Heating system for a cryogenic storage vessel

Abstract

The disclosure relates to a heating system for use with a cryogenic storage vessel and a cryogenic vessel including a heating system. The heating system has a heating element configured to heat contents contained or held inside the cryogenic storage vessel, an energising element configured to energise the heating element, and a power source configured to provide power to the energising element. The energising element is distant from or located remotely from the heating element and the heating element is configured to be wirelessly energised by the energising element.

Description

[0001] HEATING SYSTEM FOR A CRYOGENIC STORAGE VESSEL

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a heating system for a cryogenic storage vessel.

[0004] BACKGROUND OF THE INVENTION

[0005] Cryogenic systems are used for producing, maintaining and storing cryogenic liquids or cryogens, which are liquified gases, and other substances at very low temperatures. Cryogens are produced by liquefying gases by cooling them until they change state to liquid. Cryogenic systems are now widely spread in a number of different industries as they have proven to be useful in many different processes and for many different applications.

[0006] Cryogenic systems typically have cryogenic liquid storage systems comprising a storage for the cryogenic liquid. A product of cryogenic systems is boil-off gas, which are vapourised gases from the cryogenic liquid in the storage vessel. Boil-off gas is produced in a cryogenic storage vessel due to natural evaporation of the cryogenic liquid as some heat is inevitably transferred to the cryogenic liquid.

[0007] Cryogenic storage often requires controlled heat addition for the evaporation and pressurisation of the cryogenic gas at a rate that matches the intended application.

[0008] Cryogenic gases may be flammable, combustible or oxidising. Accordingly, any ignition source, must be kept out of contact with such cryogenic gases and / or liquids. It will be understood that a heat source may be an ignition source. As a result, it is difficult to provide a heat source for the cryogenic gases and / or liquids that efficiently and safely transfers heat to the cryogenic gases and / or liquids. It is an object of the invention to provide a heating system for a cryogenic storage vessel and / or a method for heating cryogenic liquids in a cryogenic storage vessel which overcomes or at least partially ameliorates some of the abovementioned drawbacks or which at least provides the public with a useful choice.

[0009] In this specification, where reference has been made to external sources of information, including patent specifications and other documents, this is generally for the purpose of providing a context for discussing the features of the invention. Unless stated otherwise, reference to such sources of information is not to be construed, in any jurisdiction, as an admission that such sources of information are prior art or form part of the common general knowledge in the art.

[0010] For the purpose of this specification, where method steps are described in a sequence, the sequence does not necessarily mean that the steps are to be chronologically ordered in that sequence, unless there is no other logical manner of interpreting the sequence.

[0011] BRIEF DESCRIPTION OF THE INVENTION

[0012] According to an aspect, the invention may be said to broadly comprise of a heating system for use with a cryogenic storage vessel, the heating system including: a heating element configured to heat the contents contained or held inside the cryogenic storage vessel; an energising element configured to energise the heating element; and, a power source configured to provide power to the energising element; wherein, the energising element is distant from or located remotely from the heating element and the heating element is configured to be wirelessly energised by the energising element.

[0013] In some configurations the heating element may be spaced apart from an inner wall of the cryogenic storage vessel. The heating system may comprise support or suspension member(s) configured to connect the heating element to the inner wall. In some configurations the heating element may be a liner provided on an inner wall of the cryogenic storage vessel.

[0014] In some configurations the heating element may be embedded or may be integral with an inner wall and / or an enclosed volume provided between the inner wall and an outer wall of the cryogenic storage vessel.

[0015] In some configurations the energising element may be spaced apart from an / the outer wall of the cryogenic storage vessel.

[0016] In some configurations the energising element may be embedded or may be integral with an / the outer wall and / or an / the enclosed volume provided between the inner wall and the outer wall of the cryogenic storage vessel.

[0017] In some configurations the heating element and the energising element may be configured to provide at least one of the following heating mechanism: inductive heating; resonance heating; piezoelectric heating; resistance heating; mechanical heating; wireless electrical transmission with Joule heating; microwave heating; and, radiant heating.

[0018] According to another aspect, the invention may be said to broadly comprise of a cryogenic apparatus including: the heating system as defined hereinabove; and, a cryogenic storage vessel comprising at least one wall defining a containment volume for containing a cryogenic fluid and an external periphery for the cryogenic storage vessel.

[0019] In some configurations the at least one wall may comprise: an inner wall defining the containment volume within the inner wall for containing the cryogenic fluid; an outer wall defining the external periphery of the cryogenic storage vessel; the inner wall spaced inwardly from the outer wall; and an enclosed volume between the outer wall and inner wall. In some configurations the containment volume may be configured to entrap at least some cryogenic vapours or gases released by the cryogenic liquid: upon contact of the cryogenic liquid with the at least one wall or the inner wall; and / or, receipt or storage by the at least one wall or the inner wall; and / or, upon heating of the cryogenic liquid by the heating system.

