Assembly, electrochemical cell device

Abstract

The invention relates to an assembly (100) for the catalytic conversion of two fluids in electrochemical cell devices (10), preferably fuel cell devices (10), comprising a first reactor (22) for an endothermic catalytic conversion of a first fluid and a second reactor (26) for an exothermic catalytic conversion of a second fluid. It is proposed that the first reactor (22) and the second reactor (26) are integrated into the assembly (100) and thermally coupled to each other.

Description

[0001] The invention relates to an assembly for the catalytic conversion of two fluids in electrochemical cell devices according to the preamble of the independent claim. The invention further relates to an electrochemical cell device comprising such an assembly. State of the art

[0002] Fuel cells offer great potential for efficient and environmentally friendly energy conversion. To fully exploit this potential, a high efficiency is crucial, which can be achieved through the optimal use of the heat energy generated during the electrochemical processes.

[0003] However, a well-known problem with fuel cells, especially high-temperature fuel cells, is the discrepancy between the heat energy produced and the heat energy required in the various operating states and phases. For example, heat is generated during electricity production in the fuel cell, while at the same time heat energy is required for certain processes within the cell or in peripheral systems.

[0004] Conventional approaches to heat regulation, which are based on separate components such as heat exchangers and elaborate control systems, are often associated with significant energy losses and a complex system design. Disclosure of the invention Advantages

[0005] The present invention describes an assembly for the catalytic conversion of two fluids in electrochemical cell devices, preferably fuel cell devices, comprising a first reactor for an endothermic catalytic conversion of a first fluid and a second reactor for an exothermic catalytic conversion of a second fluid. According to the invention, the first reactor and the second reactor are integrated into the assembly and thermally coupled to each other.

[0006] Integrating and thermally coupling the two reactors in a single assembly enables efficient heat exchange between the endothermic and exothermic reactions. This reduces the energy demand of the overall reaction and increases the efficiency of the electrochemical cell device.

[0007] The integration of the first and second reactors into a single assembly means, in particular, that the first and second reactors form a structural unit. Specifically, it is conceivable that the first and second reactors are mounted on a common support or frame. It is also conceivable that the first and second reactors are integrated within a common housing.

[0008] Thermal coupling between the first and second reactors can be achieved, in particular, through contact. It is advantageous for the first and second reactors to be in direct contact with each other, maximizing their contact area. Alternatively, the first and second reactors can be connected using a thermally conductive medium; for example, a thermal paste can be applied between them.

[0009] Each reactor contains an active catalyst material for the catalytic conversion of the respective fluid. An active catalyst material, or active materials, or simply catalyst material, is understood to be a substance or mixture of substances that increases the reaction rate by lowering the activation energy of a chemical reaction without being consumed in the process.

[0010] An electrochemical cell device or cell device is understood to be, in particular, a device designed for the electrochemical reaction of at least two fluids. The cell device comprises an electrochemical cell unit that electrochemically reacts the two fluids, as well as components that supply the cell unit with electrical energy (i.e., supply and / or remove electrical energy), and components that supply the cell unit with the two fluids. This supply can be active—for example, via supply lines, pumps, fluid reservoirs, etc.—or passive—for example, using ambient air as the fluid—without active transport. Advantageously, the cell device also includes components for the removal and / or recycling of the reacted fluids.Advantageously, the cell device also features components for heat transport, in particular for temperature control of the cell unit, for example for the use of waste heat.

[0011] Examples of cell devices include fuel cell devices and electrolysis devices. In this context, a fluid can be understood to be liquid fluids and / or gaseous fluids. In high-temperature fuel cell devices or high-temperature electrolysis devices—for example, those with solid oxide cells—the fluids are essentially gaseous. The assembly according to the invention can be used at different positions in the fluid path within the electrochemical cell device, and in particular, the two reactors of the assembly can each be used independently of each other at different positions in the fluid path within the electrochemical cell device. For example, it is conceivable that one reactor is used for fuel preparation and the other reactor for exhaust gas treatment.

[0012] In this context, an electrochemical cell unit refers specifically to a unit comprising multiple electrochemical cells. An electrochemical cell unit is also called an electrochemical stack or simply a stack. Typically, the electrochemical cells are stacked on top of each other. Advantageously, a cell can have a plate-shaped support on which the functional layers, particularly electrolyte layers, are arranged, as well as a plate-shaped interconnector with raised sections. The interconnector is positioned between the cell's support and another support of an adjacent cell. The interconnector establishes electrical contact between the adjacent cells. Furthermore, the interconnector creates a gap, and thus a flow-through space, between the cell's support and another support of an adjacent cell.This enables the supply of fluids to the substrates or the functional layers arranged on them. Advantageously, the cells are electrically connected in series. It is also conceivable that the cells are electrically connected in parallel. The cells can advantageously be arranged in a stack on a common chassis or substrate, or in a common housing. Examples of electrochemical cell units are fuel cell units or electrolysis cell units.

