Anti-enrichment composite cryoline

Abstract

A cryogenic insulated pipe 26 having a conformally-bonded aerogel paper layer 30 on an outer surface of the pipe. Aspects include: the conformally-bonded aerogel paper layer is conformally bonded to t

Description

Technical Field

[0001] The present disclosure relates to insulation systems, and more particularly, to insulation systems for use at cryogenic temperatures. The disclosure has particular utility in connection with insulation systems for use with insulating cryogenic piping or cryogenic conduits for transferring highly volatile materials, such as liquid hydrogen between cryogenic storage tanks and fuel cells for powering vehicles such as aircraft, and will be described in connection with such utility, although other utilities are contemplated. Background and Summary

[0002] This section provides background information related to the present disclosure which is not necessarily prior art. This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all its features.

[0003] Exhaust emissions from transport vehicles are a significant contributor to climate change. Conventional fossil-fuel-powered terrestrial transport vehicles, watercraft, and aircraft release CO2 emissions. Also, conventional fossil-fuel-powered aircraft emissions include non-CO? effects due to nitrogen oxide (NOx), vapor trails and cloud formation triggered by the altitude at which aircraft operate. These non-CO2 effects are believed to contribute twice as much to global warming as aircraft CO2 and are estimated to be responsible for two-thirds of aviation’s climate impact.

[0004] The use of cryogenic fluids, such as liquid hydrogen (LH2) for powering fuel-cell-powered aircraft, offers an attractive alternative to conventional liquid fossil-fuel-burning engines. Liquid hydrogen is stored in a liquid state at very low temperature, i.e., below -252°C (2IK), in high pressure cryogenic tanks. Typically, cryogenic tanks are multiwalled structures with supports or studs maintaining space between the walls. The space between the tank walls may contain insulating material and / or is evacuated, i.e., to form a vacuum.

[0005] In use, LH? fuel is flowed from cryogenic storage tanks through cryogenic pipes to the fuel cells, which create electrical energy for powering electric motors. However, pockets or inclusions between the cold cryogenic pipes and their surrounding insulation may permit gaseous oxygen from ambient air to become liquid. The liquid oxygen may ignite if brought into contact with a combustible material (e.g., drippings onto the tarmac or organic polymers within insulation). Water from ambient air also may build up in the outer layers of cryogenic pipe insulation, which may lead to degradation of the cryogenic pipe insulation performance and foreign object debris risk from thermal cycling, causing pieces of the cryogenic pipe insulation to break off. Water buildup also may substantially increase weight, cause corrosion to critical components in or below the tank, and / or create a fertile environment for pathogens, such as certain bacteria.

[0006] In accordance with the present disclosure, cryogenic pipes running between a cryogenic storage tank and a fuel cell are thermally insulated by an insulation system having a conformally-bonded aerogel paper layer adjacent to the pipe surface to prevent pockets of disbond between the pipe and insulation. An insulative blanket is applied over the aerogel paper, and a breathable glass composite layer is applied over the insulative blanket to protect the insulative blanket and to prevent moisture / ice buildup in the insulative blanket.

[0007] More particularly, in accordance with the present disclosure, cryogenic pipes are insulated using a composite insulation formed as follows. A resin layer formed of, e.g., an epoxy or another thermoset material selected to have low out-gassing is applied to a pipe outer surface. The resin layer typically will have a resin weight fraction of 20 to 80 %, preferably 40 to 50 %, more preferably about 45%. A layer of aerogel paper is tightly wrapped over the resin layer before the resin layer sets, bonding the layer of aerogel paper conformally to the pipe outer surface. The layer of aerogel paper, being closely bonded to the outer surface of the cryogenic pipe, prevents pockets / inclusions where ambient oxygen may condense and build up. The layer of aerogel paper may have a thickness of 0.1 to 10 mm, preferably 0.35 to 3 mm, more preferably 1 -2 mm.

