RU2800343C1 - Liquefied gas and/or liquid storage unit - Google Patents

Abstract

FIELD: gas storage.

SUBSTANCE: group of inventions relates to a unit (1) for storage of liquefied gas and/or liquid. The unit (1) for storage of liquefied gas and/or liquid includes a sealed tank (71) for storing liquefied gas and/or liquid, consisting of a metal tank (71) having a wall having an inner surface and an outer surface. The wall comprises a bottom wall (10), an upper wall (9) and a side wall (8). Layer (3) covers the surface of the wall (8, 9, 10) of the tank (71) and is made of a polymer material or a mixture of polymer materials and is deformable. The unit comprises an intermediate layer (5) located between the coating layer (3) and the wall (8, 9, 10) of the tank (71). The coating layer (3) is fixed and/or intermittently fixed on the intermediate layer (5), and/or the intermediate layer is fixed and/or intermittently fixed on the wall (8, 9, 10), and said intermediate layer (5) allows gas to circulate for pressing said intermediate layer (5) and therefore the coating layer (3) against the wall (8, 9, 10) of the tank (71).

EFFECT: increased tightness and strength of the tank.

19 cl, 7 dwg

Description

[1] The invention relates to the field of installations for the storage of liquefied gas and/or hazardous liquids, containing, in particular, an independent sealed tank type A, B or C according to the IGC code. In the context of the present invention, the definitions given for independent tanks type A, B and C according to the IGC code refer to the "International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk", edition 2016.

[2] Accordingly, the invention relates in particular, but not exclusively, to the field of sealed tanks for storing and/or transporting liquefied gas at low temperature, such as tanks for transporting ammonia. These tanks can also be installed on land or on a floating structure.

[3] Document FR2996556 is known in the art, which describes a lining or lining for a compressed natural gas (CNG) tank of a polyamide type with at least one impact modifier ranging from 10% to 30% by weight, which impact modifier may consist of rubber. Also, US20090203845 describes a hydrogen container containing a polyamide and copolyamide lining containing 15% to 20% impact agent.

[4] Also known is US20120080106, which describes a pressurized liquid fluid tank with a metal main wall and a lining made of polyethylene, a polyethylene-based copolymer, or a C ₃ -C ₈ block polyolefin.

[5] Finally, document DE202010017414 describes a cylindrical gas container containing a lining consisting of a polyamide matrix, functional additives, olefin-acrylic acid ester copolymers and shock absorbers.

[6] All of these solutions undoubtedly improve the tightness of the tank, but they are very imperfect in terms of their main function of preventing leakage from the storage space or the ingress of foreign matter after the tank walls have been breached, while being complex and expensive to install in the tank.

[7] Moreover, the polymer lining often does not adhere well to the metal wall, and by installing it, it is especially difficult to achieve a result in terms of improving the tightness of the tank, since there is some heterogeneity on different internal surfaces.

[8] In view of this fact, the Applicant sought to eliminate the shortcomings of such tanks and after various experiments and analyzes found that it would be desirable and particularly advantageous to separate the lining or inner lining from the tank wall.

[9] Moreover, in tanks of this type it is impossible to detect a leak, in particular, to prevent the leakage of liquefied gas or dangerous liquid into the installation structure.

[10] Based on this, the Applicant has designed a system that is simple and highly efficient in use and allows fixing the lining in an optimal way, considering, first of all, its sealing function - hereinafter the term "lining" is replaced by the expression "coating layer" - as well as to implement other very useful functions, in particular, monitoring, control and alerting in case of any loss of tightness of the tank, using a reliable, modular and relatively inexpensive system and before this loss of tightness is reflected in storage space leakage that is critical to the design of the facility, typically a vessel, including in situations where the tank wall is damaged due to a collision/shock or traffic accident.

[11] Accordingly, the present invention relates to a liquefied gas and/or liquid storage plant comprising:

- a sealed tank for storing liquefied gas and/or liquid, consisting of a metal tank having a wall having an inner surface and an outer surface, while the wall contains a bottom wall, a top wall and a side wall connecting the bottom wall and the top wall, limiting the space for storing liquefied gas and/or liquid, and

- a layer covering the inner surface of the tank wall, made of a polymeric material or a mixture of polymeric materials, the coating layer being deformable.

[12] The invention is characterized in that the storage installation comprises an intermediate layer located between the coating layer and the tank wall, in that the coating layer is fixed and/or fixed in an intermittent manner on the intermediate layer and/or in that the intermediate layer is fixed and/or fixed in an intermittent manner on the wall, and in that said intermediate layer allows the gas to circulate in order to:

- press said intermediate layer and therefore the coating layer against the tank wall and/or

- by means of a fluid detection device, to allow detection of liquid or gas coming from the storage space in the event of loss of sealing of the coating layer and/or outside said storage space in case of loss of sealing of the tank.

[13] Thus, the coating layer is not attached to the tank or to the container, so that the specified layer is not subjected to the same deformation as the tank, in the event of an impact from the outside.

[14] Without being exhaustive, this type of coating/interlayer arrangement, together with the fact that the interlayer allows gas to circulate to press it and/or to detect fluid coming from the reservoir or from outside, offers the following properties and advantages:

- leveling the surface of the polymer coating layer in the tank,

- limitation of friction between the polymer coating layer and the inner surface of the tank wall,

- thanks to flushing with an inert gas such as nitrogen, the prevention of corrosion of the inner surface of the tank,

- gas circulation in the intermediate layer, allowing to monitor this space, that is, a simple analysis of any fluid circulating in it, in order to detect any leakage coming from the storage space or outside the tank.

[15] By "loss of seal" is meant the existence of a fluid leak either at the level of the coating layer (= loss of seal of the storage space) or at the level of at least one wall of the tank (= loss of seal of the tank) penetrating into the intermediate layer.

