JPH07269160A - Lng tank and installation method thereof - Google Patents

Abstract

PURPOSE:To build a LNG tank of high quality in a short term. CONSTITUTION:A LNG tank 1 with liquidproof bank 6 is assembled in a factory. The LNG tank 1 is constituted so that a tank main body 4 of which the outer circumferential part is coverd with cold reserving construction is loaded on a bottom slab 2 through a mechanism 5 allowing thermal expansion of the tank main body, and the liquidproof bank 6 is built on the outer circumferential part of the bottom slab 2. The LNG tank 1 is transported on the water to the spot, and transported to the installation spot by transportation on land with a transport device or water transportation utilizing a conduit to the spot, and hence it is installed on the installation plane 7.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to LNG storing LNG.
The present invention relates to an installation method for tanks and LNG tanks.

[0002]

2. Description of the Related Art Among LNG tanks, a large self-supporting LNG tank constructed on the ground is as shown in FIG.
A tank main body b is placed on a concrete bottom plate a via a bottom cold insulating material / supporting material c, and a cold insulating material holding structure d is erected on an outer peripheral portion of the tank main body b to hold the cold insulating material holding structure. A space between the d and the tank body b is filled with a cold insulating material e such as granular pearlite, and a concrete liquid barrier f is constructed on the outer peripheral portion of the bottom slab a. In addition, g is a canopy, h is a ground freezing prevention heater embedded in the bottom slab a, and i is LNG.

[0003]

In the above LNG tank, since the tank body b repeats thermal expansion and contraction due to the temperature change accompanying the LNGi being taken in and out of the tank body b, how to allow the thermal expansion and contraction occurring at that time. Whether or not to do so is an important issue. Therefore, conventionally, the tank body b is placed on the bottom cooler / support material c without being fixed, and the tank body b is circumferentially disposed between the side plate of the tank body b and the bottom plate a. However, it has been devised such as providing a large number of anchor straps, and therefore there is a problem that the structure becomes complicated. Furthermore, if LNGi leaks from the tank body b,
Although a force to move the bottom slab a by heat acts, the bottom slab usually has its peripheral portion fixed to the ground, so that excessive stress may occur in the peripheral portion. .

Further, in the case of the above LNG tank, since all the construction work must be carried out locally, a great deal of labor is required to carry in and install the construction equipment, and the labor cost for the local construction becomes enormous and high. There is a problem of cost, and after the bottom slab a, the heater h, and the bottom cooler / supporter c are installed, the tank body b, the cooler holding structure d, and the canopy g
Since the construction work such as the above and the filling work of the cold insulating material e have to be performed, there is a problem that the construction period is long.

Therefore, the present invention allows the heat expansion and contraction movement of the tank body without complicating the structure, and even if LNG leaks from the tank body, the bottom plate is partially excessive. LNG that does not generate stress
It is intended to provide a tank, and further to provide an LNG tank installation construction method capable of efficiently installing the LNG tank in a short period of time.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention places a tank main body on a bottom plate which is integral with a liquid barrier, and between the lower surface of the tank main body and the upper surface of the bottom plate. In addition, the tank main body thermal expansion and contraction mechanism that allows the thermal expansion and contraction due to the temperature change of the tank main body only in the radial direction is interposed, and further, between the lower surface of the bottom plate and the tank installation surface,
The bottom slab thermal expansion and contraction mechanism is provided to allow the thermal expansion and contraction of the slab only in the radial direction.

Further, in the LNG tank, it is preferable that a sealed space is formed around the tank body by a liquid barrier and the inert gas is sealed in the sealed space.

Further, the LNG tank body is assembled at the factory so as to be slidable in the radial direction on the bottom plate integrated with the liquid barrier, and LNG is assembled.
Produce a tank, transport the LNG tank to the site by water,
Installation of the LNG tank characterized by transporting the landed LNG tank to the installation site by a transportation device, and then mounting the LNG tank on a support table constructed on the tank installation surface using a crane. The construction method.