[0008] The aerogel paper is then covered by an insulative blanket. The insulative blanket may be a blanket of aerogel material of 5 to 50mm thickness, preferably 5 to 20mm thickness, more preferably about 10 mm thickness with a density of 3 to 300 kg / m3, preferably 110 to 220 kg / m3, more preferably 160 kg / m3. A protective outer layer of scrim glass composite is then wrapped around the insulative blanket, providing a breathable, protective outer layer. Alternatively, the insulative blanket may be formed on an inside surface of the protective outer layer, and the insulative blanket / protective outer layer composite applied together over the aerogel paper.

[0009] The insulation system may be applied to the cryogenic pipe using standard pipe insulation wrapping methods. In one embodiment, the one or more layers of aerogel paper are counter-wrapped around the cryogenic pipe, bedded in a pre-applied resin layer. Also, tape attachments may be used to fix the insulative blanket to the cryogenic pipe. Also, a foil backing may be used as a surface for tape application.

[0010] In accordance with aspect A of the disclosure, there is provided a cryogenic insulated pipe comprising a pipe having a conformally-bonded aerogel paper layer on an outer surface of the pipe.

[0011] In one embodiment, the conformally-bonded aerogel paper layer is conformally-bonded to the pipe outer surface in a pre-applied resin layer.

[0012] In another embodiment, an insulative blanket is provided over the aerogel paper.

[0013] In a further embodiment a breathable layer is provided over the insulative blanket.

[0014] In one embodiment, the insulative blanket comprises an aerogel material.

[0015] In another embodiment the insulative blanket comprises a spray-on foam, or expanded cork.

[0016] In yet another embodiment, the cryogenic insulated pipe is configured to transport liquid hydrogen.

[0017] According to aspect B of the disclosure, there is provided a method for forming a cryogenic insulated pipe as above described in aspect A, comprising providing a pipe, and covering an outer surface of the pipe with a conformally-bonded layer of aerogel paper.

[0018] In one embodiment, the outer surface of the pipe is coated with a resin, and the coated pipe wrapped with the aerogel paper before the resin sets.

[0019] In another embodiment, an insulative blanket is added over the aerogel paper layer.

[0020] In one embodiment, the insulative blanket comprises an aerogel.

[0021] In another embodiment, the insulative blanket comprises a spray-on foam or an expanded cork.

[0022] In a further embodiment, a breathable protective layer is added over the thermal insulating layer.

[0023] In a further embodiment, the protective layer comprises a glass composite.

[0024] According to aspect C of the disclosure there is provided a vehicle comprising an insulated cryogenic pipe as above described in aspect A.

[0025] In one embodiment the vehicle comprises a fuel-cell-powered vehicle.

[0026] In another embodiment, the vehicle comprises fuel-cell-powered aircraft.

[0027] In still another embodiment, the vehicle comprises a rocket.

[0028] According to aspect Al of the present invention there is provided a cryogenic insulated pipe comprising a pipe having a conformally-bonded aerogel paper layer on an outer surface of the pipe.

[0029] Preferably the conformally-bonded aerogel paper layer is conformally-bonded to the pipe outer surface in a pre-applied resin layer.

[0030] Preferably further comprising an insulative blanket over the aerogel paper.

[0031] Preferably further comprising a breathable layer over the insulative blanket.

[0032] Preferably the insulative blanket comprises an aerogel material.

[0033] Preferably the insulative blanket comprises a spray-on foam or expanded cork.

[0034] Preferably the cryogenic insulated pipe is configured to transport liquid hydrogen.

[0035] According to aspect Bl of the present invention there is provided a method for forming a cryogenic insulated pipe according to aspect Al, comprising providing a pipe and covering an outer surface of the pipe with a conformally-bonded layer of aerogel paper.

[0036] Preferably including the step of coating the outer surface of the pipe with a resin and wrapping the coated pipe with the aerogel paper before the resin sets.

[0037] Preferably comprising the step of adding an insulative blanket over the aerogel paper layer.

[0038] Preferably the insulative blanket comprises an aerogel.

[0039] Preferably the insulative blanket comprises a spray-on foam or an expanded cork.

[0040] Preferably including the step of adding a breathable protective layer over the thermal insulating layer.

[0041] Preferably the protective layer comprises a glass composite.

[0042] According to aspect Cl of the present invention there is provided a vehicle comprising an insulated cryogenic pipe according to aspect A1.

