Fuel cell system for converting energy and operating method for operating fuel cell system

Abstract

The invention relates to a fuel cell system (100) for converting energy, the fuel cell system (100) comprising a number of fuel cell stacks (101, 103), a computing unit (115), and a memory (117), a plurality of different configurations being stored in the memory (117) for starting and / or shutting down the number of fuel cell stacks (101, 103) under cold start conditions, and for switching off the number of fuel cell stacks (101, 103) under cold start conditions. The computing unit (115) is configured to select a corresponding configuration scheme from the plurality of configuration schemes and to operate the fuel cell system (100) in accordance with the selected configuration scheme.

Description

Technical Field

[0001] The invention relates to a fuel cell system for converting energy and to an operating method for operating a fuel cell system. Background Art

[0002] The hydrogen-based PEM fuel cell is seen as a mobility concept of the future, as it emits only water as exhaust gas and enables fast filling times.

[0003] In particular, in the commercial vehicle sector, systems with multiple fuel cell stacks are attractive because they can achieve high overall performance at low costs due to the number of parts. If multiple fuel cell stacks are combined into a fuel cell system, they can be operated as a common subsystem to achieve space and cost advantages.

[0004] A particular challenge is the cold start of such fuel cell systems. Here, the fuel cell stack must be brought into a safe operating range above the freezing point of water, because otherwise the produced water freezes and prevents the transport of reactants to the catalyst layer. Disturbances in electrical power and severe cell aging, especially when hydrogen is consumed, are consequences that must be avoided.

[0005] Particularly challenging are solutions without external heating, in which the fuel cell stack is heated solely by the heat generated by itself.

[0006] Although there is no threat of re-freezing above freezing point, each fuel cell stack is nevertheless limited in capacity: the still lower operating temperatures between +5° C. and +40° C. result in high dynamic losses, so that the achievable rated power still does not reach normal operation at 60° C.

[0007] Furthermore, an impermissible accumulation of liquid water can occur, since the saturation vapor pressure is very low. This is followed by a potentially critical degradation of the reactant supply, as in the case of freezing.

[0008] Methods and systems are known in which both the cold start and the subsequent heating phase are carried out largely independently of the driver's wishes. As a result, either insufficient power delivery may occur due to too slow heating, or high hydrogen consumption may occur due to rapid but inefficient heating. Summary of the invention

[0009] Within the framework of the present invention, a fuel cell system and an operating method for operating a fuel cell system are proposed. Further features and details of the present invention are derived from the detailed technical solution, the description and the drawings. Here, the features and details described in conjunction with the operating method according to the present invention are of course also applicable to the fuel cell system according to the present invention, and vice versa, so that the disclosures for the various inventive aspects are always mutually referenced or mutually referenceable.

[0010] The invention is used in particular to provide a possibility for energy-saving and robust operation of a fuel cell system.

[0011] According to a first aspect of the present invention, a fuel cell system for converting energy is therefore proposed.

[0012] The proposed fuel cell system includes several fuel cell stacks, a computing unit and a memory, wherein a plurality of different configuration schemes are stored in the memory for starting and / or shutting down the several fuel cell stacks under cold start conditions, and the computing unit is configured to select a corresponding configuration scheme from the multiple configuration schemes and operate the fuel cell system corresponding to the selected configuration scheme.

[0013] In the context of the present invention a computing unit is understood to be a computer, a processor, a controller or any other programmable switching circuit.

[0014] In the context of the present invention, a configuration is understood to be a number of predefined settings or operating parameters.

[0015] In the context of the present invention, a cold start is understood to be a process in which the fuel cell system is started up when the ambient temperature is below an ambient temperature threshold of, for example, 4° C., so that water freezing may occur in the fuel cell system.

[0016] In the context of the present invention, a user is understood to be a user and / or operator and / or manufacturer of a fuel cell system.

[0017] The proposed fuel cell system is based on a plurality of different configuration options, which can be selected according to the respective operating conditions of the fuel cell system in order to configure the fuel cell system according to the operating conditions, in particular to prepare for a cold start.

[0018] The computing unit may be configured to determine a geographical location of the fuel cell system, to obtain a location-dependent configuration scheme selected on another fuel cell system within a predetermined circle around the determined geographical location, and to select the location-dependent configuration scheme for operating the fuel cell system so as to operate the fuel cell system in accordance with the selected configuration scheme.

