DE102016216572A1 - Method for monitoring a pressure vessel system in a vehicle and pressure vessel system in a vehicle - Google Patents

Abstract

A method for monitoring a pressure vessel system (10) in a vehicle is shown, wherein the pressure vessel system (10) comprises a pressure vessel (20) for storing a fuel, in particular hydrogen, wherein the pressure vessel (20) comprises an inner vessel (23) for Storing the fuel, comprising an outer container (22) and an evacuated space (25) for thermal insulation disposed between the inner container (23) and the outer container (22), comprising the steps of: detecting the pressure in the space (25) at a first time and at a second time, the second time being later than the first time; Comparing the pressure increase per unit time between the first time and the second time with a maximum rise value and / or comparing the detected pressure at the first time and / or the second time with a pressure limit; Determining that the gap (25) no longer performs a thermal isolation function when the pressure rise per unit time is above the maximum rise value and / or the sensed pressure is above the pressure threshold at the first time and / or at the second time; and generating an indication signal when it is determined that the gap (25) no longer satisfies a thermal insulation function.

Description

The invention relates to a method for monitoring a pressure vessel system in a vehicle and a pressure vessel system in a vehicle.

High-pressure gas tank systems (also called "CGH2 systems") are designed to permanently heat fuel at ambient temperatures at a pressure of about 350 bar (= overpressure relative to the atmospheric pressure), furthermore preferably above about 500 bar and more preferably above about 700 to save cash.

Cryogenic pressure vessel systems (also called "CcH2 systems") are known from the prior art. For example, the EP 1 546 601 B1 such a system.

Cryogenic pressure vessels for storing fuel, particularly hydrogen, include an outer vessel, an inner vessel for storing the fuel, and an evacuated space for thermal insulation between the outer vessel and the inner vessel. Due to the heat insulation in the form of the evacuated interspace, the amount of heat input from the environment into the fuel in the inner container is kept low.

The thermal insulation ensures that the cryogenic fuel heats up only very slowly. With the heating of the fuel, the pressure of the fuel in the cryogenic pressure vessel or in the inner container increases. Upon reaching a pressure limit or exceeding the pressure limit / maximum pressure or the maximum operating pressure of the pressure vessel, fuel from the pressure vessel in the environment or environment must be drained, otherwise under unfavorable circumstances, damage to the pressure vessel threatens.

If air or gas penetrates into the evacuated space, z. B. by a hole or a leak, the vacuum in the space is destroyed or deteriorated. This leads to a (possibly sudden or rapid) pressure increase in the gap. As a result, the heat input per unit time or the amount of heat flow from the environment in the fuel in the pressure vessel increases. Consequently, the pressure of the fuel increases until under certain circumstances a maximum operating pressure of the pressure vessel is reached or (minimally) exceeded. Then, fuel must be drained from the pressure vessel by a pressure relief device from the pressure vessel to exclude under unfavorable circumstances possible damage to the pressure vessel. The pressure relief device may, for. B. include a safety valve and / or a rupture disc. By discharging fuel from the pressure vessel into the environment upon reaching the maximum operating pressure of the pressure vessel can under unfavorable circumstances, especially in confined spaces, a fuel-air mixture with fire and / or explosion and / or suffocation arise. The loss of vacuum in the gap may pass unnoticed (for the driver and the environment), so that the discharge of fuel due to the heating of the fuel in the pressure vessel by the environment takes place surprisingly or unexpectedly. The driver or persons in the vicinity of the vehicle can therefore not take appropriate protective measures or bring them to safety.

It is a preferred object of the technology disclosed herein to reduce or eliminate at least some of the disadvantages of the previously known solutions. Other preferred objects may result from the beneficial effects of the technology disclosed herein. The object (s) is / are solved by the subject matter of claim 1 of the independent claims and by the subject-matter of claim 10 of the independent claims. The dependent claims are preferred embodiments.

In particular, the object is achieved by a method for monitoring a pressure vessel system in a vehicle, wherein the pressure vessel system comprises a pressure vessel for storing a fuel, in particular hydrogen, wherein the pressure vessel an inner container for storing the fuel, an outer container and between the inner container and comprising an evacuated space for heat insulation arranged in the outer container, comprising the steps of: detecting the pressure in the space at a first time and at a second time, the second time being later than the first time; Comparing the pressure increase per unit time between the first time and the second time with a maximum rise value and / or comparing the detected pressure at the first time and / or the second time with a pressure limit; Determining that the gap no longer satisfies a thermal insulation function when the pressure rise per unit time is above the maximum rise value and / or the detected pressure is above the pressure threshold at the first time and / or at the second time; and generating a notification signal if it is determined that the gap no longer fulfills a thermal insulation function.

