Filling system for a pressurised container and method for operating the filling system

Abstract

The invention relates to a filling system for a pressure vessel and a method for limiting the filling rate of a pressure vessel, in particular for filling a high-pressure vessel with a gas.A filling system (100) according to the invention for filling a high-pressure vessel (4) with a fluid at a variable filling rate, wherein the high-pressure vessel (4) is in particular a high-pressure vessel (4) for storing a gas with an inner container and a reinforcing layer surrounding the inner container, depending on an internal pressure pi,H prevailing in the high-pressure vessel (4), with a main line (2) that can be shut off via a filling-side solenoid valve (1), has a main line (2) with a main line bypass (5) with a filling pressure reduction device (6) for reducing the filling pressure, wherein the main line bypass (5) branches off from the main line (2) upstream of the filling-side solenoid valve (1) when filling the high-pressure vessel (4) in the flow direction x of the fluid.Furthermore, the filling system (100) according to the invention comprises an internal pressure determining device (10) and a control unit (11), wherein the control unit (11) is configured to receive an internal pressure value pi,H from the internal pressure determining device (10) and to compare it with a predetermined first threshold value pthreshold,1 and a predetermined second threshold value pthreshold,2, wherein the control unit (11) is further configured to open the filling-side solenoid valve (1) if the internal pressure pi,H in the high-pressure container (4) corresponds at least to the predetermined first threshold value pthreshold,1 and to close the filling-side solenoid valve (1) if the internal pressure pi,H in the high-pressure container (4) is below the predetermined second threshold value pthreshold,2.

Description

Field of invention

[0001] The invention relates to a filling system for a pressure vessel and a method for limiting the filling rate of a pressure vessel, in particular for filling a high-pressure vessel with a gas.

[0002] The filling rate, as used here, refers to the volume flow rate at which the pressure vessel is filled. This volume flow rate can be influenced by the pressure in the main filling line. Background of the invention

[0003] In recent years, interest in the use of alternative fuels in the automotive industry has increased dramatically. As a result, more and more vehicles powered by gaseous fuels such as natural gas, LPG (liquefied petroleum gas), or hydrogen are entering the market. This applies to all types of vehicles, including cars, especially passenger cars, but also commercial vehicles such as trucks or buses, construction equipment, rail vehicles, as well as watercraft, aircraft, and spacecraft. Furthermore, the increasing production of natural gas and fracked gas, particularly in countries without a suitable pipeline network, necessitates storage in pressurized containers.

[0004] Currently used cylindrical high-pressure vessels have a reinforcing layer made of fiber-reinforced composite material, consisting of fibers embedded in a matrix material. This outer layer is wound onto an inner vessel (the so-called liner) of the high-pressure vessel, which acts as the winding core, using a winding process. While the inner vessel guarantees, for example, the gas tightness of the high-pressure vessel, the fiber-reinforced composite layer provides the necessary mechanical stability. Type 3 high-pressure vessels use a metallic inner vessel (metallic liner), for example, made of aluminum or steel, while Type 4 high-pressure vessels use a plastic inner vessel (liner). However, pressure vessels consisting of only one or more metallic materials are also known. The terms liner and inner vessel are used synonymously in this document.

[0005] Pressure vessels are filled with hydrogen gas. Since hydrogen filling stations, in particular, can experience very high pressures and low temperatures, and hydrogen is highly reactive in combination with oxygen, hydrogen refueling systems must meet stringent requirements. Furthermore, the safety of refueling vehicles and the sequential filling of various containers must be guaranteed at filling stations.

[0006] The maximum operating pressure, particularly when filling a high-pressure tank or high-pressure tank system with hydrogen, can vary depending on the application, ranging from 200 to 1200 bar, typically between 350 and 875 bar. A high-pressure tank system consists of multiple individual high-pressure tanks, which are usually filled from a common main line, ensuring that each tank has the same internal pressure. This high-pressure tank or system can then supply hydrogen to a fuel cell or combustion engine.

[0007] Particularly with Type 4 high-pressure vessels, the problem can arise that filling an empty high-pressure vessel with the aforementioned pressures can damage the liner. In this document, "empty" refers to a high-pressure vessel with an internal pressure below a certain threshold, for example, 20 bar. At an internal pressure of 20 bar or below, the liner can detach, at least locally, from the reinforcing layer. If such a high-pressure vessel with an internal pressure of 20 bar or less is suddenly subjected to a filling pressure of, for example, 800 bar, the liner can explosively reattach itself to the reinforcing layer, thereby also instantly unfolding any wrinkles in the detached wall of the inner vessel.Due to locally excessive strain rates, high stresses can occur in the liner material; in particular, the liner can be damaged by a local exceedance of the permissible stress of the liner material.

[0008] In the field of medical oxygen pressure vessels, it is known to design the withdrawal valve as a residual pressure valve. This residual pressure valve prevents the pressure vessel from being completely emptied by closing at a predetermined residual pressure and preventing further withdrawal of the stored gas. For medical oxygen cylinders, this residual pressure threshold is typically seven bar. It is important to prevent complete emptying of the cylinder, as complete emptying with the withdrawal valve open could allow ambient air to enter the cylinder, potentially leading to bacterial growth. Medical oxygen cylinders are typically steel cylinders without a liner.

[0009] For high-pressure vessels, especially those not used for storing medical gases where potential microbial contamination is not a concern, it is desirable that the storage capacity be fully usable, meaning that the high-pressure vessel can be completely emptied and subsequently refilled. Furthermore, it is desirable that the filling system, or the filling system and the high-pressure vessel, is purgeable. If the high-pressure vessel is to be used, for example, for storing reactive fluids, particularly hydrogen, then gas exchange must be possible in the filling system, or the filling system and the high-pressure vessel, for maintenance and / or repair work. This means that the filling system, or the filling system and the high-pressure vessel, can be inertized with a non-flammable gas, such as nitrogen.Furthermore, it may be necessary to flush the high-pressure tank and the filling system before refilling the high-pressure tank with a different fluid than the one previously stored. This also applies if the high-pressure tank is filled with an inert gas, for example for maintenance purposes, and is now to be refilled with a fuel, such as hydrogen gas. Summary of the invention

[0010] The present invention is based on the objective of improving the prior art. In particular, it is an object of the invention to provide a filling system for a high-pressure vessel, especially for filling a high-pressure vessel with a gas, with which the risk of damage to the liner during filling is minimized, wherein the filling system or the filling system and the high-pressure vessel are to be cleanable.

[0011] Initially, the problem addressed is the solution of a filling system for filling a high-pressure vessel with a fluid at a variable filling rate. The high-pressure vessel is, in particular, a high-pressure gas storage vessel with an inner container and a reinforcing layer surrounding the inner container, such as a high-pressure vessel of type 4. The filling rate depends on an internal pressure π,H prevailing in the high-pressure vessel and includes a main line that can be shut off via a filling-side solenoid valve. The main line has a bypass with a filling pressure reduction device for reducing the filling pressure. Viewed in the direction of fluid flow during filling of the high-pressure vessel, the bypass is located upstream of a filling-side solenoid valve, via which the main line can be shut off.branching off from the main line, the filling system further comprises a fluid drain and an interface for fluid injection, as well as a discharge-side valve, an interface for fluid injection, a drain opening, an interface to the high-pressure tank with valve, a high-pressure-side pressure sensor via which the pressure present in the main line downstream of the filling-side solenoid valve (viewed in the direction of fluid flow) can be determined, a low-pressure-side pressure sensor, and a control unit. The control unit is configured to receive an internal pressure value pi,H from the high-pressure-side pressure sensor and compare it with a predetermined first threshold value pthreshold,1 and a predetermined second threshold value pthreshold,2. The control unit is further configured to open the filling-side solenoid valve if the internal pressure pi,H in the high-pressure tank is at least equal to the predetermined first threshold value pthreshold,2.1 corresponds to closing the filling-side solenoid valve, provided that the internal pressure pi,H in the high-pressure tank is below the specified second threshold p threshold,2.

