Control unit and method for adjusting the pressure in an extraction line of a pressure vessel

Abstract

According to the present application, the technology disclosed herein relates to a control unit (150) for a pressure vessel system (100) comprising at least one pressure vessel (110, 120) having a pressure vessel valve (206) configured to conduct fuel (104) from the pressure vessel (110, 120) into an extraction line (113, 123) for feeding an energy converter (103). The control unit (150) is provided to determine that a filling process of the pressure vessel (110, 120) is occurring or has occurred. Further, the control unit (150) is provided to cause, in response thereto, a pulsed opening of the pressure vessel valve (206) in time before an extraction request of fuel (104) for operating the energy converter (103) in order to bring a pressure in the extraction line (113, 123) close to a pressure in the pressure vessel (110, 120).

Description

TECHNICAL FIELD

[0001] The technology disclosed herein relates to a pressure vessel system having one or more pressure vessels, for example a pressure vessel system for a motor vehicle. Furthermore, the technology disclosed herein relates to a method for adjusting a pressure in an extraction line of a pressure vessel of such a pressure vessel system and a corresponding control unit. BACKGROUND

[0002] A motor vehicle can have at least one fuel cell which generates electrical energy on the basis of a fuel, such as hydrogen, for operating the vehicle, in particular for driving the vehicle. The fuel can be stored in a pressure vessel system having at least one pressure vessel. By opening a valve, in particular a so-called on-tank valve (OTV), the fuel can be guided from the pressure vessel through an extraction line to the fuel cell of the vehicle.

[0003] During operation of the pressure vessel system, there can be significant pressure differences between different components of the pressure vessel system, in particular between the one or more pressure vessels and the one or more lines, which leads to a relatively high load of the system of pressure vessels and / or to an inaccurate fuel supply of the fuel cell. SUMMARY

[0004] It is a preferred task of the technology disclosed herein to reduce or eliminate at least one of the drawbacks of previously known solutions or to propose an alternative solution. It is a preferred task of the technology disclosed herein to enable a pressure vessel system to be operated as protectively and / or as accurately as possible in an efficient manner.

[0005] According to an aspect, a control unit for a pressure vessel system, in particular for a pressure vessel system of a motor vehicle, for example for a passenger car, for a motorcycle, for a commercial vehicle, etc., is described. The pressure vessel system is here generally used for storing a fuel which is gaseous in ambient conditions. The pressure vessel system can for example be used in a motor vehicle which is operated with compressed natural gas, also referred to as compressed natural gas or CNG, or with liquefied natural gas, also referred to as liquid natural gas or LNG, or with hydrogen gas, in particular H2, as fuel. The pressure vessel system is generally in fluid connection with at least one energy converter which is provided for converting the chemical energy of the fuel into one or more other forms of energy.

[0006] Such a pressure vessel system comprises at least one pressure vessel, in particular a composite overwrap pressure vessel. The pressure vessel can be for example a cryogenic pressure vessel or a high-pressure gas vessel.

[0007] The high-pressure gas tank is configured to store fuel continuously at ambient temperature at a nominal operating pressure (= overpressure compared to atmospheric pressure) of at least 350 bar overpressure or at least 700 bar overpressure. The cryogenic pressure vessel is suitable for storing fuel at the above-mentioned operating pressure also at temperatures which are significantly (e.g. more than 50 Kelvin or more than 100 Kelvin) below the operating temperature of the motor vehicle.

[0008] The pressure vessel system described in this document comprises at least one pressure vessel with a pressure vessel valve, wherein the pressure vessel valve is configured to guide the (gaseous) fuel from the pressure vessel into an extraction line for feeding an energy converter. Here, usually a pressure converter is arranged between the extraction line and the energy converter, which pressure converter is provided for converting the fuel from the extraction line having a relatively high pressure (e.g. 100 bar overpressure or more) into fuel having a relatively low pressure (e.g. 15 bar overpressure or less). If necessary, the fuel pressure can be further reduced at the energy converter (e.g. to 2 bar overpressure or less). For this purpose, a proportional valve or an ejector can be used.

[0009] The pressure vessel valve can be a so-called on-tank valve (OTV) or part of an OTV. The combination of an electromagnetically actuated valve, a manually actuated valve and, if possible, a thermal pressure relief device (TPRD) is usually referred to as an OTV. The electromagnetically actuated valve and the manually actuated valve can in particular be connected in series, wherein one or both of them can each constitute a tank shut-off valve.

[0010] The energy converter is provided for converting the chemical energy of the fuel into one or more other forms of energy, e.g. into electrical energy and / or into kinetic energy. The energy converter can be, for example, an internal combustion engine or a fuel cell system or a fuel cell stack with at least one fuel cell.

[0011] The control unit is provided for determining that a filling process of the pressure vessel is occurring or has occurred. The filling of the pressure vessel can here take place via a filling inlet of the pressure vessel system and via a supply line from the filling inlet to the pressure vessel. The control unit can be provided for determining sensor data of a pressure sensor in the supply line to the pressure vessel. The filling process of the pressure vessel can then be determined to be occurring or to have occurred in a precise and reliable manner on the basis of the sensor data of the pressure sensor in the supply line, in particular on the basis of a pressure rise in the supply line.

[0012] The control unit is further provided for causing the pressure vessel valve to be opened (already) in time before an extraction request for fuel for operating the energy converter in response to the identified filling process. In other words, it can also be caused (during and / or after the filling process) to open the pressure vessel valve even in the absence of a specific extraction request for fuel for operating the energy converter.

