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

Abstract

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 other pressure tank (203, 205), the method (100) comprising the steps of: identifying (101) a first temperature progression in the first pressure tank (201); identifying (103) another temperature progression in the at least one other pressure tank (203, 205); comparing (105) the first temperature progression with the another temperature progression; and closing (107) at least one tank valve (217) of the pressure tank system (200) if the first temperature progression differs from the another temperature progression.

Description

[Technical Field]

[0001] The present invention relates to a method for protecting a pressure tank in a pressure tank system, a pressure tank system and a program product as set out in the accompanying claims. [Background technology]

[0002] For maintenance purposes, in a pressure tank system comprising multiple pressure tanks, a first pressure tank may be emptied, i.e. depressurized, and gaseously isolated from the rest of the pressure tank system, which is still under pressure.

[0003] Improper restart of a pressure tank system without prior matching of the pressure level in the first pressure tank with the pressure in the rest of the tank system can result in uncontrolled mass flow from the rest of the tank system or another pressure tank into the first pressure tank when the tank valve of the pressure tank system is opened, also known as backfill.

[0004] During normal operation, pressure differences may occur under certain conditions, such as unequal refilling of pressure tanks, and when the tank valve is opened, fluid flow occurs from the pressure tank with a higher pressure level to the pressure tank with a lower pressure level.

[0005] The backfilling leads to a pressure equalization of all the pressure tanks in the pressure tank system, which can result in the first pressure tank being unacceptably heated and therefore potentially being damaged. Summary of the Invention

[0006] Within the scope of the present invention, 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 can be seen from the respective dependent claims, the description and the drawings. It is clear that features and details explained in the context of the method according to the invention also apply in the context of the pressure tank system according to the invention or the program product according to the invention, and vice versa, so that reference is or can always be made to each other in the disclosure of the individual inventive aspects.

[0007] The present invention is particularly useful for providing a safe pressure tank system.

[0008] Thus, according to a first aspect of the present invention, a method for protecting a pressure tank in a pressure tank system is presented, the pressure tank system comprising a first pressure tank and at least one further pressure tank.

[0009] The method presented includes the steps of identifying a first temperature profile in a first pressure tank, identifying another temperature profile in at least one other pressure tank, comparing the first temperature profile with the other temperature profile, and closing a tank valve of the first pressure tank if the first temperature profile differs from the other temperature profile.

[0010] By pressure tank is meant in the context of the present invention a tank that can be filled at high pressure, in particular up to 1000 bar, preferably up to 700 bar. An example of a pressure tank intended in the present invention may be a hydrogen tank for storing hydrogen.

[0011] By tank valve is meant in the context of the present invention a tank valve of a pressure tank which is designed to close, in particular reversibly close, the outlet opening and / or the inlet opening of the pressure tank.

[0012] A temperature transition is to be understood in the context of the present invention as a number of temperature values ​​within a given period of time.

[0013] The presented invention is based on the principle of recognizing backfilling, i.e., uncontrolled inflow of fluid from the at least one further pressure tank into the first pressure tank, on the basis of a difference in the temperature profiles of the first pressure tank and the at least one further pressure tank, by ascertaining a first temperature profile of the first pressure tank, i.e., measuring it, for example, via a temperature sensor arranged in the first pressure tank, in particular within the first pressure tank, and by ascertaining a second temperature profile of the at least one further pressure tank, i.e., measuring it, for example, via a temperature sensor arranged in the at least one further pressure tank, in particular within the at least one further pressure tank.

[0014] The first temperature profile and the further temperature profile can be determined, for example, within a time domain extending from the opening of at least one tank valve of the pressure tank system to a predetermined time after the opening of the tank valve. It is clear that the first temperature profile and the further temperature profile can also be determined periodically at predetermined time intervals.

[0015] In particular, different tank valves of different pressure tanks in a pressure tank system may initially be in different closed states and then, when switching to the same closed or open state, the first temperature transition and the further temperature transition may be identified.