An advantage of this is that, upon detection that the heat-insulating function of the gap is no longer present or the gap has a relatively high pressure, therefore no longer has a vacuum and therefore has only a low heat insulation function and / or the vacuum in a very short period of time (eg, less than 10 seconds or less than 1 second) has been destroyed or deteriorated rapidly, an alert signal is generated and based on the indication signal corresponding protection reactions or safeguards can be performed. This increases the safety of the pressure vessel system. Thus, a loss of vacuum or vacuum vacancy deterioration and / or a rapid increase in pressure (eg, less than 1 second) above a predetermined maximum rise in the pressure in the gap may be reacted based on the strobe signal. The pressure rise may be determined by forming a ratio between the difference between the pressure in the gap at the second time and the pressure in the gap at the first time and the difference between the second time and the first time: Pressure increase = (p _{at time t2} -p _{at time t1} ) / (t2-11)

The statement that the space no longer satisfies a heat-insulating function also includes that the space still has a small heat-insulating function. Important for determining that the gap no longer fulfills any thermal insulation function is that the gap no longer has (high) vacuum for thermal insulation or threatens to do so in the near future. The gap may have mechanical elements for thermal insulation. If the gap no longer has a vacuum or a sufficiently good / high vacuum, this is considered to be "the gap no longer fulfills any thermal insulation function".

The pressure limit may be a fixed value of the pressure in the gap, e.g. 1 × 10 ^-3 mbar or 1 × 10 ^-4 mbar or 1 × 10 ^-5 mbar. It is also conceivable that the pressure limit depends on the ambient temperature or outside temperature. The pressure limit may depend on the pressure in the gap in the initial presence of the vacuum (ideal state). If the vacuum in the desired or ideal state z. B. has a residual pressure of 1 · 10 ^-6 mbar, the pressure limit is 1 · 10 ^-4 mbar. The pressure limit may also be in fixed proportion to the original (target) pressure in the gap. The ratio between the original pressure / target pressure and pressure limit can be z. For example, about 1 × 10 ^-4 , about 1 × 10 ^-3 , about 1 × 10 ^-2, or about 1 × 10 ^-1 .

The maximum rise value can be z. 1 × 10 ^-1 mbar / second or 1 × 10 ^-2 mbar / second or 1 × 10 ^-3 mbar / second. Other values are conceivable The pressure in the gap may be measured at predetermined intervals (eg ten times per second or once per second) or at other time intervals. The period between the first time and the second time may, for. 1/100 second, 1/10 second, half second, one second, 10 seconds or 30 seconds.

By recognizing that the vacuum has worsened / has been destroyed or has deteriorated rapidly, it can thus already be anticipated or, at an early point in time, already be assumed that the (predetermined) pressure limit value will be reached or exceeded.

The method may further comprise the steps of: detecting the temperature and pressure of the fuel in the pressure vessel; Determining the density of the fuel in the pressure vessel based on the sensed temperature and the sensed pressure; Comparing the density with a density value, the density value being dependent on the ambient temperature; and determining whether the fuel density is supercritical or subcritical depending on the result of comparing the density with the density value. One advantage of this is that, depending on whether there is a supercritical density of fuel in the pressure vessel or a subcritical density of fuel in the pressure vessel, different protection reactions can be taken. A subcritical density of fuel in the pressure vessel is present when no fuel has to be vented from the pressure vessel into the environment at a thermal equilibrium state between the fuel and the environment. That is, when the fuel in the pressure vessel has reached the temperature of the environment, the pressure of the fuel in the pressure vessel is below the maximum operating pressure of the pressure vessel, so that no fuel has to be vented from the pressure vessel into the environment. This equilibrium state corresponds to the storage of warm fuel (eg CGH2). A supercritical density of fuel in the pressure vessel is present when fuel must be discharged from the pressure vessel into the environment at a thermal equilibrium state between the fuel in the pressure vessel and the environment. That is, when the fuel in the pressure vessel has reached the temperature of the environment or during the adjustment of the temperature of the fuel in the pressure vessel the ambient temperature, is the pressure of the fuel at or above the maximum operating pressure of the pressure vessel, so that fuel must be vented from the pressure vessel.

On the hint signal, the removal of fuel from the pressure vessel can be prevented. This can be safely prevented that a (stationary) vehicle that is in a safer environment, eg. B. outdoors, is moved. This prevents the vehicle from being moved into a less safe environment (eg a closed space such as a garage or a tunnel). A time-delayed removal prevention can also take place. In this way, the vehicle can still be parked safely (eg outdoors).

