DE102016223253A1 - Method, controller and system for providing hydrogen for refueling a vehicle - Google Patents

Abstract

The invention relates to a method for providing hydrogen for refueling a vehicle (190). The method includes a step of heating hydrogen stored in at least a partially liquid state to produce gaseous hydrogen at a first pressure. Also, the method includes a step of relaxing the gaseous hydrogen from the first pressure to a second pressure, wherein the gaseous hydrogen is passed through an electrochemical device (110). The electrochemical device (110) comprises a proton conductive membrane unit (112) having a first side and a second side, a first electrode (114) applied to the first side of the membrane unit (112), and a second side of the membrane unit (112) second electrode (116) and at least one with the first electrode (114) and the second electrode (116) electrically connectable or connected electrical memory (120) and / or consumers (120). The first pressure is higher than the second pressure. The gaseous hydrogen at the first pressure is applied to the first side of the membrane unit (112). The gaseous hydrogen at the second pressure is applied to the second side of the membrane unit (112). The method further includes a step of collecting the gaseous hydrogen at the second pressure for refueling the vehicle (190).

Description

State of the art

The invention is based on a device or a method according to the preamble of the independent claims. The subject of the present invention is also a computer program.

Vehicles powered by hydrogen, in particular vehicles with a fuel cell, can usually be refueled with gaseous hydrogen at filling stations provided for this purpose.

Disclosure of the invention

Against this background, with the approach presented here, a method, furthermore a control unit which uses this method, a system, a use and finally a corresponding computer program according to the main claims are presented. The measures listed in the dependent claims advantageous refinements and improvements of the independent claim device are possible.

According to embodiments, energy recovery or energy conversion can be carried out in particular with regard to a hydrogen infrastructure provided for refueling vehicles during the evaporation of liquid hydrogen for the refueling operation. In this case, in particular a proton-conductive membrane can be used to use a differential pressure between two containers filled with hydrogen or between two sides of the membrane for energy.

Advantageously, according to embodiments, for example, a so-called well-to-wheel balance or balance from well to wheel can be improved in terms of hydrogen mobility. In a well-to-wheel balance, for example, a CO ₂ emission of a vehicle can be reduced by about 15 to 20 percent, for example. For this purpose, in particular, energy which has been used for liquefying the hydrogen, can be recovered on evaporation of the hydrogen at a filling station or the like and made available in the form of electric current. A used for this purpose, the proton conductive membrane having electrochemical device can do without moving parts, be maintenance-free and DC directly and without electromechanical components, such as a generator or the like produce. Due to the avoidance of mechanically moving parts, for example, a maintenance effort can be reduced or minimized. In particular, it is also possible to provide a low-noise or noiseless device in a sensitive environment. The elimination of mechanically moving parts in an electrochemical device having the proton-conductive membrane also induces the elimination of lubricants, as would occur in mechanical expansion units. Thus, contamination of the hydrogen with lubricants can be prevented and a required purity of hydrogen for vehicles can be reliably maintained.

A method for providing hydrogen for refueling a vehicle is presented, wherein the method has at least the following steps:

Heating hydrogen stored in at least a partially liquid state to produce gaseous hydrogen at a first pressure;

Relaxing the gaseous hydrogen from the first pressure to a second pressure, wherein the gaseous hydrogen is passed through an electrochemical device, the electrochemical device comprising a proton conductive membrane unit having a first side and a second side, a first electrode applied to the first side of the membrane unit , a second electrode applied to the second side of the membrane unit and at least one electrical memory electrically connectable or connected to the first electrode and the second electrode and additionally or alternatively having consumers, the first pressure being higher than the second pressure, the gaseous hydrogen with the first pressure applied to the first side of the membrane unit, the gaseous hydrogen with the second pressure being applied to the second side of the membrane unit; and

Collecting the gaseous hydrogen at the second pressure for an output to refuel the vehicle.