[0016] In order to avoid damage to the first pressure tank, for example due to unacceptably strong heating caused by backfilling, in particular when the first temperature profile differs from the other temperature profile, i.e. when backfilling is recognized, fluid flow is prevented by closing the outlet opening of the at least one other pressure tank and / or by closing the inlet opening of the first pressure tank.

[0017] To close the inlet or outlet opening of each pressure tank, a tank valve or tank valve element is used, which is provided at the inlet and / or outlet opening of the pressure tank.

[0018] The first temperature profile is compared to the other temperature profile to identify when the first temperature profile differs from the other temperature profile. By comparing the first temperature profile to the other temperature profile, the backfill itself can be identified very quickly, particularly more quickly than if only the first temperature profile were observed.

[0019] If the first temperature profile differs from the other temperature profile, an indication may be output indicating a recognized backfill.

[0020] A notification indicating the recognized backfill can be output, i.e., shown for example on a display and / or stored in a memory device, in order to communicate information about the recognized backfill to a user or to control a technical system in response to the recognized backfill. The notification can, for example, be an error notification, which is stored in an error memory device of the pressure tank system or of the corresponding vehicle.

[0021] Matching the first temperature profile with the other temperature profile may be performed, for example, by calculating a mathematical ratio or quotient between the first temperature profile and the other temperature profile, for example, by dividing the average value of the first temperature profile by the average value of the second temperature profile, and if the result is above a threshold, it may be assumed that the first pressure tank is heated differently than the at least one other pressure tank and is backfilling.

[0022] Furthermore, the gradient, in particular the slope, of the first temperature progression may be mathematically related to the gradient, in particular the slope, of the further temperature progression, so as to match the first temperature progression with the further temperature progression.

[0023] By matching the slope of the first temperature transition with the slope of the other temperature transition, the rate of change of the first temperature transition can be compared with the rate of change of the other temperature transition, thereby very quickly recognizing a difference in the first temperature transition with respect to the other temperature transition and closing at least one tank valve of the pressure tank system.

[0024] Furthermore, the first temperature progression may be matched to the further temperature progression by determining the difference between the slope of the first temperature progression and the slope of the further temperature progression.

[0025] The difference between the first temperature profile and the further temperature profile reflects the actual state of the temperature difference between the first pressure tank and the at least one further pressure tank very accurately, so that even slight changes can be quickly recognized.

[0026] Additionally, the difference may be checked against a predetermined threshold, and at least one tank valve may be closed only if the difference is greater than the threshold.

[0027] The thresholds prevent the respective tank valves from being closed and preventing fluid flow based on normal fluctuations or on a false positive identification of a backfill.

[0028] Furthermore, the threshold value may be determined as a function of the external temperature of the first pressure tank and / or the at least one further pressure tank.

[0029] In order to take into account external, i.e. ambient, heat input when recognizing a backfill and to avoid false positives due to heating of the first pressure tank due to heat input from its surroundings, the threshold value may be adapted depending on the external, i.e. ambient temperature of the first pressure tank, for example by increasing or decreasing the threshold value proportionally to the external temperature.

[0030] Furthermore, the at least one tank valve may be closed only when the first temperature transition increases relative to the further temperature transition and / or when the further temperature transition decreases relative to the first temperature transition.

[0031] In order to prevent the at least one tank valve of the pressure tank system from being unintentionally closed when the first pressure tank and the at least one further pressure tank are uniformly heated, for example by ambient energy, the check provided by the present invention can be based on a relationship or ratio of the first temperature profile to the further temperature profile, such that the at least one tank valve is closed only when the first temperature profile increases relative to the further temperature profile, for example the external temperature.

[0032] Furthermore, the first temperature progression may be ascertained by a temperature sensor located in the first pressure tank, and the further temperature progression may be ascertained by a temperature sensor located in the at least one further pressure tank.

[0033] Furthermore, if the first temperature profile is different from the other temperature profile, a first tank valve of the first pressure tank may be closed to close the inflow of the first pressure tank and / or at least one other tank valve of the at least one other pressure tank may be closed to close the outflow of the at least one other pressure tank.

