JPH0631712B2 - Anti-vibration bar and its arrangement / installation method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a mechanism for supporting a heat transfer tube of a nuclear steam generator so as to prevent vibration, and in particular, a protection mechanism arranged between rows of heat transfer tubes in a nuclear steam generator. It relates to the swing bar.

The present invention provides a novel vibration damping bar installed in a U-shaped curved portion of a tube bundle in a nuclear steam generator in order to suppress tube vibration caused by a mixture of steam and water flowing through a U-shaped heat transfer tube. Concerning the configuration and its installation method. If the vibration isolator is not installed, the U-shaped heat transfer tube vibrates, and if suppression is not performed, leakage will occur and the primary coolant in the steam supplied to the turbine generator will be leaked. It will be a loss.

Conventional anti-vibration bars are generally of constant cross section, eg square or elliptical. On the other hand, the U-shaped heat transfer tube has a substantially constant cylindrical cross section, so that there is a gap between the vibration isolation bar and the U-shaped heat transfer tube. The gap between the U-shaped heat transfer tube and the vibration isolating bar is not desirable in terms of the performance or reliability of the heat transfer tube, and it is difficult to reduce this gap. Since the U-shaped heat transfer tube and the vibration isolation bar have dimensional tolerances, it is difficult to maintain close contact between the two even when assembled. For example, general tolerances are vibration isolation bar and U
It occurs at the outer diameter with the letter-shaped heat transfer tube. Due to the formation of the U-shaped heat transfer tube, the bend may have an elliptical cross section and the straight portions may not be aligned exactly parallel to each other. Furthermore, the holes in the tube support plate are not provided at equal intervals, and the intervals between adjacent U-shaped heat transfer tubes in the curved portion may not be uniform.

SUMMARY OF THE INVENTION The main object of the present invention is to provide a new and improved anti-vibration bar which reduces the clearance in the U-shaped heat transfer tube of a nuclear steam generator, thereby improving the degree of tube support. is there.

For this purpose, the tube bundle is composed of a plurality of rows of heat transfer tubes, each of the heat transfer tubes allows a high-temperature coolant to flow therethrough, and in order to fix the heat transfer tubes to prevent vibration of the heat transfer tubes, A vibration-isolating bar arrangement / attachment method in which the vibration-isolating bars are arranged and attached to a tube bundle of a steam generator in which a vibration-isolating bar having a tubular shape is arranged between adjacent rows in the tube bundle. After inserting at least one vibration isolating bar between them, a compressed fluid is introduced into the inserted vibration isolating bar, and the vibration isolating bar is placed between the heat transfer tubes and the vibration isolating bars in the adjacent rows. The present invention resides in an anti-vibration bar arrangement / attachment method, which is characterized by expanding so as to minimize the gap.

The invention will be apparent from the following description of a preferred embodiment of the invention, which is shown by way of example only in the accompanying drawings.

1A and 1B of the accompanying drawings, a conventional type of nuclear steam generator 8 is provided with a bundle 11 of a number of U-shaped heat transfer tubes 13 oriented vertically. Shown as one. These heat transfer tubes 13 are arranged in the lower cylindrical body 9 of the steam generator 8, and at the bottom end thereof,
A generally hemispherical channel head 17 as shown in FIG. 1A is connected. The channel head 17 is separated by a partition 18 into a first half, commonly known as a hot leg 20, and a second half, commonly known as a cold leg 22. Hot cooling water from the nuclear reactor is guided to the steam generator 8 and enters the hot leg 20 through the primary coolant inlet 24. This high-temperature cooling water flows from the hot leg 20 to the openings of the plurality of U-shaped heat transfer tubes 13, is guided to the cold leg 22 through the heat transfer tubes 13, and finally passes through the primary coolant outlet 26 and the steam generator. Get out of 8.

