JP4585414B2 - Vibration preventing device and heat exchanger using the same - Google Patents

Description

  The present invention relates to a vibration preventing device for preventing vibration of a heat transfer tube and a heat exchanger using the same.

A steam generator of a pressurized water nuclear power plant is provided with a large number of heat transfer tubes bent in a U shape and having ends fixed to a tube plate. The heat transfer tube has a U-shaped bent portion as a free end.
The heat transfer tubes form a heat transfer tube group arranged in an annual ring shape in the same plane, that is, so that the radius of curvature of the bent portion gradually increases from the inside toward the outside. A number of these heat transfer tube groups are arranged in parallel to each other in a direction perpendicular to the arrangement surface.
In each heat transfer tube group, the number of heat transfer tubes gradually decreases from the center toward the outside, and the radius of curvature of the heat transfer tubes located on the outside gradually decreases.
Thereby, the bent portion of the heat transfer tube forms a substantially hemispherical shape as a whole.

In the steam generator, a high-temperature coolant pressurized from the nuclear reactor flows inside the heat transfer tube and heats the heat transfer tube. The feed water supplied from above the heat transfer tube is in contact with the outer surface of the heat transfer tube, is heated, evaporates and flows vertically along the heat transfer tube, and appears in the form of steam at the top of the steam generator .
Thus, the heat transfer tube is vibrated by the flow of the fluid existing inside and outside the heat transfer tube. This vibration causes damage to the heat transfer tube. In a remarkable case, for example, the fixed support portion is broken due to fatigue, and the gap support portion is broken due to wear thinning.

In order to prevent vibration of the heat transfer tubes, a brace is attached between adjacent heat transfer tube groups in the bent portion so as to come into contact with both heat transfer tubes.
All the brace brackets are fixed integrally to prevent them from coming out.
Thus, what was shown to patent document 1 was used well as what fixes a brace | restoration metal fitting integrally.
In this method, a curved support bar is disposed outside the bent part, and the outer end of each brace is fixed to the support bar by welding.

As another method for integrating the outer ends of the brace, for example, a method using a screw as shown in Patent Document 2 has been proposed.
This is a fixing means including a screw, a spacer, and a nut.
The screw includes a head portion having a groove fitted to the brace and a screw portion protruding from the groove. The spacer is a cylinder having the same height as the width of the brace. The spacer has a screw hole on one end surface and a thread portion protruding on the other end surface.
Pass the threaded part of the screw through the hole provided in the brace, and fit the brace into the groove on the head. Align the screw part of the screw with the screw hole of the spacer, rotate the spacer, and fasten the screw, brace and spacer. The hole of the next brace is passed through the threaded portion of the spacer, and the next brace is fastened with a nut. This is repeated to fix all the brace brackets.

US Patent No. 3007679 US Pat. No. 5,514,250

However, since the one shown in Patent Document 1 uses welding, the support rod extends due to the heat of welding and shrinks when it cools, but the amount of expansion / contraction varies depending on the location, so the gap between the brace brackets varies. There was a problem. If the spacing of the brace brackets varies, a gap is generated between the brace bracket and the heat transfer tube, and the brace bracket may be damaged during operation.
In the case of the one shown in Patent Document 2, it is necessary to perform screwing work at two places in order to attach one brace bracket, and it is necessary to attach the brace brackets one by one. There is a problem that the work takes a long time.
In addition, when the mounting position of the spacer is the same among a plurality of bracelets, a screw cannot be installed on the structurally intermediate bracelet. For this reason, since the head of the screw that restricts the movement in the rotation direction is not engaged with the intermediate brace, there is a possibility that the brace will rotate during operation.
Furthermore, since the spacer is attached to the inner side of the tip of the brace, the tip portion of the brace forms a free end. For this reason, the tip of the brace may vibrate due to the fluid flowing around the heat transfer tube, affecting the overall vibration.
In addition, the head and the nut become an extra bulge, and the flow of the fluid is obstructed accordingly.

