Leak-tightness testing concept for an anode sub-module

Abstract

The invention relates to a system (2) for testing an anode sub-module (30), which is provided for supplying the anode of a fuel cell with hydrogen gas in a controlled manner, the system comprising: an adapter plate (20) which is designed to receive the anode sub-module (30) to be tested; a pneumatic unit (1) which is pneumatically connected to the adapter plate (20) and is designed to supply the anode sub-module (30) with at least one test gas via the adapter plate (20); and a testing device (12, 90) which makes it possible to test the leak-tightness of the anode sub-module (30) to be tested.

Description

[0001] Description

[0002] title for an anode submodule

[0003] The invention relates to a system for rinsing and testing an anode submodule and a method for rinsing and testing an anode submodule.

[0004] State of the art

[0005] Fuel cell systems are frequently used for generating electricity from hydrogen in vehicles, preferably commercial vehicles, especially for long-distance applications. Such a fuel cell system comprises a fuel cell stack and fuel cell submodules that supply the fuel cell stack with hydrogen and oxygen, which are necessary for its operation. These fuel cell submodules include, in particular, anode submodules designed to supply the anodes of the fuel cells with hydrogen gas in a controlled manner.

[0006] An anode submodule can include a hydrogen metering valve, an anode recirculation blower, a jet pump, a low-pressure sensor and / or a medium-pressure sensor.

[0007] During the production of such fuel cell systems, various tests, especially leak tests, are carried out in series production. However, these tests cannot currently be performed during maintenance and repair work on a fuel cell system in workshops. It is therefore an object of the invention to provide a system and a method that make it possible to carry out adequate leak tests even in workshops.

[0008] The system according to the invention for testing an anode submodule, which is designed to supply the anode of a fuel cell with hydrogen gas in a controlled manner, comprises: an adapter plate designed to receive the anode submodule to be tested; and a pneumatic unit that can be pneumatically connected to the adapter plate and that is designed to supply the anode submodule with at least one test gas via the adapter plate. The system further comprises a test device that makes it possible to check the leak tightness of the anode submodule to be tested.

[0009] With a pneumatic unit according to the invention, the anode submodule under test can be purged, and various leak tests, such as a pressure hold test and / or the supply of a test gas detectable by a gas detector to the anode submodule, can be performed. The pneumatic unit makes it possible to control the test sequence and the test parameters. Therefore, with the aid of a system according to the invention, it is possible to carry out leak tests in workshops that are comparable to the leak tests performed during the series production of such anode submodules.

[0010] The invention further comprises a method for purging and / or testing an anode submodule designed to supply the anode of a fuel cell with hydrogen gas in a controlled manner, wherein the method comprises the following steps:

[0011] (a) Placing the anode submodule to be tested on an adapter plate designed to receive the anode submodule to be tested and comprising at least one air supply element designed to supply test gas to the anode submodule arranged on the adapter plate;

[0012] (b) Supplying at least one test gas to the anode submodule from a pneumatic unit pneumatically connected to the adapter plate, in order to

[0013] (b1) to flush the anode submodule; and / or (b2) to check the tightness of the anode submodule.

[0014] In one embodiment, checking the tightness of the anode submodule includes performing a pressure drop test on the anode submodule.

[0015] In one embodiment, checking the tightness of the anode submodule comprises supplying the anode submodule with a test gas detectable by a gas detector and detecting test gas escaping from the anode submodule with a gas detector.

[0016] Nitrogen, compressed air, or a forming gas can be used as a test gas. Compressed air or nitrogen can be used in particular for pressure drop testing and for purging the anode submodule. A forming gas is used especially for locating a possible leak in the anode submodule.

[0017] In one embodiment, the test device is designed as part of the pneumatic unit. The test device can, in particular, be designed as a pressure gauge (manometer) that makes it possible to measure the pressure of the test gas and to detect a pressure drop that may be caused by a leak in the anode submodule.

[0018] In one embodiment, the test device comprises a gas detector configured to detect test gas escaping from the anode submodule through a leak, in order to identify a leak in the anode submodule. The gas detector can, in particular, be configured to detect the uncontrolled escape of a forming gas used as a test gas from the anode submodule.

[0019] The pneumatic unit can comprise a first pressure range and a second pressure range. The pressure of the test gas can be higher in the first pressure range than in the second pressure range.

[0020] In one embodiment, the first pressure range comprises a pressure regulator and a first pressure relief valve. The pressure regulator can be configured to supply test gas at a pressure pi. n to receive pressures exceeding 1000 kPa (10 barg) and to discharge the test gas at a reduced pressure pout in the range of 0 kPa to 400 kPa (4 barg).