A portion of the steam generator 8 mainly including the tube bundle 11 and the channel head 17 is called an evaporator portion 10. As shown in FIG. 1A, the steam generator 8 further includes an upper shell 30.
Having a steam drum portion 32, which includes a steam separator 34. The feed water is adapted to flow into the steam generator 8 via an inlet nozzle 28 arranged in the upper shell 30, to be sprayed and mixed with the water taken out by the steam separator 34. This water supply travels down an annular channel around tube bundle 11 and is introduced into the bottom of tube bundle 11. Since the high-temperature cooling water flows through the U-shaped heat transfer tube 13 in the tube bundle 11, the mixed water of the feed water and the recirculated water boils. The steam thus produced rises into the steam drum section 32. Steam flows from the steam generator 8 to the steam outlet 3
Before entering the turbine generator (not shown) via 6, the steam separator 34 removes the water contained therein from the steam.

As shown in FIG. 1A, the U-shaped heat transfer tube 13 is supported in the form of a tube bundle 11 by a series of the lower tube support plate 12 and the upper tube support assembly 14. As shown in FIGS. 1A and 1B, the upper tube support assembly 14 comprises a plurality of retainer rings 16a, 16b, 16c. As clearly shown in FIG. 1A, each retainer ring 16 is substantially elliptical. Assuming that the retainer ring 16c is placed at the top of the tube bundle 11, the retainer rings 16a, 16
The major axis and minor axis of b and 16c are decreasing in order. A plurality of sets of anti-vibration bars 15 are arranged between adjacent rows of the U-shaped heat transfer tubes 13. Although one set of such anti-vibration bars 15 is shown in FIG. 1B, it is understood that another continuous set of similar anti-vibration bars 15 are placed before and after the illustrated set. See. Each of the vibration isolation bars 15a, 15b, 15c is V-shaped, and its end portion extends to the outer circumference of the tube bundle 11 and is connected to a corresponding retainer ring 16. For example, one end of the vibration isolation bar 15a may be attached to the retainer ring 1 by temporary welding.
6a, and similarly the other end of the vibration-proof bar 15a is fixed to the retainer ring 16a.

FIG. 1B shows a cross section of the tube bundle 11 and shows the vibration isolation bars 15a, 15b,
The place where 15c is arranged so as to support the upper end of the U-shaped heat transfer tubes 13 (in particular, the arrangement of the U-shaped heat transfer tubes 13a to 13n arranged in one row) is described.

In FIG. 2, the anti-vibration bar 15 is received and the anti-vibration bar 15 is received.
A test rig 40 is shown having a series of indentations 50 at. The test rig 40 includes an upper plate 42a, a front plate 42d, and a rear plate 42b.
And lower plate 42c, which are fastened together by bolts as shown. The upper plate 42a includes the first and second
Have first and second rows of holes 46, 48 for receiving rows of test heat transfer tubes 13 ", 13 ', respectively. As shown in FIGS. The vibration isolation bar 15 is arranged between the first and second rows of the test heat transfer tubes 13 ', 13 ". Each of the first row of holes 48 has substantially the same shape and dimensions as the test heat transfer tube 13 'to secure the test heat transfer tube 13', while
The second row of holes 46 is substantially elliptical so that the second row of test heat transfer tubes 13 "can be moved toward the first row of test heat transfer tubes 13 '. According to this, various intervals are set between the pair of test heat transfer tubes 13 ′ and 13 ″, so that the irregular intervals between the U-shaped heat transfer tubes 13 in the normal tube bundle 11 can be reproduced. . As shown in FIG. 2, a set of micrometer heads 44
a, 44b, 44c are paired test heat transfer tubes 13 ', 13 "
It is designed to be rotated by hand so that various intervals can be set.