[16] Hazardous liquid refers to a flammable, toxic or corrosive/reactive liquid. When it comes to "liquefied gases", this expression is known in itself and is defined, inter alia, in the IGC code. It may refer, for example, to methane or ammonia, preferably ammonia, as will be shown below.

[17] Accordingly, for example, liquefied natural gas (LNG) is, of course, part of the definition of liquefied gases, but may equally meet the definition of a hazardous liquid, since it is, in particular, flammable. Similarly, here ammonia is primarily a "dangerous liquid" as it is toxic, flammable and corrosive, but is often found in such tanks in the form of a liquefied gas. Finally, kerosene and diesel oil or fuel oil are defined here as "hazardous liquids" due to their toxicity, especially the risk of aquifer contamination.

[18] By "gas circulation" it is meant that the intermediate layer is permeable to gases so that any type of gas can be forced to circulate between any two spaced points of the intermediate layer, usually between a point located on the upper wall and a point located on the lower wall, provided that between these two points a classical pump or a circulation pump is used, with a slight increase or decrease in pressure, usually at least 5 mbar, applied at these two points without any - or significant deformation of the intermediate layer.

[19] More precisely, if we consider only the material that forms the intermediate layer, then, therefore, the intrinsic permeability of the latter is at least equal to:

- 100 mDarcy (1 mDarcy = 0.0987 x 10 ^-12 m ² ) in air and at ambient temperature (20°C) according to ISO 8841, when the interlayer consists essentially of glass fibers or another type of fiber such as basalt, carbon, aramid or stainless steel fibers;

- 100 mD in air and at ambient temperature (20°C) according to ISO 7229 (2015) when the intermediate layer consists essentially of a plastic or rubber matrix impregnated with textile fibres;

- 100 mD in air and at ambient temperature (20°C) according to ISO 2782-1 (2016) when the intermediate layer consists essentially of a thermoplastic, elastomer or rubber.

[20] It should be noted here that when the intermediate layer consists essentially of a plastic or rubber matrix impregnated with textile fibers, or consists essentially of a thermoplastic, elastomer or rubber, it preferably contains channels or the like to allow gas to circulate through them.

[21] In a broader sense, the present invention is intended to be used regardless of the shape and size of the tank. Thus, here it is simply defined that the tank comprises a top wall, a bottom wall and a side wall, which has, in particular, a cylindrical or again polyhedral shape, in which, respectively, any flat side wall (only one curved side wall) or, conversely, a group of side walls is virtually absent.

[22] Also in its broadest sense, the coating layer may consist of any types of polymers or mixtures of polymers, provided that they are compatible with their use, that is, in particular, chemically and physically compatible (without physico-chemical reaction or degradation) with the liquefied gas and/or hazardous liquid contained in the tank.

[23] As a non-limiting example, the coating layer according to the invention may be composed of polytetrafluoroethylene (PTFE), polyethylene, preferably high density polyethylene, polyvinyl chloride (PVC), propylene, polyamide, preferably nylon, polyphenylene sulfide (PPS), polyvinylidene fluoride (PVDF), neoprene, ethylene propylene diene monomer (EPDM) and its solaminates, fluororubber (FC) ), such as Viton ^® , or perfluoroelastomers (PFE), such as Kalrez ^® , natural rubber and its derivatives, or a mixture of at least two of these polymers (multilayer or mixed matrix).

[24] Typically, the terms "external" and "internal" are used to define the relative position of one element with respect to another, with reference to the internal and external regions of the tank.

[25] Other preferred features of the invention are briefly described below.

[26] In order to press the intermediate layer, the storage installation preferably comprises a system for pressing the intermediate layer against the vessel wall, comprising:

- means for reducing the pressure of the intermediate layer with an average pressure reduction of at least 5 mbar i.d.; and/or

means for pressurizing the storage space of the tank with an average pressure increase of at least 5 mbar.

[27] In the context of the present invention, the terms "average pressure drop" and "average pressure increase" mean that:

- to pressurize the storage space, the average pressure increase takes into account the pressures at the level of various places on the surface of the coating, which are distributed at least above the side wall, top wall and bottom wall of the tank or on them;

- for depressurization of the intermediate layer, the average depressurization takes into account the depressurization at the level of various places on the coating layer, which are distributed at least above the side wall, top wall and bottom wall of the tank or on them;

[28] The intermediate layer is preferably:

- attached to the tank wall by mechanical and/or chemical means and/or

- chemically fixed on the coating layer.

[29] By "mechanical fixation" is meant that the fixation in question between two elements is made possible by the element forming a physical connection without resorting to electrical, magnetic, electromagnetic or again chemical energy (adhesion or the like).

[30] The coating layer preferably has a thickness of 1 millimeter (mm) to 9 millimeters inclusive, preferably 2 mm to 6 mm inclusive.

[31] In accordance with one particularly interesting aspect of the invention, the coating layer - polymer or mixture of polymers - preferably has a glass transition temperature T _v less than the liquefaction temperature of the liquefied gas and/or hazardous liquid at atmospheric pressure.

[32] The coating layer preferably consists of an elastomer, preferably EPDM. Of course, as previously indicated, this kind of preferred choice of coating layer is directly related to the nature of the liquefied gas and/or hazardous liquid contained in the tank.

[33] For hydrocarbons such as diesel oil or kerosene, a coating layer made from ^Kalrez® or ^Viton® will be preferred.

[34] The coating layer preferably contains reinforcing fibers, preferably glass fibers.

[35] As non-limiting preferred examples of reinforcing fibers, basalt, carbon, aramid or stainless steel fibers present in the polymer or mixture (matrix) of polymers in the form of a mat, felt or textile can equally be listed.

[36] The intermediate layer preferably has a thickness of 2 mm to 30 mm inclusive, preferably 4 mm to 10 mm inclusive.