  In view of the above-described problems, the present invention provides a vibration preventing device that reliably sets the interval between the brace brackets to a required value, reliably prevents the movement thereof, and is easy to assemble, and a heat exchanger using the same. With the goal.

In order to solve the above problems, the present invention employs the following means.
That is, the vibration preventing device according to the present invention is a brace that is mounted so that both end portions are fixed to a tube plate and are in contact with adjacent heat transfer tubes between a plurality of heat transfer tubes having U-shaped free ends. A spacer that is interposed between the bracket and the adjacent bracket, and has a groove that fits the bracket on the opposite surface facing the one bracket, the bracket and the clamp And fastening means for connecting the spacers adjacent to each other.

According to the present invention, the brace mounted between the heat transfer tubes is fitted into the groove portion of the spacer and connected by the fastening means in a state of being sandwiched by the surface opposite to the groove portion of the next spacer. Is done.
The next brace is fitted in the groove portion of the next spacer, and is connected by the tightening means while being sandwiched by the surface opposite to the groove portion of the next spacer. By repeating this, the fixing work of the brace is performed. This fixing work can be performed together with the installation work of the brace or separately after the installation.
As described above, since the intervals of all the brace brackets are defined by the spacers, the required intervals can be reliably ensured by adjusting the dimensions of the spacers.
Moreover, since all the bracelets are assembled in a state where they are fitted in the groove portions of the spacers, it is possible to reliably prevent the possibility of movement such as rotation of the bracelets.
As a result, it is possible to prevent a gap from being formed between the brace and the heat transfer tube, so that vibration of the heat transfer tube can be effectively prevented.
Further, since the fastening work is only required once to fix one brace, the vibration preventing device can be easily assembled in a short time.

  In the vibration preventing apparatus according to the present invention, the tightening means is a bolt, and a screw hole that is screwed into the bolt is provided only in the spacer located on the opposite side of the head of the bolt. It is characterized by.

In this way, the tightening means is a bolt, and since the screw hole that is screwed into the bolt is provided only in the spacer located on the opposite side of the bolt head, the brace is sandwiched between the spacers. In this state, the brace is fixed by inserting a bolt from one spacer and screwing the bolt into the screw hole of the other spacer.
Therefore, the vibration preventing device can be easily assembled in a short time.
Since the spacer is provided with a groove portion that prevents movement such as rotation of the brace, the head portion of the bolt may be the minimum necessary size. Moreover, since the spacer provided with the screw hole has the function of a nut, it is not necessary to provide a separate nut.
For this reason, since there are few extra protrusions, the risk of hindering the flow of fluid can be minimized. Moreover, since the number of members can be reduced, the anti-vibration device can be manufactured at low cost.

  The vibration preventing device according to the present invention is the most distant among the spacers located on the side opposite to the head of the bolt, when the tightening positions of three or more spacers adjacent to each other are substantially the same. Only the spacer is provided with a screw hole to be screwed with the bolt.

Thus, when the tightening positions of three or more spacers adjacent to each other are substantially the same, only the spacer farthest among the spacers located on the side opposite to the bolt head is screwed into the bolt. Since screw holes are provided, a bolt is inserted from the spacer on one end side while holding the brace between each spacer, and a plurality of bolts are screwed into the screw holes on the spacer on the other end. The brace can be fixed with bolts at once.
As a result, the vibration preventing device can be assembled more easily in a short time.

  Further, the vibration preventing device according to the present invention includes a screw hole for tightening one of the spacers and the brace, in the spacer located in the middle of different tightening positions between the spacers on both sides adjacent to each other. A through hole through which the bolt to be tightened in cooperation with the other spacer is provided.