[0021] In one embodiment, the second pressure range includes a second pressure relief valve, wherein the second pressure relief valve is designed to open at a pressure in the range of 300 kPa (3.0 barg) to 400 kPa (4.0 barg), in particular at a pressure of 350 kPa (3.5 barg).

[0022] In one embodiment, the second pressure range includes a third pressure relief valve, wherein the third pressure relief valve is designed to open at a pressure in the range of 300 kPa (3.0 barg) to 400 kPa (4.0 barg), in particular at a pressure of 350 kPa (3.5 barg).

[0023] The pressure relief valves act as safety valves to prevent potentially dangerous overpressure in the second pressure zone. A third pressure relief valve increases system safety through redundancy.

[0024] In one embodiment, the pressure of the test gas in the first pressure range during operation of the system is less than 700 kPa (7 barg), and the test gas occupies a volume of less than 0.5 dm³ in the first pressure range. 3 a.

[0025] In one embodiment, the pressure of the test gas in the second pressure range during operation of the system is less than 350 kPa (3.5 barg), and the test gas occupies a volume of less than 3 dm³ in the first pressure range. 3 a.

[0026] In one embodiment, the adapter plate has at least one fastening element that makes it possible to attach the anode submodule to be tested to the adapter plate. The adapter plate can, in particular, have several fastening elements.

[0027] In one embodiment, the at least one fastening element comprises at least one thread and / or at least one screw. In one embodiment, the adapter plate has at least one air supply element configured to supply test gas to an anode submodule arranged on the adapter plate.

[0028] In one embodiment, the adapter plate has at least one air discharge element designed to discharge the test gas from an anode submodule arranged on the adapter plate.

[0029] In one embodiment, a sealing ring, in particular an O-ring, is provided on the adapter plate, which is designed to seal the connection between the anode submodule and the adapter plate in a fluid-tight manner.

[0030] An embodiment of the invention is described below with reference to the accompanying figures.

[0031] Brief description of the characters

[0032] Figure 1 shows an anode submodule to be tested, which is mounted on an adapter plate.

[0033] Figure 2 shows a schematic view of an adapter plate of the system according to the invention for testing an anode submodule.

[0034] Figure 3 shows a pneumatic unit that is part of a system according to the invention for testing an anode submodule.

[0035] Figure 4 shows a schematic pneumatic circuit diagram of the pneumatic unit.

[0036] Character description

[0037] Figure 1 shows an example of an anode submodule 30 to be tested, which is mounted on an adapter plate 20. The adapter plate 20 is part of a system 2 according to the invention for testing an anode submodule.

[0038] The adapter plate 20 is designed so that a test gas can be supplied to the anode submodule 30 via the adapter plate 20. This makes it possible to purge the anode submodule 30 in its removed state and / or to check the leak tightness of the anode submodule 30.

[0039] Figure 2 shows a view of an adapter plate 20 according to an embodiment of the present invention without an anode submodule 30 arranged thereon.

[0040] The adapter plate 20 has several mounting elements 26 that allow the anode submodule 30 under test to be attached to the adapter plate 20. The positions of the mounting elements 26 can be configured for a specific anode submodule 30. Additional positions for mounting elements 26 can also be provided, allowing anode submodules of different designs to be attached to the adapter plate 20.

[0041] The fastening elements 26 can be designed, for example, as bolts, threaded bolts and / or screws.

[0042] Furthermore, the adapter plate 20 comprises at least one air supply element 22, which is configured to supply test gas to an anode submodule 30 arranged on the adapter plate 20; and an air discharge element 24, which is configured to discharge test gas from an anode submodule 30 arranged on the adapter plate 20.

[0043] The positions of the air supply element 22 and the air exhaust element 24 can also be adapted to a specific anode submodule 30. However, multiple positions for the air supply element 22 and the air exhaust element 24 can also be provided, making it possible to arrange anode submodules of different designs on the adapter plate 20 and supply them with a test gas.

[0044] A sealing ring 25, in particular an O-ring, is provided on the adapter plate 20 to seal the interface between the anode submodule 30 and the adapter plate 20 in a fluid-tight manner. Figure 3 shows a view of a front side of a pneumatic unit 1 of a system 2 according to the invention for testing an anode submodule 30.

[0045] Figure 4 shows a schematic pneumatic circuit diagram of a system 2 according to the invention for testing an anode submodule 30.

[0046] A test gas is supplied to the pneumatic unit 1 from a gas source 50 (not shown in Figure 3). The test gas can be, for example, compressed air, nitrogen, or a suitable forming gas.

[0047] In the direction of flow of the test gas (from left to right in Figures 3 and 4), the pneumatic unit 1 comprises a first pressure relief valve 3, a pressure regulator 4 with a first pressure gauge (manometer) 5, a filter unit 6, a second pressure relief valve 8a, a third pressure relief valve 8b, a shut-off valve 10 and a second pressure gauge (manometer) 12.