[0020] In some configurations the cryogenic apparatus may comprise a first port, the first port being a first exit port configured to facilitate dispensing of the cryogenic vapours or gases out of the cryogenic storage vessel at a specific rate.

[0021] In some configurations the cryogenic apparatus may comprise at least one second port, the second port including one of: a fill port configured to facilitate filling of the containment volume with the cryogenic liquid; and / or, a second exit port configured to facilitate dispensing of the cryogenic liquid out of the cryogenic storage vessel.

[0022] In some configurations the cryogenic storage vessel may be made of or may comprise a non-electrically conductive material.

[0023] In some configurations the heating system may comprise a wireless energy transfer mechanism.

[0024] In some configurations the wireless energy transfer mechanism may be configured to implement one of: inductive heating, resonance heating, mechanical heating, resistance, wireless electrical transmission with Joule heating, piezoelectric heating, microwave heating, and radiant heating.

[0025] In some configurations the cryogenic storage vessel may be made of or may comprise an electrically conductive material.

[0026] In some configurations the heating system may comprise a wireless energy transfer mechanism. In some configurations the wireless energy transfer mechanism may be configured to implement at least radiant heating.

[0027] In some configurations the cryogenic storage vessel may be generally made of or may generally comprise an electrically conductive material and may further comprise features made of or comprising a non-electrically conductive material.

[0028] In some configurations the non-electrically conductive features of the cryogenic storage vessel may comprise one or more of: one or more windows; one or more outward protrusions; and, one or more inward protrusions.

[0029] In some configurations the heating system may comprise a wireless energy transfer mechanism.

[0030] In some configurations the wireless energy transfer mechanism may be configured to implement one of: inductive heating, resonance heating, mechanical heating, resistance, wireless electrical transmission with Joule heating, piezoelectric heating, microwave heating, and radiant heating.

[0031] In some configurations the one or more windows may comprise an optically transparent feature and the heating system may be configured to implement radiant heating.

[0032] In some configurations the outer wall may comprise a first protrusion extending inwardly towards the inside of the cryogenic storage vessel and configured to house the energising element. The inner wall may comprise a second protrusion extending inwardly towards the inside of the cryogenic storage vessel and the heating element may be provided at, near or proximal the second protrusion. The second protrusion may surround at least an end portion of the first protrusion, the at least end portion comprising the energising element, and the heating element surrounds an outer surface of the second protrusion. The heating system may be configured to implement inductive heating or resistance heating. In some configurations the inner wall may comprise a first protrusion extending outwardly towards the outside of the cryogenic storage vessel and configured to house the heating element. The outer wall may comprise a second protrusion extending outwardly towards the outside of the cryogenic storage vessel and the energising element may be provided at, near or proximal the second protrusion. The second protrusion may surround at least an end portion of the first protrusion, the at least end portion comprising the heater element, and the energising element surrounds an outer surface of the second protrusion. The heating system may be configured to implement inductive heating or resistance heating.

[0033] In some configurations the enclosed volume may be configured to insulate the contents of the cryogenic storage vessel from an ambient environment and associated temperatures external the cryogenic storage vessel. The enclosed volume may comprise one or more layers of insulating materials. The enclosed volume may be configured to comprise or contain a vacuum space.

[0034] In some configurations the enclosed volume may be configured to comprise or contain an aerogel.

[0035] In some configurations the enclosed volume may be configured to have a surface area heat leak that ranges from at least about 0.5 W / m2 to about 20 W / m2.

[0036] In some configurations the cryogenic fluid in the cryogenic storage vessel may be hydrogen, oxygen, or liquid natural gas.

[0037] In some configurations the cryogenic storage vessel may be made of or may comprise a lightweight composite material. The cryogenic storage vessel may be a cryogenic fuel tank suitable for the storage and dispensing of cryogenic hydrogen used in cryogenic fuel applications. Other aspects of the invention may become apparent from the following which is given by way of example only and with reference to the accompanying drawings.

[0038] As used herein the term “and / of’ means “and’ or “of’, or both.

[0039] As used herein “(sj’ following a noun means the plural and / or singular forms of the noun. The term “comprising” as used in this specification and claims means “consisting at least in part of." When interpreting statements in this specification and claims which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as “comprise" and “comprised’ are to be interpreted in the same manner.