As shown in FIGS. 3 and 4, the oval vibration isolating bar 15 has a constant minor axis in the initial stage before being pressurized as described below. The anti-vibration bar 15 according to the invention is a tubular one which has the property of being deformed by the use of fluid pressure, whereby a minimum clearance contact is achieved in the U-shaped heat transfer tube 13, thus Vibration support in the heat tube 13 is improved. In particular, as shown in FIG. 5, a series of indentations 50a, 50b, 50c.
Is formed on the vibration isolation bar 15 by supplying a compressed fluid to the vibration isolation bar 15. The minor axis B of the elliptical vibration isolating bar 15 before pressure is applied is shown in FIG. As shown in FIG. 5 and FIG. 6, a pair of dents 50a, 50b, 50c are attached to the vibration isolating bar 15, and the minor axis A of the vibration isolating bar 15 between each pair is short due to the supply of the compressed fluid. It is slightly increased compared to the diameter B. By using fluid pressure, the minor axis C of the deformed anti-vibration bar 15 at a point approximately midway between adjacent indentations 50 is significantly increased. It will be appreciated that the deformation causes the minor axis A to increase slightly from the initial minor axis B. As shown particularly in FIG. 5, the depression 5
The 0 surface tends to follow the contours of the opposing test heat transfer tubes 13 ', 13 ", thus minimizing the size of the gap between the vibration isolator bar 15 and the test heat transfer tubes 13', 13". . The minimum gap between the heat transfer tube and the vibration isolation bar 15 is
5 improves the support provided to the test heat transfer tube 13,
This reduces vibration and reduces the risk of leakage of primary cooling water. By maintaining a gap of 3 mm or less, the desired tube support and vibration reduction is obtained.

Such mechanical deformation of the vibration isolation bar 15 is performed after the U-shaped heat transfer tubes 13 are assembled and installed as the tube bundle 11. In the preferred embodiment of the present invention, there is provided an apparatus and method for hydraulically deforming a vibration isolation bar 15 as shown in FIG. FIG. 7 shows the test heat transfer tubes 13 ', 1 supported by the test rig 40 as described above.
Shown is a vibration isolator bar 15 disposed between the first and second rows of 3 ". A pump 72 supplies a conditioned compressed fluid such as water to the vibration isolator bar 15, thereby preventing vibration. Swing bar 1
5 expands and a series of dents 50 as shown in FIG.
The a, 50b and 50c are attached to the vibration isolation bar 15. Anti-vibration bar 1
In this preferred method of pressurizing and mounting 5, the U-shaped heat transfer tubes 13 are first assembled into a tube bundle 11 as shown in FIGS. 1A and 1B, after which the required deformation is carried out. It will be appreciated that the pump 72 is coupled to each of the anti-vibration bars 15 in sequence or in any other desired order.

As shown in FIG. 7, the pump 72 is connected to one end of the vibration isolation bar 15 by a conduit 66 and a fluid connector 64b. The other end of the vibration isolation bar 15 is attached to the fluid coupler 64a. Since the fluid coupler 64a functions to prevent leakage of the compressed fluid, the pressure inside the vibration isolation bar 15 can be increased. Pump 72 includes conduit 66 and fluid coupler
The fluid is sent to the vibration isolation bar 15 via 64b. Pressure gauge 6
8 is provided in the circuit between the pump 72 and the vibration isolating bar 15, whereby the fluid pressure is measured. Further, the pressure recording device 70 is connected to the pressure gauge 68,
Recording of fluid pressure is continued, mainly to confirm maximum fluid pressure.

In one embodiment of the present invention, an elliptical vibration isolation bar 15 'having a major axis of 1 cm and a minor axis of 0.75 cm was positioned by a test rig 40, as shown in FIGS. 8A and 8B. Located between the first and second rows of test heat transfer tubes 13 ', 13 ". Fluid pressure was pumped into the isolation bar 15' and gradually increased by pump 72 to maximum pressure. In the example, the oval anti-vibration bar 15 'has a wall thickness of 0.5 mm and is made from stainless steel known as type 304.

As shown in FIGS. 2 and 5, each pair of test heat transfer tubes 13 ′, 13 ″ has six positions 1, 2, 3, 4 ,.
5, 6 and each pair is spaced 2.5 cm from the adjacent pair. In order to prove the feasibility of this method by deformation, the distance between the test heat transfer tubes 13 ', 13 "of each pair from the 1st to the 6th is 9.4 m, respectively.
m, 8.6mm, 9.4mm, 7.6mm, 9.4mm, 7.6m
It is set to m so as to reproduce the fluctuations and intervals found in the heat transfer tubes 13 in the general tube bundle 11. Pressure slowly increased by 35 kg / cm pump 72 every ^two to a maximum of 350 kg / cm ² was then returned to the pressure to zero. As a result, as shown in Table 1 below, relatively constant minor axes A and C were obtained.

