Support structures for multilayer insulation systems

Abstract

Embodiments described herein relate to assemblies including support structures in MLI systems. An assembly can include a first layer of low-emissivity material and a second layer of low-emissivity material disposed outside of the first layer, such that a gap is formed between the first layer and the second layer. The assembly further includes a spacer disposed between the first layer and the second layer. The spacer maintains a spacing between the first layer and the second layer while minimizing heat conduction between the first layer and the second layer.

Description

SUPPORT STRUCTURES FOR MULTILAYER INSULATION SYSTEMSCross-Reference to Related Applications

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 571,121, filed on March 28, 2024, entitled, “SUPPORT STRUCTURES FOR MULTILAYER INSULATION SYSTEMS, AND METHODS OF PRODUCING THE SAME,” the disclosure of which is incorporated by reference herein in its entirety.Statement of Government Support

[0002] This invention was made with government support under grant no. DE-AR0001575 awarded by the U.S. Department of Energy. The government has certain rights in the invention.Technical Field

[0003] Embodiments described herein relate to discrete spacers included in multilayer insulation systems.Background

[0004] Multilayer Insulation (MLI) is a type of thermal insulation that consists of multiple layers of thin sheets and is commonly utilized in vacuum spaces, particularly in systems such as spacecraft, satellites, and cryogenic storage where thermal control is critical. Despite its widespread use, MLI’s performance may be limited by contact and heat conduction across material layers. These issues can be attributed to the inherent design and assembly of the typical MLI, where layers are in close proximity. Ensuring separation between the layers and minimizing conduction area while maintaining significant conduction length enhances the insulation’s effectiveness.Summary

[0005] Embodiments described herein relate to assemblies including support structures in MLI systems. Specifically, embodiments described herein relate to discrete spacers configuredto completely isolate layers in a multilayer insulation system. This design minimizes thermal conduction and enables accurate computation of heat loss through the insulation.

[0006] An assembly can include a first layer of low-emissivity (e.g., reflective) material and a second layer of low-emissivity material disposed outside of the first layer, such that a gap is formed between the first layer and the second layer. The assembly further includes a spacer disposed between the first layer and the second layer. The spacer maintains a spacing between the first layer and the second layer while minimizing heat conduction between the first layer and the second layer. In some embodiments, the assembly can further include an insulated material disposed inside the first layer. In some embodiments, the spacer is a first spacer and the gap is a first gap and the assembly further includes a third layer of low-emissivity material disposed outside of the second layer of low-emissivity material, such that a second gap is formed between the second layer of low-emissivity material and the third layer of low- emissivity material. In such embodiments, the assembly includes a second spacer disposed between the second layer of low-emissivity material and the third layer of low-emissivity material, the second spacer configured to maintain a spacing between the second layer of low- emissivity material and the third layer of low-emissivity material and minimize heat conduction between the second layer of low-emissivity material and the third layer of low-emissivity material.

[0007] In some embodiments, the spacer can include a plurality of strips of stiff material extending from a first radial location on an interior surface of the second layer to a second radial location on the interior surface of the second layer, such that each strip from the plurality of strips contacts an outside surface of the first layer of low-emissivity material.Brief Description of the Drawings

[0008] FIG. l is a block diagram of a MLI assembly, according to an embodiment.

[0009] FIGS. 2A-2B are illustrations of layers of low emissivity material with support structures, according to an embodiment.

[0010] FIG. 3 is an illustration of layers of low-emissivity material with support structures, according to an embodiment.

[0011] FIG. 4 is an illustration of layers of low-emissivity material with a support structure, according to an embodiment.

[0012] FIGS. 5A-5B are illustrations of layers of low-emissivity material with support structures, according to an embodiment.|0013] FIG. 6 is an illustration of a spacer, according to an embodiment.

[0014] FIG. 7 shows a longitudinal cross section of layers of low-emissivity material with support structures, according to an embodiment.

[0015] FIG. 8 shows a longitudinal cross section of layers of low-emissivity material with support structures, according to an embodiment.

[0016] FIG. 9 is a cross-sectional view of a segment of an MLI assembly, according to an embodiment.

[0017] FIG. 10 is an illustration of helix-shaped spacers with various form factors, according to various embodiments.

[0018] FIG. 11 is an illustration of a method of applying a helix-shaped spacer, according to an embodiment.Detailed Description

[0019] Embodiments described herein relate to support structures for multilayer insulation systems. Often in MLI systems, the MLI has unpredictable heat losses because of erratic or unpredictable contact between layers as well as conduction through insulative material placed between the MLI layers. Formation of discrete spacers that fully separate layers enables reduction of thermal conduction and accurate calculation of heat loss via insulation. In common MLI systems, thin layers of aluminized mylar have been utilized. These designs can include 30-50 layers to meet the required standards for proper insulation. This can be expensive from a material cost perspective. Additionally, such designs can lead to a large span of heat leak values. This design also has a decaying return from additional insulation layers. In other words, the additional energy savings recedes quickly after just a few layers. By designing distinct spacers to completely isolate low-emissivity layers, thermal conduction can be effectively diminished. Additionally, these spacers allow for a reduction in layer count, which is an added benefit. Consequently, this design enables a more precise estimation and modeling of heat loss through insulation.

[0020] The MLI systems including distinct spacers, as described in multiple embodiments herein, are engineered to maintain a stable temperature within their interior volume, regardlessof the conditions in the ambient or external environment. Specifically, these MLI systems can be employed to mitigate heat loss from a thermally insulated material (e.g., a material located within the MLI’s interior volume or enveloped by the MLI) to a colder environment, or to prevent excessive heating of the thermally insulated material due to a warmer external environment.

[0021] The MLI systems, as described herein, are versatile and can be utilized in numerous applications where maintaining a stable temperature is critical. These include spacecraft, launch vehicles, satellites, and electric vehicles. They are also beneficial in renewable energy and energy storage systems, as well as in measurement devices like calorimeters that require precise temperature control. Furthermore, these systems can be integrated into transportation and storage systems for cryogenics, food, fuel, and beverages. They may also find use in conjunction with thermal sources such as furnaces and / or steam pipes. The MLI systems can be used in vacuum jacket systems. The MLI systems can also be utilized in indoor applications to maintain stable temperatures for desired equipment and / or cabling. For example, they can be employed in indoor environments requiring consistent temperature control, such as laboratories, medical facilities, and manufacturing plants. The MLI systems described herein can be used in indoor energy storage systems, maintaining the desired operational temperatures. These systems can also be suitable for use in advanced computing environments (e.g., data centers) that require thermal stability for high-performance processors and storage systems.

[0022] Embodiments described herein can also be incorporated into power transmission lines (e.g., overhead transmission lines or underground transmission lines with superconductors), wherein heat management is important. For example, the MLI systems of present technology can be integrated into transmission lines including superconductors that need to be kept at low temperatures (e.g., by flowing a cryogenic fluid alongside the superconductor material). Conventional MLI systems often include mesh layers. Embodiments described herein include layers of low-emissivity material that are separated by discrete spacers without a mesh layer. Such an assembly can significantly reduce the conduction between adjacent layers of low-emissivity MLI and may reduce or eliminate the possibility of contact across the low-emissivity layers of MLI. This is accomplished by eliminating thick layers of insulative material and instead separating low-emissivity layers using discrete spacers. In some embodiments, the spacers described herein can reduce conduction between layers via the use of wires, helical coils, fibers, cables, straight pins, strips, strings, or springs (e.g., compressionor tension springs) to support and separate the layers. In some embodiments, the spacers include tensioned members such as tensioned springs, tensioned wires or tensioned cables.

[0023] Embodiments described herein related to MLI systems with discrete spacers may provide one or more benefits including, for example: (1) a decrease in heat leak, thereby improving the overall efficiency of the system; (2) a highly predictable heat loss, enabling better control and management of the system; (3) a reduction in the number of layers of low- emissivity MLI, simplifying the structure and potentially reducing costs; (4) an elimination of the need for multiple spacer layers, leading to a more compact design; (5) an ability to optimize specific geometric constraints, providing flexibility in various applications. These advantages present a significant improvement over traditional MLI systems.

[0024] Rigidity of the layers of the MLI can enable discrete spacers. Rigidity of layers can provide structural support to the MLI design and can be designed to optimize specific geometric constraints. Rigid or stiff MLI layers can be rolled from thin sheet metal, manufactured out of extruded tubes, and / or printed out of plastic. In some embodiments, the MLI layers can include a coating disposed thereon to reduce emissivity. In some embodiments, support can be directly attached to outer layers. In some embodiments, support can act radially outward from the inner layers.

[0025] The spacers such as wires, fibers, cables and / or springs can provide a highly efficient structure for carrying structural load to support layers of a structure and keep them spaced apart from one another. This can greatly reduce the cross-sectional area by which heat can be conducted across layers. The spacers can also provide a relatively long path, along which heat is conducted. This further reduces the overall thermal conduction from one layer to another. In some embodiments, the spacers can include at least one of helically wound coils or tensioned helically wound springs, which serve to increase the overall length of the path for heat to be conducted across. Lastly, the low-emissivity layers of MLI can be self-supporting between spacers. This enables the spacers to be located with a low density or periodicity, further reducing the overall heat transfer between layers.

[0026] Such a system can be manufactured in several ways. For example, thin slots, holes or apertures can be cut into outer layers of MLI, on which wires, fibers, cables, coils, strings, and / or springs can be placed or wrapped. The spacers may be directly attached to inner layers. In some embodiments, the spacers may not be attached directly attached to the inner layers, and can instead support the inner layers as a cradle. In the absence of a mesh spacer layerbetween layers of an MLI system, the heat conduction path between layers can be more accurately predicted or modeled. The performance of such a system can be characterized with great efficiency.

[0027] All combinations of the foregoing concepts and additional concepts discussed herein (provided such concepts are not mutually inconsistent) are contemplated as being part of the subject matter disclosed herein. The terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.

[0028] The drawings are primarily for illustrative purposes, and are not intended to limit the scope of the subject matter described herein. The drawings are not necessarily to scale; in some instances, various aspects of the subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate an understanding of different features. In the drawings, like reference characters generally refer to like features (e.g., functionally similar and / or structurally similar elements).