Further, the LNG tank body is assembled at the factory so as to be slidable in the radial direction on the bottom plate integrated with the liquid barrier, and LN
After manufacturing the G tank and transporting the LNG tank to the site as it is, the LNG tank is guided to the above-mentioned water conduit that has been built up to the installation site, and transported to the position above the tank installation surface of the installation site by water. After that, the LNG tank installation method may be characterized in that the LNG tank is lowered by draining water around the tank installation surface and installed on a support table constructed on the tank installation surface.

Furthermore, when the LNG tank is guided to the installation site by the water conduit, the water conduit may be constructed by a weir frame.

[0011]

[Operation] Since the heat expansion / contraction allowing mechanism which allows the heat expansion / contraction only in the radial direction is interposed between the bottom plate upper surface and the tank body and between the bottom plate lower surface and the tank installation surface, respectively, the tank It is possible to stably support the thermal expansion and contraction of the main body and the bottom plate.

Also, after transporting the LNG tank in which the LNG tank main body is slidable in the radial direction on the bottom plate with the liquid barrier built in the factory to the site, the installation site is carried out by the transport device or the water conduit. Since it will be transported to and installed in, high quality tanks can be built in a short period of time.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

1 (a) and 1 (b) show an embodiment of the present invention, in which 1 is an LNG tank with a self-supporting dike, the outer periphery of which is a cold insulation structure on the bottom plate 2. The tank body 4 surrounded by 3 is placed via the tank body heat expansion / contraction allowing mechanism 5 for allowing the heat expansion / contraction movement only in the radial direction around the center of the tank body bottom plate 4a, In addition, a liquid barrier 6 composed of an upper dam body 6a and a lower dam body 6b is constructed around the outer periphery of the bottom slab 2 to form a sealed space S around the tank body 4, and the sealed space S is formed in the sealed space S. An inert gas was sealed in, and a bottom plate heat expansion / contraction mechanism 8 that allowed heat expansion / contraction only in the radial direction from the center of the bottom plate 2 was interposed between the bottom plate 2 and the tank mounting surface 7. It is as a configuration. The height of the lower levee body 6b of the liquid levee 6 is set higher than the level when all the LNG 9 in the tank body 4 leaks. 10 is an LNG injection tube, 1
Reference numeral 1 is an LNG discharge pipe provided with a pump P, 12 is a vaporized gas suction / discharge pipe used for injecting and discharging LNG 9, and 13 is a vent pipe for inert gas.

The tank main body heat expansion / contraction allowing mechanism 5 fixes prismatic block-shaped chocks 14 downward at required locations including the center of the lower surface of the tank main body bottom plate 4a,
In addition, a positioning member 15 for positioning and holding the chock 14 in the central portion, a guide member 16 for guiding the chock 14 other than the central portion so as to be slidable only in the radial direction, and a tank at a position excluding the respective chocks 14 A support stand 17 that slidably supports the lower surface of the main body bottom plate 4a is attached to the upper surface of the bottom plate 2.

The bottom slab thermal expansion and contraction mechanism 8 is, like the tank main body thermal expansion and contraction mechanism 5, provided with a chock 18 at a required portion including the central portion of the lower surface of the bottom slab 2 and on the tank mounting surface 7 side. A positioning member 19 for positioning and holding the central chock 18, and a guide member 20 for guiding the chock 18 other than the central part so as to be slidable only in the radial direction,
A support base 21 that slidably supports the lower surface of the bottom slab 2 is provided.

The LNG tank 1 of the present invention is manufactured in a factory, and in parallel with this, a positioning member 19, a guide member 20 and a support 21 which constitute the bottom plate thermal expansion / contraction allowing mechanism 8 are installed at the local tank. Try to build it on surface 7. An example of the LNG tank 1 manufactured in the factory is shown in FIG.
As shown in (b), after being transported by water to the site, it is transported by land to the installation site 24 and installed on the tank installation surface 7.

