Highly efficient, lightweight and safe multi-layer thermal insulation and fire protection layer

Abstract

Fire protection layer (1) comprising a multilayer structure: a first stack (50) comprising alternating polymer film layers (10) and glass fiber-comprising layers (20); and a second stack (50) comprising alternating polymer film layers (10) and glass fiber-comprising layers (20); and a steel foil (15), wherein the polymer film layers (10) are metallically coated on both sides.

Description

SPECIALIZATION The present invention relates to fire-resistant tanks for the storage, safekeeping, and / or transport of cryogenic fluids. In particular, the invention relates to fire-resistant layers for insulating such tanks for, for example, liquid hydrogen or liquefied natural gas, and their production. BACKGROUND Fuels such as liquid hydrogen (LH2) or liquefied natural gas (LNG) are stored at very low temperatures for extended periods. This requires tanks, so-called cryogenic tanks, with very good thermal insulation in a very small space [cf. Ebe21, Mit06, US 5419139 A , DE 10 2009 020 138 B3 ]. Double-walled cryogenic tanks have proven effective, with a high vacuum (10⁻³ 10⁻⁷ mbar / 10⁻¹ 10⁻⁵ Pa) typically maintained in the space between the walls. The double wall can be additionally filled with a powder for insulation purposes. Its thickness is then typically up to 100 mm or more. Alternatively, multiple layers of highly reflective thermal radiation and transmissive layers acting as spacers are arranged parallel to the walls in the space between the inner and outer walls. These layer arrangements are commonly referred to as multilayer insulation (MLI) or superinsulation. The thickness of multilayer insulation is typically 20 to 35 mm, but can also be up to 50 mm. US 2025 / 0242181A1 discloses an ultrathin direct flame-retardant barrier. GB 2 584 443 A discloses vacuum-insulated devices or a vacuum-insulated cryogenic system with an insulating layer.DE 10 2005 014 479 A1 discloses a container for cryogenic liquids. In the industry, a distinction is made between combustible and non-combustible multilayer insulations (e.g. COOLCAT 2 NW and COOLCAT 2NF; [cf. Bey24]). Common combustible multilayer insulations are often based on plastic films coated on both sides with aluminum as reflective layers, typically biaxially oriented polyester films (BO-PET), which are marketed under names such as Mylar®, with meshes or nonwovens arranged between them as spacers or transmissive layers. These meshes or nonwovens are also typically made of polyester. Thanks to the high tensile strength of the polymers used in the alternating reflective and transmissive layers, these combustible multilayer insulations are mechanically robust, easy to process reliably, and, in combination with a vacuum, represent a very low thermal bridge while requiring minimal space. However, investigations into accident scenarios have shown that significant fire exposure of the tank's outer wall causes pyrolysis of the combustible layers within the double wall. This leads to an increase in pressure within the double wall, causing the thermally insulating layers to partially or even completely disappear. As a result, the optical surface property emissivity of both the inner and outer walls of the tank increases significantly. This causes the heat flow across the double wall to rise to a value greater than that of a double wall without multilayer insulation [see Ebe23, Ebe24a, Ebe24b]. This, in turn, accelerates the pressure development within the tank itself, which can ultimately cause a tank explosion with far-reaching consequences for people and buildings. Vacuum breaching to the surrounding environment has also been identified as another critical event [see...].Cav89], which, during the storage of liquefied hydrogen, leads to the condensation of liquid oxygen on the side of the tank's inner wall facing the insulation. The condensed oxygen could react explosively with the flammable multilayer insulation. The potential consequences are comparable to a fire scenario. Non-combustible multi-layer insulations represent an alternative to combustible multi-layer insulations. These consist of purely metallic aluminum foils as reflective layers and glass fibers processed as fleece or paper as transmissive layers [see Bey24]. Such systems are inherently very fragile, mechanically weak, and therefore difficult to process reliably. Furthermore, compared to combustible multi-layer insulations with the same number of layers, the heat transfer coefficient is approximately twice as high [see Bey24]. Consequently, they represent significantly larger thermal bridges. The standard practice is to address this by increasing the number of layers and thus the thickness of the non-combustible multi-layer insulation. However, this reduces the usable tank volume for the same external dimensions.Even the aluminium foil of non-combustible multi-layer insulations, which is generally considered non-combustible, fails in a relevant fire scenario, although this is associated with a significantly smaller reduction in thermal insulation than with combustible multi-layer insulations [cf. Ebe24a]. PROBLEM STATEMENT Against this background, there is a need to provide thermal tank insulation that, in a relevant fire scenario, significantly reduces the heat flow from a fire outside the tank into the tank for a period of at least 30 minutes compared to conventional superinsulations, thus surpassing their fire protection performance. On the other hand, its thickness should not exceed that of combustible multilayer insulations. BRIEF SUMMARY The invention is characterized in that metallized plastic films, characterized as combustible, are combined as IR-reflective layers with IR-transmissive layers containing glass fibers, characterized as non-combustible, which serve as spacers in a layer stack formed by the combination. This has the advantage that, in a relevant fire scenario, the transmissive layers are highly thermally resistant and therefore do not fail. In a relevant fire scenario, they thus prevent, firstly, the fusion of adjacent layers characterized as combustible; secondly, they hold the fragments remaining after pyrolysis in their position; and thirdly, they accumulate the pyrolysis products formed from the layers characterized as combustible.This ensures that, in a relevant fire scenario, a morphologically altered but still layered structure is maintained, which significantly reduces the heat flow from the fire source into the tank compared to a previously known multilayer insulation based solely on non-combustible layers. Additionally, the combination described in the invention comprises metallized polymer films, preferably double-sided metallized polymer films, as reflective layers and transmissive layers containing glass fibers, which serve as spacers between the former, and at least one stainless steel foil. The stainless steel foil is typically adjacent to a glass fiber-containing layer on both sides. In the intended operation of a tank for liquefied fuels that are gaseous under normal conditions - which is referred to here synonymously as a cryotank or cryogen tank or generally as a refractory tank - the multilayer insulation proposed according to the invention ensures significantly better thermal insulation with the same number of layers than multilayer insulations based solely on non-combustible layers and multilayer insulations based solely on combustible layers. The proposed fire protection layer suppresses the formation of thermal bridges compared to multi-layer insulations characterized as combustible, since the glass fiber-containing layers used as spacers (transmissive layers) are non-combustible, and thus combustible layers in the layer stack are no longer arranged directly adjacent to each other. This results in a significantly reduced formation of thermal bridges in a fire scenario. The considerably improved thermal insulation is advantageously achieved while maintaining the desired total insulation thickness of 20-35 mm. This means that, with the same external dimensions, the usable volume of the tank is maintained or even increased, even though the thermal insulation would otherwise only be achievable through additional layers and thus a greater overall thickness of the multi-layer insulation. Due to the improved thermal insulation, the thickness of the proposed fire protection layer can advantageously be reduced to as