[0013] The opening of the pressure vessel valve is here designed to (also before the (first time after the filling process) presence of a request for extraction of fuel for the operation of the energy converter) bring the pressure in the extraction line close to and / or equalize the pressure in the extraction line to the pressure in the pressure vessel. To this end, the pressure vessel valve can be opened during and / or following the filling process. The opening of the pressure vessel valve is here pulsed or in beats and / or is pulsed (for example, with a pulse duration of 100 milliseconds or less). Advantageously, the pressure vessel valve can be opened in a pulsed or in beats or pulsed operation for a maximum of 400 milliseconds or a maximum of 200 milliseconds or a maximum of 100 milliseconds. Thereby, a particularly precise and reliable adjustment of the pressure in the extraction line is possible. Alternatively, a continuous opening over a certain time interval (for example, between 0.5 and 2 seconds) can be carried out (especially after the end of the filling process).

[0014] During or after the filling process, the pressure in the extraction line can thus (also before the (first time after the filling process) presence of a request for extraction of fuel for the operation of the energy converter) be close to or equalized to the internal pressure of the pressure vessel. Thereby, the load of the pressure vessel system can be reduced when the pressure vessel valve is opened for an extraction request. Furthermore, the accuracy of the pressure measurement and thus the accuracy of the fuel supply can be improved when the pressure vessel valve is opened for an extraction request.

[0015] The control unit can be designed to determine the presence of a request for extraction of fuel for the operation of the energy converter after the pressure in the extraction line is close to and / or equalized to the pressure in the pressure vessel. For example, a control signal can be received from the energy converter and / or from a controller for operating the energy converter (for example, from a drive controller), which indicates that fuel should be extracted from the pressure vessel to operate the energy converter.

[0016] In response to the received extraction request, the pressure vessel valve can then be caused to open (continuously) in order to guide fuel from the pressure vessel into the extraction line for the supply of the energy converter. Due to the preparatory pressure approach (after or during the filling process), the pressure equalization occurring here in the extraction line and / or the fuel compression occurring here in the extraction line is relatively low, so that a protective and precise fuel supply of the energy converter is possible.

[0017] The control unit can be configured to cause the pressure vessel valve to be opened pulsed and / or time-limited during the refueling process in order to guide fuel from the pressure vessel into the extraction line. Alternatively or additionally, the control unit can be configured to cause the pressure vessel valve to be opened during the refueling process for a maximum of 5% or less of the total duration of the refueling process in order to bring the pressure in the extraction line close to or in equilibrium with the pressure in the pressure vessel during the refueling process. By opening the pressure vessel valve time-limited and / or pulsed, a pressure adaptation in the extraction line can be induced without this having a significant negative impact on the reliability of the refueling process.

[0018] The control unit can be configured to determine that the refueling process has ended on the basis of one or more indicators. Exemplary indicators are: the fact that no further pressure increase in the pressure vessel occurs; the fact that the pressure vessel has reached or exceeded a particular fill level (for example between 90% and 95%); the fact that the refueling inlet (in particular the refueling cap) of the pressure vessel system has been closed or shut; and / or the fact that the user of the energy converter is preparing the activation of the energy converter and an associated extraction request for fuel (for example, the user is preparing to start the vehicle by operating the start / stop button of the vehicle).

[0019] The pressure vessel valve can then be caused to be opened, although after the end of the refueling process but before the (first) extraction request, in order to guide fuel from the pressure vessel into the extraction line in response to the recognized end of the refueling process. In particular, the pressure vessel valve can be caused to be opened for a predetermined time (for example between 5 and 10 seconds) after it has been determined that the refueling process has ended. By subsequently opening the pressure vessel valve after the end of the refueling process, the influence on the refueling process due to the opening of the pressure vessel valve can be completely avoided.

[0020] The control unit can be configured to operate the pressure vessel valve in order to adjust the pressure in the extraction line to be below the pressure in the pressure vessel by a particular offset value. Alternatively or additionally, the control unit can be configured to operate the pressure vessel valve such that (after the pressure has been brought close) the pressure in the extraction line is below the pressure in the pressure vessel by a particular offset value when there is an extraction request. For example, the offset value can be a particular fixed value (for example between 20 bar and 100 bar), or the offset value can be a percentage of the internal pressure of the pressure vessel (for example between 10% and 20%). By adjusting the pressure in the extraction line in this way, it is possible to reliably monitor the internal tightness of the pressure vessel valve (based on the pressure difference between the pressure vessel and the extraction line) and thus to achieve a particularly safe and reliable operation of the pressure vessel system.

[0021] As already explained above, the control unit can be configured to cause the pressure in the extraction line to approach the pressure in the pressure vessel and / or the pressure in the extraction line to equalize with the pressure in the pressure vessel (by opening the pressure vessel valve) during the refueling process. Furthermore, the control unit can be configured to determine sensor data of a pressure sensor in the extraction line.

[0022] The pressure in the supply line to the pressure vessel can then be determined and / or checked in a precise manner on the basis of the sensor data of the pressure sensor in the extraction line. Thereby, the reliability and safety of the refueling process can be further improved.

[0023] The control unit can be configured to determine a system pressure of the pressure vessel system during the refueling process on the basis of the sensor data of the pressure sensor in the extraction line. Furthermore, the control unit can be configured to transmit the system pressure (for example via an infrared interface) to a refueling unit (in particular a refueling column) from which fuel is provided for the refueling process. Thereby, a so-called COM refueling with an improved filling of the pressure vessel can be achieved (if possible even in the event of a failure of the pressure sensor in the supply line).