[0019] To determine the geographical location of the fuel cell system, the computing unit of the fuel cell system can be communicatively connected, for example, to a navigation system of a motor vehicle supplied with energy by the fuel cell system or to a mobile computing unit. Alternatively, the computing unit itself can include a localization chip.

[0020] The determined geographic location can be transmitted to a central server, for example, to compare the determined geographic location with the geographic locations of other fuel cell systems. Accordingly, the configuration scheme set on multiple fuel cell systems can be selected and set on the corresponding fuel cell system, so that each fuel cell system automatically adapts to the corresponding geographical conditions.

[0021] Furthermore, it can be provided that the computing unit is configured to ascertain historical operating data of the fuel cell system, to assign corresponding configuration options to the ascertained operating data, and to select the configuration option assigned to the ascertained operating data so that the fuel cell system is operated according to the selected configuration option.

[0022] By selecting a corresponding configuration scheme based on historical operating data of the fuel cell system, the fuel cell system can be prepared according to the expected operating data, so that the fuel cell system automatically adapts to corresponding operating conditions, such as the load profile of a frequently driven section.

[0023] Furthermore, it can be provided that the computing unit is configured to present a plurality of different configuration options to a user of the fuel cell system on the output unit for selection and to operate the fuel cell system according to the respective configuration option selected by the user by means of the user interface.

[0024] The multiple different configuration schemes provided for the user to select enable the fuel cell system to be specially set according to the operating conditions specified by the user. For this purpose, the multiple different configuration schemes provided for selection can be displayed on a display or a touch screen, for example.

[0025] Furthermore, it can be provided that the computing unit is configured to determine route data of a motor vehicle supplied with energy by the fuel cell system, to assign corresponding configuration schemes to the determined route data, and to select the configuration scheme assigned to the determined route data so that the fuel cell system is operated according to the selected configuration scheme.

[0026] Since route data (e.g. the course, slope and / or topography of the corresponding route or route) have a strong influence on the load profile required by the fuel cell system, route data provided by a navigation system of a motor vehicle supplied with energy by the fuel cell system can be used, for example, to automatically adapt the fuel cell system to the expected load profile and / or the respectively expected environmental conditions.

[0027] Furthermore, it can be provided that the configuration scheme includes an efficiency-optimized configuration scheme, a time-optimized configuration scheme, and a lifespan-optimized configuration scheme.

[0028] Here, in order to prepare for a cold start, an efficiency-optimized configuration scheme causes only a single fuel cell stack of the several fuel cell stacks to be preconditioned (vorkonditioniert), to be started without oxygen depletion during a cold start, and during the heating phase, the first fuel cell stack of the several fuel cell stacks is operated at a predetermined low current intensity and only after a predetermined delay time, the second fuel cell stack of the several fuel cell stacks is started in addition to the first fuel cell.

[0029] Accordingly, according to the efficiency-optimized configuration, a cold start is first performed with only a single fuel cell stack. The second fuel cell stack is heated up by the already operating fuel cell stack at a later point in time. As soon as the first fuel cell stack or the already started fuel cell stack is safely above the freezing point of water, further heating is performed at a relatively low electrical power, since the fuel cells reach their highest efficiency here.

[0030] To prepare for a cold start, a time-optimized configuration provides that all of the several fuel cell stacks are preconditioned, started with oxygen depletion during a cold start, and operated with oxygen depletion in a warm-up phase according to a required load profile until a predefined threshold temperature is reached.

[0031] Accordingly, one or more fuel cell stacks are started simultaneously or at the corresponding minimum power according to a time-optimized configuration. In this case, a targeted gas depletion is carried out on the cathode side of the fuel cell stack in order to generate as much heat as possible during a cold start and, if necessary, also in a subsequent heating phase. Accordingly, the operating temperature required for the minimum power is reached in the fuel cell stack as quickly as possible. Once the required operating temperature is reached, the fuel cell stack or stacks are operated in normal operation to provide the required minimum electrical power. If the required minimum power corresponds to the rated power in extreme cases, all fuel cell stacks are heated to a normal operating temperature of about 60° C. with oxygen depletion and at the highest possible current intensity, because it is only from this temperature that the rated power can be ensured.

[0032] In addition, intermediate solutions with different achievable electrical power trajectories are conceivable. Thus, oxygen depletion can be abandoned at lower temperatures in order to provide medium electrical power earlier. In such a case, further heating is delayed and therefore the achievement of the electrical rated power is also delayed.

