Holding element for holding one or more electrical energy accumulators, and pressure vessel system

Abstract

The technology disclosed herein relates to a holding element (200) for holding one or more electrical energy accumulators (300) between two pressure vessels (110), (120), wherein an elongate bore (210) is provided for receiving one or more electrical energy accumulators (300) and two contact faces (201), (202) are provided for contact with the pressure vessels (110), (120). The technology disclosed herein further relates to a pressure vessel system (100) comprising such a holding element (200).

Description

[0001] Holding element for holding one or more electrical energy storage and pressure vessel systems

[0002] The technology disclosed here relates to a holding element for holding one or more electrical energy storage devices between a first pressure vessel and a second pressure vessel. The technology disclosed here further relates to a pressure vessel system having such a holding element.

[0003] Pressure vessels are typically used to store gaseous fuel such as hydrogen or natural gas. In particular, they can be used in motor vehicles or other mobile or stationary units. The gaseous fuel can be used, for example, to operate a fuel cell or a gas-powered combustion engine. There is an increasing desire to install pressure vessels not only in large vehicles, which typically have sufficient space, but also to equip small vehicles with pressure vessels that may have predetermined and atypical installation spaces, for example in an underbody area. Typically, it is also necessary to provide one or more electrical energy storage units in addition to the pressure vessels in order to temporarily store electrical energy.This can, for example, ensure that a fuel cell can be operated at an optimal operating point, or electrical energy can be kept available for emergency use. Even with such electrical energy storage devices, it is desirable to install them in installation spaces that are as space-efficient as possible.

[0004] It is a preferred object of the technology disclosed here to reduce or eliminate at least one disadvantage of a previously known solution or to propose an alternative solution. In particular, it is a preferred object of the technology disclosed here to provide a holding element by means of which electrical energy storage devices can be arranged between pressure vessels in a particularly space-saving manner. Further preferred objects can arise from the advantageous effects of the technology disclosed here. The objects are achieved by the subject matter of the independent patent claims. The dependent claims represent preferred embodiments.

[0005] The technology disclosed here relates to a holding element for holding one or more electrical energy storage devices between a first pressure vessel and a second pressure vessel, comprising (i) an elongated bore for receiving one or more electrical energy storage devices, (ii) a first contact surface for contacting the first pressure vessel, and (iii) a second contact surface for contacting the second pressure vessel, wherein the first contact surface and the second contact surface are expediently curved.

[0006] Using such a holding element, it is advantageously possible to arrange one or more electrical energy storage devices between pressure vessels, particularly in a space that would otherwise remain free when arranging pressure vessels with a round cross-section side by side. This space can be ideally utilized because the contact surfaces can rest against the pressure vessels, thus ensuring simple and effective support of the electrical energy storage devices. The contact surfaces can, in particular, be designed to complement the pressure vessels.

[0007] A holding element is understood to be an element that can hold the electrical energy storage device(s) in a defined spatial relationship to the pressure vessels. In particular, it can be suitable for use in an intermediate space, which arises anyway when two pressure vessels with a circular cross-section are arranged directly adjacent to one another. The elongated bore can in particular be rectilinear. The electrical energy storage devices can in particular be designed to complement the bore, so that they can preferably be accommodated in the elongated bore with the greatest possible use of space. The contact surfaces can in particular be designed with a cross-section that is constant along a longitudinal extent or along the elongated bore.

[0008] The holding element is designed to interact with electrical energy storage devices and pressure vessels. However, the electrical energy storage devices and pressure vessels are to be understood as separate elements from the holding element.

[0009] In particular, the first contact surface and / or the second contact surface can be coated with an elastically deformable layer. Such an elastically deformable layer ensures, in particular, easier adaptation to pressure vessels. In particular, the elastically deformable layer can also compensate for any expansion and / or contraction of a pressure vessel, for example due to refueling or withdrawal or a temperature change. The bore can, in particular, have a circular cross-section. The circular cross-section can, in particular, extend transversely to a longitudinal extent of the bore. The longitudinal extent of the bore can, in particular, be identical to a longitudinal extent of the holding element. For example, the holding element can have a substantially constant or even completely constant cross-section when viewed along the longitudinal extent.