little as 10 mm if only one stainless steel foil is combined with very few non-combustible glass fiber-containing layers and a correspondingly very few double-sided metallized polymer films. "Very few" in this context refers to 5 to 20, preferably 7 to 15, layers, typically ≤ 10, thus a maximum of 20 layers in the fire protection layer stack. The additional steel foil(s) arranged in the layer stack significantly improves the fire protection effect of the inventive combination of reflective layers classified as combustible with spacer layers classified as non-combustible, thereby achieving a novel multi-layered insulation. This is therefore referred to as a fire protection layer. The disadvantages of known multilayer insulations described at the outset are thus overcome by the proposed combination of reflective layers characterized as combustible with transmissive layers comprising glass fibers and characterized as non-combustible, which serve as spacers in the layer stack, and the additional combination with at least one stainless steel foil. Advantageously, the at least one stainless steel foil compartmentalizes the layer stack, composed of reflective and transmissive layers, within the interior of the double wall. SHORT FIGURE DESCRIPTION A complete disclosure of the present invention, including the best embodiment, which enables a person skilled in the art to reproduce it, is set forth, including reference to the accompanying figures, particularly in the following part of the description. Fig. 1 schematically illustrates a cross-section through the double layer of a cryogenic tank before (A) and after (B) a fire event. Fig. 2 schematically shows a cryogenic tank filled with a cryogenic fluid. Fig. 3 illustrates (A) the assumed time-dependent temperature profile ("time-temperature profile of the fire load") according to the so-called ZTV-Ing curve [see ZTV-ING]; and (B) the heat flows occurring through different multilayer insulations at the assumed outside temperatures for a fire event according to Fig. 3A. Fig. 4 schematically shows a fire protection mat.A large number of fire protection mats arranged side by side in the interior of the double wall of the tank, or even partially overlapping each other, can be advantageously used to thermally insulate a deep-freeze fluid stored in the tank, so that the thermal insulation is maintained even in the event of a fire. The following text refers to the figures mentioned, which serve to illustrate specific embodiments and features of the invention. It is understood that other embodiments may be used and structural or logical modifications may be made without departing from the scope of the present invention. The following detailed description is therefore not to be understood or interpreted as limiting, even if the scope of the present invention is initially defined by the accompanying claims. As used above and below, the word “a” or “an” in conjunction with the term “comprising” or “comprising” in the claims and / or description can mean “one” and “an”, but is also consistent with the meaning intended under patent law for “one and / or more”, “at least one” and “one or more than one”. Due to their small thickness, the terms layer and layers are used synonymously with film and films in the multilayer insulations discussed here. Therefore, a glass fiber-containing layer, whether in the form of paper with or without a binder, a layer of glass fiber non-woven fabric, or a woven fabric, is hereinafter generally referred to as a glass fiber-containing film, or simply as a glass fiber-containing film and glass fiber-containing layer, or as a glass fiber-enclosing film and glass fiber-enclosing layer; it could also be described as a layer containing glass fibers. DETAILED DESCRIPTION According to one embodiment, a fire-resistant layer is proposed that has a multilayer structure. In other words, this multilayer structure comprises a stack consisting of combustible polymer films coated with metal on both sides, interspersed with layers comprising glass fibers that are considered non-combustible, and at least one stainless steel foil arranged within the described stack. In other words, the fire-resistant mat has a multilayer structure consisting of a first stack, a second stack, and a stainless steel foil arranged between the two stacks. The first and second stacks are formed from alternating layers of polymer films coated with metal on both sides and glass fibers. Metallic-coated polymer films are advantageous for reflecting heat radiation, especially IR radiation, as they are highly reflective and optically opaque. The polymer films typically used in practice, coated on both sides with aluminum, are effective reflectors of heat radiation, while the glass fiber-containing layers, or more broadly, the layers containing silicate materials, are optically transparent. Thus, while the function of the former is to reflect heat radiation, the glass fiber-containing layers act as spacers between the reflector layers. The described combination of combustible reflector layers with non-combustible transmissive layers ensures, with the same total number of layers, that the reflective layers are not optically transparent.Layered foils offer improved thermal insulation compared to multilayer insulations based solely on non-combustible reflector and spacer layers. This allows for a reduction in the overall thickness of the proposed multilayer insulation. In the described multi-layer structure, comprising metallically coated plastic films (combustible components) and layers containing glass fibers (non-combustible components), at least one stainless steel foil serves as an additional reflector layer and as a compartment former between adjacent layer stacks. If one considers the space filled by previously known multilayer insulation in the double wall as a compartment, then the at least one additional stainless steel foil arranged in the layer stack creates, at least in sections, the formation of a further compartment. It thus divides the interior of the double wall. The multilayer insulation proposed in the embodiment described above is therefore more thermally resistant than previously known multilayer insulations. Regarding the term "in sections," it means that the cavity of the double wall cannot be divided by a single, one-piece stainless steel foil covering the entire surface of the underlying part of the fire-resistant layer. There are inevitably areas where sections of the stainless steel foil overlap and / or touch: Several circumferentially adjacent stainless steel foils are, similar to mats (English:The "blankets" of known multilayer insulation are arranged side by side and abut each other at adjacent edges, overlap each other at least partially at adjacent edges, and / or are joined together with suitable fasteners, e.g., adhesive pads, tapes, or pins. The stainless steel foil, which is comparatively rigid compared to a bidirectionally stretched, thinly metallic-coated polymer film or a fiberglass fleece, inevitably leads to the formation of gaps, mainly in the circumferential direction, between the circumferentially adjacent stainless steel foils or blankets. These gaps can be addressed by overlapping the same foil.Even if the sections of the layer stack, spatially separated by the stainless steel foil, are fluidically connected to each other to a small extent through this gap, the effect of the stainless steel foil on dividing the double-wall interior into compartments is dominant. These compartments are arranged sequentially in a radial direction with respect to a central axis of symmetry of the tank. The successive compartments of the multilayer insulation, arranged from the outside in, cause a time-delayed pyrolysis: first in the outer layers of the outermost compartment, then progressively in the next compartment arranged towards the usable volume. The fire-induced formation of pyrolysis products from the combustible components, in conjunction with the non-combustible, glass-fiber-containing layers that serve as a barrier and framework for the aggregation and fixation of the pyrolysis products, thus degrades the vacuum in the event of a fire in a time-delayed and only gradually manner. The stainless steel foil(s) further restrict convection and heat conduction. As a result, the heat flow caused by convection and heat conduction increases more slowly than with previously known multilayer insulations of the same thickness. This, in