Method for operating a fuel cell unit, fuel cell unit, temperature control module and kit

Abstract

Method for operating a fuel cell unit (10), in which an energy carrier, in particular hydrogen, is converted within a fuel cell stack arranged in a fuel cell module (16) to generate electrical energy (28) in a power generation mode (7) by reacting with an oxidizer, wherein an air flow for tempering the fuel cell stack is conveyed into the fuel cell module (16) by means of a gas conveying unit (14) of the fuel cell unit (10), wherein the air flow flowing into the fuel cell unit (10) for tempering, with heating or cooling, the fuel cell stack is tempered, i.e. heated or cooled, by means of a tempering chamber (30) filled with reaction material for reversible reaction with the energy carrier, wherein the fuel cell stack can be pre-tempered in a pre-tempering operation (5) by means of a tempering phase (1) before the start of a desired operation (6), during which the fuel cell unit (10) is operated at at least one desired operating point with regard to a power to be generated, which depends on a consumer supplied by the fuel cell unit (10), wherein at the start of operation of the fuel cell unit (10) an operating decision is made regarding the preheating operation (5), wherein a decision is made as to whether and / or in what way the preheating operation (5), comprising the tempering phase (1) and / or a pre-operation phase (2) of the fuel cell unit (10), is required, wherein the power generation operation (7) of the fuel cell stack can be started after the end of the tempering phase (1).

Description

[0001] The invention relates to a method for operating a fuel cell unit, in which an energy carrier, in particular hydrogen, is converted within a fuel cell stack arranged in a fuel cell module to generate electrical energy in a power generation mode by reacting with an oxidizer. An air flow for controlling the temperature of the fuel cell stack is conveyed into the fuel cell module by means of a gas conveying unit of the fuel cell unit. The invention further relates to a fuel cell unit, a temperature control module, and a kit.

[0002] Such an air-temperature fuel cell is described in WO 2015 / 173238 A1.

[0003] JP 2018-147730 A describes a fuel cell system and a method for operating the same, comprising a fuel cell, a hydrogen tank, a reactor, and a cooling device for dissipating heat to the environment. Heat generated by a reactor can be supplied to preheat the fuel cell. Preheating of the fuel cell begins parallel to the start of operation of the fuel cell.

[0004] JP 2004-333027 A shows a fuel cell and a high-pressure hydrogen tank with a high-pressure storage pressure of approximately 30 MPa. Two containers connected to the hydrogen supply path are supplied with hydrogen via a bypass path. Each container is filled with a hydrogen storage alloy for storing and releasing hydrogen. The containers are used to generate heat and cold for air conditioning.

[0005] US 2018 / 0 019 488 A1 shows a fuel cell system with a heat exchange line for conducting a heat exchange medium and two reactors for absorbing and desorbing hydrogen and exchanging heat with the heat exchange medium.

[0006] DE 10 2013 223 003 A1 shows a system and a method for heating a passenger compartment of a fuel cell-powered vehicle by means of a metal hydride buffer that reversibly absorbs and desorbs hydrogen gas.

[0007] The efficiency and / or usability of air-temperature fuel cells, in particular, for power generation depends on their ambient conditions. For example, it may be necessary to bring such fuel cells to an operating temperature before power output in a target operation and essentially maintain it there. To reach the operating temperature as quickly as possible, catalytic hydrogen combustion or electrical heating are used, for example, which consume hydrogen or electrical energy and thus reduce the overall efficiency of the fuel cell.

[0008] The invention is based on the object of providing a method of the type mentioned at the outset, by means of which the usability of a fuel cell unit can be ensured in an efficient manner, as well as a corresponding fuel cell unit, a corresponding temperature control module and a kit.

[0009] The problem is solved for the method with the features of claim 1, for the fuel cell unit with the features of claim 11, for the temperature control module with the features of claim 19 and for the kit with the features of claim 26.

[0010] The method provides that the air flow flowing into the fuel cell unit (used as a synonym for air volume or mass flow) is tempered, i.e. heated or cooled, for the temperature control, with heating or cooling, of the fuel cell stack by means of a temperature control chamber filled with reaction material for the reversible reaction with the energy source. The fuel cell stack can be or is pre-tempered by means of a temperature control phase (if necessary) before the start of desired operation. The option of (optionally) carrying out the temperature control phase is stored in a corresponding control device for controlling / regulating the method. For this purpose, the temperature control chamber contains the reaction material, which forms a thermochemical gas-solid reaction system with the energy source.

[0011] During the tempering phase, heat is generated by the tempering chamber, or more precisely, the reaction material contained therein. Depending on the ambient conditions, particularly the outside temperature, the tempering phase constitutes the first phase of the fuel cell unit's operation. However, it can also be omitted under appropriate ambient conditions that allow operation of the fuel cell unit without preheating, e.g., a sufficiently high outside temperature. The tempering phase can thus represent a phase of "preheating operation," which precedes the target operation for preheating the fuel cell unit or fuel cell stack.

[0012] During nominal operation, the fuel cell unit is operated at at least one desired operating point with respect to the power to be generated or to generate a specific current intensity, which depends in particular on a consumer supplied by the fuel cell unit. Such a consumer can be, for example, a small vehicle such as an electric bicycle, e.g., an electric cargo bike, or another hydrogen-powered land, air, water, or space vehicle. In this case, the fuel cell unit is particularly compact, designed for mobile use. It can also be used in a stationary application, e.g., as a power supplier.

[0013] The process according to the invention advantageously allows for efficient preheating of the fuel cell stack and (peripheral) system components of the fuel cell unit or fuel cell module, whereby the energy carrier required during the tempering phase, in particular hydrogen, is temporarily stored in a recoverable manner. No electrical energy is required for heating.

[0014] According to the invention, an operating decision regarding preheating operation is made, in particular by means of the control device, at the start of operation of the fuel cell unit, wherein a decision is made as to whether and / or in what way preheating operation is required. “In what way” includes, in particular, which phases are to be run through, e.g., first the tempering phase and / or a pre-operational phase of the fuel cell unit, if applicable, operating parameters of these phases (e.g., pressure, air flow strength, duration), or whether preheating is required at all. This can be done, for example, via a query that can, for example, include at least a temperature comparison. During the temperature comparison, a comparison is made, for example, between a relevant temperature, for example an ambient temperature and / or a temperature within the fuel cell module and / or fuel cell stack, and a minimum value of this temperature required for power generation operation, e.g.a starting temperature and / or operating temperature.

