JPH11241804A - Supporting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a supporting structure, capable of securing a strength easily while absorbing a thermal extension when the size of a bottom of a matter to be supported is changed due to a temperature change and high in reliability. SOLUTION: In a supporting structure 33 arranged on a horizontal installing surface and a matter to be supported is installed on the upper surface thereof to support the same, a plurality of supporting members are established in the vertical surfaces of the bottom part of the matter to be supported to obtain an integrated structure by connecting the matter to be supported and the supporting members. At the same time, movable supporting units 8, 10, which are deformed elastically to follow a horizontal displacement due to the thermal expansion of the bottom unit of the matter to be supported, are formed around the fixed supporting point 9 at the vicinity of central part of the bottom unit of the matter to be supported, while a vertical brace is installed from the movable supporting units 8, 10 toward the fixed supporting point 9 to obtain a truss structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for supporting a heavy load, and more particularly to a support frame for a heat recovery steam generator, for example, in which the size of a bottom portion changes with a change in temperature.

[0002]

2. Description of the Related Art Generally, in a combined cycle power plant, an exhaust heat recovery boiler that generates steam for driving a steam turbine using exhaust gas from a gas turbine or the like as a heat source is used. The arrow G in the figure indicates the direction in which the exhaust gas flows, and the same applies to other drawings hereinafter.

FIG. 8 shows an example of a conventional exhaust heat recovery boiler. The exhaust heat recovery boiler 32 is a horizontal type natural circulation boiler in which a steam drum is arranged above the equipment and heat transfer tubes are installed in a vertical direction. In the boiler duct 1, a superheater 34, a high-pressure evaporator 35, a denitration device 36, a high-pressure economizer 37, a low-pressure evaporator 38, and a low-pressure economizer 39 are arranged. In FIG. 8, exhaust gas (arrow) from a gas turbine or the like flows into an exhaust heat recovery boiler 32, and firstly, reaches a denitration device 36 via a superheater 34 and a high-pressure evaporator 35, where nitrogen oxides contained therein are removed. Thereafter, the heat passes through the high-pressure economizer 37, the low-pressure evaporator 38, and the low-pressure economizer 39 in order to exchange heat with the internal fluid in each heat transfer tube. In the high-pressure steam drum 40 and the low-pressure steam drum 41, the two-phase flow generated in the evaporator of each pressure flows in and is separated into steam and can water. The generated steam is sent to a steam turbine (not shown).

The natural-circulation-type exhaust heat recovery boiler shown in FIG. 8 does not require a circulation pump as compared with a forced circulation-type exhaust heat recovery boiler, and has the advantage of reducing power in the plant. It has advantages such as the height to the top can be kept low and the boiler can be made to be a self-supporting structure. Therefore, the boiler tends to be used in many combined cycle power plants.

By the way, in order to shorten the construction period on site, the exhaust heat recovery boiler is generally divided into a whole or a plurality of parts at a factory, and not only a boiler body such as a pressure-resistant part and a casing, but also piping, a scaffold, The so-called modularization method, in which the instrumentation equipment is installed in the factory, brought into the site, and installed, is adopted. The exhaust heat recovery boiler shown in FIG. 8 is a two-part module type, and the length of each module is about 10
m, and expansion joints 42 and 43 are disposed between the modules. This module weighs around 1000 tons or even more. In general, movement of the exhaust heat recovery boiler module during transportation or installation is performed by moving a self-propelled truck into the bottom of the casing and lifting it. For this reason, the bottom of the casing needs to be held at a height of about 3 m, which is the height of the self-propelled bogie, higher than the ground,
The support frame 33 supports the boiler duct 1.

[0006] The boiler duct 1 has a structure in which high-temperature exhaust gas passes therethrough, so that the inner surface of the casing plate is usually kept warm and the outer surface temperature can be maintained at about several tens of degrees Celsius. On the other hand, since the temperature of the support frame 33 is room temperature and a temperature difference of up to several tens of degrees Celsius occurs between the casing and the support frame 33, a difference in thermal expansion occurs between the casing and the support frame 33. Therefore, the support frame 33
Are arranged on a horizontal installation surface 27 as shown in FIGS. 9 to 10, and the boiler duct 1
Are arranged, and the columns 2, 2
It is a truss structure supported by beams 3 connecting the spaces and vertical braces 4. The support frame 33 thus configured is
Of the support points 14 to 22, only one support point 18 is a fixed support point, and the remaining support points 14 to 17 and 19 to 22 are formed as slidable slide support points using a metal touch or a slide plate. The configuration is such that thermal distortion caused by thermal expansion can be absorbed.