In response to the indication signal, the removal of fuel from the pressure vessel may be increased when the energy generated by the removed fuel in a fuel consuming device is dissipatable. As a result, in particular when there is a supercritical density of the fuel in the pressure vessel, more fuel than usual or normal can be consumed. This prevents deflation of fuel or decreases the amount of fuel that may need to be drained. If the fuel consumption device z. B. is a fuel cell, it must be checked whether the electric power generated by the increased consumption of fuel converted into heat, used to drive the vehicle and / or stored in a buffer (battery, capacitor or the like). If the or the energy generated by the increased consumption of fuel or electric power is not dissipatable, d. H. is not consumable, storable or the like, no increased removal of fuel is performed. In this situation, one (or more) corresponding converter circuit (eg, DC / DC (battery charger or fuel cell converter) or DC / AC converter (traction motor)), as an electronic load, may also supply the electrical load to the fuel cell.

On the hint signal, an optionally occurring filling process of the pressure vessel can be terminated with fuel. This prevents that further fuel is introduced into the pressure vessel. Thus, the density of the fuel in the pressure vessel is prevented from increasing from a subcritical density to a supercritical density, which may result in the discharge of fuel into the environment. In addition, fuel is saved because no fuel that may need to be discharged later in the environment, is introduced into the pressure vessel.

An audible and / or visual and / or haptic warning signal can be generated in response to the warning signal, with the warning signal being perceptible inside and / or outside the vehicle. An advantage of this is that the driver or persons in the vicinity of the vehicle are informed about the failure or rapid deterioration of a vacuum in the gap. In addition, the warning signal may change or intensify if a discharge of fuel from the pressure vessel due to an excessive pressure of the fuel in the pressure vessel is imminent (especially at a supercritical fuel density in the pressure vessel). Immediately imminent may mean, in particular, that within the next 10 minutes, the next 5 minutes or within the next minute, fuel must be released from the pressure vessel into the environment. By announcing or warning people can move away from the vehicle. This increases security.

On the hint signal, a future filling of the pressure vessel with cryogenic fuel can be prevented. In this way, in particular with a subcritical density of the fuel in the pressure vessel, the filling with non-cryogenic fuel continues to be allowed and at the same time the filling with cryogenic fuel is prevented. In this way, the vehicle continues to be able to drive and the pressure vessel can be filled with fuel, without there being any discharge of fuel into the environment.

On the hint signal, a future filling process of the pressure vessel can be terminated when the density of the pressure vessel has reached a maximum density value, wherein the density maximum value is dependent in particular on the ambient temperature. In this way, in particular with a subcritical density of the fuel in the pressure vessel, it is achieved that the vehicle continues to be refillable / fuelable while, at the same time, preventing the discharge of fuel into the environment. The maximum density value may be a predetermined maximum density value. The maximum density value may be the critical fuel density, i. H. the threshold between the subcritical density of fuel and the supercritical density of fuel.

In response to the warning signal, the vehicle can be prevented from entering a closed space, in particular a garage and / or a tunnel, in particular by reducing the power of the drive of the vehicle and / or by activating the brakes of the vehicle. As a result, a discharge of fuel in a sealed room, for. B. (low) garage or Tunnel, prevented. In particular, in a closed room, it can be when draining the fuel, for. As hydrogen, under unfavorable circumstances come to an explosive or combustible fuel-air mixture. In addition, under unfavorable circumstances, in a closed room, by displacing the breathing air, a person can suffocate while discharging fuel into the environment. By reducing the power, the vehicle can be brought to a standstill slowly. The driver can, when the vehicle is on a highway, drive the vehicle on the hard shoulder of a highway before stopping. This is particularly useful if it is recognized that the vehicle will enter a tunnel. If there is no exit from the highway in front of the tunnel, it can be assumed that the vehicle will drive into the tunnel. When lowering or decreasing the power of the vehicle (eg, by decreasing the fuel supply to a fuel consuming device / fuel cell for driving the vehicle), the hazard warning lights may be activated. If it is detected that the vehicle is about to retract (for example, is already on the ramp) in a (low) garage, the brakes of the vehicle are activated so that the vehicle can not drive into the garage. Thus, it is prevented that a discharge of fuel takes place in a closed space. The position of the vehicle or the planned route can be determined by means of the navigation system. In addition, the lowering of the power or the activation of the brakes can be communicated to the driver by optical, acoustic and / or haptic warning signals and / or displays.

It is also conceivable that the driver is warned against entering the warning signal to enter a parking garage / garage and / or a tunnel, or is requested to park and leave the vehicle at a safer place. If the driver does not acknowledge this warning or does not confirm the reading of the warning, as described above, the vehicle is prevented from entering a closed space, in particular a garage and / or a tunnel. For this purpose, z. B. the above-described lowering or reducing the performance can be performed. If the driver acknowledges the warning or confirms the reading of the warning, it may be possible to refrain from reducing the power, ie. H. the driver has the full power (again) available. As a result, the driver can be given greater freedom of choice.