[0033] In preparation for a cold start, a life-optimized configuration scheme causes only a single fuel cell stack of the several fuel cell stacks to be preconditioned, to be started without oxygen depletion during a cold start, and in a heating section a first fuel cell stack of the several fuel cell stacks to be operated at a predetermined medium current intensity and only after a predetermined delay time a second fuel cell stack of the several fuel cell stacks is started in addition to the first fuel cell stack.

[0034] Accordingly, only a single fuel cell stack is conditioned for the cold start by means of a life-optimized configuration. The intense drying of the fuel cell stack is mainly borne by the membrane. Accordingly, it can be provided that a different fuel cell stack is conditioned at each cold start or that the individual fuel cell stacks are conditioned in turn. The corresponding unconditioned fuel cell stack is then heated passively only after the cold start of the conditioned fuel cell stack.

[0035] Furthermore, it can be provided that the several fuel cell stacks include a plurality of fuel cell stacks, the plurality of fuel cell stacks are thermally coupled via a single common cooling system, and at least one of the plurality of configuration schemes causes a first fuel cell stack of the plurality of fuel cell stacks to be activated during a cold start and the other fuel cell stacks to be deactivated during the activation of the first fuel cell, and that a cooling medium flow directed to the first fuel cell stack via the cooling system is divided into a plurality of branch flows, wherein a first branch flow is directed to the first fuel cell stack and at least one other branch flow is directed to at least one other fuel cell stack of the plurality of fuel cell stacks.

[0036] For example, the total coolant volume flow can be delivered by a single correspondingly large or powerful pump and divided by a three-way valve into partial flows, which are directed to the first fuel cell stack and the second fuel cell stack. After flowing through the two fuel cell stacks, the partial flows are directed back to the pump as a total coolant flow, which can be achieved, for example, by using a further three-way valve, which bypasses the radiator during the entire cold start.

[0037] The cold start can be carried out until the temperature of the active fuel cell stack rises to a value above the ambient temperature, in particular above a threshold value of 5 K or 10 K from the ambient temperature. This is done when the heated coolant flows through the cooling circuit once and is fed back to the active fuel cell stack.

[0038] If the cooling medium volume flow required by the active fuel cell stack is less than the minimum volume flow and the cooling medium volume flow required through the inactive fuel cell stack is equal to 0, the actual cooling medium volume flow through the inactive fuel cell stack is increased to a temperature greater than 0°C by controlling the three-way valve so that the cooling medium volume flow required by the active fuel cell stack is complied with.

[0039] Since it is usually not possible to directly measure the coolant volume flow in motor vehicles, an estimation method based on pressure losses can be used for this purpose, in which two pressure differences across the coolant channels of the fuel cell stack are evaluated and calculated based on stored correlations.

[0040] Of course, it is also conceivable that the coolant volume flow continues to flow through the inactive fuel cell stack until the temperature upstream of the active fuel cell stack is safely above 0° C.

[0041] Furthermore, it can be provided that the several fuel cell stacks include a plurality of fuel cell stacks which are thermally coupled via a single common cooling system and are coupled to each other by conducting air via a single cathode subsystem, wherein the computing unit is configured to select a configuration scheme for cold starting of the plurality of fuel cell stacks according to a predetermined load requirement.

[0042] Therein, the calculation unit is configured to select a first configuration scheme if a predetermined load requirement is less than a first load threshold value, the first configuration scheme causing only a first fuel cell stack among a plurality of fuel cell stacks to be started first under lean gas conditions and a cooling mass flow greater than a predetermined cooling mass threshold value.

[0043] In order to reach the operating temperature as quickly as possible, a start with high heat generation is set by air depletion if the predefined load requirement is less than a first load threshold. In this case, the coolant is mainly guided through the active fuel cell stack in order to quickly bring the entire coolant volume to a temperature above 0°C.

[0044] If, by evaluating the measured values ​​inherent to the fuel cell, such as the total / single cell voltage, the cathode outlet temperature and / or the coolant inlet / outlet temperature, it is determined that an ice layer has formed on the cathode side, which acts as a barrier, the coolant mass flow can be reduced and the air quality can be increased. In this case, the supply of still cold coolant to the fuel cell stack is throttled and the heat diffusion in the fuel cell stack is promoted. For this purpose, for example, the coolant mass flow is divided into sub-flows. Once the first fuel cell stack has been completely heated and switched to normal operation, the second fuel cell stack is heated passively and then kept warm.

[0045] If the predetermined load requirement is less than the second load threshold but greater than the first load threshold, a second configuration scheme is selected, which causes the first fuel cell stack among the multiple fuel cell stacks to be started under lean gas conditions and a cooling mass flow greater than the predetermined cooling mass threshold, and the other fuel cell stacks among the multiple fuel cell stacks to be started under rich gas conditions.

