Method and apparatus for filling a storage tank using a liquid cryogenic agent pump supply system with reduced heat leakage.

Abstract

A system and method for minimizing heat leakage to a liquid cryogenic pump incorporating a bayonet includes a male bayonet portion received within a female bayonet portion, each having a circular cross-section and comprising an outer tube surrounding an inner tube and a ring between them under vacuum, wherein the liquid cryogenic pump is contained within the male bayonet portion.

Description

[Technical Field]

[0001] Cross-reference of related applications This patent application claims priority to U.S. Patent Application No. 18 / 196,026, filed on 11 May 2023, and U.S. Patent Application No. 18 / 196,031, filed on 11 May 2023, both of which are incorporated herein by reference in their entirety.

[0002] This invention relates to mounting a rotating machine in a manner that minimizes heat leakage, weight, and other related values. [Background technology]

[0003] Cryogenic liquids are defined by publication C-7 of the Compressed Gas Society as cooled liquid gases with a boiling point of -90°C at 14.7 psi(a). Therefore, they are typically stored in adiabatic containers at relatively low temperatures. Liquid cryogenic agents are typically stored at superatmospheric pressure, but their pressure is usually orders of magnitude lower than that of cryogenic agents stored in gaseous form. Typical cryogenic agents used industrially include hydrogen, nitrogen, oxygen, argon, xenon, krypton, helium, and carbon dioxide.

[0004] One technology for supplying liquid cryogenic agents such as liquid hydrogen (LH2) is to pump the liquid cryogenic agent to high pressure. For smaller non-hydrogen energy end-use applications, LH2 pumps are typically used to reach pressures of up to 3,000 psig (206.8 bar). For the hydrogen energy market, various applications, namely medium-pressure and high-pressure applications, typically encounter higher pressures. Medium-pressure applications, such as filling trailers, forklifts, or buses with gaseous hydrogen, require hydrogen at a pressure of approximately 6,000 psig (413.7 bar). High-pressure applications, such as filling light or heavy vehicles, require hydrogen at a pressure of approximately 12,000 psig (827.4 bar).

[0005] Cryogenic piston pumps of various sizes, orientations, and mechanical drive configurations are available and produced by several companies. The basic design of the single-stage cryogenic pump cylinder is similar across these pumps. While pumping hydrogen to medium and high pressures, these single-stage pumps exhibit relatively lower volumetric efficiency and yield compared to the same pumping of liquid nitrogen or other liquefied industrial gases.

[0006] While not specific to any particular type of liquid cryogenic agent, especially in the case of LH2, the main factors affecting pump performance at intermediate pressure pump supply locations include (1) the number of operating hours of the cold end, (2) the presence of adequate cooling of the cold end cylinder, (3) the pump discharge pressure, and (4) the effective net suction head (NPSH). A ) is included. NPSH A This is the effective net suction head at the pump inlet.

[0007] Pumping all cryogenic liquids presents many challenges not encountered with non-cryogenic liquids, but due to its physical properties, liquid hydrogen is even more difficult to pump than other cryogenic liquids. Hydrogen, especially gaseous hydrogen, has low viscosity. Its boiling point is very low (i.e., less than 100°F lower than oxygen, nitrogen, and argon), so any additional heat can produce gaseous hydrogen. When pumping liquid hydrogen, once the hydrogen begins to pass through the pump's piston rings, the rings tend to gradually align, thereby allowing a more direct path for the hydrogen through the rings. This increases hydrogen evaporation and reduces pumping efficiency.

[0008] Furthermore, the low critical pressure of hydrogen limits the ability to subcool LH2 using artificial head pressure. The density of LH2 decreases rapidly (e.g., about 40% at 150 psi) because it increases proportionally with the low critical pressure. Although helium also has a very low boiling point, hydrogen is still relatively difficult to pump because helium has a very high viscosity. Since helium has a much lower latent heat of vaporization than hydrogen, applications requiring the pumping of liquid helium are very rare.

[0009] The pressure rating of the container limits the level of the surface pressure quantity (e.g., H A ), and the continuous heat entering the system increases the vapor pressure of the liquid (e.g., H VP ), so reaching an appropriate NPSH A is a problem for applications involving the pumping supply of liquid cryogens, especially hydrogen. One way to generate NPSH A is to have a head pressure greater than the vapor pressure of the liquid. Those skilled in the art will recognize that there is a limit to the head pressure that can be added to the system considering the maximum operating pressure limit of the container.

[0010] NPSH A Another factor that makes it difficult to maintain NPSH VP in the liquid cryogen is the continuous introduction of heat into the system. A high level of approach to insulation (i.e., super insulation) limits the heat input from natural heat leakage to a very low value, but still a large amount of heat from the pump can be conducted. Much of this heat is absorbed into the liquid cryogen, which increases the vapor pressure (H

[0011] Minimizing the delivered heat quantity of the original liquid cryogen is extremely important to extend the period during which an appropriate NPSH A (e.g., container pressure ≒ LH2 vapor pressure + 25 psi) can still be reached. When the original vapor pressure is low, an appropriate NPSH A can be maintained for several days before the container pressure reaches the maximum operating limit. Ideally, the vapor pressure of the delivered liquid cryogen should be as low as possible, which is typically a vapor pressure in the range of 10 - 20 psig (0.69 bar(g)). If heat leakage can be prevented, such a low vapor pressure (i.e., quality) of the liquid cryogen can be maintained.

[0012] Maintaining the quality of cryogenic liquids such as pump-supplied cryogens is difficult due to heat leakage from the ambient atmosphere to the cryogenic liquid. This is especially the case when the seal between two adjacent parts of the piping is in direct contact with the ambient atmosphere. Therefore, the transportation of cryogenic liquids over a non-negligible distance is typically achieved using vacuum jacketed piping (VJP).

[0013] A VJP is constructed from an inner tube, which transports a cryogenic liquid arranged within an outer tube. Conductive heat leakage from the outer tube to the inner tube, which is in contact with ambient temperature conditions, is avoided by separating the outer tube from the inner tube, and the position of the inner tube within the outer tube is stabilized using a spacer made of a material with low thermal conductivity. Convective heat leakage from the outer tube to the inner tube is avoided by placing an annular space between the tubes under vacuum. Radiative heat leakage from the outer tube to the inner tube is minimized by placing a reflective material between the outer and inner tubes.

[0014] To maintain a continuous vacuum throughout a series of VJPs, adjacent sections must be carefully welded together or joined together using a mechanical joint called a "bayonet joint." When a bayonet joint is used, the vacuum in the VJP is separated from the vacuum in the bayonet joint. The different elements of a bayonet joint are typically fastened together with bolted flanges or V-band clamps.