Additionally, 'to the maximum value determined beforehand the pressure, for example, raising above 350 kg / cm ^2, anti-vibration bars 15', especially anti-vibration bars 15 of the elliptical cylindrical heat transfer tube 13 Testing has shown that the outer shape of the is deformed. The above-described deformation of the U-shaped heat transfer tubes 13 may adversely affect their structural integrity, which is due to the vibration isolation bar 1
It must be avoided by limiting the predetermined maximum value from the point of view of the particular configuration of 5, eg material and size.

9A and 9B, another embodiment of the present invention is shown, in which the anti-vibration bar 1
5 "is an upper side wall which is relatively thicker than the side walls 15b and 15d
It is shaped as a rectangle with 15a and a lower sidewall 15c.
The dimensions B and C shown in FIG. 9A are 7.5 m, respectively.
It is m, 12.5 mm. FIG. 9B shows the anti-vibration bar 15 "after the anti-vibration bar 15" has been inflated by air and the side wall 15d has been curved.

A third embodiment is shown in FIGS. 10A and 10B, in which the anti-vibration bar 15 comprises flexible side walls 15e, 1.
It has side walls 15f, 15h interconnected by 5g.
The dimensions B and C are the same as those of the vibration isolation bar 15 "shown in Fig. 9A. Of the above three embodiments, the oval vibration isolation bar 1 is used.
5'is preferable because it can be manufactured relatively easily and inexpensively.

[Brief description of drawings]

1A and 1B are respectively a perspective view of a nuclear steam generator in which a U-shaped heat transfer tube is supported by an upper tube support assembly according to the present invention, and a vibration isolation bar and vibration isolation of the present invention. FIG. 2 is a sectional view particularly showing a state where the bar is assembled to the upper tube support assembly, and FIG. 2 shows the first row and the second row of the test heat transfer tubes in which the vibration isolating bars are arranged. Perspective views of a test rig for carrying out, FIG. 3 and FIG.
The figures are plan views of a row of test heat transfer tubes showing the vibration isolating bar before and after deformation, respectively, and FIGS. 4 and 6 are the cross sectional view of the vibration isolating bar and FIG. 3, respectively. FIG. 5 is a side view of the arrangement of FIG. 5, FIG. 7 is a schematic illustration of the test rig of FIG. 2 connected to a controllable source of compressed fluid, and FIGS. 8A and 8B are oval shapes, respectively. FIGS. 9A and 9B are a second embodiment of the present invention and show a vibration isolating bar and a view showing the vibration isolating bar in contact with a U-shaped heat transfer tube, respectively. FIG. 10A and FIG. 10B are views showing a shape of a rectangular vibration isolating bar and a place where the vibration isolating bar is in contact with a U-shaped heat transfer tube, respectively, in a third embodiment of the present invention. The shape of a rectangular anti-vibration bar with foldable sides and such anti-vibration bar in contact with a U-shaped heat transfer tube. It is a diagram showing a place. In the figure, 8: steam generator, 11: tube bundle, 13: heat transfer tube, 13 ', 13 ": test heat transfer tube, 15, 15', 15", 15: vibration-proof bar, 40: test rig, 50, 50a, 50b, 50c: Dent 72: Pump

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 999999999 Shikoku Electric Power Co., Inc. 2-5 Marunouchi, Takamatsu City, Kagawa Prefecture (71) Applicant 999999999 2-82 Watanabe-dori, Chuo-ku, Fukuoka City, Fukuoka Prefecture (71) Applicant 999999999 Japan Atomic Power Co., Ltd. 1-6-1, Otemachi, Chiyoda-ku, Tokyo (72) Inventor Robert Matsuconaussie Wilson Surfside Drive, Pittsburgh, Pennsylvania, USA 636 (72) Invention Inventor Bahia Bencatara Mana Gaudha, South Nineth Street, Yang Gutdo, Pennsylvania, USA 703 (72) Inventor Robert Matsukunes Wepphua, Pittsburgh, Pittsburgh, USA Bulls Street 465 (56) Reference Patent Sho 60-171304 (JP, A)

Claims (12)