This method can be implemented, for example, in software or hardware or in a mixed form of software and hardware, for example in a control unit. In the step of heating, energy may be applied to a device for heating. In the step of relaxing, a flow of hydrogen through the electrochemical device may be effected or enabled. In the step of relaxing and additionally or alternatively in the collecting step, at least one valve or the like can be controlled to control a flow of hydrogen. The membrane unit may have at least one membrane which is permeable to protons. The electrical storage and / or consumer may represent an electrical resistance electrically connected between the first electrode and the second electrode. Optionally, the electrochemical device may comprise the membrane unit, the first electrode and the second electrode, wherein the electrical memory and / or consumer may be provided as a separate or separate unit from the electrochemical device.

In one embodiment, in the step of relaxing using the electrochemical device, compression energy may be converted to electrical energy. Such an embodiment offers the advantage that usable energy can be provided by utilizing a pressure difference between the first side and the second side of the membrane unit.

Also, in the step of heating, the hydrogen may be heated to a temperature of at least 0 degrees Celsius. Such an embodiment offers the advantage that icing of the membrane unit is prevented and thus reliable energy conversion can be achieved.

The approach presented here also creates a control unit which is designed to execute, to control or to implement the steps of a variant of a method presented here in corresponding devices. Also by this embodiment of the invention in the form of a control device, the object underlying the invention can be achieved quickly and efficiently.

For this purpose, the control unit can have at least one arithmetic unit for processing signals or data, at least one memory unit for storing signals or data, at least one interface to a sensor or an actuator for reading sensor signals from the sensor or for outputting control signals to the actuator and / or or at least a communication interface for reading or outputting data embedded in a communication protocol. The arithmetic unit may be, for example, a signal processor, a microcontroller or the like, wherein the memory unit may be a flash memory, an EEPROM or a magnetic memory unit. The communication interface can be designed to read or output data wirelessly and / or by line, wherein a communication interface that can read or output line-bound data, for example, electrically or optically read this data from a corresponding data transmission line or output in a corresponding data transmission line.

In the present case, a control device can be understood as meaning an electrical device which processes sensor signals and outputs control and / or data signals in dependence thereon. The control unit may have an interface, which may be formed in hardware and / or software. In the case of a hardware-based embodiment, the interfaces can be part of a so-called system ASIC, for example, which contains various functions of the control unit. However, it is also possible that the interfaces are their own integrated circuits or at least partially consist of discrete components. In a software training, the interfaces may be software modules that are present, for example, on a microcontroller in addition to other software modules.

In an advantageous embodiment, the control device is used to control the provision of hydrogen for refueling a vehicle. For this purpose, the control unit can access, for example, sensor signals such as temperature signals and pressure signals. The control takes place via actuators such as heating elements and valves or the like.

• eine Ausführungsform des vorstehend genannten Steuergeräts;
• die elektrochemische Vorrichtung;
• eine erste Schnittstelle zu mindestens einem Speicherbehälter für Wasserstoff in zumindest teilweise flüssigem Zustand;
• mindestens eine Vorrichtung zum Erwärmen des Wasserstoffs in dem mindestens einen Speicherbehälter und zusätzlich oder alternativ zwischen dem mindestens einen Speicherbehälter und der elektrochemischen Vorrichtung; und
• eine zweite Schnittstelle zu mindestens einem Sammelbehälter für den gasförmigen Wasserstoff mit dem zweiten Druck,
• wobei die elektrochemische Vorrichtung fluidisch zwischen die erste Schnittstelle und die zweite Schnittstelle geschaltet ist, wobei das Steuergerät
• signalübertragungsfähig zumindest mit der mindestens einen Vorrichtung zum Erwärmen verbindbar oder verbunden ist.

A system for providing hydrogen for fueling a vehicle is also presented, the system having at least the following features:

• an embodiment of the aforementioned control device;
• the electrochemical device;
• a first interface to at least one storage tank for hydrogen in at least partially liquid state;
• at least one device for heating the hydrogen in the at least one storage container and additionally or alternatively between the at least one storage container and the electrochemical device; and
• a second interface to at least one gaseous hydrogen sump having the second pressure,
• wherein the electrochemical device is fluidically connected between the first interface and the second interface, wherein the control device
• signal transmission capability is connectable or connected at least with the at least one device for heating.

In connection with the system, an embodiment of the aforementioned controller may be advantageously used or used to effect or control the provision of hydrogen for refueling a vehicle.

