JP6550004B2 - Steam turbine - Google Patents

Description

  Embodiments of the present invention relate to a steam turbine.

  Generally, in steam turbines used in thermal power plants and the like, types such as high pressure turbines, medium pressure turbines and low pressure turbines exist according to the difference in pressure of steam as a working fluid. The intermediate pressure turbine may be integrally formed with the high pressure turbine to constitute a turbine assembly. The structure around the steam inlet passage of the intermediate pressure turbine in this case is shown in FIG.

  As shown in FIG. 13, the intermediate pressure turbine 100 has a casing 102 and a turbine rotor 103 rotatably provided in the casing 102. A stationary member 105 forming a ground space 104 with the turbine rotor 103 is supported in the casing 102, and a contact surface 107 of the stationary member 105 is in contact with the contact surface 106 of the casing 102. It is fitting. Further, the stationary member 105 has a key-shaped stationary member key-shaped portion 108 provided on the downstream side thereof, and is adapted to lock a stationary vane inner ring key portion 114 described later.

  Further, the stator outer ring 109 is supported by the casing 102, and the contact surface 111 of the stator outer ring 109 is in contact with and fitted to the abutted surface 110 of the casing 102. The stationary blade inner ring 113 is supported on the stationary blade outer ring 109 via the stationary blade 112. The vane inner ring 113 has a key-shaped vane inner ring key portion 114 provided on the downstream side thereof, and is locked to the stationary member key portion 108 described above. Then, the abutting surface 116 of the stationary blade inner ring key portion 114 is in contact with and fitted to the abutted surface 115 of the stationary member key shaped portion 108. In this manner, the stationary vane inner ring 113 is supported by the casing 102 via the stationary vane 112 and the stationary vane outer ring 109, and is also supported by the casing 102 via the stationary member 105.

  By the way, in the ground space 104 formed between the stationary member 105 and the turbine rotor 103 and between the stationary blade inner ring 113 and the turbine rotor 103, high-pressure main steam from the high-pressure turbine not shown in FIG. It flows in as cooling steam CS. The above-described structure in which the abutting surface 116 of the stationary blade inner ring 113 abuts on the abutted surface 115 of the stationary member 105 has a steam inlet whose cooling steam CS flowing into the ground space 104 has a lower pressure than the ground space 104. This is to suppress the flow into the passage 101. That is, when the abutment surface 116 of the stationary blade inner ring 113 abuts on the abutted surface 115 of the stationary member 105, the space between the abutted surface 115 of the stationary member 105 and the abutment surface 116 of the stationary blade inner ring 113 A gap is prevented from being formed to suppress the cooling vapor CS in the ground space 104 from leaking to the steam inlet passage 101.

  Further, with the increase in temperature of the reheat steam RS flowing into the steam inlet passage 101 of the intermediate pressure turbine 100, the temperatures of the stator outer ring 109, the stator blades 112 and the stator inner ring 113 may increase. Furthermore, with the increase in pressure of the reheat steam RS, the differential pressure between the upstream side and the downstream side of the stationary blade outer ring 109, the stationary blade 112, and the stationary blade inner ring 113 increases. For this reason, the amount of strain of the stator outer ring 109, the stator vane 112 and the inner ring 113 tends to increase over time, and the amount of creep deformation of the inner ring 113 can increase. On the other hand, the stationary blade inner ring 113 is supported by the stationary member 105 by bringing the abutting surface 116 of the stationary vane inner ring 113 into contact with the abutted surface 115 of the stationary member 105 as described above. It is possible to suppress an increase in the amount of creep deformation of the wing inner ring 113.

  When assembling the stationary member 105 and the stationary blade inner ring 113, the stationary member 105 is first attached to the casing 102, and the abutment surface 107 of the stationary member 105 is abutted against the abutted surface 106 of the casing 102 to fit. Match. Next, the vane 112 and the vane inner ring 113 are attached to the vane outer ring 109. Thereafter, the vane outer ring 109 to which the vane 112 and the vane inner ring 113 are attached is attached to the casing 102. At this time, the abutment surface 111 of the stator vane outer ring 109 abuts and fits on the abutted surface 110 of the casing 102. At the same time, the stationary vane inner ring key portion 114 is locked to the stationary member key portion 108. That is, the abutment surface 116 of the stationary blade inner ring key portion 114 abuts and fits on the abutted surface 115 of the stationary member key-shaped portion 108, and the stationary vane inner ring 113 is supported by the stationary member 105. Thus, the stationary member 105 and the vane inner ring 113 are assembled.

JP-A-8-246805 JP 2012-62828 A

  However, the dimensional deviation between the two abutted surfaces 106 and 110 of the casing 102, the dimensional deviation between the abutment surface 107 of the stationary member 105 and the abutted surface 115, and As the dimensional deviation between the abutment surface 111 and the abutment surface 116 of the vane inner ring 113 increases, assembly may become difficult. That is, when the dimensional deviation occurs, the stationary vane inner ring key portion 114 may interfere with the stationary member key portion 108 and the stationary vane inner ring key portion 114 can not be locked to the stationary member key portion 108. Alternatively, a gap may be formed between the abutting surface 116 of the stationary blade inner ring key portion 114 and the abutted surface 115 of the stationary member key portion 108. When this gap is formed, there arises a problem that the cooling vapor CS in the ground space 104 flows into the steam inlet passage 101 through the gap.