[0015] Conventional liquid hydrogen pumps are not completely vacuum-insulated. For example, relatively large heat leaks can occur through the crankshaft and flange. Traditionally, pumps are placed in a reservoir to provide convenient access for maintenance, and in this arrangement, the liquid cryogenic agent is isolated from the ambient temperature by a single layer of material. For example, when a flanged VJP is connected to a flanged outlet of a liquid cryogenic agent pump, the inner surface of the flange is in direct contact with the liquid cryogenic agent, while the outer surface is in direct contact with the ambient temperature. As a result, heat leaks are continuously generated by the liquid hydrogen pumped by the liquid hydrogen pump.

[0016] Liquid hydrogen trailers are currently designed to carry the maximum possible amount of hydrogen within DOT regulations. To reach maximum capacity, the container on the trailer must have the largest possible dimensions. The diameter of the container is equal to the width of the trailer. The space required for the valve at the rear of the trailer must be minimized so that the container can achieve its maximum length and maximum load capacity. The weight of the LH2 trailer also reaches the legal limit, as the container and onboard equipment are heavy.

[0017] The LH2 pump and its associated oil reservoir, installed on the trailer, often occupy a considerable amount of space on the trailer. Furthermore, the LH2 pump and its associated oil reservoir are often very heavy. [Overview of the Initiative] [Problems that the invention aims to solve]

[0018] In light of the above-mentioned cutting-edge technologies, those skilled in the art of systems for pump-fed liquid cryogenic agents will recognize the need for an improved pump-feed system that is free from all the drawbacks associated with these cutting-edge technologies. [Means for solving the problem]

[0019] One embodiment of the present invention discloses a liquid cryogenic pump supply system that reduces heat leakage and incorporates a bayonet. The pump supply system may include a first bayonet section having a circular cross-section and including an outer tube surrounding an inner tube, with an annular space defined between them, configured to be sealed and evacuated to maintain a vacuum; a second bayonet section having a circular cross-section and including an outer tube surrounding an inner tube, with an annular space defined between them, configured to be adapted to be evacuated to maintain a vacuum, wherein the first bayonet section is concentrically received within the second bayonet section and sealed to the second bayonet section; and a liquid cryogenic pump housed within the first bayonet section.

[0020] In an optional embodiment of the pump supply system, The first and second bayonet sections are reversibly detachable and are not welded together so that the liquid cryogenic pump can be maintained or replaced without having to break the weld. The system is An energized seal includes an annular elastic seal containing a spring arranged between an annular internal contact surface on a female part and an annular internal flange that seals the end of a first bayonet part, wherein the energized seal is hereinafter referred to as a cold seal, and the energized seal is an energized seal, An annular gasket, hereinafter referred to as a worm seal, arranged between an annular outer flange connected to the outer tube of the first bayonet part and a corresponding annular outer flange connected to the outer tube of the second bayonet part, wherein the annular outer flanges can further include an annular gasket that is bolted or clamped together to provide a liquid-tight seal. · The first bayonet part is upstream of the second bayonet part. · The first bayonet part is downstream of the second bayonet part in the direction of the flow of the liquid cryogen pumped from the liquid cryogen pump. · The system further includes a third bayonet part having a circular cross-section and including an outer tube surrounding an inner tube, an annular space being defined therebetween and being adapted and configured to be hermetically evacuated to maintain a vacuum therein, and can further include a filter housed inside the third bayonet part. The first bayonet part is arranged between the third bayonet part and the second bayonet part. The upstream ends of the inner and outer tubes of the third bayonet part are adapted and configured to be welded to the corresponding inner and outer tubes of the vacuum-jacketed pipe. The first bayonet part has an upstream end that is a female end and a downstream end that is a male end. The downstream end of the third bayonet part is received concentrically within the upstream end of the first bayonet part. The downstream end of the first bayonet part is received concentrically within the second bayonet part, and / or · The system can further include a source of liquid cryogen, a vacuum-jacketed pipe in fluid communication between the liquid cryogen source and the first bayonet part, and a hose adapted and configured to be connected in a liquid-tight manner to a storage tank, receive the liquid cryogen pumped from the liquid cryogen pump, and feed the received liquid cryogen into the storage vessel. The vacuum-jacketed pipe has a circular cross-section and includes an outer tube surrounding an inner tube, an annular space being defined therebetween and being adapted and configured to be hermetically evacuated to maintain a vacuum therein. The downstream ends of the inner and outer tubes are welded in a liquid-tight manner to the upstream ends of the inner and outer tubes of the third bayonet section. The hose has a circular cross-section and includes an outer tube surrounding an inner tube, with an annular space defined between them, configured to be sealed and evacuated to maintain a vacuum within that space. The upstream end of the hose is received within the downstream end of the second bayonet section. The flange on the outer tube of the hose is fastened in a liquid-tight manner to the corresponding flange on the downstream end of the outer tube of the second bayonet section.

[0021] In yet another embodiment, the liquid cryogenic pump supply system is a bayonet including a first bayonet section and a second bayonet section, wherein the first bayonet section includes a bayonet configured to receive into the second bayonet section and a liquid cryogenic pump housed within the bayonet, wherein the first and second bayonet sections are configured to be reversibly disassembled relative to each other so that they can be disassembled without the need to cut the bayonet or break the welds, and the bayonet includes an upstream end and a downstream end.

[0022] In an optional embodiment of the pump supply system, The bayonet further includes a third bayonet portion having a male cross-section that is inserted into the female cross-section of the first bayonet portion and is configured to be received by the female cross-section. The bayonet further includes a third bayonet section arranged upstream of the first bayonet section, the third bayonet section housing a filter configured to reduce the risk of clogging of the internal components of the liquid cryogenic pump. The upstream end is configured to be connected in a liquid-tight manner to the cross section of the vacuum-jacketed piping, thereby creating a fluid connection with the liquid cryogenic source. • The connection is made via welding. The downstream end is configured to be connected in a liquid-tight manner to the downstream section of a vacuum-jacketed pipe or liquid cryogenic agent hose, thereby fluidly connecting to either the point of use where the liquid cryogenic agent is used or consumed, or to a storage container. The first bayonet section includes an outer tube surrounding an inner tube, defining a first internal space between them, configured to be fitted with a sealed exhaust to maintain a vacuum within it, the first bayonet section having an upstream end and a downstream end, the second bayonet section includes an outer tube surrounding an inner tube, defining a second internal space between them, configured to be fitted with a sealed exhaust to maintain a vacuum within it, the first bayonet section has a male cross section that is concentrically received within the female cross section of the second bayonet section and sealed to the second bayonet section, The pump supply system may further include a first flange arranged on the downstream end, configured to close the downstream end of the first internal space. The pump supply system may further include a cold seal configured to have one side that contacts a relatively high-pressure and low-temperature liquid cryogenic agent during use, and a second side that contacts a relatively low-pressure and high-temperature annular gap between the outer surface of a male cross-section and the inner surface of a female cross-section. • A cold seal is an electrically conductive seal having an elastic material that encloses the spring. The pump supply system may further include a worm seal having a first side that contacts an annular gap and a second side that contacts a relatively high-temperature ambient environment. • A worm seal includes a gasket sandwiched between a pair of flanges. The system may also include channeled wiring configured to supply power to the liquid cryogenic pump, the channeled wiring extending into the first bayonet section and connected to the liquid cryogenic pump, and / or The channeled wire is coiled inside the annular gap of the bayonet, which increases the heat conduction path of the channeled wire and thereby reduces heat transfer to the outer surface of the bayonet.