[0024] The control unit can be configured to determine sensor data of a pressure sensor in the supply line to the pressure vessel. The pressure in the supply line indicated by the sensor data of the pressure sensor in the supply line can then be compared with the pressure in the extraction line indicated by the sensor data of the pressure sensor in the extraction line. The refueling process of the pressure vessel (which usually also includes determining the filling level of the pressure vessel) and / or the pressure vessel valve can then be monitored and / or controlled in accordance with the comparison result. For example, in accordance with the comparison result, a signal (for example a stop signal) can be transmitted to a refueling unit for the refueling process. For example, the refueling unit can then stop the refueling process. Thereby, the reliability of the operation of the refueling process and / or the pressure vessel device can be further improved.

[0025] As already explained above, the control unit can be configured to cause the pressure in the extraction line to approach the pressure in the pressure vessel and / or the pressure in the extraction line to equalize with the pressure in the pressure vessel. This can occur during and / or after the refueling process. The filling level of the pressure vessel can then be determined and / or checked on the basis of the sensor data of the pressure sensor in the extraction line. Information about the filling level can then be output via a user interface. By taking into account the pressure in the extraction line, the accuracy of the determined filling level can be improved (compared to determining the filling level on the basis of the sensor data of the pressure sensor in the supply line).

[0026] The pressure vessel system can comprise, if possible, at least two pressure vessels, which each have a pressure vessel valve (the pressure vessels being filled in the context of a filling process). The control unit is provided to cause the pressure vessel valves of the at least two pressure vessels to be opened in turn and / or alternately in order to bring the pressure in the extraction line to approximate the pressure in the pressure vessels. Thereby, the load of the pressure vessel system can be further reduced.

[0027] Alternatively or additionally, the control unit can be provided to cause the pressure vessel valve of the pressure vessel which has the lower pressure loss (for example the shortest supply line in the case of pressure vessels of the same size and / or the smaller mass flow in the case of pressure vessels of different sizes) on the supply line for the filling process (of two or all pressure vessels) to be opened in order to bring the pressure in the extraction line to approximate the pressure in the pressure vessels. Thereby, it can be achieved that the pressure in the extraction line is approximated to the highest pressure of the pressure vessel system, so that the load of the pressure vessel system can be further reduced at the time of an extraction request.

[0028] According to a further aspect, a pressure vessel system, in particular for a motor vehicle, is described. The pressure vessel system comprises at least one pressure vessel with a pressure vessel valve, which is configured to guide fuel from the pressure vessel into the extraction line for the supply of an energy converter. Furthermore, the pressure vessel system comprises a control unit as described in this document, which is provided to operate the pressure vessel valve (in order to bring the pressure in the extraction line to approximate the internal pressure of the pressure vessel).

[0029] According to a further aspect, a (road) motor vehicle (in particular a passenger car or a van or a bus or a motorcycle) is described, which comprises a pressure vessel system as described herein.

[0030] According to a further aspect, a method for operating a pressure vessel system is described, which comprises at least one pressure vessel with a pressure vessel valve, which is configured to guide fuel from the pressure vessel into the extraction line for the supply of an energy converter. The method comprises determining that a filling process of the pressure vessel is occurring or has occurred. Furthermore, the method comprises causing the pressure vessel valve to be opened in time before an extraction request of fuel for operating the energy converter (in particular before the first extraction request after the identified filling process) in order to bring the pressure in the extraction line to approximate the pressure in the pressure vessel, the opening of the pressure vessel valve here can preferably take place pulsed or in pulses and / or in beats in order to bring the pressure in the extraction line to approximate the pressure in the pressure vessel in as precise and protective a manner as possible.

[0031] The control unit is arranged for causing the pressure vessel valve to be opened only if the internal pressure of the pressure vessel is at least 30% or at least 50% or at least 70% of the maximum filling pressure or of the nominal operating pressure, especially during a filling process.

[0032] According to another aspect, a software (SW) program is described. The SW program can be arranged for execution on a processor (e.g. in a controller of a vehicle) and for thereby executing the method described in this document.

[0033] According to another aspect, a storage medium is described. The storage medium can comprise a SW program arranged for execution on a processor and for thereby executing the method described in this document.

[0034] It is noted that the methods, devices and systems described herein can be used alone or in combination with other methods, devices and systems described herein. Furthermore, each aspect of the methods, devices and systems described in this document can be combined in a variety of ways. BRIEF DESCRIPTION OF DRAWINGS

[0035] The application is described in more detail below with the help of embodiments. In the drawings:

[0036] Figure 1 An exemplary pressure vessel system with multiple pressure vessels is shown;

[0037] Figure 2 An exemplary valve arrangement for a pressure vessel is shown; and

[0038] Figure 3 A flow chart of an exemplary method for adjusting the pressure in a withdrawal line of a pressure vessel is shown. DETAILED DESCRIPTION

[0039] As explained in the introduction, the present document relates to enabling a pressure vessel system to perform an operation as protective and / or as precise as possible. In this document, Figure 1 An exemplary pressure vessel system 100 with a first pressure vessel 110 and a second pressure vessel 120 is shown. The pressure vessels 110, 120 have a valve arrangement 112, 122 (e.g. an OTV) respectively, via which the inflow and outflow of fuel 104 to / from the pressure vessels 110, 120 can be controlled.

[0040] Figure 1The pressure vessel system 100 shown in the middle comprises supply lines 111, 121 which are configured to guide fuel 104 from the filling inlet 101 to the pressure vessels 110, 120. The first supply line 111 is guided to the input of the first valve device 112 of the first pressure vessel 110. The second supply line 121 is guided in a corresponding manner to the input of the second valve device 122 of the second pressure vessel 120. Both pressure vessels 110, 120 can thus be filled from the filling inlet 101. The pressure vessel system 100 can comprise pressure sensors 118, 128 which are provided for detecting sensor data related to the pressure in the respective supply line 111, 121.

