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EP-4533570-B1 - EXHAUST GAS TREATMENT DEVICE FOR FUEL CELL ASSEMBLY

EP4533570B1EP 4533570 B1EP4533570 B1EP 4533570B1EP-4533570-B1

Inventors

  • WAGENBLAST, Max
  • SWOBODA, JAN
  • PETERSEN, NIELS
  • POLLAK, MARKUS
  • Köhler, Jürgen

Dates

Publication Date
20260513
Application Date
20230523

Claims (20)

  1. Exhaust gas aftertreatment device (10) for a fuel cell arrangement (50), comprising: an inlet (20) which is fluidically connectable to the fuel cell arrangement (50) for receiving exhaust gas discharged from the fuel cell arrangement (50), preferably air enriched with water vapour and/or water; an outlet (30) for discharging the exhaust gas after it has flowed through the exhaust gas aftertreatment device (10); an exhaust gas dehumidifier (12A) for removing water and/or water vapour from the exhaust gas; an exhaust gas condenser (14) for liquefying and/or separating water from the exhaust gas, wherein the exhaust gas dehumidifier (12A) and the exhaust gas condenser (14) are fluidically connected in series; and a fluidic switching device (32, 34, 36, 38, 40) for switching between at least two switching configurations of the exhaust gas dehumidifier (12A) and the exhaust gas condenser (14), wherein the switching configurations comprise: a) a first switching configuration in which the exhaust gas condenser (14) is fluidically connected upstream of the exhaust gas dehumidifier (12A), and b) a second switching configuration in which the exhaust gas condenser (14) is fluidically connected downstream of the exhaust gas dehumidifier (12A).
  2. Exhaust gas aftertreatment device (10) according to claim 1, wherein the switching configurations further comprise a third switching configuration in which at least a portion of the exhaust gas can be passed past the exhaust gas condenser (14).
  3. Exhaust gas aftertreatment device (10) according to claim 1 or 2, wherein the switching device (32, 34, 36, 38, 40) comprises a first line (32) via which the output of the exhaust gas condenser (14) and the input of the exhaust gas dehumidifier (12A) are fluidically connectable, and a second line (34) via which the output of the exhaust gas dehumidifier (12A) and the input of the exhaust gas condenser (14) are fluidically connectable.
  4. Exhaust gas aftertreatment device (10) according to one of the preceding claims, wherein the switching device (32, 34, 36, 38, 40) comprises a plurality, preferably at least three, of valve devices (36, 38, 40).
  5. Exhaust gas aftertreatment device (10) according to claims 3 and 4, wherein the plurality of valve devices (36, 38, 40) are controllable such that the exhaust gas a) in the first switching configuration first flows through the exhaust gas condenser (14), is routed via the first line (32) to the exhaust gas dehumidifier (12A), and then flows through the exhaust gas dehumidifier (12A), and a) in the second switching configuration, first is flowing through the exhaust gas dehumidifier (12A), is routed via the second line (34) to the exhaust gas condenser (14), and then is flowing through the exhaust gas condenser (14).
  6. Exhaust gas aftertreatment device (10) according to claim 4 or 5, wherein the plurality of valve devices (36, 38, 40) are each designed as a controllable directional control valve and/or a controllable changeover valve.
  7. Exhaust gas aftertreatment device (10) according to one of the preceding claims, wherein the switching device (32, 34, 36, 38, 40) comprises a first valve device (36) which is arranged between the inlet (20) and the exhaust gas dehumidifier (12A) and between the inlet (20) and the exhaust gas condenser (14).
  8. An exhaust gas aftertreatment device (10) according to one of the preceding claims, wherein the switching device (32, 34, 36, 38, 40) comprises a first valve device (36) which is configured to a) in the first switching configuration, to disconnect a fluid connection between the inlet (20) and the exhaust gas dehumidifier (12A) and to establish a fluid connection between the inlet (20) and the exhaust gas condenser (14), and/or b) in the second switching configuration, to establish the fluid connection between the inlet (20) and the exhaust gas dehumidifier (12A) and to disconnect the fluid connection between the inlet (20) and the exhaust gas condenser (14).
  9. Exhaust gas aftertreatment device (10) according to claims 2 and 8, wherein the first valve device (36) is further configured, in the third switching configuration, to establish the fluid connection between the inlet (20) and the exhaust gas dehumidifier (12A), and to establish the fluid connection between the inlet (20) and the exhaust gas condenser (14).
