DE102020201746A1 - Method for controlling a safety valve system - Google Patents

Abstract

The invention relates to a method for controlling a safety valve system (1) with a plurality of safety valves (2) for shutting off and releasing a plurality of pressurized fuel tanks (8) connected in parallel, comprising the steps of transferring (30) at least one first safety valve (2.1) or a group of first safety valves (2.1) from a closed state (GZ) to an open state (OZ) with the application of a first opening energy (ÖE1), holding (32) the open state (OZ) of the first safety valve (2.1) or the group of the first safety valves (2.1) with the application of a first holding energy (HE1), a transfer (34) of at least one second safety valve (2.2) or a group of second safety valves (2.2) from a closed state (GZ) to an open state ( OZ) with the application of an additional second opening energy (ÖE2) and holding (36) the open neten state (GZ) of the second safety valve (2.2) or the group of the second safety valves (2.2) with the application of an additional second holding energy (HE2), the first and second safety valve (2.1, 2.2) or the group of first and second safety valves ( 2.1, 2.2) can be shifted from a closed state (GZ) to an open state (OZ) in a targeted manner in order to minimize the total opening energy (EGes) required to release a plurality of pressurized fuel tanks connected in parallel.

Description

The present invention is based on a method according to the generic type of the independent method claim and a system according to the generic type of the independent system claim.

State of the art

In pressurized fuel tanks, safety solenoid valves are used to safely close the tanks, which are closed when the power is off. This ensures that in the closed state as well as in the event of accidents and defects, a fuel leak is avoided at all times. Depending on the legal situation, a separate safety valve is required for each container, which must be attached directly to or in the container. Depending on the definition of the term container (single bottle or bottle bundle), the required number of safety valves can increase quickly. The contents of the tank inside the fuel tank are usually held back against a differential pressure of 15 - 1000 bar by means of normally closed solenoid valves. If fuel is to be withdrawn from such a tank, the valves of the individual containers must be actuated electrically by a control device for the duration of the withdrawal. To open the valves, the seat force of the valves must be overcome. Due to the high pressure differences between the inside and outside of the container, however, a very large electrical current I _A is briefly necessary to overcome the seat force. In the open state, on the other hand, the force and thus the necessary current I _{A decrease sharply.} With simultaneous activation of a plurality of valves of fuel tanks connected in parallel, the starting currents I _{A of} all valves add up, so that the control device in question for activation of the valves has to be designed for very high outputs and a very high current, which is disadvantageous.

Disclosure of the invention

According to a first aspect, the subject matter of the invention is a method with the features of the independent method claim and, according to a second aspect, a safety valve system with the features of the independent system claim. Further features and details of the invention emerge from the respective subclaims, the description and the drawings. Features and details that are described in connection with the method according to the invention naturally also apply in connection with the system according to the invention and vice versa, so that, with regard to the disclosure, reference is or can always be made to the respective individual aspects of the invention.

The advantage of the method according to the invention for controlling a safety valve system with a plurality of safety valves for shutting off and releasing a plurality of pressurized fuel tanks connected in parallel is particularly to be seen in the fact that the activation according to the invention enables a particularly energy-efficient opening of a plurality of valves. In addition, the control of a safety valve system according to the invention enables a control device for controlling the safety valve system that is optimized in terms of cost, installation space, weight and energy, in which the requirements with regard to a required current or a required power are reduced. This also leads to the avoidance of a complex structure for heat dissipation (e.g. water cooling). Furthermore, by using the method according to the invention, it is possible to optimize a mechanical load and also corresponding acoustic effects during the operation of the safety valve system.