[0015] In a particularly preferred embodiment of the method, heat is generated within the temperature control chamber during the temperature control phase, wherein the reaction material is pressurized with energy carrier from a (connected) energy carrier source under high pressure. During a reversible absorption reaction, heat is released as energy carrier is absorbed into the reaction material. This heat is absorbed by the air stream and transported to the fuel cell stack. The principle is described in the publication "Linder M, Kulenovic R, An energy-efficient air-conditioning system for hydrogen driven cars, Int. J Hydrogen Energy 2011, 36: 3215-3221". The pressure is adjusted in particular by means of a valve. "High pressure" in this context refers to a loading pressure of the temperature control chamber that is significantly higher, e.g., by at least 1 bar, than a supply pressure of the fuel cell stack, e.g., between 3 bar and 8 bar.In this way, energy stored in the form of a pressure difference between a (high-pressure) energy source and the fuel cell stack can advantageously be used to preheat the fuel cell unit.

[0016] Efficiency can be further increased while reducing heat losses if the air flow and / or the amount of heat released by the reaction material is adjusted during the tempering phase such that the amount of heat absorbed from the tempering chamber is at least largely released, e.g., at least 50%, preferably at least 70%, particularly preferably at least 90%, within the fuel cell unit, whereby the fuel cell stack and / or a peripheral device (e.g., air ducts, etc.) is tempered. For this purpose, the amount of heat released to the air flow can be controlled or regulated accordingly, in particular by means of a control device, e.g., depending on ambient and / or system conditions (conditions within the fuel cell unit), such as at least one temperature (such as ambient temperature and / or temperature of the fuel cell stack). The following can be taken into account, for example:existing sensor measurements and / or model estimates, for example taking into account existing masses to be heated with heat capacities, such as the reaction material and / or the temperature control chamber / reactor arrangement. For control purposes, the strength of the air flow can be varied, for example, via the fan power and / or the amount of heat released by the reaction material by adjusting the supplied energy carrier flow and / or the applied loading pressure. For example, a one-time setting at the beginning of the temperature control phase and / or a subsequent adjustment depending on ambient and / or system conditions, in particular at least one temperature, is possible. The existing design thus allows particularly simple control / regulation of efficient preheating, e.g. by means of control / regulation of the air flow, energy carrier flow and / or the loading pressure.

[0017] According to the invention, the power generation operation of the fuel cell stack can be started after the tempering phase has ended.

[0018] The preheating can advantageously be accelerated if the power generation operation of the fuel cell stack is started upon or after a switch-on condition, in particular a start temperature, is reached, wherein the fuel cell stack is operated in a pre-operation phase for further preheating. The waste heat generated by the fuel cell stack thereby serves to additionally preheat the fuel cell unit and / or for heating alone (without a temperature control phase). The temperature control phase, with temperature control by the temperature control chamber, can be continued, ended beforehand, or not started at all. The start temperature is in particular lower than an operating temperature of the fuel cell stack during target operation and corresponds, for example, to a system-dependent minimum switch-on temperature of the fuel cell stack. During the pre-operation phase, the fuel cell stack can be operated independently of a power consumer, wherein, for example,For example, at least one (optimal) operating point targeted during target operation has not (yet) been reached. For example, it may be partial load operation. The pre-operation phase can also be referred to as the "second phase" of the fuel cell unit's operation and takes place during preheating operation, before target operation.

[0019] In a preferred embodiment, within the power generation mode, upon reaching a switching condition, e.g., a temperature, the system switches to target operation after the pre-operation phase. The air flow flows into the fuel cell stack without temperature control via the temperature control chamber. The switching condition can be, for example, reaching the operating temperature. Target operation can be referred to as the third phase of fuel cell operation.

[0020] Preferably, the reaction material is regenerated after the tempering phase in a regeneration phase, whereby a low pressure is applied to the tempering chamber and operational readiness for the tempering phase is restored through a desorption reaction with release of the energy carrier from the reaction material. The low pressure corresponds to a discharge pressure of the tempering chamber and is lower than the high pressure. For example, it is at a supply pressure of approximately 1 bar for the fuel cell stack or slightly higher to compensate for the pressure loss occurring on the flow path to the fuel cell stack, e.g., by up to 0.2 bar, 0.5 bar, or 1 bar.

[0021] The regeneration phase preferably takes place during the target operation or after the termination of the target operation, in particular immediately thereafter, with the energy carrier released during regeneration being fed to the fuel cell stack for conversion to generate electricity. The regeneration phase takes place while the temperature control chamber is subjected to an elevated temperature and / or the low pressure, the discharge pressure.

[0022] In an efficiency-enhancing variant, the temperature control chamber is exposed to waste heat from the fuel cell stack during the regeneration phase. This allows the waste heat from the fuel cell unit to be utilized, eliminating the need for external heat input for regeneration.

[0023] Heat transfer can be achieved by transferring waste heat from the fuel cell stack to the temperature control chamber, at least largely (more than 50%) by conduction and / or radiation, particularly during power generation. The remaining portion can be achieved by another type of heat transfer (e.g., convection).

[0024] Alternatively or additionally, the heat transfer can be carried out at least largely (more than 50%) convective by means of the air flow by means of heat transport of waste heat from the fuel cell stack to the temperature control chamber, whereby the direction of the air flow is reversed by means of the gas delivery unit and the air flow from the fuel cell stack flows through the temperature control chamber, in particular after the desired operation. The remaining portion can be carried out by means of a different type of heat transport (e.g., by heat conduction). To reverse the air flow, the gas delivery unit can have two gas delivery modules, each of which generates different air flow directions and which are switched on alternately. Alternatively, a switchable gas delivery module or a switchable gas delivery unit can be present, whereby the two different air flow directions can be generated in particular by switching the direction of rotation of a rotor.

[0025] Preferably, the high pressure in absorption mode and / or the low pressure in desorption mode are adjusted within the temperature control chamber by means of at least one valve means for pressure and / or mass flow control. The valve means is in particular part of a loading and / or unloading interface and / or is arranged on the temperature control module.

[0026] With regard to the fuel cell unit, it is provided that it is designed to generate electrical energy from an energy carrier, in particular hydrogen, in particular for carrying out a method according to at least one of the preceding embodiment variants, with a fuel cell module comprising at least one fuel cell stack, a gas conveying unit for conveying an air flow for tempering the fuel cell module, and a fluid guidance system with line means and / or valve means for conveying the energy carrier from a connectable orconnected energy source into the fuel cell module, wherein the fuel cell unit comprises a control device and at least one temperature control chamber filled with reaction material for the reversible reaction with the energy source, which are arranged and designed for pre-temperature control, with cooling or heating, of the air flow tempering the fuel cell module in a temperature control phase before the start of a desired operation.

[0027] Advantageous mounting or fastening options for the temperature control chamber for integration into the fuel cell unit arise when the at least one temperature control chamber is arranged in a temperature control module, which is connected in particular to the fuel cell module in a detachable manner, directly or indirectly (with the interposition of another component, in particular another module, such as the gas delivery unit, e.g. in the form of a gas delivery module). The temperature control chamber is thus arranged locally separate from the fuel cell stack. It can, for example, be introduced or capable of being introduced at various positions within the fuel cell unit and / or be fastened to differently constructed fuel cell units. The connection can, for example, be pluggable, screwable, clippable, or clampable.