[0029] The entirety of this application (including the Cover Page, Title, Headings, Background, Summary, Brief Description of the Drawings, Detailed Description, Embodiments, Abstract, Figures, Appendices, and otherwise) shows, by way of illustration, various embodiments in which the embodiments may be practiced. The advantages and features of the application are of a representative sample of embodiments only, and are not exhaustive and / or exclusive. Rather, they are presented to assist in understanding and teach the embodiments, and are not representative of all embodiments. As such, certain aspects of the disclosure have not been discussed herein. That alternate embodiments may not have been presented for a specific portion of the innovations or that further undescribed alternate embodiments may be available for a portion is not to be considered to exclude such alternate embodiments from the scope of the disclosure. It will be appreciated that many of those undescribed embodiments incorporate the same principles of the innovations and others are equivalent. Thus, it is to be understood that other embodiments may be utilized and functional, logical, operational, organizational, structural and / or topological modifications may be made without departing from the scope and / or spirit of the disclosure. As such, all examples and / or embodiments are deemed to be non-limiting throughout this disclosure.

[0030] Also, no inference should be drawn regarding those embodiments discussed herein relative to those not discussed herein other than it is as such for purposes of reducing space andrepetition. For instance, it is to be understood that the logical and / or topological structure of any combination of any program components (a component collection), other components and / or any present feature sets as described in the figures and / or throughout are not limited to a fixed operating order and / or arrangement, but rather, any disclosed order is exemplary and all equivalents, regardless of order, are contemplated by the disclosure.

[0031] The term “determining” encompasses a wide variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Also, “determining” can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and the like. Also, “determining” can include resolving, selecting, choosing, establishing and the like.

[0032] The phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” describes both “based only on” and “based at least on.”

[0033] FIG. 1 is a block diagram of a MLI assembly 100, according to an embodiment. As shown, the MLI assembly 100 includes an internal layer 110 (i.e., a first layer), an external layer 120 (i.e., a second layer) disposed outside of the internal layer 110 such that a gap (e.g., annular or non-annular space) is formed between the internal layer 110 and the external layer 120. The MLI assembly 100 further includes a spacer 130 disposed between the internal layer 110 and the external layer 120. In some embodiments, the MLI assembly 100 may further include a former 114 disposed inside the internal layer 110, wherein the former 114 defines a shape (e.g., a tube). In some embodiments, the MLI assembly 100 may further include a thermally insulated material (e.g., a cryogen) disposed inside the internal layer 110. In some embodiments, the MLI assembly 100 may further include a coolant flow space 112 within the internal layer 110. That is, the internal layer 110 encloses the thermally insulated material, which flows through the coolant flow space 112.

[0034] In some embodiments, the gap between the internal layer 110 and the external layer 120 is under vacuum. As used herein, the term “under vacuum” refers to a pressure lower than the atmospheric pressure. In some embodiments, under vacuum refers to a pressure of no more than 500 Torr, no more than 100 Torr, no more than 50 Torr, no more than 10 Torr, or no more than 1 Torr. In some embodiments, under vacuum refers to a pressure at about 0 Torr.

[0035] In some embodiments, the gap between the internal layer 110 and the external layer 120 can include a gas. In some embodiments, the gas can include an inert gas (e.g., argon, nitrogen, neon, helium, krypton, or any combination thereof). In some embodiments, the gap between the internal layer 110 and the external layer 120 can include a liquid (e.g., water or a non-aqueous liquid).

[0036] In some embodiments, the MLI assembly 100 may further include a former 114 disposed inside the internal layer 110, the former 114 defining a shape, and an insulated material 116 (e.g., a cryogen) disposed around the former 114. In some embodiments, an electrically conductive layer (not shown) can be disposed around the former 114. A coolant flow space 112 is formed between the internal layer 110 and the former 114. In some embodiments, the insulated material 116 can be disposed around the former 114 in a coolant flow space 112.

[0037] The MLI assembly 100 can be formed into any shape (e.g., clamshell, cylindrical, cuboid etc.) suitable for intended purpose. In some embodiments, the MLI assembly 100 can be conformable. That is, shape of the MLI assembly 100 could be changed depending on where it is used. In some embodiments, the MLI assembly 100 can be in the form of a blanket. In some embodiments, the internal layer 110 and / or the external layer 120 may be formed in a tube shape.

[0038] In some embodiments, the internal layer 110 includes a first low-emissivity material and the external layer 120 includes a second low-emissivity material. In some embodiments, the first low-emissivity material and the second low-emissivity material may be same or substantially similar to each other (e.g., in terms of chemical composition, thickness, etc.) or may be different from each other (e.g., formed from different materials having different thicknesses, different tensile strengths, different optical and / or electromagnetic properties etc.). In some embodiments, the first low-emissivity material has the same chemical composition as that of the second low-emissivity material. In some embodiments, the first low-emissivity material has a chemical composition different from that of the second low-emissivity material. In some embodiments, the first low-emissivity material has the same thickness as that of the second low-emissivity material.

[0039] In some embodiments, the internal layer 110 and / or the external layer 120 may include a reflective material independently selected from the group of aluminum, silver, copper, gold, platinum, indium, nickel, chromium, zinc, tin, and alloys, such as Nichrome. In someembodiments, the low-emissivity material may be in the form of a thin film or a thin layer. In some embodiments, the low-emissivity material is a metallized thermoplastic material (i.e., a thermoplastic material that is coated with a thin layer of metal). In some embodiments, the thermoplastic material can include low density polyethylene, linear low density polyethylene, polypropylene, a nylon, and / or PVC. In some embodiments, the low-emissivity material may be disposed on a surface (e.g., an outer surface) of the internal layer 110 and / or the external layer 120 in the form of a thin film or a thin layer. In some embodiments, the internal layer 110 and / or the external layer 120 may be formed of a low-emissivity material.

[0040] The low-emissivity material may aid reducing energy absorption and emissivity at thermal wavelengths. The low-emissivity material can reduce absorption of thermal energy from the surrounding environment (when trying to keep the thermally insulated material inside the MLI cold) or reduce absorption of thermal energy from the thermally insulated material (when trying to keep the thermally insulated material warm), and the low-emissivity material can increase radiative emission from the internal layer 110 and / or the external layer 120, thereby allowing the MLI assembly 100 to operate cooler, or conduct a larger amount of current (i.e., have a greater ampacity) at the same environmental temperature. In some embodiments, the low-emissivity material can be selected such that it can protect the thermally insulated material 116 from heat during operation of the MLI assembly 100.[00411 In some embodiments, the low-emissivity material can also act as thermal insulation between the external layer 120 and the internal layer 110. In some embodiments, the low- emissivity material can reduce or limit the amount of ambient heat that reaches the coolant flow space 112.

[0042] In some embodiments, the internal layer 110 and / or the external layer 120 may include one or more reflective additives. Such reflective additives may include, but are not limited to cobalt, aluminum, bismuth, lanthanum, lithium, magnesium, neodymium, niobium, vanadium, ferrous, chromium, zinc, titanium, manganese, and nickel-based metal oxides and ceramics. The reflective additives may be included at a concentration of about 0.1% to about 30%, inclusive (by weight of the total dry composition of a layer) either individually or mixed with colorants.

[0043] In some embodiments, the external layer 120 and / or the internal layer 110 may be formulized to have a low thermal conductivity (e.g., having a thermal conductivity less than 100 W / m K measured at 25° C).

[0044] In some embodiments, the external layer 120 and / or the internal layer 110 has an emissivity of no more than about 0.5, no more than about 0.45, no more than about 0.4, no more than about 0.35, no more than about 0.3, no more than about 0.25, no more than about 0.2, no more than about 0.15, no more than about 0.1, no more than about 0.09, no more than about 0.08, no more than about 0.07, no more than about 0.06, no more than about 0.05, no more than about 0.04, no more than about 0.03, no more than about 0.02, or no more than about 0.01.

[0045] In some embodiments, the external layer 120 and / or the internal layer 110 has a thermal conductivity of less than about less than about 250 W / m K, less than about 230 W / m K, less than about 210 W / m K, less than about 200 W / m K, less than about 180 W / m K, less than about 160 W / m K, less than about 140 W / m K, less than about 120 W / m K, less than about 100 W / m K, less than about 80 W / m K, less than about 60 W / m K, less than about 40 W / m K, less than about 20 W / m K, less than about 10 W / m K, less than about 5 W / m K, less than about 3 W / m K, or less than about IW / m K at 25° C. In some embodiments, the external layer 120 and / or the internal layer 110 has a thermal conductivity of greater than about 0.1 W / m K, greater than about 2 W / m K, greater than about 5 W / m K, greater than about 10 W / m K, greater than about 30 W / m K, greater than about 50 W / m K, greater than about 70 W / m K, greater than about 90 W / m K, greater than about 110 W / m K, greater than about 130 W / m K, greater than about 150 W / m K, greater than about 170 W / m K, greater than about 190 W / m K, or greater than about 210 W / m K at 25° C. Combinations of the above-referenced values are also possible (e.g., greater than about 30 W / m K and less than about 100 W / m K or greater than about 100 W / m K and less than about 150 W / m K), inclusive of all values and ranges therebetween.

[0046] In some embodiments, the external layer 120 and / or the internal layer 110 may have a surface that is smooth and shiny (e.g., surface treated, coated with a reflective material or made of a reflective material) so as to reduce absorptivity (e.g., reduce emissivity at the thermal wavelengths from around 750 nm to 1,000 pm) so as to maintain a temperature of the thermally insulated material and to prevent the temperature of the thermally insulated material 116 from exceeding a critical temperature. In some embodiments, the internal layer 110 and / or the external layer 120 can maintain the thermally insulated material 116 at a low temperature. In some embodiments, the internal layer 110 and / or the external layer 120 can maintain the thermally insulated material 116 at a high temperature.

[0047] In some embodiments, the external layer 120 and / or the internal layer 110 may have a reflectivity of greater than about 50% (e.g., greater than 50%, greater than 60%, greater than 65%, greater than 70%, greater than 75%, greater than 80%, greater than 85%, greater than 90%, or greater than 95%, inclusive) at thermal radiative wavelengths corresponding to an operating temperature of greater than about 50 °C. In some embodiments, the external layer 120 and / or the internal layer 110 may have a reflectivity of greater than about 55%. In some embodiments, the external layer 120 and / or the internal layer 110 may have a reflectivity of greater than about 60%. In some embodiments, the external layer 120 and / or the internal layer 110 may have a reflectivity of greater than about 65%. In some embodiments, the external layer 120 and / or the internal layer 110 may have a reflectivity of greater than about 70%. In some embodiments, the external layer 120 and / or the internal layer 110 may have a reflectivity of greater than about 75%. In some embodiments, the external layer 120 and / or the internal layer 110 may have a reflectivity of greater than about 80%. In some embodiments, the external layer 120 and / or the internal layer 110 may have a reflectivity of greater than about 85%. In some embodiments, the external layer 120 and / or the internal layer 110 may have a reflectivity of greater than about 90%. In some embodiments, the external layer 120 and / or the internal layer 110 may have a reflectivity of greater than about 95%.

