JP6049582B2 - Steam turbine - Google Patents

Description

  The present invention relates to a steam turbine.

  As a steam turbine, for example, a steam turbine including a casing in which a turbine rotor is accommodated and a gland packing portion that seals between the casing and the turbine rotor as disclosed in Patent Document 1 is known. In this steam turbine, the gland packing portion is divided into two, and the first half portion is joined to the first half portion by a bolt in a state where the joining surface of the first half gland packing portion and the joining surface of the second half gland packing portion are combined. The gland packing part and the second half gland packing part are connected. Further, the casing and the gland packing part are connected by a bolt in a state where the joining surface of the casing and the gland packing part are combined. And by supplying seal steam (ground steam) to the gland packing part of the first half and providing a heat insulator in the gland packing part of the second half, the casing and the gland packing part due to thermal deformation of the casing It suppresses the leakage of steam from between.

JP 2003-13704 A

  When the temperature difference between the casing and the gland packing part increases and the difference in the amount of thermal deformation increases, for example, the joining surface of the first half gland packing part and the joining surface of the second gland packing part are aligned. There is a possibility that sufficient pressure (surface pressure) cannot be secured on the mating surfaces. As a result, steam may leak from between the gland packing portion of the first half and the gland packing portion of the second half.

  An object of the present invention is to provide a steam turbine capable of suppressing steam leakage.

  A steam turbine according to the present invention is disposed around a turbine rotor having a shaft member and a seal connected to the shaft member, and a casing casing in which a casing space is formed between the turbine rotor and the turbine A first portion disposed on a part of the periphery of the rotor and having a first joint surface, and a second part disposed on a portion of the periphery of the turbine rotor and having a second joint surface joined to the first joint surface. A ground member connected to the casing casing so as to close an opening at an end of the casing space, and a first end of the casing casing with respect to a direction parallel to the axis of the turbine rotor. Between the first region of the inner surface of the casing casing including a portion and the second region of the inner surface of the ground member including the second end of the ground member adjacent to the first end. Thermal insulation suppressed Comprising a space forming member that forms between the.

  According to the present invention, a heat insulating space in which the flow of gas is suppressed is formed at the boundary between the first end of the casing and the second end of the ground member adjacent to the first end. In the boundary portion (joint portion, joint portion) between the casing and the ground member, an increase in temperature difference between the casing and the ground member is suppressed. Therefore, it is suppressed that the difference in the amount of thermal deformation between the casing and the ground member in the vicinity of the boundary is increased. Therefore, it is possible to prevent the vapor from leaking from the mating surface obtained by combining the first joint surface of the first portion of the ground member and the second joint surface of the second portion.

  In the steam turbine according to the present invention, the heat insulating space may be formed so as to surround the shaft. As a result, an increase in temperature difference between the casing and the ground member is suppressed.

  The steam turbine which concerns on this invention WHEREIN: The dimension of the said heat insulation space may be smaller than the distance of the outer surface of the said shaft member, the said 1st area | region, and the said 2nd area | region regarding the radial direction with respect to the axis | shaft of the said turbine rotor. Thereby, a minute heat insulating space can be formed at the boundary portion between the first end portion of the casing and the second end portion of the ground member while securing a space to which the ground steam is supplied.

  In the steam turbine according to the present invention, the heat insulation space may be a sealed space. By doing so, the flow of gas is sufficiently suppressed in the heat insulating space, and a high heat insulating effect can be obtained.

  In the steam turbine according to the present invention, the space forming member is disposed around the turbine rotor at a position closer to the center of the vehicle compartment space than the ground member with respect to a direction parallel to the axis. An inner member having a connection portion connected to the inner surface, an opposing surface facing the first region and the second region, and a seal mechanism that seals between the opposing surface and the inner surface of the ground member; May be provided. By carrying out like this, the heat insulation space in which a high heat insulation effect is acquired can be formed between the 1st field of a casing casing, and the 2nd field of a ground member.

  In the steam turbine according to the present invention, the casing casing is disposed in a part of the periphery of the turbine rotor, and is disposed in a part of the periphery of the turbine rotor, a third part having a third joint surface, And a fourth portion having a fourth joint surface joined to the third joint surface. In addition to the ground member, the casing can also be divided so that, for example, maintenance can be performed smoothly.

  According to the present invention, leakage of steam can be suppressed.