turn, has a cooling and therefore protective effect on the layers of the fire protection layer according to the invention that are closest to the inner tank. In other words, the additional compartment formed by at least one steel foil arranged in the layer stack further delays the pyrolysis in the compartment(s) closer to the inner wall by ensuring lateral heat dissipation, which slows down the pyrolysis process, improves the mechanical protection of the layer stack and also mechanically stabilizes the layer stack as a whole. Advantageously, the altered structure of the morphologically modified layer stack resulting from the fire exposure is maintained even at higher temperatures, and the stabilizing effect of the glass fiber-containing layers is retained. Furthermore, at least one steel foil layer within the stack prevents the spread of pyrolysis products throughout the overall insulation, i.e., the entire stack of layers. This reduces the heat flow through or across the double wall. The steel foil in the layer stack, at least one of which is, of course, optically opaque, as are the metal-coated polymer foils. Unlike these, stainless steel has a significantly higher melting point and a low and nearly constant emissivity over a wide temperature range. This temperature range encompasses the temperatures occurring in relevant fire scenarios (see ZTV Ing - 7). All the layers mentioned—the glass fiber-reinforced layers, the metal-coated polymer foils, and the stainless steel foil of the proposed fire protection layer—are mechanically sufficiently stable, can be reliably arranged in an orderly layer stack, and can also be reliably processed in stacked form.The resulting fire protection layer is well suited for insulating transport and storage containers for compressed and / or liquefied gases and gas mixtures, as well as pipelines / cryogenic pipelines for the transfer of liquefied gases. Unlike previously known multi-layer or super-insulations, the multi-layer structure described here provides additional fire protection; that is, its behavior in the cavity of an evacuated double wall of a corresponding container (cryogenic tanks, cryotanks) prevents fire-induced failure of the thermal insulation capacity of the double wall provided with it. According to one embodiment, the polymer film layers and the glass fiber-containing layers are arranged alternately in the stack, i.e., consecutively. Typically, the stainless steel foil is surrounded on both sides by glass fiber-containing layers or glass fiber-containing films. The multiple layers of spaced-apart, metal-coated polymer films, acting as reflective layers, already provide a high degree of thermal insulation due to their emissivity. The stainless steel film(s) additionally arranged in the multilayer structure according to the invention further improve lateral heat dissipation. They thus stabilize the layer structure, or the structure of fire-induced solid pyrolysis products, even at the highest temperatures expected in a fire, as they delay the formation of hot spots. Each individual stainless steel film also suppresses the spread of pyrolysis products towards the inner tank wall and dissipates heat laterally by conduction, thereby reliably preventing the formation of local thermal bridges. Naturally, a thermal bridge is understood here to be a thermally conductive connection between the outer and inner walls of the tank. According to one embodiment, at least one of the metallic coatings on both sides of the polymer films, which function as reflective layers, is an aluminum coating. Typical polymers used in the films are polyester (bo-PET, PET), PVC, and Mylar®. Aluminum has already proven advantageous in previously known multilayer insulations, both in systems considered combustible as a thin sputtered aluminum coating and in systems characterized as non-combustible as a thin aluminum foil. The aluminum oxide that forms on the surface of these foils upon contact with air has a very low emissivity ε (approximately 0.04–0.08) compared to other metals, and this emissivity range is narrower than, for example, that of copper (0.01–0.70). The use of aluminum-coated polymer foils as a reflective layer thus enables the production of fire-resistant coatings with consistently high thermal insulation properties. According to one embodiment, the stack comprises at least 10 layers containing glass fibers, thus having, for example, at least 19 layers, assuming that the layer stack terminates on the outside with a layer containing glass fibers opposite the inner wall of the container and opposite the outer wall of the container. Advantageously, the multilayer structure corresponding to this embodiment provides a stable fire-resistant layer in the event of a fire due to the suppressed formation of thermal bridges. Because of its increased mechanical stability resulting from the steel foil, the described fire-resistant layer is easier to process than previously known, non-combustible multilayer insulations, which, in comparison, comprise at least nine aluminum foils and ten layers of glass fiber. According to one embodiment, the at least one stainless steel foil is arranged symmetrically within the layer stack of alternating aluminum-coated polymer foils as reflective layers and glass fiber-containing layers as spacers: With respect to the stainless steel foil, the sequences of metal-coated polymer foils and the glass fiber-containing layers arranged between them – each of which can be considered a stack – are therefore approximately the same thickness on both sides of the stainless steel foil, or at least approximately equal with respect to the number of layers. "At least approximately" is understood to mean "± 2 layers". In other words, the at least one stainless steel foil is preferably arranged symmetrically, for example centrally in the layer stack and thus, in a sense, "in place of a reflective polymer foil." If several stainless steel foils are provided, these are also preferably distributed symmetrically in the layer stack. The number of alternating reflector and spacer layers of a stack up to the nearest stainless steel foil in the radial direction of the tank and / or up to one of the two walls of the double wall is therefore preferably equal to or approximately plus / minus two (±2). If the layer stack consists of only one stainless steel foil, then the total number of glass fiber-reinforced layers and metal-coated polymer films between the inner wall of the container's double wall and the side of the stainless steel foil facing it is equal to the number between the opposite side of the stainless steel foil and the outer wall of the container's double wall. One stainless steel foil forms an additional compartment, thus creating a total of two compartments within the space between the double walls. If two stainless steel foils are arranged in a layer stack, the number of layers between them equals the number of layers between the inner wall of the container and the first stainless steel foil located closer to the inner wall, and the number of layers between the outer wall of the container and the second stainless steel foil located closer to the outer wall. The two stainless steel foils form three compartments in the space between the double wall. Even in the case of a total of three stainless steel foils, the number of glass fiber-reinforced layers and the number of metal-coated polymer films, which are arranged adjacent to the inner and outer surfaces of the three stainless steel foils up to the nearest stainless steel foil or up to one of the inner and outer walls of the container, are preferably approximately identical, or equal to plus / minus two (±2). The three stainless steel foils of this embodiment of the fire protection layer form a total of four compartments within the interior of the double wall. The metal-coated polymer films advantageously act as reflective layers by reflecting electromagnetic radiation, especially thermal radiation. The layers containing glass fibers or consisting entirely of glass fiber fleece or glass fiber paper serve as spacers between the metal-coated polymer films, between the metal-coated polymer films and the stainless steel foil, and between the two inner walls of the double wall. The metal-coated reflector films are particularly advantageously coated with aluminum on both sides, for example, by sputtering or vapor deposition. At least one of the aluminum-coated polymer films in