Tank system for a fluid medium, in particular hydrogen, fuel cell arrangement, hydrogen combustion engine system, fuel cell-powered vehicle, hydrogen-powered vehicle, method for determining the temperature in a tank system during the filling of the tank system with a fluid medium, in particular hydrogen

Abstract

Tank system (100) for a fluid medium, in particular hydrogen, and a method for determining the temperature in a tank system (100) during the filling of the tank system (100) with fluid medium, in particular hydrogen.

Description

[0001] The present invention relates to a tank system for a fluid medium, in particular hydrogen. Furthermore, the tank system is used in a fuel cell arrangement or in a hydrogen combustion engine system. The invention also relates to a vehicle with a fuel cell drive and a hydrogen-powered vehicle. In addition, the invention relates to a method for determining the temperature in a tank system during the filling of the tank system with a fluid medium, in particular hydrogen. State of the art

[0002] Today's hydrogen tank systems for mobile applications typically consist of several tanks, often made of carbon fiber reinforced material. These are typically pressurized to a nominal hydrogen pressure of, for example, 350 bar or 900 bar. During filling, storage, or withdrawal of hydrogen in operation, temperatures below the freezing point of water (down to -40°C during withdrawal in a 700 bar system) can occur inside the tank.

[0003] The tank containers can also contain metallic materials, for example.

[0004] DE 10 2022 211 297 A1 describes a tank system for a fluid medium and a possible temperature determination within the tank system.

[0005] The refueling of such storage devices takes place under clearly defined boundary conditions. The purpose of these boundary conditions is to prevent temperature and / or pressure increases that could either compromise the safety of the storage device or result in excessively low fill levels at the end of the refueling process. These boundary conditions were developed for carbon fiber reinforced storage devices with low length-to-diameter ratios (L / D ratios). The L / D ratio, in this context, is the ratio between the length (L) and the diameter (D) of a cylindrical storage device.

[0006] To comply with these requirements, refueling is carried out according to the SAE J2601 protocol. This protocol contains tabular recommendations for the refueling strategy, such as pressure ramp and final temperature, depending on the tank capacity, vehicle category, and the initial conditions of refueling.

[0007] These boundary conditions can be easily met by specifying pressure ramps at given tank and ambient temperatures. Even if real-time determination of the mean tank temperature during refueling is not always necessary (no communication between the filling station and the vehicle), knowledge of the tank temperature is relevant for the design and, furthermore, for the modeling of the CHSS (Compressed Hydrogen Storage System).

[0008] In the prior art, temperature probes and associated insertion lances are used for temperature determination. This provides a temperature measurement point at the inlet, but does not capture a temperature representative of the entire tank, since, for example, in tanks with high L / D ratios, a very inhomogeneous temperature distribution along the length of the tank is to be expected during filling. A single measurement point at the inlet could lead to an underestimation of the temperature in the entire tank if pre-cooled, while high temperatures are to be expected in the rear section due to displacement. Both of these factors lead to an inaccurate estimation of the exact filling condition. Installing multiple temperature sensors in different axial and radial positions often fails due to design constraints (installation space, mounting, and guidance) as well as the associated costs.Furthermore, internal components alter the flow pattern and must be checked for their hydrogen compatibility and stability at high pressure. Advantages of the invention

[0009] In contrast, the tank system according to the invention with the characterizing features of claim 1 has the advantage that the global mean temperature within the tank system can be determined in a structurally simple manner during filling.

[0010] The tank system for a fluid medium, in particular hydrogen, comprises at least one tank for storing a gaseous medium, in particular hydrogen, and a valve device. The at least one tank and the valve device are operatively connected and fluidically linked, the at least one tank having an interior space which can be filled with a gaseous medium, in particular hydrogen, via the valve device. Furthermore, a weight sensor element is arranged at one end of the tank opposite the valve device, and a pressure sensor element is arranged on the outside of the tank.