  Therefore, when the stationary vane inner ring key portion 114 interferes with the stationary member key portion 108 or between the abutment surface 116 of the stationary vane inner ring key portion 114 and the abutted surface 115 of the stationary member key portion 108 In the case where a gap is formed, adjustment processing of the contact surfaces 111 and 116 and the contact surfaces 110 and 115 is performed. In this case, there is a possibility that the assembling period will be prolonged.

  The present invention has been made in consideration of such points, and prevents creeping of the inner ring of the vane while preventing the prolongation of the assembling period and suppressing the flow of steam from the ground space into the steam inlet passage. An object of the present invention is to provide a steam turbine capable of suppressing deformation.

  A steam turbine according to an embodiment includes a casing and a turbine rotor rotatably provided in the casing. The steam turbine includes a stationary member supported by the casing and defining a portion of the steam inlet passage and defining a ground space with the turbine rotor. Further, the steam turbine is supported by the casing via a first stage vane provided downstream of the steam inlet passage, and a clearance connecting the steam inlet passage and the ground space is interposed between the steam turbine and the stationary member. It has a stationary wing inner ring. Furthermore, the steam turbine includes a seal member provided in the gap. The stationary member has a stationary body portion and a stationary extension portion provided downstream of the stationary body portion and extending in a direction orthogonal to the axial direction of the turbine rotor. The stationary blade inner ring has an inner ring main body portion and an inner ring extension portion provided upstream of the inner ring main body portion and extending in a direction orthogonal to the axial direction of the turbine rotor. The stationary extension includes a stationary facing surface provided on the upstream side, and the inner ring extension includes an inner facing surface provided on the downstream side of the stationary facing surface via a gap.

  According to the present invention, it is possible to prevent the creeping deformation of the inner ring of the stationary blade while suppressing the inflow of steam from the grand space to the steam inlet passage while avoiding the prolongation of the assembling period.

FIG. 1 is a cross-sectional view showing an example of the structure of a turbine assembly according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of the stationary member and the vane inner ring of FIG. FIG. 3 is an enlarged cross-sectional view of the stationary extension and the inner ring extension of FIG. 2; FIG. 4 is an enlarged cross-sectional view of a stationary extension and an inner ring extension in the second embodiment. FIG. 5 is a cross-sectional view showing, in an enlarged manner, the stationary extension and the inner ring extension in the third embodiment. FIG. 6 is a cross-sectional view showing, in an enlarged manner, the stationary extension and the inner ring extension in the fourth embodiment. FIG. 7 is an enlarged sectional view showing a stationary extension and an inner ring extension in the fifth embodiment. FIG. 8 is a cross-sectional view showing a modification of FIG. FIG. 9 is a cross-sectional view showing a modification of FIG. FIG. 10 is a cross-sectional view showing, in an enlarged manner, the stationary extension and the inner ring extension in the sixth embodiment. FIG. 11 is a cross-sectional view showing a modification of FIG. FIG. 12 is a cross-sectional view showing a modification of FIG. FIG. 13 is an enlarged sectional view showing a stationary member and a stator inner ring in a general turbine assembly.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A steam turbine according to an embodiment of the present invention will be described using FIGS. 1 to 3. Here, first, a turbine assembly to which the intermediate pressure turbine as a steam turbine according to the present embodiment can be applied will be described.

  As shown in FIG. 1, the turbine assembly 1 includes a high pressure turbine 10 for extracting expansion work of main steam MS supplied from a boiler (not shown), and an intermediate pressure for extracting expansion work of reheated steam RS supplied from the boiler. And a turbine 30. The turbine assembly 1 further includes a cabin 2 and a turbine rotor 3 rotatably provided relative to the cabin 2. In the present embodiment, the casing of the high pressure turbine 10 and the casing of the intermediate pressure turbine 30 are integrally formed to constitute the casing 2 described above. The cabin 2 has an inner cabin 2a and an outer cabin 2b provided outside the inner cabin 2a, and has a double-structured cabin. Further, in the present embodiment, the turbine rotor of the high pressure turbine 10 and the turbine rotor of the intermediate pressure turbine 30 are integrally formed to constitute the above-described turbine rotor 3. A generator (not shown) is connected to the turbine rotor 3.

  The high pressure steam inlet pipe 11 and the medium pressure steam inlet pipe 31 are connected to the outer casing 2b. Main steam MS from a boiler (not shown) is supplied to the high pressure turbine 10 via the high pressure steam inlet pipe 11, and reheated steam RS from the boiler is supplied to the intermediate pressure turbine 30 via the intermediate pressure steam inlet pipe 31. It is supposed to be

  The main steam MS supplied to the high pressure turbine 10 is guided to the most upstream turbine stage 13 of the plurality of turbine stages 13 by, for example, the inlet sleeve 12 a and the nozzle box 12 b provided in the casing 2. It is supposed to be. The turbine stage 13 includes a stationary blade 14 and a moving blade 15. The main steam MS passing through each of the turbine stages 13 performs expansion work on the moving blade 15, and the turbine rotor 3 is rotationally driven. The main steam MS that has performed expansion work on the moving blades 15 is discharged from the exhaust flow path 16 and supplied to the boiler to be reheated steam RS.

  Further, part of the main steam MS is supplied to the ground space 4 (described later), and performs cooling of the intermediate pressure turbine 30 as the cooling steam CS.