[0012] The following terminology should be explained in this context: First, it should be expressly noted that, within the scope of this patent application, indefinite articles and numerical specifications such as "one," "two," etc., are generally to be understood as "at least" specifications, i.e., "at least one...", "at least two...", etc., unless it is expressly clear from the respective context or it is obvious or technically necessary for a person skilled in the art that only "exactly one...", "exactly two...", etc., can be meant. Furthermore, all numerical specifications, as well as specifications relating to process parameters and / or device parameters, are to be understood in a technical sense, i.e., as being subject to the usual tolerances. Even the explicit indication of the limitation "at least" or "at least," etc., should not lead to the conclusion that the simple use of "one," i.e., without the indication of "at least," etc., implies "exactly one."

[0013] Under a Pressure vessel Here, "pressure vessel" refers to any closed or closable container with an internal volume, in which a fluid can be stored at a pressure higher than ambient pressure. This need not be a single container. An interconnected system of several pressure vessels can also be treated as a single pressure vessel for the filling system or the filling rate limiting method according to the invention, provided that the multiple pressure vessels are connected to the same main line, in which case the same internal pressure prevails in all pressure vessels. In particular, a High-pressure tankA pressure vessel is understood to be one in whose internal volume a fluid can be stored at a pressure at least two orders of magnitude higher than the ambient pressure. In particular, a Type 4 pressure vessel represents such a high-pressure vessel, comprising an inner liner made of plastic, which, for example, guarantees the gas tightness of the pressure vessel, and a reinforcing layer made of a fiber composite material, which provides the necessary mechanical stability to the pressure vessel. The fluid can be a gas, especially hydrogen. Where the term "high-pressure vessel" is used below, it also refers to a system of high-pressure vessels.

[0014] In this context, a main line is understood to be a tubular pipe through which the fluid is conveyed into the high-pressure tank during the filling process. The filling pressure supplied by an external system prevails in the main line. This external system could, for example, include a pumping device. The filling pressure could also originate from an external pressure system, such as a high-pressure system.

[0015] In this context, a filling rate refers to the volume flow rate of the fluid with which the high-pressure vessel is filled.

[0016] Under a bypass Here, a bypass line is understood to be one that allows at least part of a line to be bypassed.

[0017] A solenoid valveA solenoid valve is a valve actuated by an electromagnet. It can be a pilot-operated solenoid valve. A pilot-operated solenoid valve requires a pressure differential relative to the operating pressure to open and close. The pilot system acts as an amplifier, allowing a solenoid with low force to control fluids with high flow rates at higher pressures.

[0018] Under a Filling pressure reduction deviceA filling pressure reduction device is understood to be a device that can reduce a filling rate, i.e., a filling volume flow rate and thus the filling pressure. In a mechanical filling pressure reduction device, it operates purely mechanically. An example of a mechanical filling pressure reduction device is an orifice plate. The uniform flow of a fluid in a pipeline is constricted by the orifice plate, i.e., the cross-sectional area of ​​the fluid flow narrows, causing the velocity to increase at that point. According to Bernoulli's energy equation, this increase in velocity at the constriction point results in a reduction of the static pressure.

[0019] Under a specified thresholdHere, a value, specifically a pressure value, is understood to be externally adjustable to the system. The solenoid valve can open if the internal pressure in the high-pressure tank meets or exceeds a predetermined first threshold, and close if the internal pressure in the high-pressure tank falls below a predetermined second threshold. The first and second thresholds can be identical. However, a degree of hysteresis is typically observed, with the second threshold usually being approximately 4 bar lower than the first. For example, the predetermined first threshold could be 20 bar and the predetermined second threshold 16 bar.

[0020] Under a continuous determination of internal pressure This document should be understood to mean not only a continuous determination of the internal pressure, but also a determination of the internal pressure at regular intervals.

[0021] The pressure measured in the main line downstream of the filling-side solenoid valve (viewed in the direction of fluid flow) can be used to determine the internal pressure in the high-pressure tank. Alternatively, or in addition, the internal pressure in the high-pressure tank can also be measured directly using an internal pressure measuring device.

[0022] With the filling system according to the invention, the main line can be shut off depending on the internal pressure prevailing in the high-pressure vessel if the internal pressure prevailing in the high-pressure vessel falls below a second threshold value. In this case, the filling-side solenoid valve closes the main line, so that filling can only take place via the main line bypass. Since a filling pressure reduction device for reducing the filling rate is located in the main line bypass, filling takes place at a reduced filling rate predetermined by the filling pressure reduction device, whereby the reduced filling rate can be preset in such a way as to prevent damage to the liner during filling. Provided that the determined internal pressure corresponds to at least a predetermined first threshold value, the filling-side solenoid valve opens and the fluid takes the path of least resistance for filling, i.e., through the main line.From this point onwards, filling takes place at the full available filling rate, which makes filling significantly faster.

[0023] Furthermore, the filling system according to the invention allows a first fluid to be exchanged with a second fluid within the filling system or between the filling system and the high-pressure vessel. For this purpose, all valves can be closed. A fluid source for the second fluid can be connected at the interface to the fluid feed. When the drain opening and the interface to the high-pressure vessel are open, the first fluid escapes from the filling system and the high-pressure vessel. This can continue until a minimum pressure is reached in the high-pressure vessel, which can correspond, for example, to the first or second threshold value and which can be determined via the internal pressure measuring device for pressure measurement in the high-pressure vessel.If the discharge valve is closed and subsequently the filling solenoid valve is opened, the second fluid from the fluid source, which could be an inert gas such as nitrogen, flows through the filling system into the high-pressure vessel. This can continue until a predetermined reference pressure is reached in the high-pressure vessel, which can be determined via the internal pressure gauge. The filling solenoid valve can then be closed again. These steps can be repeated until a predefined number of cycles is reached, ensuring the desired concentration of the second fluid. Advantageously, the fluid exchange can be limited to the exchange of fluids within the filling system; that is, a fluid system can be achieved only within the filling system, while the original fluid, for example, the first fluid, remains in the high-pressure vessel.The procedure described above is modified insofar as the interface to the high-pressure tank remains closed throughout the entire process. This prevents the fluid in the high-pressure tank from escaping. Only the fluid in the filling system escapes through the drain opening. This can continue until a predefined reference pressure in the filling system, which can be determined via the high-pressure-side pressure sensor and / or the low-pressure-side pressure sensor, is reached. The filling-side solenoid valve can then be closed again as described above. These steps can be repeated until a predefined number of cycles is reached, ensuring the desired concentration of the second fluid.

[0024] Thus, the invention presented here ensures cost-effectively that pressure vessels are not overloaded during filling, for example, due to operator error. Furthermore, simple gas exchange can be carried out with minimal personnel. In its simplest form, a standard gas cylinder can be connected directly to the fluid inlet. Safe inerting of the filling system, or of the filling system and the high-pressure vessel, can be performed in a variety of locations without specially trained personnel.

[0025] In an advantageous embodiment, the filling-side solenoid valve is closed in the de-energized state. This ensures that filling always occurs at the reduced filling rate, even in the event of a power failure, thus preventing damage to the liner during filling, even in the case of a malfunction such as a power failure.