[0010] The bore can extend, in particular, parallel to a longitudinal extension of the first contact surface and / or to a longitudinal extension of the second contact surface. Along a respective longitudinal extension, a contact surface can, in particular, have a constant cross-section. This can apply, for example, to a surface of the aforementioned elastically deformable layer in a relaxed state. It can also apply to a fixed part of the retaining element or the respective contact surface.

[0011] In particular, the retaining element can be designed as an elongated profile. This allows for easy use between two pressure vessels, which are typically also elongated. Furthermore, it enables simple manufacturing. The first contact surface and / or the second contact surface can preferably have a circular segment-shaped cross-section. This allows for easy attachment to pressure vessels, which typically have a circular outer surface.

[0012] In principle, however, other cross-sections are also possible, allowing adaptation to specific pressure vessels. For example, the holding element can also be used between pressure vessels that do not have a circular outer cross-section, but rather have flat, opposing outer surfaces with round sections between them. According to one embodiment, one or more cooling channels are formed in the holding element. Such cooling channels can be used to conduct a cooling fluid, for example a cooling liquid, through the holding element. This allows the electrical energy storage devices to be cooled in a targeted manner, preventing overheating and allowing them to be operated within an ideal temperature range.

[0013] In particular, the cooling channels can extend parallel to the bore. This allows for a simple design and a flow path along the longitudinal extension of the retaining element.

[0014] According to an advantageous embodiment, the holding element has a venting groove on an outer side, wherein the venting groove is connected to the bore through one or more openings. The venting groove can, in particular, ensure that any hot gases that may arise in the event of a thermal event can be discharged to the outside, thus preventing propagation of a thermal event across multiple electrical energy storage devices. The venting groove can, in particular, be formed on a side surface of the holding element facing away from the first contact surface and the second contact surface. For example, the first contact surface, the second contact surface, and the side surface facing away from them can be arranged along an isosceles triangle, in particular apart from the fact that the contact surfaces are curved.This allows for a simple design and the diversion of any hot gases away from the electrical energy storage units and the pressure vessels.

[0015] The technology disclosed here further relates to a pressure vessel system comprising (i) a plurality of pressure vessels, (ii) at least one holding element as described herein, and (iii) one or more electrical energy storage devices, wherein each holding element is arranged between two pressure vessels, such that the contact surfaces of the holding element bear against a respective pressure vessel, and wherein the electrical energy storage devices are arranged in the elongated bore of a holding element. By means of such a pressure vessel system, electrical energy storage devices can be easily integrated into suitable spaces between pressure vessels in an installation space. This allows the best possible use of available space, whereby both pressure vessels and electrical energy storage devices can be accommodated. With regard to the holding element, all designs and variants described herein can be used.The contact surfaces can be designed to complement the pressure vessels used. This allows for a flat, space-saving and safe installation.

[0016] In particular, a retaining element can be arranged between each immediately adjacent pair of pressure vessels, with one or more electrical energy storage devices located in the elongated bore of the retaining element. This allows all suitable installation spaces to be utilized to suitably accommodate electrical energy storage devices using the retaining element.

[0017] It can be provided that exactly one holding element is arranged between each immediately adjacent pair of pressure vessels. However, it can also be provided that two holding elements are arranged, wherein in the case that the pressure vessels are horizontally adjacent, typically one holding element is arranged at the top and one holding element at the bottom. Each holding element can accommodate electrical energy storage devices in a bore. The pressure vessel system can have a housing that encloses the pressure vessels and the holding elements. Such a housing can provide external closure and, for example, protection against mechanical damage, vibrations and / or possible ingress of dirt or liquids. This can increase the safety and stability of the pressure vessel system. The holding elements can in particular be fastened to the housing. This can further increase the overall stability.

