JP4225832B2 - Turbine rotor and method of manufacturing turbine stator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a turbine rotor and a turbine stator used for a turbine generator and the like, and more particularly to a method of manufacturing a turbine rotor and a turbine stator that can be suitably used for a small-sized turbine generator.
[0002]
[Prior art]
As a device for converting thermal energy into electric power, a steam turbine power generation device including a turbine and a generator is known. In this steam turbine power generator, high-temperature and high-pressure steam is generated by a boiler or the like, and a turbine is rotated by this steam to drive a generator, thereby generating electric power.
[0003]
Recently, the development of a power generation device (power generation system) that recovers thermal energy from a relatively low temperature exhaust heat of 200 to 300 ° C. or lower using a Rankine cycle and converts the thermal energy into electric power has been actively developed. Has been done. This type of power generation device is configured as a closed system including a small turbine generator. In this power generator, power is generated by vaporizing a low-boiling working medium with a heat source such as exhaust gas and supplying the vaporized working medium to a turbine generator.
[0004]
In the turbine generator described above, the turbine and the generator are connected via a single shaft, and the generator is driven by the rotation of the turbine. This type of turbine is a so-called axial flow type multi-stage turbine, and basically includes a turbine rotor and a turbine stator. The turbine rotor is fixed to the shaft, and a turbine stator is disposed so as to accommodate the turbine rotor.
[0005]
Here, a conventional method for manufacturing a turbine rotor will be described. The turbine rotor includes a disk member concentrically fixed to a shaft, a plurality of moving blades arranged along the circumferential direction on an outer peripheral portion of the disk member, and a ring shape fixed to a tip portion of these moving blades. It basically consists of a shroud. Tenon (rivet) is formed at the tip of the rotor blade. After the hole formed in the shroud is fitted into the tenon, the top of the tenon is struck with a hammer or the like to deform the shroud. Fixed to. By providing such a shroud, it is possible to obtain effects such as reducing fluid leakage at the tip of the rotor blade.
[0006]
Next, a conventional method for manufacturing a turbine stator will be described. First, a plate member such as stainless steel is prepared, and the plate member is cut into a desired length to produce a stationary blade. Next, a plurality of stationary blades are disposed along the circumferential direction between the ring-shaped inner strip band and the outer strip band, and the stationary blades are fixed to the inner strip band and the outer strip band, respectively, by welding. Thereafter, the integrated stator blade, inner strip band, and outer strip band are disposed between the inner ring member and the outer ring member. Then, the inner strip band is welded to the inner ring member, and the outer strip band is welded to the outer ring member. In this manner, a turbine stator integrally formed from the stationary blade, the inner strip band, the outer strip band, the inner ring member, and the outer ring member is manufactured.
[0007]
[Problems to be solved by the invention]
However, the above-described conventional methods for manufacturing a turbine rotor and a turbine stator have the following problems. That is, in the above-described manufacturing method of the turbine rotor, since the disk member, the moving blade, and the shroud are provided separately, there is a problem that the strength of the turbine rotor is lowered. In addition, a process of fixing these members to each other is required, and there is a problem that manufacturing cost and manufacturing time increase. Furthermore, in the case of manufacturing a small turbine, it is difficult to employ the above method in which the shroud is fixed to the moving blade by tenon because the mechanical strength of the moving blade is weak.
[0008]
In addition, the above-described manufacturing method of the turbine stator has a problem that there are many welded portions, and manufacturing cost and manufacturing time increase. In addition, it is difficult to accurately weld small vanes, and it is difficult to apply these methods to the manufacture of small turbines.
[0009]
The present invention has been made in view of the above-described conventional problems, and can be suitably applied to the manufacture of a small-sized turbine, and the manufacture of a turbine rotor and a turbine stator that can reduce the manufacturing cost and the manufacturing time. It aims to provide a method.
[0010]
[Means for Solving the Problems]
In order to achieve the above-described object, according to one embodiment of the present invention, a cylindrical portion and a plurality of moving blades arranged in the circumferential direction on the outer peripheral surface of the cylindrical portion are integrally formed by cutting from one material. Forming the cylindrical portion and the plurality of moving blades into a cylindrical member, joining end portions of the plurality of moving blades to an inner peripheral surface of the cylindrical member, cutting out the cylindrical member, and A ring-shaped shroud portion that is integrally fixed to the rotor blade is formed.