[0040] BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The invention will now be described by way of example only with reference to the drawings in which:

[0042] FIG. 1 is a schematic view of a cryogenic storage vessel and a heating system for the cryogenic storage vessel, constructed and operative in accordance with embodiments of the invention;

[0043] FIGs. 2A and 2B are schematic cross-sectional illustrations of a portion of the cryogenic storage vessel of FIG. 1 with a heating system, constructed and operative in accordance with other embodiments of the present invention;

[0044] FIGs. 3A and 3B are schematic cross-sectional illustrations of a portion of the cryogenic storage vessel of FIG. 1 with a heating system, constructed and operative in accordance with other embodiments of the present invention;

[0045] FIG. 4 is a schematic cross-sectional illustration of a portion of the cryogenic storage vessel of FIG. 1 with a heating system, constructed and operative in accordance with another embodiment of the present invention; and,

[0046] FIGs. 5A and 5B are schematic cross-sectional illustrations of a portion of the cryogenic storage vessel of FIG. 1 with a heating system, constructed and operative in accordance with other embodiments of the present invention. DETAILED DESCRIPTION

[0047] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the various principles of the present invention. However, those skilled in the art will appreciate that not all these details are necessarily always required for practicing the invention.

[0048] Reference is now made to Fig. 1 , which is a schematic illustration of a cryogenic storage vessel and a heating system for the cryogenic storage vessel constructed and operative in accordance with some embodiments of the invention.

[0049] Fig. 1 illustrates an apparatus 100 comprising inter alia a cryogenic storage vessel 10 and a heating system 20. It will be appreciated that this figure illustrates the general principles of the structure and construction, and that the invention is not limited to the precise configuration illustrated.

[0050] As can be seen in Fig. 1 , the cryogenic storage vessel 10 may generally comprise of an outer wall 1 1 defining an external periphery of the cryogenic storage vessel.

[0051] It will be appreciated that a skilled person may arrange further layers, wall, features or elements of a given cryogenic storage vessel external this outer wall 11 . However, the external periphery defined thereby generally refers to the outermost extent of the features of the cryogenic storage vessel 10 described herein that together may provide the principal functions of temperature insulation as well as reduction / mitigation of temperature changes, thermal shock and the like described in further detail below.

[0052] The cryogenic storage vessel 10 may generally also comprise of an inner wall 12 spaced inwardly from the outer wall 1 1 so as to define therebetween an enclosed volume 13 of the cryogenic storage vessel 10. This enclosed volume 13 will be described in further detail hereinbelow but generally acts to insulate the contents of the cryogenic storage vessel 10 from the environment and associated temperatures external the cryogenic storage vessel 10.

[0053] The inner wall 12 defines a containment volume 14 of the cryogenic storage vessel 10 internally of the inner wall 12. This containment volume 14 will be described in further detail below but generally serves to contain the cryogenic liquids 15 and associated vapours or gases 16, and also serves to constrain, control and / or define in part the associated temperatures, pressures and other properties imparted onto the cryogenic storage vessel 10 by the cryogenic liquids, once received thereby.

[0054] Although the principles of the present invention are largely described herein in relation to a cryogenic storage vessel 10 having an outer wall 1 1 , an inner wall 12, and an enclosed volume 13 defined therebetween, this is an example selected for convenience of presentation, and is not limiting. For instance, in alternate configurations, the cryogenic storage vessel 10 may not have an enclosed space between the inner and outer walls 12, 11 and / or may have a single wall instead of the inner and the outer walls 12, 1 1 .

[0055] Fig. 1 also shows an exit port 17 for the cryogenic storage vessel 10 that extends through the inner wall 12, the enclosed volume 13 and the outer wall 1 1 . The exit port 17 defines a passageway that facilitates dispensing of the cryogenic gases 16 out from the cryogenic vessel storage 10 (e.g., to another vessel or container, or for use). Further, the exit port 17 may be configured, arranged, dimensioned and / or controlled such that the cryogenic gases 16 can be released from the cryogenic storage vessel 10 at a rate that matches their intended application.

[0056] Although only one port is shown in Fig. 1 , those skilled in the art would appreciate the arrangement shown in this figure is exemplary only and that any number of ports may be provided. For instance, a fill port could be provided to facilitate filling containment volume 14 with the cryogenic liquids 15. Another exit port could also be provided to facilitate dispensing of the cryogenic liquids 15 out from the cryogenic storage vessel arrangement.

[0057] The containment volume 14 may be configured to entrap or hold at least some cryogenic vapours or gases 16 emitted by the cryogenic liquids 15 upon entry of the into the cryogenic storage vessel, during storage, and / or following subsequent heating of the cryogenic storage vessel 10 in use.

[0058] The apparatus 100 also comprise a heating system 20. The heating system 20 may generally comprise of a heating element 21 configured to heat the cryogenic liquids 15 and an energising element 22 located remotely or distant from the heating element 21 . In use, the energising element 22 can be powered by a power source (not shown) and, in turn, is configured to energise the heating element 21.

[0059] The heating system 20 enables energisation of the heating element 21 using an energising element 21 located remotely from the heating element 21 . This is particularly advantageous for applications where a cryogenic storage vessel comprises flammable gases and requires controlled heat addition for the evaporation and pressurisation of that gases at a rate to match the intended application. In such applications, if the contents of the cryogenic storage vessel are heated applying an electrically powered heating device, the heating device needs to have suitable isolation from the cryogenic contents so that it does not present an ignition risk in a potentially flammable atmosphere inside the cryogenic storage vessel. In the exemplary embodiment illustrated in Fig. 1 , the heating system 20 minimizes and / or mitigates this risk as there is no physical and / or electrical connection between the heating element 21 and the energising element 22. That is, the heating element 21 is wirelessly energised by the energising element 22. The maximum heat input is restricted to ensure that the heating element 21 does not pose an ignition hazard.

