Diagnostic method for diagnosing a state of a tank valve, tank system, and program product

Abstract

The invention relates to a diagnostic method (100) for diagnosing a state of a tank valve (203) in a tank system (200), the tank system (200) having: a plurality of fuel tanks (201) that each comprise a tank valve (203); and a fuel line assembly (207) for directing fuel from the fuel tanks (201).

Description

[0001] Description

[0002] Title of a tank valve condition

[0003] The invention presented relates to a diagnostic method for diagnosing a condition of a tank valve in a tank system, a tank system and a program product

[0004] State of the art

[0005] Fuel cell systems typically have complex tank systems. For example, DE 10 2017 212 485 A1 describes a system for storing fuel in a tank system for a vehicle. The tank system comprises tubular tanks and a high-pressure fuel distributor with integrated control and safety technology. The tanks are made of metal and are connected to the high-pressure fuel distributor with integrated control and safety technology in a modular manner to form a module with a flexible geometry.

[0006] During ferry operation, the tank containers should be as well protected as possible against mechanical and / or thermal stresses such as shaking, vibration, braking, or acceleration. This also applies to the protection of the tank containers in the event of an accident. Furthermore, it is desirable to constantly monitor the tank system in order to detect any malfunctions in the tank system as early as possible.

[0007] Disclosure of the invention

[0008] Within the scope of the invention presented, a diagnostic method, a 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 diagnostic method according to the invention naturally also apply in connection with the tank system according to the invention or the program product according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0009] The invention presented is particularly used to detect and report a faulty tank valve in a tank system with multiple tanks.

[0010] Thus, according to a first aspect of the invention presented, a diagnostic method for diagnosing a condition of a tank valve in a tank system is presented, wherein the tank system comprises a plurality of fuel tanks, each comprising a tank valve, and a fuel line arrangement for conducting fuel from the fuel tanks.

[0011] The presented diagnostic method comprises determining tank-specific pressures for each fuel tank of the plurality of fuel tanks, supplying a consumer with fuel through a reference tank until a differential pressure between the reference tank and at least one diagnostic tank of the plurality of fuel tanks is less than a predetermined diagnostic threshold, opening the tank valve of the at least one diagnostic tank to direct fuel from the at least one diagnostic tank to the reference tank, and outputting an error message indicating an error in the tank valve of the at least one diagnostic tank if, after a predetermined period of time following the opening of the tank valve of the at least one diagnostic tank, a temperature in the at least one diagnostic tank drops by less than a predetermined temperature threshold and / or a pressure in the fuel line arrangement increases by less than a predetermined pressure threshold.

[0012] The presented diagnostic method is based on setting different pressure levels in different fuel tanks of a tank system, so that a controlled volume flow from a respective diagnostic tank to be checked or a corresponding pressure reduction and / or a corresponding temperature change in the diagnostic tank can be used to infer a state of a tank valve of the diagnostic tank.

[0013] To set the various pressure levels, a reference tank is selected from the multitude of fuel tanks from which a consumer, such as a fuel cell system, is exclusively supplied with fuel. Accordingly, only the tank valve of the reference tank is open, while the tank valves of the other fuel tanks are closed, so that the pressure in the reference tank is lower than the pressure in the other fuel tanks.

[0014] As soon as a differential pressure between the reference tank and at least one diagnostic tank of the plurality of fuel tanks exceeds a predefined diagnostic threshold value, which may be the case, for example, after a predefined duration of supply to the consumer from the reference tank, the tank valve or a withdrawal path of the tank valve of the at least one diagnostic tank is opened. Due to the differential pressure between the reference tank and at least one diagnostic tank, if the tank valve of the at least one diagnostic tank is functioning correctly, fuel flows from the at least one diagnostic tank into the reference tank, so that the reference tank is refilled, if necessary, through a filling path of its tank valve.

