Container for containing cryogenic fluid
The strut design, which uses a diamond-shaped support structure and a spherical joint, solves the stability problem of cryogenic fluid containers under thermal length changes and mechanical loads, achieving thermal decoupling and rigid support, and adapting to the thermal expansion of cryogenic fluid containers and vehicle vibration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-16
- Publication Date
- 2026-03-27
AI Technical Summary
Existing cryogenic fluid containers have difficulty effectively absorbing thermal changes in the inner container within the support structure, while simultaneously withstanding radial and torsional forces, especially during vehicle vibrations, which could lead to the risk of the outer container detaching.
A diamond-shaped support structure is adopted, and the support columns are connected by ball joints or universal joints to form an axially movable, radially stable and torsional rigid support structure. The support columns are made of heat-insulating material to absorb thermal length changes, and the radial and torsional forces are borne by the support structure through fixed bearings.
It achieves thermal decoupling between the inner container and the outer container, absorbs thermal expansion and contraction, ensures the stability and rigidity of the support structure, prevents the container from loosening, and adapts to vehicle vibration and acceleration/deceleration.
Smart Images
Figure CN121752838A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The invention relates to a container for containing cryogenic fluids, comprising an inner container with at least one outwardly protruding lid and an outer container with at least one inwardly recessed lid, wherein the inner container is located in the outer container at a distance on all sides, the protruding lid projects into the recessed lid, and the inner container is supported on the outer container by a first support structure and a second support structure, which engages on the inner container in diametrically opposite manner to the first support structure. BACKGROUND
[0002] In order to increase the volumetric energy density of energy sources which are gaseous under normal conditions, the energy sources are either compressed and stored in pressure vessels for transport and storage purposes or cooled to cryogenic temperatures and thus at least partially liquefied into cryogenic fluids and stored in thermally insulated containers. For driving vehicles, liquefied hydrogen gas or liquefied natural gas (LNG) is stored, for example, as cryogenic fluids with a high energy density for subsequent use in the operation of essentially conventional internal combustion engines or fuel cells in vehicles.
[0003] Due to the extremely low temperatures of such cryogenic fluids, for example, below -252°C in the case of liquid hydrogen gas or below -161°C in the case of LNG, the inner container is subjected to significant thermal length changes or contractions during filling. In a cylindrical container with a length of approximately 1 meter, the length change can be, for example, 5 millimeters or more. At least one of the respective support structures for supporting the inner container on the outer container in the cryogenic container is therefore designed as a floating bearing, which can absorb the length change of the inner container.
[0004] However, the installation of a floating bearing in a cryogenic container is complex, since the thermal bridge between the inner container and the outer container is to be kept to a minimum. Furthermore, although the floating bearing should be able to absorb the length change, it must at the same time permanently withstand radial and torsional forces occurring during operation in order to prevent the inner container from rattling the outer container due to vibrations, acceleration or deceleration of the vehicle, in particular in the event of a collision with an obstacle. SUMMARY
[0005] It is an object of the invention to create a container for cryogenic fluids with an improved support structure for thermally decoupled supporting the inner container on the outer container.
[0006] According to the invention, this object is achieved in a container of the type mentioned at the outset by providing a first support structure having a rhombus-shaped frame of four struts, the ends of the four struts at one of the two diagonally opposite corners of the rhombus being connected to the recessed lid and the ends of the four struts at the other of the two diagonally opposite corners of the rhombus being connected to the raised lid, wherein each strut is connected at one end thereof by a spherical joint and at the other end thereof by a spherical or cardan joint to the respective lid.
[0007] Thereby, the invention creates a new type of axially movable, radially force-stable and torsionally rigid support structure for the inner container in the outer container. Due to the spherical or cardan joints, the rhombus-shaped frame formed by the struts is able to compensate for length changes of the inner container, which are embodied in the movement of the raised lid perpendicularly to the plane of the rhombus. The struts form a temperature gradient in their extension direction for the thermal insulation of the inner and outer containers. Furthermore, the strut frame is not joined at its center to the raised lid but surrounds it, which leads to an extremely torsionally rigid support of the inner container in the outer container.