[37] The average reduction or increase in pressure, respectively, of the intermediate layer and the storage space produced by the pressing system is preferably at least 10 mbar id, preferably at least 15 mbar id.

[38] Note that the term "bar i.d." here it has a technical meaning known to a person skilled in the art, namely that this unit of measure refers to relative pressure measured with respect to ambient pressure, in other words, equal to absolute pressure minus atmospheric pressure or storage space pressure.

[39] In accordance with a preferred embodiment of the invention, the intermediate layer depressurization means comprises at least one pump connected to at least one opening in the tank wall so as to create a medium depressurization.

[40] In this context, the tank wall preferably contains a group of holes distributed along it. In the context of the present invention, the term "distributed" means that holes are present on the top wall and bottom wall when there are only two holes, and also on the side wall when there are at least three holes. In addition to the three holes, the walls of the tank preferably contain a number of holes proportional to their respective lengths.

[41] The installation preferably contains at least one corner connecting part sealed in a sealed manner on the inner surface at the intersection between the top and/or bottom walls and/or side wall and the corner part, the edges of which are in contact with each of at least two adjacent walls, preferably contains a section profile, at least one section of which is round.

[42] In the remainder of the description, one embodiment of this fitting will be described with respect to the attached Figure.

[43] According to one possibility proposed by the invention, the corner fitting comprises at least one communication channel extending substantially perpendicular to the axis of the connecting part for connecting a drainage layer present on each of the two adjacent walls and/or a flow channel extending substantially along the axis of the connecting part, in particular for the flow of liquefied gas and/or hazardous liquid contained in the tank.

[44] In addition to its fastening and sealing functions, a connecting part of this kind is provided primarily for the gas flow in the intermediate layer:

- during the pressing phase, by depressurizing the intermediate layer, but equally - albeit to a lesser extent - depressurizing the storage space is undesirable due to the presence of bubbles or the like. in the intermediate layer

- during the detection phase of the external fluid (i.e. during the detection of the fluid coming from the storage space or outside the tank) so that the gas circulates ideally between the different walls.

[45] According to a special feature of the present invention, the intermediate layer or drainage layer does not have a thermal insulation function. That is why, if thermal insulation is necessary or desirable, there is an element separate from the intermediate/drainage layer, preferably located on the outside of the tank when the latter consists of a tank type A, B or C according to the IGC code.

[46] In accordance with one possibility proposed by the invention, the intermediate layer preferably consists of a drainage layer designed to drain liquid coming from the storage space of the tank or outside the tank.

[47] The fluid detection device preferably includes a means capable of triggering an alert when such a fluid is detected.

[48] Such an alert may be visual and/or audible so that the operator can notice it as quickly as possible. This alert can equally and automatically command the system to secure the tank and its surroundings, for example by commanding the fluid contained in the tank to be diverted to a safe area, or to destroy said contents, for example by controlled incineration.

[49] In accordance with one embodiment of the invention, the installation includes on the bottom wall of the tank a collection area located at the lowest point of the tank, and the fluid detection device is configured to analyze the specified collection area to detect the presence of liquid (coming from the storage space or possibly outside the tank).

[50] By "at the lowest point" is meant that the collection area is located on the bottom wall of the tank, preferably at the lowest level in the direction of the earth's gravity, if this bottom wall is not flat. It may be noted that in the case of independent tanks, a conventional secondary barrier containment means of the "sump" type is usually provided, which is usually located at the level of the hull below the tank itself and in this case forms this collection site if a crack develops in the tank itself. This secondary containment means, which has a reduced volume, has the primary function of containing a leak with a moderate flow rate to protect the structure of the ship from temperatures that could damage it, and can be associated with a pumping system designed to drain too much leakage.

[51] The plant preferably comprises a circulation pump, and the inert gas is preferably circulated by the circulation pump in an intermediate or drainage layer between the at least one entry point and the at least one exit point.

[52] In the context of the present invention, the expression "inert gas" means a gas other than a liquefied gas or a dangerous liquid contained in a tank, and not capable of entering into a chemical reaction with the latter, in particular with all other components in general. This inert gas usually consists of nitrogen or a rare gas such as argon.

[53] The fluid detection device preferably detects the presence of gas and/or liquid at the entry point or exit point. According to one possibility proposed by the invention, said entry point is located at the level of the bottom wall of the tank and said exit point is located at the level of the top wall of the tank.

[54] However, the selection of the inlet and outlet of the circulating inert gas is determined by the ratio of the density d _tank of the component contained in the tank (in gaseous form) to the density d _inert of the circulating inert gas in order to benefit from the shape of the piston effect. Accordingly and preferably:

- if d _tank > d _inert : the inert gas entry or injection point is located at the top of the tank, i.e. at the level of the upper wall of the tank, and the exit point of the inert gas is located at the bottom, i.e. on the bottom wall of the tank;

- if d _tank < d _inert : the inert gas entry or injection point is at the bottom of the tank, i.e. at the level of the lower wall of the tank, and the exit point of the inert gas is located in the upper part, i.e. on the top wall of the tank.

[55] As a non-limiting example, if the tank contains ammonia and the inert gas consists of nitrogen, then the point of entry or injection of the inert gas is located at the bottom of the tank, i. on the lower wall of the latter, and the exit point is in the upper part, i.e. on the top wall of the tank.

[56] In accordance with one possibility proposed by the invention, the installation contains at least one device for filtering the gas circulating in the drainage layer, allowing, in particular, to separate particles coming from a liquefied gas and/or hazardous liquid.

[57] The two main advantages of using this kind of gas separation device, in particular, inert gas and gas coming from the tank or even from outside, are as follows:

- operation in a closed circuit on inert gas when there is no leakage;

- if the gas coming from the tank or even from outside is toxic, such filtration (also referred to as "open loop" filtration) allows it to be recovered and stored primarily on the basis that the circulating gas does not circulate in a so-called closed loop.