Further, a support frame 3 for such an exhaust heat recovery boiler is provided.
3 supports vertical load due to its own weight, vertical / horizontal load due to boiler internal pressure, horizontal load in case of storm or earthquake, etc.
7 (basic). The vertical load acting on the boiler duct is transmitted to the columns 2, 2,... Of the support frame 33 via the backstay 29 installed on the outer periphery of the boiler duct shown in FIG. 8, and transmitted to the installation surface 27 (foundation).
Further, since a horizontal force at the time of an earthquake or the like acts on the center of gravity of the boiler duct as a overturning moment, it is pulled out from the upper surface of the support frame 33, received as a compressive force and a shear force, and transmitted to the installation surface 27 (foundation).

[0008]

However, in the support frame having the above-described structure, the support frame and the boiler duct each have an independent double structure, and transmit shear force while absorbing thermal expansion. There was a problem that it became complicated. In addition, the structure was complicated to ensure the strength to resist seismic force. Further, the friction coefficient on the sliding surface is increased, and the reliability is difficult.

Accordingly, the present invention has been made to solve the above-mentioned problems, and has been made to absorb the thermal elongation even when the size of the bottom portion of the supported object changes due to a temperature change, while maintaining the strength. And provide a highly reliable support frame.

[0010]

A support frame according to the present invention is arranged on a horizontal installation surface, and is provided with a support on the upper surface side to support the support. A plurality of supporting members are erected in the bottom vertical plane, and the supported object and the supporting member are joined to form an integral structure, and a fixed support point near the center of the supported object bottom,
A movable support portion is formed around the fixed support point and elastically deforms following the displacement when the bottom of the supported object is displaced in the horizontal direction due to thermal expansion, and the vertical brace is directed from the movable support portion to the fixed support point. It is a truss structure installed.

[0011] According to the support frame of the present invention, the object to be supported and the support member are welded into an integral structure to simplify the support frame structure, and a vertical brace material that does not restrain thermal expansion is used. The difference in thermal expansion caused by the arrangement is absorbed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first to fifth embodiments of the present invention will be described with reference to the attached drawings.

FIG. 1 is a schematic side view of a support mechanism of an exhaust heat recovery boiler showing a first embodiment, FIG. 2 is a schematic perspective view of a support mechanism of the exhaust heat recovery boiler shown in FIG. 1, and FIG. FIG. 2 is a plan view of the support frame shown in FIG.

In the embodiment described below, a boiler duct will be described as an example of a supported object installed on a mounting surface. The boiler duct 1 as a supported object is a boiler duct of a heat exchanger in the exhaust heat recovery type combined cycle power plant described above. The boiler duct 1 is used to guide high-temperature and high-pressure gas exhausted from the gas turbine as described above. The size of the bottom plate changes due to the expansion.

The boiler duct 1 is supported by a support frame 33 having a plurality of support members standing vertically.
As shown in FIGS. 1 to 3, the support frame 33 has a plurality of support members, for example, three columns 2, 2, and 2, respectively, standing in a vertical plane in the boiler duct width direction, and a total of nine columns 2 are provided.
And a truss structure composed of ten vertical braces 4 arranged between the columns 2. One of the columns 2 is fixed to the fixed support portion 9 and eight to the movable support portions 5 to 8, 10 to 13 It is what it was. That is, the bottom 25 of the boiler duct 1
The vicinity of the central portion is a fixed support portion 9, and other support points 5 to 8 and 10 to 13 are set in the vertical plane around the fixed support portion 9. The support points 5 to 8 and 10 to 13 correspond to the bottom portions 24 and 26 of the boiler duct 1 as shown by broken lines in the drawing.
When displaced in the horizontal direction due to thermal expansion, movable support portions (8, 10) are formed which elastically deform following the displacement.

The bottom 25 of the boiler duct 1 has a fixed support 9 near the center, and supports 2, 2,.
... that is, the lower end sides of the movable support portions 6, 8, 10, and 12,
It is connected and supported by four vertical braces 4a, 4b, 4c, 4d and fixed. On the other hand, the other eight bottoms of the boiler duct 1 are attached to the tip of the cantilevered support 2,
For example, fixed hinges 8a, 1 fixed to the bottoms 24, 26
Oa is fixedly supported by the support ends of the movable support portions 8, 10. In the figure, 4e is a vertical brace for connecting and supporting the movable support portions 6, 5; 4f, a vertical brace for connecting and supporting the movable support portions 5, 8; 4g, a vertical brace for connecting and supporting the movable support portions 8, 11; Movable support 11, 1
2 is a vertical brace connecting and supporting 2;
A vertical brace for connecting and supporting 2 and 13, 4 j is a vertical brace for connecting and supporting the movable support portions 13 and 10, 4 k is a vertical brace for connecting and supporting the movable support portions 10 and 7 and 4 m for connecting the movable support portions 7 and 6. Vertical brace to support. 4h, 4i, 4b, 4d, 4e, and 4m shown in FIG. 3 are vertical braces connected and supported in the exhaust gas direction, and do not restrict thermal deformation. The strut 2 is designed in consideration of the weight in advance so as not to cause buckling, and is designed to be within elastic deformation even with respect to thermal expansion of the bottom.