a layer sequence: "glass fiber-containing layer / aluminum-coated polymer film / glass fiber-containing layer / aluminum-coated polymer film / etc." of the multilayer structure described above, i.e., the layer stack, is replaced by a stainless steel foil. Thus, the multilayer structure, or rather, the layer stack, exhibitsThe proposed fire-resistant layer stack incorporates at least one stainless steel foil. Its excellent thermal conductivity minimizes the risk of local overheating and extensive damage to the multilayer structure in the event of a fire. Due to its hardness, it also protects the layer stack from potential mechanical damage, for example, during the assembly of the multilayer structure. Furthermore, the stainless steel foil(s) arranged in the stack advantageously form an additional compartment that inhibits the penetration of thermal damage originating from the tank's exterior in the event of a fire into deeper layers of the multilayer structure. According to one embodiment, the layers comprising the glass fibers are selected from the group consisting of: glass fiber fleece, glass paper, a polymer-reinforced glass fiber fleece, a mineral fiber fleece, and a silicate fiber fleece. A silicate fiber fleece is known, for example, under the trade name Promaglaf®. Advantageously, the basis weight of the individual glass fiber-containing layers is below 60 g / m², preferably in the range of 10–50 m² / g, and more preferably below 30 m² / g. Such low basis weights ensure the transmissive nature of the spacer layers. The fire protection layer can also combine various types of glass fiber-containing layers. In other words, the glass fiber-containing layers contain inorganic fibers based on silicates and / or inorganic fibers with silicate components. They serve as spacers between the metallized polymer films and the stainless steel foils, both of which function as reflective layers. The glass fiber-containing layers can therefore also include borosilicate glass, other types of glass, and mineral wool. The use of other types of inorganic fibers, such as carbon fibers, leads to a significantly reduced performance of the multilayer insulation during normal operation due to the considerably lower transmission and is therefore disadvantageous.In this context, "normal operation" and "normal load" are understood to mean conditions that exist during the intended use of the cryogenic tank under typical conditions at altitudes between mean sea level (NNL) and 15,000 m above mean sea level (NNL), provided that the tank, the means of transport carrying or moving the tank, and the immediate surroundings of the tank are not affected by fire or open flame. According to one embodiment, the at least one stainless steel foil arranged in the layer stack has a maximum thickness of 0.5 mm. Typical thicknesses of the stainless steel foil are in the range of 0.01 mm to 0.5 mm, particularly between 0.05 mm and 0.5 mm, preferably at or below 0.2 mm, for example between 0.01 mm and 0.1 mm. Typical steels used for the stainless steel foils are 1.4404 (V4A, AISI 316) or 1.4301 (V2A, AISI 304). Stainless steel offers advantages over other materials, including a high melting point and a low and nearly constant emissivity over a wide temperature range. This broad temperature range encompasses temperatures during normal operation, i.e., during the typical stresses on the fire-resistant layer, as well as temperatures during relevant fire scenarios. Furthermore, stainless steel foil is mechanically sound and therefore reliably processable. According to one embodiment, the proposed fire protection layer comprises: 10-40, preferably 15-30 polymer films coated on both sides with aluminium; 12-61, preferably 18-41 layers comprising glass fibers; and 1-20, preferably 1-10 stainless steel foils; wherein the glass fiber-comprising layers are arranged between the polymer films coated on both sides with aluminium and the stainless steel foils, enclosing the stack on both sides. A greater number of layers is preferred when only very low heat flows through the thermal insulation are permissible, such as in land transport, to allow for downtime of several days without boil-off or tank venting. This advantageously saves costs. A lower number of layers is suitable for applications where larger heat flows through the thermal insulation are permissible or desirable, for example, to ensure emergency operation. Future gas-powered aircraft, particularly hydrogen-powered aircraft, represent a potential application area for the aforementioned intermediate range. According to one embodiment, a fire protection mat comprising the fire protection layer according to at least one of the aforementioned exemplary embodiments is proposed. Here, the first stack of the fire protection layer is connected to the second stack of the fire protection layer by means of a fixing agent. The fixing agent is preferably arranged at least sectionally along an outer contour of the fire protection mat and thus forms a seam, border, crimp, and / or tack along the outer contour of the fire protection mat. The mat is formed or manufactured by cutting the desired stack of layers to the desired contour dimensions of the mat, for example, using a suitably configured and guided laser beam, such that the individual layers fuse together along the contour and form a continuous edge or hem running along the contour. Alternatively, the contours of the mat can also be formed by a quilting seam and subsequent trimming or by hemming along the intended outer edges. Suitable or similar devices are known, for example, from the tailoring trade as "overlock sewing machines" or "coverlock sewing machines." The film material, preferably sewn together along its outer edges or even just loosely tacked, for example with pins, is cut with the appropriately adapted device along an outward-facing side of the (stapling) seam.A blade used for this purpose in the device can oscillate, vibrate, or rotate to ensure complete cutting of all films in the stapled, sewn, or, optionally after cutting, edge-hemmed stack of layers, or it can be designed as an oscillating, vibrating, or rotating saw blade. Naturally, this final cutting function can also be performed using a suitable laser beam, such as one aligned with a laser scanning device, of a type, power, and / or frequency (pulsed) known to those skilled in the art. To further secure the layer stack, adjacent layers can be bonded together, for example, by offsetting them at specific points, using an adhesive or by other means, such as tacks and a suitable tack gun. Advantageously, the individual sheets have openings—such as round holes or elongated slits—offset from sheet to sheet or layer to layer. These allow for the rapid and easy evacuation of the double-wall interior after all the mats forming the fire-resistant layer have been installed, in order to achieve the desired high vacuum in the double layer of the cryogenic tank within a reasonable timeframe. Typically, the contours of the described mats, intended for fire-resistant thermal insulation of a cryogenic tank or for the thermal insulation of a pipeline transporting a cryogenic fluid, are selected such that the arrangement of numerous mats on the surface of the inner wall of the double layer completely covers it. As already mentioned, adjacent mats can touch each other at their edges and / or overlap at least partially. The advantages of consistently reliable fire protection insulation achieved in this way are obvious. According to one embodiment, a fire-resistant tank is proposed that is configured for the storage and / or transport of compressed and / or liquefied gases or gas mixtures. The fire-resistant tank comprises a fire-resistant layer enclosed by a double wall, as described in at least one of the preceding embodiments. Here, compressed and / or liquefied gases and corresponding cryogenic gas mixtures are understood to be at least partially liquefied gases such as helium (LHe), hydrogen (LH2), nitrogen (LN2), argon (LAr), oxygen (LO2), natural gas (LNG), and air, for example, as an air / nitrogen mixture. A typical example is liquid hydrogen (LH2), but also cryo-compressed hydrogen (CCH2). CCH2 is stored at similar to higher temperatures as LH2, but at significantly higher pressures. This makes it possible to achieve higher volumetric energy densities. An inner and an outer wall of the double-walled tank each abut opposite sides of the fire-resistant