Methods for diagnosing hydrogen sensors, hydrogen sensors, computer programs, and computer-readable media.

Abstract

The present invention relates to a method for diagnosing a hydrogen sensor (4), comprising the steps of: inducing a temperature change in a measuring chamber by means of a heater (7); obtaining a diagnostic value in the measuring chamber by means of a temperature sensor (8); and determining a diagnosis based on the diagnostic value (11, 12). The invention also relates to a hydrogen sensor (4), a computer program (16), and a computer-readable medium (5).

Description

Technical Field

[0001] The present invention relates to a method for diagnosing a hydrogen sensor, a hydrogen sensor, a computer program, and a computer-readable medium. Background Technology

[0002] To determine the hydrogen concentration in a gas, hydrogen sensors typically have a measuring chamber to provide protection against gas flow. The inlet to this chamber is usually sealed by a diaphragm that is permeable to gas but impermeable to liquid to prevent liquid or foreign matter from entering. Unintended foreign matter deposits or liquid accumulation can occur on this diaphragm, affecting the measurement of hydrogen concentration in the gas.

[0003] Document US 9 702 836 B2 relates to a sensor with error detection capabilities. Summary of the Invention

[0004] The purpose of this invention is to provide an alternative method that is characterized by its simple implementation.

[0005] One embodiment of the present invention relates to a method for diagnosing a hydrogen sensor.

[0006] The hydrogen sensor includes a measuring chamber, a heater, and a temperature sensor.

[0007] The measuring chamber is in fluid communication with the hydrogen sensor environment via an opening in the measuring chamber.

[0008] The measuring chamber opening is sealed by a diaphragm.

[0009] A membrane is a membrane through which gases can pass but liquids cannot.

[0010] The method includes the following steps:

[0011] - A temperature change is induced in the measuring chamber using a heater;

[0012] - Diagnostic values ​​in the measurement chamber are obtained using a temperature sensor;

[0013] - Determine a diagnosis based on diagnostic values.

[0014] In this way, diagnostics of hydrogen sensors can be performed without providing additional sensor elements, as existing devices that use hydrogen sensors to measure the hydrogen concentration in a gas can be used for diagnostics.

[0015] Determining a diagnosis preferably involves determining a diagnosis for the hydrogen sensor, and more preferably a diagnosis for its diaphragm and / or the opening of its measuring chamber.

[0016] It is particularly advantageous if the heater and temperature sensor are located in the measuring chamber. This allows for faster heating and more accurate measurements.

[0017] It is also advantageous if the hydrogen sensor is used to determine the concentration of hydrogen in a gas, especially if it is a thermal conductivity sensor.

[0018] Preferably, the hydrogen sensor is a thermal conductivity sensor / thermal capacity sensor, which uses the significantly higher thermal capacity of hydrogen compared to other components in the gas being measured to determine the hydrogen concentration in the gas being measured.

[0019] If the hydrogen sensor includes a sensor housing that specifically defines a measurement chamber and / or includes a measurement chamber opening, preferably located on the surface of the sensor housing, then that is also preferred.

[0020] Furthermore, it is advantageous if the temperature change involves either heating or cooling. Heating can be performed by running the heater, i.e., raising the temperature, while cooling can be performed by turning off the heater if it was previously running.

[0021] The preferred method described involves measurement.

[0022] Furthermore, it is preferable to perform this method before determining the hydrogen concentration of the gas. This allows the sensor's functionality to be checked before use.

[0023] Furthermore, it is preferable to derive diagnostic values ​​in response to temperature changes in the measurement chamber.

[0024] Furthermore, it is preferable to determine the diagnosis in response to the determination of diagnostic values.

[0025] The preferred embodiment is characterized in that the temperature change includes operating the heater at a constant heating power, heating by means of the heater by increasing the heating power, cooling by reducing the heating power of the heater and / or shutting down the heater.

[0026] A further preferred embodiment is characterized in that the obtained diagnostic values ​​include temperature, rate of temperature change, temperature change curve, and / or time value. For example, temperature can be obtained or measured after a specific time period, particularly the temperature in the measuring chamber. The rate of temperature change is the amount of temperature change per unit time. The temperature change curve refers to the process of temperature change over a time period. If only temperature is used as the diagnostic value, the speed is particularly fast, and the rate of temperature change or temperature change curve can yield particularly accurate conclusions. The time value can be, for example, the time required to reach the target temperature from the initial temperature. If the diaphragm or the measuring chamber opening is blocked by foreign objects or liquid, the measuring chamber will heat up faster than when the diaphragm and the measuring chamber opening are unobstructed, i.e., the time required is shorter.