  The reheated steam RS supplied to the intermediate pressure turbine 30 is guided by the steam inlet passage 32 provided in the casing 2 to the most upstream turbine stage 33 of the plurality of turbine stages 33. There is. The turbine stage 33 includes the stationary blades 50 and the moving blades 34, and the reheated steam RS passing through each of the turbine stages 33 performs expansion work on the moving blades 34, and the turbine rotor 3 is rotationally driven. . The reheated steam RS that has performed expansion work on the moving blades 34 is discharged from the exhaust flow path 35 and supplied to a low pressure turbine (not shown). The moving blades 34 are implanted and fixed to a rotor disk 3 a provided on the turbine rotor 3.

  Next, the intermediate pressure turbine 30 according to the present embodiment will be described in more detail. As shown in FIGS. 2 and 3, the intermediate pressure turbine 30 includes a stationary member 40 supported by the inner casing 2 a and a stationary blade inner ring 51 supported by the inner casing 2 a. Among them, the stationary member 40 defines a part of the steam inlet passage 32 and also defines a ground space 4 with the turbine rotor 3. The vane inner ring 51 is supported by the inner casing 2a via a vane (first stage vane, hereinafter simply referred to as vane) 50 of the most upstream turbine stage 33 provided downstream of the steam inlet passage 32. ing. Here, the terms upstream and downstream are upstream with respect to the main flow direction of reheat steam RS in the intermediate pressure turbine 30 (in FIG. 2, the direction along the axial direction of the turbine rotor 3 from left to right). It is used to mean the side and the downstream side respectively.

  The stationary member 40 has a stationary body portion 41 and a stationary extension portion 42 provided downstream of the stationary body portion 41 and extending in a direction (radial direction) orthogonal to the axial direction of the turbine rotor 3. Among them, the stationary main body portion 41 includes a stationary abutment surface 43 which abuts on the first abutted surface 5 of the inner casing 2a. As shown in FIG. 2, the stationary abutment surface 43 extends in the radial direction and faces the downstream side. Thus, the movement of the stationary main body 41 to the downstream side is prevented.

  The stationary extension 42 is connected to the stationary body 41 by means of a stationary connection 45 extending in the axial direction of the turbine rotor 3. The stationary extension 42 includes a first stationary facing surface 46a provided upstream thereof. The first stationary facing surface 46 a extends in the radial direction and faces the upstream side, and faces the first inner ring facing surface 59 a of the stationary blade inner ring 51 described later. Further, the stationary extension portion 42 extends from the stationary main body portion 41 (more specifically, the stationary coupling portion 45) toward the inner peripheral side, and will be described later between the stationary main body portion 41 and the stationary extension portion 42. An inner ring receiving space 47 in which the inner ring extension 56 is received is defined. The inner ring accommodation space 47 opens to the inner circumferential side, and an inner ring extension portion 57 described later can be inserted from the inner circumferential side. The stationary extension portion 42 and the stationary connection portion 45 are formed in a key shape (or an L shape) as a whole.

  The vane inner ring 51 is supported by the inner casing 2 a via the vane 50 and the vane outer ring 52. Among them, the stationary blade 50 is provided between the stationary blade inner ring 51 and the stationary blade outer ring 52. In this manner, a vane assembly 53 including the vane 50, the vane inner ring 51 and the vane outer ring 52 is formed. The vane outer ring 52 includes an outer ring abutment surface 54 that abuts on the second abutted surface 6 of the inner casing 2a. As shown in FIG. 2, the outer ring abutment surface 54 extends in the radial direction and faces the downstream side. Thus, movement of the vane outer ring 52 to the downstream side is prevented.

  The vane inner race 51 includes an inner race main body 55 and an inner race extension 56 provided on the upstream side of the inner race main body 55 and extending in a direction orthogonal to the axial direction of the turbine rotor 3. The nozzle packing 57 is provided on the inner peripheral side of the inner ring main body 55 among them.

  The inner ring extension 56 is connected to the inner ring main body 55 by an inner ring connecting portion 58 extending in the axial direction of the turbine rotor 3. The inner ring extension 56 includes a first inner ring facing surface 59a provided downstream thereof. The first inner ring facing surface 59a extends in the radial direction, faces the downstream side, and faces the first stationary facing surface 46a of the stationary member 40 described above. Further, the inner ring extension 56 extends from the inner ring main body 55 (more specifically, the inner ring connecting portion 58) toward the outer peripheral side, and between the inner ring main portion 55 and the inner ring extension 56, the above-mentioned stationary state A stationary member accommodation space 60 is defined in which the extension 42 is accommodated. The stationary member accommodation space 60 is open to the outer peripheral side, and the stationary extension portion 42 can be inserted from the outer peripheral side. That is, when the stationary vane inner ring 51 is brought close to the stationary member 40 from the inner peripheral side, the stationary extension portion 42 is accommodated in the stationary member accommodation space 60 which is approached from the inner peripheral side. The inner ring extension 56 and the inner ring connecting portion 58 are formed in a key shape (or L shape) as a whole.

  As shown in FIG. 3, a clearance 38 is interposed between the first stationary facing surface 46 a of the stationary member 40 described above and the first inner ring facing surface 59 a of the stationary blade inner ring 51. The gap 38 communicates the steam inlet passage 32 with the ground space 4. That is, the gap 38 extends from the steam inlet passage 32 to the ground space 4 between the stationary member 40 and the vane inner ring 51. More specifically, the gap 38 is a portion between the stationary main body 41 and the inner ring extension 56, a portion between the stationary connecting portion 45 and the inner ring extension 56, a stationary extension 42 and the inner ring extension 56 And a portion between the stationary extension 42 and the inner ring connecting portion 58, and a portion between the stationary extension 42 and the inner ring body 55.