According to one embodiment, the at least one electrical storage and additionally or alternatively consumers can have a galvanic cell, an electrical capacitor or an electrical voltage converter. Such an embodiment offers the advantage that, depending on the specific application, the electrical energy converted from the compression energy can be used in a suitable manner or made available for use.

Furthermore, the membrane unit of the electrochemical device may comprise a catalyst. In this case, a catalyst material may be applied to at least one proton-permeable membrane of the membrane unit. Such an embodiment offers the advantage that a splitting and recombination of the hydrogen can be facilitated and accelerated.

There is also a use of an electrochemical device comprising a proton conductive membrane unit having a first side and a second side, a first electrode applied to the first side of the membrane unit, a second electrode applied to the second side of the membrane unit and at least one to the first electrode and the second electrode comprises electrically connectable or connected electrical storage and additionally or alternatively consumers, for expanding vaporized gaseous hydrogen upon providing hydrogen for fueling a vehicle, wherein compression energy is converted to electrical energy.

Also of advantage is a computer program product or computer program with program code which can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and for carrying out, implementing and / or controlling the steps of the method according to one of the embodiments described above is used, especially when the program product or program is executed on a computer or a device.

• 1 eine schematische Darstellung eines Systems zum Bereitstellen von Wasserstoff gemäß einem Ausführungsbeispiel für einen Betankungsvorgang eines Fahrzeugs;
• 2 ein Ablaufdiagramm eines Verfahrens zum Bereitstellen gemäß einem Ausführungsbeispiel;
• 3 eine schematische Darstellung einer elektrochemischen Vorrichtung gemäß einem Ausführungsbeispiel; und
• 4 eine schematische Darstellung eines Systems zum Bereitstellen von Wasserstoff gemäß einem Ausführungsbeispiel.

Embodiments of the approach presented here are shown in the drawings and explained in more detail in the following description. It shows:

• 1 a schematic representation of a system for providing hydrogen according to an embodiment for a refueling operation of a vehicle;
• 2 a flowchart of a method for providing according to an embodiment;
• 3 a schematic representation of an electrochemical device according to an embodiment; and
• 4 a schematic representation of a system for providing hydrogen according to an embodiment.

Before embodiments of the invention are described below with reference to the figures, first a brief discussion of the background and principles of exemplary embodiments will be given.

Hydrogen is for many industries, eg. For example, the mineral oil industry or the chemical industry, an established chemical commodity in large quantities, for example, more than 500 billion Nm ³ / a. For example, the hydrogen used is often produced on site by means of steam reforming from fossil natural gas in large-scale plants. For the emerging mobility based on PEM fuel cells (PEM = Proton exchange membrane; Proton exchange membrane) in particular a hydrogen infrastructure is necessary. This induces the transport of hydrogen to gas stations. Are already available, for example truck transports with pressure tanks for up to 880bar or cryogenic hydrogen at about -253 ° C.-pressure tank, due to the low density of hydrogen (8.9 g / Nm ³⁾ both way only small gravimetric transport volumes per truck Charge condition. For this reason, the industry in hydrogen logistics prefers, for example, liquid hydrogen with a gravimetric energy density of 71 kg / m ³ . Cryogenic hydrogen is energy-intensive in production, up to 30% of its calorific value. Cryogenic hydrogen is usually vaporized prior to filling in the tank of a vehicle by supplying heat and preheated to, for example, about minus 40 degrees Celsius. The evaporation of the cryogenic hydrogen results in a natural pressure increase, which is the basis for the pressure-sensitive storage technology (eg, 700 bar) in the vehicle. The amount of energy used to liquefy hydrogen can affect a so-called well-to-wheel CO ₂ (fuel-to-wheel balance) record of fuel cell vehicles. Known technologies for energy conversion are, for example, displacement machines or thermal turbomachines. These would have to be designed for operation under a hydrogen atmosphere in order to be able to withstand hydrogen corrosion. The technologies mentioned generate maintenance and are noisy. Furthermore, they are optimized for a single operating pressure.

In the following description of favorable embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and similar acting, with a repeated description of these elements is omitted.