[Claims] 1. A tube bundle (11) comprising a plurality of rows of heat transfer tubes (13), each of said heat transfer tubes (13) circulating a high temperature coolant to prevent vibration of said heat transfer tubes (13). In order to do the heat transfer tube (13)
The tube bundle (11) of the steam generator (8) has a tube-shaped vibration isolation bar (15) arranged between adjacent rows of the tube bundle (11) to fix In the vibration-isolating bar arranging / mounting method of arranging and mounting (15), at least one vibration-isolating bar (15) is inserted between adjacent rows of the tube bundle (11), and then the compressed fluid is inserted. The vibration isolation bar (15) and expands the vibration isolation bar (15) so as to minimize the gap between the heat transfer tubes (13) in the adjacent row and the vibration isolation bar (15). Anti-vibration bar arrangement / mounting method characterized by 2. The maximum pressure at which the pressure of the compressed fluid is sufficient to bring the outer circumference of the vibration isolating bar (15) into contact with the heat transfer tubes (13) in the adjacent rows, and the heat transfer tubes are never deformed. The anti-vibration bar arrangement / attachment method according to claim 1, wherein the number is increased within a range up to the level. 3. The vibration isolating bar arrangement / attaching method according to claim 2, wherein the pressure of the compressed fluid is gradually increased to a maximum level. 4. The vibration isolating bar arrangement / attachment method according to claim ² , wherein the pressure of the compressed fluid is gradually increased in increments of 35 kg / cm ² until it reaches a maximum level. 5. A vibration damping bar (15) made of stainless steel, the maximum level of which is set to about 350 kg / cm ^2. Claims 1 to 4. The anti-vibration bar arrangement / attachment method according to any one of the items. 6. A tube bundle (11) comprising a plurality of rows of heat transfer tubes (13), each of said heat transfer tubes (13) circulating a high temperature coolant to prevent vibration of said heat transfer tubes (13). In order to do the heat transfer tube (13)
The tube bundle (11) of the steam generator (8) has a tube-shaped vibration isolation bar (15) arranged between adjacent rows of the tube bundle (11) to fix (15) A vibration-isolating bar arrangement / attaching method, wherein the tube bundle is attached.
After inserting at least one vibration isolating bar (15) between the adjacent rows in (11), a compressed fluid is introduced into the inserted antivibration bar (15), and the vibration isolating bar (15) is introduced. In the vibration isolation bar used in the vibration isolation bar arrangement / attachment method, the heat transfer tubes (13) in the adjacent rows and the vibration isolation bar (15) are expanded so that the gap between them is minimized, Each of the vibration isolation bars (15) is hollow, and has contact points forming first and second rows on opposite sides so as to receive and support the heat transfer tubes (13) in the adjacent rows, Anti-vibration bar, characterized in that each of said contact points is shaped as a recess (50) for receiving said heat transfer tube (13). 7. The heat transfer tubes (13) arranged in a line are spaced apart from each other by a predetermined constant distance.
And the contact points forming the second row are spaced from each other by the same distance as the predetermined distance, and the dents (50) are adjacent to the heat transfer tubes (1
The antivibration bar according to claim 6, which has a similar outer shape to ensure close contact between 3) and the antivibration bar (15). 8. The antivibration device according to claim 6 or 7, wherein each of the antivibration bars (15) has an elliptical shape whose cross section has a short diameter and a long diameter. bar. 9. A vibration isolating bar (15), each of which has a rectangular cross section, as claimed in claim 6 or 7.
Anti-vibration bar described in paragraph. 10. A rectangular shape having a length and a width, and when the length is larger than the width, the contact points forming the first and second rows have the length of the vibration-proof bar (15). 10. The vibration isolation bar according to claim 9, wherein the vibration isolation bar is arranged along the height. 11. Anti-vibration bars (15) each having a first side and a second side disposed along a length and facing each other, and disposed along a width. In the case of having a third side portion and a fourth side portion which face each other, the third side portion and the fourth side portion have a relatively thin wall thickness and 10. The invention of claim 9 wherein the first and second sides are folded inward for easy movement to contact adjacent rows of heat transfer tubes. Anti-vibration bar as described. 12. The vibration isolation bar according to claim 6, wherein the thickness of the hollow vibration isolation bar (15) is 0.5 mm.