[0060] In the embodiment illustrated on Fig. 1 , the heating element 21 is shown as being positioned within the containment volume 14 inside the cryogenic storage vessel 10 while the energising element 22 is shown as being positioned outside of the cryogenic storage vessel 10. However, in other embodiments of the invention, different configurations allowing remote energisation of the heating element 21 by the energising element 22 may be possible and will be described in further detail hereinbelow with reference to the other figures.

[0061] In an embodiment of the invention, the energising element 22 is an induction device comprising a magnetic field generating device. The magnetic field generating device is designed and arranged for inductive heating of the heating element 21 . The magnetic field generating device generates an alternating electromagnetic field for this purpose. This induces circular electric currents (e.g., eddy currents) in the heating element 21 which in turn heat the heating element 21 by Joule effect. To achieve this, the heating element 21 may be made or comprise an electrically conductive material. For example, but not limited to, the heating element 21 may be a metal or a semiconductor, which may include a ferromagnetic material (e.g., a ferritic stainless steel).

[0062] In other embodiments of the invention, different wireless heating solutions could be used instead of inductive heating to energise the heating element 21 . For example, but not limited to, the cryogenic storage vessel 10 and the heating system 20 may be configured to implement resonance heating, microwave heating, radiant heating, resistance heating, mechanical heating, electric or piezoelectric heating. For example, in one configuration, the energising element 22 may comprise of an inner copper coil provided within the storage vessel 10 and an outer copper coil provided outside of the storage vessel 10, such that, in use, an electric current may be induced on the inner coil so as to heat a resistance heating element 21 . Other wireless heating options will be apparent to those skilled in the art.

[0063] The cryogenic storage vessel 10 may be configured to be non-electrically conductive or electrically conductive depending on the heating solution implemented. For instance, the outer wall 1 1 , the inner wall 12, and / or the enclosed volume 13 may be made of or comprise material(s) that is / are non-electrically conductive. Selecting non-electrically conductive material(s) (e.g., fibre reinforced epoxy or plastic) is particularly advantageous when the energising element 22 is an inductive device. In this embodiment of the invention, using non-electrically conductive material(s) ensures that eddy currents are not formed in the different elements of the cryogenic storage vessel 10, but solely in the heating element 21 . In turn, heating of the contents of the cryogenic storage vessel 10 is better controlled.

[0064] The cryogenic storage vessel 10 may be configured to be electrically conductive. For instance, the outer wall 1 1 , the inner wall 12, and / or the enclosed volume 13 may be made of or comprise material(s) that is / are electrically conductive. This configuration may be used, for example, but not limited to, with a radiant heating solution. Examples of radiant heating solutions will be described hereinbelow with reference to the other figures.

[0065] The cryogenic storage vessel 10 may also be configured to have portions or sections being electrically conductive and other portions or sections being non- electrically conductive. For instance, the outer wall 1 1 , the inner wall 12, and / or the enclosed volume 13 may be generally made of or comprise material (s) that is / are electrically conductive and comprises non-electrically conductive portion(s) around an area where the heating is provided. The non-electrically conductive portion(s) of the cryogenic storage vessel 10 may comprise, for example, but not limited to, at least one window or at least one inward or outward protrusion near or proximal the heating system 20. The heating element 21 may then be energised by the energising device 22 through the at least one window or protrusion. These configurations allowing remote energisation of the heating element 21 by the energising element 22 will be described in further detail hereinbelow with reference to the other figures.

[0066] Turning now to the enclosed space 13, the enclosed space 13 may generally comprise or make use of any appropriate insulation mechanism known in the art and will generally determine the overall thermal transfer from the environment external to the cryogenic storage vessel 10 to the cryogenic liquids 15. The enclosed space 13 may also be configured to provide the level of insulation required in steady-state conditions ( / .e., once the pressure and temperatures in the containment volume 14 reach equilibrium). For instance, the enclosed space 13 may be configured to contain or comprise a vacuum space between the inner and outer walls 12, 11 for the purpose of insulation. In addition, the enclosed space 13 comprising the vacuum space may be configured to contain or comprise one or more insulative materials.

[0067] In another instance, the enclosed space 13 may be configured to contain or comprise an aerogel between the inner and outer walls 12, 1 1 for the purpose of insulation. Aerogels are a class of synthetic porous ultralight material derived from a gel, in which the liquid component for the gel has been replaced with a gas, without significant collapse of the gel structure. The result is a solid with extremely low density and extremely low thermal conductivity. In addition, the enclosed space 13 comprising the aerogel may be configured to contain or comprise one or more insulative materials.

