Steam turbine, blade, and method for improving performance and reliability of steam turbine

Abstract

The steam turbine comprises: a shaft that rotates around a rotating axis; a plurality of rotating blades that extend radially from the outer peripheral surface of the shaft and are arranged circumferentially; a machine chamber body that covers the shaft and the rotating blades from the outer peripheral side; a plurality of fixed blades that are arranged along the inner peripheral surface of the machine chamber body; and a material supply portion that supplies a film-forming material having hydrophobic properties to the surface of at least one of the rotating blades and the fixed blades, the material supply portion comprising: a storage portion; a supply flow path formed inside the machine chamber for circulating the film-forming material; and a discharge portion formed inside at least one of the rotating blades and the fixed blades for guiding the film-forming material to the surface.

Description

Technical Field

[0001] The present invention relates to a steam turbine, a blade and a method for improving the performance and reliability of a steam turbine.

[0002] This application claims priority based on Japanese Patent Application No. 2020-062296 filed in Japan on March 31, 2020, the contents of which are incorporated herein by reference. Background Art

[0003] A steam turbine comprises a shaft rotatable about an axis of rotation; multiple turbine blades arranged at intervals along the shaft's outer circumference; a casing covering the shaft and turbine blades from the outer circumference; and multiple turbine stator blades arranged alternately with the turbine blades on the inner circumference of the casing. An intake port for drawing in steam from the outside is formed on the upstream side of the casing, while an exhaust port is formed on the downstream side. The high-temperature, high-pressure steam drawn in through the intake port is regulated in direction and velocity by the turbine stator blades before being converted into rotational force for the shaft by the turbine blades.

[0004] Steam passing through the turbine loses energy as it moves from upstream to downstream, causing its temperature and pressure to decrease. Consequently, in the downstreammost turbine stator blade layer, some of the steam condenses and forms fine droplets in the airflow. Some of these droplets adhere to the surfaces of the turbine stator blades. These droplets immediately grow on the blades, forming a liquid film. The area surrounding the liquid film is constantly exposed to the high-speed steam flow. However, as the film grows and its thickness increases, some of it is torn apart by the steam flow, scattering as coarse droplets. These scattering droplets are gradually accelerated by the steam flow as they flow downstream. Larger droplets have greater mass, making them less likely to be accelerated to steam speed by the steam flow. They are unable to pass between the turbine blades with the main stream of steam and collide with them. The circumferential speed of the turbine blades can sometimes exceed the speed of sound, so when these scattering droplets collide with the turbine blades, they erode their surfaces, sometimes causing corrosion. Furthermore, the collision of these droplets can hinder the rotation of the turbine blades, sometimes causing brake loss.

[0005] To prevent the adhesion and growth of such droplets, various technologies have been proposed. For example, Patent Document 1 below describes a technique for removing moisture generated on the surface of a turbine nozzle (turbine stator blade) by heating it with an electric heater. Patent Document 1 also describes a technique for measuring the thickness of the water film and optimizing the amount of heating by the electric heater.

[0006] Previous technical literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent No. 5703082 Summary of the Invention

[0009] Technical issues to be solved by the invention

[0010] However, for example, the velocity of the fluid flowing between turbine stator blades is as high as 200 to 400 m / s. Furthermore, the thickness of the water film is approximately several hundred microns. Therefore, the technique described in Patent Document 1 results in significant errors when measuring the thickness of the water film, potentially preventing accurate moisture removal using the electric heating element.

[0011] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a steam turbine, a blade, and a method for improving the performance and reliability of a steam turbine, which further improve the performance and reliability.

[0012] Means for solving technical problems

[0013] In order to solve the above-mentioned problems, the steam turbine involved in the present invention comprises: a shaft rotating around a rotating shaft; a plurality of rotating blades extending radially from the outer peripheral surface of the shaft and arranged circumferentially; a machine chamber body covering the shaft and the rotating blades from the outer peripheral side; a plurality of fixed blades extending radially from a position on the inner peripheral surface of the machine chamber body more upstream than the rotating blades and arranged circumferentially; and a material supply portion supplying a film-forming substance having hydrophobicity to water droplets attached to the surface to the surface of at least one of the rotating blades and the fixed blades, the material supply portion comprising: a storage portion storing the film-forming substance; a supply flow path formed inside the machine chamber body for circulating the film-forming substance guided from the storage portion; and a discharge portion formed inside at least one of the rotating blades and the fixed blades for guiding the film-forming substance to the surface.

[0014] A method for improving the performance and reliability of a steam turbine according to the present invention includes supplying a film-forming substance having hydrophobic properties to water droplets adhering to the surface of at least one of a rotor blade and a stationary blade of the steam turbine.

