Methods for operating fuel cell systems in automobiles, particularly commercial vehicles, and automobiles

Abstract

The present invention relates to a method for operating a fuel cell system (10) of a motor vehicle (12), the fuel cell system (10) comprising at least one hydrogen tank (14), at least one fuel cell (18) capable of supplying hydrogen from the hydrogen tank (14), and a cooling device (30) for cooling at least a portion of the fuel cell system (10), in which the energy consumption of the cooling device (30) is predicted according to a planned driving route of the motor vehicle (12), a future time-pressure curve of the pressure that will prevail in the hydrogen tank (14) is predicted, and a future time-energy curve of the amount of thermal energy to be supplied from the cooling device (30) to the hydrogen tank (14) according to the predicted energy consumption in accordance with the energy curve in order to realize the pressure curve is predicted.

Description

Technical Field

[0001] The present invention relates to a method for operating a fuel cell system of a motor vehicle, particularly a commercial vehicle. The present invention further relates to a motor vehicle, particularly a commercial vehicle.

Background Art

[0002] A method for predictive operation of a motor vehicle equipped with a fuel cell system is described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a method for operating a fuel cell system of a motor vehicle and a motor vehicle so as to achieve particularly efficient operation.

Means for Solving the Problems

[0005] This object is solved by a method having the features of claim 1 and a motor vehicle having the features of claim 6. Advantageous embodiments having developments suitable for the object of the present invention are presented in the other claims.

[0006] A first aspect of the present invention relates to a method for operating a fuel cell system in an automobile, also simply called a vehicle, preferably in the form of a commercial vehicle, particularly a heavy freight vehicle. The fuel cell system has at least one hydrogen tank, also simply called a tank. Hydrogen (H2) is receivable into or received by the hydrogen tank. The fuel cell system, also called a fuel cell device or fuel cell equipment, consists of at least one fuel cell capable of supplying hydrogen from the hydrogen tank. As is well known, the chemical reaction energy of hydrogen and an oxidizer supplied to a fuel cell is converted by the fuel cell into electrical energy, which is supplied by the fuel cell. In particular, for example, oxygen contained in the air is used as an oxidizer and is similarly receivable into or supplied to the fuel cell. The electrical energy supplied or supplied by the fuel cell can be stored at least temporarily in an electrical energy storage device designed in particular as a battery, specifically as a secondary battery. Furthermore, it is conceivable that the electrical energy can be supplied to or supplied to at least one electric engine. This electrical energy can be supplied, particularly directly, by a fuel cell, bypassing the electrical energy storage device, and here, alternatively or additionally, the electrical energy stored in the electrical energy storage device can be supplied to the electric engine. By supplying electrical energy to the electric engine, the electric engine can operate in motor mode and therefore act as an electric motor, thereby enabling the vehicle to be driven electrically, particularly purely electrically.

[0007] A fuel cell system also has a cooling device, which can cool at least a portion of the fuel cell system. In particular, a liquid coolant can be flowed through at least a portion of the cooling device, for example, which can cool at least a portion of the fuel cell system. The cooling device is also called a cooling system.

[0008] To enable particularly efficient, and especially energy-efficient, operation of fuel cell systems and, by extension, automobiles, the method according to the present invention predicts, i.e., predictively determines, the energy consumption of the cooling system in accordance with the planned route of the automobile, particularly by the automobile's electronic computer. This is understood to mean, in particular, that the energy consumption is determined and, in particular, calculated at a first time or first period, where the first time or first period is the time when the automobile is traveling along or has departed from the planned route, i.e., while actually traveling along the route, and which precedes a second period in time. In other words, the energy consumption is determined before the automobile travels along the route, or while the automobile is not (yet) traveling along the route. The route may include at least one or more refueling operations, also called simply refueling. Refueling operations are, in particular, planned refueling processes that may be performed in the future as needed, since the route is a planned route, during which hydrogen is filled into the tank, in particular from the outside of the tank, so that the tank is at least partially filled with hydrogen. For example, refueling operations are necessary, anticipated, or determined to ensure that the vehicle can travel along the entire route, particularly. Furthermore, the planned route may include at least one or more stops. In particular, since the route is a planned route, the stops are planned stops, which are such that the vehicle is, for example, stopped for a particularly continuous period, and / or the vehicle is not driven for a particularly continuous period by the fuel cell system, and / or the fuel cell system is not operating for a particularly continuous period. In particular, during stops, the discharge of hydrogen from the hydrogen tank and / or the supply of electrical energy by the fuel cell are omitted.In particular, the predicted energy consumption is a temporal energy consumption, and therefore a temporal energy consumption curve of the energy consumption of the cooling system, and the energy consumption or energy consumption curve is determined, calculated or estimated and thereby a predicted energy consumption curve, which characterizes the energy or amount of energy that is likely to be consumed by the cooling system when the vehicle is traveling along the route, i.e., when the vehicle is being driven or during that time.