The detailed procedure of the installation method shown in FIG. 2 will be described in detail. First, the LNG tank 1 with a liquid barrier as shown in FIG. It is transported by water to the site by the barge 22. Next, after adjusting the height of the carrier 22 and the unloading pier (adjusting the ballast of the carrier 22 according to the tide level) at the site, the carrier 23 such as a dolly as a carrier that was kept on standby was installed. Let's get on the ship 22 and make full use of jack-up operation etc.
The LNG tank 1 is transferred on top.

After that, the LNG tank 1 is unloaded by transferring the transport vehicle 23 from the top of the barge 22 to the land, and as shown in FIG.
Transport the tank 1 to the installation site 24.

On the other hand, at the installation site 24, in parallel with the work of assembling the LNG tank 1 and transporting it over water, the positioning member 19, the guide member 20, and the support 21 in the bottom plate thermal expansion and contraction allowing mechanism 8 are arranged on the tank installation surface 7. And (2) should be installed accurately (see Fig. 1), and the L
When the NG tank 1 is transported, the LNG tank 1 is installed by hanging it down on the tank installation surface 7 using a large crane (a hook is shown in the figure) 25. At this time, as shown in FIG. 1, the chock 18 at the center of the lower surface of the bottom slab 2 is engaged with the positioning member 19 and the other chock 18 is engaged with the guide member 20, and the portion without the chock 18 is provided. Is brought into contact with and supported by the upper surface of the support base 21.

In the above, the LNG tank 1 is not assembled in sequence at the installation site 24, but is assembled in the factory, so that an accurate and high-quality LNG tank 1 can be constructed. Further, at the installation site 24, it is only necessary to perform the foundation work in parallel with the assembly work and the transportation work of the LNG tank 1. Compared with the conventional construction method in which the bottom slab 2 and the dike 6 are sequentially constructed after the completion of the foundation work. Therefore, the construction period can be significantly shortened, and it is not necessary to bring in a large number of construction equipment or the like to the installation site 24, and the site construction can be drastically reduced, which is advantageous in terms of cost.

As shown in FIG. 1, when the LNG tank 1 is completed and the LNG 9 is put in and taken out of the tank body 4, the tank body 4 is thermally expanded and contracted due to temperature change. Since the tank main body thermal expansion / contraction allowing mechanism 5 is interposed between the bottom plate 4a and the bottom plate 2, the tank main body 4 can be moved by thermal expansion / contraction only in the radial direction from the central portion, and the overall position is It will be held constant. That is, the tank body bottom plate 4
The chock 14 fixed to the center of the lower surface of a is the bottom plate 2
The chock 14, which is fitted into the upper positioning member 15 and fixed at its position, is fixed at another position, and the chock 14 is arranged along the radial direction from the central portion.
Since it is slidably engaged with and the portion without the chock 14 is slidably supported on the upper surface of the support stand 17, it is possible to allow heat transfer due to thermal expansion and contraction of the tank body 4. Therefore, heat transfer of the tank body can be dealt with by a simple structure without attaching a large number of anchor straps between the side plate of the tank body 4 and the bottom plate 2 as in the conventional case.

Further, in the above case, in the unlikely event that the LNG 9 leaks from the tank body 4,
The liquid barrier 6 prevents leakage to the outside of the tank. On this occasion,
When the cold heat of the LNG 9 is transferred to the bottom plate 2, the bottom plate 2 is contracted by heat, but between the lower surface of the bottom plate 2 and the tank mounting surface 7, the bottom plate heat expansion / contraction allowance similar to the tank main body heat expansion / contraction allowance 5 described above. Since the mechanism 8 is interposed, the bottom slab 2 is thermally expanded and contracted along the radial direction from the central portion. Therefore, unlike the conventional case, excessive stress does not act on the outer peripheral portion of the bottom slab 2.