[0011]
According to the present invention, since the moving blade is cut out integrally with the cylindrical portion from one material, the moving blade can be precisely manufactured. Therefore, a small and highly efficient turbine rotor can be manufactured. Further, since the number of parts can be reduced, the manufacturing cost and the manufacturing time can be reduced, and further, a turbine rotor having high strength and reliability can be manufactured.
[0012]
In another aspect of the present invention, a cylindrical portion and a plurality of stationary blades arranged along the circumferential direction on the outer peripheral surface of the cylindrical portion are integrally formed from one material by cutting, and the cylindrical portion And inserting the plurality of stationary blades into the turbine casing, joining the ends of the plurality of stationary blades and the inner peripheral surface of the turbine casing, cutting out the cylindrical portion, and integrating with the plurality of stationary blades A ring-shaped shroud portion is formed to be fixed to.
In this case, it is preferable that the turbine stator is divided into two along the axial direction after the shroud portion is formed.
[0013]
According to the present invention, since the stator blade is cut out integrally with the cylindrical portion from one material, the stator blade can be precisely manufactured. Therefore, a small and highly efficient turbine stator can be manufactured. In addition, since the number of parts can be reduced and the welding process can be omitted, the manufacturing cost and the manufacturing time can be reduced, and furthermore, a turbine stator having high strength and reliability can be manufactured.
[0014]
According to another aspect of the present invention, a turbine rotor manufactured by the manufacturing method according to claim 1 and / or a turbine stator manufactured by the manufacturing method according to claim 2 or 3 is provided. It is a generator.
[0015]
According to the manufacturing method according to the present invention described above, a small turbine rotor and a turbine stator can be manufactured, so that a small turbine generator can be manufactured. Therefore, it is possible to realize a turbine generator that is preferably used in a power generation apparatus (power generation system) that uses relatively low-temperature exhaust heat such as exhaust gas and exhaust hot water as a heat source.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1A to FIG. 1D are views for explaining a turbine rotor manufacturing method according to an embodiment of the present invention.
[0017]
As shown in FIG. 1A, first, a block-shaped material 11 is prepared. Next, as shown in FIG. 1 (b), the block-shaped material 11 is cut out, and a plurality of stages (six stages in this embodiment) of movement are arranged on the cylindrical portion 12 and the outer peripheral surface of the cylindrical portion 12. The wings 13 are integrally formed. A plurality of moving blades 13 are provided for each stage, and the plurality of moving blades 13 are arranged at equal intervals along the circumferential direction of the cylindrical portion. The plurality of stages of moving blades 13 are formed such that the length of the moving blades 13 in the radial direction gradually decreases for each stage.
[0018]
Next, the integrally formed columnar portion 12 and moving blade 13 are inserted into a cylindrical member 14 having a stepped inner peripheral surface 14a, and the end of the moving blade 13 of each step is connected to the stepped inner periphery. Each is brought into contact with the surface 14a. In this state, the end of the moving blade 13 and the inner peripheral surface 14a of the cylindrical member 14 are joined by a joining means such as brazing. Then, as shown in FIG. 1 (d), the cylindrical member 14 is cut out to form a plurality of ring-shaped shroud portions 15 that are integrally fixed to the end portions of the moving blades 13 at each stage. Thereafter, an axial hole 12a extending in the axial direction is formed at the center of the cylindrical portion 12, and thus the turbine rotor 10 is completed.
[0019]
FIG. 2A to FIG. 2D are views for explaining a method for manufacturing a turbine stator according to an embodiment of the present invention. As shown in FIG. 2A, first, a block-shaped material 21 is prepared. Next, as shown in FIG. 2 (b), the block-shaped material 21 is cut out, and the cylindrical portion 22 and a plurality of stages (six steps in this embodiment) arranged on the outer peripheral surface of the cylindrical portion 22 are static. The wings 23 are integrally formed. Each stage has a plurality of stationary blades 23, and the stationary blades 23 of each stage are arranged at equal intervals along the circumferential direction of the cylindrical portion 22. The plurality of stages of stationary blades 23 are formed such that the radial length of the stationary blades 23 is gradually shortened for each stage.