[0011] In this way, temperature monitoring can be carried out indirectly in a structurally simple manner by determining the weight of the tank container during filling and by measuring the pressure.

[0012] In the first advantageous further development, it is provided that the tank containers comprise a fiber-reinforced plastic.

[0013] In a further embodiment, it is advantageous for the tank containers to be made of steel. Using steel allows for a simple and cost-effective tank system.

[0014] In a further advantageous design, the tank container is provided for to be cylindrical in shape.

[0015] The described tank system is preferably suitable for use in a fuel cell arrangement for storing hydrogen for the operation of a fuel cell.

[0016] The described tank system is particularly suitable for use in a hydrogen combustion engine system.

[0017] In advantageous applications, the refueling device can be used in vehicles with a fuel cell drive.

[0018] In advantageous applications, the refueling device can be used in vehicles with a hydrogen propulsion system.

[0019] Furthermore, the invention comprises a method for determining the temperature in a tank system during the filling of the previously described tank system with a fluid medium, in particular hydrogen, comprising the following steps: a. Determining the mass of the filled tank container by measuring the change in weight of the tank container over time using the weight sensor element and simultaneously measuring the pressure inside the tank container using the pressure sensor element; b. Determining the mass flow rate and density using the determined mass from step a and a mass of the tank before filling the tank; c. Determining the temperature in the tank using the determined fluid mass, the measured pressure and the density using a pressure / density diagram.

[0020] In this way, the global average temperature in the entire tank can be indirectly determined during the refueling of the respective tank container. Brief description of the drawing

[0021] The invention is described in more detail below with reference to the drawing.

[0022] It shows: Fig. 1 a schematic top view of a tank system according to the invention in one possible embodiment, Fig. 2. Procedure diagram for determining the temperature in a tank system during the filling of the tank system with a fluid medium, in particular hydrogen, Fig. 3 Temperature distribution as a function of pressure and density in a tank system in a simplified schematic view, Fig. 4 a hydrogen-powered vehicle with a fuel cell arrangement or a hydrogen combustion engine system with a tank system according to the invention in a simplified schematic view.

[0023] All figures are merely schematic representations of the tank system according to the invention or its components according to exemplary embodiments of the invention. In particular, distances and size relationships are not shown to scale in the figures. Description of the exemplary embodiment

[0024] Fig. Figure 1 shows a schematic top view of a tank system 100 according to the invention for a fluid medium, in particular hydrogen, in one possible embodiment. In this embodiment, the tank system 100 has a cylindrical tank container 200 with a longitudinal axis 400 for storing a fluid medium, in particular hydrogen. In an alternative embodiment, the tank system 100 can have several tank containers 200, which can be in fluidic contact, for example, via a connecting line.

[0025] Furthermore, the tank 200 has a valve device 4, which is operatively connected to the tank 200 and with which it is fluidically linked. The valve device 4 is integrated into an end region 204 of the tank 200, for example via a screw connection, and partially projects into an interior space 2 of the tank 200. For example, a lance (not shown here) is arranged on the valve device 4, which projects into the interior space 2 of the tank and thus ensures optimal distribution of the fluid medium during filling of the tank 200.

[0026] In addition, a weight sensor element 32 is arranged in the interior of the tank container 2 at one end 205 of the tank container 200 facing away from the valve device 4, and a pressure sensor element 30 is arranged on an outer side 206 of the tank container 200.

[0027] The tank container 200 typically comprises a fiber-reinforced plastic. Alternatively, the tank container 200 can also be made of steel. Steel enables a cost-effective construction of the tank container 200.

[0028] Furthermore, the invention comprises a method for determining the temperature in a tank system during the filling of the previously described tank system with a fluid medium, in particular hydrogen, comprising the following steps, as shown in Fig. 2 shown in a process diagram: a. Determining 500 of the mass of the fueled tank container by determining the change in weight of the tank container over time using the weight sensor element and simultaneously measuring the pressure inside the tank container using the pressure sensor element; b. Determine the mass flow rate and density using the determined mass from step a and a mass of the tank before filling the tank; c. Determine the temperature in the tank container using the determined fluid mass, the measured pressure and the density using a pressure / density diagram.