[0028] Advantageous heat transfer between the reaction material and the air flow can be achieved by thermally connecting the temperature control chamber to form a reactor arrangement with at least one air duct, preferably a plurality of air ducts, within which the air flow can be temperature-controlled during operation. The air duct is arranged, in particular, at least in sections in or on the temperature control module. In this way, a compact fuel cell unit is achieved with the option of easily adding the pre-temperature control function, with the temperature control module combining essential design features for this purpose.

[0029] The compact design comprising essential components is further enhanced if the temperature control chamber comprises at least one loading and / or unloading interface for fluidic coupling to an energy source and / or the fuel cell module, which is assigned a valve means through which the energy source can flow into or out of the temperature control chamber. The valve means (and / or a connection of the loading and / or unloading interface) is arranged in particular in or on the temperature control module. This allows for easy connection of the temperature control module to the energy source and / or the fuel cell module.

[0030] The fuel cell unit is preferably constructed in a modular manner from modules comprising at least the temperature control module and the fuel cell module, and preferably at least one gas delivery module (to form / as part of the gas delivery unit), wherein the individual modules are assembled, in particular detachably, to form a body. The gas delivery unit can also be attached to and / or integrated into one of the other modules. The individual modules are preferably arranged in partial housings that are attached to one another, such that no overall, surrounding housing is present. The partial housings are preferably mechanically stable or self-supporting. An additional mounting platform or supporting housing can advantageously be dispensed with. The body forms, in particular, a compact, mechanically stable (e.g., wearable in one piece) coherent unit. The modular design allows individual modules to be easily replaced.In addition, individual modules can advantageously be prefabricated in a type of kit and assembled to form specific fuel cell units, whereby individual modules can be designed differently depending on the requirements, for example performance class. For this purpose, the modules are preferably geometrically coordinated with one another and / or certain boundary conditions, in particular fixing points and / or areas, for example the size of the air-flow-through sides of the air-flow modules, and / or the position and / or complementary design of certain connections, for example of piping, are kept constant even with different (performance) designs. This design also enables existing fuel cell systems to be easily retrofitted to form a fuel cell unit, whereby the temperature control module can, for example,It can be easily attached and secured to the outside of an existing fuel cell module or gas delivery unit. This advantageously allows for easy installation of individual modules as needed, e.g., the temperature control module depending on the season. Disassembly also reduces the size and weight of the fuel cell unit.

[0031] In a particularly compact and efficient design variant, air-flow modules (modules through which air conveyed by the gas conveying unit flows), in particular, if applicable, the gas conveying module, the temperature control module and / or the fuel cell module, are arranged directly (and preferably without spacing) one behind the other, wherein at least one filter means and / or spacer means can be arranged between them. This results in a series connection of the air-flow modules with advantageously short flow paths and heat capacities that have little influence on temperature, which can cause temperature hysteresis and / or efficiency losses, particularly in alternating operation. In a design variant that is easy to retrofit, for example, the temperature control module is arranged towards the environment, to which the gas conveying unit and the fuel cell module are connected, so that a structure in the arrangement "temperature control module" - "gas conveying module" - "fuel cell module" - and, if applicable,(when configured with a gas delivery unit comprising two gas delivery modules) again results in a "gas delivery module." It is also possible to arrange the temperature control module directly next to the fuel cell module and isolate the gas delivery module(s) from the environment, which has the advantage of lower heat losses.

[0032] A particularly efficient and compact fuel cell unit can be provided if the air-permeable modules are of essentially the same size on opposite, air-permeable sides, which in particular form the largest side surfaces of the modules, and are mounted adjacent to one another. This results in a compact overall unit with advantageously large flow cross-sections, which allows the pressure loss of the air flow to be kept comparatively low.

[0033] Advantageous assembly or retrofitting options arise if the conduit means and / or valve means for forming the fluid guidance system are arranged in or on several of the modules, in particular the temperature control module and the fuel cell module, whereby a pressure-tight flow system is formed after assembly of the modules.

[0034] The temperature control module according to the invention is designed for use in a fuel cell unit, in particular according to one of the above embodiments, wherein it has at least one of the features relating to the temperature control module or the temperature control chamber. Such a temperature control module can also be used independently of the claimed method with a different and / or additional method for operating the fuel cell unit, e.g., with continuous operation, wherein, for example, two existing temperature control chambers / modules are operated alternately. Such a method is specified in German patent application DE 10 2020 117 997.9, filed with the German Patent and Trademark Office on July 8, 2020, which was still unpublished at the time of filing.

[0035] A more uniform distribution of the reaction material within the temperature control chamber, a more uniform gas supply, and / or a reduced pressure loss during the flow of the energy carrier or the reaction material through the temperature control chamber can be achieved if at least one means for positioning the reaction material is arranged within the temperature control chamber (or a sub-chamber of the temperature control chamber) of the reactor arrangement, which means is particularly designed to allow gas to pass through it. This can be, for example, at least one filter and / or spacer, e.g., in the form of a filter candle, whereby 3D printing can be used as the manufacturing process and / or silicone foam can be used as the material.

[0036] Particularly in the case of an elongated temperature control chamber, with the energy carrier flowing in the longitudinal direction, it may be expedient for the positioning means to be designed as an elongated hollow body with a gas-permeable wall, with the reaction material, in particular, being positioned outside and a gas channel, through which the energy carrier can pass, being formed inside. For a uniform gas supply, the positioning means is arranged, in particular, coaxially to a central longitudinal axis of the temperature control chamber and symmetrically within the temperature control chamber, e.g., cylindrically.

[0037] A uniform distribution of reaction material can be achieved over the length of the temperature control chamber if the positioning means (or a plurality thereof) is designed in the form of a transverse element, in particular a transverse disk, whose contour essentially corresponds to the cross-section of the temperature control chamber, wherein in particular a plurality of said elements are arranged at uniform intervals over the length of the temperature control chamber and transversely (in particular at right angles) to the longitudinal axis of the temperature control chamber. In this way, the temperature control chamber is divided into individual spatial segments that are in flow communication with one another. In combination with the elongated hollow body, the transverse elements in particular have an opening corresponding to the cross-section of the hollow body, through which the hollow body can extend.

[0038] In a particularly compact, efficient embodiment, the temperature control chamber of the reactor arrangement has several, e.g., two, subchambers arranged in elongated, in particular tubular, containers that flank a heat-transferring structure in the vertical direction y, in particular running parallel to the containers, which is arranged in thermal contact with the containers. The air duct(s) run through the heat-transferring structure, in particular in the depth direction z. Each subchamber can be equipped, as stated above, with at least one positioning means for subdividing it into space segments.