1 shows a schematic representation of a system 100 for providing hydrogen according to an embodiment for a refueling operation of a vehicle 190 , The system 100 is designed to provide hydrogen for refueling at least the vehicle 190 provide. The system 100 For example, it is implemented as part of a hydrogen refueling station for vehicles 190. In the vehicle 190 For example, it is a fuel cell vehicle. In other words, the vehicle points 190 a fuel cell.

The system 100 has an electrochemical device 110 on. The electrochemical device 110 has a proton conductive membrane unit 112 having a first side and a second side, one on the first side of the membrane unit 112 applied first electrode 114 and one on the second side of the membrane unit 112 applied second electrode 116 on. Here is the membrane unit 112 between the first electrode 114 and the second electrode 116 arranged. According to one embodiment, the proton conductive membrane unit 112 the electrochemical device 110 have a catalyst or be coated with a catalyst material.

According to one embodiment, the electrochemical device 110 also at least one electrical storage 120 and / or consumers 120 on. According to the in 1 illustrated embodiment is an electrical memory 120 and / or electrical consumers 120 with the first electrode 114 and the second electrode 116 electrically connected. Here is the electrical storage 120 and / or electrical consumers 120 separate or separate from the electrochemical device 110 intended. Thus, the electric storage 120 and / or electrical consumers 120 depending on the embodiment, a part of the electrochemical device 110 or from the electrochemical device 110 be separated. The electrical storage 120 and / or consumers 120 has in particular a galvanic cell, an electrical capacitor or an electrical voltage converter.

The system 100 also has a first interface 130 , a second interface 140 and at least one heating device 150 or device 150 to warm up. The first interface 130 is adapted to a fluidic connection between the electrochemical device 110 or the first side of the proton-conductive membrane unit 112 and at least one storage container 170 manufacture. According to the in 1 The exemplary embodiment shown is merely a storage container by way of example 170 intended. The storage tank 170 is by means of the first interface 130 fluidically with the electrochemical device 110 connected. The storage tank 170 is configured to store hydrogen in at least partially liquid state.

According to the in 1 illustrated embodiment, the system 100 by way of example only a heating device 150 on. The heater 150 is designed to store the hydrogen in the storage tank 170 and / or between the storage container 170 and the electrochemical device 110 to heat to produce gaseous hydrogen at a first pressure.

The second interface 140 is adapted to a fluidic connection between the electrochemical device 110 or the second side of the proton-conductive membrane unit 112 and at least one collecting container 180 manufacture. Thus, the electrochemical device 110 is fluidic between the first interface 130 and the second interface 140 connected. According to the in 1 The exemplary embodiment shown is merely a collecting container by way of example 180 intended. The collection container 180 is via the second interface 140 fluidically with the electrochemical device 110 connected. The collection container 180 is adapted to hydrogen in the gaseous state and at a second pressure for a refueling operation of the vehicle 190 to collect. The second pressure of hydrogen is less than the first pressure of hydrogen. The gaseous hydrogen is at the first pressure on the first side of the membrane unit 112 or on the side of the first electrode 114 wherein the gaseous hydrogen at the second pressure on the second side of the membrane unit 112 or on the side of the second electrode 116 is applied.

The system 100 also has a controller 160 on. The control unit 160 is configured to control the provision of hydrogen for refueling the vehicle 190. The control unit 160 is at least with the heater 150 signal transmitting enabled connected.

The control unit 160 has a first device 162 , a second device 164 and a third device 166 on. The first device 162 is configured to heat the hydrogen stored in at least partially liquid state or the heating device 150 to drive to heat the stored in at least partially liquid state hydrogen to produce gaseous hydrogen at the first pressure. For example, this is the first device 162 with the heater 150 signal transmitting enabled connected. The second device 164 is configured to enable, to control or to control a release of the gaseous hydrogen from the first pressure to the second pressure. In particular, the second device 164 formed to the gaseous hydrogen through the electrochemical device 110 to lead or to let flow. Here, for example, the second device 164 with the first interface 130 signal transmitting enabled, for example, to control a valve or the like. The third device 166 is configured to collect the gaseous hydrogen at the second pressure for an output to refuel the vehicle 190 to effect, enable or control. Here is, for example, the third device 166 with the second interface 140 signal transmitting enabled, for example, to control a valve or the like.

In particular, the controller 160 set up or adapted to steps of one of the following in 2 process or similar procedure in appropriate units.

