JP2002242812A - Field installation and assembly method for horizontal shaft valve hydraulic turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a field installation and assembly construction period of a large sized horizontal shaft valve hydraulic turbine. SOLUTION: A horizontal shaft valve hydraulic turbine has a stay vane 8 bonded to an outer casing 10 and an inner casing 11 and buried and fixed to a concrete provided around the outer casing 10 and is shipped from a factory by being divided to several parts for restriction on a transport. In the field installation and assembly method of the horizontal shaft valve hydraulic turbine, the outer casing 10 and the stay vane 8 are connected to each other by a welding at the field. A concrete is provided in the state that a guide vane mechanism 15 is tightened to a flange 22 of the outer casing 10 by a bolt and a seal welding is applied to a division connection part 21 of the outer casing 10. Thereafter, a substantial welding of the division connection part 21 is carried out. Thereby, a deformation of the outer casing flange 22 caused by a curing heat and, placement vibration of the concrete, and a welding heat is inhibited. As a result, a construction period is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of installing and assembling a large horizontal shaft turbine at a site, and more particularly to a method of burying concrete in a stay vane portion.

[0002]

2. Description of the Related Art FIG. 8 is a longitudinal sectional view showing a general structure of a valve turbine. In FIG. 8, a closed vessel (valve) 2 is placed in a flowing water channel 1, and a water turbine runner 3 is provided at an end on the downstream side (right side in FIG. 8). A generator 4 is housed inside the valve 2, and its rotor 5 is connected to the water turbine runner 3 via a shaft 6. The turbine runner 3
The flowing water channel 1 is rotated by the reaction force of the water flowing from the upstream side (left side in FIG. 8) as shown by the arrow, and the rotor 3 is driven to generate electric power. A guide vane 7 is arranged on the upstream side of the water turbine runner 3, and the flow rate of the water flow is adjusted according to the load of the generator 4 by the opening degree of the guide vane 7 which is opened and closed by an operation device (not shown).

[0003] The valve 2 is supported by a concrete structure 9 forming the water channel 1 through a pair of stay vanes 8 standing upright. The stay vane 8 is a hollow cylindrical body, serves as a passage for various wirings and pipes, and also serves as a manhole through which a person enters and exits the valve 2. One end of the stay vane 8 is connected to a conical outer casing 10 forming a part of the wall of the water channel 1, and the other end is connected to a conical inner casing 11 forming a part of an outer shell of the valve 2. The valve 2 is held in a flowing water channel by being embedded and fixed in a concrete structure 9 made of concrete cast around the outer casing 10. A rectifier 12 having a triangular cross section is connected to the downstream end surface of the stay vane 8.

The guide vane 7 is supported so as to be openable and closable across an outer guide vane ring 13 and an inner guide vane ring 14. The guide vane 7 includes a guide vane operating device (not shown), an outer guide vane ring 13 and an inner guide vane ring. Together with the guide vane ring 14, it is integrally assembled as a guide vane mechanism 15. The guide vane mechanism 15 is connected to the valve 2 by bolting the respective flanges of the outer guide vane ring 13 and the inner guide vane ring 14 to the respective flanges of the outer casing 10 and the inner casing 11. The outer guide vane ring 13 is connected to one end of a discharge ring 16 surrounding the turbine runner 3, and the other end of the discharge ring 16 is connected to a suction pipe 17 formed of a concrete structure.

Here, in the case of a large valve turbine, the stay vanes 8 and the outer casing 1 are not provided for reasons of transportation restrictions.
0 is shipped from the factory in a state of being divided into several parts as shown in FIG. 9, for example. That is, in the example of FIG. 9, the upper and lower stay vanes 8 are connected to the outer casing side 8.
a and the inner casing 8b. Also, the outer casing 10 has two upstream and downstream sides.
And the upstream and downstream parts are further divided into 1
It is divided into four parts each of 0a to 10d and 10e to 10h, and is divided into eight parts as a whole. The upper and lower divided portions 8a of the stay vane 8 are divided into the divided portions 1 of the outer casing 10.
It is shipped in a state where it is connected to Oa and 10c, and the divided part 8b is shipped in a state where it is connected to the inner casing 11. Although not shown in FIG.
Divided into outer casing split parts 10e, 1
0g and the inner casing 11, respectively, before being shipped. The divided portions 8a, 8b and 10a to 10h are integrally connected on site by welding. The manner of this division is appropriately determined depending on the capacity of the water turbine, and is various.