[0068] In a further example, an insulative arrangement for the enclosed space 13 may be that of a plurality of microspheres known in the art of cryogenic vessels, a thick foam arrangement known in the art of cryogenic vessels and / or a multi-layer vacuum jacket insulation arrangement known in the art of cryogenic vessels, where multiple layers of insulative material(s) (such as polyester film(s), silk netting(s) and / or nylon netting(s)) are densely embedded into a vacuum annulus or jacket space between said inner and outer walls 12, 11 .

[0069] The enclosed space 13 may be configured to have a surface area heat leak that ranges from at least about 0.5 W / m2 to about 20 W / m2. However, those skilled in the art may envisage other ranges of heat leak per surface area depending on a configuration of the cryogenic storage vessel arrangement 10.

[0070] Appropriate insulation will allow the cryogenic vapours or gases 16 to be dispensed (via the exit port 17, for instance) in applications where a certain temperature is desired or required. Those skilled in the art will appreciate that the insulative arrangement selected for the enclosed space 13 will depend on many factors, such as, for example, but not limited to, the intended application, the materials selected for the cryogenic storage vessel 10, in particular whether these materials are thermally or non-thermally conductive, and the selected heating system 20.

[0071] Reference is now made to Fig. 2A, which is a schematic cross-sectional illustration of a portion of the cryogenic storage vessel 10 of Fig. 1 with the heating system 20, constructed and operative in accordance with an embodiment of the present invention.

[0072] The heating element 21 of the heating system 20 may be spaced apart from the inner wall 12 and located within the containment volume 14 by support or suspension member(s), or spacer(s) 23 that operatively connect the heating element 21 to the inner wall 12. These are shown in Fig. 2 and may comprise of any number of support or suspension members known in the art of cryogenic vessel design, such as, for example: metal or composite hangers / flanges, tensile suspension members (cables etc.) and the like. In some configurations, where the material(s) chosen for the heating element 21 and inner wall 12 allow, the support member(s) 23 may be glued or welded to both the heating element 21 and inner wall 12 so as to operatively connect the two.

[0073] The support member(s) 23 may be configured through either material selection or physical configuration (thickness, size etc.) to also minimise the amount of thermal transfer passing from the heating element 21 to the inner wall 12. Any number of support member(s) 23 may be provided as necessary to appropriately space the heating element 21 apart from the inner wall 12, as long as they together provide sufficient support for the heating element 21 so as to allow it to accommodate gravitational and inertial loads during transport and / or use of the cryogenic storage vessel 10.

[0074] The advantage of this configuration is that the heating element 21 is in direct contact with the contents of the cryogenic storage vessel 10 and not in direct contact with the inner wall 12, thereby preventing and / or reducing heating of the cryogenic storage vessel 10 itself. In another embodiment (not shown in Fig. 2A), the heating element 21 of the heating system 20 may not be spaced apart from the inner wall 12, but rather may be provided as a liner disposed on the inner wall 12. The liner is therefore located within the containment volume 14 and can be configured to be energised and heated directly by the energising element 22.

[0075] The energising element 22 may be spaced apart from the outer wall 1 1 and located outside of cryogenic storage vessel 10 at a location near or proximal the heating element 21. In another example, the energising element 22 may be provided outside the cryogenic storage vessel 10 but in direct contact with the outside surface of the outer wall 1 1 .

[0076] An advantage of these configurations is that an efficient energisation and heating of the heating element 21 can occur. Another advantage is that the heating element 21 is in direct contact with the contents of the cryogenic storage vessel 10 and not in direct contact with the inner wall 12, thereby preventing and / or reducing heating of the cryogenic storage vessel 10 itself.

[0077] Reference is now made to Fig. 2B, which is a schematic cross-sectional illustration of a portion of the cryogenic storage vessel 10 of Fig. 1 with the heating system 20, constructed and operative in accordance with another embodiment of the present invention.

[0078] In this embodiment, the heating system 20 is similar to the one described in relation to Fig. 2A. In particular, the heating element 21 may also be spaced apart from the inner wall 12 and located within the containment volume 14 by support or suspension member(s), or spacer(s) 23 that operatively connect the heating element 21 to the inner wall 12. However, the energising element 22a, 22b, 22c may no longer be located outside the cryogenic storage vessel 10, but rather may be embedded or may be integral with the outer wall 11 (energising element 22a), and / or the enclosed volume 13 (energising element 22b), and / or the inner wall 12 (energising element 22c). Reference is now made to Fig. 3A, which is a schematic cross-sectional illustration of a portion of the cryogenic storage vessel 10 of Fig. 1 with the heating system 20, constructed and operative in accordance with another embodiment of the present invention.