[0018] In particular, at least one degassing groove can be formed in the housing, which is connected to a bore in the holding element via openings in a holding element. This allows for the direct discharge to the outside of any hot gases that may arise, for example, during a thermal event in an electrical energy storage device. Damage to other electrical energy storage devices or pressure vessels is thereby advantageously avoided. The grooves in the holding element and in the housing can advantageously be complementary to one another. In particular, they can be aligned flush with one another. This allows for a particularly advantageous and efficient discharge of gases to the outside.

[0019] According to an advantageous embodiment, the pressure vessels are secured transversely to their longitudinal direction by means of the retaining elements. This allows the fastening elements to assume an additional function, namely that of securing the pressure vessels. This advantageously eliminates the need for additional pressure vessel securing elements.

[0020] In particular, a pressure vessel system can have one or more cover plates, which can be fastened in particular to the end faces of the holding elements. Such cover plates can prevent dirt or liquid from penetrating the holding elements. In addition, the cover plates can be made larger and thus rest on the pressure vessels at points where they already have a smaller cross-sectional area compared to their maximum cross-sectional area at the ends. The cover plates can also exert pressure in the longitudinal direction on the electrical energy storage devices. Such a longitudinal direction can relate in particular to the electrical energy storage devices and / or to the pressure vessels. In order to exert such pressure, the cover plates can be clamped against one another in pairs, in particular by being fastened to holding elements.

[0021] Electrical energy storage devices can be provided, in particular, for storing electrical energy, in particular for driving at least one (traction) drive motor. In particular, they can be designed as high-voltage storage devices. Electrical energy storage devices can, in particular, be integrated into an on-board electrical system that operates at a higher voltage than a fuel cell system.

[0022] A pressure vessel can be used in particular to store gaseous fuel under ambient conditions in a motor vehicle, for example a passenger car, a motorcycle or a commercial vehicle. The pressure vessel system can be used, for example, in a motor vehicle that is powered by compressed (also called compressed natural gas or CNG) or liquefied (also called liquefied natural gas or LNG) natural gas or with hydrogen. The pressure vessel system is typically fluidly connected to at least one energy converter that is designed to convert the chemical energy of the fuel into other forms of energy. A pressure vessel can in particular be designed as a composite overwrapped pressure vessel. The pressure vessel can, for example, be a cryogenic pressure vessel or a high-pressure gas vessel.High-pressure gas cylinders are designed to permanently store fuel at ambient temperatures at a nominal working pressure (also called NWP) of at least 350 bar (= overpressure compared to atmospheric pressure) or at least 700 bar (= overpressure above atmospheric pressure). A cryogenic pressure cylinder is suitable for storing fuel at the aforementioned operating pressures even at temperatures that are significantly (e.g., more than 50 K or more than 100 K) below the operating temperature of the vehicle.

[0023] The pressure vessel system can also be designed as a pressure vessel assembly. The pressure vessel assembly can, in particular, comprise the pressure vessels and the other components mentioned, as well as supporting, fastening, and / or protective elements permanently connected to the pressure vessels, for example, protective shields, shielding, barrier layers, covers, coatings, or wrappings. The supporting, fastening, and / or protective elements can expediently only be removable temporarily and preferably only by specialist personnel and / or not non-destructively. Such a pressure vessel assembly is particularly suitable for shallow installation spaces, in particular in the underfloor area beneath the vehicle interior. The pressure vessel assembly can preferably be mounted as a whole in the installation space provided in the motor vehicle. For this purpose, the pressure vessel assembly can have common body connection points by means of which the system as a whole can be fastened in the motor vehicle.A pressure vessel assembly or pressure vessel system preferably comprises more than three, or more than five, or more than seven, or more than ten pressure vessels. The aforementioned housing can expediently be an enclosure that encloses at least the high-voltage components of the energy storage device. The housing can advantageously serve for fire protection, contact protection, intrusion protection, and / or protection against moisture and dust. The housing can, for example, be made at least partially from a metal, in particular from aluminum, an aluminum alloy, steel, or a steel alloy. At least one or more of the following components can be accommodated in the at least one housing: storage cells, electrical energy storage devices, power electronics components, contactor(s) for interrupting the power supply to the motor vehicle, cooling elements, electrical conductors, and control unit(s).It is advisable to pre-assemble the components before the assembly is installed in the vehicle.

