RU2564484C2 - Tank for cold of cryogenic liquid - Google Patents

Abstract

FIELD: packaging industry.

SUBSTANCE: tank for cold or cryogenic liquids containing a double shell, which comprises an internal barrier, an external barrier located at a distance from the internal barrier and the structures mutually connecting the internal barrier with the external barrier, at least one distributive pipe with holes for gas passing for distribution of inert gas in intermediate space; this distributive pipe is located in intermediate space between the internal barrier and the external barrier of the tank bottom. Also it contains the feeding pipe for inert gas located outside of the double shell which passes through the external barrier and is interconnected with the distributive pipe; the source of inert gas connected to the feeding pipe outside of the tank shell, gas outlet from intermediate space in the external barrier of the top wall of the tank and gas detectors in the area of gas outlet.

EFFECT: invention is aimed at creation of the tank for cold or cryogenic liquids where thermal losses are reduced and the possibility of avoidance of leakages is provided.

19 cl, 12 dwg

Description

Technical field

The present invention relates to a reservoir for cold or cryogenic liquids.

Preferably, the reservoir of the invention is used for transporting and / or storing cold or cryogenic liquids on board ships or other floating facilities or offshore structures, or on land.

State of the art

Cryogenic liquids have low boiling points. Therefore, they are transported or stored at very low temperatures. Such liquids are, in particular, liquefied natural gas, methane, propane, butane or other cryogenic liquids. For liquefied methane (LNG - liquefied natural gas), the transport or storage temperature is approximately -164 ° C.

Tanker vessels for transporting liquefied gas with membrane tanks are known in which the tank membranes are not self-supporting structures and are held in the hull of the vessel. Tanker vessels for transporting liquid gas with self-supporting reservoirs are also known. It is also known the construction of tanks made of aluminum to reduce weight.

Patent Document WO 2006/001711 A2 describes a reservoir for storing liquids, especially at very low temperatures, which contains outer plates forming at least part of the upper wall, side walls and bottom. The reservoir has an internal cellular structure, and hydraulic communication devices are provided between the cells of the cellular structure. At least a portion of the outer plates has a sandwich-like construction. They are equipped with an internal barrier and an external barrier, between which stiffening reinforcing structures can be located. The outer plates may also be provided with reinforcing elements that protrude into the reservoir. Due to the fact that sandwich designs are external plates, the structural elements of self-supporting reservoirs make the reservoir impervious to gas and liquid and can serve to insulate the reservoir. A further advantage of a sandwich type construction is the ability to place gas detection means between two layers of a sandwich type structure.

When the gas sensor is located between the layers of the outer plates, leaks that occur away from the gas sensor may remain undetected. Because of this, tank leaks can occur that damage the structure of the vessel.

Patent Document WO 2008/103053 A1 describes a double-skinned self-supporting tank with internal and external walls and internal horizontal supports. The walls of the tank consist of horizontal sections of profile bearing elements with two parallel flanges, which are connected to each other by a jumper. The sections of the profile bearing elements are mounted one above the other and welded to each other on adjacent longitudinal sides of their flanges. At the ends they are connected to each other by means of connecting parts. Profile supporting elements have ribs protruding from the inner wall. Knits are welded to the ribs, on which the supports passing inside the tank are fixed. This tank also has an inner and outer liquid-tight barrier. The document does not describe means for detecting leaks in the internal and external barriers.

Disclosure of invention

Based on the solutions of the prior art, the present invention is to create a reservoir for cold or cryogenic liquids, which facilitates the establishment of leaks, reduced heat loss and provides the possibility of eliminating leaks.

The solution to this problem is provided in the tank, which has the characteristics of paragraph 1 of the claims. Preferred examples of implementation are set forth in the dependent clauses.

