DE102020106620A1 - Pressure vessel system and process - Google Patents

Abstract

The technology disclosed here relates according to the invention to a pressure vessel system 5 with a pressure vessel 10, in the wall 20 of which a conductor 30 runs, the parameters of which are monitored to detect damage. The technology disclosed here also relates to an associated method.

Description

The technology disclosed here relates to a pressure vessel system and an associated method.

Pressure vessel systems are used, for example, in motor vehicles to provide a supply of gaseous fuel. For example, it can be hydrogen or natural gas. For this purpose, a pressure vessel system typically has one or more pressure vessels. Gaseous fuels can be used in an energy converter of the motor vehicle such as a fuel cell or a gas-powered internal combustion engine.

Pressure vessels can experience mechanical damage, which can impair their stability.

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 increase the safety of a pressure vessel system. Further preferred objects can result from the advantageous effects of the technology disclosed here. The objects are achieved by the subject matter of the independent claims. The dependent claims represent preferred configurations.

The technology disclosed here relates to a pressure vessel system comprising (i) at least one pressure vessel with a wall, (ii) at least one conductor, in particular an electrical conductor, which runs through the wall, and (iii) an evaluation unit which is configured to have a to measure electrical parameters of the conductor. Using the measured electrical parameter, in particular, conclusions can be drawn about the condition of the wall; for example, a certain value of the parameter or a change in the parameter can be used to infer damage.

The pressure vessel system is intended in particular for a motor vehicle (e.g. passenger cars, motorcycles, commercial vehicles). The pressure vessel system is used to store fuel that is gaseous under ambient conditions. The pressure vessel system can be used, for example, in a motor vehicle that is operated with compressed (also called compressed natural gas or CNG) or liquefied (also called liquid natural gas or LNG) natural gas or with hydrogen. The pressure vessel system is typically fluidly connected to at least one energy converter which is set up to convert the chemical energy of the fuel into other forms of energy.

The pressure vessel can in particular be a composite overwrapped pressure vessel. The pressure vessel can be, for example, a cryogenic pressure vessel or a high-pressure gas vessel. High-pressure gas tanks are designed to store fuel permanently at ambient temperatures at a nominal operating pressure (also called nominal working pressure or NWP) of at least 350 barg (= overpressure compared to atmospheric pressure) or at least 700 barg or more. A cryogenic pressure vessel is suitable for storing the fuel at the aforementioned operating pressures even at temperatures which are well below the operating temperature of the motor vehicle.

The conductor can in particular be an electrical conductor, for example it can be a metallic wire. This can in particular be introduced into the wall in order to carry out the electrical measurements described. In particular, it can be insulated from any other conductive components in the wall. For example, it can be embedded in a matrix material of the wall which is electrically insulating.

According to a preferred embodiment, the conductor runs at a distance of 0.5 mm to 1.5 mm, or in particular 1 mm, below an outer surface of the wall. Damage near the surface can detect this conductor and thus lead to a change in the measured electrical parameter. This allows such damage to be detected.

Damage to the wall typically also leads to damage to the incorporated conductor. Damage to the conductor can then be determined by changing an electrical property of the conductor.

According to a preferred embodiment, the pressure vessel system has a further conductor which runs through the wall. The evaluation unit is configured to measure a further electrical parameter of the further conductor. As a result, damage can also be recognized at the location of the further conductor, which enables even better monitoring.

The further electrical parameter can be physically or electrically of the same type as the parameter. The designation “further” only serves to distinguish it from the parameter already mentioned above. The other one However, electrical parameters can also be of a different type physically or electrically.

The further conductor is in particular an electrical conductor which runs through the wall and is preferably electrically insulated from other electrically conductive components, in particular the conductor. The further electrical conductor can in particular be embedded in an electrically insulating matrix material of the wall.

The further conductor can in particular run further inside than the conductor. This makes it possible to identify if or whether damage extends to the depth in which the further conductor extends. Deeper damage will typically also damage the lower-lying further conductor and the evaluation unit can determine this. The further electrical parameter will in particular only change if the damage is so deep that it reaches the further electrical conductor and damages it in the same way or changes one of its measurable properties in a measurable way. This can be done in particular by joint evaluation with the conductor, as will be described in more detail below.