The method according to the invention for controlling a safety valve system can be used in particular in motor vehicles, such as passenger cars or trucks. Use in other vehicles or means of transport, such as forklifts, cranes, ships or flying objects, is also conceivable. Use in stationary systems is also conceivable. The method according to the invention for controlling a safety valve system with a plurality of safety valves for shutting off and releasing a plurality of pressurized fuel tanks connected in parallel comprises the steps of transferring at least one first safety valve or a group of first safety valves from a closed state to an open state while applying a first opening energy, holding the open state of the first safety valve or the group of first safety valves while applying a first holding energy, transferring at least one second safety valve or a group of second safety valves from a closed state to an open state while applying an additional second opening energy and holding the open state of the second safety valve or the group of the second safety valves with the application of e in an additional second holding energy. According to the invention, it is provided here that the first and second safety valve or the group of first and second safety valves are shifted from a closed state to an open state in a targeted manner in order to minimize the total opening energy required to release a plurality of pressurized fuel tanks connected in parallel.

In the context of the invention, a safety valve system can in particular be understood to mean an interconnected system comprising a plurality of preferably separately controllable valves. According to the invention, the majority of the fuel tanks connected in parallel with one another can each have at least one of their own, preferably separately controllable, safety valve. A connection (parallel connection) of the fuel tanks can be formed here, for example, via a gas or liquid guide system, hereinafter referred to as a feed system for short, which can preferably be arranged between the fuel tanks and the motor or between the fuel tanks and a fuel cell system . A transfer of valves from a closed state to an open state, which takes place deliberately offset in time, can advantageously take place via a conscious, controlled switching behavior for switching valves. With regard to the transfer of valves, which are deliberately offset in time, it goes without saying that more than two safety valves or more than two groups of safety valves can also be transferred from a closed state to an open state in order to release the required total opening energy of the plurality of pressurized fuel tanks connected in parallel. The frequency between the switching processes can in particular be varied. In the context of the invention, the total opening energy is also understood to mean the sum of the energy to be expended to open and / or keep open all the valves of a safety valve system involved in an opening process.

With regard to a simple and, in particular, precisely controllable opening and closing of valves of a fuel tank, it can advantageously be provided according to the invention that the first and second opening energy and / or the first and second holding energy are in the form of electrical energy, preferably by applying an electrical voltage , provided. The application of an electrical voltage preferably forms a magnetic field via which the opening process or the holding process of the valves involved is controlled. As an alternative to voltage regulation, the valve control can also be current-regulated. In the context of a structurally simple embodiment, it can advantageously be provided that the energy is introduced continuously, preferably in the form of continuous ramps. In the context of a particularly finely metered and / or rapidly switchable embodiment, a discontinuous, in particular pulsed, introduction of energy can alternatively be provided. Thus, according to the invention, regulation can take place in the form of a continuous voltage supply or power supply or in the form of a pulsed voltage supply or power supply.

As part of an energy-optimized switching behavior of the valves of the safety valve system, provision can also be made that the safety valves are transferred from a closed state to an open state in a targeted manner offset in time in such a way that the second opening energy is less than the first opening energy. The opening energy for the other valves depends on the valve construction and the entire system.

In an embodiment which is particularly advantageous with regard to the opening energy requirement, a first valve or a first valve group is activated and there is a wait until the pressure in the inlet system corresponds to the pressure or almost the pressure in the fuel tanks. The necessary opening energy for the further valve or the further valve group is in this case significantly less than for the first valve or the first valve group, but nevertheless higher than the holding energy due to the air gap to be overridden.

In an embodiment variant for particularly fast filling of the inlet system, a first valve or a first valve group is activated and a further valve or a further valve group is activated before the pressure in the induction system has risen to the pressure of the fuel tanks. The premature activation of the other valves leads to a very rapid filling of the induction system due to the pressure difference between the inlet system and the fuel tank that still exists at this point in time. The initially existing pressure difference, however, also leads to higher necessary opening energies than in the energy-optimized design variant described above with a similar or the same pressure in the inlet system and fuel tank.

Depending on the desired system design, the energy or filling time of the safety valve system can be optimized by selecting the point in time at which the further valve or the further valve group is activated.

