Hydrogen tank system and hydrogen vehicle

Abstract

The invention relates to a hydrogen tank system (100) for storing hydrogen, comprising: – at least a first hydrogen container (110) and a second hydrogen container (120), which are designed to store hydrogen, each having a first lance (111) and a second lance (121), which are designed to introduce hydrogen into the hydrogen containers (110, 120), – a hydrogen line (130), which fluidically interconnects the first hydrogen container (110) and the second hydrogen container (120) via the first lance (111) and the second lance (121) and is connectable to a tank nozzle (150), via which hydrogen can be supplied, wherein the first hydrogen container (110) has a larger volume than the second hydrogen container (120), and at least part of the second lance (121) has a smaller cross-section than the first lance (111). The invention also relates to a hydrogen vehicle (200).

Description

[0001] Description

[0002] title

[0003] Hydrogen tank system and hydrogen vehicle

[0004] The invention relates to a hydrogen tank system and a hydrogen vehicle.

[0005] State of the art

[0006] When refueling a hydrogen tank, the compression of the hydrogen within the tank causes the hydrogen and thus the tank to heat up considerably. To prevent the tank material from overheating, standardized refueling protocols are in place for refueling hydrogen tanks, especially for hydrogen vehicles. These refueling protocols determine the refueling speed depending on the ambient temperature, the temperature of the hydrogen provided by the filling station, the initial state of the tank system (pressure, temperature), and its configuration (volume of the individual tanks and total volume of the tank system).

[0007] This typically involves refueling so quickly that the permissible tank temperature (approximately 85°C) is barely reached, taking safety factors into account. This always assumes a more or less homogeneous temperature distribution of the hydrogen within the tank.

[0008] To achieve mixing of the hydrogen within the tank, the hydrogen is fed into the tank via a lance. The lance's task is to shape the flow of hydrogen into the tank so that the temperature distribution is as homogeneous as possible. Otherwise, temperature hotspots would form, and the tank material would be exposed to unacceptably high temperatures. For this purpose, lances are currently designed with a diameter of approximately 4 to 5 mm to ensure a sufficiently high velocity at the outlet, which is necessary for mixing.

[0009] Disclosure of the invention

[0010] A hydrogen tank system and a hydrogen vehicle are proposed. Further features and details of the invention emerge from the dependent claims, the description, and the drawings. Features and details described in connection with the hydrogen tank system according to the invention naturally also apply in connection with the hydrogen vehicle according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0011] According to the invention, a hydrogen tank system for storing hydrogen is provided, comprising:

[0012] - at least one first hydrogen container and one second hydrogen container, which are designed to store hydrogen, each with a first lance and a second lance, which are designed to introduce hydrogen into the hydrogen containers (110, 120),

[0013] - a hydrogen line which fluidically connects the first hydrogen tank and the second hydrogen tank via the first lance and the second lance and is connectable to a tank nozzle via which hydrogen can be refueled, wherein the first hydrogen tank has a larger volume than the second hydrogen tank and the second lance has at least partially a smaller cross-section than the first lance.

[0014] A hydrogen tank system can be designed to store hydrogen, in particular as an energy carrier, and to release it as needed. The hydrogen tank system can be designed as a vehicle hydrogen tank system. In other words, the hydrogen tank system can be designed to be arranged on a vehicle and, in particular, to store hydrogen, which serves to supply the vehicle with energy.

[0015] Stockpiling hydrogen can mean storage that ensures that only insignificant amounts of hydrogen escape unintentionally and can be made available on demand, in particular for the operation of a vehicle.

[0016] A hydrogen container can be understood as a spatially physical object suitable for receiving and storing hydrogen. In other words, the hydrogen container can be designed as a tank for hydrogen. Provision can be made for additional hydrogen containers of different sizes. In particular, provision can be made for two large hydrogen containers, in particular with a volume between 300 and 1000 liters, and three small hydrogen containers, in particular with a volume between 50 and 200 liters.

[0017] It can be provided that at least the hydrogen tank, the first, or the second lance is connected to the hydrogen line via a connecting element, which can be designed, in particular, as a hydrogen tank valve. A hydrogen tank valve can be designed to provide a connection between the hydrogen line and the hydrogen tank. Furthermore, the hydrogen tank valve can be designed to at least close the hydrogen tank or, if necessary, to enable hydrogen to be removed from the hydrogen tank. Furthermore, it can be provided that the hydrogen tank valve has the first or the second lance.