[0046] If the predefined load requirement is less than the second load threshold but greater than the first load threshold, the load requirement exceeds the electrical energy provided by the active fuel cell stack. In addition, the goal is to heat up the first fuel cell stack as quickly as possible, so operation with high coolant mass flow and low air mass is again initially set.

[0047] In order to set the fuel cell system to the increased energy demand, the second fuel cell stack is additionally activated. Due to the low coolant mass flow, operation with high air quality is provided here. Accordingly, the second fuel cell stack contributes primarily to the provision of electrical energy and serves secondarily for heating the coolant. Nevertheless, in this case, the start-up process is slightly accelerated by the low additional heat contribution of the second fuel cell stack.

[0048] If the pre-set load requirement is greater than the second load threshold, a third configuration scheme is selected, which causes the first fuel cell stack and the other fuel cell stack to alternate periodically and precisely phase-shifted between a first operating point and a second operating point, at the first operating point a high coolant flow above a pre-set coolant threshold and a high heat production above a pre-set thermal threshold, and at the second operating point a low coolant flow below a pre-set coolant threshold and a low heat production below a pre-set thermal threshold.

[0049] If the predefined load requirement is greater than the second load threshold, the load requirement exceeds the statically stable operating range of the fuel cell system at low temperatures. The second fuel cell stack cannot therefore be operated continuously in such a way that an optimal balance between water production and heat production is ensured. In this case, a "switching mode" is therefore set, in which the two fuel cell stacks alternate periodically and with precise phase shift between an operating point with high coolant flow and high heat production and an operating point with low coolant flow and low heat production. This results in a uniform power output on average.

[0050] On the coolant side, the cyclic switching takes place via valves and / or via speed control of the corresponding pumps.

[0051] At the same time, in both fuel cell stacks, variables inherent to the fuel cell stack are continuously monitored and, if necessary, the power output of the fuel cell stack is briefly limited or the activation interval is adapted.

[0052] A measured variable intrinsic to the respective fuel cell stack can be used as a trigger criterion for the switchover. However, the fuel cell stack with the respective critical operating values ​​is decisive for this clocking. At the beginning of the life of the fuel cell stack, deviations can occur due to minimal differences in the power provided. Towards the end of the life of the fuel cell stack, the state of the respective fuel cell stack also decisively influences the cold start.

[0053] If the fuel cell system has an estimate of the corresponding state of the fuel cell stack, these variables can also be introduced into the pilot control of the switching mode.

[0054] According to a second aspect, the invention relates to an operating method for operating a fuel cell system.

[0055] The proposed operating method includes: starting a possible configuration of the proposed fuel cell system when the ambient temperature is below a predetermined temperature threshold, and / or shutting down the fuel cell system when the ambient temperature is below a predetermined temperature threshold, wherein, in order to start and / or shut down the fuel cell system, a corresponding configuration scheme is selected from a plurality of configuration schemes and the fuel cell system is operated according to the selected configuration scheme.

[0056] It can be set to determine the geographical location of the fuel cell system, obtain a location-related configuration scheme selected on another fuel cell system within a predetermined circle around the determined geographical location, and select the location-related configuration scheme for operating the fuel cell system so that the fuel cell system operates according to the selected configuration scheme, or obtain historical operating data of the fuel cell system, assign corresponding configuration schemes to the obtained operating data and select the configuration scheme assigned to the obtained operating data so that the fuel cell system operates according to the selected configuration scheme, or display a plurality of different configuration schemes for selection to a user of the fuel cell system on an output unit, and operate the fuel cell system according to the corresponding configuration scheme selected by the user with the aid of a user interface, or obtain route data of a motor vehicle supplied with energy by the fuel cell system and assign corresponding configuration schemes to the obtained route data and select the configuration scheme assigned to the obtained route data so that the fuel cell system operates according to the selected configuration scheme.