[0043] In one alternative the vehicle comprises a fuel-cell-powered vehicle.

[0044] In one alternative the vehicle comprises a fuel-cell-powered aircraft.

[0045] In one alternative the vehicle comprises a rocket.

[0046] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. Brief Description of the Drawings

[0047] Further features and advantages of the disclosure will be seen in the following detailed description, taken in conjunction with the accompanying drawings. The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations and are not intended to limit the scope of the present disclosure. In the drawings: Fig. 1 is a schematic view of a hydrogen fuel-cell-powered aircraft in accordance with the present disclosure; Fig. 2 is a simplified cross-sectional view of an insulated cryogenic pipe insulation system in accordance with the present disclosure, at the pipe midline; Fig. 3 is a flow diagram of a process for insulating a cryogenic pipe in accordance with the present disclosure; and Fig. 4 is a flow diagram of an alternative process for insulating a cryogenic pipe in accordance with the present disclosure. Detailed Description

[0048] Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0049] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, component and / or groups, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0050] When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0051] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another element, component, region, layer, or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0052] Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0053] As used herein, “cryogenic pipe(s)”; and “cryogenic conduit(s)” are used interchangeably, and are intended to describe pipe or conduit sections as well as fittings on the pipe(s) and conduit(s), and the ends of the pipe(s) and conduit(s), e.g., where the pipe(s) and conduit(s) are affixed to cryogenic tanks at one end, and the fuel cells at the other end.

[0054] Referring to Fig. I, there is illustrated a hydrogen fuel-cell-powered aircraft 10 in accordance with the present disclosure. Aircraft 10 comprises a fuselage 12, wings 14 and two electric motors 16 powering propulsors 18. Electric motors 16 are powered by hydrogen fuel cells 20 which are supplied with hydrogen fuel from cryogenic hydrogen fuel tank 22 via cryogenic fuel lines 24.

[0055] Referring to Fig. 2, cryogenic fuel lines 24 comprise a conduit or pipe 26 formed of metal or a reinforced composite material. A resin layer 28 formed of epoxy or another thermoset resin material chosen to have a low-outgassing is applied to the pipe 26 outer surface. Any commercially available thermoset (e.g., epoxy), or thermoplastic material having a low outgassing and fire resistance may be used in the practice of this disclosure. Preferred examples are Hexcell epoxy resin matrix systems, either the Hexply prepreg resin or Hexflow infusion resin available from Hexcell. A layer of aerogel paper 30, preferably 1 mm thick, is applied over the resin layer 28. Any commercially available aerogel paper material may be used in the practice of this disclosure. Preferred is Aerogel Paper available from Aerogel Solutions. The aerogel paper layer 30 should be applied over the resin layer 28 before the resin layer sets and should be wrapped so as to closely conform to the pipe surface whereby to prevent pockets / inclusions where atmospheric oxygen may condense and build up. An insulative blanket 32 is then wrapped over the aerogel paper layer 30. Insulative blanket 32 preferably is formed of an aerogel blanket material. Any commercially available aerogel blanket material may be used in the practice of this disclosure. In a preferred embodiment, aerogel blanket 32 comprises Cryogel Aerogel Insulation available from Aspen Aerogels, though similar nanoporous insulation materials could be used, having a thickness of about 10 mm and an aerial mass of about 160 kg / m3.

[0056] An outer layer of scrim glass composite sheet 34 (e.g., Teflon-coated glass as a sleeve, braided PTFE glass scrim, or non-glass Kevlar or Dacron Nomex) is bonded over insulative blanket 32, providing a breathable and protective outer layer. In some embodiments, scrim glass composite sheet 34 is made breathable with a tight weave to prevent foreign object debris (FOD) damage.

[0057] Referring to Fig. 3, the cryogenic pipe insulation system is formed as follows: resin layer 28 is applied to the outer surface of pipe 26 in a first coating step 40, such as by brush or spray coating. Thereafter, one or more layers of aerogel paper 30 is applied to the resin, before the resin sets, tightly wrapping the aerogel paper to the pipe, for example, by hand in a wrapping step 42. The aerogel paper 30 may be applied in one or more layers.