  The seal member 70 is provided in the gap 38. The seal member 70 according to the present embodiment has a seal fin 71. The seal fin 71 is disposed in a portion of the gap 38 between the stationary extension portion 42 and the inner ring connecting portion 58, and is attached to the stationary extension portion 42 of the stationary member 40. More specifically, the seal fin 71 is attached to the inner circumferential side of the stationary extension 42. The sealing member may not be a sealing fin as long as it has a desired sealing function.

  Next, the operation of the present embodiment having such a configuration will be described. Here, a method of assembling the stationary member 40 and the vane inner ring 51 will be described.

  First, the stationary member 40 is attached to the inner casing 2a. At this time, the stationary abutment surface 43 of the stationary member 40 abuts and fits on the first abutted surface 5 of the inner casing 2a. Subsequently, the stationary member 40 is fixed to the inner casing 2a by a bolt or the like (not shown).

  Next, the vane inner ring 51 is attached to the inner casing 2a. In this case, first, the vane 50 and the vane inner ring 51 are attached to the vane outer ring 52, and the vane assembly 53 including the vane outer ring 52, the vane 50 and the vane inner ring 51 is obtained. Thereafter, the vane assembly 53 is attached to the inner casing 2a. At this time, the outer ring contact surface 54 of the vane outer ring 52 is in contact with and fitted to the second contact surface 6 of the inner casing 2 a. Subsequently, the vane outer ring 52 of the vane assembly 53 is fixed to the inner casing 2a by a bolt or the like (not shown).

  When the stationary blade assembly 53 is attached to the inner casing 2 a, the inner ring extending from the inner ring main body 55 toward the outer peripheral side to the inner ring accommodating space 47 formed between the stationary main body 41 and the stationary extension 42 The extension portion 56 is inserted from the inner peripheral side, and the inner ring extension portion 56 is accommodated in the inner ring accommodation space 47.

  Further, since the gap 38 is interposed between the first inner ring facing surface 59 a and the first stationary facing surface 46 a, the inner ring extension portion 56 is easily accommodated in the inner ring accommodation space 47. In particular, the dimensional deviation between the abutted surfaces 5 and 6 of the inner casing 2a, the dimensional deviation between the stationary abutment surface 43 of the stationary member 40 and the first stationary opposing surface 46a, and the vane inner ring 51 The inner ring extension portion 56 of the inner race 51 of the stationary blade is a stationary member of the stationary member 40 even when there is a dimensional deviation between the first inner ring facing surface 59a of the first embodiment and the outer ring abutment surface 54 of the stationary blade outer ring 52. Interference with the extension portion 42 can be suppressed. Therefore, it is possible to eliminate the need for the adjustment processing which has been performed in the case of interference, and it is possible to suppress the extension of the assembling period.

  Thus, the stationary member 40 and the vane inner ring 51 are attached to the inner casing 2a, and the intermediate pressure turbine 30 having the steam inlet passage 32 is obtained.

  By the way, the pressure of the cooling steam CS supplied to the ground space 4 is higher than the reheat steam RS supplied to the steam inlet passage 32 of the intermediate pressure turbine 30. As a result, part of the cooling steam CS tends to flow into the steam inlet passage 32 through the gap 38 between the stationary member 40 and the vane inner ring 51. However, as described above, since the seal fin 71 is provided in the gap 38, the cooling steam CS can be suppressed from flowing into the steam inlet passage 32 from the ground space 4 through the gap 38.

  Further, during operation of the intermediate pressure turbine 30, the temperature of the stator outer ring 52, the stator blade 50 and the stator inner ring 51 is increased by the reheated steam RS flowing into the steam inlet passage 32. Furthermore, with the high pressure of the reheated steam RS, the differential pressure between the upstream side and the downstream side of the vane outer ring 52, the vane 50 and the vane inner ring 51 increases. For this reason, the vane inner ring 51 may be creep-deformed downstream. In this case, since the gap 38 is formed between the first inner ring opposing surface 59a of the inner race 51 and the first stationary opposite surface 46a of the stationary member 40, creep deformation of the inner ring 51 is initially performed. As a result, the vane inner ring 51 is displaced downstream. Thereafter, the first inner ring facing surface 59a abuts on the first stationary facing surface 46a, and the stationary blade inner ring 51 is locked to the stationary member 40, and creep deformation of the inner surface 51 of the vane to the downstream side can be prevented.

  As described above, according to the present embodiment, the clearance 38 is interposed between the first inner race facing surface 59 a of the stationary blade inner race 51 and the first stationary facing surface 46 a of the stationary member 40. As a result, when the stationary member 40 and the stationary vane inner ring 51 are assembled, the stationary vane inner ring 51 can be prevented from interfering with the stationary member 40. Therefore, it is possible to eliminate the need for the adjustment processing which has been performed in the case of interference, and it is possible to suppress the extension of the assembling period.

  Further, according to the present embodiment, the seal fin 71 is provided in the gap 38 between the stationary blade inner ring 51 and the stationary member 40. This can suppress the inflow of the cooling steam CS from the ground space 4 to the steam inlet passage 32 passing through the gap 38.