[0006] In such a horizontal valve turbine, installation of the stay vane portion has conventionally been performed by the following procedure. That is, as shown in FIG. 10, for example, the stay vanes 8 and the outer casing 10 that are separately shipped are combined and installed on the gantry 19 of the installation foundation 18, and the split connecting portions 20 of the stay vanes 8 and the split connecting portions 21 of the outer casing 10 are installed. Are integrated by welding.
Thereafter, as shown in FIG. 11, concrete is cast around the outer casing 10. In that case, the split connection unit 2
Deformation (undulation) of the outer casing flange 22 is inevitable due to (1) field welding, hardening heat of concrete and driving vibration. For this reason, as shown in FIG. 11, the deformation of the flange 22 has been corrected by machining using a machine tool 23 or manually by a grinder. The illustrated machine tool 23 has a cutter 2 attached to the tip of an arm 23b that rotates around a shaft 23a supported in the inner casing 14.
3c is attached, and the flange surface is cut by a cutter 23c rotated and driven by a motor 23d.

[0007]

However, such a conventional method has the following problems. Due to the welding of the split connecting portion 21 and the casting of concrete, a large deformation occurs on the flange surface of the outer casing 10. Therefore, in order to suppress this deformation as much as possible, FIG.
2, between the outer casing 10 and the concrete structure 9, the outer casing 10 and the inner casing 1
Since a large number of reinforcing members 24 must be attached to the inside of the inner casing 11 or the like between them, it takes a lot of time to set up the reinforcing members 24. Note that a pipe jack, a turnbuckle type stay, or the like is used as the reinforcing member 24. The outer casing flange surface is corrected manually by a machine tool 23 or a grinder. However, since the machine tool 23 is large (by the way, the diameter of the flange 22 is 10 m or more for a large valve turbine). However, manual correction requires a great deal of man-hour and skill. The dimension A (see FIG. 8) between the flange surface of the outer guide vane ring 13 and the flange surface of the inner guide vane ring 14 is strictly controlled from the viewpoint of the assembling accuracy of the guide vane mechanism 15; Due to the deformation of the flange surface, an error is likely to occur between the distance between the flange surfaces of the outer and inner casings 13 and 14 and the dimension A,
In order to bring the corresponding flange surfaces into good contact with each other when the guide vane mechanism 15 is tightened, it is necessary to repeat the above-described interval adjustment, and this operation requires a lot of time.

It is an object of the present invention to prevent deformation of the outer casing when the stay vanes are buried, to simplify the work of tightening the flange mechanism, to shorten the on-site construction period, and to improve the installation accuracy.

[0009]

In order to solve the above problems SUMMARY OF THE INVENTION In the present invention, fundamentally review the conventional installation and assembly procedures, and performs as follows.
First, the present invention combines the divided stay vane and the outer casing, installs them on an installation base, welds the divided connection of the stay vane, and then seal-welds the divided connection of the outer casing from the outside. Then, concrete is poured around the outer casing, and then, after the concrete has hardened, the split connection portion of the outer casing is fully welded from the inside (claim 1).

[0010] The inventor of the present invention has learned from the experience of installing and assembling a large number of large-sized valve turbines that a large influence on the deformation of the flange surface of the outer casing is welding of the outer casing performed before placing concrete, and the concrete is hardened with concrete. Later welding was found to cause little deformation of the flange surface. Claim 1 is based on this finding, and after sealing welding the split connecting portion of the outer casing to such an extent that concrete does not infiltrate at the time of casting concrete, the concrete is poured as it is and after the concrete is hardened, The main welding of the split connection portion of the casing is performed. According to the first aspect, at the time of the main welding of the outer casing, the periphery of the outer casing is hardened with concrete, so that the flange surface is hardly deformed even if it receives welding heat.

According to a first aspect of the present invention, a guide vane mechanism in which the outer guide vane ring, the inner guide vane ring, the guide vane, and the guide vane operating device are integrally assembled is installed on an installation base, and the guide vane mechanism includes the guide vane mechanism. After the outer casing and the inner casing are bolted together, the seal welding is preferably performed, and then concrete is poured around the outer casing (claim 2).

In the outer casing in which the divided parts are combined, slight displacement of the divided parts is allowed before welding of the divided connection parts. Therefore, if the guide vane mechanism is fastened to the outer casing and the inner casing at the stage of combining the divided portions of the outer casing, the flange surfaces of the outer casing and the inner casing conform to the dimension A between the flange surfaces of the guide vane mechanism (FIG. 8). Go to
Easily adheres to the flange surface of the guide vane mechanism. Therefore, if the bolts are tightened as they are, the outer casing and the inner casing are connected to the guide vane mechanism in a manner similar to each other, so that the distance between the outer casing and the inner casing and the flange surface between the guide vane mechanism can be adjusted. It becomes unnecessary. In this case, in order to improve the positional deviation at the divided connecting portions, it is preferable to combine the divided portions with a slight gap between the end faces of the butted portions. The seal welding and concrete casting of the split connection portion are performed after the guide vane mechanism is tightened.

