JP5582004B2 - Fixing method of heat transfer tube runout prevention bar - Google Patents

Description

  The present invention relates to a method for fixing a heat transfer tube runout prevention bar.

  A heat exchange type steam generator is formed by arranging a plurality of U-shaped heat transfer tubes on the same surface to form a heat transfer tube group, and by stacking a plurality of these heat transfer tube groups to form a substantially cylindrical shape. ,It is configured. In this steam generator, an anti-vibration bar (an anti-vibration member) is provided in order to prevent fluid excitation vibration in the U-shaped arc portion when the fluid flows in the heat transfer tube and to prevent vibration damage. The shake prevention bar is a substantially V-shaped member inserted between each arc portion (U-shaped portion) of the heat transfer tube group to be stacked (see, for example, Patent Document 1).

  This shake prevention bar has tip caps at both ends thereof. Then, the shake prevention bars are respectively disposed between the stacked heat transfer tube groups so that the tip caps protrude outside the arc portion. Thereafter, the side surface (welded surface) of the tip cap is welded and fixed to a separately prepared fixing member, whereby a number of shake prevention bars are integrated via the fixing member.

JP-A-8-75387

By the way, the number of shake prevention bars is large, and since the welding fixing of these shake prevention bars to the fixing members is performed in a very narrow space, the welding work of the tip cap is very difficult and requires a lot of time. It has become. In particular, since the positions of the end caps to be stacked vary widely and it is difficult to align the respective welded surfaces, it takes a lot of time just to align the welded surfaces.
In addition, since it is necessary to accurately position the shake prevention bar with respect to the heat transfer tubes (heat transfer tube group), for example, a reference position (reference line) is conventionally set by a laser device, for example, and both ends of the shake prevention bar are respectively set to the reference position. In other words, the runout prevention bar is stacked on the heat transfer tube group while being positioned so as to be positioned on the reference position. However, it is necessary to align both ends of the shake preventing bar with the reference position every time, and it takes a lot of time to arrange the shake preventing bar.

Therefore, conventionally, since the work of properly arranging the anti-vibration bar with respect to the heat transfer tube and further welding the fixing member takes a very long time, it is desired to facilitate the work and shorten the work time. Yes.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a fixing method of a heat transfer tube runout prevention bar that facilitates work and shortens work time.

In the heat transfer tube shake prevention bar fixing method of the present invention, the tip of the shake prevention bar having a tip cap at the end is preset between each of the plurality of heat transfer tubes arranged horizontally and stacked in advance. A stacking step of sequentially arranging and stacking so as to be a reference position;
A welding step of welding the welding surfaces of the plurality of tip caps to the fixing members,
In the laminating step, using a holding jig having a reference surface parallel to the welding surface of the tip cap, the welding surface protrudes and the reference surface is parallel to the welding surface. When holding the tip cap and also laminating the shake prevention bar, make sure to stack the holding jig,
In the welding step, the fixing member is welded after aligning the reference surfaces of the holding jigs so that the welding surfaces of the plurality of tip caps are flush with each other. .

  Further, in the fixing method of the heat transfer tube shake prevention bar, in the laminating step, after repeating the process of arranging and laminating the shake prevention bar for a predetermined number of stages, the reference position is confirmed again, and in the subsequent process, It is preferable to make the tip end the reference position confirmed again.

  The holding jig is preferably provided with a positioning portion that aligns the reference planes when the holding jigs are stacked on each other.

According to the fixing method of the heat transfer tube shake prevention bar of the present invention, in the laminating step, the tip cap is held by the holding jig so that the welding surface of the tip cap protrudes and the reference surface is parallel to the welding surface. Since the holding jig is also laminated when the holding bar is further laminated, the position of the end of the shaking prevention bar is almost the same as the preset reference position depending on the position of the holding jig to be laminated. Can be matched. Therefore, it is not necessary to match the both ends of the shake prevention bar to the reference position each time using a laser device or the like, and the working time can be shortened.
Also, in the welding process, the welding cap surfaces are aligned with each other by aligning the reference surface of the holding jig so that the welding surfaces of the tip caps are directly flush with each other. Compared to the above, the work can be made easier and the time required for the welding process can be remarkably shortened.
Therefore, in this fixing method, the work can be facilitated and the working time can be significantly shortened as compared with the conventional method.