[0013] An electrochemical cell is understood to be, in particular, an arrangement that provides usable electrical energy through chemical reactions or is intended for the chemical production or conversion of substances by applying a voltage. An electrochemical cell has at least two or more functional layers. The functional layers comprise at least two electrode layers and a separating layer or electrolyte layer. The electrode layers each function as an electron conductor and are conductively connected to the separating layer or electrolyte layer. Also important for the electrode layers are ion transport and catalytic activity or oxygen exchange capacity between the electrode layer and the gas phase. The separating layer or electrolyte layer functions, in particular, as an ion conductor. Furthermore, the separating layer or electrolyte layer...Electrolyte layer provided for the separation of the two gas compartments, for example the separation between air and fuel gas in a fuel cell.

[0014] In particular, the term "cell" or "electrochemical cell" shall be understood to mean a fuel cell or an electrolysis cell. In this context, the term "fuel cell" or "electrolysis cell" shall be understood to mean, in particular, at least a part, especially a subassembly, of a fuel cell system, in particular a solid oxide fuel cell system, and / or an electrolysis cell device, in particular a high-temperature electrolyzer. In particular, the electrochemical cell may also comprise the entire fuel cell, in particular the entire solid oxide fuel cell, the entire electrolyzer, in particular the entire high-temperature electrolyzer, a stack of fuel cells and / or electrolysis cells, and / or a combination of several stacks of fuel cells and / or electrolysis cells.Preferably, the electrochemical cell is designed to convert a fuel into electrical energy in an electrochemical combustion process by supplying an oxidant. Alternatively or additionally, the electrochemical cell is designed to separate a fluid into at least two components in a separation process by supplying electrical energy. "Designed" is understood to mean, in particular, specially configured, specially designed, and / or specially equipped. The phrase "designed" means, in particular, that an object fulfills and / or performs this specific function in at least one application and / or operating state.

[0015] The cell, or electrochemical cell, can be, in particular, an electrolysis cell, especially a solid oxide electrolysis cell (SOEC). Alternatively, the electrolysis cell can also be a proton-conducting electrolysis cell, or protonic ceramic electrolysis cell (PCEC), based on a proton-conducting oxide (PCO). The electrochemical cell can also be a fuel cell, for example, a solid oxide fuel cell (SOFC). It is also conceivable that the fuel cell is designed like a proton conductor or proton-conducting oxide (PCO). Such fuel cells are also referred to as protonic ceramic fuel cells (PCFC).A fuel cell is specifically designed to convert at least one chemical reaction energy of at least one, in particular continuously supplied, fuel gas, in particular hydrogen, and at least one oxidizing agent, in particular oxygen, into electrical energy.

[0016] A fuel cell device is understood to be, in particular, a device that forms a component, especially a functional one, particularly a structural and / or functional component, of a fuel cell system, or the entire fuel cell system. In this context, a fuel cell system is understood to be, in particular, a system for the stationary and / or mobile generation of, in particular, electrical and / or thermal energy using at least one fuel cell unit.

[0017] A fuel cell system comprises one or more fuel cell units. Typically, a fuel cell system includes components and lines designed to supply fuel and air to the fuel cell unit. Furthermore, a fuel cell system includes components and lines for removing exhaust gases from the fuel cell unit. Advantageously, fuel cell systems include a recirculation circuit comprising components and lines designed to return unreacted fuel and / or unreacted air to the fuel cell unit. Overall, a fuel cell system includes at least one or more fans designed to convey a fluid, in particular a gaseous fluid. The fluid can be, in particular, fuel, air, exhaust gas, or a combination thereof.The blowers can be, in particular, air supply blowers, fuel supply blowers, exhaust gas exhaust blowers, and / or recirculation blowers. Advantageously, the fuel cell system includes one or more heat exchangers, especially to recover heat from the exhaust gas, or more specifically, the anode and cathode exhaust gases, and to transfer this heat back to the fluids supplied to the fuel cell unit—especially air, fuel, and / or recirculated fluid. The terms heat exchanger and heat transfer unit are used synonymously here.

[0018] Advantageous further developments of the assembly are possible due to the features listed in the dependent claims.

[0019] The assembly is further improved by the fact that the first reactor at least partially encloses the second reactor. This partial enclosure of the second reactor by the first reactor allows for a compact design of the assembly and further improves heat transfer between the reactors.

[0020] In the context of the present invention, the phrase "a first reactor enclosing a second reactor" refers in particular to a spatial arrangement of the reactors in which the second reactor is at least partially surrounded by the first reactor, such that there is direct contact between the outer walls of the second reactor and the inner walls of the first reactor, or such contact is established via an intervening element with good thermal conductivity. The enclosure can be complete or incomplete; that is, the first reactor can surround the second reactor, for example, in a cylindrical, tubular, or even capsule-like form. This arrangement enables efficient heat flow from the second reactor to the first reactor.For example, in the context of the present invention, which relates to an assembly for the catalytic conversion of fluids in fuel cell devices, the first reactor, which can be configured as a reformer, can cylindrically enclose the second reactor, which can be configured as an afterburner. This allows the heat released during afterburning in the second reactor to be optimally transferred to the reformer in order to support the endothermic reforming reaction taking place there.