In particular, the object is achieved by a pressure vessel system in a vehicle, the pressure vessel system comprising: a pressure vessel for storing a fuel, in particular hydrogen, the pressure vessel having an inner vessel for storing the fuel, an outer vessel and an evacuated vessel located between the inner vessel and outer vessel A space for heat insulation comprises, a pressure measuring device for detecting the pressure in the gap at a first time and at a second time, wherein the second time is temporally after the first time, and a controller for comparing the pressure increase per unit time between the first time and second time with a maximum rise value and / or to compare the detected pressure at the first time and / or the second time with a pressure limit, to determine that the gap no Wärmeisolierungsfun ction more satisfied when the pressure rise per unit time is above a maximum rise value and / or the detected pressure at the first time and / or the second time above the pressure limit, and for generating an indication signal when it is determined that the gap no longer fulfills a thermal insulation function.

An advantage of this is that, upon detection that the heat-insulating function of the gap is no longer present or the gap due to the relatively high pressure no longer has a vacuum and therefore has only a low heat insulation function and / or the vacuum in a very short period of time (z B. less than 10 seconds or less than 1 second) has been destroyed, a warning signal is generated and on the basis of the warning signal corresponding protective reactions or safeguards can be performed. This increases the safety of the pressure vessel system. In particular, a loss of vacuum or a deterioration of the vacuum in the intermediate space and / or a rapid increase in pressure (for example within less than 1 second) in the intermediate space can thus be reacted on the basis of the warning signal. The pressure rise is determined by forming a ratio between the difference between the pressure at the first time and the pressure at the second time and the difference between the second time and the first time: Pressure increase per unit time = (p _{at time t2} -p _{at time t1} ) / (t2-t1)

The fuel may be a gaseous fuel (at standard pressure of 1,000 bar and standard temperature of 0 ° C), in particular hydrogen, liquefied petroleum gas (LPG), liquefied natural gas (LNG) or compressed natural gas (CNG).

In response to the indication signal, the corresponding measure (immediately afterwards) can be initiated or carried out on the basis of the generation of the notification signal. In particular conceivable that the warning signal initiates the appropriate action or reaction. In response to the hint signal, it may also mean that certain actions (refueling with cryogenic fuel, etc.) are prevented after generating the notification signal.

In a service facility and / or workshop, the pressure vessel system can be reset again, so that measures that have been initiated or carried out or carried out (eg prevention of the filling with cryogenic fuel) have been terminated (eg. B. refueling with cryogenic fuel is possible again).

The evacuated gap (in the normal state or ideal state) has a high vacuum when the gap meets the thermal insulation function.

The technology disclosed herein relates to a compressed hydrogen storage (CHS) system for storing gaseous fuel under ambient conditions. Such a pressure vessel is in particular a pressure vessel which is installed or can be installed in a motor vehicle. The pressure vessel can be used in a motor vehicle, which is operated for example with compressed ("compressed natural gas" = CNG) or liquefied (LNG) natural gas or with hydrogen. Such a pressure vessel may be, for example, a cryogenic pressure vessel (= CcH2 system) or a high-pressure gas vessel (= CGH2 system).

High-pressure gas container systems (= CGH2 systems) are designed, essentially at ambient temperatures, fuel (eg hydrogen) permanently at a max. Operating pressure (also called maximum operating pressure or MOP) of about 350 barü (= overpressure relative to the atmospheric pressure), further preferably of about 500 barü and more preferably of about 700 barü store.

The cryogenic pressure vessel system (= CcH2 system) comprises a cryogenic pressure vessel. The cryogenic pressure vessel may store fuel in the liquid or supercritical state. A supercritical state of aggregation is a thermodynamic state of a substance which has a higher temperature and a higher pressure than the critical point. The critical point denotes the thermodynamic state in which the densities of gas and liquid of the substance coincide, that is, it is single-phase. While one end of the vapor pressure curve in a pT diagram is marked by the triple point, the critical point represents the other end. For hydrogen, the critical point is 33.18 K and 13.0 bar. A cryogenic pressure vessel is particularly suitable for storing the fuel at temperatures significantly below the operating temperature (meaning the temperature range of the vehicle environment in which the vehicle is to be operated) of the motor vehicle, for example at least 50 Kelvin, preferably at least 100 Kelvin or At least 150 Kelvin below the operating temperature of the motor vehicle (usually about -40 ° C to about + 85 ° C). The fuel may be, for example, hydrogen, which is stored at temperatures of about 34 K to 360 K in the cryogenic pressure vessel. The cryogenic pressure vessel may in particular comprise an inner container which is designed for max. Operating pressures (also called maximum operating pressure or MOP) to about 350 barü (= overpressure relative to the atmospheric pressure), preferably up to about 500 barü, and particularly preferably up to about 700 barü. The fuel is stored in the inner container. The outer container preferably closes off the pressure vessel to the outside. Preferably, the cryogenic pressure vessel comprises a vacuum with an absolute pressure in the range of 10 ^-9 mbar to 10 ^-1 mbar, further preferably from 10 ^-7 mbar to 10 ^-3 mbar and particularly preferably from about 10 ^-5 mbar that at least partially between the inner container and the outer container in an evacuated (intermediate) space or vacuum V is arranged. Storage at temperatures (just) above the critical point has the advantage over storage at temperatures below the critical point that the storage medium is present in a single phase. For example, there is no interface between liquid and gaseous.

