Patent ID: 12196372

The figures shown in this disclosure represent various aspects of the versions presented, and only differences will be discussed in detail.

DETAILED DESCRIPTION

Disclosed versions will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all of the disclosed versions are shown. Indeed, several different versions may be provided and should not be construed as limited to the versions set forth herein. Rather, these versions are provided so that this disclosure will be thorough and fully convey the scope of the disclosure to those skilled in the art.

This specification includes references to “one version” or “a version”. The instances of the phrases “one version” or “a version” do not necessarily refer to the same version. Particular features, structures, or characteristics may be combined in any suitable manner consistent with this disclosure. All features disclosed in the specification, including the claims, abstract, and drawings, and all the steps in any method or process disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. Each feature disclosed in the specification, including the claims, abstract, and drawings, can be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise.

As used herein, “comprising” is an open-ended term, and as used in the claims, this term does not foreclose additional structures or steps.

As used herein, “configured to” means various parts or components may be described or claimed as “configured to” perform a task or tasks. In such contexts, “configured to” is used to connote structure by indicating that the parts or components include structure that performs those task or tasks during operation. As such, the parts or components can be said to be configured to perform the task even when the specified part or component is not currently operational (e.g., is not on).

As used herein, the terms “first”, “second”, etc., are used as labels for nouns that they precede, and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.).

As used herein, an element or step recited in the singular and preceded by the word “a” or “an” should be understood as not necessarily excluding the plural of the elements or steps. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As also used herein, the term “combinations thereof” includes combinations having at least one of the associated listed items, wherein the combination can further include additional, like non-listed items.

As used herein, the phrase “at least one of,” when used with a list of items, means different combinations of one or more of the listed items may be used, and only one of each item in the list may be needed. In other words, “at least one of” means any combination of items and number of items may be used from the list, but not all of the items in the list are required. The item may be a particular object, a thing, or a category.

Now referring toFIG.1,FIG.1is an illustration of a perspective view of an exemplary tank system10, such as a vacuum jacketed tank system10a, of the disclosure disposed within a structure12comprising an aircraft14. As shown inFIG.1, the aircraft14comprises a fuselage16with a plurality of fuselage barrel sections18joined together, and an outer aero skin20at a fuselage mold line22. As shown inFIG.1, the tank system10is disposed or positioned in an aft fuselage barrel section18aof the fuselage16. The tank system10may also be structurally integrated with the aft fuselage barrel section18aof the fuselage16. The tank system10may be disposed or positioned in, or structurally integrated with other fuselage barrel sections18of the fuselage16. As further shown inFIG.1, the aircraft14comprises wings24, propulsion units26, and a tail28. The tail28includes a vertical stabilizer30(seeFIG.1) and horizontal stabilizers32(seeFIG.1).

Now referring toFIG.2,FIG.2is an illustration of a block diagram of an exemplary tank system10, such as a vacuum jacketed tank system10a, of the disclosure, for use in, and powering of, an exemplary structure12, such as an aircraft14, for example, a hydrogen-powered aircraft14a. The blocks inFIG.2represent elements, and lines connecting the various blocks do not imply any particular dependency of the elements. Furthermore, the connecting lines shown in the various Figures contained herein are intended to represent example functional relationships and/or physical couplings between the various elements, but it is noted that other alternative or additional functional relationships or physical connections may be present in versions disclosed herein. One or more of these blocks may be combined, divided, or combined and divided into different blocks when implemented in an illustrative example. Further, the illustrations of the tank system10inFIG.2are not meant to imply physical or architectural limitations to the manner in which an illustrative example may be implemented. Other components in addition to, or in place of, the ones illustrated may be used. Some components may be unnecessary.

As shown inFIG.2, the structure12may also comprise other vehicles such as a rotorcraft36, a watercraft38, a train40, an automobile42, a truck44, or another suitable vehicle. Further, as shown inFIG.2, the structure12may also comprise a non-vehicle structure, such as a power plant46, a power station (PS)48, including a portable power station (PS)48aor a stationary power station (PS)48b, or another suitable non-vehicle structure.

As shown inFIG.2, the tank system10, such as the vacuum jacketed tank system10a, comprises a vacuum tank (VT)50, such as an external vacuum tank (VT)50a. The vacuum tank50has an exterior52(seeFIG.2) and an interior54(seeFIG.2). The vacuum tank50is under a vacuum55(seeFIG.2) in the interior54. The vacuum tank50has external pressure because of the difference between the inside the vacuum tank50under vacuum55and outside the vacuum tank50with pressure. The vacuum tank50is under pressure because the vacuum55cannot push against anything. As shown inFIG.3A, the vacuum tank50has a vacuum tank main portion56extending between vacuum tank end portions58, such as a forward vacuum tank end portion58aand an aft vacuum tank end portion58b. The vacuum tank main portion56has a vacuum tank skin60(seeFIG.3A). In one version, the vacuum tank50may further comprise one or more blowout panels62(seeFIGS.2,3A) formed in a vacuum tank wall64(seeFIG.3A) of the vacuum tank50. In another version, the vacuum tank50may further comprise one or more outflow valves63(seeFIG.2). In yet another version, the vacuum tank50may further comprise a large orifice or opening at a center of the aft vacuum tank end portion58b(seeFIG.3A) to provide venting and that is designed to open up at 125% of limit load pressure, and the structure12, such as the aircraft14, is designed to a 150% limit load pressure, so a pressure that reaches 125% may be considered an emergency condition152(seeFIG.2). This large orifice or opening may be advantageous to provide a way for the tank system10, including the vacuum tank50and the pressure tank80, to vent to the air78, such as the ambient air78a, outside the tank system10, to prevent a rapid pressure build up that could lead to an explosion, such as what occurs with the phenomenon known as BLEVE (boiling liquid expanding vapor explosion).

In one version, the vacuum tank50has a spherocylinder shape66(seeFIG.3A), or capsule shape, comprising a three-dimensional geometric shape with the vacuum tank main portion56having a substantially cylinder shape68(seeFIG.3A), and the vacuum tank end portions58each having a semi-ellipsoid shape70(seeFIG.3A). In other versions, the vacuum tank end portions58may have a hemisphere shape, or another curved shape. In other versions, the vacuum tank50has another suitable three-dimensional geometric shape.

In one version, the vacuum tank skin60has a longitudinal cross section72(seeFIG.3A) with a profile geometry74(seeFIG.3A) comprising a straight profile76(seeFIG.3A). In other versions, the vacuum tank skin60has a longitudinal cross section72with a profile geometry74having another suitable shape. The vacuum tank50, such as the external vacuum tank50a, is designed to withstand external pressure caused by air78(seeFIG.2), such as ambient air78a(seeFIG.2), on the outside of the vacuum tank50and the vacuum55(seeFIG.2) inside the interior54of the vacuum tank50. The primary stresses in the vacuum tank50, such as the external vacuum tank50a, are compression in both the longitudinal and the hoop directions.

As shown inFIG.2, the tank system10further comprises a pressure tank (PT)80, such as an internal pressure tank (PT)80a, mounted within the vacuum tank50. The pressure tank80is configured to contain, and contains, a cryogenic fluid82(seeFIG.2). As shown inFIG.2, the cryogenic fluid82comprises one of, liquid hydrogen84, liquid natural gas86, or another suitable cryogenic fluid, and is designed to function as a fuel and to provide fuel power to the structure12, such as the aircraft14, or other structure. The pressure tank80, such as the internal pressure tank80a, carries the cryogenic fluid82under pressure. The primary stresses in the pressure tank80, such as the internal pressure tank80a, are tension in both the longitudinal and the hoop directions.

As shown inFIG.2, the pressure tank80has an exterior88and an interior90. As shown inFIG.3B, the pressure tank80has a pressure tank main portion92extending between pressure tank end portions94, such as a forward pressure tank end portion94aand an aft pressure tank end portion94b. The pressure tank main portion92has a pressure tank skin96(seeFIG.3B). As shown inFIGS.2,3B, the pressure tank main portion92further has one or more openings100formed through the pressure tank skin96, or wall, at one or more locations102(seeFIG.3B) on the pressure tank main portion92.

In one version, each of the one or more openings100has a circular shape104(seeFIG.2) and each has a diameter106(seeFIG.2). In other versions, each of the one or more openings100has another suitable shape. In one version, the diameter106of each opening100has a length108(seeFIG.2) in a range of from 1 (one) inch (2.54 centimeters) to 12 (twelve) inches (30.48 centimeters) in length. In another version, the diameter106of each opening100has a length108(seeFIG.2) in a range of from 1 (one) inch (2.54 centimeters) to 2 (two) inches (5.08 centimeters) in length. In other versions, the diameter106of each opening100has another suitable length108.

In one version, each of the one or more openings100is the same size with each diameter106having a length108that is the same or equal. In another version, one or more of the openings100are the same size with each diameter106having a length108that is the same or equal, and one or more of the openings100are of one or more different sizes with each diameter106having one or more lengths108that are different. In yet another version, each of the one or more openings100are of different sizes with each diameter106having a length108that is different.

In one version, the one or more openings100comprise a number in a range of 1 (one) opening100to 6 (six) openings100. In other versions, the one or more openings100comprise a number in a range of 1 (one) opening100to 20 (twenty) openings100. In other versions, the openings100comprise a number greater than 20 (twenty) openings100.

The pressure tank80is designed and made of a material (MAT.)110(seeFIG.2) that is durable and suitable to withstand the extremely low temperatures of the cryogenic fluid82stored in the pressure tank80, such as the liquid hydrogen84, the liquid natural gas86, or another suitable cryogenic fluid. The vacuum tank50is also designed or made of the material110that is durable and suitable to withstand the extremely low temperatures of the cryogenic fluid82once the cryogenic fluid82stored in the pressure tank80is released and contacts the vacuum tank50.

For example, for liquid hydrogen84to be in a fully liquid state at atmospheric pressure, the liquid hydrogen84needs to be cooled to 20.28 K (Kelvin) (minus 252.87 degrees C. (Celsius); minus 423.17 degrees F. (Fahrenheit)). Further, for example, for the liquid natural gas86to be in a fully liquid state at atmospheric pressure, the liquid natural gas86needs to be cooled to 110.93 K (Kelvin) (minus 162 degrees C. (Celsius); minus 260 degrees F. (Fahrenheit)).

In one version, the pressure tank80and/or the vacuum tank50are formed of a metal material (MAT.)110a(seeFIG.2) including steel, stainless steel, aluminum alloy, titanium alloy, copper, copper alloy, or another suitable metal material. In another version, the pressure tank80and/or the vacuum tank50are formed of a polymer material (MAT.)110b(seeFIG.2), including thermoplastic, polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), high density polyethylene, polyamide, elastomer, rubber, or another suitable polymer material. In another version, the pressure tank80and/or the vacuum tank50are formed of a composite material (MAT.)110c(seeFIG.2), including carbon fiber reinforced polymer (CFRP), or another suitable composite material. In another version, the pressure tank80and/or the vacuum tank50are formed of another suitable material designed to withstand extremely low temperatures of the cryogenic fluid82. The pressure tank80and the vacuum tank50may be made of the material110that is the same or may be made of the material110that is different.