FIG. 1 is a schematic configuration diagram illustrating an example of a steam turbine according to the present embodiment. FIG. 2 is a side sectional view showing the vicinity of the boundary between the casing and the ground member according to the present embodiment. FIG. 3 is a front view showing an example of the casing according to the present embodiment. FIG. 4 is a perspective view showing an example of a ground member according to the present embodiment. FIG. 5 is a diagram illustrating an example of a sealing mechanism according to the present embodiment. FIG. 6 is a diagram illustrating an example of a steam turbine according to a comparative example. FIG. 7 is a diagram illustrating temperature distributions of the casing and the ground member according to the comparative example. FIG. 8 is a view showing temperature distributions of the casing and the ground member according to the present embodiment.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings, but the present invention is not limited thereto. The requirements of the embodiments described below can be combined as appropriate. Some components may not be used. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each part will be described with reference to this XYZ orthogonal coordinate system. One direction in the predetermined plane is the X-axis direction, the direction orthogonal to the X-axis direction in the predetermined plane is the Y-axis direction, and the direction orthogonal to each of the X-axis direction and the Y-axis direction (that is, the vertical direction) is the Z-axis direction. To do. Further, the rotation (inclination) directions around the X axis, Y axis, and Z axis are the θX, θY, and θZ directions, respectively. The X axis is orthogonal to the YZ plane. The Y axis is orthogonal to the XZ plane. The Z axis is orthogonal to the XY plane. The XY plane includes an X axis and a Y axis. The XZ plane includes an X axis and a Z axis. The YZ plane includes a Y axis and a Z axis.

  FIG. 1 is a schematic configuration diagram illustrating an example of a steam turbine 1 according to the present embodiment. In FIG. 1, the steam turbine 1 includes a low-pressure casing 100 and a high-pressure casing 200. The high-pressure casing 200 includes a casing 3 disposed around the turbine rotor 2. In the present embodiment, it is assumed that the axis (rotary axis) of the turbine rotor 2 and the X axis are parallel.

  The casing 3 is arranged around the turbine rotor 2, and is arranged around the turbine rotor 2 and the casing casing 4 in which the casing space SP is formed between the casing 3 and the end of the casing space SP. And a gland casing 5 connected to the casing casing 4 so as to close the opening 24 of the vehicle. The opening 24 and the ground casing 5 are disposed on both sides of the vehicle casing 4 with respect to the X-axis direction.

  FIG. 2 is an enlarged view of a part of FIG. 1, and is a side sectional view showing the vicinity of the boundary between the vehicle casing 4 and the ground casing 5. FIG. 2 is a cross-sectional view showing the vicinity of the ground casing 5 arranged on the + X side with respect to the center of the vehicle interior space SP. FIG. 3 is a front view showing an example of the casing 3 of the steam turbine 1.

  As shown in FIGS. 1, 2, and 3, the turbine rotor 2 includes a rotatable shaft member 21 and a plurality of seals 22 connected to the shaft member 21. As shown in FIG. 1, the turbine rotor 2 is rotatably supported by a bearing 32. The bearing 32 is disposed outside the casing casing 4. The bearing 32 is supported by a bearing base provided on a foundation base 35 made of concrete or the like.

  The casing casing 4 is disposed around the turbine rotor 2. The casing casing 4 connects the casing space SP, which is the internal space of the casing casing 4, and the external space, and has an opening 24 in which at least a part of the turbine rotor 2 is disposed. With respect to the X-axis direction, the openings 24 are formed on both sides of the passenger compartment casing 4 and are arranged at both ends of the passenger compartment space SP. With respect to the X-axis direction, the center portion of the turbine rotor 2 is disposed inside the casing casing 4, and both end portions of the turbine rotor 2 are disposed outside the casing casing 4. A steam supply port is provided in the upper part of the casing 4. Steam (main steam) is supplied to the passenger compartment space SP of the passenger compartment casing 4 via the steam supply port.

  The casing casing 4 is divided into an upper casing casing 4A and a lower casing casing 4B. The upper casing casing 4 </ b> A is disposed at a part of the periphery of the turbine rotor 2, and the lower casing casing 4 </ b> B is disposed at a part of the periphery of the turbine rotor 2. The upper casing casing 4A has a joint surface Pa1. Lower casing casing 4B has joint surface Pb1 joined to joint surface Pa1. Each of the bonding surface Pa1 and the bonding surface Pb1 is parallel to the XY plane.