The further conductor can in particular run at a distance of 2 mm to 4 mm, or in particular 3 mm, below an outer surface of the wall. It can therefore run further inward than the conductor, which has already been mentioned above.

In particular, the conductor can run in a straight line or spiral shape with respect to a longitudinal axis of the pressure vessel. For example, it can run along a circumference or along a longitudinal axis of the pressure vessel. If it runs in a spiral, a larger surface area can advantageously be covered with just one conductor.
The further conductor can run in a straight line or in a spiral shape, in particular with respect to a longitudinal axis of the pressure vessel. For example, it can run along a circumference or along a longitudinal axis of the pressure vessel. If it runs spirally or in windings, a larger surface area can advantageously be covered with just one conductor.

In particular, a distance between windings of the electrical conductor and / or of the further electrical conductor can be at most 5 mm. This can apply in particular axially, i.e. viewed in a longitudinal axis of the pressure vessel. In this way, an axial resolution that is sufficient or good for typical purposes can be achieved. The same can apply to the distance between separate conductors or additional conductors.

The electrical parameter can in particular be a resistance or an inductance. The further electrical parameter can in particular be a resistance or an inductance. For example, in the case of an undamaged wall, a resistance of the conductor or of the further conductor can be very low. If the conductor or the further conductor is damaged, the resistance increases considerably, and in the event of severing up to the impossibility of further current flow. As an alternative to the resistance, an inductance can also be evaluated.

The evaluation unit is preferably configured to detect damage to the pressure vessel in the event of a change in the electrical parameter that is greater than a threshold value. The threshold value can, for example, be specified relatively or absolutely. A change in the electrical parameter indicates that damage, in particular mechanical damage, has reached the conductor.

The evaluation unit is preferably configured to detect deep damage in the event of a change in the further electrical parameter that is greater than a further threshold value. The further threshold value can, for example, be specified relatively or absolutely. A change in the further electrical parameter indicates that damage, in particular mechanical damage, has reached the further conductor. As already mentioned above, the further conductor is in particular lower than the conductor, so that a change in the further electrical parameter indicates a correspondingly deep damage. Damage and deep damage can be implemented, for example, in the form of variables or other logical elements in the evaluation unit and can, for example, cause specific consequences.

The evaluation unit can in particular be configured to output a warning when damage is detected and / or when deep damage is detected. This can be output optically, acoustically or via a telemetry system, for example. In this way, for example, the driver of a motor vehicle can be requested to visit a workshop in order to have the pressure vessel checked.

The evaluation unit can in particular be configured to prevent the pressure vessel from being refueled if damage is detected and / or if deep damage is detected. If the severity of the damage gives rise to this, a tightened safety measure can be initiated which ensures that the pressure vessel is no longer under one higher pressure than currently available is set, so that, for example, a bursting of the pressure vessel due to the deep damage when the pressure is increased during refueling can be prevented.

According to a preferred embodiment, the pressure vessel system also has a memory, specifically in particular for storing a measured electrical parameter and / or further electrical parameter and / or recognized damage and / or recognized deep damage. Values can thus be stored directly in a memory of the pressure vessel system, which enables particularly reliable monitoring over the service life and makes manipulation more difficult. The memory can in particular be an RFID memory.

In particular, an identifier or a “fingerprint” of the undamaged pressure vessel can be stored in the memory. In addition, permissible deviations from the new condition can be stored. The evaluation unit then measures the electrical parameters, for example, and always has the correct individual basic data available. It is also advantageous to store the latest measured value back in the storage unit of the tank. A downstream user can thus understand the history of the pressure vessel.

It is preferred to use a data security facility that ensures that the data is not misused, incorrectly written, overwritten or deleted.

A unit accommodating the pressure vessel system, for example a motor vehicle, should preferably be able to determine the integrity of the data and only allow the application of pressure if it has been positively determined and confirmed.