[0048] In some embodiments, the external layer 120 and / or the internal layer 110 may have solar absorptivity of less than 0.6 (e.g., less than 0.55, less than 0.5, less than 0.45, less than 0.4, less than 0.35, less than 0.3, less than 0.25, less than 0.2, less than 0.15, or less than 0.1, inclusive) at a wavelength in a range of 2.5 microns to 15 microns, inclusive (e.g., 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 11, 12, 13, 14, or 15 microns, inclusive), at an operating temperature of the MLI assembly 100 in a range of 30 °C to 250 °C, inclusive (e.g., 50, 60, 90, 100, 120, 140, 160, 180, 200, 220, 240, or 250 °C, inclusive). In some embodiments, the outer surface of the external layer 120 may be surface treated (e.g., plasma treated, texturized, etc.) to have the solar absorptivity as described above.

[0049] In some embodiments, the external layer 120 and / or the internal layer 110 can be an electrically conducting layer. In some embodiments, the external layer 120 and / or the internal layer 110 can be a solid dielectric layer to reduce fire risk. In some embodiments, the external layer 120 and / or the internal layer 110 can provide additional structural reinforcement for the MLI assembly 100. In some embodiments, the external layer 120 and / or the internal layer 110 can aid in preventing damage from projectiles incident upon the MLI assembly 100. In some embodiments, the external layer 120 and / or the internal layer 110 can be composed ofat least one of metal or metal alloy. In some embodiments, the external layer 120 and / or the internal layer 110 may include aluminum.

[0050] In some embodiments, the external layer 120 and / or the internal layer 110 can have a thickness of at least about 100 pm, at least about 150 pm, at least about 200 pm, at least about 250 pm, at least about 300 pm, at least about 400 pm, at least about 500 pm, at least about 600 pm, at least about 700 pm, at least about 800 pm, at least about 900 pm, at least about 1 mm, at least about 2 mm, at least about 3 mm, at least about 4 mm, at least about 5 mm, at least about 6 mm, at least about 7 mm, at least about 8 mm, or at least about 9 mm. In some embodiments, the external layer 150 can have a thickness of no more than about 10 mm, no more than about 9 mm, no more than about 8 mm, no more than about 7 mm, no more than about 6 mm, no more than about 5 mm, no more than about 4 mm, no more than about 3 mm, no more than about 2 mm, no more than about 1 mm, no more than about 900 pm, no more than about 800 pm, no more than about 700 pm, no more than about 600 pm, no more than about 500 pm, no more than about 400 pm, no more than about 300 pm, or no more than about 200 pm. Combinations of the above-referenced thicknesses of the external layer 150 are also possible (e.g., at least about 500 pm, and no more than about 10 mm, or at least about 1 mm and no more than about 5 mm), inclusive of all values and ranges therebetween. In some embodiments, the external layer 120 and / or the internal layer 110 can have a thickness of about 500 pm, about 600 pm, about 700 pm, about 800 pm, about 900 pm, about 1 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, or about 10 mm. In some embodiments, the external layer 120 and / or the internal layer 110 can have a thickness from about 170 pm to about 250 pm.

[0051] In some embodiments, the external layer 120 and / or the internal layer 110 can include a continuous tube (not shown in FIG. 1). In some embodiments, the external layer 120 can have the same or substantially similar thermal contraction to that of the former 114. In some embodiments, the MLI assembly 100 is configured such that a fluid (including a liquid, a vapor, a gas, or any combination thereof) can flow outside of the internal layer 110. In some embodiments, fluid can flow or be contained in a space (e.g., an annular region) between the internal layer 110 and the external layer 120. In some embodiments, the MLI assembly 100 may further include a continuous tube, disposed within the internal layer 110 but outside the former 114, such that a coolant flow space 112 can be defined entirely within the continuous tube, entirely outside the continuous tube, or defined both within and outside the continuous tube.

[0052] In some embodiments, the external layer 120 and / or the internal layer 110 can be load bearing, such that the external layer 120 and / or the internal layer 110 can provide mechanical support for the MLI assembly 100. In some embodiments, an additional tube (not shown) can be placed inside the internal layer 110 to provide mechanical support. Alternatively, or in addition, a cable, a metal rope, a solid rod, or any combination thereof can be placed inside the internal layer 110 to provide mechanical support.

[0053] In some embodiments, the external layer 120 may include one or more layers (e.g., two, three, four layers) of material. In some embodiments, the external layer 120 can include about 1, about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10, or more layers of material (not shown in FIG. 1). In some embodiments, the external layer may include two layers (not shown in FIG. 1). In such two layers embodiments, the external layer 120 may include a second layer disposed on the internal layer 110 (i.e., the first layer) and a third layer disposed on the second layer. In some embodiments, a second spacer (not shown in FIG. 1) can be disposed between the second layer and the third layer. In some embodiments, the second spacer may be configured to maintain a spacing between the second layer and the third layer and / or to minimize heat conduction between the second layer and the third layer. In some embodiments, the second layer and / or the third layer within the external layer 120 includes a reflective or low-emissivity material. In some embodiments, the second layer and the third layer may include the same low-emissivity material in terms of chemical composition. In some embodiments, the second layer and the third layer within the external layer 120 may include different low-emissivity materials in terms of chemical composition. The low-emissivity material(s) included within the second layer and the third layer may be same as or different from the low-emissivity material included within the internal layer 110 (i.e., first layer).

[0054] In some embodiments, the thermally insulated material 116 can be disposed on or around the former 114. In some embodiments, the thermally insulated material 116 may include one or more cryogenic fluids. In some embodiments, the cryogenic fluid may include at least one of ethane, ethylene, krypton, methane, oxygen, argon, nitrogen, neon, hydrogen, xenon, or helium.

[0055] In some embodiments, the thermally insulated material 116 may include at least one of liquefied natural gas (LNG) or liquefied hydrogen (LH2). In some embodiments, the thermally insulated material 116 may include at least one of renewable natural gas (RNG) or compressed natural gas (CNG). In some embodiments, the thermally insulated material 116 may include a compressed gas.

[0056] In some embodiments, the thermally insulated material 116 may include a superconductor material. In some embodiments, the superconductor material may include a plurality of superconductor wires or tapes. The wires or tapes can, for example, include nonspiral wound wires or tapes (i.e., wires or tapes laid along a surface such as a surface of a former, discussed further below), multiple tapes interleaved with spacers, etc.

[0057] In some embodiments, the superconductor material can be disposed on the former 114 in a single layer. In some embodiments, the number of layers of the superconductor material, the thickness of the superconductor material, the type of superconductor material can be selected or adjusted based on a desired application. In some embodiments, the plurality of wires or tapes can be wound around the former 114 and conform to the shape of the former 114. In some embodiments, the superconductor wires or tapes can be wound around the former 114 in a spiral pattern. In some embodiments, the superconductor wires or tapes can be wound around the former 114 in a non-spiral pattern. In some embodiments, the superconductor wires or tapes can be wound around the former 114 in a single layer. In some embodiments, the number of layers of the superconductor wires or tapes, the width of the superconductor wires or tapes, the angle and direction of winding can be selected or adjusted based on a desired application. For example, these parameters can be adjusted to minimize AC losses and / or to minimize self-inductance of the MLI assembly 100. Similarly, a number of layers with desired winding angles may be selected to produce desired mechanical and / or electrical characteristics of the MLI assembly 100. In some embodiments, the superconductor wires or tapes can be wound around the former 114 in about 2 layers, about 3 layers, about 4 layers, about 5 layers, about 6 layers, about 7 layers, about 8 layers, about 9 layers, or about 10 layers, inclusive of all values and ranges therebetween.

[0058] In some embodiments, the superconductor wires or tapes can, individually or collectively, have a width (i.e., a dimension orthogonal to a longitudinal axis of the superconductor wires or tapes) of at least about 500 pm, at least about 600 pm, at least about 700 pm, at least about 800 pm, at least about 900 pm, at least about 1 mm, at least about 2 mm, at least about 3 mm, at least about 4 mm, at least about 5 mm, at least about 6 mm, at least about 7 mm, at least about 8 mm, at least about 9 mm, at least about 1 cm, at least about 2 cm, at least about 3 cm, at least about 4 cm, at least about 5 cm, at least about 6 cm, at least about 7 cm, at least about 8 cm, or at least about 9 cm. In some embodiments, the superconductor wires or tapes can have a width of no more than about 10 cm, no more than about 9 cm, no more than about 8 cm, no more than about 7 cm, no more than about 6 cm, no more than about5 cm, no more than about 4 cm, no more than about 3 cm, no more than about 2 cm, no more than about 1 cm, no more than about 9 mm, no more than about 8 mm, no more than about 7 mm, no more than about 6 mm, no more than about 5 mm, no more than about 4 mm, no more than about 3 mm, no more than about 2 mm, no more than about 1 mm, no more than about 900 pm, no more than about 800 pm, or no more than about 700 pm, no more than about 600 pm. Combinations of the above-referenced widths of the superconductor wires or tapes are also possible (e.g., at least about 500 pm and no more than about 10 cm or at least about 1 mm and no more than about 1 cm), inclusive of all values and ranges therebetween. In some embodiments, the superconductor wires or tapes can have a width of about 500 pm, about 600 pm, about 700 pm, about 800 pm, about 900 pm, about 1 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 1 cm, about 2 cm, about 3 cm, about 4 cm, about 5 cm, about 6 cm, about 7 cm, about 8 cm, about 9 cm, or about 10 cm.

[0059] In some embodiments, a coolant (e.g., cooling fluid) can flow through the coolant flow space 112 In some embodiments, the coolant can move through the coolant flow space 112 as a liquid. In some embodiments, the coolant can move through the coolant flow space 112 as a gas. In some embodiments, the coolant can move through the coolant flow space 112 as both a liquid and a gas. In some embodiments, the coolant can move through the flow space 112 as a vapor. In some embodiments, the coolant can move through the flow space 112 as a liquid and a vapor. In some embodiments, the coolant can move through the flow space 112 as a vapor and a gas. In some embodiments, the coolant can move through the flow space 112 as a liquid, a vapor, and a gas.