layer described above, thus thermally insulating the usable volume of the tank. Advantageously, the contents of the described tank are reliably protected from excessive heat and the resulting hazards, even during a fire. Relevant fires can include pool fires of flammable liquids, jet fires from escaping flammable gases, and fires involving adjacent objects. Other relevant fires can originate, for example, from adjacent attachments and cladding, cables, tires, fuel, or cargo of the transport vehicle carrying or moving the tank, all of which carry significant fire loads. Design fires such as the ZTV Ing curve, the standard temperature curve (ETK), or the hydrocarbon curve (HC) are suitable for characterizing such fires. All these curves have in common that flame temperatures exceeding 1000°C are reached, against which the fire protection layer described here provides sufficient thermal resistance. According to one embodiment, a high vacuum exists in the double wall, i.e., its interior, i.e., the volume enclosed by the inner wall and outer wall with the fire protection layer arranged in this volume, or the fire protection mats described above, is evacuated. As is well known, this improves thermal insulation, since the heat flow through convection and conduction in a vacuum decreases with increasing vacuum quality. According to one embodiment of the fireproof tank, the double wall of the tank has a substantially hemispherical shape, or the shape of a hemisphere, on the two opposite sides of a cylindrical part. Alternatively, the fireproof tank can also have a spherical shape, which has proven effective for large LH2 tanks, for example. The advantage of this design is that it has a low volume-to-surface-area ratio, which reduces thermal bridging. Furthermore, this shape is very well suited to withstanding the pressure in the inner tank and the vacuum in the double wall. According to one embodiment, one of the two opposing sides of the refractory tank has a fixed bearing with a closable opening for a fluidic connection to the usable volume of the refractory tank. The other of the two opposing sides optionally includes a floating bearing, typically in a horizontal design of the refractory cryogenic tank. However, this side typically does not have a closable opening for a fluidic connection to the usable volume of the refractory tank. Advantageously, these tanks have a smaller surface area relative to their usable volume compared to angular shapes and are more stable against pressure fluctuations and loads. The fire-resistant layer proposed here results in a lower heat flux density in the event of a fire compared to conventional combustible and non-combustible multi-layer insulations. This leads to a more homogeneous heating of the fluid and a reduction in the pressure rise rate. According to one embodiment, the proposed fire-resistant layer, consisting of a stack of double-sided aluminum-coated polymer films (reflective layers), glass fiber-containing layers (so-called transmissive layers) arranged between these as spacers, and a stainless steel foil arranged symmetrically in the multilayer structure with respect to the number of layers mentioned, is configured such that the heat flow through the fire-resistant layer is reduced by at least a factor of 4 to 7 compared to, firstly, a multilayer insulation consisting of the combustible double-sided aluminum-coated polymer films (reflective layers) and, between these as spacers, also combustible meshes or nonwovens made of a plastic (often polyester) as transmissive layers, and secondly, the heat flow of a multilayer insulation.which is composed of aluminum layers (reflective layers) that are considered non-combustible and, between these, layers containing glass fibers that are also considered non-combustible and serve as transmissive layers. The aforementioned factor results in a reduction of the heat flow, which affects the boiling regime of the cryogenic fluid and thus promotes the homogeneous heating of the fluid, causing the pressure to rise more slowly by a factor of 1 to 10. At its maximum, this results in a factor between 4 and 70 by which the volumetric flow rate of gaseous fluid from the tank—i.e., the loss of the stored cryogenic fluid due to boil-off—can be reduced by the fire protection layer proposed above and below. Pressure relief valves must be designed so that the mass flow resulting from the vaporization of the initially liquid gas can be discharged safely without increasing the internal pressure of the tank. The reduction in maximum heat flow achievable with the proposed fire-resistant coating of the refractory tank reduces the required mass flow at the same pressure. This has the advantage that the proposed refractory tank can be equipped with smaller and therefore more cost-effective safety valves without compromising operational safety. This also increases the possible usable volume and thus the tank's payload, especially for small tanks. A small tank is defined here as one with a usable volume typically less than 1 m³. Such tanks are commonly used, for example, in LNG or LH₂-powered trucks in road freight transport. According to one embodiment, a pipeline is proposed that includes a fire-resistant layer according to one of the embodiments disclosed above. In other words, the pipeline is circumferentially enclosed at least partially, preferably almost completely, and more preferably entirely by the fire-resistant layer or a mat comprising it, as described above and below. The inner wall of the pipeline comprises steel, aluminum, titanium, copper, nickel, an alloy comprising at least one of the aforementioned metals, or a polymer. Preferably, to ensure minimum flexibility, the pipeline is configured as a bellows, at least partially. In a radial direction extending from a central or symmetry axis, the pipeline has an outer wall spaced apart from the inner wall.In the space formed between the inner and outer walls of the section of the pipeline enclosed by the fire-resistant layer, a sequence or stack of layers is present in a radial direction (relative to a central axis of the pipeline). This layer consists of polymer films coated on both sides with aluminum, layers comprising glass fibers, and at least one steel foil. According to a preferred embodiment, rigid pipeline sections can be connected to one another by bellows sections. Optionally, the space between the inner wall and the outer wall of the pipeline can be evacuated at least in sections, so that a high vacuum is present in the section in question, preferably in adjacent sections of the pipeline. The advantages achieved with such a pipeline for the transport of a cryogenic fluid correspond to those described above and below for the respective embodiments of the fire-resistant layer. Such a pipeline, at least partially equipped with the fire-resistant layer, can be used, for example, as a transfer line and / or pipeline and can be used at a suitable terminal in a port for handling cryogenic fluids. The use of the transfer line incorporating the fire-resistant layer significantly increases the safety of the corresponding port facility. According to a further embodiment, the material of at least the inner wall of the pipeline is adapted for contact with a cryogenic fluid, in particular a cryogenic liquid, selected from: liquefied argon (LAr), liquefied carbon dioxide (LCO2), liquefied hydrogen (LH2), liquefied helium (LHe), liquefied nitrogen (LN2), liquefied oxygen (LO2), and liquefied natural gas (LNG). The fluids mentioned above place different demands, known to those skilled in the art, on the materials that can be used in each case. The decisive fire protection effect of the multi-layered fire protection layer proposed here is advantageous for all metallic materials of the above-mentioned pipelines, such as aluminium, copper, brass, titanium, nickel, tungsten, and / or alloys thereof, as well as for stainless steel. According to one embodiment, a manufacturing process for a fire-resistant layer and / or a fire-resistant mat is proposed. The manufacturing process comprises the following steps: 1) providing a first stack of alternating polymer film layers, which can be characterized as combustible reflector layers; and glass fiber-containing layers, which can be characterized as non-combustible transmissive layers or as combustible spacer layers; 2) placing a stainless steel foil on an outer layer of the glass fiber-containing layers of the first