[0041] The pressure vessel system 100 further comprises a first extraction line 113 which is connected to the output of the first valve device 112 and a second extraction line 123 which is connected to the output of the second valve device 122. Fuel 104 can be guided from the pressure vessels 110, 120 via the extraction lines 113, 123 to the pressure converter 102. Typically, the pressure in the pressure vessels 110, 120 is higher than the operating pressure of the energy converter 103 (e.g. of a fuel cell or a fuel cell stack). For example, the operating pressure of the energy converter 103 can be approximately 2 bar. The pressure in the pressure vessels 110, 120 is for example 20, 50, 100, 200 times or more of the operating pressure of the energy converter 103. The pressure converter 102, in particular a pressure regulator, can be provided for reducing the pressure of the fuel 104 from the pressure vessels 110, 120 (e.g. to an intermediate pressure in the range of 10 to 20 bar). The pressure of the fuel 104 can then be further reduced at the energy converter 103 to the operating pressure of the energy converter 103.

[0042] The pressure vessel system 100 can comprise one or more pressure sensors 116, 126 which are provided for detecting sensor data related to the pressure in the respective extraction line 113, 123. The pressure sensors 116, 126 can here each comprise at least one temperature sensor which is provided for detecting sensor data related to the temperature of the measuring diaphragm of the pressure sensor 116, 126 (wherein the temperature of the measuring diaphragm of the pressure sensor 116, 126 is typically related to the temperature of the fuel 104 in the extraction line 113, 123).

[0043] Figure 2An exemplary valve arrangement 112, 122 for a pressure vessel 110, 120 is shown. The valve arrangement 112, 122 comprises an inflow interface 201 for coupling a supply line 111, 121 and an outflow interface 203 for coupling an extraction line 113, 123. Fuel 104 supplied through the inflow interface 201 can be filtered in an inflow filter 202 in order to avoid or reduce contamination of the pressure vessel 110, 120 and / or a sealing seat of the valve arrangement 112, 122.

[0044] An inflow channel 221 for supplying fuel 104 comprising the inflow interface 201 and an outflow channel 223 for discharging fuel 104 comprising the outflow interface 203 can be coupled to each other at a coupling point 216 and to a common channel 222. The common channel 222 can connect the coupling point 216 with an interior space of the pressure vessel 110, 120.

[0045] The common channel 222 can have an electrically operable valve 206. The electrically operable valve 206 can be electrically connected via a data bus with a data interface 210 of the valve arrangement 112, 122. Via the data interface 210 a control signal can be received which indicates whether the electrically operable (pressure vessel) valve 206 should be opened or closed. The electrically operable valve 206 can comprise for example a solenoid valve. The control signal can be provided by a control unit 150 of the pressure vessel system 100.

[0046] In parallel to the electrically operable valve 206 a check valve 215 can be arranged. The check valve 215 can be arranged such that an escape of fuel 104 from the pressure vessel 110, 120 is avoided, but a supply of fuel 104 into the pressure vessel 110, 120 (for example during refueling) is enabled by overcoming a restoring force of the check valve 215. Furthermore, the electrically operable valve 206 can be bypassed, if necessary, by a manual valve 207. The manual valve 207 can be opened manually, for example by a service person, in order to at least partially discharge the fuel of the pressure vessel 110, 120.

[0047] The inflow channel 221 and the outflow channel 223 can thus jointly extend from the coupling point 216 via the common channel 222 into the interior space of the pressure vessel 110, 120. Here, the common channel 222 can be guided past a further manual valve 214 which can be used to manually close or open the pressure vessel 110, 120. Furthermore, the common channel 222 can be guided past a further outflow filter 212 with which the fuel 104 can be filtered before being supplied to the energy converter 103.

[0048] The valve arrangement 112, 122 can further comprise a temperature sensor 213 with an evaluation unit 208, which is connected with a data interface 210. Thereby, sensor data regarding the temperature of the pressure vessel 110, 120 and / or the temperature of the stored fuel 104 can be provided. Further, the valve arrangement 112, 122 can comprise a pressure relief unit 209 (e.g. a thermal pressure relief device, TPRD), which is configured to open the pressure vessel 110, 120 upon reaching or exceeding a temperature threshold, in order to vent the fuel 104 through a venting unit (in particular an opening) 211 and thereby to reduce the pressure in the interior of the pressure vessel 110, 120.

[0049] The outflow conduit 223 can have a flow restriction unit 205 between the coupling point 216, at which the outflow conduit 223 and the inflow conduit 221 meet, and the outflow interface 203, which is configured to restrict and, if necessary, to prohibit a backflow of fuel 104 from the outflow interface 203 to the coupling point 216. The flow restriction unit 205 can have a check valve 10, which is configured to completely prohibit the backflow. Alternatively or in addition, the flow restriction unit 205 (e.g. in parallel to the check valve) can have a throttle valve, which is configured to limit the backflow to a certain maximum value (e.g. to a maximum value of the mass flow and / or the volume flow).

[0050] In a corresponding manner, a flow restriction unit 204 can also be arranged on the inflow conduit 221 between the inflow interface 201 and the coupling point 216, which limits the backflow of fuel 104 from the pressure vessel 110, 120 to a certain maximum value (e.g. by a throttle valve) and / or blocks the backflow of fuel (e.g. by a check valve). Thereby, the fuel flow can be limited for pressure equalization by the supply line 111, 121 (e.g. at the beginning of a filling process).

