Mobile service device and flushing procedure for hydrogen systems

Abstract

The invention relates to a mobile device for purging, inerting, and checking a hydrogen system, comprising a frame, a first pressurized gas container for an inert gas, a second pressurized gas container for a forming gas, a piping system with a coupling for connecting to the hydrogen system, and an exhaust line, wherein the first pressurized gas container, the second pressurized gas container, and the piping system are arranged on the frame, wherein the first pressurized gas container is connected to the piping system via an inert gas line with a first solenoid valve, and the second pressurized gas container is connected to the piping system via a forming gas line with a second solenoid valve, wherein the inert gas line and the forming gas line open into a first piping node, from which a working gas line extends to a second piping node, and wherein a coupling for connecting to the hydrogen system and an exhaust line extend from the second piping node.wherein the exhaust line has a third solenoid valve. Furthermore, the invention comprises a method for purging, inerting, and checking a hydrogen system, as well as the use of a trolley for this purpose.

Description

[0001] The invention relates to a mobile device for rinsing, inerting and checking a hydrogen system.

[0002] From DE 43 06 064 A1, a method and a system for the residual emptying and degassing of liquefied gas containers, in particular railway tank cars, tank trucks, and liquefied gas storage tanks, are known. The method is carried out in three phases, wherein in the first phase, liquefied gas is driven out of the container under constant pressure and temperature with the addition of heat. In the second phase, pressure equalization is achieved between the container and a liquefied gas condenser. In the third phase, any remaining liquefied gas is displaced by introducing inert gas into the container.

[0003] From DE 40 26 101 A1 a pressure holding fitting with lock chamber comprising a suction flange part, with suction chamber, a valve chamber, a lock chamber, which is placed on a container under gas pressure, for the purpose of replacing a fitting.

[0004] EP 4 119 834 A1 describes a double-walled hydrogen tank assembly for vehicles, wherein a counter-pressure of inert gas is introduced into the space between an inner hydrogen tank wall and an outer hydrogen tank wall to suppress the formation of microcracks.

[0005] CN 2 08 652 121 U describes an emergency containment vessel for leaking gas cylinders comprising a trolley, a pressure vessel mounted on the trolley, and a flanged flap for connecting and opening the pressure vessel, wherein a first annular projection is arranged at the opening end of the pressure vessel and a second annular projection is arranged on the flanged door. The emergency containment vessel further comprises a locking bar with a circumferential groove on its inner side in which the first and second annular projections are arranged.

[0006] According to JP 2005-54963A, a hydrogen extraction device for hydrogen tanks comprises a hydrogen extraction system and an inert gas exchange system. The hydrogen extraction system includes, in sequence from the hydrogen tank outlet: a first valve, a pressure reducer, a needle valve, a first shut-off valve, and a leak detection valve, with a line branching off between the needle valve and the shut-off valve, leading in sequence to a further shut-off valve and a hydrogen concentration meter. The inert gas exchange system comprises an inert gas exchange line branching off between the hydrogen tank outlet and the first valve, and connected via a check valve, a second valve, and a second shut-off valve to an inert gas container.

[0007] In the search for alternative fuels, hydrogen is the focus of many applications as an energy carrier.

[0008] However, the volatile and reactive nature of hydrogen presents new challenges, especially for workshops, particularly when a standard workshop workstation is to be adapted for working on a hydrogen system, such as in a hydrogen-powered vehicle.

[0009] The object of the invention is to prepare a hydrogen system for maintenance or repair work without requiring any infrastructure measures. This object is achieved by a mobile flushing device with the features of claim 1, a method for flushing a hydrogen system with the features of claim 12, and the use of a trolley for flushing a hydrogen system with the features of claim 19.

[0010] Advantageous further training is the subject of claims 2 to 11 and 13 to 18.