[0079] In this embodiment, the heating system 20 is similar to the one described in relation to Fig. 2A. In particular, the energising element 22 may also be spaced apart from the outer wall 1 1 and located outside of the cryogenic storage vessel. However, the heating element 21 a, 21 b may no longer be spaced apart from the inner wall 12 of the cryogenic storage vessel 10, but rather may be embedded or may be integral with the inner wall 12 (heating element 21 a) and / or the enclosed volume 13 (heating element 21 b).

[0080] Reference is now made to Fig. 3B, which is a schematic cross-sectional illustration of a portion of the cryogenic storage vessel 10 of Fig. 1 with the heating system 20, constructed and operative in accordance with another embodiment of the present invention.

[0081] In this embodiment, the heating element 21 a, 21 b may be embedded or may be integral with the inner wall 12 (heating element 21 a) and / or the enclosed volume 13 (heating element 21 b), while the energising element 22a, 22b may be embedded or may be integral with the outer wall 1 1 (energising element 22a) and / or the enclosed volume 13 (energising element 22b).

[0082] An advantage of the configurations described in Figs. 2A to 3B is that an efficient energisation and heating of the heating element 21 is provided due to the close proximity of the heating and energising elements 21 , 21 a, 21 b, 22, 22a, 22b of the heating system 20.

[0083] Reference is now made to Fig. 4, which is a schematic cross-sectional illustration of a portion of the cryogenic storage vessel 10 of Fig. 1 with the heating system 20, constructed and operative in accordance with another embodiment of the present invention.

[0084] In this embodiment, one or more window(s) 17 may be provided or formed in one or more portions of the outer wall 1 1 of the cryogenic storage vessel 10. The window may include an optically transparent feature. In use, the heating system 20 may be positioned or provided near, at or proximal the window 17 so as to improve and / or allow efficient heat or energy transfer. As apparent from Fig. 4, the energising element 22 may be provided outside the cryogenic storage vessel close to the window 17 and wireless energise the heating element 21. Although shown as provided within the enclosed space 13, it will be apparent that the heating element 21 could be provided at any other suitable location.

[0085] In an embodiment, the window may be made of a non-electrically conductive material while the cryogenic storage vessel 10 (in particular, some portions of the outer and inner walls 11 ,12) may generally be made of an electrically conductive material. This configuration is particularly suited for an inductive heating system 20, but can be implemented with any other wireless heating system using magnetic means. This configuration can also be used with a wireless heating system using radiant heating. For example, a radiant energising element such as, but not limited to, an infra-red heating lamp, a ceramic heater, or a silicone heater, may be positioned or provided near, at or proximal the window 17 to radiate heat through the outer wall 1 1 . This will in turn energise the heating element 21 and / or heat the inner wall 12 such that heat may be transferred to the cryogenic liquids 15.

[0086] Reference is now made to Figs. 5A and 5B, which are schematic cross-sectional illustrations of a portion of the cryogenic storage vessel 10 of Fig. 1 with the heating system 20, constructed and operative in accordance with embodiments of the present invention.

[0087] In this embodiment, one or more protrusion(s) 1 1 a, 12a may be provided or formed in one or more portions of the outer and inner walls 1 1 , 12 of the cryogenic storage vessel 10. Fig. 5A illustrates a first protrusion 1 1 a of the outer wall 1 1 extending inwardly towards the inside of the cryogenic storage vessel 10. The first protrusion 1 1 a may be configured or dimensioned so that at least an end portion extends through the inner wall 12. The first protrusion 11 a may be dimensioned to house the energising element 22, preferably close to the at least end portion. Similarly, Fig. 5A shows a second protrusion 12a of the inner wall 12 that extends inwardly towards the inside of the cryogenic storage vessel 10. The second protrusion 12a may be dimensioned so as to receive and / or house the first protrusion 1 1 a. As illustrated in Fig. 5A, the heating element 21 may surround an outer surface of the second protrusion 12a to improve and / or allow efficient heat or energy transfer between the energising element 22 and the heater element 21 .

[0088] Fig. 5B shows another embodiment with one or more protrusion(s) 1 1 a, 12a being provided or formed in one or more portions of the outer and inner walls 1 1 , 12 of the cryogenic storage vessel 10. Fig. 5B illustrates a first protrusion 12a of the inner wall 12 extending outwardly towards the outside of the cryogenic storage vessel 10. The first protrusion 12a may be configured or dimensioned so that at least an end portion extends through the outer wall 1 1 . The first protrusion 12a may be dimensioned to house the heating element 21 , preferably close to the at least end portion. Similarly, Fig. 5A shows a second protrusion 11 a of the outer wall 11 that extends outwardly towards the outside of the cryogenic storage vessel 10. The second protrusion 11 a may be dimensioned so as to receive and / or house the first protrusion 12a. As illustrated in Fig. 5A, the energising element 22 may surround an outer surface of the second protrusion 1 1 a to improve and / or allow efficient heat or energy transfer between the energising element 22 and the heater element 21. The (relative) positioning of the energising and heater elements 21 , 22, as shown in Figs. 5A and 5B, is provided as example(s) only and is not limiting.