[0015] The refilling of the reference tank or the outflow of fuel from the at least one diagnostic tank correlates with a temperature drop in the at least one diagnostic tank and a pressure increase in the fuel line arrangement of the tank system, so that if there is no temperature drop in the at least one diagnostic tank and / or no pressure increase in the fuel line arrangement of the tank system after the tank valve of the at least one diagnostic tank has been opened, it can be assumed that the tank valve of the at least one diagnostic tank is faulty or that no fuel has flowed from the at least one diagnostic tank. The determination of respective tank-specific pressures can, for example,by means of pressure sensors assigned to the respective fuel tanks or based on calculations using temperatures determined by temperature sensors assigned to the respective fuel tanks, so that pressure sensors in the fuel tanks can be dispensed with.

[0016] Optionally, the presented diagnostic procedure includes sorting the tank-individual pressures according to their size, ie, sorting the tank-individual pressures in ascending or descending order according to their size.

[0017] It can be provided that the at least one diagnostic tank comprises only that fuel tank of the plurality of fuel tanks which has a second lowest tank-individual pressure.

[0018] To determine, for example, the fuel tank of the plurality of fuel tanks which has a second lowest tank-individual pressure, the tank-individual pressures are ordered according to the invention, ie, for example, sorted in ascending or descending order.

[0019] By selecting the fuel tank with the second lowest individual tank pressure as the diagnostic tank, the fuel tank with the lowest individual tank pressure can be selected as the reference tank, so that if necessary, all fuel tanks can be selected one after the other as diagnostic tanks in ascending order of individual tank pressure.

[0020] It can further be provided that the at least one diagnostic tank comprises the fuel tank from the plurality of fuel tanks that has the second-lowest tank-specific pressure and a number of fuel tanks, each of which has a tank-specific pressure that differs from the second-lowest tank-specific pressure by at most one diagnostic tank threshold value. By selecting a plurality or a group of fuel tanks as diagnostic tanks that have a similar pressure level, the diagnostic method can be carried out particularly quickly.

[0021] It can further be provided that the at least one diagnostic tank comprises only that fuel tank of the plurality of fuel tanks which has a highest tank-individual pressure.

[0022] By selecting the fuel tank from the multitude of fuel tanks as the diagnostic tank which has the highest tank-specific pressure, a differential pressure which is greater than the diagnostic threshold value can be set particularly quickly when supplying the consumer with fuel from the reference tank.

[0023] It can further be provided that the at least one diagnostic tank comprises the fuel tank from the plurality of fuel tanks which has a highest tank-specific pressure and a number of fuel tanks which each have a tank-specific pressure which differs from the highest tank-specific pressure by at most one diagnostic tank threshold value.

[0024] By selecting a large number or group of fuel tanks as diagnostic tanks that have a similar pressure level, the diagnostic procedure can be carried out particularly quickly.

[0025] It may further be provided that the diagnostic procedure is continued with at least one further fuel tank, as a new at least one diagnostic tank.

[0026] To continue the diagnostic procedure with at least one additional fuel tank as the new at least one diagnostic tank, the new at least one diagnostic tank, e.g., the fuel tank with a tank-specific pressure that is next higher or next lower than the previous diagnostic tank, is selected. Accordingly, when a pressure difference between the new at least one diagnostic tank and the reference tank is reached that is greater than the diagnostic threshold, or after a predefined waiting time for diagnosing a faulty condition of the previous diagnostic tank or its tank valve, the new at least one diagnostic tank is opened. The diagnostic procedure is then continued analogously to the procedure for the original diagnostic tank.

[0027] Accordingly, it can further be provided that the new at least one diagnostic tank is opened if, after a predetermined period after the tank valve of the at least one diagnostic tank has been opened, a temperature in the at least one diagnostic tank drops by less than a predetermined temperature threshold value and / or a pressure in the fuel line arrangement increases by less than a predetermined pressure threshold value, or if a differential pressure between the reference tank and the new at least one diagnostic tank is greater than the diagnostic threshold value.

[0028] It can further be provided that the diagnostic method further comprises determining first tank-individual temperatures for each fuel tank of the plurality of fuel tanks at a first point in time and determining second tank-individual temperatures for each fuel tank of the plurality of fuel tanks at a second point in time, wherein the determination of the tank-individual pressures for each fuel tank of the plurality of fuel tanks is carried out based on a ratio between a respective first tank-individual temperature and a respective second tank-individual temperature.