[0020]
Next, the integrally formed cylindrical portion 22 and the stationary blade 23 are inserted into a turbine casing 24 having a stepped inner peripheral surface 24a, and the end portion of each stage of the stationary blade 23 is connected to the stepped inner surface. Each is brought into contact with the peripheral surface 24a. In this state, the end portion of each stage of the stationary blade 23 and the inner peripheral surface 24a of the turbine casing 24 are joined by a joining means such as brazing. A plurality of through holes 24 b extending perpendicularly to the axial direction are formed in the turbine casing 24 before or after the joining step. Thereafter, as shown in FIG. 2D, the cylindrical portion 22 is cut out to form a plurality of ring-shaped shroud portions 25 that are integrally fixed to the stationary blades 23 of each stage. The turbine stator 20 manufactured in this way is divided into two along its central axis. The two divided bodies of the turbine stator 20 are fixed to each other by screwing nuts to bolts (not shown) inserted through the through holes 24b.
[0021]
FIG. 3 is a cross-sectional view illustrating a turbine generator including a turbine rotor and a turbine stator manufactured using a manufacturing method according to an embodiment of the present invention.
As shown in FIG. 3, the turbine generator includes an axial-flow turbine (expander) 1 and a main shaft 6 that connects the turbine 1 and a generator (not shown). A high-temperature and high-pressure fluid as a working medium is introduced into the turbine 1 from the center of the turbine 1.
[0022]
In this embodiment, a liquid-phase working medium is vaporized by a steam generator or the like installed outside to generate a high-temperature and high-pressure fluid (gas-phase working medium). As the working medium, HCFC123 (dichlorotrifluoroethane) or trifluoroethanol (CF ₃ CH ₂ OH) having a boiling point of around 40 ° C. is preferably used.
[0023]
The turbine 1 includes a turbine rotor 10 fixed to the main shaft 6 and a turbine stator 20 disposed outside the turbine rotor 10. The turbine rotor 10 includes a plurality of stages (six stages in the present embodiment) of moving blades 13 arranged along the axial direction, and a shroud portion 15 that is integrally fixed to the moving blades 13. The turbine stator 20 includes a turbine casing 24 that houses the turbine rotor 10, a plurality of stages (six stages in this embodiment) of stationary blades 23 that are integrally fixed to the inner peripheral surface of the turbine casing 24, and stationary blades 23. And a shroud portion 25 fixed integrally. The turbine rotor 10 and the turbine stator 20 are manufactured by the method described above.
[0024]
A labyrinth mechanism 30 is provided on the radially inner side of each stage of the stationary blade 23. By providing this labyrinth mechanism 30, fluid leakage between stages can be prevented, and the efficiency of the turbine 1 can be increased. As described above, the turbine stator 20 is divided into two along the axial direction, and the two divided bodies screw nuts (not shown) into bolts (not shown) inserted through the through holes 24b. Are fixed to each other.
[0025]
The moving blades 13 and the stationary blades 23 are alternately arranged along the axial direction. The inner diameter of the turbine casing 24 is gradually increased along the fluid flow direction, and the radial lengths of the rotor blades 13 and the stationary blades 23 are configured to be increased step by step along the fluid flow direction. With such a configuration, the high-temperature and high-pressure fluid supplied to the turbine 1 is reduced in pressure in the turbine 1 and discharged from the turbine 1 as a relatively low-temperature and low-pressure fluid.
[0026]
An outer cylinder 3 is provided outside the turbine casing 24. Between the turbine casing 24 and the outer cylinder 3, a flow path 32 through which the fluid discharged from the turbine 1 flows is formed. A bearing bracket 34 is disposed on the low pressure side (discharge side) of the turbine 1, and a main bearing 7 that rotatably supports the main shaft 6 is accommodated in the bearing bracket 34. The turbine-side surface of the bearing bracket 34 has a shape that is smoothly curved from the turbine rotor 10 to the flow path 32. With such a configuration, the fluid flowing out of the turbine 1 flows along the surface of the bearing bracket 34, and the flow direction is changed. In addition, the arrow shown in FIG. 3 shows the flow of the fluid.
[0027]
A main shaft 6 that connects the turbine 1 and the generator is rotatably supported by a main bearing 7, a turbine side auxiliary bearing 8, and a generator side auxiliary bearing (not shown). The main bearing 7 is disposed between the turbine 1 and the generator, and is disposed at a substantially center of gravity position of the entire rotating body including the main shaft 6, the turbine rotor 10, and the generator rotor (not shown). The main bearing 7 is a so-called parallel combination bearing in which rolling bearings 7a and 7b are arranged along the axial direction. The turbine side auxiliary bearing 8 is an end of the main shaft 6 on the turbine side and is disposed on the high pressure side of the turbine 1.