[0023] In yet another embodiment, a method is provided for delivering liquid cryogenic agent from a liquid cryogenic agent source to a storage tank, the method comprising the steps of providing a bayonet system having inline pumps arranged between them, the bayonet system having an upstream end and a downstream end, the bayonet system being attached to an upstream conduit, the upstream conduit being in fluid communication with the liquid cryogenic agent source, the bayonet system being attached to a downstream conduit, the downstream conduit being in fluid communication with the storage tank, the upstream and downstream conduits being cleared and cooled, and the liquid cryogenic agent being delivered from the liquid cryogenic agent source to the storage tank.

[0024] In an optional embodiment of a method for delivering liquid cryogenic agents, The bayonet system further includes a first bayonet section and a second bayonet section, the first bayonet section being configured to be received within the second bayonet section, and the first and second bayonet sections being configured to be reversibly disassembled relative to each other so that they can be disassembled without the need to cut the bayonet or break the weld. The bayonet system further includes a third bayonet portion having a male cross-section, which is inserted into the female cross-section of a first bayonet portion and configured to be received by the female cross-section. The bayonet system further includes a third bayonet section arranged upstream of the first bayonet section, the third bayonet section housing a filter configured to reduce the risk of clogging of the internal components of the liquid cryogenic pump. The upstream end of the bayonet system is configured to be connected to the upstream conduit in a liquid-tight manner, thereby creating a fluid connection with the liquid cryogenic source. • The connection is made via welding. The downstream end of the bayonet system is configured to connect to a downstream conduit in a liquid-tight manner, and the downstream conduit is a vacuum-jacketed pipe or liquid cryogenic hose such that the fluid connection is fluid to either a storage container or a point of use where the liquid cryogenic agent is used or consumed. The first bayonet section includes an outer tube surrounding an inner tube, defining a first internal space between them, configured to be sealed and evacuated to maintain a vacuum, and the first bayonet section has an upstream end and a downstream end; the second bayonet section includes an outer tube surrounding an inner tube, defining a second internal space between them, configured to be evacuated to maintain a vacuum, and the first bayonet section has a male section that is concentrically received within the female section of the second bayonet section and sealed against the female section. The bayonet system further includes a first flange arranged on the downstream end, configured to close the downstream end of the first internal space. The bayonet system further includes a cold seal configured to have one side that contacts a relatively high-pressure and low-temperature liquid cryogenic agent during use, and a second side that contacts a relatively low-pressure and high-temperature annular gap between the outer surface of the male cross section and the inner surface of the female cross section. • A cold seal is an electrically conductive seal having an elastic material that encloses the spring. The bayonet system further includes a worm seal having a first side that contacts an annular gap and a second side that contacts a relatively high-temperature ambient environment. • A worm seal includes a gasket sandwiched between a pair of flanges. The bayonet system further includes channeled wiring configured to supply power to the liquid cryogenic pump, the channeled wiring extending into the interior of the first bayonet section and connected to the liquid cryogenic pump, The channeled wire is coiled inside the annular gap of the bayonet, which increases the heat conduction path of the channeled wire and thereby reduces heat transfer to the outer surface of the bayonet. The liquid cryogenic agent is selected from the group consisting of liquid hydrogen, liquid helium, liquid nitrogen, liquid argon, liquid oxygen, and liquid carbon dioxide. • The liquid cryogenic agent is liquid hydrogen. The downstream conduit includes a liquid cryogenic agent hose, which is configured to connect to the downstream end of the bayonet system by inserting the male end of the liquid cryogenic agent hose into the female end of the downstream end of the bayonet system, thereby creating a releasable connection. The bayonet system comprises: a first bayonet section having a circular cross-section and including an outer tube surrounding an inner tube, with an annular space defined between them, configured to be sealed and evacuated to maintain a vacuum; a second bayonet section having a circular cross-section and including an outer tube surrounding an inner tube, with an annular space defined between them, configured to be adapted to be evacuated to maintain a vacuum, wherein the first bayonet section is concentrically received within the second bayonet section and sealed to the second bayonet section; and a liquid cryogenic pump housed within the first bayonet section. The first and second bayonet sections are reversibly detachable and are not welded together, and / or, so that the liquid cryogenic pump can be maintained or replaced without having to break the weld. The bayonet system includes an energizing seal comprising a spring-containing, annularly shaped elastic seal arranged between an annular internal contact surface on a female part and an annular internal flange sealing the end of a first bayonet part, the energizing seal being hereinafter referred to as a cold seal, and an annular gasket hereinafter referred to as a worm seal arranged between an annular external flange connected to the outer tube of the first bayonet part and a corresponding annular external flange connected to the outer tube of the second bayonet part, the annular external flanges being bolted or clamped together to provide a liquid-tight seal.

[0025] To further understand the nature and purpose of the present invention, the following detailed description should be referred to in conjunction with the accompanying drawings, which are given the same or similar reference numerals for the same elements. [Brief explanation of the drawing]

[0026] [Figure 1]Figure 1 is a schematic cross-sectional view of a first bayonet equipped with a liquid cryogenic agent pump in a configuration according to the first embodiment of the present invention. [Figure 2] Figure 2 is a schematic cross-sectional view of the second bayonet for connecting to the first bayonet section in Figure 1, in the configuration of the first embodiment. [Figure 3] Figure 3 is a cross-sectional perspective view of the first embodiment of the assembled bayonet section from Figures 1 and 2, with the components removed. [Figure 4] Figure 4 is a cross-sectional perspective view of a second embodiment of the present invention, in which the order of the first and second bayonet sections is reversed from that in Figure 3, with the components removed. [Figure 5] Figure 5 is a schematic cross-sectional view of the third bayonet section equipped with a liquid cryogenic agent pump in the configuration of the third embodiment of the present invention. [Figure 6] Figure 6 is a schematic cross-sectional view of the first bayonet in the configuration of the third embodiment, for the connection between the third bayonet in Figure 5 and the second bayonet in Figure 7. [Figure 7] Figure 7 is a schematic cross-sectional view of the second bayonet section in the configuration of the third embodiment. [Figure 8] Figure 8 is a cross-sectional perspective view of the third embodiment of the assembled bayonet section from Figures 5 to 7, with the components removed. [Modes for carrying out the invention]

[0027] Instead of placing the liquid cryogenic agent pump inside an oil reservoir where heat leakage cannot be adequately avoided, the applicants propose placing the pump inside a bayonet. Since the bayonet can be disassembled without breaking the welds and disrupting any VJP vacuum, the pump may conventionally be replaced or maintenance may conventionally be performed on it.