[0024] The electrical energy storage devices can be designed, in particular, as round cells. These can be housed, in particular, in a cylindrical cell housing (or "cell can"). If the active materials of the round cell expand during operation, the housing is subjected to tensile stress in the peripheral area. Comparatively thin housing cross-sections can thus advantageously compensate for the forces resulting from this swelling. The cell housing is preferably made of steel or a steel alloy.

[0025] In particular, venting openings in the electrical energy storage devices can be arranged so that they point into the groove or are aligned transversely to a longitudinal extent of the groove. A venting opening can serve, in particular, to allow gases that arise to escape from the cell housing. By being arranged towards the groove, gases are first guided into the groove and can then be discharged, for example, via the aforementioned venting grooves. A thermal fault or thermal event is usually a fault in which an exothermic chemical reaction occurs. The fault can, in particular, be an event that causes non-operational and self-reinforcing heat production in the individual cells. Under certain circumstances, propagation could then begin. Such a fault can be caused, for example, by an internal short circuit in an individual cell or by the source of a fire.

[0026] In other words, it is advantageous if a cell string is mounted between hydrogen pressure tanks or pressure vessels. This typically requires consideration of requirements regarding technical safety, crash performance, acoustics, etc. The cell string mounting should ensure the integration of functionalities such as cooling, a degassing strategy, electrical cell string insulation, and / or secure electrical contact between individual cells of the cell string over the entire service life. The required installation space for the mounting is limited to the free space between the pressure vessels in the energy module.

[0027] The basic principle of the cell strand attachment described here can be seen in the use of a solid body that is adapted to the geometry of the free installation space between the hydrogen storage units or the battery cells.

[0028] pressure vessels and extends over the entire length of the cylindrical area of ​​the pressure vessels. A hole is drilled into this body for the cell string, into which the selected cell format can be inserted. The basic geometry of the casing for attaching the cell string corresponds, for example, to an isosceles triangle whose legs are circular. The legs have a radius adapted to the tank diameter with the appropriate allowance. This string is placed on the hydrogen tanks or pressure vessels using support mats and is firmly screwed to the casing of the energy module. In this way, the cell string housing also provides support for the hydrogen pressure tanks or pressure vessels in the y and z directions. The fastening concept for the pressure vessels can thus be further simplified. Potential for accommodating a larger quantity of hydrogen can be exploited.In the x-direction, a cell string can be secured in the housing via a rubber ring and a cover screwed to the string housing. The rubber ring serves as a tolerance compensation and clamps the battery cell string. In the y- and z-direction, the battery cell string can be held by the cell string housing. Additionally, each battery cell can be glued in place via an injection hole. Alternatively, the cells can be clamped in the channel of the housing string via a terminal block with springs and a clamping cover. An additional recess for a venting channel can be provided at the base of the isosceles triangle.

[0029] In particular, the fastening element can extend over the entire length of the cylindrical region of pressure vessels. An extension only partially along this length and / or an extension beyond it are also possible. The bore can, in particular, extend over the entire length of the fastening element. In this case, a partial extension of the bore is also possible. The technology disclosed here will now be described with reference to the figures.

[0030] Showing:

[0031] Fig. 1 : a pressure vessel system,

[0032] Fig. 2: a holding element,

[0033] Fig. 3: the pressure vessel system of Fig. 1 with additional components, and Fig. 4: a part of the pressure vessel system.

[0034] Fig. 1 shows a purely schematic view of a pressure vessel system 100. The pressure vessel system 100 comprises a first pressure vessel 110 and a second pressure vessel 120 for storing gaseous fuel. A retaining element 200 is arranged in an installation space extending between the pressure vessels 110, 120, which is created by the round shape of the pressure vessels 110, 120.