In one version, like the vacuum tank50, the pressure tank80has a spherocylinder shape66a(seeFIG.3B), or capsule shape, comprising a three-dimensional geometric shape with the pressure tank main portion92having a substantially cylinder shape68a(seeFIG.3B), and the pressure tank end portions94each having a semi-ellipsoid shape70a(seeFIG.3B). In other versions, the pressure tank80has another suitable three-dimensional geometric shape. As shown inFIG.3B, the pressure tank80has a pressure tank outer surface112aand a pressure tank inner surface112b, and the vacuum tank50has a vacuum tank outer surface114aand a vacuum tank inner surface114b. As shown inFIG.3B, the pressure tank outer surface112acorresponds, or substantially corresponds, to the vacuum tank inner surface114b.

In one version, the pressure tank skin96has a longitudinal cross section72a(seeFIG.3B) with a profile geometry74a(seeFIG.3B) comprising a straight profile76a(seeFIG.3B). In other versions, the vacuum tank skin60has a longitudinal cross section72awith a profile geometry74ahaving another suitable shape.

As shown inFIG.2, the pressure tank80further comprises a removable plug assembly116. The removable plug assembly116comprises one or more removable plug elements118, where each of the one or more removable plug elements118is configured to plug and to unplug each of the one of the one or more openings100. For example, one removable plug element118plugs and unplugs one opening100. The number of removable plug elements118corresponds to the number of openings100.

In one version, the removable plug element118comprises a first portion (PORT.)120(seeFIGS.2,4B), such as an outer portion120a(seeFIG.4B), having a cylindrical (CYLIND.) body124a(seeFIGS.2,4B), with a diameter106a(seeFIGS.2,4B) having a length108a(seeFIGS.2,4B). The removable plug element118further comprises a second portion (PORT.)122(seeFIGS.2,4B), such as an inner portion122a(seeFIG.4B), coupled to, or integral with, the first portion120, such as the outer portion120a. The second portion122, such as the inner portion122a, has a cylindrical (CYLIND.) body124b(seeFIGS.2,4B), with a diameter106b(seeFIGS.2,4B) having a length108b(seeFIGS.2,4B). As shown inFIG.4B, the length108bof the diameter106bof the second portion122, such as the inner portion122a, is greater than the length108aof the diameter106aof the first portion120, such as the outer portion120a. In other versions, the first portion120, such as the outer portion120a, and the second portion122, such as the inner portion122a, have other suitable shapes.

The first portion120, such as the outer portion120a, is of a sufficient size and the length108aof the diameter106aallows the first portion120, such as the outer portion120a, of the removable plug element118to fit within the opening100, and the length108aof the diameter106amay be in a range of slightly less than 1 (one) inch (2.54 centimeters), for example, 0.99 inch (2.51 centimeters) to slightly less than 12 (twelve) inches (30.48 centimeters), for example, 11.99 inches (30.45 centimeters) in length. In other versions, the length108aof the diameter106aof the first portion120, such as the outer portion120a, has another suitable length that allows the removable plug element118to fit within the opening100.

In one version, each of the one or more removable plug elements118is the same size and shape or configuration. In another version, each of the one or more removable plug elements118is a different size and shape or configuration. In yet another version, one or more of the removable plug elements118is the same size and shape or configuration, and one or more of the removable plug elements118is a different size and shape or configuration.

In one version, the one or more removable plug elements118comprise a number in a range of 1 (one) removable plug element118to 6 (six) removable plug elements118. In other versions, the one or more removable plug elements118comprise a number in a range of 1 (one) removable plug element118to 20 (twenty) removable plug elements118. In other versions, the removable plug elements118comprise a number greater than 20 (twenty) removable plug elements118.

Each of the one or more removable plug elements118is made of the material110that is durable and able to withstand the low temperatures of the cryogenic fluid82, including the liquid hydrogen84, the liquid natural gas86, or another suitable cryogenic fluid. In one version, the one or more removable plug elements118are formed of the metal material110a(seeFIG.2) including steel, stainless steel, aluminum alloy, titanium alloy, copper, copper alloy, or another suitable metal material. In another version, the one or more removable plug elements118are formed of the polymer material110b(seeFIG.2), including thermoplastic, polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), high density polyethylene, polyamide, elastomer, rubber, or another suitable polymer material. In another version, the one or more removable plug elements118are formed of the composite material110c(seeFIG.2), including carbon fiber reinforced polymer (CFRP), or another suitable composite material. In another version, the one or more removable plug elements118are formed of another suitable material designed to withstand the extremely low temperatures of the cryogenic fluid82. In one version, the one or more removable plug elements118and the pressure tank80are made of the same material110. In another version, the one or more removable plug elements118and the pressure tank80are made of different materials110.

As shown inFIG.2, the tank system10may optionally comprise a plug seal126. The plug seal126is coupled to one or more of the removable plug elements118at the one or more openings100, when the removable plug element118is inserted and fitted within the opening100. As shown inFIG.4B, the plug seal126surrounds a base121of the first portion120and is seated against top surface portions123of the second portion122. The plug seal126comprises an O-ring, a gasket, or another suitable plug seal member. The plug seal126is made of a polymer material110b(seeFIG.2), such as plastic, elastomer, rubber, or another suitable plastic material. The plug seal126is discussed in further detail below with respect toFIG.4B.

A sealant128(seeFIG.4B), such as an adhesive sealant, is preferably applied to one or more surfaces of the plug seal126(seeFIG.4B) and/or applied to one or more locations130a(seeFIG.4B) on the pressure tank inner surface112bat the opening100, to further seal at the opening100and at the removable plug element118contacting the opening100. Alternatively, the sealant128, such as the adhesive sealant, may be used instead of the plug seal126, to seal at and around the opening100and at and around the removable plug element118at the one or more locations130a(seeFIG.4B) of the pressure tank inner surface112b(seeFIG.4B). The sealant128, such as the adhesive sealant, may comprise an epoxy adhesive, a silicone adhesive, or another suitable adhesive sealant capable of withstanding the extreme low temperatures of the cryogenic fluid82within the pressure tank80.

As shown inFIG.2, the tank system10may optionally further comprise a membrane seal132. In one version, as shown inFIG.5B, the membrane seal132is used in addition to, and in conjunction with, the plug seal126. In another version, the membrane seal132is used instead of the plug seal126. As shown inFIG.5B, in one version, the membrane seal132is positioned over, and adjacent to, the second portion122, such as the inner portion122a, of the removable plug element118, over the plug seal126, and is coupled to locations130b(seeFIG.5B) on the pressure tank inner surface112b(seeFIG.5B). The membrane seal132is coupled to the pressure tank inner surface112bwith an attachment element such as adhesive or another suitable attachment element. The membrane seal132may comprise a metal foil, such as an aluminum foil or another suitable metal foil material, may comprise a polymeric material or plastic material, or may comprise another suitable material. Preferably, the membrane seal132is configured to be torn to allow the removable plug element118to be pulled through the membrane seal132, when the removable plug element118is released from the opening100. The membrane seal132is discussed in further detail below with respect toFIG.5B.

As shown inFIG.2, in another version, alternative to the removable plug assembly116with the removable plug elements118, the pressure tank80may comprise a valve assembly134with one or more valves135, each valve135located at the one or more openings100. The one or more valves135are configured to close and to open to allow the cryogenic fluid82to exit and to flow from the pressure tank80, through the one or more openings100.

As shown inFIG.2, the pressure tank80further comprises a retraction mechanism136positioned within the interior90of the pressure tank80. The retraction mechanism136is coupled, or attached, to the one or more removable plug elements118of the removable plug assembly116. In one version, as shown inFIGS.2,3B, and4A, the retraction mechanism136comprises a central rotatable tube138having a length140(seeFIG.3B) that runs along a longitudinal centerline142(seeFIG.3B). The retraction mechanism136further comprises an actuator144(seeFIGS.2,3B) coupled to the central rotatable tube138. The actuator144is configured to rotate the central rotatable tube138. In one version, the actuator144preferably comprises a spring actuator with a latch that releases a spring to remove the removable plug elements118from the openings100. In other versions, the actuator144may comprise a mechanical actuator powered by a motor or electric power, a hydraulic actuator powered by a motorized pump, or another suitable actuator.

As shown inFIGS.2,3B, and4A, in one version, the retraction mechanism136further comprises one or more cables145attached to the central rotatable tube138and attached to the one or more removable plug elements118, or attached to the one or more valves135. As shown inFIG.4A, each cable145has a first end146aattached to the central rotatable tube138, and each cable145has a second end146battached to the removable plug element118, or attached to the valve135. When the central rotatable tube138is rotated by the actuator144, the cables145attached to the removable plug elements118start winding around an exterior138a(seeFIG.3B) of the central rotatable tube138. This puts tension into the cables145.

As shown inFIG.2, the retraction mechanism136may further comprise a safety lock mechanism148to provide unintended operation prevention149of the removable plug assembly116, that is, to prevent unintended or accidental operation or activation of the removable plug assembly116, causing the removable plug elements118to be released from the openings100. The safety lock mechanism148may be attached at any number of locations on the retraction mechanism136. The safety lock mechanism148is configured to be quickly disengaged, so that the retraction mechanism136is activated to release the removable plug assembly116or the valve assembly134.

The retraction mechanism136is activated or caused to operate with an activation system150(seeFIG.2). The activation system150is activated when an emergency condition152(seeFIG.2), or an emergency situation, occurs. As shown inFIG.2, the activation system150comprises an automatic activated activation system150a, an operator activated activation system150b, a pilot activated activation system150c, or another suitable activation system.

As shown inFIG.2, the emergency condition152, or emergency situation, comprises one or more of, an emergency landing154of the aircraft14, when the structure12comprises an aircraft14, a forced landing155of the aircraft14, when the structure12comprises an aircraft14, the pressure tank80experiencing an elevated acceleration level156of acceleration157, or high acceleration, of the aircraft14, when the structure12comprises an aircraft14, the pressure tank80experiencing an elevated force level158of force159, or high force, an event160causing a breach162or a potential breach162aof the vacuum tank50, and/or an airflow164or a potential airflow164aof the air78, such as the ambient air78a, into the pressure tank80, or another type of emergency condition experienced by the structure12, for example, the aircraft14. The emergency landing154encompasses a crash landing. An example of an elevated force level158includes projectiles, such as bullets, or missiles, or other types of projectiles, being fired at the vacuum tank50and/or the pressure tank80. Further, the emergency condition152includes any condition or event where there is an increased probability that the vacuum tank50might be breached to cause the air78, such as ambient air78a, to flow into the pressure tank80. If the air78, such as the ambient air78a, mixes with the cryogenic fluid82, such as the liquid hydrogen84or liquid natural gas86, in the pressure tank80, the resulting mixture is highly volatile and explosive with a very low activation energy. The removable plug assembly116of the tank system10allows the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, to exit in the emergency condition152.