According to the invention, a reservoir for cold or cryogenic liquids comprises

- double lining of the tank of light metal, which limits the space of the tank wall of the bottom of the tank, the side walls of the tank and the upper wall of the tank,

- moreover, the double lining of the tank contains an internal barrier, an external barrier located at a distance from the internal barrier, and structures connecting to each other the internal barrier with the external barrier,

- at least one distribution pipe located in the intermediate space between the inner barrier and the outer barrier of the bottom of the tank with openings for the passage of gas for distributing inert gas in the intermediate space,

- at least one inert gas feed pipe located outside the double lining of the tank, which passes through the outer barrier and communicates with the distribution pipe,

- a source of inert gas connected to the supply pipe outside the lining of the tank,

- a gas outlet from the intermediate space in the outer barrier of the upper wall of the tank and

- means for detecting gas in the field of gas release.

The tank of the invention is a double skin tank. The double lining of the tank forms the wall of the tank bottom, the side walls of the tank (also called “tank bulkheads”) and the roof or upper wall of the tank. The bottom wall, side walls and upper wall surround the tank space, which is used to receive cold or cryogenic liquids. The double lining of the tank is made of light metal, preferably aluminum or aluminum alloy.

The double skin of the tank contains an internal barrier and an external barrier. Both barriers are impervious to liquids and gases. The inner and outer barriers are separated from each other, so that between the barriers there is an intermediate space. In the intermediate space, the inner and outer barriers are connected to each other using structures. Preferably, these structures are partitions or ribs or other suitable parts. In particular, they can be profile partitions of profile load-bearing elements, from which an internal and / or external barrier is formed. Designs of self-supporting double-skinned tanks that can be used as the tank of the invention are described in patent documents WO 2006/001711 A2 (exemplary embodiments of FIGS. 5 and 8), WO 2008/103053 A1 (all exemplary embodiments) and in the international patent PCT / EP application 2010/006954 (exemplary embodiment of FIG. 16). These exemplary embodiments are incorporated herein by reference.

The tank according to the invention contains in the bottom wall a distribution pipe with openings for the passage of gas for the distribution of inert gas. Further, at least one inert gas supply pipe is located outside the double skin of the tank, which passes through the outer barrier and communicates with the distribution pipe. The supply pipe is connected to the distribution pipe either by means of a connecting pipe or by means of a short region of the intermediate space. The gas passage openings may be round, oval, or elongated or slit-like.

Further, the reservoir contains a source of inert gas. Preferably, the inert gas is nitrogen. However, it can also be carbon dioxide, argon or other noble or inert gas. The source of inert gas may be, in particular, an apparatus for generating or storing nitrogen. Installations for generating or storing enough nitrogen in any case are necessary on board tankers to provide an inert atmosphere in the hold space.

The distribution pipe evenly distributes the inert gas in the intermediate space of the tank bottom wall. From the edges of the tank bottom wall, the inert gas uniformly rises to the side walls of the tank and is evenly distributed from the upper cores of the side walls to the upper wall of the tank. The gas outlet is preferably located at the highest point of the upper wall of the tank. Preferably, the gas outlet is in the form of a gas outlet pipe that extends through the outer barrier of the upper wall of the tank or through the dome of the tank and communicates with the intermediate space of the double skin.

Through the gas outlet pipe, the gas entering the intermediate space can be discharged from the intermediate space. If the inner barrier of the tank lining is not tight, liquid or gas penetrates from the tank into the intermediate space and partially evaporates immediately. Natural gas, preferably methane, rising or entrained in the gas stream can be detected even at the smallest concentrations by continuous or cyclic monitoring in the gas outlet or in an adjacent piping system. Gas detection means are located, for example, in the inert gas circuit between the gas outlet pipe and means for possibly compressing or cooling the inert gas to return it to the bottom of the tank, however, they are preferably located in the immediate vicinity of the gas outlet or on the gas outlet pipe. The means for detecting gas may in particular be a gas sensor for detecting gaseous substances. The gas sensor may in particular be a sensor for detecting methane or other combustible gases.

