JPH08312894A - Low temperature liquefied gas tank - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce heat input from the bottom of the inner tank. [Structure] Inside a support member 31 that supports the bottom of the inner tank 23, a heat insulating chamber 41 is provided so as to divide the support member 31 into upper and lower parts.
Is provided to the heat insulation chamber 41, and the refrigerant supply pipe 46 and the refrigerant discharge pipe 47 are provided.
It is possible to prevent heat input from the bottom portion of the inner tank 23 by supplying and discharging the refrigerant through the cooling chamber and cooling the heat insulating chamber 41. At this time, the heat insulating chamber 41 is provided with a partitioning member for partitioning the inside into a plurality of small chambers extending in the vertical direction, so that the heat insulating chamber 41 has a load bearing strength, the load of the inner tank 23 itself, and the stored low temperature. The load of the liquefied gas 22 can be supported without any hindrance. By forming a plurality of through-holes that allow the small chambers to communicate with each other in the partition member, the cooling medium can be spread throughout the heat insulating chamber 41 to uniformly cool the heat insulating chamber 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low temperature liquefied gas tank.

[0002]

2. Description of the Related Art Low temperature liquefied gas such as liquefied natural gas is generally stored in a low temperature liquefied gas tank 1 as shown in FIG.

The low-temperature liquefied gas tank 1 has an adiabatic space outside the inner tank 3 capable of storing a low-temperature liquefied gas 2 such as liquefied natural gas, and is surrounded by an outer tank 4 to form an inner tank in the adiabatic space. The heat insulating layer 5 is formed by filling a heat insulating material such as polyurethane foam between the side surface of the outer shell 3 and the side surface of the outer tank 4.

The outlet 9 of the evaporative emission gas pipe 8 having the inlet 7 connected to the upper portion of the inner tank 3 is passed through the outer tank 4 and taken out to the outside.

A support member 11 for supporting the inner tank 3 is provided between the foundation 10 and the bottom of the inner tank 3 in the heat insulating space.

The support member 11 is a light bone concrete 1
2. An outermost peripheral support member 14 formed by combining pearlite concrete 13 and the like, a peripheral support member 16 formed of pearlite concrete 15 and the like, a center support member 18 formed of foam glass 17 and the like.

The perlite concretes 13 and 15 and the foam glass 17 are, so to speak, porous materials such as pumice stone, and each have a load bearing strength necessary for supporting the load of the inner tank 3 and a certain degree of heat insulating performance. .

In the figure, 19 is a low temperature liquefied gas inlet / outlet of the low temperature liquefied gas tank 1, and 20 is an evaporated gas generated inside the low temperature liquefied gas tank 1.

In the low temperature liquefied gas tank 1 having the above structure, the low temperature liquefied gas 2 is stored in the inner tank 3. Further, the heat insulation between the outside and the inner tank 3 is performed by the heat insulation layer 5.

The evaporative gas 20 formed by evaporating the low temperature liquefied gas 2 in the inner tank 3 is an inlet portion 7 formed in the upper portion of the inner tank 3.
To the evaporative gas discharge pipe 8, and through the evaporative gas discharge pipe 8 is discharged to the outside through an outlet portion 9 formed outside the outer tub 4. A valve (not shown) may be provided at the outlet 9 of the evaporative emission tube 8 to adjust the emission amount of the evaporative emission 20.

At the bottom of the inner tank 3, the load of the inner tank 3 itself,
Since the load of the stored low temperature liquefied gas 2 is applied, the inner tank 3
It is necessary to support the bottom part of the inner member 3 with the supporting member 11.
The outer edge of the inner tank 3, which requires the highest load bearing strength because its own load is concentrated, is supported by an outermost peripheral support member 14 that is a combination of light bone concrete 12, pearlite concrete 13, etc., and is mainly used for low temperature liquefaction. A central support member 18 composed of foam glass 17 and the like supports the central portion which requires the smallest load bearing strength by applying the load of gas 2.
A portion between the two, which requires an intermediate load-bearing strength, is provided near the outer periphery supporting member 1 made of pearlite concrete 15 or the like.
I am trying to support it with 6.

[0012]

However, the above-mentioned conventional low temperature liquefied gas tank has the following problems.

That is, since the load of the inner tank 3 itself and the load of the stored low temperature liquefied gas 2 are applied to the bottom of the inner tank 3,
The bottom of the inner tub 3 must be supported by the support member 11, but the light-bone concrete 1 used to support the bottom of the inner tub 3
2, the perlite concrete 13, the perlite concrete 15, and the foam glass 17 are much inferior to the heat insulating material such as polyurethane foam used in the heat insulating layer 5 on the side portion, and therefore, a large amount of water is introduced from the bottom. I had a fever.

