JP3782747B2 - Steam turbine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steam turbine, and more particularly to a steam turbine capable of effectively suppressing vibrations of a rotor during turbine operation.
[0002]
[Prior art]
FIG. 15 is a side cross-sectional view showing a main configuration of a conventional steam turbine. The steam turbine 100 includes a rotor 110, a base 120, and a bearing 130. The rotor 110 has a turbine blade 111 and is inserted through the passenger compartment 112 and installed. The base 120 has a column shape and is formed by placing concrete before and after the passenger compartment 112. The bearing 130 lays a base plate 131 horizontally on the top of the base 120 and is fixedly installed on the base plate 131 to support the rotor 110 from the front and rear outside the vehicle compartment 112.
[0003]
[Problems to be solved by the invention]
Here, in the recent 1 million kilowatt-class steam turbine, the rotor 110 is enlarged, but its rigidity is insufficient, and the rotor 110 vibrates when the turbine is operating, thereby destroying the turbine blade 111 and the casing 112. There was a problem. However, in the conventional steam turbine 100, there has not been much research on suppression of such vibration.
[0004]
[Means for Solving the Problems]
Here, according to research by the inventors, it has been found that the vibration of the rotor 110 is effectively suppressed if the distance between the bearings 130 and 130 supporting the rotor 110 is narrowed. However, since the steam turbine usually has a condensate chamber (not shown) below the passenger compartment 112, there is a limit to the interval between the foundations 120 and 120. As a result, the distance between the bearings 130 and 130 is also constant. There is a problem that the above cannot be narrowed. In addition, there is a configuration in which the rotor 110 is supported by the casing 112 as in the past, but in recent large-scale steam turbines, the rotor 110 is heavy, so that the rigidity of the casing 112 itself is insufficient and the rotor 110 is supported. There is a problem that it cannot be done.
[0009]
In addition, a steam turbine according to the present invention includes a rotor having turbine blades, a bearing that supports the rotor, and a projecting portion that projects in the axial direction of the rotor toward the turbine blade, and the projecting portion. And the overhanging portion embeds a rib-shaped reinforcing member having a plurality of holes in the base base while projecting from the base base, and the reinforcement The projecting part and the base were integrated by forming a steel plate on the member.
[0010]
In this invention, the overhanging portion is formed by embedding a rib-shaped reinforcing member in the base and laying a steel plate on the reinforcing member, so that the unity with the base is high, and against the vibration of the rotor There is an advantage that the bearing can be stably held. Moreover, compared with the case where a steel plate is not laid, there exists an advantage which can improve durability of the overhang | projection part with respect to a vibration more.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments. In addition, constituent elements of the embodiments described below include those that can be easily replaced by those skilled in the art or those that are substantially the same.
[0014]
(Embodiment)
FIG. 1 is a side cross-sectional view showing a main configuration of a steam turbine according to an embodiment of the present invention. 2 is an enlarged cross-sectional view showing the vicinity of the base of the steam turbine shown in FIG. 1, and FIG. 3 is a perspective view showing the base shown in FIG. In the figure, the same components as those in the conventional steam turbine 100 are denoted by the same reference numerals, and the description thereof is omitted. The steam turbine 1 includes a rotor 110, a base 10, and a bearing 130. One base stand 10 is installed in the vicinity of the front and rear of the vehicle compartment 112, respectively. The base 10 is configured by embedding a reinforcing member 12 in an upper portion of a concrete portion 11 and further laying a rectangular steel plate 13 thereon. The concrete portion 11 is formed by placing concrete in a columnar shape and has a substantially flat top portion. The reinforcing member 12 has a substantially rectangular plate shape, and a plurality of reinforcing members 12 are embedded with the surface thereof standing on the upper surface of the concrete portion 11. At this time, the reinforcing member 12 is embedded so that an end portion thereof extends in the axial direction of the rotor 110 and protrudes toward the turbine blade 111 (chamber 112 side). Further, the protruding portion of the reinforcing member 12 has a substantially triangular shape, and has a shape that can effectively support the load from above.
