is determined, and the guide 45 is designed and manufactured.
  • the moving blade distal end face 31 of the cover 27 is, for example, cut and formed to locate the manufactured guide 45 on a side close to the diffuser 10 with respect to the seal fin 38 provided on the moving blade opposed surface 40 when viewed on the meridional plane cross section.
  • the guide 45 including the guide surface 47 formed to incline upward in the direction from the seal fin 38 toward the diffuser 10 is provided on the moving blade distal end face 31. Therefore, as in the first embodiment, it is possible to prevent the wall surface boundary layer flow with low flow velocity flowing near the outer circumferential wall 10A of the diffuser 10 from separating from the outer circumferential wall 10A of the diffuser 10 and suppress an increase in a pressure loss. In addition, in this embodiment, an effect explained below is obtained.
  • the guide 45 is provided as the concave section recessed from the moving blade distal end face 31 to the rotation axis side. Therefore, it is possible to more surely prevent interference of the guide 45 and the seal fin 38. It is possible to improve reliability of the low-pressure turbine 9.
  • Fig. 9 is a diagram of a last-stage moving blade 48d according to this embodiment viewed from the radial direction outer side.
  • portions equivalent to the portions in the first embodiment are denoted by the same reference numerals and signs and explanation of the portions is omitted as appropriate.
  • the last-stage moving blade 48d according to this embodiment is different from the last-stage moving blade 21d according to the first embodiment in that the shape and the position of a guide 49 are different.
  • the other components are the same as the components of the last-stage moving blade 21d according to the first embodiment.
  • the guide 49 when viewed from the radial direction outer side (the stationary body side), the guide 49 is provided along the rear edge portion (the edge portion on the diffuser 10 side) of the moving blade distal end face 31 of the cover 27.
  • the other components are the same as the components of the guide 32 according to the first embodiment.
  • the rear edge portion of the moving blade distal end face 31 of the cover 27 extends in the rotating direction while meandering.
  • the guide 49 is provided to meander along the rear edge portion of the moving blade distal end face 31 of the cover 27.
  • the guide 49 is a projecting section.
  • the guide 49 may be a concave section recessed from the moving blade distal end face 31 to the rotation axis side.
  • the guide 49 since the guide 49 is provided along the rear edge portion of the moving blade distal end face 31 of the cover 27, the guide 49 can be provided in a position separated to the diffuser 10 side from the seal fin 38 (see Fig. 6 ) provided on the moving blade opposed surface 40. Therefore, it is possible to more surely avoid the interference of the guide 49 and the seal fin 38. It is possible to further improve the reliability of the low-pressure turbine 9.
  • Fig. 10 is a diagram of a last-stage moving blade 50d according to this embodiment viewed from the radial direction outer side.
  • portions equivalent to the portions in the first embodiment are denoted by the same reference numerals and signs and explanation of the portions is omitted as appropriate.
  • the last-stage moving blade 50d according to this embodiment is different from the last-stage moving blade 21d according to the first embodiment in that the shape and the position of a guide 51 are different.
  • the other components are the same as the components of the last-stage moving blade 21d according to the first embodiment.
  • the guide 51 when viewed from the radial direction outer side, the guide 51 is provided to close a channel 52 in a region (the first cover 27A) on the rear surface side of the blade section 26 on the moving blade distal end face 31 of the cover 27 of the last-stage moving blade 50d.
  • the guide 51 is a projecting section.
  • the guide 51 may be a concave section recessed from the moving blade distal end face 31 to the rotation axis side.
  • the guide 51 when viewed from the radial direction outer side, the guide 51 is provided to close the channel 52 in the region on the rear surface side of the blade section 26 on the moving blade distal end face 31 of the cover 27. Therefore, when the last-stage moving blade 50d is viewed from the direction indicated by the vector W, the guide 51 is formed in a ring shape to cover the exterior of a plurality of last-stage moving blades that rotate around the rotation axis. Therefore, in this embodiment, an effect same as the effect in the first embodiment can be obtained. In addition, in this embodiment, an effect explained below is obtained.
  • the guide 51 only has to be provided in the region on the rear surface side of the blade section 26 on the moving blade distal end face 31 of the cover 27. Therefore, it is unnecessary to provide the guide 32 on the moving blade distal end face 31 of the cover 27 from the end portion on the upstream side to the end portion on the downstream side in the rotating direction. Accordingly, it is possible to suppress an increase in manufacturing cost of the guide.
  • Fig. 11 is a partially enlarged view showing the distal end portion 30 of a last-stage moving blade 54d according to this embodiment.
  • portions equivalent to the portions in the first embodiment are denoted by the same reference numerals and signs and explanation of the portions is omitted.
  • the last-stage moving blade 54d according to this embodiment is different from the last-stage moving blade 21d according to the first embodiment in that the positions of the guide 32 and the seal fin 38 are interchanged.
  • the other components are the same as the components of the last-stage moving blade 21d according to the first embodiment.
  • the seal fin 38 is provided on the moving blade distal end face 31 of the cover 27 instead of being provided on the moving blade opposed surface 40 of the outer diaphragm 17d.
  • the guide 32 is provided on the moving blade opposed surface 40 instead of being provided on the moving blade distal end face 31.
  • the guide surface 41 of the guide 32 when the last-stage moving blade 54d is assembled to the low-pressure turbine 9, when viewed on the meridional plane cross section, is formed to incline downward in the direction from the seal fin 38 to the diffuser 10.
  • the guide surface 41 is formed in a concave shape toward the rotation axis from the upstream edge portion to the downstream edge portion.
  • the seal fin 38 is provided on the moving blade distal end face 31 instead of being provided on the moving blade opposed surface 40 and the guide 32 is provided on the moving blade opposed surface 40 instead of being provided on the moving blade distal end face 31, it is possible to cause the supersonic leak flow 43 flowing on the downstream side of the seal fin 38 in the gap 42 to collide with the guide surface 41 to cause the oblique shock wave W and decelerate the leak flow 43. Therefore, as in the first embodiment, it is possible to prevent the wall surface boundary layer flow with low flow velocity flowing near the outer circumferential wall 10A of the diffuser 10 from separating from the outer circumferential wall 10A of the diffuser 10 and suppress an increase in a pressure loss.
  • the present invention is not limited to the embodiments explained above and includes various modifications.
  • the embodiments are explained in detail in order to clearly explain the present invention.
  • the embodiments are not always limited to embodiments including all the components explained above.
  • a part of the components of a certain embodiment can be replaced with the components of another embodiment.
  • the components of another embodiment can be added to the components of a certain embodiment.
  • the guide surface is formed in the convex shape or the concave shape toward the rotation axis from the upstream edge portion to the downstream edge portion.
  • the essential effect of the present invention is to provide a moving blade that can suppress an increase in a pressure loss due to separation of a leak flow from a diffuser wall surface.
  • the present invention is not always limited to the configuration explained above as long as the essential effect is obtained.
  • the guide surface may be linearly formed from the upstream edge portion to the downstream edge portion.
  • the configuration is illustrated in which the outer diaphragm 17d is opposed to the cover 27.
  • the present invention is not always limited to the configuration as long as the essential effect of the present invention is obtained.
  • a configuration may be adopted in which the member opposed to the cover 27 is the stationary body 14 and, for example, the casing 16 is opposed to the cover 27.
  • the moving blade according to the present invention is applied to the last stage of the low-pressure turbine 9.
  • an application target of the moving blade according to the present invention is not limited to the last stage of the low-pressure turbine.
  • the present invention can also be applied to the last stages of the high-pressure turbine 3 and the intermediate-pressure turbine 6.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
EP17170642.7A 2016-07-08 2017-05-11 Aube mobile et turbine utilisant l'aube mobile Withdrawn EP3266984A3 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2016135801A JP2018003812A (ja) 2016-07-08 2016-07-08 動翼およびそれを用いたタービン