Above all, the outer edge portion of the inner tank 3 and its vicinity, which require the greatest load bearing strength due to the concentrated load of the inner tank 3 itself, are particularly light bone concrete 12 and pearlite concrete 13 having poor heat insulation performance. Since there was no choice but to use perlite concrete 15, etc., the ratio of heat input from here was large.

In view of the above situation, it is an object of the present invention to provide a low temperature liquefied gas tank capable of reducing heat input from the bottom of the inner tank.

[0016]

According to the present invention, a bottom portion of an inner tank for storing a low temperature liquefied gas is supported on a foundation through a supporting member, and the supporting member can be vertically divided inside the supporting member. A heat insulating chamber, a partition member for partitioning the interior into a plurality of small chambers extending in the vertical direction is provided in the heat insulating chamber, a plurality of through holes capable of communicating each small chamber are formed in the partition member, and a refrigerant supply pipe is provided in the heat insulating chamber. A low-temperature liquefied gas tank is characterized in that a refrigerant discharge pipe is connected.

In this case, the heat insulating chamber may be provided on the entire bottom surface of the inner tank.

Alternatively, the heat insulating chamber may be provided only in the portion of the bottom of the inner tank where the heat input is large.

Further, the evaporative gas discharge pipe for discharging the evaporative gas generated inside the inner tank to the outside may be used as the refrigerant supply pipe and the refrigerant discharge pipe.

A heat shield plate may be provided between the layers of the heat insulation tank surrounding the side surface of the inner tank, and the refrigerant discharge pipe may be wound around the heat shield plate.

A position deviation preventing projection may be provided on the upper surface or the lower surface of the heat insulating chamber.

[0022]

The operation of the present invention is as follows.

The bottom of the inner tank for storing the low-temperature liquefied gas is supported on the foundation via a supporting member. The bottom of the inner tank has the load of the inner tank itself and the stored low-temperature liquefied gas. Since the load is applied, the supporting member must have a load-bearing strength, and heat insulation performance cannot be expected.
The heat input from the bottom of the inner tank cannot be avoided.

Therefore, a heat insulating chamber capable of vertically dividing the support member is provided inside the support member, and a refrigerant supply pipe is provided in the heat insulating chamber.
By connecting the refrigerant discharge pipe to supply and discharge the refrigerant to and from the heat insulation chamber to cool the heat insulation chamber, heat input from the bottom of the inner tank can be prevented.

At this time, a partition member for partitioning the interior into a plurality of small chambers extending in the vertical direction is provided in the heat insulating chamber so that the heat insulating chamber has a load-bearing strength, the load of the inner tank itself and the stored low temperature. The load of liquefied gas can be supported without any trouble.

By forming a plurality of through holes through which the small chambers can communicate with each other in the partition member, the refrigerant can be spread throughout the heat insulating chamber and the heat insulating chamber can be cooled uniformly.

In this case, by providing the heat insulating chamber on the entire bottom surface of the inner tank, heat input from the entire bottom surface of the inner tank can be prevented.

Alternatively, by providing the heat-insulating chamber only in the portion where the heat input to the bottom of the inner tank is large, it is possible to prevent the heat input from the portion where the heat input to the bottom of the inner tank is particularly large.

Further, by using the evaporative gas discharge pipe for discharging the evaporative gas generated in the inner tank to the outside as the refrigerant supply pipe and the refrigerant discharge pipe, a special refrigerant supply pipe and a special refrigerant discharge pipe are provided. You can eliminate the need.

In addition, by using the refrigerant that has cooled the heat insulating chamber at the bottom of the inner tank for cooling the heat shield plate provided between the heat insulating layers on the side surfaces of the inner tank, the refrigerant can be effectively used. Like

The displacement of the heat insulation chamber can be prevented by providing the displacement prevention projections on the upper surface or the lower surface of the heat insulation chamber.

[0032]

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

1 to 6 show a first embodiment of the present invention.

Low temperature liquefied gas tank 2 which is the object of the present invention
1 has an adiabatic space outside the inner tank 23 that can store the low temperature liquefied gas 22 such as liquefied natural gas or liquid hydrogen or liquid helium, and is surrounded by an outer tank 24. A heat insulating layer 25 is formed by filling a heat insulating material such as polyurethane foam between the side surface of the above and the side surface of the outer tank 24.