[0018] A lance can be understood as a tubular conduit designed to conduct the hydrogen coming from the hydrogen line into the hydrogen tank. In addition to the tubular conduit, the lance can comprise other elements, such as for attachment to the hydrogen tank, insulation, or sealing. The introduction of hydrogen can involve flowing from a hydrogen line through the lance into the hydrogen tank. In other words, hydrogen, which is supplied to the hydrogen line, for example, via a tank nozzle, can flow via the line to a lance, which then supplies the hydrogen to the hydrogen tank.

[0019] A hydrogen line can be thought of as a system of pipes that connects the two hydrogen tanks via the lances. Furthermore, the hydrogen line can have a connection to a tank nozzle through which hydrogen can be added to the hydrogen line.

[0020] A fluidic connection can be understood as meaning that a fluid, in particular hydrogen, can flow between the connection points, in particular without significant amounts of the fluid escaping.

[0021] A fuel tank nozzle can be understood as an opening through which the hydrogen tank can be filled and / or emptied. In the context of hydrogen vehicles, the fuel tank nozzle can be understood as an interface through which the vehicle's hydrogen tank is connected to a hydrogen filling station for filling the hydrogen tank. According to the invention, the fuel tank nozzle is connected to the hydrogen line through which the hydrogen then flows into the hydrogen tank.

[0022] Hydrogen refueling can be understood as the supply of hydrogen to the tank nozzle, whereby the hydrogen flows downstream from the tank nozzle via the hydrogen line, through the lances into the respective hydrogen containers.

[0023] The cross-section can be understood as the area through which the fluid can flow in a main flow direction. The cross-section of the lance can, for example, be essentially circular. However, other cross-sections such as elliptical or rectangular cross-sections are conceivable without departing from the scope of the invention. The fact that the second lance has at least partially a smaller cross-section than the first lance can therefore also be understood to mean that the second lance has at least partially a smaller diameter than the first lance. For the case described above with two large and three small hydrogen containers, it can further be provided that the diameter of the lances of the large hydrogen containers is between 3 and 6 mm and the diameter of the lances of the small hydrogen containers is between 1 and 3 mm.

[0024] Overall, the hydrogen tank system according to the invention offers the advantage that the hydrogen tanks of a hydrogen tank system can be filled with a well-mixed mixture. The reduced cross-section of the second lance increases the exit velocity in the second hydrogen tank, thereby improving mixing. The increased pressure loss resulting from the smaller cross-section is unproblematic because the second hydrogen tank requires additional throttling anyway to ensure even filling of all hydrogen tanks.

[0025] Within the scope of the invention, it can be advantageous for the cross-section of at least the second lance to be adapted to an expected mass flow, in particular according to a refueling protocol of the hydrogen tank system. It can be provided that the refueling protocol is determined as a function of at least one environmental variable, in particular at least the ambient temperature, the temperature of the hydrogen provided by the filling station, the initial state of the hydrogen tanks (pressure, temperature) or the configuration of the hydrogen tanks (volume of the individual hydrogen tanks and total volume of the hydrogen tank system), the refueling speed. Furthermore, the refueling protocol can provide for refueling to take place at just the speed that a permissible tank temperature, in particular 85°C, is just not reached, particularly taking safety factors into account.The mass flow can be understood as a physical quantity that indicates the amount of hydrogen flowing through a specific cross-section per unit of time. It can be specified, for example, in kilograms per second (kg / s). Adaptation can be understood as selecting the cross-section such that a minimum inflow velocity is guaranteed with the expected mass flow. This minimum inflow velocity corresponds to the required mixing of the hydrogen in the tank to achieve a substantially homogeneous temperature distribution. Adapting to the expected mass flow has the advantage that the inflow velocity can be adjusted even more precisely, thus also achieving a homogeneous temperature distribution.

[0026] Within the scope of the invention, it can be provided that at least the first lance or the second lance has an angle to the longitudinal axis of the hydrogen tank and / or is mounted at an angle to the longitudinal axis of the hydrogen tank, wherein the angle is in particular more than 5°. It can further be provided that the angle is between 8° and 12°, in particular 10°. The angled configuration has the advantage that the hydrogen flow quickly impacts a wall of the hydrogen tank, forming a flow vortex and improving mixing within the hydrogen tank.

[0027] It is further conceivable that at least the first lance or the second lance has a first cross-section at a connection point to the hydrogen line and a second cross-section at a connection point to the hydrogen tank, wherein the second cross-section is smaller than the first cross-section. The tapering provides the advantage of increasing the flow velocity within the lance, thereby improving mixing in the hydrogen tank.

