JPH1061902A - Installation method and installation structure for horizontal heat transfer pipes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a work period and hence improve safety of assembling work at altitudes by reducing ground work in installation of a group of horizontal heat transfer pipes to facilitate parallel works by making minimum an interval between the heat transfer pipes or suspension pipes in a small block, and closely disposing packaging frames. SOLUTION: A packaging frame 16 is disposed on a small block of a group of heat transfer pipes such that it is located more inside a suspension pipe 13 so as to be in close contact with a heat transfer pipe coil disposed outermost in the small block. After completion of construction of a support steel frame of a boiler body a plurality of lifting apparatus 17 are disposed on a top large beam 11, and a spring bolt 2 is lowered onto the ground, and further on a lower part of the bolt suspension means such as a wire and a rod is mounted on a suspension pipe header 14. Then, the heat transfer pipe is suspended for welding to such a height that a butt welding position that is a lower end of a stub group 15 of the suspension pipe header 14 exceeds a butt welding position with a suspension pipe 13 that is an upper end of the small block of the heat transfer pipe group installed on the uppermost stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the installation of a large-sized boiler, and in particular, in order to effectively conduct convective heat transfer with exhaust gas, a straight pipe portion is formed substantially at right angles to a gas flow in a gas flow path. The present invention relates to an installation method and an installation structure of a horizontally placed heat transfer tube group placed horizontally.

[0002]

2. Description of the Related Art FIG. 9 shows a typical configuration of a large-sized boiler having a horizontal heat transfer tube group. As shown in the figure, a large-sized boiler such as a commercial thermal power boiler has a boiler main body disposed in a boiler main body storage space inside a boiler building, and a boiler main body supporting steel frame group 1 composed of steel columns and beams. Sling bolt 2 with top beam 11 at the top as support point
It is suspended and supported by.

[0003] The boiler main body includes, for example, a boiler furnace chamber 3 in which fuel is burned, a sub-side wall chamber 4 serving as a flow path of combustion exhaust gas from the boiler furnace chamber 3, and a gas flow from the sub-side wall chamber 4. It is roughly divided into three rear heat transfer wall chambers 5 provided on the downstream side, each of which is constituted by a group of heat transfer tubes. Further, a ceiling wall 6 which is a group of heat transfer walls is provided at a ceiling portion of each room, and forms a space called a penthouse 7 on a roof portion of the boiler building.

[0004] The heat transfer wall group has a wall structure integrated by alternately connecting and welding heat transfer parts on a flat plate such as a membrane bar or a fin to a heat transfer tube. Has been constructed.

On the downstream side of the gas flow in the boiler furnace chamber 3 and inside the sub-side wall chamber 4, suspended heat transfer tube groups 8 and heat transfer tubes are arranged, and each of the heat transfer tube groups 8 is provided in the penthouse 7. With the header 9 as a supporting point, it is suspended from the top girders 11 via the sling bolts 2.

The rear heat transfer wall chamber 5 is surrounded by a rear heat transfer partition wall 53, a rear heat transfer front wall 51, a rear heat transfer side wall 52 and a rear heat transfer partition wall 53 close to the boiler furnace chamber 3. The rear heat transfer wall front chamber 5b surrounded by the rear heat transfer wall front chamber 5a and the rear heat transfer partition 53, the rear heat transfer side wall 52, and the rear heat transfer rear wall 54 remote from the boiler furnace chamber 3 are provided. In each room, a superheater 10a, a reheater 10c, and an evaporator 10b are provided in each room in addition to a suspended heat transfer tube group and a heat transfer tube.
Or a horizontal type heat transfer tube group 10 such as a economizer 10d,
Heat transfer tubes 12a, 12b and the like are arranged.

As shown in FIGS. 11 and 12, the heat transfer tube group 10 includes a plurality of heat transfer tube coils assembled in a coil shape by bending and welding, and a plurality of heat transfer tube coils are provided at a predetermined interval Q in a boiler can width direction. The heat transfer tube groups are arranged side by side in the rear heat transfer wall chamber 5 so that the straight tube portions of the heat transfer tube groups are perpendicular to the gas flow. The interval Q is set in consideration of the convective heat transfer efficiency.