[0039] In a particularly weight-optimized design, the containers can form a supporting structure of the reactor arrangement to which the heat-transfer structure is attached.

[0040] To achieve good mechanical stability with high efficiency in terms of heat transfer, it is expedient if the heat-transferring structure has transverse structures, e.g. cross struts, which run in the transverse direction x, in particular at right angles to the containers and connect them to one another, which run parallel to one another and / or are connected to one another with lamellar structures, e.g. aligned in the height direction y, between which the air ducts are formed.

[0041] In an alternative and / or additional particularly compact, efficient embodiment, the temperature control chamber of the reactor arrangement has a plurality of sub-chambers which are arranged in, in particular, a plurality of elongated channels which are arranged parallel in the transverse direction x, alternating with heat-transferring structures, in particular lamellar structures.

[0042] An advantageously compact, "flat" design of the temperature control module can be achieved if the dimension in the depth direction z is smaller than the dimension in the transverse direction x and / or height direction y, e.g., a maximum of half or a quarter of the transverse direction x and / or height direction y. Preferably, the reactor assemblies are constructed at least partially from (lightweight) aluminum, whereby, in combination with their other design, they can have a low weight of, for example, 240 g for a dimension of 120 mm x 120 mm x 18 mm or less than 400 g for a dimension of 120 mm x 120 mm x 20 mm. The size of the temperature control modules depends, for example, on the geometry of the fuel cell unit.

[0043] The reaction material is a material that forms a gas-solid reaction system with the energy carrier, which reacts reversibly with the energy carrier, releasing / absorbing heat. Pressure and temperature in the reaction system are related to a material-specific equilibrium characteristic, so that the amount of heat released can be controlled by the pressure. The reaction material is, in particular, a metal (unloaded state) or metal hydride (loaded state), or a complex hydride. Suitable materials include, for example, a LaNi5 alloy or LmNi. 0.91 Sn 0.15 . In addition, the reaction material can also contain a graphite component to improve heat transfer.

[0044] When the temperature control chamber is filled with the reaction material, the reaction material is present in particular in particulate form, e.g. in the form of pressed bodies or pellets. The particle size is such that the reaction material does not oxidize completely upon filling, i.e. the surface-to-volume ratio is so small that no significant oxidation reaction can occur. At the same time, activation of the reaction material to ensure (full) operational readiness of the temperature control module should be possible at least under similar (e.g., deviating by a maximum of + / - 50% or + / - 20%) or the same boundary conditions regarding pressure and temperature as those prevailing during operation of the fuel cell unit. An example of a suitable particle size for LaNi5 when activated under a pressure of 8 bar and temperatures between -20 °C and 60 °C is 80 mesh (around 0.2 to 0.3 mm).

[0045] During activation, at least one, preferably five to ten, absorption / desorption cycle is performed, involving absorption and desorption of energy carriers in the reaction material. This allows the removal of an oxide layer on the respective reaction material particles, which forms when the particles are handled in an oxygen-containing atmosphere. In particular, the particle size must be selected such that, at least after activation (under operating conditions), the mass transfer of energy carriers at the molecular level can preferably occur completely within the particles. During activation, the reaction material decomposes and, after activation, is present in a smaller particle or grain size.

[0046] The invention further relates to a kit for a fuel cell unit according to one of the preceding claims, comprising at least one temperature control module and a fuel cell module designed for assembly with the fuel cell unit. The gas delivery unit can be separately mounted in a modular manner (with at least one gas delivery module) or, for example, be assigned to the fuel cell module.

[0047] The invention will be explained in more detail below using exemplary embodiments with reference to the drawings. They show: Fig. 1 a schematic representation of a fuel cell unit according to the invention, with a gas delivery module, comprising a temperature control module, during a temperature control phase, Fig. 2 a schematic representation of a further embodiment of a fuel cell unit according to the invention, with two gas delivery modules, comprising a temperature control module, during a regeneration phase, Fig. 3 a process diagram of a method for operating a fuel cell unit, in particular according to Fig. 1 and / or 2, Fig. 4 a section of a temperature control room in perspective view in longitudinal section, Fig. 5 a reactor arrangement of a temperature control module in front view, and Fig. 6 another embodiment of a reactor arrangement of a temperature control module in front view.

[0048] Fig. 1 and Fig. 2 schematically show embodiments of a fuel cell unit 10, as it can be used, for example, in a mobile application, in particular a small vehicle such as an electric bicycle, e.g. an electric cargo bike, or another land, air, water or space vehicle powered by hydrogen, and / or as, for example, a power supplier in a stationary application.

[0049] The fuel cell unit 10 comprises a fuel cell module 16 with at least one fuel cell stack. The fuel cell stack serves to generate electrical energy 28 (see Fig. 2) from an energy source, in particular hydrogen, by reaction with an oxidiser, here in particular oxygen contained in air, in a power generation plant 7.

[0050] Furthermore, the fuel cell unit 10 has a gas delivery unit 14, which is Fig. 1 comprises, by way of example, a single gas conveying module 13 with a gas conveying device (not shown), in particular a fan. By means of the gas conveying unit 14, an air flow is conveyed through the fuel cell module 16 during operation for the purpose of tempering, cooling and / or heating the fuel cell stack and / or other peripheral system components within the fuel cell unit 10, in particular those surrounding the fuel cell stack. The air flow is reversible with respect to the flow direction, which is Fig. 1 is realized by means of a fan whose direction of rotation can be changed.

[0051] According to the invention, the fuel cell unit 10 has a temperature control chamber 30 filled with reaction material, which is arranged in particular in a temperature control module 12. The temperature control chamber 30 with the reaction material serves to pre-temperature the fuel cell stack and / or other system components of the fuel cell unit 10 in a temperature control phase 1 (cf. Fig. 3) before a desired operation 6 of the fuel cell unit 10, as in Fig. 1. The temperature control is carried out by controlling the temperature of the air flow flowing into the fuel cell unit 10. Heat is transferred between the temperature control chamber 30 and the air flow, whereby the air flow is heated from an air temperature T before flowing into the fuel cell module 16. L by a temperature increase dT (of e.g. 25 K) to a temperature T L +dT is particularly preheated.

[0052] The heat is generated within the temperature control chamber 30 by means of the reaction material, which reacts reversibly with the energy carrier. Details of the process are described in connection with Fig. 3 is specified.

[0053] The fuel cell unit 10 further comprises a control device (not shown here) for controlling or regulating the operation of the fuel cell unit 10.