[0057] In addition, it can be set that the configuration scheme includes an efficiency-optimized configuration scheme, a time-optimized configuration scheme and a life-optimized configuration scheme, wherein, in order to prepare for a cold start, the efficiency-optimized configuration scheme causes only a single fuel cell stack among several fuel cell stacks to be pre-conditioned and started without oxygen depletion during a cold start, and during a heating phase, a first fuel cell stack among several fuel cell stacks is operated under a predetermined low current intensity and a second fuel cell stack among several fuel cell stacks is started in addition to the first fuel cell stack only after a predetermined delay time, wherein, in order to prepare for a cold start, the time-optimized configuration scheme causes all of several fuel cell stacks to be pre-conditioned The invention relates to a method of preconditioning the fuel cell stacks, starting them with oxygen depletion during a cold start, and operating the fuel cell stacks with oxygen depletion during a heating phase according to a required load trajectory until a predetermined threshold temperature is reached, and wherein, in order to prepare for the cold start, a life-optimized configuration scheme causes only a single fuel cell stack of several fuel cell stacks to be preconditioned, starting them without oxygen depletion during a cold start, and operating a first fuel cell stack of several fuel cell stacks at a predetermined medium current intensity during the heating phase and starting a second fuel cell stack of several fuel cell stacks in addition to the first fuel cell stack only after a predetermined delay time.

[0058] Furthermore, it can be provided that the several fuel cell stacks include a plurality of fuel cell stacks, the plurality of fuel cell stacks are thermally coupled via a single common cooling system, and at least one of the plurality of configuration schemes causes a first fuel cell stack of the plurality of fuel cell stacks to be activated during a cold start and other fuel cell stacks to be deactivated during activation of the first fuel cell stack, and that a cooling medium flow directed to the first fuel cell stack via the cooling system is divided into a plurality of branch flows, wherein a first branch flow is directed to the first fuel cell stack and at least one other branch flow is directed to at least one other fuel cell stack of the plurality of fuel cell stacks.

[0059] In addition, it can be arranged that the fuel cell system includes a plurality of fuel cell stacks, the plurality of fuel cell stacks are thermally coupled via a single common cooling system and are coupled to each other by conducting air via a single cathode subsystem, and for cold starting of the plurality of fuel cell stacks, a configuration scheme is selected according to a predetermined load requirement, and if the predetermined load requirement is less than a first load threshold, a first configuration scheme is selected, the first configuration scheme causing first only a first fuel cell stack of the plurality of fuel cell stacks to be started under lean gas conditions and a cooling mass flow greater than a predetermined cooling mass threshold, and if the predetermined load requirement is less than a second load threshold but greater than the first load threshold, a second configuration scheme is selected, the second configuration scheme causing the plurality of fuel cell stacks to be started. A first fuel cell stack among a plurality of fuel cell stacks is started under lean gas conditions and with a cooling mass flow greater than a predetermined cooling mass threshold, and another fuel cell stack among the plurality of fuel cell stacks is started under rich gas conditions, and if a predetermined load requirement is greater than a second load threshold, a third configuration scheme is selected, the third configuration scheme causing the first fuel cell stack and the other fuel cell stacks to alternate periodically and precisely phase-shifted between a first operating point and a second operating point, with a high cooling medium flow greater than a predetermined cooling medium threshold and a high heat production greater than a predetermined thermal threshold at the first operating point, and a low cooling medium flow less than a predetermined cooling medium threshold and a low heat production less than a predetermined thermal threshold at the second operating point.

[0060] The advantages described in detail with respect to the fuel cell system for energy conversion according to the first aspect of the invention also apply to the operating method for operating a fuel cell system according to the second aspect of the invention.

[0061] Other advantages, features and details of the present invention are apparent from the following description, in which embodiments of the present invention are described in detail with reference to the accompanying drawings. The features mentioned in the technical solution and the description are important to the present invention individually or in any combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The accompanying drawings show:

[0063] Figure 1 : Schematic diagram of a first possible configuration of the proposed fuel cell system,

[0064] Figure 2 : Another possible configuration of the proposed fuel cell system,

[0065] Figure 3 : Description of the temperature and power profiles when using a possible configuration of the proposed operating method,

[0066] Figure 4 : Detailed view of a possible configuration of the proposed operating method. DETAILED DESCRIPTION

[0067] The drawings are described sequentially. Like reference numerals denote like features.

[0068] exist Figure 1 A fuel cell system 100 for converting energy is described in The fuel cell system 100 comprises a first fuel cell stack 101 , a second fuel cell stack 103 , a common cooling system 105 with a pump 107 , a first valve 109 and a second valve 111 , and a radiator 113 .

[0069] Furthermore, the fuel cell system 100 comprises a computing unit 115 and a memory 117 .

[0070] A plurality of different configuration schemes are stored in the memory 117 for starting and / or shutting down the first fuel cell stack 101 and the second fuel cell stack 103 under cold start conditions.