Inside the heat insulating layer 25, an extremely thin (about 2-3 mm thick) heat shield plate 26 made of aluminum or stainless steel is arranged so as to surround the side surface of the inner tank 23, After winding the middle part of the evaporative gas discharge pipe 28 having the inlet 27 connected to the upper part of the inner tank 23 around the heat shield plate 26, the outlet 29 of the evaporative gas discharge pipe 28 is connected to the outer tank 24, A temperature boundary is formed at the position of the heat shield plate 26.

A support member 31 for supporting the inner tank 23 is provided between the foundation 30 and the bottom of the inner tank 23 in the heat insulating space.
Is provided.

The support member 31 is made of light bone concrete 32.
An outermost peripheral support member 34 formed by combining pearlite concrete 33 and the like, a peripheral support member 36 formed of pearlite concrete 35, a central support member 38 formed of foam glass 37 and the like.

The perlite concretes 33 and 35 and the foam glass 37 are, so to speak, porous materials such as pumice stone, and each have a load bearing strength necessary for supporting the load of the inner tank 23 and a certain degree of heat insulating performance. .

In the figure, 39 is a low temperature liquefied gas tank 21.
Low temperature liquefied gas inlet / outlet 40, low temperature liquefied gas tank 21
It is the vaporized gas generated inside.

In the present invention, the support member 3 is provided inside the support member 31 that supports the bottom of the inner tank 23 on the foundation 30.
A heat insulating chamber 41 capable of dividing 1 into upper and lower parts is provided.

The heat insulating chamber 41 has a disk shape as shown in FIG. 2 which covers the entire supporting member 31 so as to cover the entire bottom surface of the inner tank 23.

Positional deviation preventing projections 42 are provided at appropriate positions on the upper surface and the lower surface of the heat insulating chamber 41.

A partition member 44 for partitioning the inside into a plurality of small chambers 43 extending in the vertical direction is provided in the heat insulating chamber 41.

Since the partition member 44 serves as a strength member of the heat insulating chamber 41, for example, as shown in FIG. 3, a honeycomb structure partitioning the small chamber 43 into a hexagon,
As shown in FIG. 4, the small chamber 43 has a lattice structure that divides it into squares.

Then, as shown in FIGS. 3 and 4, the partition member 44 is provided with a plurality of through holes 45 capable of communicating between the small chambers 43.

Further, a refrigerant supply pipe 46 capable of supplying and discharging the refrigerant 48 and a refrigerant discharge pipe 47 are connected to the heat insulating chamber 41.

At this time, as shown in FIG. 1, the adiabatic chamber 41 is connected in the middle of the evaporative emission pipe 28 so that the evaporative emission pipe 28 can be used as the refrigerant supply pipe 46 and the refrigerant exhaust pipe 47. May be.

Further, in FIG. 1, the evaporative emission gas pipe 28 is 1
Although only a book is drawn, when a plurality of evaporative emission pipes 28 are provided, the heat insulation chamber 41 is set to the evaporative emission pipes 28.
It is divided into the same number of blocks as the number of
Through holes 45 are formed so that the small chambers 43 to which they belong communicate with each other, and the corresponding blocks and the evaporative gas discharge pipes 28 are connected to each other.

The heat insulating chamber 41 and the partition member 44 are made of a material having good thermal conductivity such as aluminum or stainless steel.

Next, the operation will be described.

In the low temperature liquefied gas tank 21, the low temperature liquefied gas 22 is stored in the inner tank 23. The heat insulation between the outside and the inner tank 23 is performed by the heat insulation layer 25. The low temperature liquefied gas 22 may be liquefied natural gas, liquid hydrogen, liquid helium, or the like.

The evaporative gas 40 formed by evaporating the low temperature liquefied gas 22 in the inner tank 23 enters the evaporative gas releasing pipe 28 from the inlet 27 formed in the upper part of the inner tank 23, and the evaporative gas releasing pipe 28 It is designed to be discharged to the outside through an outlet 29 formed in the outer tub 24. A valve (not shown) is provided at the outlet 29 of the evaporative emission gas pipe 28, and the evaporative emission 40
It is also possible to adjust the release amount of.

When the vaporized gas 40 passes through the vaporized gas release pipe 28, the vaporized gas 40 is cooled by the cold heat of the vaporized gas 40.
Since the heat shield plate 26 around which the heat shield plate 26 is wound is cooled to near the liquid temperature of the low temperature liquefied gas 22 as shown by the line C in FIG. 5, a temperature boundary is formed at the position of the heat shield plate 26. Therefore, the heat input to the inside of the heat shield plate 26 is reduced, and the evaporation of the stored low temperature liquefied gas 22 is suppressed as compared with the case where the heat shield plate 26 is not provided (in the case of the line D in FIG. 5). Will be able to.