According to the present invention, the brace is fitted into the groove portion of one spacer, the brace is clamped by two spacers having a screw hole and a through hole, and a bolt is inserted from the one spacer side. Screw into the screw holes of the second spacer. Next, the brace is fitted in the groove of the second spacer, the brace is clamped by the three spacers, the bolt is inserted from the through hole of the two spacers, and is screwed into the screw holes of the three spacers. .
Thus, by providing a through hole and a screw hole in the intermediate spacer, a single brace can be fixed by a single bolt fastening even at different fastening positions.
Further, by adjusting the interval between the through hole and the screw hole, it is possible to cope with the difference in the tightening position.

  Moreover, in the vibration preventing apparatus according to the present invention, the end of the spacer is disposed at substantially the same position as the end of the brace.

Thus, since the edge part is arrange | positioned in the substantially same position as the edge part of a brace | sticker metal fitting, a brace | sticker metal fitting does not protrude from the edge part of a spacer, and forms a free end.
For this reason, it is possible to prevent the tip of the brace from vibrating due to the fluid flowing around the heat transfer tube and affecting the overall vibration.

  A heat exchanger according to the present invention includes the vibration preventing device according to any one of claims 1 to 5.

As described above, since the vibration preventing device according to any one of claims 1 to 5 is provided, the gap between the heat transfer tube and the brace can be set within a required range, and if necessary, no gap. it can.
Thereby, since it can prevent that a heat exchanger tube vibrates during a driving | operation, accidents, such as a heat exchanger tube being damaged, can be prevented and the stable driving | operation can be performed over a long period of time.

According to the present invention, since all the bracelets are defined by the spacers, the required intervals can be ensured by adjusting the spacer dimensions.
Further, since all the brace fittings are assembled in a state of being fitted in the groove portion of the spacer, it is possible to effectively prevent the heat transfer tube from vibrating.
Further, since the fastening work is only required once to fix one brace, the vibration preventing device can be easily assembled in a short time.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, the present invention is applied to a steam generator (heat exchanger) 1 of a pressurized water nuclear power plant. In addition, this invention is not limited by this embodiment. The constituent elements of this embodiment include those that can be easily replaced by those skilled in the art or those that are substantially the same.
FIG. 1 is a longitudinal sectional view showing an overall schematic structure of the steam generator 1.
The steam generator 1 includes a substantially cylindrical lower shell 3 and a substantially cylindrical upper shell 5.
The lower body 3 is provided with a first water chamber 7, a second water chamber 9, a tube plate 11, a large number of heat transfer tubes 13, and a tube group outer cylinder 15.

The first water chamber 7 and the second water chamber 9 are arranged so as to bisect the lower portion of the lower body 3. The first water chamber 7 is provided with a primary coolant inlet nozzle 17 for introducing the primary coolant from the nuclear reactor.
The second water chamber 9 is provided with a primary coolant outlet nozzle 19. The primary coolant heat-exchanged by the steam generator 1 and collected in the second water chamber 9 is sent out toward the reactor through the primary coolant outlet nozzle 19.

The heat transfer tube 13 is a tube bent into a U shape.
Both end portions of the heat transfer tube 13 are fixed to a tube plate 11 provided at the upper part of the first water chamber 7 and the second water chamber 9 so as to penetrate the tube plate 11. The heat transfer tube 13 extends upward from the tube plate 11.
The curved portion 21 which is a free end is located at the upper end portion of the lower body 3.
The attachment positions of the both ends of the heat transfer tube 13 to the tube plate 11 are positions where one communicates with the first water chamber 7 and the other communicates with the second water chamber 9.