[0054] Fig. 2 shows a variant of the fuel cell unit 10, in which, in contrast to the Fig. 1, the gas conveyor unit 14 has two gas conveyor modules 13, 15. The gas conveyor modules 13, 15 each have, for example, non-reversible fans that can convey opposite directions of the air flow and, when the air flow is reversed (cf. method description for Fig. 3) are switched on or off accordingly. The different gas delivery modules 13, 15 or fans are preferably arranged on one side of the fuel cell module 16.

[0055] The Fig. The fuel cell unit 10 shown in Figure 2 is, for example, in the power generation mode 7 with generation of electrical energy 28, specifically during regeneration of the temperature control module 12 in a regeneration phase 4 (cf. Fig. 3).

[0056] In the Fig. 1 and Fig. 2, the temperature control chamber 30 is arranged in a temperature control module 12. Preferably, the temperature control module 12 is in particular detachably attached to the fuel cell unit 16. In the embodiments shown in Fig. 1 and Fig. In the examples shown in Figure 2, the fastening is indirect, with the gas delivery module 13 interposed. Direct fastening of the temperature control module 12 to the fuel cell module 16 is also possible, in particular between the gas delivery module 13 and the fuel cell module 16. Due to the detachable fastening, the temperature control module 12 can be easily mounted on and removed from the fuel cell unit 10 (e.g., screwed, clipped, inserted), e.g., depending on requirements, such as the season or time of year.

[0057] For a compact design, at least some of the conduits 20 for supplying the fuel cell stack with energy carrier are arranged on the temperature control module 12. The conduits 20 are, in particular, a pressure line 22 between the energy source and the temperature control chamber 30 (indicated in Fig. 1) and / or a low-pressure line 24 (indicated in Fig. 2), which opens from the temperature control chamber 30 to the fuel cell stack. The conduit means 20 may comprise further components, such as valve means, here pressure / flow regulator 26 (or others), or, for example, a bypass line (not shown) for direct communication between the energy source and the fuel cell stack, bypassing the temperature control chamber 30 or temperature control module 12.

[0058] For the fluid-mechanical coupling of the temperature control chamber 30 with the energy source and / or the fuel cell stack or the fuel cell module 16, at least one loading and / or unloading interface is assigned to the temperature control chamber 30 within the conduit means 20. The loading and / or unloading interface comprises a connection 48 (see Fig. 5) and / or a valve means (not shown here) through which the energy carrier can flow into or out of the temperature control chamber 30, in particular while regulating the inlet pressure and / or the flow rate. For a compact, part-optimized design, the valve means is arranged, for example, on or in the temperature control module 12.

[0059] As in the Fig. 1 and Fig. 2, the fuel cell unit 10 can be composed of individual modules. For easy retrofitting, at least the temperature control chamber 30 is preferably arranged in the temperature control module 12, wherein Fig. 1 and Fig. 2, the gas delivery unit 14 is also modular.

[0060] Preferably, in particular, the temperature control module 12 is designed to be self-supporting and mechanically stable (cf. Fig. 5, Fig. 6) and / or detachably attached to the fuel cell unit 30.

[0061] The air-permeable modules, here, for example, the gas delivery modules 13, 15, the temperature control module 12, and the fuel cell module 16, are preferably arranged one behind the other, if necessary with the interposition of filter means and / or spacers (not shown here). To ensure the lowest possible pressure loss, the air-permeable modules can be configured to be substantially the same size, adapted to each other, and mounted adjacent to each other on opposite, air-permeable sides.

[0062] Fig. 3 shows, in a process diagram, an example of a sequence of operations of the fuel cell unit 10, as it can be controlled or regulated with the control device.

[0063] How Fig. As shown in Figure 3, the operation of the fuel cell unit 10 is divided into different operating phases. This is, on the one hand, a pre-tempering operation 5, in particular a pre-heating operation, in which, if necessary, the fuel cell stack is heated to operating conditions, e.g., to an optimal operating temperature T B The pre-tempering operation 5 can, in turn, include, for example, a tempering phase 1 (first phase) and / or, optionally following tempering phase 1, a pre-operation phase 2 (second phase) of the fuel cell stack, depending on the ambient conditions. The individual operating phases are explained in more detail below.

[0064] Pre-tempering operation 5 is followed by a target operation 6, in which the fuel cell unit 10 is operated at at least one desired operating point with respect to the power to be generated or to generate a specific current intensity, which depends in particular on a consumer supplied by the fuel cell unit 10. For this purpose, the target operation 6 comprises at least one target operating phase 3 (third phase).

[0065] In the present case, the target operation 6 further comprises a regeneration phase 4 (fourth phase), during which the operational readiness of the temperature control chamber 30 is restored. The regeneration phase 4 can occur at any time during the power generation operation 7 of the fuel cell stack. The power generation operation 7 refers to the operation of the fuel cell unit 10 during which the fuel cell stack generates power by converting energy sources, i.e., it comprises pre-operation phase 2, target operation phase 3, and regeneration phase 4. For advantageous waste heat utilization, the regeneration phase 4 occurs during (overlapping with) the target operation phase 3 or following the target operation phase 3.

[0066] When the operation of the fuel cell unit 10 starts, an operating decision is first made, preferably by means of the control device, regarding the preheating operation 5, wherein a decision is made as to whether or which phase 1, 2 of the preheating operation 5 is required. This can be done, for example, via a query that can include, for example, at least one temperature adjustment 8 and / or 9. During the temperature adjustment 8, for example, a comparison is made between a relevant temperature T, for example an ambient temperature and / or a temperature within the fuel cell module 16 and / or fuel cell stack, and a minimum value of this temperature required for power generation operation 7, for example a starting temperature T S .

[0067] For example, if the temperature T is below the starting temperature T sof the fuel cell stack, the temperature within the fuel cell stack and / or fuel cell module 16 is first increased in the tempering phase 1 by means of the tempering chamber 30 by the temperature lift dT, e.g. to the starting temperature T s raised.

[0068] If the temperature T is above the starting temperature T s , but below the (optimal) operating temperature T B , the pre-operation phase 2 can be started immediately and the tempering phase 1 can be skipped, whereby the temperature within the fuel cell stack and / or fuel cell module 16 can be reduced, for example, to the operating temperature T B is raised.

[0069] If the temperature T is at or above the operating temperature T B , no preheating operation 5 is required and operation begins directly with the target operating phase 3 as the first and only operating phase, or the target operating phase 6.

[0070] If the temperature control module 12 is dismantled, the operating decision can be made, for example, regarding the start of the second or third phase (pre-operation phase 2 or target operation phase 3).

