JP5036155B2 - Mounting method of seat liner in hydraulic machine - Google Patents

Description

The present invention relates to a seat liner mounting method in a hydraulic machine such as a water turbine or a pump turbine, and more particularly, to a seat liner mounting method in a hydraulic machine having a configuration effective for improving performance in mounting a seat liner .

  In recent years, extending the life of existing hydropower plants and reducing maintenance costs are important issues. Among them, sediment wear in the flow path due to sediment contained in the water flow is one of the major problems because it degrades performance and reliability.

  A Francis-type pump turbine as an example of a conventional hydraulic machine has a configuration in which a plurality of guide vanes are sandwiched between upper and lower covers facing each other as described in, for example, Japanese Patent Laid-Open No. 10-103213. It has become. Here, a seat liner is attached to the upper cover and the lower cover with bolts or the like. The bolts are spot welded at an arbitrary position so that the bolts can be easily removed for rotation prevention and when replacing the seat liner.

JP-A-10-103213

  By the way, if there is a part where the shape of the object changes suddenly in the water flow, the flow is disturbed and a vortex is generated. Since solid materials such as earth and sand are mixed in the water used in the hydraulic machine, the earth and sand in the turbulent water flow collides with a liner or the like that forms a flow path, and wear occurs at the collision portion. Here, it is said that the faster the flow containing earth and sand, the greater the amount of wear due to earth and sand. Since the flow is fast around the guide vane, sediment wear is particularly likely to occur.

  In the part where the seat liner is bolted, the head of the bolt exposed in the flow path has a slight gap between the bolt hole and this gap creates a flow turbulence. In particular, since the flow velocity is high here, there is a problem that earth and sand wear occurs in the gap portion and the seat liner wears.

The objective of this invention is providing the attachment method of the seat liner in the hydraulic machine which can reduce earth and sand abrasion in the attachment part of a seat liner .

(1) In order to achieve the above object, the present invention provides a plurality of guide vanes rotatably held between upper and lower covers, and between the upper and lower covers and the guide vanes. A seat liner attachment method in a hydraulic machine having a seat liner attached to the side by a plurality of bolts, wherein a predetermined number of bolts of the plurality of bolts are in a specific opening state of the guide vane, The gap between the bolt and the bolt hole provided in the seat liner is arranged at a position overlapping the guide vane so that the gap is not exposed to the flow path, and the specific opening state of the guide vane is determined at the design stage. The guide vane opening state is estimated to be the most frequently used, and is arranged at a position overlapping the guide vane in the specific opening state of the guide vane. The number of bolts overlaps with the guide vane at an opening other than the opening range of 50% to 100% including the specific opening state and normally used in the opening control of the guide vane. More than the number of bolts arranged at the position .
By such a method, earth and sand wear at the seat liner attachment portion can be reduced.

(2) In the above (1), preferably, the bolts arranged at positions overlapping with the guide vanes are arranged so that there is one for each of the guide vanes on the stay vane side and the runner side across the guide vane shaft. It is.
(3) In the above (1), preferably, the plurality of remaining bolts bolt, said bolt and bolt holes, said guide when a specific opening state of the vane, the bolt nearest guide It is spot-welded or line-welded in at least one place at a position in contact with a line drawn parallel to the camber line of the vane.

(4) In order to achieve the above object, the present invention includes a plurality of guide vanes rotatably held between the upper and lower covers, and between the upper and lower covers and the guide vanes, of a method of attaching the seat liner in a hydraulic machine having a seat liner that is attached by bolts to the upper and lower cover side, and the bolt and the bolt hole, when a specific opening state of the guide vanes, the bolt At the position where it is in contact with a line drawn parallel to the camber line of the nearest guide vane, spot welding or linear welding is performed at at least one place, and the specific opening state of the guide vane is most frequently used in the design stage. The guide vane opening state is estimated to be large .
By such a method, earth and sand wear at the seat liner attachment portion can be reduced.

  According to the present invention, earth and sand wear at the attachment portion of the seat liner can be reduced.

Hereinafter, the structure of the hydraulic machine by one Embodiment of this invention is demonstrated using FIGS.
Initially, the structure of the hydraulic machine by this embodiment is demonstrated using FIG.1 and FIG.2. Here, a Francis pump turbine will be described as an example of a hydraulic machine.
FIG. 1 is a cross-sectional view of a principal part showing a configuration of a hydraulic machine according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a main part of FIG.