[0028] In certain embodiments, the pump can be fitted onto a trailer while maximizing the LH2 load capacity. Current LH2 trailers are limited by the weight of the rear axle and the diameter of the barrel. As a result, by using a design that reduces the footprint and weight, certain embodiments of the present invention can maximize the LH2 load capacity.

[0029] It is known to those skilled in the art that a typical oil reservoir has several drawbacks, namely (1) it is heavier, (2) it is more complicated to operate, (3) it requires more space than the area where the equipment is already located, and (4) it is larger.

[0030] heavier A typical oil reservoir has a large flange on top of it. This flange is thick because it has a large diameter and must accommodate the maximum pressure in the system. Minimizing weight is important to maximize the load capacity of the LH2. Additional connections (steam return) also add weight.

[0031] More complex operations, namely piping and maintenance activities A typical oil reservoir has a non-disconnecting flange. Due to this flange, there is significant heat leakage, and the vapor area is retained within the reservoir. Also, a typical reservoir has a lot of metal, which retains heat and causes evaporation when cooled. To remove the evaporated gas from the reservoir and maintain the proper liquid level, a gas return line is connected to the top of a typical reservoir. This additional line adds complexity. Moreover, because of the significant amount of metal, it takes longer to heat up after pump operation and cool down before pump operation.

[0032] A typical oil reservoir has a pump mounted on the upper flange. To perform maintenance on the pump, the upper flange and pump must be lifted straight out of the reservoir. A crane is often required for this maintenance, which is an expensive and time-consuming operation.

[0033] Space from an area that already has equipment The LH2 load capacity on an LH2 trailer is limited by the amount of space available to store the LH2 and weight on the rear axle. Ideally, adding a pump to an LH2 trailer does not interfere with the LH2 load capacity. A typical oil reservoir takes up significant space already occupied by existing components. Moving components reduces the volume of the LH2 trailer and thus the load capacity.

[0034] In addition to the direct space occupied by the oil reservoir, additional piping takes up space, and maintenance access is required to remove the large flange containing the discharge piping and the pump to be installed. A typical oil reservoir has piping that is cut horizontally, and the pump must be removed vertically, so that not all of the space required for maintenance is used by other components. The proposed solution requires only one shaft to cut the piping and remove the pump, thereby reducing the space the pump takes up in the cabinet design.

[0035] bigger A typical oil reservoir has an evaporation area near the non-insulated flange and has more connections to the reservoir, which makes its dimensions significantly larger than the pump system of the proposed solution.

[0036] Embodiments of the Invention The bayonet may include at least first and second bayonet portions, the first bayonet portion being received within the second bayonet portion. In other words, the first bayonet portion includes a male portion that is inserted into and received by the female portion of the second bayonet, and is provided with a seal arranged between them to prevent liquid cryogenic agent from leaking into the space between the male and female portions.

[0037] In one embodiment, the bayonet further includes a third bayonet portion having a male cross-section that is inserted into the female cross-section of a first bayonet portion and received by the female cross-section. Regardless of which embodiment is selected, each pair adjacent to the assembled bayonet portion (i.e., the first and second bayonet portions and the third and first bayonet portions) is reversibly engaged and disengaged from each other so that each pair can be disassembled without having to cut any VJP or bayonet portion or break any welds.

[0038] Each bayonet section includes an inner tube concentrically arranged within an outer tube with an annular gap between them, which is intended to be maintained under vacuum to vacuum-insulate the liquid cryogenic agent and the pump. The outer diameter of a given bayonet section may be constant throughout its length. Alternatively, one or more bayonet sections may have one or more cross-sections having an outer diameter different from the other cross-sections of one or more bayonet sections in question. In this alternative embodiment, the different cross-sections of one or more bayonet sections may, as desired, be tapered or flared at the base.

[0039] In terms of the flow direction of the liquid cryogenic agent, the upstream ends of the inner and outer tubes of the upstreammost bayonet section are configured to be welded in a liquid-tight manner to the corresponding inner and outer tubes of the VJP cross-section immediately upstream of the bayonet. On the other hand, with respect to the downstreammost bayonet section, the downstreammost cross-section of the bayonet section is a female section configured to receive the liquid cryogenic agent hose. In other words, the upstreammost end of the hose is a male section that is received within the female cross-section of the downstreammost bayonet section.

[0040] If necessary, other equipment for handling cryogenic liquids, such as filters, sensors, and / or instruments, may also be housed in the first bayonet section or further in the second and / or third bayonet sections.

[0041] Each assembled pair of bayonet sections includes a cold seal having one side in contact with a relatively high-pressure, low-temperature liquid cryogenic agent and another side in contact with a relatively low-pressure, high-temperature annular gap between the outer surface of the male section and the inner surface of the female section. Each assembled pair of bayonet sections also includes a worm seal having one side in contact with the annular gap and another side in contact with a relatively high-temperature ambient environment. The cold seal may be any seal known in the field of cryogenic liquids that is suitable for use in pressurized (i.e., pumped) cryogenic liquid services, such as maintaining a seal between the higher-pressure liquid cryogenic agent side and the lower-pressure side at ambient pressure. However, since typical bayonet seals are not always perfectly satisfied in vibrating environments (due to deformation that induces vibration of the seal), the bayonet may preferably utilize an energized seal as the cold seal. An energized seal is typically an annular-shaped member made of an elastic material that encloses a spring. The vibrational energy is damped by the presence of the spring. Examples of electrically conductive seals include springs enclosed by hollow O-rings or cup seals. Similarly, worm seals may be any seal known in the field of cryogenic liquids to adequately seal a cryogenic environment from an ambient temperature environment. Typically, a worm seal is made from one flange of a pair of assembled bayonet parts and the corresponding flange of the other pair of assembled bayonet parts, with a gasket (such as a helical gasket) sandwiched between them and bolted together.