[0058] An insulative blanket 32 is then applied over the aerogel paper 30. Insulative blanket 32 may be applied by wrapping in step 44 or may be formed in place. Preferably, insulative blanket 32 is formed of an aerogel blanket which is wrapped over the aerogel paper 30. Preferred aerogel blankets in the practice of the disclosure are metal oxide aerogels such as silica aerogels, which are formed as composite aerogels incorporating fibrous batting. The aerogels are produced by aggregation of colloidal particles, typically under acidic conditions, to form 3-dimensional gel microstructures. Aerogel insulation is preferred since aerogels have extremely high specific surface areas and, when cooled to cryogenic temperatures, are capable of absorbing gases such as oxygen. Alternatively, insulative blanket 32 may comprise spray-on foam insulation or expanded cork. A protective top layer or composite sheet 34, for example, comprising a breathable glass / composite layer is then applied over insulating blanket 32 and taped in place in step 46.

[0059] Referring to Fig. 4, in an alternative process, the insulating blanket 32 may be pre-formed on composite sheet 34 in an off-line step 48, and the pre-formed material is applied on the outer surface of the aerogel paper 30 and taped in place in step 50.

[0060] A feature and advantage of the instant disclosure which results from the bonding of aerogel paper directly to the outer surface of a cryogenic pipe is that the aerogel paper prevents ambient oxygen condensation and concentration at the cryogenic pipe surface. This in turn minimizes the risk of flammability, degraded performance, and failure / debris. Also, the scrim glass composite sheet over the insulative blanket allows the insulative blanket to “breathe”, preventing moisture buildup inside the insulative blanket.

[0061] It should be noted that in addition to bonding aerogel paper directly to the outer surface of the cryogenic pipe, aerogel paper also may be directly bonded to fittings on the pipe, as well as to bridge the area where the pipe is fitted to the fuel tank at one end and to the fuel cells at the other end.

[0062] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. By way of example, but not limitation, the cryogenic piping advantageously may be employed as cryogenic fuel lines and / or liquid oxidant lines for rockets and space vehicles. The cryogenic piping also may be employed with conventional land and sea vehicles including, for example, LNG tankers, and as piping for fixed cryogenic storage tanks,

[0063] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. Various changes and advantages may be made in the above disclosure without departing from the spirit and scope thereof.

Claims

1. A cryogenic insulated pipe comprising a pipe having a conformally-bonded aerogel paper layer on an outer surface of the pipe.

2. The cryogenic insulated pipe of claim 1, wherein the conformally-bonded aerogel paper layer is conformally-bonded to the pipe outer surface in a pre-applied resin layer.

3. The cryogenic insulated pipe of claim 1 or claim 2, further comprising an insulative blanket over the aerogel paper.

4. The cryogenic insulated pipe of claim 3, further comprising a breathable layer over the insulative blanket.

5. The cryogenic insulated pipe of claim 3 or claim 4, wherein the insulative blanket comprises an aerogel material.

6. The cryogenic insulated pipe of claim 3 or claim 4, wherein the insulative blanket comprises a spray-on foam or expanded cork.

7. The cryogenic insulated pipe of any of claims 1-6, wherein the cryogenic insulated pipe is configured to transport liquid hydrogen.

8. A method for forming a cryogenic insulated pipe as claimed in any of claims 1-7, comprising providing a pipe and covering an outer surface of the pipe with a conformally-bonded layer of aerogel paper.

9. The method of claim 8, including the step of coating the outer surface of the pipe with a resin and wrapping the coated pipe with the aerogel paper before the resin sets.

10. The method of claims 8 or 9, comprising the step of adding an insulative blanket over the aerogel paper layer.

11. The method of claim 10, wherein the insulative blanket comprises an aerogel.

12. The method of claim 10, wherein the insulative blanket comprises a spray-on foam or an expanded cork.

13. The method of any of claims 10-12, including the step of adding a breathable protective layer over the thermal insulating layer.