[58] Of course, such filtration is not the only solution if an open loop is available: the circulating gas can be additionally injected at the outlet to the burner. For a tank containing ammonia, the steam (exhaust gas) can also be washed with water, and the ammonium solution thus recovered is treated independently.

[59] The fluid detection device preferably consists of a mass spectrometer, an infrared spectrometer, an electrochemical cell, and/or a katharometer.

[60] In a situation where the reservoir contains ammonia, the fluid detection device preferably consists of an electrochemical cell, i.e. a storage battery, in which the ammonia will feed the electrolyte of the cell. Equally, capacitive sensors can be provided to measure the fluctuation in the dielectric constant of an open capacitor, or absorption spectroscopy or mass spectrometry can be used. Of course, the selection of the most appropriate fluid detection device depends primarily on the nature of the fluid contained in the reservoir.

[61] The intermediate layer or drainage layer preferably consists of:

- mat, felt, mesh or woven textiles made of glass, basalt, polyethylene and/or polypropylene fibers and their knots; or

- aggregate material based on resin and mineral granules and/or polymers; or

- a composite material with a thermosetting matrix, preferably based on epoxy, or a thermoplastic matrix, preferably based on polyethylene, polypropylene and/or polyamide, preferably reinforced with glass or basalt fibers or wood particles.

[62] With regard to the nature of the interstitial or drainage layer, fluid detection requires a material that can withstand the working pressure in question—if pressure reduction is applied to press it down or gas circulation, or if the latter requires the application of local pressurization—and that still has a permeability that allows gas circulation. In this regard, in one application, particle board panels, wood particles co-extruded with a thermoplastic matrix, or fiber cement panels can be envisaged.

[63] Generally speaking, for non-planar tank wall geometries, the “textile” approach—mat, felt, mesh, or woven fiber textiles, and resin and mineral granule and/or polymer aggregates—is favored in which the intermediate or drainage layer adapts to the tank walls. Without limiting the invention, with planar geometries, all the solutions mentioned above are possible and suitable.

[64] The means for pressurizing the storage space of the reservoir preferably comprises a compressor or pressurized gas container connected to the storage space of the closed reservoir so as to communicate pressurization by neutral gas or liquefied gas destined for said reservoir.

[65] In the context of the present invention, the term "compressor" refers to any type of means capable of transmitting a gas at an increased pressure relative to its inlet pressure, and the expression "neutral gas" means any gas other than a liquefied gas or hazardous liquid present in the storage space, which is not capable of entering into any chemical reaction or physical interaction with the coating layer and the intermediate layer, such as nitrogen, for example.

[66] The liquefied gas and/or hazardous liquid preferably consist of liquid ammonia. The present invention is actually intended for use in particular, but not exclusively, in tanks containing ammonia.

[67] The metal tank preferably consists of an independent tank of type A, B or C as defined in the IGC code.

[68] Independent tanks are self-supporting tanks. They do not form part of the ship's hull and are not essential to the strength of the hull. There are three categories of independent tanks, namely type A, B or C tanks.

[69] By way of example, a Type A tank is a tank whose design is substantially based on conventional ship design analysis methods that conform to recognized standards. If these tanks are essentially constructed with flat surfaces, the design vapor pressure P _o must be less than 0.07 MPa (megapascals). If the temperature of the cargo at atmospheric pressure is below -10°C, a secondary barrier must be provided in the manner specified in section 4.5 of said IGC code. This barrier must be constructed in accordance with the provisions of this IGC code.

[70] The invention also relates to a method for installing a coating layer and an intermediate/drainage layer in a tank of a liquefied gas and/or hazardous liquid storage facility according to any one of the preceding claims, comprising the successive steps of:

- fix the intermediate/drainage layer on the inner surface of the tank wall,

- fix the coating layer on the intermediate/drainage layer,

- preferably bring the tank to operating temperature,

depressurizing the intermediate layer to an average depressurization of at least 5 mbar id, preferably at least 10 mbar id, or pressurizing the storage space of the reservoir to a pressure of at least 5 mbar id, preferably at least 10 mbar id.

[71] By "brought to operating temperature" is meant that the coating layer is exposed to a temperature equal to or slightly above the temperature of the liquefied gas or hazardous liquid intended to fill the storage space. More precisely, this operating temperature is equal to the temperature T of the liquefied gas or hazardous liquid plus 20 degrees Celsius (T + 20°C), preferably plus 10 degrees Celsius (T + 10°C).

[72] The present invention also relates to a vessel for the transport of liquefied gas and/or hazardous liquids, which includes a hull, an outer deck and at least one inner deck and a storage unit, as briefly described above, located in the hull, on the outer deck or on the inner deck.

[73] Again, as mentioned above, the invention is intended to apply equally to a storage installation containing a pressurized tank, which may consist of an above ground surface tank, a semi-underground or underground (above-ground) storage tank, or an offshore tank. These tanks or tanks can be installed on land or on a floating structure. In the case of a floating structure, the tank may be designed to transport liquefied gas or hazardous liquids, or to receive liquids that serve as fuel for propulsion of the floating structure.

[74] The invention also relates to a cold liquid product transfer system comprising a vessel as described above, insulated pipes positioned to connect a vessel-mounted vessel hull tank to a floating or land-based external storage unit, and a pump for driving a flow of cold liquid product through the insulated pipes from the floating or land-based external storage unit to the ship's tank or vice versa.

[75] Finally, the invention relates to a method for loading or unloading a vessel as defined above, in which a cold liquid product is supplied through insulated pipes from a floating or land-based external storage facility to the vessel's tank or vice versa.

[76] The invention will become more clearly understood and its other objects, details, features and advantages will become more apparent in the course of the following description with reference to the accompanying drawings of specific embodiments of the invention given as an illustrative and non-limiting example.