[0029] By determining the tank-individual pressures for each fuel tank of the plurality of fuel tanks based on a ratio between a respective first tank-individual temperature and a respective second tank-individual temperature, pressure sensors on the fuel tanks can be dispensed with.

[0030] According to a second aspect, the present invention relates to a tank system for storing fuel. The present tank system comprises a plurality of fuel tanks, each comprising a tank valve, a fuel line arrangement for conducting fuel from the fuel tanks, and a computing unit.

[0031] The computing unit is configured to carry out a possible embodiment of the presented diagnostic procedure.

[0032] The presented diagnostic procedure is used in particular to diagnose the condition of the presented tank system.

[0033] In particular, it can be provided that the computing unit is configured to determine tank-individual pressures for each fuel tank of the plurality of fuel tanks, to supply a consumer with fuel through a reference tank until a differential pressure between the reference tank and at least one diagnostic tank of the plurality of fuel tanks is greater than a predetermined diagnostic threshold value, to open the tank valve of the at least one diagnostic tank in order to direct fuel from the at least one diagnostic tank to the reference tank and to output an error message indicating an error in the tank valve of the at least one diagnostic tank, in the eventthat after a predetermined period after opening the tank valve of the at least one diagnostic tank, a temperature in the at least one diagnostic tank drops by less than a predetermined temperature threshold and / or a pressure in the fuel line arrangement increases by less than a predetermined pressure threshold.

[0034] According to a third aspect, the presented invention relates to a program product with program code means, wherein the program code means configure a computing unit to carry out a possible embodiment of the presented diagnostic method when the program code means are executed on the computing unit.

[0035] Advantages that are described in detail for the diagnostic method for diagnosing the condition of a tank valve in a tank system according to the first aspect of the invention apply equally to the tank system for storing fuel according to the second aspect of the invention and the program product according to the third aspect of the invention. Further advantages, features, and details of the invention emerge from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination.

[0036] drawing

[0037] They show:

[0038] Figure 1 shows a possible design of the presented diagnostic procedure,

[0039] Figure 2 shows a possible design of the tank system presented,

[0040] Figure 3 shows a detailed representation of the diagnostic procedure according to Figure 1,

[0041] Figure 4 shows a detailed representation of another possible embodiment of the presented diagnostic procedure.

[0042] Description of the embodiments

[0043] Figure 1 shows a diagnostic method 100 for diagnosing a condition of a tank valve in a tank system, the tank system having a plurality of fuel tanks, each comprising a tank valve and a fuel line arrangement for conducting fuel from the fuel tanks.

[0044] The diagnostic method 100 comprises a first determination step 101 in which tank-specific pressures are determined for each fuel tank of the plurality of fuel tanks, a supply step 103 in which a consumer is supplied with fuel by a reference tank until a differential pressure between the reference tank and at least one diagnostic tank of the plurality of fuel tanks is greater than a predetermined diagnostic threshold, an opening step 105 in which the tank valve of the at least one diagnostic tank is opened in order to direct fuel from the at least one diagnostic tank to the reference tank, and an output step 107 in which an error message indicating an error in the tank valve of the at least one diagnostic tank is output in the eventthat after a predetermined period after opening the tank valve of the at least one diagnostic tank, a temperature in the at least one diagnostic tank drops by less than a predetermined temperature threshold and / or a pressure in the fuel line arrangement increases by less than a predetermined pressure threshold.

[0045] Optionally, the diagnostic method 100 comprises an ordering step 109 in which the tank-specific pressures are ordered according to their size and / or a second determination step 111 in which first tank-specific temperatures are determined for each fuel tank of the plurality of fuel tanks at a first point in time and a third determination step 113 in which second tank-specific temperatures are determined for each fuel tank of the plurality of fuel tanks at a second point in time, so that in the first determination step 101 the tank-specific pressures for each fuel tank of the plurality of fuel tanks can be determined based on a ratio between a respective first tank-specific temperature and a respective second tank-specific temperature.

[0046] Figure 2 shows a tank system 200 for storing fuel, in particular hydrogen.

