Method for operating a tank device for storing gaseous fuel, and tank device for storing gaseous fuel

Abstract

The present invention relates to a method for operating a tank arrangement (1) for storing gas fuel for a vehicle, the tank arrangement (1) comprising a plurality of tank vessels (TB1, TB2, ..., TBn) and at least one valve device (2).Furthermore, the present invention relates to a tank arrangement (1) for storing gas fuel for a vehicle (F), having a plurality of tank vessels (TB1, TB2, ..., TBn) and at least one valve device (2) in the tank vessels.

Description

[Technical Field]

[0001] The present invention relates to a method for operating a tank arrangement for storing gaseous fuel, and to a tank arrangement for storing gaseous fuel. [Background technology]

[0002] Known compressed storage tanks may be equipped with safety devices and / or valves. Fuel cell systems with tank arrangements or tanks for gaseous media are known. To stabilize the compressed storage tank and prevent or at least reduce the escape of gas when the temperature of the storage medium rises or when a leak occurs, the tank may be equipped with, for example, a valve. However, as a further consequence, it may be desirable to have better knowledge of the tank fill level of the tank arrangement in order to better operate the vehicle and its fuel supply when in operation.

[0003] In a typical H2 tank system with multiple gas tanks, each equipped with its own tank valve, and not every tank equipped with its own pressure sensor, determining the tank level in one tank after pressure equilibrium has been reached, and in multiple tanks, is desirable.

[0004] Patent Document 1 describes a tank having an armature and a valve, where the valve is attached to the armature. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] German Patent No. 112006003013 Summary of the Invention

[0006] The present invention provides a method for operating a tank arrangement for storing gaseous fuel as set forth in claim 1 and a tank arrangement for storing gaseous fuel as set forth in claim 7.

[0007] Preferred developments are the subject of the dependent claims.

[0008] The idea behind the present invention is to provide a method for operating a tank device for storing gaseous fuel, and a tank device for storing gaseous fuel, which allows better recognition of open safety valves or leaks in the tank device.

[0009] According to the present invention, in a method for operating a tank system for storing gas fuel, a determination is made of each tank level in each tank container and an average tank level of the entire tank system at a predetermined time from the determined temperature and the determined tank pressure for each tank container; a difference is formed of each determined tank level in each tank container and an average tank level of the entire tank system at a predetermined time against the tank level of each tank container most recently determined and stored from the previous operation before closure of each valve device and against the averaged and stored tank level of the entire tank system; a comparison is made of each determined difference with each predetermined threshold value; and a leak is estimated if the difference exceeds the predetermined threshold value.

[0010] The entire tank system may be all tank vessels and the entire piping system. The predetermined threshold may correspond to an acceptable threshold for a particular operation.

[0011] The average tank level of the entire tank system can be determined from the tank levels of all tank vessels (averaged over these, taking into account the individual tank volumes), or additionally, the averaging can take into account the tank levels of all tank vessels as well as the volume of the piping system known to the manufacturer.

[0012] The tank apparatus includes a plurality of tank containers; at least one valve device connecting each tank container to a gas piping system, with at least one valve device connected to each tank container, each valve device set up to introduce and / or discharge gas fuel into and / or separate the tank contents of each tank container toward the gas piping system; at least one high pressure sensor in the gas piping system, at least one temperature sensor in each tank container; and a control device connected to the temperature sensor, the high pressure sensor, and the valve device.

[0013] In a preferred embodiment of the method, the determination of the tank pressure for each tank vessel is made by a pressure sensor in each tank vessel at a predetermined time before the opening of each valve device.

[0014] In a preferred embodiment of the method, the tank pressure for each tank container is determined in such a way that the piping pressure measured by the pressure sensor of the gas piping system at each predetermined time point is assumed to be the uniform pressure for each tank container, wherein each predetermined time point is within the time zone up to the maximum expected required time for pressure equilibration in each tank container after direct opening of each valve device.

[0015] In a preferred embodiment of the method, the threshold for the difference between the determined and stored tank levels individually and / or collectively depends on the time since the opening of the valve device.

[0016] In a preferred embodiment of the method, the threshold value for the difference between the determined and stored tank levels depends individually and / or collectively on the difference in the respective temperature changes of the respective tank containers since the time of closure of the respective valve device resulting from previous operation.

[0017] In a preferred embodiment of the method, the threshold for the difference between the determined and stored tank levels depends individually and / or collectively on the fuel mass removed by the consuming system since the opening of the respective valve device.

[0018] According to the present invention, a tank apparatus for storing gas fuel for a vehicle comprises a plurality of tank containers; a valve device in at least one tank container connecting the tank containers to a gas piping system, at least one valve device connected to each tank container, the valve device being set up to introduce and / or discharge gas fuel into each tank container and / or separate the tank contents of each tank container towards the gas piping system; at least one high pressure sensor in the gas piping system, at least one temperature sensor in each tank container; and a control device connected to the temperature sensor, the high pressure sensor and the valve device and set up to perform the method according to the present invention.