In addition, as part of an energy-optimized switching behavior of the valves of the safety valve system, it can also be provided that the safety valves are transferred from a closed state to an open state in a targeted manner offset in time in such a way that the first holding energy essentially corresponds to the amount of the second opening energy and / or in Substantially corresponds to the amount of the second holding energy.

(mit N = Anzahl der Ventile, EÖ₁= erste Öffnungsenergie und HE₁ = erste Halteenergie), anstatt einer Annäherung von $${\text{E}}_{\text{Ges}}\approx \text{N}\cdot {\text{E}\ddot{\text{O}}}_1$$

ohne die Anwendung des erfindungsgemäßen Verfahrens.Alternatively, only the second opening energy can essentially correspond to the amount of the second holding energy. According to the invention, an essentially equal amount is understood to mean a deviation of less than 30%, preferably of less than 20%, in particular of less than 10%, with respect to the higher value in each case. In the context of such an assumption, the total opening energy E _Ges can be approximated as $${\text{E.}}_{\text{Ges}}\approx 1\cdot {\text{E.}\ddot{\text{O}}}_1+\left(\text{N}-1\right)\cdot {\text{<figure-callout id="1" label="HE" filenames="DE102020201746A1\_0004.png" state="{{state}}">HE</figure-callout>}}_1,$$

(with N = number of valves, EÖ ₁ = first opening _{energy and HE 1} = first holding energy), instead of an approximation of $${\text{E.}}_{\text{Ges}}\approx \text{N}\cdot {\text{E.}\ddot{\text{O}}}_1$$

without using the method according to the invention.

Due to the air gap to be overridden for the other valves or valve groups, a certain excess force must be provided. Therefore, the opening energy of further valves or valve groups is higher than the holding energy of the first valve or the first valve group but significantly smaller than the opening energy of the first valve or the first valve group. This can be formulated as follows: $$\begin{array}{c}{\text{E.}\ddot{\text{O}}}_1>>{\text{E.}\ddot{\text{O}}}_{\mathrm{2\; ..}\text{<figure-callout id="1" label="N" filenames="DE102020201746A1\_0004.png" state="{{state}}">N</figure-callout>}}\\ 1\cdot {\text{E.}\ddot{\text{O}}}_1+\left(\text{N}-1\right)\cdot {\text{<figure-callout id="1" label="HE" filenames="DE102020201746A1\_0004.png" state="{{state}}">HE</figure-callout>}}_1<1\cdot {\text{E.}\ddot{\text{O}}}_1+\left(\text{N}-1\right)\cdot {\text{E.}\ddot{\text{O}}}_{\mathrm{2\; ..}\text{N}}<<\text{N}\cdot {\text{E.}\ddot{\text{O}}}_1\\ \left({\text{with E}\ddot{\text{O}}}_{\mathrm{2\; ..}\text{N}}=\ddot{\text{O}}\text{opening energy further valves}\right)\end{array}$$

With regard to a simple and convenient control of the safety valves in question, it can also be provided that the safety valves are transferred from an open state to a closed state by switching off or reducing the holding energy and / or opening energy below a critical value. This can be done in a simple manner, for example, by using solenoid valves to which a corresponding voltage must be applied in order to open.

In order to ensure an energetically particularly effective switching behavior, it can advantageously be provided according to the invention that a suitable switching time for switching the safety valves is determined by detecting measured values by means of a detection unit. A suitable switching time can be determined in particular with regard to a preferred time interval and a preferred sequence of opening of valves, in particular via current pressure measurements by means of pressure sensors.

The invention also relates to a safety valve system, in particular for carrying out a method described above. Here, the safety valve system comprises a plurality of safety valves for shutting off and releasing a plurality of pressurized fuel tanks connected in parallel as well as a control device for controlling the safety valves, the control device being designed and arranged within the safety valve system in such a way that the safety valves are deliberately offset in time from the control device can be converted from a closed state into an open state in order to minimize a required total opening energy for releasing a plurality of pressurized fuel tanks connected in parallel. The safety valve system according to the invention thus has the same advantages as have already been described in detail with regard to the method according to the invention.