[0048] An output 14 of the second pressure gauge 12 is connected via a connecting line 15, which is not shown in Figure 3, to the air supply element 22 of the adapter plate 20, so that test gas from the pneumatic unit 1 can be supplied to an anode submodule 30 to be tested, which is arranged on the adapter plate 20, via the connecting line 15 and the air supply element 22.

[0049] As shown schematically in Figure 4, the pneumatic unit 1 has a first pressure area 16 and a second pressure area 18.

[0050] The first pressure relief valve 3 and the pressure regulator 4 of the pneumatic unit 1 are located in the first pressure area 16.

[0051] The pressure regulator 4 is specifically designed to receive the test gas at a pressure pin of more than 1000 kPa (10 barg) from the gas source 50, e.g., a gas cylinder, and to discharge it at a lower pressure pout (pout < Pin), in particular at a reduced pressure pout in the range of 0 kPa to 400 kPa (0–4 barg), into the second pressure range 18. The first pressure relief valve 3 is a safety valve that opens when the gas pressure pGasi in the first pressure range 16 exceeds a predetermined value pnmiti. The first pressure relief valve 3 can, in particular, be designed to open when the gas pressure pGasi in the first pressure range 16 exceeds a pressure pnmiti between 6 barg and 7 barg, in particular a pressure pnmiti of 7 barg.

[0052] The first pressure gauge 5 is provided at the inlet of the second pressure zone 18, which is connected to the outlet of the pressure regulator 4. The first pressure gauge 5 makes it possible to measure and monitor the pressure of the test gas flowing from the first pressure zone 16 into the second pressure zone 18. In particular, the pressure regulator 4 can be adjusted depending on the pressure displayed by the first pressure gauge 5.

[0053] Downstream of the first pressure gauge 5 is a filter unit 6, which is designed and configured to filter the test gas flowing through the pneumatic unit 1 in order to remove particles that may be present in the test gas.

[0054] Two pressure relief valves 8a, 8b are provided at the outlet of the filter unit 6. The two pressure relief valves 8a, 8b can be configured to open from a pressure piimit2 in the range of 300 kPa (3 barg) to 400 kPa (4 barg), in particular at a pressure pnm® of 350 kPa (3.5 barg) in the second pressure range 18, in order to prevent a dangerous overpressure in the second pressure range 18.

[0055] In the embodiment shown in Figures 3 and 4, two pressure relief valves 8a, 8b are provided to increase the safety of the pneumatic unit 1 through redundancy. Embodiments are also possible in which only a single pressure relief valve 8a, 8b is present in the second pressure zone 18.

[0056] Downstream of the pressure relief valves 8a and 8b, a shut-off valve 10 is provided, which allows the supply of test gas from the pneumatic unit 1 to the adapter plate 20 and the anode submodule 30 to be selectively enabled and disabled. A second pressure gauge 12 is provided at the outlet of the shut-off valve 10; this second pressure gauge 12 allows the pressure p to be measured. ou t to measure, with which the test gas is output from the pneumatic unit 1 to the adapter plate 20 and the anode submodule 30.

[0057] In the first pressure range 16, for example, the test gas occupies a volume Vi of less than 0.5 dm³ 3 one. In the second pressure range 18, the test gas can, for example, have a volume V2 of less than 3 dm³. 3 take.

[0058] According to an embodiment of the invention, a method for rinsing and / or testing an anode submodule 30 comprises the following steps:

[0059] (a) Placing and securing the anode submodule 30 to be tested on the adapter plate 20 as shown in Figure 1, so that a gas inlet of the anode submodule 30 is pneumatically connected to the air supply element 22 formed on the adapter plate 20;

[0060] (b) pneumatically connecting the air supply element 22 of the adapter plate 20 to the outlet 14 of the pneumatic unit 1 ;

[0061] (c) Supplying at least one test gas from a gas source 50 to the pneumatic unit 1 , and

[0062] (d) Operating the pneumatic unit 1 to supply the anode submodule 30 arranged on the adapter plate 20 with at least one test gas at a predetermined pressure p ou to supply t. The pressure p can be increased in this process. ou t, with which the test gas is dispensed from the pneumatic unit 1, in particular with the pressure regulator 4 of the pneumatic unit 1, can be set and / or monitored with the second pressure gauge 12.

[0063] When the anode submodule 30 is purged, the test gas exiting the anode submodule 30 is discharged into the environment through a filter 40, an outlet valve 60 and a silencer 80, which are provided at the gas outlet of the anode submodule 30.

[0064] To check the tightness of the anode submodule 30, the gas outlet of the anode submodule 30 is blocked, e.g., by closing the outlet valve 60. The tightness of the anode submodule 30 can then be checked, for example, by monitoring the pressure of the test gas in system 2, for instance, with the second pressure gauge 12. An excessively large or rapid pressure drop in system 2 indicates that the anode submodule 30 is leaking.