As shown in FIGS. 9 and 11, the horizontal heat transfer tube group installed in the rear heat transfer wall rear chamber 5b is illustrated by a plurality of hanging tubes 13 arranged between the heat transfer tube coils. When a plurality of heat transfer tube groups are installed in the exhaust gas flow path for the gas flow, the entire number of the hanging tubes 13 is butt-welded for each stage. By the connection, a plurality of stages of heat transfer tube groups are supported over the entire stage by a plurality of hanging tubes 13 arranged between the heat transfer tube coils via support fittings (not shown).

The hanging tube 13 is a stub 1 of a hanging tube header 14 provided in the penthouse 7.
5, and the heat transfer tube group is supported by a hanging tube header 14 via the hanging tube 13.

Further, the header 14 is suspended from the top girders 11 via the sling bolts 2 and is installed, for example, at a height of 40 m or more from the ground.

[0011] Further, in order to improve heat transfer efficiency, the horizontal type heat transfer tube group is provided in each of the chambers, for example.
100 at pitch of 100 mm in the width direction of the boiler can
To 300 rows, and the hanging pipes 13 have the same number of rows because they are arranged between the heat transfer tube coils.

As shown in FIG. 11 and FIG. 12, the transport and installation of the horizontal heat transfer tube group as described above is performed by first setting each heat transfer tube group in a small row of 20 to 30 rows in the boiler can width direction at the factory. It is divided into blocks, and the blocks are packed and shipped with frame pillars 16a, frame beams 16b, and reinforcing materials 16c.

The size of the small block is set according to the suspending ability of the sling bolts 2 at the time of setting and the working efficiency at the time of lifting. When the heat transfer tube group has a plurality of stages, each heat transfer tube group is substantially formed. Since the small blocks are divided into small blocks of the same size and all the stages of the small blocks are simultaneously lifted, the pipe row pitch of the hanging tubes 13 is set to a common dimension over all the stages.

Next, as shown in FIG. 10, at the installation site, after the boiler main body supporting steel frame 1 has been erected, a plurality of lifting devices 17 such as center hole jacks 17a are installed on the top girders 11, and the sling bolts 2 are installed. Is lowered on the ground, a lifting beam 18 is attached to the lower part of the sling bolt 2, and a hanging means such as a wire or a rod is attached to the hanging header 14.

The division dimensions of the lifting beam 18 and the suspension pipe header 14 are set in accordance with the size of the small block.

Next, the butt welding position at the lower end of the stub group 15 of the hanging tube header 14 is the butt welding position at the upper end of the small block of the heat transfer tube group installed at the top. Lift until dodge height.

Next, the small block of the heat transfer tube group to be installed at the uppermost stage that has been transported is moved substantially immediately below the hanging tube header 14, and the frame column 16a, the frame beam 16b, and the reinforcing member 1 are moved.
6c and other packaging frames 16 are dismantled and removed by ground work,
As a first-stage connection, the hanging pipes 13 are grooved and butt-welded. At the same time, the groove and the butt welding work are also performed on the heat transfer tube groups to integrate the upper and lower blocks.

In the case where the heat transfer tube group has a plurality of stages, the lifting of the second stage and the subsequent stages up to the level of dodging the small blocks of the next stage, the disassembly of the packing frame, the loading, welding, and lifting are sequentially performed. After the small block of the heat transfer tube group installed at the lowermost stage is attached by welding, the entire stage is lifted to the set position.

In addition, in the groove welding and butt welding of the hanging pipes 13, the pipe row pitch varies due to the removal of the packing frame 16, and the vertical groove cannot be aligned. It was necessary to attach a pipe row pitch adjusting part (not shown) to each pipe by bolting.

[0020]

The prior art described above has the following problems. That is, in the case where the horizontal heat transfer tube group is transported and installed on site, first, the small block is sized in consideration of the transportation and installation efficiency in the factory, but according to the related art, as shown in FIG. In order to prevent the tube row pitch Q of each heat transfer tube from being damaged due to vibration or the like during transportation, the packing frame 16 is attached after being substantially the same as the dimensions at the time of installation or at a wide interval.