By imparting an inert atmosphere to the atmosphere in the intermediate space of double lining of the tank with an inert gas, even a small leak in the internal barrier can be detected in a short time. Gases escaping from the tank are typically less dense than inert gases. So, for example, methane has a density of 0.72 kg / m ³ and nitrogen has a density of 1.25 kg / m ³ . As a result, the gas flowing out of the tank space is collected under the upper wall of the tank or under the gas outlet. The increased concentration of leaked gas under the upper wall of the tank facilitates its detection at the gas outlet or behind the gas outlet from the intermediate space. It does not matter where the leak is, since the leaked gas always collects under the upper wall of the tank. This effect takes place even when the inert gas atmosphere in the intermediate space is stationary, that is, there is no gas flow created from the outside. The collection of gas escaping from the space of the tank under the upper wall of the tank can be accelerated by creating an inert gas flow in the intermediate space.

Another advantage of the tank in dangerous cases is that through the supply pipe from the intermediate space in the area of the wall of the bottom of the tank can be removed fluid that has entered the intermediate space as a result of leakage in the internal barrier. Liquid can enter through the gas passage openings in the distribution pipe and from there enter the supply pipe when the distribution pipe is connected to the supply pipe. In an exemplary embodiment, which will be described later, liquid may enter the supply pipe through a gap between the distribution pipe and the supply pipe or through the gap between the distribution pipe and the connection pipe connecting it to the supply pipe. So, for example, when a gas leak is established from the tank space by means of gas detection means, the liquid leaked from the tank space can be pumped out of the intermediate space by the pump. Due to the use of the supply pipe in combination with the ability to pump liquids from the intermediate space in case of danger, double cladding can preferably be performed in such a way as to satisfy the minimum requirements for strength and requirements for rated loads without the need to provide additional dimensions for the installation of an emergency pump for pumping liquid from the intermediate space. However, the supply pipe can be designed in such a way that a pump can be connected to it with little labor, or it can be made in the form of a pump sump to accommodate at least one pump in it.

According to a preferred embodiment, the feed pipe is connected to a source that provides an inert gas flow. This may be a continuous or intermittently interrupted inert gas stream. The advantage of the solution is that gases escaping from the tank space can be detected at particularly low concentrations, so that the leak can be detected very quickly. Another advantage is that due to the inert gas flow, the double lining of the tank is cooled. For this, according to the following preferred embodiment, cold or cryogenic inert gas is introduced into the intermediate space. Due to the supply of cold or cryogenic inert gas, the double skin is cooled from the inside, and the heat received from the outside is carried out by the flow of inert gas from the exhaust pipe. Due to this, the supply of heat from the environment of the tank to the liquid contained in the space of the tank can be reduced or completely eliminated. At the same time, it is better controlled, reduced to a minimum or the evaporation of liquid in the space of the tank is prevented. For this, the temperature of the inert gas is preferably selected in accordance with the boiling point of the liquids stored in the space of the tank. To reduce the supply of heat to the tank space, it is best that the temperature of the inert gas is below the boiling point of the liquid. This is possible, for example, when nitrogen is used as the inert gas in the liquefied gas tank. To better detect the escape of gas from the tank space, the inert gas temperature can also be selected slightly above the boiling point of the liquid.

The tank according to the invention can be made in such a way that the constant sheathing of the tank forms only an internal barrier, which constantly withstands loads from cryogenic liquids. In this case, the outer barrier serves only to limit the intermediate space from the outside. If necessary, the external barrier can serve to hold the liquid leaving the space of the tank for a limited time and protect the environment from cold or cryogenic liquids for a predetermined period of time in accordance with regulatory rules. An example of the implementation of such a self-supporting tank is described in international patent application PCT / EP2010 / 006954 on the example of execution in Fig.16. This description is incorporated herein by reference.