• - Messen eines elektrischen Parameters eines Leiters, welcher in einer Wandung des Druckbehälters verläuft, und
• - Erkennen einer Beschädigung basierend auf einer Änderung des elektrischen Parameters.

The technology disclosed here also relates to a method for detecting damage to a pressure vessel, which has the following steps:

• - Measuring an electrical parameter of a conductor which runs in a wall of the pressure vessel, and
• - Detection of damage based on a change in the electrical parameter.

This takes place in particular on the assumption that the damage to the container causes damage to or a change in a property of the conductor at the same time.

Damage to a pressure vessel can thus be recognized in an advantageous manner, as has already been described above with reference to the pressure vessel system disclosed here. Reference is made to the above statements.

In particular, the damage can be recognized if the change in the electrical parameter goes beyond a permissible level.

• - Messen eines weiteren elektrischen Parameters eines weiteren Leiters, welcher in der Wandung innenliegend zum Leiter verläuft, und
• - Erkennen einer tiefen Beschädigung basierend auf einer Änderung des weiteren elektrischen Parameters.

According to a preferred embodiment, the method has the following steps:

• - Measuring a further electrical parameter of a further conductor, which runs in the wall inside the conductor, and
• - Detection of deep damage based on a change in the further electrical parameter.

In this way, damage of different severity can be distinguished from one another, as has already been explained above.

In particular, the deep damage can be recognized if the change in the further electrical parameter goes beyond a permissible level.

According to a preferred embodiment, a warning is output when damage is detected and / or when deep damage is detected. In this way, a driver can be informed of damage and, for example, be prompted to visit a workshop.

According to a preferred embodiment, if damage is detected and / or if deep damage is detected, refueling of the pressure vessel is prevented. In particular, this can be done when deep damage is detected. In this way, in the event of deep damage, which is more likely to be a safety hazard, an increase in the pressure in the pressure vessel due to refueling can be prevented.

According to a preferred embodiment, a measured electrical parameter and / or further electrical parameters and / or a recognized damage and / or a recognized deep damage is stored in a memory of the pressure vessel. Monitoring of the pressure vessel can thus be made possible in an advantageous manner. Because they are stored in the pressure vessel, manipulation of this data is made much more difficult.

With the technology disclosed here, in particular, non-destructive monitoring and checking of pressure vessels is possible. It is not necessary to remove the pressure vessel for this. In particular, the technology disclosed here for pressure vessels of type III or type IV, however can also be used for other types of pressure vessels.

The wall can in particular be designed as a fiber-reinforced layer.

In other words, mechanical damage to a COPV (Composite Overwrapped Pressure Vessel) can sever a thin metallic and insulated wire that is incorporated into the COPV close to the surface. This severance can be determined electrically (continuity, determination of the inductance of the coil created by the winding). This signal is evaluated by control electronics. This information is requested and used to enable operation. If the test reveals that the intactness of the wire has changed compared to the target state, it can be assumed that the wire has been severed, caused by mechanical damage. Depending on the severity of the damage, continued operation may be permitted, but subsequent refueling should preferably be blocked and a corresponding warning / information given to the driver.

To detect slight mechanical damage, for example, a wire is introduced radially at a shallow depth (preferably 1 mm from the outer surface) during the manufacturing process of the COPV. This wire is preferably strong enough not to tear robustly during the production of the COPV, and thin enough to reliably tear in the event of slight mechanical damage to the COPV. The detection of light (up to 1 mm penetration depth) and severe (penetration depth greater than 3 mm) damage is particularly valuable. In order to recognize this, for example, a second wound wire is introduced at a greater depth and read out using the readout mechanisms mentioned below.

A continuity test can be carried out in particular with contacts that are led to the outside. At the externally accessible contacts, the inserted winding can be checked for electrical continuity using a resistance measurement signal. If continuity can be determined, no mechanical damage can be assumed. If no electrical continuity can be determined, at least slight mechanical damage can be assumed. The difference between the electrical conductivity of the wire used and the COPV base material is so great that a clear assignment of the passage measurement is possible.