[0009] In this method, the future temporal pressure curve of the pressure present in the hydrogen tank, and in particular the pressure brought about or that can be brought about by the hydrogen received or that can be received in the hydrogen tank, is also predicted, that is, predetermined or predicted, in particular depending on the route traveled. Thus, the future temporal pressure curve is, for example, a planned, particularly specified or configurable temporal pressure curve, and the pressure curve is, for example, a set, i.e., a target curve that is to result.

[0010] In the method according to the present invention, in order to realize a pressure curve, a future temporal energy curve is also predicted for the amount of thermal energy that is supplied from the cooling device to the hydrogen tank, i.e., the amount of thermal energy that is intended to be supplied, according to the energy curve, in accordance with the predicted energy consumption of the cooling device. That is, the energy curve defines a time curve, which is determined by the amount of thermal energy that is supplied by the cooling device to the hydrogen tank, particularly when the vehicle departs from or is traveling along a route, in order to realize a pressure curve, taking into account the predicted energy consumption of the cooling device. As a result, the cooling device can provide thermal energy to be supplied to the hydrogen tank in at least one or more sub-sections of the travel route, and consequently the hydrogen tank is used as a thermal buffer or heat sink. Thus, excessively high thermal loads, i.e., excessively high temperatures of the cooling device, can be avoided without, for example, cooling the cooling device by a fan, particularly an electric fan. Thus, this method is a method for predicting heat or temperature control of a fuel cell system. Therefore, the present invention is based particularly on the following findings and considerations: Generally, in automobiles equipped with fuel cells, and thus also called fuel cell vehicles, a powerful cooling system is used, which can discharge power losses from the fuel cell, particularly during high-load stages of the fuel cell, and maintain the relatively narrow temperature operating range of the fuel cell, i.e., ensure that the fuel cell or the temperature of the fuel cell remains within its temperature operating range. Therefore, cooling devices are used in particular to cool the fuel cell and thereby maintain the temperature operating range. For example, the temperature operating range is at least essentially ±8 to 10°C. In addition, in the case of fuel cell vehicles designed as heavy commercial vehicles, the cooling system receives additional heat input from activated sustained braking devices designed, for example, retarders, brake resistors, etc. In particular, the cooling system is also used to cool the vehicle's retarder, sustained braking device designed, for example, as a brake resistor. Conventionally, the cooling system (cooling device) cools the retarder and the vehicle's fuel cell simultaneously for at least a certain time interval.In the high-load phase of a fuel cell system, this leads to a longer startup period, i.e., a longer period during which the electric fan operates, for example, the period during which 30 or 40 kW of power is required or available. The aforementioned coolant is cooled by a fan, which is a component of a cooling device or cooling system, for example, particularly via a heat exchanger, in particular by a fan, when the fan is operating, by conveying air flowing around a heat exchanger designed as an air-cooled heat exchanger. The heat exchanger transfers heat from the coolant to the air flowing around the heat exchanger and conveyed using the fan. Furthermore, for example, a permanent heat flow may be required, particularly to heat cryogenic liquid hydrogen, and this heat flow can utilize heat supplied from a heat source, provided that the cooling system (cooling device) is designed accordingly. For example, fuel cells and retarders can be used as heat sources, also known as waste heat, and can be used to heat hydrogen that is received or can be received in a hydrogen tank within a tank and / or hydrogen discharged from the hydrogen tank on its way to the fuel cell. Therefore, the hydrogen that can be received or has been received in the hydrogen tank, or the hydrogen tank itself, can be used as a heat sink, for example, in high-load stages where the energy consumption of the cooling device is high, by operating the aforementioned fan, for example, the cooling system (cooling device) can be mitigated by buffering the heat in the hydrogen tank, especially waste heat, thereby saving energy. In other words, the method according to the present invention makes it possible to discharge heat, especially waste heat, from the cooling device, especially the coolant, in a particularly efficient and effective manner, not only by or solely by the operation of the aforementioned fan, but in particular by the fact that the amount of thermal energy is discharged from the cooling device, especially the coolant, according to the energy curve and supplied to the hydrogen tank, especially the hydrogen received in the hydrogen tank.