According to a further exemplary embodiment, the inner and outer barriers are permanent casing of the tank. In this design, the liquid exiting the space of the tank is held in the double skin of the tank for a long time. However, such double-skinned tanks are relatively expensive. Examples of these tanks are described in patent documents WO 2006/001711 A2 and WO 2008/103053 A1. These exemplary embodiments of the two patent publications are hereby incorporated by reference.

According to an exemplary embodiment, at least one distribution pipe extends in the direction of the main extent of the reservoir. Due to this, a uniform distribution of inert gas is achieved in the direction of the main length of the tank. In the aspect of obtaining manufacturing advantages, a solution is preferred when the distribution pipe is straight. According to a further exemplary embodiment, the distribution pipe is located on the central axis of the tank. This ensures a uniform distribution of inert gas across the width of the tank.

According to a further exemplary embodiment, the distribution pipe extends from one side wall of the tank to the opposite side wall of the tank and at both ends can be connected to additional distribution pipes that extend under the lower edges of the respective side walls of the tank and are provided with additional openings for gas passage to supply an inert gas into the intermediate space between the inner and outer barriers of the respective side walls of the tank. Due to this, the distribution of inert gas in the side walls of the tank is improved. There is no need for rigid connections, since the distribution pipes facing each other with corresponding holes without rigid connections to each other perform the same task and have the advantage of free resizing under the influence of temperature.

According to a further exemplary embodiment, the structures that connect the inner and outer barriers to each other contain openings that allow the distribution of inert gas through the structures. Preferably, the structures are baffles or ribs that would otherwise inhibit the transfer of an inert gas flow between different regions of the double skin of the tank.

According to the following exemplary embodiment, the supply pipe is passed through the outer barrier of the side wall and communicates with the distribution pipe. Preferably, the supply pipe is passed through the outer barrier of the side wall near the bottom of the tank to provide a short communication distance with the distribution pipe.

According to the following exemplary embodiment, an opening of the distribution pipe is located at a short distance from the inside of the supply opening of the outer barrier into which the supply pipe enters. Inert gas may flow from the supply opening to a distribution pipe opening close to it. Through the gap between the supply opening and the distribution pipe opening, inert gas can partially directly enter the intermediate space of the tank bottom. Due to this, additional uniformity in the distribution of inert gas in the bottom wall is achieved. In addition, this improves the ability to drain fluid from the wall of the bottom of the tank through the feed pipe, as it directly communicates with the bottom of the tank through the feed hole.

The distance between the supply opening and the pipe opening compensates for the excellent thermal expansion of the distribution pipe and the tank bottom wall. A rigid connection between the supply pipe or the supply opening and the distribution pipe could be damaged due to the difference in thermal expansions.

According to an exemplary embodiment, the pipe opening is located in the end region of the distribution pipe expanding towards the pipe end. This contributes to the flow of inert gas into the hole of the pipe.

According to a preferred embodiment, supply pipes are provided for both ends of the distribution pipe. This further contributes to a uniform distribution of inert gas at the bottom of the tank.

According to the following exemplary embodiment, the gas outlet pipe is located in the highest region of the upper wall of the tank or the dome of the tank. Preferably, gases escaping from the space of the reservoir accumulate at this location, so that the detection of escaping gases is improved by this measure.

According to the following exemplary embodiment, at least one supply pipe is made in the form of a pump sump for installing a pump for pumping liquid from the intermediate space of the tank lining. According to a further exemplary embodiment, the pump is a sump pump or an emergency pump. According to a further exemplary embodiment, a sump pump or an emergency pump is installed in the supply pipe and sealed around the perimeter of the supply pipe. Preferably, the feed pipe has a vertical orientation.