[0008] In a particularly advantageous embodiment of the invention, the rhombus is a square. This leads to a symmetrical distribution of forces and movements in the support structure on all sides.
[0009] Preferably, each strut is connected at both ends by a respective spherical joint to the respective lid, thereby enabling a minimization of the torque and bending forces on the struts when using the frame formed by the struts.
[0010] It is particularly advantageous if each spherical or cardan joint comprises a first part mounted on the respective strut end and a second part connected in a hinged manner to the first part and mounted on the respective lid, while the two second parts at one corner of the rhombus are rigidly connected to each other and mounted together on the respective lid. This means that only two parts have to be mounted on one lid and two parts on the other lid, which reduces the part requirement and significantly simplifies production.
[0011] Preferably, the two rigidly connected second parts can form a corner piece, which is screwed, crimped or welded to the respective lid. Such a corner piece strengthens and stabilizes the connection of the strut to the respective lid.
[0012] Preferably, the diameter line between the first support structure and the second support structure is the longitudinal axis of the inner container, which extends through the apex of the raised lid. In an elongated inner container, the greatest thermal length changes are expected on the longitudinal axis, so that the described floating bearing support structure is particularly useful there.
[0013] It is particularly advantageous if the rhombus surrounds the described diameter line concentrically. This enables a symmetrical deflection of the struts when the inner container changes the length and the position of the lid along the longitudinal axis, so that the distance between the inner container and the outer container perpendicular to the longitudinal axis does not change.
[0014] When the struts are made of a thermally insulating material, a particularly good thermal decoupling between the inner container and the outer container is achieved. The struts can be made of a fiber-reinforced plastic material, in particular a glass fiber-reinforced plastic material, particularly advantageously. This material combines high thermal insulation with additional elasticity to absorb thermal length changes of the inner container and enables excellent strength to absorb radial forces and torsional rigidity of the support structure.
[0015] The second support structure, which is located opposite the first support structure, which serves as a floating bearing, can be designed as a simple fixed bearing. It can then preferably be used to guide at least one connection line leading from the outside of the container to the inner container.
[0016] The inner container and the outer container can be made of any pressure-resistant and low-temperature-resistant material, for example stainless steel. Preferably, the inner container and the outer container are made of aluminum, which combines low weight with good pressure resistance and low-temperature resistance. BRIEF DESCRIPTION OF DRAWINGS
[0017] The application will be described in detail below on the basis of exemplary embodiments shown in the drawings. In the drawings: Figure 1 The container of the application is shown in a longitudinal sectional view, in which the first support structure, which serves as a floating bearing, is shown only schematically; Figure 2 and Figure 3 The inner container of the container of Figure 2 ) and in a perspective view Figure 3 ) of the support structure, which serves as a floating bearing; Figure 1 Figure 4 The components of one of the individual ball joints of the floating bearing of Figure 2 and Figure 3 are shown in a perspective view; and Figure 5 One of the individual corner pieces of the floating bearing of Figure 2 and Figure 3 is shown in a perspective view, including two struts connected by a ball bearing, which are shown in a partial view. DETAILED DESCRIPTION
[0018] Figure 1 A container 1 for accommodating a cryogenic fluid is shown. The cryogenic fluid can for example be hydrogen, which in a state at least partially liquefied exists at temperatures of up to -252°C and below and at pressures of up to 16 bar or above depending on the container design, or a similar cryogenic fluid that can be used for internal combustion engines or fuel cells, for example liquefied natural gas (LNG) with temperatures of up to -161°C and below. The container 1 is for example installed in the manner of a conventional fuel tank on the side of the chassis or frame of a commercial vehicle, for example a truck or passenger car, which is not shown in more detail.