As shown in FIG. 3, the bottom of the boiler duct 2 extends from the lower end of the column 2, that is, the movable support portions 6, 8, 10, and 12.
Vertical brace 4a, 4b, 4c, 4d near the center of 5
Is arranged, a starting point of thermal expansion of the boiler duct 1 (fixed support portion 9) is formed. In addition, vertical brace 4
a, 4b, 4c and 4d act as members for countering the horizontal force and transmit the horizontal force to the mounting surface 27 (foundation).
The pillars 2 (eight in this figure) having no thermal expansion starting point (fixed support point 9) follow the thermal expansion of the boiler duct 1 at the time of thermal expansion, and are movable in the boiler duct width direction and in the longitudinal direction. , 6 ', 7', 8 ', 10', 11 ', 12', 1
3 'thermally expands and elastically deforms (bends) as indicated by broken lines, so that thermal expansion is not restricted.

As described above, the support frame of the present invention joins and integrates the support member (post 2) and the object to be supported (boiler duct 1), and eliminates the absorption of thermal expansion due to sliding while ensuring sufficient rigidity. Because of the simple structure, reliability can be improved. In addition, since it has a simple structure, it is possible to reduce the size and weight and save resources.

In the above embodiment, an exhaust heat recovery boiler has been described as an example of a heat exchanger of a boiler duct. However, the present invention is not limited to this, and is applicable to a case in which a large device that causes thermal expansion is supported. It is generally applicable.

Next, a second embodiment of the present invention will be described with reference to FIG.

A supporting frame 33 according to the second embodiment is
In the vertical plane outside the bottom of the boiler duct 1, which is a supported object, the columns 2, 2, which are two support members, are erected, and the bottom of the boiler duct 1 and the columns 2, 2 are welded together to form an integrated structure. The center of the bottom is a fixed support point 30 and the lower ends of the columns 2 and 2 and the center of the bottom of the boiler duct 1 are connected and supported by a vertical brace 4.

The basic structure of the support frame 33 is as follows.
This embodiment is the same as the first embodiment, except that two columns 2 are arranged in the vertical plane, and the fixed support is not provided near the lower portion of the back stay 29. Therefore, the truss structure has the vertical braces 4 arranged so that the fixed support points 30 are provided near the lower portions of the beams 28 extending between the back stays 29, 29.

In this embodiment, as in the first embodiment, the boiler duct 1 and the column 2 are welded to form an integral structure, so that sufficient rigidity is ensured and thermal expansion due to slippage is ensured. Since the absorption is eliminated and the structure is simplified, the reliability can be improved. In addition, since it has a simple structure, it is possible to reduce the size and weight and save resources. Further, even if the bottom of the boiler duct 1 is displaced in the horizontal direction due to thermal expansion, the boiler duct 1 is supported in a fixed state at a fixed support point 30 at the center of the bottom of the boiler duct, while the movable support around it elastically deforms following the displacement. Therefore, the difference in thermal expansion can be absorbed.

The third embodiment of the present invention will be described with reference to FIG.

The support frame 33 according to the third embodiment is
Four columns 2, 2, 2, 2 are erected in the vertical plane, and the fixed support 3
This is a truss structure in which the vertical braces 4, 4 are arranged so as to have zero. And since the boiler duct 1 and the support | pillar 2 are welded and it has an integral structure, the same effect as 2nd Embodiment can be expected.

A fourth embodiment of the present invention will be described with reference to FIG.

The support frame 33 according to the fourth embodiment is
Five pillars 2, 2, 2, 2, and 2 are erected in the vertical plane, and the bottom of the boiler duct 1 and the upper ends of the pillars 2, 2, 2, 2, and 2 are welded to form an integrated structure. The center of the bottom is a fixed support point A, and the upper end of the boiler duct 1 and the columns 2 and 2 disposed on both sides thereof are vertically brace 4.
It is a truss structure that is connected and supported. The support frame 33 of this embodiment also has the same effect as that of the first embodiment because the boiler duct 1 and the column 2 are welded to form an integral structure.