  Further, according to the present embodiment, the first inner ring facing surface 59 a of the stationary blade inner ring 51 is opposed to the first stationary facing surface 46 a of the stationary member 40 via the gap 38. As a result, even when the vane inner ring 51 creep-deforms to the downstream side, the first inner ring opposing surface 59a of the vane inner ring 51 abuts on the first stationary opposing surface 46a of the stationary member 40, and the vane inner ring 51 deformation can be prevented. For this reason, it is possible to suppress an increase in the amount of creep deformation of the vane inner ring 51.

  Further, according to the present embodiment, the stationary extension portion 42 extends from the stationary main body portion 41 toward the inner peripheral side, and the inner ring extension portion 56 extends from the inner ring main body portion 55 toward the outer peripheral side. Therefore, when assembling the stationary member 40 and the vane inner ring 51, the stationary member 40 can be attached to the inner casing 2a first, and then the vane inner ring 51 can be attached to the inner casing 2a. That is, the stationary member 40 having a relatively large mass can be attached to the inner casing 2a first, and then the stationary vane assembly 53 of the stationary vane outer ring 52, the stationary vane 50 and the stationary vane inner ring 51 has a relatively small mass. Can be attached to the inner compartment 2a. Thus, the inner ring extension 56 of the inner ring 51 can be accommodated in the inner ring accommodation space 47 of the stationary member 40 while adjusting the position of the stator assembly 53 having a relatively small mass. For this reason, the assemblability of the stationary member 40 and the stationary blade inner ring 51 can be improved, and the assembling period can be shortened.

  In the above-described embodiment, an example in which the seal fin 71 is attached to the inner peripheral side of the stationary extension portion 42 has been described. However, the present invention is not limited to this, and the seal fin 71 may be attached to the outer peripheral side of the inner ring connecting portion 58. Also in this case, the cooling steam CS can be suppressed from flowing from the ground space 4 to the steam inlet passage 32 through the gap 38.

Second Embodiment
Next, a steam turbine according to a second embodiment of the present invention will be described with reference to FIG.

  The second embodiment shown in FIG. 4 is mainly different in that the seal fin is disposed in a portion of the gap between the inner ring extension and the stationary connecting portion, and the other configuration is the same as that in FIG. The third embodiment is substantially the same as the first embodiment shown in FIG. In FIG. 4, the same parts as those of the first embodiment shown in FIGS. 1 to 3 are indicated by the same reference numerals and the detailed description will be omitted.

  In the present embodiment, as shown in FIG. 4, the seal fin 71 is disposed in a portion of the gap 38 between the inner ring extension portion 56 and the stationary connection portion 45. More specifically, the seal fin 71 is attached to the inner peripheral side of the stationary connection portion 45.

  As described above, according to the present embodiment, the seal fin 71 is disposed in a portion of the gap 38 between the inner ring extension portion 56 and the stationary connection portion 45. This can suppress the inflow of the cooling steam CS from the ground space 4 to the steam inlet passage 32 passing through the gap 38. In addition, the seal fin 71 can be disposed at a deep position in the inner ring accommodation space 47, and the possibility of the seal fin 71 being damaged when assembling the stationary member 40 and the vane inner ring 51 can be reduced. It is possible to improve the quality.

  In the above-described embodiment, an example in which the seal fin 71 is attached to the inner peripheral side of the stationary connecting portion 45 has been described. However, the present invention is not limited to this, and the seal fin 71 may be attached to the outer peripheral side of the inner ring extension 56. Also in this case, the cooling steam CS can be suppressed from flowing from the ground space 4 to the steam inlet passage 32 through the gap 38.

Third Embodiment
Next, a steam turbine according to a third embodiment of the present invention will be described with reference to FIG.

  In the third embodiment shown in FIG. 5, the stationary extension portion extends from the stationary main body portion toward the outer peripheral side, and the inner ring extension portion extends from the inner ring main body portion toward the inner peripheral side. However, the other configuration is substantially the same as that of the first embodiment shown in FIGS. In FIG. 5, the same parts as those of the first embodiment shown in FIGS. 1 to 3 are designated by the same reference numerals and their detailed description will be omitted.

  In the present embodiment, as shown in FIG. 5, the stationary extension portion 42 extends outward from the stationary main body portion 41 (more specifically, the stationary connection portion 45). The inner ring accommodation space 47 defined between the stationary main body 41 and the stationary extension 42 is open to the outer peripheral side, and the inner ring extension 56 is insertable from the outer peripheral side. That is, when the stationary member 40 is brought closer to the stationary blade inner ring 51 from the inner peripheral side, the inner ring extension portion 56 is accommodated in the inner ring accommodation space 47 which approaches from the inner peripheral side. Also in the present embodiment, the stationary extension portion 42 and the stationary connecting portion 45 are formed in a key shape (or L shape) as a whole.

  Further, the inner ring extension portion 56 extends from the inner ring main body portion 55 (more specifically, the inner ring connecting portion 58) toward the inner peripheral side. The stationary member accommodation space 60 defined between the inner ring main body 55 and the inner ring extension 56 is open at the inner peripheral side, and the stationary extension 42 is insertable from the inner peripheral side. Also in the present embodiment, the inner ring extension portion 56 and the inner ring connecting portion 58 are formed in a key shape (or L shape) as a whole.

  In the present embodiment, the seal fin 71 is disposed in a portion of the gap 38 between the stationary extension portion 42 and the inner ring connecting portion 58, and is attached to the inner ring connecting portion 58 of the vane inner ring 51. . In more detail, the seal fin 71 is attached to the inner peripheral side of the inner ring connecting portion 58.