It is a schematic diagram which shows the principal part of a steam generator. It is a schematic diagram which shows the state by which the front-end | tip cap was fixed with the fixing member. (A) is a schematic diagram which shows the state which laminated | stacked the tip cap, (b) is an AA arrow directional cross-sectional view of (a). It is a perspective view which shows typically the state which laminated | stacked the holding block.

The present invention will be described in detail below.
First, the schematic configuration of the main part of the steam generator obtained by carrying out the fixing method of the heat transfer tube shake prevention bar of the present invention will be described.
FIG. 1 is a schematic view showing a main part of the steam generator. As shown in FIG. 1, a heat transfer tube runout prevention bar (hereinafter referred to as a runout prevention bar) X1 is a long and thin plate having a rectangular cross section and an overall V shape. A plurality of letter-shaped heat transfer tubes Y1 are installed with respect to the heat transfer tube group Y formed concentrically and on the same plane.

  A plurality of heat transfer tube groups Y are horizontally stacked in the steam generator container at the time of assembly with a predetermined gap in the vertical direction (height direction) on the paper surface. The curved side is assembled so that all the heat transfer tube groups Y are stacked to form a hemispherical shape. A vibration preventing bar X1 for suppressing and preventing vibration of the heat transfer tube Y1 is provided for each gap between the heat transfer tube groups Y stacked in this manner (that is, between the heat transfer tubes Y1). As shown in FIG. 1, a plurality are inserted and arranged.

  As shown in FIG. 1, a shake prevention bar group X having a different length and bending angle is inserted into one gap to form a shake prevention bar group X for one stage. However, each of the plurality of shake prevention bars X1 inserted into one gap has a length and a length so that the bent center portion X11 is arranged in a straight line and the end portion X12 is arranged in an arc. Bending angle is set. Further, these shake preventing bars X1 are arranged so that both end portions thereof protrude to the outside of the heat transfer tube group Y, respectively.

As shown in the schematic diagram of FIG. 2, tip end caps 10 are attached to the respective end portions (both end portions) protruding from the heat transfer tube group Y in these shake prevention bars X1. The tip cap 10 has a substantially square cylindrical shape, and is attached by being attached to the shake prevention bar X1 by being extrapolated.
Then, as shown in FIG. 2, after the shake preventing bars X1 (shake preventing bar group X) are arranged and stacked in the gaps of the heat transfer tube groups Y stacked in multiple stages, these stacked shake preventing bars are stacked. One side surface of the tip cap 10 at the end corresponding to X1 is welded and fixed to the arc plate-like fixing member 11. Thereby, the principal part of the steam generator is formed by fixing the end of the shake preventing bar X1 to the fixing member 11.

  Next, based on the assembly method of the steam generator principal part which consists of the heat exchanger tube group Y and the shake prevention bar group X of such a structure, one Embodiment of the fixing method of the heat exchanger tube shake prevention bar of this invention is described. .

In the present embodiment, as shown in FIG. 2, the heat transfer tube group Y is stacked horizontally, and the shake preventing bar X1 is inserted and disposed at a predetermined position therebetween, and stacked. In addition, about the shake prevention bar X1, you may attach the front-end | tip cap 10 to the both ends beforehand, and may attach it after insertion arrangement | positioning.
At that time, particularly with respect to the shake preventing bar X1 arranged in the lowermost layer, the both end portions (tip portions) thereof are accurately aligned with the reference positions so as to be the reference positions set in advance by, for example, a laser measuring device or the like. deep.

  In the present embodiment, the alignment to the reference position is performed every time the arrangement / stacking of the shake prevention bar X1 is repeated a predetermined number of steps as will be described later. That is, for example, assuming that the number of stacked layers of about 5 to 10 steps is one repeating unit, the both ends of the shake preventing bar X1 inserted and arranged at the beginning are accurately aligned with the reference position by the laser measuring device or the like. Do. Then, with respect to the subsequent end portion alignment, the alignment is sequentially performed with reference to the end portion that has been accurately aligned. At that time, alignment is performed using a holding jig described later as a guide.