[0026] In an advantageous embodiment, the filling-side solenoid valve is a pilot-operated solenoid valve. A pilot-operated solenoid valve requires only a pressure differential equal to the operating pressure to open and close. The actuator here merely performs a pilot function, thereby relieving the main sealing element. The medium pressure, or the existing pressure differential, lifts the main seal. With this type of control, high pressures can be controlled with small solenoids at large nominal diameters.

[0027] In an advantageous embodiment, the filling pressure reduction device for reducing the filling rate is a mechanical filling pressure reduction device. The use of a mechanical filling pressure reduction device results in a simple, reliable, and low-maintenance system. Furthermore, the risk of sparking from electrical contacts or similar components is minimized, which is particularly advantageous when working with flammable, especially highly flammable, gases such as hydrogen.

[0028] In an advantageous embodiment, the mechanical filling pressure reduction device for reducing the filling rate includes an orifice. This allows the filling rate to be reduced in a simple and reliable manner.

[0029] In a further advantageous embodiment of the filling system, the high-pressure-side pressure sensor is configured to determine the internal pressure prevailing in the main line, viewed downstream of the solenoid valve in the direction of fluid flow during filling. The filling pressure can be determined in the main line, viewed downstream of the solenoid valve in the direction of fluid flow during filling, at a point close to the filling pressure reduction device. Since the pressure in the main line, viewed downstream of the solenoid valve in the direction of fluid flow during filling, is the same as in the high-pressure tank(s), even when several high-pressure tanks are to be filled simultaneously, it is sufficient to determine the pressure at this point.

[0030] In another advantageous embodiment of the filling system, the system includes a pressure switch that incorporates the high-pressure-side pressure sensor and the control unit. Such a pressure switch is simple and robust in design and requires only a power supply of, for example, ±5V DC, ±12V DC, or ±24V DC, which is easy to implement, for instance, in a vehicle. The standard electrical system voltage in a modern passenger car is typically 12V DC, and in a commercial vehicle, typically 24V DC. Therefore, if these voltages are used, the filling system does not require its own power source or voltage converter.

[0031] In another advantageous embodiment of the filling system, the control unit has a digital control system. The pressure switch can, for example, be designed as a digital pressure switch. If a higher-level system already has a digital control system, the control of the solenoid valve can be easily integrated into this control system without significant effort.

[0032] In another advantageous embodiment of the filling system, the main line has a check valve. This prevents the fluid from flowing back. Additionally, the main line bypass can also have a check valve, thus preventing the fluid from flowing back through the main line bypass as well. Without the check valve, this could occur, for example, if a high-pressure tank with a higher internal pressure than the filling system is connected to the filling system.

[0033] In another advantageous embodiment of the filling system, the solenoid valve is pilot-operated. A pilot-operated solenoid valve requires a pressure differential relative to the operating pressure to open and close. The pilot system acts as an amplifier, enabling a solenoid with low force to control fluids with high flow rates at higher pressures.

[0034] According to another aspect, the stated problem solves a method for limiting a filling rate when filling a high-pressure vessel, in particular a high-pressure vessel for storing a gas with an inner container and a reinforcing layer surrounding the inner container, depending on an internal pressure prevailing in the high-pressure vessel, via a filling system with a main line that can be shut off via a solenoid valve and a main line bypass with a mechanical filling pressure reduction device for reducing the filling rate, wherein the filling-side solenoid valve is closed in the de-energized state, wherein the internal pressure in the main line seen in the flow direction x downstream of the filling-side solenoid valve is continuously determined and compared with predetermined first and second threshold values ​​pthreshold,1, pthreshold,2, wherein the filling-side solenoid valve is opened or closed.remains in place if the specified internal pressure corresponds at least to the specified first threshold p threshold,1 and the filling-side solenoid valve is closed, or remains in place if the specified internal pressure is below the specified second threshold p threshold,2.

[0035] In this document, "continuous determination of internal pressure" refers not only to constant measurement but also to measurement at regular intervals. For example, the internal pressure can be determined at essentially regular intervals using a pulsed method, where the pulse rate can also be varied depending on the difference between the measured internal pressure and the predetermined first or second threshold. Thus, it is possible, for instance, to measure the internal pressure more frequently when the difference between the measured internal pressure and the predetermined first or second threshold is small, for example, on the order of less than 20 bar, and to increase the pulse rate when the difference between the measured internal pressure and the predetermined first or second threshold is larger.

[0036] The internal pressure measuring device for direct pressure measurement in the high-pressure vessel is optional. The filling-side solenoid valve is closed when the pressure measured by the high-pressure-side pressure sensor is below the second threshold, pthrow,2. Similarly, the filling-side solenoid valve is closed when the internal pressure measured by the internal pressure measuring device for direct pressure measurement in the high-pressure vessel is below the second threshold, pthrow,2. Preferably, the filling-side solenoid valve remains closed even if the internal pressure measured by the internal pressure measuring device for direct pressure measurement in the high-pressure vessel is above the first threshold, pthrow,1, but the pressure measured by the high-pressure-side pressure sensor is below the second threshold, pthrow,2. Conversely, the filling-side solenoid valve is open when the pressure measured by the high-pressure-side pressure sensor is above the first threshold, pthrow,1.

[0037] If the internal pressure in the high-pressure vessel falls below a second threshold, the main line is shut off via the filling-side solenoid valve, and filling occurs via the main line bypass. Since the main line bypass contains a filling pressure reduction device to reduce the filling rate, filling takes place at a reduced rate predetermined by the device. This reduced rate can be set to prevent damage to the liner during filling. Provided the internal pressure meets at least a predetermined first threshold, the solenoid valve opens, and the fluid takes the path of least resistance, i.e., through the main line. From this point onward, filling occurs at the full available rate, significantly speeding up the process.

[0038] In an advantageous embodiment of the method according to the invention, the filling rate is limited by the flow of the fluid through a filling pressure reduction device, for example an orifice, during filling, provided that the determined internal pressure pi,H , is below a predetermined second threshold p threshold,2.

[0039] In a further advantageous embodiment of the method according to the invention, the internal pressure is continuously determined via a high-pressure-side pressure sensor, which determines the internal pressure in the main line in the direction of fluid flow during filling, viewed behind the solenoid valve.

[0040] The pressure measured by the high-pressure-side pressure sensor in the high-pressure-side piping system allows conclusions to be drawn about the internal pressure pi,H in the high-pressure tank, thus ensuring the protection of the inner vessel. Even if the interface or the valve contained therein to the high-pressure tank is closed, the internal pressure pi,H in the high-pressure tank cannot be lower than the pressure measured by the high-pressure-side pressure sensor in the high-pressure-side piping system, because otherwise pressure equalization would occur via the filling bypass with its integrated check valve.

[0041] According to another aspect, the object of the invention is a method for fluid exchange in the filling system according to the invention with the following steps: First, a counter in the control unit is set to 0 and in a next step is increased by 1.

[0042] The system then ensures that the filling-side solenoid valve, the discharge-side valve, and the interface to the high-pressure tank are closed. The control unit can query the valve positions for this purpose. If one or more of these valves are open, they are closed.

[0043] The system then ensures that a fluid source containing a second fluid is connected to the fluid inlet interface and that the fluid inlet interface is open. The fluid inlet interface may, for example, have a fitting with a valve, and the internal pressure in the fitting, viewed in the direction of flow during filling, can be monitored by the control unit upstream of the valve. Furthermore, the valve position in the fitting may be monitored by the control unit or displayed visually, and can be changed. If the valve in the fitting is closed, it is opened, for example, via the control unit or manually.