Furthermore, since the load of the inner tank 23 itself and the load of the stored low temperature liquefied gas 22 are applied to the bottom of the inner tank 23, it is necessary to support the bottom of the inner tank 23 by the support member 31. However, since the load of the inner tub 23 itself is concentrated, the outer edge portion of the inner tub 23, which requires the largest load bearing strength, is supported by the outermost peripheral support member 34 formed by combining the light bone concrete 32 and the pearlite concrete 33. , The central portion which requires the minimum load-bearing strength mainly due to the load of the low-temperature liquefied gas 22 is supported by the center support member 38 made of foam glass 37, etc. This portion is supported by a support member 36 near the outer periphery made of perlite concrete 35 or the like.

The load-bearing strength is 3% for light bone concrete.
2, the perlite concrete 33, the perlite concrete 35, and the foam glass 37 become lower in this order. On the contrary, the heat insulation performance becomes higher in the order of the light bone concrete 32, the perlite concrete 33, the perlite concrete 35, and the foam glass 37.

As described above, the inner tank 2 is provided at the bottom of the inner tank 23.
Since the load of 3 itself and the load of the stored low-temperature liquefied gas 22 are applied, the bottom of the inner tank 23 must be supported by the support member 31, but the light-bone concrete 32 used for supporting the bottom of the inner tank 23. Or perlite concrete 33
Or perlite concrete 35 or foam glass 3
No. 7 has a large heat input from the bottom because it has much poorer heat insulating performance than a heat insulating material such as polyurethane foam used for the heat insulating layer 25 on the side.

Therefore, in the present invention, the support member 3 is provided inside the support member 31 that supports the bottom of the inner tank 23 on the foundation 30.
1 is provided with a heat insulation chamber 41 that can be divided into upper and lower parts, and the heat insulation chamber 41 is supplied with a refrigerant 48 via a refrigerant supply pipe 46.
After cooling 1 with the refrigerant 48, the refrigerant is discharged from the refrigerant discharge pipe 47.

As a result, the temperature of the coolant 48 (see the coolant 48 as described below)
When the vaporized gas 40 is used as the vaporized gas 40, the temperature is cooled to a temperature close to the liquid temperature of the low temperature liquefied gas 22 and a temperature boundary is formed at the position of the heat insulating chamber 41. The heat input is reduced and the evaporation of the low temperature liquefied gas 22 stored in the inner tank 23 can be suppressed as compared with the case where the heat shield plate 26 is not provided (in the case of the line in FIG. 6).

At this time, as shown in FIG. 1, by connecting the heat insulating chamber 41 to the middle of the evaporative emission pipe 28 and using the evaporative emission pipe 28 as the refrigerant supply pipe 46 and the refrigerant exhaust pipe 47, Evaporative gas 4 flowing through the evaporative gas discharge pipe 28
Since the heat insulation chamber 41 can be cooled at 0, it is not necessary to prepare a special refrigerant 48, and the configuration can be simplified.

Further, since the heat insulation chamber 41 has a disk shape as shown in FIG. 2 which extends over the entire support member 31, it is possible to insulate the entire bottom surface of the inner tank 23.

Then, in the heat insulating chamber 41, the inside of the heat insulating chamber 41 is divided into a hexagonal small chamber 43 as shown in FIG. 3 or a lattice-like partition that divides it into rectangular small chambers 43 as shown in FIG. Since the member 44 is provided, it is possible to secure the pressure resistance required to support the load of the inner tank 23 itself and the load of the low temperature liquefied gas 22 stored in the inner tank 23.

Further, as shown in FIGS. 3 and 4, the partition member 44 for giving strength to the heat insulating chamber 41 is formed with a plurality of through holes 45 capable of communicating between the small chambers 43. It is possible to evenly distribute the refrigerant 48 to each of the small chambers 43 inside the chamber 41 and evenly cool the heat insulating chamber 41.

If the heat insulating chamber 41 and the partition member 44 are made of aluminum or stainless steel having good heat conductivity, the heat insulating chamber 41 can be cooled efficiently.

By providing the heat insulating chamber 41 to reduce the heat input from the bottom, the evaporation amount of the low temperature liquefied gas 22 in the inner tank 23 is reduced, and the amount of the evaporated gas 40 sent to the heat insulating chamber 41 is also reduced. Evaporative gas 4 in the heat insulation chamber 41
When 0 decreases, the heat insulation effect decreases, the heat input to the inner tank 23 increases, and the amount of the evaporative gas 40 generated also increases.
The amount of evaporative gas 40 sent to the device increases and the adiabatic effect increases, and when the adiabatic effect increases, the amount of evaporative gas 40 generated decreases again. Since the equilibrium state is reached at and the equilibrium state is continued, the heat insulating chamber 41 can sufficiently perform the function of reducing heat input from the bottom.