[0019] However, the cryogenic fluid can also be a refrigerant, for example liquid nitrogen, which is used to operate a cooling system of a refrigerated truck, for example a food transport vehicle. The container 1 can therefore also be used to store such a refrigerant on a truck or a truck trailer.
[0020] In order to thermally insulate the cryogenic fluid with respect to the outside environment, the container 1 has a double-walled construction and consists in particular of an inner container 2 and an outer container 3 which surrounds the inner container on all sides at a distance A. The intermediate space 4 between the inner container 2 and the outer container 3 is generally evacuated, but can additionally or alternatively be filled with a thermal insulation material.
[0021] Since the cryogenic fluid in the inner container 2 is generally under pressure, the (at least) inner container 2 is designed as a pressure vessel made of metal, for example stainless steel or aluminum. The outer container 3 can likewise be made of metal, but can also be made of plastic, since it must only withstand the ambient pressure relative to the vacuum in the intermediate space 4.
[0022] The inner container 2 has a substantially cylindrical shell 5, which is closed at both ends by outwardly protruding covers 6, 7. "Substantially cylindrical" is to be understood to mean a cylinder having an arbitrary base or cross-sectional area, whether circular, oval, rectangular, square, square with rounded corners or any other shape. For maximum pressure resistance, the shell 5 and thus the inner container 2 has a circular cross-section.
[0023] The outer container 3 essentially adapts to the outer shape of the inner container 2 while maintaining a distance A on all sides to create the intermediate space 4. In particular, the outer container 3 likewise consists of a substantially cylindrical shell 8 and two covers 9, 10 which block the shell 8 at the end portions and are recessed towards the inside. It should be understood that the distance A does not have to be the same on all sides of the inner container 2. The covers 6, 7, 9, 10 are for example welded to the respective shell 5, 8 by means of circumferential weld seams 11, 12.
[0024] Any type of curved bottom known in pressure vessel manufacturing with an outwardly convex curvature can be used for the lid 6, 7, 9, 10, for example an elliptical bottom, a dished bottom, a spherical cap bottom, etc. An inverted head ("inverted dished end") can also be used for the lid 6, 7, 9, 10, which has a centrally inwardly curved area surrounded by an outwardly curved edge area. Such an inversion is also subsumed under the term "outwardly convex lid" herein due to its at least edge-side convex design.
[0025] In order to establish the full distance A, the inner vessel 2 is supported on the outer vessel 3 by two support structures 13, 14, which engage on diametrically opposite sides of the inner vessel 2. In order to absorb thermal length changes of the inner vessel 2 in the direction of the diameter line D between the first support structure 13 and the second support structure 14, the first support structure 13 is designed as a floating bearing in the direction of the diameter line D, i.e. it allows the lid 7 to move in the direction of the diameter line D, while the second support structure 14 is a fixed bearing. Alternatively, the second support structure 14 can also be such a floating bearing.
[0026] The first support structure 13 is only shown schematically in the following detailed description Figure 1 The second support structure 14, when designed as a fixed bearing, can for example be formed by a sleeve 15 of a thermally insulating material, which passes in a sealed manner through aligned openings in the inner and outer vessels 2, 3 and can be used for the sealed passage of connection lines 16, which lead from the outside of the vessel into the inner vessel 2 and there end in for example a filling opening 17, a removal opening 18, a vent opening 19 and a heat exchanger 20.
[0027] In the example shown, the two support structures 13, 14 are arranged at the end faces of the inner vessel 2, which is here elongate, so that the diameter line D is at the same time the longitudinal axis of the inner vessel 2. In the case of an inner vessel 2 which is rotationally symmetrical about its longitudinal axis, the longitudinal axis or diameter line D passes through the apex S of the lid 6, 7. However, this is not essential: the support structures 13, 14 can also engage diametrically opposite on other sides of the inner vessel 2 (provided that the inner vessel 2 has there the outwardly convex lid for the first support structure 13 described below), wherein the diameter line D between the support structures 13, 14 is no longer coincident with the longitudinal axis of the inner vessel 2.