The technology disclosed herein will now be explained with reference to the figure. It shows:

1 a schematic view of the pressure vessel system disclosed here.

The pressure vessel system 10 includes a pressure vessel 20 for storing a cryogenic fuel, in particular hydrogen. The fuel may be from the pressure vessel 20 a fuel cell, which is used to drive the vehicle, in which the pressure vessel system 10 and the fuel cell are arranged is formed.

The pressure vessel 20 includes an outer container 22 , an inner container 23 for storing the fuel and an evacuated space 25 between the outer container 22 and the inner container 23 , The evacuated space 25 or the vacuum in the gap 25 serves to heat insulation of the inner container 23 against the environment. Thereby, the heat quantity input per unit time from the environment in the fuel in the inner container 23 kept low.

If the vacuum deteriorates and / or collapses or is destroyed within a short period of time (eg, less than 1 minute or less than 10 seconds), because air or gas or liquid enters the gap 25 penetrates, this causes the gap 25 no longer the function of a heat insulation of the inner container 23 exercises. Therefore, the fuel in the inner container heats up 23 by heat input from the environment quite quickly.

The pressure vessel system 10 also includes a fuel consumption device 40 , z. As a fuel cell, for driving the vehicle. The fuel consumption device 40 is via a fluid line 30 in which a tank shut-off valve 35 is arranged with the pressure vessel 20 connected. The tank shut-off valve 35 is from the controller 50 via a control line 70 controlled or opened and closed.

A control device 50 of the pressure vessel system 10 measures by means of a pressure measuring device 60 the pressure in the gap 25 between outer container 22 and inner container 23 , The pressure is from the controller 50 at least at a first time and at a second time, which is later than or after the first time, measured. The control device 50 saves the measured pressure values. In addition, the control device forms 50 a ratio (pressure increase per unit of time) between the pressure difference between the two times and the time between the two times. The pressure increase per unit time is determined as follows: Pressure increase per unit time = (p ₂ - p ₁ ) / (t ₂ - t ₁ ) t ₂ is the second time;
t ₁ is the first time;
p ₂ is the pressure in the gap at the second time;
p ₁ is the pressure in the gap at the first time.

If the pressure p1 and / or p2 is above a pressure limit, or / and the pressure rise is above a pressure increase value or a maximum increase value, the controller stops 50 notice that the gap 25 no longer fulfills the thermal insulation function. If the pressure is above a pressure limit, or / and the pressure rise is above the maximum rise value, it means that the vacuum in the gap is no longer present and / or has deteriorated rapidly or has been destroyed.

A condition (besides, or alternatively, the pressure rise above, or alternatively, the pressure rise value) for determining that the gap no longer performs a heat-insulating function is that the pressure (at the first and / or second time) is above a pressure threshold (e.g. 1 mbar, 2 mbar, 5 mbar or 20 mbar). The pressure limit can be fixed.

Without thermal insulation function (ie without high vacuum) or with only very low heat insulation function by mechanical elements in the intermediate space, the temperature of the fuel in the inner container increases 23 quickly, which increases the pressure of the fuel. When the pressure of the fuel reaches the maximum operating pressure of the pressure vessel 20 reaches or exceeds fuel needs from the pressure vessel 20 be drained to prevent damage to the pressure vessel 20 to prevent. A boil-off / blow-off management (BMS) system, if present, can only convert a small amount of fuel per unit of time. The additional amount of fuel per unit of time passes directly into the environment or environment.

When the controller 50 determines that the gap 25 no longer fulfills any thermal insulation function is provided by the controller 50 generates a warning signal. On the hint signal various protective reactions or protective measures can be carried out, which is a discharge of fuel from the pressure vessel 20 into the environment through a pressure relief device, such. As a safety valve and / or a rupture disk, reduce the amount of fuel drained or reduce the negative consequences or risks when discharging the fuel.