[0027] The above-mentioned possible diagnostic values ​​are preferably relative or absolute values.

[0028] Preferably, the initial temperature in the measuring chamber is determined before the method begins or before the temperature change begins, and especially preferably it is taken into account when determining a diagnosis or obtaining a diagnostic value.

[0029] Another preferred embodiment is characterized in that the method includes a step of comparing the obtained diagnostic value with a stored diagnostic value. The stored diagnostic value is, for example, a previously obtained diagnostic value or comparison value obtained experimentally. Alternatively, it may be a previously obtained diagnostic value or comparison value obtained by the method of the present invention. In other words, it is a historical diagnostic value or comparison value obtained at a previous time, which is used as the stored diagnostic value or comparison value. Preferably, the comparison is performed after the (diagnostic value) is obtained and / or before a diagnosis is determined.

[0030] Another preferred embodiment is characterized in that the stored diagnostic value and the obtained diagnostic value belong to the same type. For example, the obtained temperature change curve is compared with the stored temperature change curve, or the obtained time value is compared with the stored time value.

[0031] Another preferred embodiment is characterized in that a diagnostic determination is made when the obtained diagnostic value reaches, falls below, and / or exceeds a stored diagnostic value. These variations enable the handling of different application conditions of the sensor.

[0032] Another preferred embodiment is characterized in that the temperature change in the measuring chamber and the determination of the diagnostic value are performed simultaneously, at different times, or immediately after each other. This alters the mutual influence between the temperature change and the determination of the (diagnostic value).

[0033] Another preferred embodiment is characterized in that the temperature change in the measuring chamber and the determination of the diagnostic value begin and / or end simultaneously, at different times, or immediately after each other. This can also change the mutual influence between the temperature change and the determination.

[0034] Another preferred embodiment is characterized in that the determination of temperature changes and / or diagnostic values ​​in the measurement chamber begins when the temperature in the measurement chamber is below or above a specific temperature, and / or the determination of temperature changes and / or diagnostic values ​​in the measurement chamber ends when the temperature in the measurement chamber is below or above a specific temperature.

[0035] Another preferred embodiment is characterized in that the determination of the diagnosis includes determining whether the diaphragm is blocked by a foreign object or liquid. These two determinations involve two typical causes that influence the resulting diagnostic value. Therefore, based on the diagnostic value, especially when comparing the obtained diagnostic value with a stored diagnostic value, a conclusion can be drawn regarding one of these two states, where the stored diagnostic value corresponds to one of these two states.

[0036] Furthermore, it is advantageous that if the membrane is determined to be blocked by foreign matter or liquid, the hydrogen sensor cannot be used or measurement is impossible. Preferably, if the method according to the invention determines that the membrane is blocked by foreign matter or liquid, measurement is not possible. Therefore, it is recommended to repeat the method multiple times, especially with time intervals.

[0037] Alternatively, one could consider labeling, marking, or storing measurements of hydrogen concentration in the gas being tested obtained via a hydrogen sensor after it has been determined that the diaphragm is blocked by foreign objects or liquid as unreliable or erroneous. This would prevent the measurements from being used to regulate or control a system, especially a fuel cell system.

[0038] As an alternative to or supplement to one of the two aforementioned embodiments, it is conceivable to increase the heating power of the heater to remove foreign matter or liquid. Alternatively or supplementarily, it is conceivable to temporarily increase the flow rate of the gas to be measured to remove foreign matter or liquid.

[0039] Furthermore, it is particularly preferred that if a diagnosis is performed and, according to the diagnosis, there is no liquid or foreign matter in the opening of the diaphragm or measuring chamber, the method is terminated.

[0040] Another preferred embodiment is characterized in that the method is a computer-implemented method.