[0071] The computing unit 115 is configured to select a corresponding configuration option from a plurality of configuration options and to operate the fuel cell system 100 according to the selected configuration option.

[0072] exist Figure 2 , a fuel cell system 100 is described in which a first valve 109 is set to a cooling medium flow to a first fuel cell stack 101 and a second valve 111 is set to a cooling medium flow to a second fuel cell stack 103. A third valve 201 rejoins the cooling medium flow out of the first fuel cell stack 101 and the cooling medium flow out of the second fuel cell stack 103 to a pump 107 or a radiator 113.

[0073] Accordingly, the total coolant flow provided by the pump 107 can be divided into sub-coolant flows by valves 109, 111 and 201, so that, for example, the sub-coolant flow supplied to the first fuel cell stack 101 is minimized while the pump power of the pump 107 remains unchanged, and thus causes particularly rapid heating of the first fuel cell stack 101.

[0074] exist Figure 3 The schematic diagram 301 is used to describe the operation according to Figure 1 or Figure 2 Method 300 for operating a fuel cell system.

[0075] Schematic diagram 301 expands a time axis 303 , a temperature axis 305 , and a power axis 307 .

[0076] The freezing point line 309 extends at a temperature of 0° C. Accordingly, the freezing point line 309 divides the schematic diagram 301 into a cold start region below the freezing point line 309 and a heating region above the freezing point line 309 .

[0077] Line 311 corresponds to a temperature threshold value and line 313 corresponds to an operating temperature of 60° C.

[0078] Line 315 corresponds to the minimum power and line 317 corresponds to the rated power.

[0079] The first profile 319 corresponds to the temperature profile in the first fuel cell stack which is started using the time-optimized configuration.

[0080] The second profile 321 corresponds to the temperature profile in a second fuel cell stack that is passively heated or preconditioned by the first fuel cell stack.

[0081] The third profile 323 corresponds to the temperature profile in the third fuel cell stack which is started up using the efficiency-optimized configuration.

[0082] Fourth profile 325 corresponds to the temperature profile in a fourth fuel cell stack that is passively heated or preconditioned by the third fuel cell stack.

[0083] Arrow 327 indicates first profile 319 in normal operation. Arrow 329 indicates profile 327 for rapid heating in an operating range with oxygen depletion.

[0084] Arrow 331 indicates fourth profile 325 in an operating range with low current intensity.

[0085] Figure 4 A diagram 400 is shown which is developed on its abscissa over time and on its ordinate over the thermal energy provided and the coolant flow.

[0086] Four curves are shown which were ascertained for a fuel cell system operated in a so-called switching mode.

[0087] The first curve 401 corresponds to the thermal energy provided by the first fuel cell stack.

[0088] The second curve 403 corresponds to the thermal energy provided by the second fuel cell stack.

[0089] The third curve 405 corresponds to the coolant flow through the first fuel cell stack.

[0090] Fourth curve 407 corresponds to the coolant flow through the second fuel cell stack.

[0091] It can be seen from curves 401 , 403 , 405 , 407 that the first fuel cell stack and the second fuel cell stack alternate periodically and with a precise phase shift between operating points with high coolant flow and high heat production and operating points with low coolant flow and low heat production.

Claims

1. A fuel cell system (100) for converting energy, wherein: The fuel cell system (100) comprises: - a plurality of fuel cell stacks (101, 103), - a computing unit (115), and - a memory (117), A plurality of different configuration schemes are stored in the memory (117) for starting and / or shutting down the plurality of fuel cell stacks (101, 103) under cold start conditions, and The computing unit (115) is configured to select a corresponding configuration scheme from the plurality of configuration schemes and to operate the fuel cell system (100) according to the selected configuration scheme.

2. The fuel cell system (100) according to claim 1, characterized in that: The computing unit (115) is configured to: determining a geographical location of the fuel cell system (100), determining a location-dependent configuration that is selected on a further fuel cell system within a predetermined circle around the determined geographical location, and The location-dependent configuration is selected for operating the fuel cell system, so that the fuel cell system (100) is operated according to the selected configuration.

3. The fuel cell system (100) according to claim 1 or 2, characterized in that: The calculation unit (115) is configured to obtain historical operating data of the fuel cell system (100), A corresponding configuration scheme is assigned to the ascertained operating data, and the configuration scheme assigned to the ascertained operating data is selected in order to operate the fuel cell system (100) according to the selected configuration scheme.

4. The fuel cell system (100) according to one of the preceding claims, characterized in that The computing unit (115) is configured to: A plurality of different configuration options are displayed on an output unit to a user of the fuel cell system (100) for selection and The fuel cell system (100) is operated according to a corresponding configuration selected by a user via a user interface.