Further, in the LNG tank 1, since the sealed space S is formed by the liquid barrier 6 around the tank body 4 and the inert gas is enclosed in the sealed space S, the tank body 4 is The cold insulation structure 3 that surrounds the outer peripheral portion does not come into contact with the atmosphere, and it is possible to prevent moisture from adhering, and thus the cold insulation function (insulation function) of the cold insulation structure
Can be prevented from being damaged, and the cold insulation function can be stably maintained for a long period of time.

In the above-described embodiment, the case where the carrier 23 such as a dolly is used as a carrier for carrying the LNG tank 1 on site is shown. However, the product can be floated and carried by the pressure of air. The air slide thus configured may be used.

Next, (a) and (b) of FIG. 3 show another example of the installation method of the LNG tank 1. The LNG tank 1 assembled at the factory is transferred to the land by a carrier such as a carrier 23. It is designed to be transported by water to the installation site for installation without transportation. That is, the LN shown in FIG.
After the G tank 1 itself functions as a floating body and is floated on the water as it is and transported on the water, as shown in (a) of FIG. 3, a headrace such as an excavation that was built in advance from the quay part to the installation site 24. L led to 26 and led to headrace 26
As shown in FIG. 3B, the NG tank 1 is installed at the installation site 24.
The water is transported to a position above the tank installation surface 7 of. When it is loaded to a position above the tank mounting surface 7, the periphery of the tank mounting surface 7 is partitioned to drain water.
The G tank 1 is gradually lowered to be installed on the tank installation surface 7.

The use of the installation method shown in FIGS. 3A and 3B has the advantage that the large-sized transportation device and the crane 25 need not be used.

Next, FIGS. 4 (a) and (b) show still another embodiment of the installation method of the LNG tank 1, which is shown in FIG. 3 (a) / (b). Instead, the LNG tank 1 is transported to the installation site 24 by water and installed by using the water conduit 26 formed by the weir frame 27. That is, the weir frame 27 is constructed by sequentially driving the top plates so that the required amount of water is projected from the installation site 24 to the sea side through the portion of the quay in advance, and the part of the weir frame 27 that projects to the sea side is the entrance. An opening / closing gate 28 such as a lock gate is provided at the entrance 27a as the portion 27a,
8 is closed and water is poured into the weir frame 27 so that the water conduit 26
The open / close gate 28 is opened, and the LNG tank 1 transported by water is introduced into the inlet 27a of the weir frame 27, and then the open / close gate 28 is opened.
Then, water is poured into the weir frame 27 using a pump to form the weir frame 27 as a water conduit 26, and the LNG tank 1 is levitated at the inlet portion 27a and above the tank installation surface 7 of the installation site 24. Then, the LNG tank 1 is gradually lowered by using a pump or by draining the water in the weir frame 27 by opening the opening / closing gate 28, and then the tank mounting surface 7 is reached. Try to install. After installing the tank, the weir frame 27 is removed.

When the installation method shown in (a) and (b) of FIG. 4 is adopted, the above-ground part between the quay part and the installation site is excavated in order to form the headrace 26, as in the case of constructing a trench. There is an advantage that it is not necessary.

In the above embodiment, the tank body bottom plate 4 is used.
The case where the chock 14 at the center of the lower surface of a is positioned and held by the positioning member 15 is shown, but instead of the positioning member 15, the guide member 16 may be used in the front-back or left-right direction. Further, although the LNG tank 1 is shown in the case of a square shape, it may be in a cylindrical shape, and further, the case of the liquid breakwater 6 including the upper dam body 6a and the lower dam body 6b is shown. However, it is needless to say that only the lower bank body 6b may be used, and various modifications may be made without departing from the scope of the present invention.