[0015] Effects of the Invention

[0016] According to the present invention, a steam turbine having further improved performance and reliability, a blade, and a method for improving the performance and reliability of a steam turbine can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a diagram showing the structure of a steam turbine according to the first embodiment of the present invention.

[0018] Figure 2 It is an enlarged view showing the internal structure of the steam turbine according to the first embodiment of the present invention.

[0019] Figure 3 This is a diagram showing a turbine stator blade according to the first embodiment of the present invention as viewed from the pressure surface side.

[0020] Figure 4 It is a cross-sectional view of a turbine stator blade according to the first embodiment of the present invention.

[0021] Figure 5 It is a plan view showing a modified example of the shape of the outlet of the discharge portion according to the first embodiment of the present invention.

[0022] Figure 6 This is a diagram showing a modification of the turbine stator blade according to the first embodiment of the present invention, viewed from the pressure surface side.

[0023] Figure 7 This is a diagram showing a steam turbine according to a second embodiment of the present invention as viewed from the radial direction.

[0024] Figure 8 This is a diagram showing a steam turbine according to a second embodiment of the present invention as viewed from the direction of the rotation axis.

[0025] Figure 9 This is a diagram showing a turbine stator blade according to a third embodiment of the present invention as viewed from the pressure surface side. DETAILED DESCRIPTION

[0026] [First embodiment]

[0027] (Steam turbine structure)

[0028] Below, reference Figures 1 to 4 , a steam turbine 100 according to a first embodiment of the present invention will be described. Figure 1 and Figure 2 As shown, the steam turbine rotor 1 is provided, which extends in the direction of the rotation axis O; a steam turbine casing 2 which covers the steam turbine rotor 1 from the outer peripheral side; and a material supply unit 5 .

[0029] The steam turbine rotor 1 includes a shaft 3 extending along a rotation axis O and a plurality of rotor blades 30 provided on the outer circumferential surface of the shaft 3. A plurality of rotor blades 30 are arranged at regular intervals along the circumferential direction of the shaft 3. In the direction of the rotation axis O, rows (rotor blade layers) of the plurality of rotor blades 30 are also arranged at regular intervals. Figure 2As shown, the rotor blade 30 includes a rotor blade body 31 (turbine rotor blade) and a rotor blade shroud 34. The rotor blade body 31 protrudes radially outward from the outer peripheral surface of the steam turbine rotor 1. When viewed radially, the rotor blade body 31 has a blade-shaped cross-section. The rotor blade shroud 34 is provided at the leading end (radially outer end) of the rotor blade body 31. At the base end (radially inner end) of the rotor blade body 31, a platform 32 is integrally formed with the shaft 3.

[0030] like Figure 1 As shown, the steam turbine casing 2 has: a roughly cylindrical casing body 2H (machine room body) covering the steam turbine rotor 1 from the outer peripheral side; and fixed blades 20, which are arranged on the inner peripheral surface of the casing body 2H. A steam supply pipe (not shown) for sucking steam is provided on one side of the steam turbine casing 2 in the direction of the rotation axis O. A steam discharge pipe (not shown) for discharging steam is provided on the other side of the steam turbine casing 2 in the direction of the rotation axis O. Steam flows from one side to the other side in the direction of the rotation axis O inside the steam turbine casing 2. In the following description, the flow direction of the steam is simply referred to as the "flow direction". In addition, the side from which the steam flows is called the upstream side, and the side from which the steam flows away is called the downstream side.

[0031] A plurality of rows of stationary blades 20 are provided on the inner circumference of the steam turbine housing 2. Figure 2 As shown, the stationary blade 20 includes a stationary blade body 21 (turbine stationary blade), a stationary blade shroud 22, and an outer ring 24. The stationary blade body 21 is a blade-shaped component connected to the inner peripheral surface of the steam turbine casing 2 via the outer ring 24. Furthermore, a stationary blade shroud 22 is provided at the front end portion (radially inner end portion) of the stationary blade body 21. Similar to the rotating blade 30, a plurality of stationary blades 20 are arranged on the inner peripheral surface along the circumferential direction and the direction of the rotation axis O. The rotating blade 30 is configured to enter the area between the adjacent plurality of stationary blades 20. That is, the stationary blades 20 and the rotating blades 30 extend in a direction intersecting the flow direction of the steam (radially relative to the rotation axis O). In addition, in the following description, the stationary blades 20 and the rotating blades 30 are sometimes simply collectively referred to as blades 90.

