METHOD FOR OPERATING A TANK SYSTEM FOR STORING GAS FUEL AND TANK SYSTEM FOR STORING GAS FUEL

Abstract

To provide a method for operating a tank system for storing gas fuel and a tank system for storing gas fuel, which can better detect leaks in the tank container. A method for operating a tank system (1) for storing gaseous fuel includes the tank system (1), the tank system (1) having one or more tank containers (TB1, TB2, ..., TBn) and at least one valve device (2).The tank system (1) for storing gaseous fuel includes one or more tank containers (TB1, TB2, ..., TBn) and at least one valve device (2).

Description

[Technical Field]

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

[0002] Known pressure accumulator tanks may have built-in safety devices and / or valves. In addition, fuel cell systems are known that have tank assemblies or tanks for gaseous media. The pressure accumulator tanks may be equipped with valves for refrigerating or removing the tank contents.

[0003] In a typical H2 tank system with multiple gas tanks, each equipped with its own tank valve, not every tank is equipped with its own pressure sensor. It is desirable to determine the tank level in the tank after achieving pressure compensation in the case of multiple tanks.

[0004] Patent Document 1 describes a tank having a joint and a valve, the valve being attached to the joint. [Prior art documents] [Patent documents]

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

[0006] The present invention provides a method for operating a tank arrangement for storing gaseous fuel according to claim 1 and a tank arrangement for storing gaseous fuel according to claim 7.

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

[0008] The idea underlying the present invention is to present a method for operating a tank system for storing gaseous fuel and a tank system for storing gaseous fuel, which allows better recognition of leaks in the tank container.

[0009] The present invention provides a method for operating a tank arrangement for storing gaseous fuel, the tank arrangement comprising one or more tank containers and at least one valve device for connecting the tank containers to a gas pipeline system, the at least one valve device being connected to each tank container, each valve device being configured to take in and / or take out gaseous fuel into the respective tank container and / or to block tank contents of the respective tank container to the gas pipeline system, the tank arrangement further comprising at least one high pressure sensor provided in the gas pipeline system, at least one temperature sensor provided in each tank container, and a control device connected to the temperature sensor, the high pressure sensor and the valve device, the method comprising the steps of determining and storing a gas temperature in each of the tank containers via the temperature sensor and at least one pressure in the gas pipeline system at a first time point before closing of the valve device, a step of determining a gas temperature via a temperature sensor at a second time point before subsequent actuation control of the valve device; a step of calculating an expected gas pressure in each of the tank containers based on the stored gas temperature in the tank containers and the pressure in the gas pipeline system at the first time point and the gas temperature in the tank at the second time point; a step of identifying the tank container with the lowest calculated expected gas pressure; a step of actuating and opening the valve device of the tank container with the lowest calculated expected gas pressure; a step of determining a pressure in the gas pipeline system at a third time point that will steadily occur after pressure buildup in the gas pipeline system, for example, in a high pressure region and / or a medium pressure region; a step of calculating a difference between the calculated expected gas pressure of the opened tank container and the pressure that will steadily occur after pressure buildup in the gas pipeline system, for example, that determined in the high pressure region and / or the medium pressure region; and a step of comparing the difference with an acceptable threshold value and, if the difference exceeds the threshold value, estimating a tank leak.

[0010] During the stationary state of a vehicle having a hydrogen accumulator system, different pressures may occur in the individual tank vessels. This may result from different temperature changes in the individual tank vessels, for example, temperature increases or decreases due to different tank configurations or different ambient boundary conditions. The subsequent actuation control may correspond to the opening of a valve device.

[0011] According to a preferred embodiment of the method, the calculated expected gas pressure in the gas pipeline system at the third time point is determined as a function of the gas pressure in the tank container at the second time point for which the calculated tank pressure is the smallest and the pressure in the gas pipeline system.

[0012] According to a preferred embodiment of the method, the calculated expected gas pressure in the gas pipeline system at the third time point is determined as a function of the pressure in the medium pressure gas pipeline system at the second and third times.