In order to ensure a switching behavior that is particularly effective in terms of energy, it can furthermore advantageously be provided according to the invention that a detection unit is provided for the detection of measured values for determining a suitable switching point in time. The detection unit can be in the form of a pressure measuring unit, for example, and can preferably have a plurality of pressure sensors. In addition to a detection unit for detecting a suitable switching time, a processing unit can also be provided for determining a suitable switching time on the basis of the values determined by the detection unit. In this case, the detection unit can advantageously be connected to the processing unit and the control unit via a control line or the like and, in the context of a compact arrangement, for example, be integrated into a control unit or the like. In an embodiment that can be flexibly arranged and easily integrated, the individual components can also be wirelessly connected to one another via WLAN, Bluetooth or NFC or the like.

With a view to simple and convenient control of the safety valves in question, it can furthermore be provided that the safety valves are in the form of normally closed valves, preferably in the form of solenoid valves.

In the context of a compact and fully integrated design of an objective security system, it can furthermore be provided according to the invention that a plurality of pressurized fuel tanks connected in parallel is provided, each fuel tank preferably having at least one separately controllable safety valve, the fuel tanks being connected to one another in parallel, in particular via a feed system. A feed system can in this case preferably be in the form of gas lines or fuel lines or the like, which can in particular be arranged between the safety valves and a motor or a fuel cell system.

The invention also relates to a fuel cell system comprising an above-described safety valve system, in particular for use in a motor vehicle.

Further advantages, features and details of the invention emerge from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can be essential to the invention individually or in any combination.

• 1 eine schematische Darstellung der einzelnen Schritte eines erfindungsgemäßen Verfahrens zur Ansteuerung eines Sicherheitsventilsystems,
• 2 eine schematische Darstellung des Aufbaus eines erfindungsgemäßen Sicherheitsventilsystems gemäß einem ersten Ausführungsbeispiel,
• 3 eine schematische Darstellung des Energieprofils bei der Durchführung eines Teils des erfindungsgemäßen Verfahrens zur Ansteuerung eines Sicherheitsventilsystems,
• 4a eine schematische Darstellung einer erfindungsgemäßen Ansteuerungssequenz zur Ansteuerung der Ventile eines Sicherheitsventilsystems gemäß einem ersten Ausführungsbeispiel,
• 4b eine schematische Darstellung einer erfindungsgemäßen Ansteuerungssequenz der Ventile eines Sicherheitsventilsystems gemäß einem zweiten Ausführungsbeispiel.

Show it:

• 1 a schematic representation of the individual steps of a method according to the invention for controlling a safety valve system,
• 2 a schematic representation of the structure of a safety valve system according to the invention according to a first embodiment,
• 3 a schematic representation of the energy profile when performing part of the method according to the invention for controlling a safety valve system,
• 4a a schematic representation of a control sequence according to the invention for controlling the valves of a safety valve system according to a first embodiment,
• 4b a schematic representation of an inventive control sequence of the valves of a safety valve system according to a second embodiment.

1 shows a schematic representation of the individual steps of a method according to the invention for controlling a safety valve system 1 .

The method according to the invention here comprises the steps of transferring 30th at least one first safety valve 2.1 or a group of first safety valves 2.1 from a closed state GZ in an open state OZ with the application of a first opening energy ÖE ₁ , a holding 32 the open state OZ of the first safety valve 2.1 or the group of the first safety valves 2.1 with the application of a first holding energy HE ₁ , a transfer 34 at least one second safety valve 2.2 or a group of second safety valves 2.2 from a closed state GZ in an open state OZ applying an additional second opening energy ÖE ₂ and holding 36 the open state OZ of the second safety valve 2.2 or the group of the second safety valves 2.2 with the application of an additional second holding energy HE ₂ , the first and second safety valve 2.1 , 2.2 or the group of first and second safety valves 2.1 , 2.2 deliberately offset in time from a closed state GZ in an open state OZ be transferred in order to minimize the total opening energy E _Ges required to release a plurality of pressurized fuel tanks connected in parallel.

