Computer-implemented method for parameterizing a control of a cryogenic hydrogen dispensing from a cryogenic pressure tank

Abstract

A computer-implemented method is provided for parameterizing a control system for withdrawing cryogenic hydrogen from a cryogenic pressure tank to supply a motor vehicle with hydrogen. The method involves receiving information about a property of the motor vehicle, about its current and / or planned use, and / or about its environment. This is followed by determining the anticipated effect of these conditions on a change in the fill level and / or temperature of the stored hydrogen. Subsequently, the necessary conditioning of the stored hydrogen is defined to prepare for the determined anticipated effect.The procedure further includes providing at least one parameter for controlling the withdrawal of hydrogen from the cryogenic pressure tank, so that the conditioning to be carried out in preparation for the determined anticipated effect is at least partially achieved by the withdrawal according to the control.

Description

[0001] The present invention describes a computer-implemented method and systems for the efficient regulation of the withdrawal of cryogenic hydrogen from a cryogenic pressure tank for the hydrogen supply of a motor vehicle. Furthermore, system-related aspects, including a control device for carrying out the method and a hydrogen storage system, are disclosed.

[0002] Hydrogen (H2) powered motor vehicles, such as those with one or more fuel cells and / or a hydrogen combustion engine as a drive system, have several advantages compared to battery electric vehicles (BEVs) or vehicles powered by fossil fuels.

[0003] One advantage of hydrogen-powered vehicles is their range, which is generally significantly greater than that of battery-powered vehicles and comparable to that of vehicles powered by fossil fuels. For example, trucks powered by liquid (sLH₂) or cryogenically compressed (CcH₂) hydrogen achieve ranges of approximately 1,000 km when fully loaded (40t), while comparable battery-electric models have only demonstrated ranges of up to 500 km (e.g., Daimler Trucks eActros 600).

[0004] Another advantage is the rapid refueling, which takes only a few minutes for hydrogen-powered vehicles, compared to the several hours typically required to charge the batteries of a battery electric vehicle (BEV). For example, the use of CcH2 allows a long-haul truck to be refueled with 80 kg of cryogenically compressed hydrogen for a range of approximately 1000 km in about 10 to 15 minutes. This results in less downtime for the hydrogen-powered vehicle, and refueling can generally be carried out within the legally mandated rest periods for drivers in many countries.

[0005] Refueling with liquid or cryogenically compressed hydrogen can be improved by pre-heating the tank(s) before receiving the cryogenic hydrogen. However, to refuel a tank with liquid hydrogen, the tank must first be cooled to a suitable temperature of -253°C to -259°C to allow the storage of hydrogen in a liquid state. This is currently achieved, for example, by purging the tank with liquid hydrogen or cryogenic hydrogen gas, which results in a loss of the hydrogen that evaporates (if it is vented) or a loss of cooling capacity (if the evaporated hydrogen is re-liquefied). In contrast, cryogenically compressed hydrogen has the advantage of being less sensitive to temperature fluctuations.However, even when refueling a cryogenic pressure tank with CcH₂, an excessively warm tank can lead to a pressure increase, potentially causing the tank's maximum permissible operating pressure to be reached. This necessitates stopping the refueling process before the maximum possible fill level (gravimetrically) of hydrogen under cryogenic conditions is reached. For example, a cryogenic pressure tank for storing CcH₂ with an internal volume of 500,000 cc (0.5 m³) at -235°C (-38 K) and 300 bar pressure can hold approximately 35 kg of H₂, which is nearly three times the amount possible at 20°C and 300 bar pressure (approximately 13.5 kg). The challenges of "warm" refueling of hydrogen-powered vehicles are described in detail, for example, in WO 2008 / 003616 A1.

[0006] When operating a cryogenic pressure tank, it is essential to provide the consumer, such as one or more fuel cells and / or one or more hydrogen combustion engines of a motor vehicle, with a consistently sufficient hydrogen mass flow rate, for example, 2.5 g / s to 5 g / s for the fuel cells of a heavy truck. WO 2009 / 071208 A1 describes exemplary operating procedures for cryogenic pressure tanks. The tank(s) are emptied according to a predefined scheme, pursuing various objectives in addition to supplying the consumer. One aim is to increase the possible service life by rapidly and adiabatically reducing the tank's internal pressure, as this lower pressure increases the amount of heat that the stored hydrogen can absorb.Heat is only added when the tank's internal pressure approaches the two-phase boundary and / or the required mass flow rate cannot be achieved otherwise. This necessitates a high heat input towards the end of the operating cycle, when heat transfer is already severely limited due to the low residual density in the tank.

[0007] WO2016 / 083365 A1 describes a predictive operating procedure for a motor vehicle in which a coolant flow is predictively divided between two consumers, namely a fuel cell and an intercooler.

[0008] WO2017 / 041963A1 describes a method for optimizing the fill level achievable during refilling of a cryogenic pressure tank, in which continuous heating to completely empty the tank towards the end of the driving cycle is dispensed with.

[0009] The objective is to improve a method for parameterizing a control system for the withdrawal of cryogenic hydrogen from a cryogenic pressure tank to supply a motor vehicle with hydrogen, a control device, a hydrogen storage system, a motor vehicle, and a method for controlling the withdrawal of cryogenic hydrogen from a cryogenic pressure tank to supply a motor vehicle with hydrogen, in such a way that the disadvantages inherent in the prior art are at least partially avoided and the prior art is enriched. Optionally, the objective can also be to increase the range of a hydrogen-powered motor vehicle and / or to facilitate the refueling of cryogenic hydrogen into a cryogenic pressure tank.

[0010] The problem is solved by a method for controlling the withdrawal of cryogenic hydrogen from a cryogenic pressure tank, a control unit for controlling the withdrawal of cryogenic hydrogen stored in a cryogenic pressure tank, a hydrogen storage system for storing cryogenic hydrogen, a motor vehicle, and a method for parameterizing a control system for the withdrawal of cryogenic hydrogen from a cryogenic pressure tank. Optional embodiments are specified in the dependent claims and in the description.