Since the initiation of the activation system150to activate the retraction mechanism136may result in very large thermal leakage of the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, from the pressure tank80to the outside ambient environment, measures are taken to ensure that the activation system150is initiated or activated only when necessary. Initiation or activation of the activation system150greatly reduces the range of a vehicle such as an aircraft14, if the activation system150is initiated or activated for all of the pressure tanks80of the aircraft14.

The activation system150is designed to be initiated or activated with the occurrence of several conditions or situations. In one version, the activation system150is operator or pilot actuated or activated, for example, with the operator activated activation system150bor the pilot activated activation system150c. If the operator or pilot anticipates an emergency condition152for which it is likely that the pressure tank80or pressure tanks80may rupture, for example, the emergency landing154or the forced landing155of the aircraft14, the operator or pilot may manually initiate or activate the activation system150, such as the operator activated activation system150bor the pilot activated activation system150c, from the flight deck or the cockpit of the aircraft14with a control for the activation system150located in the flight deck or the cockpit. The control that is located in the flight deck or the cockpit may have features to ensure that it cannot be accidentally initiated or activated.

In another version, the activation system150is automatically activated, for example, with the automatic activated activation system150a. If the structure12, such as the aircraft14or other vehicle, experiences elevated acceleration levels156of acceleration157, or high acceleration, of the aircraft14or other vehicle over a predetermined threshold of acceleration157, the activation system150, such as the automatic activated activation system150a, has a sensor that senses the elevated acceleration level156of acceleration157, and is then automatically initiated or activated.

In yet another version, the activation system150is automatically activated, for example, with the automatic activated activation system150a. If the pressure tank80of the structure12, such as the aircraft14or other vehicle, experiences elevated acceleration levels156of acceleration157, or high acceleration, above a predetermined threshold of acceleration157in a vicinity of the one or more pressure tanks80, or if the pressure tank80experiences elevated force levels158of force159, or high force, above a predetermined threshold of force159in a vicinity of the one or more pressure tanks80, the activation system150, such as the automatic activated activation system150a, has a sensor that senses the elevated acceleration level156of acceleration157, and has a sensor that senses the elevated force level158of force159, and is then automatically initiated or activated.

In yet another version, an operator or a pilot of the vehicle, such as the aircraft14, can manually override the activation system150, such as the automatic activated activation system150a, that is initiated or activated by the elevated acceleration levels156of acceleration157above the predetermined threshold of acceleration157of the aircraft14or in the vicinity of the pressure tanks80. For example, there may be situations in which elevated acceleration levels156of acceleration157are present and it is not desirable to initiate the activation system150, such as the automatic activated activation system150a. In this situation, the operator or the pilot may use an override control located in the flight deck of the cockpit to override or disable the automatic initiation of the automatic activated activation system150acaused by the elevated acceleration levels156of acceleration157.

As further shown inFIGS.2,3B, the tank system10, such as the vacuum jacketed tank system10afurther comprises a vacuum cavity166that forms a gap168between the pressure tank outer surface112aand the vacuum tank inner surface114b. The size of the gap168is a consequence of the geometry and design of the vacuum tank50and the pressure tank80. For example, in one version, the gap168has a typical length of 1 (one) inch (2.54 centimeters). However, the gap168may have another suitable length. The pressure tank80is designed to fit the internal mold surface of the vacuum tank, thus maximizing the volume of the pressure tank80relative to the enclosed volume of the vacuum tank50. If the gap168is small, this may result in favorable efficiency.

The vacuum cavity166formed around the pressure tank80provides an area for the air78to flow into and liquefy, should the vacuum tank50be breached. The vacuum cavity166limits the thermal transfer between the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, and the ambient air78a. When the pressure tank80and the vacuum tank50are breached, the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, flows from the pressure tank80through the vacuum tank50and out into the air78, such as the ambient air78a. Since the pressure tank80is pressurized with a pressure greater than the ambient air78a, the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, flows outward into the ambient air78a, instead of the air78, such as the ambient air78aflowing into the pressure tank80. This is important as it prevents the formation of a mixture forming of the liquid air and the liquid hydrogen84or liquid natural gas86, which is explosive.

The pressure tank80, such as the internal pressure tank80a, is configured with the removable plug assembly116having the removable plug elements118that are quick to release, or is configured with the valve assembly134having the valves135that are quick to open, to allow the rapid flow of the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, from the pressure tank80into the vacuum cavity166between the pressure tank80and the vacuum tank50. The one or more removable plug elements118or the one or more valves135are installed at the one or more openings to provide a quick release of the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, from the pressure tank80into the vacuum cavity166

The removable plug elements118or the valves135prevent the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, from escaping from the pressure tank80during normal conditions or normal operation, when the structure12and the tank system10are not experiencing an emergency condition152. The one or more openings100formed through the pressure tank skin96(seeFIG.3B) of the pressure tank80allow the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, to quickly or rapidly flow into the vacuum cavity166in the emergency condition152or emergency situation, when the one or more removable plug elements118are pulled away from, and out of, the openings100, or the one or more valves135are opened to the openings100. In one version, the retraction mechanism136pulls the one or more removable plug elements118away from, and out of, the one or more openings100during the emergency condition152or emergency situation. In another version, the retraction mechanism136causes the one or more valves135to open at the one or more openings100during the emergency condition152or emergency situation.

The vacuum tank50, such as the external vacuum tank50a, provides a barrier between the ambient air78aand the vacuum cavity166. The vacuum tank50, such as the external vacuum tank50a, is designed to withstand the external pressure loading which is a result of the pressure of the ambient air78aacting on the vacuum tank outer surface114aof the vacuum tank50, and nothing acting on the vacuum tank inner surface114bof the vacuum tank50. Further, the vacuum tank50, such as the external vacuum tank50a, maintains the vacuum cavity166between the vacuum tank50and the pressure tank80, and also carries the external pressure load resulting from that vacuum55(seeFIG.2).

When an emergency condition152occurs, the retraction mechanism136is activated to pull the one or more removable plug elements118away from, and out of, the one or more openings100and into the interior90of the pressure tank80, to allow the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, to exit and to flow from the pressure tank80, through the one or more openings100, and into the vacuum cavity166. When the vacuum tank50has a breach162(seeFIG.2), the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, is further allowed to exit and to flow out into the air78, such as the ambient air78a.

Now referring toFIGS.3A-3B,FIG.3Ais an illustration of a side view of an exemplary vacuum tank50, such as an external vacuum tank50a, of an exemplary tank system10(see alsoFIG.2), such as a vacuum jacketed tank system10a, of the disclosure.FIG.3Bis an illustration of a cross-sectional side view of an exemplary pressure tank80, such as an internal pressure tank80a, within the vacuum tank50, such as the external vacuum tank50a, ofFIG.3A, of the exemplary tank system10(see alsoFIG.2), such as the vacuum jacketed tank system10a, of the disclosure.

As shown inFIGS.3A-3B, the vacuum tank50comprises the exterior52having the vacuum tank outer surface114a, and the interior54(seeFIG.3B) having the vacuum tank inner surface114b(seeFIG.3B). The vacuum tank50is under a vacuum55(seeFIG.2) in the interior54. The vacuum tank50withstands external pressure caused by ambient air78a(seeFIG.2) on the outside and on the exterior52of the vacuum tank50and the vacuum55inside the interior54of the vacuum tank50.

As shown inFIGS.3A-3B, the vacuum tank50has a vacuum tank main portion56extending between vacuum tank end portions58, such as the forward vacuum tank end portion58aand the aft vacuum tank end portion58b. As shown inFIG.3A, the vacuum tank main portion56has a vacuum tank main portion length170. As further shown inFIG.3A, the forward vacuum tank end portion58ahas a forward length172a, and the aft vacuum tank end portion58bhas an aft length172b. As shown inFIG.3A, in this version of the vacuum tank50, the forward length172aand the aft length172bare the same size lengths, and the forward length172aand the aft length172bare each less length size than the size of the vacuum tank main portion length170. In another version, the forward length172aand the aft length172bmay be different size lengths.

As shown inFIG.3A, the vacuum tank main portion56has end rings174(see alsoFIG.3B), including a forward end ring174aand an aft end ring174b. The forward end ring174ais a structure attached around a circumference at a forward end175a(seeFIG.3A) of the vacuum tank main portion56, and the forward end ring174ais positioned between the forward end175aof the vacuum tank main portion56and the forward vacuum tank end portion58a. The aft end ring174bis a structure attached around a circumference at an aft end175b(seeFIG.3A) of the vacuum tank main portion56, and the aft end ring174bis positioned between the aft end175bof the vacuum tank main portion56and the aft vacuum tank end portion58b.

As shown inFIG.3A, the vacuum tank50has a spherocylinder shape66, or capsule shape, comprising a three-dimensional geometric shape with the vacuum tank main portion56having a substantially cylinder shape68, and the vacuum tank end portions58each having a semi-ellipsoid shape70. In other versions, the vacuum tank50has another suitable three-dimensional geometric shape. The vacuum tank50may have an untapered, straight profile, may have a tapered profile, or may have another suitable profile.

The vacuum tank main portion56has the vacuum tank skin60(seeFIG.3A). As shown inFIG.3A, in this version, the vacuum tank skin60of the vacuum tank main portion56has the longitudinal cross section72with the profile geometry74comprising the straight profile76. However, in other versions, the vacuum tank skin60may have the longitudinal cross section72with the profile geometry74having another suitable profile geometry.

As shown inFIG.3B, stiffener members176, such as stringers176a, in the longitudinal direction may be coupled, or attached, to various portions along the vacuum tank outer surface114aon the exterior52of the vacuum tank50. The stiffener members176, such as the stringers176a, are removed inFIG.3Afor clarity.

As shown inFIG.3A, the vacuum tank50further comprises blowout panels62formed in the vacuum tank wall64(seeFIG.3A) of the vacuum tank50. The exterior of the blowout panels62is preferably flush or continuous with the exterior of the vacuum tank skin60. The blowout panel62is a safety device used to relieve pressure inside the tank system10and to convey any explosive effect from inside the tank system10to outside the tank system10in the ambient air78a. The blowout panels62are designed to open at a predetermined pressure to avoid a potentially explosive atmosphere or to safely convey any explosive effects.FIGS.3A-3Bfurther show the longitudinal centerline142of the vacuum tank50and the pressure tank80.

As shown inFIG.3B, the pressure tank80, such as the internal pressure tank80a, is mounted within the vacuum tank50, and is attached to the interior54of the vacuum tank50with tank attach fittings178, such as a forward tank attach fitting178aand an aft tank attach fitting178b. The pressure tank80is configured to contain, and contains, the cryogenic fluid82(seeFIG.2), such as the liquid hydrogen84, the liquid natural gas86, or another suitable cryogenic fluid.