The heat transfer tubes 13 are arranged along planes parallel to each other. Within each plane, the heat transfer tubes 13 are arranged so that the radius of curvature of the curved portion 21 increases sequentially from the inside toward the outside. In other words, the curved portion 21 is arranged so as to form an annual ring shape, and the heat transfer tube group 23 is formed.
In the heat transfer tube group 23 positioned at the center of the axis of the lower body 3 and the heat transfer tube group 23 positioned outside, the number of the heat transfer tubes 13 to be configured decreases sequentially from the upper side toward the outside.
That is, the radius of curvature of the curved portion 21 of the heat transfer tube 13 constituting the uppermost portion of the heat transfer tube group 13 located on the outside gradually decreases toward the outside.
Thereby, the curved portion 21 of the heat transfer tube 13 forms a substantially hemispherical shape as a whole.

The straight tube portion of the heat transfer tube 13 is supported by a plurality of tube support plates 25 provided at intervals in the vertical direction.
The tube group outer cylinder 15 is provided so as to cover all the heat transfer tubes 13.
A vibration preventing device 27 for preventing vibration of the heat transfer tube 13 is attached to the aggregate of the curved portions 21 formed in a substantially hemispherical shape.
The vibration preventing device includes a brace 29 that is inserted between the heat transfer tube groups 23 and attached so as to be in contact with the heat transfer tubes 13 constituting the adjacent heat transfer tube groups 23.

The upper body 5 is provided with a water supply ring 31, a steam separator 33, a moisture separator 35, and a steam chamber 37.
The water supply ring 31 is a pipe provided in a ring shape at the lower part of the upper body 5, and has a function of supplying secondary cooling system water sent through the water supply inlet nozzle 39 to the outside of the tube group outer cylinder 15. Play.
The steam separator 33 roughly separates the water-mixed steam sent from the lower body 3 into steam and water. The water separated by the steam separator 33 is returned to the water supply line.
The steam roughly separated by the steam separator 33 is introduced into the moisture separator 35 to separate the moisture contained in the steam.
The steam from which moisture has been separated is sent from the steam chamber 37 through the steam outlet nozzle 41 to the secondary turbine.

Next, the vibration preventing device 27 will be described with reference to FIGS.
FIG. 2 is a cross-sectional view taken along the line XX of FIG. 1 and shows a state where the vibration preventing device 27 is attached. 4 is an enlarged cross-sectional view showing an A portion of FIG. FIG. 5 is a right side view of FIG. 6 is an enlarged cross-sectional view showing a portion B of FIG. 2 in an enlarged manner.
The vibration preventing device 27 is provided with a plurality of brace brackets 29, a plurality of spacers 43, and a plurality of bolts (fastening means) 45.

The brace bracket 29 is an inconel elongated plate-like body. The brace bracket 29 is smoothly bent at the center thereof, and forms a substantially V shape as a whole. (See Figure 1)
The brace bracket 29 is inserted between the adjacent heat transfer tube groups 23. Since the brace 29 is approximately the same size as the gap between the heat transfer tubes 13 constituting the adjacent heat transfer tube groups 23, both surface portions 47 constitute the adjacent heat transfer tube groups 23. It contacts the heat transfer tube 13.
The end portion of the brace 29 protrudes outward from the heat transfer tube group 23 at the mounted position.
At the end of the brace 29, a through hole 49 through which the bolt 45 passes is provided at a substantially central portion in the width direction.

The spacer 43 includes two types of end type spacers 42 and intermediate spacers 44. The end-type spacer 42 and the intermediate spacer 44 are block bodies, and are formed of, for example, stainless steel.
The end spacer 42 will be described with reference to FIGS.
The end spacer 42 is provided with a substantially rectangular interval holding portion 51 and a substantially rectangular bolt engaging portion 53.
One surface of the interval holding portion 51 and one surface of the bolt engaging portion 53 are flush with each other and form a fitting surface (opposing surface) 55. The fitting surface 55 is formed with a fitting groove (groove portion) 57 into which the brace bracket 29 is fitted along the longitudinal direction.

