Tank system for hydrogen applications, fuel cell assembly, hydrogen internal combustion engine system, fuel cell-operated vehicle, hydrogen-operated vehicle, method for measuring average temperature in tank system

Abstract

The invention relates to a tank system (100) for hydrogen applications wherein the tank system (100) comprises at least one tank container (200) for storing hydrogen and a valve assembly (5). The at least one tank container (200) interacts with the valve assembly (5) and is fluidically connected to one another, the at least one tank container (200) having a tank container interior (20) which can be filled with hydrogen by means of the valve assembly (5). The tank system (100) has a sensor element (8) for measuring a temperature in the tank container interior (20). Furthermore, the sensor element (8) comprises an acoustic transducer element (80). The invention further relates to a fuel cell assembly, a hydrogen internal combustion engine system, a fuel cell-operated vehicle, a hydrogen-operated vehicle and a method for measuring the average temperature in a tank system.

Description

TECHNICAL FIELD

[0001] The invention relates to a tank system for hydrogen applications. Furthermore, the tank system is also applied in fuel cell assemblies or hydrogen internal combustion engine systems. The invention also relates to a vehicle operated with a fuel cell and a vehicle operated with hydrogen. Furthermore, the invention also relates to a method for measuring the average temperature in a tank system. BACKGROUND

[0002] DE 10 2017 212 485 A1 describes a device for storing compressed fluid, which is used as fuel for a vehicle, wherein the device comprises at least two tubular tank containers and at least one high-pressure fuel distributor with at least one integrated regulating and safety technology.

[0003] In order to quickly and safely fill the device with compressed fluid, for example hydrogen, in order to provide the compressed fluid, for example, to a consumer system such as a fuel cell assembly or a hydrogen internal combustion engine system, it is advantageous to precisely determine, for example, the temperature or the pressure. These parameters influence the inflow rate into the device and thus the filling speed.

[0004] Furthermore, in order to have a safe filling, a continuous monitoring, for example of the temperature, is advantageous, since the device for storing compressed fluid is usually designed for a temperature of the carbon fiber reinforced container, which is not allowed to exceed 85 degrees Celsius. However, during the filling of hydrogen, temperature fluctuations can occur due to the negative Joule-Thomson effect, which can lead to damage to the device if the temperature exceeds, for example, 85 degrees Celsius. Therefore, the hydrogen is cooled to -40 degrees Celsius before being filled by a refueling station in order to minimize the overheating of the container. The actually existing temperature in the container is related to the tank temperature, the tank pressure, but also to the ambient temperature.

[0005] So far, the measurement of the temperature takes place with conventional thermocouples or measuring resistors. Of course, the temperature in the vicinity of the temperature sensor is thus only taken. However, during the filling, due to the strong change in temperature within the container, it is desirable to measure the temperature over a larger volume within the container.

[0006] In addition, the measurement signal of conventional sensors responds to the actual temperature only with a severe delay. This is caused by the heat capacity of the sensor material itself and the limited heat conduction capability. Furthermore, in mobile applications, this is exacerbated due to the unavoidable vibration loads and the resulting mechanical design of such sensors. SUMMARY

[0007] In contrast, the tank system according to the invention with the features of claim 1 has the advantage that an accurate and fast measurement of the tank temperature is achieved by applying an alternative sensor concept, in particular during the filling of the tank system.

[0008] To this end, the tank system comprises at least one tank container for storing hydrogen and a valve assembly. The at least one tank container interacts with the valve assembly and is in fluid connection therewith. The at least one tank container has a tank container interior space which can be filled with hydrogen by means of the valve assembly. The tank system further has a sensor element for measuring the temperature within the tank container interior space. Furthermore, the sensor element comprises an acoustic transducer element.

[0009] Thus, the temperature within the tank container interior space can be determined in a highly efficient manner and almost without delay. Furthermore, the temperature at different locations within the tank container interior space is thus also taken into account and the average temperature of the tank container interior space is thus determined.

[0010] In a first advantageous development, the acoustic transducer element is an ultrasonic transducer element.