[0044] Next, ensure that the drain opening is open. The drain opening may, for example, have a valve whose position can be monitored and changed by the control unit. If the valve is closed, it is opened via the control unit. This process can be carried out analogously to the previous step.

[0045] Now, the outflow valve is opened, for example, via the control unit.

[0046] The pressure in the filling system is continuously measured and compared, for example, in the control unit with a predetermined minimum pressure, whereby the discharge-side valve is closed, for example, via the control unit, if the measured pressure in the filling system is less than or equal to the predetermined minimum pressure.

[0047] After the discharge valve has been closed, the filling-side solenoid valve is opened, for example via the control unit, and the continuously determined pressure in the filling system is compared, for example in the control unit, with a predetermined reference pressure, whereby the filling-side solenoid valve is closed, for example via the control unit, if the continuously determined pressure in the filling system is equal to or greater than the predetermined reference pressure.

[0048] The counter value is then compared with a predefined cycle number, for example in the control unit, and the steps of increasing the counter value by 1 until the filling-side solenoid valve closes are repeated if the counter value is less than the predefined cycle number.

[0049] This method ensures that a simple gas exchange in the filling system can be carried out with minimal personnel and at low cost, for example, for maintenance and / or repair purposes. Since a simple gas cylinder containing the second fluid can be connected directly to the fluid feed interface, safe inerting of the filling system is possible in a wide variety of locations without specially trained personnel.

[0050] According to another aspect, the problem underlying the invention solves a method for fluid exchange in the filling system according to the invention and a high-pressure tank connected to the filling system according to the invention via the interface to the high-pressure tank with the following steps: First, a counter in the control unit is set to 0 and in a next step is increased by 1.

[0051] The system then ensures that the filling-side solenoid valve, the discharge-side valve, and the interface to the high-pressure tank are closed. The control unit can query the valve positions for this purpose. If one or more of these valves are open, they are closed.

[0052] The system then ensures that a fluid source containing a second fluid is connected to the fluid inlet interface and that the fluid inlet interface is open. The fluid inlet interface may, for example, include a fitting with a valve, and the internal pressure in the fitting, viewed in the direction of flow during filling, can be monitored by the control unit upstream of the valve. Furthermore, the valve position in the fitting may be monitored and modifiable by the control unit. For example, if the valve in the fitting is closed, it will be opened by the control unit.

[0053] Next, it is ensured that the drain opening is open. The drain opening may, for example, have a valve, the valve position of which can be monitored and changed by the control unit. If the valve is closed, it is opened via the control unit.

[0054] Now, the outflow valve is opened, for example, via the control unit.

[0055] Now the interface to the high-pressure tank is opened. This interface can, for example, have a connector with a valve, the position of which can be monitored and changed by the control unit.

[0056] The pressure in the filling system is continuously measured and compared, for example, in the control unit with a predetermined minimum pressure, whereby the discharge-side valve is closed, for example, via the control unit, if the measured pressure in the filling system is less than or equal to the predetermined minimum pressure.

[0057] After the discharge valve has been closed, the filling-side solenoid valve is opened, for example via the control unit, and the continuously determined pressure in the filling system is compared, for example in the control unit, with a predetermined reference pressure, whereby the filling-side solenoid valve is closed, for example via the control unit, if the continuously determined pressure in the filling system is equal to or greater than the predetermined reference pressure.

[0058] The counter value is then compared with a predefined cycle number, for example in the control unit, and the steps of increasing the counter value by 1 until the filling-side solenoid valve closes are repeated if the counter value is less than the predefined cycle number.

[0059] The method for fluid exchange in the filling system according to the invention differs from the method for fluid exchange in the filling system according to the invention and in a high-pressure vessel connected to the filling system according to the invention in that, after opening the discharge-side valve according to step f. and before continuously determining the pressure in the filling system and comparing the determined pressure with a predetermined minimum pressure, wherein the discharge-side valve is closed when the determined pressure in the filling system is less than or equal to the predetermined minimum pressure according to step g., the interface to the high-pressure vessel is opened.

[0060] This method ensures that a simple and cost-effective gas exchange can be carried out in the filling system and the high-pressure vessel with minimal personnel effort, for example, for maintenance and / or repair purposes, or when a second pressure vessel needs to be filled with a second fluid after a first fluid has been filled into the first pressure vessel, provided that the first and second fluids are not to be mixed. Since a simple gas cylinder containing the second fluid can be connected directly to the fluid inlet interface, safe inerting of the filling system and the second pressure vessel is possible in a wide variety of locations without the need for specially trained personnel.

[0061] According to another aspect, the problem underlying the invention solves a method for residual pressure protection when withdrawing a fluid from the high-pressure container with the filling system according to the invention, comprising the following steps: Continuously determining the internal pressure pi,H in the main line viewed in the flow direction x behind the filling-side solenoid valve and checking whether the internal pressure pi,H is less than the specified second threshold p threshold,2, whereby this check is repeated until this condition is met and in the case that the internal pressure pi,H is less than the specified second threshold p threshold,2, closing the discharge-side valve.

[0062] The fluid is drawn from the high-pressure tank via the discharge valve. It can happen that the withdrawal continues for so long that a predetermined second threshold value, pthreshold,2, is undershot, creating the risk that the liner will detach, at least locally, from the reinforcement layer and thus be damaged during refilling, as described earlier.

[0063] The method according to the invention stops the fluid withdrawal before the internal pressure pi,H in the high-pressure vessel falls below the second threshold p threshold,2, thus avoiding the described risk.

[0064] Further advantages, special features and expedient further developments of the invention will become apparent from the dependent claims and the following presentation of preferred embodiments with reference to the illustrations.

[0065] They show Fig. 1: a schematic diagram of the filling system according to the invention; Fig. 2: a schematic diagram of the inventive method for limiting the filling rate of a high-pressure container for storing a gas; Fig. 3: a schematic diagram of the inventive method for fluid exchange in the inventive filling system; Fig. 4:a schematic diagram of the inventive method for fluid exchange in the filling system according to the invention and in a high-pressure container connected to the filling system according to the invention; Fig. 5: a schematic diagram of the inventive method for residual pressure protection during the withdrawal of a fluid from the high-pressure container with the inventive filling system.

[0066] Fig. 1Figure 1 shows a schematic diagram of the filling system 100 according to the invention. The filling system 100 has an interface to the fluid supply 3, via which a fluid source 18 can be connected. In the simplest case, the fluid source 18 can consist of a fluid storage device, for example, a gas cylinder. However, a pipeline in which fluid is transported can also serve as the fluid source 18. The interface 3 can be reversibly closed, for example, with a valve. If a fluid source 18 is connected and the interface to the fluid supply 3 is open, fluid, for example, a gas such as hydrogen, can flow through the filling system 100 in the flow direction x indicated by the arrow.