stack; 3) providing and arranging a second stack of alternating polymer film layers and glass fiber-containing layers; and optionally fixing the arranged first stack, the steel foil arranged thereon, and the second stack, as well as optionally further steel foils and stacks to one another, by means of a fixing agent.The fixing agent is selected from among: an adhesive, a stapling thread, a tack seam, a stitch, a braid, and / or a crimp. The choice of fixing agent can depend on the total number of stacks arranged one above the other and the number of stainless steel foils arranged between them. Advantageously, all layers or foils of the stacks have the same or substantially the same dimensions and outer contours. This facilitates their fixation to one another, forming a fire-resistant mat. A plurality of fire-resistant mats, preferably comprising approximately the same total number of layers or foils, can, when arranged appropriately side by side or in an at least partially overlapping arrangement, form a closed insulating layer that substantially completely covers the inner wall (liner) of a cryogenic tank.If the described layers and stainless steel foils arranged between them are placed on the inner wall of the container and subsequently covered with an outer wall that seals fluidically to the inner wall, creating a double wall of the container whose interior can also be evacuated, then a cryogenic tank is ultimately provided which, compared to a previously known cryogenic tank, is characterized by very good processability, very good thermal insulation performance and a heat flow reduced by a factor of 4 to 7 in the event of a fire. The features of the embodiments described above can be combined in any way desired. DETAILED CHARACTER DESCRIPTION Before the embodiments are explained in more detail below with reference to the figures, it should be noted that identical elements in the figures are designated with the same or similar reference numerals and that a repeated description of these elements is omitted. Furthermore, the figures are not necessarily to scale; rather, the focus is on explaining the basic structure of the fire-resistant layer disclosed herein, a double wall of a tank or cryogenic container comprising such a layer, and the corresponding tank or cryogenic container, and a fluidic connection for conveying a liquefied gas or liquefied gas mixture, for example, a pipeline / cryogenic conduit (not shown) connected or connectable to a cryogenic tank, which is surrounded or insulated by the fire-resistant layer disclosed herein. Fig. 1 schematically illustrates in A an embodiment of the arrangement of alternately stacked layers 50, comprising optically opaque metal-coated polymer films 10 and optically transparent glass fiber layers 20, for example, a glass fiber fleece 20. The layer stacks 50 formed by the alternately arranged metal-coated films 10 and the glass fiber layers 20 are enclosed by sheets, in particular sheets arranged substantially parallel to one another, which form an evacuable cavity of the double wall 100 in the form of an inner wall 30 and an outer wall 40. The materials of the inner wall 30 and the outer wall 40 are particularly adapted to the respective fluid stored in the tank 1000. The cavity contains at least two layer stacks 50. The individual layers 10, 20 of the layer stacks 50 are typically arranged parallel to the metallic walls 30, 40 of the double wall 100 of the cryogenic tank 1000.Thus, the double wall 100 forms the cryogen container 1000. The cryogen container 1000 has a usable volume 2, 2a, which is adapted to hold the cryogenic or cold fluid. The designation “+vacuum” shown in the schematic Figs. 1A and 1B refers to the vacuum, preferably a high vacuum, created by evacuation in the double wall. Fig. 1 schematically illustrates in B, with all other reference numerals the same, the state of the reflective layers of the fire-induced layer stack 50' located near the outside of the tank in the case of fire, which are pyrolyzed in this way. Solid residues 60 and pyrolysis gases 70 are produced by the thermal decomposition of the polymers. The solid residues 60 collect and agglomerate with the glass fiber layers 20, thus forming a heat-radiation-blocking layer 80. This heat-radiation-blocking layer 80 and the steel foil 15 remain stable during the further course of the fire and protect the foils 10, 20 located between it and the inner wall of the double wall 30 from thermal degradation, so that the stack 50 formed by them remains unchanged. Fig. 2 schematically shows the structure of a tank 1000, cryotank 1000, or cryogen tank 1000 containing a cryogenic fluid 2, 2a. The cryogenic fluid 2, 2a essentially comprises two phases: the liquid phase 2 and a gas phase 2a above it. The cryogen tank 1000 is filled via a closable opening 200, which is located near a fixed bearing 200. The tank 1000 comprises a usable volume 2, 2a directly enclosed by the inner wall 30. The inner wall 30, as well as the outer wall 40, which forms a cavity with it, are typically made of a sheet, for example, steel, aluminum, titanium, or an alloy containing these materials. The fire-resistant layer 1 is arranged in the designated cavity. Opposite the lockable opening 200 and the corresponding hemisphere is a loose bearing 400. The level indicator shows that the filled tank contains a liquid and a gas phase. In a vertical design of the cryogenic tank (not shown), the loose bearing 400 is typically not required. At the location of the fixed bearing 200, a fluidic connection is arranged through the double wall of the cryogenic tank 1000, which can be closed by a suitable valve. Elsewhere, at least one additional fluidic connection (not shown) is provided, penetrating the double wall and opening into the usable volume of the tank. This connection is sealed to the outside by a safety valve (not shown). The opening pressure of the safety valve corresponds to the operating pressure of the tank 1000, i.e., the pressure of the cryogenic tank 1000 filled with cryogenic fluid 2, 2a. In a cryogenic tank 1000, the fluid 2, 2a is always stored below ambient temperature, so energy from the environment constantly flows into the fluid 2, 2a, and its pressure in the usable volume steadily increases.Under normal operating conditions, the pressure increase can be countered by reliquefaction or extraction of the gas phase, e.g., as fuel. In the event of a fire, high heat flux densities via the thermal insulation in the double wall 1 can lead to exceptionally high pressure rise rates, which are due to non-homogeneous heating of the stored fluid. [Otremba et al., 2018]. Figure 3 shows in A the assumed "temperature-time profile of the fire load" for a fire with successful fire suppression, according to the so-called ZTV-Ing curve [ZTV-ING - Part 7]. This is based on a full fire phase (until extinguishing) of 25 minutes 5 minutes after ignition. The temperature profile shown in Fig. 3(B) takes into account a fire in a tunnel [Haack, 1998], which can be considered an exemplary critical infrastructure for a cryogenic tank. The temperature profile during a fire in a tunnel most closely approximates the relevant case here, i.e., the effect of a fire on a cryogenic tank located in a tunnel. In particular, Fig. 3(B) shows, according to a practical embodiment, the heat flow over time for the inventive multilayer insulation consisting of combustible and non-combustible layers and a stainless steel foil (solid line), a multilayer insulation characterized as completely combustible (dashed line), and a multilayer insulation characterized as completely non-combustible (dash-dot line), taking into account the fire scenario shown in Fig. 3(A) according to ZTV-Ing.The inventive design of the multilayer insulation reduces the potential heat flow in such a fire scenario by a factor of 4 to 7, resulting in a reduction of the boil-off by a factor of 4 to 70. In the assumed fire scenario according to ZTV-Ing (see Fig. 3A), the flame temperature rises from 15°C to a maximum temperature of 1200°C within 5 minutes. This is followed by the full-scale fire phase, in which the maximum temperature is maintained for 25 minutes. The cooling phase then follows, in which the temperature drops linearly to 15°C within 110 minutes. For the calculation of the heat transfer from the flame to the tank with the multi-layer insulation, a heat transfer coefficient of 10 Wm-2K-1 was assumed to take convection into