[0011] The amount of thermal energy is the thermal energy or heat discharged from the cooling device, particularly the cooling medium, or characterizing them, thereby preventing excessive temperature buildup in the cooling device without activating the fan. In order to discharge the amount of thermal energy (heat) from the cooling device, that amount of thermal energy is supplied to the hydrogen tank, and therefore the hydrogen tank is used, at least temporarily, as a heat buffer or heat sink. In particular, when more heat is supplied to the hydrogen tank, i.e., when more heat is added to the hydrogen tank, the vaporization of hydrogen in the hydrogen tank increases, and the pressure inside the hydrogen tank rises. The pressure inside the hydrogen tank must not rise above a limit value, in particular a predetermined limit value, in particular the tank load limit value, and the pressure inside the hydrogen tank, also called tank pressure, should be reduced before the refueling process, also called the tank process, and / or before particularly long periods of idling or stopping of the vehicle. The method according to the present invention ensures energy savings by selectively setting, in particular by increasing, the tank pressure on the one hand, and by matching the pressure ratio, in particular, before the refueling process and / or shutdown time, thereby enabling particularly advantageous and particularly efficient operation of the fuel cell system and the entire vehicle. The pressure curve and energy curve are also called trajectories, in particular the pressure curve is also called the pressure trajectory and the energy curve is also called the thermal energy trajectory. The amount of thermal energy is, for example, the amount of target thermal energy supplied to the hydrogen tank, i.e., supplied to realize, i.e., cause, the pressure trajectory. In this way, in the method, the pressure trajectory and the associated thermal energy trajectory are determined predictively. Furthermore, the energy consumption of the cooling system is determined and specifically calculated predictively to determine at least one or more time intervals, i.e., stages, in which energy discharge from the cooling system to the hydrogen tank occurs or should occur. Energy discharge is understood to mean that, in particular during each stage, an amount of thermal energy, and therefore heat, is provided by the cooling system and supplied or can be supplied to the hydrogen tank, in order to set, i.e., cause, a predicted pressure curve.Therefore, the present invention can reduce the energy consumption of a fuel cell system compared to conventional solutions, particularly with respect to thermal management, and thereby reduce the overall energy consumption of the vehicle compared to conventional solutions. This allows the vehicle to be operated in a particularly energy-efficient and cost-effective manner. Furthermore, it can at least delay or avoid overloading of the cooling system, which would otherwise lead to the shutdown of components such as the vehicle's drivetrain.

[0012] In an advantageous embodiment of the present invention, in order to enable particularly efficient operation of the fuel cell system and, by extension, the entire vehicle, the pressure curve and energy curve, i.e., the trajectory, are predicted such that in the first operating stage of the cooling system, the predicted energy consumption is greater in the first operating stage than in the second operating stage, and more thermal energy is supplied from the cooling system to the hydrogen tank than in the second operating stage. This allows the hydrogen tank to be used effectively and efficiently as a thermal buffer, at least temporarily, thereby avoiding excessive temperatures in the cooling system without the need to actively cool the cooling system, for example, by a so-called fan. This means, in particular, that the time integral of the energy curve in each first operating stage is greater than the second integral of the energy curve in each second operating stage. That is, the first portion of the amount of thermal energy is greater than the second portion of the amount of thermal energy, the first portion is supplied to the hydrogen tank by the cooling system in each first operating stage, and the second portion is supplied to the hydrogen tank in each second operating stage. In particular, the first portion is greater than zero, and in this case, the second portion is greater than zero or equal to zero.

[0013] It has been shown to be particularly advantageous if no heat energy is transferred from the cooling system to the hydrogen tank during at least one of the second operating phases. On the one hand, this can effectively and efficiently prevent excessive temperatures in the cooling system. On the other hand, it can avoid excessive pressure increases in the hydrogen tank.

[0014] A further embodiment is characterized in that the pressure curve is predicted such that the pressure is always, i.e., continuously, below the maximum pressure, in particular a predetermined maximum pressure, throughout the entire pressure curve. As a result, thermal energy can be effectively and efficiently transferred from the cooling device to the hydrogen tank, while simultaneously avoiding excessive load or damage to the hydrogen tank.

[0015] In order to enable the hydrogen tank to be used particularly effectively and efficiently as a heat buffer, further embodiments of the present invention provide that at least the pressure curve is predicted in accordance with at least one refueling process provided for filling the hydrogen tank and / or in accordance with at least one stop time of the vehicle, during which the vehicle is stopped and not driven by the fuel cell system and not in particular running. In particular, the refueling process and / or stop time are part of a planned route.

[0016] A second aspect of the present invention preferably relates to a commercial vehicle, more particularly a motor vehicle in the form of a heavy cargo vehicle, also called simply a vehicle, which is designed to carry out the method according to the first aspect of the present invention.