[77] Figure 1 is a schematic view of a storage apparatus according to a first embodiment of the invention, in which the pressing system comprises an intermediate layer depressurizing means.

[78] Figure 2 schematically illustrates a storage apparatus according to a second embodiment of the invention, in which the pressing system comprises means for pressurizing the storage space of the reservoir.

[79] Figure 3 schematically illustrates a storage facility in accordance with one embodiment of the invention in which a fluid detection device at the level of the intermediate layer is installed and used.

[80] Figure 4 illustrates schematically in section a corner portion that can be used in a storage tank in accordance with the invention.

[81] Figure 5 illustrates, schematically in section, another corner portion that can be used in a storage tank in accordance with the invention.

[82] Figure 6 is a schematic perspective view of a corner connecting part between the walls of a storage tank according to the invention.

[83] Figure 7 is a schematic cutaway view of a methane tanker storage facility and a tank loading/unloading terminal.

[84] Here the term "vertical" means continuing in the direction of the earth's gravitational field. Here, the term "horizontal" means continuing in a direction perpendicular to the vertical direction.

[85] The present invention is illustrated below with reference to a vessel. In fact, it is in this type of construction, in particular accommodating a known storage facility, that the Applicant has been able to pinpoint potential dysfunctions and thus solve them thanks to the present invention. However, it may be envisaged to apply the features of the present invention to another kind of structure, such as, for example, a land or sea vessel type structure.

[86] The Figure 1 illustrates an embodiment in which the pressing system of the intermediate layer 5 comprises a pump 6 connected to a set of holes 7 on various side walls 8, top wall 9 and bottom wall 10 of the tank 71 of the storage unit 1, in accordance with the invention.

[87] Here there are fifteen holes 7 distributed in a balanced manner depending on the dimensions of each of the walls 8, 9 and 10 so as to produce the same pressure reduction throughout the intermediate or drainage layer 5. When the pump 6 is activated to reduce the pressure of the intermediate layer 5, this layer 5 is pressed against the wall 8, 9 or 10 of the tank 71, dragging the coating layer 3 with it as it moves.

[88] As mentioned above, the intermediate layer 5 can be attached to the supporting surface, in this example the wall 8, 9 or 10 of the tank 71, using adhesive or any kind of separate fastening. Alternatively, the intermediate layer 5 is attached to the cover layer 3 and lines the wall surfaces 8, 9 and 10 which are not intended to accommodate joints or fixation zones.

[89] The sealed coating layer 3 consists of parts of a web of polymeric material bonded together by welding, vulcanization or adhesive bonding, wherein the intermediate layer 5 may consist, in addition to the features described above, of plates made of a material such as a thermoset composite material, preferably based on epoxy, or a thermoplastic composite material, preferably based on polyethylene (PE), polypropylene (PP), polyamide (PA), optionally reinforced/filled with glass or bases. alt fibers, either monolithic, or expanded and machined, or formed on at least one of their surfaces in such a way as to create an array of channels allowing gas to flow through them.

[90] During the process of applying the coating layer 3 and the intermediate layer 5, it is preferable, once the last layers 3, 5 have been applied and fixed, to bring the reservoir up to operating temperature. As indicated above, this stage of reaching the operating temperature is aimed at stretching the coating layer 3, which has high elastic properties, so that this layer 3, at the time of depressurization of the intermediate layer 5, is pressed against this layer 5 with the smoothest possible surface without bumps or layers, when the tank 71 is filled with liquefied gas and / or hazardous liquid.

[91] Of course, this operating temperature is most often a temperature below zero if the tank contains liquefied gas, and this will lead to more or less shrinkage of the coating layer 3. Thus, the Applicant has been able to determine that it is particularly preferable, in particular in the case of liquefied gases, to reach a temperature equal to or slightly higher than the temperature of the liquefied gas, i.e. up to 10° C. above the average temperature of the liquefied gas (some temperature fluctuation may exist in a liquid of this kind between the upper and lower layers), or even up to 20° C. exceeding this temperature, depending on the liquefied gas present in the tank 71. However, reaching this operating temperature is equally degree preferably in a situation where the hazardous liquid contained in the tank is at a temperature greater than 0°C, close to 0°C or even slightly higher.

[92] The elasticity properties of the coating layer 3 are also high, and this layer 3 preferably has elongation at break properties of 100% to 300% inclusive. In addition to aspects of its use in tank 71, a coating layer 3 of this kind also makes it possible to improve the reliability of tank 71 in the event of collision incidents with boarding or objects falling on tank 71. Thus, in the event of a serious impact on tank 71, tank 71 may actually burst locally, thereby losing its function as a sealed container. The coating layer 3 experiences substantially the same deformation, but due to its elastic properties and since the anchorages/fixations between the combination of the coating layer 3/intermediate layer 5 and the walls 8, 9 and 10 of the tank 71 are preferably discontinuous in such a way as to distribute any local deformation of the structure over large areas, or these anchoring/fixation zones are capable either mechanically and/or due to their own properties to absorb mechanical forces, or, conversely, have such dimensions, in order to deform to some extent before the coating layer can be damaged, the coating layer 3 retains its tightness even when deformed leading to a so-called open rupture of the tank 71.

[93] Also, the fact that the polymer or polymers forming the coating layer 3 have a glass transition temperature T _v less than the temperature of the liquefied gas in particular, as well as the hazardous liquid, is advantageous, since this allows a layer 3 to be sufficiently ductile and resilient, on the one hand, for its use in the tank and then when filling the tank, and also for its resistance to any mechanical stress or force that the tank 71 may be subjected to.