[0060] In some embodiments, the coolant flow space 112 can be filled with a flowing liquid coolant. If the material cooled by the liquid coolant (e.g., the conductor material or the superconductor material) includes one or more cryogenically cooled superconductors, the liquid coolant can be a liquid cryogen (e.g., liquid nitrogen, liquid helium, liquid hydrogen, liquid neon, liquid natural gas, or liquid air). In such embodiments, the heat energy entering the MLI assembly 100 from the surroundings should be minimized. In some embodiments, the external layer 120 and / or the internal layer 110 can be formed to minimize the amount of heat from the surrounding environment that reaches superconductor material. In use, a temperature gradient may exist across the thickness of the external layer 120 and / or the internal layer 110, such that the internal layer 110 (or an inner surface thereof closest to the coolant flow space112) is at the temperature of the coolant while the external layer 120 (or an outer surface thereof farthest to the surrounding environment) is at ambient temperature.

[0061] In some embodiments, the spacer 130 can be configured to maintain a spacing between the internal layer 110 and the external layer 120. In some embodiments, the spacing between the internal layer 110 and the external layer 120 can be at least about 500 pm, at least about 600 pm, at least about 700 pm, at least about 800 pm, at least about 900 pm, at least about 1 mm, at least about 2 mm, at least about 3 mm, at least about 4 mm, at least about 5 mm, at least about 6 mm, at least about 7 mm, at least about 8 mm, at least about 9 mm, at least about 1 cm, at least about 2 cm, at least about 3 cm, at least about 4 cm, or at least about 5 cm. In some embodiments, the spacing between the internal layer 110 and the external layer 120 can be no more than about 10 cm, no more than about 9 cm, no more than about 8 cm, no more than about 7 cm, no more than about 6 cm, no more than about 5 cm, no more than about 4 cm, no more than about 3 cm, no more than about 2 cm, no more than about 1 cm, no more than about 9 mm, no more than about 8 mm, no more than about 7 mm, no more than about 6 mm, no more than about 5 mm, no more than about 4 mm, no more than about 3 mm, no more than about 2 mm, or no more than about 1 mm. Combinations of the above-referenced diameters are also possible (e.g., at least about 500 pm and no more than about 1 cm or at least about 1 cm and no more than about 10 cm), inclusive of all values and ranges therebetween.

[0062] In some embodiments, the spacer 130 can be configured to minimize heat conduction between the internal layer 110 and the external layer 120. In some embodiments, the spacer 130 may be formulized to have a low thermal conductivity (e.g., having a thermal conductivity less than 100 W / m K measured at 25° C). In some embodiments, the spacer 130 may have a thermal conductivity of less than about less than about 250 W / m K, less than about 230 W / m K, less than about 210 W / m K, less than about 200 W / m K, less than about 180 W / m K, less than about 160 W / m K, less than about 140 W / m K, less than about 120 W / m K, less than about 100 W / m K, less than about 80 W / m K, less than about 60 W / m K, less than about 40 W / m K, less than about 20 W / m K, less than about 10 W / m K, less than about 5 W / m K, less than about 3 W / m K, or less than about IW / m K at 25° C. In some embodiments, the spacer 130 may have a thermal conductivity of greater than about 0.1 W / m K, greater than about 2 W / m K, greater than about 5 W / m K, greater than about 10 W / m K, greater than about 30 W / m K, greater than about 50 W / m K, greater than about 70 W / m K, greater than about 90 W / m K, greater than about 110 W / m K, greater than about 130 W / m K, greater than about 150 W / m K, greater than about 170 W / m K, greater than about 190 W / m K, or greater than about210 W / m K at 25° C. Combinations of the above-referenced values are also possible (e.g., greater than about 30 W / m K and less than about 100 W / m K or greater than about 100 W / m K and less than about 150 W / m K), inclusive of all values and ranges therebetween.

[0063] In some embodiments, the spacer 130 may structurally reinforce the MLI assembly 100 by acting as a mechanical tensile support element. That is, in some embodiments, the spacer 130 may improve the mechanical bearing capacity of the MLI assembly 100.

[0064] In some embodiments, the spacer 130 may be configured to tension against an internal surface of at least one of the internal layer 110 or the external layer 120. That is, in some embodiments, the spacer 130 may be placed between the layers of the MLI assembly 100 in such a way that the spacer 130 may be subjected to a certain amount of tension or axial force.

[0065] The spacer 130 disposed between the internal layer 110 and the external layer 120 may include two or more discrete spacers that aid to fully separate the internal layer 110 and the external layer 120 from each other such that thermal conduction between the layers 110, 120 can be reduced compared to a MLI assembly that lacks a spacer between its layers. Using discrete spacers may reduce or eliminate the possibility of contact across the adjacent layers (i.e., the internal layer 110 and the external layer 120).(0066[ The spacer 130 may be attached a surface (e.g., an exterior surface) of the internal layer 110 and / or a surface (e.g., an interior surface) of the external layer 120 by any suitable means such that the spacer 130 is disposed between the internal layer 110 and the external layer 120. In some embodiments, the spacer 130 may be attached to an exterior surface of the internal layer 110 and an interior surface of the external layer 120.

[0067] In some embodiments, the spacer 130 may be directly attached to the surfaces of the internal layer 110 and the external layer 120. In some embodiments, the spacer 130 may be bonded to the surfaces via an epoxy. In some embodiments, thin slots or holes can be cut into the internal layer 110 and / or the external layer 120, on which the spacer 130 can be placed, wrapped or attached. In such embodiments, the spacer 130 can penetrate through the internal layer 110 and / or the external layer 120.

[0068] In some embodiments, the spacer 130 can include a tensioned support (e.g., a tensioned spring) to support and separate the internal layer 110 and the external layer 120. In some embodiments, the tensioned members may include at least one of tensioned wires, tensioned springs or tensioned coils. In some embodiments, the spacer 130 may include at least one of wires, coils, fibers, cables, pins, or springs. In some embodiments, the springs mayinclude at least one of compression or tension springs. In some embodiments, the spacer 130 possesses flexibility, allowing it to be compressed to a specific degree.

[0069] In some embodiments, the spacer 130 may be in a form of a plurality of strings. In some embodiments, the plurality of strings can contact the internal layer 110 (e.g., an exterior surface of the internal layer 110) and / or the external layer 120 (e.g., an interior surface of the external layer 120).

[0070] In some embodiments, the spacer 130 may be in a form of a plurality of strips. In some embodiments, the spacer 130 may include a plurality of strips formed of a stiff material. In some embodiments, the plurality of strips of stiff material can extend from a first radial location on an interior surface of the external layer 120 to a second radial location on the interior surface of the external layer 120, such that each strip from the plurality of strips can contact an outside surface of the internal layer 110.

[0071] In some embodiments, the spacer 130 may include a spring (e.g., a plurality of springs). In some embodiments, the spring can contact the internal layer 110 (e.g., an exterior surface of the internal layer 110) and / or the external layer 120 (e.g., an interior surface of the external layer 120) such that the spring is longitudinally placed between the internal layer 110 and the external layer 120.

[0072] In some embodiments, the external layer 120 may include two or more layers of material (e.g., a low-emissivity material) spaced apart from each other with the help of a spacer. In such embodiments, the spacer 130 disposed between the internal layer 110 and the external layer 120 may be a first spacer and the MLI assembly may include multiple spacers (a second, a third, a fourth, a fifth spacer etc.) between the adjacent layers within external layer 120.

[0073] In some embodiments, the external layer 120 may include two layers of material (i.e., a first layer and a second layer of the external layer 120). In some embodiments, the number of spacers between the internal layer 110 and the first layer of the external layer 120 and the number of spacers between the first layer of the external layer 120 and the second layer of the external layer 120 may be equal. In some embodiments, the number of spacers between the first layer of the external layer 120 and the second layer of the external layer 120 may be greater than or less than the number of spacers between the internal layer 110 and the first layer of the external layer 120.{0074] FIG. 2A is a side top view and FIG. 2B is a cross-sectional view of a MLI assembly 200. The MLI assembly 200 includes a first layer 210 (i.e., an internal layer) formed into a tubeshape, a second layer 220 (i.e., an external layer) disposed outside of the first layer 210, such that an annular space 218 is formed between the first layer 210 and the second layer 220. The MLI assembly 200 includes an inner volume 210i enclosed by the first layer 210. In some embodiments, the first layer 210 may be formed of a first low-emissivity material and / or the second layer 220 may be formed of a second low-emissivity material. In some embodiments, the first low-emissivity material and the second low-emissivity material are the same or substantially similar in terms of chemical composition. In some embodiments, at least one of the annular space 218 or the inner volume 21 Oi is under vacuum.

[0075] The MLI assembly 200 further includes spacers 230a, 230b, 230c (collectively referred to as spacers 230a-c) disposed between the first layer 210 and the second layer 220. In some embodiments, a thermally insulated material (not shown in FIGS. 2A-2B) the same or substantially similar to the thermally insulated material described above can be disposed within the inner volume 21 Oi.

[0076] The MLI assembly further may include a coolant flow space disposed onto the thermally insulated material and enclosed by the first layer 210. That is, the coolant flow space may be placed between the thermally insulated material and the first layer 210.(0077] In some embodiments, the conductor assembly 200 may further include a former (not shown in FIGS. 2A-2B) defining a shape disposed inside the inner volume 21 Oi. In some embodiments, the former may be disposed inside the inner volume 21 Oi such that a space (e.g., an annulus) can be formed between the former and the first layer 210 of reflective material. In some embodiments, the insulated material can be disposed around the former. In some embodiments, the former may be the same or substantially similar to the former 114, as described above with respect to FIG. 1. In some embodiments, the internal layer 210 and the external layer 220 can be the same or substantially similar to the internal layer 110 and the external layer 120, as described above with reference to FIG. 1. Thus, the internal layer 210 and the external layer 220 are not described in greater detail herein.

[0078] In some embodiments, the spacers 230a-c are configured to maintain a spacing between the first layer 210 of low-emissivity material and the second layer 220 of low- emissivity material. In some embodiments, the spacers 230a-c are configured to minimize heat conduction between the first layer 210 of low-emissivity material and the second layer 220 of low-emissivity material. The MLI assembly 200 further includes slots 232a, 232b, 232c (collectively referred to as slots 232a-c) disposed on the external layer 220. In someembodiments, the slots 232a-c can be arranged as a row extending along the circumference of the external layer 220. The MLI assembly 200 may further include a continuous wire 230 passes through the slots 232a-c and the annular space 218. In some embodiments, a portion of the continuous wire 230 passing through the annular space 218 can form the spacers 230a-c. In some embodiments, as depicted in FIG. 2B, the continuous wire 230 can be designed to extend throughout the MLI assembly 200 in such a way that the wire 230 alternates between passing through slots 232a-c and the annular space 218. This design can enhance the mechanical properties, such as tensile strength, of the spacers 230a-c. In some embodiments, the continuous wire 230 may be configured to support a portion of the tensile forces of suspension of the MLI assembly 200.