For this reason, when the heat transfer tube block size La × Wa is directly lifted during installation,
Is larger than the storage size by adding La '
× Wa ′, and interferes with the adjacent packing frame.
It was necessary to remove the packing frame 16 before lifting on the ground at the installation site.

However, in this method, since the packaging frame cannot be used for lifting, at least the hanging tube 1
3 on the ground almost directly below the installation position of the heat transfer tube group,
In order to prevent dispersion of the hanging pipes 13, it is necessary to attach a pipe row pitch adjusting component (not shown) to each of the hanging pipes 13 by bolting, and then to perform a groove alignment and a butt welding operation. When all of the heat transfer tube groups are lifted over the boiler can width in small block units, a long working period of, for example, three months is required.

In addition, the work area on the ground is limited at the site where the boiler is installed. If the work period on the ground is prolonged as described above, the boiler building below the heat transfer tube group and the storage Preparations for installation of fans, hoppers, casings, piping, flue, etc. placed in the space could not be made.

Further, since each heat transfer tube group is lifted with substantially the same size as the set size L × W at the end of the installation, the heat transfer tube group is interposed between the heat transfer tube group and each wall surrounding the rear heat transfer wall chamber 5 which is a storage space for the heat transfer tube group. Since there is almost no work space for welding etc., the rear heat transfer wall and the heat transfer tube group cannot be lifted at the same time, so the heat transfer tube group had to be lifted first, and then the rear heat transfer wall was lifted. However, each work after the lifting was performed in a narrow part, which was very difficult.

In the prior art, no consideration was given to shortening the installation work period of the boiler body. Specifically, no consideration has been given to reducing the ground work and shortening the period of parallel work in installing the rear heat transfer wall and the horizontal heat transfer tube group, and improving the safety of assembly work at high places. For this reason, the installation work period was long.

An object of the present invention is to reduce the work on the ground in the installation of the horizontal heat transfer tube group and shorten the work period by enabling parallel work, and to improve the safety of the assembling work at a high place. It is an object of the present invention to provide a method of transporting and installing a horizontal heat transfer tube group and a transporting and installing structure capable of achieving the following.

[0027]

SUMMARY OF THE INVENTION An object of the present invention is to provide a superheater, a reheater, and an evaporator, wherein a straight pipe portion is disposed horizontally in an exhaust gas flow path from a boiler so that a straight pipe section is at right angles to a gas flow. vessel,
In a method of installing a horizontal heat transfer tube group each including a plurality of heat transfer tube coils, such as a economizer, the heat transfer tube group is divided into a plurality of small heat transfer tube groups, and further, the heat transfer tube coils of the small heat transfer tube group are further divided. Packed so that the tube row spacing in the width direction of the can is smaller than the installation dimensions, including the packing, and transported it to the site, and carried it almost directly below the storage part of the horizontal heat transfer tube group in the boiler building. , Remove the packaging after lifting,
This is achieved by a first means for expanding the row of tubes of the heat transfer tube group in the width direction of the can so that the spacing becomes the installation dimension.

In the method for installing a horizontal heat transfer tube group according to the first means, of the heat transfer tube group in which a plurality of stages are arranged with respect to the gas flow, the upstream heat transfer tube group previously carried in may be loaded this time. The heat transfer tube group on the downstream side is lifted above the dodging height, the packages are joined at the minimum number of places, the heat transfer tube group on the downstream side to be carried in next time is lifted over the dodging height, and the lifting is performed sequentially, After the joining of the packing of the heat transfer tube group on the side is completed, all the stages are lifted to the installation position, the packing is removed and lowered, and the tube row of each heat transfer tube group is set so that the interval is the installation size. This is achieved by a second means for spreading in the width direction of the can.