[0013] According to a preferred embodiment of the method, the calculated expected gas pressure in the gas pipeline system at the third time point is determined depending on the gas mass consumed by the consumer between the second and third times.

[0014] According to a preferred embodiment of the method, after opening the valve device provided in the tank vessel having the lowest pressure at the second time point, the temperatures of the remaining tank vessels are monitored, thereby validating the identification of the tank vessel having the lowest pressure.

[0015] According to a preferred embodiment of the method, the identification of the tank vessel with the lowest pressure is validated by not performing a temperature rise in the other tank vessels that is greater than a predetermined tolerance.

[0016] According to the present invention, a tank system for storing gas fuel comprises one or more tank containers, at least one valve device connected to each tank container and configured to take in and / or take out gas fuel from each tank container and / or to block the tank contents of each tank container towards the gas pipeline system, a gas pipeline system connected to the at least one valve device, at least one high pressure sensor provided in the gas pipeline system, at least one temperature sensor provided in each tank container, and a control device connected to the temperature sensor, the high pressure sensor and the valve device and configured to perform the method according to the present invention.

[0017] One or more tank vessels together with a gas pipeline system may form a gas accumulator system.

[0018] The gas pipeline system can be used to supply gas fuel to the tank container and also to deliver gas from the tank container to the vehicle engine or fuel cell. The valve device can have a closable valve, which can be electrically opened and closed. Pressure compensation between the tanks can be achieved by opening the tank valve and releasing gas into the supply line to the gas pipeline system.

[0019] The vehicle may be a fuel cell vehicle. The gas fuel may in this case be a gaseous gas for the operation of the fuel cell, for example hydrogen, or any other gas available for this purpose. Alternatively, the gas fuel may be a gas for a vehicle operated using gas, for example CNG or LPG. The gas fuel may be a liquefied gas.

[0020] The sensor device may comprise one or more sensors that are able to recognize pressure decreases and / or pressure gradients and / or temperature gradients and / or temperatures within the tank vessel or gas line system.

[0021] The controller may be connected to and be able to read the valve arrangements and sensors of one or more tank vessels.

[0022] The method may feature the features and advantages listed in connection with the tank device, and vice versa.

[0023] Further features and advantages of embodiments of the present invention can be seen from the following description of the accompanying drawings.

[0024] The invention will be explained in more detail below on the basis of exemplary embodiments shown in the schematic drawings in the drawing. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a schematic diagram of a tank system for storing gas fuel according to one embodiment of the present invention; [Figure 2] 1 is a block diagram of method steps of a method of operating a tank system for storing gas fuel for a vehicle, according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] In the drawings, like reference numerals refer to like or functionally identical elements.

[0027] FIG. 1 shows a schematic diagram of a tank system for storing gas fuel according to one embodiment of the present invention.

[0028] 1, a tank arrangement 1 for storing gaseous fuel for a vehicle F comprises a plurality of tank vessels TB1, TB2, TBx, for example hydrogen cylinders that are filled or can be filled with hydrogen. The tank arrangement 1 comprises a plurality of valve arrangements 2, each of the tank vessels (TB1, TB2, ..., TBx) being connected to a specific valve arrangement 2, the valve arrangement 2 being configured to introduce and / or extract gaseous fuel into at least one tank vessel, a gas pipeline system GL connected to at least one valve arrangement 2, at least one high-pressure sensor piH provided in the gas pipeline system GL, at least one temperature sensor Ti provided in each tank vessel, and a control device SE connected to the temperature sensor Ti and the high-pressure sensor piH and configured to read the temperature sensor Ti and the high-pressure sensor piH, and connected to the valve arrangement 2 (not shown for reasons of clarity) and configured to close and / or open the valve arrangement 2.

[0029] The gas line GL may have a high-pressure region HD and an intermediate-pressure region MD. In this case, the high-pressure region HD is connected to a valve device 2 of the tank container, and a take-off valve AV may be arranged between the high-pressure region and the intermediate-pressure region. In the high-pressure region HD, a temperature sensor Ti and a pressure sensor piH may be present, which may measure, for example, a first pressure at a first time. In the intermediate-pressure region MD, a temperature sensor Ti and a pressure sensor piM may be present.