In the context of the method according to the invention, it can be provided that the first and second opening energy EÖ ₁ , EÖ ₂ and / or the first and second holding energy HE ₁ , HE _{2 are provided} in the form of electrical energy, preferably by applying an electrical voltage.

The safety valves 2 can be deliberately offset in time from a closed state GZ in an open state OZ are transferred so that the second opening energy ÖE _{2 is} less than the first opening energy ÖE ₁ .

It is also conceivable that the safety valves 2 so deliberately offset in time from a closed state GZ in an open state OZ be transferred that the first holding energy HE ₁ , essentially corresponds to the amount of the second opening energy ÖE ₂ and / or essentially the amount of the second holding energy HE ₂ .

A suitable switching point for switching the safety valves 2 can in this case preferably by the detection of measured values by means of a detection unit 12th be determined.

2 shows a schematic representation of the structure of a safety valve system according to the invention 1 according to a first embodiment.

According to this first exemplary embodiment, the safety valve system comprises 1 a plurality of safety valves 2 (present in the form of the safety valves 2.1 - 2.5 formed) to shut off and release a plurality of pressurized fuel tanks connected in parallel 8th as well as a control unit 10 to control the safety valves 2 , the control unit 10 presently designed in this way and within the safety valve system 1 is arranged that the safety valves 2 from the control unit 10 deliberately offset in time from a closed state GZ in an open state OZ Can be converted to a required total opening energy E _Ges for releasing a plurality of pressurized fuel tanks connected in parallel 8th to minimize.

For the detection of measured values to determine a suitable switching point in time for the safety valves 2 , has the safety valve system according to the invention 1 here a detection unit 12th which can be formed, for example, in the form of a pressure measuring unit and can preferably have a plurality of pressure sensors or the like. The detection unit 12th is present via the control line 9 with a processing unit 14th to determine a suitable switching time based on the detection unit 12th determined values connected. Via the control line 9 is the detection unit 12th furthermore with a plurality of sensors in the present case in the form of pressure sensors 12 ' connected. In addition, the safety valve system according to the invention 1 a plurality of pressurized fuel tanks connected in parallel 8th on, each of which has a separately controllable safety valve 2 ( 2.1 - 2.5 ) and via the discharge system 18th for supplying fuel to the fuel cell system 20th are interconnected in parallel. The one with the detection unit 12th connected sensors 12 ' are both inside the pressurized fuel tanks 8th , as well as within the single-line system 18th arranged. In addition to a connection to the detection unit 12th instructs the processing unit 14th via the control line 9 a connection to the control unit 10 on. As can be seen here, the safety valve is located 2.1 of the fuel tank 8th already in the open state, so that within the pipe system 18th there is already a significantly higher pressure and the differential pressure between the fuel tanks that have not yet been opened 8th and the pipe system 18th has thus been minimized compared to the initial conditions, so that the required opening energy ÖE or holding energy HE for opening or holding the valves 2.2 - 2.5 is significantly less than that for opening the first safety valve 2.1 necessary energy.

3 shows a schematic representation of the energy profile when performing part of the method according to the invention for controlling a safety valve system 1 .

How according to 3 recognizable is the required first opening energy ÖE ₁ for a transfer 30th a first safety valve 2.1 or a group of first safety valves 2.1 from a closed state GZ in an open state OZ significantly higher than that after a transfer 30th to hold 32 the open state OZ of the first safety valve 2.1 or the group of the first safety valves 2.1 required holding energy HE ₁ .

4a shows a schematic representation of a control sequence according to the invention according to a first embodiment.