As shown inFIG.3B, the pressure tank80comprises the exterior88having the pressure tank outer surface112a, and the interior90having the pressure tank inner surface112b. As further shown inFIG.3B, the pressure tank80comprises the pressure tank main portion92extending between pressure tank end portions94, such as the forward pressure tank end portion94aand the aft pressure tank end portion94b. As shown inFIG.3B, the pressure tank main portion92has a pressure tank main portion length180. In one version, the pressure tank main portion length180(seeFIG.3B) is the same length, or substantially the same length, as the vacuum tank main portion length170(seeFIG.3A)

As shown inFIG.3B, the pressure tank main portion92has end boundaries182, including forward end boundaries182aand aft end boundaries182b. As shown inFIG.3B, the forward end boundaries182aare positioned between a forward end184aof the pressure tank main portion92and the forward pressure tank end portion94a, and the aft end boundaries182bare positioned between an aft end184bof the pressure tank main portion92and the aft pressure tank end portion94b.

As shown inFIG.3B, the pressure tank80has a spherocylinder shape66a, or capsule shape, comprising a three-dimensional geometric shape with the pressure tank main portion92having a substantially cylinder shape68a, and the pressure tank end portions94each having a semi-ellipsoid shape70a. In other versions, the pressure tank80has another suitable three-dimensional geometric shape.

The pressure tank main portion92has the pressure tank skin96(seeFIG.3B). As shown inFIG.3B, in this version, the pressure tank skin96of the pressure tank main portion92has the longitudinal cross section72awith the profile geometry74acomprising the straight profile76a. However, in other versions, the pressure tank skin96may have the longitudinal cross section72awith the profile geometry74ahaving another suitable profile geometry. The pressure tank80may or may not be designed to be very closely related geometrically to the vacuum tank50. For example, the longitudinal cross section72awith the profile geometry74ahaving the straight profile76aof the pressure tank80may correspond to the longitudinal cross section72with the profile geometry74having the straight profile76of the vacuum tank50.

FIG.3Bfurther shows the vacuum cavity166with the gap168between the pressure tank outer surface112aof the pressure tank80and the vacuum tank inner surface114bof the vacuum tank50. The gap168is determined based on the geometry and design of the pressure tank80and the vacuum tank50. In one version, the pressure tank80may be designed to fit the inner mold line or inner mold surface of the vacuum tank50, thus maximizing the volume of the pressure tank80relative to the enclosed volume of the vacuum tank50.

As shown inFIG.3B, the pressure tank main portion92further has openings100formed through the pressure tank skin96at one or more locations102on the pressure tank main portion92. As shown inFIG.3B, the pressure tank main portion92has 4 (four) openings100on a top side185aand4(four) openings100on a bottom side185b. Each opening100on the top side185ais opposite each respective opening100on the bottom side185b.

As further shown inFIG.3B, the pressure tank80comprises the removable plug assembly116. The removable plug assembly116comprises removable plug elements118, where each of the removable plug elements118is configured to plug and to unplug each of the openings100. The number of removable plug elements118corresponds to the number of openings100. As shown inFIG.3B, the removable plug assembly116has 4 (four) removable plug elements118plugged in, or inserted in, the4(four) openings100on the top side185a, and the removable plug assembly116has 4 (four) removable plug elements118plugged in, or inserted in, the4(four) openings100on the bottom side185b.

As shown inFIG.3A, the pressure tank80further comprises the retraction mechanism136positioned within the interior90of the pressure tank80. The retraction mechanism136comprises the central rotatable tube138having a length140(seeFIG.3B) that runs along the longitudinal centerline142(seeFIG.3B). The retraction mechanism136further comprises the actuator144(seeFIG.3B) coupled to the central rotatable tube138. The actuator144is configured to rotate the central rotatable tube138.

As shown inFIG.3B, in one version, the retraction mechanism136further comprises one or more cables145attached to the central rotatable tube138and attached to the one or more removable plug elements118. As shown inFIG.3B, each cable145has a first end146aattached to the central rotatable tube138, and each cable145has a second end146battached to the removable plug element118. When the central rotatable tube138is rotated by the actuator144, the cables145attached to the removable plug elements118start winding around an exterior138a(seeFIG.3B) of the central rotatable tube138. This puts tension into the cables145.

Now referring toFIG.4A,FIG.4Ais an illustration of a cross-sectional front view of an exemplary tank system10, such as a vacuum jacketed tank system10a, of the disclosure, showing a version of a removable plug assembly116with six (6) removable plug elements118with plug seals126. As shown inFIG.4A, the tank system10, such as the vacuum jacketed tank system10a, comprises the vacuum tank50, such as the external vacuum tank50a, having the exterior52with the vacuum tank outer surface114a, and the interior54with the vacuum tank inner surface114b.FIG.4Ashows the vacuum tank main portion56and shows air78, such as ambient air78a, surrounding the exterior52of the vacuum tank10. The vacuum tank50is under a vacuum55(seeFIG.2) in the interior54.

As shown inFIG.4A, the tank system10further comprises the pressure tank80, such as the internal pressure tank80a, mounted within the vacuum tank50. The pressure tank80is configured to contain the cryogenic fluid82(seeFIGS.2,9A), such as liquid hydrogen84(seeFIGS.2,9A), liquid natural gas86(seeFIG.2), or another suitable cryogenic fluid. As shown inFIG.4A, the pressure tank80has the exterior88with the pressure tank outer surface112a, and the interior90with the pressure tank inner surface112b.FIG.4Bshows the pressure tank main portion92with the pressure tank skin96. As shown inFIG.4A, the openings100, such as six (6) openings100, are formed through the pressure tank skin96at locations102on the pressure tank main portion92. As shown inFIG.4A, each removable plug element118is inserted through each opening100and is securely fitted in each opening100. The removable plug elements118prevent the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, from escaping from the pressure tank80during normal conditions or operation. As shown inFIG.4A, in this version, the six (6) removable plug elements118are spaced apart from each other in an equal distance spaced relationship204around a perimeter205of the pressure tank80.

As shown inFIG.4A, the pressure tank80further comprises the retraction mechanism136positioned within the interior90of the pressure tank80. The retraction mechanism136comprises the central rotatable tube138, the cables145, and the actuator144(seeFIG.3B). The retraction mechanism136is coupled, or attached, to the removable plug elements118of the removable plug assembly116, via the cables145. Each cable145has a first end146a(seeFIG.4A) attached to the central rotatable tube138and a second end146b(seeFIG.4A) attached to the removable plug element118. As shown inFIG.4A, there are six (6) cables145, and each cable145is coupled, or attached, to one removable plug element118. When the central rotatable tube138is rotated by the actuator144(seeFIG.3B), the cables145attached to the removable plug elements118start winding around an exterior138a(seeFIG.3B) of the central rotatable tube138. This puts tension into the cables145. As shown inFIG.4A, the number of removable plug elements118corresponds to the number of openings100and corresponds to the number of cables145. The retraction mechanism136is configured to pull the removable plug elements118away from, and out of, the openings100during the emergency condition152(seeFIG.2).

FIG.4Afurther shows the vacuum cavity166and the gap168formed between the vacuum tank inner surface114bof the vacuum tank50and the pressure tank outer surface112aof the pressure tank80. As shown inFIG.4A, the gap168has a width186from the vacuum tank inner surface114bto the pressure tank outer surface112a, and the width186of the gap168may be constant and uniform between the vacuum tank50and the pressure tank80.

Now referring toFIG.4B,FIG.4Bis an illustration of a cross-sectional enlarged front view of a version of an exemplary removable plug element118of the circle4B ofFIG.4A. In one version, as shown inFIG.4B, the removable plug element118comprises the first portion120, such as the outer portion120a, having the cylindrical body124awith a diameter106ahaving a length108a. As shown inFIG.4B, the removable plug element118further comprises the second portion122, such as the inner portion122a, coupled to, or integral with, the first portion120, such as the outer portion120a, and having the cylindrical body124bwith a diameter106bhaving a length108b. As shown inFIG.4B, the length108bof the diameter106bof the second portion122, such as the inner portion122a, is greater than the length108aof the diameter106aof the first portion120, such as the outer portion120a. In other versions, the first portion120, such as the outer portion120a, and the second portion122, such as the inner portion122a, have other suitable shapes. The first portion120, such as the outer portion120a, is of a sufficient size and the length108aof the diameter106aallows the first portion120, such as the outer portion120a, of the removable plug element118to fit within the opening100. As shown inFIG.4B, exterior side surfaces188of the first portion120are in contact with walls190of the opening100formed in the pressure tank80. The second portion122, such as the inner portion122a, is of a sufficient size and the length108bof the second portion122is greater than the length108aof the first portion120to prevent the removable plug element118from moving radially past the pressure tank skin96.

As shown inFIG.4B, the plug seal126is coupled to the removable plug element118at the opening100, to provide a sealing of the opening100when the removable plug element118is inserted and fitted within the opening100. As shown inFIG.4B, the plug seal126surrounds the base121of the first portion120and is seated against the top surface portions123of the second portion122.

As shown inFIG.4B, a sealant128(seeFIG.4B), such as an adhesive sealant, may optionally be applied to one or more surfaces of the plug seal126and/or applied to one or more locations130aon the pressure tank inner surface112bat the opening100, to further seal at the opening100and at the removable plug element118contacting the opening100. Alternatively, the sealant128, such as the adhesive sealant, may be used instead of the plug seal126, to seal at and around the opening100and at and around the removable plug element118at the one or more locations130a(seeFIG.4B) on the pressure tank inner surface112b(seeFIG.4B).

FIG.4Bfurther shows the second end146bof the cable145attached to an inner end192of the second portion122.FIG.4Bfurther shows the vacuum tank50, and the vacuum cavity166and the gap168formed between the vacuum tank inner surface114bof the vacuum tank50and the pressure tank outer surface112aof the pressure tank80.FIG.4Bfurther shows the air78, such as the ambient air78a, outside the vacuum tank50.

Now referring toFIG.5A,FIG.5Ais an illustration of a cross-sectional front view of an exemplary tank system10, such as the vacuum jacketed tank system10a, of the disclosure, showing another version of a removable plug assembly116with six (6) removable plug elements118, where each removable plug element118is further sealed with a membrane seal132. As shown inFIG.5A, the membrane seal132is used in addition to, and in conjunction with, the plug seal126for each removable plug element118.

Like the tank system10inFIG.4A, the tank system10shown inFIG.5Acomprises the vacuum tank50, such as the external vacuum tank50a, having the exterior52with the vacuum tank outer surface114a, the interior54with the vacuum tank inner surface114b, and the vacuum tank main portion56.FIG.5Ashows the air78, such as ambient air78a, surrounding the exterior52of the vacuum tank50.