[0032] Steam is supplied to the steam turbine casing 2 via the upstream steam supply pipe. As it passes through the steam turbine casing 2, it alternately passes through the stationary blades 20 and the rotating blades 30. The stationary blades 20 straighten the flow of steam, and the rectified steam mass pushes against the rotating blades 30, thereby imparting a rotational force to the steam turbine rotor 1. The rotational force of the steam turbine rotor 1 is extracted from the shaft end and used to drive external equipment (such as a generator). As the steam turbine rotor 1 rotates, the steam is discharged through the downstream steam discharge pipe to subsequent equipment (such as a condenser).

[0033] Although not shown in detail, the shaft 3 is rotatably supported inside the steam turbine casing 2 via a journal bearing and a thrust bearing.

[0034] (Structure of the fixed blade body)

[0035] Next, refer to Figure 2 , the structure of the fixed blade body 21 is explained. The fixed blade body 21 extends in a direction intersecting the flow direction, that is, in a radial direction (radially relative to the rotation axis O). When viewed from the radial direction, the cross-section of the fixed blade body 21 is blade-shaped. More specifically, the leading edge 21F, which is the end edge on the upstream side of the flow direction, is curved. The trailing edge 21R, which is the end edge on the downstream side, is tapered as the circumferential dimension gradually decreases when viewed from the radial direction. From the leading edge 21F to the trailing edge 21R, the fixed blade body 21 curves gently from one circumferential side relative to the rotation axis O to the other side. Moreover, with respect to the fixed blade body 21, the dimension in the direction of the rotation axis O decreases as it moves radially inward. Of the pair of circumferential surfaces of the fixed blade body 21, the surface facing the upstream side is referred to as the pressure surface 21P, and the surface facing the downstream side is referred to as the negative pressure surface 21Q.

[0036] An outer ring 24 is attached to the radially outer end of the fixed blade body 21. The outer ring 24 is annular with the rotation axis O as its center. Among the surfaces of the outer ring 24, the surface facing upstream is designated as the ring upstream surface 24A, the surface facing inward is designated as the ring inner surface 24B, and the surface facing downstream is designated as the ring downstream surface 24C. The ring upstream surface 24A and the ring downstream surface 24C extend in the radial direction relative to the rotation axis O. The radial dimension of the ring upstream surface 24A is larger than the radial dimension of the ring downstream surface 24C. Therefore, in this embodiment, as an example, the ring inner surface 24B gradually expands radially outward as it moves toward the downstream side. In addition, the outer ring 24 forms a part of the steam turbine casing 2. That is, the ring inner surface 24B is a part of the inner surface of the steam turbine casing 2.

[0037] The ring downstream surface 24C faces the rotor blade shroud 34 of the rotor blade 30 adjacent to the stator blade 20, with a gap S therebetween. Of the surfaces of the rotor blade shroud 34, the surface facing upstream is designated as the shroud upstream surface 34A, the surface facing inward is designated as the shroud inner circumferential surface 34B, and the surface facing downstream is designated as the shroud downstream surface 34C. Specifically, the ring downstream surface 24C faces the shroud upstream surface 34A with a gap S therebetween.

[0038] (Structure of Material Supply Unit)

[0039] Next, refer to Figures 1 to 3Next, the structure of the material supply unit 5 will be described. The material supply unit 5 is provided to supply a film-forming substance (FFS) to the surface of at least one of the stationary blades 20 and the rotating blades 30. Details of the film-forming substance will be described later.

[0040] like Figure 1 As shown, the material supply unit 5 has a storage unit 51, a supply flow path 52 and a discharge unit 53. The storage unit 51 is a container for storing the film-forming material. The supply flow path 52 is a flow path formed inside the steam turbine casing 2, through which the film-forming material guided from the storage unit 51 flows. The material supply unit 5 supplies the outer ring 24 from one or more supply flow paths 52 set in a horizontal plane, etc., and the supply flow path 52 extends in a ring shape with the rotation axis O as the center inside the outer ring 24. In addition, Figure 1 In the example shown, the supply flow path 52 is formed only in the first-stage stationary blades 20 (particularly, the last-stage stationary blades 20). However, the supply flow paths 52 may be provided corresponding to the stationary blades 20 of all stages.

[0041] like Figure 2 As shown, the end of the supply flow path 52 radially penetrates the outer ring 24 and opens on the radially inner surface (ring inner peripheral surface 24B). The discharge portion 53 extends further radially inward from this opening to the interior of the fixed blade body 21. The discharge portion 53 is a flow path that guides the film-forming material to the surface of the fixed blade body 21. The discharge portion 53 extends radially from the radially outer end of the fixed blade body 21 to a length of 1 / 3 of the blade height. Alternatively, a structure can be adopted in which the supply flow path 52 extends over the entire area in the blade height direction.