The width of the fitting groove 57 is substantially the same as the width of the brace 29. The depth of the fitting groove 57 is slightly smaller than the thickness of the brace 29.
The interval holding portion 51 is provided with a contact surface 59 that faces the fitting surface 55. The distance between the bottom of the fitting groove 57 and the contact surface 59 is set to be substantially the same as the interval between the brace brackets 29, that is, the diameter of the heat transfer tube 13.
In the interval holding portion 51, a screw hole 61 having an axial center orthogonal to the contact surface 59 is provided at a substantially central portion in the width direction of the contact surface 59 so as to penetrate to the fitting groove 57. The screw hole 61 is screwed with the bolt 45.
In addition, since the screw hole 61 should just secure the screwing dimension of the volt | bolt 45, the screw hole 61 does not need to be penetrated depending on the case.

The bolt engaging portion 53 is provided with a through hole 63 whose axis center is orthogonal to the fitting surface 55 at a position corresponding to the through hole 49 of the brace fitting 29.
The diameter of the through hole 63 is set such that the bolt 45 passes therethrough.
The distance from the end of the bolt engaging portion 53 opposite to the interval holding portion 51 to the axial center of the through hole 63 is substantially the same as the distance from the end of the brace 29 to the axial center of the through hole 49. It is comprised so that it may become.
Since the length of the bolt engaging portion 53 in the direction along the fitting groove 57 is determined by the position of the end of the brace 29 fitted in the fitting groove 57, it is formed in various sizes according to the installation location. Is done. (See Figs. 4 and 6)

The intermediate spacer 44 will be described with reference to FIGS.
The intermediate spacer 44 is made of, for example, stainless steel and has a substantially rectangular shape.
The intermediate spacer 44 is provided with a fitting surface (opposing surface) 67 in which a fitting groove (groove portion) 65 into which the brace metal fitting 29 is fitted is formed along the longitudinal direction.
The width of the fitting groove 65 is substantially the same as the width of the brace 29. The depth of the fitting groove 65 is slightly smaller than the thickness of the brace 29.

The intermediate spacer 44 is provided with a contact surface 69 that faces the fitting surface 65. The distance between the bottom of the fitting groove 65 and the contact surface 69 is set to be substantially the same as the interval between the brace brackets 29, that is, the diameter of the heat transfer tube 13.
The intermediate spacer 44 is provided with a through hole 71 whose axis center is orthogonal to the fitting surface 55 at a position corresponding to the through hole 49 of the brace bracket 29.
The diameter of the through hole 63 is set such that the bolt 45 passes therethrough.
The distance from one end surface along the fitting groove 67 of the intermediate spacer 44 to the axial center of the through hole 63 is configured to be substantially the same as the distance from the end of the brace 29 to the axial center of the through hole 49. ing.

The bolt 45 will be described with reference to FIGS. 13 and 14.
The bolt 45 is made of stainless steel, for example, and includes a head portion 73, a flange 75, a screw portion 77, and an intermediate portion 79.
The length of the screw portion 77 is constant, but the length of the intermediate portion 79 is determined in various sizes depending on the number of spacers 41 and the brace fitting 29 to be locked.

A method for assembling the vibration preventing device 27 according to this embodiment described above will be described.
The steam generator 1 is assembled in a state where it is laid down so that the center of the axis is substantially horizontal and the heat transfer tube group 23 extends in a substantially horizontal direction.
In this state, the heat transfer tubes 13 are sequentially assembled from the lower heat transfer tube group 23.
In the bent portion 21 of the assembled heat transfer tube group 23, the brace fitting 29 is mounted between the heat transfer tube groups 23 with the end portion protruding from the bent portion 21.

Next, an operation for fixing the end of the brace 29 will be described.
Further, as shown in part A (FIGS. 4 and 5) of FIG. 2, there is a portion where the number of the heat transfer tubes 13 constituting the heat transfer tube group 23 does not change so much between the adjacent heat transfer tube groups 23.
In this portion, since the end position of the brace fitting 29 protruding from the heat transfer tube group 23 is substantially constant with the adjacent one, the end positions of the plurality of brace fittings 29 are aligned. Like that.
This part of the brace 29 is fixed using the end spacer 42 and the intermediate spacer 44.