As shown inFIG.5A, the tank system10further comprises the pressure tank80, such as the internal pressure tank80a, mounted within the vacuum tank50, and the pressure tank80is configured to contain the cryogenic fluid82(seeFIGS.2,9A), such as liquid hydrogen84(seeFIGS.2,9A), liquid natural gas86(seeFIG.2), or another suitable cryogenic fluid. As shown inFIG.5A, the pressure tank80has the exterior88with the pressure tank outer surface112a, the interior90with the pressure tank inner surface112b, the pressure tank main portion92with the pressure tank skin96, and the openings100, such as six (6) openings100, formed through the pressure tank skin96at locations102on the pressure tank main portion92. As shown inFIG.5A, in this version, the six (6) removable plug elements118are spaced apart from each other in the equal distance spaced relationship204around the perimeter205of the pressure tank80.

FIG.5Afurther shows the retraction mechanism136positioned within the interior90of the pressure tank80, and having the central rotatable tube138and the cables145. Each cable145has the first end146a(seeFIG.5A) attached to the central rotatable tube138and the second end146b(seeFIG.5A) attached to the removable plug element118. As shown inFIG.5A, there are six (6) cables145, and each cable145is coupled, or attached, to one removable plug element118. When the central rotatable tube138is rotated by the actuator144(seeFIG.3B), the cables145attached to the removable plug elements118start winding around an exterior138a(seeFIG.5A) of the central rotatable tube138. This puts tension into the cables145.

FIG.5Afurther shows the vacuum cavity166and the gap168formed between the vacuum tank inner surface114bof the vacuum tank50and the pressure tank outer surface112aof the pressure tank80. As shown inFIG.5A, the gap168has the width186from the vacuum tank inner surface114bto the pressure tank outer surface112a, and in this version, the width186of the gap168is constant and uniform between the vacuum tank50and the pressure tank80.

Now referring toFIG.5B,FIG.5Bis an illustration of a cross-sectional enlarged front view of another version of the exemplary removable plug element118of the circle5B ofFIG.5A, where the removable plug element118is further sealed with the membrane seal132in addition to the plug seal126.

Like the removable plug element118inFIG.4B, the removable plug element118inFIG.5Bcomprises the first portion120, such as the outer portion120a, having the cylindrical body124a, the second portion122, such as the inner portion122a, coupled to, or integral with, the first portion120, such as the outer portion120a, and having the cylindrical body124b. As shown inFIG.5B, the exterior side surfaces188of the first portion120are in contact with walls190of the opening100formed in the pressure tank80.

As shown inFIG.5B, the plug seal126is coupled to the removable plug element118at the opening100, to provide a further sealing of the opening100when the removable plug element118is inserted and fitted within the opening100. As shown inFIG.5B, the plug seal126surrounds the base121of the first portion120and is seated against the top surface portions123of the second portion122.

FIG.5Bfurther shows the membrane seal132comprising a first portion193a, a second portion193b, a flexible body194formed between the first portion193aand the second portion193b, an inner surface195, and an outer surface196. A similar arrangement exists in the pressure tank80longitudinal direction in addition to the pressure tank80circumferential direction shown inFIG.5B. As shown inFIG.5B, the inner surface195of the membrane seal132is positioned over, and adjacent to, a bottom end198and sides200of the second portion122, such as the inner portion122a, of the removable plug element118, and is positioned over, and adjacent to, outer sides126aof the plug seal126. In this version, as shown inFIG.5B, the membrane seal132covers the second portion122of the removable plug element118, and covers the plug seal126. As shown inFIG.5B, the inner surface195of the membrane seal132at the first portion193aand at the second portion193bis coupled to, and positioned adjacent to, locations130bon the pressure tank inner surface112b. The membrane seal132is coupled to the pressure tank inner surface112bwith an attachment element such as adhesive or another suitable attachment element. Preferably, the membrane seal132is configured to be torn to allow the removable plug element118to be pulled through the membrane seal132, when the removable plug element118is released from the opening100.

A sealant128(seeFIG.4B), such as an adhesive sealant, may optionally be applied to one or more surfaces of the plug seal126and/or applied to one or more locations130a(seeFIGS.4B,5B) on the pressure tank inner surface112bat the opening100, to seal at the opening100and at the removable plug element118contacting the opening100. Alternatively, the sealant128, such as the adhesive sealant, may be used instead of the plug seal126, to seal at and around the opening100and at and around the removable plug element118at the one or more locations130a(seeFIGS.4B,5B) of the pressure tank inner surface112b. As a further alternative, the membrane seal132(seeFIG.5B) may be used alone, without the plug seal126(seeFIG.5B) or the sealant128(seeFIG.4B).

FIG.5Bfurther shows the second end146bof the cable145attached to a portion196aof the outer surface196of the membrane seal132. Alternatively, the second end146bof the cable145is fitted through an opening in the membrane seal132and attached to the bottom end198of the second portion122.FIG.5Bfurther shows the vacuum tank50, and the vacuum cavity166and the gap168formed between the vacuum tank inner surface114bof the vacuum tank50and the pressure tank outer surface112aof the pressure tank80.FIG.5Bfurther shows the air78, such as the ambient air78a, outside the vacuum tank50.

Now referring toFIG.6A,FIG.6Ais an illustration of a cross-sectional front view of an exemplary tank system10, such as the vacuum jacketed tank system10a, of the disclosure, showing yet another version of a removable plug assembly116with one (1) removable plug element118with a plug seal126and another version of a retraction mechanism136in the form of a latch spring retraction mechanism136apositioned within the interior90of the pressure tank80. Like the tank system10inFIGS.4A,5A, as shown inFIG.6A, the tank system10, such as the vacuum jacketed tank system10a, comprises the vacuum tank50, such as the external vacuum tank50a, the pressure tank80, such as the internal pressure tank80a, mounted within the vacuum tank50, and the vacuum cavity166and the gap168formed between the vacuum tank inner surface114bof the vacuum tank50and the pressure tank outer surface112aof the pressure tank80. As shown inFIG.6A, the gap168has the width186from the vacuum tank inner surface114bto the pressure tank outer surface112a, and the width186of the gap168is constant and uniform between the vacuum tank50and the pressure tank80.FIG.6Ashows the air78, such as ambient air78a, surrounding the exterior52of the vacuum tank50. In this version, the pressure tank80has one (1) opening100(seeFIG.6A) formed through the pressure tank skin96at location102on the pressure tank main portion92.

Now referring toFIG.6B,FIG.6Bis an illustration of a cross-sectional enlarged front view of the removable plug element118and the retraction mechanism136, such as in the form of the latch spring retraction mechanism136a. In this version, as shown inFIG.6B, the latch spring retraction mechanism136acomprises a latch member234that pivots around a pivot pin235, and the latch member234has a latch hook portion236configured to couple to the removable plug element118. As shown inFIG.6B, the latch member234is coupled, or attached, to a portion242of the pressure tank inner surface112b. The retraction mechanism136, such as the latch spring retraction mechanism136a, is coupled, or attached, to the removable plug element118via the latch hook portion236of the latch member234. As further shown inFIG.6B, the latch spring retraction mechanism136acomprises one or more springs238coupled to the removable plug element118, such as to the second portion122, such as the inner portion122a. The retraction mechanism136, such as the latch spring retraction mechanism136a, is configured to pull the removable plug element118away from, and out of, the opening100during the emergency condition152(seeFIG.2).FIG.6Bfurther shows a plug retention cage240in the interior90of the pressure tank80. As shown inFIG.6B, the plug retention cage240is coupled, or attached, to portions244a,244b, of the pressure tank inner surface112band positioned around the removable plug element118, such as the second portion122, for example, the inner portion122a, of the removable plug element118.

As further shown inFIG.6B, the removable plug element118comprises the first portion120, such as the outer portion120a, having the cylindrical body124a, and the second portion122, such as the inner portion122a, coupled to, or integral with, the first portion120, such as the outer portion120a, and having the cylindrical body124b.FIG.6Bfurther shows the plug seal126coupled to the removable plug element118at the opening100formed through the pressure tank skin96, to provide a sealing of the opening100when the removable plug element118is inserted and fitted within the opening100. As shown inFIG.6B, the plug seal126surrounds the first portion120and is seated against the second portion122.FIG.6Bfurther shows the gap168formed between the vacuum tank inner surface114bof the vacuum tank50and the pressure tank outer surface112aof the pressure tank80.FIG.6Bfurther shows the air78, such as ambient air78a, outside the vacuum tank50.

Now referring toFIG.7,FIG.7is an illustration of a cross-sectional front view of an exemplary tank system10, such as the vacuum jacketed tank system10a, of the disclosure, showing yet another version of the removable plug assembly116with two (2) removable plug elements118, each with the plug seal126. Like the tank system10inFIGS.4A,5A,6, as shown inFIG.7, the tank system10, such as the vacuum jacketed tank system10a, comprises the vacuum tank50, such as the external vacuum tank50a, the pressure tank80, such as the internal pressure between the vacuum tank inner surface114bof the vacuum tank50and the pressure tank outer surface112aof the pressure tank80. As shown inFIG.7, the gap168has the width186from the vacuum tank inner surface114bto the pressure tank outer surface112a, and the width186of the gap168is constant and uniform between the vacuum tank50and the pressure tank80.FIG.7shows the air78, such as ambient air78a, surrounding the exterior52of the vacuum tank50.

In this version, the pressure tank80has two (2) openings100(seeFIG.7) formed through the pressure tank skin96at locations102on the pressure tank main portion92. As shown inFIG.7, the pressure tank80further comprises the retraction mechanism136positioned within the interior90of the pressure tank80, where the retraction mechanism136comprises the central rotatable tube138, two (2) cables145, and the actuator144(seeFIG.3B). The retraction mechanism136is coupled, or attached, to the removable plug elements118via the cables145. Each cable145has the first end146a(seeFIG.7) attached to the central rotatable tube138and the second end146b(seeFIG.7) attached to the removable plug element118. When the central rotatable tube138is rotated by the actuator144(seeFIG.3B), the cables145attached to the removable plug elements118start winding around an exterior138a(seeFIG.7) of the central rotatable tube138. This puts tension into the cables145. The retraction mechanism136is configured to pull the removable plug elements118away from, and out of, the openings100during the emergency condition152(seeFIG.2).

As further shown inFIG.7, each removable plug element118comprises the first portion120, such as the outer portion120a, having the cylindrical body124a, and the second portion122, such as the inner portion122a, coupled to, or integral with, the first portion120, such as the outer portion120a. The second portion122has the cylindrical body124b(seeFIG.7). As shown inFIG.7, in this version, the two (2) removable plug elements118are positioned opposite each other in an opposing position202.