account, and an emissivity of the flame of 1 and an emissivity of 0.5 for the tank surface were assumed to take thermal radiation into account. It is evident that a fire protection layer according to the structure proposed here, comprising a non-combustible glass fiber material such as glass fiber fleece, combined with combustible double-sided aluminium-coated polymer films and a steel foil, results in the lowest heat flux (kW / m2) over the entire period under consideration (solid line), while the previously known MLI consisting solely of non-combustible films (dash-dot line) results in a medium heat flux (kW / m2) and previously known MLI consisting solely of combustible films (dashed line) results in the highest heat flux (kW / m2). In this context, fire protection means that the maximum and typical heat flow from the environment into the stored fluid is significantly reduced in a fire scenario compared to conventional thermal insulation systems. Fig. 4 schematically shows the layer structure of a fire-resistant layer 1 in the form of a fire-resistant mat 500. The fire-resistant mat 500 shown here comprises two stacks 50 of alternately arranged reflector layers 10 (aluminum-coated polymer films 10) and layers 20 containing or consisting of glass fibers, which serve as transmissive spacers 20 between the reflector films 10 and a stainless steel foil 15 arranged symmetrically between the two stacks 50. The schematic does not show how the layers are fixed to one another. Naturally, a fire-resistant mat can have more than one stainless steel foil 15, for example, one or two additional stainless steel foils 15 and, accordingly, one or two additional layer stacks 50. EXAMPLE OF EXECUTION The various embodiments and aspects of the present invention, as described above and claimed in the claims, are illustrated by example by the following example, which is intended to illustrate, but not to limit, the invention. According to the practical embodiment, the temperature profile during a 30-minute tunnel fire is shown in Fig. 3(A), and its influence on the heat flow in kW / m² emanating from a double-walled cryogenic tank 1000 is shown in Fig. 3(B). The double-walled cryogenic tank 1000, insulated with a fire-resistant layer 1 described herein, is shown in Fig. 2. The fire-resistant layer 1 is arranged within the double wall 100 formed by the inner wall 30 and outer wall 40 of the tank, in which a high vacuum is maintained. Within this fire-resistant layer 1, a stainless steel foil 15 is arranged symmetrically between 40 pairs of reflector and spacer layers 10, 20. Directly adjacent to this stainless steel foil 15, which has a thickness of 0.05 mm, a layer of glass fleece is arranged on both sides as a transmissive layer 20.The reflective layers 10 of the fire protection layer 1 consist of 15 alternating stacks of identical layers (20 pairs) of double-sided aluminium-coated polyester films (Mylar®) with a thickness of 12 µm and layers of glass fleece arranged on both sides of the stainless steel foil. SUMMARY Essential aspects of the embodiments and exemplary embodiments described above can alternatively and additionally be described in other words as follows: 1. Providing a multi-layer insulation for the thermal insulation of a cryogenic tank or a cryogenic pipeline, or providing an insulating layer for the space-saving and explosion-preventing storage of cryogenic fluids in tanks under conditions of fire, for example, a pool fire or a jet fire in the immediate vicinity of the tank; 2. The proposed tanks for storing cryogenic fluids comprise a double wall in whose cavity, evacuated to a high vacuum, the described foil system is located; 3.The proposed multilayer insulation is characterized in that it comprises metal-coated plastic films, glass fiber films or glass fiber fleece, and at least one stainless steel film in the form of a layer stack, wherein the at least one stainless steel film and the metal-coated plastic films are each separated from each other by the glass fiber films or glass fiber fleece; 4. As an alternative to glass fiber films or a glass fiber fleece, one or more films comprising a composite of metal-coated plastic film and glass fibers embedded in this plastic can also be used in the layer stack; 5. The structure of the fire protection layer described here and its production are intended for use in a cryogenic tank or in a fluidic connection with a cryogenic tank. The fire-resistant layer protects the inner tank of the cryogenic tank, which contains the cryogenic fluid, and the connection containing or carrying this fluid from impermissible heating in the event of a fire. The temperature load on the cryogenic tank under consideration, insulated with the fire-resistant layer, and on the correspondingly thermally insulated fluidic connection to it, is determined by the ZTV-Ing curve [see ZTV-Ing - Part 7], which represents an assumed temperature profile during a tunnel fire [Haack, 1998]. The multi-layer insulation proposed here, in conjunction with the evacuated cladding (double wall), is characterized by the fact that the enclosed usable volume is thermally insulated for a fire load (heat flow) of 50–100 kW / m² to such an extent that even in a relevant fire scenario, the achieved thermal insulation and the mechanical protection provided by the metallic double wall do not fail, and the cryogenic fluid contained in the usable volume reliably prevents the tank from bursting. In particular, the proposed fire-resistant layer degrades in the vacuum of the wall enclosed by the double wall in such a way that the cryogenic tank is gradually brought to a still safe state during external fire exposure.Furthermore, the foil system, with a small amount of foil relative to the total insulation thickness, provides very good thermal insulation, is very easy and efficient to process, is cost-effective in relation to the materials used, and is therefore well suited overall for a cryogenic tank, for example for the storage and transport of liquefied gases, especially liquefied hydrogen and oxygen, as well as liquefied natural gas. According to the proposed embodiments, the advantages of previously separate combustible and non-combustible foil systems are realized, while their respective disadvantages are mitigated. The additional use of one or more stainless steel foils in the layer stack of the novel MLI effectively creates compartments within the multilayer structure, thereby reducing the temperature stress occurring in the event of a fire. The proposed structure thus acts as a fire-resistant layer and is accordingly referred to as such here. Regarding the storage of liquid hydrogen, with the same number of foils, the addition of at least one steel foil allows for the production of thermally and mechanically improved insulation. Similarly, the proposed multilayer insulation enables the production of thinner insulation structures while maintaining the same thermal stability requirements during relevant fire scenarios. The latter increases the payload of the cryogenic tank in a technically regulated or generally limited installation space. With regard to the storage of LH2, the quality and process reliability in the manufacturing of the fire-resistant layer and the corresponding cryogenic tank are increased, while production time and thus manufacturing costs of the cryogenic tank are reduced. Overall, the safety of tanks for cryogenic fluids is significantly enhanced, ensuring the acceptance of cryogenic tanks equipped with the fire-resistant layer and fluidic connections insulated with it by industrial, commercial, and private users. This makes the fire-resistant layer advantageous compared to known multi-layer insulations for the safety of the tank as well as for the safety of people and structures. Furthermore, other safety-relevant systems, such as rupture discs or safety valves located within the cryogenic tank's installation space, can be made smaller. This increases the cryogenic tank's payload capacity in situations with technically regulated or generally limited installation space. All aspects mentioned here for increasing the payload enable, for embodiments of the cryogenic tank as a fuel tank for a gas-powered vehicle, an increase in the vehicle's range with one tankful and are beneficial for the user. Although specific embodiments have been presented and described herein, it is within the scope of the present invention to modify the illustrated embodiments appropriately without deviating from the scope of protection of the present invention. The following claims represent a first, non-binding attempt to define the invention in general terms. References [Bey24] Beyond Gravity, Cryogenic Insulation Products, Vienna; 01 / 2023; https: / / www.beyondgravity.com / sites / default / files / media_document / 2024-02 / Beyond-Gravity-Cryogenic-Insulation-Products_Coolcat_Superinsulation_cryo_ruag%20space.pdf; Accessed December 2024 .