  The upper casing 4A has an upper flange 41 including a joint surface Pa1. The lower casing casing 4B has a lower flange 42 including a joint surface Pb1. By joining the joint surface Pa1 and the joint surface Pb1, the upper casing casing 4A and the lower casing casing 4B are fastened with bolts, and the upper casing casing 4A and the lower casing casing 4B are connected. A vehicle casing 4 is formed. The opening 24 is formed between the upper casing casing 4A and the lower casing casing 4B.

  As shown in FIG. 2, the ground casing 5 has an outer gland (ground member) 51 disposed so as to block the opening 24 at the end of the vehicle interior space SP from the outside, and the outer casing 51 with respect to the X-axis direction. And an inner gland (inner member) 52 disposed at a position close to the center of the room space SP and disposed so as to close the opening 24 at the end of the vehicle interior space SP. Each of the outer gland 51 and the inner gland 52 is disposed around the turbine rotor 2.

  As shown in FIG. 2, the casing 4 has a joint surface Pb2 joined to the joint surface Pa2 of the outer ground 51. A joint surface Pb2 of the casing 4 is an attachment surface to which the outer gland 51 is attached. The joint surface Pb2 of the casing 4 is an annular surface that is disposed around the opening 24 and faces outward with respect to the center of the casing space SP. Each of the joint surface Pa2 and the joint surface Pb2 is parallel to the YZ plane orthogonal to the axis of the turbine rotor 2. The mating surface P2 obtained by combining the joint surface Pa2 and the joint surface Pb2 is orthogonal to the mating surface P1 obtained by combining the joint surface Pa1 and the joint surface Pb1.

  FIG. 4 is a perspective view of the outer ground 51. The outer gland 51 is disposed so as to cover the space between the casing casing 4 and the turbine rotor 2 disposed in the opening 24 of the casing casing 4, and suppresses the leakage of steam from the opening 24. In the present embodiment, ground steam (seal steam) is supplied from the supply port 81 provided in the outer ground 51 to the ground space GS between the outer ground 51 and the inner ground 52. In addition, at least a part of the ground vapor supplied to the ground space GS is discharged from the discharge port 82 provided in the outer ground 51.

  As shown in FIGS. 3 and 4, the outer ground 51 is annular in the YZ plane. At least a part of the outer ground 51 is connected to the vehicle casing 4. The outer ground 51 and the vehicle casing 4 are fastened with the bolts 37 in a state where the joint surface Pa2 of the vehicle casing 4 and the joint surface Pb2 of the outer ground 51 are combined, so that the outer ground 51 and the vehicle casing 4 And are connected.

  The outer gland 51 is divided into an upper outer gland 51A and a lower outer gland 51B. The upper outer ground 51 </ b> A is disposed at a part of the periphery of the turbine rotor 2, and the lower outer ground 51 </ b> B is disposed at a part of the periphery of the turbine rotor 2. The upper outer ground 51A has a joint surface Pa3. Lower outer ground 51B has a joint surface Pb3 joined to joint surface Pa3. Each of the bonding surface Pa3 and the bonding surface Pb3 is parallel to the XY plane. In the present embodiment, the mating surface P1 obtained by combining the joint surface Pa1 and the joint surface Pb1 and the mating surface P3 obtained by combining the joint surface Pa3 and the joint surface Pb3 are arranged in the same plane.

  The upper outer ground 51A has an upper flange 27 including a joint surface Pa3. The lower outer ground 51B has a lower flange 28 including a joint surface Pb3. The upper outer ground 51A and the lower outer ground 51B are fastened with the bolt 38 in a state where the joint surface Pa3 and the joint surface Pb3 are combined, and the upper outer ground 51A and the lower outer ground 51B are connected to each other. 51 is formed.

  The inner gland 52 is disposed so as to cover the space between the casing casing 4 and the turbine rotor 2 disposed in the opening 24 of the casing casing 4, and suppresses the leakage of steam from the opening 24. At least a portion of the inner gland 52 is connected to the vehicle casing 4. In the YZ plane, the inner ground 52 is annular. Similar to the outer ground 51, the inner ground 52 may be divided into an upper inner ground and a lower inner ground. The inner ground 52 may be formed by connecting the upper inner ground and the lower inner ground with a bolt or the like. Note that the inner ground 52 may not be divided.