[0034] According to a second aspect, the present invention is presented relating to a pressure tank system.

[0035] The pressure tank system presented includes a first pressure tank, at least one other pressure tank, the first pressure tank having a tank valve and a first temperature sensor, the at least one other pressure tank having a tank valve and another temperature sensor, and a computing unit configured to perform one possible configuration of the presented method.

[0036] According to a third aspect, the present invention relates to a program product comprising program code means which, when executed on a computing unit, configures the computing unit to perform one possible configuration of the method as presented.

[0037] A computing unit is to be understood in the context of the present invention as a computer, a processor, a sub-processor, a controller or any other programmable circuit.

[0038] Further advantages, features and details of the invention can be seen from the following description, in which examples of the invention are described in detail with reference to the drawings, in which it is to be noted that each of the features mentioned in the claims and in the description may be essential to the invention either alone or in any combination. [Brief explanation of the drawings]

[0039] [Figure 1] FIG. 1 shows one possible configuration of the method presented. [Figure 2] 1 is a schematic diagram of one possible configuration of the pressure tank system presented. DETAILED DESCRIPTION OF THE INVENTION

[0040] FIG. 1 illustrates a method 100 of protecting a pressure tank in a pressure tank system, the pressure tank system including a first pressure tank and at least one additional pressure tank.

[0041] The method 100 presented comprises a first checking step 101 of checking a first temperature progression in a first pressure tank, a second checking step 103 of checking another temperature progression in at least one other pressure tank, a checking step 105 of checking the first temperature progression with said another temperature progression, and a closing step 107 of closing at least one tank valve of the pressure tank system, in particular the tank valve closing the inlet opening of the first pressure tank and / or the tank valve closing the outlet opening of said at least one other pressure tank, if the first temperature progression differs from said another temperature progression.

[0042] 2 shows a pressure tank system 200. The pressure tank system 200 comprises a first pressure tank 201, further pressure tanks in the form of a second pressure tank 203 and a third pressure tank 205, and a computing unit 207.

[0043] A first temperature sensor 209 is disposed in the first pressure tank 201, a second temperature sensor 211 is disposed in the second pressure tank 203, and a third temperature sensor 213 is disposed in the third pressure tank 205.

[0044] The first pressure tank 201 has a first tank valve 217 that opens or closes the outlet and / or inlet openings of the first pressure tank 201. For this purpose, the tank valve 217 may have an inlet valve element and an outlet valve element.

[0045] The second pressure tank 203 has a second tank valve 219 that opens or closes the outlet and / or inlet openings of the second pressure tank 203. For this purpose, the tank valve 219 may have an inlet valve element and an outlet valve element.

[0046] The third pressure tank 205 has a third tank valve 221 that opens or closes the outlet and / or inlet openings of the third pressure tank 205. For this purpose, the tank valve 221 may have an inlet valve element and an outlet valve element.

[0047] The first pressure tank 201, the second pressure tank 203, and the third pressure tank 205 are fluidly connected, for example, via pressure lines or via pressure lines and a manifold 223, so that when the first pressure tank 201 is emptied or its pressure is significantly reduced relative to the second and third pressure tanks 203 and 205, fluid will flow from the second and third pressure tanks 203 and 205 into the first pressure tank 201, i.e., backfill, if the switching states of the tank valves 217, 219, and 221 of the pressure tanks 201, 203, and 205 allow it.

[0048] This backfilling leads to a temperature drop due to reduced pressure in the second pressure tank 203 and the third pressure tank 205, as shown diagrammatically by arrows 225 and 227, and a temperature increase due to compression in the first pressure tank 201, as shown diagrammatically by arrow 229.

[0049] Upon recognition of backfill, fluid flow is prevented by closing the outlet openings of the pressure tanks 203, 205 using tank valves 219, 221 and / or by closing the inlet openings of the first pressure tank 201 using tank valve 217, for example to prevent damage to the first pressure tank 201 due to an unacceptably high temperature rise. Furthermore, tank valves 217, 219, 221 may be used to close the outlet and / or inlet openings of all pressure tanks 201, 203, 205 upon recognition of backfill.

