JPH0425699A - Liquefied gas storage underground tank - Google Patents

Abstract

PURPOSE:To keep off a freeze of peripheral ground in an economical manner by installing a ring fresh-air inlet blade in an opening at the ground side of an interspace part, in an underground tank which consists of a tank body storing liquefied gas, an end dam wall surrounding the circumference and an interspace part formed in the interval. CONSTITUTION:In this tank, there are provided with a tank body 10 storing liquefied gas G and a ring end dam wall 12 surrounding this tank body which is composed of a tubular side wall part 10a, a disklike bottom plate part 10b and an arched ceiling part 10c, and an adiabatic cold insulant layer is installed in each inner surface side of the side wall part 10a and the bottom plate part 10b. A first space part 18 is formed between the bottom plate part 10b and a foundation slab 14 of the tank body 10, and likewise a ring second space part 20 is formed between the side wall part 10a and an involute wall part 12b. Adjoining an upper end opening of the second space part 20, there is provided a fresh-air inlet blade 22. In consequence, heat insulation can be done so efficiently without using any other energy source.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an underground tank for storing liquefied gas.

(Prior Art) As a means for storing liquefied gas, underground tanks, which are wholly or partially buried underground, are known.

This type of underground tank is normally ventilated to eliminate the negative effects of cold heat, but simple natural ventilation is inefficient, so ventilation equipment that is activated when there is a risk of freezing due to cold heat is required. It is provided.

FIG. 2 shows an example of a conventional underground tank equipped with such ventilation equipment.

The underground tank shown in the figure has an annular side wall 1 and a second side wall 1.
It has a disk-shaped bottom plate 2 integrated with the lower end of the inner tank 3. Cold insulation material 4. Outer tank 5 holding cold insulation material 4. A slab 6 that supports the inner and outer tanks 3 and 5 and a column 7 that supports the slab 6 are provided.

8 is ventilation equipment that is driven when natural ventilation is insufficient.

However, underground tanks with such a structure have the following technical problems.

(Problem to be solved by the invention) In other words, in the underground tank with the structure shown in Figure 2, natural ventilation alone is inefficient because no special measures are taken, and, for example, freezing due to cold heat is prevented. If there is a risk, the ventilation equipment 8 is activated to remove cold heat and prevent freezing. However, it required energy such as electricity, which was an economic problem.

This invention was made in view of these conventional problems, and its purpose is to provide an underground tank for storing liquefied gas that does not require an energy source and can economically prevent the surrounding ground from freezing. Our goal is to provide the following.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a tank body for storing liquefied gas, an earth retaining wall surrounding the outer periphery of the tank body, and an earth retaining wall surrounding the tank body and the earth retaining wall. The underground tank has a space formed between the tank and a wall, and is characterized in that an annular outside air intake blade is provided at an opening on the ground side of the space.

(Operation and Effect of the Invention) According to the underground tank for storing liquefied gas having the above structure, since the space is provided between the tank body and the earth retaining wall, a heat insulation effect is obtained by the air layer in the space. This prevents the surrounding ground from freezing, and in this space,
Since the outside air intake blade is installed in the opening, the space is naturally ventilated by the wind blowing from the outside.
Heat insulation can be efficiently achieved without using other energy sources.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of an underground tank for storing liquefied gas according to the present invention.

The underground tank shown in the figure includes a tank main body 10 that stores liquefied gas G such as LNG or LPG, and an annular earth retaining wall built around the tank main body 10 at intervals. 12.

The tank body 10 is composed of a cylindrical side wall portion 10a, a disc-shaped bottom plate portion 10b, and an arch-shaped ceiling portion 10c. However, a layer of insulating cold material is provided.

In this embodiment, the earth retaining wall 12 includes a continuous underground wall section 12a constructed from above ground, and an inner wall section formed integrally on the inner surface of the continuous underground wall section 12a by cutting the inside after constructing the underground wall section 12a. It is composed of a winding wall portion 12b.

A foundation slab 14 is integrally formed at the lower end of the inner wall portion 12b with a gravel layer 13 provided below. It is installed on a slab 17 supported by pillars 16 at a predetermined distance from the foundation slab 14.

In the underground tank configured as described above, a disk-shaped first space 18 having a thickness corresponding to the height of the support column 16 is formed between the bottom slab portion 10b of the tank body 10 and the foundation slab 14. At the same time, an annular second space 20 is formed between the side wall 10a and the inner wall 12b, and these spaces 18.degree. 20 are in communication with each other.

In this embodiment, outside air intake blades 22 are provided facing the upper end opening of the annular second space 20.

The outside air intake wing 22 has one end connected to the ceiling 1 of the tank body 10.
It is composed of a plate-shaped wing section 22a fixed to 0c, and reinforcing members 22b that support the wing section 22a from below at appropriate locations. The free end side is installed with an inclination above the horizontal plane.

Now, in the underground tank configured as described above, there is a first
A space 18 is formed, and a second space 20 communicating with this space 18 or a side wall 1 of the tank body 10 is formed.
0a and the inner wall portion 12b of the retaining wall 12, the outer periphery of the underground portion of the tank body 10 is connected to the space portion 1.
8.20, and this air layer provides a heat insulating effect, thereby preventing the surrounding ground from freezing, and the opening on the ground side of the second space 2o is Since the outside air intake blades 22 are provided, the space 18.degree. 20 is naturally ventilated by the wind blown from the outside, and the space can be efficiently insulated without using any other energy source.

[Brief explanation of drawings]

FIG. 1 is an overall sectional view showing an embodiment of an underground tank for storing liquefied gas according to the present invention, and FIG. 2 is an overall sectional view showing a conventional underground tank. 10...Tank body 10b...Bottom plate part 12a...Continuous underground wall part 14...Foundation slab 20...Second space part 10a...Side wall part 12...Earth retaining wall 12b...Inner wall portion 18...First space portion 22...Outside air intake blade

Claims (1)

[Claims] An underground tank having a tank body for storing liquefied gas, an earth retaining wall surrounding the outer periphery of the tank body, and a space formed between the tank body and the earth retaining wall, the tank having a space formed between the tank body and the earth retaining wall. An underground tank for storing liquefied gas characterized by having an annular outside air intake blade provided at the opening on the ground side.