14. The method of claim 13, wherein the protective layer comprises a glass composite.

15. A vehicle comprising an insulated cryogenic pipe as claimed in any of claims 1-8.

16. The vehicle of claim 15, wherein the vehicle comprises a fuel-cell-powered vehicle.

17. The vehicle of claim 16, wherein the vehicle comprises a fuel-cell-powered aircraft.

18. The vehicle of claim 15, wherein the vehicle comprises a rocket.Amendments to the Claims have been filed as follows:25 07 24What is Claimed:

1. A cryogenic insulated pipe comprising a pipe having:(a) a conformally-bonded aerogel paper layer on an outer surface of the pipe;(b) an insulative blanket over the aerogel paper; and(c) a breathable protective layer over the insulative blanket.

2. The cryogenic insulated pipe of claim 1, wherein the conformally-bonded aerogel paper layer is conformally-bonded to the pipe outer surface in a pre-applied resin layer.

3. The cryogenic insulated pipe of claim 1, wherein the insulative blanket comprises an aerogel material.

4. The cryogenic insulated pipe of claim 1, wherein the insulative blanket comprises a spray-on foam or expanded cork.

5. The cryogenic insulated pipe of any of claims 1-4, wherein the cryogenic insulated pipe is configured to transport liquid hydrogen.

6. The cryogenic insulated pipe of claims 1-5, wherein the breathable protective layer comprises a breathable glass composite material.

7. The cryogenic insulated pipe of claim 6, wherein the breathable glass composite material comprises a woven or braided glass sheet.

8. A method for forming a cryogenic insulated pipe as claimed in any of claims 1-5, comprising the steps in sequence of:(a) providing a pipe and covering an outer surface of the pipe with a conformally-bonded layer of aerogel paper;(b) adding an insulative blanket over the aerogel paper layer; and(c) adding a breathable protective layer over the thermal insulating layer.25 07 249. The method of claim 8, including the step of coating the outer surface of the pipe with a resin and wrapping the coated pipe with the aerogel paper before the resin sets.

10. The method of claim 8, wherein the insulative blanket comprises an aerogel.

11. The method of claim 8, wherein the insulative blanket comprises a spray-on foam or anexpanded cork.

12. The method of claim 8, wherein the breathable protective layer comprises a breathable glass composite material.

13. The method of claim 12, wherein the breathable glass composite material comprises a woven or braided glass sheet.

14. A vehicle comprising an insulated cryogenic pipe as claimed in any of claims 1-7.

15. The vehicle of claim 14, wherein the vehicle comprises a fuel-cell-powered vehicle.

16. The vehicle of claim 16, wherein the vehicle comprises a fuel-cell-powered aircraft.

17. The vehicle of claim 15, wherein the vehicle comprises a rocket.Application No: GB2318873.3Examiner: Mr Euros MorrisClaims searched: AllDate of search: 2 February 2024Patents Act 1977: Search Report under Section 17Documents considered to be relevant:Category Relevant to claims Identity of document and passage or figure of particular relevance X 1-18 US2018 / 320824 Al (FAY RALPH MICHAEL ET AL): See paragraphs 0003-0004, 0027-0028, 0048-0049, 0051 and Figs 10A-12B X 1-18 KR1020190107464 A (KOREA GAS CORP): Whole document relevant. X 1-18 CN212509859U (LIAONING MINGYANG PIPE IND CO LTD): See Fig 1, 2 and related passages. X 1-18 US2020 / 080680 Al (JOHNS MANVILLE): Whole document relevant, esp paragraphs 0027-0028, 0081-0082 X 1-18 CN212407990 U (SHANGHAI HAIWEISITE INSULATION ENG CO LTD): Whole document relevant. X 1-18 US2010 / 154917 Al (BATALLAS MAURICE; SINGH PETER): Whole document relevant, esp paragraphs 0091-0092, 0096 0125-0131 and Figs 2 and 3.X Document indicating lack of novelty or inventive step A Document indicating technological background and / or state of the art. Y Document indicating lack of inventive step if P Document published on or after the declared priority date but combined with one or more other documents of same category. before the filing date of this invention. & Member of the same patent family E Patent document published on or after, but with priority date earlier than, the filing date of this application.Field of Search:International Classification:Subclass Subgroup Valid From F16L 0059 / 14 01 / 01 / 2006 B32B 0001 / 08 01 / 01 / 2006

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