[0050] To recognize backfilling, the calculation unit 207 compares the temperature profile determined by the first temperature sensor 209, in particular the slope of the first temperature profile determined by the first temperature sensor 209, with other temperature profiles determined by the second temperature sensor 211 and / or the third temperature sensor 213, in particular the slope.

[0051] If the first temperature profile deviates from the further temperature profile and, based on a comparison of these temperature profiles, a backfill condition is assumed, the fluid flow is prevented by closing the tank valve elements at the outlet openings of the pressure tanks 203, 205 and / or the tank valve elements at the inlet openings of the pressure tank 201, or the tank valve elements at the outlet and / or inlet openings of all pressure tanks are closed. [Explanation of symbols]

[0052] 100 How to protect pressure tanks in a pressure tank system 101 First confirmation step 103 Second confirmation step 105 Matching Steps 107 Closure Step 200 Pressure Tank System 201 First Pressure Tank 203 Second Pressure Tank 205 Third Pressure Tank 207 arithmetic unit 209 First Temperature Sensor 211 Second temperature sensor 213 Third Temperature Sensor 217 First Tank Valve 219 Second Tank Valve 221 Third Tank Valve 223 Manifold 225 Arrow, temperature drop 227 Arrow, temperature drop 229 Arrow, temperature rise

Claims

1. A method (100) for protecting a pressure tank (201) in a pressure tank system (200), comprising: The pressure tank system (200) comprises a first pressure tank (201) and at least one further pressure tank (203, 205); The method (100) comprises: a step (101) of determining a first temperature progression in the first pressure tank (201); determining (103) another temperature progression in said at least one other pressure tank (203, 205); matching (105) the first temperature progression with the other temperature progression; closing (107) at least one tank valve (217) of the pressure tank system (200) if the first temperature transition is different from the other temperature transition; Including, A method (100) for protecting a pressure tank (201) in a pressure tank system (200).

2. 2. The method (100) of claim 1, further comprising outputting an annunciation indicating a recognized backfill if the first temperature profile differs from the other temperature profile.

3. 3. The method (100) of claim 1 or 2, wherein the first temperature progression is matched to the other temperature progression by mathematically relating the slope of the first temperature progression to the slope of the other temperature progression.

4. 4. The method (100) of claim 3, wherein the first temperature progression is matched to the other temperature progression by determining a difference between the slope of the first temperature progression and the slope of the other temperature progression.

5. 5. The method (100) of claim 4, characterized in that the difference is checked against a predetermined threshold and the tank valve (217) is closed only if the difference is greater than the threshold.

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

7. 3. The method (100) according to claim 1 or 2, characterized in that the at least one tank valve (217) is closed only when the first temperature transition increases relative to the other temperature transition and / or when the other temperature transition decreases relative to the first temperature transition.

8. 8. The method (100) according to any one of claims 1 to 7, characterized in that the first temperature progression is determined by a temperature sensor (209) arranged in the first pressure tank (201) and the further temperature progression is determined by a temperature sensor (211, 213) arranged in the at least one further pressure tank (203, 205).

9. 9. The method (100) according to claim 1, characterized in that, if the first temperature profile is different from the further temperature profile, a first tank valve (217) of the first pressure tank (201) is closed to close the inflow 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 to close the outflow of the at least one further pressure tank (203, 205).

10. A pressure tank system (200), comprising: The pressure tank system (200) comprises: a first pressure tank (201); at least one other pressure tank (203, 205); A calculation unit (207); Equipped with The first pressure tank (201) has a tank valve (217) and a first temperature sensor (209); the at least one other pressure tank (203, 205) has a tank valve (219, 221) and a further temperature sensor (211, 213); The computing unit (207) is configured to perform the method (100) of any one of claims 1 to 9. Pressure tank system (200).

11. 10. A program product comprising program code means that, when said program code means is executed on a computing unit, causes said computing unit to perform the method (100) of any one of claims 1 to 9.

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