5. The fuel cell system (100) according to one of the preceding claims, characterized in that The computing unit (115) is configured to determine route data of a motor vehicle supplied with energy by the fuel cell system (100). A corresponding configuration scheme is assigned to the ascertained route data, and the configuration scheme assigned to the ascertained route data is selected in order to operate the fuel cell system (100) according to the selected configuration scheme.

6. The fuel cell system (100) according to one of the preceding claims, characterized in that The configuration scheme includes an efficiency-optimized configuration scheme, a time-optimized configuration scheme, and a life-optimized configuration scheme. The efficiency-optimized configuration scheme provides for the preparation of a cold start by preconditioning only a single fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103), starting without oxygen depletion during a cold start, operating a first fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) at a predetermined low current intensity during a warm-up phase, and starting a second fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) in addition to the first fuel cell stack (101, 103) only after a predetermined delay time, The time-optimized configuration scheme causes all of the plurality of fuel cell stacks (101, 103) to be preconditioned in preparation for a cold start, to start in an oxygen-depleted state during a cold start, and to operate the fuel cell stacks (101, 103) in an oxygen-depleted state during a warm-up phase according to a required load trajectory until a predetermined threshold temperature is reached, and The life-optimized configuration scheme causes, in order to prepare for a cold start, only a single fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) to be preconditioned, to be started without oxygen depletion during a cold start, and to operate a first fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) at a predetermined medium current intensity during a warm-up phase and to start a second fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) in addition to the first fuel cell stack (101, 103) only after a predetermined delay time.

7. The fuel cell system (100) according to one of the preceding claims, characterized in that The plurality of fuel cell stacks (101, 103) include a plurality of fuel cell stacks (101, 103), the plurality of fuel cell stacks (101, 103) being thermally coupled via a single common cooling system (105), and At least one of the multiple configuration schemes causes a first fuel cell stack (101, 103) among the multiple fuel cell stacks (101, 103) to be activated during a cold start and other fuel cell stacks (101, 103) to be deactivated during the activation of the first fuel cell stack (101, 103), and a cooling medium flow directed to the first fuel cell stack (101, 103) through the cooling system (105) is divided into a plurality of sub-flows, wherein a first sub-flow is directed to the first fuel cell system (101, 103) and at least one other sub-flow is directed to at least one other fuel cell stack (101, 103) among the multiple fuel cell stacks (101, 103); wherein the amount of the guided cooling medium is set so that a desired amount of cooling medium is delivered to the first fuel cell stack.

8. The fuel cell system (100) according to one of the preceding claims, characterized in that The plurality of fuel cell stacks (101, 103) include a plurality of fuel cell stacks (101, 103) thermally coupled via a single common cooling system (105) and air-conductively coupled to each other via a single cathode subsystem, and The calculation unit (115) is configured to select a configuration scheme for cold starting of the plurality of fuel cell stacks (101, 103) according to a predetermined load requirement. Wherein, the computing unit (115) is configured to: If the predetermined load demand is less than a first load threshold, a first configuration is selected, which causes only a first fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) to be started up first under lean gas conditions and a cooling mass flow greater than a predetermined cooling mass threshold, If the predetermined load requirement is less than a second load threshold value but greater than the first load threshold value, a second configuration scheme is selected, which causes a first fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) to be started under lean gas conditions and a cooling mass flow greater than a predetermined cooling mass threshold value, and another fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) to be started under rich gas conditions, and If the predetermined load requirement is greater than the second load threshold, a third configuration scheme is selected, which causes the first fuel cell stack (101, 103) and the other fuel cell stack (101, 103) to alternate periodically and precisely phase-shifted between a first operating point and a second operating point, at which a high coolant flow above a predetermined coolant threshold and a high heat production above a predetermined thermal threshold are performed, and at which a low coolant flow below a predetermined coolant threshold and a low heat production below a predetermined thermal threshold are performed.

9. An operating method (300) for operating a fuel cell system (100), wherein: The operating method (300) comprises: - starting up the fuel cell system (100) according to one of the preceding claims 1 to 8 at an ambient temperature below a predefined temperature threshold, and / or - shutting down the fuel cell system (100) according to one of the preceding claims 1 to 8 when the ambient temperature falls below the predefined temperature threshold value, A corresponding configuration scheme is selected from the plurality of configuration schemes for starting and / or shutting down the fuel cell system (100), and the fuel cell system (100) is operated according to the selected configuration scheme.