  As shown in FIG. 2, the inner gland 52 has a connection portion 53 that is connected to the inner surface of the vehicle casing 4. In the present embodiment, a recess 54 is formed on the inner surface of the casing 4. The connecting portion 53 includes a convex portion that fits into the concave portion 54. Further, the inner ground 52 has a convex portion 55 that extends outward with respect to the center of the vehicle interior space SP in the X-axis direction. The convex part 55 is arrange | positioned so that the axis | shaft of the turbine rotor 2 may be enclosed.

  With respect to the X-axis direction, the first region 61 on the inner surface of the casing casing 4 including one end portion (the end portion on the + X side in the example shown in FIG. 2) of the inner casing casing 4 and the inner surface of the casing casing 4 The heat insulating space HS is defined by the second region 62 of the outer ground 51 including one end portion of the inner surface of the outer ground 51 adjacent to one end portion (the end portion on the −X side in the example shown in FIG. 2). The heat insulation space HS is formed between the first region 61 of the casing 4, the second region 62 of the outer gland 51, the inner gland 52, and the seal mechanism 70. In the present embodiment, the inner gland 52 and the seal mechanism 70 function as a space forming member that forms the heat insulating space HS between the first region 61 and the second region 62.

  The inner gland 52 is disposed on the convex portion 55 and is disposed between the facing surface 56 facing the first region 61 and the second region 62 with a gap therebetween, and between the connecting portion 53 and the facing surface 56, and the vehicle interior space. And a side surface 57 facing outward with respect to the center of the SP. The side surface 57 faces the seal mechanism 70 via a gap. In the present embodiment, each of the first region 61, the second region 62, and the facing surface 56 is substantially parallel to the X axis.

  The seal mechanism 70 seals between the facing surface 56 and the inner surface of the outer ground 51. In the present embodiment, the heat insulating space HS includes a first region 61 of the casing 4, a second region 62 of the outer ground 51, a facing surface 56 of the inner ground 52, a side surface 57 of the inner ground 52, and a sealing mechanism. 70.

  The heat insulation space HS is a closed space (closed space). In the present embodiment, the heat insulating space HS is a sealed space. The heat insulating space HS is formed so as to surround the axis of the turbine rotor 2. The ground space GS is arranged so as to be adjacent to the heat insulating space HS. A space forming member including the inner gland 52 (the convex portion 55) and the seal mechanism 70 is disposed at the boundary between the heat insulating space HS and the ground space GS. The first region 61 and the second region 62 form a boundary portion between the casing casing 4 and the outer ground 51. The heat insulating space HS is disposed between the first region 61 and the second region 62 and the ground space GS.

  In the heat insulation space HS, the flow of gas is suppressed. In the present embodiment, the gas flow (airflow velocity) in the heat insulating space HS is smaller (lower) than the gas flow (airflow velocity) in the ground space GS. Ground steam is supplied to the ground space GS from the outside of the ground space GS through the supply port 81. Gas (such as ground vapor) is not supplied to the heat insulation space HS from the outside of the heat insulation space HS. Further, a seal mechanism 70 is disposed between the heat insulating space HS and the ground space GS, and the inflow of ground vapor from the ground space GS to the heat insulating space HS is suppressed. That is, in this embodiment, the inflow amount per unit time of the gas from the outside to the heat insulation space HS is smaller than the inflow amount per unit time of the gas (ground vapor) from the outside to the ground space GS.

  Regarding the radial direction with respect to the axis of the turbine rotor 2, the dimension Wa of the heat insulation space HS is larger than the distance W1 between the outer surface of the shaft member 21 and the first region 61 and the distance W2 between the outer surface of the shaft member 21 and the second region 62. small. The heat insulating space HS is a minute space formed at the boundary between the casing 4 and the outer ground 51.

  FIG. 5 is a diagram illustrating an example of the seal mechanism 70 according to the present embodiment. The seal mechanism 70 is fixed to the inner surface of the outer ground 52 and has a fixing member 71 having an internal space, an elastic member 72 such as a leaf spring disposed in the internal space of the fixing member 71, and at least a part of the fixing mechanism 71. And a seal member 73 disposed in the internal space. The fixing member 71 has an opening 74 that connects the internal space and the external space of the fixing member 71. At least a part of the seal member 73 is disposed in the opening 74. A part of the seal member 73 is disposed in the internal space of the fixed member 71, and a part of the seal member 73 is disposed in the external space of the fixed member 71 through the opening 74. In the internal space of the fixing member 71, the elastic member 72 is disposed between the outer ground 51 and the seal member 73. The elastic member 72 generates a force (urging force) that presses the seal member 73 against the inner ground 52 (the convex portion 55). Thereby, the seal member 73 and the inner ground 52 are sufficiently in contact with each other. Therefore, it is suppressed that the gas of the heat insulation space HS flows out or the gas of the ground space GS flows into the heat insulation space HS.