According to the second aspect of the present invention, the outer casing and the inner casing are fastened and fixed to the guide vane mechanism before the concrete is poured, so that the outer casing is restrained by the guide vane mechanism, and the concrete casing thereafter is driven. Deformation of the outer casing flange due to concrete hardening heat and casting vibration during installation is prevented.

Further, in the second aspect, the split connection portion of the flanges of the outer casing and the inner casing for tightening the guide vane mechanism performs a main welding and a finish of the flange surface before the concrete casting, and the flange is connected to the flange. after tightening the guide vane mechanism, it is preferable to pouring the concrete (claim 3). In other words, although the main welding of the divided connection portions of the outer casing and the inner casing is performed as much as possible after the concrete is cast, welding and finishing (smoothing of the welded portion) are completed only on the tightening surface of the guide vane mechanism. Thus, once the guide vane mechanism is fastened to the outer casing and the inner casing, it is not necessary to remove the guide vane mechanism thereafter even during the main welding of the split connection portion. When the guide vane mechanism is tightened, a sealing material (such as an O-ring) necessary for water sealing between the flange surfaces is naturally inserted.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to the horizontal valve turbine shown in FIG. 8 will be described below with reference to FIGS. 1 to 7 and with reference to FIG.
Here, FIGS. 1 to 5 are views showing a procedure of an installation and assembling process, and FIG. 6 is an enlarged perspective view of a portion P in FIG. FIG. 7 shows FIG.
(A) shows a seal welding state, and (B) shows a main welding state. Note that the same reference numerals are used for the portions corresponding to the conventional example. First, as shown in FIG. 1, a divided portion 8 a (FIG. 9) of the lower stay vane 8 is installed on a gantry 19 provided on an installation foundation 18 and fixed with foundation bolts. The divided portions 8a are sequentially combined, and the portions between the divided portions are temporarily fixed. This temporary fixing is performed by welding fastening pieces to key points (for example, two to three places) at the butted ends of the divided parts, and tightening the bolts between the fastening pieces. Then, centering is performed in this state, and the turnbuckle type stay 2 is used.
While holding at 5, the split connecting portions 20 of the upper and lower stay vanes 8 are welded from outside and inside.

Next, as shown in FIG. 2, the divided portions 10b, 10d, 10e to 10h (FIG. 9) of the outer casing 10 are sequentially hung and combined, similarly temporarily fixed, and integrated as shown in FIG. I do. In this state, the main welding of only the divided connection portion 21 of the outer casing flange 22 and the finishing (smoothing) of the connection surface are performed. As shown in FIG. 6, this welding is performed on the connecting surface 22a of the flange 22 and the inner surface of the reinforcing rib 22b, which cannot be welded when the guide vane mechanism 15 is tightened, at the divided connecting portion 21 of the flange 22. Next, in FIG. 3, the guide vane mechanism 15 which has been partially assembled in advance is suspended, and FIG.
As shown in (1), it is installed on the gantry 19 together with the hanging fitting 26, and the transit 27 is used to center the outer casing 10. A seal material (round rubber) is mounted in a groove on a flange surface (not shown) of the guide vane mechanism 15.

Outer casing 10 and guide vane mechanism 1
When the centering of the guide vane 5 is completed, the guide vane mechanism 15 is bolted to the outer casing 10 and the inner casing 11 with bolts. At the time of this tightening, the flange surfaces of the outer casing 10 and the inner casing 11 and the guide vane mechanism 1
If there is a front / rear misalignment with the flange surface on the fifth side, the stay vane 8 and the divided portion of the outer casing 11 move following the guide vane mechanism 15 according to the tightening of the tightening bolt, and the gap between the flange surfaces is good. Adhere to

After the guide vane mechanism 15 is tightened, the split connection portion 21 of the outer casing 10 is subjected to seal welding. In this method, the minimum welding is performed so that concrete does not enter through the gap between the split connecting portions 21 when the concrete is poured. As shown in FIG.
A patch 28 is applied to 1 from the outside, and welding is performed along the corner 29. With this, stay vane 8, outer casing 1
The zero and the outer guide vane ring 13 are integrally unitized.