[0030] The pressure in the high pressure region at a first time allows the pressures p1.1, p1.2, ... p1.x in the tank vessel at other times to be inferred.

[0031] The first point in time relates to a state of the vehicle where the engine and / or fuel cell are running, the valve arrangement is open, but it may be imminent that the pressure in the high pressure region HD of the gas line GL and the pressure in the tank vessel are the same (or at least the same within any tolerance).

[0032] The valve may be closed when the vehicle is stopped. Before stopping (first time point), the tank and gas pipeline system may be pressure compensated. The second time point may correspond to a time before the vehicle is started and before the valve is opened. Optionally, the calculation of the tank pressure at the second time point may be performed under the assumption that the pipeline system (also the high-pressure system and the medium-pressure system) and the tank container are temperature compensated (e.g., when the ambient temperature is equal to all tank temperatures).

[0033] At a third point (after the valve opens), the resulting pressure can be measured in the high pressure and medium pressure regions.

[0034] The method allows monitoring the tightness of the tank. Furthermore, at a first time point, the pressure in the intermediate pressure region may also be measured. At a second time point, in particular before a restart of the vehicle and / or fuel cell and when the valve device provided on the tank container is still closed, the temperature and pressure in the high pressure region and the intermediate pressure region may also be measured.

[0035] Due to temperature changes in the standstill state, the pressure in the tank vessels may differ, for example in the event of a leak. For example, the pressure in the xth tank vessel at the second time point can be calculated by p2.x = p1.x * (T2.x / T1.x), where the index 1 represents the magnitude at the first time point and the index 2 represents the magnitude at the second time point. At the third time point, i.e. after opening the valve in the tank vessel with the lowest pressure, the required masses in the high-pressure and intermediate-pressure regions for the pressure buildup in MD and HD, and possibly the mass to the consumer, may be determined, and it may be advantageous to know whether p3MD > p2MD, p3HD > p2HD, i.e. whether the pressure in the intermediate-pressure region at the third time point is greater than the pressure in the intermediate-pressure region at the second time point (and similarly for the high-pressure region).

[0036] In some cases, the mass of gas fuel already received by the consumer may be taken into account (eg, determined from the volumetric flow rate over a given time period).

[0037] FIG. 2 shows a block diagram of method steps of a method for operating a tank system for storing gas fuel for a vehicle, according to one embodiment of the present invention.

[0038] According to the present invention, a method for operating a tank system for storing gas fuel includes steps S1 and S2 of determining a gas temperature in each of the tank containers via a temperature sensor and at least one pressure in the gas pipeline system at a first time point before closing of the valve device and storing the results; step S3 of determining a gas temperature in each of the tank containers via a temperature sensor at a second time point before subsequent driving control of the valve device; and step S4 of determining an expected gas pressure in each of the tank containers based on the stored gas temperature in the tank containers and the pressure in the gas pipeline system at the first time point and the gas pressure in the tank at the second time point. the gas temperature and the calculated predicted gas pressure; step S5 of identifying the tank container having the smallest calculated predicted gas pressure; step S6 of controlling and opening the valve device of the tank container having the smallest calculated predicted gas pressure; step S7 of determining the steady-state pressure occurring after the pressure in the gas pipeline system has been increased at a third time point; step S8 of calculating the difference between the calculated predicted gas pressure of the opened tank container and the steady-state pressure occurring after the pressure in the gas pipeline system has been increased; and step S9 of comparing this difference with an acceptable threshold value and, if the difference exceeds this threshold value, estimating a tank leak.

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

[0040] 1 Tank device 2 Valve gear AV take-off valve F vehicle GL Gas Pipeline System HD High pressure region MD medium pressure range p1.1, p1.2,... p1.x Pressure inside the tank vessel piH high pressure sensor piM Pressure Sensor S1, S2, S3, S4, S5, S6, S7, S8, S9 steps SE control device TB1,TB2,...,TBx Tank containers Ti Temperature Sensor

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