[0028] The first support structure 13, which serves as a floating bearing, is in the example shown Figures 2 to 5The design shown therein allows for thermal expansion and contraction of the inner container 2, more precisely for a diametrical displacement of the convex lid 7 relative to the second support structure 14 and thus relative to the outer container 3 in the direction of the diameter line D, while at the same time absorbing radial forces perpendicular to the diameter line D in the manner of a radial bearing. Furthermore, the support structure 13 is designed to be torsionally rigid, i.e. it prevents the lid 7 and thus the inner container 2 from rotating relative to the outer container 3 about the diameter line D or longitudinal axis.
[0029] The support structure 13 comprises four struts 21 to 24 which are assembled in the form of a frame to form a rhombus (here a square). Each of the struts 21 to 24 has two end portions 21 ', 21 "; 22', 22"; 23', 23"; 24', 24". The struts 21 to 24 represent the edges of the rhombus. At the corners 25 to 28 of the rhombus, the end portions 21 " / 22', 22" / 23', 23" / 24' and 24" / 21'of two adjacent struts 21 to 24 are thus placed next to one another.
[0030] In the example shown, the rhombus formed by the struts 21 to 24 is a planar rhombus, i.e. all the struts 21 to 24 lie in a common plane and have the same length. However, this is not mandatory; if necessary, the struts 21 to 24 can also not lie in a common plane, especially in the case of irregularly shaped lids 7, 10. In the example shown, the rhombus formed by the struts 21 to 24 concentrically surrounds the diameter line D and the apex S of the lid 7.
[0031] The struts 21 to 24 have, for example, the shape of a rod, bar, strip or band and are made of a thermally insulating material, such as plastic. In particular, each of the struts 21 to 24 is made of a rod or strip of a fibre-reinforced plastic material, such as a glass fibre-reinforced plastic material. For example, a resin-impregnated, cured fibre mat, a woven fabric, a knitted fabric or a non-woven fabric made of glass fibres, carbon fibres, basalt fibres and / or stone fibres, etc., can be used for this purpose, which is punched, cut, pressed, moulded, injection moulded, etc. to form the struts 21 to 24.
[0032] The end portions 21 ", 22', 23", 24' of the struts 21 to 24 which are located at one set of two diagonally opposite corners 25, 27 of the rhombus are each connected to the concave lid 10 by a spherical joint 29, 30, 33, 34, and the end portions 24", 21 ', 22", 23' of the struts 21 to 24 which are located at the other set of two diagonally opposite corners 26, 28 of the rhombus are each connected to the convex lid 7 by a spherical joint 31, 32, 35, 36.
[0033] If desired, one of the two spherical joints 36 / 29, 30 / 31, 32 / 33, 34 / 35, each of which is located at the end 21' / 21", 22' / 22", 23' / 23", 24' / 24" of the same strut 21 to 24, can in each case be a universal joint (two degrees of freedom) instead of a spherical joint (three degrees of freedom).
[0034] Each spherical or universal joint 29 to 36 consists of two hingedly connected parts, more particularly of a first part A mounted on the respective strut end 21' to 24', 21" to 24" and a second part B hingedly connected to the first part and mounted on the respective cover 7 or 10.
[0035] Figure 4 An example of a spherical joint 29-36 is shown, comprising a first part A in the form of an eye-like head 37 having a long shank 38 fixedly connected to the respective end 21' to 24', 21" to 24", for example by clamping, crimping, gluing, screwing, welding, one-piece forming, etc. The eye-like head 37 has a spherical opening in which a ball 39 is rotatably and pivotably mounted. The ball 39 has a central bore 40 through which a bearing pin 41 of an angular piece 42 ( Figure 5 ) or 43 ( Figure 3 ) passes.
[0036] In the example shown, the ball 39 including its opening 40 and, where applicable, the respective angular piece 42, 43 including the bearing pin 41 form the second part B of the spherical joint 29 to 36.