[0035] The holding element 200 has a first contact surface 201 and a second contact surface 202. These are each designed in the shape of a circular arc segment and each abut against a segment of one of the pressure vessels 110, 120. Thus, the first contact surface 201 abuts the first pressure vessel 110. The second contact surface 202 abuts the second pressure vessel 120.

[0036] Elastically deformable layers 250 are arranged on the contact surfaces 201, 202, which establish contact with the pressure vessels 110, 120. This allows for better adaptation to the pressure vessels 110, 120, and even in the event of a change in the external cross-section of the respective pressure vessel 110, 120, for example, due to a filling or removal process, adaptation can be achieved by means of the elastically deformable layer 250.

[0037] An elongated bore 210 is arranged in the holding element 200, which extends transversely to the plane of the paper in Fig. 1, which also extends transversely to the plane of the paper in Fig. 1. Several electrical energy storage devices 300, which are designed as round cells, are arranged in this bore. Only one of these electrical energy storage devices 300 is visible here. Directly above the elongated bore 210 is a degassing groove 220, the functionality of which will be discussed later. The degassing groove is designed as a notch on an upper side surface of the holding element 200. This upper side surface points in a direction opposite to the contact surfaces 201, 202.

[0038] Furthermore, two cooling channels 230 are arranged in the holding element 200, through which cooling fluid can be conducted. This allows the electrical energy storage devices 300 to be cooled. Furthermore, three threaded holes 240 are arranged on the front side, which serve to attach a cover plate to be described further below.

[0039] Fig. 2 shows the holding element 200 in a separate view. It can be seen that the venting groove 220 extends parallel to the elongated bore 210 directly below it. Several slot-shaped openings 225 are arranged in the venting groove 220, which in this case extend transversely to the longitudinal extent. Any gas that would escape from electrical energy storage devices 300 in the event of a thermal event can be discharged to the outside through the openings 225. This can prevent the holding element 200 from being damaged, for example, due to such escaping gas. Otherwise, reference is made to the description of Fig. 1.

[0040] Fig. 3 shows the pressure vessel system 100 with additional components, namely a housing 105, which is only partially shown here, and a cover plate 205. The cover plate 205 is attached to the front of the holding element 200 by means of a total of three screws 207, which engage in the threaded holes 240. The cooling channels 230 of the holding element 200 continue into respective connection openings 208 of the cover plate 205. A venting groove 107 is arranged in the housing 105, which is directly opposite the venting groove 220 of the holding element 200. This creates a common receiving space for any escaping gas, which is formed by the two venting grooves 107, 220. Gas can enter this receiving space through the openings 225. The gas can then be discharged laterally along the longitudinal extent of the holding element 200. This allows for controlled routing of any escaping hot gas.

[0041] Fig. 4 shows an electrical energy storage device 300 and a cover plate 205 separately. The screws 207 are also shown. The cover plate 205 has a receptacle 206, which is round and pot-shaped. The electrical energy storage device 300 is inserted into this receptacle 206 and held therein. In this case, a rubber ring 209 is arranged between the electrical energy storage device 300 and the cover plate 205. This serves for bracing and tolerance compensation. This allows for advantageous fastening and fixing of the electrical energy storage device 300. In particular, in this way, pressure can also be exerted on several electrical energy storage devices 300 along the longitudinal direction, so that they are advantageously electrically contacted with one another.Such pressure can be exerted in particular by clamping two cover plates 205 attached to opposite ends of the pressure vessel system 100 towards each other by means of the screws 207.

[0042] For the sake of readability, the term "at least one" has been partially omitted. If a feature of the technology disclosed here is described in the singular or indefinitely (e.g., the pressure vessel, the energy storage device, etc.), the plural form is also intended to be disclosed (e.g., the at least one pressure vessel, the at least one energy storage device, etc.).