[0021] In the preferred case where the second reactor is cylindrical and the first reactor is at least partially hollow cylindrical, the partial enclosure can be achieved, for example, as follows: The cylindrical second reactor is arranged coaxially within the hollow cylindrical first reactor, with the cylinder axis of both reactors being essentially identical. The first reactor encloses the second reactor like a mantle, but not necessarily over the entire length of the second reactor. For example, the first reactor can enclose only a central section of the second reactor, while its ends remain open. It is essential that there is direct contact between the outer walls of the second reactor and the inner walls of the first reactor over a significant portion of the second reactor's mantle surface to ensure effective heat flow.This partial enclosure enables a compact design while simultaneously providing a sufficient heat transfer surface to efficiently support the endothermic reaction in the first reactor with the waste heat from the exothermic reaction in the second reactor.

[0022] It is also advantageous if the second reactor at least partially surrounds the first. Reversing this principle, with the second reactor at least partially surrounding the first, offers an alternative way to integrate the reactors and can be advantageous depending on the specific requirements of the application.

[0023] It is also advantageous if the first or second reactor has a base body that is essentially hollow cylindrical. Using a hollow cylindrical base body for one or both reactors allows for simple and cost-effective manufacturing of the assembly.

[0024] Advantageously, one reactor has a substantially hollow cylindrical base body, and the other reactor has a substantially cylindrical base body, which is arranged within the hollow cylindrical base body. In the context of the present invention, the term "substantially hollow cylindrical" means, in particular, that the base body has a geometric shape resembling a cylinder with a continuous, central recess. This recess is designed to create a cavity for at least partially accommodating the other reactor. Within the base body—that is, within the base body outside the recess—the catalytic conversion of the corresponding fluid is provided. Advantageously, an active catalytic material and, optionally, a structure that promotes the catalytic conversion of the fluid are arranged there.The walls of the hollow cylindrical base body can directly form the boundary of the reaction space, in particular a fluidic separation on the inner wall of the hollow cylindrical base body.

[0025] In this context, "essentially" hollow cylindrical or cylindrical should be understood to mean in particular that the basic body may deviate from the ideal geometry of a hollow cylinder or cylinder, for example by means of rounded edges, flattened sides or additional connections, but retains the basic shape of a hollow cylinder or cylinder.

[0026] The base body advantageously has a large surface area; for example, it can be a honeycomb structure, a porous structure (such as a solid foam or foam structure), an arrangement of plates, in particular a structured bundle of plates arranged along the fluid flow direction, or the like. The surface of the base body allows for a large area of ​​active catalytic material—either as part of the base body material and / or as a coating. The base body is preferably formed in one piece; however, it is also possible for the base body to be composed of several sub-bodies, which may be connected and / or spatially separated. Typically, the base body is made of a ceramic, a metallic ceramic (such as cordierite), and / or a metal, in particular a special steel (such as steel DIN / EN 1.4767).

[0027] The assembly is further improved by the fact that the first reactor and / or the second reactor each have a base body with channels for conveying the first fluid and / or second fluid, advantageously with cross-connections between the channels.

[0028] The channels in the base body allow for the targeted guidance of fluids through the respective reactors. Advantageously, the channels contain or are coated with an active catalytic material. Cross-connections between the channels can further optimize heat exchange, particularly by generating turbulence in the fluid.

[0029] Advantageously, the basic structure has a plurality of channels, which extend particularly along a fluid flow direction within the reactor and which contain at least the active catalytic material in sections. This also allows for a particularly large surface area, thus enabling high catalytic performance per reactor volume.

[0030] It is also advantageous if the first reactor and / or the second reactor each have a base body with a plate bundle. Using a plate bundle in the base body offers another advantageous way to design the reactors, providing a large surface area for the catalytic reaction.

[0031] In particular, the plate bundle can include plates that are wound around each other and / or intertwined, for example along a fluid flow direction. The plates can be designed as sheets; it is conceivable that the plates are structured, for example, with a corrugated structure.

[0032] It is also advantageous if the first reactor and / or the second reactor each have a flow element at an interface between the first reactor and the second reactor for influencing, in particular deflecting, the flow of the first fluids and / or second fluids.

[0033] Flow elements at the interface between the reactors allow for targeted manipulation of the fluid flow, thereby further optimizing heat transfer. In particular, the flow path of the fluid, especially at the interface, can be extended by the flow elements, for example, through a mandrel-shaped flow path and / or a helical flow path along a cylindrical interface. It is also conceivable that the flow elements are designed to improve heat transfer by generating turbulence in the fluid.

[0034] In the context of the present invention, a flow element is understood to be, in particular, an element or structure designed to selectively influence the movement of the fluid within the first or second reactor. This can be achieved, for example, by deflecting, swirling, accelerating, or decelerating the flow. Flow elements can include, for example, guide vanes, baffle plates, nozzles, specially shaped channels, or internals with a defined surface structure. In the context of the present invention, guide vanes can, for example, be arranged such that they guide the hot exhaust gases of the second reactor (e.g., of an afterburner) closely along the outer wall of the first reactor (e.g., of a reformer) to ensure effective heat transfer.