The four brace brackets 29a, 29b, 29c, and 29d shown on the left side of FIG. The fixing of the brace brackets 29a, 29b, 29c, and 29d will be described.
First, the brace fitting 29a is fitted into the fitting groove 57 of the end spacer 42a so that the through hole 49 thereof coincides with the through hole 63 of the bolt engaging portion 53.
Next, after holding the brace 29a so that the through hole 71 coincides with the through hole 49 by the contact surface 67 of the intermediate spacer 44a, the brace 29b is inserted into the fitting groove 65 of the intermediate spacer 44a. The through hole 49 is fitted so as to coincide with the through hole 71.

Next, after holding the brace 29b so that the through hole 71 coincides with the through hole 49 by the contact surface 69 of the intermediate spacer 44b, the brace 29c is inserted into the fitting groove 65 of the intermediate spacer 44b. The through hole 49 is fitted so as to coincide with the through hole 71.
Next, after holding the brace bracket 29c so that the through hole 71 coincides with the through hole 49 by the contact surface 67 of the intermediate spacer 44c, the brace bracket 29d is inserted into the fitting groove 65 of the intermediate spacer 44c. The through hole 49 is fitted so as to coincide with the through hole 71.
Next, the brace 29d is clamped by the end spacer 42b so that the screw hole 61 coincides with the through hole 49.

Next, a bolt 45 having a long intermediate portion 79 is inserted from the through hole 63 of the end type spacer 42a, inserted through each through hole 49 and each through hole 71, and the screw portion 77 is inserted into the screw hole 61 of the end type spacer 42b. Engage with.
In this state, the bolt 45 is turned so that the screw portion 77 and the screw hole 61 of the end type spacer 42b are screwed together, and the end type spacer 42a, the brace bracket 29a, the intermediate spacer 44a, the brace bracket 29b, the intermediate spacer 44b, The brace bracket 29c, the intermediate spacer 44c, the brace bracket 29d, and the end spacer 42b are fastened simultaneously.
At this time, the end-type spacer 42 b functions as a nut with respect to the bolt 45.

Accordingly, the brace brackets 29a, 29b, 29c, and 29d are fixed at a predetermined interval, that is, at an interval between the heat transfer tubes 13.
Thereafter, the flange 75 of the bolt 45 that contacts the contact surface 59 of the end spacer 42a is welded to the contact surface 59 at a plurality of locations. (See Figure 5)
The welded portion 81 reliably prevents the bolt 45 from being loosened.
As described above, since the plurality of brace brackets 29a, 29b, 29c, and 29d can be fixed by one bolt tightening, the fixing work of the brace bracket 29 can be performed efficiently.

Further, as shown in part B (FIG. 6) of FIG. 2, there is a portion where the number of the heat transfer tubes 13 constituting the adjacent heat transfer tube group 23 changes rapidly.
In this portion, the end position of the brace fitting 29 protruding from the heat transfer tube group 23 by a substantially constant length is greatly deviated from the adjacent one. It is done.
Each end-type spacer 42 opposes the brace fitting 29 where the fitting surface 55 and the contact surface 59 are adjacent to each other, and both end portions along the longitudinal direction of the bolt engaging portion 53 are both of the brace fittings 29. It is formed so as to coincide with the end.
Further, the length of the bolt engaging portion 53 in the longitudinal direction is set by the positions of the end portions of the brace fittings 29 on both sides, and this portion is formed to be considerably long.

