PROTECTIVE REFORMER DEVICE FOR THE PROTECTION OF AN ANODE SECTION OF A FUEL CELL STACK

Abstract

The present invention relates to a protective reformer device (10) for the protection of an anode section (112) of a fuel cell stack (110) against oxidizing damage during a heating-up process, having a gas duct (20) with a gas inlet (22) and a gas outlet (24) for conducting fuel gas from an anode feed section (120) of the fuel cell stack (110), wherein a catalytic converter section (30) is arranged in the gas duct (20) for a catalytic oxidation of at least part of the fuel gas into a protective gas for feeding to the anode section (112), wherein, furthermore, the gas duct (20) has a temperature control device (40) in thermally transmitting contact with the catalytic converter section (30) for an active temperature control of the catalytic converter section (30).

Claims

1. Protective reformer device (10) for the protection of an anode section (112) of a fuel cell stack (110) against oxidising damage during a heating-up process, having a gas duct (20) with a gas inlet (22) and a gas outlet (24) for conducting fuel gas from an anode feed section (120) of the fuel cell stack (110), wherein a catalytic converter section (30) is arranged in the gas duct (20) for a catalytic oxidation of at least part of the fuel gas into a protective gas for feeding to the anode section (112), wherein, furthermore, the gas duct (20) has a temperature control device (40) in thermally transmitting contact with the catalytic converter section (30) for an active temperature control of the catalytic converter section (30).

2. Protective reformer device (10) according to claim 1, characterised in that the temperature control device (40) is designed as a heating device, as a cooling device or as a combined heating and cooling device.

3. Protective reformer device (10) according to claim 1, characterised in that the temperature control device (40) is designed at least partially as an independent temperature control device (40) independent of fluid flows of the fuel cell stack (110).

4. Protective reformer device (10) according to claim 1, characterised in that the temperature control device (40) is designed at least partially as a heat exchanger (50), wherein the gas duct (20) forms a first heat exchanger side (52) of the heat exchanger (50).

5. Protective reformer device (10) according to claim 4, characterised in that the second heat exchanger side (54) of the heat exchanger (50) is formed at least partially by a cathode feed section (140) of the fuel cell stack (110).

6. Protective reformer device (10) according to claim 4, characterised in that the second heat exchanger side (54) of the heat exchanger (50) is formed at least partially by a cathode discharge section (142) of the fuel cell stack (110).

7. Protective reformer device (10) according to claim 4, characterised in that the second heat exchanger side (54) of the heat exchanger (50) is formed at least partially by an anode discharge section (122) of the fuel cell stack (110).

8. Protective reformer device (10) according to claim 4, characterised in that at least one valve device (60) is provided upstream of the second heat exchanger side (54) of the heat exchanger (50) for a variation of the fluid fed to the second heat exchanger side (54).

9. Protective reformer device (10) according to claim 1, characterised in that the gas duct (20) and/or the catalytic converter section (30) are at least partially manufactured using an additive process.

10. Fuel cell system (100), having at least one fuel cell stack (110) with an anode section (112) and a cathode section (114), an anode feed section (120) for feeding reformed anode feed gas from a reformer (130) to the anode section (112), a cathode feed section (140) for feeding cathode feed gas to cathode section (114), a reformer (130) for reforming reformer feed gas, a reformer feed section (132) for feeding the reformer feed gas to the reformer (130), an anode discharge section (122) for discharging anode exhaust gas, a cathode discharge section (142) for discharging cathode exhaust gas, wherein a protective reformer device (10) with the features of claim 1 is arranged in the anode feed section (120) between the reformer (130) and the anode section (112).

11. Fuel cell system (100) according to claim 10, characterised in that the anode feed section (120) has a main anode feed section (120a) and a bypass anode feed section (120b), wherein the protective reformer device (10) is arranged in the bypass anode feed section (120b).

12. Fuel cell system (100) according to claim 10, characterised in that a starting burner device (150) is arranged in the cathode feed section (140), in the cathode discharge section (142) and/or in the anode discharge section (122).

13. Method for the protection of an anode section (112) of a fuel cell stack (110) of a fuel cell system (100) with the features of claim 10, having the following steps: monitoring an anode temperature in the anode section (112), monitoring a protective reformer temperature of the protective reformer device (10), cooling and/or heating the protective reformer device (10) on the basis of the monitored temperatures by means of the temperature control device (40).

14. Method according to claim 13, characterised in that the step of cooling and/or heating is carried out on the basis of a specified operating corridor of the protective reformer device (10).

15. Method according to claim 13, characterised in that the step of cooling and/or heating is carried out on the basis of a minimum anode temperature and/or of a maximum temperature difference with respect to a cathode temperature of the cathode section (114) of the fuel cell stack (110).

Description

[0040] Further advantages, features and details of the invention emerge from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention, taken individually or in any combination. In each case schematically:

[0041] FIG. 1 shows an embodiment of a protective reformer device according to the invention,

[0042] FIG. 2 shows a further embodiment of a protective reformer device according to the invention,

[0043] FIG. 3 shows an embodiment of a fuel cell system according to the invention,

[0044] FIG. 4 shows a further embodiment of a fuel cell system according to the invention,

[0045] FIG. 5 shows a further embodiment of a fuel cell system according to the invention,

[0046] FIG. 6 shows a further embodiment of a fuel cell system according to the invention,

[0047] FIG. 7 shows a further embodiment of a fuel cell system according to the invention.

[0048] An embodiment of a protective reformer device 10 according to the invention is represented schematically in FIG. 1. This is equipped with a gas duct 20 via which fuel gas can be supplied via a gas inlet 22 and the fuel gas or the generated protective gas can be discharged again via the gas outlet 24. During a heating-up process of the fuel cell system 100, fuel gas is fed to the gas duct 20 via the gas inlet 22. The temperature of the catalytic converter section 30 can be set via the temperature control device 40.