[0035] The present invention further describes an electrochemical cell device, in particular a fuel cell device, comprising an electrochemical cell unit and at least one assembly according to the present invention. The integration of the assembly according to the invention into an electrochemical cell device enables the efficient use of the waste heat from the exothermic reaction for the endothermic reaction, thereby increasing the overall efficiency of the cell device. Furthermore, the design of the electrochemical cell device is simplified, thus avoiding indirect thermal coupling of endothermic and exothermic assemblies via heat exchangers and corresponding piping. In this way, the electrochemical cell device can be designed to be more compact, reliable, easier to maintain, and more cost-effective.

[0036] The first reactor is advantageously designed as a reformer. This design enables the efficient conversion of fuel into a hydrogen-rich gas mixture, which can then be fed to the electrochemical cell unit, particularly in the context of a fuel cell system.

[0037] In the context of a fuel cell system, especially a high-temperature fuel cell system such as a solid oxide fuel cell system, the functioning of the reformer is typically based on steam reforming, in which natural gas or methane is at least partially converted into hydrogen.

[0038] For a catalytic reformer, especially for use in fuel cell devices, the active catalyst material is particularly advantageous if it has high activity for methane steam reforming. Transition metals, especially nickel, are typically suitable, but cobalt, iron, and / or copper are also options. Precious metals such as platinum or rhodium are also conceivable. It is possible to combine the active catalyst material with a promoter such as cerium, lanthanum, and / or potassium. A promoter can improve the reactor's activity and stability, as well as its resistance to coking.

[0039] The second reactor is advantageously designed as an afterburner. Its catalytic afterburner configuration enables the efficient afterburning of unburned fuel from the electrochemical cell, thereby reducing emissions and further increasing the overall efficiency of the cell device, particularly in the context of a fuel cell system.

[0040] For a catalytic afterburner, the active catalyst material is advantageously a substance that increases the reaction rate for the oxidation of methane and / or hydrogen. Examples of active catalyst materials for such oxidation reactions are precious metals, non-ferrous metals, and / or ferrous metals, such as iron, nickel, manganese, cobalt, and others. The active catalyst material can be a mixture of precious metals, non-ferrous metals, and / or ferrous metals. Platinumoid metals, for example, platinum and / or palladium, have proven particularly suitable as precious metals. Palladium or a combination of palladium and platinum, optionally incorporating other active catalyst materials, are especially advantageous.

[0041] In principle, it is conceivable that the reactors each have a catalytic layer, wherein the catalytic layer contains the active catalytic material and optionally a support material. This improves the catalytic activity and stability of the catalytic reactor. It is advantageous for the base body to be coated with the support material. It is also conceivable that the catalytic material is mixed with a support material and the base body is coated with this mixture. The support material is also referred to as the catalytic support material.

[0042] Typically, the support material contains one or more metal oxides. For example, the support material may contain titanium oxide, silicon oxide, aluminum oxide, and / or zirconium oxide, advantageously with high porosity. It is also possible for the support material to contain neodymium oxide, cerium oxide, praseodymium oxide, hafnium oxide, yttrium oxide, and / or rare earth elements, and mixtures and mixed oxides thereof. It is also conceivable that the support material contains molecular sieves such as zeolites.

[0043] The catalytic material is typically applied to the support material, advantageously in the form of nanoparticles. In particular, the catalytic material is applied to a support material already present on the substrate. For example, the catalytic material can be applied by impregnation, especially by dry impregnation and / or wet impregnation. The aim is to distribute a desired amount of the catalytic material to specific locations within the internal pore structure of the support material and to fix it there in one or more subsequent steps. Fixation can be achieved, for example, by changing process parameters, by adding additives—especially for changing pH values—by changing the oxidation state and / or process temperature; in particular, processes for drying, calcination, and / or reduction are conceivable.

[0044] For example, to produce the support material, an aqueous powder suspension of metal oxides can be applied to the substrate. Such a powder suspension is also known as a washcoat. This powder suspension is then partially dried so that the support material forms on the substrate. Subsequently, the catalytic material, in particular metals in their aqueous acid or salt solutions, can be impregnated onto the support material and then activated by calcination.

[0045] Furthermore, the catalyst can contain oxides of lantanoids and actinides as promoters and / or stabilizers; oxides of alkaline earth metals and, for example, tin oxides, and in certain applications also alkali metal oxides, are conceivable. Drawings

[0046] The drawings show exemplary embodiments of the assembly as well as an electrochemical cell device incorporating the assembly, which are explained in more detail in the following description. They show Fig. 1 a schematic representation of the fluid-technical circuitry of an electrochemical cell device and Fig. Figures 2 to 4 each show a schematic representation of different variants of the assembly. Description

[0047] In the different versions, identical parts receive the same reference numbers.