The brace fitting 29 is fitted into the fitting groove 57 of the end spacer 42 so that the through hole 49 thereof coincides with the through hole 63 of the bolt engaging portion 53.
Next, the brace 29 is clamped by the next end type spacer 42 so that the screw hole 61 coincides with the through hole 49.
Next, the bolt 45 is inserted from the through hole 63 of the first end-type spacer 42, the through-hole 49 of the brace 29 is inserted, and the screw portion 77 is engaged with the screw hole 61 of the next end-type spacer 42.
In this state, the bolt 45 is turned to screw the screw portion 77 and the screw hole 61 of the next end-type spacer 42 to fasten the end-type spacer 42, the brace 29, and the next end-type spacer 42 at the same time.
At this time, the next end type spacer 42 functions as a nut with respect to the bolt 45.

Then, the next brace bracket 29 is fitted into the fitting groove 57 of the next end spacer 42 so that the through hole 49 of the brace bracket 29 matches the through hole 63 of the bolt engaging portion 53.
Then, the brace 29 is clamped by the next end type spacer 42 so that the screw hole 61 coincides with the through hole 49.
The bolt 45 is inserted from the through-hole 63 of the next end-type spacer 42, the through-hole 49 of the next brace 29 is inserted, and the screw portion 77 is engaged with the screw hole 61 of the next end-type spacer 42. .
In this state, the bolt 45 is turned so that the screw portion 77 and the screw hole 61 of the next end type spacer 42 are screwed together, and the next end type spacer 42, the brace 29, and the next end type spacer 42 are moved. Conclude at the same time.
By repeating this, the ends of the brace 29 are sequentially fixed.
Thereafter, the flanges 75 of the bolts 45 in contact with the contact surface 59 of the end spacer 42 are welded to the contact surface 59 at a plurality of locations to prevent the bolts 45 from loosening.

In this way, where the end positions (tightening positions) of the adjacent brace brackets 29 are substantially the same, the plurality of brace brackets 29 with one bolt 45 using the end spacer 42 and the intermediate spacer 44. Can be fixed. Further, in the places where the end positions (tightening positions) of the adjacent brace brackets 29 are different, the brace brackets 29 can be fixed with a single bolt 45 using the end spacer 42.
Therefore, since one brace 29 can be fixed by at least one fastening operation, the brace 29 can be easily fixed in a short time.

Further, the interval between the adjacent brace brackets 29 is defined by the distance between the bottoms of the fitting grooves 57 and 65 of the end spacer 42 or the intermediate spacer 44 and the contact surfaces 59 and 69.
Since this distance is set to be substantially the same as the diameter of the heat transfer tube 13, the brace 29 is securely fixed at a position in contact with the heat transfer tubes 13 on both sides.
Further, since all the brace brackets 29 are assembled in the state of being fitted in the fitting grooves 57 and 65, the brace brackets 29 do not move within the surface portion 47.
As a result, it is possible to prevent a gap from being formed between the brace 29 and the heat transfer tube 13, so that vibration of the heat transfer tube 13 can be effectively prevented.

Further, the distance from the end of the bolt engaging portion 53 opposite to the interval holding portion 51 to the axis center of the through hole 63 and the end surface along the fitting groove 67 of the intermediate spacer 44 to the axis center of the through hole 63. Is configured to be substantially the same as the distance from the end of the brace 29 to the axial center of the through hole 49, so that the end positions of the end spacer 42 and the intermediate spacer 44 and the brace The position of the end portion 29 is substantially the same.
As described above, since the end portions of the end spacer 42 and the intermediate spacer 44 are arranged at substantially the same position as the end portions of the brace bracket 29, the brace bracket 29 is connected to the end spacer 42 and the intermediate spacer 44. It does not protrude from the end and forms a free end.
For this reason, it is possible to prevent the tip portion of the brace 29 from vibrating due to the fluid flowing around the heat transfer tube 13 and affecting the overall vibration.