  First, the case of power generation operation will be described. The stays 6 are arranged in a blade row on the inner periphery of the casing 1 connected to an iron pipe that conducts water from an upper pond (not shown). The guide vane 7 is disposed on the inner peripheral side of the stay 6 and is sandwiched between the upper cover 2 and the lower cover 3. The runner 8 is attached to the lower end of the main shaft. The water flow from the runner 8 is guided to a lower pond (not shown) by a suction pipe or the like.

  The high-pressure water introduced into the casing 1 flows through the stay 6 and flows through the guide vane 7 for adjusting the flow rate toward the runner 8, transfers energy, and then flows out to the suction pipe. In the case of pumping operation, the water flow is pumped from the suction pipe by the runner 8 and flows out to the casing 1 through the stay vane 6 through the guide vane 7 for adjusting the flow rate.

  Here, in the hydraulic machine as described above, the guide vane 7 needs to be moved in order to adjust the flow rate flowing into or out of the runner 8, so that the guide vane 7 can rotate around its axis. It has become.

  2, the upper cover 2 and the lower cover 3 have a plurality of plate-like mainly metal sheet liners 4U and 4L and a cover liner 5U, 5L is attached with a plurality of bolts 9. The head of the mounting bolt 9 is exposed to the flow path, and there is a gap between the bolt 9 and the bolt holes formed in the seat liners 4U and 4L and the cover liners 5U and 5L. Is disturbed. In particular, in the vicinity of the seat liner 4U, 4L mounting position, the flow passage is particularly narrow due to the guide vanes 7, so that the flow is particularly fast, and the earth and sand contained in the turbulent water flow is at high speed. Sediment wear occurs.

Next, the first mounting structure of the seat liner in the hydraulic machine according to the present embodiment will be described with reference to FIG.
FIG. 3 is a main part plan view showing a first mounting structure of the seat liner in the hydraulic machine according to the embodiment of the present invention. 1 and 2 indicate the same parts.

  In FIG. 3, a line L1 indicated by a two-dot chain line indicates an arc centered on the axis of the runner 8 shown in FIG. The guide vane shafts 7a of the guide vanes 7 are arranged on the line L1 at equal intervals. Here, the angle θ1 is an angle formed by a tangent line of the arcuate line L1 passing through the center of the guide vane shaft 7a and a line connecting the rear end of the guide vane 7 and the center of the guide vane shaft 7a. When the opening angle of the guide vane 7 changes from 0% opening to 100% opening, the angle θ1 changes from 5 ° to 30 °, for example.

  Here, the guide vane opening includes a position in a guide vane opening state that is predicted to be most frequently used in the design stage. The opening degree is, for example, 70% opening degree. The position of the guide vane 7 indicated by a solid line in FIG. 3 indicates the position of the guide vane opening state that is predicted to be most frequently used in the design stage. In this embodiment, the bolts 9 </ b> A and 9 </ b> B are arranged at positions that overlap the guide vane 7 in the axial direction (that is, positions within the projection plane of the guide vane 7). With such an arrangement of the bolts 9, the gap between the bolts 9 and the bolt holes provided in the seat liner is not exposed to the flow path. As shown in FIG. 2, there is a slight gap between the sheet liner forming the flow path and the guide vane 7 in order to rotate the guide vane 7. Therefore, even if the bolt 9 and the guide vane 7 are arranged so as to overlap in the axial direction, the flow enters the gap, but the flow is very small, and the flow disturbance generated from the gap between the bolt and the bolt hole is very small. Since it is within the range, earth and sand muds can be reduced.

  Here, the most frequently used guide vane opening state is, for example, the opening with the longest total operation time of the year during power generation.

  In FIG. 3, a guide vane 7 'indicated by a one-dot chain line indicates a state where the angle θ1 is 17.5 ° and the guide vane opening is 50%. Even in this state, the bolts 9A and 9B are located at positions overlapping the axial direction of the guide vane 7 '. Further, a guide vane 7 ″ indicated by a broken line indicates a state in which the angle θ1 is 30 ° and the guide vane opening degree is 100%. Even in this state, the bolts 9A and 9B are shafts of the guide vane 7 ″. It is located at a position that overlaps the direction. That is, when the guide vane opening is in the range of 50% to 100% opening, the bolts 9A and 9B are located at positions overlapping the axial direction of the guide vane 7. For example, if the 70% opening is the most frequently used guide vane opening state, the opening control of the guide vane is generally controlled within the opening range of 50% to 100% opening. In many cases, the sand mud can be reduced within the range of openings that are normally used.