2 shows a flowchart of a method 200 for providing according to an embodiment. The procedure 200 is executable to provide hydrogen for refueling a vehicle or for refueling a vehicle. Here is the procedure 200 to provide in connection with the system 1 or a similar system, in conjunction with the electrochemical device 1 or a similar device and / or in conjunction with the controller 1 or a similar controller executable.

In one step 210 heating is used in the process 200 heated to provide at least partially liquid state stored hydrogen to generate gaseous hydrogen at a first pressure. The following will be in one step 220 of relaxing, the gaseous hydrogen is expanded from the first pressure to a second pressure, wherein the gaseous hydrogen is passed through an electrochemical device. The first pressure is higher than the second pressure. The electrochemical device is equivalent to or similar to the electrochemical device 1 , The gaseous hydrogen at the first pressure is applied to the first side of the membrane unit. The gaseous hydrogen at the second pressure is applied to the second side of the membrane unit. The following will be in one step 230 collecting the gaseous hydrogen at the second pressure for an output to refuel the vehicle.

In particular, in step 220 relaxing using the electrochemical device in the process 200 to provide compression energy converted into electrical energy. It is according to an embodiment in step 210 of heating the hydrogen to a temperature of at least 0 degrees Celsius.

3 shows a schematic representation of an electrochemical device 110 according to an embodiment. The electrochemical device 110 here resembles the electrochemical device out 1 wherein the electrochemical device 110 in 3 of the electrochemical device 1 except that corresponds to that of the first electrode 114 and the second electrode 116 the electrochemical device 110 with an electric power source 320 are electrically connected. The electrochemical device 110 This is separate from or outside of a system for providing hydrogen as the system 1 arranged.

In 3 is the proton-conductive membrane unit 112 with the current-carrying electrodes applied thereto 114 and 116 and a catalyst charge not explicitly shown. Located on both sides of the first electrode 114 as well as on the side of the second electrode 116 pure hydrogen, are by applying an electrical voltage to the electrodes 114 and 116 by means of the power source 320 Hydrogen protons (+ or H +) through the membrane unit 112 be conducted. The associated electrons (e) are guided over the electrical path, as indicated by an arrow in 3 is illustrated.

The Nernst equation (equation 1) describes the concentration dependence of the electrode potential in the ideal case (no losses, eg ohmic losses). The quotient of the activity of the redox partners (aOx and aRed) is to be equated with the concentration of hydrogen in the containers on the anode side and cathode side. For pure hydrogen this means that the quotient can also be determined from the absolute pressures between cathode and anode (P2 / P1). By applying an electrical voltage above the standard electrode potential E ° can also by means of the electrochemical device 110 generate a hydrogen overpressure on the cathode side, which is proportional to the applied voltage. $$e=e°+\frac{RT}{z_{e}F}\text{ln}\frac{a_{\text{Ox}}}{a_{\text{Red}}}$$

4 shows a schematic representation of a system for providing hydrogen according to an embodiment. The system in 4 corresponds or resembles the system 1 , In this case, the system in particular the electrochemical device 110 and according to the in 4 illustrated embodiment, only two heating devices 150 shown by way of example. In other words, the system according to the in 4 shown embodiment, two heaters 150 on. Furthermore, in 4 merely by way of example two storage containers 170 and a sump 180.

Here is a first of the heaters 150 designed to be hydrogen in a first of the storage tanks 170 to heat to vaporize the hydrogen. In the first of the storage tanks 170 there is a two-phase storage of hydrogen, ie, the hydrogen is in the liquid state and in the gaseous state. A second of the heaters 150 is configured to heat gaseous hydrogen in a second of the storage containers 170 to at least 0 degrees Celsius.

The electrical consumer 120 or memory 120 represents an electrical resistance 120 or a current sink 120 , This is due to the high hydrogen pressure on the side of the first electrode 114 through the membrane unit 112 passed through hydrogen protons (H +) and the electrons through the current sink 120 guided. Above the current sink 120 falls due to the current flow to a voltage. The electrochemical device 110 or the electrochemical element 110 is formed at a pressure gradient between the cathode and the anode to act as a power generator. Is instead of a current sink or a resistor, a battery, a capacitor or a voltage converter as an electrical consumer 120 or memory 120 used, this energy can be harnessed. The real, achievable efficiency can be due to fluid mechanics and ohmic resistors in the structure, for example, about 50 to 70 percent.