[0051] After a normal filling of the one or more pressure vessels 110, 120, the pressure in the one or more pressure vessels 110, 120 and in the one or more supply lines 111, 121 is typically significantly higher than the pressure in the one or more extraction lines 113, 123. If an extraction of fuel 104 is requested after the filling, for example by the energy converter 103, a relatively strong pressure impulse can occur in the one or more extraction lines 113, 123, in the case of which the pressure in the one or more extraction lines 113, 123 rises relatively quickly. This can lead to a relatively high load for the one or more extraction lines 113, 123, for the one or more pressure sensors 116, 126, for the pressure transducer 102 and for possible connecting elements. In addition, the temperature in the one or more extraction lines 113, 123 can increase significantly due to the rapid compression of the remaining fuel mass in the one or more extraction lines 113, 123 when the pressure vessel valve 206 is opened. The temperature increase is typically only detected time-delayed by the temperature sensors of the one or more pressure sensors 116, 126, so that a (correct) temperature compensation of the sensor data of the one or more pressure sensors 116, 126 of the one or more extraction lines 113, 123 cannot be carried out, which can lead to inaccuracies in determining the pressure in the one or more extraction lines 113, 123. This can in turn have a negative effect on the functionality, for example the leakage monitoring of the pressure vessel valves 206 of the one or more pressure vessels 110, 120.

[0052] The control unit 150 of the pressure vessel system 100 can be configured to detect an operating situation in which the internal pressure in the pressure vessel 110, 120 is higher than, in particular by a certain percentage or by a certain absolute value, the internal pressure in the extraction line 113, 123 of the pressure vessel 110, 120. This can be the case, for example, as a result of a filling of the pressure vessel 110, 120.

[0053] In addition, the control unit 150 can be configured to cause one or more measures to be carried out in order to cause the pressure in the extraction line 113, 123 to be brought closer to the internal pressure in the pressure vessel 110, 120 (for example, up to a value which is lower than the internal pressure by a certain offset value) before a fuel extraction request for the operation of the energy converter 103.

[0054] In particular, the pressure vessel valve 206 of the pressure vessel 110, 120 can be opened pulsed or continuously in order to guide fuel 204 from the pressure vessel 110, 120 into the extraction line 113, 123 (in the absence of a request for fuel extraction by the energy converter 103 therefor). The pressure vessel valve 206 can be opened at different points in time and / or in response to different triggers, for example

[0055] - during the refilling process;

[0056] - as soon as no pressure increase in the pressure vessel 110, 120 occurs (during the refilling process);

[0057] - as soon as the refilling cap of the refilling inlet 101 is closed;

[0058] - when the driver door of the vehicle is opened after the refilling process;

[0059] - when it is identified that the driver of the vehicle is not present (for example, by means of a seat occupancy sensor, an interior space camera, a seat belt, etc.);

[0060] - when the vehicle is started (but no fuel extraction request by the energy converter 103 exists yet).

[0061] By pre-approaching the pressure in the extraction line 113, 123 to the internal pressure of the pressure vessel 110, 120, a pressure surge can be avoided in a reliable manner when the pressure vessel valve 206 is opened in response to a fuel extraction request by the energy converter 103. Thereby, the load of the pressure vessel system 100 can be reduced (for example, due to a pressure surge in the line 113, 123 and / or due to a relatively high flow rate at the valve seat of the pressure vessel valve 206). Furthermore, a reliable fuel extraction for operating the energy converter 103 can be ensured thereby. In particular, the measurement accuracy of the pressure sensor 116, 126 in the extraction line 113, 123 can be improved, which enables an exact pressure equalization of the fuel pressure in the extraction line 113, 123 and in the pressure vessel 110, 120 and / or which enables a reliable operation of safety functions (for example, monitoring of an excess of mass flow).

[0062] In other words, during the refilling of the pressure vessel 110, 120, the pressure vessel valve 206 can be actuated in a clocked manner (for example, in the millisecond range, approximately 15-75 ms), so that the extraction line 113, 123 is (at least partially) filled. If possible, this can be done without the pressure vessel valve 206 being fully open. Alternatively, a full opening of the pressure vessel valve 206 can be implemented. Here, the full opening of the pressure vessel valve 206 is preferably only carried out over a relatively short period of time (for example, 0.3-2 seconds) during the refilling process, so that the state "refilling is in progress while the valve 206 is open" is as short as possible, and thus the advantages of the separate supply line 111, 121 and the extraction line 113, 123 are mostly maintained for specific fault situations and / or functional faults (for example, a leak in the extraction line 113, 123, a defective pressure converter 102, and a corresponding pressure increase in the medium-pressure line to the energy converter 103).

[0063] An alternative or complementary point in time for the (if possible in beat) manipulation of the pressure vessel valve 206 is the point in time immediately after the refueling process:

[0064] - when no pressure increase in the pressure vessel 110, 120 occurs any more, and / or when the filling level of the pressure vessel is at least 93% or 95%; and / or

[0065] - when the refueling flap is closed.

[0066] Alternatively or additionally, the manipulation of the pressure vessel valve 206 can take place at a specific point in time when the extraction of the fuel 104 is prepared, for example when the vehicle has been started and the pressure vessel valve 206 has to be opened for the extraction. In this case, a relatively short, beat-like opening pulse sequence of the pressure vessel valve 206 can precede the actual extraction.

[0067] The manipulation of the one or more pressure vessel valves 206 can be related to the pressure difference between the pressure in the supply line 111, 121 and the pressure in the extraction line 113, 123. In a pressure vessel system 100 with multiple pressure vessels 110, 120, the manipulation of the pressure vessel valves 206 of different pressure vessels 206 can take place in a sequence (not all valves 206 at the same time, in particular not always only one valve 206 per switching process). Thereby, the number of cycles of valve manipulations and thus the load of the valves 206 can be reduced. On the other hand, the extraction line 113, 123 can still be filled step by step (in beats - according to the manipulation sequence) here.