Each of the superheater, the reheater, the evaporator, the economizer, etc., which is disposed horizontally in the exhaust gas flow path from the boiler so that the straight pipe section is at a right angle to the gas flow. In the installation structure of a horizontal heat transfer tube group including a plurality of heat transfer tube coils, the heat transfer tube group is divided into a plurality of small heat transfer tube groups, and the tubes in the can width direction of the heat transfer tube coils of the small heat transfer tube group. The row spacing is a dimension smaller than the installation dimensions including the packaging, and the packaging can be removed after lifting,
This is achieved by a third means in which the row of the heat transfer tubes can be widened in the width direction of the can to make the interval between the rows of cans an installation dimension.

[0030]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, FIGS.
An embodiment of the present invention will be described with reference to FIG. FIGS. 1 to 6 are explanatory views of a procedure for lifting a group of horizontal heat transfer tubes according to an embodiment of the present invention, a plan view for explaining a working space in a storage space, a small block structure, and mounting of a packing frame. FIG. 2 shows an explanatory diagram when a tube row pitch of a heat transfer tube coil or a hanging tube is minimized, and an explanatory diagram of a lifting mode for each small block of a horizontal heat transfer tube group.

First, at the factory, each heat transfer tube group is divided into small blocks of 20 to 30 rows in the width direction of the boiler can, as shown in FIG. The pipe row pitch is adjusted to P smaller than the set dimension Q after the installation is completed. In the present embodiment, a case where the interval P is minimum is shown.

Next, as shown in FIG. 4, a packing frame 16 composed of a frame post 16a, a frame beam 16b, and a reinforcing material 16c is placed on the small block thus prepared as shown in FIG. It is arranged closer to the innermost heat transfer tube coil in the small block, and the dimensions of the packaging frame 16 are set to fit within R × Wb.

As described above, the distance between the heat transfer tubes or the suspension tubes 13 in the small block is minimized, and the packing frame 16 is closely arranged so that the adjacent heat transfer tube coil and the packing frame 16 during transportation are connected to each other. Can be prevented from being damaged due to contact or rubbing due to vibration or bending of the device.
Further, since the dimensions of the packaging frame 16 are set to fit in R × Wb, the packaging frame 16 does not interfere with the dimension of the rear heat transfer wall chamber 5 serving as a storage space in the longitudinal direction of the can. Further, as shown in FIG. 3, the heat transfer tube group is divided into eight small blocks for the dimension in the width direction of the can. Space 20 can be secured.

On the other hand, conventionally, the width Wa of the small block in the width direction substantially coincides with the dimension between the on-site joining points 21 between the small blocks, so that a work space is hardly obtained, and the welding operation is completed on the ground. I had to keep it.

In the present embodiment, in consideration of lifting with the packing frame 16 attached, the height of the frame post 16a is set to Hb, and the height of the frame post 16a in the longitudinal direction of the heat transfer tube coil is set. It is set so as to substantially match the dimension between the butt welding positions of the downcomer 13 with the upper and lower stages.

Next, the lifting of the horizontal heat transfer tube group according to the embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows the lifting procedure in chronological order from left to right in the figure.

First, after the boiler main body supporting steel frame 1 is erected, a plurality of lifting devices 17 such as a plurality of center hole jacks 17a are installed on the top beam 11 and the sling bolts 2 are mounted.
Is lowered on the ground, a lifting beam 18 is attached to the lower part of the sling bolt 2, and a hanging means such as a wire or a rod is attached to the hanging header 14. In this case, a suspending means such as a wire or a rod is attached to the suspended header 14 directly from the top girders 11, and the suspended beam 18
Can also be omitted.

The stub group 1 of the hanging pipe header 14
In the vicinity of the butt welding position, which is the lower end of the stub group 5, a pipe row pitch adjusting means 17 is attached. Set the pipe row pitch to.

Next, the butt welding position at the lower end of the stub group 15 of the hanging tube header 14 is butt-welded with the hanging tube 13 at the upper end of the small block 10a of the heat transfer tube group installed at the uppermost stage. Lift up to dodge height.

Next, the small block 10a of the heat transfer tube group installed at the uppermost stage which has been transported is moved substantially immediately below the hanging tube header 14, and the first stage is carried out without dismantling the packing frame 16. In this connection, the hanging pipes 13 are grooved and butt-welded.