  10. Exhaust gas aftertreatment device (10) according to one of the preceding claims, wherein the switching device (32, 34, 36, 38, 40) comprises a second valve device (38) , which is arranged between the exhaust gas condenser (14) and the outlet (30), and preferably between the exhaust gas condenser (14) and a first line (32) of the switching device (32, 34, 36, 38, 40).
  11. Exhaust gas aftertreatment device (10) according to one of the preceding claims, wherein the switching device (32, 34, 36, 38, 40) comprises a second valve device (38) which is configured a) in the first switching configuration, and preferably in the third switching configuration, to disconnect a fluid connection between the exhaust gas condenser (14) and the outlet (30) and to establish a fluid connection between the exhaust gas condenser (14) and the exhaust gas dehumidifier (12A), and/or b) in the second switching configuration, to establish the fluid connection between the exhaust gas condenser (14) and the outlet (30) and to disconnect the fluid connection between the exhaust gas condenser (14) and the exhaust gas dehumidifier (12A).
  12. Exhaust gas aftertreatment device (10) according to one of the preceding claims, wherein the switching device (32, 34, 36, 38, 40) comprises a third valve device (40) arranged between the exhaust gas dehumidifier (12A) and the outlet (30), and preferably between the exhaust gas dehumidifier (12A) and a second line (34) of the switching device (32, 34, 36, 38, 40).
  13. Exhaust gas aftertreatment device (10) according to one of the preceding claims, wherein the switching device (32, 34, 36, 38, 40) comprises a third valve device (40) which is configured, a) in the first switching configuration, and preferably in a third switching configuration, to disconnect a fluid connection between the exhaust gas dehumidifier (12A) and the exhaust gas condenser (14) and to establish a fluid connection between the exhaust gas dehumidifier (12A) and the outlet (30), and/or b) in the second switching configuration, to establish the fluid connection between the exhaust gas dehumidifier (12A) and the exhaust gas condenser (14) and to disconnect the fluid connection between the exhaust gas dehumidifier (12A) and the outlet (30).
  14. Exhaust gas aftertreatment device (10) according to one of the preceding claims, wherein the exhaust gas aftertreatment device (10) further comprises a control device configured to control the switching device (32, 34, 36, 38, 40) to switch between at least two switching configurations of the exhaust gas dehumidifier (12A) and the exhaust gas condenser (14) in dependence on at least one of the following conditions: - at least one operating condition and/or one operating point of the fuel cell arrangement (50); - at least one ambient condition of the fuel cell arrangement (50) and/or the Exhaust gas aftertreatment device (10); - a total pressure of the exhaust gas upon entry of the exhaust gas into the exhaust gas aftertreatment device (10); and/or - a proportion, preferably a molar fraction, a mass flow and/or a current density, of water vapour in the exhaust gas upon entry of the exhaust gas into the exhaust gas aftertreatment device (10).
  15. Exhaust gas aftertreatment device (10) according to one of the preceding claims, wherein the exhaust gas condenser (14) comprises at least one water condensation device (14A) and a water separator (14B), which is preferably arranged downstream of the water condensation device (14A) in the flow path.
  16. Drive device (100) for a motor vehicle, preferably a commercial vehicle, comprising: a fuel cell arrangement (50); and an exhaust gas aftertreatment device (10) according to one of the preceding claims.
  17. A drive device (100) according to claim 16, further comprising: an intake tract (60), preferably the air supply side of a cathode path for the fuel cell arrangement (50), for supplying air, preferably oxygen, to the fuel cell arrangement (50); and an exhaust gas tract (70), preferably an exhaust gas side of the cathode path, for discharging exhaust gas, preferably air enriched with water vapour and/or water, from the fuel cell arrangement (50), wherein the exhaust gas aftertreatment device (10) is designed as part of the exhaust gas tract (70).
  18. A drive device (100) according to claim 17, wherein the exhaust gas dehumidifier (12A) is designed as part of a humidifier device (12) for transferring the water vapour and/or water extracted from the exhaust gas from the exhaust gas tract to the intake tract.
  19. Drive device (100) according to claim 18, wherein the switching device (32, 34, 36, 38, 40) is configured to switch between the switching configurations in response to a partial pressure difference of the water vapour and/or water transferred by means of the humidifier means (12).
  20. Motor vehicle, preferably a commercial vehicle, comprising a drive device (100) according to any one of claims 15 to 19 and/or an exhaust gas aftertreatment device (10) according to any one of claims 1 to 14.