[0048] In Fig. Figure 1 shows a schematic circuit diagram of an electrochemical cell device 10. The electrochemical cell device 10 is, by way of example, a fuel cell device 10. In the illustrated embodiment, the fuel cell device 10 is designed as a high-temperature fuel cell device 10 for dual-fuel operation, which can be operated with hydrogen, natural gas, or a mixture of both. It has two fuel sources 14, one for hydrogen and one for natural gas, which can be used alone or in combination. The fuel cell device 10 comprises a fuel cell unit 12, which is, by way of example, designed as a SOFC fuel cell stack.

[0049] The fuel cell unit 12 is fluidically connected to a first fuel source 14a via a first fuel supply line 16a. More precisely, an anode side 12b of the fuel cell unit 12 is fluidically connected to the first fuel source 14a via the first fuel supply line 16a. In this way, a first fuel, in this case hydrogen, can be supplied to the fuel cell unit 12 or its anode side 12b.

[0050] For example, the first fuel source 14a is a gas connection for an external fuel supply line that provides hydrogen. Also for example, downstream of the first fuel source 14a in the first fuel supply line 16a, a first mass flow controller 46a for the first fuel is directly connected. In this way, the fuel flow required for the operation of the fuel cell unit 12 can be adjusted.

[0051] Additionally, the fuel cell device 10 has a second fuel source 14b. The fuel cell unit 12 is fluidically connected to the second fuel source 14b via a second fuel supply line 16b. More precisely, the anode side 12b of the fuel cell unit 12 is fluidically connected to the second fuel source 14b via the second fuel supply line 16b. In this way, a second fuel, in this case natural gas, can be supplied to the fuel cell unit 12 or its anode side 12b. For example, the second fuel source 14b is a gas connection for an external fuel supply line that provides natural gas.

[0052] As an example, a second mass flow controller 46b for the second fuel is connected directly downstream of the second fuel source 14b in the flow direction of the second fuel in the second fuel supply line 16b. In this way, the fuel flow required for the operation of the fuel cell unit 12 can be adjusted. By adjusting the first mass flow controller 46a and the second mass flow controller 46b accordingly, the mixture of the first fuel and the second fuel supplied to the fuel cell unit 12 can be adjusted.

[0053] The first fuel supply line 16a and the second fuel supply line 16b are fluidically connected at a first mixing section 40a. During operation of the fuel cell device 10, the first fuel and the second fuel mix at the first mixing section 40a. From the first mixing section 40a onwards, the first fuel supply line 16a and the second fuel supply line 16b merge to form a common fuel supply line 16, which is designed to deliver the mixture of the two fuels to the fuel cell unit 12. The first mixing section 40a is located in the recirculation circuit 36. The exact position of the first mixing section 40a relative to the other components is shown below. In particular, the first fuel supply line 16a is fluidly connected to the fuel supply line 16. In particular, the second fuel supply line 16b is fluidly connected to the fuel supply line 16.In particular, the fuel supply line 16 is directly connected to the fuel cell unit 12 or its anode side 12b in terms of flow technology.

[0054] A reformer 22 is arranged on the fuel supply line 16. The reformer 22 is a first reactor 22 of an assembly 100, which, in addition to the first reactor 22, also includes a second reactor 26. The reformer 22 is designed to reform the fuel, in particular the second fuel, especially the natural gas. In this way, the fuel—especially the second fuel, preferably the natural gas—is converted in the reformer 22 into a reformed fuel, at least partially. The reformer 22 is required, in particular, in operating conditions in which natural gas, or predominantly natural gas, is supplied to the fuel cell unit 12. In the exemplary embodiment, the reformer 22 is arranged in the flow direction of the mixture of the two fuels in the common fuel supply line 16, directly upstream of the fuel cell unit 12.

[0055] The fuel cell unit 12 is fluidically connected to an air source 18 via an air supply line 20. More precisely, a cathode side 12a of the fuel cell unit 12 is fluidly connected to the air source 18 via the air supply line 20. In this way, the fuel cell unit 12, or rather its cathode side 12a, can be supplied with air during operation. As an example, an air blower 48 is fluidically arranged on the air supply line 20 between the air source 18 and the fuel cell unit 12. The air blower 48 is designed to supply air to the fuel cell unit 12, or rather its cathode side 12a. Advantageously, the air blower 48 is controllable, or rather, the airflow strength can be adjusted. In this way, the airflow required for the operation of the fuel cell unit 12 can be set. In the exemplary embodiment, the air source 18 is designed as an opening for outside air which has an air filter.The air filter is designed to filter pollutants and / or impurities out of the air.

[0056] In the fuel cell unit 12, the fuel or reformed fuel is electrochemically converted during operation with the help of oxygen from the air, generating electrical energy and heat. The electrical energy is absorbed and converted, for example, by power electronics connected to the fuel cell unit 12; for instance, the direct current from the fuel cell unit 12 can be converted into alternating current for external use. For clarity, the power electronics are shown in Fig. 1 not shown.