The protective reactions or protective measures can be taken depending on whether a supercritical or subcritical density of fuel in the pressure vessel 20 is present when the alert signal is generated. A subcritical density of fuel in the pressure vessel 20 is present when in a thermal equilibrium state between the fuel and the environment no fuel from the pressure vessel 20 must be drained. That is, when the fuel has reached the temperature of the environment (= thermodynamic equilibrium state), the pressure of the fuel is below the maximum operating pressure of the pressure vessel 20 , so no fuel from the pressure vessel 20 must be drained. A supercritical density of fuel in the pressure vessel 20 is present when fuel in a thermal equilibrium state between fuel and environment from the pressure vessel 20 must be drained. That is, when the fuel has reached the temperature of the environment, the pressure of the Fuel at or above the maximum operating pressure of the pressure vessel 20 , so that fuel from the pressure vessel 20 must be drained.

The density of the fuel in the pressure vessel 20 can by measuring the temperature and pressure in the pressure vessel 20 (taking into account the volume of the pressure vessel) are determined. In addition, the ambient temperature can be detected. In particular, the expected highest ambient temperature in the near future (eg within the next few hours or days) can also be taken into account on the basis of weather forecast data or historical data.

At a supercritical density, the removal of fuel from the pressure vessel 20 being stopped. Alternatively, the removal of fuel from the pressure vessel 20 be increased if a secure customer is available. If the fuel is hydrogen and the fuel consumption device 40 a fuel cell, leads to an increased removal of fuel from the pressure vessel 20 for the fuel cell to produce more electricity. This additional current may be supplied to a battery or accumulator, converted into heat in a power resistor (eg, a coil), and / or stored in a (super) capacitor and / or an electrical converter (e.g. B. operated as an electronic load) can be supplied. The decision whether the removal of fuel from the pressure vessel 20 is stopped or prevented, or an increased removal of fuel is performed, the control means based on an algorithm in which several factors including the prevailing situation (eg position in a tunnel, congestion or loss or destruction of the vacuum by a Accident). It is also conceivable for the driver to be notified of various options for action and / or warnings for selection in response to the notification signal, and for the action option or options for action to be carried out on the basis of the driver's decision. It is conceivable that the driver decides whether the removal of fuel from the pressure vessel 20 stopped or prevented or increased removal of fuel is performed. An exception to this may be an imminent or imminent entry into a garage or a tunnel. Here then the control device alone can make the decision.

Upon the hint signal, at a supercritical density of the fuel in the pressure vessel 20 a filling station or a gas station (eg, via an infrared interface) to be informed that the filling process is interrupted or terminated. At the same time, future filling can be prevented (eg by blocking the tank shut-off valve 35 ).

In addition, the driver and / or people in the vehicle or around the vehicle can be informed by means of optical and / or acoustic and / or haptic warning signals on the indication signal, that the gap 25 no longer fulfills any thermal insulation function and has a supercritical density of fuel in the pressure vessel 20 is available. For this purpose, z. For example, an ad with text may be used. It is also conceivable that at the fuel filler flap of the vehicle, a warning light, for. B. a red warning light, lit or flashing. It is also conceivable that the door pins light up. In addition, the hazard warning light can be switched on.

On the hint signal can, in particular at a supercritical density of the fuel in the pressure vessel 20 Also, a message to a service or emergency center will be sent.

In addition, it may be due to the hint signal, in particular at a supercritical density of the fuel in the pressure vessel 20 , a retraction of the vehicle in a closed space, such. As a garage or a tunnel, are actively prevented. For this purpose, when it is detected that the vehicle is entering a closed space (eg by means of position data and / or data from the navigation system), the power of the drive of the vehicle is reduced in response to the notification signal. The power of the drive can be reduced so much that it is no longer possible to drive on or only at a walking pace. Alternatively or additionally, the brakes can be activated. The latter can be carried out at low speeds, z. B. on a ramp that leads to a garage. Thus, a retraction of the vehicle and consequently a discharge of fuel from the pressure vessel 20 into the environment in a closed room prevented. This increases safety, as it prevents the suffocation of people and / or the emergence of an explosive or combustible air-fuel mixture.

At a subcritical density, the driver may be aware of the failure or omission of the isolation function of the gap, in response to the indication signal 25 be informed, z. B. via an acoustic and / or optical and / or haptic warning signal. At a subcritical density, even after the generation of the notification signal, a filling of the pressure vessel 20 to be possible. However, before reaching a supercritical fuel density in the pressure vessel 20 the filling process is terminated or aborted (eg by communication from the Vehicle with the filling station / filling station or by closing the tank shut-off valve 35 ). Filling the pressure vessel 20 with cryogenic fuel is prevented even at a subcritical density. If the vehicle has two refueling couplings, one for cryogenic pressurized refueling and the other for pressurized refueling, the cryogenic refueling coupling (eg via a lock) may also be locked. In addition, at a subcritical density, a message may also be sent to a service location and / or at a supercritical density to an emergency site. At a supercritical density of the fuel in the pressure vessel 20 becomes a filling of the pressure vessel 20 regardless of the type of fuel (cryogenic or non-cryogenic).