[0011] In a further advantageous development, the acoustic transducer element is constructed in multiple parts, wherein the acoustic transducer element comprises a transmitter for emitting acoustic signals and a receiver for receiving acoustic signals. Thus, one component of the acoustic transducer element can be constructed as a transmitter, for example, and another component of the acoustic transducer element can be constructed as a receiver.

[0012] In a further configuration of the application, it is advantageously provided that the tank container has an end plug element at an end opposite the valve assembly, the acoustic transducer element being arranged in the end plug element.

[0013] In a further configuration of the application, it is advantageously provided that the acoustic transducer element is arranged in the valve assembly.

[0014] In a further advantageous development, the acoustic transducer element is arranged in a wall region of the tank container.

[0015] Thus, the acoustic transducer element can be integrated into the tank system in a simple manner in terms of design and a compact design of the tank system can be achieved.

[0016] The tank system described is preferably suitable for a fuel cell assembly for storing hydrogen for operating a fuel cell.

[0017] The tank system described is preferably suitable for a hydrogen internal combustion engine system for storing hydrogen for operating a hydrogen internal combustion engine.

[0018] In an advantageous application, the tank system can be used in a vehicle having a fuel cell drive.

[0019] In an advantageous application, the tank system can be used in a vehicle having a hydrogen drive.

[0020] Furthermore, the application also comprises a method for measuring the average temperature in the tank system described above, the method comprising the following steps: a. determining the gas pressure in the tank container and the sound velocity of the sound signal emitted by the sound transducer element; b. determining the gas temperature in the tank container from the gas pressure and the sound velocity determined in step a, and from stored reference values for the relationship between sound velocity, gas pressure and gas temperature, and / or from a physical model for the relationship between sound velocity, gas pressure and gas temperature.

[0021] In an advantageous development, the sound velocity of the sound signal emitted by the sound transducer element is determined by means of a transit time measurement, comprising the following steps: a. emitting a short-pulsed sound signal into the tank container by means of the sound transducer element; b. receiving the sound signal by means of the sound transducer element after reflection of the sound signal on an element opposite the sound transducer element; c. determining the transit time of the sound signal from the time difference between the emission of the sound signal and the reception of the sound signal; d. determining the sound velocity of the sound signal from the transit time determined in step c and the geometry of the tank container.

[0022] In an advantageous development, the sound velocity of the sound signal emitted by the sound transducer element is determined by means of a pulsed resonance frequency measurement, comprising the following steps: a. emitting a sound signal having a broadband frequency spectrum into the tank container for a predefined time period by means of the sound transducer element; b. detecting the frequency spectrum present in the attenuated sound field in the tank container after the end of the time period by means of the sound transducer element; c. determining the resonance frequency in the attenuated sound field of the tank container; d. determining the sound velocity of the sound signal from the resonance frequency determined in step c and the geometry of the tank container.

[0023] In an advantageous development, the sound velocity of the sound signal emitted by the sound transducer element is determined by means of a resonance frequency measurement, comprising the following steps: a. emitting a continuous sound signal into the tank container by means of the sound transducer element; b. detecting the resonance frequency in the tank container by means of varying the sound frequency of the sound signal and analyzing the power coupled in; c. determining the sound velocity of the sound signal from the resonance frequency detected in step b and the geometry of the tank container.

[0024] Thus, by means of an alternative sensor concept for determining the temperature of the hydrogen gas in the tank system by means of the sound velocity, the temperature of the hydrogen gas can be determined. Furthermore, by means of the propagation of the sound signal through the entire interior space of the tank container, the average temperature of the hydrogen gas in the tank container can be determined almost in real time. In a preferred embodiment, the sound signal is an ultrasonic signal.

[0025] Furthermore, the present application also relates to a storage unit for carrying out the above-mentioned method, wherein reference values for the relationship between the sound velocity, the gas pressure and the gas temperature are stored in the storage unit.

[0026] The storage unit can be, for example, a controller, in particular a controller of the tank system or of a consumer system, for example a fuel cell assembly or a hydrogen internal combustion engine system.

