Fuel cell device and method of monitoring and structurally adapting a fuel cell device

Abstract

A fuel cell device has a mounting plate on which a fuel cell unit having a predefined number of fuel cells is arranged, the mounting plate and the fuel cell unit comprising media connections for guiding media, in particular for guiding a coolant and for guiding reactants, and electrical contact points for electrically connecting the fuel cell unit to the mounting plate. Further media connections and further electrical contact points are designed or arranged on the fuel cell unit in such a way that the fuel cell unit can be connected or is connected to a second fuel cell unit with a mechanical fluid connection for further guidance of the media and electrical connection for power uptake.

Claims

1. A method for monitoring and structurally adapting a fuel cell device including a mounting plate, and a first fuel cell unit having a predefined number of fuel cells, the first fuel cell unit arranged on the mounting plate, wherein the mounting plate and the first fuel cell unit include first media connections for guiding media and first electrical contact points for electrically connecting the first fuel cell unit to the mounting plate, and wherein second media connections and second electrical contact points are designed or arranged on the first fuel cell unit in such a way that the first fuel cell unit can be connected or is connected to a second fuel cell unit in a mechanical fluid connection for further guidance of the media and electrical connection for power uptake, the method comprising: detecting one or more operating parameters of the fuel cell device by a control device; recording and evaluating a chronological course of the one or more operating parameters; if the evaluating shows that a power output of the fuel cell device is too limited, then expanding the fuel cell device by one or more fuel cell units; and if the evaluating shows that the power output of the fuel cell device is too large, then reducing the fuel cell device by one or more fuel cell units; wherein a tolerance range is predefined for at least one of the operating parameters of the fuel cell device, and, for the at least one operating parameter, a volumetric flow rate of one or more of the media flowing through the mounting plate and the one or more fuel cell units is adjusted without expanding and reducing the fuel cell device by one or more of the fuel cell units.

2. The method according to claim 1 wherein the volumetric flow rate of one or more of the media through the fuel cell device is adapted in such a way that the fuel cell device corresponds to an optimum as regards the associated operating parameter, at which the fuel cell device achieves a predetermined maximum power.

3. The method according to claim 1, wherein the at least one operating parameter relates to a voltage level of the fuel cell device, a pretension force of the fuel cell units of the fuel cell device combined to form a stack, or a pressure loss of media within the fuel cell device.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) Further advantages, features, and details are provided in the claims, the following description, and the drawing.

(2) FIG. 1 is a highly schematized exploded view of a modular expandable fuel cell device with a stack formed of three fuel cell units and a mounting end plate.

DETAILED DESCRIPTION

(3) In FIG. 1, a fuel cell device 1 is shown in an exploded view comprising a mounting plate 2 on which a first fuel cell unit 3a with a predefined number of fuel cells is arranged. The fuel cell unit 3a may comprise only one fuel cell or may comprise a plurality of fuel cells, for example, 10, 20, or 100 fuel cells. The mounting plate 2 and the fuel cell unit 3a have media connections 4 for guiding media, in this case for guiding reactants, and electrical contact points 5 for electrically connecting the fuel cell unit 3a to the mounting plate 2.

(4) Each of the fuel cells comprises an anode, a cathode, and a proton-conducting membrane separating the anode from the cathode. The membrane is formed of an ionomer, such as a sulfonated tetrafluoroethylene polymer (PTFE) or a perfluorinated sulfonic acid (PFSA) polymer. Alternatively, the membrane may be formed as a hydrocarbon membrane.

(5) A catalyst may additionally be admixed to the anodes and/or the cathodes, wherein the membrane may be coated on its first side and/or on its second side with a catalyst layer of a noble metal or a mixture comprising noble metals such as platinum, palladium, ruthenium or the like, which serve as reaction accelerators in the reaction of the respective fuel cell.