[0037] In the case of the spherical joints 29, 30, 33, 34, the angular piece 42 is fixedly connected to the recessed cover 10, for example by clamping, crimping, gluing, screwing, welding, one-piece forming, etc. For example, the angular piece 42 has a bore 44 through which it can be screwed to the cover 10 by means of a screw (not shown). In the case of the spherical joints 31, 32, 35, 36, the angular piece 43 is fixedly connected to the raised cover 7, for example by clamping, crimping, gluing, screwing, welding, one-piece forming, etc. In the example shown, the angular piece 43 is welded to the raised cover 7.
[0038] In the shown example, two ball joints 29 / 30, 31 / 32, 33 / 34, 35 / 36 each share a common second part B, i.e. (at corners 25 and 27) a corner piece 42 having two bearing pins 41 attached to it at an angle, or (at corners 26 and 27) a corner piece 43 having two bearing pins 41 attached to it at an angle. It goes without saying that, alternatively, each ball joint 29-36 can have a dedicated second part B, i.e. it is attached to the respective cover 7, 10 by a dedicated corner piece 42, 43.
[0039] The present application is not limited to the shown embodiments, but encompasses all variants, modifications and combinations thereof falling within the scope of the following claims.
Claims
1. A container for containing cryogenic fluids, comprising: A container (2) having at least one outwardly protruding lid (7) and an outer container (3) having at least one inwardly recessed lid (10), the container (2) being located within the outer container (3) and spaced apart by a distance (A) on all sides, the protruding lid (7) protruding into the recessed lid (10), and the container (2) being supported on the outer container (3) by a first support structure (13) and a second support structure (14), the second support structure (14) being engaged on the container (2) in a manner diametrically opposed to the first support structure (13), characterized in that the first support structure (13) comprises four pillars (21 to 24) forming a rhombus. The ends (21", 22", 23", 24") of the four pillars located at one set of two opposite diagonal corners (25, 27) of the rhombus are connected to the recessed cover (10), and the ends (22", 23", 24", 21") of the four pillars located at another set of two opposite diagonal corners (26, 28) of the rhombus are connected to the raised cover (7). Each pillar (21 to 24) is connected to the corresponding cover (7, 10) at one end (21', 22', 23', 24') via a ball joint (29 to 36) and at the other end (21", 22", 23", 24") via a ball or universal joint (29 to 36).
2. The container according to claim 1, characterized in that, The rhombus is a square.
3. The container according to claim 1 or 2, characterized in that, Each support (21 to 24) is connected to the corresponding cap (7, 10) at its two ends (21', 21", 22', 22", 23', 23", 24', 24") via a corresponding ball joint (29 to 36).
4. The container according to any one of claims 1 to 3, characterized in that, Each spherical or universal joint (29 to 36) includes a first component (A) mounted on the respective support end (21', 21", 22', 22", 23', 23", 24', 24") and a second component (B) hinged to the first component and mounted on the respective cover (7, 10). Meanwhile, two second components (B) located at one corner (25 to 28) of the rhombus are rigidly connected to each other and mounted together on the respective cover (7, 10).
5. The container according to claim 4, characterized in that, Two rigidly connected second parts (B) form corner pieces (42, 43), which are threaded, crimped or welded to the corresponding caps (7, 10).
6. The container according to any one of claims 1 to 5, characterized in that, The diameter line (D) between the first and second support structures (13, 14) is the longitudinal axis of the inner container (2), which extends through the apex (S) of the raised lid (7).
7. The container according to claim 6, characterized in that, The rhombuses concentrically surround the diameter line (D).
8. The container according to any one of claims 1 to 7, characterized in that, The four pillars (21 to 24) are made of insulating material.
9. The container according to claim 8, characterized in that, The four pillars (21 to 24) are made of fiber-reinforced plastic material, preferably glass fiber-reinforced plastic material.
10. The container according to any one of claims 1 to 9, characterized in that, The inner container (2) and the outer container (3) are made of aluminum.