[0068] By such a manipulation of the pressure vessel valves 206 of the pressure vessels 110, 120 during refueling, the pressure in the extraction line 113, 123 can be equalized with the internal pressure of the pressure vessels 110, 120. Furthermore, for a subsequent request for extraction of the fuel 104 (for example when the vehicle is driven away), the duration until the extraction preparation is completed can be reduced. Furthermore, the influence of the above-mentioned erroneous pressure measurement can be eliminated or at least reduced.

[0069] Alternatively or additionally, the pressure equalization or pressure approximation between the filling path 111, 121 and the extraction path 113, 123 can take place immediately after the end of the refueling process and / or shortly before an expected request for extraction. For example, the pressure approximation can be triggered by a driver presence recognition (door opening, seat occupancy, etc.). Alternatively or additionally, the pressure approximation can be triggered with a specific delay time (for example 10 seconds) after the end of the refueling process (for example after a determination that no pressure increase in the pressure vessel 110, 120 occurs any more or after the refueling flap is closed).

[0070] Preferably, the extraction paths 113, 123, especially in case of no immediate request for extraction, are preferably not filled up to the pressure in the filling paths 111, 113, especially up to the pressure in the pressure vessel 110, 120, but only up to the filling pressure minus a certain offset value, for example 50 bar, or variable, approximately -5-20% of the filling pressure. Thus, a diagnosis of the tightness of the one or more closed pressure vessel valves 206 can be achieved (based on the pressure difference between the internal pressure in the pressure vessel 110, 120 and the pressure in the extraction line 113, 123).

[0071] The (if possible beat by beat) opening of the pressure vessel valves 206 of the pressure vessels 110, 120 and / or equalizing or approaching the pressure in the extraction line 113, 123 to the pressure in the supply line 111, 121 during the filling process enables a check of the plausibility of the pressure in the supply line 111, 121 by means of a pressure measurement of the pressure in the extraction line 113, 123 during the ongoing filling. Thereby, the diagnostic capability and thus the safety during the filling can be improved (for example, in case of a failure of the pressure sensor 118, 128 in the supply line 111, 121 during the filling or in case of an error in the pressure identification).

[0072] The control unit 150 can be provided for providing an extended emergency operation function for the filling process. In particular, the control unit 150 can be provided for detecting a defect and / or a failure of the pressure sensor 118, 128 of the supply line 111, 121 to the pressure vessel 110, 120 during the ongoing filling process. In response thereto, the pressure vessel valves 206, in particular the OTVs, of the pressure vessels 110, 120 can be actuated beat by beat or continuously in order to equalize the pressure in the extraction line 113, 123 to the pressure in the supply line 111, 121.

[0073] The filling can then be continued using the sensor data of the pressure sensors 116, 126 of the extraction line 113, 123. Here, in particular in case of a continuous opening of the pressure vessel valves 206, a so-called COM filling can be continued, in which a feedback on the system pressure is provided to the fuel pump for the filling in order to achieve a higher filling level of the pressure vessels 110, 120 within the scope of the ongoing filling process. The feedback on the system pressure can be provided based on the sensor data from the pressure sensors 116, 126 of the extraction line 113, 123.

[0074] If possible, the pressure vessel valves 206 of all (in particular both) pressure vessels 110, 120 of the pressure vessel system 100 can be opened, or at least the pressure vessel valves 206 of the pressure vessels 110, 120 with the lower pressure loss in the filling path (which in the case of pressure vessels 110, 120 of the same size are the pressure vessels 110, 120 with the shorter supply lines 111, 121). It can thus be ensured that, based on the sensor data of the pressure sensors 116, 126 of the extraction lines 113, 123, the maximum system pressure within the pressure vessel system 100 can be detected (and, if possible, feedback thereto can be provided).

[0075] Equalizing the pressure in the extraction lines 113, 123 with the pressure in the supply lines 111, 121 makes it possible to determine the system pressure, in particular the internal pressure in the pressure vessel or vessels 110, 120, after the filling process with increased accuracy. Depending on the position of the pressure sensors 118, 128 (relatively close to the filling inlet 101 or relatively close to the pressure vessels 110, 120), the pressure indicated by the pressure sensors 118, 128 in the supply lines 111, 121 has a relatively large dynamic share (which is caused by the pressure loss on the supply lines 111, 121). By measuring the pressure in the extraction lines 113, 123 during or after the filling process, it is thus possible to determine the filling level of the pressure vessel or vessels 110, 120 with increased accuracy (because the pressure in the extraction lines 113, 123 has no dynamic share and because the pressure measurement in the extraction lines 113, 123 is not distorted by the medium temperature of the filling mass flow). In particular, it is thus possible to increase the continuity or stability of the filling level indication (filling level when the valves 206 are open and filling level when the valves 206 are closed).

[0076] Figure 3 A flow chart of an exemplary (if possible computer-implemented) method 300 for operating the pressure vessel system 100 is shown. The method 300 is in particular designed to increase the accuracy of the operation of the pressure vessel system 100 and / or to reduce the load on the pressure vessel system 100 due to the filling process during or after the filling process.

[0077] The pressure vessel system 100 comprises at least one pressure vessel 110, 120 with a pressure vessel valve 206 (in particular an OTV) which is configured to guide the fuel 104 from the pressure vessel 110, 120 to an extraction line 113, 123 of the pressure vessel 110, 120 for the supply of an energy converter 103 (in particular a fuel cell stack).