[0011] A computer-implemented method is provided for parameterizing a control system for withdrawing cryogenic hydrogen from a cryogenic pressure tank to supply a motor vehicle with hydrogen. The method includes receiving information about a property of the motor vehicle. Additionally or alternatively, the method includes receiving information about the current and / or planned use of the motor vehicle. Additionally or alternatively, the method includes receiving information about the motor vehicle's environment. The method further includes determining the anticipated effect of the motor vehicle's property and / or the current and / or planned use of the motor vehicle and / or the environment on a change in the fill level and / or temperature of the stored hydrogen.The procedure also includes determining the necessary conditioning of the stored hydrogen in preparation for the identified, anticipated effect.

[0012] Furthermore, the method includes providing at least one parameter for controlling the withdrawal of hydrogen from the cryogenic pressure tank such that, by withdrawing the hydrogen from the cryogenic pressure tank according to the control, the conditioning to be carried out in preparation for the determined, anticipated effect of the hydrogen is at least partially carried out.

[0013] Furthermore, a control device for regulating the withdrawal of cryogenic hydrogen from a cryogenic pressure tank for supplying a motor vehicle with hydrogen is provided, wherein the control device is configured to execute a method as disclosed.

[0014] Furthermore, a hydrogen storage system for storing cryogenic hydrogen to supply a motor vehicle with hydrogen is provided. The hydrogen storage system comprises a cryogenic pressure tank, a valve for controlling the withdrawal of hydrogen from the cryogenic pressure tank, and a heat supply element for supplying heat to the hydrogen stored in the cryogenic pressure tank. In addition, the hydrogen storage system includes a control device for regulating changes in the fill level of the hydrogen stored in the cryogenic pressure tank via the valve and / or the temperature of the hydrogen stored in the cryogenic pressure tank via the heat supply element.

[0015] Furthermore, a motor vehicle with one or more hydrogen consumers is provided. The motor vehicle has a control device and / or a hydrogen storage system as disclosed.

[0016] Furthermore, a method for controlling the withdrawal of cryogenic hydrogen from a cryogenic pressure tank for supplying a motor vehicle with hydrogen is provided. The method may include receiving a parameter for use in controlling the withdrawal of the cryogenic hydrogen. This parameter may be provided by a method disclosed. It is also possible for the control of the cryogenic hydrogen withdrawal to be carried out using the received parameter. The method may include repeatedly receiving a parameter for use in controlling the withdrawal of the cryogenic hydrogen. It may also include adjusting the control using the repeatedly received parameter.

[0017] Cryogenic hydrogen is hydrogen at extremely low temperatures. The temperature of cryogenic hydrogen can be 200 K or less. Specifically, the supply of cryogenic hydrogen can include liquid hydrogen and / or gaseous hydrogen under high pressure and / or cryogenically compressed hydrogen (CcH2), gaseous hydrogen under pressure between 1 bar and approximately 500 bar at cryogenic temperatures between 30 K and approximately 200 K.

[0018] A cryogenic pressure tank is a tank designed to store cryogenic or cryogenically compressed hydrogen at a supercritical pressure, allowing the hydrogen to be extracted from the tank in a controlled manner to supply one or more consumers. Further characteristics that a cryogenic pressure tank may possess are described, for example, in WO 2013 / 143773 A1.

[0019] A cryogenic pressure tank can be, in particular, a tank that is suitable and / or designed for storing cryogenically compressed gaseous hydrogen under high pressure. A cryogenic pressure tank can also be referred to as a CcH₂CRYOGAS tank.

[0020] Density and pressure are the values ​​that the stored hydrogen exhibits in its current state, particularly when filled. A predetermined minimum pressure can be the pressure that the extracted hydrogen must have to supply one or more consumers. For supplying a fuel cell with hydrogen, a predetermined minimum pressure in the range of 5 bar to 15 bar may be required. For supplying an internal combustion engine, such as a hydrogen combustion engine, a predetermined minimum pressure in the range of 8 bar to 50 bar may be required. For example, at least one fuel cell and / or at least one internal combustion engine may be connected as consumers, requiring a supply of hydrogen at a system-related minimum pressure for proper operation.This can represent or influence the predetermined minimum pressure. If a pressure drop is expected between the hydrogen outlet from the cryogenic tank and the one or more consumers, the predetermined minimum pressure for the hydrogen stored in the cryogenic tank can depend on the system-related minimum pressure of the consumer(s) and on the expected pressure drop. A drop below the predetermined minimum pressure of the hydrogen stored in the cryogenic tank can therefore result in the consumer(s) not being adequately supplied with hydrogen. This can lead to the consumer no longer being able to operate properly and / or to the consumer being damaged, as described by way of example in the following publication.

[0021] CM Rangel et al.: "Fuel Starvation: Irreversible Degradation Mechanisms in PEM Fuel Cells", WHEC 2010, Essen, Germany, Session Title / No. Electrochemistry of PEM Fuel Cells / FC. 1 (June 4, 2014).

[0022] Regulating the heat input into the cryogenic pressure tank serves to heat the cryogenic hydrogen stored within it in a controlled manner, causing it to expand and thus increasing its pressure. By controlling the heat input, the pressure profile of the stored hydrogen in the cryogenic pressure tank can be influenced. Optionally, a heat exchanger can be incorporated into the cryogenic pressure tank for this purpose, as described, for example, in WO 2013 / 143773 A1.

[0023] A heat supply element can optionally include a heat exchanger or be designed as such. The heat exchanger can be located inside the cryogenic pressure tank to transfer heat from a fluid flowing through the heat exchanger to the hydrogen stored in the cryogenic pressure tank.

[0024] The method for controlling the withdrawal of cryogenic hydrogen can be designed to regulate the withdrawal quantity and / or the withdrawal quantity per unit of time, such as a flow rate of withdrawn hydrogen. For supplying a truck's fuel cell with hydrogen, a mass flow rate of 3 g / s to 5 g / s may be required, depending on the truck's power requirements. For supplying an internal combustion engine, such as a hydrogen combustion engine and / or a turbine, mass flow rates of 10 g / s and more may be required, depending on the vehicle's power requirements. This can be achieved, optionally, by controlling the opening and / or closing of one or more valves through which the hydrogen to be withdrawn from the cryogenic pressure tank can flow.Controlling the withdrawal of cryogenic hydrogen can optionally include controlling the input of heat into the stored hydrogen to bring the temperature and / or pressure of the hydrogen stored in the cryogenic pressure tank within a predetermined range and / or maintain it there. The control system for withdrawing cryogenic hydrogen from the cryogenic pressure tank can thus serve to control the removal of hydrogen from the cryogenic pressure tank or to control the emptying of the cryogenic pressure tank.