[0042] like Figure 3 or Figure 4 As shown, the outlet E of the discharge portion 53 is formed in a plurality of areas on the pressure surface 21P of the fixed blade body 21 and on the side of the leading edge 21F. A plurality of these outlets E are arranged at intervals along the radial direction (for example, three). Figure 3 or Figure 4 In the example, the shape of the outlet E is circular.

[0043] The film-forming material, pumped from the reservoir 51 by a pump or the like (not shown), is sprayed onto the pressure surface 21P from the outlet E of the discharge portion 53 via the supply flow path 52. The film-forming material thereby forms a hydrophobic film covering at least a portion of the pressure surface 21P. The supply rate of the film-forming material is preferably set to 2 to several hundred ppm relative to the flow rate of the water film formed by steam condensation or water droplet adhesion on the pressure surface 21P. The supply of the film-forming material can be continuous or intermittent.

[0044] Furthermore, the method for improving the performance of the steam turbine 100 according to the present embodiment includes the step of supplying a film-forming substance to the surface (pressure surface 21P) of the stator blade body 21 .

[0045] (Film-forming substance)

[0046] Specifically, as the film-forming substance, it is preferable to use a volatile amine compound (film-forming amine) or a volatile non-amine compound having volatility, surface activity, and corrosion resistance.

[0047] Specific examples of volatile amines include monoamines such as dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, nonadecanylamine, eicosylamine, and behenylamine; monoamines such as oleylamine, ricinoleylamine, linoleylamine, and linoleylamine; mixed amines such as coconut oil amine and solidified tallow amine; and mixtures thereof.

[0048] Furthermore, polyamines represented by the following general formula are also preferably used.

[0049] R 1 -[NH-(CH2) m ] n -NH2

[0050] In addition, in the above formula, R 1 represents a saturated or unsaturated hydrocarbon having 10 to 22 carbon atoms, m is an integer from 1 to 8, and n is an integer from 1 to 7. When n is 2 or more, multiple [NH-(CH2) m ] n It can be the same or different.

[0051] R 1 The hydrocarbon group may be straight-chain or branched. Furthermore, it may be cyclic. Specifically, alkyl, alkenyl, alkadienyl, alkynyl, etc. are mentioned. More preferably, straight-chain alkyl and straight-chain alkenyl groups are used, and the number of carbon atoms in this case is set to 15 to 22. From the viewpoint of inhibiting corrosion, m is preferably set to an integer of 2 to 6. As (CH2) mThe group includes methylene, ethylene (dimethylene), propylene (trimethylene) or butylene (tetramethylene), but propylene is more preferred. From the viewpoint of corrosion suppression, n is preferably an integer of 1 to 3.

[0052] Specific examples of such polyamines include dodecylaminomethyleneamine, dodecylaminodimethyleneamine, dodecylaminotrimethyleneamine (N-octadecyl-1,3-propylenediamine), the tetradecyl, hexadecyl, and octadecyl compounds corresponding to these polyamines, octadecenylaminotrimethyleneamine, octadecenylaminobis-(trimethylamino)-trimethyleneamine, palmitylaminotrimethyleneamine, and tallowalkyldiamine ethoxylate. Furthermore, N-oleyl-1,3-propylenediamine (i.e., N-octadecenylpropane-3-diamine), which is readily available at a sufficient purity, is more preferably used. Also preferably used is the trade name "Ethidu omine" from Akzo.

[0053] As the volatile non-amine compound, polyethylene (20) sorbitan monostearate, sorbitan monostearate, sorbitan monolaurate can be used.

[0054] In addition, only one of these substances may be used as the film-forming substance, or two or more of them may be mixed to form the film-forming substance.

[0055] (Effect)

[0056] According to the above configuration, film-forming substance (FFS) is directly supplied to the surface of the stator blade body 21 via the discharge portion 53. This forms a hydrophobic film on the surface, reducing the likelihood of condensed water droplets adhering to the stator blade wall. This suppresses the generation of coarse water droplets caused by the water film on the stator blade wall being released from the trailing edge of the stator blade into the steam, thereby preventing corrosion caused by coarse water droplets colliding with the downstream rotor blades 30. Furthermore, this reduces acceleration losses, which are energy lost to accelerating the coarse water droplets, and impulse losses, which are caused by the coarse water droplets braking the rotor blades 30. This improves turbine efficiency. Furthermore, the film-forming substance has a turbulent friction-reducing effect (the Thomas effect), thereby improving the flow field of the fluid on the surface of the stator blade body 21 and reducing blade-shaped losses, thereby further improving turbine efficiency. Furthermore, since the film-forming substance forms a film on the metal surface, it also provides an anti-corrosion effect.