The driver of the vehicle can be informed of the warning signal that no cryogenic filling of the pressure vessel 20 is allowed, but a filling with non-cryogenic fuel is possible. In addition, the driver can be informed on the hint signal that the retraction in closed spaces, eg. As garages or tunnels is prohibited. In addition, the driver can be informed on the warning signal that the vehicle should be parked on a well-ventilated open area without ignition sources (ie without hot objects or hot surfaces). Also, the driver can be informed on the hint signal that the service or a workshop should be contacted and / or approached. If during operation the subcritical density is reached through consumption, the driver can be informed by a warning signal about the lifting of the restrictions.

It is also conceivable that as part of a so-called automatic emergency call (eCall, emergency call) is transmitted as additional information or additional information that the isolation function of the cryogenic pressure vessel 20 failed and whether a supercritical and / or subcritical density of fuel in the pressure vessel 20 is present. Also, a service point can be automatically informed about the failure of the isolation function.

On the hint signal may mean that the appropriate action is initiated or carried out due to the generation of the notification signal. In particular, it is conceivable that the warning signal initiates the appropriate action or reaction.

• – Entnahme wird gestoppt, Betankung wird abgebrochen und gesperrt (z. B. Tankabsperrventil wird geschlossen)
• – Alternativ zum Entnahmestopp kann auch die Entnahme erhöht werden, wenn ein sicherer Abnehmer zur Verfügung steht. Ein sicherer Abnehmer könnte z. B. ein Leistungswiderstand, eine Batterie oder ein Superkondensator für ein elektrisch betriebenes Fahrzeug (z. B. Brennstoffzelle) sein. Die Entscheidung ob ein Entnahmestopp oder eine Entnahmesteigerung umzusetzen ist, wird in Abhängigkeit des Tankbefüllungsgrades, der Leistungsabnehmerverfügbarkeit und ggf. anderen Faktoren wie z. B. der vorherrschenden Situation (z. B. Tunnel, Stau oder Unfall) von einem Steuergerätealgorithmus entschieden. Alternativ kann dem Fahrer auch eine oder mehrere Verhaltensoptionen angeboten werden und der Fahrer entscheidet. Als Leistungswiderstand kann auch eine Spule mit einer anderen Funktion (z. B. E-Motor) oder ein entsprechender Wandlerbetrieb (z. B. als elektronische Last) dienen.
• – An die Tankstelle wird ein Betankungsabbruch kommuniziert (z. B. über IR-Schnittstelle)
• – Fahrer, Betankender und Umwelt werden über ein bevorstehendes Abblasen von Treibstoff informiert (z. B. rotes Licht an Tankklappe, leuchtende Türpins, Anzeigehinweis für Fahrer)
• – Ferner kann eine online Nachricht an eine Service- oder Notfallstelle geschickt werden

At a supercritical density of the fuel in the pressure vessel 20 The following actions can be performed on the alert signal (either one by one or several together or all together):

• - withdrawal is stopped, refueling is aborted and blocked (eg tank shut-off valve is closed)
• - Alternatively to the withdrawal stop, the withdrawal can also be increased if a secure buyer is available. A safe buyer could z. A power resistor, a battery or a supercapacitor for an electrically powered vehicle (eg, fuel cell). The decision whether a withdrawal stop or a removal increase is to be implemented, is dependent on the tank filling level, the power user availability and possibly other factors such. The prevailing situation (eg tunnel, congestion or accident) is decided by a controller algorithm. Alternatively, the driver can also be offered one or more behavioral options and the driver decides. A power resistor can also be a coil with another function (eg electric motor) or a corresponding converter operation (eg as an electronic load).
• - A refueling stop is communicated to the filling station (eg via IR interface)
• - The driver, refueling station and the environment are informed about an impending release of fuel (eg red light on the fuel filler flap, illuminated door pins, indication for driver)
• - Furthermore, an online message can be sent to a service or emergency center

• – Fahrer wird über Ausfall der Isolationsfunktion informiert
• – Die Betankung wird vor Erreichen einer überkritischen Treibstoffdichte im Drucktank abgebrochen (z. B. durch Kommunikation an die Tankstelle oder Schließen des Tankabsperrventils oder eines eigens dafür installierten Zusatzventils)
• – Ferner kann eine online Nachricht an eine Service- oder Notfallstelle geschickt werden
• – Die Option kryogene Betankung wird gesperrt

At a subcritical density of the fuel in the pressure vessel 20 The following actions can be performed on the alert signal (either one by one or several together or all together):

• - Driver is informed about failure of the isolation function
• Refueling is stopped before reaching a supercritical fuel density in the pressure tank (eg by communication to the filling station or closing of the tank shut-off valve or a specially installed additional valve)
• - Furthermore, an online message can be sent to a service or emergency center
• - The option cryogenic refueling is blocked

For the sake of legibility, the term "at least one" has been omitted for simplicity. If a feature of the technology disclosed herein is described in the singular or indefinite (eg, the / a pressure vessel, the / a control device, etc.) so should also be simultaneously disclosed with their plurality (eg, the at least one Pressure vessel, the at least one control device, etc.).