10. The operating method (300) according to claim 9, characterized in that: - determining a geographical location of the fuel cell system (100), determining a location-dependent configuration scheme selected on another fuel cell system within a predetermined circle around the determined geographical location, and selecting the location-dependent configuration scheme for operating the fuel cell system (100) so as to operate the fuel cell system (100) in accordance with the selected configuration scheme, or - obtaining historical operating data of the fuel cell system (100), assigning a corresponding configuration scheme to the obtained operating data, and selecting the configuration scheme assigned to the obtained operating data, so as to operate the fuel cell system (100) according to the selected configuration scheme, or - presenting a plurality of different configuration schemes to a user of the fuel cell system (100) on an output unit for selection, and operating the fuel cell system (100) according to the corresponding configuration scheme selected by the user via a user interface, or - determining route data of a motor vehicle supplied with energy by the fuel cell system (100), assigning a corresponding configuration scheme to the determined route data, and selecting the configuration scheme assigned to the determined route data in order to operate the fuel cell system (100) in accordance with the selected configuration scheme.

11. The operating method (300) according to claim 9 or 10, characterized in that: The configuration scheme includes an efficiency-optimized configuration scheme, a time-optimized configuration scheme, and a life-optimized configuration scheme. The efficiency-optimized configuration scheme provides for the preparation of a cold start by preconditioning only a single fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103), starting without oxygen depletion during a cold start, operating a first fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) at a predetermined low current intensity during a warm-up phase, and starting a second fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) in addition to the first fuel cell stack (101, 103) only after a predetermined delay time, The time-optimized configuration scheme causes all of the plurality of fuel cell stacks (101, 103) to be preconditioned in preparation for a cold start, to start in an oxygen-depleted state during a cold start, and to operate the fuel cell stacks (101, 103) in an oxygen-depleted state during a warm-up phase according to a required load trajectory until a predetermined threshold temperature is reached, and The life-optimized configuration scheme causes, in order to prepare for a cold start, only a single fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) to be preconditioned, to be started without oxygen depletion during a cold start, and to operate a first fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) at a predetermined medium current intensity during a warm-up phase and to start a second fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) in addition to the first fuel cell stack (101, 103) only after a predetermined delay time.

12. The operating method (300) according to any one of claims 9 to 11, characterized in that: The plurality of fuel cell stacks (101, 103) include a plurality of fuel cell stacks (101, 103), the plurality of fuel cell stacks (101, 103) being thermally coupled via a single common cooling system (105), and At least one of the multiple configuration schemes causes a first fuel cell stack (101, 103) among the multiple fuel cell stacks (101, 103) to be activated during a cold start and other fuel cell stacks (101, 103) to be deactivated during the activation of the first fuel cell stack (101, 103), and a cooling medium flow directed to the first fuel cell stack (101, 103) through the cooling system (105) is divided into multiple branch flows, wherein a first branch flow is directed to the first fuel cell stack (101, 103) and at least one other branch flow is directed to at least one other fuel cell stack (101, 103) among the multiple fuel cell stacks (101, 103).

13. The operating method (300) according to any one of claims 9 to 12, characterized in that: The fuel cell system (100) includes a plurality of fuel cell stacks (101, 103) which are thermally coupled via a single common cooling system (105) and air-conductingly coupled to each other via a single cathode subsystem, and In order to cold start the plurality of fuel cell stacks (101, 103), a configuration scheme is selected according to a predetermined load requirement, and If the predetermined load demand is less than a first load threshold, a first configuration is selected, which causes only a first fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) to be started up first under lean gas conditions and a cooling mass flow greater than a predetermined cooling mass threshold, If the predetermined load requirement is less than a second load threshold value but greater than the first load threshold value, a second configuration scheme is selected, which causes a first fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) to be started under lean gas conditions and a cooling mass flow greater than a predetermined cooling mass threshold value, and another fuel cell stack (101, 103) of the plurality of fuel cell stacks (101, 103) to be started under rich gas conditions, and If the predetermined load requirement is greater than the second load threshold, a third configuration scheme is selected, which causes the first fuel cell stack (101, 103) and the other fuel cell stack (101, 103) to alternate periodically and precisely phase-shifted between a first operating point and a second operating point, at which a high coolant flow above a predetermined coolant threshold and a high heat production above a predetermined thermal threshold are performed, and at which a low coolant flow below a predetermined coolant threshold and a low heat production below a predetermined thermal threshold are performed.

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