  FIG. 3A illustrates a plurality of anti-vibration bars X1 and a heat transfer tube Y1 that are stacked (stacked) when the arrangement / stacking of the anti-vibration bars X1 is repeated or repeated after a predetermined number of stages. As shown in FIG. 3B, which is a cross-sectional view taken along line AA in FIG. 3A, the heat transfer tube clamp 12 and the bar holding member 13 are attached, and the heat transfer tube Y1 is prevented from shaking corresponding thereto. Fix the bar X1.

  That is, as shown in FIG. 3B, the U-shaped portion of the heat transfer tube Y1 is gripped by using a pair of heat transfer tube clamps 12. As shown in FIG. 3A, the heat transfer tube clamp 12 includes a grip portion 12a for detachably holding the heat transfer tube Y1, and a screw portion 12b for operating the grip portion 12a. . The bar holding member 13 is attached to the heat transfer tube clamp 12 in the vicinity of the screw portion 12b.

  The bar holding member 13 is used by being positioned outside the heat transfer tube Y1 as shown in FIG. And it has the substantially U-shaped holding | maintenance part 13a which formed the groove | channel (not shown) holding the edge part side of the shake prevention bar X1, as shown in FIG.3 (b). The bar holding member 13 is screwed so as to be movable with respect to the heat transfer tube clamp 12, for example, and is thus movable in the length direction of the heat transfer tube Y1 shown in FIG.

  In order to fix the shake preventing bar X1 to the heat transfer tube Y1 using the heat transfer tube clamp 12 and the bar holding member 13 having such a configuration, first, the end portion side of the shake preventing bar X1 to be fixed is sandwiched between the heat transfer tubes. A pair of heat transfer tube clamps 12 are arranged at a predetermined interval in Y1. And each screw part 12b is operated and the heat exchanger tube Y1 is hold | gripped by the holding part 12a. Subsequently, the bar holding member 13 provided in each heat transfer tube clamp 12 is moved to the shake preventing bar X1 side, and the side end portion of the shake preventing bar X1 is held by the holding portion 13a.

  In this way, by holding both side end portions of the shake preventing bar X1 with the pair of holding portions 13a, the shake preventing bar X1 is fixed to the heat transfer tube Y1 via the heat transfer tube clamp 12 and the bar holding member 13. Can do. In the above description, the heat transfer tube clamp 12 is fixed to the heat transfer tube Y1, and then the bar holding member 13 is operated to hold the shake preventing bar X1 by the holding portion 13a. After temporarily fixing to the heat transfer tube Y1, the shake preventing bar X1 is held by the holding portion 13a of the bar holding member 13 by moving the heat transfer tube clamp 12 along the heat transfer tube Y1, and then the heat transfer tube clamp 12 is fixed. You may make it fix to the heat exchanger tube Y1.

Here, the holding / fixing of the shake preventing bar X1 to the heat transfer tube Y1 is sequentially performed from the lowest level of the stacked (or stacked) heat transfer tubes Y1 to the upper level.
At that time, for the shake prevention bar X1 to be held and fixed, the tip cap 10 is attached in advance to each end portion (tip portion), and the tip cap 10 is held by a holding block (holding jig) 14. Keep it.

  As shown in FIG. 4, the holding block 14 has a U-shape in a side view formed by connecting a lower plate portion 14 a and an upper plate portion 14 b arranged in parallel with an intermediate portion 14 c. The tip cap 10 is configured to be held by a concave cap holding portion 15 surrounded by the plate portion 14a, the upper plate portion 14b, and the intermediate portion 14c. That is, by inserting one side surface of the tip cap 10 into the cap holding portion 15 and abutting one side surface of the tip cap 10 against the inner surface of the intermediate plate 14c, the holding block 14 is connected to the lower plate portion 14a and the upper plate portion 14a. The tip cap 10 is held between the plate portion 14b.

  Further, when holding the tip cap 10 in this manner, the cap holding portion 15 projects the side surface opposite to the one side surface to the outside of the cap holding portion 15 so as to be exposed. Thereby, this protruded side surface becomes the welding surface 10a welded to the fixing member 11 shown in FIG.

  In the present embodiment, the outer surface 16 of the intermediate portion 14c of the holding block 14 is parallel to the inner surface. Therefore, it is also parallel to one side surface of the tip cap 10 that is in contact with the inner surface, and is also parallel to the welding surface 10a on the side opposite to the one side surface. Thereby, the outer surface 16 serves as a reference surface parallel to the welding surface 10 a of the tip cap 10.