[0028]
The main bearing 7 and the turbine side auxiliary bearing 8 are supplied with lubricating oil for lubrication and cooling. Lubricating oil discharged from a lubricating oil supply pump (not shown) is supplied to the main bearing 7 and the turbine side auxiliary bearing 8 via the lubricating oil supply passages 41 and 42. The lubricating oil supplied to the main bearing 7 and the turbine side auxiliary bearing 8 returns to the lubricating oil supply pump via the lubricating oil recovery passages 44 and 45. Lubricating oil is also supplied to the generator side auxiliary bearing from the lubricating oil supply pump. In addition, you may provide a lubricating oil cooler and a dust filter as needed.
[0029]
The above-described turbine generator is suitably used for a power generation apparatus (power generation system) that uses a relatively low-temperature exhaust heat such as exhaust gas at about 200 to 400 ° C. or exhaust hot water at 100 to 150 ° C. as a heat source. Such a power generation system that uses relatively low-temperature exhaust heat is generally used for small-scale applications, and a small-sized turbine generator having a power generation output of 10 kw or less is used. According to the method for manufacturing the turbine rotor and the turbine stator according to the present embodiment shown in FIGS. 1 (a) to 1 (d) and FIGS. 2 (a) to 2 (d), a small-sized turbine rotor and turbine stator are provided. Can be manufactured with high accuracy, and a small and highly efficient turbine generator can be manufactured.
[0030]
【The invention's effect】
As described above, according to the present invention, the moving blade is cut out integrally with the cylindrical portion from one material, and therefore the moving blade can be precisely manufactured. Therefore, a small and highly efficient turbine rotor can be manufactured. Further, since the number of parts can be reduced, the manufacturing cost and the manufacturing time can be reduced, and further, a turbine rotor having high strength and reliability can be manufactured.
[0031]
Further, since the stationary blade is also integrally cut with the cylindrical portion from one material, like the above-described moving blade, it is possible to manufacture the stationary blade precisely. Therefore, a small and highly efficient turbine stator can be manufactured. Further, since the number of parts can be reduced and the welding process can be omitted, the manufacturing cost and the manufacturing time can be reduced, and furthermore, a turbine stator having high strength and reliability can be manufactured.
[Brief description of the drawings]
FIG. 1A to FIG. 1D are views for explaining a method for manufacturing a turbine rotor according to an embodiment of the present invention.
FIGS. 2A to 2D are views for explaining a method for manufacturing a turbine stator according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a turbine generator including a turbine rotor and a turbine stator manufactured by using a manufacturing method according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Turbine 3 Outer cylinder 6 Main shaft 7 Main bearing 8 Turbine side auxiliary bearing 10 Turbine rotor 11,21 Material 12,22 Cylindrical part 12a Shaft hole 13 Rotor blade 14 Cylindrical member 15,25 Shroud part 20 Turbine stator 23 Stator blade 24 Turbine casing 30 Labyrinth mechanism 32 Channel 34 Bearing bracket 41, 42 Lubricating oil supply channel

Claims (4)

A cylindrical portion and a plurality of moving blades arranged along the circumferential direction on the outer peripheral surface of the cylindrical portion are integrally formed from one material by cutting,
Inserting the cylindrical portion and the plurality of moving blades into a cylindrical member;
Joining the ends of the plurality of blades and the inner peripheral surface of the cylindrical member;
A method of manufacturing a turbine rotor, comprising: cutting out the cylindrical member to form a ring-shaped shroud portion that is integrally fixed to the plurality of blades. A cylindrical part and a plurality of stationary blades arranged along the circumferential direction on the outer peripheral surface of the cylindrical part are integrally formed from one material by cutting,
Inserting the cylindrical portion and the plurality of stationary blades into a turbine casing;
Joining the ends of the plurality of stationary blades and the inner peripheral surface of the turbine casing;
A method of manufacturing a turbine stator, wherein the cylindrical portion is cut out to form a ring-shaped shroud portion that is integrally fixed to the plurality of stationary blades. After forming the shroud portion, manufacturing work process of turbine stator according to claim 2, characterized in that dividing the turbine stator into two in the axial direction. A turbine generator comprising the turbine rotor produced by the production method according to claim 1 and / or the turbine stator produced by the production method according to claim 2 or 3.

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