JP2671177B2 - Cooling structure inside the low temperature liquid storage tank roof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, LNG and LPG.
The present invention relates to a cold insulation structure for the inner surface of the roof of a storage tank that stores a low temperature liquid such as low temperature liquefied gas.

[0002]

2. Description of the Related Art The structure of a conventional cryogenic liquid storage tank is shown in FIG. As shown in this figure, in a low-temperature liquid storage tank 20 having a conventional membrane-type inner tank, a dome roof 21 is installed above the side wall 12 of a cylindrical outer tank.
A heat insulating material such as a heat insulating panel 25 is spread over the bottom surface 13 and the side wall 12 of the outer tank, and corrugation (folds) is formed on the heat insulating material.
Arranging the membrane thin plates 26 with
A liquid-tight mechanism is used for the inner tank.

Further, the airtight structure of the roof portion is maintained on the inner surface of the dome roof, and as the cold insulating structure in the upper part (roof portion) of the storage tank, the circular cold insulating material holding deck 27 suspended from the dome roof 21 keeps the cold insulating material. It was general to suspend the material 23 to form a cold insulation mechanism. On the other hand, in the cold insulation structure of the roof portion in another conventional low temperature liquid storage tank shown in FIG. 3, the cold insulation material 33 is directly installed on the inner surface of the roof along the aggregate of the dome roof 31.

[0004]

However, in the structure in which the cold insulating material is suspended from the inner surface of the dome roof as shown in FIG. 2, the liquid level fluctuation in the storage tank which occurs during an earthquake occurs. Due to the load due to (sloshing), the cold insulating material 23 suspended from the dome roof and the cold insulating material holding deck 27
There was a risk that the etc. would be destroyed. That is, when the cold insulating material 23 is hung from the dome roof, these support beams have to be long, and thus there is a risk that the load due to sloshing cannot be withstood.

Further, in the case where the cold insulation material is directly installed on the roof frame of the dome roof as shown in FIG. 3, heat convection easily occurs in the cold insulation material installed on the sloping portion of the dome roof, and the cold insulation effect is obtained. There was a problem from the perspective. For this reason, it is not possible to use a low-cost cool material such as glass wool material, and therefore, there is no choice but to use a solid material such as urethane or a foam material as a cool material, which causes a problem of high manufacturing cost. there were. Further, in order to install the cold insulating material directly on the inner surface of the dome roof, the cold insulating material must be bent into a spherical shape according to the shape of the inner surface of the dome, and the construction must be performed.

The present invention has been made by paying attention to the above points, and obtains a cold insulation structure on the inner surface of the roof of a low temperature liquid storage tank which has sufficient anti-sloshing strength and cold insulation effect and is easy to construct. The purpose is to

[0007]

In order to achieve the above object, in the cold insulation structure on the inner surface of the roof portion of the low temperature liquid storage tank according to the invention of claim 1 of the present application, the roof portion of the outer tank formed in a flat plate shape and the roof portion are provided. A flat cold insulation material holding deck member that is horizontally laid horizontally by a supporting member that is suspended from the cold insulation material, and a cold insulation material that is arranged so as to fill between the inner surface of the roof portion and the cold insulation material holding deck member. It is characterized by consisting of.

Further, the invention according to claim 2 is characterized in that, of the cold insulating material, at least the cold insulating material at a portion in contact with the inner wall portion of the inner tank is made of an elastic cold insulating material.

[0009]

The cold-insulating structure for the inner surface of the roof of the cryogenic liquid storage tank according to the present invention has the following functions because it is constructed as described above. That is, since it has the roof portion of the outer tub configured in the shape of a flat plate and the flat cold insulation material holding deck member which is horizontally laid horizontally by the support member hung from the roof portion, the roof inner surface and the cold insulation material are provided. The distance between the holding deck members is significantly smaller than that in the case of the dome type roof, and the deck supporting member is shortened, so that the strength against the load generated by sloshing is increased.

Further, since the cold insulating material filled between the flat inner surface of the roof portion and the flat cold insulating material holding deck member horizontally extending horizontally is installed horizontally, the cold insulating material is installed inside the cold insulating material. The structure makes it difficult for heat convection to occur. Therefore, not only solid materials such as urethane and foam, but also glass
It is also possible to use a lumber or the like. Moreover, since the cold insulating material can be installed on the flat plate portion, the construction is easy and highly reliable.

According to the second aspect of the present invention, at least the portion of the cold insulating material in contact with the inner wall of the inner tank is made of an elastic cold insulating material. Therefore, for example, the shape of the inner tank due to thermal contraction and expansion. It deforms in response to changes, and no gap is formed between the cold insulating material and the side wall, so that a good cold insulating effect can be maintained. Hereinafter, the present invention will be described in more detail through examples.

[0012]

FIG. 1 shows a cryogenic liquid storage tank according to an embodiment of the present invention.
This will be described with reference to FIG. In this figure, a cylindrical outer tank 10
Consists of a reinforced concrete storage tank skeleton, and the skeleton cooler 5 is installed on the entire inner wall (excluding the roof).
An inner tank 6 for sealing the stored low temperature liquid 9 through the cold insulating material 5 is provided. Since the inner tank 6 receives both contraction due to temperature change and internal pressure change, it is made of a stretchable membrane thin plate provided with corrugations.