[0067] Viewed in the flow direction x, at the interface to the fluid feed 3, the fluid can initially flow through a main line 2. The main line 2 can be closed by a filling-side solenoid valve 1. Viewed in the flow direction x, upstream of the filling-side solenoid valve 1, a main line bypass 5 branches off from the main line 2. A filling pressure reduction device 6 is arranged in the main line bypass 5. The filling pressure reduction device 6 is designed here as a mechanical filling pressure reduction device 6 in the form of an orifice and can reduce the volume flow of the fluid flowing through it, which leads to a reduction in the filling rate and thus to a reduction in the build-up of filling pressure in a high-pressure tank 4 connected to the high-pressure tank 17 via an interface. By using a mechanical filling pressure reduction device, the system is simple and therefore reliable and requires little maintenance.Furthermore, the risk of sparking from electrical contacts or similar is minimized, which is particularly advantageous when working with flammable, especially highly flammable gases such as hydrogen. Viewed in the flow direction x, a main line bypass valve 13 is arranged downstream of the filling pressure reduction device 6, with which the main line bypass can be closed. Additionally, a check valve 20 is arranged downstream of the main line bypass valve 13 in the main line bypass 5, viewed in the flow direction x. A check valve 19 is also arranged downstream of the filling-side solenoid valve 1 in the main line 2, viewed in the flow direction x. The main line bypass valve 13 can be omitted to simplify the filling system. The check valve 20 in the main line bypass 5 can also be omitted if any minor leakage is acceptable.

[0068] Viewed in the direction of flow x, downstream of the check valve 19 located in the main line 2 and downstream of the point where the main line bypass 5 rejoins the main line 2, there is a branch that leads via a pressure reducer 14 and a discharge valve 7 to a drain opening 9. The drain opening 9 can be reversibly closed, for example, by means of another valve. In the illustrated embodiment, a consumer 8 is arranged downstream of the discharge valve 7 in this branch, viewed in the direction of flow x.

[0069] The high-pressure tank 4 can be filled via a main line bypass 21. This main line bypass 21 branches off at the interface to the high-pressure tank 17 and allows the high-pressure tank 4 to be filled with a higher flow rate than that permitted by the solenoid valve at interface 17. Filling of the high-pressure tank 4 is only possible via this main line bypass 21, as a further check valve 22 is located in the main line bypass 21, preventing backflow of fluid from the high-pressure tank 4. Fluid can only be withdrawn from the high-pressure tank 4 via interface 17. However, withdrawal typically occurs at a lower flow rate than is desired for rapid filling.

[0070] The filling system 100 can, for example, be arranged in a vehicle, such as a hydrogen-powered vehicle. The vehicle can be a road vehicle, rail vehicle, watercraft, or even a work machine such as construction equipment. In this case, the consumer 8 is the vehicle's drive motor, which obtains its drive energy, for example, from hydrogen stored in the high-pressure tank 4. The filling system 100 serves not only to fill the high-pressure tank 4 in the sense of refueling, but also to extract the hydrogen from the high-pressure tank 4 and supply the fuel to the drive motor. The hydrogen can then be combusted directly in the drive motor. In other embodiments, the drive motor is an electric machine, with the drive current being generated by a fuel cell that produces electricity from the hydrogen.

[0071] In the illustrated embodiment, the filling-side solenoid valve 1, the discharge-side valve 7, the main line bypass valve 13, and the valve at the interface to the high-pressure tank 17 are designed as pilot-operated solenoid valves that are closed in the de-energized state. In this illustrated embodiment, all valves are controlled by a control unit 11, as indicated by the dashed lines in the figure. The filling system 100 has a high-pressure-side pressure sensor 15 arranged upstream of the pressure reducer 14 in the flow direction x.In addition, the filling system shown in the figure has an internal pressure determining device 10 for pressure measurement directly in the high-pressure vessel 4 and a low-pressure-side pressure sensor 16, arranged behind the pressure reducer 14 in the flow direction x, as an additional pressure determining device, wherein these pressure determining devices can communicate with the control unit, as indicated by the dashed lines in the figure.

[0072] With the filling system 100 according to the invention, the main line 2 can be shut off depending on the internal pressure prevailing in the high-pressure vessel 4 if the internal pressure prevailing in the high-pressure vessel 4 is below a second threshold value pthreshold,2. In this case, the filling-side solenoid valve 1 closes the main line 2, so that filling can only take place via the main line bypass 5 and thus via the filling pressure reduction device to reduce the filling rate 6 at a reduced filling rate. The reduced filling rate can be preset such that damage to the liner during filling is prevented. If the specified internal pressure corresponds to at least a predetermined first threshold value pthreshold,1, the filling-side solenoid valve 1 opens and the fluid takes the path of least resistance for filling, i.e., through the main line 2.From this point onwards, filling takes place at the full available filling rate, which makes filling significantly faster.

[0073] The internal pressure determining device 10 for pressure measurement in the high-pressure vessel 4 is optional.

[0074] The filling-side solenoid valve 1 is closed when the pressure measured by the high-pressure-side pressure sensor 15 is below the second threshold value pthreshold,2. Likewise, the filling-side solenoid valve 1 is closed when the internal pressure measured by the internal pressure measuring device 10 for pressure measurement in the high-pressure vessel 4 is below the second threshold value pthreshold,2. Preferably, the filling-side solenoid valve 1 is also closed even if the internal pressure measured by the internal pressure measuring device 10 for pressure measurement in the high-pressure vessel 4 is above the first threshold value pthreshold,1, but the pressure measured by the high-pressure-side pressure sensor 15 is below the second threshold value pthreshold,2.

[0075] The filling-side solenoid valve 1, on the other hand, is open when the pressure measured by the high-pressure-side pressure sensor 15 is above the first threshold p threshold,1.

[0076] Furthermore, with the filling system 100 according to the invention, a first fluid can be exchanged with a second fluid within the filling system 100 and the high-pressure vessel 4, or only within the filling system 100. Detailed process descriptions can be found in the descriptions of the following figures.

[0077] Fig. 2Figure 1 shows a schematic diagram of the inventive method 200 for limiting the filling rate of a high-pressure vessel 4 for storing a gas with an inner container and a reinforcing layer surrounding the inner container, as a function of the internal pressure pi,H prevailing in the high-pressure vessel (4) by means of the inventive filling system. The internal pressure pi,H in the high-pressure vessel 4 can be deduced from the pressure measured by a high-pressure-side pressure sensor 15 in the main line 2, viewed in the flow direction x of the fluid, downstream of the filling-side solenoid valve 1. Additionally or alternatively, the internal pressure pi,H in the high-pressure vessel 4 can also be measured directly using an internal pressure measuring device 10 for pressure measurement in the high-pressure vessel 4.In the first step 210, the internal pressure pi,H in the main line 2, viewed in the flow direction x, is continuously determined downstream of the filling-side solenoid valve 1 or in the high-pressure tank 4. Subsequently, in the next step 220, it is checked whether the internal pressure pi,H in the main line 2, viewed in the flow direction x, downstream of the filling-side solenoid valve 1 or in the high-pressure tank 4 is greater than or equal to a predefined first threshold value pthreshold,1. If this is not the case, the process skips to step 240 and the filling-side solenoid valve 1 is opened. However, if the query in step 220 is answered with "yes", the filling-side solenoid valve is closed in the next step 230.The system is left closed and then, in step 225, checks whether the internal pressure pi,H in the main line 2, viewed in the flow direction x, downstream of the filling-side solenoid valve 1 or in the high-pressure tank 4, is less than a predefined second threshold value pthreshold,2. If this is the case, the system jumps to step 230 and closes the filling-side solenoid valve 1. However, if the internal pressure pi,H in the main line 2, viewed in the flow direction x, downstream of the filling-side solenoid valve 1 or in the high-pressure tank 4, is greater than or equal to the predefined second threshold value pthreshold,2, i.e., if the query in step 225 is answered with "no", step 225—the query to determine whether the internal pressure pi,H in the main line 2, viewed in the flow direction x, downstream of the filling-side solenoid valve 1 or in the high-pressure tank 4, is less than a predefined second threshold value pthreshold,2—is repeated until the result of query 225 is "yes".