Now referring toFIG.8,FIG.8is an illustration of a cross-sectional front view of an exemplary tank system10, such as the vacuum jacketed tank system10a, of the disclosure, showing yet another version of the removable plug assembly116with four (4) removable plug elements118, each with the plug seal126. Like the tank system10inFIGS.4A,5A,6,7, as shown inFIG.8, the tank system10, such as the vacuum jacketed tank system10a, comprises the vacuum tank50, such as the external vacuum tank50a, the pressure tank80, such as the internal pressure between the vacuum tank inner surface114bof the vacuum tank50and the pressure tank outer surface112aof the pressure tank80. As shown inFIG.8, the gap168has the width186from the vacuum tank inner surface114bto the pressure tank outer surface112a, and the width186of the gap168is constant and uniform between the vacuum tank50and the pressure tank80.FIG.8shows the air78, such as ambient air78a, surrounding the exterior52of the vacuum tank50.

In this version, the pressure tank80has four (4) openings100(seeFIG.7) formed through the pressure tank skin96at locations102on the pressure tank main portion92. As shown inFIG.8, the pressure tank80further comprises the retraction mechanism136positioned within the interior90of the pressure tank80, where the retraction mechanism136comprises the central rotatable tube138, four (4) cables145, and the actuator144(seeFIG.3B). The retraction mechanism136is coupled, or attached, to the removable plug elements118via the cables145. Each cable145has the first end146a(seeFIG.8) attached to the central rotatable tube138and the second end146b(seeFIG.8) attached to the removable plug element118. When the central rotatable tube138is rotated by the actuator144, the cables145attached to the removable plug elements118start winding around an exterior138a(seeFIG.3B) of the central rotatable tube138. This puts tension into the cables145. The retraction mechanism136is configured to pull the removable plug elements118away from, and out of, the openings100during the emergency condition152(seeFIG.2).

As further shown inFIG.8, each removable plug element118comprises the first portion120, such as the outer portion120a, having the cylindrical body124a, and the second portion122, such as the inner portion122a, coupled to, or integral with, the first portion120, such as the outer portion120a. The second portion122has the cylindrical body124b(seeFIG.8). As shown inFIG.8, in this version, the four (4) removable plug elements118are spaced apart from each other in an equal distance spaced relationship204aaround the perimeter205of the pressure tank80.

Now referring toFIGS.9A-9H,FIGS.9A-9Hshow an activation sequence206with various positions208of a version of the removable plug assembly116disposed in the pressure tank80, such as the internal pressure tank80a, which is mounted within the vacuum tank50, such as the external vacuum tank50a, of the tank system10, such as the vacuum jacketed tank system10aof the disclosure.FIGS.9A-9Hshow the tank system10, such as the vacuum jacketed tank system10a, comprising the vacuum tank50, such as the external vacuum tank50a, the pressure tank80, such as the internal pressure tank80a, mounted within the vacuum tank50, and the vacuum cavity166and the gap168formed between the vacuum tank inner surface114bof the vacuum tank50and the pressure tank outer surface112aof the pressure tank80.FIGS.9A-9Hfurther show the pressure tank80with six (6) openings100formed through the pressure tank skin96at locations102(seeFIG.9A) on the pressure tank main portion92(seeFIG.9A), and show six (6) removable plug elements118.FIGS.9A-9Hfurther show the retraction mechanism136positioned within the interior90of the pressure tank80, and further show the central rotatable tube138and six (6) cables145of the retraction mechanism136.

For clarity,FIGS.9A-9Hdo not show the plug seals126(seeFIG.4B) and the membrane seals132(seeFIG.5B) coupled to the removable plug elements118, and do not show the sealant128(seeFIG.4B). However, the plug seals126and/or the membrane seals132and/or the sealant128may be used with the removable plug elements118in the tank system10shown inFIGS.9A-9H.

FIG.9Ais an illustration of a cross-sectional front view of the exemplary tank system10, such as the vacuum jacketed tank system10a, showing the removable plug assembly116with six (6) removable plug elements118, and showing a first position208aof the activation sequence206. As shown in the first position208ainFIG.9A, the tank system10is in an intact configuration210, and shows all of the six (6) removable plug elements118inserted, fitted within, and plugging the six (6) openings100, respectively, formed through the pressure tank skin96at locations102on the pressure tank main portion92. As shown inFIG.9A, the six (6) removable plug elements118are in a plugged position212.

As shown inFIG.9A, the pressure tank80contains the cryogenic fluid82, such as the liquid hydrogen84, within the interior90of the pressure tank80. The removable plug elements118function in a similar manner to the pressure tank skin96(seeFIG.9A) in that the removable plug elements118form the surface that contains the cryogenic fluid82, such as the liquid hydrogen84.

As shown inFIG.9A, the vacuum tank50, such as the external vacuum tank50a, provides a barrier214between the air78, such as the ambient air78a, and the vacuum cavity166. The vacuum tank50is designed to withstand the external pressure loading, which is a result of the pressure of the air78, such as the ambient air78a, acting on the vacuum tank outer surface114a(seeFIG.9A), and nothing on the vacuum tank inner surface114b. The vacuum cavity166forming the gap168between the pressure tank80and the vacuum tank50limits the thermal transfer between the cryogenic fluid82, such as the liquid hydrogen84, and the air78, such as the ambient air78a.

FIG.9Bis an illustration of a cross-sectional front view of the tank system10, such as the vacuum jacketed tank system10a, with removable plug assembly116ofFIG.9A, showing a position208, such as a second position208b, of the activation sequence206. As shown in the second position208binFIG.9B, the retraction mechanism136is activated when an emergency condition152(seeFIG.2) occurs. As shown inFIG.2, the emergency condition152comprises one of, an emergency landing154of an aircraft14, a forced landing155of an aircraft14, the pressure tank80experiencing an elevated acceleration level156of acceleration157of the aircraft14, the pressure tank80experiencing an elevated force level158of force159, and an event160causing a breach162or a potential breach162aof the vacuum tank50, and/or causing an airflow164or a potential airflow164aof the air78, such as the ambient air78a, into the pressure tank80. The retraction mechanism136is activated with an activation system150(seeFIG.2) comprising one of, an automatic activated activation system150a(seeFIG.2), or an operator activated activation system150b, such as a pilot activated activation system150c(seeFIG.2), when the structure12comprises an aircraft14.

Activation of the retraction mechanism136causes the actuator144(seeFIGS.2,3B) to rotate the central rotatable tube138(seeFIG.9B) in a rotation direction215(seeFIG.9B), such that the cables145attached to the central rotatable tube138start winding around the central rotatable tube138. This puts tension into the cables145, and as the cables145wind around the central rotatable tube138, the cables145attached to the removable plug elements118pull removable plug elements118away from the openings100, so that the removable plug elements118are released from the openings100.

As shown inFIG.9B, the rotation of the central rotatable tube138in the rotation direction215and the winding of the cables145around the central rotatable tube138pull the removable plug elements118towards a center216of the pressure tank80. Due to the enforced shortening of the distance between the removable plug elements118and the tangent to the central rotatable tube138, the removable plug elements118are pulled into the interior90of the pressure tank80towards the center216of the pressure tank80, thus pulling the removable plug elements118away from their respective openings100. With the openings100that were previously filled by the removable plug elements118now open, the cryogenic fluid82, such as the liquid hydrogen84, starts to flow into the vacuum cavity166.FIG.9Bshows an outflow218of the cryogenic fluid82, such as the liquid hydrogen84, from the interior90of the pressure tank80through the openings100and into the vacuum cavity166.

FIG.9Cis an illustration of a cross-sectional front view of the tank system10, such as the vacuum jacketed tank system10a, with the removable plug assembly116ofFIG.9A, showing a position208, such as a third position208c, of the activation sequence206. As shown inFIG.9C. the retraction mechanism136is still activated and the actuator144(seeFIGS.2,3B) is still rotating the central rotatable tube138in the rotation direction215to further wind the cables145around the central rotatable tube138, and to further pull the removable plug elements118further away from the openings100, so that the removable plug elements118do not interfere with the free flow of the cryogenic fluid82, such as the liquid hydrogen84, through the openings100. As shown inFIG.9C, in the third position208c, the removable plug elements118are pulled further away from the openings100, as compared to the position of the removable plug elements118in the second position208b(seeFIG.9B).

FIG.9Cshows the cryogenic fluid82, such as the liquid hydrogen84, continuing to flow from the interior90of the pressure tank80through the openings100and into the vacuum cavity166.FIG.9Cshows further outflow218of the cryogenic fluid82, such as the liquid hydrogen84, from the interior90of the pressure tank80through the openings100and into the vacuum cavity166.FIG.9Cshows the cryogenic fluid82, such as the liquid hydrogen84, flowing in a first outflow direction220a, such as a left direction, out of each opening100into the vacuum cavity166, and flowing in a second outflow direction220b, such as a right direction, out of each opening100into the vacuum cavity166. As shown inFIG.9C, in the third position208c, the volume of the vacuum cavity166is approximately half-filled with the cryogenic fluid82, such as the liquid hydrogen84.

FIG.9Dis an illustration of a cross-sectional front view of the tank system10, such as the vacuum jacketed tank system10a, with the removable plug assembly116ofFIG.9A, showing a position208, such as a fourth position208d, of the activation sequence206. As shown inFIG.9D, the cryogenic fluid82, such as the liquid hydrogen84, continues to flow from the interior90of the pressure tank80through the openings100and into the vacuum cavity166.FIG.9Dshows even further outflow218of the cryogenic fluid82, such as the liquid hydrogen84, from the interior90of the pressure tank80through the openings100and into the vacuum cavity166.FIG.9Dshows the cryogenic fluid82, such as the liquid hydrogen84, further flowing in the first outflow direction220a, such as the left direction, out of each opening100into the vacuum cavity166, and further flowing in the second outflow direction220b, such as the right direction, out of each opening100into the vacuum cavity166. As shown inFIG.9D, in the fourth position208d, the volume of the vacuum cavity166is almost completely filled with the cryogenic fluid82, such as the liquid hydrogen84.

As shown inFIG.9D, the retraction mechanism136has stopped and the central rotatable tube138has stopped rotating. The removable plug elements118have performed their function of unplugging the openings100to release the cryogenic fluid82, such as the liquid hydrogen84, into the vacuum cavity166. As shown inFIG.9D, in the fourth position208d, the removable plug elements118now begin to sink towards a bottom area222of the pressure tank80.

FIG.9Eis an illustration of a cross-sectional front view of the tank system10, such as the vacuum jacketed tank system10a, with the removable plug assembly116ofFIG.9A, showing a position208, such as a fifth position208e, of the activation sequence206. As shown inFIG.9E, the operation of the retraction mechanism136is completed, and having performed their function, the cables145and removable plug elements118are in an inactive condition224and hang from the central rotatable tube138at the bottom area222of the pressure tank80. The tank system10is designed such that in the inactive condition224, the cables145and the removable plug elements118do not interfere with any outflow218(seeFIG.9E) of the cryogenic fluid82, such as the liquid hydrogen84, out of the pressure tank80and through the openings100, if the vacuum tank50is breached.