[0089] Those skilled in the art would appreciate that other configurations or positioning may be possible as long as a suitable wireless heat or energy transfer is provided between elements 21 and 22. Further, although the configurations shown in Figs. 5A and 5B are particularly suited for an inductive heating system 20 or a resistance heating system 20 (optionally comprising a stirrer or agitator configured to transfer the heat to the cryogen), it will be apparent to those skilled in art that any other suitable wireless heating system can be used. This configuration is also suited for a radiant heating system. For example, a radiant energising element such as, but not limited to, an infra-red heating lamp, a ceramic heater, or a silicone heater, may be positioned and / or attached to the outer wall 1 1 within protrusion 1 1 a of Fig. 5A, preferably close to the at least end portion. The radiant energising element can be configured to heat at least the end portion of the protrusion 1 1 a of the outer wall 1 1. This will in turn energise the heating element 21 and / or the protrusion 12a of the inner wall 12 such that heat may be transferred to the cryogenic liquids 15. Similarly, a radiant energising element such as, but not limited to, an infra-red heating lamp, a ceramic heater, or a silicone heater, may be attached to the outer wall 1 1 and / or positioned at, near, proximal or around the protrusion 1 1 a of the outer wall 1 1 of Fig. 5B. The radiant energising element can be configured to heat at least the end portion of the protrusion 1 1 a of the outer wall 1 1. This will in turn energise the heating element 21 provided within the protrusion 12a of the inner wall 12, preferably close to the at least end portion, and / or the protrusion 12a of the inner wall 12 such that heat may be transferred to the cryogenic liquids 15.

[0090] This heating system 20 for use with the cryogenic storage vessel 10 may be particularly useful with gases that are flammable or combustible, otherwise undesirable to be in contact with a source of ignition. In an exemplary embodiment, the apparatus 100 may take the form of a cryogenic fuel tank suitable for the storage and dispensing of, for example, cryogenic hydrogen used in cryogenic fuel applications (such as for vehicles, aircrafts, and the like). However, those skilled in art will appreciate that the cryogenic storage vessel 10 described hereinabove may be used with any suitable cryogenic fluids (such as, for example, but not limited to nitrogen, oxygen, liquid natural gas (LNG)) and for any suitable applications (such as, for example, but not limited to industrial or scientific applications that use liquid or gaseous cryogens).

[0091] To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting. Where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

Claims

CLAIMS1 . A heating system for use with a cryogenic storage vessel, the heating system comprising: a heating element configured to heat the contents contained or held inside the cryogenic storage vessel; an energising element configured to energise the heating element; and, a power source configured to provide power to the energising element; wherein, the energising element is distant from or located remotely from the heating element and the heating element is configured to be wirelessly energised by the energising element.

2. The heating system of claim 1 , wherein the heating element is spaced apart from an inner wall of the cryogenic storage vessel.

3. The heating system of claim 2, comprising support or suspension member(s) configured to connect the heating element to the inner wall.

4. The heating system of claim 1 , wherein the heating element is a liner provided on an inner wall of the cryogenic storage vessel.

5. The heating system of claim 1 , wherein the heating element is embedded or is integral with an inner wall and / or an enclosed volume provided between the inner wall and an outer wall of the cryogenic storage vessel.

6. The heating system of any one of claims 1 to 5, wherein the energising element is spaced apart from an / the outer wall of the cryogenic storage vessel.

7. The heating system of any one of claims 1 to 5, wherein the energising element is embedded or is integral with an / the outer wall and / or an / the enclosed volume provided between the inner wall and the outer wall of the cryogenic storage vessel.

8. The heating system of any one of claims 1 to 7, wherein the heating element and the energising element are configured to provide at least one of the following heating mechanism: inductive heating; resonance heating; piezoelectric heating; resistance heating; mechanical heating; wireless electrical transmission with Joule heating; microwave heating; and, radiant heating.

9. A cryogenic apparatus comprising: the heating system of any one of claims 1 to 7; and, a cryogenic storage vessel comprising at least one wall defining a containment volume for containing a cryogenic fluid and an external periphery for the cryogenic storage vessel.

10. The cryogenic apparatus of claim 9, wherein the at least one wall comprises: an inner wall defining the containment volume within the inner wall for containing the cryogenic fluid; an outer wall defining the external periphery of the cryogenic storage vessel; the inner wall spaced inwardly from the outer wall; and an enclosed volume between the outer wall and inner wall.11 . The cryogenic apparatus of claim 9 or 10, wherein the containment volume is configured to entrap at least some cryogenic vapours or gases released by the cryogenic liquid: upon contact of the cryogenic liquid with the at least one wall or the inner wall; and / or, receipt or storage by the at least one wall or the inner wall; and / or, upon heating of the cryogenic liquid by the heating system.