When the seal welding is completed, the stay vanes 8
After confirming the installation core of the outer casing 10 again and correcting it if necessary, concrete is poured around the outer casing 10 as shown in FIG. The gantry 19
A part of is buried in concrete as it is. In this concrete casting, since the stay vane 8, the outer casing 10 and the outer guide vane ring 13 are integrated as a strong unit, even if the concrete hardening heat, the driving vibration, etc. act from the outside, the outer casing 10
Such deformation is suppressed, and even if there is a deformation, the entire unit is affected, so that local deformation such as a flange surface does not occur.

Then, when the concrete hardens,
The final main welding of the divided connection portion 21 of the stay vane 8, the outer casing 10, and the rectifier 12 is performed. FIG. 7B shows the main welded portion 30 of the outer casing 10. The main welding is performed from the inside of the split welded portion 21 along a groove formed in advance. In this welding, the outer casing 10
Is hardened with concrete from the outside, so that deformation of the outer casing flange 22 due to welding hardly occurs. After all welding is completed, the fastening bolts between the outer casing 10 and the outer guide vane ring 13 are slightly loosened, and the outer casing 10 is welded and cast into concrete.
Of the inner guide vane ring 13
After fixing the installation core with a pipe jack etc., tighten the tightening bolt firmly and finish the work.

[0021]

As described above, according to the present invention, the stay vane and the outer casing buried in the concrete and the outer guide vane ring not buried are integrally installed and assembled to perform centering, concrete placement and welding. This has led to a reduction in reinforcement work, elimination of flange surface modification, and elimination of guide vane mechanism tightening adjustment work.For example, for a horizontal shaft turbine with a capacity of 23,700 KW, installation time was reduced by about 1.5 months. ,
About 10% of installation costs can be saved.

[Brief description of the drawings]

FIG. 1 is an installation assembly process diagram showing an embodiment of the present invention, and is a longitudinal sectional view in a state where a stay vane is installed on an installation base stand.

FIG. 2 is a longitudinal sectional view showing a step of combining a divided portion of an outer casing with a stay vane of FIG. 1;

FIG. 3 is a longitudinal sectional view showing a step of combining a guide vane mechanism with an outer casing and an inner casing of FIG. 2;

FIG. 4 is a longitudinal sectional view showing a process of centering and bolting the guide vane mechanism combined in FIG. 3;

5 is a longitudinal sectional view showing a state where concrete is cast around the outer casing in FIG.

FIG. 6 is an enlarged perspective view of a portion P in FIG. 3;

FIG. 7 is an enlarged view of a portion Q in FIG. 4, wherein (A) shows a seal welding state and (B) shows a main welding state.

FIG. 8 is a longitudinal sectional view showing a general configuration of a horizontal valve turbine.

FIG. 9 is a perspective view showing an example of division of a stay vane and an outer casing in FIG. 8;

10 is a longitudinal sectional view showing a conventional example in which a stay vane, an inner casing, and an outer casing in FIG. 9 are installed on an installation base.

FIG. 11 is a longitudinal sectional view showing a step of placing concrete around the outer casing in FIG. 10 and correcting deformation of the flange.

FIG. 12 is a right front view of FIG. 10;

[Explanation of symbols]

 REFERENCE SIGNS LIST 9 concrete structure 10 outer casing 11 inner casing 12 straightening body 13 outer guide vane ring 14 inner guide vane ring 15 guide vane mechanism 21 outer casing split connection portion 22 outer casing flange 28 metal plate 29 seal welding portion 30 welding portion

Claims (3)

[Claims] 1. A stay vane which is connected to an outer casing and an inner casing and is embedded and fixed in concrete cast around the outer casing. The outer casing and the stay vane are divided into several parts. These parts are connected on site by welding, and the outer casing and the inner casing are bolted to the outer guide vane ring and the inner guide vane ring via flanges, respectively. In the on-site installation / assembly method of the horizontal valve turbine, the divided stay vanes and the outer casing are combined and installed on an installation base, and the divided connection parts of the stay vanes are welded, and then the divided connection parts of the outer casing are set outside. After seal welding from the outer case Casting concrete around the ring, and after the concrete has hardened, the split connection portion of the outer casing is fully welded from the inside from the inside, and a method for locally assembling and mounting the horizontal shaft valve turbine is provided. 2. A guide vane mechanism in which the outer guide vane ring, the inner guide vane ring, the guide vane, and the guide vane operating device are integrally assembled is installed on an installation base, and the guide vane mechanism includes the outer casing and the guide casing. 2. The method of claim 1, wherein the seal welding is performed after bolting the inner casing, and then concrete is poured around the outer casing. 3. The split connecting portion of the flanges of the outer casing and the inner casing for tightening the guide vane mechanism performs main welding and finishing of a flange surface before placing the concrete, and the guide vane mechanism is attached to the flange. 3. The method according to claim 2, wherein the concrete is cast after tightening.