[0019] In a preferred embodiment of the tank system, multiple tank vessels are connected to the same gas line.

[0020] In a preferred embodiment of the tank arrangement, the control device is set up to open the valve device of the tank container when the vehicle is put into service.

[0021] The gas line serves to supply gas fuel to the tank container and may also serve to convey gas from the tank container to the vehicle's engine or fuel cell. The valve device may include a closable valve that can be electrically opened and closed.

[0022] The vehicle may be a fuel cell vehicle, in which case the gas fuel may be a gaseous gas for the operation of the fuel cell, such as hydrogen or any other conceivable gas, or alternatively the gas fuel may be a gas for a gas-powered vehicle, such as CNG or LPG, in which case it may be a liquefied gas.

[0023] In a vehicle with a fuel cell system, there are tank containers filled with gaseous fuel, one or more of which may be under high pressure (nominal up to approximately 700 bar). During the stationary period of a vehicle with an H2 storage system, different pressures may occur in the individual tanks. This is due to different temperature changes in the individual tanks, for example due to different heating and cooling caused by different tank constructions and different environmental conditions of the tanks. These differences or effects can be taken into account for the individual tanks.

[0024] Each tank vessel may have one or more valve devices, such as a thermally actuated safety valve (TPRD) or a shut-off valve. All such tank vessels may be connected to a gas line into which the inlet lines of the individual tank vessels may communicate, leading to the fuel cell. Through the connection with the inlet lines and through the gas lines, each tank vessel may reach pressure equilibrium with the inlet line and the gas line, or a tank vessel with a relatively low pressure may be refilled by a tank vessel with a relatively high pressure. If a leak occurs, it may be impossible to reach a predetermined total discharge pressure in the gas line, thereby allowing a leak to be estimated in at least one tank vessel connected to the piping system.

[0025] In one embodiment, each tank vessel can be individually detected to have a pressure that is clearly too low (leak), in which case the directly measured pressure may be lower than the pressure at the previous stop of the vehicle, taking into account temperature changes.

[0026] In the case where not all tank vessels are equipped with pressure sensors, if a leak occurs in a tank vessel, the (HD) piping system (within the high pressure range) can be made to follow the pressure of the defective tank vessel through refilling. After controlling the valves, the defective tank vessel can be refilled with other tank vessels. As a result, the expected piping pressure (resulting from all tank vessels), corrected by the expected temperature fluctuations from the previous operation (before the shutdown), cannot be reached. A pressure gradient that is too low can then be measured in the (HD) piping system (below the threshold). As a result, it can be inferred that a large amount of extracted hydrogen is occurring in at least one tank vessel based on the leak or the activation of the TPRD.

[0027] The tank device is characterized by the features and advantages mentioned in connection with the method, and vice versa.

[0028] Other features and advantages of the embodiments of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.

[0029] The invention will now be described in more detail with reference to an embodiment shown in the schematic diagrams of the drawings. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a schematic diagram illustrating a tank apparatus for storing gas fuel for a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] The same reference numerals in the drawings represent the same or functionally the same parts.

[0032] FIG. 1 shows a schematic diagram of a tank apparatus for storing gas fuel for a vehicle according to an embodiment of the present invention.

[0033] A tank system 1 for storing gas fuel for a vehicle comprises a plurality of tank vessels TB1, TB2, ..., TBn and at least one valve device 2 of the tank vessels connecting the tank vessels TB1, TB2, ..., TBn with a gas piping system GL, at least one valve device 2 connected to each tank vessel TB1, TB2, ..., TBn, the valve device 2 being set up to introduce and / or discharge gas fuel into each tank vessel TB1, TB2, ..., TBn and / or separate the tank contents of each tank vessel TB1, TB2, ..., TBn in the direction of the gas piping system, and at least one high pressure sensor of the gas piping system GL, at least one temperature sensor of each tank vessel, and a control device connected to the temperature sensor, the high pressure sensor and the valve device and set up to perform the method according to the present invention.

[0034] In the method, from the determined temperature and the determined tank pressure for each tank container, a determination is made of each tank level in each tank container and an average tank level for the entire tank system at a predetermined time; a difference is formed of each determined tank level in each tank container and an average tank level for the entire tank system at a predetermined time against the tank level of each tank container most recently determined and stored from the previous operation before closure of each valve device and against the averaged and stored tank level of the entire tank system; a comparison is made of each determined difference with each predetermined threshold; and a leak is estimated if the difference exceeds the predetermined threshold.

[0035] Leaks in the tank vessels or in one of the tank vessels can be identified, which may be a leak in the tank vessel wall itself or a leak in the valve device.

[0036] Methods for recognizing open valves, such as thermally actuated safety valves (TPRD for short), or for recognizing gross leaks can be implemented, for example, at shutdown.

[0037] FIG. 1 shows a system consisting of a tank arrangement 1 and a hydrogen storage with a fuel cell device BZE.