Alternatively, for example, a wire wrap around the cylindrical storage container can be used. This electrically represents a coil with an inductance. It has a characteristic damping behavior in an alternating electric field. It is therefore possible to read out this damping behavior as a characteristic fingerprint from the vehicle (or from a test device when it is removed). The comparison with the target value (= undamaged winding) is carried out, for example, by comparing it with the initial data stored in the vehicle and, in the dismantled state, with the data stored in the RFID chip.

• - In RFID-Speicher am Tank: Das Ergebnis der Durchgangsprüfung wird mit Zeitstempel in dem am Tank verfügbaren RFID Chip dauerhaft gespeichert, damit diese Information auch nach Ausbau aus dem Fahrzeug verfügbar ist.
• - Per connected-Funktionalitäten wird das Ergebnis der Zustandserkennung an ein Backend übermittelt.
• - Ein Speicher für den e-call (Telemetriefunktion) wird mit dem Ergebnis der Zustandserkennung belegt.

A permanent storage of the status detection can take place, for example, as follows:

• - In RFID memory on the tank: The result of the continuity test is permanently stored with a time stamp in the RFID chip available on the tank, so that this information is also available after removal from the vehicle.
• - The result of the status detection is transmitted to a backend via connected functionalities.
• - A memory for the e-call (telemetry function) is occupied with the result of the status detection.

• - Zuverlässige Erkennung mechanischer Schädigungen.
• - Vermeidung der Notwendigkeit den ganzen COPV auszubauen um die Inspektion durchführen zu können.
• - Direkte Koppelbarkeit der Zustandserkennung mit Fahrfreigabe-Logik des Fahrzeugs.
• - Möglichkeit der Sperrung der Betankungsfreigabe bei negativem Ergebnis.

In particular, the following advantages are achieved with the technology disclosed here:

• - Reliable detection of mechanical damage.
• - Avoidance of the need to expand the entire COPV in order to be able to carry out the inspection.
• - The status recognition can be directly coupled with the vehicle's drive release logic.
• - Possibility of blocking the refueling approval in the event of a negative result.

• 1: ein Druckbehältersystem in einer Querschnittsansicht, und
• 2: einen Teil des Druckbehältersystems mit schematischen Beschädigungen.

The technology disclosed here will now be described with reference to the figures. Show:

• 1 : a pressure vessel system in a cross-sectional view, and
• 2 : Part of the pressure vessel system with schematic damage.

1 shows purely schematically a pressure vessel system 5 in a cross-sectional view. The pressure vessel system 5 has a pressure vessel 10 on. This has a wall 20th on which an interior 15th of the pressure vessel 10 encloses. In the interior 15th Pressurized gaseous fuel such as hydrogen or natural gas can be stored.

The wall 20th is formed in the present case from a fiber composite material. In the wall 20th are a leader 30th and another leader 40 arranged, which spirally through the wall 20th run and are electrically conductive. As shown is the other conductor 40 further inside than the ladder 30th arranged. Both leaders 30th , 40 are with an evaluation unit 50 of the pressure vessel system 5 connected, the connections shown are to be understood here only schematically, ie they can also be designed with two wires, for example.

The pressure vessel system also has a memory 60 on. This is with the evaluation unit 50 tied together.

The evaluation unit 50 is designed and configured to continuously monitor electrical parameters such as electrical resistance and / or inductance of the two conductors 30th , 40 to measure and evaluate. Different types of damage can be recognized on the basis of changes in the electrical parameters.

2 shows the pressure vessel 10 in a perspective view. There are two different types of wall damage 20th drawn.

The damage S1 represents a long, flat cut. This extends to a depth that the ladder 30th is severed, but not the other conductor 40 which is further inside. With such a cut, only the change in an electrical parameter of the electrical conductor is achieved 30th , but not further electrical conductors 40 from the evaluation unit 50 recognized. The evaluation unit 50 thus detects damage, but not deep damage. In such a case, in particular, a warning can be issued to a driver of a motor vehicle that he should visit a workshop and the pressure vessel 10 should be checked.