[0029] The temperature is determined indirectly by measuring the weight of the tank 200 during filling. The mass flow rate and the mass of the filled tank 200 can be determined by measuring the weight change over time. Subtracting the mass of the typically empty tank 200 from this mass yields the fluid mass. The temperature can then be inferred from the density and, by simultaneously measuring the pressure in the tank, from this fluid mass. For tank 200 that is not empty, the fill level before filling is assumed to be known. In this case, a homogeneous temperature distribution can be assumed before filling.

[0030] The resolution of the pressure sensor element 30 and the weight sensor element 32 is selected to achieve sufficient temperature resolution. Fig. Figure 3 shows such a typical temperature distribution for different temperatures depending on the pressure in MPa and the density in kg / m³. 3 In a simplified schematic view of a tank system 100, temperature curves between 233 K and 323 K are shown, for example. The temperature in the tank 200 can be determined from the pressure and density. Typically, the tanks 200 are pressurized with hydrogen at a nominal pressure of, for example, 350 bar or up to 900 bar (35 MPa or up to 90 MPa).

[0031] Fig.Figure 4 shows a simplified schematic view of a hydrogen-powered vehicle 72, which can be operated, for example, with a fuel cell arrangement 70 as a fuel cell-powered vehicle 73, or with a hydrogen combustion engine system 71. The fuel cell arrangement 70 or the hydrogen combustion engine system 71 has the tank system 100 according to the invention for supplying hydrogen. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 211 297 A1

[0004]

Claims

[1] Tank system (100) for a fluid medium, in particular hydrogen, wherein the tank system (100) comprises at least one tank container (200) for storing gaseous medium, in particular hydrogen, and a valve device (4), wherein the at least one tank container (200) and the valve device (4) are operatively connected and fluidically linked, wherein the at least one tank container (200) has a tank container interior (2) which can be filled with gaseous medium, in particular hydrogen, through the valve device (4), characterized by , that a weight sensor element (32) is arranged in the interior of the tank container (2) at one end (205) of the tank container (200) facing away from the valve device (4) and a pressure sensor element (30) is arranged on an outside (206) of the tank container (200). [2] Tank system (100) according to claim 1, characterized by that the tank containers (200) comprise a fiber-reinforced plastic. [3] Tank system (100) according to any one of the preceding claims, characterized by , that the tank containers (200) comprise steel. [4] Tank system (100) according to any one of the preceding claims, characterized by , that the tank container (200) is cylindrical in shape. [5] Fuel cell arrangement (70) with a tank system (100) for storing hydrogen for the operation of a fuel cell according to one of the preceding claims. [6] Hydrogen combustion engine system (71) with a tank system (100) for storing hydrogen according to one of claims 1 to 4. [7] Fuel cell powered vehicle (73) with a tank system (100) for storing hydrogen according to one of claims 1 to 4. [8] Hydrogen-powered vehicle (72) with a tank system (100) for storing hydrogen according to any one of claims 1 to 4. [9] Method for determining the temperature in a tank system (100) during the filling of the tank system (100) according to one of claims 1 to 4 with a fluid medium, in particular hydrogen, comprising the following steps: a. Determining (500) a mass of the fueled tank container (200) by determining the change in weight of the tank container (200) over time using the weight sensor element (32) and simultaneously measuring the pressure in the interior of the tank container (2) using the pressure sensor element (30); b. Determining (501) the mass flow rate and density from the determined mass from step a and a mass of the tank container (200) before filling the tank container (200); c. Determine (502) the temperature in the tank container (200) using the determined fluid mass, the measured pressure and the density by means of a pressure / density diagram.

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