12. The cryogenic apparatus of claim 1 1 , comprising a first port, the first port being a first exit port configured to facilitate dispensing of the cryogenic vapours or gases out of the cryogenic storage vessel at a specific rate.

13. The cryogenic apparatus of any one of claims 9 to 12, comprising at least one second port, the second port comprising one of: a fill port configured to facilitate filling of the containment volume with the cryogenic liquid; and / or, a second exit port configured to facilitate dispensing of the cryogenic liquid out of the cryogenic storage vessel.

14. The cryogenic apparatus of any one of claims 9 to 13, wherein the cryogenic storage vessel is made of or comprises a non-electrically conductive material.

15. The cryogenic apparatus of claim 14, wherein the heating system comprises a wireless energy transfer mechanism.

16. The cryogenic apparatus of claim 15, wherein the wireless energy transfer mechanism is configured to implement one of: inductive heating, resonance heating, mechanical heating, resistance, wireless electrical transmission with Joule heating, piezoelectric heating, microwave heating, and radiant heating.

17. The cryogenic apparatus of any one of claims 9 to 13, wherein the cryogenic storage vessel is made of or comprises an electrically conductive material.

18. The cryogenic apparatus of claim 17, wherein the heating system comprises a wireless energy transfer mechanism.

19. The cryogenic apparatus of claim 18, wherein the wireless energy transfer mechanism is configured to implement at least radiant heating.

20. The cryogenic apparatus of any one of claims 9 to 13, wherein the cryogenic storage vessel is generally made of or generally comprises an electrically conductive material and further comprises features made of or comprising a non-electrically conductive material.

21. The cryogenic apparatus of claim 20, wherein the non-electrically conductive features of the cryogenic storage vessel comprise one or more of: one or more windows; one or more outward protrusions; and, one or more inward protrusions.

22. The cryogenic apparatus of claim 20 or 21 , wherein the heating system comprises a wireless energy transfer mechanism.

23. The cryogenic apparatus of claim 22, wherein the wireless energy transfer mechanism is configured to implement one of: inductive heating, resonance heating, mechanical heating, resistance, wireless electrical transmission with Joule heating, piezoelectric heating, microwave heating, and radiant heating.

24. The cryogenic apparatus of 21 , wherein the one or more windows comprises an optically transparent feature and the heating system is configured to implement radiant heating.

25. The cryogenic apparatus of claim 21 , wherein the outer wall comprises a first protrusion extending inwardly towards the inside of the cryogenic storage vessel and configured to house the energising element.

26. The cryogenic apparatus of claim 25, wherein the inner wall comprises a second protrusion extending inwardly towards the inside of the cryogenic storage vessel and the heating element is provided at, near or proximal the second protrusion.

27. The cryogenic apparatus of claim 26, wherein the second protrusion surrounds at least an end portion of the first protrusion, the at least end portion comprising the energising element, and the heating element surrounds an outer surface of the second protrusion.

28. The cryogenic apparatus of claim 21 , wherein the inner wall comprises a first protrusion extending outwardly towards the outside of the cryogenic storage vessel and configured to house the heating element.

29. The cryogenic apparatus of claim 28, wherein the outer wall comprises a second protrusion extending outwardly towards the outside of the cryogenic storage vessel and the energising element is provided at, near or proximal the second protrusion.

30. The cryogenic apparatus of claim 29, wherein the second protrusion surrounds at least an end portion of the first protrusion, the at least end portion comprising the heater element, and the energising element surrounds an outer surface of the second protrusion.

31. The cryogenic apparatus of any one of claims 25 to 30, wherein the heating system is configured to implement inductive heating or resistance heating.

32. The cryogenic apparatus of any one of claims 9 to 31 , wherein the enclosed volume is configured to insulate the contents of the cryogenic storage vessel from an ambient environment and associated temperatures external the cryogenic storage vessel.

33. The cryogenic apparatus of claim 32, wherein the enclosed volume comprises one or more layers of insulating materials.

34. The cryogenic apparatus of claim 32 or 33, wherein the enclosed volume is configured to comprise or contain a vacuum space.

35. The cryogenic apparatus of any one of claims 9 to 34, wherein the enclosed volume is configured to comprise or contain an aerogel.

36. The cryogenic apparatus of any one of claims 32 to 35, wherein the enclosed volume is configured to have a surface area heat leak that ranges from at least about0.5 W / m2 to about 20 W / m2.

37. The cryogenic apparatus of any one of claims 9 to 36, wherein the cryogenic fluid in the cryogenic storage vessel is hydrogen, oxygen, or liquid natural gas.

38. The cryogenic apparatus of any one of claims 9 to 37, wherein the cryogenic storage vessel is made of or comprises a lightweight composite material.

39. The cryogenic apparatus of claim 38, wherein the cryogenic storage vessel is a cryogenic fuel tank suitable for the storage and dispensing of cryogenic hydrogen used in cryogenic fuel applications.

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