Next, operation | movement of the steam generator 1 concerning this embodiment is demonstrated.
A high-temperature and high-pressure primary coolant from a reactor (not shown) is introduced into the first water chamber 7 from the primary coolant inlet nozzle 17. The primary coolant is introduced from the first water chamber 7 to one end of each heat transfer tube 13, circulates in each heat transfer tube 13, and is discharged from the other end of each heat transfer tube 13 to the second water chamber 9. The primary coolant is returned from the second water chamber to the reactor.
The heat transfer tube 13 is maintained at a high temperature by the circulation of the primary coolant.

The secondary cooling system water supplied from the water supply ring 31 of the upper body 5 passes through the outside of the tube group outer cylinder 15 and is supplied into the lower body 3 from the vicinity of the tube plate 11.
The water in the secondary cooling system is vaporized to generate steam when rising around the heat transfer tube 13 maintained at a high temperature.
This steam-mixed water is introduced into the steam separator 33 and roughly separated into steam and water.
The steam roughly separated by the steam separator 33 is introduced into the moisture separator 35 and the contained moisture is removed.

The steam from which moisture has been separated by the moisture separator 35 is sent from a steam outlet nozzle 41 installed at the top of the upper body 5 to a secondary turbine (not shown). The turbine is rotationally driven by this steam, and the generator is driven by this power to generate electricity.
During operation of the steam generator 1, a high-speed fluid passes inside and outside the heat transfer tube 13, but the heat transfer tube 13 is effectively prevented from generating vibration by the vibration preventing device 27.
Thus, since the heat transfer tube 13 does not vibrate, accidents such as damage to the heat transfer tube 13 due to vibration can be prevented, and the steam generator 1 can perform stable operation over a long period of time.

It is a longitudinal section showing the whole schematic structure of a steam generator concerning one embodiment of the present invention. It is XX sectional drawing of FIG. It is a perspective view which shows the edge part of the brace | restoration metal fitting concerning one Embodiment of this invention. It is the A section enlarged view of FIG. FIG. 5 is a right side view of FIG. 4. It is the B section enlarged view of FIG. It is a front view of the end type spacer concerning one embodiment of the present invention. FIG. 8 is a right side view of FIG. 7. FIG. 8 is a plan view of FIG. 7. It is a front view of the intermediate spacer concerning one embodiment of the present invention. It is a left view of FIG. It is a top view of FIG. It is a front view of the volt | bolt concerning one Embodiment of this invention. FIG. 14 is a right side view of FIG. 13.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steam generator 11 Tube board 13 Heat exchanger tube 27 Vibration prevention apparatus 29 Anti-locking bracket 42 End type spacer 43 Spacer 44 Intermediate spacer 45 Bolt 55, 63 Fitting surface 57, 65 Fitting groove 61 Screw hole 63, 71 Through hole 73 head

Claims (6)

A brace that is fixed to the tube plate and mounted between the plurality of heat transfer tubes having U-shaped free ends so as to come into contact with adjacent heat transfer tubes,
A spacer that is interposed between adjacent brace brackets, and has a groove part that fits the bracelet on a facing surface facing one of the bracelets;
Tightening means for connecting the brace and the spacer adjacent to each other with the clasp,
An anti-vibration device comprising:   2. The vibration according to claim 1, wherein the tightening means is a bolt, and a screw hole to be screwed into the bolt is provided only in the spacer located on the opposite side of the head of the bolt. Prevention device.   When the tightening positions of three or more spacers adjacent to each other are substantially the same, only the spacer farthest among the spacers located on the side opposite to the head of the bolt is screwed into the bolt. The vibration preventing device according to claim 2, wherein a screw hole is provided. In the spacer located in the middle of different tightening positions between the spacers on both sides adjacent to each other,
The screw holes for tightening one of the spacers and the brace;
The vibration preventing device according to claim 2, further comprising a through hole through which the bolt to be tightened in cooperation with the other spacer.   The vibration preventing device according to any one of claims 1 to 4, wherein an end of the spacer is disposed at substantially the same position as an end of the brace. A heat exchanger comprising the vibration preventing device according to any one of claims 1 to 5.

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