[0057] Furthermore, according to the above configuration, the plurality of outlets E of the discharge portion 53 are arranged at intervals in the radial direction on the front edge 21F side of the pressure surface 21P. Therefore, the film forming material can be stably supplied to a wider range of the pressure surface 21P.

[0058] The first embodiment of the present invention has been described above. Various changes or modifications may be made to the above structure without departing from the spirit of the present invention. For example, the outlet E of the discharge portion 53 may be formed on the negative pressure surface 21Q in addition to the pressure surface 21P. Furthermore, the outlet E may be formed only on the negative pressure surface 21Q.

[0059] According to this configuration, the film-forming material can be stably supplied to a wider range of the negative pressure surface 21Q.

[0060] Furthermore, the opening of the outlet E' of the discharge portion 53 can be set as follows Figure 5 The semicircle shown. Figure 5 In the example of FIG, the outlet E′ is formed so that its radial dimension gradually increases from the upstream side toward the downstream side. That is, the upstream end edge L1 of the outlet E′ is curved into a curve convex toward the upstream side. The downstream end edge L2 extends in the radial direction.

[0061] According to the above configuration, the outlet E' is formed so that the radial dimension thereof increases toward the downstream side. Therefore, the film-forming material can be supplied to a wider range, so that the film is expanded toward the downstream side.

[0062] Moreover, if Figure 6 As shown, a configuration can also be adopted in which multiple rows (for example, rows R1 and R2) of outlets E are formed from the upstream side to the downstream side, with the radial positions of the outlets E differing between adjacent rows. In this configuration, one discharge portion 53A, one discharge portion 53B is formed corresponding to each row R1, one discharge portion 53B corresponding to each row R2.

[0063] With this configuration, even if one of the outlets E or discharge sections 53A, 53B of a particular row is blocked, the film-forming material can be continuously supplied through the other outlets E (or the other of the discharge sections 53A, 53B) of the adjacent row. This allows for further stable operation of the steam turbine 100.

[0064] [Second embodiment]

[0065] Next, refer to Figure 7 and Figure 8 , the second embodiment of the present invention will be described. In addition, the same symbols are given to the same structures as the first embodiment, and detailed descriptions are omitted. Figure 7 and Figure 8As shown, in this embodiment, the material supply unit 5 further includes a plurality of inner peripheral surface discharge portions 54 extending radially inward from the above-mentioned supply flow path 52. The inner peripheral surface discharge portion 54 extends from the supply flow path 52 extending in an annular shape inside the steam turbine casing 2 toward the inner peripheral side, and the outlet E2 opens on the inner peripheral surface 24B of the ring. With respect to the inner peripheral surface discharge portion 54, at least one (at least one) inner peripheral surface discharge portion 54 is provided between mutually adjacent stator blades 20. Figure 7 In the example, there are two). As for the inner peripheral surface discharge portion 54, a plurality of them are arranged at intervals along the circumferential direction. Figure 8 In order to simplify the illustration, the fixed blades 20 are omitted.

[0066] According to the above configuration, the film-forming material can be supplied from the ring inner circumferential surface 24B to the wall surface of the stationary blade 20 via the inner circumferential surface discharge portion 54. Furthermore, by providing the inner circumferential surface discharge portion 54, the film-forming material can be supplied to both the pressure surface 21P and the suction surface 21Q of the stationary blade body 21.

[0067] The second embodiment of the present invention has been described above. In addition, various changes or modifications can be made to the above structure without departing from the main purpose of the present invention. For example, the discharge portion 53 described in the first embodiment and the inner peripheral surface discharge portion 54 described in the second embodiment can also be used in combination.

[0068] [Third embodiment]

[0069] Next, refer to Figure 9 , the third embodiment of the present invention is described. In addition, the same symbols are given to the same structures as the above embodiments, and detailed descriptions are omitted. Figure 9 As shown, in this embodiment, the structure of the discharge portion 53B differs from that of the aforementioned embodiments. The discharge portion 53B is in the form of a block formed integrally from a porous material M. Furthermore, the porous material M is embedded so as to be flush with the surface (pressure surface 21P) of the stator blade body 21. The porous material M is preferably a porous body of ceramic or metal formed using a layered molding technique (additive manufacturing, 3D printing) or the like.

[0070] According to the above configuration, the film-forming substance can be discharged in an oozing manner from the discharge portion 53B formed of the porous material M. This allows a smaller amount of the film-forming substance to be uniformly supplied to a wider area.

[0071] The third embodiment of the present invention has been described above. Various changes or modifications may be made to the above structure without departing from the spirit of the present invention. For example, the porous material M of the discharge portion 53B described in the third embodiment may be applied to the inner circumferential surface discharge portion 54 described in the second embodiment.