Description

The invention relates to an exhaust aftertreatment device for a fuel cell arrangement, a drive device with the exhaust aftertreatment device, and a motor vehicle, in particular a commercial vehicle, with the drive device. Fuel cell systems, which serve, for example, as drive systems for motor vehicles, typically use hydrogen, which is supplied to the anodes of the fuel cells, and oxygen from the ambient air, which is supplied to the cathodes of the fuel cells, to react and produce water (vapor) and thereby generate electrical energy. The resulting water vapor (so-called product water) is then carried away with the exhaust gas, i.e., with the unreacted hydrogen and, in particular, with the ambient air, which contains the unreacted oxygen. For such fuel cell systems to function properly, it is important that the membranes between the anode and cathode sides of the fuel cells maintain a certain level of moisture. To ensure this, it is known, for example, to humidify the ambient air drawn in by means of a humidifier, thus introducing the required moisture into the fuel cells. Known humidifiers are designed, for example, to transfer water vapor from the exhaust gas to the intake ambient air. Usually, not all of the water vapor contained in the exhaust gas is necessary for this, so the remaining water vapor is released unused into the environment with the exhaust gas. DE 10 2020 124754 discloses an exhaust aftertreatment device for a fuel cell arrangement comprising an exhaust gas dehumidifier and an exhaust gas liquefier, wherein the exhaust gas dehumidifier and the exhaust gas liquefier are fluidically connected in series. Therefore, the object of the invention is to provide a solution that at least partially avoids the disadvantages of previous solutions. In particular, it is an object of the invention to provide the most efficient possible technology for extracting the highest possible amount of water (vapor) generated in the fuel cells from the exhaust gas for further use. The problem is solved by the features of the independent claims. Advantageous further developments are specified in the dependent claims and the description. According to a first general aspect of the invention, an exhaust gas aftertreatment device for a fuel cell arrangement is provided. The exhaust gas aftertreatment device comprises an inlet, an outlet, an exhaust gas dehumidifier, and an exhaust gas liquefier. The inlet is fluidically connected to the fuel cell assembly to receive exhaust gas discharged from the fuel cell assembly, in particular air enriched with water vapor and/or water. The water vapor and/or water is, in particular, water generated during the operation of the fuel cell assembly (and/or product water). The outlet is designed to discharge the exhaust gas after it has passed through the exhaust gas aftertreatment device. The exhaust gas dehumidifier is designed to remove water and/or water vapor from the exhaust gas. The exhaust gas dehumidifier can be configured to remove a predetermined quantity, in particular a predetermined mass flow rate, of water and/or water vapor from the exhaust gas. The predetermined quantity can depend, for example, on at least one operating condition, an operating point, and/or at least one environmental condition of the fuel cell assembly and/or the exhaust gas aftertreatment device. The removal of water and/or water vapor occurs, in particular, without condensation of the water vapor. The exhaust gas dehumidifier can be designed, in particular, as part of a humidification unit and/or a moisture exchanger. The humidification unit and/or the moisture exchanger can include a humidifier and/or be designed to transfer the water vapor and/or water extracted from the exhaust gas from the exhaust gas dehumidifier to the humidifier. The exhaust gas condenser is designed to liquefy water vapor and/or separate (liquefied) water from the exhaust gas. The exhaust gas condenser can, for example, include at least one water condensation unit and a water separator, which is preferably fluidically connected downstream of the water condensation unit. The liquefaction of water vapor is achieved in particular by condensing the water vapor. The water condensation device can be, for example, a gas-to-gas heat exchanger, in particular an air-to-air heat exchanger. The liquefied and/or separated Water can, for example, be collected for (further) use or at least fed into another device. The liquefied and/or separated water can, for example, be reused as evaporative cooling water. The exhaust gas dehumidifier and the exhaust gas condenser are connected fluidically in series. The exhaust aftertreatment device further includes a fluidic switching device for switching between at least two switching configurations of the exhaust dehumidifier and the exhaust liquefier. The switching configurations include a first switching configuration in which the exhaust gas condenser is fluidically connected upstream of the exhaust