[0025] The control system can have several phases. These phases, including the control phase and / or the hydrogen withdrawal phase, can represent different time periods with varying control objectives. The phases can be sequential, occurring immediately one after the other or spaced apart.

[0026] An "essentially adiabatic" withdrawal means that the withdrawal occurs without an actively induced heat exchange between the stored hydrogen and its surroundings. "Essentially adiabatic" is understood to mean that a negligible, and optionally a technically unavoidable, heat exchange can occur, for example, through the input of radiant heat via a vacuum insulation surrounding the storage tank. Essentially adiabatic withdrawal can optionally be achieved by controlling the process during the withdrawal without actively adding heat to the stored hydrogen. This can optionally be accomplished by using a heat input element belonging to the hydrogen storage system, which may optionally include a heat exchanger, to ensure that no heat is introduced into the stored hydrogen during the adiabatic withdrawal.The regulation of the hydrogen withdrawal from the cryogenic pressure tank in the first phase can therefore be carried out in such a way that no active supply of heat is added to the hydrogen stored in the cryogenic pressure tank during the first phase.

[0027] In contrast, during the second phase, in which extraction takes place with the active supply of heat, heat can be supplied to the stored hydrogen by means of a heat supply element belonging to the hydrogen storage system, which may optionally include a heat exchanger, for example to maintain the temperature and / or pressure of the stored hydrogen in a predetermined range and / or to bring it into a predetermined range.

[0028] A switching pressure level can correspond to a pressure value and / or a pressure range, at which point the control system should transition from the first phase to the second phase. In other words, the switching pressure level can represent a pressure threshold at which the control system should switch from the first to the second phase.

[0029] A minimum measurement accuracy for measuring the quantity of hydrogen stored in a cryogenic pressure tank is a limit value that specifies the required measurement accuracy. This quantity measurement can be based on measuring the temperature and pressure of the hydrogen stored in the cryogenic pressure tank, allowing the quantity of stored hydrogen to be determined from the recorded temperature and pressure readings. Temperature measurement, in particular, can be subject to significant errors. Depending on the thermodynamic state of the stored hydrogen and, optionally, on the distance of the hydrogen's thermodynamic state from the two-phase boundary, the resulting measurement error can have varying effects on the measurement error of the quantity measurement.The closer the thermodynamic state of the stored hydrogen is to the two-phase boundary, the greater the potential impact on measurement error and accuracy. Therefore, the specified minimum measurement accuracy can entail boundary conditions for a minimum temperature and / or pressure of the stored hydrogen, such that a derived minimum temperature and / or pressure, and optionally a resulting combination of temperature and pressure, must not be undercut. Determining the switchover pressure level as a function of the minimum measurement accuracy can be achieved by setting the switchover pressure level such that switching at this pressure level prevents the minimum measurement accuracy from being undercut.

[0030] Setting a switching pressure level as the control threshold for a transition from the first to the second phase can include using the switching pressure level as a limit value, upon reaching which the control transitions from the first to the second phase.

[0031] A method for parameterizing the control of cryogenic hydrogen withdrawal from a cryogenic pressure tank is understood as a method for defining one or more parameters for controlling the withdrawal. The parameterization can optionally be performed once before or during the initial commissioning of a cryogenic pressure tank and / or a hydrogen storage system. Alternatively or additionally, the parameterization can be performed at regular or irregular intervals, for example, during each or some filling processes of the cryogenic pressure tank and / or during scheduled and / or unscheduled maintenance work on the cryogenic pressure tank and / or the hydrogen storage system. The method can optionally be implemented as a computer-implemented method, meaning that some or all of the process steps are carried out by a computer and / or a control unit.In the case of execution as a computer-implemented method, the parameterization can be carried out at the beginning of each journey and / or adjusted during the journey based on updated information.

[0032] The control unit may include a processing unit or be designed as such. The processing unit may optionally be a computer and / or a microcontroller. The control unit may include a processor, data storage, and one or more interfaces for communication with external components. Optionally, the control unit may be connected to sensors of the hydrogen storage system and / or the cryogenic pressure tank, optionally to a temperature sensor and / or a pressure sensor.

[0033] A hydrogen storage system can be a system for storing and providing cryogenic hydrogen to supply a consumer with hydrogen, whereby the hydrogen storage system can include a cryogenic pressure tank for storing hydrogen, and optionally a tank for storing hydrogen compressed under high pressure and / or cryogenically compressed hydrogen (CcH2).

[0034] A motor vehicle can be configured as a hydrogen-powered vehicle. The vehicle can have one or more hydrogen consumers, such as one or more hydrogen combustion engines and / or one or more fuel cells. The vehicle can be configured as a commercial vehicle. It can be a passenger car, light truck, van, lorry, coach, agricultural machine, construction machine, locomotive, watercraft (optionally a boat, ship, or underwater vehicle), and / or aircraft (optionally an airplane, helicopter, or multicopter). The vehicle can optionally be configured such that a coolant used to cool the hydrogen combustion engine and / or at least one of the fuel cells is used as the heat transfer fluid.The vehicle can be operated with a manned driver or optionally unmanned / autonomously.

[0035] The fact that a process is computer-implemented means that some or all of the process steps are carried out by a computer.

[0036] The revelation offers the advantage that the extraction of the hydrogen stored in the cryogenic pressure tank can be made particularly efficient.

[0037] This can offer the advantage of reducing the heat input into the stored hydrogen, and / or allowing heat input to occur at higher hydrogen densities, where heat absorption and transfer are more efficient. This may make it possible to design the heat transfer element required for heat input to be smaller, more compact, and / or more cost-effective.