In this case, of the packing frame 16 of the small block 10a installed on the top of the lifting beam 18, the frame column 16a
If suspending means such as a wire or a rod for suspending is provided, and this is coupled to the upper end of the frame post 16a,
Since the load of the small block 10a can be transmitted, the groove of the hanging pipes 13 and the butt welding can be performed after lifting, and the work on the ground can be reduced.

In the second and subsequent stages, after the small blocks of the next stage are lifted up to the dodge height, only the frame columns 16a are joined together, and the small block installed at the lowermost stage, for example, 10d is connected to the frame columns 16a. After the connection, as shown in FIG. 5, the entire stage is lifted up to the set position.

Next, after all stages have been lifted to the set position,
After performing the butt welding of the hanging pipes and the heat transfer pipes of each stage, the packing frame 16 is disassembled and lowered to the ground.

Next, the pipe row pitch adjusting means 17 is removed, the pipe row pitch is adjusted to the set size, and the small blocks of the same heat transfer tube group are connected to each other by the constraining means at the on-site junction 20 to form a heat transfer tube group. And complete the installation.

FIG. 2 shows another embodiment of the present invention. In this embodiment, a portion from the hanging pipe header 14 to a butt welding position with the hanging pipe 13 is hoisted at an initial stage of installation, and then a hanging means such as a wire or a rod is directly provided from the top girders 11. Is lowered to the ground, and the small blocks are coupled to the frame pillars 16a of the packing frame 16 and the like, so that all stages are sequentially lifted.

According to this embodiment, the entire heat transfer tube group can be installed in a parallel operation, and the production, transportation, and lifting can be performed in order from the heat transfer tube group installed at the uppermost stage according to the installation process. Therefore, efficient process management can be performed.

FIGS. 7 and 8 show still another embodiment of the present invention. In this embodiment, the range of the small block is obtained by combining the small blocks in the upper and lower rows.
According to the present embodiment, since the upper and lower small blocks are assembled in advance at the factory, the time required for lifting at the installation site and butt welding after lifting can be reduced by half.

In the present invention, when the horizontal heat transfer tube group 10 in the factory is divided into small blocks by dividing it in the boiler can width direction, the structure of the small blocks is determined by the tube row pitch of each heat transfer tube coil,
That is, the tube row pitch of the hanging tubes is smaller than the set size at the end of installation, and the packing frame is arranged closely to the heat transfer tube coil outside each small block. Interference in the boiler width direction can be prevented, and a sufficient working space can be secured when lifted to the set position.

For this reason, it is not necessary to disassemble the packaging frame of the small block on the ground, and when there are a plurality of heat transfer tube groups, the connection of the upper and lower stages is performed by welding the minimum number of points between the packaging frames. And ground work that needs to be reduced as much as possible in order to promote the installation work can be reduced.

Further, the installation of each wall surrounding the rear heat transfer wall chamber 5 serving as a storage space for the horizontal heat transfer tube group 10 is performed because a sufficient work space is generated between the heat transfer tube group and the horizontal heat transfer tube group. It can be performed in parallel with the lifting of the heat transfer tube group, and after all lifting work on the rear heat transfer wall room is completed, several hundreds of lifting tubes, heat transfer tube groups and the rear heat transfer wall room can be safely surrounded in a sufficient work space. Welding of the joint with the wall can be performed.

The uppermost one of the small blocks after the lifting operation is supported by the hanging pipe header 14 via the hanging pipe 13, but is suspended from the hanging pipe header 14. The tube row pitch of the downcomer 13 is a set dimension at the end of the installation in the suspended pipe header 14, and the pipe row pitch of the small block, that is, the pipe row pitch of the small block in the portion where the downcomer 13 is connected to the uppermost stage, that is, The pitch is set smaller than the dimension set at the end of installation.

For this reason, by removing the tube row pitch adjusting means 17 at the final stage of installation, the tube row pitch of all the heat transfer tube coils constituting the heat transfer tube group can be reduced to the set dimensions at the end of installation by a simple operation. Can be adjusted.