[94] If a tank 71 is considered containing ammonia, the boiling point of which at atmospheric pressure is minus thirty-four degrees Celsius (-34°C), then it is preferable to choose a polymer or a mixture of polymers having a glass transition temperature - at least one of the polymers in the case of a mixture - below this temperature. Apart from its resilience and elongation at break properties, EPDM, which has a T _v of about -55° C., is usually a particularly interesting candidate for forming the coating layer 3 of the tank 71 of the storage unit 1 according to the invention. In a situation of this kind, reaching an operating temperature of -34° C. before or at the time of depressurization of the intermediate layer 5 is particularly advantageous.

[95] As will be shown below in the context of the pressurization of the storage space 4 of the reservoir 71, shown in particular in the attached Figure 2, reaching the operating temperature may coincide with the step of pressurizing by injection of gas or droplets under pressure at a temperature equivalent to the temperature of the contents of the reservoir 71 or slightly higher. Injecting pressurized ammonia vapor or gas into tank 71 typically allows the pressurization step and the operating temperature step to be performed simultaneously, these two steps being designed to achieve optimal pressing and optimal positioning of the coating layer 3 in tank 71. It is important to note that, as indicated above, the operating temperature step is a non-essential step, even though it is required or preferred.

[96] Figure 2 illustrates an embodiment in which the pressing system of a storage unit 1 according to the invention comprises pressurizing means 11, which may consist of a vessel, ideally containing a pressurized gas identical to a liquefied gas and/or hazardous liquid, or a compressor or the like, connected to the storage space 4 of the vessel 71.

[97] Accordingly, in this embodiment, the pressurization of the storage space 4 allows, possibly with the operating temperature step as indicated above, to obtain the same or substantially the same result as in the context of the first embodiment shown in Figure 1.

[98] Although described herein independently with reference to the appended Figures 1 and 2, it is possible to completely combine the first and second embodiments in order to obtain a clamping system containing a pressure reducing means 6 of the intermediate layer 5 with a means 11 of pressurizing the storage space 4 of the reservoir 71.

[99] Figure 3 shows a storage facility 1 according to the invention with a device for detecting fluid coming from storage space 4 or outside of tank 71 in a situation where tank 71 has been damaged and leaked at least locally.

[100] In this embodiment, in which the storage unit 1 comprises a fluid detection device, the intermediate layer 5 may consist of a drainage layer, even if such a layer is particularly preferred, if the detected fluid consists essentially of a liquid and is not in a substantially gaseous form, and the reservoir has a collection area, not shown in the attached Figures, which is described above.

[101] Regardless of whether the intermediate layer 5 consists of a drainage layer or not, the intermediate chamber 5 must be permeable to gases. Accordingly, in the complete architecture shown in Figure 3, the detection device comprises at least one inert gas circulation means 21 in the intermediate/drainage layer 5 and one circulating gas analysis means 20 in order to allow detection of a fluid that is contained in the reservoir 71 and/or comes from outside the reservoir 71, such as air, for example, if the detected amount of oxygen (O ₂ ) is too high.

[102] Accordingly, here, a detection device of this kind comprises a circulation pump 21 for circulating an inert gas from a container 22 for storing said inert gas to an inlet 23 and then an outlet 24 of the intermediate/drainage layer 5. The circulating gas coming from the intermediate/drainage layer 5 is then analyzed by an analysis means 20 connected to a control means 25 configured to control/command said analysis means 20 in this way to detect the presence of a "foreign" fluid (i.e., fluid coming from space 4 or outside of tank 71), possibly in a significant amount - an amount threshold can be set in advance to determine whether the detection of a foreign component or substance should be positive or not - in order to trigger an alert and/or safety aid for the storage facility 1 or for the surrounding structure, ship 70 or otherwise.

[103] In an embodiment of this kind, the circulating pump 21 can serve as a pump to depressurize the intermediate/drainage layer 5 in order to press the latter for installation and fixation in the tank 71. Accordingly, the embodiment illustrated in Figure 3 allows both pressing the intermediate/drainage layer 5 against the walls 8, 9, 10 of the tank 71, and detecting any leakage from the storage space 4 or loss tightness of the tank itself 71.

[104] Moreover, although the embodiments in Figures 1 and 2, which illustrate the pressing system of the intermediate/drainage layer 5, and the embodiment in Figure 3, which illustrates a method for detecting fluid after a loss of tightness of the storage space 4 and/or reservoir 71, are described independently, both of these embodiments can be combined with each other, preferably two of these embodiments or three embodiments can be taken together.

[105] As previously indicated, the analysis means 20 may consist of an electrochemical cell, an infrared spectrometer, or a mass spectrometer. In the situation where the reservoir 71 contains ammonia, this analysis means 20 preferably consists of an electrochemical cell.

[106] Optionally, the detection device 20, 21 may preferably comprise a means 26 for cleaning, e.g. flushing and/or filtering, the gas circulating in the intermediate/drainage layer 5, which can direct some or all of these gases into a vent pipe 27, usually found on a ship 70 for transporting liquefied gas and/or hazardous liquid.

[107] Based on the fact that the circulating inert gas is used in the loop system, that is, with the recovery of the specified gas for reuse in the group of circulation loops, the detection device 20, 21 may contain a dosing means 28, allowing to deliver, with the need to top up from the storage tank 22 or without it, a sufficient amount of inert gas to (re)circulate the inert gas in the intermediate/drainage layer 5. Additionally, in the Figure 3 shows a number of valves 29 which allow the circulation of the inert gas to be controlled, but their number or positions are not exhaustive or precise.

[108] As with the pressure system of the intermediate/drainage layer 5 illustrated by the two embodiments in Figures 1 and 2, and the system 20, 21 for detecting liquid or gas coming from the storage space 4 in the event of a loss of containment of the coating layer 3 and/or outside said storage space 4 in the event of a loss of containment of the reservoir illustrated in accordance with one embodiment in Figure 3, in the broadest sense, the essential features of the invention are the presence of an intermediate/ the drainage layer 5 and that, due to its (high) permeability to gases, this layer 5 allows the gas to circulate for one and/or the other of the functions which, due to this fact, are connected by a common principle.