[0047] The tank system 200 comprises a plurality of fuel tanks 201, each comprising a tank valve 203 and a temperature sensor 205, a fuel line arrangement 207 for conducting fuel from the fuel tanks 201 to a consumer 209, a computing unit 211 and a pressure sensor 213.

[0048] The computing unit 209 is configured to perform the diagnostic method 100 according to Figure 1. Figure 3 shows a diagram 300 which extends over time on its abscissa and over a pressure on its ordinate.

[0049] A curve 301 represents a curve of a pressure in a first fuel tank, a curve 302 represents a curve of a pressure in a second fuel tank, and a curve 303 represents a curve of a pressure in a third fuel tank. A curve 304 represents a curve of a pressure in a fuel line arrangement.

[0050] At a first time T1, the first fuel tank, which has the lowest pressure among the fuel tanks, is opened exclusively as a reference tank to supply a consumer, so that the curve 301 and the curve 304 decrease.

[0051] At a second time T2, the second fuel tank, which has a second lowest pressure among the fuel tanks, is opened as the first diagnostic tank because a differential pressure between the curve 301 of the pressure in the reference tank and the curve 302 of the pressure in the first diagnostic tank has become greater than a diagnostic threshold value, as indicated by arrow 305.

[0052] Accordingly, due to a correctly functioning tank valve of the first diagnostic tank, fuel flows from the first diagnostic tank into the fuel line arrangement and the reference tank, so that a pressure in the reference tank or course 301 increases.

[0053] At a third time T3, the third fuel tank is opened as a second diagnostic tank because a differential pressure between the curve 302 of the pressure in the second fuel tank as the new reference tank and the curve 303 of the pressure in the second diagnostic tank has become greater than the diagnostic threshold value, as indicated by arrow 307.

[0054] Accordingly, due to a correctly functioning tank valve of the second diagnostic tank, fuel flows from the second diagnostic tank into the fuel line arrangement and the new reference tank, so that a pressure in the new reference tank or course 302 increases.

[0055] Figure 4 shows a diagram 400 which extends over time on its abscissa and over a pressure on its ordinate.

[0056] A curve 401 represents a curve of a pressure in a first fuel tank, a curve 402 represents a curve of a pressure in a second fuel tank, and a curve 403 represents a curve of a pressure in a third fuel tank. A curve 404 represents a curve of a pressure in a fuel line arrangement.

[0057] At a first time T1, the first fuel tank, which has the lowest pressure among the fuel tanks, is opened exclusively as a reference tank to supply a consumer, so that the curve 401 and the curve 404 decrease.

[0058] At a second time T2, the third fuel tank, which has a highest pressure among the fuel tanks, is opened as the first diagnostic tank, since a differential pressure between the curve 401 of the pressure in the reference tank and the curve 403 of the pressure in the first diagnostic tank has become greater than a diagnostic threshold value, as indicated by arrow 405.

[0059] Accordingly, due to a correctly functioning tank valve of the first diagnostic tank, fuel flows from the first diagnostic tank into the fuel line arrangement and the reference tank, so that a pressure in the reference tank or course 401 increases.

[0060] At a third time T3, the second fuel tank is opened as the second diagnostic tank, since a differential pressure between the curve 401 of the pressure in the reference tank and the curve 402 of the pressure in the second diagnostic tank has become greater than the diagnostic threshold, as indicated by arrow 407. Accordingly, due to a correctly functioning tank valve of the second diagnostic tank, fuel flows from the second diagnostic tank into the

[0061] Fuel line arrangement, the third fuel tank and the reference tank, so that a pressure in the third fuel tank and the reference tank or

[0062] Courses 401 and 403 rise at least briefly.

Claims

Claims 1. A diagnostic method (100) for diagnosing a condition of a tank valve (203) in a tank system (200), wherein the tank system (200) comprises a plurality of fuel tanks (201), each comprising a tank valve (203) and a fuel line arrangement (207) for conducting fuel from the fuel tanks (201), the diagnostic method (100) comprising: - determining (101) tank-individual pressures for each fuel tank (201) of the plurality of fuel tanks (201), - supplying (103) a consumer (209) with fuel through a reference tank of the plurality of fuel tanks (201) until a differential pressure between the reference tank and at least one diagnostic tank of the plurality of fuel tanks (201) is greater than a predetermined diagnostic threshold value, - opening (105) the tank valve (201) of the at least one diagnostic tank to direct fuel from the at least one diagnostic tank to the reference tank, - Outputting (107) an error message indicating an error in the tank valve of the at least one diagnostic tank in the event that, after a predetermined period after opening the tank valve of the at least one diagnostic tank, a temperature in the at least one diagnostic tank drops by less than a predetermined temperature threshold value and / or a pressure in the fuel line arrangement (207) increases by less than a predetermined pressure threshold value.

