Method and device for protecting a pressure tank in a pressure tank system

Abstract

The proposed invention relates to a method (100) for protecting a pressure tank (201) in a pressure tank system (200), the pressure tank system (200) comprising a first pressure tank (201) and at least one further pressure tank (203, 205), and the method (100) comprising the following steps: - determining (101) a first temperature profile in the first pressure tank (201), - determining (103) a further temperature profile in the at least one further pressure tank (203, 205), - comparing (105) the first temperature profile with the further temperature profile, and - closing (107) at least one tank valve (217) of the pressure tank system (200) if the first temperature profile differs from the further temperature profile.

Description

[0001] Description

[0002] title

[0003] Method and device for protecting a pressure tank in a pressure tank system

[0004] The presented invention relates to a method for protecting a pressure tank in a pressure tank system, a pressure tank system and a program product according to the appended claims.

[0005] State of the art

[0006] For maintenance purposes, it may happen that a first pressure tank in a pressure tank system with several pressure tanks is emptied, i.e. depressurized and pneumatically separated from the rest of the pressure tank system which is still under pressure.

[0007] Improper restart of the pressure tank system without prior pressure equalization of the pressure level in the first pressure tank and the pressure in the rest of the tank system leads in this case to an uncontrolled mass flow from the rest of the tank system or other pressure tanks into the first pressure tank when the tank valves of the pressure tank system are opened, which is also referred to as backfilling.

[0008] Even in normal operation, under certain conditions, such as uneven refueling of the pressure tanks, a pressure difference can occur, whereby a fluid flow occurs from pressure tanks with a higher pressure level to pressure tanks with a lower pressure level when the tank valves are opened.

[0009] Backfilling leads to pressure equalization in all pressure tanks of the pressure tank system. This poses the risk of excessive heating of the first pressure tank and resulting damage to the first pressure tank.

[0010] Disclosure of the Invention Within the scope of the invention presented, a method for protecting a pressure tank in a pressure tank system, a pressure tank system, and a program product are presented. Further features and details of the invention emerge from the respective subclaims, the description, and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the pressure tank system according to the invention or the program product according to the invention, and vice versa, so that with regard to the disclosure, reference is always made to the individual aspects of the invention.

[0011] The invention presented serves in particular to provide a safe pressure tank system.

[0012] Thus, according to a first aspect of the invention presented, a method for protecting a pressure tank in a pressure tank system is presented, wherein the pressure tank system comprises a first pressure tank and at least one further pressure tank.

[0013] The presented method comprises determining a first temperature profile in the first pressure tank, determining a further temperature profile in the at least one further pressure tank, comparing the first temperature profile with the further temperature profile, and closing a tank valve of the first pressure tank in the event that the first temperature profile differs from the further temperature profile.

[0014] In the context of the present invention, a pressure tank is understood to mean a tank that can be filled with high pressure, in particular a pressure of up to 1000 bar, preferably 700 bar. A pressure tank provided according to the invention can, for example, be a hydrogen tank for storing hydrogen.

[0015] In the context of the invention presented, a tank valve is understood to mean a tank valve of a pressure tank which is configured to close, in particular to reversibly close, an outlet opening and / or an inlet opening of the pressure tank.

[0016] In the context of the invention presented, a temperature curve is understood to mean a plurality of temperature values ​​within a period of time.

[0017] The presented invention is based on the principle that backfilling, i.e. an uncontrolled inflow of fluid from the at least one further pressure tank into the first pressure tank, is detected based on a difference in the temperature profiles of the first pressure tank and the at least one further pressure tank. For this purpose, it is provided that a first temperature profile of the first pressure tank is determined, i.e., for example, measured via a temperature sensor arranged on the first pressure tank, in particular in the first pressure tank, and a further temperature profile of the at least one further pressure tank is determined, i.e., for example, measured via a temperature sensor arranged on the at least one further pressure tank, in particular in the at least one further pressure tank.

[0018] The initial temperature profile and the subsequent temperature profile can, for example, be determined over a time period that runs from the opening time of at least one tank valve of the pressure tank system to a specified time after the opening time. Of course, the initial temperature profile and the subsequent temperature profile can also be determined regularly at a specified time interval.