[0042] The bayonet is connected between the upstream and downstream sections of the VJP or to the liquid cryogenic hose. The upstream section of the VJP is fluidly connected directly or indirectly to the liquid cryogenic storage tank downstream. In the case of the downstream section of the VJP, the VJP is fluidly connected upstream to either a point of use where the liquid cryogenic is used or consumed, or to a storage container. In the case of the liquid cryogenic hose, it will be recognized by those skilled in the art that the liquid cryogenic hose is similar to the VJP, and that the VJP includes an outer tube concentrically surrounding an inner tube, with an annular space between them, which is maintained under vacuum. In contrast to the VJP, it will be further understood by those skilled in the art that the liquid cryogenic hose includes a flexible section that can be flexibly attached to other cryogenic liquid handling equipment such as a liquid cryogenic storage tank.

[0043] A bayonet restricts heat transfer from the surrounding environment to a cryogenic liquid by reducing the cross-sectional area of ​​the annular gap between the outer surface of the male cross-section and the inner surface of the female cross-section. By reducing the cross-sectional area, heat leakage through convection is correspondingly reduced. A bayonet also restricts such heat transfer by increasing the distance of the path for conductive heat transfer (over the length of the gap between the outer surface of the male cross-section and the inner surface of the female cross-section), for example, from the cold seal of the bayonet to the worm seal of the bayonet.

[0044] The cryogenic liquid pump is sealed within the bayonet, but the pump must be supplied with power. In certain embodiments of the present invention, an insulated wire contained within a channel may be used so that the flow of the liquid cryogenic agent into which a portion of the channeled wiring is immersed does not cause deformation of the channeled wiring. This can be achieved by housing the insulated wire within the channel and inserting it into the first bayonet portion, passing through the outer tube of the first bayonet portion, through the annular gap between the inner and outer tubes, and into the first bayonet portion immersed in the liquid cryogenic agent. The channeled wiring extends inside the liquid cryogenic agent and is connected to the pump motor.

[0045] Since a portion of the channel is in contact with the surrounding environment outside the bayonet section, techniques are used to reduce heat leakage. First, the vacuum matching of the annular gap between the inner and outer tubes is maintained by welding the outer surface of the channel to the ports inside the outer and inner tubes. This, of course, significantly reduces any heat conduction through convection. Next, the wire / channel may be coiled inside the annular gap to increase the heat conduction path. In fact, the length of a coiled channel / wire is several times longer, about an order of magnitude longer than the length of a channel / wire immersed in liquid cryogenic agent. The coiling also allows for thermal contraction and expansion of the channel / wire when cooled or heated during operation. This significantly increases the length of the path available for heat transfer by conduction. Finally, the cross-sectional area of ​​the channel is relatively small. For example, when a 0.25-inch pipe can be selected for the channel, a wall thickness of only 0.035 inches may be selected. This results in a cross-sectional area of ​​only 0.013 inches square. This relatively small cross-sectional area correspondingly reduces heat transfer by a relatively small amount through conduction.

[0046] A pump supply system can be used to pump liquid cryogenic agents for any purpose, but in one embodiment of the present invention, it may be used for the delivery of liquid cryogenic agents from an industrial producer of liquid cryogenic agents to a user of liquid cryogenic agents (e.g., a customer). More specifically, the system may be mounted on a tank truck and used to pump liquid cryogenic agents from the tank truck's tank to one of the storage containers. Examples of such systems are disclosed in U.S. Patent No. 2021-0364129A1, U.S. Provisional Patent Application No. 63 / 282,115 filed November 22, 2021, and U.S. Provisional Patent Application No. 63 / 283,120 filed November 24, 2021, the disclosures of which are incorporated herein by reference in their entirety.

[0047] A liquid cryogenic agent pump supply system may be used to pump any non-conductive liquid cryogenic agent. Non-limiting examples include liquid hydrogen, liquid helium, liquid nitrogen, liquid oxygen, liquid carbon dioxide, and liquid argon. Typically, the liquid cryogenic agent is liquid hydrogen.

[0048] The applicants hereby describe a process for filling a storage tank using the liquid cryogenic pump supply system of the present invention. In the process of filling a liquid storage tank, the upstream VJP is connected to a source of liquid cryogenics, such as a liquid cryogenics tanker towed by a semi-track tractor. A liquid cryogenics hose is connected to the storage tank to be filled. After the hose is cleared and cooled, one or more valves are activated to allow the liquid cryogenics to flow from the source to the storage tank and to start a liquid cryogenics pump so that the liquid cryogenics can be pumped from the source to the storage tank.

[0049] Referring to Figures 1 to 8, the applicants hereby describe specific embodiments of the present invention.

[0050] In the first embodiment, as shown in Figure 1, the first bayonet section includes an inner cylindrical tube 1 concentrically arranged within an outer cylindrical tube 3 with an annular gap 5 between them, which is intended to be maintained under vacuum to provide vacuum insulation for the liquid cryogenic agent and the liquid cryogenic agent pump 7. The liquid cryogenic agent pump 7 is secured to a flange 9 on the inner tube 1 by bolts 11. The wires 13 are contained within a protective channel 15. The flange 17 is formed on the outer surface of the outer tube 3. Although not shown as such in Figure 1, the flange 17 is intended to form part of a worm seal between the first bayonet section and the second bayonet section, as shown in Figure 3.

[0051] The downstream ends of the inner tube 1 and outer tube 3 are welded to the annular flange 19 (indicated by dots) so that the annular gap 5 can be maintained under vacuum. Although not shown in Figure 1, the upstream ends of the inner tube 1 and outer tube 3 are intended to be welded to the inner and outer tubes to match the corresponding diameters of the VJP. This is shown in Figure 3.

[0052] As shown in Figure 2, the second bayonet section also includes an inner cylindrical tube 21 concentrically arranged within an outer cylindrical tube 23 with an annular gap 25 between them, which is intended to be maintained under vacuum to provide vacuum insulation for the liquid cryogenic agent and the pump 7. The contact surface 22 is provided on the surface of the inner tube 21. A cold seal is provided between the contact surface 22 and the annular gap 19 of the first bayonet section, as described below with respect to Figures 3-4. The upstream ends of the inner tube 21 and the outer tube 23 are sealed with flanges 27. The flanges 27 along the flange 17 of the first bayonet section form a component of the worm seal, which is described below with respect to Figures 3-4. The downstream end of the annular gap 25 is sealed with a plate 24. A flange 26, which forms part of the worm seal, described in more detail below, is formed on the downstream end of the outer tube 23.

[0053] As shown in Figure 3, the first bayonet portion is concentrically received within the second bayonet portion. The cold seal 29 is maintained between the flange 19 and the contact surface 22 of the first bayonet portion. The cold seal 29 may be of the type discussed above. The worm seal is formed from a gasket 33 sandwiched between flanges 17 and 27, which is secured by bolts 35.