[0027] In an alternative embodiment, the storage unit or the controller can also be an integrated component part of the sensor element itself. BRIEF DESCRIPTION OF DRAWINGS

[0028] The present application is explained in detail below with reference to the drawings.

[0029] The drawings show: Figure 1a schematic top view of a system according to the present application in a first embodiment; Figure 1b schematic top view of a system according to the present application in a second embodiment; Figure 1c schematic top view of a system according to the present application in a third embodiment; Figure 2 flow chart of a method according to the present application; Figure 3 flow chart of a method according to the present application; Figure 4 flow chart of a method according to the present application; Figure 5 flow chart of a method according to the present application; Figure 6 schematic top view of a system according to the present application in a third embodiment;

[0030] All drawings are merely schematic and the distances and size relationships in the drawings are not true to scale. DETAILED DESCRIPTION

[0031] Figure 1aA schematic top view of a tank system 100 according to the application for hydrogen applications in a first embodiment is shown. In this embodiment, the tank system 100 comprises one tank container 200 with a longitudinal axis 400 for storing hydrogen. In an alternative embodiment, the tank system 100 can have a plurality of tank containers 200, which can be in fluid communication via connecting lines.

[0032] Furthermore, the tank container 200 has a valve assembly 5, which interacts with the tank container 200 and is in fluid connection therewith. Here, the valve assembly 5 is integrated in the neck region 26 of the tank container 200 and projects into the tank container interior space 20 of the tank container 200. Via the valve assembly 5, the tank container interior space 20 can be filled, for example, from an external filling station with hydrogen. Furthermore, via the valve assembly 5, hydrogen can also be guided from the tank container interior space 20 in the direction of a consumer system, for example, a fuel cell assembly 70 or a hydrogen internal combustion engine system 71.

[0033] At the end 25 opposite the valve assembly 20, the tank container 200 has an end plug element 9. In this end plug element 9, a sensor element 8 is integrated. In order to measure the temperature in the tank container 200, the sensor element 8 comprises a sound transducer element 80. In an alternative embodiment, it can be provided that the sound transducer element 80 is constructed in multiple parts, wherein the sound transducer element 80 comprises a transmitter for emitting a sound signal and a receiver for receiving a sound signal. Thus, one part of the sound transducer element 80 can be constructed as a transmitter, for example, and another part of the sound transducer element 80 can be constructed as a receiver.

[0034] Furthermore, the sound transducer element 80 is here an ultrasonic transducer element.

[0035] Figure 1b A schematic top view of a tank system 100 according to the application for hydrogen-operated vehicles in a second embodiment is shown. The second embodiment essentially corresponds to the first embodiment of the Figure 1a The difference between the two lies only in the arrangement of the sensor element 8 comprising the sound transducer element 80. In the second embodiment, the sensor element 8 comprising the sound transducer element 80 is integrated in the valve assembly 5.

[0036] Figure 1c A schematic top view of a tank system 100 according to the application for hydrogen-operated vehicles in a third embodiment is shown. The third embodiment essentially corresponds to the first embodiment of the Figure 1a The difference between the two lies only in the arrangement of the sensor element 8 comprising the sound transducer element 80. In the third embodiment, the sensor element 8 comprising the sound transducer element 80 is integrated in the wall region 202 of the tank container 200.

[0037] The sensor element 8 comprising the acoustic transducer element 80 works as follows: In order to measure the average temperature in the tank system 100, a method 500 is proposed below, which comprises the following steps, as also illustrated in Figure 2 as a flow chart in a. determining 40 the gas pressure in the tank vessel 200 and the speed of sound of the acoustic signal emitted by the acoustic transducer element 80; b. determining 41 the gas temperature in the tank vessel 200 from the gas pressure and the speed of sound determined in step a and from stored reference values for the relationship between speed of sound, gas pressure and gas temperature and / or a physical model for the relationship between speed of sound, gas pressure and gas temperature.

[0038] In the case of using a physical model for the relationship between speed of sound, gas pressure and gas temperature, the reference values are determined only at the run-time of the physical model or in real-time.