According to a further exemplary embodiment, the reservoir comprises means for measuring pressure in the intermediate space of the lining of the reservoir and / or means for measuring ambient pressure around the reservoir and / or means for measuring pressure in the space of the reservoir and / or means for estimating the measured pressure in the intermediate space and / or surrounding space and / or in the space of the tank. If the outer barrier is tight, the pressure in the intermediate space of the double skin of the tank is somewhat excessive compared to the environment of the tank (for example, the hold space of the vessel). By constantly or periodically monitoring the pressure in the intermediate space of the double skin, it can be determined whether the gas escapes from the intermediate space to the outside due to the leakage of the outer barrier. When the pressure in the environment of the tank is not lower than atmospheric pressure, for example, due to the fact that there is pressure in the enclosed hold space of the vessel and inert gas with a slight overpressure is supplied to it, preferably the pressure in the environment is also determined and compared with the pressure in the intermediate space. Further, by means of pressure monitoring means in the intermediate space of the tank and in the space of the tank itself, it can be determined whether these two pressures are different from each other or coincide. When the inner barrier is sealed, the pressure in the tank space is higher than the pressure in the intermediate space. If the internal barrier is damaged, for example, with large breaks, the pressure in the space of the tank and in the intermediate space coincides. Evaluation tools can produce a result, for example, by issuing an acoustic and / or optical signal, so that maintenance personnel can take appropriate measures to eliminate the hazard.

According to the following exemplary embodiment, the tank is located on a floating installation. Preferably, the reservoir is located on the ship. However, in principle, the reservoir may be located on an offshore construction site or on land.

Brief List of Drawings

Next, with reference to the accompanying drawings will be described in detail examples of the invention. In the drawings:

figure 1 depicts a longitudinal section of a tank according to the invention in the first embodiment;

figure 2 depicts the same tank in cross section;

figure 3 depicts a distribution pipe for an inert gas in the intermediate space of the bottom of the same tank;

figure 4 depicts the same tank in the following detailed image;

5 shows in an enlarged view the lower region of the same tank with pressure measuring points;

6 depicts in an enlarged detailed view of the lower region of the tank according to the invention in a second embodiment;

Fig.7 depicts in an enlarged detailed view of the lower region of the same tank with a built-in sump pump or emergency pump;

Fig.8 depicts in an enlarged detailed form provided with cut-out sheets of the walls of the double lining of the tank;

Fig.9 depicts the bottom of the tank in both examples in section along the line aa in Fig.6 and 7;

figure 10 depicts an enlarged view of the node of figure 9;

11 depicts the direction of flow of an inert gas in one of the above-mentioned reservoir, shown in a schematic longitudinal section;

12 depicts an enlarged detailed view of the use of a sump pump or an emergency pump when aspirating liquid from an intermediate space.

The implementation of the invention

The invention will be explained in two different examples of the execution of the tank 1, which differ in the design of the double skin of the tank. In a first exemplary embodiment, the reservoir has in principle the same construction as described in the exemplary embodiments in PCT / EP 2010/006954. In a second exemplary embodiment, the tank has in principle the same construction as described in patent document WO 2006/001711 A2 or WO 2008/103053 A1. Matching or substantially matching features of different tanks will be indicated with reference to the drawings relating to various exemplary embodiments. Identical elements are denoted by the same reference numerals.

The instructions “top” and “bottom” refer to the orientation of the tank, in which the upper wall of the tank is located vertically above the wall of the bottom of the tank.

According to figures 1 and 2, the tank 1 according to the invention has a bottom wall 1.1, side walls 1.2-1.5 and the upper wall 1.6 of the tank. The bottom wall 1.1 and the upper wall 1.6 are horizontal and the side walls 1.2-1.5 are substantially vertical. The longitudinal side walls 1.2 and 1.3 at the lower and upper edges contain oblique sections 1.2.1, 1.2.2 and 1.3.1, 1.3.2. Due to this, the cross section of the tank is aligned with the cross section of the tanker for transporting liquefied gas. The bottom wall 1.1, the side walls 1.2-1.5 and the upper wall 1.6 surround the reservoir space 1.7.