[0015]
The steel plate 13 is laid so that the reinforcing member 12 is a rib and the top of the concrete portion 11 is covered in the axial direction of the rotor 110 while covering the portion where the reinforcing member 12 protrudes. As a result, the concrete part 11 is formed with a projecting part 15 projecting to the turbine blade 111 side. In an actual process, the reinforcing member 12 and the steel plate 13 are integrated by welding from the beginning, and are embedded in the concrete portion 11 at a time. A plurality of holes 14 for injecting concrete are provided in the central portion of the reinforcing member 12. 4 to 7 are a perspective view (FIG. 4), a side view (FIG. 5), a front view (FIG. 6), and a rear view (FIG. 7) showing a structure in which the reinforcing member 12 and the steel plate 13 are integrated. Indicates. A steel base plate 16 is disposed horizontally on the steel plate 13, and is further filled with a grout 17 between the steel plate 13 and fixed. The bearing 130 is fixedly held on the horizontal base plate 16 and supports the rotor 110 of the turbine. At this time, the bearing 130 is installed close to the turbine blade 111 side at the projecting portion 15 of the base 10 so as to narrow the span of the rotor 110 (see FIGS. 1 and 2). That is, the bearing 130 is installed on the overhanging portion 15 of the base 10 so that the rotor 110 is supported near the turbine blade 111 and the overhanging portion 15 is not provided. Reduce the support interval. Thereby, the vibration of the rotor 110 at the time of turbine operation is suppressed.
[0016]
According to this embodiment, when the overhanging portion 15 is provided in the base 10 and the support interval of the rotor 110 is reduced by installing the bearing 130 in the overhanging portion 15, the overhanging portion 15 is not provided. As compared with the above, there is an advantage that the vibration of the rotor 110 during the turbine operation can be effectively suppressed. Moreover, since the overhang | projection part 15 was comprised with the steel plate 13 and the reinforcement member 12, the bearing 130 can be hold | maintained more firmly and the vibration of the rotor 110 can be suppressed effectively.
[0017]
In this embodiment, the reinforcing member 12 is made of steel. However, this increases the strength of the base 10 that supports the bearing 130 as compared with the case of using concrete, and the durability against vibration is increased. It is preferable in terms of improvement. However, the present invention is not limited to this, and the reinforcing member 12 may be formed of an equivalent material other than steel as long as it has durability against vibration.
[0018]
Further, in this embodiment, the shape of the reinforcing member 12 projecting from the concrete portion 11 of the foundation 10 is substantially triangular, but this is preferable in that the load from the bearing 130 can be effectively dispersed. However, the present invention is not limited to this, and the protruding portion may have another shape. For example, as a result of making the reinforcing member 12 a simple rectangle, a portion protruding from the concrete portion 11 may be a square, or a trapezoid or other arbitrary geometric shape.
[0019]
In this embodiment, the plate-shaped reinforcing member 12 is used. However, the present invention is not limited to this, and a member having a columnar shape, a block shape, a pipe shape, or any other shape may be used. In other words, the reinforcing member 12 may be any member that supports the load from the bearing 130 on the overhanging portion 15 and gives strength sufficient to withstand the vibration.
[0020]
Further, in this embodiment, the steel plate 13 is laid on the upper part of the base 10, but this is preferable in terms of enhancing durability against vibration of the base 10. However, the present invention is not limited to this, and the steel plate 13 may be omitted and the base plate 16 may be laid directly on the reinforcing member 12. This configuration also has an advantage that the support interval of the rotor 110 by the bearing 130 can be narrowed and the durability against vibration can be enhanced.
[0021]
In this embodiment, the steel plate 13 is laid so as to cover not only the portion where the reinforcing member 12 protrudes but also the concrete portion 11. This is because the load from the bearing 130 is dispersed and the durability against vibration is reduced. It is preferable at the point which can raise. However, the present invention is not limited thereto, and the steel plate 13 may be laid so as to cover only the portion where the reinforcing member 12 projects. According to the research by the inventors, it has been found that even with such a configuration, durability against vibration is improved.
[0022]
In this embodiment, the shape, structure, and size of the overhang portion 15 are not limited. In other words, the overhanging portion 15 has a main function in that the support interval between the bearings 130 and 130 is narrowed, and the shape and the like are not limited as long as this function is provided. Therefore, the shape and the like of the overhanging portion 15 may be appropriately changed within the range obvious to those skilled in the art according to the specification of the applied steam turbine. However, the overhang portion 15 needs to have a structure that can withstand the load and vibration from the bearing 130.
[0023]
( Other examples )
FIG. 8 is a cross-sectional view of an essential part showing an example different from the above-described embodiment , and FIG. 9 is an assembled perspective view showing the foundation shown in FIG. In the same figure, the same code | symbol is attached | subjected to the component same as the steam turbine 100 of the said embodiment, and the description is abbreviate | omitted. In the steam turbine 2, a steel base bracket 21 is embedded in the concrete portion 11, and a steel reinforcing member 22 is attached to the base bracket 21 together with the steel plate 13 to form an overhang portion 25 of the base platform 20. The base metal fitting 21 has a plurality of plate-like protrusions 21a on the surface of a rectangular plate-like member, and has a plurality of key-like cross-section anchor portions 21b on the back surface thereof. 10 and 11 show the reinforcing member 22 integrated with the steel plate 13, and FIG. 12 shows a front view of the base metal fitting 21. In the base metal fitting 21, the anchor portion 21b is embedded in the upper side surface of the concrete portion 11 and on the turbine blade 111 side, and the protruding portion 21a is installed with its plate-like surface standing in the axial direction of the rotor 110 (FIG. 8). And FIG. 9).