How according to 4a recognizable, a first to fourth is present at regular time intervals 2.1 - 2.4 Safety valve from a closed state GZ in an open state OZ promoted.

4b shows a schematic representation of a control sequence according to the invention in accordance with a second exemplary embodiment.

According to this second embodiment, the group of the first two safety valves 2.1 from a closed state GZ in an open state OZ before the two second safety valves 2.2 from a closed state GZ in an open state OZ to get promoted.

Claims (10)

Method for controlling a safety valve system (1) with a plurality of safety valves (2) for shutting off and releasing a plurality of pressurized fuel tanks (8) connected in parallel, comprising the steps: transferring (30) at least one first safety valve (2.1) or a group of first safety valves (2.1) from a closed state (GZ) to an open state (OZ) with the application of a first opening energy (ÖE ₁ ), - holding (32) the open state (OZ) of the first safety valve (2.1) or the group the first safety valves (2.1) applying a first holding energy (HE ₁ ), - transferring (34) at least one second safety valve (2.2) or a group of second safety valves (2.2) from a closed state (GZ) to an open state (OZ ) with the application of an additional second opening energy (ÖE ₂ ), - holding (36) the open state (GZ) of the second Sicherheitsve ntils (2.2) or the group of the second safety valves (2.2) with the application of an additional second holding energy (HE ₂ ), characterized in that the first and second Safety valve (2.1, 2.2) or the group of first and second safety valves (2.1, 2.2) can be shifted from a closed state (GZ) to an open state (OZ) in a targeted manner in order to release _{the required total opening energy (E Ges)} a plurality of pressurized fuel tanks connected in parallel. Procedure according to Claim 1 , characterized in that the first and second opening _{energy (ÖE 1} , ÖE ₂ ) and / or the first and second holding energy (HE ₁ , HE ₂ ) is provided in the form of electrical energy, preferably by applying an electrical voltage. Procedure according to Claim 1 or 2 , characterized in that the safety valves (2) are shifted from a closed state (GZ) to an open state (OZ) in such a targeted manner that the second opening energy (ÖE ₂ ) is less than the first opening energy (ÖE ₁ ) . The method according to any one of the preceding claims, characterized in that the safety valves (2) are transferred from a closed state (GZ) to an open state (OZ) in a targeted manner offset in time such that the first holding energy (HE ₁ ) essentially corresponds to the amount corresponds to the second opening energy (ÖE ₂ ) and / or essentially the amount of the second holding energy (HE _2). Method according to one of the preceding claims, characterized in that the safety valves (2) by switching off or reducing the holding energy (HE) and / or opening energy (ÖE) from an open state (OZ) to a closed state (GZ ) are transferred. Method according to one of the preceding claims, characterized in that a suitable switching time (S) for switching the safety valves (2) is determined by detecting measured values by means of a detection unit (12). Safety valve system (1), in particular for carrying out a method according to one of the Claims 1 until 6th , comprising: - a plurality of safety valves (2) for shutting off and releasing a plurality of pressurized fuel tanks (8) connected in parallel, - a control device (10) for controlling the safety valves (2), characterized in that the control device (10) is designed and arranged within the safety valve system (1) in such a way that the safety valves (2) can be transferred from a closed state (GZ) to an open state (OZ) by the control device (10) in a targeted manner in order to achieve a required total opening energy ( E _Ges ) to minimize the release of a plurality of pressurized fuel tanks connected in parallel. Safety valve system (1) Claim 7 , characterized in that a detection unit (12) for detecting measured values for determining a suitable switching time (S) is provided. Safety valve system according to one of the Claims 7 or 8th , characterized in that the safety valves are in the form of normally closed valves, preferably in the form of solenoid valves. Safety valve system according to one of the Claims 7 until 9 , characterized in that a plurality of pressurized fuel tanks (8) connected in parallel is provided, each fuel tank (8) preferably having at least one separately controllable safety valve (2), the fuel tanks (8) being connected to one another in parallel, in particular via a feed system.

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