On top of the upper wall 1.6 is the dome 5.1 of the tank, through which liquid is supplied to the space 1.7 of the tank and can be taken from it. Top 5.1 dome is closed by plate 5 of the dome.

The tank 1 is formed by panels, which consist of parallel, butt welded to each other supporting profile elements or profiles of the lining of the tank. The panels are connected to each other in horizontal and vertical walls of the tank using connecting profiles 30, and at the corners are connected to oblique sections of the tank using corner profiles 31.

The intermediate space 11 between the inner barrier 2 and the outer barrier is not filled with insulating material, nor is it divided into separate closed areas. As a rule, both barriers 2, 3 are connected by partitions or ribs 33 or other structural elements in order to guarantee an even distance between both barriers 2, 3 without creating obstacles for gas passage. The partitions or ribs 33 are not welded together, so that an unhindered gas flow in the double lining of the tank is ensured. Partitions 33 are predominantly profile partitions of load-bearing profile elements from which the panels are formed.

Reinforcing profiles 32 protrude into the space 1.7 of the tank from the skin profiles. In this case, they are preferably profile walls of the bearing profile elements.

The transverse or longitudinally extending structural elements 30, 31, which could interfere with the passage of the inert gas flow from the bottom wall 1.1 to the upper wall 1.6 of the tank, are provided with cut holes 10 in the ribs or partitions 33, so that a continuous gas flow is ensured.

In the bottom 1.1 of the tank is a distribution pipe 8 for inert gas, equipped with many holes 10 for the passage of gas (see figure 3, 9, 10).

The distribution pipe 8 extends in the longitudinal direction of the tank 1 on its longitudinal central axis. At one end, a supply pipe 6 for inert gas is connected to the distribution pipe 8, and at the other end, a supply pipe 7 made in the form of a pump sump of a larger cross section is connected to it (cf. FIGS. 1, 6, 7, 9, 10). Preferably, the reservoir 1 and the supply pipes 6, 7, 8 are surrounded by insulation.

According to Fig.6, 9, 10, the supply pipe 6 and made in the form of a pump sump supply pipe 7 communicate with the supply holes 9 in the outer barriers 3 of the side walls 1.4, 1.5 of the tank. The distribution pipe 8 at its ends expands with the formation of a cone, while the corresponding hole 8.1, 8.2 of the pipe is located at a short distance in front of the feed hole 9.

According to Figs. 7 and 12, a sump pump 18 can be integrated in the supply pipe 7. The pressure pipe 19, through which the sump pump 18 pumps out liquid, passes upward through the supply pipe 7. The pressure pipe 19 can be connected to a loading pipe network rigidly mounted on the deck liquid medium.

According to Fig.6, 9, 10, the distribution pipe 8 near its openings 8.1, 8.2 is connected to additional distribution pipes 8.3, 8.4. Additional distribution pipes 8.3, 8.4 pass under the lower edges of the side walls 1.4, 1.5 of the tank and are equipped with their own holes 20.1 for gas passage.

9 and 10, the positions 10 indicate the holes in the partitions 33 between the inner barrier 2 and the outer barrier 3, which allow gas to pass. Holes 10 are shown in FIG.

9 and 10, arrows 21 indicate the passage of inert gas in the intermediate space of the wall 1.1 of the tank bottom. In the side walls 1.4, 1.5 of the tank, gas flows rise upward perpendicular to the plane of the drawing. At the upper edges of the side walls 1.4, 1.5, an inert gas enters the upper wall 1.6. From there, it is evenly distributed over the top wall 1.6. In the highest region of the intermediate space 11 of the double shell of the tank on both sides of the dome 5.1 there are nozzles 4 of the inert gas outlet.

11 shows the path of inert gas from the cooling device through the intermediate space 11 of the double skin 2 of the tank to the nozzles 4 of the gas outlet. In the direction of flow behind the gas outlet pipes 4, means 22 for detecting gas are located. The outgoing inert gas is cooled by the refrigeration generator 17 to a predetermined operating temperature during the technical process, for example, by means of high pressure compression.