[0079] In some embodiments, the spacers 230a-c include a plurality of strips of stiff or rigid material. As shown in FIG. 2, spacers 230a-c can extend from a first radial location on an interior surface of the second layer 220 of low-emissivity material to a second radial location on the interior surface of the second layer 220 of low-emissivity material, such that each spacer can contact an outside surface of the first layer 210 of low-emissivity material.

[0080] Spacers 230a-c can be of any length depending on diameters of the internal layer 210 and / or the external layer 220 to enable each spacer (230a, 230b, and 230c) to extend from the first to the second radial location on the interior surface of the second layer 220, while also contacting the outer surface of the first layer 210. Although FIG. 2B depicts spacers 230a-c as extending linearly from the first to the second radial location on the interior surface of the second layer 220, any configuration that facilitates contact with the outer surface of the first layer 210 is possible.[0081 [ In some embodiments, the spacers 230a-c may have a cylindrical shape. In some embodiments, the spacers 230a-c can have diameters of at least about 10 pm, at least about 20 pm, at least about 30 pm, at least about 40 pm, at least about 50 pm, at least about 60 pm, at least about 70 pm, at least about 80 pm, at least about 90 pm, at least about 100 pm, at least about 200 pm, at least about 300 pm, at least about 400 pm, at least about 500 pm, at least about 600 pm, at least about 700 pm, at least about 800 pm, at least about 900 pm, at least about 1 mm, at least about 2 mm, at least about 3 mm, at least about 4 mm, at least about 5 mm, at least about 6 mm, at least about 7 mm, at least about 8 mm, or at least about 9 mm. In some embodiments, the spacers 230a-c can have diameters of no more than about 10 mm, no more than about 9 mm, no more than about 8 mm, no more than about 7 mm, no more than about 6 mm, no more than about 5 mm, no more than about 4 mm, no more than about 3 mm,no more than about 2 mm, no more than about 1 mm, no more than about 900 pm, no more than about 800 pm, no more than about 700 pm, no more than about 600 pm, no more than about 500 pm, no more than about 400 pm, no more than about 300 pm, no more than about 200 pm, no more than about 100 pm, no more than about 90 pm, no more than about 80 pm, no more than about 70 pm, no more than about 60 pm, no more than about 50 pm, no more than about 40 pm, no more than about 30 pm, or no more than about 20 pm. Combinations of the above-referenced diameters are also possible (e.g., at least about 10 pm and no more than about 10 mm or at least about 50 pm and no more than about 1 mm), inclusive of all values and ranges therebetween.

[0082] In some embodiments, the spacers 230a, 230b and 230c may have same or substantially similar length and / or thickness. In some embodiments, the spacers 230a, 230b and 230c may have different lengths and / or thicknesses.100831 In some embodiments, the spacers 230a-c may have a varying thickness along their length (i.e., having a varying diameter in a longitudinal direction).[00841 In some embodiments, the spacers 230a-c may be independently formed from a stiff or rigid material selected from at least one of fiber composite material, metal, metal alloys, plastic, ceramic, or silicone. In some embodiments, the spacers 230a-c may be independently formed from a flexible material that allows some degree of freedom (e.g., vibration or compression). In some embodiments, the spacers 230a-c may be compressible to a certain degree. In some embodiments, the spacers 230a-c may be selected to have a low thermal conductivity (e.g., having a thermal conductivity less than 100 W / m K measured at 25° C). In some embodiments, the spacers 230a-c may have a thermal conductivity of less than about less than about 250 W / m K, less than about 230 W / m K, less than about 210 W / m K, less than about 200 W / m K, less than about 180 W / m K, less than about 160 W / m K, less than about 140 W / m K, less than about 120 W / m K, less than about 100 W / m K, less than about 80 W / m K, less than about 60 W / m K, less than about 40 W / m K, less than about 20 W / m K, less than about 10 W / m K, less than about 5 W / m K, less than about 3 W / m K, or less than about IW / m K at 25° C. In some embodiments, the spacers 230a-c may have a thermal conductivity of greater than about 0.1 W / m K, greater than about 2 W / m K, greater than about 5 W / m K, greater than about 10 W / m K, greater than about 30 W / m K, greater than about 50 W / m K, greater than about 70 W / m K, greater than about 90 W / m K, greater than about 110 W / m K, greater than about 130 W / m K, greater than about 150 W / m K, greater than about 170 W / m K, greater than about 190 W / m K, or greater than about 210 W / m K at 25° C. Combinations ofthe above-referenced values are also possible (e.g., greater than about 30 W / m K and less than about 100 W / m K or greater than about 100 W / m K and less than about 150 W / m K), inclusive of all values and ranges therebetween.

[0085] FIG. 3 is an illustration of layers of a MLI assembly 300, according to an embodiment. The MLI assembly 300 includes a first layer 310 formed into a tube shape, a second layer 320a disposed outside of the first layer 310, such that a first annular space 318a is formed between the first layer 310 and the second layer 320a. The MLI assembly 300 can include a third layer 320b, as illustrated in FIG. 3, disposed outside of the second layer 320a, such that a second annular space 318b is formed between the second layer 320a and the third layer 320b. The MLI assembly 300 may further include a first spacer including spacers 330a, 330b, 330c (collectively referred to as spacers 330a-c) disposed in the first annular space 318a and a second spacer including spacers 330d, 330e, 33 Of, 330g (collectively referred to as spacers 330d-g) disposed in the second annular space 318b. The MLI assembly 300 includes an inner volume 3 lOi enclosed by the first layer 310.

[0086] In some embodiments, a thermally insulated material (not shown in FIG. 3) the same or substantially similar to the thermally insulated material described above can be disposed within the inner volume 3 lOi. In some embodiments, the MLI assembly 300 may further include an insulated assembly defining a shape disposed inside the inner volume 3 lOi. In some embodiments, the insulated assembly may be disposed inside the inner volume 3 lOi such that a space (e.g., an annulus) can be formed between the insulated assembly and the first layer 310. In some embodiments, the thermally insulated material can be disposed around the insulated assembly. In some embodiments, the insulated assembly can include a former. In some embodiments, the former can be the same or substantially similar to the former 114, as described above with respect to FIG. 1.

[0087] In some embodiments, the first layer 310 (i.e., internal layer), the second layer 320a and the third layer 320b (collectively referred to as external layer) can be the same or substantially similar to the internal layer 110 and the external layer 120, as described above with reference to FIG. 1. Thus, the internal layer 310 and the external layers 320a, 320b are not described in greater detail herein.

[0088] In some embodiments, at least one of the inner volume 3 lOi, the first annular space 318a or the second annular space 318b is under vacuum. 1

[0089] In some embodiments, the spacers 330a-c can extend from a first radial location on an interior surface of the second layer 320a to a second radial location on the interior surface of the second layer 320a, such that each spacer can contact an outside surface of the first layer 310.

[0090] In some embodiments, the spacers 330d-g can extend from a first radial location on an interior surface of the third layer 320b to a second radial location on the interior surface of the third layer 320b, such that each spacer can contact an outside surface of the second layer 320a.|0091] The arrangement of the spacers 330a-c and the spacers 330d-g between adjacent layers (the first 310, second 320a and the third 320b layers) of the MLI assembly 300, as shown in FIG. 3, may strengthen the assembly 300 against mechanical stresses that can be generated within the assembly 300, for example, as a result of the conductor dead weight, ice formation, and wind loading.

[0092] In some embodiments, the spacers 330a-c may be configured to maintain a spacing between the first layer 310 and the second layer 320a and minimize heat conduction between the first layer 310 and the second layer 320a.

[0093] In some embodiments, the spacers 330d-g may be configured to maintain a spacing between the second layer 320a and the third layer 320b and minimize heat conduction between the second layer 320a and the third layer 320b.

[0094] In some embodiments, the spacers 330a-c and / or the spacers 330d-g can include a plurality of strips of stiff material. The stiff material may be same or substantially similar to the stiff material described above with respect to FIG. 1 and FIGS. 2A-2B.

[0095] The MLI assembly 300 can further include slots (not shown in FIG. 3) disposed on the second layer 320a and / or the third layer 320b. In some embodiments, the slots can be arranged as a row extending along the circumference of the second layer 320a and / or the third layer 320b. The MLI assembly 300 may further include a continuous wire (not shown in FIG. 3) passing through the slots and the annular space 318a and / or 318b. In some embodiments, a portion of the continuous wire passing through the annular space 318a can form the spacers 330a-c. In some embodiments, a portion of the continuous wire passing through the annular space 318b can form the spacers 330d-g. In some embodiments, the continuous wire may be configured to support a portion of the tensile forces of suspension of the MLI assembly 300.

[0096] FIG. 4 illustrates of layers of a MLI assembly 400 with a support structure (i.e., a spacer), according to an embodiment. The MLI assembly 400 includes an internal layer 410 (e.g., a first layer) of a first low-emissivity material formed into a tube shape, an external layer 420 (e.g., a second layer) of a second low-emissivity material disposed outside of the internal layer 410 such that an annular space 418 is formed between the internal layer 410 and the external layer 420. The MLI assembly 400 can include a spring 430, as shown in FIG. 4, disposed between the internal layer 410 and the external layer 420. In some embodiments, the MLI assembly 400 may further include any support structure (e.g., wires, fibers, cables), placed between the internal layer 410 and the external layer 420, that can be configured to maintain a spacing between the two layers (i.e., 410 and 420). The MLI assembly 400 includes an inner volume 410i enclosed by the first layer 410. In some embodiments, at least one of the inner volume 41 Oi, or the annular space 418 is under vacuum.100971 In some embodiments, the annular space 418 can include a gas. In some embodiments, the gas can include an inert gas (e.g., argon, nitrogen, neon, helium, krypton, or any combination thereof). In some embodiments, the annular space 418 can include a liquid (e.g., water or a non-aqueous liquid). In some embodiments, the annular space 418 can include a getter, or a solid material that adsorbs gas to create a low pressure. The getter can reduce pressure in the annular space 418, particularly as the temperature in the annular space 418 cools. In some embodiments, the annual space 418 can include an aerogel, a solid foam, and / or microspheres. In some embodiments, the annular space can include a gas that can be cryopumped. In some embodiments, the annular space 418 can include a pumped gas. In some embodiments, the annular space 418 can include a high surface adsorbent material that can reduce the pressure in the annular space 418 (e.g., activated charcoal).