  Note that the heat insulating space HS described with reference to FIG. 2 and the like is a heat insulating space HS formed on one side (+ X side) of the vehicle interior space SP in the X-axis direction. As shown in FIG. 1, the ground casing 5 including the outer ground 51 and the inner ground 52 is disposed also on the other side (−X side) of the passenger compartment space SP in the X-axis direction, so that the heat insulating space HS is formed. . In the gland casing 5 disposed on the other side (−X side) of the vehicle interior space SP, the vehicle interior casing including the other end portion (−X side end portion) of the inner surface of the vehicle interior casing 4 in the X-axis direction. 4 and the second region 62 of the outer ground 51 including one end portion (the end portion on the + X side) of the inner surface of the outer ground 51 adjacent to the other end portion of the inner surface of the casing casing 4. Thus, a heat insulating space HS is defined. The first area 61 and the second area 62 form a boundary portion between the casing casing 4 and the outer ground 51 on the other side (−X side) of the casing space SP with respect to the X-axis direction. The heat insulating space HS includes a first region 61 of the casing casing 4 and a second region 62 of the outer gland 51, and an inner gland 52 disposed on the other side (−X side) of the cabin space SP with respect to the X-axis direction. It is formed between the sealing mechanism 70.

  Next, the operation of the steam turbine 1 according to this embodiment will be described. High-temperature and high-pressure steam (main steam) is supplied to the passenger compartment space SP through the steam supply port 23. The turbine rotor 2 is rotated by the steam supplied to the passenger compartment space SP. Further, the ground steam is supplied to the ground space GS through the supply port 81.

  When the main steam is supplied to the vehicle interior space SP and the ground steam is supplied to the ground space GS, the temperature difference between the vehicle interior casing 4 and the outer ground 51 may increase. When the casing casing 4 and the outer gland 51 are connected to each other, the temperature difference between the casing casing 4 and the outer gland 51 increases, and the difference in the amount of thermal deformation between the casing casing 4 and the outer gland 51 increases. There is a possibility that sufficient pressure (surface pressure) may not be secured on the mating surface P3 obtained by combining the joint surface Pa3 of the upper outer ground 51A and the joint surface Pb3 of the lower outer ground 51B. For example, even if the temperature of the casing casing 4 becomes high and the amount of thermal deformation of the casing casing 4 increases, the temperature of the outer gland 51 does not become as high as the temperature of the casing casing 4, and the heat of the outer gland 51 increases. If the deformation amount is small, there is a possibility that a force acts on the outer gland 51 as the casing casing 4 is thermally deformed. For example, a force may act on at least one of the upper outer ground 51A and the lower outer ground 51B so that the joint surface Pa3 and the joint surface Pb3 are separated from each other. As a result, steam (ground steam) may leak from between the joint surface Pa3 of the upper outer ground 51A and the joint surface Pb3 of the lower outer ground 51B.

  In the present embodiment, since the heat insulating space HS is provided at the boundary between the casing casing 4 and the outer gland 51, the casing casing 4 and the outer gland in the vicinity of the boundary between the casing casing 4 and the outer gland 51. An increase in the temperature difference of the ground 51 is suppressed.

  FIG. 6 is a diagram illustrating an example of a steam turbine 1J according to a comparative example. The steam turbine 1J according to the comparative example does not have the heat insulating space HS.

  FIG. 7 shows respective temperature distributions of the casing casing 4 and the outer gland 51 when the main steam is supplied to the casing space SP of the steam turbine 1J according to the comparative example and the ground steam is supplied to the ground space GS. It is a schematic diagram. FIG. 7 shows a temperature distribution in a cross section parallel to the XY plane in the vicinity of the boundary portion between the casing 4 and the outer ground 51. As shown in FIG. 7, in the steam turbine 1J according to the comparative example, it can be seen that the temperature difference between the casing casing 4 and the outer ground 51 becomes large in the vicinity of the boundary portion between the casing casing 4 and the outer ground 51. .