  When assembling the stationary member 40 and the vane inner ring 51 shown in FIG. 5, the vane inner ring 51 is first attached to the inner casing 2a. In this case, first, the vane 50 and the vane inner ring 51 are attached to the vane outer ring 52, and the vane assembly 53 including the vane outer ring 52, the vane 50 and the vane inner ring 51 is obtained. Thereafter, the vane assembly 53 is attached to the inner casing 2a. At this time, the outer ring contact surface 54 of the vane outer ring 52 is in contact with and fitted to the second contact surface 6 of the inner casing 2 a. Subsequently, the vane outer ring 52 of the vane assembly 53 is fixed to the inner casing 2a by a bolt or the like (not shown).

  Next, the stationary member 40 is attached to the inner casing 2a. At this time, the stationary abutment surface 43 of the stationary member 40 abuts and fits on the first abutted surface 5 of the inner casing 2a. Subsequently, the stationary member 40 is fixed to the inner casing 2a by a bolt or the like (not shown).

  When the stationary member 40 is attached to the inner casing 2a, the stationary extension extends from the stationary body portion 41 toward the outer peripheral side to the stationary member housing space 60 formed between the inner ring main body 55 and the inner ring extension 56 The portion 42 is inserted from the inner peripheral side, and the stationary extension portion 42 is accommodated in the stationary member accommodation space 60.

  Further, since the gap 38 is interposed between the first stationary opposing surface 46 a and the first inner wheel opposing surface 59 a, the stationary extension portion 42 is easily accommodated in the stationary member accommodation space 60. In particular, the dimensional deviation between the abutted surfaces 5 and 6 of the inner casing 2a, the dimensional deviation between the stationary abutment surface 43 of the stationary member 40 and the first stationary opposing surface 46a, and the vane inner ring 51 The stationary extension portion 42 of the stationary member 40 is the inner ring of the stator inner ring 51 even when the dimensional deviation between the first inner ring facing surface 59 a and the outer ring abutment surface 54 of the stator outer ring 52 occurs. Interference with the extension 56 can be suppressed. Therefore, it is possible to eliminate the need for the adjustment processing which has been performed in the case of interference, and it is possible to suppress the extension of the assembling period.

  Thus, the stator inner ring 51 and the stationary member 40 are attached to the inner casing 2a, and the intermediate pressure turbine 30 having the steam inlet passage 32 is obtained.

  As described above, according to the present embodiment, the inner ring extension portion 56 extends from the inner ring main body portion 55 toward the inner peripheral side, and the stationary extension portion 42 extends from the stationary main body portion 41 toward the outer peripheral side. Therefore, when assembling the stationary vane inner ring 51 and the stationary member 40, the stationary vane inner ring 51 can be attached to the inner casing 2a first, and then the stationary member 40 can be attached to the inner casing 2a.

  Further, according to the present embodiment, the seal fin 71 is disposed in a portion of the gap 38 between the stationary extension portion 42 and the inner ring connecting portion 58. This can suppress the inflow of the cooling steam CS from the ground space 4 to the steam inlet passage 32 passing through the gap 38. Further, the seal fin 71 can be disposed at a deep position in the stationary member accommodation space 60, and the possibility of the seal fin 71 being damaged when assembling the stationary member 40 and the vane inner ring 51 can be reduced. Reliability can be improved.

  In the above-described embodiment, an example in which the seal fin 71 is attached to the inner peripheral side of the inner ring connecting portion 58 has been described. However, the present invention is not limited to this, and the seal fin 71 may be attached to the outer peripheral side of the stationary extension 42. Also in this case, the cooling steam CS can be suppressed from flowing from the ground space 4 to the steam inlet passage 32 through the gap 38.

Fourth Embodiment
Next, a steam turbine according to a fourth embodiment of the present invention will be described with reference to FIG.

  The fourth embodiment shown in FIG. 6 is mainly different in that the seal fin is disposed in a portion of the gap between the inner ring extension and the stationary connecting portion, and the other configuration is the same as that in FIG. Is substantially the same as the third embodiment shown in FIG. In FIG. 6, the same parts as those of the third embodiment shown in FIG. 5 are designated by the same reference numerals and their detailed description will be omitted.

  In the present embodiment, as shown in FIG. 6, the seal fin 71 is disposed in a portion of the gap 38 between the inner ring extension portion 56 and the stationary connection portion 45. More specifically, the seal fin 71 is attached to the inner peripheral side of the inner ring extension 56.

  As described above, according to the present embodiment, the seal fin 71 is disposed in a portion of the gap 38 between the inner ring extension portion 56 and the stationary connection portion 45. This can suppress the inflow of the cooling steam CS from the ground space 4 to the steam inlet passage 32 passing through the gap 38. In addition, the seal fin 71 can be disposed at a deep position in the inner ring accommodation space 47, and the possibility of the seal fin 71 being damaged when assembling the stationary member 40 and the vane inner ring 51 can be reduced. It is possible to improve the quality.

  In the above-described embodiment, the seal fin 71 is attached to the inner peripheral side of the inner ring extension 56. However, the present invention is not limited to this, and the seal fin 71 may be attached to the outer peripheral side of the stationary connection portion 45. Also in this case, the cooling steam CS can be suppressed from flowing from the ground space 4 to the steam inlet passage 32 through the gap 38.

Fifth Embodiment
Next, a steam turbine according to a fifth embodiment of the present invention will be described with reference to FIG.