[0057] Following the electrochemical reaction in the fuel cell unit 12, the exhaust gas or cathode exhaust gas generated on the cathode side 12a is discharged from the fuel cell unit 12 via a cathode exhaust line 24a. The cathode exhaust line 24a is fluidically connected to the fuel cell unit 12, specifically to its cathode side 12a. The exhaust gas or anode exhaust gas generated on the anode side 12b is discharged from the fuel cell unit 12 via an anode exhaust line 24b. The anode exhaust line 24b is fluidically connected to the fuel cell unit 12, specifically to its anode side 12b. The anode exhaust gas may contain unreacted fuel as well as potentially unreformed fuel.

[0058] The fuel cell unit 12, or rather its cathode side 12a, is fluidically connected to an afterburner 26 via the cathode exhaust line 24a. In this way, during operation, the cathode exhaust can be routed from the fuel cell unit 12 to the afterburner 26 via the cathode exhaust line 24a. The afterburner 26 is the second reactor of the assembly 100. The fuel cell unit 12, or rather its anode side 12b, is fluidically connected to the afterburner 26 via the anode exhaust line 24b. The anode exhaust line 24b includes a flow divider 34 between the fuel cell unit 12 and the afterburner 26. The flow divider 34 is fluidly connected to a recirculation line 36.It is provided that the anode exhaust gas flowing from the anode side 12b during operation is split at the flow divider 34 into a first partial flow and a second partial flow, wherein the first partial flow is fed to the afterburner 26 via the anode exhaust line 24b and the second partial flow is fed to a recirculation circuit 38 via the recirculation line 36. The recirculation line 36 is fluidically connected to the recirculation circuit 38, or rather, it forms part of the recirculation circuit 38.

[0059] By means of the afterburner 26, the anode exhaust gas or any unreacted and / or unreformed fuel it may contain is reacted during operation with the addition of the cathode exhaust gas or the oxygen contained therein from the air, thereby generating additional heat – the afterburner 26 is an exothermic reactor. In the exemplary embodiment, the afterburner 26 is a catalyst for the oxidation of methane and hydrogen and is designed as a catalytic afterburner. According to the invention, the heat generated in the afterburner 26 is used for the endothermic reformer 22. The reformer 22 and afterburner 26 are integrated in the assembly 100 and thermally coupled, which enables simple and low-loss heat transfer from the afterburner 26 to the reformer 22. In this way, the efficiency of the fuel cell device 10 can be increased compared to prior art embodiments. The assembly 100 is designed in Fig. 2 and the accompanying character description are explained in more detail.

[0060] The afterburner 26 is fluidically connected to an exhaust outlet 30 via an exhaust line 28. During operation, the exhaust gases are routed out of the fuel cell device 10 through the exhaust outlet 30 via the exhaust line 28. Advantageously, during operation, the waste heat from the exhaust gases of the fuel cell unit 12, in particular the cathode exhaust and the anode exhaust, or the exhaust gas from the afterburner, is returned to the fuel cell unit 12. In the exemplary embodiment, the fuel cell device 10 has a cathode heat exchanger 32a. The cathode heat exchanger 32a is designed to transfer heat from the exhaust gases flowing from the fuel cell unit 12 or the afterburner 26 to the air, which is supplied to the fuel cell unit 12 or its cathode side 12a via the air supply line 20. In this way, the efficiency of the fuel cell device 10 can be further increased.In the exemplary embodiment, the cathode heat exchanger 32a is arranged in front of the fuel cell unit 12 at the air supply line 20 with respect to the air flow direction.

[0061] In the exemplary embodiment, a filter 44 is arranged in the air supply line 20 in the direction of airflow immediately upstream of the fuel cell unit 12. By way of example, the filter 44 is arranged in the air supply line between the cathode heat exchanger 32a and the fuel cell unit 12. The filter 44 is designed to filter particles and gaseous contaminants from the air. In this way, contamination of the fuel cell unit 12 can be reduced or prevented.

[0062] Advantageously, the cathode heat exchanger 32a is arranged on the air supply line 20 downstream of the air blower 48 with respect to the air flow direction. In the exemplary embodiment, the cathode heat exchanger 32a is arranged on the exhaust gas line 28 downstream of the afterburner 26 with respect to the exhaust gas flow direction. In particular, the afterburner 26 is fluidically connected to the cathode heat exchanger 32a via the exhaust gas line 28. This is illustrated by example in the Fig. In the embodiment shown in Figure 1, an adjustable air bypass line 66 is arranged on the air duct 20, which is designed to direct an adjustable portion of the airflow past the cathode heat exchanger 32a. In this way, the temperature of the air arriving at the fuel cell unit 12 can be adjusted.

[0063] In the exemplary embodiment, the fuel cell device 10 has an anode heat exchanger 32b. The anode heat exchanger 32b is designed to transfer heat from the anode exhaust gases flowing from the fuel cell unit 12 or its anode side 12b to the fuel, which is supplied to the fuel cell unit 12 or its anode side 12b via the fuel supply line 16. In this way, the efficiency of the fuel cell device 10 can be further increased. In the exemplary embodiment, the anode heat exchanger 32b is arranged upstream of the fuel cell unit 12 in the fuel supply line 16 with respect to the fuel flow direction. By way of example, the anode heat exchanger 32b of the fuel supply line 16 is arranged upstream of the reformer 22 in the fuel flow direction.In the exemplary embodiment, the anode heat exchanger 32b is arranged fluidically downstream of the fuel cell unit 12 and downstream of the flow divider 34 on the recirculation line 36 with respect to the flow direction of the anode exhaust gas. In particular, the flow divider 34 is fluidically connected to the anode heat exchanger 32b via the recirculation line 36.