[0019] In particular, the first temperature profile and the further temperature profile can be determined when the different tank valves of different pressure tanks of a pressure tank system are initially in a different closed state and then change to the same closed state or to an open state.

[0020] In order to avoid damage to the first pressure tank, for example due to excessive heating due to backfilling, it is provided in particular that a fluid flow is prevented by closing an outlet opening of the at least one further pressure tank and / or closing an inlet opening of the first pressure tank in the event that the first temperature profile differs from the further temperature profile, ie backfilling is detected.

[0021] To close the inlet opening or outlet opening of a respective pressure tank, tank valves or tank valve elements are used at the inlet opening and / or outlet opening of the pressure tank.

[0022] To detect cases where the first temperature profile differs from the subsequent temperature profile, the first temperature profile is compared with the subsequent temperature profile. By comparing the first temperature profile with the subsequent temperature profile, backfilling can be identified very quickly, especially faster than by considering only the first temperature profile.

[0023] It can be provided that in the event that the first temperature curve differs from the further temperature curve, a message is issued which signals a detected backfilling.

[0024] To inform a user about a detected backfilling or to control a technical system in response to a detected backfilling, the message can be output, i.e., for example, shown on a display and / or stored in a memory that signals a detected backfilling. The message can, for example, be an error message that is stored in the error log of a pressure tank system or a corresponding vehicle.

[0025] The comparison of the first temperature profile with the further temperature profile can be carried out, for example, by calculating a mathematical ratio or a division of the first temperature profile and the further temperature profile. For example, an average value of the first temperature profile can be divided by an average value of the second temperature profile, so that if the result lies above a threshold value, it can be assumed that the first pressure tank heats up differently than the at least one further pressure tank and that refilling is taking place. It can also be provided that the first temperature profile is compared with the further temperature profile by mathematically relating a gradient, in particular an increase in the first temperature profile, to a gradient, in particular an increase in the further temperature profile.

[0026] By comparing the gradient of the first temperature curve with the gradient of the further temperature curve, a rate of change of the first temperature curve is compared with a rate of change of the further temperature curve, so that a different curve of the first temperature curve to the further temperature curve is recognized very quickly and at least one tank valve of the pressure tank system can be closed.

[0027] It can further be provided that the first temperature profile is compared with the further temperature profile by forming a difference between the gradient of the first temperature profile and the gradient of the further temperature profile.

[0028] A difference between the first temperature curve and the further temperature curve very accurately represents an actual state of a difference in the temperature of the first pressure tank and the at least one further pressure tank, so that even minor changes can be quickly detected.

[0029] It can further be provided that the difference is compared with a predetermined threshold value and that at least one tank valve is closed only if the difference is greater than the threshold value.

[0030] A threshold value prevents the fluid flow from being stopped by closing the respective tank valves due to normal fluctuations or a false positive detection of backfilling. It can further be provided that the threshold value is determined depending on the outside temperature of the first pressure tank and / or the at least one additional pressure tank.

[0031] To take external heat input, i.e., from the environment, into account when detecting backfilling and to avoid false positive detection of backfilling due to heating of the first pressure tank by heat input from the environment of the first pressure tank, the threshold value can be adjusted depending on the external temperature, i.e., the ambient temperature of the first pressure tank. For this purpose, the threshold value can be increased or decreased proportionally to the external temperature.

[0032] It can further be provided that the at least one tank valve is closed only in the event that the first temperature profile increases relative to the further temperature profile and / or the further temperature profile decreases relative to the first temperature profile.

[0033] To prevent the at least one tank valve of the pressure tank system from accidentally closing in the event of uniform heating of the first pressure tank and the at least one further pressure tank, for example, due to ambient energy, the adjustment provided according to the invention can be carried out based on a relationship or ratio between the first temperature profile and the further temperature profile. For example, it can be provided that the at least one tank valve is only closed when the first temperature profile increases compared to the further temperature profile, such as an outside temperature.

[0034] It can further be provided that the first temperature profile is determined by means of a temperature sensor arranged on the first pressure tank and the further temperature profile is determined by means of a temperature sensor arranged on the at least one further pressure tank.

[0035] It may also be provided that in the event that the first

[0036] Temperature profile differs from the further temperature profile, a first tank valve of the first pressure tank is closed to close an inlet of the first pressure tank and / or at least one further tank valve of the at least one further pressure tank is closed to close an outlet of the at least one further pressure tank.

[0037] According to a second aspect, the presented invention relates to a pressure tank system.

[0038] The presented pressure tank system comprises a first pressure tank, at least one further pressure tank and a computing unit, wherein the first pressure tank comprises a tank valve and a first temperature sensor, wherein the at least one further pressure tank comprises a tank valve and a further temperature sensor, and wherein the computing unit is configured to carry out a possible embodiment of the presented method.

[0039] According to a third aspect, the presented invention relates to a program product with program code means which, when executed on a computing unit, configure the computing unit to carry out a possible embodiment of the presented method.

[0040] In the context of the invention presented, a computing unit is understood to mean a computer, a processor, a subprocessor, a control unit or any other programmable circuit.

[0041] Further advantages, features, and details of the invention will become apparent from the following description, which describes exemplary embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination.

[0042] They show:

[0043] Figure 1 shows a possible design of the presented procedure,

[0044] Figure 2 shows a schematic representation of a possible embodiment of the presented pressure tank system. Figure 1 shows a method 100 for protecting a pressure tank in a pressure tank system, wherein the pressure tank system comprises a first pressure tank and at least one further pressure tank.

[0045] The presented method 100 comprises a first determination step 101 in which a first temperature profile in the first pressure tank is determined, a second determination step 103 in which a further temperature profile in the at least one further pressure tank is determined, a comparison step 105 in which the first temperature profile is compared with the further temperature profile, and a closing step 107 in which at least one tank valve of the pressure tank system, in particular a tank valve for closing an inlet opening of the first pressure tank and / or a tank valve for closing an outlet opening of the at least one further pressure tank is closed in the event that the first temperature profile differs from the further temperature profile.

[0046] Figure 2 shows a pressure tank system 200. The pressure tank system 200 comprises a first pressure tank 201 and further pressure tanks in the form of a second pressure tank 203 and a third pressure tank 205, as well as a computing unit 207.

[0047] A first temperature sensor 209 is arranged on the first pressure tank 201, a second temperature sensor 211 is arranged on the second pressure tank 203 and a third temperature sensor 213 is arranged on the third pressure tank 205.

[0048] The first pressure tank 201 comprises a first tank valve 217 for opening or closing an outlet opening and / or an inlet opening of the first pressure tank 201. For this purpose, the tank valve 217 can comprise an inlet valve element and an outlet valve element.

[0049] The second pressure tank 203 comprises a second tank valve 219 for opening or closing an outlet opening and / or an inlet opening of the second pressure tank 203. For this purpose, the tank valve 219 can comprise an inlet valve element and an outlet valve element. The third pressure tank 205 comprises a third tank valve 221 for opening or closing an outlet opening and / or an inlet opening of the third pressure tank 205. For this purpose, the tank valve 221 can comprise an inlet valve element and an outlet valve element.

[0050] The first pressure tank 201, the second pressure tank 203 and the third pressure tank 205 are connected in a fluid-conducting manner, for example via pressure lines or pressure lines and manifold 223, so that when the first pressure tank 201 is emptied or its pressure is reduced further than the second pressure tank 203 and the third pressure tank 205, fluid flows from the second pressure tank 203 and the third pressure tank 205 into the first pressure tank 201, ie a refilling takes place, provided that a switching state of the tank valves 217, 219, 221 of the pressure tanks 201, 203, 205 allows this.

[0051] The refilling leads to a temperature drop due to decompression in the second pressure tank 203 and the third pressure tank 205, as indicated by arrows 225 and 227, and to a temperature increase due to compression in the first pressure tank 201, as indicated by arrow 229.

[0052] To prevent damage to the first pressure tank 201, for example, due to an excessively high temperature rise, fluid flow is prevented by closing the outlet openings of the pressure tanks 203, 205 using the tank valves 219, 221 and / or by closing an inlet opening of the first pressure tank 201 using the tank valve 217 when backfilling is detected. Furthermore, the tank valves 217, 219, 221 can be used to close the outlet openings and / or inlet openings of all pressure tanks 201, 203, 205 when backfilling is detected.

[0053] To detect backfilling, the computing unit 207 compares a temperature profile determined by the first temperature sensor 209, in particular a gradient of the first temperature profile determined by the first temperature sensor 209, with a further temperature profile, in particular a gradient, determined by the second temperature sensor 211 and / or the third temperature sensor 213. In the event that the first temperature profile deviates from the further temperature profile and, based on the comparison of the temperature profiles, it is assumed that backfilling is occurring, fluid flow is prevented by closing a tank valve element at the outlet opening of the pressure tanks 203, 205 and / or closing a tank valve element at the inlet opening of the pressure tank 201, or the tank valve elements at the outlet opening and / or inlet opening of all pressure tanks are closed.

Claims

Claims 1. A method (100) for protecting a pressure tank (201) in a pressure tank system (200), wherein the pressure tank system (200) comprises a first pressure tank (201) and at least one further pressure tank (203, 205), and wherein the method (100) comprises: - determining (101) a first temperature profile in the first pressure tank (201), - determining (103) a further temperature profile in the at least one further pressure tank (203, 205), - comparing (105) the first temperature profile with the further temperature profile, - closing (107) at least one tank valve (217) of the pressure tank system (200) in the event that the first temperature profile differs from the further temperature profile.

2. Method (100) according to claim 1, characterized in that in the event that the first temperature profile differs from the further temperature profile, a message is issued which signals a detected backfilling 3. Method (100) according to claim 1 or 2, characterized in that the first temperature profile is compared with the further temperature profile by mathematically relating a gradient of the first temperature profile to a gradient of the further temperature profile.

4. Method (100) according to claim 3, characterized in that that the first temperature curve is compared with the further temperature curve by forming a difference between the gradient of the first temperature curve and the gradient of the further temperature curve.

5. Method (100) according to claim 4, characterized in that the difference is compared with a predetermined threshold value and the tank valve (217) is closed only in the event that the difference is greater than the threshold value.

6. Method (100) according to claim 5, characterized in that the threshold value is determined as a function of an outside temperature of the first pressure tank (201) and / or of the at least one further pressure tank (203, 205).

7. Method (100) according to claim 1 or 2, characterized in that the at least one tank valve (217) is closed only in the event that the first temperature profile increases relative to the further temperature profile and / or the further temperature profile decreases relative to the first temperature profile.

8. Method (100) according to one of the preceding claims, characterized in that the first temperature profile is determined by means of a temperature sensor (209) arranged on the first pressure tank (201) and the further temperature profile is determined by means of a temperature sensor (211, 213) arranged on the at least one further pressure tank (203, 205).

9. Method (100) according to one of the preceding claims, characterized in that that in the event that the first temperature profile differs from the further temperature profile, a first tank valve (217) of the first pressure tank (201) is closed in order to close an inlet of the first pressure tank (201) and / or at least one further tank valve (219, 221) of the at least one further pressure tank (203, 205) is closed in order to close an outlet of the at least one further pressure tank (203, 205).

10. Pressure tank system (200), wherein the pressure tank system (200) comprises: - a first pressure tank (201), - at least one further pressure tank (203, 205), - a computing unit (207), wherein the first pressure tank (201) comprises a tank valve (217) and a first temperature sensor (209), wherein the at least one further pressure tank (203, 205) comprises a tank valve (219, 221) and a further temperature sensor (211, 213), and wherein the computing unit (207) is configured to carry out a method (100) according to one of claims 1 to 9.

11. A program product comprising program code means which, when executed on a computing unit, configure the computing unit to execute a method (100) according to any one of claims 1 to 9.

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