[0031]

As described above, according to the LNG tank of the present invention, between the tank body and the bottom slab, there is provided the tank body heat expansion / contraction allowing mechanism which allows the heat expansion / contraction of the tank body only in the radial direction. Since it is interposed, it is possible to allow thermal expansion and contraction of the tank main body without attaching many anchor straps in the circumferential direction between the bottom of the tank main body and the bottom plate, and between the bottom plate and the tank installation surface, Since the bottom plate heat expansion and contraction allowance mechanism that allows heat expansion and contraction of the bottom plate only in the radial direction is installed, heat transfer of the bottom plate can be allowed and excessive stress is generated in the outer peripheral portion of the bottom plate. This can be prevented in advance, and by forming a sealed space around the tank body with a liquid barrier, and enclosing inert gas in the sealed space, moisture adheres to the cold insulation structure on the outer periphery of the tank body. Made stop, it is possible to maintain the cold function stably for a long period of time.

Further, according to the installation method of the LNG tank of the present invention, the LNG tank assembled at the factory with the dike is transported to the site by water, and then on-site by the land transportation by the carrier or the water transportation by the headrace. , LNG tanks are transported to the installation site for installation, so L
The NG tank can be of high quality, and the construction period can be drastically shortened because the on-site construction is drastically reduced, the tank can be constructed at low cost, and the above-mentioned headrace can be constructed as a weir frame. By forming by, it is possible to achieve an excellent effect that it is not necessary to excavate the above-ground portion.

[Brief description of drawings]

FIG. 1 shows an outline of an embodiment of an LNG tank of the present invention, in which (A) is a cut side surface and a view taken along the line AA of (B), and (B) is a B-B of (A). FIG.

FIG. 2 shows an embodiment of a method for installing an LNG tank, and (a) and (b) are schematic views showing different processes.

FIG. 3 shows another embodiment of the installation method of the LNG tank, and (a) and (b) are schematic diagrams showing different processes.

FIG. 4 shows still another embodiment of the LNG tank installation method, wherein (a) is a schematic sectional side view and (b) is a schematic plan view.

FIG. 5 is a schematic diagram showing an example of a conventional LNG tank.

[Explanation of symbols]

 1 LNG tank 2 Bottom plate 4 Tank body 5 Tank body 5 Heat expansion / contraction allowance mechanism 6 Levee dike 7 Tank installation surface 8 Bottom plate heat expansion / contraction allowance mechanism 21 Support platform 23 Transport vehicle (transporter) 24 Installation site 26 Water channel 27 Weir frame S Closed space

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kei Fujitani 2-1-1 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Ltd. Tokyo No. 1 Factory

Claims (5)

[Claims] 1. A tank main body is placed on a bottom plate integrated with a liquid barrier, and thermal expansion and contraction due to temperature change of the tank main body is radiated only between the lower surface of the tank main body and the upper surface of the bottom plate in the radial direction. The heat expansion and contraction allowance mechanism of the tank main body is installed to allow it, and further, between the bottom surface of the bottom plate and the tank installation surface,
An LNG tank having a configuration in which a bottom plate heat expansion / contraction allowing mechanism that allows heat expansion / contraction of the bottom plate only in a radial direction is interposed. 2. The LNG tank according to claim 1, wherein the periphery of the tank body is sealed by a liquid barrier to form a sealed space, and inert gas is sealed in the sealed space. 3. An LNG tank body is assembled in a factory so that it can be slid in a radial direction on a bottom slab integrated with a liquid barrier, and an LNG tank is manufactured. The LNG tank is transported to the site by water and unloaded at the site. An LNG tank installation method characterized in that the LNG tank is transported to a site of installation by a transportation device, and then the LNG tank is mounted on a support table constructed on a tank installation surface by using a crane. 4. The LNG tank body is assembled on a bottom slab that is integral with the liquid barrier to be slidable in the radial direction at the factory to produce an LNG tank, and the LNG tank is directly transported to the site by water and then to the installation site. The LNG tank is guided to a pre-established water conduit and transported by water to a position above the tank installation surface at the installation site. Then, the water around the tank installation surface is drained to lower the LNG tank and the tank. An LNG tank installation method characterized by being installed on a support table constructed on the installation surface. 5. The method for installing an LNG tank according to claim 4, wherein the water conduit is formed by a weir frame.