[0038] Furthermore, this technology offers the advantage of increasing the efficiency of refueling the cryogenic tank through preconditioning. For example, the temperature of the hydrogen remaining in the cryogenic tank can be adjusted to a temperature that allows for particularly efficient hydrogen refueling by appropriately controlling the withdrawal process. By maintaining the hydrogen in the cryogenic tank at a particularly low temperature, the need to cool the tank before refueling can be eliminated. Alternatively, this can allow the refueling of warm hydrogen, with the temperature of the warm hydrogen being at least partially compensated for by mixing it with the remaining cold hydrogen.This allows for an optional reduction in the cost of the hydrogen added during refueling, as hydrogen can be more cost-effective at higher temperatures than hydrogen at lower temperatures.

[0039] Furthermore, this offers the advantage of avoiding potentially unnecessary refueling stops, since, due to the knowledge of the next refueling stop, the state of the hydrogen does not need to be conditioned for (almost) complete extraction from the cryogenic pressure tank, for example by excessive heat input.

[0040] Furthermore, the disclosure offers the advantage that, by determining the anticipated impact based on the received information, the state of the stored hydrogen can be proactively and preventively preconditioned to a state that allows for better handling of the anticipated impact than would be possible without parameterization as disclosed, taking the anticipated impact into account. This can offer the advantage of increasing the range with the remaining hydrogen, reducing the required heat input, extending the possible operating time, and / or reducing refueling effort. As a result, the added value of the hydrogen stored in the cryogenic pressure tank and / or the vehicle can be increased, and the vehicle's operating costs can be reduced.

[0041] Furthermore, the disclosure offers the advantage that conventional methods for controlling the withdrawal of cryogenic hydrogen from a cryogenic pressure tank can be combined with a disclosed method. In other words, conventional methods can be improved by the present disclosure through their combination with a disclosed parameterization. This offers the possibility of improving the efficiency of motor vehicles with conventional cryogenic pressure tanks and conventional control systems.

[0042] The information about a characteristic of the motor vehicle may include at least one piece of information about one or more of the following aspects: (i) information about the actual fuel consumption of the motor vehicle; (ii) information about the mass and / or load state of the motor vehicle; (iii) information about the driving dynamics of the motor vehicle; (iv) information about the acceleration profile of the motor vehicle; (v) information about the temperature of the coolant and / or a consumer and / or a battery and / or a brake and / or a retarder and / or a clutch of the motor vehicle, optionally with the hydrogen being preconditioned to absorb waste heat from one or more of these elements for cooling purposes.It is also conceivable that aspect (vi) contains information about the actual and / or anticipated energy consumption of a hydrogen consumer in and / or on the vehicle, such as a refrigerated body of a refrigerated vehicle. Furthermore, (vii) user input stored in the vehicle can be recorded as one of the pieces of information, such as a selected withdrawal and / or performance profile for the vehicle.

[0043] Information regarding the actual and / or planned use of the motor vehicle may include at least one piece of information about one or more of the following aspects. These aspects may include: (i) a planned route, (ii) information about gradients and / or inclines along the planned route, (iii) the road conditions along the planned route, (iv) the traffic flow along the planned route, (v) the proportion of urban, rural, and / or motorway sections along the planned route, (vi) the availability and / or location of hydrogen refueling stations along the planned route, (vii) anticipated waiting times along the planned route, (viii) planned rest periods of a user of the motor vehicle, (ix) planned idle times of the motor vehicle, (x) availability and / or price information of accessible hydrogen refueling stations, and (xi) compatibility information regarding accessible hydrogen refueling stations.

[0044] Information about the environment of the motor vehicle may include at least one piece of information about one or more of the following aspects: (i) weather data, (ii) temperature at the location of the motor vehicle and / or at one or more locations along a planned route, (iii) solar radiation at the location of the motor vehicle and / or at one or more locations along a planned route, (iv) wind or current speed at the location of the motor vehicle and / or at one or more locations along a planned route, (v) humidity at the location of the motor vehicle and / or at one or more locations along a planned route, and (vi) type and / or amount of precipitation at the location of the motor vehicle and / or at one or more locations along a planned route.

[0045] Optionally, data on past journeys of the same or a comparable motor vehicle or simulation data can also be used as information about a property of the motor vehicle, information about an environment of the motor vehicle, or information about an environment of the motor vehicle.

[0046] The information provided can enable predictive parameterization or adjustment of the control system, thereby facilitating improved utilization of the available state dynamics of the stored hydrogen. This allows for the detection of varying requirements for hydrogen withdrawal from the cryogenic pressure tank and / or heat absorption by the stored hydrogen, and enables the state of the stored hydrogen to be at least partially adapted to these requirements through preconditioning.

[0047] The received information can include multiple pieces of information about the vehicle's characteristics, its current and / or planned use, and / or its environment. The anticipated impact can be determined by considering these multiple pieces of information. This determination can also be performed using a weighted approach. This can optimize the accuracy of the anticipation and thus allow for even more precise parameterization of the control system.

[0048] Defining the required conditioning can include specifying a target pressure range and / or temperature range for the stored hydrogen in preparation for an anticipated effect. This allows the stored hydrogen to be conditioned to maximize potential heat input, such as from vehicle idling, particularly high ambient temperatures, and / or the absorption of waste heat from a consumer. Alternatively or additionally, especially when no significant heat input is anticipated, the stored hydrogen can be conditioned to maintain a predetermined minimum distance between the two-phase boundary. This can improve the accuracy of measurements of the amount of hydrogen remaining in the cryogenic pressure tank and / or further reduce the risk of partial or complete liquefaction of the hydrogen.

[0049] Defining the required conditioning can involve adjusting and / or specifying a minimum pressure and / or maximum pressure and / or minimum temperature and / or maximum temperature of the stored hydrogen for control purposes. By setting the minimum pressure and / or minimum temperature, a minimum distance between the hydrogen's state and the two-phase boundary can be achieved. This can reduce the risk of unwanted liquefaction of the stored hydrogen. Furthermore, this can ensure a minimum level of accuracy in the quantity measurement, as technically induced deviations in temperature measurements have a lesser impact on the quantity measurement deviations at a greater distance from the two-phase boundary.By means of the maximum temperature and / or the maximum pressure, the hydrogen stored in the cryogenic pressure tank can be kept in a state range in which the cryogenic pressure tank is protected from excessive mechanical stresses due to the pressure and / or efficient refueling of hydrogen is possible.