[0078] The method 300 comprises determining 301 that a filling process of the pressure vessel 110, 120 is occurring or has occurred. This can be identified, for example, on the basis of a pressure rise in the supply line 111, 121 leading to the pressure vessel 110, 120 and / or the filling inlet 101 being open.

[0079] Furthermore, the method 300 comprises, in response to the identified filling process, causing 302 the pressure vessel valve 206 to be opened in time before a request for extraction of fuel 104 for operation of the energy converter 103. Thus, it can be caused that fuel 104 has already been guided from the pressure vessel 110, 120 into the extraction line 113, 123 in time before the (first) request for extraction in order to bring the pressure in the extraction line 113, 123 close to the pressure in the pressure vessel 110, 120 and / or to reduce the pressure difference between the internal pressure in the pressure vessel 110, 120 and the pressure in the extraction line 113, 123. Here, the pressure difference can be reduced in a precise manner by opening the pressure vessel valve 206 in pulses or in a metrical manner.

[0080] By the measures described in this document, a particularly protective and precise operation of the pressure vessel system 100 (in particular following a filling process) can be achieved.

[0081] The invention is not limited to the exemplary embodiments shown. In particular, it should be noted that the description and the drawings merely illustrate the principles of the proposed method, device and system.

[0082] List of drawing references

[0083] 100 pressure vessel system

[0084] 101 filling inlet

[0085] 102 pressure converter

[0086] 103 energy converter

[0087] 104 fuel

[0088] 110, 120 pressure vessel

[0089] 111, 121 supply line

[0090] 112, 122 valve arrangement

[0091] 113, 123 extraction line

[0092] 116, 126 pressure sensor (extraction line)

[0093] 118, 128 pressure sensor (supply line)

[0094] 150 control unit

[0095] 201 inflow interface

[0096] 202 inflow filter

[0097] 203 outflow interface

[0098] 204, 205 flow restriction unit

[0099] 207 manual valve (in parallel to the electrically operable valve)

[0100] 208 evaluation unit

[0101] 209 pressure reduction unit

[0102] 210 data interface

[0103] 211 venting unit

[0104] 212 outflow filter

[0105] 213 temperature sensor

[0106] 214 manual valve (in series to the electrically operable valve)

[0107] 215 non-return valve (in parallel to the electrically operable valve)

[0108] 216 coupling point

[0109] 221 inflow channel

[0110] 222 common channel

[0111] 223 outflow channel

[0112] 300 Method for adjusting the pressure in the withdrawal line of a pressure vessel

[0113] 301, 302 Method steps

Claims

1. Control unit (150) for a pressure vessel system (100), the pressure vessel system comprising at least one pressure vessel (110, 120) having a pressure vessel valve (206) configured to conduct fuel (104) from the pressure vessel (110, 120) into an extraction line (113, 123) for feeding an energy converter (103); wherein, The control unit (150) is configured to - determine that a refilling process of the pressure vessel (110, 120) is occurring or has occurred; and - in response thereto, cause the pressure vessel valve (206) to open in time before an extraction request for fuel (104) for operating the energy converter (103), in order to bring the pressure in the extraction line (113, 123) close to the pressure in the pressure vessel (110, 120), thus enabling the pressure vessel valve (206) to be opened even in the absence of an extraction request for fuel for operating the energy converter (103).

2. The control unit (150) according to claim 1, wherein The control unit (150) is configured to cause the pressure vessel valve (206) to open pulsed and / or to open time-limited during the refilling process, in order to guide fuel (104) from the pressure vessel (110, 120) into the extraction line (113, 123).

3. The control unit (150) according to claim 1 or 2, wherein The control unit (150) is configured to cause the pressure vessel valve (206) to open pulsed in time before an extraction request for fuel (104) for operating the energy converter (103).

4. The control unit (150) according to claim 3, wherein The control unit (150) is configured to cause the pressure vessel valve (206) to open for a maximum of 400 milliseconds or a maximum of 200 milliseconds or a maximum of 100 milliseconds.

5. The control unit (150) according to claim 1 or 2, wherein The control unit (150) is configured to - determine that the refilling process has ended based on one or more indicators; and - in response thereto, cause the pressure vessel valve (206) to open before an extraction request for fuel (104), in order to guide fuel (104) from the pressure vessel (110, 120) into the extraction line (113, 123).

6. The control unit (150) according to claim 5, wherein The one or more indicators include: - the fact that no pressure increase in the pressure vessel (110, 120) is occurring anymore; - the fact that the pressure vessel (110, 120) has reached or exceeded a certain fill level; - the fact that a refilling inlet (101) of the pressure vessel system (100) has been closed; and / or - the fact that a user of the energy converter (103) is preparing an activation of the energy converter (103) and an associated extraction request for fuel (104).

7. The control unit (150) according to claim 5, wherein The control unit (150) is configured to cause the pressure vessel valve (206) to open for a predetermined time after determining that the refilling process has ended.

8. The control unit (150) according to claim 1, wherein The control unit (150) is configured to operate the pressure vessel valve (206) in order to adjust the pressure in the extraction line (113, 123) to be below the pressure in the pressure vessel (110, 120) by a certain offset value.

9. The control unit (150) according to claim 1, wherein The control unit (150) is configured to operate the pressure vessel valve (206) such that the pressure in the extraction line (113, 123) is below the pressure in the pressure vessel (110, 120) by a certain offset value when there is an extraction request.

10. The control unit (150) according to claim 8 or 9, wherein The offset value is between 20 bar and 100 bar; and / or, the offset value is between 10% and 20% of the internal pressure of the pressure vessel.