[0041] The objective of the hydrogen sensor is achieved by providing a hydrogen sensor comprising a measuring chamber, a heater, and a temperature sensor, wherein the measuring chamber is in fluid communication with the environment of the hydrogen sensor via a measuring chamber opening, wherein the measuring chamber opening is closed by a diaphragm that is permeable to gases but impermeable to liquids, and devices suitable for performing the steps of the method according to the invention.

[0042] It is also preferable if the hydrogen sensor is also connected to a controller, which in particular includes stored diagnostic values. It is also advantageous if the controller includes an evaluation unit that performs the determination of the diagnosis and / or compares the obtained diagnostic value with the stored diagnostic value.

[0043] It is particularly advantageous if the heater and temperature sensor are located in the measuring chamber. This allows for faster heating and more accurate measurements.

[0044] It is also advantageous if the hydrogen sensor is used to determine the hydrogen concentration in the gas. Such sensors are used in the exhaust pipes of fuel cell systems.

[0045] It is also preferred if the hydrogen sensor includes a sensor housing that specifically defines the measuring chamber.

[0046] The objective in terms of the computer program is achieved by the computer program comprising commands that cause the hydrogen sensor according to the invention to perform the steps of the method according to the invention.

[0047] The objective regarding computer-readable media is achieved by providing a computer-readable medium on which a computer program according to the invention is stored.

[0048] If the computer-readable medium is part of the controller, such as as permanent or temporary storage, it is also preferred.

[0049] Advantageous improvements of the present invention are described in the following description of the accompanying drawings. Attached Figure Description

[0050] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. In the figures:

[0051] Figure 1 Motor vehicles were shown.

[0052] Figure 2 The channel with a hydrogen sensor is shown.

[0053] Figure 3 The method flowchart is shown. Detailed Implementation

[0054] Figure 1 A motor vehicle 1 with an electric drive unit and a fuel cell system 2 is shown. The fuel cell system 2 includes a channel 3, which is designed as an exhaust channel for the fuel cell system 2, and the hydrogen concentration in the exhaust channel can be determined by means of a hydrogen sensor 4.

[0055] Figure 2 It shows Figure 1 The method comprises a channel 3 and a hydrogen sensor 4. The hydrogen sensor 4 is fixed in an opening in the channel wall of the channel 3 and includes a measuring chamber that is in fluid communication with the channel 3 through a measuring chamber opening. The measuring chamber opening is sealed by a diaphragm 5 that is permeable to gas but impermeable to liquid. A heater and a temperature sensor / thermosensitive device are installed in the measuring chamber of the hydrogen sensor 4. Since hydrogen has a higher heat capacity than other components of the measured gas, the concentration of hydrogen in the measured gas can be determined using the heater and the temperature sensor. In other words, the hydrogen sensor 4 is a thermal conductivity sensor. The hydrogen sensor 4 is coupled to a controller 14, which integrates a computer-readable medium 15 in the form of permanent memory. A computer program 16 is stored on the computer-readable medium 15 and includes commands that cause the hydrogen sensor 4 and / or the evaluation unit integrated in the controller 14 to perform the steps of the method according to the invention.

[0056] Figure 3The method according to the invention is shown in, as in Figure 1 and Figure 2 The flowchart describes the process of using the device. First, the method 6 is initiated, and then a temperature change 7 is achieved in the measuring chamber of the hydrogen sensor via a heater. Temperature change 7 involves a heating process that raises the temperature in the measuring chamber. Simultaneously with temperature change 7, a diagnostic value 8 is obtained from the temperature sensor. The obtained diagnostic value is the time required for the measuring chamber to reach a certain temperature. This diagnostic value is then compared 10 with a stored diagnostic value 9. If the obtained diagnostic value is lower than the stored diagnostic value 9, it means that the temperature in the measuring chamber is rising faster than usual, because the stored diagnostic value 9 corresponds to the time value that can be obtained when the diaphragm of the hydrogen sensor is not blocked by liquid or foreign matter. If the obtained diagnostic value is lower than the stored diagnostic value 9, it is therefore determined 11 that the diaphragm or the opening of the measuring chamber is blocked by foreign matter or liquid. The method can then be restarted later to determine if the diagnosis still exists. Alternatively, it is also possible to continue running the heater and remove the liquid or foreign matter. Furthermore, it is possible to initiate a cleaning procedure to clean the diaphragm or the opening of the measuring chamber. It is also possible that the measured value of the hydrogen concentration in the gas being measured is incorrectly stored and therefore cannot be used in subsequent methods. If the obtained diagnostic value is at least equivalent to the stored diagnostic value 9, then it is determined that 12 the diaphragm or measuring chamber opening is free of liquid or foreign matter. 13 The method is then terminated, thereby allowing the measurement method for determining the hydrogen concentration in the gas to be measured to be initiated.