A fifth embodiment of the present invention will be described with reference to FIG.

The support frame 33 according to the present embodiment has four columns 2, 4 in a vertical plane in the width direction of the boiler duct.
The truss structure is such that two, two, and two are erected, a fixed support point 31 is provided near the center of the bottom of the boiler duct 1, and a vertical brace 4 is installed between the side columns 2a, 2b. Therefore, FIG.
In each of the modules 1, 3, 4, and 5 backstays shown in Nos. 6 to 6, even if there are four pillars in the boiler width direction, the same effect as in the first embodiment can be obtained. .

[0030]

As described above, according to the support frame of the present invention, the vertical braces are arranged so that the vicinity of the center of the bottom of the supported object is set as the starting point of thermal expansion (fixed support point). Even if is displaced in the horizontal direction due to thermal expansion, it is supported in a fixed state near the center of the supported object, but the movable support around it elastically deforms following the above displacement, so that it is not restricted by thermal expansion.

Further, since the support member and the object to be supported are integrally welded to ensure a sufficient rigidity and eliminate the absorption of thermal expansion due to slip, the structure is simple, so that the reliability can be improved. There is no need to install some beams.

Further, the simple structure as described above allows a reduction in size and weight and a saving of resources.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a support mechanism of an exhaust heat recovery boiler according to a first embodiment.

FIG. 2 is a schematic perspective view of a support mechanism of the exhaust heat recovery boiler shown in FIG.

FIG. 3 is a plan view of a support frame of the exhaust heat recovery boiler shown in FIG.

FIG. 4 is a schematic side view of a support frame of an exhaust heat recovery boiler according to a second embodiment.

FIG. 5 is a schematic side view of a support frame of an exhaust heat recovery boiler according to a third embodiment.

FIG. 6 is a schematic side view of a support frame of an exhaust heat recovery boiler according to a fourth embodiment.

FIG. 7 is a longitudinal sectional view showing a support frame of an exhaust heat recovery boiler according to a fifth embodiment, viewed from a section in a boiler width direction.

FIG. 8 is a side view showing a conventional example of an exhaust heat recovery boiler.

FIG. 9 is a side view showing a conventional example of a support frame for an exhaust heat recovery boiler.

10 is a diagram showing a support frame of the exhaust heat recovery boiler shown in FIG. 9 as viewed from above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Boiler duct 2 ... Support 4 ... Vertical brace 5-8, 10-13 Movable support 9 ... Fixed support 25 ... Boiler duct bottom 33 ... Support frame

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takayuki Nagashima 2-4 Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Keihin Works Co., Ltd.

Claims (5)

[Claims] 1. A supporting frame which is disposed on a horizontal installation surface, supports an object to be supported on an upper surface thereof, and supports a plurality of supporting members on a bottom vertical surface of the object. The supported object and the support member are joined to form an integral structure, and a portion near the center of the bottom of the supported object is used as a fixed support point, and the bottom of the supported object is thermally expanded around the fixed support point. A truss structure in which, when displaced in the horizontal direction, a movable support portion that elastically deforms following the displacement is formed, and a vertical brace is provided from the movable support portion toward the fixed support point. Frame. 2. The supporting frame according to claim 1, wherein three support members are respectively erected on a vertical plane of the bottom of the supported object, and the bottom of the supported object and an upper end surface of the support member are welded to form an integral structure. And a truss structure in which a lower end of the movable support member and an upper end of the fixed support member arranged at both ends are connected and supported by a vertical brace. 3. The support frame according to claim 1, wherein each of the two support members is erected in a vertical plane outside the bottom of the supported object,
The bottom of the supported object and the upper end surface of the support member are welded into an integral structure, and the center of the bottom of the supported object is a fixed support point, and the lower ends of the support members and the center of the bottom of the supported object are vertically braceed. A support frame characterized by a truss structure that is connected and supported. 4. The support frame according to claim 1, wherein four support members are respectively erected on a vertical plane of the bottom of the supported object, and the bottom of the supported object and an upper end face of the support member are welded to form an integral structure. A support truss structure in which the lower end of the two support members at the center and the center of the supported object are connected and supported by a vertical brace with the center of the bottom of the supported object being a fixed support point. . 5. The support frame according to claim 1, wherein five support members are respectively erected on a vertical plane of the bottom of the supported object, and the bottom of the supported object and an upper end surface of the support member are welded to form an integral structure. A truss structure in which the center of the bottom of the supported object is a fixed support point, and the upper end of the fixed support member and the lower ends of the movable support members disposed on both sides thereof are connected and supported by vertical braces. Support frame.