[0064] In the exemplary embodiment, the anode heat exchanger 32b is arranged, with respect to the flow direction of the exhaust gas of the afterburner, downstream of the afterburner 26 and upstream of the cathode heat exchanger 32a on the exhaust pipe 28.

[0065] In the exemplary embodiment, the recirculation circuit 38 is designed to return a portion of the anode exhaust gases from the anode side 12b of the fuel cell unit 12. The recirculation circuit 38 has a second mixing section 40b, into which the recirculated fluid is fed into the second fuel supply line 16b, where it is mixed with fresh second fuel. The second fuel supply line 16b and the recirculation line 36 are fluidically connected at the second mixing section 40b. The second mixing section 40b is in Fig. In the embodiment shown in Figure 1, with respect to the flow direction of the second fuel or the second fuel mixed with the recirculated fuel, the second fuel supply line 16b is arranged fluidically downstream of the second fuel source 14b and upstream of the fuel cell unit 12, for example upstream of the first mixing section 40a, at which the first fuel supply line 16a is fluidically connected to the second fuel supply line 16b. The first mixing section 40a is fluidically arranged, with respect to the flow direction of the second fuel or a mixture of the first fuel, the second fuel, and the recirculated fuel, immediately upstream of the (primary) anode heat exchanger 32b.

[0066] In the Fig. In the embodiment shown in Figure 1, the recirculation blower 42 is arranged, by way of example, on the second fuel supply line 16b. With regard to the flow direction of the second fuel or of the second fuel mixed with the recirculated fuel in the second fuel supply line 16b, the recirculation blower 42 is arranged, by way of example, downstream of the second mixing section 40b and upstream of the first mixing section 40a.

[0067] As an example, the condenser heat exchanger 50 is arranged on the second fuel supply line 16b. In this embodiment, the condenser heat exchanger 50 is positioned downstream of the recirculation fan 42 and upstream of the first mixing section 40a with respect to the flow direction of the second fuel or the second fuel mixed with the recirculated fuel. In this way, during operation, the recirculated fuel mixed with the second fuel first flows through the condenser heat exchanger 50, where the water vapor is at least partially condensed. Subsequently, the recirculated fuel flows through the first mixing section 40a, where fresh first fuel – in this case, hydrogen – is added to the mixture of recirculated fuel and second fuel – in this case, natural gas.

[0068] In the Fig. In the embodiment shown in Figure 1, the recirculated fluid in the condenser heat exchanger 50 is cooled by air supplied by a secondary air supply that is independent of the primary air supply via air source 18. For example, the fuel cell device 10 has a secondary air source 18b. The secondary air source 18b is fluidically connected to the condenser heat exchanger 50 via a secondary air supply line 20b. The secondary air source 18b is, for example, designed as an opening for outside air, which includes a filter for coarse particles. The air is discharged from the condenser heat exchanger 50 and from the fuel cell device 10 via an air outlet 68. A secondary air blower 48b is arranged on the secondary air supply line 20b. Fluidically, the secondary air blower 48b is arranged between the secondary air source 18b and the condenser heat exchanger 50.The secondary air blower 48b is advantageous because it is adjustable in terms of airflow strength.

[0069] The adjustable secondary air blower 48b allows, in particular, the adjustment of the airflow through the condenser heat exchanger 50, thus enabling adjustment of the cooling capacity and the heat extracted from the recirculated fluid. Specifically, the condensation temperature can be set using the secondary air blower.

[0070] In the Fig. In the embodiment shown in Figure 1, a condensate drain 58 is connected to the condenser heat exchanger 50, which is designed to remove condensate from the condenser heat exchanger 50. By way of example, the condensate drain 58 connects the condenser heat exchanger 50 fluidically to a condensate outlet 60.

[0071] Fig. Figure 2 shows a schematic sectional view through the assembly 100. The assembly is essentially cylindrical. By way of example, the first reactor 22 encloses the second reactor 26. By way of example, the first reactor 22 has a base body 102, which is essentially hollow and cylindrical. In the exemplary embodiment, the second reactor 26 has a base body 102, which is essentially cylindrical. Advantageously, the diameter of the base body 102 of the second reactor 26 largely corresponds to the inner diameter of the base body 102 of the first reactor 22, so that the base body 102 of the second reactor 26 is arranged inside the base body 102 of the first reactor 22. In the exemplary embodiment, the base body 102 of the first reactor 22 contacts the base body 102 of the second reactor 26 at an interface 106.In this way, efficient heat exchange is provided between the first reactor 22 and the second reactor 26. In the exemplary embodiment, the interface 106 corresponds to an inner surface of the hollow cylindrical base body 102 of the first reactor 22 or to an outer surface of the base body 102 of the second reactor 26.