[0098] In some embodiments, the internal layer 410 and the external layer 420 can be the same or substantially similar to the internal layer 110 and the external layer 120, as described above with reference to FIG. 1. Thus, the internal layer 410 and the external layer 420 are not described in greater detail herein.10099 [ In some embodiments, a thermally insulated material (not shown in FIG. 4) the same or substantially similar to the thermally insulated material described above can be disposed within the inner volume 410i. In some embodiments, the MLI assembly 400 may further include an insulated assembly (not shown in FIG. 4) defining a shape disposed inside the inner volume 41 Oi. In some embodiments, the insulated assembly can include a former. In some embodiments, the insulated assembly may be disposed inside the inner volume 41 Oi suchthat a space (e.g., an annulus) can be formed between the former and the first layer 410. In some embodiments, a superconductor material can be disposed around the former. In some embodiments, the former may have a cylindrical shape.101001 In some embodiments, the spring 430 can be configured to maintain a spacing between the internal layer 410 and the external layer 420. In some embodiments, the spring 430 can be configured to minimize heat conduction between the internal layer 410 and the external layer 420.

[0101] In some embodiments, the spring 430 can be pre-tensioned. That is, the spring 430 may be subjected to a certain amount of tension or axial force before being put between the layers of the MLI assembly 400. This pre-tensioning process can reduce the effects of initial set or relaxation in the spring, leading to better long-term performance and stability. The pretensioned spring may be configured to tension against an internal surface of the second layer 420.10102] The spring 430 can be disposed between the internal layer 420 and the external layer 430 by any suitable means. In some embodiments, the spacer 130 may be directly attached to the surfaces of the internal layer 110 and the external layer 120. For example, thin slots or holes can be cut into the internal layer 110 and / or the external layer 120, on which the spring 130 can be mounted. In such embodiments, the spacer 130 can penetrate through at least one of the internal layer 110 and / or the external layer 120. In some embodiments, the spring 430 can be attached to a surface using various methods, including direct welding or fastening with screws, bolts, or clips, as well as through the use of brackets or specially designed mounts, each chosen based on the specific requirements of the application. In some embodiments, the spring 430 may be mounted on any one of the first layer 410 or the second layer 420. In some embodiments, the spring 430 may not contact to the second layer 420. In some embodiments, the spring 430 may be bonded to any one of the first layer 410 or the second layer 420 via an epoxy.

[0103] The spring 430 may include a plurality of springs (not shown in FIG. 4). The plurality of springs may have any suitable shape. For example, the plurality of springs may independently include at least one of coil springs, leaf springs, conical springs, torsion bar springs, disc springs (Belleville springs), wave springs, or constant force springs. The shape and geometric properties (total number of coils, outer diameter, length etc.) of the spring 430can be tailored based on geometries and mechanical properties of the internal layer 410 and the external layer 420.

[0104] The spring 430 can be made from a variety of materials, including high-carbon steels, alloy steels, stainless steels, metals (e.g., non-ferrous metals), as well as polymer materials like fiberglass and certain high-performance plastics, each chosen based on the conductor’s mechanical and environmental requirements.

[0105] FIGS. 5A-5B are illustrations of layers of a MLI assembly 500, according to an embodiment. The MLI assembly 500 includes a first layer 510 (i.e., internal layer) formed into a tube shape, and a second layer 520a disposed outside the first layer 510 such that such that a first annular space 518a is formed between the first layer 510 and the second layer 520a. The MLI assembly 500 further includes a third layer 520b disposed outside the second layer 520a such that a second annular space 518b is formed between the second layer 520a and the third layer 520b. The MLI assembly 500 further includes a fourth layer 520c disposed outside the third layer 520b such that a third annular space 518c is formed between the third layer 520b and the fourth layer 520c. The MLI assembly 500 further includes a fifth layer 520d disposed outside the fourth layer 520c such that such that a fourth annular space 518d is formed between the third layer 520c and the fourth layer 520d. The second 520a, the third 520b, the fourth 520c and the fifth 520d layers can be collectively referred to as external layer 520a-d. As shown in FIGS. 5A-5B, the four layers 520a, 520b, 520c, 520d of the external layer 520a-d are disposed on each other sequentially such that the second 518b, the third 518c, and the fourth 518d annular space can be formed between each adjacent layer. The MLI assembly 500 includes an inner volume 5 lOi enclosed by the first layer 510. In some embodiments, at least one of the inner volume 5 lOi, the first annular space 518a, the second annular space 518b, the third annular space 518c, or the fourth annular space 518d is under vacuum.

[0106] The MLI assembly 500 may further include a spacer 530 disposed in the first annular space 518a and / or in the second annular space 518b. In some embodiments, the MLI assembly 500 can further include a spacer (not shown in FIGS. 5A-5B) disposed in the third annular space 518c and / or in the fourth annular space 518d. In some embodiments, as shown in FIGS. 5A-5B, the third annular space 518c and the fourth annular space 518d may lack any spacer.

[0107] In some embodiments, at least one of the first spacer 530a, the second spacer 530b, the third spacer or the fourth spacer may include a plurality of springs. In some embodiments,the plurality of springs may include two or more springs. In some embodiments, the plurality of springs can be the same or substantially similar to the spring 430, as described above with reference to FIG. 4.[01081 Springs are generally constructed to have an initial tension, that force that keeps the coils together in a set position. That is, initial tension is the load or force necessary to overcome the internal force to start coil separation. Accordingly, the plurality of springs may have initial tension prior to being placed between the layers of the MLI assembly 500.

[0109] In some embodiments, the plurality of springs may be pre-tensioned. That is, the plurality of springs may be subjected to a certain amount of tension or axial force in addition to their initial tension before being put between the layers of the MLI assembly 500.

[0110] In some embodiments, the plurality of springs may be configured to tension against an internal surface of at least one of the second layer 520b, the third layer 520c, the fourth layer 530c and the fifth layer 540d. That is, in some embodiments, the plurality of springs may be placed between the layers of the MLI assembly 500 in such a way that the plurality of springs may be subjected to a certain amount of tension or axial force.

[0111] In some embodiments, the plurality of springs can contact an exterior surface of the internal layer 510 and an interior surface of the first layer 520a. In some embodiments, the plurality of springs can contact an exterior surface of the second layer 520b and an interior surface of the third layer 520b. In some embodiments, the plurality of springs can contact an exterior surface of the third layer 520b and an interior surface of the fourth layer 520c. In some embodiments, the plurality of springs can contact an exterior surface of the fourth layer 520c and an interior surface of the fifth layer 520d.

[0112] In some embodiments, the plurality of springs positioned between consecutive layers might not align with each other. For instance, the plurality of springs situated between the first layer 510 and the second layer 520a might not follow the same radial path as the plurality of springs located between the second layer 520a and the third layer 520b.

[0011] In some embodiments, the plurality of springs may penetrate through the first layer 510. In some embodiments, the plurality of springs may penetrate through the second layer 520a. In some embodiments, the plurality of springs may penetrate through the third layer 520b. In some embodiments, the plurality of springs may penetrate through the fourth layer 520c. In some embodiments, the plurality of springs may penetrate through the fifth layer 520d.

[0114] In some embodiments, a thermally insulated material (not shown in FIGS. 5A-5B) the same or substantially similar to the thermally insulated material described above can be disposed within the inner volume 510i. In some embodiments, the MLI assembly 500 may further include a former (not shown in FIGS. 5A-5B) defining a shape disposed inside the inner volume 51 Oi. In some embodiments, the former may be disposed inside the inner volume 51 Oi such that a space (e.g., an annulus) can be formed between the former and the first layer 510. In some embodiments, a superconductor material can be disposed around the former. In some embodiments, the former may be the same or substantially similar to the former 114, as described above with respect to FIG. 1.

[0115] FIG. 6 is an illustration of a spacer, according to an embodiment. The spacer includes a spring 630 having a width W (i.e., an outer diameter) and a length L. The width W of the spring 630 refers to the widest distance across the exterior of the spring, measured perpendicular to the axis around which the spring 630 is wound. In some embodiments, the spring 630 may have axially opposed ends 631 and 633, positioned opposite to each other along the longitudinal direction. The length of the spring 630 can be defined as the longitudinal distance between the first end 631 and the second end 632 when the spring 630 is in its natural or unloaded state. In other words, the length of the spring 630 is measured when no external force is acting on the spring 630.

[0116] In some embodiments, the spring can be the same or substantially similar to the spring 430 and 530, as described above with reference to FIG. 4 and FIGS. 5A-5B.

[0117] In some embodiments, the spring 630 can have the width W of at least about 100 pm, at least about 300 pm, at least about 500 pm, at least about 1 mm, at least about 3 mm, at least about 5 mm, at least about 7 mm, at least about 1 cm, at least about 2 cm, at least about 3 cm, at least about 4 cm, at least about 5 cm, at least about 6 cm, at least about 7 cm, at least about 8 cm, at least about 9 cm, or at least about 10 cm. In some embodiments, the spring 630 can have the width W of no more than about 30 cm, no more than about 25 cm, no more than about 20 cm, no more than about 15 cm, no more than about 10 cm, no more than about 5 cm, no more than about 1 cm, no more than about 5 mm, or no more than about 1 mm. Combinations of the above-referenced widths W are also possible (e.g., at least about 500 pm, and no more than about 1 cm, or at least about 1 mm and no more than about 5 cm), inclusive of all values and ranges therebetween.

[0118] In some embodiments, the spring 630 can have the length L of at least about 500 pm, at least about 1 mm, at least about 3 mm, at least about 5 mm, at least about 7 mm, at least about 1 cm, at least about 2 cm, at least about 3 cm, at least about 4 cm, at least about 5 cm, at least about 6 cm, at least about 7 cm, at least about 8 cm, at least about 9 cm, at least about 10 cm, or at least about 20cm. In some embodiments, the spring 630 can have the length L of no more than about 50 cm, no more than about 40 cm, no more than about 30 cm, no more than about 25 cm, no more than about 20 cm, no more than about 15 cm, no more than about 10 cm, no more than about 5 cm, no more than about 1 cm, no more than about 5 mm, or no more than about 1 mm. Combinations of the above-referenced lengths L are also possible (e.g., at least about 1 mm, and no more than about 10 cm, or at least about 1 cm and no more than about 20 cm), inclusive of all values and ranges therebetween.