[0050] Providing at least one parameter for controlling hydrogen withdrawal from the cryogenic pressure tank can include providing a parameter for controlling heat input into the hydrogen stored in the cryogenic pressure tank. In other words, the provided parameter can be used to control the heat input. This heat input allows for the control of the temperature and pressure of the stored hydrogen. By suspending and / or stopping the heat input, a reduction in pressure and / or temperature can be achieved while the hydrogen is withdrawn continuously. This can be suitable for preconditioning the stored hydrogen.

[0051] Providing a parameter for controlling the heat input can include providing a switching pressure level. It is conceivable that at this switching pressure level, the control transitions from essentially adiabatic extraction to extraction with active heat input into the hydrogen stored in the cryogenic pressure tank, and / or vice versa.

[0052] Providing a parameter for controlling the heat input can include specifying a target temperature. Reaching the target temperature can trigger the control system to switch to an essentially isothermal extraction.

[0053] Depending on requirements, one or more different objectives can be pursued through parameterization and / or the control system itself. These objectives can optionally be considered during parameterization using appropriate weighting functions. Examples of such objectives include an optimized hydrogen mass flow to the consumer, a "safety margin" to the two-phase boundary, mechanical and / or thermal relief of the cryogenic pressure tank, use of the tank as a heat sink to absorb waste heat, a reduction in valve switching cycles to reduce wear and / or noise, and / or efficient planning of refueling processes and / or optimal conditioning of the cryogenic pressure tank for a refueling process, either for the most energy-efficient refueling possible and / or for (gravimetric) maximization of hydrogen uptake.

[0054] The hydrogen storage system can include one or more sensors to measure the pressure and temperature of the hydrogen stored in the cryogenic pressure tank. The sensors can have a communication link with the control unit. Optionally, the control unit can have a communication link with one or more other vehicle control units to receive the information. Optionally, the communication link can conform to a standard commonly used in motor vehicles, such as CAN or LIN. Optionally, the communication links can be wired and / or wireless, for example, via Ethernet, WiFi, Bluetooth, NFC, and / or other common standards.

[0055] The terms "control unit" and "control device" are used synonymously in the context of this disclosure.

[0056] The features and embodiments mentioned above and explained below are not only to be regarded as disclosed in the combinations explicitly mentioned, but are also covered by the disclosure content in other technically meaningful combinations and embodiments.

[0057] Further details and advantages will now be explained in more detail using the following examples and optional embodiments with reference to the figures.

[0058] They show: Fig. 1 A hydrogen storage system according to an optional embodiment; Fig. 2A A method for parameterizing a control system for hydrogen withdrawal from a cryogenic pressure tank according to an optional embodiment; Fig. 2A A method for controlling hydrogen withdrawal from a cryogenic pressure tank according to an optional embodiment; Fig. 3 A motor vehicle according to an optional embodiment. Figs. 4A - 4F State diagrams illustrating various optional control concepts for hydrogen withdrawal from a cryogenic pressure tank.

[0059] For the sake of simplicity, identical or similar elements in the various embodiments are designated with the same reference numerals in the following figures.

[0060] Figure 1Figure 1 shows a hydrogen storage system 12 according to an optional embodiment in a more detailed view. This system includes a cryogenic pressure tank 16, which is shown including optional additional components. The hydrogen storage system can be based on a conventional cryogenic pressure tank 16, as described in WO 2013 / 143773 A1. Cryogenic hydrogen can be stored in the cryogenic pressure tank 16 to supply a consumer 14, for example, an internal combustion engine, which can optionally be configured as a hydrogen combustion engine, and / or a fuel cell of the motor vehicle 300 (see Figure 1). Figure 3), under absolute pressure values ​​of the tank's internal pressure on the order of 150 bar or more, but at least under supercritical pressure at 13 bar and more. This cryogenic pressure tank 16 can have a pressure-resistant inner tank 20, within which the cryogenic hydrogen is in a supercritical state, as well as an insulating layer 22 surrounding the inner tank 20, in which a vacuum can essentially be present, i.e., a pressure less than 1 mbar, and an outer shell 24 enclosing this vacuum. The inner tank 20 can be filled with cryogenic hydrogen in the supercritical state via a combined, and thus single-flow, filling and extraction line 26, and hydrogen can be extracted from the inner tank 20 via this filling / extraction line 26, which leads into a cryogenic valve unit 28. For this purpose, a first or second valve can be connected to the cryogenic valve unit 28.An external heat exchanger 30 is connected, through which, on the one hand, a first heat transfer circuit 32 and, on the other hand, a supply line 34 leading from the cryogenic valve unit 28 and connecting to the filling / extraction line 26, ultimately leads to the aforementioned consumer 14. The supply line 34 can be in heat-transferring contact with the first heat transfer circuit 32 via the heat exchanger 30, so that the hydrogen carried in the supply line 34 is heated in the external first heat exchanger 30.

[0061] Following the external first heat exchanger 30, the supply line 34 can be routed to a second valve unit 36, through which the supply line 34 passes a control valve 38 and a pressure adjustment unit 40 before reaching the consumer 14. A branch line 42 can branch off from the control valve 38, through which hydrogen extracted from the cryogenic pressure tank 16 and heated in the first (external) heat exchanger 30 can be introduced into a second (internal) heat exchanger 44, provided as a heat supply element 18 within the inner tank 20 of the cryogenic pressure tank 16, in order to supply heat to the hydrogen.After flowing through this second heat exchanger 44 located within the cryogenic pressure tank 16, specifically within the inner tank 20, the hydrogen can be introduced via a return line 46 into the supply line 34 downstream of the branch of the branch line 42. This return line 46 first passes through a third (external) heat exchanger 48, which is connected in parallel to the first (external) heat exchanger 30 and supplied by the same heat transfer fluid circuit 32. In this third heat exchanger 48, the hydrogen cooled in the second internal heat exchanger 44 is reheated by heat exchange with the aforementioned heat transfer fluid circuit 32. Thus, the hydrogen conveyed through the branch line 42, the second internal heat exchanger 44, and the return line 46 can serve as a heat transfer medium for heating the hydrogen stored in the cryogenic pressure tank 16.