[0072] Furthermore, as a modification common to all embodiments, a structure in which a film-forming substance is supplied to the rotor blades 30 in addition to the stationary blades 20 can be employed. This coating formed on the surfaces of the rotor blades 30 can further enhance the corrosion resistance of the rotor blades 30. In this case, a flow path can be formed within the shaft 3, and the film-forming substance can be supplied through this flow path to the surfaces of the rotor blades 30. Since the supply mechanism for the stationary blades 20 and the film-forming substance can be shared, the anti-touch performance of the rotor blades 30 can be enhanced with a minimal configuration.

[0073] [Note]

[0074] The steam turbine 100 and the method of improving the performance of the steam turbine 100 described in each embodiment can be understood as follows, for example.

[0075] (1) A steam turbine 100 according to a first embodiment includes: a shaft 3 that rotates about a rotation axis O; a plurality of rotor blades 30 that extend radially from an outer peripheral surface of the shaft 3 and are arranged circumferentially; a casing body (casing body 2H) that covers the shaft 3 and the rotor blades 30 from an outer peripheral side; a plurality of stationary blades 20 that extend radially from an inner peripheral surface of the casing body at a position upstream of the rotor blades 30 and are arranged circumferentially; and a material supply unit 5 that supplies a film-forming material that is hydrophobic to water droplets adhering to the surface of at least one of the rotor blades 30 and the stationary blades 20, the material supply unit 5 including: a storage unit 51 that stores the film-forming material; a supply flow path 52 formed inside the casing body and through which the film-forming material guided from the storage unit 51 flows; and a discharge unit 53 formed inside at least one of the rotor blades 30 and the stationary blades 20 and guides the film-forming material to the surface.

[0076] According to the above configuration, film-forming substance (FFS) is directly supplied to the surface of the stator blade body 21 via the discharge portion 53. This forms a hydrophobic film on the surface, reducing the likelihood of condensed water droplets adhering to the stator blade wall. This suppresses the generation of coarse water droplets caused by the water film on the stator blade wall being released from the trailing edge of the stator blade into the steam, thereby preventing corrosion caused by coarse water droplets colliding with the downstream rotor blades 30. Furthermore, this reduces acceleration losses, which are energy lost to accelerating the coarse water droplets, and impulse losses, which are caused by the coarse water droplets braking the rotor blades 30, thereby improving turbine efficiency. Furthermore, the film-forming substance has a turbulent friction-reducing effect (Thomas effect), thereby improving the flow field of the fluid on the surface of the stator blade body 21 and reducing blade-shaped losses, thereby further improving turbine efficiency. Furthermore, since the film-forming substance forms a film on the metal surface, it also provides a corrosion-resistant effect.

[0077] (2) In the steam turbine 100 according to the second embodiment, a plurality of outlets E of the discharge portion 53 are arranged at intervals in the radial direction on the leading edge 21F side of the pressure surface 21P of at least one of the rotor blade 30 and the stator blade 20 .

[0078] According to the above configuration, the film forming material can be stably supplied to a wider range of the pressure surface 21P.

[0079] (3) In the steam turbine 100 according to the third embodiment, a plurality of outlets E of the discharge portion 53 are arranged at intervals in the radial direction on the leading edge 21F side of the suction surface 21Q of at least one of the rotor blade 30 and the stator blade 20 .

[0080] According to the above configuration, the film-forming material can be stably supplied to a wider range of the negative pressure surface 21Q.

[0081] (4) In the steam turbine 100 according to the fourth embodiment, the outlet E' of the discharge portion 53 is formed so that its radial dimension increases from the upstream side toward the downstream side when viewed in the circumferential direction.

[0082] According to the above configuration, the film-forming material can be supplied to a wide range so that the film can be expanded toward the downstream side.

[0083] (5) In the steam turbine 100 according to the fifth embodiment, the outlets E of the discharge portion 53 are arranged in a plurality of rows from the upstream side to the downstream side, and the radial positions of the outlets E are different between adjacent rows.

[0084] According to the above configuration, even when the outlets E of a specific row are blocked, the film-forming material can be continuously supplied through the other outlets E of the adjacent row.

[0085] (6) In the steam turbine 100 involved in the sixth embodiment, the material supply portion 5 further includes a plurality of inner peripheral surface discharge portions 54, which extend from the supply flow path 52 toward a portion of the inner peripheral surface of the machine room body corresponding to the leading edge 21F of at least one of the rotating blades 30 and the fixed blades 20, and are arranged at intervals along the circumferential direction.