[0078] If the internal pressure pi,H in the high-pressure vessel 4 falls below the second threshold value, the main line 2 is shut off via the filling-side solenoid valve 1, and filling takes place via the main line bypass 5. Since the main line bypass 5 contains a filling pressure reduction device 6 to reduce the filling rate, filling occurs at a reduced rate predetermined by the filling pressure reduction device 6. This reduced filling rate can be set such that damage to the liner during filling is prevented. Provided the specified internal pressure pi,H is at least equal to the predetermined first threshold value, the filling-side solenoid valve 1 opens, and the fluid takes the path of least resistance for filling, i.e., through the main line 2. Additionally, the main line bypass valve 13 can be closed, preventing any further fluid flow through the main line bypass.The main line bypass valve 13 can also be omitted, as the fluid will automatically take the path of least resistance, i.e., it will flow through the main line 2 when the filling-side solenoid valve 1 is open. Should some of the fluid nevertheless flow through the main line bypass 5, this is not detrimental. From the moment the filling-side solenoid valve 1 opens, filling will always occur at the full available filling rate, thus significantly speeding up the process. The internal pressure pi,H is monitored, compared to the threshold values, and the filling-side solenoid valve 1 is controlled by the control unit 11.

[0079] The internal pressure pi,H in the high-pressure tank 4 can be inferred from the pressure measured by the high-pressure-side pressure sensor 15 in the high-pressure-side piping system with regard to the protection of the inner container of the high-pressure tank 4. Even if the interface 17 or the valve contained therein to the high-pressure tank 4 were closed, the internal pressure pi,H in the high-pressure tank 4 cannot be lower than the pressure measured by the high-pressure-side pressure sensor 15 in the high-pressure-side piping system, since otherwise pressure equalization would occur via the filling bypass 21 with the check valve 22 contained therein.

[0080] Fig. 3Figure 1 shows a schematic diagram of the inventive method 300 for fluid exchange in the inventive filling system 100. In a first step 310, a counter in the control unit 11 is set to the value 0, and then incremented by 1 in step 311. In the next step 315, the system checks whether the filling-side solenoid valve 1, the discharge-side valve 7, and the interface to the high-pressure tank 17 are closed. If at least one of these valves is open, i.e., if query 315 is answered with "no," the system proceeds to step 316, in which valves 1 and 7, as well as the interface to the high-pressure tank 17, are closed. From here, the system returns to the previously described query 315, which is now answered with "yes." In the next step 320, the system checks whether a fluid source 18 containing a second fluid is connected to the interface 3 for fluid injection. The fluid source can consist of a storage container, for example, a gas cylinder.A connection to a pipeline for the second fluid is also conceivable as fluid source 18. If no fluid source with the second fluid is connected, such a fluid source is connected to interface 3 for fluid inlet in step 321, and then the process jumps back to the previously described query 320, which is now answered with "yes". Next, step 322 checks whether interface 3 for fluid inlet is open, and if it is not, it is opened in step 323. Then, the process jumps back to the previously described query 322, which is now answered with "yes". Next, step 330 checks whether the drain opening 9 is open, and if it is not, it is opened in step 331. Finally, the process jumps back to the previously described query 330, which is now answered with "yes".In step 340, the discharge valve 7 is opened, and in the next step 350, the pressure in the filling system 100 is continuously determined via the high-pressure-side pressure sensor 15 and / or the low-pressure-side pressure sensor 16 and the control unit. "Continuous determination" here refers not only to a constant measurement of the internal pressure but also to measurements taken at regular intervals. In step 360, the system checks whether the measured pressure is less than or equal to a predetermined minimum pressure. If the answer is "no," the pressure in the filling system 100 is continuously measured, and check 360 is repeated until the condition is met. Because the discharge valve 7 is open, fluid escapes from the filling system 100, causing the pressure in the filling system 100 to drop.As long as the measured pressure is greater than the predetermined minimum pressure, i.e., query 360 is answered with "no", the system returns to step 350, the continuous determination of the pressure in the filling system 100. If the measured pressure is less than or equal to the predetermined minimum pressure, query 360 is answered with "yes", and the system advances to step 361, in which the discharge-side valve 7 is closed. Subsequently, in step 362, the filling-side solenoid valve 1 is opened, allowing the second fluid to flow into the filling system 100. In the following query step 370, the system checks whether the continuously measured pressure in the filling system 100 is equal to or greater than a predetermined reference pressure. This check is repeated until query 370 is answered with "yes", i.e., the measured pressure in the filling system 100 is equal to or greater than the predetermined reference pressure.If this condition is met, in the following step 371 the filling-side valve 1 is closed and query 380 checks whether the counter value is less than the predefined number of cycles. If this is the case, the process jumps back to incrementing the counter value by 1 in step 311 and repeats the previously described sequence. However, if the result of query 380 is no, i.e., the counter value equals the predefined number of cycles, the fluid exchange process in the filling system 100 is completed with step 390.

[0081] Maintenance and / or repair work on the Filling System 100 can now be carried out safely, even if the Filling System 100 was previously filled with a reactive fluid, such as hydrogen. The method can also be used to refill a system filled with an inert gas with a flammable process gas after work has been carried out, for example, to ensure that a required hydrogen concentration is present.

[0082] The process can be carried out fully automatically, for example by the control unit 11. This allows for the safe inerting of the filling system 100 at a wide variety of locations without specially trained personnel.

[0083] Fig. 4Figure 1 shows a schematic diagram of the inventive method 400 for fluid exchange in the inventive filling system 100 and in a high-pressure tank 4 connected to the inventive filling system 100. Analogous to the previously described method, in a first step 410 a counter in the control unit 11 is set to the value 0, and subsequently incremented by 1 in step 411. In the next step 415, a query is performed to determine whether the filling-side solenoid valve 1, the discharge-side valve 7, and the interface to the high-pressure tank 17 are closed. If at least one of these valves is open, i.e., query 415 is answered with "no," the process proceeds to step 416, in which valves 1 and 7, as well as the interface to the high-pressure tank 17, are closed. From here, the process returns to the previously described query 415, which is now answered with "yes."In the next step, 420, the system checks whether a fluid source 18 containing a second fluid is connected to interface 3 for fluid inlet. The fluid source can consist of a storage container, such as a gas cylinder. A connection to a pipeline for the second fluid is also conceivable as a fluid source 18. If no fluid source containing the second fluid is connected, in step 421 such a fluid source is connected to interface 3 for fluid inlet, and then the system returns to the previously described query 420, which is now answered with "yes". Subsequently, in step 422, the system checks whether interface 3 for fluid inlet is open, and if it is not, it is opened in step 423. The system then returns to the previously described query 422, which is now answered with "yes".Step 430 then checks whether the drain opening 9 is open, and if it is not, it is opened in step 431. The system then returns to the previously described check 430, which is now answered with "yes". Next, in step 440, the discharge-side valve 7 is opened, and in the following step 450, the interface 17 to the high-pressure tank 4 is opened. In the subsequent step 460, the pressure in the filling system 100 is continuously determined via the high-pressure-side pressure sensor 15 and / or the low-pressure-side pressure sensor 16 and the control unit 11. "Continuous determination" here refers not only to a constant measurement of the internal pressure but also to measurements taken at regular intervals. Finally, in step 470, it is checked whether the measured pressure is less than or equal to a predetermined minimum pressure.If this query is answered with "no", the pressure in filling system 100 is continuously measured in step 450, and query 470 is repeated until the condition is met. Because the discharge valve 7 is open, fluid escapes from filling system 100, causing the pressure in filling system 100 to drop. As long as the measured pressure is greater than the predetermined minimum pressure, i.e., query 470 is answered with "no", the process returns to step 460, the continuous measurement of the pressure in filling system 100. If the measured pressure is less than or equal to the predetermined minimum pressure, query 470 is answered with "yes", and the process advances to step 471, in which the discharge valve 7 is closed. Subsequently, in step 472, the filling solenoid valve 1 is opened, allowing a second fluid to flow into filling system 100.In the following query step 480, it is checked whether the continuously measured pressure in the filling system 100 is equal to or greater than a predetermined reference pressure. This query is repeated until query 480 is answered with "yes," meaning the measured pressure in the filling system 100 is equal to or greater than the predetermined reference pressure. If this condition is met, in the following step 481, the filling-side valve 1 is closed, and query 490 checks whether the counter value is less than a predefined number of cycles. If this is the case, the process returns to the counter value incremented by 1 in step 411, and the previously described sequence is repeated. However, if the result of query 490 is "no," meaning the counter value is equal to the predefined number of cycles, then the fluid exchange process 400 in the filling system 100 and high-pressure tank 4 is completed with step 500.