(6) Fuel (e.g., hydrogen) can be supplied to the anode via an anode compartment. In a polymer electrolyte membrane fuel cell (PEM fuel cell), fuel or fuel molecules are split into protons and electrons at the anode. The PEM allows the protons to pass through, but is impermeable to the electrons. For example, the reaction: 2H.sub.2.fwdarw.4H.sup.++4e.sup.− (oxidation/electron release) occurs at the anode. As the protons pass through the PEM to the cathode, the electrons are directed to the cathode or to an energy storage device via an external power circuit.

(7) The cathode gas (e.g., oxygen or oxygen-containing air) can be supplied to the cathode via a cathode compartment, so that the following reaction occurs on the cathode side: O.sub.2+4H.sup.++4e.sup.−.fwdarw.2H.sub.2O (reduction/electron uptake).

(8) The particularity of the present fuel cell device 1 is that further media connections 4 and further electrical contact points 5 are designed or arranged on the first fuel cell unit 3a in such a way that the fuel cell unit 3a can be connected or is connected to a second fuel cell unit 3b with a mechanical fluid connection for further guidance of the media and electrically for power uptake. In this way, the fuel cell device 1 is designed as a modular system that can be flexibly adapted to the actual conditions of use of the fuel cell device 1. For this reason, an additional third fuel cell unit is here shown as an example, which in turn can be connected or is connected to the second fuel cell unit 3b by means of mechanical fluid connections 4 for further guidance of the media and electrical contact points 5 for electrical connection for power uptake. The use of further fuel cell units 3a, 3b, 3c is possible, so that a plurality of fuel cell units 3a, 3b, 3c may be present in the modular fuel cell device 1. The fuel cell units 3a, 3b, 3c are combined in the present case to form a stack 6, an example of which additionally shows a mounting end plate 7 which is in contact with the fuel cell unit 3c arranged furthest away from the mounting plate 2 and which tensions the stack 6 to the mounting plate 2 by means of at least one—not shown in greater detail—tension element. Suitable tension elements are straps, rods or the like.

(9) In order to detect a pretensioning force of this tensioning element, a sensor can be provided which transmits its signals to a control unit 8 shown schematically. In the present case, this control unit 8 is connected for communication with the mounting plate 2 and has a memory. The control unit 8 is designed to inquire about one or more operating parameters of the fuel cell device 1 and to record a chronological course of the one or more operating parameters.

(10) In such a case, the fuel cell device 1 can be expanded by one or more fuel cell units 3a, 3b, 3c if the evaluation of the chronological course of the operating parameters shows that the power output of the fuel cell device 1 is set out as too limited. In the opposite case, if the evaluation shows that the power output of the fuel cell device 1 is set out as too large, the fuel cell device 1 can be reduced by one or more fuel cell units 3a, 3b, 3c.

(11) If it is found that the operating parameters are within a tolerance range; a volume flow of one or more media flowing through the mounting plate 2 and the one or more fuel cell units 3a, 3b, 3c is adjusted for this one operating parameter, forgoing an expansion and a reduction of the fuel cell device 1 by one or more of the fuel cell units 3a, 3b, 3c.

(12) For example, the power requirement, the operating time or the velocity profile of the fuel cell device 1 used in a fuel cell vehicle can be considered as operating parameters. Other operating parameters are possible.

(13) A particularly suitable expansion possibility, not shown in more detail, is offered by the design of the fuel cell device 1 with a mounting frame associated with the mounting plate 2. In this case, this mounting frame has a plurality of drawer compartments into which the fuel cell units 3a, 3b, 3c can be inserted or from which they can be removed. Moreover, the mounting frame comprises media lines and electrical lines in such a way that the fuel cell units 3a, 3b, 3c inserted in the drawer compartments are mechanically connected for fluids and electrically connected to the mounting plate 2.

(14) Embodiments of the present invention are characterized by a modular expansion capability for the fuel cell stack, in particular the fuel cell device 1 with its fuel cell units 3a, 3b, 3c. The fuel cell device 1 thereby provides a modular construction system that can be flexibly adapted to the behavior of the user. Moreover, it can be implemented with limited installation space and at low cost, since the fuel cell units 3a, 3b, 3c may be of identical design.

(15) In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled.