Method for controlling a tank system in operation, tank system, computer program product, and computer-readable medium

Abstract

The invention relates to a method for controlling a tank system (100) in operation. The tank system has a plurality of tanks (12), each of which comprises a valve (13), and a line system (39). The tank system supplies at least one load (40) with a fluid, and the method has the following steps: a) supplying the at least one load from all of the tanks, b) closing all of the valves (13) for a defined test duration, c) opening the valve of a first tank and detecting an expected pressure increase by means of the line system, d) supplying the load from the first tank, e) when a defined target pressure is reached, opening the valve of a second tank and detecting an expected pressure increase by means of the line system, f) supplying the load from the second tank, and g) repeating steps e) and f) one after the other for each of the other tanks until all of the valves have been opened so that the at least one load is supplied from all of the tanks.

Description

[0001] Description

[0002] title

[0003] Method for controlling a tank system in operation, tank system, computer program product and computer-readable medium

[0004] The invention generally relates to the field of storage devices for fuels or gases. More specifically, the invention relates to a method for controlling an operating tank system, a tank system, a computer program product, and a computer-readable medium.

[0005] State of the art

[0006] Fuel tank systems for motor vehicles typically have tanks or reservoirs containing a fluid to supply a consumer. To supply the consumer reliably and according to its needs, the tanks or reservoirs must be able to be opened or closed. A closing and / or opening function of a tank valve can also ensure a certain degree of safety when supplying the consumer. However, this requires the valve's closing and opening functions to function flawlessly.

[0007] In practice, as a safety measure for a tank system, and in particular for a tank system for a motor vehicle, the switching behavior of the valve(s) in the tank system is regularly checked. So-called diagnostic procedures are performed. Known diagnostic procedures can lead to significantly increased requirements regarding the required number of switching cycles of the valves. This, in turn, can shorten the service life of the valves. Disclosure of the Invention

[0008] The method according to the invention for controlling a tank system in operation for a motor vehicle with the features of independent claim 1 has the advantage that the tank system can be controlled and operated reliably and with high safety over a long period of time and diagnostic processes can still be carried out with high regularity.

[0009] The method according to the invention allows the number of switching cycles of the valves to be further reduced without, however, reducing the reliability of a diagnostic process.

[0010] The proposed method therefore reduces the number of switching cycles for the tank system valves and enables improved diagnostic capabilities for both leaks in the tank system and faulty closing and / or opening functions. The proposed method enables the tank system to be controlled more efficiently, better, and more reliably than with existing methods.

[0011] Features, details and advantages that are described in connection with the method according to the invention for controlling a tank system in operation for a motor vehicle naturally also apply in connection with the tank system, the computer program product and / or the computer-readable medium and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is or can always be made to each other.

[0012] A first aspect of the present invention relates to a method for controlling an operating tank system, in particular a tank system for a motor vehicle. The tank system comprises a plurality of tanks and a line system. Each tank is provided with a valve. The tank system supplies at least one consumer with a fluid.The method comprises the following steps: a) supplying the at least one consumer from all tanks of the plurality of tanks, b) closing all valves of the plurality of tanks for a defined test duration, c) opening a valve of a first tank of the plurality of tanks and detecting an expected pressure increase by means of the line system, in particular in the line system, d) supplying the consumer from the first tank, e) upon reaching a predefined target pressure, opening a valve of a second tank of the plurality of tanks and detecting an expected pressure increase by means of the line system, in particular in the line system, and f) supplying the consumer from the second tank, g) repeating steps e) and f) one after the other with the respective further tanks, and.

[0013] Step g) is carried out until all valves of all tanks of the plurality of tanks have been opened so that the at least one consumer is supplied from all tanks of the plurality of tanks.

[0014] In other words, the pressures in all tanks are initially brought to the same value by supplying at least one consumer from all tanks, preferably for a predefined period of time. Once the same pressure has been achieved in all tanks, all valves in all tanks are initially closed for a relatively short period of time, or for a defined test duration. During this time, in a fault-free tank system, the pressure in the piping system should preferably drop, in particular by an expected amount. The test duration can therefore be defined based on a predefined and / or expected pressure drop. Immediately after such a pressure drop is detected, the tanks, or rather the valves of the tanks, can be opened one after the other, whereby it is always necessary to wait until the pressure in the opened tank has dropped by a predefined pressure difference before opening the next tank.In particular, when opening the next tank, the already opened tank can remain open because, for physical reasons, the fluid will not flow out of the already opened tank due to the pressure difference. This can significantly reduce the number of switching cycles of the valves in the tank system. If the pressures in all tanks are the same, step b) can be carried out immediately afterwards. Alternatively, the consumer can continue to be supplied from all tanks even though the condition of equalized pressures has been reached. In this case, however, the frequency with which a diagnostic procedure is carried out can be reduced. It can therefore be advantageous to initiate step b) as early as possible. The time at which step b) is initiated can, however, depend on the operating parameters of the consumer and / or the motor vehicle.

[0015] After all valves of all tanks have been opened consecutively according to steps e) and f), the consumer can again be supplied from all tanks. The entire process can then be repeated, and in particular, restarted at step b). Step a), i.e., supplying the consumer from all tanks, can be carried out for a predefined period of time. In principle, the consumer can be supplied from all tanks until the pressures in all tanks have equalized.

[0016] The tank system can be a fluid supply system for a consumer, in particular for a motor vehicle fuel system. The tank system can be used in other applications. For example, the tank system can be used in stationary applications, construction machinery, marine applications, or rail vehicles. The tank system can be a hydrogen tank system. The tank system can be a tank system for a fluid, such as a liquid fuel or a gaseous fuel. The tank system can have two or more tanks. The tanks can have different tank volumes.

[0017] The tank can be a fluid storage device or a container. Each tank is provided with a valve, whereby the term "valve" is to be understood broadly in the context of the present disclosure. The valve can be a valve device. For example, the valve or valve device can comprise a tank valve, a safety valve and a check valve. The valve device can also be provided with a temperature-controlled valve on the tank (TPRD), whereby such a valve only opens as an emergency valve in the event of a fire. The valve can be defined, for example, by its function, namely that it can close and open the corresponding tank. The valve can be configured to close the corresponding tank in a fluid-tight manner so that no fluid can be drawn from the tank.

[0018] The line system of the tank system can detect pressures and / or pressure differences, for example, in lines of the tank system. The line system can comprise lines, sensors, and / or distributors. The line system can be configured to detect pressure differences, whether pressure increases or pressure decreases, along a filling path and / or removal path of the tanks. The line system can, in particular, comprise a main distributor, a pressure regulator unit, and at least one pressure sensor. The main distributor can be fluidly connected to a main filling path and to a tank path. Each of the tanks of the plurality of tanks can be fluidly connected to the main distributor via a line.

[0019] When determining the expected pressure increase, the pressure, also referred to as fluid pressure, can be measured in the flow direction downstream of the main distributor / manifold. The pressure increase can be referred to as an expected pressure increase because, assuming the valve of the first tank is functioning properly, the pressure in the piping system, particularly in the filling path of the first tank, should increase substantially abruptly when the valve is opened. Since the valve can be expected to function properly, it can be referred to as an expected pressure increase.

[0020] In step e), you can basically wait until the pressure in the tank (and accordingly in the piping system) has dropped by a predefined pressure difference due to fluid being withdrawn from the first tank. The target pressure can, for example, be defined based on a predefined pressure difference. In other words, because the consumer can only be supplied from one tank, the pressure in the corresponding tank (and thus in the piping system) drops. As soon as the pressure in the first tank (and accordingly in the piping system) has dropped by a predefined pressure difference, the valve of the second tank can be opened so that the consumer can now only be supplied from the second tank. This is possible in particular because the pressure in the second tank is higher than the target pressure when the second tank is opened. When the valve of the second tank is opened, an expected pressure increase is detected via the piping system.

[0021] Step g) can be understood to mean that a third tank can take the role of the second tank during the next repetition of steps e) and f), and the second tank can take the role of the first tank, etc.

[0022] Whenever a valve is opened or closed, in the context of the present disclosure, the valve can be said to be energized or controlled.

[0023] Such a method can therefore enable fast, reliable, and precise diagnosis of the function(s) of the tank valves. This allows for immediate safe operation and / or control of the tank system. Furthermore, such a method can increase the functional robustness of the system against operation with the tank unnoticed and not opened. Furthermore, diagnostic processes can be performed frequently during tank system operation.

[0024] It is advantageous if, when closing all valves of the plurality of tanks for the defined test duration, the defined test duration is predefined, and in particular determined, based on an expected pressure drop. The pressure drop, or the pressure in the piping system, is recorded during the test duration. Based on the recorded pressure drop, the closing function of the valves of the plurality of tanks is checked. Because all valves must be closed for a short time, a so-called "stuck-open test" can be carried out. This can advantageously make it possible to check the shut-off function of all valves of all tanks, since a pressure drop in the piping system by a (pre)defined threshold can be detected.

[0025] It is advantageous to check the opening function of the valve of the corresponding tank when detecting the expected pressure increase. In other words, it can be verified whether the expected pressure increase has actually been or will be detected. If the expected pressure increase is detected, it can be concluded that the opening function of the valve of the corresponding tank is faultless.

[0026] It should be noted that the expected pressure increase can usually be quantified (in advance). The same applies analogously to an expected pressure drop.

[0027] It is advantageous if, after the at least one consumer has been supplied from all tanks of the plurality of tanks according to step g), steps a) to g) are performed again. In other words, the method can be performed in a loop. In the context of the present disclosure, the method can be referred to as a diagnostic process. Such a diagnostic process can therefore be repeated continuously during operation of the tank system. This can further increase the safety of the tank system during operation.

[0028] It is advantageous if each tank is provided with a check valve. The target pressure is predefined such that in step e), the pressure drops by a pressure difference less than or equal to the differential opening pressure of the check valve. In other words, a pressure reduction can be selected such that it is less than or equal to the differential opening pressure of the check valves integrated in the valves. This ensures that the first tank (whose valve has remained open) cannot be filled with fluid from the second tank. The check valve can be a filling valve or a so-called passive check valve.

[0029] It is advantageous if, when all valves of the plurality of tanks are closed in step b), all tanks of the plurality of tanks have an approximately equal pressure level. In other words, by steps a) and b), and in particular by step b), the pressures in all tanks of the tank system can be equalized to a test pressure or pressure level. A second aspect of the present invention relates to a tank system for supplying a consumer with a fluid. The tank system has a plurality of tanks and a line system. Each tank of the plurality of tanks is provided with a valve. The tank system is controllable according to a method as described above and below. The tank system can be a hydrogen tank system, so that the fluid can preferably be hydrogen.The piping system may include, among other things, a high-pressure sensor configured to detect a pressure increase and / or a pressure drop in the piping system. The plurality of tanks may comprise two or more tanks. The tanks may have different storage volumes.

[0030] Because the tank system can be controlled according to the method according to the invention, the tank system can be long-lasting. This method allows the number of tank valve switching operations to be kept to a minimum, while at the same time the tank system can be subjected to constant diagnostic testing.

[0031] All advantages which have been explained in connection with the method according to the first aspect of the invention apply equally to the tank system according to the second aspect of the invention.

[0032] It is advantageous if the line system has at least one pressure sensor, in particular a high-pressure sensor. Such a pressure sensor can be arranged, for example, in the flow direction of the fluid when supplying the at least one consumer, downstream of a main distributor of the line system. The line system can also have a high-pressure sensor and a medium-pressure sensor. Such a medium-pressure sensor can be arranged in a pressure control unit of the line system.

[0033] According to one embodiment of the tank system, each tank of the plurality of tanks is connected to the line system via a tank valve of the valve. Each tank valve has a filling path and a removal path. The filling path and the removal path can be designed as a single path. Alternatively, it is conceivable for the filling path to be separate from the removal path. Each tank valve can be connected to a line of the line system. Each line can be fluidly connected directly or indirectly (for example, via a primary distributor) to a main distributor of the line system.

[0034] It should be noted that a motor vehicle can be equipped with such a tank system. The at least one consumer can be a fuel system of the motor vehicle. Such a motor vehicle can also have all the advantages explained with regard to the tank system according to the invention and / or with regard to the method according to the invention.

[0035] A third aspect of the present invention relates to a computer program product comprising instructions which, when executed by a computer unit of a control device, in particular a control device of a tank system, as described above and below, cause the computer unit to execute a method as described above and below.

[0036] A fourth aspect of the present disclosure relates to a computer-readable medium on which the computer program product as described above is stored.

[0037] drawing

[0038] In the following, embodiments of the invention are described with reference to the figures.

[0039] Figure 1 shows schematically a tank system according to an embodiment,

[0040] Figure 2 shows a flow diagram according to a further embodiment of the method, Figure 3 shows schematically pressure curves in tanks of a tank system according to the invention, and

[0041] Figure 4 shows schematically a pressure curve in the line system of a tank system according to the invention.

[0042] Description of the embodiments

[0043] Similar, similarly acting, identical, or identically functioning elements are provided with similar or identical reference numerals in the figures. The figures are merely schematic and not to scale.

[0044] Fig. 1 schematically shows a tank system 100 according to an embodiment. The tank system 100 of Fig. 1 can be part of a motor vehicle. The tank system 100 has a plurality of tanks 12 and a line system 39. Each tank 12 is provided with a (private) valve 13. A fluid is to be stored in the tanks 12 so that the tank system 100 can supply at least one consumer 40 with this fluid. The tanks 12 are fluidly connected to a distributor 14, 30 via a line 31, 32. A primary distributor 14 can be provided for a first group of tanks 12. The lines 31 which are fluidly connected to the tanks 12 of the first group can be referred to as primary lines 31. The tanks 12 of the first group can be fluidly connected to a main distributor 30 via the primary distributor 14.Tanks 12 from a second group of tanks can be directly connected to the main manifold 30 via so-called secondary lines 32 for fluid communication. Alternative designs regarding the tanks 12 and the manifolds 14, 30 are also conceivable. The design of Fig. 1 is merely exemplary and should not be considered restrictive in any way.

[0045] The line system 39 generally comprises several elements and / or components, as indicated by the crossed-out box in Fig. 1. The line system 39 has at least one pressure sensor 36, which can be arranged, for example, on the main distributor 30. The line system 39 can have a line 31, 32. Furthermore, the line system 39 can have a tank path 34. The fluid can be made available to the consumer 40 via the tank path 34. A pressure regulator unit 42 can be provided on the tank path 34, which can serve to regulate the pressure with which the consumer 40 is supplied with fluid. It is conceivable that the pressure regulator unit 42 is combined with further control units. In the exemplary embodiment in Fig. 1, the consumer 40 is a fuel system. The tank system 100 or the line system 39 of the tank system 100 can further have a main filling path 33.The main distributor 30 is therefore fluidly connected to the main filling path and to the tank path 34. The line system 39 is configured to detect pressure changes in the lines 31, 32 and / or in the tank path 34. The line system 39 can be referred to as a high-pressure system, since the line system 39 is fundamentally configured to detect pressure changes or pressure gradients in the lines 31, 32 using a high-pressure sensor 36.

[0046] Each valve 13 of the tanks 12 is configured to permit or prevent the removal or supply of fluids from or into the tank 12. Each valve 13 serves to open and close the associated tank 12. Each valve 13 can be controlled by a control unit. Such a control unit can be part of the line system 39. The valves 13 can be controlled according to the method according to the invention.

[0047] The tanks 12 of the tank system 100 of Fig. 1 also each have an end plug 15, also known as an end plug. Such an end plug 15 can be designed with an additional safety device. The safety devices in the end plugs 15 are preferably temperature-controlled. Alternatively or additionally, tanks 12 of the plurality of tanks can be provided with a temperature sensor 16.

[0048] The pressure regulator unit 42 of the line system 39 is preferably equipped with a medium pressure sensor 41 and a pressure regulator 43.

[0049] Fig. 2 shows a flow chart according to a further exemplary embodiment of the method. The method can be used to control an operating tank system 100 for a motor vehicle. In particular, the method can be used to carry out diagnostic processes for the valves 13 of the tanks 12. Accordingly, an operating strategy can be proposed which provides for the at least one consumer, in a first method step a), to initially be supplied from all tanks 12 over a period of time until the individual tank pressures are equalized. Directly or indirectly thereafter, in a second method step b), all valves of the tanks are vented in order to close them for a defined test duration t0. If the tank system 100 and all valves 13 of the tank system 100 are fault-free, this leads to a pressure drop in the line system 39. This pressure drop can be detected by the line system 39.This allows a so-called "stuck-open test" to be carried out. It should be noted that this takes place during operation of the tank system 100. However, the operation of the tank system 100 is not impaired as a result, since the test duration t0 can be selected to be correspondingly short. The pressure curve during the test duration t0 can be evaluated, for example, by a control unit to confirm the shut-off function of all tank valves. It should be noted that the pressure drop in the line system 39 should occur by a defined threshold. After confirmation of the shut-off function, in a further third method step c), the valve 13.1 of the first tank 12.1 can be energized or opened. The consumer 40 can therefore be supplied with fluid from the first tank 12.1. Immediately after the opening of the valve 13.1 of the first tank 12.1, the opening of the valve 13.1 can be confirmed by detecting a pressure increase in the line system 39 by a defined threshold.This occurs in the third method step c). Alternatively, the third method step c) detects a pressure buildup in the line system 39 to the original pressure Po, or the original pressure level of the corresponding tank 12.1, less a second threshold. The first and / or second threshold are preferably significantly smaller than the pressure buildup. The pressure buildup is preferably slightly smaller than the original pressure level.

[0050] In the fourth method step d), the consumer 40 is supplied exclusively from the first tank 12.1, which is why the pressure in the first tank 12.1 decreases. In method step e), the system waits until a defined pressure reduction dp has been detected in the line system 39 (see Fig. 4). When a predefined target pressure Pi, i.e., the defined pressure reduction dp, is reached, the valve 13.2 of the second tank 12.2 is opened. Since the pressure in the second tank 12.2 at this time is (still) at the original pressure Po, the consumer is inevitably supplied exclusively from the second tank 12.2 (without the valve 13.1 of the first tank 12.1 having to be closed).

[0051] It should be noted that the pressure reduction dp must be selected to be less than or equal to the differential opening pressure of the filling valves integrated in the valves 13 or tank valves, to prevent the fluid from flowing from the second tank 12.2 into the first tank 12.1 (where a lower pressure now prevails). In other words, since the previous tank 12.1 was only reduced by a pressure less than or equal to the opening pressure of the filling valve, no refilling of the first tank 12.1 begins after the second tank 12.2 is opened. The first tank 12.1 remains at the lower pressure level, and the at least one consumer 40 is supplied only from the second tank 12.2 at its slightly higher pressure level. Thus, all tank pressures are known throughout the process, allowing for precise tank level determination. The last opened and discharging tank is at the currently measured pressure level of the line system 39.The tanks that have not yet been opened are at the known pressure level (i.e., the original pressure Po) before initiating process step b) and the previously opened tanks are at the pressure level reduced by the pressure reduction dp compared to the original pressure Po.

[0052] In a fifth method step e), an expected pressure increase is detected via the line system 39. In other words, immediately after the opening of the valve 13.2 of the second tank 12.2, the opening of the valve 13.2 can be detected by detecting a pressure increase in the line system 39 by a defined threshold. Alternatively, a pressure build-up to the original pressure level minus a second threshold can be detected. It should be noted that, in comparison with known diagnostic processes, the pressure drop and the pressure increase can be quantified in this case. Finally, steps e) and f) are repeated in a seventh method step g) with the respective additional tanks 12. The loop continues until all tanks are opened. If all tanks 12, or all valves 13 of all tanks 12, have been opened, the consumer 40 is again supplied from all tanks.The process can then be carried out again, in particular from process step b).

[0053] Fig. 3 shows schematically pressure curves in tanks 12 of a tank system 100 according to the invention and Fig. 4 shows schematically a pressure curve (detected) in the line system 39 of a tank system 100 according to the invention. The curves of Figs. 3 and 4 can be obtained when a tank system 100 having three tanks 12.1, 12.2, 12.3 is controlled according to a method according to the invention, as described, for example, with reference to Fig. 2. It should be noted that the curves of Figs. 3 and 4 correspond, ie were obtained when carrying out the same method. Fig. 3 shows the curves of the tank pressures Ti, T2, T3 from the three tanks 12.1, 12.2, 12.3. Up to the time t0, the consumer 40 is supplied from all three tanks 12.1, 12.2, 12.3. The pressures in all three tanks were equalized to the original pressure Po in process step a). At to in process step b), all valves 13.1, 13.2, and 13.3 are released to close them. All valves 13.1, 13.2, 13.3 of the tank system 100 remain closed for a defined test duration to, which is why the pressure in the line system 39 drops, see Fig. 4. At h the third method step c) can be initiated.

[0054] Finally, the method can be aborted if a faulty valve 13 of the tank system 100 is detected. In response to a detected faulty valve of the tank system 100, it is conceivable to open all valves 13. Furthermore, it is conceivable to output an error signal to a user of the consumer 40. This can be done, for example, by a control unit.

[0055] Additionally, it should be noted that the terms "comprising" and "having" do not exclude other elements, and the indefinite articles "a" or "an" do not exclude a plurality. Furthermore, it should be noted that features and steps described with reference to one of the above embodiments may also be used in combination with other features and steps of other embodiments described above. Reference signs in the claims are not to be considered limitations.

Claims

Claims 1 . Method for controlling an operating Tank system (100), wherein the tank system (100) has a plurality of tanks (12) and a line system (39), and each tank (12) is provided with a valve (13), and wherein the tank system (100) supplies at least one consumer (40) with a fluid, the method comprises the following steps: a) supplying the at least one consumer (40) from all tanks (12) of the plurality of tanks (12), b) closing all valves (13) of the plurality of tanks (12) for a defined test duration, c) opening a valve (13) of a first tank (12) of the plurality of tanks (12) and detecting an expected pressure increase by means of the line system (39), d) supplying the consumer (40) from the first tank, e) upon reaching a predefined target pressure, opening a valve (13) of a second tank (12) of the plurality of tanks (12) and detecting an expected pressure increase by means of the line system (39), f) supplying the consumer (40) from the second tank (12),g) Repeating steps e) and f) successively with the further tanks (12), and wherein step g) is carried out until all valves (13) of all tanks (12) of the plurality of tanks (12) have been opened, so that the at least one consumer (40) is supplied from all tanks (12) of the plurality of tanks (12).

2. Method according to claim 1, characterized in that that when all valves (13) of the plurality of tanks (12) are closed for the defined test duration, the defined test duration is predefined based on an expected pressure drop, wherein the pressure drop is detected during the test duration and a closing function of the valves (13) of the plurality of tanks (12) is checked based on the detected pressure drop.

3. Method according to one of the preceding claims, characterized in that when the expected pressure increase is detected, an opening function of the valve (13) of the corresponding tank (12) is checked.

4. Method according to one of the preceding claims, characterized in that after the at least one consumer (40) has been supplied from all tanks (12) of the plurality of tanks (12) according to step g), steps a) to g) are carried out again.

5. Method according to one of the preceding claims, characterized in that each tank is provided with a check valve, and wherein the target pressure is predefined such that in step e) the pressure drops by a pressure difference less than or equal to a differential opening pressure of the check valve.

6. Method according to one of the preceding claims, characterized in that when all valves (13) of the plurality of tanks (12) are closed in step b), all tanks (12) of the plurality of tanks (12) have an approximately equal pressure level.

7. Tank system (100) for supplying a consumer (40) with a fluid, comprising a plurality of tanks (12) and a line system (39), wherein each tank of the plurality of tanks (12) is provided with a valve (13), and wherein the tank system (100) is controllable according to a method according to one of claims 1 to 6.

8. Tank system (100) according to claim 7, characterized in that the line system (39) has at least one pressure sensor.

9. Tank system according to one of claims 7 or 8, characterized in that each tank of the plurality of tanks (12) is connected to the line system (39) via a tank valve of the valve (13), and wherein each tank valve has a filling path and a removal path.

10. Computer program product comprising instructions which, when executed by a computer unit of a control device, in particular a control device of a tank system (100) according to one of claims 7 to 9, cause the computer unit to execute a method according to one of claims 1 to 6.

11. A computer-readable medium on which the computer program product according to claim 10 is stored.

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