[0011] The mobile device according to the invention for purging, inerting and checking a hydrogen system comprises a frame, a first pressurized gas container for an inert gas, a second pressurized gas container for a forming gas, a piping system with a coupling for connecting to the hydrogen system and an exhaust line, wherein the first pressurized gas container, the second pressurized gas container and the piping system are arranged on the frame, wherein the first pressurized gas container is connected to the piping system via an inert gas line with a first solenoid valve and the second pressurized gas container is connected to the piping system via a forming gas line with a second solenoid valve, wherein the inert gas line and the forming gas line open into a first piping node, from which a working gas line leads to a second piping node, wherein a connecting coupling for connecting to the hydrogen system and an exhaust line extend from the second piping node.the exhaust pipe has a third solenoid valve.

[0012] By mounting the first pressurized gas cylinder for an inert gas and the second pressurized gas cylinder for a forming gas on a single frame, the mobile device requires no additional pressurized gas supply, such as external gas cylinders or house connections, and can operate autonomously. This makes the device spatially independent and therefore mobile. The piping system, with a coupling such as a bayonet coupling or a hose for connection to the hydrogen system, allows a connection between the device and an object to be purged, inerted, and / or inspected. Connecting the inert gas line and the forming gas line to a single working gas line at the first junction simplifies operation by allowing the device to supply forming gas and / or inert gas through the same working gas line to the single coupling, thus preventing any confusion between the lines.An exhaust pipe allows for the controlled release of hydrogen. A third solenoid valve prevents the sudden and uncontrolled release of pressurized hydrogen from the hydrogen system, thus improving safety during operation.

[0013] In a further technically advantageous embodiment, the device has an additional coupling for connecting to a hydrogen system.

[0014] An additional coupling, such as a bayonet coupling or a hose, can allow inert gas to flow into the hydrogen system and exhaust gas to flow out simultaneously. This allows for better purging.

[0015] In a technically advantageous embodiment, a fourth solenoid valve is arranged in the working gas line before the third line node.

[0016] A fourth solenoid valve can prevent incoming working gas or inert gas and outgoing exhaust gas from mixing or influencing each other in terms of flow during purging between the second and third pipe nodes.

[0017] In a further technically advantageous embodiment, the device has a hydrogen sensor and a computing unit that outputs a signal depending on a hydrogen concentration detected by the hydrogen sensor.

[0018] A hydrogen sensor can reliably detect even small amounts of hydrogen. A hydrogen concentration of 5% should be avoided to suppress reactions of hydrogen with nitrogen within a forming gas. The hydrogen sensor measures the hydrogen concentration and can determine whether it is higher or lower than the specified level. The processing unit can either directly extract the hydrogen concentration from sensor data or calculate it indirectly. A signal can then be output if the hydrogen concentration exceeds a certain threshold. For example, the hydrogen concentration should be below 5% after purging with inert gas. The hydrogen concentration can be measured, for instance, in the exhaust system.

[0019] In a further technically advantageous embodiment, the piping system has a particle filter that is arranged between the first piping node and the second piping node.

[0020] Hydrogen systems are high-tech systems that are sometimes sensitive to impurities. Therefore, a device with a particle filter can remove such impurities before they enter the hydrogen system. The placement of the filter between the first and second line nodes, i.e., in the working gas line, is particularly advantageous, as this allows potential impurities from both the inert gas line and the forming gas line to be filtered out by a single particle filter.

[0021] In a further technically advantageous embodiment, the piping system has a check valve that is arranged between the first and the second piping node.

[0022] Such a check valve prevents exhaust gas from the hydrogen system from flowing towards the working gas line. The placement of the check valve allows for a further simplification of the piping system.

[0023] In a further technically advantageous embodiment, the piping system has a pressure sensor at the second and / or third piping node.

[0024] A pressure sensor at the second junction can monitor the pressure of the working gas in the working gas line. A pressure sensor at the third junction can monitor the pressure at the third junction. The pressure at the third junction can be caused either by an inflowing working gas or by an outflowing exhaust gas.