2. Diagnostic method (100) according to claim 1, characterized in that that the at least one diagnostic tank comprises only that fuel tank (201) of the plurality of fuel tanks (201) which has a second lowest tank-individual pressure.

3. Diagnostic method (100) according to claim 1, characterized in that the at least one diagnostic tank comprises the fuel tank (201) from the plurality of fuel tanks (201) which has a second lowest tank-individual pressure and a number of fuel tanks (201) which each have a tank-individual pressure which differs from the second lowest tank-individual pressure by at most one diagnostic tank threshold value.

4. Diagnostic method (100) according to claim 1, characterized in that the at least one diagnostic tank comprises only that fuel tank (201) of the plurality of fuel tanks (201) which has a highest tank-individual pressure.

5. Diagnostic method (100) according to claim 1, characterized in that the at least one diagnostic tank comprises that fuel tank (201) from the plurality of fuel tanks (201) which has a highest tank-individual pressure and a number of fuel tanks (201), each having a tank-individual pressure which differs from the highest tank-individual pressure by at most one diagnostic tank threshold value.

6. Diagnostic method (100) according to one of the preceding claims, characterized in that the diagnostic method (100) is continued with at least one further fuel tank (201), as a new at least one diagnostic tank.

7. Diagnostic method (100) according to claim 6, characterized in that the new at least one diagnostic tank is opened if, after a predetermined period after the opening of the tank valve of the previous at least one diagnostic tank, a temperature in the previous at least one diagnostic tank drops by less than a predetermined temperature threshold value and / or a pressure in the fuel line arrangement (207) increases by less than a predetermined pressure threshold value, or if a differential pressure between the reference tank and the new at least one diagnostic tank is greater than the diagnostic threshold value.

8. Diagnostic method (100) according to one of the preceding claims, characterized in that the diagnostic method further comprises: - determining (111) first tank-individual temperatures for each fuel tank (201) of the plurality of fuel tanks (201) at a first time, - determining (113) second tank-individual temperatures for each fuel tank (201) of the plurality of fuel tanks (201) at a second time, wherein the determination of the tank-individual pressures for each fuel tank (201) of the plurality of fuel tanks (201) is carried out on the basis of a ratio between a respective first tank-individual temperature and a respective second tank-individual temperature.

9. Tank system (200) for storing fuel, the tank system (200) comprising: a plurality of fuel tanks (201), each comprising a tank valve (201), a fuel line arrangement (207) for conducting fuel from the fuel tanks (201), a computing unit (211), the computing unit (211) being configured to carry out a diagnostic method (100) according to one of claims 1 to 8.

10. Tank system (200) according to claim 9, characterized in that the computing unit (211) is configured to: - to determine tank-individual pressures for each fuel tank (201) of the plurality of fuel tanks (201), - supplying a consumer (209) with fuel through a reference tank until a differential pressure between the reference tank and at least one diagnostic tank of the plurality of fuel tanks is greater than a predetermined diagnostic threshold value, - to open the tank valve of the at least one diagnostic tank in order to direct fuel from the at least one diagnostic tank to the reference tank, - to output an error message indicating an error in the tank valve of the at least one diagnostic tank in the event that, after a predetermined period after the tank valve of the at least one diagnostic tank has been opened, a temperature in the at least one diagnostic tank drops by less than a predetermined temperature threshold value and / or a pressure in the fuel line arrangement (207) increases by less than a predetermined pressure threshold value.

11. A program product comprising program code means, wherein the program code means configure a computing unit to perform a diagnostic method (100) according to one of claims 1 to 8 when the program code means are executed on the computing unit.

Images