[0043] The foregoing description of the present invention is for illustrative purposes only and not for the purpose of limiting the invention. Various changes and modifications are possible within the scope of the invention and its equivalents.

[0044] List of reference symbols

[0045] 100 pressure vessel system

[0046] 105 housings

[0047] 107 Degassing groove

[0048] 110 first pressure vessel

[0049] 120 second pressure vessel

[0050] 200 holding element

[0051] 201 first investment area

[0052] 202 second investment area

[0053] 205 cover plate

[0054] 206 recording

[0055] 207 screws

[0056] 208 connection openings

[0057] 209 Rubber ring

[0058] 210 elongated bore

[0059] 220 Degassing groove

[0060] 225 openings

[0061] 230 cooling channels

[0062] 240 threaded holes

[0063] 250 elastically deformable layer

[0064] 300 electrical energy storage units

Claims

Claims 1 . Holding element (200) for holding one or more electrical energy storage devices (300) between a first pressure vessel (110) and a second pressure vessel (120), comprising - an elongated bore (210) for receiving one or more electrical energy storage devices (300), - a first contact surface (201) for contact with the first pressure vessel (110), and - a second contact surface (202) for contact with the second pressure vessel (120), wherein the first contact surface (201) and the second contact surface (202) are curved.

2. Holding element (200) according to claim 1, wherein the first contact surface (201) and / or the second contact surface (202) are covered with an elastically deformable layer (250).

3. Holding element (200) according to claim 1 or 2, wherein the bore (210) has a circular cross-section.

4. Holding element (200) according to one of the preceding claims, wherein the bore (210) extends parallel to a longitudinal extension of the first contact surface (201) and / or to a longitudinal extension of the second contact surface (202).

5. Holding element (200) according to one of the preceding claims, which is designed as an elongated profile.

6. Holding element (200) according to one of the preceding claims, wherein the first contact surface (201) and / or the second contact surface (202) have a circular segment-shaped cross-section.

7. Holding element (200) according to one of the preceding claims, in which one or more cooling channels (230) are formed.

8. Holding element (200) according to claim 7, wherein the cooling channels (230) extend parallel to the bore (210).

9. Holding element (200) according to one of the preceding claims, which has a degassing groove (220) on an outer side, wherein the degassing groove is connected to the bore (210) by one or more openings (225).

10. Holding element (200) according to claim 9, wherein the degassing groove (220) is formed on a side surface of the holding element (200) facing away from the first contact surface (201) and the second contact surface (202).

11. Pressure vessel system (100), comprising - several pressure vessels (110, 120), - at least one holding element (200) according to one of the preceding claims, and - one or more electrical energy storage devices (300), wherein each holding element (200) is arranged between two pressure vessels (110, 120) in each case, so that the contact surfaces (201, 202) of the holding element (200) bear against a respective pressure vessel (110, 120), and wherein the electrical energy storage devices (300) are arranged in the elongated bore (210) of a holding element (200).

12. Pressure vessel system (100) according to claim 11, wherein a holding element (200) is arranged between all immediately adjacent pairs of pressure vessels (110, 120), in the elongated bore (210) of which one or more electrical energy storage devices (300) are located.

13. Pressure vessel system (100) according to claim 11 or 12, which comprises a housing (105) which encloses the pressure vessels (110, 120) and the holding elements (200).

14. Pressure vessel system (100) according to claim 13, wherein the holding elements (200) are attached to the housing (105).

15. Pressure vessel system (100) according to claim 13 or 14, wherein at least one degassing groove (107) is formed in the housing (105), which is connected to a bore (210) of the holding element (200) via openings (225) in a holding element (200).

16. Pressure vessel system (100) according to one of claims 11 to 15, wherein the pressure vessels (110, 120) are fixed transversely to their longitudinal direction by means of the holding elements (200).

17. Pressure vessel system (100) according to one of claims 11 to 16, which has one or more cover plates (205) which are fastened to the end faces of the holding elements (200).

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