[0017] For example, the pressure trajectory and thermal energy trajectory, i.e., the pressure curve and energy curve, are determined, i.e., predicted, so that more heat is discharged from the cooling system to the hydrogen tank, i.e., supplied to the hydrogen tank, during high-load stages when the energy consumption of the cooling system increases. Here, preferably, the maximum pressure limit or the maximum pressure that characterizes it is maintained, i.e., the tank pressure is always below the maximum pressure.

[0018] For example, the pressure trajectory and thermal energy trajectory are determined and particularly predicted to be reduced, especially in the partial load and / or low load stages of the cooling system, for example, in each partial load and / or low load stage, the cooling system has lower energy consumption than in each high load stage, and therefore the heat supply from the cooling system to the hydrogen tank, and thus the supply of thermal energy from the cooling system to or to the hydrogen tank, is reduced, especially compared to each high load stage. That is, it is adjusted or completely stopped, that is, prevented, and this is especially to allow a pressure drop in the hydrogen tank, i.e., a reduction in the pressure in the hydrogen tank, as a result of hydrogen consumption that takes place, for example, while hydrogen is being moved from the hydrogen tank and supplied to the fuel cell, especially compared to each high load stage. For example, the hydrogen consumption along the route and the pressure curve of the pressure in the hydrogen tank, also known as pressure development, are known, and that is, the predictive determination, especially the calculation, of the route, also known as the tour, can be carried out in a predictively planned manner. In other words, for example, the planned route includes, in particular, the predicted consumption of hydrogen from the hydrogen tank by the fuel cell system and / or at least one other further consumption.

[0019] For example, if a refueling process is not planned or known, a possible refueling process can be assumed when the amount of hydrogen in the hydrogen tank, also known as the fill level, falls below a threshold, a predetermined or determinable threshold, and the aforementioned functions for buffering waste heat from the cooling system in the hydrogen tank are restricted, i.e., reduced or mitigated or completely blocked, i.e., deactivated.

[0020] Further advantages, features, and details of the present invention will become apparent from the following description of preferred exemplary embodiments and the drawings. In the description, the features and combinations of features described above, as well as those features and combinations of features described hereinafter and / or shown alone in the figures, can be used not only in the combinations shown in each case but also in other combinations or alone without departing from the scope of the present invention.

Brief Description of the Drawings

[0021] [Figure 1] Preferably, it is a schematic diagram of a fuel cell system of an automobile in the form of a commercial vehicle, particularly a large truck. [Figure 2] It is a flowchart for explaining a method for operating the fuel cell system of the automobile schematically shown in FIG. 2. [Figure 3] It is a partial schematic cross-sectional view of a tank system of a fuel cell system composed of a hydrogen tank.

Embodiments for Carrying Out the Invention

[0022] In the figures, the same or functionally identical elements are given the same reference numerals.

[0023] Regarding the schematic diagram, FIG. 1 shows the fuel cell system 10 of the automobile 12 schematically shown in FIG. 2, and the automobile 12 is in the form of a commercial vehicle, particularly a large truck. Hereinafter, a method for operating the fuel cell system 10 will be described with reference to FIGS. 1 to 3, and by this method, particularly efficient and particularly energy-efficient operation of the fuel cell system 10 and thus the entire automobile 12 can be achieved.

[0024] From Figure 1, it can be seen that the fuel cell system 10 has at least one hydrogen tank 14, which is particularly schematic in Figure 1 and also simply called a tank, and which can receive or receive hydrogen. Viewed together with Figure 3, it can be seen that the hydrogen tank 14 is a component of the tank system 16, also called a tank device, which will be described in detail below. Since the hydrogen is received pressurized into the hydrogen tank 14, there is a pressure in the hydrogen tank 14, also called tank pressure, caused by the hydrogen received into the hydrogen tank 14, and this pressure is, for example, in the range of 6 bar to 15 bar (including the values ​​at both ends), and in particular must be within that range. In particular, the hydrogen tank 14 contains both the liquid and gaseous phases of hydrogen. The fuel cell system 10 also includes at least one fuel cell 18 that can be supplied with hydrogen from the hydrogen tank 14, as indicated by arrow 20 in Figure 1. For this purpose, hydrogen is discharged from the hydrogen tank 14 and supplied to the fuel cell 18, particularly in a gaseous state. The fuel cell 18 can be understood as, for example, a fuel cell stack, or as a component of a fuel cell stack which may have multiple fuel cells 18.