4 In other words, shows a schematic structure at a hydrogen filling station. The hydrogen is delivered in liquid form. By supplying heat by means of the heaters 150 this evaporates and there is an increase in pressure. The hydrogen is heated to a temperature of at least or above 0 degrees Celsius, so that the proton-conductive membrane unit 112 stays moist and does not freeze.

The absolute pressure on the cathode side and the pressure difference between cathode and anode side is dependent on a pressure in the hydrogen storage on the anode side and an electrical resistance or voltage drop at a given current between the electrodes 114 and 116 , Components on the cathode side should be dimensioned according to the existing pressures. For example, at pressures of about 880bar on the anode side, hydrogen storage may be provided for a refueling operation of a vehicle 190 while on the cathode side pressures of more than 1000bar be present.

If an exemplary embodiment comprises a "and / or" link between a first feature and a second feature, then this is to be read so that the embodiment according to one embodiment, both the first feature and the second feature and according to another embodiment either only first feature or only the second feature.

Claims (10)

A method (200) of providing hydrogen for refueling a vehicle (190), the method (200) comprising at least the following steps: Heating (210) hydrogen stored in at least partially liquid state to produce gaseous hydrogen at a first pressure; Venting (220) the gaseous hydrogen from the first pressure to a second pressure, wherein the gaseous hydrogen is passed through an electrochemical device (110), the electrochemical device (110) comprising a proton conductive membrane unit (112) having a first side and a second side Side, a first electrode (114) applied to the first side of the membrane unit (112), a second electrode (116) applied to the second side of the membrane unit (112) and at least one to the first electrode (114) and the second electrode ( 116) having electrically connectable or connected electrical accumulators (120) and / or consumers (120), the first pressure being higher than the second pressure, the gaseous hydrogen being at the first pressure on the first side of the membrane unit (112), wherein the gaseous hydrogen at the second pressure is applied to the second side of the membrane unit (112); and Collecting (230) the gaseous hydrogen at the second pressure for refueling the vehicle (190). Method (200) according to Claim 1 characterized in that compression energy is converted to electrical energy in step (220) of relaxing using the electrochemical device (110). Method (200) according to one of the preceding claims, characterized in that, in step (210) of the heating, the hydrogen is heated to a temperature of at least 0 degrees Celsius. A controller (160) arranged to execute steps of the method (200) according to any one of the preceding claims in respective units. A system (100) for providing hydrogen for refueling a vehicle, the system (100) having at least the following features: the controller (160) according to one of the preceding claims; the electrochemical device (110); a first interface (130) to at least one storage tank (170) for hydrogen in at least partially liquid state; at least one device (150) for heating the hydrogen in the at least one storage tank (170) and / or between the at least one storage tank (170) and the electrochemical device (110); and a second interface (140) to at least one collecting vessel (180) for the gaseous hydrogen with the second pressure, wherein the electrochemical device (110) is fluidically connected between the first interface (130) and the second interface (140), wherein the controller (160) is connectable or connectable to at least one heating device (150) for signal transmission capability. System (100) according to Claim 5 , characterized in that the at least one electrical memory (120) and / or load (120) comprises a galvanic cell, an electrical capacitor or an electrical voltage converter. System (100) according to one of Claims 5 to 6 characterized in that the membrane unit (112) of the electrochemical device (110) comprises a catalyst. Use of an electrochemical device (110) comprising a proton conductive membrane unit (112) having a first side and a second side, a first electrode (114) attached to the first side of the membrane unit (112), a second side of the membrane unit (112 ) applied second electrode (116) and at least one with the first electrode (114) and the second electrode (116) electrically connectable or connected electrical memory (120) and / or consumers (120), for releasing vaporized gaseous hydrogen at providing hydrogen for refueling a vehicle (190), wherein compression energy is converted to electrical energy. A computer program adapted to execute the method (200) according to any one of the preceding claims. Machine-readable storage medium on which the computer program is based Claim 9 is stored.

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