[0025] In a further technically advantageous embodiment, the piping system has a pressure reducer that is arranged between the third piping node and the exhaust pipe.

[0026] Hydrogen systems regularly operate at high pressures up to 60 bar, sometimes up to 200 bar, and even up to 875 bar. Such pressures can cause damage during venting, for example, through icing. Therefore, a pressure reducer can make the venting of hydrogen easier to manage and safer. It also allows, for example, the exhaust gas not only to be released into the environment but also to be fed into an exhaust gas treatment system or an exhaust gas storage tank without the risk of overpressure in the downstream system. Furthermore, the pressure reducer can also protect downstream components, such as a hydrogen sensor, from high pressures, allowing these components to be designed with less robust components and thus at a lower cost.

[0027] In a further technically advantageous embodiment, the device has an electronic interface that can be connected to an electronic interface of a hydrogen system for data exchange.

[0028] Hydrogen systems typically contain a variety of electrical components such as sensors, processing units, and control electronics. These components control and monitor the hydrogen system. An electronic interface allows for data exchange, simplifying or even partially automating purging, inerting, and monitoring of the hydrogen system. Furthermore, the hydrogen system can be controlled, for example, by deactivating or selectively activating or controlling internal processes. Sensor data can also be provided by the hydrogen system and received by the device via the interface.

[0029] In a further technically advantageous embodiment, the cable system has an earthing point or a connection point for an earthing point.

[0030] An earthing point or a connection point for an earthing point can prevent static charge build-up and thus reduce the risk of hydrogen ignition and electric shocks from touching by third parties.

[0031] In a further technically advantageous embodiment, the piping system can have a return line for returning gas from the hydrogen system, which leads into the working gas line.

[0032] A return line can enable the sustainable reuse of gas from the hydrogen system. Instead of being released into the environment, the gas can be reintroduced after purging, inerting, and checking the hydrogen system, thus eliminating the need to dispose of waste gas and the need to add new gas.

[0033] Another aspect of the invention relates to a method for purging a hydrogen system comprising the following steps: a) Connecting a rinsing device to the hydrogen system; b) Releasing a gas from the hydrogen system; c) Allow inert gas to flow into the hydrogen system; d) Checking the hydrogen concentration of the released gas; e) Repeat steps b. - d. until the hydrogen concentration falls below a target value;

[0034] The method according to the invention allows for particularly simple and effective purging of a hydrogen system. First, the purging device, especially a mobile purging device, is connected to the hydrogen system, for example, by means of a coupling or a hose connection. In a further step, the gas in the hydrogen system is depressurized, i.e., the excess pressure is released and discharged through an exhaust line, for example, released into the environment or recycled. Subsequently, inert gas is introduced into the hydrogen system, filling it with the inert gas. Once the hydrogen system is filled with the inert gas, for example, as determined by a pressure measurement, the gas in the hydrogen system is released in a controlled manner. The gas flows through the piping system, particularly through the exhaust line.The hydrogen concentration in the piping system is measured, for example, using a hydrogen sensor. If the hydrogen concentration exceeds a threshold value, such as 5%, the previous step—allowing the inert gas to flow into the hydrogen system—is repeated after the exhaust gas has been discharged. The hydrogen concentration is then measured again during the discharge process. If the hydrogen concentration is below the threshold value, the system is purged and thus ready for repairs, maintenance, or other work on the hydrogen system or the overall system connected to it.

[0035] In a further technically advantageous embodiment, forming gas can be introduced into the hydrogen system. Forming gas is a low-reactivity gas mixture with a hydrogen content low enough to remain harmless but high enough to be detected by hydrogen sensors. For example, the hydrogen system can be filled with forming gas to allow the use of a mobile detector with a hydrogen sensor for leak detection in the vicinity of the hydrogen system, such as at a workshop workstation. This allows potential leaks to be identified before the hydrogen system is refilled with hydrogen, thus preventing hazards and saving the need for further purging and repair. A particularly advantageous feature is the output of a warning signal, such as an audible or electrical signal, which can control a display or trigger the audible signal itself.