[0049] In particular, this is achieved by heating and/or cooling of the catalytic converter section 30. The embodiment shown in FIG. 1 is a separate temperature control device 40 which has for example a separate coolant or also an electrical heating or a separate heating medium. In this way, the defined temperature control thermally activates the catalytic converter section 30 and at the same time protects this from undesirable damage, so that an activated catalytic converter section 30 can convert the fuel gas flowing through the gas duct 20 into a protective gas in a catalytically oxidising manner. The produced protective gas is now fed to the anode section 112 via the gas outlet 24, so that a reducing atmosphere can be created there to protect the anode section 112.

[0050] FIG. 2 is based on a similar core concept for the production of protective gas in the gas duct 20. However, here the temperature control device 40 of the protective reformer device 10 is designed as a heat exchanger 50. The gas duct 20 with the gas inlet 22 and gas outlet 24 therefore forms the first heat exchanger side 52. A second heat exchanger side 54 permits heat-transmitting contact via a wall, in particular directly with the catalytic converter section 30, so that fluid flowing through the second heat exchanger side 54 can provide a heat transfer with the catalytic converter section 30. With cold fluid on the second heat exchanger side 54, a cooling of the catalytic converter section 30 thus takes place and, correspondingly, with hot fluid a heating of the catalytic converter section 30 takes place. Otherwise, the embodiment shown in FIG. 2 can be integrated into the heating-up process in the same way as explained with reference to FIG. 1.

[0051] FIG. 3 shows, schematically, the simplest embodiment of a fuel cell system 100 according to the invention. Here, the fuel cell stack 110 is shown with an anode section 112 and a cathode section 114. Fuel gas can be fed via a reformer feed section 132 to a reformer 130 in which, in normal operation, the fuel gas is used or converted for use in the fuel cell stack 110, specifically in the anode section 112. For the heating-up process, the protective reformer device 10 according to the invention is arranged between the reformer 130 and the anode section 112. With the help of a for example electrically-acting temperature control device 40, in this case formed separately, an active heating or also an active cooling or a combination of heating and cooling can be provided for the inflowing fuel gas, so that the catalytic converter section in the protective reformer device 10 can be activated accordingly in order to ensure a reducing protective gas atmosphere during the heating-up process in the anode section 112.

[0052] Corresponding exhaust gas from the anode section 112 is discharged via the anode discharge section 122. In this simple embodiment, the cathode side of the cathode section 114 is completely separated from the protective reformer device 10 according to the invention.

[0053] FIG. 4 shows a further development in which the anode feed section 120 is divided into a main anode feed section 120a and a bypass anode feed section 120b. In this way, during the heating-up process the protective reformer device 10 can, via appropriate valve devices 60, be integrated into the inflow to the anode section 112 and deactivated in the normal operating state. In other words, this makes possible an increased controllability of the flow through the protective reformer device 10.

[0054] FIG. 5 shows a different embodiment and a further integration of the protective reformer device 10. Here, the temperature control device 40 is designed as a heat exchanger 50, so that a heating or cooling and thus a temperature control through fluid flows within the fuel cell system 100 is made possible. In the variant shown in FIG. 5, for this purpose supply air, as cathode feed gas, is introduced into the heat exchanger 50 directly via the second heat exchanger side 54 and then fed to the cathode section 114 via the cathode feed section 140. If cold air is sucked in, a cooling function can be provided in this way. However, other heat exchangers or start burners can naturally also be used to heat up the supply air sucked in from the outside, and thus the cathode feed gas, before reaching the second heat exchanger side 54, so that, alternatively, a heating function can also be provided here.

[0055] In the embodiment shown in FIG. 6, cathode exhaust gas which is discharged from the cathode section 114 via the cathode discharge section 142 is used instead of the cathode feed gas. In the embodiment shown in FIG. 6, this cathode exhaust gas first flows through the normal reformer 130 on its other heat exchanger side and then through the second heat exchanger side 54 of the protective reformer device 10. This represents in particular a heating option for the catalytic converter section 30.

[0056] FIG. 7 shows an extended embodiment which in particular allows a switchability of the temperature control device 40 as a heat exchanger 50. Here, cathode exhaust gas from the cathode discharge section 142 and anode exhaust gas from the anode discharge section 122 are brought together in a valve device 60. This can involve both a qualitative and a quantitative switching. In addition, it can be seen from FIG. 7 that starting burner devices 150 are provided at different points in order to have additional influence on the temperature and the heating-up process of the fuel cell stack 110.

[0057] The above explanation of the embodiments describes the present invention exclusively in the context of examples. Naturally, individual features of the embodiments can, insofar as technically expedient, be freely combined with each other without departing from the scope the present invention.

LIST OF REFERENCE SIGNS

[0058] 10 protective reformer device [0059] 20 gas duct [0060] 22 gas inlet [0061] 24 gas outlet [0062] 30 catalytic converter section [0063] 40 temperature control device [0064] 50 heat exchanger [0065] 52 first heat exchanger side [0066] 54 second heat exchanger side [0067] 60 valve device [0068] 100 fuel cell system [0069] 110 fuel cell stack [0070] 112 anode section [0071] 114 cathode section [0072] 120 anode feed section [0073] 120a main anode feed section [0074] 120b bypass anode feed section [0075] 122 anode discharge section [0076] 130 reformer [0077] 132 reformer feed section [0078] 140 cathode feed section [0079] 142 cathode discharge section [0080] 150 starting burner device