[109] Figures 4 and 5 illustrate, in schematic section, corner portions 35, 36 that can be positioned and fixed between walls 8, 9, 10 of tank 71, such as between side wall 8 and bottom wall 10, as shown in these two Figures.

[110] These corner portions 35, 36 preferably have joint radii of 50 to 1000 mm inclusive on the inner surface of the tank so that the cover layer 3 and the intermediate/drainage layer 5 resist pressure forces at the corners well.

[111] Corner portions 36 may consist of molded or extruded polymer rods with molded metal inserts to be welded to walls 8, 10 of tank 71 and located in the end profile. These fastening zones are then covered with the end of the middle second profile section.

[112] Figure 6 shows a variant consisting of a corner fitting 37 fixed between two adjacent walls 8, 10 of the tank 71. The corner fitting 37 may be composed of sectors of metal tubes whose radius is a suitable radius of curvature given the angle between the two adjacent walls 8, 10 of the considered corner edge of the tank 71. The tube sector may then be covered with a polymer lining attached to the latter by vulcanization or by curing. gluing.

[113] In addition to attaching the cover layer 3 and/or the intermediate/drainage layer 5 in areas where the corner pieces 35, 36 or the corner fittings 37 are fixed, the cover layer 3 and/or the intermediate/drainage layer 5 for large tanks is preferably attached in an intermittent manner, i.e. locally, to the walls 8, 9 and 10 of the tank 71.

[114] This attachment can be achieved, for example, by gluing the cover layer 3 and/or intermediate/drainage layer 5 to the walls 8, 9, 10 of the tank 71 continuously or otherwise. On the vertical walls 8 of the tank 71, the web forming the cover layer 3 and/or the intermediate/drainage layer 5 may, for example, have substantially continuous horizontal bonding zones between ten (10) and fifty (50) centimeters (cm) high and spaced two (2) to five (5) meters apart, for example.

[115] On the top walls 9 and the side walls 8, a tighter bonding, possibly in accordance with a particular mesh, will prevent the formation of excessive pits in loose areas. In these areas, full bonding can also be provided using the coating layer 3 facing the intermediate/drainage layer 5. In this case, the material of the intermediate/drainage layer 5 is bonded directly to the walls 8, 9, 10 of the tank 71.

[116] Figure 7 is an example of a marine terminal comprising a loading and unloading station 75, a subsea pipe 76 and a surface installation 77 that interacts with a storage installation in accordance with the invention, that is, a tank 71 having its essential features, and preferably some or all of its additional features, preferably in the context of the first or second embodiments described above. In Figure 7, it can be seen that the tank 71 is installed at the level of the inner deck of the ship 70, but, of course, the same tank can be installed on the upper deck or at the level of any other part of the hull of the ship 70.

[117] It is obvious that the reservoir can be built in the traditional way, so that it can be freely compressed relative to the hull of the vessel 70 and is not subject to the same elongation. In this case, the reservoir 71 rests on a support surface built into the housing, optionally equipped with a thermal bridge destroyer, for example made of wood. The unique area of the bottom wall 10 of the tank 71 is directed in both directions, and the support shoes located on the hull, on the wall and on the ceiling serve as an anti-float so that the tank remains attached to the vessel 70 in the event of a loss of buoyancy of the vessel 70 itself. heat flow with the contents of the reservoir 71.

[118] Embedded systems may be envisaged for liquefied gases whose equilibrium temperature at quasi-atmospheric pressure is greater than -50°C, in which reservoir 71 forms part of the vessel 70 structure, or, in other words, in which a portion of vessel 70 serves as reservoir 71. At these temperatures, low carbon steels actually make it possible to ensure that no loss of elasticity is dangerous to the structure, except for other special thermal schemes. In this case, external thermal insulation can also be provided.

[119] The loading and unloading station 75 is a fixed offshore installation containing a movable arm 74 and a tower 78 that supports the movable arm 74. The movable arm 74 holds a bundle of insulated flexible tubes 79 that can be connected to the loading and unloading pipes 73. The orientable movable arm 74 adapts to all overall dimensions of methane carriers . A connecting pipe, which is not shown, continues inside the tower 78. The loading and unloading station 75 allows loading the methane tanker 70 from the onshore installation 77 or unloading the methane tanker 70 into the onshore installation 77. The latter contains tanks 80 for storing liquefied gas and connecting pipes 81 connected via a subsea pipeline 76 to the loading and unloading station 75. conduit 76 allows the transfer of liquefied gas between the loading and unloading station 75 and land installation 77 over a long distance, for example, 5 km, which allows the methane tanker 70 to remain a long distance from the coast during loading and unloading operations.

[120] The pumps on board the vessel 70 and/or the pumps equipped with the surface unit 77 and/or the pumps equipped with the loading and unloading station 75 are used to create the pressure necessary to transfer the liquefied gas.

[121] Although the invention has been described in connection with a variety of specific embodiments, it is clear that it is in no way limited to them and that it covers all technical equivalents and combinations of the described means, if the latter are within the scope of protection of the invention.

[122] The use of the verbs "include" or "comprise" and their conjugate forms does not preclude the presence of elements or steps other than those set forth in the claims.

[123] In the claims, any reference numeral in parentheses should not be interpreted as limiting the claim.