[0025] Waste heat, also simply called heat, is illustrated by arrows 22 and 24 and is discharged or supplied, for example, from the fuel cell 18 during operation. Waste heat, also simply called heat, is discharged, i.e., supplied, from at least one sustained braking device 28 of the vehicle 12, particularly during the operation of the sustained brake 28. The vehicle 12 is braked, for example, by the sustained braking device 28 designed as a retarder, particularly so as not to increase or decrease the speed at which the vehicle 12 travels along the road. For example, the waste heat from the fuel cell 18 and the waste heat from the sustained braking device 28 constitute the total waste heat. For example, as illustrated by arrow 22, a first portion of the total waste heat is discharged to a cooling device 30 of the fuel cell system 10, also called a cooling system, which is particularly schematically shown in Figure 1, in such a way that the first portion of the total waste heat is transferred, for example, via a heat exchanger, to the coolant of the cooling device 30. Thus, the fuel cell 18 and preferably the sustained braking device 28 are also cooled by the cooling device 30. It is shown that a second portion of the total waste heat can be transferred to the hydrogen tank 14 and thus to the hydrogen received in the hydrogen tank 14, particularly via a heating device 32 of the fuel cell system 10, also called a heater, as schematically shown in Figure 1, and as a result, the second portion of the total waste heat is kept away from the cooling device 30, i.e., not discharged by the cooling device 30, as indicated by arrow 24. This allows the heat load on the cooling device 30 to be kept particularly low. The cooling device 30 has a cooling circuit through which a coolant can flow. For example, the cooling device 30 includes an electrically operated fan that can transport air. The air can flow, for example, around a radiator through which the coolant flows. As a result, heat is transferred from the coolant through the radiator to the air transported by the fan that flows around the radiator and can cool the coolant.As illustrated by arrows 22 and 24, not all of the waste heat is discharged to or through the cooling device 30; rather, a second portion of all waste heat is transferred to the hydrogen tank 14 and, for example, buffered by the hydrogen tank 14, so that the excessively long operating time of the fan over the entire period can be kept advantageously low, and as a result, particularly efficient and especially energy-efficient operation of the cooling device 30 and, consequently, the fuel cell system 10 as a whole can be achieved.

[0026] As illustrated by arrow 34 in Figure 1, the transfer of heat, i.e., a second portion of total waste heat, to the hydrogen tank 14 causes vaporization of the liquid hydrogen contained in the hydrogen tank 14, i.e., vaporization of at least a portion of the liquid phase of hydrogen in the hydrogen tank 14, thereby increasing the tank pressure. As will be described in more detail below, the hydrogen tank 14, and in particular the tank system 16, are used to reduce the load on the cooling system 30 by buffering waste heat, i.e., a second portion of total waste heat in the hydrogen tank 14, during high-load stages when the energy consumption of the cooling system 30 is large, thereby saving energy, especially electrical energy. For this purpose, as will be described in more detail below, the energy consumption of the cooling system 30 is predicted according to the planned, for example, predicted driving route of the vehicle 12. Furthermore, the future time-dependent pressure curve of the pressure currently occurring in the hydrogen tank 14, i.e., the tank pressure, is predicted. For example, the pressure curve, also called the energy consumption and pressure trajectory, is predicted, i.e., predictively determined, by an electronic computer, in particular by the vehicle 12. Furthermore, in order to realize the pressure curve, an electronic computer predicts the future temporal energy curve of the amount of thermal energy, also called the energy trajectory or thermal energy trajectory. This amount of thermal energy is supplied, for example, to the hydrogen tank 14 via the cooling device 30 according to the predicted energy consumption, in accordance with the energy curve provided by the cooling device 30, i.e., it is intended to be supplied or should be supplied. Therefore, the amount of thermal energy is heat, i.e., the thermal energy or amount of thermal energy illustrated by arrow 24 in Figure 1, for example. That is, arrow 24 is, for example, the second part of total waste heat, and indicates the amount of thermal energy that can be supplied or is supplied to the hydrogen tank 14 by the cooling device 30, for example, via or by the coolant, according to the predicted energy consumption, in order to realize the pressure curve, in particular while the vehicle 12 is traveling along the planned route, in particular while it is actually traveling.