[0028] It is also conceivable for hydrogen to flow passively through the hydrogen line. In other words, it can be provided that the hydrogen flow through the hydrogen line is not influenced by additional valves or other active elements. In other words, it can be provided that the flow through the hydrogen line is determined solely by the tank protocol, the hydrogen line, as well as the lances and the hydrogen containers. This allows mixing and uniform filling of the hydrogen containers to be achieved particularly easily and cost-effectively. Furthermore, within the scope of the invention, it can be provided that a cross-section of the first lance or the second lance tapers downstream of the hydrogen tank only at the very end of the first lance or the second lance. Furthermore, it can be provided that the cross-section widens again, particularly suddenly, within the lance.

[0029] It is also conceivable that the smaller cross-section could be designed as an orifice plate. This measure would achieve particularly good mixing.

[0030] With regard to the present invention, it is conceivable that the cross-section of the first lance is related to the volume of the first hydrogen tank essentially as the cross-section of the second lance is related to the volume of the second hydrogen tank. This described ratio ensures that the hydrogen tanks fill with the same flow rate and comparable mixing when the hydrogen tank system is refueled.

[0031] Furthermore, it is conceivable that at least the first hydrogen tank or the second hydrogen tank is substantially cylindrical in shape, with the lance, in particular, being arranged halfway up the hydrogen tank. Alternatively, substantially cuboidal and / or elongated shapes of the hydrogen tank can also be provided. These shapes are particularly well suited in combination with the proposed cross-sections of the lances, as they can be easily integrated into other systems, especially vehicles, while still achieving good mixing.

[0032] According to a further aspect of the invention, a hydrogen vehicle is proposed, comprising a hydrogen tank system, in particular a hydrogen tank system according to the invention, for storing hydrogen, comprising:

[0033] - at least one first hydrogen tank and one second hydrogen tank, which are designed to store hydrogen, each with a first lance and a second lance, which are designed to introduce hydrogen into the hydrogen tanks (110, 120), - a hydrogen line which fluidically connects the first hydrogen tank and the second hydrogen tank to one another via the first lance and the second lance and is connectable to a tank nozzle via which hydrogen can be refueled, wherein the first hydrogen tank has a larger volume than the second hydrogen tank and the second lance has at least partially a smaller cross-section than the first lance.

[0034] The vehicle may be designed as a motor vehicle. In principle, a motor vehicle can be any type of motor-driven vehicle. The motor vehicle may be designed as a land vehicle, a water vehicle, or an aircraft vehicle. In particular, the motor vehicle may be a car or a truck. The motor vehicle may be designed to generate at least part of its energy, in particular the energy for propulsion, from hydrogen. In particular, the vehicle may have a fuel cell for this purpose. It may also be provided that the motor vehicle is exclusively electrically powered.

[0035] Thus, the hydrogen vehicle according to the invention brings with it the same advantages as have been described in detail with reference to a hydrogen tank system according to the invention.

[0036] Further advantages, features, and details of the invention will become apparent from the following description, in which several embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination.

[0037] Fig. 1 shows a hydrogen tank system according to the invention,

[0038] Fig. 2 a hydrogen vehicle according to the invention,

[0039] Fig. 3 a first and second lance in comparison, Fig. 4 variations of the lances, and

[0040] Fig. 5 further variations of the lances.

[0041] In the following figures, identical reference numerals are used for the same technical features, even for different embodiments.

[0042] Fig. 1 shows a hydrogen tank system 100 for storing hydrogen, comprising:

[0043] - at least one first hydrogen tank 110 and one second hydrogen tank 120, which are designed to store hydrogen, each with a first lance 111 and a second lance 121, which are designed to introduce hydrogen into the hydrogen tanks 110, 120,

[0044] - a hydrogen line 130, which fluidically connects the first hydrogen tank 110 and the second hydrogen tank 120 via the first lance 111 and the second lance and is connectable to a tank nozzle 150, via which hydrogen can be refueled, wherein the first hydrogen tank 110 has a larger volume than the second hydrogen tank 120 and the second lance has at least partially a smaller cross-section than the first lance 111.

[0045] Overall, the hydrogen tank system 100 according to the invention offers the advantage that the hydrogen tanks 110, 120 of a hydrogen tank system 100 can be filled with a well-mixed mixture. The reduced cross-section of the second lance 121 increases the exit velocity in the second hydrogen tank 120, thereby increasing the mixing. The increased pressure loss resulting from the smaller cross-section is unproblematic because additional throttling is required for the second hydrogen tank 120 anyway to ensure uniform filling of all hydrogen tanks 110, 120.

[0046] Fig. 2 shows a hydrogen vehicle 200 according to the invention, in particular with a hydrogen tank system 100 according to the invention. The following drawings 2 to 5 show lances 111, 121 in different designs.