[0036] In another technically advantageous embodiment, the hydrogen system is a system that combines a hydrogen drive with a high-pressure storage system.

[0037] Hydrogen systems, especially those with a high-pressure storage tank, operate under high pressure even outside the tank, for example, 60 bar. An uncontrolled release of gas could lead to uncontrolled decompression and thus to damage, such as icing. A controlled exhaust gas release procedure from a hydrogen system mitigates this risk.

[0038] In a further technically advantageous embodiment, the rinsing device is connected to the hydrogen system at a connection point, and an inflow and outflow of fluids takes place successively via this one connection point.

[0039] A single connection point simplifies the connection process and thus the entire purging procedure, preventing operator error, such as incorrectly connected fittings. First, the gas in the hydrogen system is released through the purging device, allowing it to flow through the connection point into an exhaust line. Then, the hydrogen system is filled with a fluid, such as an inert gas or forming gas, via this single connection point. This sequence of inflow and outflow allows for a simple piping system and easy handling.

[0040] In a further technically advantageous embodiment, the flushing device is a mobile trolley and the hydrogen system is arranged in a motor vehicle between a hydrogen engine and a high-pressure tank, wherein, according to steps a) - e), a repair or maintenance is carried out on the motor vehicle and the leak-free inspection is carried out using forming gas during and / or after the repair or maintenance.

[0041] Vehicles powered by hydrogen and equipped with high-pressure tanks can regularly pose challenges for workshops. A mobile trolley, for example, can be used at a standard workshop workstation, requiring little to no infrastructure modifications to enable the workshop to perform repairs or maintenance on hydrogen-powered vehicles. The mobile trolley can be kept in the workshop and moved to the vehicle as needed to purge or inert the hydrogen system.

[0042] In a particularly advantageous technical embodiment, a data connection can be established between the motor vehicle and the flushing device in a first step.

[0043] The advantages of a data connection have already been discussed, to which reference is hereby made.

[0044] Another aspect of the invention is the use of a trolley with a pressurized gas container with inert gas, a pressurized gas container with forming gas, a piping system, an exhaust line and a coupling for connecting to a hydrogen system for inerting, purging and leak checking of a hydrogen system.

[0045] The use of a trolley according to the invention provides the possibility to inert, purge and leak test hydrogen systems independently of infrastructure.

[0046] Further features, details and advantages of the invention will become apparent from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. The drawings show: Fig. 1 An example of a mobile washing device Fig. 2 A circuit diagram of an exemplary flushing device Fig. 3 A circuit diagram of a motor vehicle with a hydrogen drive and a high-pressure storage system

[0047] In detail, it shows Fig. 1 An exemplary purging device 1 with a frame 2, a first pressure gas container 3 for N2 as an inert gas and a second pressure gas container 4 for N2H2 as a forming gas and a piping system 10 with a bayonet fitting as a connection coupling 102 for connecting to the hydrogen system 500 and a second bayonet fitting as an additional coupling 103 for connecting to the hydrogen system 500 as well as an exhaust pipe 20, wherein the exhaust pipe 20 is arranged inside the piping system 10. Likewise, a computing unit is arranged inside the casing of the piping system 10.

[0048] Fig. Figure 2 shows a circuit diagram of an exemplary mobile purging device 1 with a first pressurized gas cylinder for N2 as an inert gas with a pressure regulator 182 and a second pressurized gas cylinder for N2H2 as a forming gas with a pressure regulator 183. A piping system 10 has a connection coupling 102 and an auxiliary coupling 103 for connecting to the hydrogen system 500 and an exhaust line 20. The connection coupling 102 and the auxiliary coupling are each connected to a connection device 201, for example, a hose reel. The first pressurized gas cylinder 3 is connected to an inert gas line 11 and the second pressurized gas cylinder 4 is connected to a forming gas line 12.