As shown inFIG.9E, in the fifth position208e, the volume of the vacuum cavity166is completely filled with the cryogenic fluid82, such as the liquid hydrogen84, and the vacuum cavity166is in a filled condition226. The vacuum cavity166in the filled condition226is advantageous because the air78(seeFIG.9E), such as the ambient air78a(seeFIG.9E), has no place to flow if the vacuum tank50is breached. Since there is now no insulative layer between the cryogenic fluid82, such as the liquid hydrogen84, and the air78, such as the ambient air78a, the cryogenic fluid82, such as the liquid hydrogen84, will boil at a rapid rate. Where the tank system10is in a structure12(seeFIG.1) comprising an aircraft14(seeFIG.1), this situation is acceptable, since the aircraft14is no longer in normal operations, but is in an emergency condition152(seeFIG.2) or situation where thermal efficiency is no longer important. Even though the boiling rate is rapid, it is not rapid enough to eliminate the cryogenic fluid82, such as the liquid hydrogen84, from the aircraft14quickly enough in an emergency condition152, for example, an emergency landing154(seeFIG.2) or a forced landing155(seeFIG.2) where a crash may be imminent.

FIG.9Fis an illustration of a cross-sectional front view of the tank system10, such as the vacuum jacketed tank system10a, with the removable plug assembly116ofFIG.9A, showing a position208, such as a sixth position208f, of the activation sequence206. As shown inFIG.9F, there is a breach162in the vacuum tank wall64of the vacuum tank50that occurred during the emergency condition152(seeFIG.2), such as for the aircraft14, the emergency landing154(seeFIG.2) or the forced landing155(seeFIG.2), or another emergency condition152. As shown inFIG.9F, an outflow218aof the cryogenic fluid82, such as the liquid hydrogen84, starts to flow from and exit the vacuum cavity166through the breach162in the vacuum tank wall64of the vacuum tank50, and into the air78, such as the ambient air78a. Since the pressure tank80is pressurized with a pressure greater than the air78, such as the ambient air78a, the cryogenic fluid82, such as the liquid hydrogen84, flows outward into the air78, such as the ambient air78a, instead of the air78, such as the ambient air78a, flowing into the vacuum tank50and the pressure tank80. This is important, since it prevents the formation of a mixture forming of liquid air and liquid hydrogen84, which can be explosive.

As shown inFIG.9F, the cables145and removable plug elements118remain in the inactive condition224and hang from the central rotatable tube138at the bottom area222of the pressure tank80. In the inactive condition224, the cables145and the removable plug elements118do not interfere with any outflow218a(seeFIG.9F) of the cryogenic fluid82, such as the liquid hydrogen84, out of the breach162in the vacuum tank50.

FIG.9Gis an illustration of a cross-sectional front view of the tank system10, such as the vacuum jacketed tank system10a, with the removable plug assembly116ofFIG.9A, showing a position208, such as a seventh position208g, of the activation sequence206. As shown inFIG.9G, in the seventh position208g, the outflow218aof the cryogenic fluid82, such as the liquid hydrogen84, continues to flow from the vacuum cavity166through the breach162in the vacuum tank wall64of the vacuum tank50, and into the air78, such as the ambient air78a. FIG.9G shows the outflow218aof the cryogenic fluid82, such as the liquid hydrogen84, in the form of a plume228, such as a liquid hydrogen plume228a, outside the exterior52of the vacuum tank50. As shown inFIG.9G, the cables145and removable plug elements118remain in the inactive condition224and hang from the central rotatable tube138at the bottom area222of the pressure tank80.

FIG.9His an illustration of a cross-sectional front view of the tank system10, such as the vacuum jacketed tank system10a, with the removable plug assembly ofFIG.9A, showing a position208, such as an eighth position208h, of the activation sequence206. As shown inFIG.9H, in the eighth position208h, a portion of the plume228, such as the liquid hydrogen plume228a, is ignited into a flame230. During the emergency condition152, such as for the aircraft14, the emergency landing154(seeFIG.2) or the forced landing155(seeFIG.2), or another emergency condition152, if there are any sparks, the plume228, such as the liquid hydrogen plume228a, may be readily ignited. Also, the plume228may ignite on its own, since the activation energy between the liquid hydrogen84and air78is very low. The liquid hydrogen84and air78are only mixing on the surface of the plume228and they are contained and do not cause an explosive event. AlthoughFIG.9Hshows the plume228ignited into the flame230, the interaction between the liquid hydrogen84and air78may happen immediately and may be occurring as early as the outflow218ainFIG.9F. As shown inFIG.9H, an ignition surface232outside of the vacuum tank50is a boundary between the plume228, such as the liquid hydrogen plume228a, and the air78, such as the ambient air78a. This situation is stable, as it is controlled burning, limited by the amount of air78, such as ambient air78a, that can come into contract with the plume228, such as the liquid hydrogen plume228a, in a given amount of time. As long as there is internal pressure in both the vacuum tank50and the pressure tank80, the cryogenic fluid82, such as the liquid hydrogen84, will keep flowing outward, thus preventing the air78, such as the ambient air78a, from entering the vacuum tank50and the pressure tank80, and forming a mixture of liquid air and liquid hydrogen84. The tank system10now acts like a single tank with a double wall with the internal pressure tank80awith many holes and the external vacuum tank50anow acting like the pressure tank80with a breach162(seeFIG.9H). As shown inFIG.9H, the cables145and removable plug elements118remain in the inactive condition224and hang from the central rotatable tube138at the bottom area222of the pressure tank80.

Now referring toFIG.10,FIG.10is an illustration of a flow diagram of an exemplary version of a method280of the disclosure. In another version of the disclosure, there is provided the method280of using a tank system10having a removable plug assembly116(seeFIGS.2,4A,5A) to allow a cryogenic fluid82(seeFIG.2) to exit in an emergency condition152(seeFIG.2).

The blocks inFIG.10represent operations and/or portions thereof, or elements, and lines connecting the various blocks do not imply any particular order or dependency of the operations or portions thereof, or elements.FIG.10and the disclosure of the steps of the method280set forth herein should not be interpreted as necessarily determining a sequence in which the steps are to be performed. Rather, although one illustrative order is indicated, it is to be understood that the sequence of the steps may be modified when appropriate. Accordingly, certain operations may be performed in a different order or simultaneously.

As shown inFIG.10, the method280comprises the step282of providing the tank system10having the removable plug assembly116. The tank system10comprises a vacuum tank50(seeFIGS.2,3A) having a vacuum tank main portion56(seeFIGS.2,3A) extending between vacuum tank end portions58(seeFIGS.2,3A). The vacuum tank main portion56has a vacuum tank skin60(seeFIGS.2,3A). The tank system10further comprises a pressure tank80(seeFIGS.2,3B) mounted within the vacuum tank50. The pressure tank80is configured to contain the cryogenic fluid82. The pressure tank80comprises a pressure tank main portion92(seeFIGS.2,3B) extending between pressure tank end portions94(seeFIGS.2,3B). The pressure tank main portion92has one or more openings100(seeFIGS.2,4B,5B) formed through the pressure tank main portion92. The pressure tank main portion92further has the removable plug assembly116. The removable plug assembly116comprises one or more removable plug elements118(seeFIGS.2,4A,5A). Each of the one or more removable plug elements118is configured to plug and to unplug one of the one or more openings100. The removable plug assembly116further comprises a retraction mechanism136(seeFIGS.2,4A,5A) positioned within an interior90(seeFIGS.2,3B) of the pressure tank80. The retraction mechanism136is coupled to the one or more removable plug elements118. The tank system10further comprises a vacuum cavity166(seeFIGS.2,3B) formed between the exterior88and pressure tank outer surface112a(seeFIG.3B) of the pressure tank80and the interior54and vacuum tank inner surface114b(seeFIG.3B) of the vacuum tank50.

The step282of providing the tank system10further comprises, providing the tank system10having the removable plug assembly116further comprising a plug seal126(seeFIGS.2,4B) coupled to each of the one or more removable plug elements118at the one or more openings100, and further comprising, a membrane seal132(seeFIGS.2,5B) positioned over a second portion122, such as an inner portion122a, (seeFIG.5B) of each of the one or more removable plug elements118, and coupled to locations130b(seeFIG.5B) on a pressure tank inner surface112b(seeFIG.5B) of the pressure tank80.

The step282of providing the tank system10further comprises, providing the tank system10having the removable plug assembly116in an aircraft14(seeFIGS.1,2), and filling the pressure tank80with the cryogenic fluid82comprising one of, liquid hydrogen84(seeFIG.2), liquid natural gas86(seeFIG.2), or another suitable cryogenic fluid.

As shown inFIG.10, the method280further comprises the step284of activating the retraction mechanism136when the emergency condition152occurs. The step284of activating the retraction mechanism136may further comprise, activating the retraction mechanism136when the emergency condition152occurs comprising one of, as shown inFIG.2, an emergency landing154of the aircraft14, a forced landing155of the aircraft14, the pressure tank80experiencing an elevated acceleration level156of acceleration157of the aircraft14, the pressure tank80experiencing an elevated force level158of force159, and an event160causing a breach162or a potential breach162aof the vacuum tank50, and/or causing an airflow164or a potential airflow164aof the air78, such as the ambient air78a, into the pressure tank80. The step284of activating the retraction mechanism136further comprises, rotating, with an actuator144(seeFIGS.2,3B), a central rotatable tube138(seeFIGS.2,3B), to cause one or more cables145(seeFIGS.2,3B) attached to the central rotatable tube138and attached to the one or more removable plug elements118, to wind partially or fully around the central rotatable tube138, and to pull the one or more removable plug elements118away from the one or more openings100(seeFIGS.2,3B), so that the one or more removable plug elements118are released from the one or more openings100.

The step284of activating the retraction mechanism136further comprises, activating the retraction mechanism136with an activation system150(seeFIG.2) comprising one of, an automatic activated activation system150a(seeFIG.2), or an operator activated activation system150b, such as a pilot activated activation system150c(seeFIG.2), when the structure12comprises an aircraft14.

As shown inFIG.10, the method280further comprises the step286of using the removable plug assembly116of the tank system10to pull, with the retraction mechanism136, the one or more removable plug elements118away from the one or more openings100and into the interior90of the pressure tank80, to allow the cryogenic fluid82to exit and to flow from the pressure tank80, through the one or more openings100, and into the vacuum cavity166, and when the vacuum tank50has a breach162, to allow the cryogenic fluid82to further exit and flow out into air78, such as the ambient air78a.

Now referring toFIGS.11and12,FIG.11is an illustration of a flow diagram of an exemplary aircraft manufacturing and service method300, andFIG.12is an illustration of an exemplary block diagram of an aircraft316. Referring toFIGS.11and12, versions of the disclosure may be described in the context of the aircraft manufacturing and service method300as shown inFIG.11, and the aircraft316as shown inFIG.12.