[0062] The heating process can be controlled by the supply of the aforementioned heat transfer medium or hydrogen to the internal heat exchanger 44, and thus by a suitable switching strategy of the control valve 38. The control of the control valve 38, and therefore the heat supply to the cryogenic pressure tank, can be effected by means of a control unit 21 as disclosed.

[0063] The hydrogen storage system 12 is therefore designed for the storage of cryogenic hydrogen.

[0064] The control unit 21 can be configured to perform a function related to Figure 2A explained procedure and / or one relating to Figure 2B to carry out the explained procedure.

[0065] Figure 2Aschematically shows a computer-implemented method 200 for parameterizing a control system for extracting cryogenic hydrogen from a cryogenic pressure tank 16 to supply a motor vehicle 300 with hydrogen.

[0066] The procedure 200 includes receiving 202 information about a characteristic of the motor vehicle 300 and / or about an ongoing and / or planned use of the motor vehicle 300 and / or about an environment of the motor vehicle 300.

[0067] The procedure further includes determining 204 an anticipated effect of the property of the motor vehicle 300 and / or the taking place and / or planned use of the motor vehicle 300 and / or the environment of the motor vehicle 300 on a change in the fill level and / or on the temperature of the stored hydrogen.

[0068] Furthermore, the procedure 200 includes a determination 206 of a conditioning of the stored hydrogen to be carried out in preparation for the determined, anticipated effect.

[0069] Furthermore, the method 200 includes providing 208 at least one parameter for controlling the withdrawal of hydrogen from the cryogenic pressure tank 16 such that the conditioning to be carried out in preparation for the determined, anticipated effect of the hydrogen is at least partially carried out by withdrawing the hydrogen from the cryogenic pressure tank 16 in accordance with the control.

[0070] The information about a characteristic of the motor vehicle 300 can include at least one piece of information about one or more of the following aspects: an actual consumption of the motor vehicle 300; a mass and / or a load state of the motor vehicle 300; a driving dynamics of the motor vehicle 300; an acceleration profile of the motor vehicle 300; a temperature of the coolant and / or a consumer and / or a battery and / or a brake and / or a retarder and / or a clutch of the motor vehicle 300; an actual and / or anticipated energy consumption of a consumer of hydrogen in and / or on the motor vehicle 300; information about past journeys of the same or a comparable motor vehicle; simulation data and / or artificially aggregated data; and a user input stored in the motor vehicle 300.

[0071] Information regarding the actual and / or planned use of the motor vehicle may include at least one piece of information about one or more of the following aspects: a planned route; gradients and / or inclines along the planned route; road conditions along the planned route; traffic flow along the planned route; the proportion of urban, rural, and / or motorway sections along the planned route; the availability and / or location of hydrogen refueling stations along the planned route; anticipated waiting times along the planned route; planned break times for a vehicle user; planned vehicle idle times; availability and / or price information for accessible hydrogen refueling stations; and compatibility information for accessible hydrogen refueling stations.

[0072] The information about the environment of the motor vehicle 300 can include at least one piece of information about one or more of the following aspects: Weather data; a temperature at the location of the vehicle and / or at one or more locations along a planned route; solar radiation at the location of the vehicle and / or at one or more locations along a planned route; humidity at the location of the vehicle and / or at one or more locations along a planned route; wind or current speed at the location of the vehicle and / or at one or more locations along a planned route; and precipitation type and / or amount at the location of the vehicle and / or at one or more locations along a planned route.

[0073] The received information may contain multiple pieces of information about the characteristics of the motor vehicle 300 and / or the current and / or planned use of the motor vehicle 300 and / or the environment of the motor vehicle 300. Determining the anticipated impact 204 can be done taking the multiple pieces of information into account. Determining the anticipated impact 204 can be done by weighting the multiple pieces of information.

[0074] Specifying the conditioning to be performed (206) may include defining a target pressure range and / or temperature range for the stored hydrogen in preparation for the anticipated effect. Alternatively or additionally, specifying the conditioning to be performed (206) may include adjusting and / or specifying a minimum pressure and / or maximum pressure and / or minimum temperature and / or maximum temperature of the stored hydrogen for control purposes.

[0075] The provision of at least one parameter for controlling the withdrawal of hydrogen from the cryogenic pressure tank 16 may include providing a parameter for controlling a heat input into the hydrogen stored in the cryogenic pressure tank 16.

[0076] Providing a parameter for heat input control can include providing a switching pressure level at which the control transitions from essentially adiabatic extraction to extraction with active heat input into the hydrogen stored in the cryogenic pressure tank and / or vice versa. Providing a parameter for heat input control can also include providing a target temperature at which the control transitions to essentially isothermal extraction.

[0077] Figure 2B Figure 220 shows an example of a method for controlling the extraction of cryogenic hydrogen from a cryogenic pressure tank 16 for supplying a motor vehicle 300 with hydrogen.

[0078] Method 220 comprises receiving 222 a parameter for use in controlling the withdrawal of cryogenic hydrogen, wherein the parameter is obtained by means of a method 200 according to Figure 2Ais provided.

[0079] The procedure 220 further includes a rule 224 for the extraction of cryogenic hydrogen using the received parameter.

[0080] The method 220 may further include repeatedly receiving 222 a parameter for use in controlling the withdrawal of cryogenic hydrogen, and adjusting 226 the control using the repeatedly received parameter.

[0081] Figure 3 Figure 1 schematically shows a motor vehicle 300 according to an optional embodiment. The motor vehicle has one or more hydrogen consumers 14, as well as a control device 21 and / or a hydrogen storage system according to Figure 21. Figure 1 .

[0082] The following Figures 4A to 4F show, using state diagrams, optional, exemplary embodiments of a control system for the extraction of cryogenic hydrogen from a cryogenic pressure tank 16.

[0083] The phase diagrams show the temperature of the hydrogen stored in cryogenic pressure tank 16 in Kelvin on the horizontal axis. The vertical axis shows the density of the hydrogen stored in cryogenic pressure tank 16 in kg / m³. The solid line marks the two-phase boundary 302. In the region to the left of the two-phase boundary, i.e., at lower temperatures than the two-phase boundary, at least partial liquefaction of the hydrogen occurs in cryogenic pressure tank 16, as indicated by the designation LH₂. Since reliable measurement of the remaining hydrogen quantity and reliable withdrawal of the hydrogen cannot be ensured in this case, this thermodynamic region must be avoided.