[0027] In Figure 2, a planning module, also called a logistics plan or designed to execute a logistics plan, is shown schematicly and referenced as 35. For example, the planning module 35 plans, i.e., predictively plans, a route, also called a tour. For example, the planning module 35 is used to determine when, i.e., at what time or over what period of time, the vehicle 12 will travel along a route, also called a stretch; where, i.e., at what point on the route refueling will occur, i.e., the refueling process will be carried out; and when, i.e., at what point the vehicle 12 will be interrupted along the route or where stop times are planned, i.e., carried out. The refueling process, also called a tank process, is the process of filling the hydrogen tank 14 with hydrogen, in particular from the outside of the hydrogen tank 14, in particular from the outside of the vehicle 12 as a whole. Each stop time is a period or time interval during which the vehicle 12 is stopped and therefore not driven by the fuel cell system 10, and as a result, for example, during each stop time, the discharge of hydrogen from the hydrogen tank 14, in particular to the fuel cell 18, is omitted. When planning a route, other parameters that characterize the route or the vehicle 12 along the route are taken into consideration. These parameters include, for example, the planned operation of the vehicle 12's load capacity and / or each of the vehicle 12's consumptions, and for example, a refrigerated body for cooling the vehicle 12's cargo compartment.

[0028] Arrow 36 illustrates that relevant, in particular all relevant tour planning data characterizing the planned route is transmitted to and received by the driving strategy module 38. The driving strategy module 38 determines, and in particular calculates, the driving strategy, in particular the overall driving strategy for the planned route, also called the tour. For example, the driving strategy is determined predictively; that is, the planned driving strategy, which is whether the fuel cell system 10 is driven or driven, in particular when the vehicle 12 is actually driving along the route. This includes, for example, the torque provided by the drive unit to drive the vehicle 12 so that the vehicle 12 can complete the route, and thus drive the vehicle 12 along the route, also called the driving stretch, and also the output of the fuel cell 18, also called fuel cell power, in particular the target trajectory derived from the charge state curve of the associated buffer battery of the vehicle 12. The drive unit consists of, for example, at least one electric engine and can drive the vehicle 12 electrically, in particular purely electrically, to drive the vehicle 12 along the route. The buffer battery is a battery, particularly a secondary battery, in which electrical energy provided or available from, for example, the fuel cell 18 is at least temporarily stored, i.e., buffered. For example, a drive system, particularly an electric engine, can be supplied with the electrical energy provided by the fuel cell 18 and / or the electrical energy stored in the battery, and as a result, the vehicle 12 is electrically driven by the electric engine. The driving strategy considers at least one or more sustained braking systems of the vehicle 12, such as a sustained brake 28. That is, the driving strategy also includes, for example, a strategy for operating the sustained brake 28 along the driving route, the sustained brake 28 generating or being able to generate an additional heat input, particularly to the cooling system 30, as described above.

[0029] Furthermore, pressure and energy curves are predicted. The amount of thermal energy is the target amount of thermal energy that should be supplied to the hydrogen tank 14 in order to produce, i.e., realize, the pressure curve, especially when the vehicle 12 is traveling along the route. By predicting the energy consumption of the cooling system 30, the operating phases, also simply called phases, can be determined, during which energy is released in the hydrogen tank 14 while the vehicle 12 is traveling along the route, and therefore that amount of thermal energy can be supplied to the hydrogen tank 14. In particular, by analyzing the operating time, travel time, and habits regarding normal operating and stopping times, stopping times can be predicted, i.e., forecasted, as needed.

[0030] The determined, and in particular calculated, operating strategy is transmitted to the thermal management module 42, specifically by the operating strategy module 38, and received by the thermal management module 42, as illustrated by arrow 40. For example, the operating strategy module 38 and / or the thermal management module 42 are part of the aforementioned electronic computing device.

[0031] The pressure trajectory and thermal energy trajectory are also simply called trajectories and are target trajectories. The thermal management module 42 is designed to implement the target trajectory; that is, to realize the target trajectory, which is determined in advance, strategically and specifically calculated, and that is, the fuel cell system 10 is operated and specifically controlled or regulated, which implements the target trajectory, i.e., the fuel cell system 10 operates or is operated according to the predicted target trajectory. This is achieved, for example, by the thermal management module 42 controlling an actuator 46, also known as an actuator system or thermal system actuator, of the fuel cell system 10, in particular, as illustrated by arrow 44. The actuator 46 includes, for example, a valve, a pump, and at least one or more fans, such as the aforementioned fan. A sensor 48, also known as a thermal system sensor, is also provided. As illustrated by arrow 50, the sensor 48 can detect, for example, measurement variables such as pressure and / or temperature of the fuel cell system 10 and transmit them to the thermal management module 42, which then starts, i.e., operates, in particular, controls or adjusts the fuel cell system 10, in particular the actuators 46, in accordance with the measurement variables detected by the sensor 48, thereby implementing the target trajectory, i.e., operating the fuel cell system 10 according to the target trajectory. One of the measurement variables is, for example, the aforementioned tank pressure. One of the other measurement variables is, for example, other pressures of the fuel cell system 10. Furthermore, the measurement variables may include at least one or more temperatures of the fuel cell system 10. Each pressure is detected, for example, by its respective pressure sensor. Each temperature is detected, for example, by its respective temperature sensor. For example, the thermal management module 42 adjusts the fuel cell system 10, in particular the actuators 46, to predetermined or identifiable target values, in particular, so that the target trajectory is actually implemented. If predictively calculated target requirements, such as tank pressure and / or coolant temperature, are not met or cannot be met, the predictive operating strategy is re-determined and, in particular, recalculated, as illustrated by arrow 52.This is done particularly by the driving strategy module 38, and can be done particularly based on new state data, which is detected by, for example, the sensor 48 and thus determined by the thermal management module 42, and is transmitted to and received by the driving strategy module 38, in particular as illustrated by the arrow 52. This may be done periodically, for example, based on the current state and measurements of the vehicle 12, in each case. For example, the coolant contains at least water, so the coolant is also called, for example, cooling water.