[0049] After the respective connection points 104 and 105 to the piping system 10, the inert gas line 11 and the forming gas line 12 open into a first piping node 31. A first solenoid valve 132 is located between the first connection point 104 and the first piping node 31, and a second solenoid valve 133 is located between the second connection point 105 and the first piping node 31. After the first piping node 31, a particle filter 121 and a check valve 171 are located in the working gas line, the check valve 171 preventing fluid flow from the second piping node 32 to the first piping node 31. A first pressure sensor 302 and the auxiliary coupling 103 for connection to a hydrogen system 500 are located at the second piping node 32. A safety valve 191, 192 is arranged between the respective connection points 104, 105 and the solenoid valves 132, 133.

[0050] A fourth solenoid valve 134 is arranged between the second line node 32 and the third line node 33, the third line node 33 connecting an exhaust line 20 to the coupling 102 for connection to the hydrogen system 500. A second pressure sensor 301 is arranged at the third line node 33.

[0051] A third solenoid valve 131 is arranged between the third line node 33 and the exhaust line 20. The third solenoid valve 131 prevents uncontrolled outflow of fluid from the hydrogen system 500 when the connecting coupling 102 is connected to the hydrogen system 500 and prevents fluid flow when the working gas flows into the hydrogen system 500, thus allowing inflow and outflow through only one coupling.

[0052] A pressure reducer 181 is arranged between the third line node 33 and the third solenoid valve 131. This reducer prevents excessively high pressure from escaping on the exhaust side and protects a hydrogen sensor 341 from excessive pressure. An exhaust coupling 101 allows the exhaust line 20 to be connected to an exhaust air line or a line to the ambient air.

[0053] A hydrogen system 500 is also shown schematically with a connection at the connecting coupling 102 and at the auxiliary coupling 103. The hydrogen system 500 is electrically connected to the purging device 1 via an electronic interface 5.

[0054] Fig.Figure 3 shows an example of a hydrogen system 500, which connects a hydrogen drive 600 and a high-pressure tank 700 of a motor vehicle. The hydrogen system 500 comprises a first connection 501 for connecting a coupling of a purging device and a second connection 502 for connecting an auxiliary coupling.

[0055] The invention is not limited to one of the embodiments described above, but can be modified in a variety of ways. For example, other controllable valves can be used instead of solenoid valves.

[0056] All features and advantages arising from the claims, the description and the drawing, including design details, spatial arrangements and process steps, can be essential to the invention both individually and in various combinations. Reference symbol list 1 Mobile rinsing device 2 frames 3 first pressurized gas container 4 second pressurized gas container 5 electronic interface 6 Grounding point 10 piping system 11 Inert gas pipeline 12 Forming gas line 20 Exhaust pipe 31 First line node 32 Second line node 33 Third line node 101 Exhaust clutch 102 Connection coupling 103 Additional clutch 104 First liaison point 105 Second liaison point 121 Particle filters 131 Third solenoid valve 132 First solenoid valve 133 Second solenoid valve 134 Fourth solenoid valve 171 Check valve 181 Pressure reducers 182 First pressure regulator 183 Second pressure regulator 191 First safety valve 192 Second safety valve 201 Connection devices 301 Second pressure sensor 302 First pressure sensor 341 Hydrogen sensor 500 hydrogen systems 501 First connection 502 Second connection 600 hydrogen propulsion 700 high-pressure tank