The described tanks have the following advantages.

Due to the creation of an inert atmosphere using inert gas in the intermediate space 11 of the double shell of the tank with the created inert atmosphere in a relatively short time, small leaks in the double shell of the tank 2 can be detected by detecting gases leaving the space 1.7 of the tank into the inert gas atmosphere. When nitrogen is inert when transporting natural gas, methane can be detected in the event of a leak. Due to the significantly lower density of methane compared to nitrogen after leakage, methane is collected at the gas outlet pipes 4 at the highest points of the double lining of the tank and can be detected.

The monitoring of possible leaks in the double skin of the tank 2 can be accelerated due to the continuous flow of inert gas.

Further, the double skin of the 2 tanks is cooled. Due to the location of the supply pipes 6 and 7 in the lower region of the tank 1 and the connection of the supply pipes 6, 7 to the external barrier 3 in accordance with the rules of the classification bodies for self-supporting tank systems of type A and type B, a cold inert gas, preferably nitrogen, can be blown into the intermediate space 11 in the wall 1.1 of the tank bottom with the lowest possible temperatures, consistent with cryogenic liquids or liquids with low boiling points in the space 1.7 of the tank. A system of distribution pipes 8, 8.1, 8.2 evenly distributes cold nitrogen through the intermediate space 11 of the wall 1.1 of the tank bottom. Due to the injection of cold inert gas, the double lining of the tank is cooled, and the heat penetrating the structure from the outside is carried out by the flow of inert gas through the branch pipes 4 of the outlet. Thus, the influx of heat from the tank’s surroundings to the cryogenic liquid or liquids with a low boiling point to be transported or stored can be minimized or completely eliminated by a cooled inert gas stream, so that evaporation of cryogenic liquids can be better controlled, minimized or completely eliminated.

The tightness of the outer barrier 3 or, respectively, of the closed leak bath is checked by a slight overpressure compared to the pressure 15 around the tank. With constant or periodic monitoring of the pressure in the area between the double skin of the tank and the bath of leaks or, respectively, the outer barrier 3, a pressure drop indicates that the gas leaves the intermediate space 11 in the bilgear space 12 of the vessel surrounding the tank 1, and the outer barrier 3 has leaks (figure 5).

The pressure 16 in the hold space 12 is less than the pressure 15 in the intermediate space 11 between the inner barrier 2 and the outer barrier 3. In turn, the pressure 15 in the intermediate space 11 is less than the pressure 14 in the space 1.7 of the tank. If the pressure in the intermediate space 11 corresponds to the pressure 15 in the space 1.7 of the tank, a leak is present in the inner barrier 2. Collecting liquid in the bottom of the tank may interrupt the flow of inert gas (figure 5).

For the best use of the hold space 12, the distance between the inner barrier 2 and the outer barrier 3 is kept as small as possible. Therefore, in the event of a defect in the internal barrier and the intermediate space 11 is completely filled with liquid from the tank, an emergency pump or other pumps for cryogenic or cold liquids cannot be introduced into the intermediate space 11. Due to the implementation of the supply pipe 7 in the form of a pump sump, a sump pump 18 can be switched on, which is capable of pumping liquids from the intermediate space 11. If necessary, by draining the vessel, the intermediate space 11 can be completely emptied.