[0057] The different features of the various embodiments can also be combined with each other.

[0058] Figures 1 to 3 The features of the embodiments are not intended to be limiting, but rather to illustrate the concept of the invention.

[0059] List of reference numerals

[0060] 1 Motor vehicles

[0061] 2. Fuel Cell System

[0062] 3 channels

[0063] 4. Hydrogen sensor

[0064] 5. Membrane

[0065] Start with 6

[0066] 7. Temperature Change

[0067] 8. Conclusion

[0068] 9. Stored diagnostic values

[0069] 10 Comparison

[0070] 11 Confirmed

[0071] 12 Confirmed

[0072] 13 End

[0073] 14 Controller

[0074] 15 Computer-readable media

[0075] 16 Computer Programs

Claims

1. A method for diagnosing a hydrogen sensor (4), The hydrogen sensor (4) includes a measuring chamber, a heater, and a temperature sensor. The measuring chamber is in fluid communication with the hydrogen sensor environment via an opening in the measuring chamber. The measuring chamber opening is sealed by a diaphragm (5). The diaphragm (5) is permeable to gas but impermeable to liquid. The method includes the following steps: - The temperature change in the measuring chamber is caused by the use of a heater (7); - The diagnostic values ​​in the measuring chamber are obtained by means of a temperature sensor (8); - Determine a diagnosis based on the diagnostic value (11, 12); The method includes the step of comparing the obtained diagnostic value with the stored diagnostic value (9) (10).

2. The method according to claim 1, characterized in that, Temperature changes (7) include: operating the heater at a constant heating power, heating by means of the heater by increasing the heating power, cooling by reducing the heating power of the heater and / or shutting down the heater.

3. The method according to claim 1 or 2, characterized in that, The resulting diagnostic values ​​include temperature, rate of temperature change, temperature change curve, and / or time value.

4. The method according to claim 1, characterized in that, The stored diagnostic value (9) and the obtained diagnostic value are of the same type.

5. The method according to claim 1, characterized in that, When the obtained diagnostic value reaches, is lower than, and / or exceeds the stored diagnostic value (9), the corresponding diagnosis is determined.

6. The method according to claim 1 or 2, characterized in that, The temperature change in the measurement chamber (7) and the diagnosis value (8) are measured simultaneously, at different times, or closely adjacent to each other.

7. The method according to claim 1 or 2, characterized in that, The temperature change in the measurement chamber (7) and the determination of the diagnostic value (8) start and / or end simultaneously, at different times, or immediately before and after each other.

8. The method according to claim 1 or 2, characterized in that, When the temperature in the measuring chamber is lower or higher than a specific temperature, the temperature change in the measuring chamber (7) is initiated and / or the diagnosis of the diagnostic value (8) is initiated, and / or when the temperature in the measuring chamber is lower or higher than a specific temperature, the temperature change in the measuring chamber (7) is terminated and / or the diagnosis of the diagnostic value (8) is terminated.

9. The method according to claim 1 or 2, characterized in that, Diagnosis determination (11, 12) includes determining whether the diaphragm is blocked by foreign objects or fluid.

10. The method according to claim 1 or 2, characterized in that, This method is implemented by a computer.

11. A hydrogen sensor (4), comprising a measuring chamber, a heater, and a temperature sensor, The measuring chamber is in fluid communication with the hydrogen sensor (4) via the measuring chamber opening. The measuring chamber opening is sealed by a diaphragm (5). The diaphragm (5) is permeable to gas but impermeable to liquid. The hydrogen sensor also includes a device suitable for performing steps (7, 8, 10, 11, 12) of the method according to any one of claims 1-10.

12. A computer program (16) comprising commands to cause the apparatus of claim 11 to perform steps (7, 8, 10, 11, 12) of the method according to any one of claims 1 to 10.

13. A computer-readable medium (15) on which a computer program (16) according to claim 12 is stored.

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