  For example, when 20 guide vanes are arranged on the circumference of one water wheel, the number of bolts to which the seat liner is attached is, for example, 100. Therefore, 40 of the 100 bolts are arranged at positions overlapping the guide vane 7 in the axial direction when the guide vane opening state is predicted to be most frequently used as shown in FIG. By doing so, the wear of the mounting portion of the seat liner due to these bolts can be reduced. A method of reducing the wear of the seat liner mounting portion in the remaining 60 bolt mounting portions will be described later with reference to FIG.

Next, the second mounting structure of the seat liner in the hydraulic machine according to the present embodiment will be described with reference to FIG.
FIG. 4 is a main part plan view showing a second mounting structure of the seat liner in the hydraulic machine according to the embodiment of the present invention. 1 and 2 indicate the same parts.

  FIG. 4 is an enlarged view of the seat liner 4 and the bolts 9 in the seat liner attachment portion. The seat liner 4 is provided with a bolt hole 10. The bolt 9 is located in the bolt hole 10.

  Here, an arrow L2 indicated by a solid line is a line drawn substantially parallel to the camber line of the guide vane closest to the bolt when the guide vane opening state is the most frequently used. The guide vane camber line is a line connecting the centers of the inscribed circles of the guide vane 7.

  The bolt 9 and the bolt hole 10 are spot-welded to prevent the bolt 9 from rotating and to be easily removed when replacing the seat liner. Conventionally, the number of spot welding locations is arbitrary one, but in this example, there are two locations. Moreover, in this example, spot welding is performed on the vicinity of the above-described arrow line L2 and the two contact points in contact with the bolt 10 as shown in the figure. White portions SW1 and SW2 indicate spot welding beads.

  Even if the gap between the bolt 9 and the bolt hole 10 is exposed in the flow path due to the position of such spot welding, it is like a breakwater where the welds SW1 and SW2 stop the turbulence and vortex generated from here. Since it plays a role, the turbulence and vortex of the water flow are reduced, and the sediment of the objects constituting the flow path such as the sheet liner and the cover liner due to the earth and sand in the water flow can be reduced. This method is applied to the part where the gap between the guide vane and the bolt and the bolt hole does not overlap in the axial direction, reducing the turbulence and vortex generated from the gap between the bolt and the bolt hole, and suppressing sediment wear. .

  In FIG. 4, an arrow L2 'indicated by a one-dot chain line indicates a camber line in which the opening degree θ1 in FIG. 3 is 17.5 ° and the guide vane opening degree is 50%. An arrow L2 ″ indicated by a broken line indicates a camber line in which the angle θ1 is 30 ° and the guide vane opening is 100%. Even in these states, the gap is exposed in the flow path. The turbulence and vortices of the water flow are reduced because the turbulence and vortices generated from this place play a role like a breakwater where the welds SW1 and SW2 stop.

  In the embodiment shown in FIG. 3, there is a slight gap between the guide vane 7 and an object forming a flow path such as a liner, and water containing earth and sand flows in. Therefore, in the embodiment shown in FIG. 3 as well, the turbulence and vortex of the flow generated from the gap between the bolt and the bolt hole is further reduced by welding at the position shown in FIG. Wrinkles can be further suppressed.

Next, a first modification of the second mounting structure of the seat liner in the hydraulic machine according to the present embodiment will be described with reference to FIG.
FIG. 5 is a main part plan view showing a first modification of the second mounting structure of the seat liner in the hydraulic machine according to the embodiment of the present invention. The same reference numerals as those in FIG. 4 indicate the same parts.

  In the example shown in FIG. 4, the vicinity of two contact points where the camber line (arrow line L <b> 2) and the bolt 9 are in contact is spot-welded, for example, a total of six points of three adjacent points. Such spot welding is performed at a plurality of locations. White portions SW1A, SW1B, SW1C, SW2A, SW2B, and SW2C indicate bead of spot welding.

Next, a second modification of the second mounting structure for the seat liner in the hydraulic machine according to the present embodiment will be described with reference to FIG.
FIG. 6 is a main part plan view showing a second modification of the second mounting structure of the seat liner in the hydraulic machine according to the embodiment of the present invention. The same reference numerals as those in FIG. 4 indicate the same parts.