11. The control unit (150) according to claim 1 or 2, wherein The control unit (150) is configured to - cause the pressure in the extraction line (113, 123) to approach the pressure in the pressure vessel (110, 120) during a refueling process and / or the pressure in the extraction line to equalize with the pressure in the pressure vessel during the refueling process; - determine sensor data of a pressure sensor (116, 126) in the extraction line (113, 123); and - determine and / or check, based on the sensor data of the pressure sensor (116, 126) in the extraction line (113, 123), the pressure in a supply line (111, 121) to the pressure vessel (110, 120) via which the refueling process takes place.

12. The control unit (150) according to claim 11, wherein The control unit (150) is configured to - determine, based on the sensor data of the pressure sensor (116, 126) in the extraction line (113, 123), a system pressure of the pressure vessel system (100) during the refueling process; and - transmit the system pressure to a refueling unit from which fuel (104) is provided for the refueling process.

13. The control unit (150) according to claim 11, wherein The control unit (150) is configured to - determine sensor data of a pressure sensor (118, 128) in a supply line (111, 121) to the pressure vessel (110, 120) via which the refueling process of the pressure vessel (110, 120) takes place; - compare the pressure indicated by the sensor data of the pressure sensor (118, 128) in the supply line (111, 121) with the pressure indicated by the sensor data of the pressure sensor (116, 126) in the extraction line (113, 123); and - control the refueling process of the pressure vessel (110, 120) and / or the pressure vessel valve (206) in dependence on the comparison result. The control unit (150) is configured to 14. The control unit (150) according to claim 1 or 2, wherein - cause the pressure in the extraction line (113, 123) to approach the pressure in the pressure vessel (110, 120) and / or the pressure in the extraction line to equalize with the pressure in the pressure vessel; - determine sensor data of a pressure sensor (116, 126) in the extraction line (113, 123); and - determine and / or check, based on the sensor data of the pressure sensor (116, 126) in the extraction line (113, 123), a fill level of the pressure vessel (110, 120). The control unit (150) is configured to cause the pressure vessel valve (206) to be generally open for a maximum of 5% or less of the total duration of the refueling process during the refueling process in order to cause the pressure in the extraction line (113, 123) to approach the pressure in the pressure vessel (110, 120) during the refueling process.

15. The control unit (150) according to claim 1 or 2, wherein 16. The control unit (150) of claim 1 or 2, wherein - the control unit (150) is configured to determine, based on the sensor data of the pressure sensor (116, 126) in the extraction line (113, 123), a system pressure of the pressure vessel system (100) during the refueling process; and - the control unit (150) is configured to transmit the system pressure to a refueling unit from which fuel (104) is provided for the refueling process. - the pressure container system (100) has at least two pressure containers (110, 120) with pressure container valves (206) each; and - the control unit (150) is configured to cause - the pressure container valves (206) of the at least two pressure containers (110, 120) to be opened in turn and / or alternately in order to bring the pressure in the extraction line (113, 123) close to the pressure in the pressure containers (110, 120); and / or - the pressure container valve (206) of the pressure container (110, 120) with the lower pressure loss on the supply line (111, 121) for the filling process to be opened in order to bring the pressure in the extraction line (113, 123) close to the pressure in the pressure container (110, 120).

17. The control unit (150) according to claim 1 or 2, wherein The control unit (150) is configured to - determine sensor data of a pressure sensor (118, 128) in a supply line (111, 121) to the pressure container (110, 120) via which a filling process of the pressure container (110, 120) takes place; and - determine, on the basis of the sensor data of the pressure sensor (118, 128) in the supply line (111, 121), that a filling process of the pressure container (110, 120) is taking place or has taken place.

18. The control unit (150) according to claim 1 or 2, wherein The control unit (150) is configured to, after the pressure in the extraction line (113, 123) has been brought close to the pressure in the pressure container (110, 120), then - determine that there is a request for extraction of fuel (104) for operation of the energy converter (103); and - in response thereto, cause the pressure container valve (206) to be opened in order to direct fuel (104) from the pressure container (110, 120) into the extraction line (113, 123).

19. The control unit (150) according to claim 1 or 2, wherein The control unit (150) is configured to cause the pressure container valve (206) to be opened only if the internal pressure of the pressure container (110, 120) is at least 30% or at least 50% or at least 70% of the maximum filling pressure or of the nominal operating pressure.

20. Pressure container system (100), comprising - at least one pressure container (110, 120) with a pressure container valve (206) configured to direct fuel (104) from the pressure container (110, 120) into an extraction line (113, 123) for feeding an energy converter (103); and - a control unit (150) according to any one of claims 1 to 19, configured to operate the pressure container valve (206).

21. Method (300) for operating a pressure vessel system (100), the pressure vessel system comprising at least one pressure vessel (110, 120) having a pressure vessel valve (206) configured to conduct fuel (104) from the pressure vessel (110, 120) into an extraction line (113, 123) for feeding an energy converter (103); wherein, The method (300) comprises - determining (301) that a filling process of the pressure container (110, 120) is taking place or has taken place; and - determining (302) that there is a request for extraction of fuel (104) for operation of the energy converter (103); and - in response thereto, causing (303) the pressure container valve (206) to be opened in order to direct fuel (104) from the pressure container (110, 120) into the extraction line (113, 123). - in response thereto, causing (302) the pressure vessel valve (206) to be opened pulsed in time before a request for extraction of fuel (104) for operating the energy converter (103) in order to bring the pressure in the extraction line (113, 123) close to the pressure in the pressure vessel (110, 120), thus enabling the pressure vessel valve (206) to be opened even in the absence of a request for extraction of fuel for operating the energy converter (103).

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