The foregoing description of the present invention is for illustrative purposes only and not for the purpose of limiting the invention 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 NUMBERS

10

Pressure vessel system

20

pressure vessel

22

outer container

23

inner container

25

gap

30

fluid line

35

tank shutoff valve

40

Fuel consumption device

50

control device

60

Pressure measuring device

70

control line

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1546601 B1 [0003]

Claims (10)

Method for monitoring a pressure vessel system ( 10 ) in a vehicle, the pressure vessel system ( 10 ) a pressure vessel ( 20 ) for storing a fuel, in particular hydrogen, wherein the pressure vessel ( 20 ) an inner container ( 23 ) for storing the fuel, an outer container ( 22 ) and one between the inner container ( 23 ) and the outer container ( 22 ) arranged evacuated space ( 25 ) for heat insulation, comprising the steps of: detecting the pressure in the space ( 25 ) at a first time and at a second time, the second time being later than the first time; Comparing the pressure increase per unit time between the first time and the second time with a maximum rise value and / or comparing the detected pressure at the first time and / or the second time with a pressure limit; Find that the gap ( 25 ) no longer performs a heat-insulating function when the pressure rise per unit time is above the maximum rise value and / or the detected pressure is above the pressure threshold at the first time and / or at the second time; and generating a notification signal if it is determined that the gap ( 25 ) no longer fulfills a thermal insulation function. The method of claim 1, further comprising the steps of: detecting the temperature and pressure of the fuel in the pressure vessel ( 20 ); Determining the density of the fuel in the pressure vessel ( 20 ) based on the detected temperature and the detected pressure; Comparing the density with a density value, the density value being dependent on the ambient temperature; and determining whether the fuel density is supercritical or subcritical depending on the result of comparing the density with the density value. Method according to claim 1 or 2, wherein the removal of fuel from the pressure vessel ( 20 ) is prevented. Method according to claim 1 or 2, wherein the removal of fuel from the pressure vessel ( 20 ) is increased when the fuel removed by the fuel in a fuel consumption device ( 40 ) energy is dissipated. Method according to one of the preceding claims, wherein, depending on the indication signal, an optionally occurring filling process of the pressure vessel ( 20 ) is terminated with fuel. Method according to one of the preceding claims, wherein an audible and / or optical and / or haptic warning signal is generated on the hint signal, wherein the warning signal within and / or outside of the vehicle is perceptible. Method according to one of the preceding claims, wherein, based on the indication signal, a future filling of the pressure vessel ( 20 ) is prevented with cryogenic fuel. Method according to one of the preceding claims, wherein, following the indication signal, a future filling process of the pressure vessel ( 20 ) is terminated when the density of the pressure vessel ( 20 ) has reached a maximum density value, wherein the maximum density value is dependent in particular on the ambient temperature. Method according to one of the preceding claims, wherein on the Hint signal retraction of the vehicle in a closed space, in particular a garage and / or a tunnel is prevented, in particular by reducing the power of the drive of the vehicle and / or by activating the brakes of vehicle. Pressure vessel system ( 10 ) in a vehicle, the pressure vessel system comprising a pressure vessel ( 20 ) for storing a fuel, in particular hydrogen, wherein the pressure vessel ( 20 ) an inner container ( 23 ) for storing the fuel, an outer container ( 22 ) and one between the inner container ( 23 ) and outer container ( 22 ) arranged evacuated space ( 25 ) for thermal insulation, a pressure measuring device ( 60 ) for detecting the pressure in the space ( 25 ) at a first time and at a second time, wherein the second time is temporally after the first time, and a control device ( 50 ) - for comparing the pressure rise per unit of time between the first time and the second time with a maximum rise value and / or comparing the detected pressure at the first time and / or the second time with a pressure limit, - for determining that the gap ( 25 ) no longer fulfills a thermal insulation function if the pressure increase per unit time is above the maximum rise value and / or the detected pressure is above the pressure limit at the first time and / or at the second time, and To generate a warning signal when it is determined that the gap ( 25 ) no longer fulfills a thermal insulation function.

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