[0084] Maintenance and / or repair work on the filling system 100 and the high-pressure tank 4 can now be carried out safely, even if the filling system 100 was previously filled with a reactive fluid, for example hydrogen.

[0085] The process can be carried out fully automatically, for example, by the control unit 11. This allows for the safe inerting of the filling system 100 and the high-pressure vessel 4 at a wide variety of locations without specially trained personnel. The process can also be used to refill a system filled with inert gas with a flammable process gas after work has been carried out, for example, to ensure that a required hydrogen concentration is present.

[0086] Fig. 5Figure 600 shows a schematic diagram of the inventive method 600 for residual pressure protection during the withdrawal of a fluid from the high-pressure tank 4 using the inventive filling system 100. First, the internal pressure pi,H in the main line, viewed in the flow direction x downstream of the filling-side solenoid valve, is continuously measured. Then, it is checked 620 whether the internal pressure pi,H is less than the predetermined second threshold pthreshold,2. This check 620 is repeated until this condition is met. If the internal pressure pi,H is less than the predetermined second threshold pthreshold,2, the discharge-side valve 630 is closed.

[0087] The embodiments shown here are merely examples of the present invention and should therefore not be interpreted as limiting. Alternative embodiments considered by a person skilled in the art are likewise covered by the scope of protection of the present invention. Reference symbol list:

[0088] 1 Filling-side solenoid valve 2 Main line 3 Interface for fluid supply 4 High-pressure tank 5 Main line bypass 6 Filling pressure reduction device 7 Discharge-side valve 8 Consumer 9 Drain port 10 Internal pressure measuring device for pressure measurement in the high-pressure tank 11 Control unit 12 Interface 13 Main line bypass valve 14 Pressure reducer 15 High-pressure-side pressure sensor 16 Low-pressure-side pressure sensor 17 Interface to the high-pressure tank 18 Fluid source 19 Check valve in the main line 20 Check valve in the main line bypass 21 Filling bypass 22 Check valve in the filling bypass 100 Filling system 200 Method for limiting the filling rate of a high-pressure gas storage vessel 210 Continuously determining the internal pressure pi,H in the main line, viewed in the flow direction x downstream of the filling-side solenoid valve 220 Query: Is the internal pressure pi,H in the main line, viewed in the flow direction x downstream of the filling-side solenoid valve, greater than or equal to a predetermined first threshold pthreshold,1? 225 Query: Is the internal pressure pi,H in the main line, viewed in the flow direction x downstream of the filling-side solenoid valve, less than a predetermined second threshold pthreshold,2? 230 Closing the filling-side solenoid valve 240 Opening the filling-side solenoid valve 300 Method for fluid exchange in the filling system according to the invention 310 Setting a counter in the control unit to 0 311 Increasing the counter in the control unit by 1 315 Checking: Are the filling-side solenoid valve, the drain-side valve and the interface to the high-pressure tank closed? 316 Closing the filling-side solenoid valve, drain-side valve and the interface to the high-pressure tank 320 Checking: Is a fluid source containing a second fluid connected to the fluid inlet interface? 321 Connecting a fluid source containing a second fluid to the fluid inlet interface 322 Checking: Is the fluid inlet interface open? 323 Opening the fluid inlet interface 330 Checking: Is the drain opening open? 331 Opening the drain opening 340 Opening the drain-side valve;350 Continuously measuring the pressure in the filling system. 360 Query: Is the measured pressure less than or equal to a predetermined minimum pressure? 361 Closing the discharge valve. 362 Opening the filling solenoid valve. 370 Query: Is the continuously measured pressure in the filling system equal to or greater than a predetermined reference pressure? 371 Closing the filling solenoid valve. 380 Query: Is the counter value less than a predefined number of cycles? 390 Fluid exchange complete. 400 Method for fluid exchange in the filling system according to the invention and in a high-pressure tank connected to the filling system according to the invention 410 Setting a counter in the control unit to 0 411 Increasing the counter in the control unit by 1 415 Checking: Are the filling-side solenoid valve, the drain-side valve and the interface to the high-pressure tank closed? 416 Closing the filling-side solenoid valve, drain-side valve and the interface to the high-pressure tank 420 Checking: Is a fluid source containing a second fluid connected to the interface for fluid supply? 421 Connecting a fluid source containing a second fluid to the interface for fluid supply 422 Checking: Is the interface for fluid supply open? 423 Opening the interface for fluid supply 430 Checking: Is the drain opening open? 431 Opening the drain opening 440 Opening the drain-side valve;450 Opening of the interface to the high-pressure tank 460 Continuous measurement of the pressure in the filling system 470 Query: Is the measured pressure less than or equal to a predetermined minimum pressure? 471 Closing of the discharge valve 472 Opening of the filling solenoid valve 480 Query: Is the continuously measured pressure in the filling system equal to or greater than a predetermined reference pressure? 481 Closing of the filling solenoid valve 490 Query: Is the counter value less than the predefined number of cycles? 500 Fluid exchange complete 600 Method for residual pressure protection during the withdrawal of a fluid from a high-pressure container with the filling system according to the invention 610 Continuously determining the internal pressure pi,H of the main line seen in the flow direction x downstream of the filling-side solenoid valve 620 Comparing the determined internal pressure pi,H with a predetermined second threshold value p threshold,2: Is pi,H < p ​​threshold,2? 630 Closing the discharge-side valve pi,H Internal pressure of the main line in the flow direction x seen behind the filling-side solenoid valve or in the high-pressure tank p threshold,1 First pressure threshold p threshold,2 Second pressure threshold x Flow direction of the fluid during filling

Claims

1. A filling system (100) for filling a high-pressure vessel (4) with a fluid at a variable filling rate, wherein the high-pressure vessel (4) is in particular a high-pressure vessel (4) for storing a gas with an inner container and a reinforcing layer surrounding the inner container, depending on an internal pressure prevailing in the high-pressure vessel (4), with a main line (2) that can be shut off via a filling-side solenoid valve (1), wherein the filling system (100) further comprises a fluid drain (9) and an interface (3) for supplying a fluid, as well as a discharge-side valve (7), an interface (3) for fluid supply, a drain opening (9), an interface (17) to the high-pressure vessel (4) with valve, a high-pressure-side pressure sensor (15) and a low-pressure-side pressure sensor (16), characterized by thatThe main line (2) has a main line bypass (5) with a filling rate reduction device (6) for reducing the filling rate, wherein the main line bypass (5) branches off from the main line (2) upstream of the filling-side solenoid valve (1) when filling the high-pressure tank (4) in the flow direction (x) of the fluid, and further comprises a high-pressure-side pressure sensor (15) via which a pressure present in the main line (2) downstream of the filling-side solenoid valve (1) in the flow direction x of the fluid can be determined, and a control unit (11) wherein the control unit (11) is configured to receive an internal pressure value from the high-pressure-side pressure sensor (15) and to apply a predetermined first threshold value p Schwell,1 and a given second threshold p Schwell,2 to compare, wherein the control unit (11) is further configured to open the filling-side solenoid valve (1) if the internal pressure is at least equal to the specified first threshold pSchwell,1 corresponds and closes the filling-side solenoid valve (1) if the internal pressure received from the high-pressure-side pressure sensor (15) is below the specified second threshold p Schwell,2 lies.