[0054] The pump supply system may be connected to the upstream VJP by welding the inner tube 37 and outer tube 39 of the upstream VJP to the inner tube 1 and outer tube 3 of the first bayonet section, respectively (indicated by dots). The upstream VJP has an annular gap 41 between the inner tube 37 and outer tube 39 of the upstream VJP, which is intended to be placed under vacuum. Since they are in fluid communication with each other, the annular gap 41 of the upstream VJP and the annular gap 5 of the first bayonet section are maintained under normal vacuum. Only a portion of the upstream VJP is shown in Figure 3.

[0055] The pump supply system may be connected to the downstream VJP in the same manner as described above for the upstream VJP.

[0056] Alternatively, the pump supply system may be connected to the downstream hose 47 by inserting the male end of the hose into the female end of the second bayonet section. The expander ring 45 is attached to the uppermost part of the hose 47. An O-ring 49 forming a cold seal is compressed between the outer surface of the expander ring 45 and the surface of the inner tube 21 of the second bayonet section. The flange 26 of the second bayonet section is clamped with a clamp 51 to a flange 50 formed on the outer surface of the hose 47, which may be of the type described above. The flanges 26, 50 and clamp 51 together form a worm seal.

[0057] During operation, due to the pumping action of pump 7, the flow of liquid cryogenic agent from the source of the liquid cryogenic agent (such as a tank truck towed by a semi-truck tractor) from inside the inner pipe 37 of the upstream VJP is introduced into the inner pipe 1, passes through the liquid cryogenic agent space 2, and enters the suction inlet of pump 7. The pumped flow of liquid cryogenic agent is discharged from the outlet of pump 7. The flow exits the liquid cryogenic agent space 2 and enters the hose 47, where it is sent towards the point of use or typically a storage tank.

[0058] A second embodiment is shown in Figure 4. The second embodiment is very similar to the first embodiment, except that the order is reversed (in terms of the direction of flow of the pumped liquid cryogenic agent). The second bayonet is upstream, while the first bayonet is downstream. During operation, due to the pumping action of pump 7, the flow of liquid cryogenic agent from the source of the liquid cryogenic agent (such as a tank truck towed by a semi-truck tractor) from inside the inner pipe 37 of the upstream VJP is introduced into the inner pipe 21, passes through the liquid cryogenic agent space 2, and enters the suction inlet of pump 7. The pumped flow of liquid cryogenic agent is discharged from the outlet of pump 7. The flow exits the liquid cryogenic agent space 2 and enters the hose 47, where it is sent towards the point of use or typically a storage tank.

[0059] As shown in Figures 5 to 8, the third embodiment includes first, second, and third bayonet sections.

[0060] As shown in Figure 5, the third bayonet section includes an inner cylindrical tube 51 concentrically arranged within the outer cylindrical tube 53, with an annular gap 55 between them, the downstream end of which is welded to an annular plate 56 so as to maintain the annular gap 55 under vacuum in order to provide vacuum insulation for the liquid cryogenic agent. To prevent particles from clogging the internal components of the pump 57, a filter 54 is fastened to the annular plate 56 to filter the flow of cryogenic liquid. Finally, an annular flange 57, which forms part of the worm seal and is described below with respect to Figure 8, is formed on the outer tube 53.

[0061] As shown in Figure 6, the first bayonet section also includes an inner cylindrical tube 59 concentrically arranged within the outer cylindrical tube 60, with an annular gap 61 between them, which is intended to be maintained under vacuum to provide vacuum insulation for the liquid cryogenic agent and the liquid cryogenic agent pump 57. The upstream and downstream ends of the second bayonet section are welded to flanges 62, 68 to seal the annular gap 61. As described below, the flanges 62, 68 form part of a worm seal between the third bayonet section and the first bayonet section, and between the first bayonet section and the second bayonet section, respectively. The liquid cryogenic agent pump 57 is bolted to the inner tube 59 by the flange 79. The wires 63 are contained within a protective channel 65. The cross section of the intermediate section 67 of the first bayonet section is tapered compared to its upstream and downstream ends. The contact surface 66 is provided on the surface of the inner tube 59. With respect to Figure 8, as described below, the cold seal is provided between the contact surface 66 and the annular plate 56 of the third bayonet portion.

[0062] As shown in Figure 7, the second bayonet section also includes an inner cylindrical tube 69 concentrically arranged within an outer cylindrical tube 71, with an annular gap 73 between them, intended to be maintained under vacuum to provide vacuum insulation for the liquid cryogenic agent. The upstream ends of the inner tube 69 and the outer tube 71 are welded to annular flanges 77, 80, respectively, to seal the annular gap 73. The flange 77 along the flange 64 of the first bayonet section forms a component of the worm seal, which is described below with respect to Figure 8.

[0063] As shown in Figure 8, the male cross section of the third bayonet is received within the female cross section of the first bayonet, and the male cross section of the first bayonet is received within the female cross section of the second bayonet. A cold seal 58 is held between the flange 56 of the third bayonet and the contact surface 66 of the first bayonet. Another cold seal 90 is held between the flange 68 of the first bayonet and the contact surface 75 of the second bayonet. The cold seals 58 and 90 may be of the above type. A worm seal is formed from a gasket 88 sandwiched between flanges 57 and 62, which are secured by bolts 98. Another worm seal is formed from a gasket 92 sandwiched between flanges 64 and 77, which are secured by bolts 108.

[0064] The pump supply system may be connected to the upstream VJP by welding the inner tube 87 and outer tube 89 of the upstream VJP to the inner tube 51 and outer tube 53 (indicated by dots). The upstream VJP has an annular gap 91 between the inner tube 87 and outer tube 89 of the upstream VJP, which is intended to be placed under vacuum. Because they are in fluid communication with each other, the annular gap 91 of the upstream VJP and the annular gap 55 of the bayonet are maintained under normal vacuum. Only a portion of the upstream VJP is shown in Figure 8.

[0065] The pump supply system may be connected to the downstream VJP in the same manner as described above for the upstream VJP.

[0066] Alternatively, the pump supply system may be connected to the downstream hose 97 by inserting the male end of the hose into the female end of the second bayonet section. The expander ring 95 is attached to the uppermost part of the hose 97. An O-ring 99 forming a cold seal is compressed between the outer surface of the expander ring 95 and the surface of the inner tube 69 of the second bayonet section. The flange 76 of the second bayonet section is clamped with a clamp 101 to a flange 100 formed on the outer surface of the hose 97, which may be of the type described above. The flanges 76, 100 and clamp 101 together form a worm seal.