Legend List

1 tank

1.1 Tank bottom wall

1.2-1.5 Side walls of the tank

1.2.1, 1.2.2, 1.3.1, 1.3.2 Parts of the side walls of the tank

1.6 upper wall of the tank

1.7 Tank space

2 Inner barrier

3 External barrier

4 Gas outlet pipe (gas outlet)

5 Dome plate 5.1 Dome

6 feed pipe

7 Supply pipe

8 distribution pipe

8.1, 8.2 Pipe holes

9 feed hole

10 hole

11 Intermediate space

12 hold space

13 Reservoir (liquefied natural gas)

14 Pressure in the tank

15 Pressure in the intermediate space

16 Bilge pressure

17 Refrigerator

18 Sump Pump

19 Pressure pipe

20 gas passage hole

20.1 Pressure gas passage

21 gas flow

22 Detector

30 Connection profile

31 Corner profile

32 Reinforcing profile

33 Partition / rib

Claims (19)

1. The reservoir for cold or cryogenic liquids containing
double lining of the tank of light metal, which limits the space of the tank wall of the bottom of the tank, the side walls of the tank and the upper wall of the tank,
moreover, the double skin of the tank contains an inner barrier, an outer barrier located at a distance from the inner barrier, and structures connecting the inner barrier to the outer barrier,
at least one distribution pipe located in the intermediate space between the inner barrier and the outer barrier of the bottom of the tank with openings for gas passage for distributing inert gas in the intermediate space,
at least one inert gas feed pipe located outside the double lining of the tank, which passes through the outer barrier and communicates with the distribution pipe,
an inert gas source connected to the supply pipe outside the tank lining,
gas outlet from the intermediate space in the outer barrier of the upper wall of the tank and
means for detecting gas in the field of gas release. 2. The tank according to claim 1, characterized in that the supply pipe is connected to a source of inert gas flow. 3. The tank according to claim 1, characterized in that only the internal barrier is a permanent casing of the tank. 4. The tank according to claim 1, characterized in that the inner and outer barriers are a permanent casing of the tank. 5. The tank according to claim 1, characterized in that at least one distribution pipe extends in the direction of the main length of the tank. 6. The tank according to claim 1, characterized in that the distribution pipe is made rectilinear. 7. The tank according to claim 1, characterized in that the distribution pipe is located on the Central axis of the tank. 8. The tank according to any one of claims 1 to 7, characterized in that the distribution pipe extends from one side wall of the tank to the opposite side wall of the tank and at both ends is connected to additional distribution pipes that extend under the lower edges of the respective side walls of the tank and equipped with additional openings for the passage of gas for supplying inert gas into the intermediate space between the inner and outer barriers of the respective side walls of the tank. 9. The tank according to claim 1, characterized in that the structures that connect the inner and outer barriers to each other are partitions of the supporting profile elements from which the inner and / or outer barrier is formed. 10. The tank according to claim 1, characterized in that the structures that connect to each other the inner and outer barriers of the double skin of the tank contain openings that allow the distribution of inert gas through these structures. 11. The tank according to claim 1, characterized in that the supply pipe is passed through the outer barrier of the side wall. 12. The tank according to claim 11, characterized in that the feed pipe enters the feed hole of the external barrier, and at a short distance from the feed hole is the hole of the distribution pipe. 13. The tank according to item 12, wherein the hole of the pipe is located in the end region of the distribution pipe expanding towards the end of the pipe. 14. The tank according to claim 1, characterized in that supply pipes are provided for both ends of the distribution pipe. 15. The tank according to claim 1, characterized in that the gas outlet pipe is located in the highest region of the upper wall of the tank. 16. The tank according to claim 1, characterized in that at least one supply pipe is made in the form of a pump sump for installing a pump for pumping liquid from the intermediate space of the lining of the tank. 17. The tank according to clause 16, wherein the pump is a sump pump that is installed in a vertical supply pipe and / or sealed around the perimeter of the supply pipe. 18. The tank according to any one of claims 1 to 7, 9-17, characterized in that it contains means for measuring pressure in the intermediate space of the lining of the tank and means for measuring pressure in the space of the tank and / or means for evaluating the measured pressure in the intermediate space and / or in the space of the tank. 19. The tank according to any one of claims 1 to 7, 9-17, characterized in that it is located on a ship or on another floating installation.

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