Fuel cell system and method of operating a fuel cell system

Patent metadata

Field	Value
Publication number	US-2025087724-A1
Application number	US-202318463816-A
Country	US
Kind code	A1
Filing date	Sep 8, 2023
Priority date	Sep 8, 2023
Publication date	Mar 13, 2025
Grant date	—

Abstract

A fuel cell system has at least one fuel cell which includes an anode compartment and a cathode compartment, and a recirculation line for anode gas which leads from a gas outlet of the anode compartment to a gas inlet of the anode compartment and in which an ejector pump is arranged. The ejector pump includes a first nozzle and at least one second nozzle which is in the form of a ring nozzle arranged coaxially around the first nozzle. A respective fuel gas valve is associated with a respective nozzle and controls a supply of pressurized fuel gas to a primary gas inlet of the respective nozzle. In a low load range, only the first or only the at least one second nozzle of the ejector pump is selectively supplied with primary gas, whereas in a high load range both nozzles are supplied with primary gas simultaneously.

First claim

1 . A fuel cell system comprising at least one fuel cell which includes an anode compartment and a cathode compartment, and comprising a recirculation line for anode gas which leads from a gas outlet of the anode compartment to a gas inlet of the anode compartment and in which an ejector pump is arranged, the ejector pump including a first nozzle and at least one second nozzle which is in the form of a ring nozzle arranged coaxially around the first nozzle, and comprising at least two fuel gas valves, each fuel gas valve being associated with a nozzle and controlling a supply of pressurized fuel gas to a primary gas inlet of the respective nozzle of the ejector pump.

2 . The fuel cell system according to claim 1 , wherein the primary gas inlet of the second nozzle opens into an annular chamber of the second nozzle.

3 . The fuel cell system according to claim 1 , wherein all nozzles open axially into a suction chamber which is enlarged in comparison with the outside diameter of the second nozzle and into which the recirculation line opens laterally.

4 . The fuel cell system according to claim 3 , wherein all nozzles open into the suction chamber at their minimum cross-sectional areas.

5 . The fuel cell system according to claim 1 , wherein at least one fuel gas valve is a proportional valve and/or a valve operated in a clocked manner.

6 . The fuel cell system according to claim 1 , wherein the ejector pump is designed such that it can be selectively operated with only one nozzle or simultaneously with a plurality of nozzles.

7 . The fuel cell system according to claim 1 , wherein a shut-off valve is provided which is either connected upstream of both fuel gas valves or is formed by the first fuel gas valve.

8 . The fuel cell system according to claim 1 , wherein all of the fuel gas valves are connected in parallel.

9 . The fuel cell system according to claim 1 , wherein the first fuel gas valve is connected upstream of all further fuel gas valves and a bypass line runs from the outlet of the first fuel gas valve to the ejector pump, parallel to all further fuel gas valves.

10 . The fuel cell system according to claim 1 , wherein the first fuel gas valve is open when the ejector pump operates.

11 . A method of operating a fuel cell system, comprising at least one fuel cell which includes an anode compartment and a cathode compartment, and comprising a recirculation line for anode gas which leads from a gas outlet of the anode compartment to a gas inlet of the anode compartment and in which an ejector pump is arranged, the ejector pump including a first nozzle and at least one second nozzle which is in the form of a ring nozzle arranged coaxially around the first nozzle, and comprising at least two fuel gas valves, each fuel gas valve being associated with a nozzle and controlling a supply of pressurized fuel gas to a primary gas inlet of the respective nozzle of the ejector pump,
wherein in a low load range selectively only the first or only the at least one second nozzle of the ejector pump is supplied with primary gas and in a high load range both nozzles are supplied with primary gas simultaneously.

12 . The method according to claim 11 , wherein the supply of fuel gas to the respective primary gas inlet of the individual nozzles is freely controllable within the scope of a characteristic map, the characteristic map being determined by predefined maximum primary gas flow rates of the fuel gas valves associated with the respective nozzles.

13 . The method according to claim 11 , wherein the supply of fuel gas to the respective primary gas inlet of the individual nozzles is freely controllable within the scope of a characteristic map, the map being determined by a single curve starting at the load point established by the opening of the first fuel gas valve and the sole operation of the first nozzle, and being traversed to the maximum by a stepless opening of the second fuel gas valve up to its maximum opening degree.

Assignees

• Hoerbiger Antriebstechnik Hold

Inventors

• Rothe Felix
• Pfeiffer Christoph
• Sohmen Sebastian
• Traut Christopher

Classifications

• H01M8/04753

  of fuel cell reactants · CPC title

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title

• B05B1/20

  Perforated pipes or troughs, e.g. spray booms; Outlet elements therefor · CPC title

• H01M8/04201

  Reactant storage and supply, e.g. means for feeding, pipes · CPC title

• H01M8/04097 Primary

  with recycling of the reactants (H01M8/04119, H01M8/04104 take precedence) · CPC title