[0039] The speed of sound of the acoustic signal emitted by the acoustic transducer element 80 is determined, for example, by a transit time measurement as illustrated in Figure 3 as a flow chart in a. emitting 42 a short-pulsed acoustic signal into the tank vessel 200 by the acoustic transducer element 80; b. receiving 43 the acoustic signal by the acoustic transducer element 80 after reflection of the acoustic signal on an element opposite to the acoustic transducer element 80; c. determining 44 the transit time of the acoustic signal by the time difference between emitting the acoustic signal and receiving the acoustic signal; d. determining 45 the speed of sound of the acoustic signal by means of the transit time determined in step c and the geometry of the tank vessel 200.

[0040] Here, the element opposite to the acoustic transducer element 80 can be an inner wall of the tank vessel 200 or also a mirror element arranged on an inner wall of the tank vessel 200, in the end plug element 9 or protruding into the tank vessel 200.

[0041] In an alternative embodiment, the speed of sound of the acoustic signal emitted by the acoustic transducer element 80 can be determined by a pulsed resonance frequency measurement, for example, as illustrated in Figure 4 as a flow chart in a. emitting 46 an acoustic signal having a broadband spectrum into the tank vessel 200 by the acoustic transducer element 80 for a predefined time period; b. detecting 47 the spectrum present in the attenuated acoustic field in the tank vessel 200 after the end of the time period by the acoustic transducer element 80; c. determining 48 the resonance frequency in the attenuated acoustic field of the tank vessel 200; d. determining 49 the sound velocity of the sound signal by means of the resonance frequency found in step c and the geometry of the tank container 200.

[0042] In an alternative embodiment, the sound velocity of the sound signal emitted by the sound transducer element 80 can be determined by means of a resonance frequency measurement, comprising the following steps, for example as shown in the flow chart in Figure 5 a. emitting 50 a continuous sound signal into the tank container 200 by means of the sound transducer element 80; b. detecting 51 the resonance frequency in the tank container 200 by means of varying the sound frequency of the sound signal and analyzing the coupled-in power; c. determining 52 the sound velocity of the sound signal by means of the resonance frequency detected in step b and the geometry of the tank container 200.

[0043] Reference values for the relationship between sound velocity, gas pressure and gas temperature are stored, for example, in the storage unit 12. The storage unit 12 can be, for example, a controller, in particular a controller of the tank system 100 or of a consumer system, for example a fuel cell assembly 70 or a hydrogen internal combustion engine system 71.

[0044] In an alternative embodiment, the storage unit 12 or the controller can also be an integral component of the sensor element itself.

[0045] In a preferred embodiment, the sound signal is an ultrasonic signal.

[0046] Figure 6 A hydrogen-operated vehicle 72, which can be operated, for example, with a fuel cell assembly 70, or a fuel cell-operated vehicle 73, which can be operated with a hydrogen internal combustion engine system 71, is shown in a simplified schematic view. In order to provide hydrogen gas, the fuel cell assembly 70 or the hydrogen internal combustion engine system 71 has a tank system 100 according to the application.

[0047] In addition to the mobile application areas described above, the tank system 100 described above can also be used in stationary applications, for example solid oxide fuel cells (SOFC) or electrolysis applications as possible storage for hydrogen production. Furthermore, the tank system 100 according to the application can also be used in ships or aircraft.​

Claims

1. A tank system (100) for hydrogen applications, wherein, The tank system (100) comprises at least one tank container (200) for storing hydrogen and a valve assembly (5), wherein the at least one tank container (200) interacts with the valve assembly (5) and is in fluid connection with the valve assembly (5), wherein the at least one tank container (200) has a tank container interior (20) which can be filled with hydrogen by means of the valve assembly (5), wherein the tank system (100) has a sensor element (8) for measuring the temperature in the tank container interior (20), characterized in that the sensor element (8) comprises at least one acoustic transducer element (80).

2. The tank system (100) according to claim 1, characterized in that The acoustic transducer element (80) is an ultrasonic transducer element.