[0084] The dashed lines in Figure 4AIsobars 304 to 301 indicate pressures of 100 bar (304), 50 bar (306), 25 bar (308), and 15 bar (310). As can be seen, the isobaric lines for 15 bar and 25 bar, especially for densities of 20 kg / m³ or higher, run very close to the two-phase boundary. Therefore, a further decrease in temperature and / or pressure can lead to the hydrogen falling below the two-phase boundary and thus to at least partial liquefaction of the stored hydrogen. In particular, in such regions where the hydrogen is in a state close to the two-phase boundary, even small measurement errors in temperature measurement can have such an effect that they lead to an unintentional crossing of the two-phase boundary and to undesirable liquefaction of the hydrogen in the cryogenic pressure tank. The same applies to the other figures, in which the reference symbols have been omitted for the sake of clarity.

[0085] Figure 4AFigure 402 illustrates a control concept for an uneventful journey, optimized for reducing the number of valve switching cycles while maintaining a safe distance to the two-phase boundary 302, reducing thermal and mechanical stress on the cryogenic pressure tank 16, and ensuring a low temperature for refueling the cryogenic pressure tank 16. The state trajectory 402 exhibits alternating phases in which hydrogen is extracted essentially adiabatic without active heat input into the stored hydrogen, or in which extraction occurs with active heat input. This allows, on the one hand, a predetermined distance between the state of the hydrogen and the two-phase boundary to be maintained, and on the other hand, a temperature of the stored hydrogen and / or the cryogenic pressure tank to be maintained within a predetermined temperature range, for example, from 55 K to 75 K.

[0086] The switching pressure levels at which the process switches from essentially adiabatic withdrawal to withdrawal under active heat input, and / or the temperatures at which the process switches from withdrawal under active heat input to essentially adiabatic withdrawal, can be determined and provided as parameters for controlling the withdrawal of hydrogen from the cryogenic pressure tank according to a disclosed method.

[0087] Figure 4B Figure 403 illustrates an exemplary state trajectory in the application of a control concept according to another optional embodiment for an eventless journey as described in Figure 4A as described embodiment, in this case with a larger number of valve switching cycles but with reduced cyclic thermal stress on the cryogenic pressure tank due to a lower amplitude of the thermal fluctuations in the cryogenic pressure tank 16.

[0088] Figure 4C Figure 404 illustrates an exemplary state trajectory when applying a control concept according to another optional embodiment for an eventless journey as described in Figure 4A The described embodiment is for a case in which no refueling is planned immediately afterwards. In this case, the temperature of the stored hydrogen can drop further to tolerate a higher heat input during a subsequent idle period.

[0089] Figure 4D Figure 406 illustrates an exemplary state trajectory when applying a control concept according to another optional embodiment for a journey with a longer, anticipated idle time, during which a significant heat input 450 is anticipated. The state can be preconditioned by lowering the temperature of the stored hydrogen and adjusting the control accordingly in order to be able to absorb a larger amount of heat.

[0090] Figure 4E Figure 408 illustrates an exemplary state trajectory when applying a control concept according to another optional embodiment for a journey with a planned load section with increased consumption 452. For the load section with increased consumption, the preconditioning can provide for a temperature increase of the stored hydrogen to ensure an increased withdrawal rate of hydrogen from the cryogenic pressure tank. Subsequently, an extended adiabatic withdrawal can be provided to reduce the temperature of the remaining hydrogen and the cryogenic pressure tank again and to precondition it for possible hydrogen refueling.

[0091] During communication between the vehicle and a hydrogen refueling station operator, a refueling time can optionally be reserved, specifying defined pressure and temperature conditions for the hydrogen to be delivered. During this communication, a price for the upcoming refueling can optionally be negotiated; optionally, "warmer" hydrogen, which is not fully chilled, can be offered at a lower price, as this requires less energy for the station operator to provide, and the optional elimination of waiting time improves the station's utilization. Furthermore, during this communication, the vehicle can optionally select from a large number of stations the one that is best suited, based on its geographical location and / or the anticipated status of the station and / or the cryogenic pressure tank of the vehicle to be refueled.Various goals can be pursued in such a selection process, such as the shortest route, the least possible time loss, optimization of the amount of hydrogen to be refueled and / or the energy requirement of the refueling process, which in turn are taken into account by a corresponding weighting function.

[0092] Figure 4FFigure 1102 shows an exemplary state trajectory of a withdrawal process, in which section 1104 involves the planned addition of warm hydrogen to the cryogenic pressure tank at a pressure of 350 bar. The withdrawal process is controlled such that the initial adiabatic withdrawal is carried out up to a switchover pressure level very close to the two-phase boundary, approximately up to a pressure of 15 bar, and then a substantially isobaric withdrawal takes place until the addition of warm hydrogen. After the addition of warm hydrogen, another adiabatic withdrawal occurs. Despite the warm hydrogen, the tank is ideally preconditioned at the destination for refilling with CRYOGAS. Reference symbol list

[0093] 12 Hydrogen storage system 14 Consumer 16 Cryogenic pressure tank 18 Heat input element 20 Inner tank 21 Control unit 22 Insulation layer 24 Outer casing 26 Extraction line 28 Cryogenic valve unit 30 Heat exchanger 32 Heat transfer fluid circuit 34 Supply line 36 Second valve unit 38 Control valve 40 Pressure adjustment unit 42 Branch line 44 Heat exchanger 46 Return line 48 Heat exchanger 200 Method for parameterizing a control system for the withdrawal of cryogenic hydrogen from a cryogenic pressure tank for supplying a motor vehicle with hydrogen 202 - 208 Method steps 220 Method for controlling the withdrawal of cryogenic hydrogen from a cryogenic pressure tank for supplying a motor vehicle with hydrogen 222 - 226 Method steps 300 Motor vehicle 302 Two-phase boundary 304 - 310 Isobar lines 402 - 408 State trajectories for different control concepts 450 Heat input due to idle time 452 Phase with increased load 1102 State trajectory 1104 Refueling