  In addition, when the same holding blocks 14 are stacked on each other as will be described later, the holding blocks 14 are aligned so that the reference surfaces (outer surfaces 16) of the stacked holding blocks 14 are flush with each other. A positioning portion 17 is provided for performing the above. In the present embodiment, the positioning portion 17 includes a protrusion 17a formed on the upper surface of the upper plate portion 14b and a groove 17b formed on the lower surface of the lower plate portion 14a. The protrusions 17a and the grooves 17b are formed to have dimensions and shapes that fit with each other, and are formed at a predetermined distance from the reference surface 16.

  Under such a configuration, when the plurality of holding blocks 14 are stacked one above the other as shown in FIG. 4, the groove 17 b of the upper holding block 14 is formed on the protrusion 17 a of the lower holding block 14. And the upper holding block 14 is positioned with respect to the lower holding block 14 so that the reference surfaces (outer surfaces) 16 of these holding blocks 14 are flush with each other. Further, when the plurality of holding blocks 14 are stacked one above the other in this manner, the protrusions 17a and the grooves 17b are fitted together, so that the holding blocks 14 are not displaced after each other. The reference surface 16 is held in a flush state.

  Therefore, when the tip cap 10 is held by such a holding block 14 and the shake preventing bar X1 is sequentially fixed to the heat transfer tube Y1 from the lowermost side as described above, the end of the shake preventing bar X1 is fixed. The positioning can be performed by stacking the holding blocks 14. That is, each time the anti-vibration bar X1 is stacked, the end position of the anti-vibration bar X1 is adjusted to the reference position set by a laser measuring device or the like. In this embodiment, the end of the lowermost anti-vibration bar X1 After aligning the position of the front end cap 10 with the reference position, the holding blocks 14 that simply hold the tip cap 10 are stacked and the reference surface 19 is aligned so that each end is aligned with the reference position. It can be almost matched to.

  Note that the end portion (tip portion) of the shake preventing bar X1 forms a curved surface (hemispherical surface), and thus its position is slightly shifted as shown in FIG. Therefore, the alignment by stacking the holding blocks 14 is performed by setting the number of steps set in advance as described above, for example, the number of stacked layers of about 5 to 10 steps as one repeating unit, and after the repeating unit is finished, laser measurement is performed. Set the reference position with a device or the like and check the position again. In the subsequent processing, the end portions (tip portions) of the shake preventing bar X1 are sequentially laminated so that the reference position is confirmed again. However, this sequential lamination is also simplified by aligning the end (tip) of the first shake prevention bar X1 of the repeating unit with the reference position by the laser measuring device or the like and thereafter stacking the holding blocks 14. Thus, it is possible to perform alignment with the reference position.

  In this way, the shake prevention bar X1 is sequentially stacked while the holding block 14 is held on the tip cap 10 sequentially from the lowermost shake prevention bar X1, and the holding blocks 14 are sequentially stacked, and the positioning unit 17 performs the reference. The surface 16 is made flush. Moreover, using the heat transfer tube clamp 12 and the bar holding member 13 so that the state can be maintained, as shown in FIGS. 3A and 3B, each shake prevention bar X1 is associated with the corresponding heat transfer tube Y1. It will be fixed in order.

  When the stacking process as described above is completed, as a welding process, the tip caps 10 of the aligned shake preventing bars X1 are sequentially welded and fixed to the fixing member 11 as shown in FIG. At that time, as shown in FIG. 4, the end caps 10 are held by the holding blocks 14, and the reference surface 16 of these holding blocks 14 is flush with each other, so that the welding surface 10 a of the tip cap 10 is automatically It is matched to the same level.

Therefore, as shown in FIG. 2, the fixing member 11 can be brought into uniform contact with each of the welding surfaces 10a that are flush with each other in this manner, whereby the welding surface 10a to the fixing member 11 can be brought into contact with each other. Welding can be performed easily. In this way, by welding all the welding surfaces 10a to the fixing member 11, the end portions of the anti-vibration bar X1 are fixed to the fixing member 11, respectively, and all the anti-vibration bars X1 stacked thereby are integrated ( Fixed).
If all the shake prevention bars X1 are integrated (fixed) in this manner, the holding block 14, the heat transfer tube clamp 12, and the bar holding member 13 are all removed unless particularly required.