On the other hand, the storage tank roof portion 1 of the outer tank 10 has a flat plate structure made of reinforced concrete integrally formed with the storage tank body, and the roof portion primary airtight layer 2 is provided on the inner surface of the roof portion 1. . Further, in the central portion of the roof portion 1, a nozzle concentrated penetrating portion 11 for installing a pipe nozzle or the like (not shown)
Is provided. Further, the cold insulating material 3 is installed between the lower surface portion of the primary airtight layer 2 and the deck support beam 8 without a gap. The roof cold insulator 3 is supported by a rigid deck structure including a flat cold insulator holding deck 7 and a deck support beam 8.

Here, the roof cooling material 3 is designed so as to have a temperature gradient in the roof primary airtight layer 2 at room temperature. That is, since the roof cold insulator 3 is sandwiched between the roof primary airtight layer 2 directly attached to the inner surface of the flat roof 1 and the flat cold insulator holding deck 7, the whole structure is flat. Has been done. Therefore, since the thickness of each portion of the cold insulating material 3 is constant, the temperature gradient inside the cold insulating material is also uniform. Therefore, the primary airtight layer 2 can be installed at a normal temperature by installing it in a constant thickness determined by the cooling capacity according to the material of the cold insulating material.

As described above, according to the cold insulation structure for the roof portion of the low temperature liquid storage tank according to this embodiment, since the cold insulation material is formed flat, temperature convection of the roof portion is less likely to occur. Therefore, the cold insulation effect of the roof part becomes uniform. Further, since this cold insulating material is supported by a so-called rigid deck structure, the cold insulating material and the like are not destroyed even when a load due to sloshing is applied.

In this embodiment, the cold storage material holding deck 7
The cold insulation material 3 is installed by a rigid deck structure composed of a deck support beam 8 and a deck support beam 8. However, a cold insulation material integrally formed with the cold insulation material holding deck, for example, a cold insulation material formed in a panel shape, is used. May be installed horizontally on the lower surface of the primary airtight layer 2 of the roof part. However, as a countermeasure against sloshing, it is necessary to fix it by a supporting member that is vertically provided from the roof portion as in the above-described embodiment.

Further, in this embodiment, a part of the cold insulating material 3, that is, the cold insulating material 4 in contact with the inner tank 6 is made of an elastic cold insulating material. This is because, as described above, since the inner tank 6 that constitutes the storage tank body is configured to be expandable and contractible due to heat and internal pressure, when the inner tank 6 itself is deformed, a gap is generated at this boundary portion, This is to prevent the cold insulating material from being destroyed. Therefore, by providing the cold insulating material 4 made of an elastic material, the cold insulating effect of the storage tank itself is always maintained.

[0018]

As described above, according to the present invention, the flat portion of the outer tub has a roof portion, and a support member vertically extending from the roof portion horizontally lays a flat cold insulation. Since the material holding deck member and the cold insulating material arranged so as to fill the space between the inner surface of the roof portion and the cold insulating material holding deck member are provided between the roof inner surface and the cold insulating material holding deck. The distance is uniform at all positions and smaller than before, and the deck support beam is shortened, so that the strength against the load generated by sloshing is increased.

Further, since the cold insulating material is installed horizontally, the structure is such that heat convection hardly occurs in the cold insulating material. Therefore, not only solid materials such as urethane and foam materials but also glass wool materials can be used as the cold insulating material. Also,
Since the cold insulation material can be installed on the flat plate part, it is easy to install and highly reliable.

Further, if at least the cold insulating material in contact with the inner wall of the storage tank is made of an elastic cold insulating material, the cold insulation material and the side wall are deformed well even when the shape change due to thermal contraction and expansion of the inner tank. There is an advantage that a good cooling effect can be maintained without generating a gap.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic configuration of a low temperature liquid storage tank according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a schematic structure of a conventional low temperature liquefied gas storage tank.

FIG. 3 is a sectional view showing a schematic structure of another conventional low temperature liquefied gas storage tank.

[Explanation of symbols]

 1 Storage tank roof part 2 Roof part primary airtight layer 3 Roof part cold insulation material 4 Roof inner edge cold insulation material 5 Body part cold insulation material 6, 26 Membrane thin plate (inner tank) 7, 27 Cold insulation material holding deck 8 Deck support beam 9 Storage low temperature Liquid 10 Storage tank body (outer tank) 11 Nozzle concentrated penetration 12 Outer tank side wall 13 Outer tank bottom 20 Low temperature liquid storage tank 21, 31 Dome roof 23, 33 Cooling material 25 Insulation panel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiichi Ikeura 1-5-20 Kaigan, Minato-ku, Tokyo Within Tokyo Gas Co., Ltd. (72) Inventor Kazuo Shiobara 1-2-1, Marunouchi, Chiyoda-ku, Japan Japan Steel Pipe Co., Ltd. (72) Inventor Norio Torikai 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Inventor Nobuyuki Konoshima 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nippon Steel Pipe Co., Ltd. In-house (56) References JP 62-159894 (JP, A) Jikkai 3-41298 (JP, U) Jitsu 51-9716 (JP, Y2) J44-29713 (JP, B1) )

Claims (2)

(57) [Claims] 1. A roof portion of an outer tub having a flat plate shape, a flat cold insulation material holding deck member which is horizontally laid horizontally by a support member hung from the roof portion, and an inner surface of the roof portion. And a cold insulating material arranged so as to fill a space between the cold insulating material holding deck member and the cold insulating material holding deck member. 2. The cold insulation of the roof portion of a low temperature liquid storage tank according to claim 1, wherein at least a portion of the cold insulation material in contact with the inner wall of the inner tank is made of an elastic cold insulation material. Construction.