[0119] In some embodiments, the spring 630 may have at least 3 turns, at least 4 turns, at least 5 turns, at least 6 turns, at least 7 turns, at least 8 turns, at least 9 turns, at least 10 turns, at least 11 turns, at least 12 turns, at least 13 turns, at least 14 turns, at least 15 turns, at least 16 turns, at least 17 turns, at least 18 turns, at least 19 turns, or at least about 20 turns. In some embodiments, the spring 530 may include no more than 40 turns, no more than 39 turns, no more than 38 turns, no more than 37 turns, no more than 36 turns, no more than 35 turns, no more than 34 turns, no more than 33 turns, no more than 32 turns, no more than 31 turns, or no more than about 30 turns. Combinations of the above-referenced values are also possible (e.g., at least about 3 turns, and no more than about 10 turns, or at least about 5 turns and no more than about 30 turns), inclusive of all values and ranges therebetween.[01201 The number of turns in the spring 630 refers to the total number of times the spring 630 coils around itself in a full 360-degree rotation. In some embodiments, the number of turns may impact stiffness, compression and extension characteristics of the spring 630. It is typically determined by counting the number of coil revolutions from one end 631 to the other end 633 when the spring is in an uncompressed state.

[0121] FIG. 7 shows a longitudinal cross section view of a MLI assembly 700. The MLI assembly 700 includes a first layer 710 (i.e., an internal layer) formed into a tube shape, a second layer 720 (i.e., an external layer) disposed outside of the first layer 710, such that an annular space is formed between the first layer 710 and the second layer 720. In some embodiments, the first layer 710 may be formed of a first low-emissivity material and / or the second layer 720 may be formed of a second low-emissivity material. In some embodiments,the first low-emissivity material and the second low-emissivity material are the same or substantially similar in terms of chemical composition.

[0122] The MLI assembly 700 further includes a spacer 730 disposed between the first layer 710 and the second layer 720. The MLI assembly 700 includes an inner volume 710i enclosed by the first layer 710. In some embodiments, at least one of the inner volume 71 Oi or the annular space is under vacuum.

[0123] In some embodiments, the MLI assembly 700 is the same or substantially similar to the MLI assembly 100 described with respect to FIG. 1.|0124] In some embodiments, the spacer 130 may be in a form of a plurality of strips. In some embodiments, the spacer 130 may include a plurality of strips formed of a stiff material. In some embodiments, the plurality of strips of stiff material can extend from a radial location on an interior surface of the external layer 720 to a radial location on an exterior surface of the internal layer 710, such that each strip can have contact angle “a” with the exterior surface of the internal layer 710. In some embodiments, the contact angle of each strip with the exterior surface of the internal layer 710 is about 90 degrees. In some embodiments, the contact angle a of each strip with the exterior surface of the internal layer 710 is less than about 90 degrees, less than about 90 degrees, less than about 90 degrees, less than about 90 degrees, less than about 85 degrees, less than about 80 degrees, less than about 75 degrees, less than about 70 degrees, less than about 65 degrees, less than about 60 degrees, less than about 55 degrees, less than about 50 degrees, less than about 45 degrees, less than about 40 degrees, less than about 35 degrees, or less than about 30 degrees.

[0125] FIG. 8 shows a longitudinal cross section view of a MLI assembly 800. The MLI assembly 800 includes a first layer 810 (i.e., an internal layer) formed into a tube shape, a second layer 820a disposed outside of the first layer 810, such that a first annular space is formed between the first layer 810 and the second layer 820a. In some embodiments, the MLI assembly 800 may further include a third layer 820b disposed on the second layer 820a such that a second annular space can be formed between the second layer 820a and the third layer 820b.

[0126] The MLI assembly 800 further includes a spacer 830 (or a plurality of spacers 830) disposed between the first layer 810 and the second layer 820a and disposed between the second layer 820a and the third layer 820b. The MLI assembly 800 includes an inner volume 810i enclosed by the first layer 810. In some embodiments, MLI assembly 800 may furtherinclude a sectional divider 832 that forms segments of the MLI assembly 800 at pre-determined intervals along a longitudinal direction. In some embodiments, the sectional divider 832 may be disposed perpendicular to the longitudinal direction of MLI assembly 800 such that the sectional divider 832 can intersects the inner space 812i, the first layer 810 and the second layer 820. Creating segments through the length of the MLI assembly allows better temperature control of along the length of the MLI assembly. In addition, in case a problem occurs in one of the layers of the assembly (e.g., leak of the coolant from the coolant flow space etc.), having segments may prevent the problem spreading along the whole MLI assembly.

[0127] In some embodiments, at least one of the first annular space, the second annular space or the inner volume 81 Oi is under vacuum.

[0128] In some embodiments, the MLI assembly 800 is same or substantially similar to the MLI assembly 100 described with respect to FIG. 1.

[0129] In some embodiments, the spacer 830 may be in a form of a plurality of strips. In some embodiments, the spacer 830 may include a plurality of strips formed of a stiff material. In some embodiments, the plurality of strips of stiff material can extend from a radial location on an interior surface of the external layer 820 to a radial location on an exterior surface of the internal layer 710, such that each strip can have contact angle with the exterior surface of the internal layer 710. In some embodiments, the contact angle of each strip with the exterior surface of the internal layer 710 is about 90 degrees. In some embodiments, the MLI assembly 800 can include about 1, about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 20, about 30, about 40, about 50, about 60, about 70, about 80, about 90, about 100, about 200, about 300, about 400, about 500, about 600, about 700, about 800, about 900, about 2,000, about 3,000, about 4,000, about 5,000, about 6,000, about 7,000, about 8,000, about 9,000, or at least about 9,000 spacers 830, inclusive of all values and ranges therebetween.

[0130] FIG. 9 is a cross-sectional view of a segment of a MLI assembly 900. The MLI assembly 900 includes a first layer 910 formed into a tube shape, a second layer 920 (only a segment is shown) disposed outside of the first layer 910, such that an annular space 918 is formed between the first layer 910 and the second layer 920. The MLI assembly 900 includes an inner volume 91 Oi enclosed by the first layer 910.[0131 [ The MLI assembly 900 further includes a slot 932 disposed on a segment of the second layer 920. The slot 932 extends along the circumference of the second layer 920 (theblack dashed circle shown in FIG. 9 outlines the outer boundary of the second layer 920). In some embodiments, the slot 932 extends at least about 5 degrees, at least about 10 degrees, at least about 20 degrees, at least about 30 degrees, at least about 40 degrees, at least about 50 degrees, at least about 60 degrees, at least about 70 degrees, at least about 80 degrees, at least about 90 degrees, at least about 100 degrees, at least about 110 degrees, at least about 120 degrees, at least about 130 degrees, at least about 140 degrees, at least about 150 degrees, at least about 160 degrees, at least about 170 degrees, at least about 180 degrees, at least about 190 degrees, at least about 200 degrees, at least about 210 degrees, at least about 220 degrees, at least about 230 degrees, at least about 240 degrees, at least about 250 degrees, at least about 260 degrees, at least about 270 degrees, at least about 280 degrees, at least about 290 degrees, at least about 300 degrees, at least about 310 degrees, at least about 320 degrees, at least about 330 degrees, at least about 340 degrees, or at least about 350 degrees along the circumference of the second layer 920. In some embodiments, the slot 932 extends no more than about 355 degrees, no more than about 350 degrees, no more than about 340 degrees, no more than about 330 degrees, no more than about 320 degrees, no more than about 310 degrees, no more than about 300 degrees, no more than about 290 degrees, no more than about 280 degrees, no more than about 270 degrees, no more than about 260 degrees, no more than about 250 degrees, no more than about 240 degrees, no more than about 230 degrees, no more than about 220 degrees, no more than about 210 degrees, no more than about 200 degrees, no more than about 190 degrees, no more than about 180 degrees, no more than about 170 degrees, no more than about 160 degrees, no more than about 150 degrees, no more than about 140 degrees, no more than about 130 degrees, no more than about 120 degrees, no more than about 110 degrees, no more than about 100 degrees, no more than about 90 degrees, no more than about 80 degrees, no more than about 70 degrees, no more than about 60 degrees, no more than about 50 degrees, no more than about 40 degrees, no more than about 30 degrees, no more than about 20 degrees, or no more than about 10 degrees along the circumference of the second layer 920. Combinations of the above-referenced angles are also possible (e.g., at least about 5 degrees and no more than about 355 degrees or at least about 180 degrees and no more than about 240 degrees), inclusive of all values and ranges therebetween. In some embodiments, the slot 932 extends about 5 degrees, about 10 degrees, about 20 degrees, about 30 degrees, about 40 degrees, about 50 degrees, about 60 degrees, about 70 degrees, about 80 degrees, about 90 degrees, about 100 degrees, about 110 degrees, about 120 degrees, about 130 degrees, about 140 degrees, about 150 degrees, about 160 degrees, about 170 degrees, about 180 degrees, about 190 degrees, about 200 degrees, about 210 degrees, about 220 degrees, about 230degrees, about 240 degrees, about 250 degrees, about 260 degrees, about 270 degrees, about 280 degrees, about 290 degrees, about 300 degrees, about 310 degrees, about 320 degrees, about 330 degrees, about 340 degrees, about 350 degrees, or about 355 degrees along the circumference of the second layer 920.

[0132] The MLI assembly 900 further includes a spacer 930 that is configured to maintain a spacing between the first layer 910 and the second layer 920. In some embodiments, the spacer 930 is configured to minimize heat conduction between the first layer 910 of low- emissivity material and the second layer 920 of low-emissivity material.101331 The spacer 930 includes an arc-shaped wire. The arc-shaped wire extends outward through the slot 932 to an outer surface of the second layer 920 such that a first portion of the arc-shaped wire partially wraps arounds the inner layer 910 and a second portion of the arcshaped wire extends along the circumference of the second layer 920. That is, the spacer 930 can be a component that connects the first layer 910 to the second layer 920. This design can enhance the mechanical properties, such as tensile strength, of the spacer 930 as well as facilitate the incorporation of a spacer into the MLI assembly. In some embodiments, the spacer 930 may be configured to support a portion of the tensile forces of the MLI assembly 900. In some embodiments, the second portion of the arc-shaped wire extends about 90 degrees, about 100 degrees, about 110 degrees, about 120 degrees, about 130 degrees, about 140 degrees, about 150 degrees, about 160 degrees, about 170 degrees, about 180 degrees, about 190 degrees, about 200 degrees or about 210 degrees, along the circumference of the second layer 920.

