Method for operating a tank system and tank system for storing gas fuel

Abstract

The invention relates to a method for operating a tank system (1), in which a gas pressure in a gas line system (GL) and a gas temperature in at least one or more tank containers (TB) are determined by means of a control device (SE) having a sensor device (Si), the one or more tank containers (TB) being connected to the gas line system (GL), according to the invention, the control device determines the fill level of the tank container on the basis of the sensor device only after at least one respective release criterion is reached after the opening of the valve device on the tank container or on the plurality of tank containers, the filling level of the respective tank container is determined from the gas temperature in the respective tank container and the gas pressure of the gas line system (GL).

Description

Technical Field

[0001] The invention relates to a method for operating a tank system and a tank system for storing gaseous fuel. Background Art

[0002] Safety devices and / or valves can be installed in known pressure storage tanks. For this purpose, fuel cell systems or tanks for gaseous media with tank assemblies are known. Pressure storage tanks can be equipped with valves to shut off or release the tank contents.

[0003] In common hydrogen tank systems with multiple gas tanks, each with its own tank valve, not all tanks are equipped with their own pressure sensors. It is desirable to determine the tank fill level at the tank and, in the case of multiple tanks, the tank fill level after pressure equalization.

[0004] DE 11 2006 003 013 B4 describes a tank having a fitting and a valve, wherein the valve is fastened in the fitting. Summary of the Invention

[0005] The invention provides a method for operating a tank installation according to claim 1 and a tank installation for storing gaseous fuel according to claim 7 .

[0006] Preferred embodiments are the subject matter of the dependent claims.

[0007] The present invention is based on the idea of ​​specifying a method for operating a tank system and a tank system for storing gaseous fuel, by means of which the state of charge (SOC) of the tank system can be better ascertained.

[0008] Inaccuracies in determining the tank fill level in one or more tank containers for different tank pressures during operation and after starting of a vehicle (e.g. a fuel cell of the vehicle), for example due to different tank heating / cooling while the vehicle is stationary, can advantageously be avoided and / or reduced.

[0009] According to the present invention, in a method for operating a tank installation, a control device having a sensor device is used to determine the gas pressure in a gas line system and the gas temperature in at least one or more tank containers, wherein the one or more tank containers are connected to the gas line system, wherein the control device determines the filling level of the tank container based on the sensor device only after at least one corresponding release criterion is reached after opening a valve device on one or more tank containers, wherein the filling level of each tank container is determined from the gas temperature in the corresponding tank container and the gas pressure of the gas line system.

[0010] According to a preferred embodiment of the method, the release criterion is met after a predetermined time has elapsed after opening the at least one valve device on the tank container.

[0011] According to a preferred embodiment of the method, a release criterion is met after opening at least one valve device on the tank container in that the determined pressure gradient corresponds to the expected pressure gradient in the gas line system while taking into account permissible deviations, wherein the pressure gradient in the gas line system is determined and the following parameters are taken into account individually or in combination when determining the expected pressure gradient: the consumption mass flow of the consumer, the tank volume, the gas temperature in the tank, the line pressure, the ambient temperature.

[0012] According to a preferred embodiment of the method, the release criterion is met after opening at least one valve device on the tank container in that the determined temperature gradient corresponds to the expected temperature gradient in the corresponding tank container while taking into account the permissible deviation, wherein the temperature gradient in the tank container is determined and the following parameters are taken into account individually or in combination when determining the expected temperature gradient for the gas in the individual tank containers: the intake mass flow of the consumer device, the tank volume of one or all tank containers, the gas temperature in the tank, the line pressure, the ambient temperature.

[0013] According to a preferred embodiment of the method, the release criterion is met after opening at least one valve device on the tank container by determining the pressure balance between the individual tank containers, wherein, when determining the pressure balance for the individual tank containers, the individual tank pressures are measured by corresponding sensors and the difference between the maximum tank pressure and the minimum tank pressure is less than a predetermined value.

[0014] According to a preferred embodiment of the method, the method further comprises the following steps:

[0015] - detecting the opening of at least one valve device;

[0016] - after at least one corresponding release criterion has been reached after the valve device has been opened, determining the gas pressure in the gas line system and the gas temperature in at least one tank container by means of the sensor device; and

[0017] The storage state of the entire gas storage system is calculated from the determined gas pressure in the gas line system, the determined gas temperature in the individual tank containers, and the corresponding volume of the individual tank containers.