[0086] According to the above configuration, the film-forming material can be supplied from the inner circumferential surface of the casing body to the leading edge 21F side of at least one of the rotor blade 30 and the stationary blade 20 via the inner circumferential surface discharge portion 54. Furthermore, by providing only the inner circumferential surface discharge portion 54, the film-forming material can be uniformly supplied to both the pressure surface 21P and the suction surface 21Q of the stationary blade body 21.

[0087] (7) In the steam turbine 100 according to the seventh aspect, the discharge portion 53B is integrally formed of the porous material M.

[0088] According to the above configuration, the film-forming substance can be discharged in an oozing manner from the discharge portion 53B formed of the porous material M. This allows a smaller amount of the film-forming substance to be uniformly supplied to a wider area.

[0089] (8) In the blade 90 according to the eighth aspect, the discharge portion 53 is formed. The discharge portion 53 communicates from the inside to the surface, thereby guiding the film-forming material having hydrophobic properties with respect to water droplets adhering to the surface to the surface.

[0090] According to the above configuration, film-forming substance (FFS) is directly supplied to the surface of the stator blade body 21 via the discharge portion 53. This forms a hydrophobic film on the surface, reducing the likelihood of condensed water droplets adhering to the stator blade wall. This suppresses the generation of coarse water droplets caused by the water film on the stator blade wall being released from the trailing edge of the stator blade into the steam, thereby preventing corrosion caused by coarse water droplets colliding with the downstream rotor blades 30. Furthermore, this reduces acceleration losses, which are energy lost to accelerating the coarse water droplets, and impulse losses, which are caused by the coarse water droplets braking the rotor blades 30, thereby improving turbine efficiency. Furthermore, the film-forming substance has a turbulent friction-reducing effect (Thomas effect), thereby improving the flow field of the fluid on the surface of the stator blade body 21 and reducing blade-shaped losses, thereby further improving turbine efficiency. Furthermore, since the film-forming substance forms a film on the metal surface, it also provides a corrosion-resistant effect.

[0091] (9) In the blade 90 according to the ninth aspect, a plurality of blades 90 are arranged at intervals in the radial direction on the leading edge side of the pressure surface of the blade 90 at the outlet of the discharge portion.

[0092] According to the above configuration, the film forming material can be stably supplied to a wider range of the pressure surface 21P.

[0093] (10) In the blade 90 according to the tenth aspect, a plurality of blades are arranged at intervals in the radial direction on the leading edge side of the suction surface of the blade 90 at the outlet of the discharge portion.

[0094] According to the above configuration, the film-forming material can be stably supplied to a wider range of the negative pressure surface 21Q.

[0095] (11) In the blade 90 according to the eleventh aspect, the outlet of the discharge portion is formed so that the radial dimension thereof increases from the upstream side toward the downstream side when viewed from the circumferential direction.

[0096] According to the above configuration, the film-forming material can be supplied to a wide range so that the film can be expanded toward the downstream side.

[0097] (12) In the blade 90 according to the twelfth aspect, the outlet of the discharge portion is arranged in a plurality of rows from the upstream side to the downstream side, and the radial positions of the outlets are different between adjacent rows.

[0098] According to the above configuration, even when the outlets E of a specific row are blocked, the film-forming material can be continuously supplied through the other outlets E of the adjacent row.

[0099] (13) In the blade 90 according to the thirteenth aspect, the discharge portion is integrally formed of a porous material.

[0100] According to the above configuration, the film-forming substance can be discharged in an oozing manner from the discharge portion 53B formed of the porous material M. This allows a smaller amount of the film-forming substance to be uniformly supplied to a wider area.

[0101] (14) The method for improving the performance and reliability of the steam turbine 100 according to the fourteenth embodiment includes the following steps: supplying a film-forming substance having hydrophobic properties to the surface of at least one of the rotating blades 30 and the stationary blades 20 of the steam turbine 100. The substance has hydrophobic properties to water droplets adhering to the surface.

[0102] According to the above method, a film-forming substance (FFS) is directly supplied to the surface of at least one of the rotor blades 30 and the stationary blades 20 via a discharge unit. This forms a hydrophobic film on the surface, reducing the likelihood of condensed water droplets adhering. This suppresses the formation of coarse water droplets due to the growth of fine water droplets, thus preventing corrosion caused by coarse water droplets colliding with the downstream rotor blades 30. Furthermore, the film-forming substance has a turbulent friction-reducing effect (Thomas effect), thereby improving the flow field of the fluid on the surface of at least one of the rotor blades 30 and the stationary blades 20. Furthermore, since the film-forming substance forms a film on the metal surface, it also provides an anti-corrosion effect.

[0103] Industrial applicability

[0104] According to the present invention, a steam turbine having further improved performance and reliability, a blade, and a method for improving the performance and reliability of a steam turbine can be provided.