Further, the position deviation of the heat insulating chamber 41 is caused by the position deviation preventing projections 42, which are provided at appropriate positions on the upper surface and the lower surface of the heat insulating chamber 41, biting into the perlite concretes 33 and 35 and the foam glass 37. Can be prevented.

Further, when a plurality of evaporative emission gas pipes 28 are provided, the heat insulating chamber 41 is divided into the same number of blocks as the number of the evaporative emission gas emission pipes 28, and the small chambers 43 to which they belong are connected to each block. The through hole 45 may be formed so that the corresponding block and the evaporative emission gas pipe 28 are connected to each other. By doing so, it is possible to cool the heat insulating chamber 41 more uniformly and efficiently perform heat insulation, as compared with the case where the whole heat insulating chamber 41 is made into one block.

7 and 8 show a second embodiment of the present invention, in which the heat insulating chamber 49 is formed into a donut ring shape so that only the lower portions of the outermost peripheral supporting member 34 and the peripheral peripheral supporting member 36 are thermally insulated. Except for the above, the configuration is similar to that of the above-described embodiment, and the same operation / effect can be obtained.

According to the present embodiment, the outer edge of the inner tank 23 and its vicinity, which require the highest load bearing strength due to the concentrated load of the inner tank 23 itself, have the highest heat insulation performance among the support members 31. Since we had to use inferior light bone concrete 32 and perlite concrete 33 and 35, the ratio of heat input from here was large (80 to 90% of the heat input from the bottom), but the ratio of heat input was By heat-insulating only the lower portions of the large outermost peripheral support member 34 and the peripheral-vicinity support member 36 in the donut ring-shaped heat insulating chamber 49, it is possible to efficiently perform heat insulation in the small heat insulating chamber 49.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0070]

As described above, according to the low temperature liquefied gas tank of the present invention, the excellent effect that the heat input from the bottom of the inner tank can be reduced can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of a first embodiment of the present invention.

FIG. 2 is a perspective view of the heat insulation chamber of FIG.

FIG. 3 is a perspective view showing the shape of a partition member at the bottom of the tank.

FIG. 4 is a perspective view showing another shape of the partition member at the bottom of the tank.

FIG. 5 is a graph showing the relationship between position and temperature.

FIG. 6 is a graph showing the relationship between position and temperature.

FIG. 7 is a schematic side sectional view of a second embodiment of the present invention.

FIG. 8 is a perspective view of the heat insulating chamber of FIG.

FIG. 9 is a schematic side sectional view of a conventional example.

[Explanation of symbols]

 22 Low-temperature liquefied gas 23 Inner tank 28 Evaporated gas discharge pipe 30 Basic 31 Support member 34 Support member (outermost peripheral support member) 36 Support member (support member near outer circumference) 38 Support member (center support member) 40 Evaporated gas 41, 49 Heat insulation Chamber 42 Displacement prevention protrusion 43 Small chamber 44 Partition member 45 Through hole 46 Refrigerant supply pipe 47 Refrigerant discharge pipe

Claims (6)

[Claims] 1. A bottom portion of an inner tank for storing a low temperature liquefied gas,
A supporting member is supported on the foundation via a supporting member, and a heat insulating chamber capable of vertically dividing the supporting member is provided inside the supporting member, and a partition member for partitioning the inside into a plurality of small chambers extending in the vertical direction is provided in the heat insulating chamber. A low-temperature liquefied gas tank, characterized in that a plurality of through-holes are provided in a partitioning member so that the small chambers can be communicated with each other, and a refrigerant supply pipe and a refrigerant discharge pipe are connected to the heat insulation chamber. 2. The low temperature liquefied gas tank according to claim 1, wherein the heat insulating chamber is provided on the entire bottom surface of the inner tank. 3. The low temperature liquefied gas tank according to claim 1, wherein the heat insulating chamber is provided only in a portion of the bottom of the inner tank where heat input is large. 4. The low temperature liquefied gas tank according to claim 1, wherein the evaporative gas discharge pipe for discharging the evaporative gas generated inside the inner tank to the outside is a refrigerant supply pipe and a refrigerant discharge pipe. 5. The low temperature liquefied gas tank according to claim 1, wherein a heat shield plate is provided between layers of a heat insulating tank surrounding a side surface of the inner tank, and the refrigerant discharge pipe is wound around the heat shield plate. 6. The low temperature liquefied gas tank according to claim 1, wherein a displacement preventing projection is provided on an upper surface or a lower surface of the heat insulating chamber.