[Cav89] Cavallari, et al., 1989, Pressure Protection Against Vacuum Failures on the Cryostats for Lep SC Cavities, Proc. 4th Workshop on RF Superconductivity, pp. 781-803 Tsukuba, Japan [Ebe21] Eberwein, Robert (2021), Investigation of the hazard to persons and structures as a result of the failure of LNG fuel storage systems for vehicles in tunnels, Dissertation, Technical University of Berlin [Ebe23] Eberwein, R., Hajhariri, A., Camplese, D., Emrys Scarponi, G., Cozzani, V., & Otremba, F. (2023). Insulation materials used in tanks for the storage of cryogenic fluids in fire scenarios. In Pressure Vessels and Piping Conference July 16-21, 2023, Atlanta, USA (Vol. 87493, p.V006T07A019, Proceedings of American Society of Mechanical Engineers ).[Ebe24a] Eberwein, R., Hajhariri, A., Camplese, D., Emrys Scarponi, G., Cozzani, V., & Otremba, F. (2024), Experimental Investigation on the Behavior of Thermal Super Insulation Materials for Cryogenic Storage Tanks in Fire Incidents, Process Safety and Environmental Protection, Volume 187, 240-248 .[Ebe24b] Eberwein et al., 2024, Experimental Research Of A Tank For A Cryogenic Fluid With A Wall Rupture In A Fire Scenario, 15th ISHPMIE, Napoli, 10-14 Juni 2024 .[Haack, 1998] Haack, Alfred Fire Protection in Traffic Tunnels: General Aspects and Results of the EUREKA Project. Tunneling and Underground Space Technology, 13(4): 377-381[Mit06] Mital, Subodh K., et al. (2006) Review of current state of the art and key design issues with potential solutions for liquid hydrogen cryogenic storage tank structures for aircraft applications, NASA / TM-2006-214346[Otremba et al., 2018] Otremba, F., Bradley, I., Navarrete, J.A.R.(2018) Boiling Thermohydraulics within Pressurized Vessels, Proceedings of the World Congress on Engineering and Computer Science, October 23-25, San Francisco, USA, (WCECS) Vol II ISBN: 978-988-14049-0-9; ISSN: 2078-0958 (Print); ISSN: 2078-0966 (Online) [ZTV-Ing] Additional Technical Contractual Conditions and Guidelines for Engineering Structures; ZTV-ING, December 2023; Published by: Federal Ministry for Digital Affairs and Transport; Part 7, Tunnel Construction - Section Closed Construction Method; according to https: / / www.bast.de / DE / Publikationen / Regelwerke / Ingenieurbau / Baudurchfuehrung / ZTV-ING-Gesamtfassung.pdf; accessed February 2025. REFERENCE MARK 1 Fire protection layer 2 Usable volume, possibly containing liquid phase of the cryogenic fluid 2a Usable volume, possibly containing gas phase of the cryogenic fluid 10 Reflective foil, metal-coated polymer foil, combustible layer 15 Stainless steel foil 20 Transmissive foil, glass fiber-reinforced layer as a spacer, non-combustible 30 Inner wall of container 40 Outer wall of container 50 Stack of layers, stack of stacked layers 10, 20 50' Thermally modified stack 60 Solid (pyrolysis) residues 70 Gases formed by pyrolysis 80 Thermal radiation-blocking layer, after thermal conversion of the stack 100 Double wall of container (section) 100' Thermally modified double wall (section) 200 Fixed bearing (B), comprising a closable opening 300 Movable bearing (A) 500 Mat, blanket 1000 Cryogen tank, cryotank

Claims

Fire protection mat (500) comprising a fire protection layer (1) wherein the fire protection layer (1) comprises a multilayer structure having the following: • a first stack (50) comprising alternatingly arranged: - polymer film layers (10) and - glass fiber layers (20); and • a second stack (50) comprising alternatingly arranged: - polymer film layers (10) and - glass fiber layers (20); and • a steel foil (15) wherein the polymer film layers (10) are metallically coated on both sides, and the steel foil (15) is arranged between the first stack (50) and the second stack (50), wherein the first stack (50) is connected to the second stack (50) by a fixing agent, and wherein the fixing agent forms a crimp or pin fastening extending at least partially along an outer contour of the fire protection mat (500). Fire protection mat (500) according to claim 1, wherein the steel foil (15) is surrounded on both sides by layers (20) comprising glass fibers. Fire protection mat (500) according to one of the preceding claims, wherein the metallic coating on both sides of the polymer film layers (10) has aluminum on at least one side. Fire protection mat (500) according to one of the preceding claims, wherein the fire protection layer (1) comprises layers (20) comprising at least 10 glass fibers. Fire protection mat (500) according to one of the preceding claims, wherein the stainless steel foil (15) is arranged symmetrically in the multilayer structure, such that first stacks (50), the second stack (50) and optionally further stacks (50) have an identical number of polymer film layers (10) and glass fiber-comprising layers (20). Fire protection mat (500) according to one of the preceding claims, wherein the glass fiber-comprising layers (20) are selected from the group consisting of: a glass fiber fleece, a glass paper, a polymer-reinforced glass fiber fleece, a mineral fiber fleece, and a silicate fiber fleece. Fire protection mat (500) according to one of the preceding claims, wherein a thickness of the stainless steel foil (15) is selected below: 0.01 mm - 0.5 mm; 0.05 mm - 0.5 mm; ≤ 0.2 mm; and 0.01 mm to 0.1 mm. Fire protection mat (500) according to one of the preceding claims, comprising: 10 - 40, preferably 15 - 30 polymer films (10) coated on both sides with aluminium; 12 - 61, preferably 18 - 41 layers (20) comprising glass fibers; and 1 - 20, preferably 1 - 10 stainless steel foils (15), wherein the glass fiber-comprising layers (20) are arranged between the polymer films (10) coated on both sides with aluminium and the stainless steel foil(s) (15), and wherein the glass fiber-comprising layers (20) enclose the multilayer structure on both sides. Fireproof tank (1000) designed for the storage and / or transport of compressed and / or liquefied gases or gas mixtures, comprising a fire protection mat (500) enclosed by a double wall (100) according to one of claims 1 to 8, wherein an inner wall (30) and an outer wall (40) of the double wall (100) each adjoin opposite sides of the fire protection mat (500) and enclose a usable volume (2, 2a) of the tank (1000). Fireproof tank (1000) according to claim 9, wherein the double wall (100), in the interior of which the fire protection mat (500) is arranged, is evacuated. Fireproof tank (1000) according to claim 9 or 10, wherein the double wall (100) has a substantially hemispherical shape on two opposite sides. Refractory tank (1000) according to claim 11, wherein one of the two opposite sides has a fixed bearing (200) comprising a lockable opening of a fluidic connection to a usable volume (2) of the refractory tank (1000). Pipeline configured for transporting a cryogenic fluid (2, 2a), comprising a fire protection mat (500) according to any one of the preceding claims 1 to 8, wherein the pipeline is completely enclosed by the fire protection mat (500), and wherein the cryogenic fluid (2, 2a) is selected from: LAr, LCO2, LH2, LHe, LN2, LO2, LNG. A manufacturing method for the fire protection mat (500) according to any one of claims 1 to 8, comprising: • providing the first stack (50) of alternatingly arranged polymer film layers (10) and glass fiber layers (20); • arranging the steel foil (15) on one of the glass fiber-comprising layers of the first stack (50); • providing the second stack (50) of alternatingly arranged polymer film layers (10) and glass fiber-comprising layers (20); wherein the second stack (50) is arranged on the steel foil (15); and • fixing the first stack (50), the steel foil (15), and the second stack (50) to each other at least sectionally along the outer contour of the fire protection mat (500) by means of a crimp or a stapling with pins and forming the fire protection mat (500) comprising the fire protection layer (1) according to any one of claims 1 to 8.

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