Claims

[1] Mobile device (1) for purging, inerting and checking a hydrogen system (500) with: - a frame (2), - a first pressure gas container (3) for an inert gas, - a second pressurized gas container (4) for a forming gas, - a piping system (10) with a coupling (102) for connecting to the hydrogen system (500), - an exhaust pipe (20), wherein the first pressure gas container (3), the second pressure gas container (4) and the piping system (10) are arranged on the frame (2), wherein the first pressure gas container (3) is connected to a first solenoid valve (132) via an inert gas line (11) and the second pressure gas container (4) is connected to the piping system (10) via a forming gas line (12) and a second solenoid valve (133), wherein the inert gas line (11) and the forming gas line (12) lead into a first line node (31), from which a working gas line leads to a second line node (32), wherein a connection coupling (102) for connecting to the hydrogen system (500) and an exhaust line (20) extend from the second line node (32), wherein the exhaust pipe (20) has a third solenoid valve (131). [2] Device according to claim 1, wherein the device has an additional coupling (103) for connecting to a hydrogen system (500). [3] Device according to claim 1 or 2, characterized by , that a fourth solenoid valve (134) is arranged in the working gas line before the second line node (32). [4] Device according to one of the preceding claims, wherein the device comprises a hydrogen sensor (341) and a computing unit which outputs a signal depending on a hydrogen concentration detected by the hydrogen sensor (341). [5] Device according to one of the preceding claims, wherein the piping system (10) has a particle filter (121) arranged between the first piping node (31) and the second piping node (32). [6] Device according to one of the preceding claims, wherein the piping system (10) has a check valve (171) arranged between the first piping node (31) and the second piping node (32). [7] Device according to one of the preceding claims, wherein the line system (10) has a pressure sensor (301, 302) at the second and / or third line node (32, 33). [8] Device according to one of the preceding claims, wherein the piping system (10) has a pressure reducer (181) arranged between the third piping node (33) and the exhaust pipe (20). [9] Device according to one of the preceding claims, wherein the device (1) has an electronic interface (5) which can be connected to an electronic interface of a hydrogen system (500) for data exchange. [10] Device according to one of the preceding claims, wherein the line system (10) has an earthing point (6) or a connection point for an earthing point. [11] Device according to any one of the preceding claims, characterized by , that the piping system (10) has a return line for returning gas from the hydrogen system (500) which leads into the working gas line. [12] Method for purging a hydrogen system (500) comprising the steps: a) Connecting a rinsing device (1) to the hydrogen system (500) ; b) Release of a gas from the hydrogen system (500) ; c) Allow inert gas to flow into the hydrogen system (500); d) Checking the hydrogen concentration of the released gas; e) Repeat steps b. - d. until the hydrogen concentration falls below a target value. [13] The method of claim 12, wherein the method comprises the following further steps: - Allow forming gas to flow into the hydrogen system (500); - Monitoring the environment of the hydrogen system (500) using a hydrogen detector; - If hydrogen is detected: a warning signal is issued. [14] Method according to claim 12 or 13, wherein the hydrogen system (500) connects a hydrogen propulsion system (600) and a high-pressure storage system. [15] Method according to one of claims 12 to 14, wherein the rinsing device (1) is connected to the hydrogen system (500) via a connecting coupling (102) and fluids flow in and out successively via this connecting coupling (102). [16] Method according to one of claims 12 to 14, wherein the flushing device (1) is connected to the hydrogen system (500) via two couplings (102, 103) and the inflow and outflow of fluids takes place simultaneously via the two couplings (102, 103). [17] Method according to any one of claims 12 to 16, wherein the rinsing device (1) is a mobile trolley and the hydrogen system (500) is located in a motor vehicle between a hydrogen engine and a high-pressure tank (700), wherein, after steps a. - e., a repair or maintenance is carried out on the motor vehicle and the steps according to claim 13 are followed during and / or after the repair or maintenance. [18] Method according to claim 17, wherein a data connection is established between the motor vehicle and the rinsing device (1) in step a. [19] Use of a trolley with a pressurized gas container (3) containing inert gas, a pressurized gas container (4) containing forming gas, a piping system (10), an exhaust line (20) and a coupling (102) for connecting to a hydrogen system (500) for inerting, purging and leak testing a hydrogen system (500).

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