Claims (35)

1. Installation (1) for storage of liquefied gas and/or liquid, including: - a sealed tank (71) for storing liquefied gas and/or liquid, consisting of a metal tank (71) having a wall having an inner surface and an outer surface, while the wall contains a bottom wall (10), an upper wall (9) and a side wall (8) connecting the bottom wall (10) and the top wall (9), limiting the space (4) for storing liquefied gas and/or liquid, and - a layer (3) covering the inner surface of the wall (8, 9, 10) of the tank (71), made of a polymer material or a mixture of polymer materials and made with the possibility of deformation, characterized in that it contains an intermediate layer (5) located between the coating layer (3) and the wall (8, 9, 10) of the tank (71), the coating layer (3) is fixed and/or intermittently fixed on the intermediate layer (5), and/or the intermediate layer is fixed and/or intermittently fixed on the wall (8, 9, 10), and said intermediate layer (5) allows gas to circulate for: - pressing said intermediate layer (5) and therefore the coating layer (3) against the wall (8, 9, 10) of the tank (71) and/or - by means of a device (20, 21) for detecting a liquid or gas detection fluid coming from the storage space (4) in case of leakage of the coating layer (3) and/or outside said storage space (4) in case of leakage of the reservoir (71). 2. Installation (1) for storage according to claim 1, characterized in that for pressing the intermediate layer (5) it includes a system for pressing the intermediate layer (5) against the wall (8, 9, 10) of the tank (71), containing: means (6) for reducing the pressure of the intermediate layer (5) with an average pressure reduction of at least 5 mbar i.d.; and/or means (11) for pressurizing the storage space (4) of the reservoir (71) with an average pressure increase of at least 5 mbar. 3. Installation (1) for storage according to claim 1 or 2, characterized in that the intermediate layer (5): - attached to the wall (8, 9, 10) of the tank (71) by mechanical and/or chemical means and/or - chemically fixed on the layer (3) of the coating. 4. Storage installation (1) according to any one of the preceding claims, characterized in that the coating layer (3) has a glass transition temperature _Tv less than the liquefaction temperature of the liquefied gas and/or hazardous liquid at atmospheric pressure. 5. Storage unit (1) according to any one of the preceding claims, characterized in that the coating layer (3) consists of an elastomer, preferably ethylene propylene diene monomer (EPDM). 6. Installation (1) for storage of at least one of paragraphs. 2-5, characterized in that the means (6) for reducing the pressure of the intermediate layer (5) contains at least one pump (6, 21) connected to at least one hole (7) in the wall (8, 9, 10) of the reservoir (71) to create an average pressure reduction. 7. Storage installation (1) according to any of the preceding claims, characterized in that the intermediate layer (5) consists of a drainage layer designed to drain liquid coming from the storage space (4) of the tank (71) or outside the tank (71). 8. Installation (1) for storage according to any of the previous paragraphs, characterized in that it includes on the bottom wall (10) of the tank (71) a collection area located at the lowest point of the tank (71), while the fluid detection device (20, 21) is configured to analyze the specified collection area to detect the presence of liquid. 9. Installation (1) for storage according to any of the previous paragraphs, characterized in that it includes a circulation pump (21), while the inert gas is circulated by the circulation pump (21) in the intermediate or drainage layer (5) between at least one entry point (23) and at least one exit point (24). 10. Storage installation (1) according to any of the preceding claims, characterized in that the fluid detection device (20, 21) is configured to detect the presence of gas and/or liquid at the entry point (23) or exit point (24). 11. Storage facility (1) according to at least one of the preceding claims, characterized in that the fluid detection device (20, 21) consists of a mass spectrometer, an infrared spectrometer, an electrochemical cell and/or a katharometer. 12. Installation (1) for storage according to any of the previous paragraphs, characterized in that the intermediate layer or drainage layer (5) consists of: - mat, felt, mesh or woven textiles made of glass, basalt, polyethylene and/or polypropylene fibers and their knots; or - aggregate material based on resin and mineral granules and/or polymers; or - a composite material with a thermosetting matrix, preferably based on epoxy, or a thermoplastic matrix, preferably based on polyethylene, polypropylene and/or polyamide, preferably reinforced with glass or basalt fibers or wood particles. 13. Installation (1) for storage according to any one of paragraphs. 2-12, characterized in that the means (11) for increasing the pressure of the storage space (4) of the reservoir (71) contains a compressor or a pressurized gas container connected to the storage space (4) of the closed reservoir (71) to increase the pressure by means of neutral gas or liquefied gas intended for the specified reservoir. 14. Storage plant (1) according to any one of the preceding claims, characterized in that the liquefied gas and/or hazardous liquid consist of liquid ammonia. 15. Storage installation (1) according to any one of the preceding claims, characterized in that the metal tank (71) consists of an independent tank of type A, B or C as defined in the IGC code. 16. A method for installing a layer (3) of a coating and an intermediate/drainage layer (5) in a tank (71) of an installation (1) for storing liquefied gas and/or hazardous liquid according to any one of the preceding paragraphs, including successive steps, in which: - fix the intermediate/drainage layer (5) on the inner surface of the wall (8, 9, 10) of the tank (71), - fix the coating layer (3) on the intermediate/drainage layer (5), - preferably bring the reservoir (71) to operating temperature, - lowering the pressure of the intermediate layer (5) to an average pressure drop of at least 5 mbar id, preferably at least 10 mbar id, or increasing the pressure of the storage space (4) of the reservoir to a pressure of at least 5 mbar id, preferably at least 10 mbar id. 17. Vessel (70) for transporting liquefied gas and/or hazardous liquids, including a hull, an outer deck and at least one inner deck and a storage unit (1) according to any one of paragraphs. 1-15, located in the hull, on the outer deck or on the inner deck. 18. A system for transferring a cold liquid product, including a vessel (70) according to claim 17, insulated pipes (73, 79, 76, 81) located with the possibility of connecting a tank (71) installed in the hull of the vessel with a floating or land-based external storage unit (77), and a pump for driving the flow of a cold liquid product through insulated pipes from a floating or land-based external storage unit to the vessel tank or vice versa. 19. The method of loading or unloading a vessel (70) according to claim 17, wherein the cold liquid product is supplied through insulated pipes (73, 79, 76, 81) from a floating or land-based external installation (77) for storage to a tank (71) of the vessel or vice versa.