[0065] Alternatively or additionally, the test gas can be a detectable gas, for example a suitable forming gas, which is not normally present in ambient air, or only in a minimal concentration. In this case, system 2 can include a gas detector 90, which is arranged in the vicinity of the anode submodule 30 and is configured to

[0066] to detect test gas escaping through a leak from the anode submodule 30 and thus identify a leak in the anode submodule 30.

Claims

1. System (2) for testing an anode submodule (30) designed to supply the anode of a fuel cell with hydrogen gas in a controlled manner, the system (2) comprising: an adapter plate (20) designed to accommodate the anode submodule (30) to be tested; and a pneumatic unit (1) pneumatically connectable to the adapter plate (20) and designed to supply the anode submodule (30) with at least one test gas via the adapter plate (20); and a test device (12, 90) enabling the tightness of the anode submodule (30) to be tested to be checked.

2. System (2) according to claim 1, wherein the test device (12, 90) comprises a pressure gauge (12) and / or a gas detector (90).

3. System (2) according to claim 1 or 2, wherein the pneumatic unit (1) has a first pressure area (16) and a second pressure area (18).

4. System (2) according to claim 3, wherein the first pressure area (16) comprises a pressure regulator (4) and a first pressure relief valve (3).

5. System (2) according to claim 4, wherein the pressure regulator (4) is configured to supply test gas at a pressure pi n to receive pressures of more than 1000 kPa and to discharge the test gas at a pressure pout in the range of 0 kPa to 400 kPa, wherein the pressure pout at which the test gas is discharged from the pressure regulator (4) is in particular adjustable.

6. System (2) according to one of claims 3 to 5, wherein the second pressure range (18) comprises a second overpressure valve (8a), wherein the second overpressure valve (8a) is designed to open at a pressure in the range of 300 kPa to 400 kPa, in particular at a pressure of 350 kPa.

7. System (2) according to claim 6, wherein the second pressure range (18) comprises a third pressure relief valve (8b), wherein the third pressure relief valve (8b) is designed to open at a pressure in the range of 300 kPa to 400 kPa, in particular at a pressure of 350 kPa.

8. System (2) according to any one of claims 3 to 7, wherein the test gas in the first pressure range (16) during operation of the system (2) has a pressure of less than 700 kPa and a volume of less than 0.5 dm³ 3 occupies.

9. System (2) according to any one of claims 3 to 8, wherein the test gas in the second pressure range (18) during operation of the system (2) has a pressure of less than 350 kPa and a volume of less than 3 dm³ 3 occupies.

10. System (2) according to one of the preceding claims, wherein the adapter plate (20) has at least one fastening element (26) which makes it possible to fasten the anode submodule (30) to be tested to the adapter plate (20); wherein the at least one fastening element (26) comprises a bolt, a threaded bolt and / or a screw.

11. System (2) according to one of the preceding claims, wherein the adapter plate (20) comprises at least one air supply element (22) configured to supply test gas to an anode submodule (30) arranged on the adapter plate (20); and / or wherein the adapter plate (20) comprises at least one air discharge element (24) configured to discharge test gas from an anode submodule (30) arranged on the adapter plate (20).

12. Method for purging and testing an anode submodule (30) intended to supply the anode of a fuel cell with hydrogen gas in a controlled manner, the method comprising the following steps: (a) Placing the anode submodule (30) to be tested on an adapter plate (20), wherein the adapter plate (20) is designed to accommodate the anode submodule (30) to be tested and has at least one air supply element (22) designed to supply test gas to the anode submodule (30) arranged on the adapter plate (20); (b) Supplying at least one test gas to the anode submodule (30) from a pneumatic unit (1) which is pneumatically connected to the adapter plate (20) in order to (b1) to rinse the anode submodule (30); and / or (b2) to check the tightness of the anode submodule (30).

13. The method of claim 12, wherein checking the tightness of the anode submodule (30) comprises: performing a pressure drop test on the anode submodule (30); and / or supplying the anode submodule (30) with a test gas detectable by a gas detector (90) and detecting test gas escaping from the anode submodule (30) with the gas detector (90).

14. Method according to claim 12 or 13, wherein the pneumatic unit (1) comprises a pressure regulator (4) which makes it possible to adjust the pressure of the test gas supplied to the anode submodule (30) via the adapter plate (20); and / or wherein the pneumatic unit (1) has at least one pressure gauge (12) which makes it possible to measure the pressure of the test gas supplied to the anode submodule (30) via the adapter plate (20).

15. Method according to any one of claims 12 to 14, wherein the test gas comprises nitrogen, compressed air or a forming gas.

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