[0072] The assembly 100, or rather the two base bodies 102, extend along a flow direction 104. In this context, the flow direction 104 is understood to be the direction in which the base bodies 102 are subjected to the respective fluid flow during operation of the assembly 100. By way of example, in this embodiment, the flow direction 104 also corresponds to the direction from which the fluids flow out of the assembly 100 during operation.

[0073] In the exemplary embodiment, both base bodies 102 are approached from the same side by the first reactor 22 and the second reactor 26. Thus, in this exemplary embodiment, the first fluid and the second fluid flow parallel to each other in the assembly 100. In variants, a counterflow is also conceivable, in which, for example, the first fluid flows into the first reactor 22, for instance, in the Fig. The second fluid flows through the second reactor 26 in the defined flow direction 104 and the second fluid flows through the second reactor 26 in the opposite direction of flow 104.

[0074] The two base bodies 102 of the first reactor 22 and the second reactor 26 are each designed as a bundle of plates. The base bodies 102 each have a plurality of corrugated steel sheets, which are wound around each other and / or at least partially intertwined along the flow direction 104. In this way, channels extending in the flow direction 104 are formed. For clarity, the channels and steel sheets are shown in Fig. 2 not detailed.

[0075] In Fig. In Figure 2, the first reactor 22 is configured as a reformer 22, and the second reactor 26 is configured as an afterburner 26. The exothermic afterburner 26 is thus arranged within the largely hollow cylindrical endothermic reformer 22. In this way, the heat released during afterburning can be absorbed and utilized particularly efficiently by the reformer 22.

[0076] Fig. Figure 3 shows a variant of assembly 100, in which structurally largely the in Fig. 2 corresponds to the embodiment shown, except that here the first reactor 22 and the second reactor 26 are swapped. In Fig. 3. The second, exothermic reactor 26 has a largely hollow cylindrical base body 102, while the largely cylindrical base body 102 of the first, endothermic reactor 22 is arranged in contact within the second reactor 26. Here, the heat released in the second reactor 26 is transported inwards into the first reactor 22. As in Fig. Here too, both basic bodies 102 are also designed as plate bundles.

[0077] Fig. Figure 4 shows another variant of assembly 100. Fig. 3. The in Fig. Variant 4 shown corresponds to the variant from Fig. 3, the only difference is that the base body 102 of the second reactor 26 is not designed as a plate bundle. In Fig.In section 4, the base body 102 of the second reactor is designed as a hollow cylinder. In other words, the base body 102 has an inner tube and an outer tube, and the second reactor 26 is configured such that the second fluid flows in an internal region between the inner tube and the outer tube. The inner tube forms an interface 106 between the first reactor 22 and the second reactor 26. A catalytic component for the conversion of the second fluid is arranged in this internal region. Furthermore, flow elements 108 for deflecting the flow of the second fluid are arranged in this internal region at the interface 106. The flow elements 108 are, for example, designed as fins that extend along an imaginary spiral around the cylindrical interface 106. In this way, as the fluid flows through the second reactor 26, the flow elements 108 direct it onto a spiral path around the interface 106, or around the first reactor 22.This allows for efficient heat transfer.

Claims

[1] Assembly (100) for the catalytic conversion of two fluids in electrochemical cell devices (10), preferably fuel cell devices (10), comprising a first reactor (22) for an endothermic catalytic conversion of a first fluid, a second reactor (26) for an exothermic catalytic conversion of a second fluid, characterized by , that the first reactor (22) and the second reactor (26) are integrated into the assembly (100) and thermally coupled to each other. [2] Assembly (100) according to claim 1, characterized by that the first reactor (22) at least partially surrounds the second reactor (26). [3] Assembly (100) according to any one of the preceding claims, characterized by that the second reactor (26) at least partially surrounds the first reactor (22). [4] Assembly (100) according to any one of the preceding claims, characterized by, that the first reactor (22) or the second reactor (26) has a base body (102) which is essentially hollow cylindrical in shape. [5] Assembly (100) according to any one of the preceding claims, characterized by , that the first reactor (22) and / or the second reactor (26) each has a base body (102) with channels for conveying the first fluid and / or second fluid, advantageously with cross-connections between the channels. [6] Assembly (100) according to any one of the preceding claims, characterized by , that the first reactor (22) and / or the second reactor (26) each have a base body (102) with a plate bundle. [7] Assembly (100) according to any one of the preceding claims, characterized by, that the first reactor (22) and / or the second reactor (26) each have a flow element (108) at an interface (106) between the first reactor (22) and the second reactor (26) for influencing, in particular deflecting, the flow of the first fluids and / or second fluids. [8] Electrochemical cell devices (10), in particular fuel cell devices (10), comprising an electrochemical cell unit (12) and at least one assembly (100) according to one of the preceding claims. [9] Electrochemical cell device (10) according to claim 8, characterized by , that the first reactor (22) is designed as a reformer (22). [10] Electrochemical cell device (10) according to claim 8 or 9, characterized by , that the second reactor (26) is designed as an afterburner (26).

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