  The fifth embodiment shown in FIG. 7 is mainly different in that the seal fin is disposed in a portion of the gap between the stationary main body portion and the inner ring extension portion, and the other configuration is the same as that of FIG. The third embodiment is substantially the same as the first embodiment shown in FIG. 7, the same parts as those in the first embodiment shown in FIG. 1 to FIG. 3 are assigned the same reference numerals and detailed explanations thereof will be omitted.

  In the present embodiment, as shown in FIG. 7, the seal fin 71 is disposed in a portion of the gap 38 between the stationary main body portion 41 and the inner ring extension portion 56. More specifically, the seal fin 71 is attached to the inner ring extension 56 side of the stationary main body 41. That is, the stationary main body portion 41 includes a second stationary facing surface 46 b opposed to the inner ring extension 56 and extending in the radial direction. The inner ring extension 56 includes a second inner ring facing surface 59b that faces the second stationary facing surface 46b and extends in the radial direction. The seal fin 71 shown in FIG. 7 is attached to the second stationary facing surface 46 b and is disposed in a portion of the gap 38 that extends in the radial direction.

  As described above, according to the present embodiment, the seal fin 71 is disposed in the gap 38 between the stationary main body 41 and the inner ring extension 56. This can suppress the inflow of the cooling steam CS from the ground space 4 to the steam inlet passage 32 passing through the gap 38.

  In the embodiment described above, an example in which the seal fin 71 is attached to the second stationary facing surface 46 b of the stationary main body 41 has been described. However, the present invention is not limited to this, and the seal fin 71 may be attached to the second inner ring facing surface 59 b of the inner ring extension 56. Also in this case, the cooling steam CS can be suppressed from flowing from the ground space 4 to the steam inlet passage 32 through the gap 38.

  Further, in the above-described embodiment, an example has been described in which the seal fin 71 is disposed in a portion of the gap 38 between the stationary main body portion 41 and the inner ring extension portion 56. However, the present invention is not limited to this, and as shown in FIG. 8, the seal fin 71 may be disposed in the gap 38 between the stationary extension 42 and the inner ring extension 56. In this case, the seal fin 71 may be attached to the first stationary facing surface 46 a of the stationary extension 42 or the first inner race opposing surface 59 a of the inner ring extension 56.

  Further, as shown in FIG. 9, the seal fin 71 may be disposed in a portion of the gap 38 between the stationary extension portion 42 and the inner ring main body portion 55. That is, the stationary extension portion 42 includes a third stationary facing surface 46 c that faces the inner wheel main body 55 and extends in the radial direction. The inner ring body portion 55 includes a third inner ring facing surface 59c that faces the third stationary facing surface 46c and extends in the radial direction. The seal fin 71 shown in FIG. 9 is attached to the third stationary facing surface 46 c and is disposed in a radially extending portion of the gap 38. The seal fin 71 may be attached to the third inner ring facing surface 59 c of the inner ring extension 56.

  Further, in the embodiment described above, the stationary extension portion 42 extends from the stationary main body portion 41 (more specifically, the stationary connection portion 45) toward the inner peripheral side, and the inner ring extension portion 56 is the inner ring The example which is extended toward the perimeter side from main part 55 (more specifically, inner ring connecting part 58) was explained. However, the present invention is not limited to this, and as shown in FIGS. 5 and 6, the stationary extension 42 extends from the stationary main body 41 (more specifically, the stationary connection 45) toward the outer peripheral side. The inner ring extension 56 may extend from the inner ring body 55 (more specifically, the inner ring connecting portion 58) toward the inner circumferential side. Also in this case, the seal member 70 may be disposed at the position as shown in FIGS. 7 to 9.

Sixth Embodiment
Next, a steam turbine according to a sixth embodiment of the present invention will be described with reference to FIG.

  The sixth embodiment shown in FIG. 10 is mainly different in that the seal member has a ring member extending between the stationary member and the vane inner ring, and the other configuration is shown in FIG. It is substantially the same as the fifth embodiment. In FIG. 10, the same parts as those of the fifth embodiment shown in FIG. 7 are assigned the same reference numerals and detailed explanations thereof will be omitted.

  The seal member 70 according to the present embodiment has a ring member 72 extending from the stationary member 40 to the vane inner ring 51. The ring member 72 is attached to a portion between the stationary main body 41 and the inner ring extension 56 throughout the circumferential direction, and enters and fits in a stationary recess 48 and an inner ring recess 61 described later. Similar to the seal fin 71, the ring member 72 can suppress the cooling vapor CS from flowing from the ground space 4 into the steam inlet passage 32 through the gap 38, but the inflow of the cooling vapor CS is made more than the seal fin 71. It can be further suppressed.

  A stationary recess 48 is provided on the second stationary opposing surface 46 b of the stationary main body 41 according to the present embodiment. The stationary recess 48 is provided along the circumferential direction of the stationary main body 41, and is provided in the entire circumferential direction of the stationary body 41.

  An inner ring recess 61 is provided on the second inner ring facing surface 59 b of the inner ring extension 56. The inner ring recess 61 is provided along the circumferential direction of the inner ring extension 56, and is provided in the entire circumferential direction of the inner ring extension 56.

  The ring member 72 is preferably divided into at least two in the circumferential direction. In this case, after the stationary member 40 and the vane inner ring 51 are assembled, the ring member 72 is inserted from one of the circumferential end portions of the stationary recess 48 and the inner ring recess 61 and is fed in the circumferential direction , And can be attached to the stationary recess 48 and the inner ring recess 61.