[0134] In some embodiments, multiple spacers 930 can be positioned at different longitudinal locations along the MLI assembly 900 and offset by various angles. For example, a second spacer can be positioned about 10 cm downstream of a first spacer and offset by 120 degrees clockwise, a third spacer can be positioned about 10 cm downstream of the second spacer and offset from the second spacer by 120 degrees clockwise, and a fourth spacer can be positioned about 10 cm downstream of the third spacer and offset from the third spacer by 120 degrees clockwise. In such a setup, the fourth spacer would not in the same radial orientation as the first spacer (i.e., 120 degrees + 120 degrees + 120 degrees = 360 degrees). In some embodiments, multiple spacers 930 can be separated by a distance of about 1 cm, about 2 cm, about 3 cm, about 4 cm, about 5 cm, about 6 cm, about 7 cm, about 8 cm, about 9 cm, about 10 cm, about 20 cm, about 30 cm, about 40 cm, about 50 cm, about 60 cm, about 70 cm, about 80 cm, about 90 cm, or about 1 m, inclusive of all values and ranges therebetween. In someembodiments, multiple spacers 930 can be offset from each other by about 10 degrees, about 20 degrees, about 30 degrees, about 40 degrees, about 50 degrees, about 60 degrees, about 70 degrees, about 80 degrees, about 90 degrees, about 100 degrees, about 110 degrees, about 120 degrees, about 130 degrees, about 140 degrees, about 150 degrees, about 160 degrees, about 170 degrees, or about 180 degrees, inclusive of all values and ranges therebetween.

[0135] In some embodiments, the spacer 930 may be formed from a material selected from at least one of fiber composite material, metal, metal alloys, plastic, ceramic, or silicone. In some embodiments, the spacer 930 may be formed from a flexible material that allows some degree of freedom (e.g., vibration). In some embodiments, the spacer 930 may be compressible to a certain degree. In some embodiments, the spacer 930 may be selected to have a low thermal conductivity (e.g., having a thermal conductivity less than 100 W / m K measured at 25° C).

[0136] In some embodiments, a thermally insulated material (not shown) the same or substantially similar to the thermally insulated material described above can be disposed within the inner volume 91 Oi. The MLI assembly further may include a coolant flow space disposed onto the thermally insulated material and enclosed by the first layer 910. That is, the coolant flow space may be placed between the thermally insulated material and the first layer 910.

[0137] In some embodiments, the MLI assembly 900 may further include a former (not shown), defining a shape disposed inside the inner volume 910i. In some embodiments, the former may be disposed inside the inner volume 91 Oi such that a space (e.g., an annulus) can be formed between the former and the first layer 910 of low-emissivity material. In some embodiments, the thermally insulated material can be disposed around the former. In some embodiments, the former may be the same or substantially similar to the former 114, as described above with respect to FIG. 1.10138] In some embodiments, the internal layer 910 and the external layer 920 can be the same or substantially similar to the internal layer 110 and the external layer 120, as described above with reference to FIG. 1. Thus, the internal layer 910 and the external layer 920 are not described in greater detail herein.

[0139] In some embodiments, the first layer 910 may be formed of a first low-emissivity material and / or the second layer 920 may be formed of a second low-emissivity material. In some embodiments, the first low-emissivity material and the second low-emissivity material are the same or substantially similar in terms of chemical composition. In some embodiments, at least one of the annular space 918 or the inner volume 91 Oi is under vacuum.

[0140] FIG. 10 shows an illustration of helix-shaped spacers with various form factors, according to various embodiments. In some embodiments, the spring-shaped spacers can be the same or substantially similar to the springs 430, 530, 630 as described above with reference to FIG. 4, FIGS. 5A-5B, and FIG. 6. The spacers as described above with respect to FIG. 1, FIG. 4, FIGS. 5A-5B and FIG. 6 may have different aspect ratios (i.e., ratios of length L to width W of the spring) depending on the materials used to form the MLI assembly, the size of the MLI assembly and relative size of its layers, the spacing between the layers of the MLI assembly, the intended use of the MLI assembly etc.

[0141] In some embodiments, the ratio of the length L to the width W of the spring-shaped spacers can be at least about 0.1, at least about 0.3, at least about 0.5, at least about 1, at least about 2, at least about 3, at least about 4, at least about 5, at least about 6, at least about 7, at least about 8, at least about 9, at least about 10, at least about 20, at least about 30, at least about 40, at least about 50, at least about 60, at least about 70, at least about 80, at least about 90, at least about 100, at least about 200, at least about 300, at least about 400, at least about 500, at least about 600, at least about 700, at least about 800, at least about 900, or at least about 1,000.

[0142] FIG. 11 shows an illustration of a method 10 of applying a spring-shaped spacer, according to an embodiment. In some embodiments, the method 10 may include providing a spring-shaped spacer 1130. The method 10 may further include cutting a hole into at least one of the layers (e.g., an internal and / or an external layer) of the MLI assembly, as described above according to various embodiments. Depending on specific design or functional requirements of the spring-shaped spacer 1130, the hole can take on various shapes, such as circular, rectangular, square, oval, triangular, hexagonal, slotted, diamond-shaped, star-shaped, and irregular. In some embodiments, the spring-shaped spacer 1130 can be the same or substantially similar to the springs 430, 530, 630 as described above with reference to FIG. 4, FIGS. 5A-5B, and FIG. 6. As shown in FIG. 11, the method 10 can further include screwing the spring-shaped spacer 1130 to a surface 1100 of at least one of the layers of the MLI assembly.10143] Various concepts may be embodied as one or more methods, of which at least one example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments. As such, some of these features may be mutually contradictory, in that they cannot be simultaneously present in a singleembodiment. Similarly, some features are applicable to one aspect of the innovations, and inapplicable to others.

[0144] In addition, the disclosure may include other innovations not presently described. Applicant reserves all rights in such innovations, including the right to embodiment such innovations, file additional applications, continuations, continuations-in-part, divisionals, and / or the like thereof. As such, it should be understood that advantages, embodiments, examples, functional, features, logical, operational, organizational, structural, topological, and / or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the embodiments or limitations on equivalents to the embodiments.

[0145] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0146] As used herein, in particular embodiments, the terms “about” or “approximately” when preceding a numerical value indicates the value plus or minus a range of 10%. Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the disclosure. That the upper and lower limits of these smaller ranges can independently be included in the smaller ranges is also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.

[0147] The indefinite articles “a” and “an,” as used herein in the specification and in the embodiments, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0148] The phrase “and / or,” as used herein in the specification and in the embodiments, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and / or B”, when usedin conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.[0149| As used herein in the specification and in the embodiments, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the embodiments, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e., “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the embodiments, shall have its ordinary meaning as used in the field of patent law.

[0150] As used herein in the specification and in the embodiments, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0151] In the embodiments, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including butnot limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

CLAIMS1. An assembly, comprising: a first layer of low-emissivity material; a second layer of low-emissivity material disposed outside of the first layer of low- emissivity material, such that a gap is formed between the first layer of low-emissivity material and the second layer of low-emissivity material; and a spacer disposed between the first layer of low-emissivity material and the second layer of low-emissivity material, the spacer configured to maintain a spacing between the first layer of low-emissivity material and the second layer of low-emissivity material.

2. The assembly of claim 1, further comprising: a former disposed inside the first layer of low-emissivity material, the former defining a shape.

3. The assembly of claim 1, further comprising: a thermally insulated material disposed inside the first layer of low-emissivity material.

4. The assembly of claim 3, wherein the thermally insulated material includes a superconductor material.

5. The assembly of claim 1, further comprising: a former disposed inside the first layer of low-emissivity material, and a coolant flow space, the coolant flow space being formed between the former and the first layer of low- emissivity material.

6. The assembly of claim 1, wherein the spacer includes a plurality of strips of stiff material extending from a first radial location on an interior surface of the second layer of low- emissivity material to a second radial location on the interior surface of the second layer of low-emissivity material, such that each strip from the plurality of strips of stiff material contacts an outside surface of the first layer of low-emissivity material.

7. The assembly of claim 1, wherein the spacer includes a spring contacting an exterior surface of the first layer of low-emissivity material and an interior surface of the second layer of low-emissivity material.

8. The assembly of claim 7, wherein the spring penetrates through the first layer of low- emissivity material.

9. The assembly of claim 7, wherein the spring is bonded to the interior surface of the second layer of low-emissivity material via any one of welding, clamping or epoxying.

10. The assembly of claim 1, wherein the spacer is a first spacer and the gap is a first gap, the assembly further comprising: a third layer of low-emissivity material disposed outside of the second layer of low- emissivity material, such that a second gap is formed between the second layer of low- emissivity material and the third layer of low-emissivity material; and a second spacer disposed between the second layer of low-emissivity material and the third layer of low-emissivity material, the second spacer configured to maintain a spacing between the second layer of low-emissivity material and the third layer of low-emissivity material .

11. The assembly of claim 1, wherein the spacer includes a plurality of strings contacting an exterior surface of the first layer of low-emissivity material and an interior surface of the second layer of low-emissivity material.

12. The assembly of claim 1, wherein the spacer includes a continuous wire, the continuous wire alternating between passing through a plurality of apertures disposed on the second layer of low-emissivity material and the gap formed between the first layer of low-emissivity material and the second layer of low-emissivity material.

13. The assembly of claim 1, wherein the gap between the first layer of low-emissivity material and the second layer of low-emissivity material is under vacuum.

14. The assembly of claim 1, wherein the gap between the first layer of low-emissivity material and the second layer of low-emissivity material includes at least one of a gas or a liquid.

15. An assembly, comprising: an internal layer; an external layer disposed outside of the internal layer, such that a gap is formed between the internal layer and the external layer; and a spacer disposed between the internal layer and the external layer, the spacer configured to maintain a spacing between the internal layer and the external layer; and a thermally insulated material disposed inside the internal layer.

16. The assembly of claim 15, wherein the internal layer includes a first low-emissivity material and the external layer includes a second low-emissivity material.

17. The assembly of claim 16, wherein the first low-emissivity material and the second low-emissivity material are same in terms of chemical composition.

18. The assembly of claim 16, wherein the first low-emissivity material and the second low-emissivity material are different in terms of chemical composition.

19. The assembly of claim 15, wherein the gap between the internal layer and the external layer is an annular space.

20. The assembly of claim 15, wherein the gap between the internal layer and the external layer is under vacuum.

21. The assembly of claim 15, wherein the gap between the internal layer and the external layer includes at least one of a gas or a liquid.

22. The assembly of claim 15, wherein the spacer includes a plurality of strings contacting an exterior surface of the internal layer and an interior surface of the external layer.

23. The assembly of claim 15, wherein the spacer includes a plurality of springs contacting an exterior surface of the internal layer and an interior surface of the external layer.

24. The assembly of claim 15, wherein the spacer includes a plurality of strips of stiff material extending from a first radial location on an interior surface of the external layer to a second radial location on the interior surface of the external layer, such that each strip from the plurality of strips of stiff material contacts an outside surface of the internal layer.

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