The removal and suspension of the packing frame may be performed before the work of adjusting the pipe row pitch to the dimension at the time of completion of installation.

[0054]

According to the method for transporting and installing the horizontal heat transfer tube group and the transport and installation structure of the present invention, the horizontal heat transfer tube group is made compact, so that the transportation efficiency is improved and the lifting of each packing frame is achieved. As a result, the ground work in installation can be greatly reduced. In addition, since the work can be performed in parallel with the installation work of the other boiler body parts, the construction period can be significantly shortened, and the safety of the assembling work at a high place can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a procedure for lifting a horizontal heat transfer tube group according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a procedure for lifting a horizontal heat transfer tube group according to another embodiment of the present invention.

FIG. 3 is an explanatory diagram of a work space in a storage space of the horizontal heat transfer tube group according to the embodiment of the present invention.

FIG. 4 is a perspective view showing a small block structure of a horizontal heat transfer tube group and a mounting state of a packing frame according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram in the case where the tube row pitch of the heat transfer tube coils or the suspension tubes of the horizontal heat transfer tube group according to the embodiment of the present invention is minimized.

FIG. 6 is a perspective view of a lifting configuration for each small block of the horizontal heat transfer tube group according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram of a procedure for lifting a horizontal heat transfer tube group according to another embodiment of the present invention.

FIG. 8 is a perspective view showing a small block structure of a horizontal heat transfer tube group and a mounting state of a packing frame according to another embodiment of the present invention.

FIG. 9 is a typical configuration diagram of a large boiler having a horizontal heat transfer tube group.

FIG. 10 is an explanatory diagram of a procedure for lifting a horizontal heat transfer tube group according to a conventional example.

FIG. 11 is a perspective view showing a small block structure of a horizontal heat transfer tube group and a mounting state of a packing frame according to a conventional example.

FIG. 12 is an explanatory view of a tube row pitch of a heat transfer tube coil or a hanging tube of a horizontal heat transfer tube group according to a conventional example.

[Explanation of symbols]

 2 Sling bolt 11 Top girder 14 Hanging pipe header 15 Stub group 16 Packing frame 17 Lifting device 18 Lifting beam

Claims (3)

[Claims] 1. A method for installing a plurality of heat transfer tube groups arranged horizontally so that a straight pipe portion is substantially perpendicular to a gas flow direction in an exhaust gas flow path from a boiler. The group is divided into a plurality of small heat transfer tube groups, and the tube row spacing in the can width direction of the heat transfer tube coils of the small heat transfer tube group is
It is packed to a size reduced from the installation dimensions including the packing, transported to the site, transported to almost immediately below the storage part of the horizontal heat transfer tube group of the boiler building, and after lifting, remove the packing, A method of installing a horizontal heat transfer tube group, wherein a tube row of the heat transfer tube group is widened in the width direction of the can so that the interval becomes the installation size. 2. The heat transfer tube group in which a plurality of stages are arranged with respect to a gas flow, wherein the upstream heat transfer tube group carried in last time is replaced by the downstream heat transfer tube group carried in this time. Lifting above the dodging height, joining the packages at the minimum number of places, lifting the dosing heat transfer tube group to be carried in next time above the dodging height, performing the lifting in order, and packing the lowermost heat transfer tube group. After the joining is completed, the entire stage is lifted to the installation position, the package is removed and lowered, and the tube row of each heat transfer tube group is widened in the width direction of the can such that the interval becomes the installation size. How to install the horizontal heat transfer tube group. 3. An installation structure of a plurality of heat transfer tube groups disposed horizontally in a flow path of exhaust gas from a boiler such that a straight pipe portion is substantially perpendicular to a gas flow direction, The group consists of multiple small heat transfer tube groups,
The tube row interval in the can width direction of the heat transfer tube coil of the small heat transfer tube group is a size smaller than the installation size including the packing, and after lifting, the packing is removed, and the can row of the heat transfer tube group is expanded in the can width direction. An installation structure for a group of horizontal heat transfer tubes, characterized in that the spacing between the can rows can be made equal to the installation size.