[0018] According to the present invention, a tank device for storing gaseous fuel comprises at least one tank container into which gaseous fuel can be filled; each tank container has at least one valve device, wherein the valve device is connected to the tank container or arranged on the tank container, wherein the valve device is configured to allow gaseous fuel to enter the at least one tank container and / or to be discharged from the tank container and / or to cut off the tank contents; a gas line in a gas line system, which is connected to the at least one valve device; a control device with a sensor device, by means of which the method according to the present invention can be performed, wherein the sensor device is connected to the gas line and at least one tank container or arranged therein and is configured to determine the gas pressure in the gas line and the gas temperature in the at least one tank container.

[0019] One or more tank containers together with the gas piping system may form a gas storage system.

[0020] According to a preferred embodiment of the tank arrangement, the control device is arranged for counting the predetermined time only after opening the valve device on the tank container.

[0021] According to a preferred embodiment of the tank device, the tank device comprises a plurality of tank containers which are connected to a gas line and a sensor device, wherein the internal pressures of the tank containers can be balanced with one another within a tolerance range after a predetermined time after opening the valve devices on the tank containers.

[0022] According to a preferred embodiment of the tank arrangement, the control device is designed as a valve device for opening the tank container.

[0023] The gas line system can be used to supply gaseous fuel to the tank container and can also be used to transport gas from the tank container to the vehicle's engine or fuel cell. The valve device may include a closable valve that can be opened and closed electrically. Pressure balance between the tanks can be achieved by opening the tank valves and releasing gas into the supply line leading to the gas line system. The predetermined time until the assumed pressure balance can be so long that when multiple tank containers are opened after the start of operation of the vehicle drive (such as the function of the fuel cell or engine), the gas pressure in the gas line system and the tank container can be balanced. Therefore, the high internal pressure of the tank container can release more gaseous fuel to the gas line than the low internal pressure of another tank container until the internal pressure has reached equilibrium, and then both (or more) can release the same amount per unit time.

[0024] The vehicle may be a fuel cell vehicle. The gaseous fuel may be a gaseous gas for operating the fuel cell, such as hydrogen or other gases suitable for this purpose. Alternatively, the gaseous fuel may be a gas for gas-operated vehicles, such as compressed natural gas (CNG) or liquefied petroleum gas (LPG), in which case it may also be a liquefied form.

[0025] The sensor arrangement may comprise one or more sensors, by means of which a pressure drop and / or a pressure gradient and / or a temperature gradient and / or a temperature in the tank container or in the gas line system may be detected.

[0026] The control device can be connected to the valve devices and sensors of one or more tank containers and can read these sensors.

[0027] This method allows for optimized tank filling level determination after the vehicle has come to a standstill. The tank device can be used in a hydrogen tank system and supply hydrogen to a fuel cell.

[0028] According to a preferred embodiment of the method, the control device is designed to calculate the predetermined time until pressure equalization in the entire storage system only after starting the fuel cell in the vehicle, advantageously after opening the switching valve.

[0029] One or more tank containers are connected to the gas pipeline system, for example, via a supply line leading into the gas pipeline system. The supply line can be connected to the valve arrangement of the respective tank container. Typically, the tank filling level of the entire gas storage system (all tank containers and gas pipeline system) can be determined from the pressure profile over time in the gas pipeline system after inferring the pressure equilibrium of the gas storage system.

[0030] The method may also have features and advantages associated with the tank apparatus, and vice versa.

[0031] Further features and advantages of embodiments of the present invention will become apparent from the following description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The invention is explained in more detail below with reference to an exemplary embodiment shown in the schematic diagram of the drawing.

[0033] The accompanying drawings show:

[0034] Figure 1 : Schematic diagram of a tank apparatus for storing gaseous fuel according to one embodiment of the present invention.

[0035] In the figures, the same reference signs identify identical or functionally identical elements. DETAILED DESCRIPTION

[0036] according to Figure 1A tank system 1 for storing gaseous fuel for vehicles includes a plurality of tank containers TB1, TB2, TB3, TB4, TB5, and TB6, for example, cylinders filled or refillable with hydrogen. The tank system 1 includes a valve device 2, for example, one valve device for each tank container, which is connected to or disposed on the tank container, wherein the valve device 2 is configured to allow gaseous fuel to enter the tank container and / or to be discharged from the tank container and / or to cut off the tank contents. The tank system 1 also includes a gas line GL in a gas line system, which is connected to at least one valve device 2; and a control device SE having a sensor device Si, by means of which the method according to the present invention can be executed. The sensor device is connected to or disposed in the gas line GL and the at least one tank container and is configured to determine the gas pressure in the gas line GL and the gas temperature in the at least one tank container.

[0037] A temperature sensor Si can be located on each of the tank containers TB1 to TB6 , which can be connected to and read out by the control device SE. The tank temperature of the individual tank containers can be determined via the corresponding temperature sensors.

[0038] The sensor arrangement Si can also include multiple sensors, such as a first sensor Si1, which can be connected to the supply lines of the first three tank containers (e.g., three, although this arrangement can also vary), and a second sensor Si2, which can be connected to the remaining supply lines and the gas line GL and is configured to determine the gas pressure in the gas line GL at a predetermined time. The method according to the present invention for determining the pressure, pressure gradient, or other parameters can be performed on one, two, or more sensors. The control device SE can be configured to calculate the predetermined time and / or open the valve arrangement 2 of the tank containers (TB1, TB2, TB3, ...) only after the vehicle is started.

[0039] Although the present invention has been described in detail based on the preferred embodiments, the invention is not limited thereto but can be modified in various ways.

Claims

1. A method for operating a tank system (1), in which a control device (SE) having a sensor device (Si) determines the gas pressure in a gas line system (GL) and the gas temperature in at least one or more tank containers (TB), wherein: The one or more tank containers (TB) are connected to the gas pipeline system (GL), wherein the control device determines the filling level of the tank container based on the sensor device only after at least one corresponding release criterion is reached after opening the valve device on the tank container or the multiple tank containers, wherein the filling level of the corresponding tank container is determined from the gas temperature in the corresponding tank container and the gas pressure of the gas pipeline system (GL).

2. The method according to claim 1, wherein the release criterion is met after a predetermined time has elapsed after opening at least one valve arrangement on the tank container.

3. The method according to claim 1 , wherein the release criterion is met after opening at least one valve device on the tank container in that the determined pressure gradient corresponds to the expected pressure gradient in the gas line system, taking into account permissible deviations, wherein: The pressure gradient in the gas line system is ascertained, and the following variables are taken into account individually or in combination when determining the expected pressure gradient: the mass flow drawn from the consumer, the tank volume, the gas temperature in the tank, the line pressure, the ambient temperature.

4. The method according to claim 1 , wherein the release criterion is met after opening at least one valve device on the tank container in that the determined temperature gradient corresponds to the expected temperature gradient in the respective tank container, taking into account permissible deviations, wherein: The temperature gradient in the tank container is determined and the following variables are taken into account individually or in combination when determining the expected temperature gradient for the gas in the individual tank containers: the mass flow drawn from the consumer, the tank volume of one or all tank containers, the gas temperature in the tank, the line pressure, and the ambient temperature.

5. The method according to claim 1 , wherein the release criterion is met after opening at least one valve device on the tank container by determining a pressure balance between the respective tank containers, wherein: When determining the pressure balance for the individual tank containers, the individual tank pressures are measured by corresponding sensors, and the difference between the maximum tank pressure and the minimum tank pressure is less than a predefined value.

6. The method according to any one of claims 1 to 5, wherein the following steps are performed: - detecting the opening of the at least one valve device - after at least one corresponding release criterion has been reached after the valve device has been opened, determining the gas pressure in the gas line system and the gas temperature in the at least one tank container (TB) by means of the sensor device (Si), - calculating the storage state of the entire gas storage system from the determined gas pressure in the gas line system, the determined gas temperature in the individual tank containers, and the corresponding volume of the individual tank containers.

7. A tank device (1) for storing gaseous fuel, comprising: at least one tank container (TB) into which gaseous fuel can be filled; - each tank container has at least one valve device (2), which is connected to or arranged on the tank container (TB), wherein the valve device (2) is configured to allow gaseous fuel to enter the at least one tank container (TB) and / or to discharge gaseous fuel from the at least one tank container and / or to shut off the tank contents; a gas line (GL) in the gas line system, which is connected to the at least one valve device (2); - a control device (SE) having a sensor device (Si), with the aid of which the method according to any one of claims 1 to 6 can be carried out, the sensor device being connected to or arranged in the gas line (GL) and the at least one tank container and being configured to determine the gas pressure in the gas line (GL) and the gas temperature in the at least one tank container.

8. The tank arrangement (1) according to claim 7, wherein the control device (SE) is arranged for counting the predetermined time only after opening the valve device on the tank container.

9. The tank device (1) according to claim 7 or 8, comprising a plurality of tank containers (TB1, TB2, TB3, ...), which are connected to the gas line (GL) and the sensor device (Si), wherein: After a predetermined time after the valve means on the tank containers are opened, the internal pressures of the tank containers (TB1, TB2, TB3, . . . ) are able to equalize with each other within a tolerance range.

10. The tank installation (1) according to claim 9, in which the control device (SE) is configured as a valve device (2) for opening the tank containers (TB1, TB2, TB3, . . .).

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