[0032] For example, as illustrated by arrow 54, the thermal management module 42 can transmit to the operation module 56 at least one or more requirements for heating the hydrogen tank 14 to operate the tank system 16, in particular to adjust or control it, i.e., to supply an amount of thermal energy to the hydrogen tank 14 according to an energy curve, thereby warming, i.e. heating, the hydrogen tank 14. For example, the operation module 56 is a component of an electronic computer. The operation module 56 is called, for example, a tank control module or tank adjustment module. For example, as illustrated by arrow 54, the need for heat discharge from the hydrogen tank 14 is transmitted from the thermal management module 42 to the operation module 56 at a particularly desired time or for a desired period, and is received in particular by the operation module 56. The operation module 56 implements the requirements provided by the thermal management module 42, which are received by the operation module 56, in particular within the range of possibility and / or within the allowable pressure range corresponding to, for example, the aforementioned range of 6 to 15 bar, and reports this implementation to the thermal management module 42, as illustrated by arrow 58. This report includes, for example, the estimated amount of heat discharged from or by the hydrogen tank 14 based on the request, and the tank pressure, in particular the actual pressure caused by the hydrogen contained in the hydrogen tank 14, which is dominant within the hydrogen tank 14. The central, i.e., regulating element for effective control or adjustment is, i.e., to adjust the heat flow within the hydrogen tank 14, i.e., to adjust the amount of thermal energy supplied to the hydrogen tank 14, for example, the valve 60 schematically shown in Figure 2, for example, the pressure valve, in particular, is designed as a pressure control valve or pressure regulating valve, and is activated, for example, by the operating module 56, and therefore operated, in particular, regulated or controlled. For example, the flow or circulation of particularly gaseous hydrogen through the heat exchanger 62 shown in Figure 3 is regulated by the valve 60. The heat exchanger 62 is a component of the tank system 16, which will again be described in more detail below. For example, when the valve 60 is fully open, this allows for the maximum heat flow to the hydrogen tank 14.When valve 60 is closed, the hydrogen tank 14 is no longer heated, for example, which occurs especially under partial load, and thereby the tank pressure decreases again.

[0033] Compared to conventional solutions, the energy consumption of the fuel cell system 10 can be reduced by this method, thereby keeping the overall energy consumption of the vehicle 12 particularly low. Thus, the vehicle 12 can be operated in a particularly cost-effective manner. Furthermore, overloading of the cooling system 30, which would otherwise involve the shutdown of components such as the drive system, can be delayed or completely avoided.

[0034] The cooling device 30 has, for example, a cooling circuit 64 through which a coolant can flow, of which conduit elements 66 and 68 are partially shown in Figure 3. Conduit elements 66 and 68 are through which a coolant can flow. Conduit element 66 can supply a coolant containing heat, such as the second portion of total waste heat, to the heat exchanger 62. For example, a valve 70 located within conduit element 66 can be used to regulate the flow of coolant through conduit element 66, particularly toward the heat exchanger 62. The valve 70 can be controlled by a thermal management module 42, which can regulate, in particular control or adjust, the flow of coolant through conduit element 66 toward the heat exchanger 62 via the valve 70. The coolant can be discharged from the heat exchanger 62 via conduit element 68.