[0105] Explanation of symbols

[0106] 100-steam turbine, 1-steam turbine rotor, 2-steam turbine casing, 2H-casing body, 3-shaft, 5-material supply unit, 20-stationary blade, 21-stationary blade body, 21F-leading edge, 21P-pressure surface, 21Q-negative pressure surface, 21R-trailing edge, 22-stationary blade shroud, 24-outer ring, 24A-ring upstream surface, 24B-ring inner surface, 24C-ring downstream surface, 30- Rotating blade, 31-rotating blade body, 32-platform, 34-rotating blade shroud, 34A-upstream surface of the shroud, 34B-inner circumferential surface of the shroud, 34C-downstream surface of the shroud, 51-storage portion, 52-supply flow path, 53, 53A, 53B-discharge portion, 54-inner circumferential surface discharge portion, 90-blade, E, E′, E2-outlet, O-rotation axis, L1, L2-end edges, R1, R2-rows.

Claims

1. A steam turbine comprising: Axis, rotation around the axis of rotation; a plurality of rotating blades extending radially from an outer peripheral surface of the shaft and arranged circumferentially; a machine room body covering the shaft and the rotor blades from the outer peripheral side; a plurality of stationary blades extending radially from a position upstream of the rotating blades on the inner peripheral surface of the casing body and arranged circumferentially; and The material supplying section supplies a film-forming material having hydrophobic properties to water droplets adhering to the surface of at least one of the rotating blade and the stationary blade, The material supply unit includes: a storage portion for storing the film-forming substance; a supply flow path formed inside the casing body of the steam turbine and allowing the film-forming material guided from the storage portion to flow into at least one of the rotor blade and the stationary blade; and A discharge portion is formed inside at least one of the rotating blade and the stationary blade, and guides the film-forming substance to the surface.

2. The steam turbine according to claim 1, wherein: A plurality of outlets of the discharge portion are arranged at intervals in the radial direction on the leading edge side of the pressure surface of at least one of the rotor blade and the stationary blade.

3. The steam turbine according to claim 1 or 2, wherein: A plurality of outlets of the discharge portion are arranged at intervals in the radial direction on the leading edge side of the suction surface of at least one of the rotor blade and the stationary blade.

4. The steam turbine according to claim 1 or 2, wherein: The outlet of the discharge portion is formed so that its radial dimension increases from the upstream side toward the downstream side when viewed in the circumferential direction.

5. The steam turbine according to claim 1 or 2, wherein: The outlets of the discharge portion are arranged in a plurality of rows from the upstream side to the downstream side, and the radial positions of the outlets are different between adjacent rows.

6. The steam turbine according to claim 1 or 2, wherein: The material supply portion further includes a plurality of inner circumferential surface discharge portions extending from the supply flow path toward a portion of the inner circumferential surface of the casing body corresponding to a leading edge of at least one of the rotating blades and the stationary blades, and arranged at intervals in the circumferential direction.

7. The steam turbine according to claim 1, wherein: The discharge portion is integrally formed of a porous material.

8. A blade, which is a blade of a steam turbine, wherein: A discharge portion is formed that communicates from the interior of the blade to the surface of the blade, thereby guiding a film-forming substance having hydrophobicity with respect to water droplets adhering to the surface to the surface.

9. The blade according to claim 8, wherein: A plurality of outlets of the discharge portion are arranged at intervals in the radial direction on the leading edge side of the pressure surface of the blade.

10. The blade according to claim 8 or 9, wherein: A plurality of outlets of the discharge portion are arranged at intervals in the radial direction on the leading edge side of the suction surface of the blade.

11. The blade according to claim 8 or 9, wherein: The outlet of the discharge portion is formed so that its radial dimension increases from the upstream side toward the downstream side when viewed in the circumferential direction.

12. The blade according to claim 8 or 9, wherein: The outlets of the discharge portion are arranged in a plurality of rows from the upstream side to the downstream side, and the radial positions of the outlets are different between adjacent rows.

13. The blade according to claim 8, wherein The discharge portion is integrally formed of a porous material.

14. A method for improving the performance and reliability of a steam turbine, comprising the steps of: supplying a film-forming substance having hydrophobic properties against water droplets adhering to a surface of at least one of a rotating blade and a stationary blade of a steam turbine via a substance supply unit; The material supply unit includes: a storage portion for storing the film-forming substance; a supply flow path formed inside a casing body of the steam turbine and configured to allow the film-forming material guided from the storage portion to flow into at least one of the rotor blade and the stationary blade; and A discharge portion is formed inside at least one of the rotating blade and the stationary blade, and guides the film-forming substance to the surface.

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