3. The tank system (100) according to claim 1 or 2, characterized in that The acoustic transducer element (80) is multi-part configured, wherein the acoustic transducer element (80) comprises a transmitter for emitting acoustic signals and a receiver for receiving acoustic signals.

4. The tank system (100) according to claim 1, 2 or 3, characterized in that The tank container (200) has an end plug element (9) at an end (25) opposite the valve assembly (5), the acoustic transducer element (80) being arranged in the end plug element (9).

5. The tank system (100) according to claim 1, 2 or 3, characterized in that, The acoustic transducer element (80) is arranged in the valve assembly (5).

6. The tank system (100) according to claim 1, 2 or 3, characterized in that The acoustic transducer element (80) is arranged in a wall region (202) of the tank container (200).

7. A fuel cell assembly (70) comprising a tank system (100) according to any one of the preceding claims for storing hydrogen for operating a fuel cell.

8. A hydrogen internal combustion engine system (71) comprising a tank system (100) according to any one of claims 1 to 5 for storing hydrogen for operating a hydrogen internal combustion engine.

9. A fuel cell operated vehicle (73) comprising a tank system (100) according to any one of claims 1 to 6 for storing hydrogen.

10. A hydrogen operated vehicle (72) comprising a tank system (100) according to any one of claims 1 to 6 for storing hydrogen.

11. A method (500) for measuring the average temperature in a tank system (100) according to any one of claims 1 to 6, the method comprising the following steps: a. taking (40) the gas pressure in the tank container (200) and the speed of sound of the acoustic signals emitted by the acoustic transducer element (80); b. determining (41) the gas temperature in the tank container (200) from the gas pressure and the speed of sound taken in step a and from stored reference values for the relationship between speed of sound, gas pressure and gas temperature and / or a physical model for the relationship between speed of sound, gas pressure and gas temperature.

12. The method (500) according to the preceding claim, characterized by The speed of sound of the acoustic signals emitted by the acoustic transducer element (80) is taken by means of a transit time measurement, comprising the following steps: a. emitting (42) a short burst acoustic signal into the tank container (200) by means of the acoustic transducer element (80); b. taking (43) the time of flight of the acoustic signal from the acoustic transducer element (80) to the opposite wall of the tank container (200); and c. determining (44) the speed of sound of the acoustic signals emitted by the acoustic transducer element (80) from the time of flight taken in step b. b. receiving (43) the acoustic signal by the acoustic transducer element (80) after reflection of the acoustic signal on an element opposite to the acoustic transducer element (80); c. determining (44) the transit time of the acoustic signal by the time difference between emitting the acoustic signal and receiving the acoustic signal; d. determining (45) the sound velocity of the acoustic signal by means of the transit time determined in step c and the geometry of the tank container (200).

13. The method (500) of claim 11, wherein Determining the sound velocity of an acoustic signal emitted by the acoustic transducer element (80) by means of a pulsed resonance frequency measurement comprises the following steps: a. emitting (46) an acoustic signal with a broadband spectrum by the acoustic transducer element (80) into the tank container (200) for a predefined time period; b. detecting (47) the spectrum present in the attenuated acoustic field in the tank container (200) after the end of the time period by the acoustic transducer element (80); c. determining (48) the resonance frequency in the attenuated acoustic field of the tank container (200); d. determining (49) the sound velocity of the acoustic signal by means of the resonance frequency determined in step c and the geometry of the tank container (200).

14. The method (500) of claim 11, wherein, Determining the sound velocity of an acoustic signal emitted by the acoustic transducer element (80) by means of a resonance frequency measurement comprises the following steps: a. emitting (50) a continuous acoustic signal by the acoustic transducer element (80) into the tank container (200); b. detecting (51) the resonance frequency in the tank container (200) by means of varying the acoustic frequency of the acoustic signal and analyzing the coupled-in power; c. determining (52) the sound velocity of the acoustic signal by means of the resonance frequency detected in step b and the geometry of the tank container (200).

15. A storage unit (12) for performing the method according to any one of claims 11 to 14, wherein, Reference values for the relationship between sound velocity, gas pressure and gas temperature are stored in the storage unit (12).

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