  FIG. 8 shows respective temperature distributions of the casing casing 4 and the outer gland 51 when the main steam is supplied to the casing space SP of the steam turbine 1 according to the present embodiment and the ground steam is supplied to the ground space GS. FIG. FIG. 8 shows a temperature distribution in a cross section parallel to the XY plane in the vicinity of the boundary portion between the casing 4 and the outer ground 51. As shown in FIG. 8, in the steam turbine 1 according to the present embodiment, a heat insulating space HS in which a gas flow is suppressed is provided at the boundary between the vehicle casing 4 and the outer ground 51. In the vicinity of the boundary between the casing 4 and the outer gland 51, an increase in temperature difference between the casing casing 4 and the outer gland 51 is suppressed.

  Moreover, the leakage of steam from the mating surface P3 of the steam turbine 1 according to this embodiment is less than the leakage of steam from the mating surface P3 of the steam turbine 1J according to the comparative example.

  This is because the ground steam supplied to the ground space GS is not supplied to the boundary (the first region 61 and the second region 62) between the casing casing 4 and the outer ground 51, and as a result, the casing casing 4 It is considered that an increase in temperature difference with the outer ground 51 is suppressed. That is, when the ground steam in the ground space GS flows in the vicinity of the boundary between the casing 4 and the outer ground 51, the temperature rise of the outer ground 51 is hindered due to the ground steam in the ground space GS. it is conceivable that. That is, when the ground steam flows so as to contact the first region 61 and the second region 62, the temperature of the outer ground 51 in the vicinity of the boundary portion does not become as high as the temperature of the vehicle casing 4 due to the ground steam. The phenomenon is thought to occur.

  In the present embodiment, the ground steam in the ground space GS does not flow in the vicinity of the boundary between the vehicle casing 4 and the outer ground 51 due to the heat insulating space HS. In other words, since the first region 61 and the second region 62 that form the boundary between the casing 4 and the outer ground 51 are protected by the heat insulating space HS, the ground vapor in the ground space GS is the first region 61. And it is controlled that it flows so that the 2nd field 62 may be touched. Therefore, the phenomenon that the temperature rise of the outer ground 51 is prevented in the vicinity of the boundary portion is suppressed. And since the heat | fever of the compartment casing 4 is transmitted to the outer ground 51 via the mating surface P3 etc., the temperature of the outer ground 51 rises. Thereby, it is considered that an increase in temperature difference between the casing 4 and the outer ground 51 is suppressed in the vicinity of the boundary.

  In the vicinity of the boundary between the casing casing 4 and the outer gland 51, the temperature difference between the casing casing 4 and the outer gland 51 is suppressed, resulting in thermal deformation of the casing casing 4, The force that separates the joint surface Pa3 and the joint surface Pb3 from acting on the outer ground 51 is suppressed. That is, since the temperature difference between the casing casing 4 and the outer gland 51 is small, when the casing casing 4 is thermally deformed, the outer gland 51 is also heated with a thermal deformation amount substantially equal to the thermal deformation amount of the casing casing 4. Deform. Thereby, it is suppressed that the force which separates joining surface Pa3 and joining surface Pb3 acts on the outer ground 51. FIG. Therefore, the leakage of steam (ground steam) from between the joint surface Pa3 of the upper outer ground 51A and the joint surface Pb3 of the lower outer ground 51B is suppressed.

  As described above, according to the present embodiment, since the heat insulating space HS in which the gas flow is suppressed is formed at the boundary between the casing casing 4 and the outer gland 51, the casing casing 4 and the outer gland 51. An increase in the temperature difference between the casing 4 and the outer gland 51 is suppressed at the boundary portion (joint portion, joint portion). Therefore, the difference in the amount of thermal deformation between the casing casing 4 and the outer ground 51 is suppressed in the vicinity of the boundary portion. Therefore, it is possible to prevent the steam from leaking from the mating surface P3 obtained by combining the joint surface Pa3 of the upper outer ground 51A and the joint surface Pb3 of the lower outer ground 51B.

  In the present embodiment, since the outer gland 51 can be divided into the joint surface Pa3 of the upper outer gland 51A and the lower outer gland 51B, for example, maintenance of the steam turbine 1 can be performed smoothly.