2. The filling system (100) according to claim 1, characterized by that the filling-side solenoid valve (1) is closed in the de-energized state.

3. The filling system (100) according to one of the preceding claims, characterized by that the filling-side solenoid valve (1) is a pilot-operated solenoid valve.

4. The filling system (100) according to one of the preceding claims, characterized by that The filling pressure reduction device (6) for reducing the filling rate is a mechanical filling pressure reduction device (6).

5. The filling system (100) according to claim 4, characterized by that The mechanical filling pressure reduction device (6) has an orifice for reducing the filling rate.

6. The filling system (100) according to one of the preceding claims, characterized by , the high-pressure-side pressure sensor (15) is designed to determine the internal pressure prevailing in the main line (2) in the flow direction (x) of the fluid when filling, as seen behind the filling-side solenoid valve (1).

7. The filling system (100) according to one of the preceding claims, characterized by that the filling system (100) has a pressure switch which includes the high-pressure side pressure sensor (15) and the control unit (11).

8. The filling system (100) according to one of the preceding claims, characterized by that the control unit (11) has a digital control system.

9. Filling system (100) according to one of the preceding claims, characterized by that the main line (2) has a check valve (19).

10. The filling system (100) according to claim 9, characterized by thatthe main line bypass (5) has a further check valve (20).

11. A method (200) for limiting a filling rate when filling a high-pressure vessel (4), in particular a high-pressure vessel (4) for storing a gas with an inner vessel and a reinforcing layer surrounding the inner vessel, as a function of an internal pressure p prevailing in the high-pressure vessel (4). i,H about the filling system (100) according to one of the preceding claims, characterized by the steps a. Continuous determination of the internal pressure p i,H (210) in the main line (2) seen in the direction of flow x behind the filling-side solenoid valve (1) and comparing the determined internal pressure p i,H , with a given first threshold p Schwell,1 (220) and a given second threshold p Schwell,2 (225); b. Opening (240) of the filling-side solenoid valve (1), provided that the specified internal pressure p i,Hat least the specified first threshold p Schwell,1 corresponds to and closing (230) of the filling-side solenoid valve (1), provided that the specified internal pressure p i,H below the specified first threshold p Schwell,1 lies; c. queries (225) whether the internal pressure p i,H smaller than the specified second threshold p Schwell,2 is, where this query (225) is repeated until this condition is met and in the case that the internal pressure p i,H smaller than the specified second threshold p Schwell,2 is, closing (230) of the filling-side solenoid valve (1).

12. The method (200) according to claim 11, characterized by that the filling rate is limited by the flow of fluid through a filling pressure reduction device (6) during filling, provided that the determined internal pressure p i,H below a given second threshold p Schwell,2 lies.

13. The method (200) according to one of claims 11 or 12, characterized by that the continuous determination (210) of the internal pressure p i,H via n high-pressure-side pressure sensor (15), which determines the internal pressure in the main line (2) in the flow direction x of the fluid when filling, seen behind the filling-side solenoid valve (1).

14. A method (300) for fluid exchange in the filling system (100) according to any one of claims 1 to 10, characterized by the stepsa. Resetting a counter (310) in the control unit (11) to 0; b. Incrementing the counter (311) in the control unit (11) by 1; c. Ensuring that the filling-side solenoid valve (1), the drain-side valve (7), and the interface (17) to the high-pressure reservoir are closed (315, 316); d. Ensuring that a fluid source (18) containing a second fluid is connected to the fluid inlet interface (3) (320, 321) and that the fluid inlet interface (3) is open (322, 323); e. Ensuring that the drain port (9) is open (330, 331); f. Opening (340) the drain-side valve (7); g. Continuously determining (350) the pressure in the filling system (100) and comparing the determined pressure with a predetermined minimum pressure (360), whereby the discharge-side valve (7) is closed (361) when the determined pressure in the filling system (100) is less than or equal to the predetermined minimum pressure; h.After the discharge-side valve (7) was closed in the previous step, the filling-side solenoid valve (1) is opened (362) and the continuously measured pressure in the filling system (100) is compared with a predetermined reference pressure (370), the filling-side solenoid valve (1) being closed (371) if the continuously measured pressure in the filling system (100) is equal to or greater than the predetermined reference pressure; i. the counter value is compared with a predefined cycle number (380) and steps a. to h. are repeated if the counter value is less than the predefined cycle number.

15. The method (400) according to claim 14 for fluid exchange in the filling system (100) according to any one of claims 1 to 10 and in a high-pressure vessel (4) connected to the filling system (100) according to any one of claims 1 to 10 via the interface (17), characterized by the stepsa. Resetting a counter (410) in the control unit (11) to 0; b. Incrementing the counter (411) in the control unit (11) by 1; c. Ensuring that the filling-side solenoid valve (1), the drain-side valve (7), and the interface (17) to the high-pressure reservoir are closed (415, 416); d. Ensuring that a fluid source (18) containing a second fluid is connected to the fluid inlet interface (3) (420, 421) and that the fluid inlet interface (3) is open (422, 423); e. Ensuring that the drain port (9) is open (430, 431); f. Opening (440) the drain-side valve (7); g. Opening (450) the interface (17) to the high-pressure reservoir (4); h.Continuously determining (460) the pressure in the filling system (100) and comparing the determined pressure with a predetermined minimum pressure (470), wherein the discharge-side valve (7) is closed (471) when the determined pressure in the filling system (100) is less than or equal to the predetermined minimum pressure; i. After the discharge-side valve (7) has been closed in the previous step, opening (472) the filling-side solenoid valve (1) and comparing the continuously determined pressure in the filling system (100) with a predetermined reference pressure (480), wherein the filling-side solenoid valve (1) is closed (481) when the continuously determined pressure in the filling system (100) is equal to or greater than the predetermined reference pressure; j. Comparing the counter content with a predefined number of cycles (490) and repeating steps a. to i. if the counter content is less than the predefined number of cycles.

16. A method (600) for residual pressure protection during the withdrawal of a fluid from the high-pressure vessel (4) using the filling system (100) according to any one of claims 1 to 10, characterized by the steps a. Continuous determination (610) of the internal pressure p i,H (210) in the main line (2) viewed in the direction of flow x downstream of the filling-side solenoid valve (1); b. querying (620) whether the internal pressure p i,H smaller than the specified second threshold p Schwell,2 is, where this query (620) is repeated until this condition is met, and in the case that the internal pressure p i,H smaller than the specified second threshold p Schwell,2 is, closing (630) of the outflow side valve (7).

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