[0038] Here, several tank vessels TB1, TB2, ... are symbolized as one tank, which may be connected with a safety valve SV, e.g., TPRD, and a shut-off valve 2. The tank side TS (e.g., toward the tank station) may be connected to the tank TB1, ... by a check valve RSV. The shut-off valve may be connected to a fuel cell BZ of the fuel cell device BZE by a regulator R, in particular via a gas line GL. The gas line GL may itself have a sensor Si on the high-pressure side, i.e., before the regulator in the direction of flow, and the fuel cell side, i.e., after the regulator R, may also have such a pressure and / or temperature sensor Si. The fuel cell BZ may be connected to a fan GB and an exhaust gas area AB. The fuel cell may then supply an energy management system D, which may have, for example, a battery Batt, one or more capacitors C, an associated control device D-SE, and a motor M.

[0039] Although the present invention has been fully described above with reference to preferred embodiments, the present invention is not limited thereto and can be modified in many ways. [Explanation of symbols]

[0040] 1 Tank device 2 Valve Device TB1,TB2,...TBn Tank containers GL gas piping F vehicle

Claims

1. A method of operating a tank system (1) for storing gas fuel for a vehicle, said tank system (1) comprising: a plurality of tank vessels (TB1, TB2, . . . , TBn); at least one valve device (2) connecting each of the tank vessels (TB1, TB2; ..., TBn) with a gas piping system (GL), wherein at least one of the valve devices (2) is connected to each of the tank vessels (TB1, TB2, ..., TBn), and each of the valve devices (2) is set up for introducing and / or withdrawing gas fuel into each of the tank vessels (TB1, TB2, ..., TBn) and / or for separating the tank contents of each of the tank vessels (TB1, TB2, ..., TBn) in the direction of the gas piping system; at least one high pressure sensor in said gas piping system (GL); at least one temperature sensor in each of said tank vessels; and a control device connected to the temperature sensor, the high pressure sensor, and the valve device (2); The method includes the steps of: - from the determined temperature and the determined tank pressure for each of the tank vessels (TB1, TB2, . . . , TBn), the respective tank levels in each of the tank vessels (TB1, TB2, . . . , TBn) and the average tank level of the entire tank system are determined at a predetermined time; - forming a difference between the determined tank level in each of the tank vessels (TB1, TB2, ..., TBn) and the average tank level of the entire tank system at a predetermined time point relative to the most recently determined and stored tank level of each of the tank vessels from the previous operation before closing of the respective valve device and relative to the averaged and stored tank level of the entire tank system; - comparing each determined difference with a respective predetermined threshold; A method in which a leak is inferred if the difference is above the predetermined threshold.

2. 2. The method of claim 1, wherein the determination of the tank pressure for each of the tank vessels (TB1, TB2, . . . , TBn) is performed by a pressure sensor in each of the tank vessels at a predetermined time before the opening of each of the valve devices.

3. 2. The method according to claim 1, wherein the tank pressure for each of the tank vessels (TB1, TB2, ..., TBn) is determined by a pressure sensor in the gas piping system in such a way that the piping pressure measured at each predetermined time point is assumed as a uniform pressure for each of the tank vessels, wherein each predetermined time point is within a time zone up to the maximum expected required time for pressure equilibration in each of the tank vessels after direct opening of each of the valve devices.

4. 4. The method of claims 1 and 3, wherein the threshold for the difference between the determined and stored tank levels individually and / or collectively depends on the time after opening of the valve device.

5. 5. The method of claim 4, wherein the threshold for the difference between the determined and stored tank levels depends individually and / or collectively on the difference in the temperature change of each of the tank vessels since the time of closure of each of the valve devices resulting from previous operation.

6. 6. The method according to claim 1, wherein the threshold value for the difference between the determined and stored tank levels depends individually and / or collectively on the fuel mass extracted by the consuming system since the opening of each said valve device.

7. A tank system (1) for storing gas fuel for a vehicle (F), comprising: a plurality of tank vessels (TB1, TB2, . . . , TBn); at least one valve device (2) of the tank vessels (TB1, TB2; . . . TBn) connecting each of the tank vessels (TB1, TB2; . . . TBn) with a gas piping system (GL), at least one valve device (2) connected to each of the tank vessels (TB1, TB2, . . . TBn), the valve device (2) being set up for introducing and / or withdrawing gas fuel into each of the tank vessels (TB1, TB2, . . . TBn) and / or for separating the tank contents of each of the tank vessels (TB1, TB2, . . . TBn) in the direction of the gas piping system; at least one high pressure sensor in said gas piping system (GL); at least one temperature sensor in each of said tank vessels; and a control device connected to the temperature sensor, the high pressure sensor and the valve device (2) and set up to perform the method according to any one of claims 1 to 6; and a tank device.

8. 8. A tank arrangement (1) according to claim 7, wherein a plurality of the tank vessels (TB1, TB2, TB3, ...) are connected to the same gas line (GL).

9. 9. The tank arrangement (1) according to claim 7 or 8, wherein the control device is set up to open the valve devices (2) of the tank vessels (TB1, TB2, TB3, ...) after the vehicle has been put into service.

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