[0024]
The reinforcing member 22 is formed of a trapezoidal plate-like member, and is arranged with its surface standing on the bottom surface of the steel plate 13 and fixed by welding. The front view (FIG. 13) and side view (FIG. 14) of the base metal fitting 21 are shown in FIG. 13 and FIG. The reinforcing member 22 and the steel plate 13 are bolted to the protruding portion 21a of the base metal member 21 by the reinforcing member 22, and fixed while the steel plate 13 is laid on the upper surface of the concrete portion 11 (see FIGS. 8 and 9). As a result, the concrete part 11 is formed with a projecting part 25 that projects to the turbine blade 111 side. Further, the bearing 130 is fixedly installed on the base plate 16 by horizontally placing the base plate 16 while filling the grout 17 on the steel plate 13. Further, the bearing 130 is located on the projecting portion 25 of the base 20 closer to the turbine blade 111 and is installed so as to narrow the span of the rotor 110. Thereby, the vibration of the rotor 110 at the time of turbine operation can be suppressed.
[0025]
According to this embodiment, only the foundation fitting 21 is embedded in the concrete portion 11, and the reinforcing member 22 and the steel plate 13 are fixed to the foundation fitting 21 to form the overhang portion 25. This configuration also has an advantage that the vibration of the rotor 110 can be suppressed by narrowing the installation interval of the bearings 130. Moreover, in this modification, since the reinforcement member 22 is retrofitted and installed, there is an advantage that the overhanging portion 25 can be formed at a low cost compared to the above embodiment. Further, it is easy to remove the protruding portion 25 afterwards.
[0026]
【The invention's effect】
As described above, according to the steam turbine of the present invention, the overhanging portion is provided on the base and the bearing is held by the overhanging portion. Since the support interval of the rotor can be narrowed by the amount corresponding to the protruding portion, there is an advantage that the vibration of the rotor during turbine operation can be suppressed.
[0027]
Further, according to the steam turbine according to the present invention, in the steam turbine, the overhang portion is constituted by a steel plate or other plate-like member and a reinforcing member that reinforces the plate-like member. The durability of the protruding portion can be improved.
[0028]
Further, according to the steam turbine of the present invention, the overhanging portion is formed by embedding a rib-shaped reinforcing member in the base and laying a steel plate on the reinforcing member. It has the advantage that the bearing can be stably held against vibration of the rotor. Moreover, compared with the case where a steel plate is not laid, there exists an advantage which can improve durability of the overhang | projection part with respect to a vibration more.
[Brief description of the drawings]
FIG. 1 is a side cross-sectional view showing a main configuration of a steam turbine according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view showing the vicinity of the base of the steam turbine described in FIG.
FIG. 3 is a perspective view showing the foundation described in FIG. 2;
FIG. 4 is a perspective view showing a structure in which a reinforcing member and a steel plate are integrated.
FIG. 5 is a side view showing a structure in which a reinforcing member and a steel plate are integrated.
FIG. 6 is a front view showing a structure in which a reinforcing member and a steel plate are integrated.
FIG. 7 is a rear view showing a structure in which a reinforcing member and a steel plate are integrated.
FIG. 8 is a cross-sectional view of a main part showing a modification of the steam turbine according to the embodiment.
FIG. 9 is an assembled perspective view showing the base shown in FIG. 8;
FIG. 10 is a side view showing a reinforcing member integrated with a steel plate .
FIG. 11 is a front view showing a reinforcing member integrated with a steel plate .
FIG. 12 is a front view showing a foundation metal fitting.
FIG. 13 is a plan view showing a base metal fitting.
FIG. 14 is a side view showing a foundation metal fitting.
FIG. 15 is a side cross-sectional view showing a main configuration of a conventional steam turbine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Steam turbine 10 Base stand 12 Reinforcement member 13 Steel plate 15 Overhang part 20 Base stand 21 Foundation metal fitting 22 Reinforcement member 25 Overhang part

Claims (1)

A rotor having turbine blades;
A bearing supporting the rotor;
A projecting portion extending in the axial direction of the rotor and projecting toward the turbine blade side, and including a base for holding the bearing at the projecting portion; and
The overhanging portion is formed by embedding a rib-shaped reinforcing member having a plurality of holes in the base base while projecting from the base base, and laying a steel plate on the reinforcing member. And a steam turbine integrated with the foundation .

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