  As described above, according to the present embodiment, the ring member 72 extends between the stationary main body portion 41 and the inner ring extension portion 56 throughout the circumferential direction of the stator blade member 40 and the stator inner ring 41. This can suppress the inflow of the cooling steam CS from the ground space 4 to the steam inlet passage 32 passing through the gap 38.

  In the embodiment described above, an example in which the seal member 70 extends between the stationary main body portion 41 and the inner ring extension portion 56 has been described. However, the present invention is not limited to this, and as shown in FIG. 11, the seal member 70 may extend between the stationary extension 42 and the inner ring extension 56. Also, as shown in FIG. 12, a seal member 70 may extend between the stationary extension 42 and the inner ring body 55. Also, a sealing member 70 may extend between the stationary extension 42 and the inner ring connection 58. Additionally, a seal member 70 may extend between the stationary connection 45 and the inner ring extension 56. Also in this case, the cooling steam CS can be suppressed from flowing from the ground space 4 to the steam inlet passage 32 through the gap 38.

  Further, in the embodiment described above, the stationary extension portion 42 extends from the stationary main body portion 41 (more specifically, the stationary connection portion 45) toward the inner peripheral side, and the inner ring extension portion 56 is the inner ring The example which is extended toward the perimeter side from main part 55 (more specifically, inner ring connecting part 58) was explained. However, the present invention is not limited to this, and as shown in FIGS. 5 and 6, the stationary extension 42 extends from the stationary main body 41 (more specifically, the stationary connection 45) toward the outer peripheral side. The inner ring extension 56 may extend from the inner ring body 55 (more specifically, the inner ring connecting portion 58) toward the inner circumferential side. Also in this case, the seal member 70 may be disposed at the position as shown in FIGS. 10 to 12.

  According to the embodiment described above, it is possible to prevent the creeping deformation of the inner ring of the stationary blade while suppressing the inflow of the steam from the ground space to the steam inlet passage while avoiding the prolongation of the assembling period.

  While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

  2: Case 3: 3: Turbine rotor 4: 4: Ground space 30: Medium pressure turbine 32: Steam inlet passage 38: Clearance 40: Stationary member 41: Stationary body 42: Stationary extension 45: Stationary connection portion 46a: first stationary facing surface 50: stator blade 51: stationary blade inner ring 55: inner ring main body portion 56: inner ring extension portion 58: inner ring connecting portion 59a: first inner ring facing surface 70 : Sealing member, 71: Sealing fin, 72: Ring member

Claims (12)

A steam turbine comprising: a casing; and a turbine rotor rotatably provided in the casing;
A stationary member supported by the casing, defining a portion of a steam inlet passage and defining a ground space with the turbine rotor;
It is supported by the casing via a first stage vane provided downstream of the steam inlet passage, and a clearance connecting the steam inlet passage and the ground space is interposed between the stationary member and the stationary member. The wing inner ring,
And a seal member provided in the gap,
The stationary member includes a stationary body portion, and a stationary extension portion provided downstream of the stationary body portion and extending in a direction orthogonal to the axial direction of the turbine rotor.
The stationary blade inner ring has an inner ring main body portion, and an inner ring extension portion provided on the upstream side of the inner ring main body portion and extending in a direction orthogonal to the axial direction of the turbine rotor,
The stationary extension includes a first stationary facing surface provided upstream thereof,
The steam turbine according to claim 1, wherein the inner ring extension includes a first inner ring facing surface provided on the downstream side thereof facing the first stationary facing surface via the gap. The stationary extension extends from the stationary body toward the inner periphery,
The steam turbine according to claim 1, wherein the inner ring extension portion extends outward from the inner ring main body portion. The inner ring main body portion and the inner ring extension portion are connected by an inner ring connecting portion extending in the axial direction of the turbine rotor;
The steam turbine according to claim 2, wherein the seal member is disposed in a portion of the gap between the stationary extension portion and the inner ring connection portion. The stationary body portion and the stationary extension portion are connected by an axially extending stationary connection portion of the turbine rotor;
The steam turbine according to claim 2, wherein the seal member is disposed in a portion of the gap between the inner ring extension and the stationary connection portion. The stationary extension extends from the stationary body towards the outer periphery,
The steam turbine according to claim 1, wherein the inner ring extension portion extends from the inner ring main body toward the inner circumferential side. The inner ring main body portion and the inner ring extension portion are connected by an inner ring connecting portion extending in the axial direction of the turbine rotor;
The steam turbine according to claim 5, wherein the seal member is disposed in a portion of the gap between the stationary extension portion and the inner ring connection portion. The stationary body portion and the stationary extension portion are connected by an axially extending stationary connection portion of the turbine rotor;
The steam turbine according to claim 5, wherein the seal member is disposed in a portion of the gap between the inner ring extension and the stationary connection portion.   The steam turbine according to claim 2, wherein the seal member is disposed in a portion of the gap between the stationary main body portion and the inner ring extension portion.   The steam turbine according to claim 2, wherein the seal member is disposed in a portion of the gap between the stationary extension and the inner ring extension.   The steam turbine according to claim 2, wherein the seal member is disposed in a portion of the gap between the stationary extension portion and the inner ring main body portion.   The steam turbine according to any one of claims 1 to 10, wherein the seal member has a seal fin.   The steam turbine according to any one of claims 1 to 10, wherein the seal member includes a ring member extending from the stationary member to the inner race of the vane.

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