[0067] During operation, due to the pumping action of pump 57, the flow of liquid cryogenic agent from the source of the liquid cryogenic agent (such as a tank truck towed by a semi-truck tractor) from inside the inner pipe 87 of the upstream VJP is introduced into the inner pipe 51, passes through the liquid cryogenic agent space 2, passes through the filter 54, passes through the liquid cryogenic agent space 52 in the intermediate section 67, and enters the suction inlet of pump 57. The pumped flow of liquid cryogenic agent is discharged from the outlet of pump 57. The flow exits the liquid cryogenic agent space 52 and enters the hose 97, where it is sent towards the point of use or typically a storage tank.

[0068] This invention offers several advantages.

[0069] The flow path of the liquid cryogenic agent pumped by the pump supply system is completely vacuum-insulated. Therefore, heat leakage, deterioration of the liquid cryogenic agent's quality, and loss of the liquid cryogenic agent due to evaporation are all significantly reduced. This is a significant advantage over conventional liquid cryogenic agent pump supply systems that utilize a flange between the liquid cryogenic agent pump and a VJP or liquid cryogenic agent hose, where one side is in contact with the cryogenic temperature and the other side is in contact with the ambient temperature.

[0070] Access to the liquid cryogenic pump for maintenance or replacement becomes much more convenient. Compared to similar pumps welded in series to the VJP (as done in conventional pump supply systems), the pump is easier to install and remove by simply breaking the worm seal and separating the adjacent bayonet section.

[0071] The pump supply system of the present invention occupies a very small area because the pump is mounted in a bayonet at a location within the piping range between the source of the liquid cryogenic agent and the final destination to which the liquid cryogenic agent is pumped. This range would otherwise be occupied by the VJP in conventional liquid cryogenic agent pump supply systems.

[0072] In one embodiment of the present invention, the bayonet has a cross-section in which its uppermost end has a diameter that matches the diameter of a portion of the upstream VJP to which the pump supply system is connected. The bayonet also includes a cross-section in which its diameter expands from the diameter of the VJP to a larger diameter that accommodates a relatively large pump. Furthermore, the bayonet also includes a cross-section in which its diameter tapers from the larger diameter of the cross-section accommodating the pump to its lowermost end, where the diameter of the portion of the downstream VJP to which the pump supply system is connected matches. This is advantageous compared to conventional pump supply systems because a narrower VJP can be used, while at the same time the liquid cryogenic pump and the flowing liquid cryogenic remain completely vacuum-insulated.

[0073] In one embodiment of the present invention, the cold seal is an electrically conductive seal. The presence of a spring within the electrically conductive seal acts to suppress the vibrational energy induced by the operation of the liquid cryogenic agent pump. This is advantageous compared to conventional bayonet cold seals made of Teflon, as such seals tend to deform due to unsuppressed vibrational energy. This results in heat leakage due to the movement of the amount of liquid cryogenic agent passing through the cold seal into the annular gap between the inner and outer tubes of the bayonet.

[0074] The wiring method for liquid cryogenic pumps significantly reduces heat leakage from the ambient atmosphere to the liquid cryogenic material. Convective heat transfer is reduced by maintaining the vacuum integrity of the annular gap between the inner and outer tubes by welding the outer surface of the channel to the ports in the outer and inner tubes. The length of the path available for conductive heat transfer is significantly increased by coiling the channeled wiring within the annular gap between the inner and outer tubes of the first bayonet section. Finally, heat transfer via conduction is also significantly reduced by utilizing the relatively small cross-sectional area of ​​the channel. The combined effect of these techniques is very advantageous compared to the latest techniques for wiring liquid cryogenic pumps. Conventional techniques typically involve wiring passing through flanges, where one side is exposed to the cryogenic temperature and the other side to ambient temperature. Therefore, neither convective nor conductive heat transfer is minimized.

[0075] Although the present invention has been described in conjunction with its specific embodiments, it is evident that many alternative forms, modifications, and variations will be apparent to those skilled in the art in consideration of the foregoing. Therefore, it is intended to encompass all such alternative forms, modifications, and variations that fall within the spirit and broad scope of the appended claims. The present invention may appropriately include, constitute, or essentially constitute the disclosed elements, and may be carried out without disclosing any undisclosed elements. Furthermore, where there are terms indicating order, such as first and second, it should be understood that they are illustrative and not limiting. For example, those skilled in the art will understand that certain steps can be combined into a single step.

[0076] The single forms "a," "an," and "the" refer to multiple objects unless the context explicitly states otherwise.

[0077] In the claims, “includes” is an open transitional term meaning that any subsequently identified claim elements are a non-exclusive list, i.e., any of them are additionally included and may remain within the scope of “includes.” “Includes” is defined herein to necessarily encompass the more restrictive transitional terms “essentially constitutes” and “constitutes,” and therefore “includes” may be replaced with “essentially constitutes” or “constitutes,” and may remain within the explicitly defined scope of “includes.”

[0078] In the claims, “to provide” is defined to mean to equip, supply, make available, or prepare something. The step may be taken by any actor if there is no express language to the contrary in the claims.

[0079] The term "optional" or "optional" means that the events or situations described thereafter may or may not occur. The descriptions include examples of events or situations occurring, and examples of events or situations not occurring.

[0080] The range may be expressed herein as approximately from one specific value to and / or approximately from another specific value. Where such a range is expressed, it should be understood that other embodiments, along with all combinations within the range, are from one specific value to and / or from the other specific value.

[0081] All references identified herein, along with the specific information from which they are cited, are incorporated into this application by reference in their entirety.

Claims

1. A liquid cryogenic agent pump supply system that reduces heat leakage and incorporates a bayonet, A first bayonet section having a circular cross-section and including an outer tube (3) surrounding an inner tube (1), with an annular space (5) defined between them, configured to be sealed and evacuated to maintain a vacuum, A second bayonet section having a circular cross-section and including an outer tube (23) surrounding an inner tube (21), with an annular space (25) defined between them, configured to be adapted for exhausting to maintain a vacuum, wherein the first bayonet section is concentrically received within the second bayonet section and sealed to the second bayonet section, A system including a liquid cryogenic agent pump (7) housed within the first bayonet section.

2. The system according to claim 1, wherein the first and second bayonet portions are reversibly engaged and disengaged, and are not welded together so that the liquid cryogenic pump can be maintained or replaced without having to break the weld.

3. An energized seal (29) includes an annular elastic seal containing a spring arranged between an annular internal contact surface (22) on the female part and an annular internal flange (19) that seals the end of the first bayonet part, wherein the energized seal is hereinafter referred to as a cold seal, and the energized seal (29) is... The system according to claim 1 or 2, further comprising an annular gasket (33), hereinafter referred to as a worm seal, arranged between an annular external flange (17) connected to the outer tube of the first bayonet section and a corresponding annular external flange (27) connected to the outer tube of the second bayonet section, wherein the annular external flanges (17, 27) are bolted together or clamped to provide a liquid-tight seal.