The damage S2 represents a short, deep cut. This extends to a depth that both the head 30th as well as the other leader 40 be severed. The electrical parameters of both the conductor change accordingly 30th as well as the other head 40 . The evaluation unit recognizes accordingly 50 in this case deep damage. Since this is usually more dangerous, not only is a warning issued in this case, but the pressure vessel is also refueled 10 prevented. In this case, a more drastic measure in terms of security can be taken in this case.

For reasons of legibility, the expression “at least one” has been partially omitted for the sake of simplicity. If a feature of the technology disclosed here is described in the singular or indefinitely (e.g. the / a pressure vessel, the / a memory, etc.), the plurality of these should also be disclosed at the same time (e.g. the at least one pressure vessel, the at least one memory , Etc.).

The preceding 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 without departing from the scope of the invention and its equivalents.

List of reference symbols

5

Pressure vessel system

10

pressure vessel

15th

inner space

20th

Wall

30th

ladder

40

another leader

50

Evaluation unit

60

Storage

S1

damage

S2

damage

Claims (15)

Pressure vessel system (5), comprising - At least one pressure vessel (10) with a wall (20), - At least one conductor (30) which runs through the wall (20), and - An evaluation unit (50) which is configured to measure an electrical parameter of the conductor (30). Pressure vessel system (5) Claim 1 - wherein the conductor (30) runs at a distance of 0.5 mm to 1.5 mm, or 1 mm, below an outer surface of the wall. Pressure vessel system (5) Claim 1 or 2 - which has a further conductor (40) which runs through the wall (20), - wherein the evaluation unit (50) is configured to measure a further electrical parameter of the further conductor (40). Pressure vessel system (5) Claim 3 , - wherein the further conductor (40) extends further inward than the conductor (30). Pressure vessel system (5) Claim 3 or 4th - wherein the further conductor (40) runs at a distance of 2 mm to 4 mm, or 3 mm, below an outer surface of the wall (20). Pressure vessel system (5) according to one of the preceding claims, - wherein the conductor (30) extends in a straight line or spirally with respect to a longitudinal axis of the pressure vessel (10), and or - wherein the further conductor (40) extends in a straight line or spirally with respect to a longitudinal axis of the pressure vessel (10). Pressure vessel system (5) according to one of the preceding claims, - where the electrical parameter is a resistance or an inductance, and or - The further electrical parameter being a resistance or an inductance. Pressure vessel system according to one of the preceding claims, - The evaluation unit (50) being configured to detect damage to the pressure vessel (10) in the event of a change in the electrical parameter that is greater than a threshold value. Pressure vessel system according to Claim 3 or a claim dependent thereon, - wherein the evaluation unit (50) is configured to detect deep damage in the event of a change in the further electrical parameter that is greater than a further threshold value. Pressure vessel system according to Claim 8 or 9 - wherein the evaluation unit (50) is configured to output a warning in the event of a recognized damage and / or in the event of a recognized deep damage, and / or - the evaluation unit (50) being configured to output a warning in the event of a recognized damage and / or in the event of to prevent the pressure vessel (10) from being refueled in the event of deep damage being detected. Pressure vessel system (5) according to one of the preceding claims, - which also has a memory (60) for storing a measured electrical parameter and / or a further electrical parameter and / or a recognized damage and / or a recognized deep damage. Method for detecting damage to a pressure vessel (10), comprising the following steps: - Measuring an electrical parameter of a conductor (30) which runs in a wall (20) of the pressure vessel (10), and - Detection of damage based on a change in the electrical parameter. Procedure according to Claim 12 which further comprises the following steps: - measuring a further electrical parameter of a further conductor (40), which runs in the wall inside the conductor (30), and - recognizing a deep damage based on a change in the further electrical parameter. Procedure according to Claim 12 or 13th - where a warning is output when damage is detected and / or deep damage is detected, and / or - where the pressure vessel (10) is prevented from refueling when damage is detected and / or when deep damage is detected. Method according to one of the Claims 12 until 14th - wherein a measured electrical parameter and / or further electrical parameters and / or a recognized damage and / or a recognized deep damage is stored in a memory (60) of the pressure vessel (10).

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