[0071] The individual operating phases are explained in more detail below. During tempering phase 1, the tempering module 12 is in operation, with the energy carrier reacting with the reaction material (not shown here) within the tempering chamber 30. The air flow flowing into the fuel cell unit 10 is tempered, in particular heated, by the reaction material. To generate heat, the energy carrier is applied to the tempering chamber 30 (see FIG. Fig. 1). The temperature control chamber 30 is fluidically connected to the energy source by applying a high pressure p1, a so-called loading pressure. The high pressure p1 is significantly higher, e.g., 1 bar or more, than the supply pressure of the fuel cell stack. For example, it can be between 3 bar and 8 bar, depending on the boundary conditions, such as the reaction material and / or the required temperature or heat generation. The high pressure p1 is set, e.g., at the loading / discharging interface(s) of the conduit means 20 between the energy source and the temperature control module 12 by means of the valve means (not shown here).

[0072] The energy carrier, which forms a gas-solid reaction system with the reaction material, reacts reversibly with the reaction material in an absorption reaction. Heat is released due to the released binding enthalpy. The released heat is absorbed by the air flow that flows around the temperature control chamber 30 for heat transfer and transported to the fuel cell module 16 with the fuel cell stack. For this purpose, the temperature control chamber 30 is preferably provided with a plurality of air ducts 45, forming a reactor arrangement 40 (see FIG. Fig. 5 and Fig. 6) in thermal connection, through which the air flow flows.

[0073] For efficient preheating, the air flow and / or the amount of heat released by the reaction material is preferably adjusted during the tempering phase 1 such that at least a large portion of the heat absorbed from the tempering chamber 30, for example up to 90%, is transferred to the fuel cell stack and, for example, peripheral system components within the fuel cell unit 10, i.e., it does not escape directly into the environment with the air flow. The air flow is adjusted, for example, by varying the fan power within the gas delivery unit 14. The amount of heat released is adjusted, in particular, by controlling or regulating the loading pressure and / or energy carrier mass flow applied to the tempering chamber 30.

[0074] After reaching a switch-on condition, the pre-operation phase 2 begins. This can be done, for example, via a temperature adjustment 11 and, for example, by reaching a certain temperature, for example the start temperature T s , be defined. It would also be conceivable for the tempering phase 1 to run for a (previously, e.g., theoretically) specified duration. During the pre-operation phase 2, the tempering phase 1 can be continued in parallel with the operation of the tempering module 12 (reaction within the tempering chamber 30) or can be terminated beforehand.

[0075] At the beginning of the pre-operation phase 2, the power generation operation 7 of the fuel cell stack is started and the fuel cell stack is further preheated and reaches the (optimal) operating temperature T B The fuel cell stack, the fuel cell module 16, or the fuel cell unit 10, is further heated by the heat generated by the stack itself.

[0076] When a switching condition is reached, for example the operating temperature T B (see temperature adjustment 17), the power generation operation 7 is switched to the target operating phase 3. At this point at the latest, the temperature control phase 1 and thus the active heating of the air flow by means of the temperature control chamber 30 are expediently terminated. At least as needed, the air flow is now used for (convective) cooling.

[0077] During the target operating phase 3, the energy carrier can also flow into the fuel cell stack without the fluid-mechanical interposition of the temperature control chamber 30, for example via the bypass line.

[0078] After completion of the tempering phase 1, the reaction material is regenerated in the regeneration phase 4. In this case, the tempering chamber 30 is subjected to heat and a low pressure p2 (cf. Fig. 2; at least lower than the high pressure p1), the so-called discharge pressure, is applied. During a desorption reaction, releasing the energy carrier from the reaction material, the operational readiness of the temperature control module 12 or temperature control chamber 30 for temperature control phase 1 is restored. Expediently, any energy carrier released during regeneration is fed to the fuel cell stack for conversion to generate electricity. The discharge pressure corresponds, for example, to the supply pressure of the fuel cell stack.

[0079] The heat input to the temperature control chamber 30 during the regeneration phase 4 can be achieved by means of waste heat generated from the fuel cell stack during power generation operation 7. To transport the waste heat to the temperature control chamber 30, the direction of the air flow can be adjusted as described above. Fig. 1 or Fig. 2, or more precisely, in reverse. The air flow now flows from the fuel cell stack or fuel cell module 16, where it absorbs waste heat, into the temperature control chamber 30 and convectively supplies heat to it. The heat generated is sufficient to regenerate the reaction material, for example, within 3 to 30 minutes.

[0080] In another or additional variant, the heat can be applied at least largely by heat conduction (and / or heat radiation) from the fuel cell stack or the fuel cell module 16 to the temperature control chamber 30 or the temperature control module 12. For this purpose, mechanically connecting elements can also be designed to be particularly thermally conductive, and / or the temperature control module 12 can be mounted directly on the fuel cell module 16.

[0081] After the power generation operation 7 and / or the regeneration phase 4 has ended, the operation of the fuel cell unit 10 is terminated.

[0082] The Fig. 4 to 6 show advantageous design variants of reactor arrangements 40 or the temperature control chamber 30 (cf. Fig. 4).

[0083] Fig. Figure 4 shows, by way of example, a section of a container 32 of the exemplary elongated temperature control chamber 30 with its internal structure in a perspective view in longitudinal section. Such an internal structure is shown, for example, in the figures shown in Fig. 5 and / or Fig. 6 shown reactor arrangements 40 are appropriate.

[0084] How Fig. As shown in Figure 4, means 41 for positioning the reaction material (not shown here) of the temperature control chamber 30 are arranged within the container 32 containing the reaction material. The means 41 are designed to allow gas to flow through the energy carrier, for example, in a filter-like manner. The means 41 divide the temperature control chamber 30 (and / or optionally sub-chambers 31 of the temperature control chamber 30) into several spatial segments 33. This allows, for example, the reaction material to be positioned uniformly and / or in a manner that allows good flow, thereby achieving, in particular, a uniform gas supply to the reaction material.

[0085] For example, one of the means 41 is designed as a hollow body 34, here exemplary cylindrical, which extends symmetrically, in particular coaxially, along the longitudinal axis (here along a height direction y) of the container 32. The hollow body 34 has a gas-permeable wall 36. Thus, the hollow body 34 forms a flow path through the surrounding reaction material, reducing the pressure loss when flowing through the temperature control chamber 30. During operation, the energy carrier passes through the gas-permeable wall 36 into the reaction material.

[0086] Furthermore, transverse elements 37, particularly in the form of transverse disks, are arranged as positioning means 41, perpendicular to the longitudinal axis and evenly spaced axially along the length of the temperature control chamber 30. In combination with the hollow body 34, the transverse elements 37 each have a central opening 39 in the cross-sectional shape of the hollow body 34, in this case circular, through which the hollow body 34 protrudes.