4. The system according to any one of claims 1 to 3, wherein the first bayonet portion is located upstream of the second bayonet portion.

5. The system according to claim 1, wherein the first bayonet portion is located downstream of the second bayonet portion in the direction of the flow of liquid cryogenic agent pumped from the liquid cryogenic agent pump.

6. A third bayonet section having a circular cross-section and including an outer tube (53) surrounding an inner tube (51), with an annular space defined between them, configured to be fitted with a sealed exhaust to maintain a vacuum within that space, The device further includes a filter (54) housed inside the third bayonet section, The first bayonet portion is arranged between the third bayonet portion and the second bayonet portion. The upstream ends of the inner and outer tubes of the third bayonet section are configured to be welded to the corresponding inner and outer tubes of the vacuum-jacketed piping. The first bayonet portion has an upstream end which is a female end and a downstream end which is a male end, The downstream end of the third bayonet portion is concentrically received within the upstream end of the first bayonet portion. The system according to any one of claims 1 to 5, wherein the downstream end of the first bayonet portion is concentrically received within the second bayonet portion.

7. The system further includes a source of liquid cryogenic agent, a vacuum-jacketed pipe that provides fluid communication between the source of liquid cryogenic agent and the first bayonet section, and a hose (47) connected in a liquid-tight manner to a storage tank, which is configured to receive the liquid cryogenic agent pumped from the liquid cryogenic agent pump and to send the received liquid cryogenic agent to the storage container. The vacuum-jacketed piping has a circular cross-section and includes an outer tube (39) surrounding an inner tube (37), with an annular space (41) defined between them, and is configured to be sealed and evacuated to maintain a vacuum within that space. The downstream ends of the inner and outer tubes of the vacuum-jacketed piping are welded in a liquid-tight manner to the upstream ends of the inner and outer tubes of the bayonet. The hose has a circular cross-section and includes an outer tube surrounding an inner tube, with an annular space defined between them, configured to be sealed and evacuated to maintain a vacuum within that space. The upstream end of the hose is received within the downstream end of the second bayonet section. The system according to any one of claims 1 to 6, wherein the flange (50) on the outer tube of the hose is fastened in a liquid-tight manner to the corresponding flange (26) on the downstream end of the outer tube of the second bayonet portion.

8. A liquid cryogenic agent pump supply system with reduced heat leakage, A bayonet comprising a first bayonet portion and a second bayonet portion, wherein the first bayonet portion is configured to be received within the second bayonet portion, The bayonet contains a liquid cryogenic agent pump (7), The first bayonet portion and the second bayonet portion are configured to be reversibly engaged and disengaged from each other so that they can be disassembled without the need to cut the bayonet or break the weld. The bayonet is a system including an upstream end and a downstream end.

9. The system according to claim 8, wherein the bayonet further comprises a third bayonet portion having a male cross-section, which is inserted into the female cross-section of the first bayonet portion and configured to be received by the female cross-section.

10. The system according to claim 8 or 9, wherein the bayonet further includes a third bayonet portion arranged upstream of the first bayonet portion, the third bayonet portion housing a filter (54) configured to reduce the risk of clogging of the internal components of the liquid cryogenic pump (7).

11. The system according to any one of claims 8 to 10, wherein the upstream end is configured to be connected in a liquid-tight manner to the cross section of a vacuum-jacketed pipe, thereby providing a fluid connection to a liquid cryogenic source.

12. The system according to claim 11, wherein the connection is made by welding.

13. The system according to any one of claims 8 to 12, wherein the downstream end is configured to be connected in a liquid-tight manner to the downstream cross section of a vacuum-jacketed pipe or liquid cryogenic agent hose, thereby fluidly connecting to either a point of use where the liquid cryogenic agent is used or consumed, or to a storage container.

14. The system according to any one of claims 8 to 13, wherein the first bayonet portion includes an outer tube (3) surrounding an inner tube (1), a first internal space (5) defined between them, and is configured to be sealed and evacuated to maintain a vacuum, the first bayonet portion has an upstream end and a downstream end, the second bayonet portion includes an outer tube (23) surrounding an inner tube (21), a second internal space (25) defined between them, and is configured to be evacuated to maintain a vacuum, and the first bayonet portion has a male cross section that is concentrically received within the female cross section of the second bayonet portion and sealed to the female cross section.

15. The system according to claim 14, further comprising a first flange (19) arranged on the downstream end, configured to close the downstream end of the first internal space (5).

16. The system according to claim 14, further comprising a cold seal (29) configured to have one side surface that comes into contact with a relatively high-pressure and low-temperature liquid cryogenic agent during use, and a second side surface that comes into contact with a relatively low-pressure and high-temperature annular gap between the outer surface of the male cross section and the inner surface of the female cross section.

17. The system according to claim 16, wherein the cold seal is an electrically conductive seal having an elastic material that surrounds the spring.

18. The system according to claim 14, further comprising a worm seal (33) having a first side surface that contacts the annular gap and a second side surface that contacts a relatively high-temperature ambient environment.

19. The system according to claim 18, wherein the worm seal includes a gasket sandwiched between a pair of flanges (17, 27).

20. The system according to any one of claims 8 to 19, further comprising a channeled wiring (13) configured to supply power to the liquid cryogenic pump, the channeled wiring extending into the first bayonet portion and connected to the liquid cryogenic pump (7).

21. The system according to claim 20, wherein the channeled wire (13) is wound in a coil shape inside the annular gap of the bayonet, thereby increasing the heat conduction path of the channeled wire and thereby reducing heat transfer with the outer surface of the bayonet.

22. A method for delivering a liquid cryogenic agent from a liquid cryogenic agent source to a storage tank, comprising the following steps: To provide the bayonet described in any one of claims 1 to 21, The bayonet is attached to the upstream conduit (37, 39, 41), and the upstream conduit is in fluid communication with the liquid cryogenic source. The bayonet is attached to the downstream conduit (47), and the downstream conduit is in fluid communication with the storage tank. The upstream conduit and the downstream conduit (47) are cleared and cooled, A method comprising flowing the liquid cryogenic agent from the liquid cryogenic agent source to the storage tank.

23. The method according to claim 22, wherein the liquid cryogenic agent is selected from the group consisting of liquid hydrogen, liquid helium, liquid nitrogen, liquid argon, liquid oxygen, and liquid carbon dioxide.

24. The method according to claim 22, wherein the liquid cryogenic agent is liquid hydrogen.

25. The method according to claim 22, wherein the downstream conduit (47) includes a liquid cryogenic agent hose, and the liquid cryogenic agent hose is configured to connect to the downstream end of the bayonet system by inserting the male end of the liquid cryogenic agent hose into the female end of the downstream end of the bayonet system, thereby creating a releasable connection.

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