  According to such a fixing method of the heat transfer tube shake prevention bar, in the laminating step, the tip cap 10 is made such that the welding surface 10a of the tip cap 10 is projected and the reference surface 16 is parallel to the welding surface 10a. Is held by the holding block 14, and when the shake preventing bar X1 is further laminated, the holding block 14 is also laminated, so that the position of the end of the shake preventing bar X1 depends on the position of the holding block 14 to be laminated, It can be almost matched with a preset reference position. Therefore, it is not necessary to accurately align both ends of the shake prevention bar X1 with the reference position each time using a laser device or the like, and the working time can be shortened.

Further, in the welding process, since the reference surfaces 16 of the holding blocks 14 are made flush with each other, the welding surfaces 10a of the plurality of tip caps 10 are made flush with each other. Compared with directly aligning 10a, the work can be made easier and the time required for the welding process can be significantly shortened.
Therefore, in the fixing method of the present embodiment, the work can be facilitated and the working time can be significantly reduced as compared with the conventional method.

  In the stacking process, the process of arranging and stacking the shake prevention bar X1 is repeated for a preset number of steps, and then the reference position is confirmed again. In the subsequent processes, the reference point where the tip of the shake prevention bar X1 is confirmed again. Since the position is set, the position of the tip of the shake preventing bar X1 can be adjusted to the reference position almost accurately.

  Further, since the positioning block 17 is provided on the holding block 14, when the holding blocks 14 are stacked on each other, the reference planes 16 can be easily flushed by using the positioning block 17. And that state can be maintained. Therefore, the positioning of the welding surface 10a by making the reference surface 16 flush with each other can be performed very easily, and the working time can be greatly shortened.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.
For example, in the above-described embodiment, the shake prevention bar X1 is fixed to the heat transfer tube Y1 by using the heat transfer tube clamp 12 and the bar holding member 13. However, the present invention is not limited thereto, and these heat transfer tubes are not limited thereto. The shake preventing bar X1 may be fixed to the heat transfer tube Y1 using a fixture having various structures other than the clamp 12 and the bar holding member 13.

  In the above embodiment, the holding block 14 having a U-shape in side view is used as the holding jig. However, the holding jig has a reference surface parallel to the welding surface 10a of the tip cap 10 and is welded. As long as the structure can hold the tip cap 10 with the surface 10a protruding and the reference surface parallel to the welding surface 10a, various structures other than the holding block 14 should be used. Can do.

  Further, the positioning portion provided in the holding jig is not limited to the configuration including the protrusions and the grooves, and various structures such as protrusions and holes can be employed.

X ... shake prevention bar group, X1 ... shake prevention bar (heat transfer tube shake prevention bar), Y ... heat transfer tube group, Y1 ... heat transfer tube, 10 ... tip cap, 10a ... welding surface, 11 ... fixing member, 14 ... holding block (Holding jig), 15 ... cap holding portion, 16 ... reference surface (outer surface), 17 ... positioning portion, 17a ... ridge, 17b ... groove

Claims (3)

A laminating step in which a vibration preventing bar having a tip cap at the end is sequentially arranged and stacked between each of the plurality of heat transfer tubes that are horizontally arranged and stacked so that the tip is at a preset reference position. When,
A welding step of welding the welding surfaces of the plurality of tip caps to the fixing members,
In the laminating step, using a holding jig having a reference surface parallel to the welding surface of the tip cap, the welding surface protrudes and the reference surface is parallel to the welding surface. When holding the tip cap and also laminating the shake prevention bar, make sure to stack the holding jig,
In the welding step, the fixing member is welded after aligning the welding surfaces of the plurality of tip caps by matching the reference surface of the holding jig. Fixing method of heat transfer tube runout prevention bar.   In the laminating step, the process of placing and laminating the shake prevention bar is repeated for a preset number of steps, and then the reference position is confirmed again, and in the subsequent processes, the tip end is set to the confirmed reference position again. The fixing method of the heat exchanger tube runout prevention bar according to claim 1.   The positioning device is provided with a positioning portion for aligning the reference surfaces so that the reference surfaces are flush with each other when the holding jigs are stacked on each other. The fixing method of the heat exchanger tube shake | deflection prevention bar of 1 or 2.

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