[0087] Fig. 5 shows an advantageous variant of the reactor arrangement 40, which is particularly lightweight and compact. Here, the temperature control chamber 30 has, for example, two spatially separated subchambers 31. The subchambers 31 are arranged in the elongated, tubular containers 32. At their upper ends, the containers 32 each have connections 48 to the conduits 20, which each form part of two loading and / or unloading interfaces. The containers 32 extend, for example, in the vertical direction y and run parallel to one another along a plane. They flank a heat-transfer structure 42, which is arranged in thermal contact with the containers 32, in particular is fastened to them. The containers 32 simultaneously form a support structure 47 of the reactor arrangement 40.

[0088] The heat-transferring structure 42 comprises a plurality of heat-conducting transverse structures 43 that are attached to the containers 32. The transverse structures 43 are embodied, for example, as spaced-apart, parallel cross struts that extend perpendicular to the containers 32 in the transverse direction x. Alternating with the transverse structures 43, heat-transferring fin structures 44, oriented, for example, in the vertical direction y, are attached to the containers 32 in a heat-conducting manner, between which a plurality of air guide channels 45 are formed. The air guide channels 45 are arranged such that the air flow flows through them or the reactor arrangement 40 (at least in the main flow direction) in the depth direction z, in which the fuel cell module 16 is also arranged or can be arranged, and thereby exchanges heat with the fin structures 44.

[0089] Fig. 6 shows a further advantageous embodiment of the reactor arrangement 40. The temperature control chamber 30 also has a plurality of subchambers 31 arranged in a plurality of elongated channels 46. The elongated channels 46 run parallel to one another in the transverse direction x and are arranged alternately to form heat-transferring structures 42, in particular lamellar structures 44. A plurality of air-conducting channels 45 are formed between the lamellar structures 44. The channels 46 and / or the heat-conducting structure 42 are, for example, attached on one side to a support structure 47 extending in the vertical direction y, e.g., welded thereto. The support structure 47 has an elongated hollow space arranged in flow connection to the subchambers 31. Thus, the support structure 47 simultaneously functions as a distribution structure for conducting the energy carrier into the subchambers 31 (shown here without a connection).

[0090] The Fig. 5 and Fig. The heat-transferring structures 42 shown in Figure 6 can be closed, for pure heat conduction, or at least partially open, gas-permeable with so-called “microchannels”.

[0091] The Fig. 5 and Fig. The exemplary reactor arrangements 40 shown in Figure 6 are advantageously designed to be flat, with the dimension in the depth direction z being a maximum of one quarter of the next larger dimension in the transverse direction x and / or the height direction y. Preferably, the reactor arrangements are constructed at least partially from (lightweight) aluminum, whereby, in combination with their other design, they have a low weight of, for example, 240 g with a dimension of 120 mm by 120 mm by 18 mm ( Fig. 5) or less than 400 g with dimensions of 120 mm x 120 mm x 200 mm. The size of the temperature control modules 12 depends, among other things, on the geometry of the fuel cell unit 10.

[0092] The reactor assemblies 40 are dimensioned such that a sufficient amount of reaction material for a specific application, for example, 150 g, can be positioned or is positioned in the temperature control chamber 30. In particular, the size of the temperature control module 12 or the reactor assemblies is designed such that the amount of heat released by the reaction material during the absorption reaction corresponds at least to the amount of heat required for heating at a specific design point by a desired temperature difference dT (cf. Fig. 1), e.g. by 25 K, within a desired time period, e.g. 3 min to 5 min.

[0093] In particular, the heat capacities of heat-absorbing masses within the fuel cell unit 10 during preheating operation 5, e.g., the mass of the reaction material, the reactor assembly 40, the fuel cell stack, and / or the air flow (e.g., with respect to the design point), must be taken into account. Furthermore, any additional waste heat generated by the fuel cell stack during pre-operation phase 2 can be considered as the heat quantity, assuming, for example, a specific load, such as partial load operation at 50% of the maximum load.

[0094] Through the Fig. 5 and Fig.6, the masses of the reactor assemblies 40 shown can advantageously be kept comparatively low. Furthermore, the reactor assemblies 40 enable efficient heat transfer between the reaction material and the air flow flowing through the reactor assembly 40, while the air flow can be kept as low as possible. Due to the low masses of the reactor assembly 40 and the air flow, a comparatively low mass of reaction material is advantageously required. Thus, a fuel cell unit 10 that can be efficiently operated using the method specified above can be provided.