During pre-production, exemplary aircraft manufacturing and service method300may include specification and design302of the aircraft316and material procurement304. During manufacturing, component and subassembly manufacturing306and system integration308of the aircraft316takes place. Thereafter, the aircraft316may go through certification and delivery310in order to be placed in service312. While in service312by a customer, the aircraft316may be scheduled for routine maintenance and service314(which may also include modification, reconfiguration, refurbishment, and other suitable services).

Each of the processes of the aircraft manufacturing and service method300may be performed or carried out by a system integrator, a third party, and/or an operator (e.g., a customer). For the purposes of this description, a system integrator may include, without limitation, any number of aircraft manufacturers and major-system subcontractors. A third party may include, without limitation, any number of vendors, subcontractors, and suppliers. An operator may include an airline, leasing company, military entity, service organization, and other suitable operators.

As shown inFIG.12, the aircraft316produced by the exemplary aircraft manufacturing and service method300may include an airframe318with a plurality of systems320and an interior322. Examples of the plurality of systems320may include one or more of a propulsion system324, an electrical system326, a hydraulic system328, and an environmental system330. Any number of other systems may be included. Although an aerospace example is shown, the principles of the disclosure may be applied to other industries, such as the automotive industry, the construction industry, or another suitable industry.

Methods and systems embodied herein may be employed during any one or more of the stages of the aircraft manufacturing and service method300. For example, components or subassemblies corresponding to component and subassembly manufacturing306may be fabricated or manufactured in a manner similar to components or subassemblies produced while the aircraft316is in service312. Also, one or more apparatus embodiments, method embodiments, or a combination thereof, may be utilized during component and subassembly manufacturing306and system integration308, for example, by substantially expediting assembly of or reducing the cost of the aircraft316. Similarly, one or more of apparatus embodiments, method embodiments, or a combination thereof, may be utilized while the aircraft316is in service312, for example and without limitation, to maintenance and service314.

Disclosed versions of the tank system10(seeFIGS.2,3A-3B,4A-9A), the aircraft14(seeFIG.1) with the tank system10, and the method280(seeFIG.10) of using the tank system10provide a tank system10having a removable plug assembly116(seeFIGS.2,3B,4A-9A) to allow a cryogenic fluid82(seeFIGS.2,9A), such as liquid hydrogen84(seeFIGS.2,9A) or liquid natural gas86(seeFIG.2) to exit the tank system10in an emergency condition152(seeFIG.2). The tank system10, such as the vacuum jacketed tank system10a(seeFIGS.2,3A-3B,4A-9A), comprises the vacuum tank50(seeFIGS.3A-3B), such as the external vacuum tank50a(seeFIGS.3A-3B), the pressure tank80(seeFIG.3B), such as the internal pressure tank80a(seeFIG.3B), mounted within the vacuum tank50, and the vacuum cavity166(seeFIG.3B) and the gap168(seeFIG.3B) formed between the vacuum tank inner surface114b(seeFIG.3B) of the vacuum tank50and the pressure tank outer surface112a(seeFIG.3B) of the pressure tank80.

The pressure tank80is configured with the removable plug assembly116(seeFIGS.2,3B,4A-9A) having one or more removable plug elements118(seeFIGS.2,3B,4A-9A) that are retracted or pulled away from one or more openings100(seeFIGS.2,3B,4A-9A) formed in the pressure tank80by a retraction mechanism136, when the retraction mechanism136is activated by an activation system150(seeFIG.2) upon the occurrence of an emergency condition152(seeFIG.2). In one version, the retraction mechanism136comprises a central rotatable tube138within the interior90of the pressure tank80that is actuated by an actuator144(seeFIGS.2,3B), and comprises one or more cables145attached to the central rotatable tube138and attached to the removable plug elements118. The removable plug elements118are quickly removed from the openings100The quick removal or release of the removable plug elements118from the openings100allows the rapid outflow218(seeFIG.9B) of the cryogenic fluid82(seeFIGS.2,9A), such as liquid hydrogen84(seeFIGS.2,9A), liquid natural gas86(seeFIG.2), or another suitable cryogenic fluid from the pressure tank80to the vacuum cavity166. The removable plug elements118prevent the escape of the cryogenic fluid82(seeFIGS.2,9A), such as liquid hydrogen84(seeFIGS.2,9A) or liquid natural gas86(seeFIG.2) from the pressure tank80during normal conditions. Alternative to the removable plug assembly116, the pressure tank80, such as the internal pressure tank80a, may be configured with the valve assembly134(seeFIG.2) having the valves135(seeFIG.2) that are quick to open, to allow the rapid flow of cryogenic fluid82, such as liquid hydrogen84or liquid natural gas86, from the pressure tank80to the vacuum cavity166.

The vacuum tank50, such as the external vacuum tank50a, provides a barrier214(seeFIG.9A) between the ambient air78aand the vacuum cavity166. The vacuum tank50, such as the external vacuum tank50a, is designed to withstand the external pressure loading which is a result of the pressure of the ambient air78aacting on the vacuum tank outer surface114aof the vacuum tank50, and nothing acting on the vacuum tank inner surface114bof the vacuum tank50.

The vacuum cavity166(seeFIGS.3B,4A-9A) formed around the pressure tank80provides an area for the air78, such as the ambient air78a, to flow into and liquefy, should the vacuum tank50be breached with a breach162(seeFIG.1), such as a puncture or rupture. The vacuum cavity166limits the thermal transfer between the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, and the air78, such as the ambient air78a. When the pressure tank80and the vacuum tank50are breached, the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, flows from the pressure tank80through the vacuum tank50and out into the air78, such as the ambient air78a. Since the pressure tank80is pressurized with a pressure greater than the ambient air78a, the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, flows outward into the ambient air78a, instead of the air78, such as the ambient air78aflowing into the pressure tank80. This prevents the formation of a mixture forming of the liquid air and the liquid hydrogen84or liquid natural gas86, which can be explosive.

Further, disclosed versions of the tank system10(seeFIGS.2,3A-3B,4A-9A), the aircraft14(seeFIG.1) with the tank system10, and the method280(seeFIG.10) of using the tank system10provide for additional sealing capability of the removable plug elements118at the openings100. For example, the tank system10may optionally comprise a plug seal126(seeFIGS.2,4B), such as an O-ring, a gasket, or another suitable plug seal member coupled to each removable plug element118at the each opening100. In addition, a sealant128(seeFIG.4B), such as an adhesive sealant, may be applied to one or more surfaces of the plug seal126(seeFIG.4B) and/or applied to one or more locations130a(seeFIG.4B) on the pressure tank inner surface112bat the opening100, to further seal at the opening100and at the removable plug element118contacting the opening100. Moreover, the tank system10may optionally further comprise a membrane seal132used in conjunction with, or instead of, the plug seal126. The membrane seal132is positioned over the removable plug element118, over the plug seal126, and is coupled to locations130b(seeFIG.5B) on the pressure tank inner surface112b(seeFIG.5B). The membrane seal132is coupled to the pressure tank inner surface112b(seeFIG.5B) with one or more attachment elements. The membrane seal132, such as an aluminum foil, is configured to be torn to allow the removable plug element118to be pulled through the membrane seal132, when the removable plug element118is released from the opening100.

In addition, disclosed versions of the tank system10(seeFIGS.2,3A-3B,4A-9A), the aircraft14(seeFIG.1) with the tank system10, and the method280(seeFIG.10) of using the tank system10solve the problem of, when there is a breach162(seeFIG.2) or rupture in the external vacuum tank50aand the internal pressure tank80aof a vacuum jacketed tank system10a, preventing the air78, such as the ambient air78a, outside of the vacuum jacketed tank system10afrom entering the external vacuum tank50aand the vacuum cavity166, liquefying, and mixing with the cryogenic fluid82from the internal pressure tank80a. The improved tank system10, such as the vacuum jacketed tank system10a, and method280of using the same, prevent or avoid a potential explosive situation should the vacuum jacketed tank system10abe breached in an emergency condition152. In addition, the improved tank system10, such as the vacuum jacketed tank system10a, and method280of using the same enhance the safety of vacuum jacketed liquid hydrogen tanks or liquid natural gas tanks, for example, the internal pressure tank80acontaining the cryogenic fluid82, such as liquid hydrogen84or liquid natural gas86. Further, the improved tank system10, such as the vacuum jacketed tank system10a, and method280of using the same mitigate a safety concern for vacuum jacketed tank system certification. Upon the occurrence of the emergency condition152, or emergency situation, the activation system150(seeFIG.2) activates the retraction mechanism136. The activation system150may be an automatic activated activation system150a(seeFIG.2) that is automatically activated by the emergency condition152, or the activation system150may be an operator activated activation system150b(seeFIG.2) that is activated by an operator of the structure12(seeFIG.2), such as a pilot of an aircraft14(seeFIG.2). The emergency condition152, or emergency situation, means there is an increased probability that the vacuum tank50might be breached or ruptured, so that air78, such as ambient air78a, outside of the vacuum tank50, for example, a vacuum tank50of an aircraft14, flows into the vacuum tank50. If the air78, such as the ambient air78a, somehow mixes with the cryogenic fluid82(seeFIGS.2,9A), such as liquid hydrogen84(seeFIGS.2,9A) or liquid natural gas86(seeFIG.2), acting as fuel, in the pressure tank80, for example, when it is subsequently breached, or there is leakage, the resulting mixture is highly explosive, with a very low activation energy. For example, just slightly jostling a container of such a mixture of liquid hydrogen84and air78may cause it to explode.

The emergency condition152comprises one or more of, an emergency landing154of the aircraft14, when the structure12comprises an aircraft14, a forced landing155of the aircraft14, when the structure12comprises an aircraft14, the pressure tank80experiencing an elevated acceleration level156of acceleration157, or high acceleration, of the aircraft14, when the structure12comprises an aircraft14, the pressure tank80experiencing an elevated force level158of force159, or high force, an event160causing a breach162or a potential breach162aof the vacuum tank50, and/or an airflow164or a potential airflow164aof the air78, such as the ambient air78a, into the pressure tank80, or another type of emergency condition experienced by the structure12, for example, the aircraft14. An elevated force level158may include projectiles, such as bullets, or missiles, or other types of projectiles, being fired at the vacuum tank50and/or the pressure tank80. The removable plug assembly116of the tank system10allows the cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86, to exit or escape from the pressure tank80in the emergency condition152to fill the vacuum cavity166so that if there is a breach162of the vacuum tank50, the outside air78, such as the ambient air78a, outside the vacuum tank50, cannot flow into the vacuum cavity166as it is already filled with the escaped cryogenic fluid82, such as the liquid hydrogen84or the liquid natural gas86.

Many modifications and other versions of the disclosure will come to mind to one skilled in the art to which this disclosure pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. The versions described herein are meant to be illustrative and are not intended to be limiting or exhaustive. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, are possible from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled.