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

Abstract

The present invention provides a method for operating a tank device (1) for storing a gaseous fuel for a vehicle, the method comprising the steps of: introducing (S1) the gaseous fuel into the gas line system (GL) via a first tank container (TB1), wherein the valve device (2) on the first tank container (TB1) is opened by the control device; detecting (S2) a reaching or exceeding of a differential pressure and / or a differential quantity of the gaseous fuel in the first tank container (TB1) relative to an initial pressure and / or an initial quantity of the gaseous fuel in the first tank container (TB1); detecting (S3) a reaching or falling below a predetermined minimum demand for gaseous fuel via the gas line system (GL) by the control device; closing (S4) the first tank container (TB1) and opening (S5) at least one second tank container (TB2, ..., TBn) until a pressure equalization within a predetermined range has been achieved at the first tank container (TB1) and at the second tank container (TB2), wherein the first tank container (TB1) can be filled with the gas fuel from the gas line system (GL) even when the valve device (2) is closed.

Description

The present invention relates to a method for operating a tank device for storing a gas fuel and a tank device for storing a gas fuel.Prior ArtIn known pressure storage tanks, safety devices and / or valves can be installed. For this purpose, fuel cell systems with tank arrangements or tanks for gaseous media are known. In order to stabilize pressure storage tanks in the event of an increase in the temperature of the storage medium or in the event of a leak and to prevent or at least reduce the outflow of the gas, these can be equipped, for example, with valves. Furthermore, it may be desirable to reduce cooling of a tank with rapid extraction of hydrogen.DE112006003013B4 describes a tank with a fitting and a valve, the valve being fastened in the fitting.Disclosure of the InventionThe present invention provides a method of operating a gas fuel storage tank apparatus according to claim 1 and a gas fuel storage tank apparatus according to claim 7.Preferred refinements are the subject matter of the dependent claims.Advantages of the InventionThe idea underlying the present invention is to specify a method for operating a tank device for storing a gas fuel and a tank device for storing a gas fuel, wherein a handle of cooling a tank when gas fuel is removed quickly can be improved.According to the invention, in the method for operating a tank device, the gaseous fuel is introduced into the gas line system via a first tank container, wherein the valve device on the first tank container is opened by the control device; a detection of a differential pressure and / or a differential quantity of the gaseous fuel in the first tank container being reached or exceeded relative to an initial pressure and / or an initial quantity of the gaseous fuel in another tank container; a detection of a predetermined low demand for gaseous fuel being reached or undershot via the gas line system by the control device; closing the first tank container (the valve device) and opening at least one second tank container until a pressure equalization within a predetermined frame has been achieved on the first tank container and on the second tank container, wherein the first tank container can be filled with the gas fuel from the gas line system even when the valve device is closed.The differential pressure and / or the differential quantity and the associated initial values can be predefined depending on the size of the first tank container and relative to the second or another tank container. The low demand for gaseous fuel may be when the engine or fuel cell of the vehicle is operating in a reduced operating regime and requires less gaseous fuel than in a predefined normal operation (such as during travel). In a fuel cell with hydrogen operation, the low requirement can correspond to a so-called overrun phase. The pressure equalization within a predetermined range, for example within a predetermined tolerance, can occur in that the first tank container can be filled with the gas fuel of the other / the other tank container, for example even if the valve device on the first tank container closes an outflow of the gas fuel. It may be advantageously assumed that the differential pressure and / or the differential amount of the gas fuel in the first tank container relative to an initial pressure and / or an initial amount of the gas fuel in another of the present tank containers is considered. It can be assumed here that all other tank containers have for the most part the same pressure. The initial pressure and / or the initial amount may be related to the start of operation or to a period of time from a new (renewed) coasting phase / low demand.The tank containers can be, for example, carbon fiber tanks, which can, however, cool significantly when hydrogen is removed quickly, for example. In order to be able to better compensate or at least reduce a decrease in the temperature and to be able to better counteract a reduction in the amount of decrease and thus a reduction in the range of the system, or even to compensate for this, the method according to the invention can advantageously contribute in that the removal of the gas fuel is not limited to just a single tank container.For normal operation of the engine or of the fuel cell (outside a low demand for gas fuel), it may be provided that not all tanks are opened simultaneously, but only one tank at a time (or if the amount of gas fuel from this tank container is not sufficient, a plurality of tanks may also be opened in parallel).Because this tank can then take over the quantity of all remaining tanks, it can be the case that it can also cool down more quickly than in the case of simultaneous operation of a plurality of tanks. Starting from a certain differential quantity and / or a certain differential pressure, this tank can be closed again and one or more of the other tanks opened in a thrust phase (in the case of an only necessary low discharge quantity of the tank). These now open tank(s) may equalize the tank pressure of the first tank. Because the inflow rate into this originally used first tank may be higher in the other opened tanks than the outflow rate therefrom, the first tank may then heat up and the remaining tanks may cool. Once approximate pressure equalization has occurred, all tanks except a selected one, e.g., a second tank, may be closed and from this second tank, the vehicle may now be operated (then out of the coasting phase). In the next push phase, all the tanks can be opened again and the pressure and also the temperature in the second tank can be raised again. An advantageous effect for the heating can also be that the coldest tank (or first used tank) can have the longest pause and can thus be heated by the environment.In addition, the gas piping system (rail; connector of the tanks) can be heated by means of a heat exchanger with the cooling circuit of the gas fuel removal system (e.g. H2burner, fuel cell,... ) and thus the hydrogen which is returned to the tanks already have a higher temperature.According to the invention, therefore, tank heating can be effected by tank pressure compensation.According to a preferred embodiment of the method, upon closing the first tank container, the second tank container and at least one third tank container are opened until a pressure equalization within the predetermined frame has been achieved on the first tank container and thereafter the third tank container is closed again and only the second tank container remains opened until a (same or different) differential pressure and / or a differential quantity of the gas fuel in the second tank container relative to a (same or different) initial pressure and / or an initial quantity of the gas fuel in another of the tank containers is detected and thereafter upon a renewed detection of a reaching or dropping below a predetermined low demand of gas fuel via the gas line system, the second tank container is closed and at least the third tank container is opened until a pressure equalization within a predetermined frame is detected on the second tank container The second tank and the third tank can also be filled with the gas fuel from the gas line system when the valve device is closed.The same procedure is also possible for a plurality (more than three) of tank containers, wherein then always after a new phase of low demand a further (or new) tank container can be used for supplying the gas line system, which had not yet this role (in a specific operating sequence) and thus does not require a preceding warm-up phase during operation. It is assumed here that, after one of the tank containers already in normal operation (outside the low requirement) serves as a supply tank for the gas line system (and for the consumer), it is not used again for the supply operation until a predetermined time and thus a warm-up phase has taken place at the latter, wherein the supply operation has taken place by one or more (successively or simultaneously) of the other tank containers.According to a preferred embodiment of the method, the predetermined low demand for gas fuel is a coasting phase of a gas consumer, for example a fuel cell, of the vehicle, which is detected and / or initiated by the control device.The detection of the phase under low demand can take place via the connection to the consumer and / or via a sensor system to which the control device can be connected. The same applies to terminating the low demand regime.According to a preferred embodiment of the method, outside the predetermined low demand for gas fuel, at least one further tank container is opened with the correspondingly opened tank container in order to provide a predetermined amount of gas fuel in the gas line system.According to a preferred embodiment of the method, when more than two tank containers are operated, renewed opening of a respective tank container outside the predetermined low demand for gaseous fuel only occurs again when a temperature at the respective tank container corresponds to a maximum below the (temperatures of) tank containers, wherein a current temperature at the respective tank container is determined by means of a measurement with a pressure and / or temperature sensor system at the respective tank container.According to a preferred embodiment of the method, a respective pressure at a respective tank container is determined and the differential pressure to at least one of the remaining tank containers is determined via a pressure sensor system at the respective tank containers (and compared with a specification).According to the invention, the tank device for storing a gas fuel for a vehicle comprises a gas line system and a plurality of tank containers each having a valve device which connects the respective tank container to the gas line system; and a control device which is connected to the valve devices and is configured to carry out a method according to the invention.The control device can be configured to open and close the valve devicesAccording to a preferred embodiment of the tank device, at least one of the tank containers comprises a pressure and / or temperature sensor system.In order to be able to determine the pressure and temperature at the tanks better, each tank container can have its own tank valve and contain pressure and temperature sensors, for example.According to a preferred embodiment of the tank device, the gas line system comprises a heat exchange device which is in contact with a gas feed line to the tank containers and with which the gas fuel can be heated according to a predetermined value.According to a preferred embodiment of the tank device, the heat exchange means is connectable or connected to a cooling circuit of the vehicle. Waste heat from the vehicle can thus be used for heating the gas fuel in the gas line system.The gas line (of the gas line system) can serve for supplying the gas fuel to the tank containers and also for transporting the gas away from the tank containers to the engine or to the fuel cell of the vehicle. The valve device can comprise a closable valve which can be electrically opened and closed.The vehicle may be a fuel cell vehicle. The gas fuel can be a gaseous gas for operating a fuel cell, for example hydrogen or also other gases possible for this purpose. On the other hand, the gas fuel may also be a gas for a gas-driven vehicle, for example hydrogen, CNG or LPG, and may also be liquefied petroleum gas.In vehicles with a fuel cell system, tank containers filled with the gas fuel may be present, wherein the tank container or containers may be under high pressure.The tank device can also be distinguished by the features mentioned in connection with the method and the advantages thereof, and vice versa.Further features and advantages of embodiments of the invention will become apparent from the following description with reference to the attached drawings.Brief Description of the DrawingsThe present invention is explained in more detail below with reference to the exemplary embodiments indicated in the schematic figures of the drawing.The following are shown: FIG. 1 shows a schematic illustration of a tank device for storing a gas fuel for a vehicle according to an exemplary embodiment of the present invention during a step of the operating method according to an exemplary embodiment of the present invention. FIG. 2 shows a schematic illustration of a tank device for storing a gas fuel for a vehicle according to an exemplary embodiment of the present invention during a further step of the operating method according to an exemplary embodiment of the present invention; FIG. 3 shows a schematic illustration of a tank device for storing a gas fuel for a vehicle according to an exemplary embodiment of the present invention during a further step of the operating method according to an exemplary embodiment of the present invention; and FIG. 4 is a block diagram of method steps of the method for operating a tank device for storing a gas fuel for a vehicle according to an exemplary embodiment of the present invention.In the figures, identical reference numerals designate identical or functionally identical elements.DESCRIPTION OF THE EMBODIMENTSFIG. 1 shows a schematic representation of a tank device for storing a gas fuel for a vehicle according to an exemplary embodiment of the present invention during a step of the operating method according to an exemplary embodiment of the present invention.The tank device 1 comprises a gas line system GL and a plurality of tank containers TB 1, TB 2,..., TB 4 each having a valve device 2 which connects the respective tank container TB 1, TB 2,...TB 4 to the gas line system GL; and a control device (not shown) which is connected to the valve devices 2, wherein the control device is configured to carry out a method according to the invention.Furthermore, the gas line system GL can comprise a heat exchange device WT, which is connected to a gas supply line to the tank containers TB 1, TB 2;... TB4 and by means of which the gaseous fuel can be heated according to a predetermined condition. For this purpose, the heat exchange device WT may be connected to a cooling circuit of the vehicle.In the constellation of FIG. 1, a flow of the gas fuel from the first tank container TB 1 is shown during a normal operating phase of the consumer, such as a fuel cell. In this phase, the remaining tank containers TB 2 to TB 4 may all be closed. Below the tank illustration, a profile of the temperature of the corresponding tank container (positioned above it) is illustrated over time. It can be seen here that the only connected first tank container TB 1 has the greatest loss of temperature and the remaining and closed tank containers can have a virtually constant temperature.FIG. 2 shows a schematic illustration of a tank device for storing a gas fuel for a vehicle according to an exemplary embodiment of the present invention during a further step of the operating method according to an exemplary embodiment of the present invention.FIG. 2 shows the same arrangement as FIG. 1, but at a different operating time, in particular at a first thrust phase V of the consumer, i.e. at a low demand for gas fuel, which can be detected or else initiated by the control device.The first tank TB 1 can be closed in this phase and all other tank containers can be opened. The gas fuel can then flow from all other tank containers into the gas line system (flows F2, F3, F4) and also through the valve device and into the first tank container (flow F1) in order to equalize its pressure up to a preset or completely.The temperature-time diagram below shows the temperature profiles associated with the above tank containers over time. Here, D 1 is a course without the heat exchanger and D 2 is a course with the heat exchanger. It can be seen that the first tank container TB 1 can again have significant heating after it has cooled, in particular by filling, advantageously greater for the gas propellant in the gas line system GL already being heated by the heat exchanger WT. After the constant temperature phase from FIG. 1, the opening of the remaining tank containers now also results in cooling of the latter, but less than in the case of more rapid operation with only one tank (FIG. 1 ).FIG. 3 shows a schematic representation of a tank device for storing a gas fuel for a vehicle according to an exemplary embodiment of the present invention during a further step of the operating method according to an exemplary embodiment of the present invention.FIG. 3 shows the same arrangement as FIG. 1, but at a different operating time, in particular during a new normal operation of the consumer with a flow V of gas fuel, that is to say outside the low demand.The supply of the gas line system GL can now take over the second tank container TB 2, and all other tank containers TB 2 remain closed.The temperature-time diagram below shows the temperature profiles associated with the above tank containers over time. Here, D 1 is a course without the heat exchanger and D 2 is a course with the heat exchanger. It can be seen that the second tank container TB 2 now has a more significant cooling by a more rapid removal, but the remaining tank containers even warm up slightly, for example from the environment. The steps of FIGS. 1 to 3 can be repeated in the following (in the next thrust phase) and in particular in such a way that each tank container can be used alone once outside the low requirement. The tank containers already used alone can only be used again for feeding the gas propellant after a predetermined sequence, i.e. when a certain heating has taken place. During the push phase(s), all the tank containers can always be opened.As a variation, with small tank containers or a large demand, more than one tank container can also be used simultaneously (outside the low demand).FIG. 4 shows a block diagram of method steps of the method for operating a tank device for storing a gas fuel for a vehicle according to an exemplary embodiment of the present invention.According to the method for operating a tank device, the gaseous fuel is introduced S 1 into the gas line system via a first tank container, wherein the valve device on the first tank container is opened by the control device; a detection S 2 of a differential pressure and / or a differential amount of the gaseous fuel in the first tank container being reached or exceeded relative to an initial pressure and / or an initial amount of the gaseous fuel in another of the tank containers; a detection S 3 of a predetermined low demand for gaseous fuel being reached or undershot via the gas line system by the control device; closing S 4 of the first tank container and opening S 5 of at least one second tank container until a pressure equalization within a predetermined frame has been achieved on the first tank container and on the second tank container, wherein the first tank container can be filled with the gas fuel from the gas line system even when the valve device is closed.Although the present invention has been fully described above with reference to the preferred exemplary embodiment, it is not limited thereto, but can be modified in a variety of ways.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 112006003013B4

[0003]

Claims

Method for operating a tank device (1) for storing a gas fuel for a vehicle, wherein the tank device (1) comprises: a gas line system (GL) and a plurality of tank containers (TB1, TB2,..., TBn) each having a valve device (2) which controls the respective tank container (TB1, TB2;... TBn) connected to the gas line system (GL); and a control device connected to the valve devices (2); the method comprising the steps of: - introducing (S1) the gas fuel into the gas line system (GL) via a first tank container (TB1), wherein the valve device (2) on the first tank container (TB1) is opened by the control device; - detecting (S2) a differential pressure and / or a differential amount of the gas fuel in the first tank container (TB1) relative to an initial pressure and / or an initial amount of the gas fuel in another tank container (TB2,...) being reached or exceeded; detecting (S3) by the control device that a predetermined low demand for gas fuel has been reached or undershot via the gas line system (GL); closing (S4) the first tank container (TB1) and opening (S5) at least one second tank container (TB2,..., TBn) until a pressure equalization within a predetermined frame has been achieved at the first tank container (TB1) and at the second tank container (TB2), wherein the first tank container (TB1) can be filled with the gas fuel from the gas line system (GL) even when the valve device (2) is closed.Method according to Claim 1, in which, during the closing (S4) of the first tank container (TB1), the second tank container (TB2,..., TBn) and at least one third tank container (TB3,..., TBn) are opened (S5) until a pressure equalization within the predetermined frame has been achieved at the first tank container (TB1) and, after that, the third tank container (TB3,..., TBn) is closed again and only the second tank container (TB2) remains opened until a differential pressure and / or a differential amount of the gas fuel in the second tank container (TB2) relative to an initial pressure and / or an initial amount of the gas fuel in another tank container (TB1 is reached or exceeded, tb 3,... ) and, if a predetermined low demand for gas fuel is reached or undershot via the gas line system (GL) again, then closing (S 4) the second tank container (TB 2) and opening (S 5) at least the third tank container (TB 2,..., TBn) until a pressure equalization within a predetermined frame has been achieved at the second tank container (TB 2) and at the first and / or third tank container (TB 1, TB 2), wherein the second tank container (TB 2) and the third tank container (TB 3) can be filled with the gas fuel from the gas line system (GL) even when the valve device (2) is closed.Method according to either of Claims 1 and 2, in which the predetermined low demand for gas fuel is a coasting phase of a gas consumer of the vehicle, which is detected and / or initiated by the control device.Method according to one of Claims 1 to 3, in which, outside the predetermined low demand for gas fuel, at least one further tank container (TB2) is opened with the correspondingly opened tank container in order to provide a predetermined amount of gas fuel in the gas line system.Method according to one of Claims 1 to 4, in which, if more than two tank containers (TB1, TB2, TB3,...) are operated, renewed opening of a respective tank container (TB1, TB2,...) outside the predetermined low demand for gas fuel only occurs again if a temperature at the respective tank container (TB1, TB2,...) corresponds to a maximum among the tank containers (TB1, TB2,...), wherein a current temperature at the respective tank container (TB1, TB2,...) is determined via a measurement using a pressure and / or temperature sensor system at the respective tank container (TB1, TB2,...).Method according to one of Claims 1 to 5, in which a respective pressure at a respective tank container is determined and the differential pressure to at least one of the remaining tank containers is determined via a pressure sensor system at the respective tank containers (TB1, TB2,... ).A tank device (1) for storing a gas fuel for a vehicle, comprising: a gas piping system (GL); and a plurality of tank containers (TB1, TB2,..., TBn) each having a valve device (2) which communicates with the respective tank container (TB1, TB2;... TBn) to the gas piping system (GL); and a controller connected to the valve means (2) and configured to perform a method according to any one of claims 1 to 6.The tank device (1) according to claim 7, wherein at least one of the tank containers (TB1, TB2;... TBn) comprises a pressure and / or temperature sensor system.Tank device (1) according to claim 7 or 8, wherein the gas line system (GL) comprises a heat exchange device (WT) provided at a gas supply line to the tank containers (TB1, TB2;... TBn) and by means of which the gaseous fuel can be heated according to a predetermined value.The tank device (1) according to claim 9, wherein the heat exchange means (WT) is connectable to a cooling circuit of the vehicle.

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