Claims

[1] Method for operating a fuel cell unit (10), in which an energy carrier, in particular hydrogen, is converted within a fuel cell stack arranged in a fuel cell module (16) to generate electrical energy (28) in a power generation mode (7) by reacting with an oxidizer, wherein an air flow for tempering the fuel cell stack is conveyed into the fuel cell module (16) by means of a gas conveying unit (14) of the fuel cell unit (10), wherein the air flow flowing into the fuel cell unit (10) for tempering, with heating or cooling, the fuel cell stack is tempered, i.e. heated or cooled, by means of a tempering chamber (30) filled with reaction material for reversible reaction with the energy carrier, wherein the fuel cell stack can be pre-tempered in a pre-tempering operation (5) by means of a tempering phase (1) before the start of a desired operation (6), during which the fuel cell unit (10) is operated at at least one desired operating point with regard to a power to be generated, which depends on a consumer supplied by the fuel cell unit (10), wherein at the start of operation of the fuel cell unit (10) an operating decision is made regarding the preheating operation (5), wherein a decision is made as to whether and / or in what way the preheating operation (5), comprising the tempering phase (1) and / or a pre-operation phase (2) of the fuel cell unit (10), is required, wherein the power generation operation (7) of the fuel cell stack can be started after the end of the tempering phase (1). [2] Method according to claim 1, characterized by that during the tempering phase (1) heat is generated within the tempering chamber (30), wherein the reaction material is subjected to energy carrier from an energy carrier source under high pressure and during a reversible absorption reaction with absorption of energy carrier into the reaction material heat is released, which is absorbed by the air flow and transported to the fuel cell stack. [3] Method according to claim 2, characterized bythat the air flow and / or the amount of heat released by the reaction material during the tempering phase (1) is adjusted such that the amount of heat absorbed from the tempering chamber (30) is at least largely, e.g. at least 50%, preferably at least 70%, particularly preferably at least 90%, released within the fuel cell unit (10). [4] Method according to one of the preceding claims, characterized by that upon or after reaching a switch-on condition, in particular a starting temperature (T s ), the power generation operation (7) of the fuel cell stack is started, wherein the fuel cell stack is operated in a pre-operation phase (2) for further preheating. [5] Method according to claim 4, characterized bythat within the power generation mode (7) upon reaching a switching condition, e.g. a temperature, after the pre-operation phase (2), the system switches to the desired operation (6), wherein the air flow flows into the fuel cell stack without temperature control by means of the temperature control chamber (30). [6] Method according to one of the preceding claims, characterized by that the reaction material is regenerated after the tempering phase (1) in a regeneration phase (4), wherein a low pressure is applied to the tempering chamber (30) and the operational readiness for the tempering phase (1) is restored by a desorption reaction with release of the energy carrier from the reaction material. [7] Method according to claim 6, characterized bythat the regeneration phase (4) takes place during the desired operation (6) or after the end of the desired operation (6), in particular subsequently thereto, wherein energy carriers released during the regeneration are fed to the fuel cell stack for conversion to generate electricity. [8] Method according to claim 6 or 7, characterized by that during the regeneration phase (4) the temperature control chamber (30) is supplied with waste heat from the fuel cell stack. [9] Method according to claim 8, characterized bythat the heat is applied by means of heat transport of waste heat from the fuel cell stack to the temperature control chamber (30) by means of at least largely heat conduction and / or heat radiation, in particular during the desired operation (6), and / or that the heat is applied by means of heat transport of waste heat from the fuel cell stack to the temperature control chamber (30) at least largely convective, wherein the direction of the air flow is reversed by means of the gas conveying unit (14) and the air flow from the fuel cell stack flows through the temperature control chamber (30), in particular after the desired operation (6). [10] Method according to one of claims 2 to 9, characterized by that within the temperature control chamber (30) the high pressure in absorption mode and / or the low pressure in desorption mode is adjusted by means of at least one valve means for pressure and / or mass flow control. [11] Fuel cell unit (10) for generating electrical energy (28) from an energy source, in particular hydrogen, which is designed to carry out a method according to one of the preceding claims, with - a fuel cell module (16) comprising at least one fuel cell stack, - a gas conveying unit (14) for conveying an air flow for tempering the fuel cell module (16), - a fluid guidance system (20) with line means and / or valve means for conducting the energy carrier from a connectable or connected energy carrier source into the fuel cell module (16), wherein the fuel cell unit (10) comprises a control device and at least one temperature control chamber (30) filled with reaction material for reversible reaction with the energy carrier, which are arranged and designed for pre-temperature control, with cooling or heating, of the air flow tempering the fuel cell module (16) in a temperature control phase (1) before the start of a desired operation. [12] Fuel cell unit (10) according to claim 11, characterized by that the at least one temperature control chamber (30) is arranged in a temperature control module (12) which is in particular detachably connected directly or indirectly to the fuel cell module (16). [13] Fuel cell unit (10) according to claim 11 or 12, characterized byin that the temperature control chamber (30) is in thermally active connection with at least one air duct (45) to form a reactor arrangement (40), within which the air flow can be temperature-controlled during operation, wherein the air duct (45) is arranged in particular in or on the temperature control module (16). [14] Fuel cell unit (10) according to one of claims 11 to 13, characterized by that the temperature control chamber (30) is assigned at least one loading and / or unloading interface for fluid-mechanical coupling to an energy carrier source and / or the fuel cell module (16), which comprises a valve means via which the energy carrier can flow into or out of the temperature control chamber (30), wherein the valve means is arranged in particular in or on the temperature control module (16). [15] Fuel cell unit (10) according to one of claims 11 to 14, characterized bythat the fuel cell unit (10) is constructed in a modular manner from modules comprising at least the temperature control module (12) and the fuel cell module (16), and preferably at least one gas conveying module (13, 15), wherein the individual modules are assembled, in particular detachably, to form a body. [16] Fuel cell unit (10) according to claim 15, characterized by that air-flowable modules, in particular the temperature control module (12) and / or the fuel cell module (16) and / or the at least one gas conveying module (13, 15), are arranged directly one behind the other, wherein at least one filter means and / or spacer means can be arranged therebetween. [17] Fuel cell unit (10) according to claim 16, characterized by that the air-flowable modules are of substantially the same size on opposite, air-flowable sides, which in particular form the largest side surfaces of the modules, and are mounted adjacent to one another. [18] Fuel cell unit (10) according to one of claims 15 to 17, characterized by that the line means (20) and / or valve means for forming the fluid guidance system are arranged in or on several of the modules, in particular the temperature control module (12) and the fuel cell module (16), wherein a pressure-tight flow system is formed after assembly of the modules. [19] Tempering module (12) designed for use in a fuel cell unit (10) according to one of claims 11 to 18, wherein at least one means for positioning the reaction material is arranged within a temperature control chamber (30) of a reactor arrangement (40), which means is designed in particular to be gas-permeable and wherein the means (41) for positioning is designed as an elongated hollow body (34) with a gas-permeable wall (36), wherein in particular the reaction material is positioned outside and a gas channel (38) through which energy carriers can pass is formed inside. [20] Tempering module (12) according to claim 19, characterized by that the means (41) for positioning is designed in the form of transverse elements (37), in particular transverse discs, the outer shape of which corresponds to the cross section of the temperature control chamber (30), wherein in particular a plurality of these are arranged distributed at uniform intervals over the length of the temperature control chamber (30). [21] Tempering module (12) according to claim 19 or 20, characterized byin that the temperature control chamber (30) of the reactor arrangement (40) has a plurality of, e.g. two, sub-chambers (31) which are arranged in elongated, in particular tubular, containers (32) which flank, in the height direction (y), in particular running parallel, a heat-transferring structure (42) which is arranged in thermal contact with the containers (32), wherein the air guide channel(s) (45) run(s) through the heat-transferring structure (42), in particular in the depth direction (z). [22] Tempering module (12) according to claim 21, characterized by that the containers (32) form a support structure (47) of the reactor arrangement (40) to which the heat-transferring structure (42) is attached. [23] Tempering module (12) according to claim 21 or 22, characterized byin that the heat-transferring structure (42) has transverse structures (43) which extend in the transverse direction (x), in particular at right angles, to the containers (32), which connect them to one another, which extend parallel to one another and / or are connected to one another by lamellar structures (44), which are oriented, for example, in the height direction (y), and between which the air guide channels (45) are formed. [24] Tempering module (12) according to one of claims 19 to 23, characterized by in that the temperature control chamber (30) of the reactor arrangement (40) has a plurality of sub-chambers (31) which are arranged in, in particular, a plurality of elongated channels (46) which are arranged in the transverse direction (x) running parallel to and alternating with heat-transferring structures (42), in particular lamellar structures (44). [25] Tempering module (12) according to one of claims 19 to 24, characterized bythat the dimension in the depth direction (z) is smaller than the dimension in the transverse direction (x) and / or height direction (y), e.g. a maximum of half or a quarter of the transverse direction (x) and / or height direction (y). [26] Kit for a fuel cell unit (10) according to one of claims 11 to 18, comprising at least one temperature control module (20, 40), in particular according to one of claims 19 to 25, and a fuel cell module (30), and preferably at least one gas feed module (13, 15), which is designed for assembly to the fuel cell unit (10).

Images