[0047] Fig. 3 shows that a second lance 121 according to the invention has a smaller cross-section than the first lance 111. It can be provided within the scope of the invention that, as shown in Fig. 3, at least the first lance or the second lance has an angle to the longitudinal axis of the hydrogen container. Alternatively or additionally (not shown), it can also be provided that the first and / or second lance 111, 121 is attached at an angle to the longitudinal axis of the hydrogen container 110, 120, wherein the angle is in particular more than 5°. It can also be provided that the angle is between 8 and 12°, in particular 10°. The angling has the advantage that the hydrogen flow quickly impacts a wall of the hydrogen container 110, 120, whereby a flow vortex is formed and the mixing within the hydrogen container 110, 120 is improved.

[0048] Figure 4 shows two lances 111, 121, each with a throttle bore at one end of the lance. In the lower example, the bore is at least designed as a short bore or orifice, and the cross-section of the lances 111, 121 widens again before the hydrogen is introduced into the hydrogen tank.

[0049] Fig. 5 shows lances 111, 121 that have different angles. The lance 111, 121 shown at the bottom of Fig. 5 is straight. The lance 111, 121 shown in the middle of Fig. 5 has two angles, with the hydrogen initially directed downwards and then upwards in the flow direction. In the upper example, the lance 111, 121 is initially aligned parallel to a longitudinal direction of the hydrogen container 110, 120 in the flow direction and points upwards further downstream.

[0050] The above explanation of the embodiments describes the present invention exclusively by way of examples. Of course, individual features of the embodiments can be freely combined with one another, provided they are technically feasible, without departing from the scope of the present invention.

Claims

Claims 1 . Hydrogen tank system (100) for storing hydrogen, comprising: - at least one first hydrogen container (110) and one second hydrogen container (120) designed to store hydrogen, each with a first lance (111) and a second lance (121) designed to introduce hydrogen into the hydrogen containers (110, 120), - a hydrogen line (130) which fluidically connects the first hydrogen container (110) and the second hydrogen container (120) to one another via the first lance (111) and the second lance (121) and which can be connected to a tank nozzle (150) via which hydrogen can be refueled, wherein the first hydrogen container (110) has a larger volume than the second hydrogen container (120) and the second lance (121) has at least partially a smaller cross-section than the first lance (111).

2. Hydrogen tank system (100) according to claim 1, characterized in that the cross section of at least the second lance (121) is adapted to an expected mass flow, in particular according to a tank protocol of the hydrogen tank system (100).

3. Hydrogen tank system (100) according to one of the preceding claims, characterized in that at least the first lance (111) or the second lance (121) has an angle to the longitudinal axis of the hydrogen tank (110, 120) and / or is mounted at an angle to the longitudinal axis of the hydrogen tank (110, 120), wherein the angle is in particular more than 5°.

4. Hydrogen tank system (100) according to one of the preceding claims, characterized in that at least the first lance (111) or the second lance (121) has a first cross-section (112) at a connection point to the hydrogen line (130) and a second cross-section (122) at a connection point to the hydrogen tank (110, 120), wherein the second cross-section (122) is smaller than the first cross-section (112).

5. Hydrogen tank system (100) according to one of the preceding claims, characterized in that the hydrogen line (130) can be passively flowed through by the hydrogen.

6. Hydrogen tank system (100) according to one of the preceding claims, characterized in that a cross section of the first lance (111) or the second lance (121) downstream of the hydrogen tank (110, 120) initially tapers and widens at one end of the first lance (111) or the second lance (121), in particular suddenly.

7. Hydrogen tank system (100) according to one of the preceding claims, characterized in that the smaller cross-section is designed as a diaphragm.

8. Hydrogen tank system (100) according to one of the preceding claims, characterized in that the cross section of the first lance (111) to the volume of the first hydrogen tank (110) is essentially the same as the cross section of the second lance (121) to the volume of the second hydrogen tank (120).

9. Hydrogen vehicle (200) comprising a hydrogen tank system (100), in particular according to one of claims 1 to 8, for the storage of hydrogen, comprising: - at least one first hydrogen container (110) and one second hydrogen container (120) designed to store hydrogen, each with a first lance (111) and a second lance (121) designed to introduce hydrogen into the hydrogen containers (110, 120), - a hydrogen line (130) which fluidically connects the first hydrogen container (110) and the second hydrogen container (120) to one another via the first lance (111) and the second lance (121) and which can be connected to a tank nozzle (150) via which hydrogen can be refueled, wherein the first hydrogen container (110) has a larger volume than the second hydrogen container (120) and the second lance (121) has at least partially a smaller cross-section than the first lance (111).

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