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EP3266984A2 true EP3266984A2 (fr) 2018-01-10
EP3266984A3 EP3266984A3 (fr) 2018-01-24

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US (1) US20180010466A1 (fr)
EP (1) EP3266984A3 (fr)
JP (1) JP2018003812A (fr)
KR (1) KR20180006281A (fr)
CN (1) CN107587898A (fr)

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JP7267022B2 (ja) * 2019-01-31 2023-05-01 三菱重工業株式会社 回転機械

Citations (1)

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Publication number Priority date Publication date Assignee Title
JP2003065002A (ja) 2001-08-30 2003-03-05 Toshiba Corp 蒸気タービン動翼及び蒸気タービン

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JP4285134B2 (ja) * 2003-07-04 2009-06-24 株式会社Ｉｈｉ シュラウドセグメント
JP2010216321A (ja) * 2009-03-16 2010-09-30 Hitachi Ltd 蒸気タービンの動翼及びそれを用いた蒸気タービン
JP5574825B2 (ja) * 2010-05-26 2014-08-20 三菱重工業株式会社 シール構造、これを備えたタービン機械およびこれを備えた発電プラント
US8708639B2 (en) * 2010-10-11 2014-04-29 The Coca-Cola Company Turbine bucket shroud tail
JP5517910B2 (ja) * 2010-12-22 2014-06-11 三菱重工業株式会社 タービン、及びシール構造
JP5783570B2 (ja) * 2011-11-28 2015-09-24 三菱日立パワーシステムズ株式会社 タービン
JP2016079919A (ja) * 2014-10-20 2016-05-16 株式会社東芝 動翼及び軸流タービン

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JP2003065002A (ja) 2001-08-30 2003-03-05 Toshiba Corp 蒸気タービン動翼及び蒸気タービン

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CN107587898A (zh) 2018-01-16
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KR20180006281A (ko) 2018-01-17
US20180010466A1 (en) 2018-01-11

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