[0035] The hydrogen tank 14 can be ventilated via a vent pipe 72, and the hydrogen tank 14 can be refueled via a tank device 74. A blow-off pipe is referenced at 76, a valve designed as, for example, a tank valve is referenced at 78, and a valve formed as, for example, a safety valve is shown at 80. For example, hydrogen is discharged from the hydrogen tank 14 via a conduit element 82 and supplied to the fuel cell 18 in particular. The operating module 56 can control, for example, valves 78 and 60 and thus operate them, and it can be seen that the operating module 56 can control and operate a heat exchanger 62. The aforementioned temperature sensor is referenced at 84 in Figure 3, and the aforementioned pressure sensor is referenced at 86. The amount of hydrogen received (again) in the hydrogen tank 14 can be detected by a detection means 88, and the amount of hydrogen received in the hydrogen tank 14 is also called the fill level. The detection means 88 can provide at least one, in particular an electrical signal, characterizing the fill level, which can be received by the operating module 56. The operation module 56 can report the detected temperature, detected pressure, and detected fill level to the operation strategy module 38, which can then formulate requirements and specify them to the operation module 56. For example, the tank system 16 can be operated, controlled, or adjusted by the thermal management module 42 and the operation module 56, in particular in accordance with the detected temperature, detected pressure, and detected fill level, in particular so that the target trajectory is actually carried out, i.e., realized.

[0036] As can be seen from Figure 3, the heat contained in the coolant, and therefore the second portion of the total waste heat, is transferred via the heat exchanger 62 to the hydrogen tank 14, particularly to the hydrogen in the hydrogen tank 14, thereby warming, i.e., heating, the hydrogen in the hydrogen tank 14. This allows the hydrogen tank 14 to be used as a heat buffer, at least temporarily, thereby advantageously keeping the energy consumption of the cooling device 30 low. Furthermore, for example, the heat contained in the coolant, i.e., the second portion of the total waste heat, can be transferred via the heat exchanger 62, particularly to the hydrogen flowing through the conduit element 82 in a gaseous state, and the hydrogen is discharged from the hydrogen tank 14, for example, by the conduit element 82, and supplied to the fuel cell 18. As a result, the hydrogen supplied to the fuel cell 18, particularly in gaseous form, can be heated, particularly preheated, along the path toward the fuel cell 18, and as a result, the second portion of the waste heat can be advantageously discharged, particularly without operating the aforementioned fan. [Explanation of Symbols]

[0037] 10 Fuel cell systems 12 Automobiles 14 Hydrogen tanks 16 Tank System 18 Fuel Cell 20 Arrows 22 Arrows 24 Arrows 26 Arrows 28. Sustained braking system 30 Cooling device 32 Heating device 34 Arrows 35 Planning Modules 36 Arrows 38. Driving Strategy Module 40 Arrows 42 Thermal Management Modules 44 Arrows 46 Actuators 48 sensors 50 Arrows 52 Arrows 54 Arrows 56 Operating Module 58 Arrow 60 valves 62 Heat exchanger 64 Cooling circuit 66 Conduit Element 68 Conduit element 70 valves 72 Ventilation pipes 74 Tank equipment 76 Blow-off pipe 78 valves 80 valves 82 Conduit element 84 Temperature Sensor 86 Pressure Sensor 88 Detection means

Claims

1. A method for operating a fuel cell system (10) of an automobile (12), wherein the fuel cell system (10) comprises at least one hydrogen tank (14), at least one fuel cell (18) capable of receiving hydrogen from the hydrogen tank (14), and a cooling device (30) for cooling at least one part of the fuel cell system (10), and in the method, - The energy consumption of the cooling device (30) is predicted according to the planned driving route of the automobile (12). - The future time-dependent pressure curve of the dominant pressure in the hydrogen tank (14) is predicted, and - A method for predicting a future time energy curve of the amount of thermal energy that can be supplied from the cooling device (30) to the hydrogen tank (14) according to an energy curve, in order to realize a pressure curve, in accordance with the predicted energy consumption.

2. The method according to claim 1, characterized in that the pressure curve and the energy curve predict that in the first operating stage of the cooling device (30), the energy consumption in the first operating stage is greater than in the second operating stage of the cooling device (30), and that greater thermal energy is supplied from the cooling device (30) to the hydrogen tank (14) than in the second operating stage.

3. The method according to claim 2, characterized in that, in at least one of the second operating stages, no transfer of thermal energy from the cooling device (30) to the hydrogen tank (14) occurs.

4. The method according to claim 1, characterized in that the pressure curve is predicted to always be less than or equal to the maximum pressure over the entire pressure curve.

5. The method according to claim 1, characterized in that at least the pressure curve is predicted in accordance with at least one refueling process provided for filling the hydrogen tank (14) and / or in accordance with at least one stop time of the vehicle (12).

6. A motor vehicle (12) configured to perform the method described in any one of claims 1 to 5.

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