  In the present embodiment, the heat insulating space HS is formed so as to surround the shaft of the turbine rotor 2. This suppresses an increase in the temperature difference between the casing casing 4 and the outer gland 51 in the vicinity of the boundary between the casing casing 4 and the outer gland 51.

  In the present embodiment, the dimension Wa of the heat insulation space HS is smaller than the distance W1 between the outer surface of the shaft member 21 and the first region 61 with respect to the radial direction with respect to the shaft of the turbine rotor 2, and the outer surface of the shaft member 21. It is smaller than the distance W <b> 2 with the second region 62. Thereby, the minute heat insulation space HS can be formed at the boundary between the casing 4 and the outer ground 5 while securing the ground space GS to which the ground steam is supplied.

  In the present embodiment, the heat insulating space HS is a sealed space. Thereby, the gas flow is sufficiently suppressed in the heat insulating space HS, and a high heat insulating effect can be obtained.

  In the present embodiment, the casing 4 is divided into an upper casing 4A and a lower casing 4B. In addition to the outer gland 51, the casing 4 can also be divided, so that, for example, maintenance of the steam turbine 1 can be performed smoothly.

  In the present embodiment, a plurality of heat insulating spaces HS may be formed around the axis of the turbine rotor 2 or may be formed only in the vicinity of the mating surface P3.

  In the present embodiment, the heat insulating space HS may be completely sealed or may not be sealed. The heat insulation space HS may be a closed space or a semi-closed space. For example, the sealing mechanism 70 may completely seal the gap between the facing surface 56 and the inner surface of the outer ground 52, or between the sealing mechanism 70 and one or both of the facing surface 56 and the outer ground 52. A gap may be formed. That is, it is only necessary that the gas flow in the heat insulating space HS is suppressed more than in the ground space GS. Therefore, the seal mechanism 70 may be omitted.

  In the present embodiment, the facing surface 56 is disposed on the convex portion 55 provided on the inner ground 52. The facing surface 56 may be disposed on the outer ground 51, for example. For example, the outer ground 51 may have a convex portion extending toward the center of the passenger compartment space SP in the X-axis direction, and the convex portion may have the facing surface 56. The space forming member for forming the heat insulating space HS between the first region 61 and the second region 62 may be a member different from the outer ground 51 and the inner ground 52. For example, a member different from the outer ground 51 and the inner ground 52 may be disposed in the ground space GS so as to face the first region 61 and the second region 62.

DESCRIPTION OF SYMBOLS 1 Steam turbine 2 Turbine rotor 3 Casing 4 Casing casing 4A Upper casing casing 4B Lower casing casing 5 Ground casing 21 Shaft member 22 Seal 24 Opening 51 Outer ground 51A Upper outer ground 51B Lower outer ground 52 Inner ground 53 Connection part 56 Opposing surface 61 1st area 62 2nd area 70 Seal mechanism GS Ground space HS Thermal insulation space SP Car room space

Claims (5)

A turbine rotor having a shaft member and a plurality of seals connected to the shaft member ;
Are disposed around the turbine rotor, the cabin casing forming the vehicle compartment space between the turbine rotor,
An annular inner gland disposed around the turbine rotor and connected to an end of the casing casing so as to close an opening of the end of the casing space;
An annular outer gland disposed around the turbine rotor and connected to an end of the casing casing so as to form a gland space supplied with gland steam with the inner gland ;
A convex portion provided on the inner ground and extending toward the outer ground;
A seal mechanism that seals between the inner surface of the outer ground and the convex portion,
A heat insulating space is formed between the first region of the inner surface of the casing casing, the second region of the inner surface of the outer ground, the inner ground including the convex portion, and the sealing mechanism,
The sealing mechanism suppresses the inflow of the ground vapor from the ground space to the heat insulating space.
Steam turbine. The steam turbine according to claim 1, wherein the heat insulation space is formed so as to surround an axis of the turbine rotor . The radial directions with respect to the axis of the turbine rotor, the dimension of the insulation space, the distance between the outer surface and the first region of the shaft member, and a small claim than the distance between the outer surface and the second region of the shaft member The steam turbine according to claim 1.   The steam turbine according to claim 1, wherein the heat insulation space is a sealed space. The casing casing includes an upper casing casing disposed in a part of the periphery of the turbine rotor, and a lower casing casing disposed in a part of the periphery of the turbine rotor and connected to the upper casing casing. steam turbine according to any one of claims 1 to 4 comprising a.

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