Claims

1. Computer-implemented method (200) for parameterizing a control system for the extraction of cryogenic hydrogen from a cryogenic pressure tank (16) for supplying a motor vehicle (300) with hydrogen, characterized by the fact thatThe procedure (200) comprises: - receiving (202) information about a characteristic of the motor vehicle (300) and / or about an ongoing and / or planned use of the motor vehicle (300) and / or about an environment of the motor vehicle (300); - determining (204) an anticipated effect of the characteristic of the motor vehicle (300) and / or the ongoing and / or planned use of the motor vehicle (300) and / or the environment of the motor vehicle (300) on a change in the level and / or temperature of the stored hydrogen; - determining (206) a conditioning of the stored hydrogen to be carried out in preparation for the determined, anticipated effect;and - providing (208) at least one parameter for controlling the withdrawal of hydrogen from the cryogenic pressure tank (16) such that, by withdrawing hydrogen from the cryogenic pressure tank (16) according to the control, the conditioning to be carried out in preparation for the determined, anticipated effect of the hydrogen is at least partially carried out.; 2. Method (200) according to claim 1, wherein the information about a property of the motor vehicle (300) comprises at least information about one or more of the following aspects: - an actual fuel consumption of the motor vehicle (300); - a mass and / or a load state of the motor vehicle (300); - a driving dynamics of the motor vehicle (300); - an acceleration profile of the motor vehicle (300); - a temperature of the coolant and / or a consumer and / or a battery and / or a brake and / or a retarder and / or a clutch of the motor vehicle (300); - an actual and / or anticipated energy consumption of a hydrogen consumer in and / or on the motor vehicle (300); information about past journeys of the same or a comparable motor vehicle (300); simulation data and / or artificially aggregated data and - a user input stored in the motor vehicle (300).

3. Method (200) according to claim 1 or 2, wherein the information about an ongoing and / or planned use of the motor vehicle (300) comprises at least information about one or more of the following aspects: - a planned route; - gradients and / or inclines in the planned route; - road conditions of the planned route; - traffic flow in the planned route; - proportion of urban, rural and / or motorway sections in the planned route; - availability and / or location of hydrogen refueling stations along the planned route; - anticipated waiting times in the planned route; - planned break times of a user of the motor vehicle; - planned idle times of the motor vehicle; - availability information and / or price information of accessible hydrogen refueling stations; and - compatibility information about accessible hydrogen refueling stations.

4. Method (200) according to any one of the preceding claims, wherein the information about the environment of the motor vehicle (300) comprises at least information about one or more of the following aspects: - weather data; - a temperature at the location of the motor vehicle (300) and / or at one or more locations along a planned route; - solar radiation at the location of the motor vehicle (300) and / or at one or more locations along a planned route; - humidity at the location of the motor vehicle (300) and / or at one or more locations along a planned route; - wind or current speed at the location of the motor vehicle (300) and / or at one or more locations along a planned route; and - a type and / or amount of precipitation at the location of the motor vehicle (300) and / or at one or more locations along a planned route.

5. Method (200) according to one of the preceding claims, wherein the received information includes several pieces of information about the characteristics of the motor vehicle (300) and / or the actual and / or planned use of the motor vehicle (300) and / or the environment of the motor vehicle (300), and wherein the determination of the anticipated effect is carried out taking into account the several pieces of information.

6. Method (200) according to claim 5, wherein the determination (204) of the anticipated effect is carried out taking into account the multiple pieces of information in a weighted manner.

7. Method (200) according to one of the preceding claims, wherein determining (206) the conditioning to be carried out comprises determining a pressure range and / or a temperature range to be achieved of the stored hydrogen in preparation for the anticipated effect.

8. Method (200) according to one of the preceding claims, wherein determining (206) the conditioning to be carried out comprises adjusting and / or specifying a minimum pressure and / or a maximum pressure and / or a minimum temperature and / or a maximum temperature of the stored hydrogen for control purposes.

9. Method (200) according to one of the preceding claims, wherein providing (208) the at least one parameter for controlling the withdrawal of hydrogen from the cryogenic pressure tank (16) comprises providing a parameter for controlling a heat input into the hydrogen stored in the cryogenic pressure tank.

10. Method (200) according to claim 9, wherein providing (208) a parameter for controlling the heat supply comprises providing a switching pressure level in which the control transitions from a substantially adiabatic withdrawal to a withdrawal with active heat supply to the hydrogen stored in the cryogenic pressure tank and / or vice versa.

11. Method (200) according to claim 9 or 10, wherein providing (208) a parameter for controlling the heat input includes providing a target temperature at which the control transitions to a substantially isothermal extraction.

12. Control device (21) for regulating the withdrawal of cryogenic hydrogen from a cryogenic pressure tank (16) for supplying a motor vehicle with hydrogen, wherein the control device is configured to carry out the method (200) according to one of the preceding claims.

13. Hydrogen storage system (12) for storing cryogenic hydrogen for supplying a motor vehicle with hydrogen, the hydrogen storage system comprising: - a cryogenic pressure tank (16); - a valve (38) for controlling the withdrawal of hydrogen from the cryogenic pressure tank; - a heat supply element (18) for supplying heat to the hydrogen stored in the cryogenic pressure tank (16); and - a control device (21) for controlling a change in the fill level of the hydrogen stored in the cryogenic pressure tank (16) by means of the valve and / or a temperature of the hydrogen stored in the cryogenic pressure tank (16) by means of the heat supply element.

14. Motor vehicle (300) with one or more consumers (14) of hydrogen, characterized by the fact that the motor vehicle (300) comprises a control device (21) according to claim 12 and / or a hydrogen storage system according to claim 13.

15. Method (220) for controlling the withdrawal of cryogenic hydrogen from a cryogenic pressure tank (16) for supplying a motor vehicle (300) with hydrogen, the method comprising: - receiving (222) a parameter for use in controlling the withdrawal of the cryogenic hydrogen, wherein the parameter is provided by means of a method (200) according to any one of claims 1 to 11; - controlling (224) the withdrawal of the cryogenic hydrogen using the received parameter.

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