  In the example shown in FIG. 4, the camber line (arrow line L <b> 2) and two contact points in contact with the bolt 9 are spot-welded, whereas the guide vane closest to the bolt 9 is almost parallel to the camber line. When the line L2 is drawn, the gap between the bolt 9 and the bolt hole 10 in the vicinity of the two contact points where the line L2 is in contact with the bolt 9 has a bead width / length ratio of about twice or more. Welding with a certain length is performed in the circumferential direction or tangential direction. White portions SW1 'and SW2' indicate bead of linear welding.

  As described above, the bolt with the head exposed in the flow path for fixing the seat liner to the upper cover or the lower cover is connected to the guide vane in the most frequently used guide vane opening state in the axial direction. Although the bolt is exposed to the flow path by arranging it in the overlapping position, the flow is small enough to flow into a very small gap between the upper cover facing the guide vane and the plurality of seat liners attached to the lower cover. Since it is only exposed, the earth and sand wear force by the earth and sand contained in the small amount of water flow is small, and the earth and sand wear is less than when the gap between the bolt and the bolt hole is exposed to the mainstream.

  In addition, when a line is drawn almost parallel to the camber line of the guide vane closest to the bolt, if the vicinity of the two contact points between the line and the bolt is welded at one point or at least at a point, the bolt and It is possible to suppress the occurrence of turbulence and vortices from the gap with the bolt hole, and to reduce earth and sand sand.

As described above, by reducing earth and sand wear, a highly reliable hydraulic machine can be obtained. Furthermore, since flow disturbance due to the gap between the bolt and the bolt hole is reduced, hydraulic efficiency can be improved.

It is principal part sectional drawing which shows the structure of the hydraulic machine by one Embodiment of this invention. It is a principal part expanded sectional view of FIG. It is a principal part top view which shows the 1st attachment structure of the seat liner in the hydraulic machine by one Embodiment of this invention. It is a principal part top view which shows the 2nd attachment structure of the seat liner in the hydraulic machine by one Embodiment of this invention. It is a principal part top view which shows the 1st modification of the 2nd attachment structure of the seat liner in the hydraulic machine by one Embodiment of this invention. Ru main part plan view showing a second modification of the second attachment structure of the seat liner in hydraulic machinery according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Casing 2 ... Upper cover 3 ... Lower cover 4, 4U, 4L ... Seat liner 5U, 5L ... Cover liner 6 ... Stay vane 7 ... Guide vane 7a ... Guide vane shaft 8 ... Runner 9 ... Bolt 10 ... Bolt hole SW ... Welding bead

Claims (4)

Hydraulic power having a plurality of guide vanes rotatably held between the upper and lower covers, and a seat liner between the upper and lower covers and the guide vanes and attached to the upper and lower covers by a plurality of bolts A mounting method of a seat liner in a machine,
Among the plurality of bolts, a predetermined number of bolts , in a specific opening state of the guide vane, so that a gap between the bolt and a bolt hole provided in the seat liner is not exposed to the flow path. Arranged to overlap the guide vane ,
The specific opening state of the guide vane is a guide vane opening state that is estimated to be most frequently used in the design stage,
And in the specific opening state of the guide vane, the number of the bolts arranged at the position overlapping with the guide vane includes the specific opening state and is normally used in the opening control of the guide vane. The seat liner mounting method in a hydraulic machine , wherein the number of bolts arranged at a position overlapping with the guide vane at an opening other than the opening range of 100% to 100% opening is larger . In the mounting method of the seat liner in the hydraulic machine according to claim 1,
The bolt arranged at a position overlapping with the guide vane is arranged so as to be one for each of the guide vane on the stay vane side and the runner side across the guide vane shaft . Mounting method . In the mounting method of the seat liner in the hydraulic machine according to claim 1,
The remaining bolts of the plurality of bolts are a line drawn in parallel with the camber line of the guide vane closest to the bolt when the bolt and the bolt hole are in a specific opening state of the guide vane. in contact position, the mounting method of the sheet liner of hydraulic machinery, characterized in that the spot welding or linear welding at least at one location or more. A plurality of guide vanes pivotally held between the upper and lower covers, be between the upper and lower cover the guide vane, in the hydraulic machine having a seat liner that is attached by bolts to the upper and lower cover side A mounting method of the seat liner ,
And said bolt and bolt holes, wherein when a specific opening state of the guide vane at a position in contact with the parallel line drawn and camber line of the nearest guide vane and the bolt, the point at at least one position Welding or linear welding ,
A seat liner attachment method in a hydraulic machine, wherein the specific opening state of the guide vane is a guide vane opening state estimated to be most frequently used in a design stage .

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